ISSNMEMOIRS OF THE FACULTY OF ENGINEERING OSAKA CITY UNIVERSITY
VOL. 56.
2015

1511-0471 大阪市立大学 工学部
工学部英文紀要VOL.56（2015） 1-4

0078－6659

MEMOIRSOF THEFACULTY OF ENGINEERINGOSAKA CITY UNIVERSITY

VOL. 56
DECEMBER 2015

PUBLISHED BY THE
GRADUATE SCHOOL OF ENGINEERINGOSAKA CITY UNIVERSITY

見本

スミ

This Memoirs is annually issued. Selected original works of the members of theFaculty of Engineering are compiled herein. Abstracts of paper presented elsewhere
during the current year are also compiled in the latter part of the volume.
All communications with respect to Memoirs should be addressed to:
Dean of the Graduate School of Engineering
Osaka City University
3-3-138, Sugimoto, Sumiyoshi-ku
Osaka 558-8585, Japan

Editors

Yusuke YAMADA
Takeshi TAKIYAMA
Tomohito TAKUBO
Masafumi MURAJI
Noritsugu KOMETANI
Tetsu TOKUONO
Koichi KANA

1511-0471ࠉ኱㜰ᕷ❧኱ᏛࠉᕤᏛ㒊ᕤᏛ㒊ⱥᩥ⣖せ92/㸦㸧ࠉࢫ࣑MEMOIRS OF THE FACULTY OF ENGINEERINGOSAKA CITY UNIVERSITY
VOL. 56

DECEMBER 2015

CONTENTS
Regular Articles ··························································································· 1
Urban Engineering
Urban Design and Engineering
Vertical Impulsive Forces to a Structure on Multi-layered Grounds at Near Field Earthquake
Keiichiro SONODA and Hiroaki KITOH ·············································································· 1Applicability of Strain Softening Analysis for Tunnel Excavation
Kenichi NAKAOKA and Hiroaki KITOH ············································································

15

Study on Evaluation of Fine Fraction Content of Soil Using Soil-Metal Friction Sound for
Liquefaction Assessment by Swedish Ram Sounding
Suguru YAMADA and Akihiko OSHIMA ······································································· 29
Analysis of Resident Interest and Intentions for Community Bus Network Reorganization
Yumie SAWADA and Takashi UCHIDA ··············································································· 37
Major Issues of Bicycle Use in Urban Area from View Point of Community Development
Yurie ISHINUMA, Yasuo HINO and Yuuka WATANABE ············································ 51

Abstracts of Papers Published in Other Journals ···········································

57

Mechanical and Physical Engineering
Mechanical Engineering ·····································································

59

Physical Electronics and Informatics
Applied Physics and Electronics ····························································

67

Electric and Information Engineering······················································· 77

Applied Chemistry and Bioengineering
Applied Chemistry and Bioengineering ····················································· 81
Urban Engineering
Architecture and Building Engineering···················································· 100

Urban Design and Engineering ································································

102

ISSN

MEMOIRSOF THEFACULTY OF ENGINEERINGOSAKA CITY UNIVERSITY――――――――
VOL. 56――――――――DECEMBER 2015

PUBLISHED BY THE
GRADUATE SCHOOL OF ENGINEERINGOSAKA CITY UNIVERSITY

0078－6659

Vertical Impulsive Forces to a Structure on Multi-layered Grounds at Near Field Earthquake
Keiichiro SONODA* and Hiroaki KITOH**(Received October 2, 2015)
SynopsisAt Hyogo-ken Nanbu Earthquake 1995, a lot of instances of structural failure or damage due to vertical
impulsive ground motion were observed. Objective of the paper is to investigate vertical impulsive force
mechanism inducing failure of reinforced concrete bridge piers supported by multi-layered grounds.
KEYWORDS: seismic force, multi-layered grounds, impulsive force, reinforced concrete viaduct pier1. Preliminary
Figure 1.1 shows typical failure modes of reinforced concrete (RC) viaduct pier observed in a highway within
Kobe port area at Hyogo-ken Nanbu Earthquake 1995. The failure zone is located on only the upper portion ofcolumn and is developed on the whole cross sectional area in spite of their rectangular cross section. It will be anatural view that such failure modes were caused by strong vertical ground motion rather than strong horizontal
ground motion.

Fig.1.1 Viaduct pier failure modes observed in Harbor Highway in Kobe City (Photo by author)

Fig.1.2***

Geological map in the vicinity of Harbor Highway1)

Professor Emeritus
Professor, Urban Engineering−1−Figure 1.2 shows a geological map in the vicinity of Harbor Highway in Kobe City, which was presented by
the 3rd Port Construction Bureau of the Ministry of Transportation in Japan, in 19981). The surface zone of groundis covered by soft clay of alluvium stratum, and below that diluvium stratum is developed. The deep zone thanseveral ten meters below is occupied by stiff sand or grain stratum.
This paper is focused on characteristics of vertical stress wave propagation from the deep base ground to themulti-layered surface grounds, and is devoted to find the impulsive force mechanism against reinforced concrete
viaduct pier on multi-layered grounds due to a near field earthquake such as Hyogo-ken Naubu earthquake.
2. Plane elastic stress wave characteristics through multi-layered grounds

Fig.2.1

Multiple reflection of vertical displacement wave through multi-layered grounds2)

Kanai, K.(1957)2) has found theoretical solutions of one dimensional wave equation for multi-layered elastic
grounds shown in Fig.2.1. In those solutions, the vertical incident wave to semi-infinite base stratum is assumed
as a harmonic wave,

U 0 (t , z )  u 0 cos( pt  f 3 z )(2.1)

where p  2 / T0 ， T0 ：period， f 3  2 / L3 ， L3 ：incident wave length within the base stratum.
From the free condition at the surface ( z  0 ), the continuous conditions at the interface between 1st and 2nd strata
and the interface between 2nd and the semi-infinite base strata, the vertical displacement waves developed within
1st and 2nd strata, respectively are given as follows2）:2u
Qz) ， u1 ( z )  0 cos q1PH1
Q
U 2 (t , z )  u 2 ( z )  cos( pt  tan 1 ) ，
P
H
H
2u 
z 
z 
   1  sin q1  sin q 2  1 
u 2 ( z )  0 cos q1 cos q 2  1   H2 H2  H 2 H 2 U 1 (t , z )  u1 ( z )  cos( pt  tan 1

in which,  P 2  Q 2 ， P  cos q1 cos q 2  1 sin q1 sin q 2 ， Q   2 (cos q1 sin q 2  1 sin q1 cos q 2 ) ，

−2−

(2.2)

(2.3)

H m ( m  1,2 ) is the thickness of each stratum， q m  pH m / V pm ( m  1,2 )， V pm is wave velocity ( m  1,2 )，f m  2 / Lm ， Lm ：wave length ( m  1,2 )，  m ：ground density ( m  1,2 )，  m   mV pm /(  m1V pm1 ) ,( m  1,2 ). If the above solutions are applied to longitudinal displacement wave, those equations can betransformed into vertical stress wave solutions, exchanging Eq.(2.1) with the incident velocity wave or incident
stress wave as
V0 (t , z )  v 0 sin( pt  f 3 z ) , S 0 (t , z )   0 sin( pt  f 3 z )(2.4)

where, v0   pu 0 ,  0    3V p3  v 0 , V p3 means longitudinal wave velocity of the base stratum.
Then the velocity and stress waves developed within 1st and 2nd strata are given as
U m (t , z )Q  pu m ( z )  sin( pt  tan 1 ) ， m  1,2
tPU m (t , z )u m ( z )QS m (t , z )  E m
 Em
 cos( pt  tan 1 ) ， m  1,2zzPV m (t , z ) 

(2.5)
(2.6)

in which, E m   mV pm 2 , m  1,2 means longitudinal elastic modulus of each stratum.
In the following discussions, three types of ground property shown in Table 2.1 are considered, in which thesemi-infinite base stratum is fixed as  3  2.0t / m 3 in density and V p1  3000m / s in longitudinal wave
velocity.
Table 2.1 Ground properties consideredsecond stratum
first stratum
thickness: H 2  10,20,30,50,100m
thickness: H 1  10m
V p1 (m / s )V p 2 (m / s)
1 (t / m 3 ) 2 (t / m 3 )ground A
1.5
300
1.6
600
ground B
1.5
300
2.0
1000
ground C
1.6
600
2.0
1000
note:  m and V pm , m  1,2 mean density and longitudinal wave velocity, respectively

Fig.2.2 Vertical stress distributions within 1st and 2nd strata (ground A, H1=H2=10m, v0  1cm / s )The first numerical example was taken for the ground A with H 1  10m and H 2  10m , in which the incident−3−velocity of v 0  1cm / s (  0  0.06 MPa in incident stress) and the periods of 0.02  T0  0.7 sec wereapplied. Figure 2.2 shows the vertical stress amplitude developed within 1st and 2nd strata. As seen in this figure,the vertical stress intensities are much influenced by the periods, T0 ,of incident velocity wave in the basic stratum,and the maximum stress intensity within 1st and 2nd strata attains to 0.038 MPa and 0.051 MPa, respectively at
T0  0.04 sec , but in the lower frequency area such as T0  0.2 sec ,the stress intensities much decreases.
Next, focusing on the interface of 1st and 2nd strata which may be ordinarily situated at the supporting face of asuperstructure’s foundation, the relations between the maximum intensities of vertical stress (denoted by 12,max ) at the interface and the periods of incident velocity wave, T0 , were investigated for the grounds A, B

and C indicated in Table 2.1. Figure 2.3 shows the results for the ground A, in which  12,max attains to

0.08 MPa at T0  0.12 sec in the case of H 1  10m and H 2  30m .

Fig.2.3 Maximum stress intensities at the interface of 1st and 2nd strata（ground A, v 0  1cm / s ）Fig.2.4 Maximum stress intensities at the interface of 1st and 2nd strata（ground B, v 0  1cm / s ）Figures 2.4 and 2.5 show the results for the grounds B and C, respectively. In the ground B, the peak values of 12,max appear at T0  0.12 sec , and the maximum stress intensity attains to 0.09 MPa which iscorresponding to 1.5 times as large as  0   3V p3 v0  0.06MPa in the incident stress within the base stratum.
On the other hand, in the ground C, a large intensity of  12,max appears at T0  0.08 sec . Summarizing all the
results of Figs.2.3, 2,4 and 2.5, we can mention that the predominant large intensities of  12,max which is almost−4−

same or more than the incident stress intensity,  0  0.06 MPa ,appear only in the relatively higher frequency
zone such as T0  0.2 sec .

Fig.2.5 Maximum stress intensities at the interface of 1st and 2nd strata（ground C, v 0  1cm / s ）3. Applicability of numerical simulation procedure
In order to investigate stress wave interaction problems between
a superstructure and multi-layered grounds, it is difficult to findtheoretical solutions like Eqs. (2.5) and (2.6). Therefore, we have torely on a numerical simulation method such as finite element
method (called FEM).
As a preliminary study, applicability of one dimensional lumped
mass-spring model shown in Fig. 3.1(a) was examined incomparison with the theoretical solutions obtained previously. In
this model, 1st stratum with H 1 in thickness is divided by

m1 elements, 2nd stratum with H 2 in thickness by m2 elements,
and the base stratum with H B in thickness by m B elements. The
elastic spring constant of each element is taken as k i  EGi / D zi ,where E Gi is longitudinal elastic modulus and D zi is distance
between adjacent nodes.
Incident displacement and velocity waves in the base stratum aretaken as the same to Eqs.(2.1) and (2.4) namely
U 0 (t , z )  u 0 cos( pt  f B z )(2.1)
V0 (t , z )   pu 0 sin( pt  f B z )(2.4)
where,p  2 / T0 , f B  2 / L B , L B  V pB T0 , V pB is longitudinal
wave velocity of the base stratum.
Initial conditions are given as
U 0 (0,0)  0 ， V0 (0,0) 

Fig.3.1 Lumped mass-spring model

U 0
0t z 0,t 0(3.1)

The bottom face of base stratum ( z  0 ) is forced as−5−

U 0 (t ,0)  u 0 1  cos pt 

(3.2)
（3.3)

V0 (t.0)  v 0 sin pt

where, v 0  pu 0  (2 / T0 )  u 0 . In this model, how to determine the thickness of basic stratum, H B , isimportant, because the theoretical solutions presented in the previous section are derived for a semi-infinite basestratum.
Two methods are considered in the followings.
Method 1
The thickness of base stratum, H B , takes so large as to exclude the influence of wave reaction at the bottom

face of base stratum ( z  0 ). If the relevant observation time is taken as 0  t  Tobs , H B  3TobsV pB is
sufficient condition to exclude a wave reflection influence from the bottom face of base stratum to 1st and 2nd
strata.
Figure 3.2 shows comparison between the numerical results by a lumped mass-spring model and thetheoretical ones on the maximum stress intensities (denoted by  12,max ) at the interface of 1st and 2nd strata in
the ground A with H 1  10m , m1  20 , H 2  20m , m 2  20 and H B  1500m , m B  100 ,which is taken as
Tobs  1.5 sec . Good correlation between the numerical results and the theoretical ones is found except for very
high frequency zone of T0  0.02 sec . It can be said, therefore, that a lumped mass spring model yields a
reliable solution of one dimensional stress propagation problem, if a large thickness of base stratum, H B , isapplied such as H B  3TobsV pB .

Fig.3.2 Comparison of the numerical results with the theoretical ones on  12,max(ground A, HB=1500m, v 0  1cm / s )Method 2Here, the case of limited thickness of base stratum such as H B  3Tobs V pB is considered. In this case, theFig.3.3 Numerical results on  12,max by Method 2（ground A， H B  40m ， v0  1cm / s ）−6−

constraint conditions of Eqs.(3.2) and (3.3) are applied for only their first one period part, namely

U 0 (t ,0)  u 0 1  cos pt  , 0  t  T0

(3.4)

V0 (t ,0)  v 0 sin pt , 0  t  T0

（3.5)

Furthermore, for the time domain, t  T0 , the bottom face of base stratum ( z  0 ) is treated as a viscous boundary
shown in Fig.3.1(b) to exclude the wave reflection influence as possible.
Figure 3.3 shows the numerical results on  12,max which are obtained for the ground A of H 1  10m ,m1  20 , H 2  20m , m2  20 and H B  40m , m B  20 . Comparing Fig.3.3 with 3.2, the incident
constraints with only the first one period of Eqs.(3.4) and (3.5) yield lower stress intensities at the interface of 1stand 2nd strata in comparison with the continuous harmonic constraint by Eqs.(3.2) and (3.3). But the frequency
zone yielding the peak stress intensities is similar from each other. Therefore, Method 2 may be useful as an
approximate method for more complicated two or three dimensional stress wave problems which will be later
discussed.
4. Mechanism of vertical impulsive forces against a structure on multi-layered grounds
Characteristics of vertical forces to an overloaded structure on the multi-layered grounds shown in Fig.2.1 are
discussed through three dimensional axisymmetric FEM analyses. Here, a structure is assumed as a simple rigid
body, assuming that a reinforced concrete structure is much stiffer in comparison with the supporting groundmaterials.
Figure 4.1 shows the finite element division used. A three layered ground model similar to Fig.3.1 fornumerical analyses is applied, in which the vertical element division is m1 for the 1st stratum of H 1 inthickness, m 2 for the 2nd stratum of H 2 in thickness, and m B for the base stratum of H B in thickness, while
the horizontal element division is n1 for the structural basement of B1 in radius, and n 2 + n3 for theremaining ground region of B2 + B3 , in radius, respectively. Joint elements with no tensile resistance are inserted
between the structural basement and the ground surface.
The incident vertical displacement and velocity waves are given by the constraints of Eqs. (3.4) and (3.5) atthe bottom face of base stratum in Method 2. Namely,U z (t ,0)  u 0 (1  cos pt ) , 0  t  T0

(4.1)

V z (t ,0)  v0 sin pt , 0  t  T0

（4.2)

U x (t ,0)  0 , V x (t ,0)  0(4.3)

While for t  T0 the bottom face of base stratum is treated as a viscosity boundary, and in addition thehorizontal edges of ground are also treated as a viscosity boundary to exclude the horizontal wave reflection
effects as possible. The viscosity coefficients are applied as  0 z   BV pB , and  mx   mV pm ,  mz   mV sm ,m  1,2, B .

Table 4.1

Ground properties considered for numerical analyses
2nd stratum
1st stratum

 i (t / m 3 )Vpi(m/ s)Vsi (m/ s)

 i (t / m 3 )Vpi(m/ s)Vsi (m/ s)

ground A

1.5

300

100

１.6

600

200

ground B

1.5

300

100

2.0

1000

300

ground C

1.6

600

200

2.0

1000

300

The ground material properties in Table 4.1 are applied in which  i means density, V pi means longitudinal−7−

wave velocity and V si means transversal wave velocity of each stratum, in which the base stratum is fixed as B  2.0tm 3 ， V pB  3000m / s ， V sB  800m / s .
Elastic constants of each stratum are determined by the so called PS inspection as follows:
Longitudinal elastic modulus, G pi , transversal elastic modulus, G si ,and Poisson’s ratio,  si , are determined
respectively as si 

(C pi / C si ) 2  2

2 (C pi / C si ) 2  1， G si   si C si 2 ， E si  2(1   si )  G si

(4.4)

Fig.4.1 Three dimensional axisymmetric FEM element division
Linear elastic relations between stress vector: σ i   x

 x

z

 xz

  T are given as z  xz   T , and strain vector: ε i ~
σ i  Ei ε i(4.5)

where,−8−

10
 si /(1   si ) si /(1   si )

 /(1   )10 si /(1   si )
E si (1   si )  si
~
si
Ei 

0
0
0.5(1  2 si ) /(1   si )0
(1   si )(1  2 si ) 01 si /(1   si )  si /(1   si )


(4.6)

Numerical calculations are carried out for H 1  10m ， m1  10 ， H 2  20m ， m2  20 ， H B  40m ，m B  20 and B1  5m ， n1  5 ， B2  20m ， n 2  10 ， B3  100m ， n3  10 , in which the contact area ofstructural basement and ground surface is taken as A0  B12  79m 2 .
First, the static solutions due to the structure’s gravity force ( M u 0  g ,where g is gravity acceleration) arefound and then those are used as initial conditions for the following time-dependent response analyses. The
kinematic equations are solved using an explicit time integration scheme.

  Cu  Ku  P
Mu

(4.7)

where u ：nodal displacement vector，M ：mass matrix，C ：dumping matrix, K ：stiffness matrix, P ：nodal
force vector by the structure’s own weight，and dot means time differential.
Figures 4.2(a) and (b) show the ground reactive force responses of structural basement under M u 0  500tonin structure’s mass, v 0  0.01m/s in incident vertical velocity of the base stratum, andT0  0.02sec, 0.04 sec , 0.05 sec , 0.08 sec , 0.12 sec and 0.2 sec in the incident displacement and velocity period.
In those figures, the ground reactive forces of structure oscillate within compressive zone and their maximum
compressive forces in cases of T0  0.04 sec and 0.05 sec attain to about two times as large as the structure’s
own weight being M u 0  g and in the relatively longer period domain of T0  0.12 sec , the peak reactive forces
greatly decrease.

Fig.4.2 Ground reactive force responses of structure（ground A, M u 0  500ton , v 0  0.01m / s ）Fig.4.3 Ground reactive force responses of structure（ground A, M u 0  500ton , v 0  0.1m / s ）−9−

Similar responses of ground reactive force of the structure when v 0  0.1m / s are shown in Figs. 4.3(a), and(b). In this case, the time domains when the reactive ground forces become zero appear and pulse-likecompressive reactive ground forces are yielded. It is also noted that the maximum ground reactive forces appear in
the second peak rather than that in the first peak in the period domain of T0  0.08 sec . Since the maximum
ground reactive forces attain to about 9 times as large as the static ground reactive force and the duration ofcompressive forces is very short as T0 / 2 , such a pulse-like ground reactive force may be regarded as a kind of
impulsive vertical force against structure.

Fig.4.4

Maximum ground reactive forces in grounds A,B and C（ M u 0  500ton ， v 0  0.1m / s ）Fig.4.5 Ground reactive forces and structure’s masses（ground A, v0  0.1m / s, T0  0.04 sec ）Next, for the grounds A, B and C in Table 4.1 with the structure of M u 0  500ton , relation between the
maximum ground reactive forces and the period ( T0 ) of incident velocity being v0  0.1m / s are shown in
Fig.4.4 in which the maximum ground reactive forces appear at T0  0.04 sec for the ground A, at

T0  0.08 sec for the ground B and at T0  0.05 sec for the ground C, respectively, and those peak values
considerably vary by the different ground characteristics. It can be noted, however, that the larger ground reactive
forces in comparison with the static reactive force of 4.9 MN appear only in a high frequency zone ofT0  0.08 sec .

−10−

Furthermore, to examine influence of the weight of structure on ground reactive force, the cases of
M u 0  200ton ， 500ton and 1000ton under v 0  0.1m / s at T0  0.04 sec are also calculated and theresults of Fig.4.5 are obtained. In this figure, it can be seen that the maximum ground reactive forces becomelarger as M u 0 is larger, but the ratio of those to the static ground reactive forces becomes smaller such as 9.1 for
M u 0  200ton and 6.1 for M u 0  1000ton .
5. Axial stress characteristics of viaduct pier column on multi-layered grounds
Here, axial stress characteristics of reinforced concrete columnof viaduct pier supported on multi-layered grounds are investigated.
The ground properties are same as those in Table 4.1. Same FEM
element divisions as Fig.4.1 are applied for the ground part, and forthe viaduct pier, a simple model as shown in Fig.5.1 which isconsisting of rigid footing and rigid structure and elastic spring forcolumn is applied, in which spring constant of the column is sought
as k c  E c Ac / H c ,where E c :Yong’s modulus of column

concrete, Ac :the cross sectional area of column, H c :height ofcolumn.
The incident vertical displacement and velocity at the bottom ofbase stratum are given by Eqs. (4.1), (4.2) and (4.3)．
Figure 5.1 shows the three dimensional axisymmetric viaductmodel used here. The column height and cross sectional area are
H c and Ac , respectively. The radius of footing basement is B1 ,and the finite element division for multi-layered grounds are sameas Fig.4.1, in which H 1  10m , H 2  20m , H B  40m , B1  5m ，B 2  20m , and B3  100m .
First numerical example is given for the case of H c  10m ,Fig.5.1 Viaduct pier model on
multi-layered grounds

Ac  3.14m 2 , the bottom face area of footing is A f  78m 2 , mass ofsuperstructure ( M u 0 ) is 500ton and mass of footing ( M f ) is 380ton . Figs 5.2(a) and (b) show axial stressresponse of column with Hc = 10m under v 0  0.1m / s for the ground A in Table 4.1. The maximum intensity ofaxial column stress appears at T0  0.04 sec or 0.05 sec , which attains to 20MPa in compression and 19MPa in
tension. Figure 5.3 shows relation between the peak stress intensities and periods ( T0 ) for the grounds A, B and C
in Table 4.1. It can be seen that high stress intensities only appear in the vicinity of T0  0.05 sec and in thefrequency zone of T0  0.08 sec , those intensities much diminish. On the other hand, Fig.5.4 shows a similar
relation for the case of H c  20m and Ac  3.14m 2 . The peak column stress intensities become lower than thosein Fig.5.3 for H c  10m , but the zone inducing a large stress intensity expands.

Fig.5.2 Axial stress responses of column under v 0  0.1m / s (ground A, H c  10m )−11−Eigen period of viaduct pier of Fig.5.1 with the footing base fixed can be estimated by
Tst 0  2

M u0
E A
, kc  c c
kc
Hc

(5.1)

where, Tst 0 :eigen-period, E c :Young’s Modulus of column, k c :spring constant. Putting M u 0  500 ton,Ac  3.14m 2 , and Ec  30GPa , one obtains Tst 0  0.046 sec for H c  10m and Tst 0  0.065 sec for
H c  20m . Therefore, considering the predominant period ( TG 0 ) for ground reactive forces as shown in Fig.4.4,

it can be regarded that the axial stress amplitude of column enlarges by a kind of resonance by Tst 0 and TG 0 .

Fig.5.3 Maximum axial stress intensities of column with H c  10m (under v 0  0.1m / s )Fig.5.4 Maximum axial stress intensities of column with H c  20m (under v 0  0.1m / s )−12−Summarizing the results of Figs 5.3 and 5.4, we can mention that the maximum tensile stress intensities
being 15 or 19 MPa that appear in the vicinity of T0  0.05 sec , are sufficient to induce a tensile fracture ofcolumn concrete under v0  0.1m / s . Therefore, it may be expected that, by the acting of repeated tensile andcompressive stresses, a tensile and compressive combined fracture mode is induced in a viaduct reinforced
concrete column section, which were observed at Hyogo-ken Nanbu earthquake.
5. Summary(1) Stress wave propagation characteristics within a multi-layered elastic grounds consisting of top alluvium
stratum, middle diluvium stratum and base stiff stratum were investigated using one dimensional elastic wave
theory. The vertical stress intensities were much influenced by the ground property and the incident velocity
wave period, T0 , in the base stratum. Noticing the interface of top and middle strata, significant large verticalstress intensities appeared in the short period zone such as T0  0.2 sec , while those intensities diminishes
greatly as larger than T0 = 0.2 sec .
(2) First, applicability of numerical simulation method using a lumped mass-spring model was examined as apreliminary study. Following the characteristics of ground reactive forces of an overloaded structure on the top
ground surface were investigated by three dimensional axisymmetric FEM analyses. As the results obtained, inthe case of v0  0.01sec ,where v 0 is the incident velocity of the bottom of base stratum, the ground reactive
forces of structure remained within a compressive region, but in the case of v 0  0.1 sec , the dynamic groundtensile forces exceeded the static ground compressive forces and a pulse-like ground compressive reactive
force was formed in the high frequency zone of 0.02 sec  T0  0.08 sec . The peak value of such a pulse-likeground reactive force became much larger as the own weight of structure increased.
(3) The last numerical analyses were devoted to investigate the axial stress characteristics of a viaduct pier column
on the multi-layered grounds. The ground models were the same ones used before and a simple model of
viaduct pier consisting of rigid structure, rigid footing and a elastic spring for the column were applied. The
numerical examples indicated that the significant large stress intensities of column section appeared when theincident velocity wave period was near the vertical eigen period of the viaduct column. Therefore, it can besaid that a reinforced concrete viaduct column is apt to fracture in a combined tensile and compressive mode
by a resonance effect of vertical vibration in both the multi-layered grounds and the viaduct pier column.
6. Acknowledgements
The authors express much appreciation for valuable discussions with Shunsuke Sakurai, Professor Emeritusof Kobe University and Taijiro Nonaka, Professor Emeritus of Kyoto University.
7. References
1) The 3rd Port Construction Bureau of the Ministry of Transportation in Japan: Restoration document of Seismic
disaster in Kobe Port (1998) (in Japanese)2) K. Kanai, Bull. Earthq. Res. Inst., 35, 457 (1957)
3) K. Sonoda, H. Kobayashi, and T. Nakajima, On Quasi-impact Failure of Civil Engineering Structures by
Earthquake, Symposium on Damage to Structures by Impulsive Effects of the Hyogoken-Nanbu Earthquake,
Architectural Institute of Japan (1997) (in Japanese)
4) K. Sonoda, N. Takada, and H. Kobayashi, Proceedings of Second International Conference on Earthquake
Resistant Engineering Structure (ERES), WIT Press, Southampton, UK, pp.83-92 (1999)−13−

Applicability of Strain Softening Analysis for Tunnel Excavation
Kenichi NAKAOKA* and Hiroaki KITOH**(Received October 2, 2015)
Synopsis
As a one of alternative model to predict the behavior of tunnel excavation in unconsolidated ground, thestrain hardening up to softening model has been proposed in this paper. The model based on plastic theory
has been formulated, not in ordinary stress space but in strain one because of consistent unloading definition
due to strain softening. Material model parameters were estimated from unconfined and tri-axial
compression tests. After the defined model parameters applied into FEM procedure, centrifuge test model
has been simulated. As the results, obtained surface settlement and lateral face displacement were wellagreed with experimental results. Furthermore, the distribution of predominant shear strain around tunnel
obtained was also comparable with the sliding phenomena observed in the experimental test. In conclusion,
the proposed model can be applicable to tunnel stability problem in unconsolidated ground.
KEYWORDS: Strain softening, Lade model, Finite element analysis, Tunnel face stability, Strain-space
1. Introduction
New Austrian Tunneling Method: NATM is being increasingly used for excavation of shallow tunnels
within unconsolidated soils. The main reason is that the lower cost for tunnel construction than that by shieldtunneling method and lower impact for traffic than that by open cut method around the construction site.
Some reports have indicated that a tunnel excavation by NATM within unconsolidated soil often expands
the high shear zone, called, “shear band,” from the tunnel sides upward1). And by experiment it was shownthat the “shear band” expands also from tunnel face towards surface samely2). If this zone approaches thesurface, it can cause large settlement of surface above the tunnel and lead to tunnel collapse in the worth case.
Therefor a numerical model is required that can simulate the expanding of the shear band to determine thestability of a tunnel in unconsolidated soil. Usually, however, normal elasticex.3) or elasto-plastic modelsex.4)
are used in the analysis of tunnel stability, so it is insufficient to evaluate behavior of ground around thetunnel. It is not easy to observe the extension of actual shear bands or to simulate experimentally. So,
validation of strain softening model for the evaluation of extension of shear band is not progressing. It isconsidered the reason that the model does not become widely used as the analysis method for a design.
Therefore, it is important to increase the validation example about the extension of shear band.
Lee5) and Akutagawa6) developed a strain softening model to predict ground behavior taking into accountthe shear band caused by tunnel excavation. And applied to evaluation the expanding of shear band from
actual tunnel sides upward. After that, it was shown that the strain softening model can simulate the surface
settlement that was considered to have been caused by the shear band. Nakaoka et al7) expanded the model tothree dimensional problem, and it was shown that the model can simulate the discontinuous displacement
developed from tunnel face in centrifugal experiment that was carried out by Takahashi et al8).
The manner of this model is that, if material yielded, stress is redefined by shrinking of Mohr’s stresscircle to fit into the Mohr-Coulomb criterion line. The strain softening is taken account by reducing thecohesion and internal frictional angle according to maximum shear strain. Also, the anisotropy is considered
by decreasing of shear stiffness on local coordinates along a slip line in consideration of shear band
developing. The model doesn’t use dilatancy parameter, so the model became simple mathematically, andincrease a practicality.
On the other hand, it is considered that the numerical model based on plastic theory that was developed for
simulation of the soil behavior will become one of the choices for design of tunnel in unconsolidated ground.
However the numerical model like that was not investigated whether it can simulate correctly the shear bandaround the tunnel. Then, we focused on the numerical model that was developed by Lade9) (Lade model).
This model intended for evaluation of non-cohesive sandy soil. And by taking into the plastic work as anindex, this model can simulates strain hardening and softening seamlessly.
The model is newly added the cohesion term for cohesive soil. A strain-space-based plasticity formulation* Student, Doctor Course of Department of Civil Engineering (Obayashi Corporation)** Professor, Department of Urban Engineering, Osaka City University−15−

is used to represent strain hardening and softening behavior completely. After that the numerical model ismounted on the code of finite element method (FEM), and applicability is ascertained by simulating about
the centrifuge tests of tunnel model.
In this paper, at first, Lade model that takes into account of cohesion is outlined. And, the parameters suchas for strain hardening and softening are estimated by fitting to strain-stress curve of unconfined and tri-axial
compression tests using the same compounding material with soil in tunnel model. After that, the centrifuge
model tests8) are simulated with parameters obtained as previously shown, and by comparing analysis resultswith model tests, applicability of the numerical model is discussed.
2. Strain hardening and softening model(1) Strain softening model
Lade proposed an elasto-plastic constitutive model that was specified the strain hardening and softening
formation to present the nonlinear behavior of non-cohesive soil6). Using parameters of the numerical modelthat was estimated by tri-axial compression tests, he showed that the model can simulate well the strain
hardening and softening behavior of non-cohesive soil. Mizuno10) studied about applying the model on
concrete material, the strain hardening and softening behavior of concrete in tri-axial compression test under
low confined stress which was from 0.3 to 1.2% of uniaxial compressive strength was simulated7). Mizuno
described an elasto-plastic constitutive law that involves strain hardening and softening should be formulated
in strain-space.
In this study, we apply the Lade model modified by Mizuno using strain-space-based plasticity
formulation. Denoting that the loading function f in stress-space and F in strain-space respectively, andcorresponding increment df and dF according to increment of stress dij and increment of strain dij are
represented as shown in Eq.1 and Eq.2.

df 

f
d ij
 ij

(1)

dF 

F
d ij
 ij

(2)

As shown in right half of Fig.1, when df > 0, it means hardening by loading. On the other hand, when df< 0, it means elastic unloading or unloading by softening. It cannot determine which is the real state of
unloading only by the stress. As shown in left half of Fig.1, applying the loading function defined in strain
space, it means elastic unloading with dF < 0. On the other hand, it means hardening or softening by loadingwith dF > 0. There is no need to distinguish which is the state of loading. Strain hardening and softening aredescribed in constitutive law continuously in strain space. Thus, the problem seen in formulation in stressspace can be solved. Loading function applied in this study is represented by Eq.3 in stress-space.
11Strain space
Strain-hardening or
Strain-softening

Stress space
df=0
Strain-hardening byloading
df>0

dF>0
dF<0
dF=0

2
2

df<0
Unloading orSoftening by loading

Unloading

3
3
Loading surface

Fig.1 Stress state in stress-space and strain-space

−16−

m

 Pa    1
  
I 1  a 3  1 I 1  a J 2  J 3   0
f  I 1  a   27  f p 3 I 1  a     27

3

(3)

Here, the meanings of the parameters in equation are shown below:
a: As shown in Fig.2, the amount of parallel shift of the yield surface along hydrostatic axis in tensile
direction.
m: Curvature of the yield surface. If m = 0, the distance between yield surface and hydrostatic axis becomeslinear relationship with respect to hydrostatic pressure. If m > 0, the relationship becomes concave downwith respect to hydrostatic pressure. And if m < 0, the relationship becomes concave up.
fp: Strain hardening and softening, parameter, which is defined as a function of plastic work Wp. The
parameter defines the material strength, the value is 0 initially. It increases owing to hardening andbecomes maximum value 1 when the corresponding stress attains at its peak. Afterward, it decreases
with softening.
Pa: pressure of the atmosphere.
I1, J2, J3 are the stress invariants, these are shown in Eqs.4 ~ 6, respectively, using strain invariants.
fp=5, m=0

fp=10, m=0

3
fp=5, m=1

3
fp=10, m=1

fp=5, m=0.5
fp=10, m=0.5

2

1

1

2

Fig.2 Lade loading surface according to m and fp

I1   ii  3K ( ii   iip )  3K I1  AI1
1
J 2  sij sij  2 2 (eij  eijp )(eij  eijp )  B J 2218J 3  sij s jk ski   3 (eij  eijp )(e jk  e jkp )(eki  ekip )  C J 3
2
3

(4)
(5)
(6)

The loading function in strain space is described as Eq.7.
m

  1


P
1
3

a
    AI1  a   AI1  a BJ 2  C J 3   0
F  AI1  a    27  f p 3 AI1  a     27
A  3K3

B  4

(7)
(8)

2

(9)

C  8 3(10)

Where, ijp, eij, eijp means plastic strain, deviator strain, deviator plastic strain respectively. K and  are elastic
volumetric modulus and shear modulus, respectivelyK

13(1  2 )

−17−

(11)



1
2(1   )(12)(2) Procedure of non-linear calculation
A finite element method: FEM is used for this study. The method of calculation of non-linearity is to
apply a gradually increasing load. Fig. 3 is the flowchart of the calculation.
Modified Newton Raphson scheme is employed to converge residual force. The scheme is as follows: At
first, overall stiffness matrix K is made, and strain increment  is obtained with K and increment of load
fload. Next, plastic strain p is obtained by elasto-plastic constitutive equation using the previous values of, and e and Wp to be explained in detail. Now, it is possible to obtain the current stress increment:
=De，where D is elastic stiffness matrix, and e= - p is relevant elastic strain in increment. Thenthe current stress: updated owing to the obtained increment. Residual force of next step is estimated from 
obtained as above. Stress of next step is obtained by loading the residual force. Again,  is changed by the that is calculated under new . Residual force generated by stress change is calculated again. When the
maximum residual force becomes less than allowable value, the calculation is terminated.
start
Formation of total stiffnes K
Calculation of incremental load fload
F= fload
F=F+fr
Calculation of incremental displacement uu=K-1F
Calculation of incremental strain 
Calculation of p, e from constitutive equation
e=-p
Calculation of and 
=Dee, =
Calculation of residual force fr

fr< allowable valueNO

YES
Step=end

NO

YES
end

Fig.3 Flowchart of non-linear analysis
3. Defining of model parameters(1) The parameters and procedure of definition
The parameters were defined using the results of unconfined and tri-axial compression test. Test
specimens had the same composition as the material applied to the centrifuge model experiment8). The
material was soil cement as mixture of low plasticity kaolin clay and cement. Kaolin clay is an article on themarket, which plastic index: IP=10%. Cement content was 100kg/m3 to become the unconfined compressive
strength 70kPa of target strength. Fig. 4 shows the proceeding of each parameters definition.

−18−

a (Constant)
Mohr's stress circle

Wppeak0(Const.)1,m (Const.)
least-square
methodWp (Variable)
Measuring thearea (Fig.6)

P，l (Const.)
from the relation between aplastic work and cfp (Variable)
Eq. 13

1， 2 (Const.)
currving-fitting

Fig.4 Procedure of parameters settingMaterial parameters were as follows: Young's modulus E=16.6MPa, Poisson’s ratio =0.4, and as theparameters that define the loading function, a and m these define the shape of curved surface, fp that is theparameter of material strength, 1 that defines the maximum value of fp, and the parameters Wppeak0, P, l, 1,
2 to link fp and plastic work Wp. Eq. 13 shows the relation between fp and Wp. The number of the essential
parameters was eight.
11
Wp   Wp  e  Pa 
f p  1 ()  exp  P  W
W ppeak
ppeak
a





(13)

l

 
W ppeak  P c  Pa  W ppeak 0
 Pa 

(14)   1 c   2(15)Here, c is confined pressure of the triaxial compressive test. On the FEM calculation, the average ofmaximum principal stress and intermediate principal stress was used as confined pressure in which negativevalue means compression. The relation between strain and stress that was obtained by the unconfinedcompression test and the triaxial compression test is shown together with the results of calculation later. And
to be consistent with the results of the uniaxial compression test, it was multiplied by a constant on the
results of the triaxial compression test. To define the parameter, the results obtained in this way were used.
(2) Definition of each parameter a, m, 1
The first parameter a is the shift distance of curved surface of loading function along the hydrostatic axis
as Fig.2, which was estimated as the intersection point of envelope line and  axis shown in Fig.5. The
parameter a is an absolute value. From Fig.5, it was estimated to be 532kPa.

−19−

（kPa）

60
50 Unconfined c=50kPa
40
30
20
10
0
0
-50
-100

c=100kPa
c=200kPa-150
（kPa）

-200

-250

-300

Fig.5 Mohr's stress circle at each confining stress
The parameter 1 and m represent peak strength and curvature of loading surface respectively; those were
estimated by the assigning parameter a that described above to plastic-potential function. After that,parameter m and 1 were adjusted to minimize the standard variation of 1 that is obtained by each of theelement tests. From element tests, it was set to m=1.08, 1=7.10.
(3) Definition of each parameters Wppeak0，P，l
Plastic work is estimated from strain-stress curve obtained from the compression tests. Here, it isassumed that the material is in elastic state when unloading. The plastic work can be obtained by measuring
the area of hatching in Fig.6.
σ

Wp

0

ε

Fig.6 Work of plasticity
Wppeak is the plastic work when difference of principal stress by tri-axial compression test becomesmaximum. Wppeak0 is also the plastic work when axial stress of unconfined test becomes maximum. Table 1
shows the Wppeak0 values estimated from the results of each test. By using the parameters of Wppeak0, P and l,
Wppeak under confined pressure c can be calculated by Eq.14. From relationship between (Wppeak0 - Wppeak)/Paand c/Pa in double logarithmic plot shown in Fig.7, P and l were estimated by least-square technique as
P=0.00779 and l=0.761. If the values of Wppeak0, P and l are increased, strain at peak stress is increased.
Table 1 Wppeak (kPa)
Confined Pressurec (kN/m2)
0
50
100
200

−20−

Wppeak
0.66
1.07
1.56
1,82

（Wppeak-Wppeak0）/Pa

0.1

0.01

0.001
0.1

1

10

c/Pa

Fig.7 Relation of (Wppeak0 - Wppeak)/Pa and c/Pa

8
7
6
5
4
3
2
1
0

c=50kPa
Test result
Analysis
fp

8
7
6
5
4
3
2
1
0

0.0

0.1

0.2
Wp/Pa

0.3

0.4

c=100kPa
Test result
Analysis
fp

fp

fp

(4) Definition of each parameters 1, 2Among the parameters included in the function fp shown by Eq.3,  value mainly defines the gradient ofstrain-stress curve after peak. It is assumed that  is proportional to the confining pressure c as shown by
Eq.15. Procedure of defining  is as follows. At first, measured value fp is calculated by assigning theparameters a and m to the loading function that is shown as Eq.3. Next, the parameters 1, Wppeak0, P and l are
assigned into Eq.13 and Eq.14. And by curve-fitting which is done to conform the calculated value of fp to
the measured value,  is estimated. Fig. 8 shows the results of the curve-fitting.  obtained under eachconfining pressures are shown in Fig.9. However,  becomes large value unrealistically because softening did
not occurred almost in the case of the confining pressure=200kPa. So the case was eliminated. Parameter 1
as the gradient of relationship between c and  was defined as 0.130 from the figure. Also, the intercept 2
was defined as 0.453. Table 2 shows the parameters set as explained.

0.0

0.1

0.2

0.3

Wp/Pa

8
7
6
5
4
3
2
1
0

8
7
6
5
4
3
2
1
0

c=50kPa
Test result
Analysis

0.0

0.1

0.2
Wp/Pa

0.3

c=200kPa
Test result
Analysis

0.0

0.1

0.2
0.3
Wp/Pa

0.4

Fig.8 Relationship between Wp and fp that obtained by curve-fitting

−21−

0.4

0.5



16
14
12
10
8
6
4
2
0

0

0.05

0.1

0.15

c (MN/m2)

Fig.9 Relationship between  and cTable 2 The parameters for numerical simulation
Parametersvalue

the amount of parallel shift (a)Degrees of loading function curvature (m).
the maximum value of fp (1)
Relation between Wppeak and c (P)Relation between Wppeak and c (P)Relation between fp and Wp (1)
Relation between fp and Wp (2)
The value of Wppeak at c =0
Atmospheric pressure (Pa)Young's modulus (E)Poisson's ratio ()Density ()0.532 MPa
1.08
7.1
0.00779
0.761
130 m2/MN
0.453
6.57×10-4MPa
0.101 MPa
16.6MPa
0.4
1740 kg/m3

4. The results of numerical analysis(1) The results of simulation of element test
Fig. 10 shows the results of both simulation of the unconfined compression tests and the tri-axial
compression tests. The results of simulations of unconfined tests were similar with the test results. The
results of peak strength by simulation of tri-axial compression tests were also similar with the test results.
The obtained gradients after peak, however, were slower than those from the test results.
As shown in Fig. 8, we tried to fit the simulation results with actual measurement, but a difference still
remained. It is considered that this is the reason of difference between numerical simulation and test resultsin Fig. 10. Because peak stress is in agreement, and analysis results approach test results as strain increases,
we expected that the numerical analysis could obtain the similar results with the experiment.

−22−

120

Unconfinedprincipal stress deviations (kPa)principal stress deviations (kPa)

120
100

Test1
Test2
Test3
Analysis

80
60
40
20
0
0

5

10

c=50kPa

100
80
60
40
Test result
Analysis

20
0
0

15

5

10

1 (%)
120

c=100kPa

principal stress deviations (kPa)principal stress deviations (kPa)

120
100
80
60
40

Test result
Analysis

20
0

0

5

15

1 (%)

10

c=200kPa

100
80
60
40
Test result
Analysis

20
0
0

15

5

10

1 (%)15

1 (%)

Fig.10 The results of simulation of unconfined compression and triaxial compression tests(2) Numerical simulation of centrifuge model tests(a) Outline of the tests
The tunnel model for centrifuge is shown in Fig.11 and Fig.128). Model ground was installed in steel
container, called container hereafter as shown in Fig.12. The half hole was created in the model ground as thetunnel face from the start. After that, centrifugal acceleration was gradually increased up to 80G. The shapeof tunnel is hemicycle and its diameter was 10cm as shown in Fig.11. When acceleration attained to 80G, It
correspond to tunnel diameter of 8m and earth covering of 16m. The tunnel was regarded as a half pipe ofright side toward the tunnel face. Tunnel body except 5cm interval close to the face was supported by acrylic
half pipe. The support prevented a collapse of tunnel body before the collapse of tunnel face focusing on inthis experiment. Front face of container was covered by acrylic board to measure the displacement of groundthrough the board.

Non supported section

30cm

20cm
10cm

Supported with acrylic
half pipe

20cm

40cm

5cm

45cm

10cm

Fig.11 Tunnel face of centrifuge model tests−23−

Fig.12 The model on loading stage8)
Settlement of ground surface just above the tunnel face and lateral displacement of center of tunnel facewere measured. It is targeted the experiment condition close to undrained by not installing the drainage in thecontainer.
(b) Analytical modelFig. 13 shows analytical model, in which the view point of displacement for comparison with theexperiment is shown. Dimension of analysis model was same as the experimental model.
Tunnel supporting was also modeled by solid elements as shown in Fig.13, and the relevant elements
were assigned enough high elasticity compared to elements for ground. As the boundary condition,
displacement of model bottom was fixed, and normal direction of surface around the model was also fixed. It
is not assigned boundary condition in ground surface. All load of numerical analysis was dead load of ground.
Gravity acceleration was increased gradually up to 80G as same as the experiment. The total number ofincrement step was 100.

Surfacesettlement

・

Lateraldisplacementof face

40cm

Elements
of support

・Tunnel face37627 nodes
34334 elements

Fig.13 Finite element mesh(c) Analysis results
Fig. 14 shows relation between centrifuge acceleration and settlement, and also another relation between
acceleration and lateral displacement. For reference, it also shows the results of elastic analysis. From theexperimental results (〇), we can see the rapidly increasing of displacement at about 55G. Elastic analysis
indicated with straight lines could not follow naturally such the behavior. On the other hand, settlement
gradient of analysis indicated with blue line curve increased at about 50G. Finally, the obtained settlement
reached 16mm at 80G. It can be seen that the analysis evaluated the settlement obtained by experiment well.
Lateral face displacement of the experiment rapidly increased at about 55G similarly with the settlement.
After that, at about 70G, a crack extended from bottom of the face upward. Finally it caused a collapse.

−24−According to analysis indicated with red curve, lateral displacement increased rapidly at about 50G. It
simulated well the lateral face displacement of the experiment.
Centrifuge gravity (G)
0

0

20

40

60

80

-2

Displacement (mm)-4Elastic (Surface)
Elastic (Face)

-6
-8
-10
-12
-14
-16
-18

Lateral disp. of face (Exp.)
Surface settlement (Exp.)
Lateral disp. of face (Ana.)
Surface settlement (Ana.)-20

Fig.14 Comparison between results of analysis and experimentFig. 15 shows the crack location obtained by experiment when acceleration was 50G. Also, thedistribution of maximum shear strain at 50G obtained by analysis is shown together.
At 40G, crack as broken line in experimental model extended upward from bottom of the tunnel facewhere the stress concentrated. At 50G, the crack as solid line reached to crown of the face. As the obtained
result, shear strain in the bottom and top of the tunnel face was larger than 5%. Crack and large shear strain
area were limited in location close to the face in this stage. We could not find the behavior that these region
extending upward beyond the face crown.

Support
Crack

Crack

1.00
0.7
0.5
0.3
0.2
0.15
0.1
0.05
0.025

Fig.15 Left: cracking of the experimental model in 50G8), Right: distribution of
maximum shear strain by analysis in 50G
Fig. 16 shows the experimentally obtained crack location and calculated maximum shear strain
distribution at 80G. With the experimental model, crack extended upward from bottom of tunnel face, andfinally it led the collapse of tunnel face. Also, crack extended vertically from the edge of near the tunnel face.
Also by the analysis, high strain region extended upward from front of the tunnel face and from edge ofacrylic support, the region which is called shear band. So, it could be drawn that the numerical model
simulates the behavior of the experimental model well.

−25−

The crack from the edge of acrylic support in the experimental model did not reach to surface of ground.
On the other hand, the shear band in analysis reached to surface. The reason of this difference is that there
are some blocks fell into the tunnel discontinuously from around of the tunnel face in the experimental model.
So, mass load of fell blocks do not apply to upper ground of tunnel.
On the other hand, a behavior that fall of discontinuous block cannot be simulated in the numericalmodel, so the load acting on the upper ground does not decrease. It is considered that the load acting on
upper ground of numerical model become larger than experiment. So shear band in the numerical model
reached to surface whereas crack in the experimental model did not reach.

1.00
0.7
0.5
0.3
0.2
0.15
0.1
0.05
0.025

Crack

Crack

Fig.16 Left: cracking of the experimental model in 80G8), Right: distribution of
maximum shear strain by analysis in 80G
Fig. 17 shows the displacement by analysis at 80G. From the figure, it can be seen that ground of front oftunnel face displaces like flow in the direction of the tunnel.

SupportFig.17 Displacement vector by analysis at 80G−26−

5. Conclusion
In this study, to evaluate the applicability of strain softening-hardening model to problem of stability oftunnel face in unconsolidated ground with shear band extensions, Lade type elasto-plastic model that is
added cohesion term is applied.
At first, unconfined compression tests and tri-axial compression tests with same composition specimen ofcentrifuge ground model are simulated by numerical model. And by fitting results to elemental tests, eightparameters are estimated. After that, centrifuge model tests are simulated. The results of these, the relation
between lateral face displacement and centrifuge acceleration and relation between surface settlement andacceleration are estimated well. Also, location of crack developed in experimental model is well predicted as
shear band by numerical model.
By using the method of evaluate the nonlinearity by modifying the stress, Lade type elasto-plastic modelthat predict the strain softening and hardening can be applied to problem of tunnel stability. It can be
determined that it becomes an option in the case of tri-axial compression test data is available.
6. References
1) W. H. Hansmire, and E. J. Cording, J. Geotech. Eng., 111, 1301 (1985)
2) D. Steripi, and A. Cividini, Rock Mech. Rock Eng., 37, 277 (2004)
3) H. Ohtsu, Y. Hakoishi, M. Nago, and H. Taki, Proceedings of the South East Asian Symposium on
Tunneling and Underground Space Development, 157-164 (1995)
4) S. Abdel-Baki, A. Ata and M. Hamza, Proceedings of the North American Tunneling ’96, 11 (1996)
5) J. Lee, S. Akutagawa, T. Kitagawa, A. Isogai, and T. Matsunaga, Proceeding of Tunnel Engineering, 15,
69 (2005)
6) S. Akutagawa, K. Matsumoto, and H. Nagai, Proceeding of Tunnel Engineering, 10, 113 (2000) (inJapanese)
7) K. Nakaoka, K. Hata, S. Akutagawa, and S. Takahashi, Proceeding of 2nd International Conference on
Computational Methods in Tunneling, 2, 281 (2009)8) S. Takahashi, S. Sugie, T. Kuwahara, and M. Toriihara, Proceeding of the Japan National Conference on
Geotechnical Engineering, 40, 1867 (2005) (in Japanese)
9) P. V. Lade, Int. J. Solid Struct., 13, 1019 (1977)
10) E. Mizuno, and S. Hatanaka, J. Eng. Mech.-ASCE, 118, 1546 (1992)−27−

Study on Evaluation of Fine Fraction Content of Soil Using Soil-Metal Friction Sound for
Liquefaction Assessment by Swedish Ram Sounding
Suguru YAMADA and Akihiko OSHIMA
(Received October 2, 2015)
Synopsis
This article presents a possible idea for evaluating fine fraction content of subsurface soil through an operationof Swedish Ram Sounding (SRS) by employing acoustic properties of friction sound generating by friction occurs
between surface of metallic penetration cone and surrounding soil. A series of soil-metal friction test was
performed on silica sand with various fines content using a modified direct box shear apparatus to simulate afriction phenomenon between SRS cone and surrounding soil. As a result of experiments, it was found that thesound pressure level (SPL) of friction sound was depended on relative density as well as fines content of sandy
specimen. Based on obtained testing results, an idea for evaluating fines content of ground by SRS wastentatively proposed.
KEYWOEDS: Liquefaction, Dynamic corn penetration, Friction, Sound pressure level
1. Introduction
In response to liquefaction-caused severe damages in residential ground during the 2011 off the Pacific coastof Tohoku Earthquake, demands for applying measures against liquefaction to residential properties has beenrisen up in Japan. It is, however, not simple to assess the safeness against liquefaction in an individual residential
property with applying conventional FL method, in which grain-size properties of particular stratum are required,because of the difficulty to take soil samples from ground by conventional field investigation techniques whichhave been employed in the small house constructions. Therefore, it is necessary to develop technologies, withreasonable cost, evaluating grain-size properties of soil for the residential ground, in order to achieve liquefaction
assessment to residential properties.
In the present study, it was attempted evaluating fines content by employing the friction sound generating
underground during the work of Swedish Ram Sounding (SRS). The SRS, a dynamic cone penetration test, hasbeen recently becoming a major field investigation technique for residential property in Japan. As a part ofprocess in SRS work, the torque is measured by rotating a penetration rod at every 0.2m in the penetration length
to correct the effect of skin friction resistance on number of blow (Ndm). A stainless steel cone with a diameter of
45mm was made 2 turns at an angular velocity approximately 47deg/sec in the ground during torque measurement.
Meanwhile, the generated friction sound by the friction of cone with soil was recorded. If this frictional behaviouris assumed as the shear occurs between stainless steel and soil, it can be thought that the recorded sound was
generated when large shear deformation was developed between stainless steel and soil. Therefore in this study, aseries of direct box shear test was performed on silica sand with various fines content using a direct box shear
apparatus, simulating the friction behaviour between stainless steel and soil in the torque measurement. The
friction sound was recorded during shear, then relations between sound pressure level (SPL) of friction sound andfines content was well as relative density of specimens were investigated.
2. Apparatus and Experimental Procedure
Direct box shear test
Direct box shear tests were performed using a standard type direct box shear apparatus (JGS 0560-2000)1). An
upper shear box of the apparatus was switched to a plate of stainless steel (SUS304) in which a piezoelectricLecturer, Department of Urban Engineering
Professor, Department of Urban Engineering−29−

microphone was installed. The friction sound generated by shearing between soils and stainless steel wasrecorded. A schematic of upper and lower box of direct shear apparatus used is shown in Figure 1. Soils used forthe direct box shear tests were silica sands which were prepared so that their fines content (Fc) to be 0, 9.8, 19.6,
29.4, 49.0, 68.6 and 98.0% by mixing 2 kinds of commercially available silica sands were Silica No5 and Fine
Silica, whose Fc are 2% and 98%, respectively. Both were produced at a factory in Gihu prefecture, Japan. Soilsamples were given IDs as SM0, SM10, SM20, SM30, SM50, SM70 and SM100 in ascending order of fines
content. The grain size distribution curves of all soil sample used in this investigation are shown in Figure 2.
Specimens of 10mm in height and 60mm in diameter were prepared by the tamping method with 3 different
conditions in initial density which were loose, middle and dense conditions. Table 1 summarizes physicalproperties of soil samples and testing conditions in direct box shear tests. Contents shown in the table are fines
content (Fc), maximum and minimum void ratio (emax and emin), relative densities before consolidation (Dri) andafter consolidation (Drc), consolidation stress (n) and the displacement rate in the direct shear. All the specimens
were subjected to one dimensional consolidation pressure at n=50kPa, after that shear load was applied to theupper box until shear displacement reached to 15mm at 10mm/min of the constant shear rate. The friction sound
was recorded continuously while shearing. The shear force was applied by rotating a screw jack handle manually
to reduce mechanical noise would be recorded together with friction sound as much as possible.

mic AMP

piezoelectric
microphone(mm)

Shear
force
Specimen
Loading plate

Consolidation force
60mmPercent finer by weight (%)

PC(REC)
Stainless-steel
plate

100
SM10 080(F ine silica san d)

SM7 0

60

SM5 0

40

SM30
SM2 0

20
0
0.001

SM10

0.01

SM0 (S ilica s an d N o.5)

0.1

1Grain size (mm)100mm×100mm

Fig. 1 Shear box used for direct box shear test.

Fig. 2 Grain size distribution curves of silica sandmixture used in direct box shear tests.

Table 1. Physical properties of soil samples and experimental conditions in direct box shear tests.
Fc
(%)

e max

e min

SM0
(Silica sand No.5)

0

0.63

1.00

SM10

9.8

0.49

0.92

SM20

19.6

0.40

0.88

SM30

29.4

0.40

0.95

SM50

49.0

0.46

1.16

SM70

68.6

0.62

1.42

SM100

98.0

0.91

2.07

Soil name

InitialDensity
Loose
Middle
Dense
Loose
Dense
Loose
Dense
Loose
MiddleDense
Loose
Middle
Dense
Loose
Dense
Dense

−30−

D ri
(%)
10
48
78
-6
80
-11
82
-13
49
81
-6
52
81
25
82
82

D rc
(%)
38
77
80
22
86
32
87
49
81
88
70
74
85
74
86
91

n
(kPa)

Disp. rate
(mm/min)50

10.0

Swedish Ram Sounding (SRS)
Swedish Ram Sounding (SRS) which is corresponding to a DPSH-A (Super Heavy-A) in the dynamic probing
category according to ISO 22476-2(2005)2), measures two parameters; the one is the number of blow (Ndm) per
0.2m in penetration length with dropping a hammer having the mass of 63.5kg from the height of 0.5m, the otheris the toque (Mv) required to rotate the rod at every 0.2m of penetration length in N-m. The SRS Nd-value can begiven by following equation, in which Mv is employed to correct the skin friction resistance from Ndm (Dahlgerg
and Bergdahl, 19743) and Oshima, 20134)). The SRS Nd-value can be considered nearly equal to the SPT N-value(NSPT) because the equal potential energy of free-falling hammer per unit penetration length has been adopted inboth tests.

N SPT  N dm  0.04M v(1)

Figure 3 is a schematic of a condenser microphone embedded penetration cone used for recording friction soundby SRS. Note, the reason for employing the condenser microphone which is different kind from that used in the
direct box shear test was to prevent the microphone from breaking or coming off during SRS work. A condenser
microphone has higher structural strength than a piezoelectric microphone. The cone was screwed to thepenetration rod, so that both could rotate together while the torque measurement. The torque was measured atevery 0.2m of penetration depth by rotating penetration rod. The friction sound recording was continued while
each 1m dynamic penetration would be completed.

Hollow rod
mic AMPPC(REC)
Spring

105mm

Anvil
(Stainless-steel)mic cap
Condenser
microphone(mm)
Cone(Stainless-steel)90°

mmFig. 3 Schematic of penetration cone used for SRS.
Measurement and Analysis of Friction Sound
The sound sensed by a microphone was amplified by a mic-amplifier then recorded at a sampling frequency of
44.1 kHz using PC software in both of direct box shear test and SRS. Employing a recorded sound by SRS
performed at Urayasu city (Yamada and Oshima, 2015)5) as an example, the procedure of analyzing the friction
sound is described below.
Figure 4 shows a waveform of sound which was recorded continuously during 1 m dynamic penetration, thecorresponding penetration depth was from 10.4m to 11.4m. The process of SRS work and the position of
microphone, which is equal to depth of the cone, are indicated in the figure. Where, “blow” and “tor” indicate therammer blow process and the torque measurement process, respectively. It is observed that amplitude of soundrecorded in all blow process was over the range of recordable volume, and amplitude in every torquemeasurements process demonstrates almost constant values. Considering facts that the cone was stationary in the−31−ground and almost no signal was observed at the time from the end of “blow” to the start of “tor”, the soundrecorded in the torque measurement process can be determined as the sound generated by friction between outer
periphery of stainless steel cone and surrounded soil.
blow

tor blow tor

blow

tor

tor

blow

blow

tor

Sound pressure (Pa) orSound pressure level (dB)SRSprocess

10.6m
10.4m

10.8m

11.0m

11.2m

11.4m

mic position (depth)

Fig. 4 Example of waveform recorded in SRS (Yamada and Oshima, 2015).
Figure 5 (a) shows a time history of sound pressure recorded at 10.6m in depth shown in Figure 4. The data
shown in the figure is the signal of friction sound which was extracted from a raw data by applying the spectral
subtraction (Boll, 1979)6). The data of 2 seconds before the start of torque measurement, cone was stationary at
this time, were applied as a noise sample to the denoising. Figure 5(b) shows the corresponding sound pressurelevel (SPL) to Figure 5(a). The SPL can be calculated by following equation as an expression in Decibel.
 p2 
SPL  10 log10  2 
p 
 0 

(in dB)(2)

Where, p is the sound pressure in Pa and p0 is a referential sound pressure equal to 20Pa which is known as
minimum sound pressure human being can recognize.
Figure 5(c) shows a spectrogram calculated from the data shown in Figure 5(a) in the gray scale display inwhich the larger SPL is indicated by deeper black color. Where, the spectrogram is often-used expression in the
acoustic phonetics which expresses a time series variation of the frequency spectrum indicating the intensity of
frequency component by color gradations. It can be understood from Figures 5(b) and (c) that the friction soundrecorded during the torque measurement is indicating stable SPL with approximately 65dB as well as showing theless variation in the frequency spectrum along time. In the present study, therefore, an average of SPL of entire
data recorded in single torque measurement is defined as the mean SPL, representing an acoustic property of thefriction sound.
3. Experimental Result

As an example of the field measurement by SRS, the results obtained at a site in Osaka city is shown in Figure
6. As for details of site profile etc., refer Mine et al. (2015)7). The figure illustrates relations between mean SPL
and Fc at same depth. The data of Fc were obtained from soil samples of SPT performed at same date. Symbols
are indicating an individual soil classifications. A general trend can be observed that the mean SPL decreases withan increasing in Fc, the trend seems to be independent from the difference of soil type. This result may suggestthat there is a correlation between the loudness of the friction sound and the grain-size characteristics.

−32−

SRS, Urayasu Minato, 10.6m

0.05
0.00
-0.05

(a)

Torque measurement (approx. 15.3sec)

-0.10
80

SPL (dB)

Sound Pressure,
p(Pa)

0.10

(b)

70
60
50
40

frequency, (Hz)

30
10

4

10

3

(c)

60
50
40
(dB)

2

10
-2

0

2

4

6

8

10

12

14

16

18

Time (sec)Fig. 5 Time histories: (a) sound pressure, (b) sound pressure level and (c) power spectrum.

mean SPL (dB)

50
40
30

Suminoe-ku, Osaka

20
10
0

0

: CH
: M LS: CLS: M L-S: CL-S: CLS-G: SF: SFG: S-FG

10

50

20

30

40

60

SRS
70

80

90 100Fines content, F c (%)
Fig. 6 Relation between SPL and fines content, result of field measurement by SRS.
Figure 7(a) and (b) show relations between shear stress and shear displacement as well as SPL and shear
displacement obtained from direct box shear test on SM10 with loose density. In Figure 7(b), the Black coloredindicates SPL recorded with 44.1 kHz in sampling frequency and the Yellow colored indicates data of their 4096
period (approximately 0.09 sec) moving average. The shear stress indicates almost constant value with small
fluctuation after peak shear stress appeared at the beginning of the shearing. It can be observed in Figure 7(b) that
SPL indicates larger value at the shear displacement less than approximately 1mm, and after that it indicatesconstant value in average showing large fluctuations in conjunction with the change of shear stress. Since almost
constant value in both shear stress and SPL were obtained from all test conducted in the present study, the mean
SPL which is a parameter represents an acoustic property of the friction sound was defined as an averaged SPL
value obtained from 10 second’s data between 35 and 45 sec, which is corresponding to the range of the shear
displacement from 5.8 to 7.5mm.

−33−

Shear stress(kN/m 2 )10

Direct shear test,  n =50kPa, F c =10%, D ri =0%5(a)

SPL (dB)

07035~45sec(b)

Disp. rate: 10mm/min

Yellow: moving average
deviations

extracted

50
30
10
0

5

10

15

Shear Displacement (mm)Fig. 7 Example result of direct box shear test: (a) Shear stress vs. shear disp.; (b) SPL vs. shear disp.
Figure 8 shows a relationship between mean SPL and Fc obtained from all direct box shear test performed. It
should be mentioned that there is large difference in the mean SPL between SRS and direct box shear test. Thisdifference can be considered to be due to that there were differences in the type of microphone, the shape ofapparatus and the shear rate among the tests. However, a general trend can be observed that the mean SPL
decreases with increasing in Fc except for the results of SM0 (Fc=0%) specimens. This observed trend is agreed
with that shown in Figure 6 which was obtained from the field measurement by SRS. A probable reason for thesmaller mean SPLs were resulted on SM0 is that most of particles were hard to move during shear because SM0
has narrow grain size range i.e. there is a minor difference in grain size among adjoining particles. Same reason
might be applicable to the result on SM100. Figure 9 illustrates relations of mean SPL and relative density after
consolidation (Drc). Lines indicated in the figure can be given by Equation 2 will be described later. It is evidence
that mean SPLs of sandy soil with constant Fc are depended on Drc and they decrease with an increases in Drc. It
can be considered that soil particles in specimens with high density should be difficult to move because thedegree of confinement acting to soil particles to be greater when density of specimen is higher.

35

Direct shear test n =50kPa

25

Mean SPL (dB)mean SPL (dB)

30

20
15
10

: Loose: M iddle: Dense

5
0
0

10

20

30

35-45sec
40

50

60

70

80

Fines content, F c (%)

Fig. 8 Relation between mean SPL and fines content.

 n =50kPa

70 %

30 %

25

10 %

20
15
10
5
0
0

90 100

50 %

30

: SM0
: SM10: SM2 0
: SM30: SM5 0
: SM7 0

Direct shear test

10

30

20

20 %
Fc =0%

40

50

60

70

80

90 100Relative density, D r c (%)

Fig. 9 Relation between mean SPL and relative density
after consolidation.

−34−

1.0

100

(Mean SPL) / (SPL 0 )SPL 0 (dB)Direct shear test
80  n =50kPa
60
40
20
0
0

10

20

30

40

50

60

70

80

0.8

n

0.6
0.4
0.2
0.0
0

90 1001: SM0: SM10: SM2 0
: SM30: SM5 0: SM 7 0

 n =50kPa
Direct shear test

10

30

20

40

50

60

70

80

90 100Relative density, D r c (%)

Fines content, F c (%)

Fig. 10 Relationship between SPL for Drc=0% andfines content.

Fig. 11 Normalized mean SPL versus Relative density
after consolidation.

Direct shear test n =50kPa

Slope, n

-0.2
-0.4
-0.6
-0.8
-1.0
0

10

20

30

40

50

60

70

80

90 100Fines content, F c (%)

Calculated mean SPL (dB)

Relative density, D r (%)
0.0 ×10 - 2

35
30

19

43
50 %

60

74

85

95

70 %
30 %

25

20 %

20
10 %

15
10

Fc =0%

5
0
0

5

10

15

20

25

SRS N dFig. 12 Relation between relative density dependence
factor n and fines content.

Fig. 13 Relation between Calculated mean SPL and
SRS Nd-value.

4. An idea for evaluating fine fraction content of soil by SRS

Based on experimental results discussed above, a tentative idea for evaluating Fc at site by SRS is described
below. If relations between the mean SPL and Drc shown in Figure 9 are able to be assumed to be linearly
approximated on each Fc, the intercepts of approximated lines are equivalent to the mean SPLs at Drc=0%. By
defining these intercepts as SPL0, a relation of SPL0 and Fc is illustrated in Figure 10. The SPL0 indicates almost
same value in the range of Fc from 0 to 30%, and it increases linearly with increasing of Fc when Fc is greaterthan 30%. This trend may indicates that fine particles does not contribute to the magnitude of friction sound ofvery loose sandy soils in the range of Fc up to 30%. However, there is some doubt about the reliability on SPL0s
of Fc =50 and 70% because they were obtained from results of two experiments on specimens whose Drc weregreater than 70%. Additional experiments are needed to confirm the accuracy of this trend.
In order to define the available range of the mean SPL of friction sound of soils having various relative
densities and Fc, the normalized mean SPL was determined by dividing measured mean SPL by SPL0. Hence,
every relation between the mean SPL and Drc can be approximated by a straight line passing through an intercept
1 as shown in Figure 11. The slopes of approximation lines taking negative value represent the magnitude of
dependency on relative density in the mean SPL. By reading slopes (n) of each lines from Figure 11, a
relationship between n and Fc was illustrated in Figure 12. The values of n are corresponded to the range ofvariation in the mean SPL shown in Figure 8.
Therefore, the mean SPL can be expressed in the linear expression given by Equation 3. The lines drawn foreach Fc in Figure 9 were calculated by Equation 3.

−35−

meanSPL  nDr  SPL0

(in dB)(3)

According to the well-known expression of Meyerhof (1957)8), the relative density (Dr) can be expressed in afunction of SPT N-value (NSPT) and the effective overburden stress v’ as below,
Dr  21N SPT
0.7   v' 98(in Percent)(4)This equation has been employed for evaluating liquefaction resistance by insitu sounding (e.g. Ishihara,
19969)). Additionally, the NSPT in Equation 4 can be considered to be equal to SRS Nd-value when the torqueMv=0 is substituted in Equation 1, for a simple assumption. Hence, the mean SPL can be expressed in a functionof SRS Nd-value by substituting Equation 4 in Equation 3.Then, relationships between calculated mean SPL and
SRS Nd-value can be obtained as shown in Figure 13. Note that all the value shown in the figure were calculatedwith the effective overburden stress v’=50kPa which is equal to the normal stress applied to specimens in directbox shear tests. Although Figure 13 was derived from the direct box shear tests on limited number of silica sands
contain non-plastic fines, it may be indicating a prospect that the fines content of particular stratum can be
estimated by measuring the friction sound adding to the conventional measurement of Ndm and Mv in a single SRS
work.
5. Conclusions

Direct box shear tests were performed on silica sands with various fines content, simulating the friction ofstainless steel cone with surrounding soil occurring during the torque measurement in SRS. The results indicatesthat the mean SPL obtained from both SRS test and direct box shear tests are affected by the relative density as
well as by fines content. An idea to determine the fines content from conventional SRS work was proposed.
However, the idea is tentative and should not be applied in practice at this moment, because it was based on
results of direct box shear tests performed under considerably limited conditions, not only carried out using
different equipment from that used in the field measurement by SRS. In order to develop an evaluating method offines content using Soil-Metal friction sound by SRS, it is necessary to accumulate more experimental data on
various kinds of soil by further testing in which reasonable conditions in the field measurement should beconsidered.
6. References
1) Japanese Geotechnical Society, Method for consolidated constant pressure direct box shear test on soils. JGS
0561-2000 (2000)
2) International Organization for Standardization, Geotechnical investigation and testing –Field testing- Part 2;
Dynamic probing. ISO 22476-2: 2005 (2005)
3) R. Dahlberg, and V. Bergdahl, Investigations of the Swedish Ram Sounding method, Proc. European
Symposium on Penetration Testing, 2, 93 (1974)
4) A. Oshima, Geotechnical engineering magazine, 61, 40 (2013) (in Japanese)
5) S. Yamada, and A. Oshima, Proc. of 15th ARC of SMGE (2015) (in press)
6) S. F. Boll, IEEE Transactions on Acoustics. Speech and Signal Processing, 27, 113 (1979)
7) S. Mine, et al. Ground investigation at Suminoe-ku, Osaka (Part1: Sounding), Proc. of 50th annual conf. ofJGS, 169-170 (2015) (in Japanese)
8) G. G. Meyerhof, Proc. 4th Int. Conf. on SMFE, 1, 110 (1957)
9) K. Ishihara, OXFORD engineering science series, 56, 287 (1996)−36−

Analysis of Resident Interest and Intentions for Community Bus Network Reorganization
Yumie SAWADA* and Takashi UCHIDA**(Received October 2, 2015)
Synopsis
Continuous reorganization of a community bus network to maintain the service is extremely important.
This study specifically examines residents, who must play an important role in the reorganization of acommunity bus network, in terms of their interests and intentions for reorganization of community bus
network. The target case is Akashi community bus "Taco Bus." This bus is well known in the PDCA cycle.
The questionnaire results of the reveal usage conditions and socioeconomic characteristics in addition to
the state of their interests and intentions. Based on the data of the questionnaire, the interests and intentions
are classified into five groups by principal component analysis and cluster analysis. To clarify the groupcharacteristics, discriminant analysis was conducted. We discuss the problems of maintaining a bus network
based on the group characteristics.
KEYWORDS: Public transportation, Transportation poor, PDCA cycle, Questionnaire, Statistical analysis

1. Research Background and Objectives(1) Research background
Recently, the Bus business has not been very rewarding. In rural areas, many bus services have been forced
to stop. In urban areas, numerous problems such as heavy traffic and reorganization of bus networks andproviding efficient services have decreased the number of passengers. Management rationalization of buseshas been demanded in both areas. However, in the local government, the need exists for the maintenance oflife transportation of residents to maintain and improve the welfare services of residents.
In Japan, aging has become a serious problem. Aging of the population in Japan is expected to proceed
faster than in Western countries. In the future, people will increasingly give up driving because of aging.
However, social participation of elderly people as workers is expected to increase. Their demand formobility is expected to increase.
In February 2002, because of the revision of road transport laws, supply and demand adjustment
regulations in omnibus businesses have been discontinued. Buses have attracted attention as a mode of
public transport. The introduction of a “Community Bus” that maintains close contact with the community is
expected to be useful for community development and activity.
Maintaining convenience and ongoing review and improvement for utilization is extremely important in
the community bus management. It is conducted in many areas. Takebayashi1) et al. introduced manyfavorable comments from residents related to the method of service review in the PDCA cycle, including theoperational review criteria.
(2) Research objectives
This study targets Akashi community bus "Taco Bus," which is carrying out reorganization of community
bus network steadily2). Because residents serve important roles in the reorganization, their interests andintentions for the reorganization become clear by doing the questionnaire survey. The following must be*Students, Master Couse of Department of Urban Engineering** Professor, Department of Urban Engineering−37−

clarified through analyses.
1) Understanding the state of resident interests and intentions
2) Grouping resident interests and intentions3) Elucidating characteristics of the group(3) Research approach
The flow of research is presented in Figure 1. First, material of Akashi City local public transport meeting
understands outline about the Taco Bus such as methods of handling, the number of users, methods andachievements for reorganization and promotions to resident. Second, a questionnaire is administered toresidents. The questionnaire is constructed around promotions to resident. By multivariate analysis of thequestionnaire data, the interests and intention are classified into groups to reveal the impact factors.
2. Questionnaire(1) Questionnaire objectives
It is necessary to understand how residents have knowledge and emphasize efforts of promotion ofutilization and reorganization of the community bus network. The results can be used to clarify whether
some willingness exists to cooperate in these efforts, in addition to the resident interests and intentions.
These objectives guide the pursuit of basic knowledge for executing an ideal reorganization for a community
bus network.

Fig. 1 Flow of research.

−38−

(2) Questionnaire outline
This study questionnaire survey is targeted at Akashi citizens with a specific examination of Taco Bus users.
The survey dates are August 28, 2014 (Thursday), 30 (Saturday), 31 (Sunday), and September 4 (Thursday),
6 (Saturday), 7 (Sunday). The locations are JR Nishi Akashi Station, Okubo Station, Uozumi Station, andSanyo Higashi Futami Station. At each location, the questionnaire survey is administered twice on holidays
and once on weekdays. This survey was administered face-to-face or through distribution and recovery ofquestionnaires by post.
(3) Question contents
The questionnaire consists of seven questions (Table 2): [1] Knowledge of utilization promotion measures,[2] Number of use of utilization promotion measures, [3] Importance evaluation of utilization promotion
measures, [4] Cooperation intention to maintain the operation, [5] Relation with Taco Bus on the daily life,[6] Respondent attributes, and [7] Free description.
Individual conditions for the Taco Bus are shown by “[1] Knowledge of utilization promotion measures”,“[2] Frequency of use of utilization promotion measures,” and “[5] Relation with Taco Bus on the daily life”.
In addition, “[3] Importance evaluation of utilization promotion measures” and “[4] Cooperation intention tomaintain the operation” are the resident interests and intentions. This study compares the individual
conditions and the resident interests and intentions.
This study only uses postal recovery. Utilization promotion measures are (13) from (1) in [1], [2], and [3].
In “[4] Cooperation intention to maintain the operation,” (1)–(6) are concrete cooperation contents, (7)–(9)are negative choices for cooperation.
3. Characteristic analysis of resident interests and intentions(1) Methods of analysis
This study groups the respondents for each characteristic of resident interests and intentions. First, do
principal component analysis using the answers of “[3] Importance evaluation of utilization promotion
measures” and “[4] Cooperation intention to maintain the operation.” Second, respondents are divided into
groups by doing cluster analysis using principal component scores.
(2) Principal component analysis
This study does principal component analysis. The data to be handled are 22 items: (13) from (1) of “[3]Importance evaluation of utilization promotion measures” and (9) from (1) of “[4] Cooperation intention tomaintain the operation” (Table 3). In fact, (7) and (8) are integrated.
The eigenvalue, contribution rate, and cumulative contribution rate of each principal component are shownin Table 4. The eigenvector of each principal component is shown in Table 5 and Figure 2. As a condition ofdetermining the principal component number, the principal component is 1.0 or more of the eigenvalues.
This analysis uses four principal components.
These components are characterized in Figure 2 by each eigenvector.
1st: The positive degree of evaluation for the current measures
All “Importance evaluation of utilization promotion measures” are positive values and “[4] (7) (8) Do notcooperate” are negative values.
2nd: Having intention of contribution including the specific use“[4] (1) Discussion in familiar place about easier use”, “[4] (2) Joint purchase of book of tickets and freepasses”, “[4] (3) Suggestion of using Taco Bus to surrounding residents” and “[4] (5) Cooperate if there arepeople who are working to support” were positive values.
3rd: (+) Emphasizing substantial cooperation for improvement vs. (-) Cooperation with using or existing
efforts“[4] (1) Discussion in familiar place about easier use” is a positive value. “[4] (3) suggestion of using TacoBus to surrounding residents”, “[4] (4) Taking as many Taco Buses as possible” and “[4] (6) Taking
advantage of existing efforts” are negative values.
4th: (+) No idea – although having intention to cooperate vs. (-) No intention to cooperate“[4] (9) No idea” is a positive value. “[4] (7) (8) Do not cooperate” is a negative value.

−39−

Table 1 Questionnaire outline
MethodLocation
Subject
Date
Recovery number

Face-to-face or the distribution and mailing recovery of questionnaires
Nishi Akashi Station, Okubo Station, Uozumi Station (JR)Higashi Futami Station (Sanyo)
Passengers and passers-by (Taco bus users and Akashi citizen)
Twice on holidays and once on weekdays at each place
August 28, 2014 (Thursday), 30 (Saturday), 31 (Sunday)
September 4 (Thursday), 6 (Saturday), 7 (Sunday).
Face-to-face: 182
Mailing recovery: 231(Rate 33.4％)

Table 2 Question contents
Content[1]
Knowledge

Utilization promotion
measures[2]
Number of use[3]
Importance valuation[4]
Cooperation intention to maintain the operation[5]
Relation with Taco Bus on the daily life

[6]
Respondent attributes

Item(1) Taco bus Akashi eco family system(2) Book of tickets(3) Taco bus supporter(4) Taco bus cheer shop
(5) Bingo and a stamp rally on Taco bus(6) Taco bus with Christmas decoration(7) Cooperation with the local community such as high school
students and child care support organizations(8) Visitation of facilities along the way(9) Events surrounding Taco bus(10) Giving Akashi city bus trial ticket(11) Information transmission by Twitter and Facebook(12) Performance reporting in the "Akashi regional public
transportation conference"(13) Regional briefings(1) Discussion in familiar place about easier use(2) Joint purchase of book of tickets and free passes(3) Suggestion of using Taco bus to surrounding residents(4) Taking as many Taco buses as possible(5) Cooperate if there are people who are working to support(6) Taking advantage of existing efforts(7) Difficult to cooperate now(8) Do not cooperate(9) No idea(10) Other(1) Ride frequency of Taco bus(2) Bus utilization on the survey day(3) Taco bus stop on home nearest(4) Knowledge of the route map distribution location of Taco bus(5) How to get information about Taco bus(6) Thinking that there is a bus in life
(1) Sex(2) Age(3) Who do live together(4) Postal code
(5) Available move means(6) Usage of the bus other than Taco bus(7) Bus usage of housemate[7] Free description−40−

Table 3 Data for principal component analysis[3]
Importance evaluation ofutilization promotion
measures[4]
Cooperation intention tomaintain the operation

Variable
Taco bus Akashi eco family system
Book of tickets
Taco bus supporter
Taco bus cheer shop
Bingo and a stamp rally on Taco bus
Taco bus with Christmas decoration
Cooperation with the local community such as highschool students and child care support organizations(8) Visitation of facilities along the way(9) Events surrounding Taco bus(10) Giving Akashi city bus trial ticket(11) Information transmission by Twitter and Facebook(12) Performance reporting in the "Akashi regional public
transportation conference"(13) Regional briefings(1) Discussion in familiar place about easier use(2) Joint purchase of book of tickets and free passes(3) Suggestion of using Taco Bus to surrounding residents(4) Taking as many Taco buses as possible(5) Cooperate if there are people who are working tosupport(6) Taking advantage of existing efforts(7) (8) Do not cooperate(9) No idea
(1)
(2)
(3)
(4)
(5)
(6)
(7)

Range of variables

1. Not really important
2. Not important
3. Neutral
4. Important
5. Very important

0. No
1. YesTable 4 Eigenvalue, contribution rate, and cumulative contribution rate of each principal component
NO
1
2
3
4

Eigenvalue
8.181
1.908
1.287
1.146

Contribution rate (%)
38.955
9.084
6.130
5.455

Cumulative contribution rate (%)
38.95548.03954.16959.625(3) Cluster analysis
This study classifies the respondents using the principal component scores obtained in (2), and does
hierarchical cluster analysis by Ward Method. A summary of the treated cases is shown in Table 6. A
dendrogram is shown in Figure 3. Results of cluster analysis show that they can be grouped into five at a
position where coupling distance is 10. The five groups are named A, B, C, D, and E from the top.
(4) Group characteristics
This section explains characteristics of each group obtained by (3). Figure 4 shows the first principal
component scores of the respondents to the X-axis and the fourth principal component scores to the Y-axis.
Figure 5 shows the second principal component scores to the X-axis and the third principal componentscores to the Y-axis.
Specifically with respect to Figure 4, on the X-axis, the higher the value is, the more positive a respondent isabout the current measures. On the Y-axis, the higher the value is, it is no idea - although having intention tocooperate. There is a concrete cooperation intention around the origin. The lower the value is, the lessintention a respondent has to cooperate. Therefore, the group on the lower left of Figure 4 is negative aboutmaintaining bus operations. The group around the origin has awareness of the issues about maintaining theoperation and concrete cooperation intentions. At the top of Figure 4, a respondent has no idea about
cooperation. At the bottom of Figure 4, a respondent has awareness of issues related to maintaining theoperation, but no cooperation intention.

−41−

Table 5 Eigenvector of each principal component
Variable
(1)
(2)
(3)
(4)
(5)
(6)
(7)

Taco bus Akashi eco family system
Book of tickets
Taco bus supporter
Taco bus cheer shop
Bingo and a stamp rally on Taco bus[3]
Taco bus with Christmas decoration
Importance
Cooperation with the local community such as highevaluation ofschool students and child care support organizations
utilization(8)
Visitation of facilities along the way
promotion(9)
Events surrounding Taco bus
measures(10) Giving Akashi city bus trial ticket(11) Information transmission by Twitter and Facebook(12) Performance reporting in the "Akashi regional public
transportation conference"(13) Regional briefings(1) Discussion in familiar place about easier use(2) Joint purchase of book of tickets and free passes(3) Suggestion of using Taco Bus to surrounding[4]
residents
Cooperation(4) Taking as many Taco buses as possible
intention tomaintain the (5) Cooperate if there are people who are working tosupportoperation(6) Taking advantage of existing efforts(7) (8) Do not cooperate(9) No idea
E=∑

1
.783
.739
.722
.786
.776
.655

Eigenvector (E)
2
3
-.185
-.178
-.225
-.276
.034
.222
-.093
.190
-.192
.018
.017
.077

4
.097
.230
.074
.008
.032
-.084

.786

-.092

.106

.006

.828
.814
.768
.702

-.108
-.223
-.132
.120

.106
.105
.101
-.031

-.008
-.100
-.029
-.173

.734

-.067

.011

-.157

.776
.142
.276

.101
.653
.587

-.006
.479
.212

-.242
.253
.091

.198

.423

-.401

.014

.325

.384

-.443

.061

.240

.588

.221

-.066

.347
-.483
-.106

.288
-.191
-.312

-.543
.199
.167

.089
-.493
.784

0.4 ≤ | | < 0.6

0.6 ≤ | |Specifically with respect to Figure 5, on the X-axis, higher values represent a contribution intention
including the specific use. On the Y-axis, higher values signify substantial cooperation for improvement.
Lower values indicate cooperation with existing efforts. Therefore, the group on the left of Figure 5 isreluctant to contribute. The group on the upper right is emphasizing importance of cooperation to theimprovement. The group on the lower right is cooperative about using buses or existing efforts.
The characteristics of these figures give the name of each group.
A: Negative about maintaining bus operations
A is on the lower left of Figure 4 and near the origin of Figure 5.
B: Having concrete cooperation intentions and emphasizing the importance of cooperation for improvement
B dominates the area near the origin of Figure 4 and the upper right of Figure 5.
C: Having awareness of issues related to maintaining operations, but no ideas about cooperation
C is on the top of Figure 4 and on the left of Figure 5.
D: Having concrete cooperation intentions and cooperation related to using buses or existing efforts
D dominates the area near the origin of Figure 4 and the lower right of Figure 5.
E: Having awareness of issues related to maintaining the operations, but reluctant to make contributions
E is located at the bottom near the origin of Figure 4 and on the left of Figure 5.

−42−

Fig. 2 Eigenvector of each principal component.

−43−

Table 6 Summary of the treated cases
Effective number
Number
%
122
52.6

No.

Loss
Number110%
47.4

Distance cluster coupling

A

B

C

D

E

Fig. 3 Dendrogram.

−44−

Total
Number%232
100.0

Fig. 4 First – Fourth principal component

Fig. 5 Second – Third principal component−45−

4. Extraction of objective factors related to resident interests and intentions(1) Methods of analysis
This study does discriminant analysis to understand what kind of objective factors affect the group. The
factors mean "[2] Number of uses of utilization promotion measures,” "[5] Relation of Taco Bus to daily
life," and "[6] Respondent attributes" among the questions. They are used as explanatory variables for thisanalysis.
(2) Discriminant analysis
Explained variables are the 5 groups obtained in 3. Explanatory variables are shown in Table 7. In all, there
are 37 variables. These are considered that particularly affect the groups.
A summary of the treated analysis case is presented in Table 8. The eigenvalue, contribution rate,
cumulative contribution rate and canonical correlation of each discrimination function are shown in Table 8.
Standardized canonical discriminant function coefficients are shown in Table 9. Standardized canonicaldiscriminant function coefficients are shown in Table 10. Table 11 and Figure 7 show the center of gravity of
the group. It is obtained by canonical discriminant functions that are evaluated in the group average but notstandardized. A summary of the classification is shown in Table 12. Table 13 presents classification results.
The result shows that 51.7% of the original grouped cases are classified correctly.
From Table 13, B, D, and E show that the accuracy of the analysis is low. B is misjudged in C and E. D is
misjudged in E and vice versa because B, C, D, and E show similar distributions at the 1st principal
component (Figure 4). Especially, B, D, and E show similar distributions at the 4th principal component. D
and some E are negative values at the 3rd principal component. Misclassifications reveal similar
characteristics of each group. These are not related to the objective factors. Therefore, this misclassification
presents no problems for these analyses.
To clarify the objective factors affecting the group, we next specifically examine standardized canonicaldiscriminant function coefficients (Table 10). Regarding 0.4 ≤ | |, one can describe the descending orderof influence.
1st discriminant function:
It is common practice to use a book of tickets. There is no spouse among housemates. It is common to use
Taco Bus with Christmas decorations. There are no bus users in the family.
2nd discriminant function:
The young user does not live with a sibling. The frequency of ticket book use is low. There is no bus user inthe family.
3rd discriminant function:
There is no son or daughter among housemates. It is possible to drive a car. It is common to use a Taco Bus.
Sex is female.
4th discriminant function:
There is a bus user in family. It is possible to drive a car and advanced age. The user live with a spouse.

−46−

Table 7 Explanatory variables for discriminant analysis
Variable[2]
Number ofuses ofutilization
promotionmeasures[5]
Relation with
Taco Bus on
the daily life

Range of variables(1) Taco bus Akashi eco family system(2) Book of tickets(5) Bingo and a stamp rally on Taco bus

1. Never use
2. Use3. Use well(6) Taco bus with Christmas decoration
1. Almost everyday
2. A few days for a week
3. Once for a week
4. Once for a month
5. Usually not used, only when necessary use
6. Not use
7. Blank
1. Don't know or Blank
2. Know or Nothing
1. Male2. Female
1. Under 10 years
2. The teens
3. Twenties
4. Thirties
5. Forties
6. Fifties
7. Sixties
8. Seventies
9. Eighties
10. 90 years or older.

(1) Ride frequency of Taco bus(3) Taco bus stop on home nearest(1) Sex(2) Age[6]
Respondent
attributes
(3)

(5)

1) Parent
2) Son or daughter3) GrandchildWho do you4) Grandparents
live together
5) Spouse
6) Sibling7) Live alone
Available
1) Carmove means 2) Motorbike(6) Usage of the bus other than Taco bus(7) Bus usage of housemate

0. No
1. Yes

0. Can't
1. Can
1. Use2. Don't use
1. Yes
2. No

Table 8 Summary of the treated analysis case
Effective number
Exclusion Not classified
Missing one or more explanatory variables
Not classified and missing one or more explanatory variables
Total
Total

−47−

Number
118
93
4
17
114
232

%
50.9
40.1
1.7
7.3
49.1
100.0

Table 9 Eigenvalue, contribution rate, cumulative contribution rate and canonical correlation of eachdiscrimination function
Function
12
3
4

Eigenvalue
.494
.289
.223
.122

Contribution rate (%)
43.8
25.6
19.8
10.8

Cumulative contribution rate (%)
43.8
69.4
89.2
100.0

Canonical correlation
.575
.473
.427
.329

Table 10 Standardized canonical discriminant function coefficients(1)Taco bus Akashi eco family system(2)Book of tickets(5)Bingo and a stamp rally on Taco bus(6)Taco bus with Christmas decoration(1) Ride frequency of Taco bus

Function coefficients (a)
1
2
3
4
.068
.039
.027
.266
.818
-.408
.214
.217
-.001
.236
-.134
-.312
.344
.175
-.184
.332
.473
.221
-.449
.254

(3) Taco bus stop on home nearest

.108

.323

.210

.070

(1) Sex(2) Age
1) Parent
2) Son or daughter3) Grandchild(3) 4) Grandparents5) Spouse
6) Sibling7) Live alone
1) Car(5)2) Motorbike(6) Usage of the bus other than Taco bus(7) Bus usage of housemate

-.087
-.274
-.227
.210
-.077
-.151
-.603
.124
.160
-.205
-.262
-.020
.108

.151
-.415
.185
-.031
-.267
.330
.394
.448
.370
-.206
.147
.200
.404

.448
.069
.270
-.608
.311
.074
.030
-.165
.154
.452
.375
.151
.006

.216
.436
-.054
.096
.026
-.173
.367
.251
.226
.497
-.289
-.259
.574

Variable[2]
Number of uses ofutilization promotion
measures[5]
Relation with Taco Bus on
the daily life

[6]
Respondent attributes

0.4 ≤ | |Table 11 Center of gravity of group
Group
A
B
C
D
E

1
.150
-.949
-1.110.755.308Function2
3-.889-1.979
-.144
.231
-.187
-.313
-.662
.335
.571
-.079

−48−

4
-.398
-.286
1.215
.078
-.001

Fig. 6 Center of gravity of the group.
Table 12 Summary of the classification
TreatedExclusion Not classified
Missing one or more explanatory
variables
Used for classification

232
0
21
211

Table 13 Classification resultA

Original data

Number

%

A
B
C
D
E
Cases that are not grouped
A
B
C
D
E
Cases that are not grouped

4
1
0
4
4
8
80.0
3.3
0.0
14.8
8.2
8.6

−49−

Prediction data
B
C
D
0
0
0
14
8
1
1
5
0
2
3
13
5
6
9
28
22
25
0.0
0.0
0.0
46.7
26.7
3.3
14.3
71.4
0.0
7.4
11.1
48.1
10.2
12.2
18.4
30.1
23.7
26.9

E
1
6
1
5
25
10
20.0
20.0
14.3
18.5
51.0
10.8

Total
5
30
7
27
49
93
100.0
100.0
100.0
100.0
100.0
100.0

5. Conclusion
This study provided the following results.
1)
Resident interests and intentions for the reorganization were divisible into five groups. These fivegroups are described below:
A: Negative about maintaining bus operations
B: Having concrete cooperation intentions and emphasizing the importance of cooperation forimprovement
C: Having awareness of issues related to maintaining operations, but no ideas about cooperation
D: Having concrete cooperation intentions and cooperation related to using buses or existing efforts
E: Having awareness of issues related to maintaining the operations, but reluctant to make contributions2)
Because there is awareness of issues related to maintaining operations in the group other than A, mostresidents have the idea that it is necessary to maintain the bus network.
3)
Results of discriminant analysis show that differences in cooperation methods and thoughts about thebus are affected by the presence of housemates, age, sex, manner of using the Taco Bus and the ability
to drive a car.
Studies of the near future must provide cooperation methods commensurate with the characteristics, such asage or home environment. For example, C, “Having awareness of issues related to maintaining operations,but no ideas about cooperation,” presents a concrete cooperation method; E, “Having awareness of issues
related to maintaining the operations, but reluctant to make contributions,” presents an indirect cooperation
method.
6. References
1)

H. Takebayashi, and Y. Nitta, J. Jpn. Assoc. Inclusive Soc., 10, 29 (2008) (in Japanese)2)

Y. Kurashima, and T. Uchida, Proc. Infrastructure Planning, 48, 1-4 (2013) (in Japanese, CD-ROM)−50−

Major Issues of Bicycle Use in Urban Area from View Point of Community Development
Yurie ISHINURA*, Yasuo HINO** and Yuuka WATANABE***(Received October 5, 2015)

Synopsis
The problems of illegally parked bicycles have been shifting in a central area from around rail station. In
order to improve such problem, the activities based on public involvement must be necessary, because there are
not only many small stores without parking facilities of bicycles, but also many stakeholders such as habitants andthe store owners and the visitors, who have different interests. However, it is not always revealed the differencesof interests for using bicycles among them. Then the aims of this study must be to investigate the consciousness ofeach stakeholder in the commercial area in Osaka city. As a result, it became clear that the illegal parked bicycles
must be the common problem among of them, nevertheless the thinking of community development may bedifferent. These interesting findings should be important information to realize the activity based on the public
involvement.
KEYWORDS: Illegally parked bicycle, Community development, Commercial area, Public involvement,
Questionnaire survey
1. Introduction
The problems of illegally parked bicycles have been shifting in a central area from around rail stationaccording to improving the bicycle parking facilities1). Therefore, in the local government, although theregulations about the supplying parking facilities with the building was enforced in 2010, it is hard to expect theimmediate effect. Therefore some urgent solutions must be required. On the other hand, there is the way of
thinking to use the convenience of the bicycle in the commercial area for community development. However,there are various stakeholders such as habitants and the store owners and the visitors, who have different interests.
Therefore in order to improve such problem, the activities involved such stakeholders to realize the desirable
community development must be necessary2).
Then the aims of this study must be to investigate the consciousness of each stakeholder in Horie area of
Nishi-ku district as a commercial area in Osaka city, in order to improve the common problems concerned withillegal parked bicycles. By using the questionnaire survey to the inhabitants, shop owners and/or managers andvisitors, it may be expected to know the consciousness about “the desirable image of community development”,“the achievement of its community development”, “major issues of community development”, and “the way ofbicycle use”. These findings must be expected to be not only the important information but also realize theactivities based on the public involvement
2. Outline of Target Area
Horie area located in city center of Osaka city is
divided into three zones as the residential zone
(North-horie(1) and South-horie(1)), the mixture zone
NorthNorth-horie(2)North-horie(1)horie(3)(North-horie(2) and South-horie(2)) and the commercial
Residential
MixtureCommercial
zone (North-horie(3) and South-horie(3)) by the pattern
zone
zone
zone
of major land use, as shown in Figure 1.
South-horie(3)South-horie(1)South-horie(2)There are many illegal parked bicycles in all zones.
But it must be clear that illegally parked bicycle number
has increased especially in the commercial zone, as
shown in Figure 2.
Fig. 1 Out lone of target area
(Horie area of Nishi-ku district, Osaka city)* Student, Master Course of Dept. of Urban Engineering, Osaka City University** Professor, Dept. of Urban Engineering, Osaka City University*** Engineer, Yachiyo Engineering Co., Ltd−51−

(bicycles)
600

2013

500

434

259

244

200

402

392

400
300

2014

513

194

188

South
horie(1)Northhorie(2)

136

314

278

237

100
0
North
horie(1)Residential zoneSouthhorie(2)Northhorie(3)Mixture zoneSouthhorie(3)Commercial zone

Fig. 2 Change of number of illegally parked bicycles by each zone

3. Outline of survey
In order to investigate the differences of consciousness for community development and thinking way ofbicycle use by each stakeholder, the questionnaire survey was conducted for residents and store managers in Northand South horie(3) as the commercial zone and South-horie(2) as the mixture zone. The number of distribution ofquestionnaire sheets and respondents were shown in Table 1.
The major questionnaire items are individual and household (only residents) attributes, conditions ofpossession and use of bicycles, parking facility, town development (ideal town and degree of achievement ofideal) and measures for parking problems as shown in Table 2.
Table 1 Number of distribution of questionnaire sheets and respondents
The numberof the distribution
The numberof respondents
The response rate

resident

store manager

630 households

111 stores

60 house holds(82 persons)10%

41 stores
37%

Table 2 Major questionnaire items for each stakeholder
Resident
Survey method

Store manager
Survey method

Distribution
method・Delivering to each house with cooperation of
the neighborhood association

Distribution
methodCollection
method・Postal service

RecoverymethodMain study subject

Main study subject

Question items
for Household

Question items
for Individuals

・Hearing to managers with cooperation of
the neighborhood and store manager
・Direct distribution to stores・Postal service
・Direct collection(1)Sex(2)AgeHousehold(3)Residence career
attribute(4)Family composition(5)Zip code
(1)Number of own Bicycles
The bicycle use(2)Preparation of parking spacestorage space(3)Place of the parking(1)Sex
Personal(2)Ageattribute(3)Occupation(1)Future vision of town/Development criterion(2)Present conditions of the town
(3)Problems of the town
Town
development (4)Point at issue of illegally parked bicycles(5)Need of the bicycle use(6)Reason of the need of the bicycle use(1)Need of measures for illegally parked bicycles(2)Responsible persons/organizations(3)Cooperation intention to an activity(4)Measures of for illegal parked bicycles(5)Method of preparing bicycle parking facilities
Measures for
Parking problems (5-1)Cooperative intention to prepare parking facilities

Personal
attribute

The bicycle use
storage space

Town
development(1)Sex(2)Age(3)Store name(4)Industry type(5)Zip code(6)Employee number(7)Visitor number(1)Permission of the bicycle use of the employee(2)Number of employee' bicycles(3)Having bicycle parking or not in the store(4)Responsible person for cost of bicycle parking facilities(5)Degree of preparation bicycle parking facilities(1)Future vision of town/Development criterion(2)Present conditions of the town
(3)Problems of the town(4)Point at issue of illegally parked bicycles(5)Need of the bicycle use(6)Reason of the need of the bicycle use(1)Need of measures for illegally parked bicycles(2)Responsible persons/organizations(3)Cooperation intention to an activity(4)Measures of for illegal parked bicycles

Measures for(5)Method of preparing bicycle parking facilities
Parking problems(5-1)Cooperative intention to prepare parking facilities(5-2)Cooperative intention to on-road parking facilities(5-2)Cooperative intention to on-road parking facilities−52−

This survey aims to clarify the differences of the direction of town development, the thinking of bicycle andproblems of community development. These results may be useful to realize the work shop to deepen mutual
understandings, and follow the actual activities to improve the bicycle problems based on the public involvement.

4. Way of thinking for community development and the bicycle use
The conditions of the ideal town for residents must be "safety and security" and "environment for residence",
while "activity” and "prosperous business condition" must be important to store managers, as shown in Figure 3.
Furthermore, it was clear that both of stakeholders evaluated their ideals were not enough to achieve, as shown in
Figure 4. The common one of reasons of insufficient evaluation must be existence of illegal parked bicycles asshown in Figure 5.
Residents(n=85)

15%

4%

Store
managers(n=44)

49%

18%

43%
0%

10%

16%

20%

30%

Town activity
Environments for residence

40%

18%

50%

60%

5%

70%

Commercial prosperous
Community activity

1% 11%
2%
14%

2%
2%

80%

90%

100%

Safety and security town
Mobility and accessibility

Fig. 3 Conditions of ideal town

Residents(n=78)

29%

Store
managers(n=41)

58%

20%
0%

10%

13%

56%
20%
30%
Fully achieve

24%

40%
50%
Even

60%
70%
Not achieve

80%

90%

100%

Fig. 4 Evaluation of achievement of ideal town
Residents(n=92)

41%

Store
managers(n=44)

9%

32%
0%

10%

13%

16%

20%

30%

Illegally parked bicycle

40%

Many cars

17%

20%

32%

20%
50%

60%

Much waste

70%

80%

90%

Many signboards

100%

Few plants

Fig. 5 Major problems of town
On the other hand, the evaluation of bicycle use are different of them, nevertheless they recognize theconvenience of bicycle as shown in Figure 6. That is, store managers evaluate the convenience for visitors, while
residents evaluate the convenience for their shopping.
Anyway, the illegal parked bicycles must be common problems. Therefore, it should be important to improve
the problem with keeping the convenience for each stakeholder.
Residents(n=81)

43%

Store
managers(n=41)

50%
0%

Necessary

10%

20%

2%
2%

43%
30%

Rather necessary

8% 3%

43%

40%

50%

Rather not necessary

60%

Fig. 6 Necessity of bicycle use

−53−

70%

Not necessary

80%

90%
Even

100%
Others5. Measures for illegal parking of bicycles based on cooperation of stakeholders
Both residents and store managers recognize the necessity of measures against illegal parked bicycles,
nevertheless they evaluate the convenience of bicycle use. Therefore, it must be essential to cooperate to improve
the problem. As for this issue, both residents and store managers respond the necessity of all stakeholders, while
they require the governmental measures as shown in Figure 7. This result may mean the possibility of activities
based on public involvement. Especially, it may be possible to realize the cooperation concerned with sharing cost
and/or offering space as shown in Figure 8. As an example of measure with cooperation of them, almost
respondents show the cooperation consciousness of road use for bicycle parking, as shown in Figure 9. This result
may show the possibility of not only introducing the temporary measure but also realizing the public involved
activity in near future.
Residents(n=72)

13%

19%

Store
managers(n=33)

68%

27%
0%

10%

Governmental measures

27%
20%

30%

46%

40%

50%

60%

Cooperate with a government and residents

70%

80%

90%

100%

Cooperation of all stakeholders

Fig. 7 Responsibility of measures against illegal parked bicycles

Residents(n=37)

14%Store
managers(n=26)

19%
0%

16%

32%

4%

38%

27%

10%
20%
30%
Cost and/or space

40%
Cost

50%
50%

60%
Space

70%
80%
Not cooperative

90%

100%

Fig. 8 Methods of cooperation against illegal parked bicycles

Residents(n=10)

10%Storemanagers(n=15)

80%

20%
0%

10%
20%
Positive cooperation

10%

73%
30%

40%
50%
60%
Rather cooperation

7%
70%
80%
90%
Non-cooperation

100%

Fig. 9 Cooperation consciousness of road use for bicycle parking

6. Conclusion and next stepIn this paper, some important findings concerned with illegal parked bicycles as a common problem forresidents and store managers as different stakeholders in community development. These findings may be
important information to not only introduce the temporary measure against illegal parked bicycles but also realize
the continuous activities for community development based on public involvement.
Therefore, as the next step, it may be expected to hold the workshop with residents, store managers, visitors,
local government and university members, in order to improve the bicycle problem and town development.
7. Acknowledgement
This study was implemented under the support of Nishi-ku local government, Osaka city. We would like tothank members of staffs of local government, members of the work shop in Takakiya district and all respondents
to the questionnaire surveys.

−54−

8. References
1) Construction Bureau of Osaka City, Fundamental Plan for Improving the Environments of Bicycle Use (2011)(in Japanese)
2) Y. Ishimura, Y. Hino, X. Yamashiro, and T. Uchida, Proc. Ann. Conf. JSCE Kansai Chapter, IV-57 (2014) (inJapanese)−55−Abstracts of Papers
Published in Other Journals

Mechanical and Physical Engineering
Mechanical Engineering
Residual Bubble Volume Formed behind a Sphere Plunging into Liquid BathKenji KATOH, Ryosuke MINAMI, Tatsuro WAKIMOTO, Yoshiaki UEDA (Setsunan Univ.) and Manabu
IGUCHI (Osaka Electro-Communication Univ.)
Japanese Journal of Multiphase Flow, Vol. 28, pp. 547-553 (2015) (in Japanese)
An air cavity is formed behind a spherical particle plunging into a liquid bath. The residual bubble attachedto the sphere has an important effect on the performance of CaO particle used for desulfurization of melted
iron. Based on the water model with the same kinematic viscosity as the melted iron, the behavior of air
cavity was observed for the spheres coated by two kinds of water repellent preparations. In this report, thevolume of residual bubble was theoretically estimated for the quasi-static immersion of sphere as a reference
condition. First the critical depth at which the axi-symmetric meniscus breaks is obtained by using Laplace
equation. Then the bubble volume was obtained from a simple energy minimum principle in which we
considered the effect of the interfacial energy including the wetting behavior and the liquid potential energy.
The calculated volumes can approximate fairly well the measured results for two kinds of contact angles of
115° and 162°.
Development of a Wave Power Generation System Using a Slit Type Break Water (Water Wheel andBending Plate Type Generators)
Kenji KATOH, Tatsuro WAKIMOTO, Takaaki SHIGEMATSU and Shin’ya YOSHIOKA
Proc. Int. Conf. on Jets, Wakes and Separated Flows 2015, Stockholm June 16-18, No. 2148169 (6 pages,
USB memory) (2015)
A mini wave power generation system was proposed to be installed in a vertical slit type breakwater. The
merits of the system are listed as follows. (i) no occupation of sea surface, (ii) maintenance facility, and (iii)high energy efficiency by using accelerated flow from the slit of breakwater. In this study, a new type ofgenerator is proposed to perform higher efficiency. An elastic rectangular plate connected to a wheel and axle
via a wire is set in the water chamber. When the wave drag bends the plate, a tension appears in the wire andthe wheel connected to a generator is rotated. In order to estimate the power of the proposed systems in thereal scale, the wave energy flowing into the breakwater was simulated numerically. More than 60% wave
energy is collected in the water chamber behind the slit with 1/6 opening ratio. Although the output of thebending plate is rather small, the power per unit occupied sea area is superior to that of other types inliteratures.
Experimental Observation and Numerical Simulation of Dynamic Wetting Behavior of Triple-Phase
Contact line Passing over a Wall DefectKenji KATOH, Tatsuro WAKIMOTO, Shuhei HIGASHIDA, Yasufumi YAMAMOTO (Kansai Univ.) and
Takahiro ITO (Nagoya Univ.)
Proc. ASME-JSME-KSME Joint Fluids Engineering Conf. 2015, Soul July 26-31, No. 19427 (2 pages, USB
memory) (2015)
The effect of wall defects (impurities) on the dynamic wetting behavior was investigated experimentally andnumerically. In the experiment, a silicon plate coated by SAMs (Self-Assembled Monolayers) was used as atest plate and a circular defect (diameter 300μm) was made artificially by using a Ga beam to strip the SAMs
film locally. The test plate was drawn up from the bath of test liquid with a constant speed (Capillary number
Ca=0.02～0.1) and the dynamic wetting behavior of triple-phase contact line was observed. The local
contact angle on the centerline of the circular defect was measured precisely by using the deflection of alaser beam from the liquid surface. The same problem was simulated numerically with the GNBC
(Generalized Navier Boundary Condition) to represent the slip motion of contact line on the wall. The stick
slip motion of contact line observed experimentally was reproduced in the numerical results. The local
contact angle and slip velocity of contact line qualitatively agree between numerical and experimental
results. The work necessary to deform the liquid surface increases and approaches a limit at higher Ca
number. This tendency should be responsible to determine Ca dependence of the macroscopic contact angle.
Development of Wave Power Generation System using a Slit Type Breakwater: Optimization of
Waterwheel and Scaling Law
Tatsuro WAKIMOTO, Kenji KATOH, Takaaki SHIGEMATSU and Shin’ya YOSHIOKA−59−

J. of JSEM, Vol. 15, pp. 26-30 (2015)
We developed a new wave power generation system installed in a slit type breakwater. This system has great
advantages of no requirement of sea surface affecting on shipping route or fishing ground. In this system,
accelerated flow from the slit of the breakwater drives waterwheels. In this study, the output power of thewaterwheels was measured using a 1/12 reduced scale model to examine the optimal condition of type,
diameter and mounting configuration of the waterwheels. Scaling law for estimating real scale output powerfrom the reduced scale experiment was also examined by numerical simulation. A single mounted crossflow
waterwheel achieved the maximum output power when its diameter is 1.5 times the width of the slit. Output
power was predicted to be proportional to 3.5th power of scale and the square of wave height.
Measurement of Dynamic Surface Tension for Liquid Metal by Capillary Jet Method
Tatsuro WAKIMOTO and Kenji KATOH
Proc. Int. Conf. on Jets, Wakes and Separated Flows 2015, Stockholm June 16-18, No. 2147116 (6 pages,
USB memory) (2015)
Most liquid metal is oxidized easily and its surface tension is decreased for a certain time. In this study, anovel measurement method for the temporal variation of surface tension, i.e. dynamic surface tension, is
proposed. This method is based on the phenomenon that a downward trajectory of a capillary jet ejectedhorizontally from a small orifice with slow speed depends on not only inertia force and gravity force but alsosurface tension, which varies downstream by the oxidization. We derived a theory model to predict the jet
trajectory and determined dynamic surface tension of the liquid metal from the theoretical trajectory which
gives the most excellent approximation of an experimentally measured trajectory. Actual measurement for
Wood’s alloy in various oxygen concentrations demonstrates very fast surface tension variation of the orderof 10 ms and proved the effectiveness of this method.
Experimental Analysis of Stabilization Mechanism of a Liquid Sheet Formed with Aqueous Surfactant
Solution (Influence of Molecular Adsorption Density)
Tatsuro WAKIMOTO and Kenji KATOH
Proc. 13th Int. Conf. on Liquid Atomization and Spray Systems, Tainan August 23-27, No. D3-1-023 (5 pages,
USB memory) (2015)
Surfactant is commonly added to ink or paint as dispersive agents for pigment or dye. The surfactant alsointerferes with the atomization of the liquid sheet injected from a spray nozzle since it has stabilizing effecton liquid surface, as soap film. However, the stabilization mechanism of liquid sheets formed with surfactant
solutions is not fully understood. To investigate the stabilization mechanism, slight force was applied to theliquid sheet non-invasively, and time variable sheet thickness was measured optically until the rupture of theliquid sheet. The slight force was created using thermo-capillary effect. When the soap film is heated locallywith a laser, spatial temperature distribution induces Marangoni force. The Marangoni force pulls the heatedspot out-ward and causes the rupture. We estimated Marangoni force from absorbed heat in the liquid sheet
and demonstrated the relation between the time required for the rupture and Marangoni force using aqueous
solutions of 1, 10 and 25ppm of a typical anionic surfactant, dodecyl sodium sulfate (SDS). Brittle fractureof the soap film is observed by the measurement of sheet thickness. Sheet thickness decreases gradually toabout 0.7 μm from the initial value of 1 μm, and then suddenly ruptured in spite of continuous increase of
Marangoni force. We also estimated molecular adsorption density of the surfactant at each concentration andinvestigated the dependency of the measured rupture time on molecular adsorption density. The dependency
indicated that stabilizing effect of surfactant grows discontinuously from 0 to 0.03μmol/m2 and increases
with the adsorption density linearly above 0.03μmol/m2.
Relation between Micelle Disintegration and Turbulent Transition in Drag-Reducing Surfactant
Solution Flow
Tatsuro WAKIMOTO, Koichi ARAGA(Kinki University Technical College), Kenji KATOH and Shin’ya
MORIMOTO
Proc. ASME-JSME-KSME Joint Fluids Engineering Conf. 2015, Soul July 26-31, No. 19561 (2 pages, USB
memory) (2015)
It is widely known that the addition of a certain kind of surfactant reduces drag in a pipe flow. This effect isconsidered to be a result of suppression of turbulent transition caused by ordered structure of rod-likemicelles, which is referred to as Shear-Induced Structure, SIS. However, this hypothesis is not verified
conclusively and the mechanism of the drag reduction is not fully understood because the detection of SIS isvery difficult in an actual moving flow. In this study, we determine the relationship between the SIS and the−60−turbulent transition in a pipe flow by simultaneous measurement of the amount of the micelles andcoefficient of pipe friction. The amount of micelles was measured by fluorescence probe method. When the
micelles are formed, fluorescence intensity is reduced since the fluorescence probe is entrapped in the
micelle. In this study, it is revealed that the fluorescence intensity also decreases with SIS construction. In
addition, experimental results demonstrate that fluorescence intensity change has high correlation toturbulent transition. It suggests that disintegration of SIS in near-wall region causes turbulent transition.
Ultrasonic Detection of Uncured Region in GFRP Laminates for Rehabilitation of Sewerage Pipes
Akihiro WADA, Tomohiro YAMASAKI, Eiji KITAGAWA and Hiroshi ITO
J. Jpn. Soc. Comp. Mat., Vol.41, No.4, pp.128-137 (2015) (in Japanese)A new technique using Lamb wave is proposed to detect uncured region in GFRP laminates nondestructively.
Polymer based composites play an increasingly important role in the field of civil engineering in recent years.
For example, laminated sheets consisting of thermoplastic layer, organic fabric sheets and SMC (Sheet
Molding Compound) are used to rehabilitate aged sewerage pipes. The cylindrical laminate is inserted in
the pipe, and is inflated and cured by steam blowing to create close-fit pipe. This CIPP (Cured in Place
Pipe) is one of several trenchless rehabilitation methods to repair aged pipes. In this study, ultrasonic Lambwave is applied to the detection of uncured region in a laminated composite plate. Oblique incidence
method in which ultrasonic waves are launched by the transducer inclined at a selected angle is applied toexcite specific mode of Lamb waves in the laminate. Wheel type probes are used to improve inspection
efficiency. Beside wave attenuation, AU parameters which are derived from power spectrum of abroadband signal are introduced. It is found that application of AU parameters leads to the improvement of
the detectability of uncured region.
Study on Locomotion Mechanisms of an outer- pipe Inspection Robot
Naoto IMAJO, Yogo TAKADA and Mikiji KASHINOKI
Proc. of the 6th International Conference on Positioning Technology, pp.173-178 (2014)
In petrochemical plants, there are a large number of steel pipes running horizontally, vertically, and obliquely,
and inspecting them is difficult and time-consuming. There is therefore a strong demand for practical pipe
inspection robots to aid in this task. Although several such robots already exist, their mechanism forovercoming obstacles is too bulky to use them on narrow pipes. The aim of the present study is to develop an
outer-pipe inspection robot that can move along narrow pipes and wires, and a prototype two-wheel-drive
robot has been developed. The wheels are rimless, and each of the sixteen spokes is tipped by a permanent
magnet, which allows the robot to remain attached to even a vertical steel pipe. Moreover, the robot has amechanism for adjusting the camber angle of the right and left wheels, allowing it to tightly grip pipes withdifferent diameters. The robot is equipped with guides at the rear to hold the pipe and prevent yawing motion
when it moves along the pipe. Experiments were conducted to check the performance of the inspection robot
using steel pipes with different diameters, placed horizontally, vertically or obliquely. The robot attempted tomove a certain distance along a pipe, and its success rate was measured. It was found that the robot could
successfully travel along pipes with vertical or oblique orientations, although it sometimes fell fromhorizontal pipes. The most likely reason for this is identified and discussed. Nevertheless, the tests confirmed
the practical potential of the robot for pipe-inspection tasks.
Multi-channel Laser Doppler Velocimetry Using a Two-dimensional Optical Fiber Array for Obtaining
Instantaneous Velocity Distribution Characteristics
Tomoaki KYODEN, Youichi YASUE, Hiroki ISHIDA, Shunsuke AKIGUCHI, Tsugunobu ANDOH, Yogo
TAKADA, Tsunenobu TERANISHI and Tadashi HACHIGA
Japanese Journal of Applied Physics, Robotics, Vol.54, p.012501 (2015)
A laser Doppler velocimeter (LDV) has been developed that is capable of performing two-dimensional (2D)
cross-sectional measurements. It employs two horizontal laser light sheets that intersect at an angle of 13.3°.
Since the intersection region is thin, it can be used to approximately determine the 2D flow field. An 8 × 8array of optical fibers is used to simultaneously measure Doppler frequencies at 64 points. Experiments wereconducted to assess the performance of the LDV, and it was found to be capable of obtaining spatial andtemporal velocity information at multiple points in a flow field. The technique is fast, noninvasive, andaccurate over long sampling periods. Furthermore, its applicability to an actual flow field was confirmed bymeasuring the temporal velocity distribution of a pulsatile flow in a rectangular flow channel with an
obstruction. The proposed device is thus a useful, compact optical instrument for conducting simultaneous
2D cross-sectional multipoint measurements.

−61−

High-resolution In-situ LDV Monitoring System for Measuring Velocity Distribution in Blood Vessel
Tomoaki KYODEN, Shotaro ABE, Hiroki ISHIDA, Shunsuke AKIGUCHI, Tsugunobu ANDOH, Yogo
TAKADA, Tsunenobu TERANISHI and Tadashi HACHIGA
Optics Communications, Vol. 353, pp. 122-132 (2015)
We herein describe a cross-sectional multiple-point laser Doppler velocimetry (CS-MLDV) system formonitoring blood vessels that are sutured and connected during an operation. In order to observe thecondition of a blood vessel during an operation, the previously developed linear MLDV (L-MLDV) system
can realize velocity distribution imaging of the carotid artery in a living mouse by means of traverse laser
light. We subsequently developed a CS-MLDV system, which can measure the instantaneous
two-dimensional (2D) flow velocity, by upgrading the optical components and signal processing used in
L-MLDV. The validity of the CS-MLDV results was verified through comparison with the results of acomputational fluid dynamics (CFD) analysis. The results of the CFD analysis were similar to theexperimental results obtained under the same flow field condition. Moreover, an instantaneous 2D velocity
distribution can be obtained even for the case of flowing blood. Finally, we carried out in-vivo measurement
in a mesenteric vessel of a mouse in order to demonstrate the potential of the CS-MLDV for use in surgery.
Development and Evaluation of Compact Robot Imitating a Hermit Crab for Inspecting the Outer
Surface of Pipes
Naoto IMAJO, Yogo TAKADA and Mikiji KASHINOKIJournal of Robotics, Vol. 2015, Article ID 312780 (7 Pages) (2015)
Terrestrial hermit crabs which are a type of hermit crabs live on land, whereas typical hermit crabs inhabit
the sea. They have an ability of climbing a tree vertically. Their claws allow them to hang on the tree. In thisstudy, an outer-pipe inspection robot was developed. Its locomotion mechanism was developed in imitationof the terrestrial hermit crab’s claws. It is equipped with two rimless wheels. Each of the spokes is tippedwith a neodymium magnet, which allows the robot to remain attached to even a vertical steel pipe. Moreover,
the robot has a mechanism for adjusting the camber angle of the right and left wheels, allowing it to tightly
grip pipes with different diameters. Experiments were conducted to check the performance of the robot using
steel pipes with different diameters, placed horizontally, vertically, or obliquely. The robot attempted to movea certain distance along a pipe, and its success rate was measured. It was found that the robot could
successfully travel along pipes with vertical orientations, although it sometimes fell from oblique or
horizontal pipes. The most likely reason for this is identified and discussed. Certain results were obtained inlaboratory. Further experiments in actual environment are required.
Effects of NaOCl Aqueous Solutions and Ethyl Alcohol Solutions on Removing Protein Surface
Contaminants and Re-establishing Antibacterial Activities of Copper-Alloyed Stainless Steel
Hiroshi KAWAKAMI, Hideaki NISHIKUBO, Keita HIRAYAMA, Satoshi SUZUKI (Nisshin Steel Co.,
Ltd.), Yoshihiro SATO and Yasushi KIKUCHI
Biocontrol Sci., Vol. 20, pp. 193-198 (2015)
Effects of wiping copper-alloyed stainless steel surfaces with disinfectants to remove protein surface
contaminants and re-establish their antibacterial activities were quantitatively studied. Disinfectants usedwere sodium hypochlorite aqueous solutions and ethyl alcohol aqueous solutions. Wiping with NaOCl
aqueous solutions effectively removed protein surface contaminants. Ethyl alcohol aqueous solutions werealso effective for cleaning, but their efficiency was less than that of NaOCl aqueous solutions. When theamount of residual surface contaminants was reduced to 0.4 ng/mm2, the surfaces of the copper-alloyedstainless steel regained antibacterial activities to the same level as those in a clean surface condition.
Mechanical properties of Fiber/Matrix Interface in Polymer Matrix Composites
Jun KOYANAGI, Shinji OGIHARA, Hayato NAKATANI, Tomonaga OKABE and Satoru YONEYAMA
Advanced Composite Materials, Vol. 23, pp. 551-570 (2014)
This paper reviews the mechanical properties of interface adhesion between the fiber and matrix mainly byinterpreting the authors’ past articles. First, the methods for evaluating interface mechanical properties aredescribed considering micromechanical testing using single-fiber composite specimens. In particular, thetest-type dependence of the obtained interfacial strength is discussed, and this paper suggests that the
cruciform specimen technique is an appropriate testing method. Then, this paper presents another way toobtain interface properties that is extracted from a bulk composite test. Moreover, the time and temperaturedependence of the interface strength and the interface failure envelope under a combined stress state are−62−described, respectively. Interface toughness is also discussed at the end of this paper, and it is implied that thevalue might be much lower than those presented in many conventional articles.
A Two-step Hybrid Technique for Accurately Localizing Acoustic Source in Anisotropic Structures
Without Knowing Their Material Properties
Tribikram KUNDU, Xiaojuan YANG, Hayato NAKATANI and Nobuo TAKEDA
Ultrasonics, Vol. 56, pp. 271-278 (2015)
Acoustic source localization techniques generally assume straight line propagation of waves from theacoustic source to the sensor. However, it is well-known that in anisotropic plates the acoustic energy does
not always propagate in straight lines. Even for isotropic plates containing a cavity or an inclusion between
the acoustic source and the sensor the straight line propagation assumption is violated. In such cases only
options available in localizing acoustic source is to use relatively expensive distributed sensor systems, or tofollow time reversal techniques based on the impulse response functions which is labor intensive andcomputationally demanding. A two-step hybrid technique is proposed in this paper for predicting acoustic
source in anisotropic plates. During the first step it was assumed that the waves propagated along straightlines from the acoustic source to the sensor. The source was localized with this simplifying assumption. Then
this first prediction was improved in the second step by solving an optimization problem. Experimental
results showed that the second step always moved the estimates towards the actual source location. Thus italways reduced the prediction error irrespective of whether the final prediction coincided with the actual
source location or not.
Effect of Fiber Discontinuity on Mechanical Properties of Interlaminar-toughened CFRP Laminates
Yu NAGATA, Hayato NAKATANI, Akira MATSUBA, Yousuke KOUNO and Shinji OGIHARA
Transactions of the JSME, Vol. 81, No. 825 (2015) (in Japanese)
In fabricating complicated laminated composite structures by using prepregs, various kinds of fiber
discontinuities such as ply drop-off and seams can be formed. Special care must be taken for the fiber
discontinuity since they can induce stress concentration, and damage onset and growth originated from them
may lead to catastrophic failure of the structure. The present study evaluates mechanical behaviour in
unidirectional CFRP laminates that contain centered or dispersed fiber discontinuities fabricated by using
interlaminar-toughened CFRP prepregs. Tensile testing has shown that higher onset stress of the interlaminardelamination between continuous and discontinuous plies can be achieved by interlaminar-toughened CFRP
with centered fiber discontinuity compared to that for conventional CFRP prepregs. As for the specimen withdispersed fiber discontinuities, fracture stress keeps almost constant with more than 20 mm of interval of thedispersed fiber discontinuities. By applying the onset stress of the delamination that is experimentallyobtained using centered discontinuity to an analytical model, critical energy release rate by the delamination
onset is calculated. Then it is indicated that one can predict the fracture stress of the specimen with thedispersed fiber discontinuities with more than 20 mm interval of the discontinuities by using the criticalenergy release rate. This indicates that fracture of the laminate is dominated by the interlaminar delamination
between discontinuous plies with more than 20 mm of interval.
Distance-domain Based Localization Techniques for Acoustic Emission Sources: A Comparative Study
Krzysztof GRABOWSKI, Mateusz GAWRONSKI, Hayato NAKATANI, Pawel PACKO, Ireneusz BARAN,
Wojciech SPYCHALSKI, Wieslaw STASZEWSKI, Tadeusz UHL and Tribikram KUNDU
Proc. SPIE 9438, Health Monitoring of Structural and Biological Systems 2015, 94381T (2015);
doi:10.1117/12.2084296, (from Conference Volume 9438, San Diego, California, USA, March 8, 2015)
Acoustic Emission phenomenon is of great importance for analyzing and monitoring health status of criticalstructural components. In acoustic emission, elastic waves generated by sources propagate through thestructure and are acquired by networks of sensors. Ability to accurately locate the event strongly depends on
the type of medium (e.g. geometrical features) and material properties, that result in wave signals distortion.
These effects manifest themselves particularly in plate structures due to intrinsic dispersive nature of Lambwaves. In this paper two techniques for acoustic emission source localization in elastic plates are compared:
one based on a time-domain distance transform and the second one is a two-step hybrid technique. A
time-distance domain transform approach, transforms the time-domain waveforms into the distance domain
by using wavenumber-frequency mapping. The transform reconstructs the source signal removing distortions
resulting from dispersion effects. The method requires input of approximate material properties andgeometrical features of the structure that are relatively easy to estimate prior to measurement. Hence, themethod is of high practical interest. Subsequently, a two-step hybrid technique, which does not require a−63−priori knowledge of material parameters, is employed. The method requires a setup of two predefinedclusters of three sensors in each. The Lamb wave source is localized from the intersection point of thepredicted wave propagation directions for the two clusters. The second step of the two-step hybrid technique
improves the prediction by minimizing an objective function. The two methods are compared for analytic,
simulated and experimental signals.
Suppression of Interlaminar Crack in UD-CFRP containing Fibre Discontinuity using Polyamide
Mesh
Hayato NAKATANI, Tatsuya IMAMURA and Katsuhiko OSAKA
Proc. 20th International Conference on Composite Materials, Copenhagen, Denmark, July 19-24, Paper ID
1115-6 (2015)
A fiber discontinuity in fibre reinforced composite laminates may act as a source of stress concentration thatinduces damage onset. A mesh made of thermoplastic polyamide (PA) as an interlayer is inserted between
fiber continuous and discontinuous plies in order to suppress an interlaminar cracking as a second damage
mode in unidirectional CFRP laminates that contain centred fiber discontinuity. It is experimentally shownthat by inserting PA mesh the onset stress of the interlaminar crack increased significantly. The end notchedflexure (ENF) testing using unidirectional CFRP laminates with PA mesh inserted demonstrates that themode II interlaminar fracture toughness GIIC = 1.91 kJ/m2 can be achieved; this should be compared to 1.30
kJ/m2 without PA mesh. It is also shown that the mode II interlaminar fracture toughness GIIC’ = 3.67 kJ/m2
which is related to the second critical load, not the first one, during ENF testing should be applied to theprediction of the crack onset stress by using an analysis model that incorporates energy release rate by thecrack growth.
Optimization of Acoustic Source Localization in Large Plates
Krzysztof GRABOWSKI, Mateusz GAWRONSKI, Hayato NAKATANI, Pawel PACKO, Wieslaw J.
STASZEWSKI, Tadeusz UHL and Tribikram KUNDU
Proc. 10th International Workshop on Structural Health Monitoring 2015, Stanford University, Palo Alto,
CA, USA, Sep. 1-3, DOI:10.12783/SHM2015/194 (2015)
Acoustic Emission (AE) is a phenomenon of great importance for structural health monitoring (SHM). One
of important applications of AE in SHM is the localization of a source of acoustic energy in the structure. For
certain types of structures and for large propagation distances where dispersion phenomenon is prominent, it
is hard to estimate proper location of the damage. This paper discusses some aspects of AE source
localization techniques. It is shown how an acoustic source in large plates can be localized using only six
sensors and without a priori knowledge of any material parameter, thus omitting the need of considering
dispersion phenomena. The method is based on a predefined three-sensor setup, required to determine theLamb wave propagation direction by detecting the angle at which the Lamb wave hits the array. As
introduced in earlier works, the propagation direction of the Lamb wave is detected using arrival timedifferences between sensors, measured by correlating only the first dip and peak of the recorded signals.
With another propagation direction detected by another sensor cluster the acoustic source can be localized as
an intersection point of the two directions for planar structures. In this paper special orientation of the sensor
cluster is suggested in order to apply the technique to a narrow plate. This modification enables to evaluate awider area and avoid possible errors in detected propagation directions from some acoustic source locations.
The method is compared with another source localization technique based on combined time-domain
dispersion removal approach and localization. The dispersion removal technique reconstructs the source
signal compensating distortions resulting from dispersion effects and transforms the time domain response
directly into the distance one. Both methods are verified numerically and experimentally through artificial
sources.
Nondestructive Evaluation and 3-D Imaging of Impact Damage in CFRP/Ti Fibre-Metal Laminates
using Synchrotron Radiation Laminography
Hayato NAKATANI, Kentaro KAJIWARA, Koichi AKITA and Shinji OGIHARA
Proc. 14th Japanese-European Symposium on Composite Materials, Kanazawa, Japan, Sep. 16-18,
ExtAbst_Nakatani.pdf (USB Memory) (2015)
Fibre-Metal Laminates (FMLs) are hybrid materials that consist of thin layers of metal and fibre-reinforced
polymer, and have already been applied several military and commercial aircraft. It is well-known that there
is a difficulty in non-destructive assessment of damage in FMLs using laboratory radiography or X-ray
computed tomography since FMLs have laminate structure of materials with different X-ray absorption−64−coefficient. Synchrotron radiation laminography at SPring-8 in Japan is employed to assess low velocity
impact damage in CFRP/Ti laminates as FMLs. During computed laminography synchrotron radiation beam
is irradiated to an object with the axis of rotation inclined at an angle and thus it is suitable for the laterally
extended geometry of composite laminate plates. It is verified that how each damage mode, such as crack intitanium layer, fibre break, matrix cracking, interlaminar delamination in CFRP layers and interfacialdebonding between CFRP and titanium layers, can be observed in obtained reconstructed slice images.
Three-dimensional imaging of the low velocity impact damage is also demonstrated by stacking thereconstructed slice images, and that is to our knowledge a novel result.
Lattice Rotation in Fe-20%Cr Alloy Single Crystals Subjected to Sliding Wear
Yoshihisa KANEKO and Mutsumi NISHIIJ. Soc. Mater. Sci. Japan, Vol. 64 pp.281-286 (2015)
Sliding wear tests were conducted on Fe-20%Cr alloy single crystals having (001), (110) and (111) surfaces,
using the ball-on-disk type friction machine under the condition of 10N vertical load and 30m wear distance.
After the wear tests, the single crystals were cut to investigate microstructures developed below the worn
surface. The cross-sectional observation revealed that subsurface regions of all the worn single crystals werecomposed of fine grains which were generated by severe plastic deformation introduced by the sliding wear
process. It was confirmed from EBSD analyses that, below the fine-grained regions, all the single crystals
rotated around the axis which is almost perpendicular to the wear direction. Such lattice rotation was
expected to be a preceding event for the grain boundary formation in the fine-grained region. The lattice
rotations were evaluated by the misorientation angles from the single crystal matrices. Extent of the lattice
rotation depended on crystallographic orientation of the single crystals. The depth where the misorientation
angle is 10° increased in ascending order of (001), (110) and (111) single crystals, suggesting that the lattice
rotation was promoted favorably at the (111) single crystal. In order to understand the orientation dependenceof the lattice rotation, we considered three slip deformation models (horizontal shear, vertical shear andresolved shear stress models) which incorporated the geometrical relationship between a slip system andwear direction.
Multi-scale modeling of degradation behavior for crystalline polymer
Masakazu KUDO, Junichi TAKAHASHI, Toshiharu YAMAMOTO, Makoto UCHIDA and Yoshihiro
TOMITA
J. Soc. Mater. Sci. Japan, Vol. 64, pp. 311-366 (2015)
Coarse-grained molecular dynamics simulations are conducted, for the purpose of the study on the
microscopic structure change of crystalline polymer due to degradation. Interlamellar structure changes areobserved during the degradation, decreasing loop and bridge chains, increasing short tail chains. From theelongation simulation of lamellar structure, craze strength is dropped during the degradation, because of
decreasing oriented interlamellar chains and drawing of the molecular chains from the crystal part.
Multi-scale modeling is conducted to demonstrate the relationship between microscopic structure changes
and macroscopic mechanical properties. As a result, macroscopic fracture strain is reduced by thedegradation, because craze growth rate becomes faster with the degradation.
Computational simulation of micro- to macroscopic deformation behavior of cavitated rubber blended
amorphous polymer using second-order homogenization method
Makoto UCHIDA and Naoya TADAKey Engineering Materials, Vol. 626, pp. 74-80 (2015)
To evaluate the effect of the size of the microstructure on the mechanical property of the cavitated rubber
blended (voided) amorphous polymer, the FEM simulation based on the rate form second-orderhomogenization method, in which rates of the macroscopic strain and strain gradient are given to themicrostructure, was performed. Computational simulations of micro- to macroscopic deformation behaviors
of amorphous polymers including different sizes and volume fractions of the voids were performed.
Non-affine molecular chain network theory was employed to represent the inelastic deformation behavior of
the amorphous polymer matrix. With the increase in the volume fraction of the void, decrease and periodical
fluctuation of stress and localized deformation in the macroscopic field were observed, and were moreemphasized with the increase in the size of the void. These results were closely related to the non-uniform
deformation and volume increase of the void in the microscopic field.

−65−

Potential difference distribution on flat plate around semi-ellipsoidal thinning on the back surface
Naoya TADA, Makoto UCHIDA and Manabu NOHARA
Proceedings of the ASME 2014 Pressure Vessels & Piping Conference (PVP2014), Paper No.
PVP2014-28684 (2014)
Local wall thinning is one of serious problems in aged power generating plants and is known to occur mainly
by Flow Accelerated Corrosion (FAC) and Liquid Droplet Impingement (LDI) erosion. As the thinninggrows inside the pipes, it is difficult to detect and evaluate it from the outer surface of pipe. The
direct-current potential difference method (DC-PDM) is thought to be a suitable non-destructive technique tomonitor the initiation and growth of these damages. In this study, an approximate analysis method of thepotential difference around a semi-ellipsoidal thinning on the back surface of flat plate is presented and theaccuracy is discussed based on the results obtained by the finite element analyses.
Transient Viscoelastic Behavior of Glassy Epoxy Networks with Various Crosslink Densities under
Large Deformation
Shin’ya YOSHIOKA and Ryuki MASUDA
J. Soc. Mat. Sci. Jpn., Vol.64, pp.52-56 (2015). (in Japanese)
The single relaxation time of glassy epoxy networks having different crosslink densities was evaluatedduring uniaxial compression processes by using a simple nonlinear single relaxation model to study theeffect of crosslinked molecular structures on the transient nonlinear viscoelastic behavior of glassy epoxy
networks. The model consisted of two elastic springs expressing linear viscoelastic behavior and a dashpot
with variable viscosity as a single parameter representing strain-induced structural change. We calculated thestrain-dependent relaxation time τSS during the compression by fitting the model to the experimental
stress-strain curves obtained at various strain rates and at temperatures T 18°C lower than the glass transition
temperature Tg of the material being compressed. With increasing strain εn, τSS obtained for each epoxy
network steeply decreased in the pre-yield region of strain and then reached to low steady values appearing
in strain ranges larger than the yield strain, reproducing previously reported typical behavior observed forglassy polymers under large deformation. When compressed at an identical strain rate, τSS-εn relations for all
epoxy networks almost coincided each other despite the difference in the crosslink density. This result
indicates that, if the deformation is performed at the same condition i.e., strain rate and T-Tg, strain-induced
variation of relaxation time in the epoxy glasses is almost not influenced by crosslinked molecular structures.

−66−

Physical Electronics and Informatics
Applied Physics and Electronics
4H-SiC/Si Heterojunction Bipolar Transistors Fabricated by Surface Activated Bonding
Jianbo LIANG, Sae SHIMIZU, Shota NISHIDA, Naoteru SHIGEKAWA and Manabu ARAI (New Japan
Radio Co. Ltd.)ECS Solid State Lett., Vol. 4, Q55 (3 pages) (2015)
4H-SiC/Si heterojunction bipolar transistors with emitter-up (E-up) and collector-up (C-up) configurations
were fabricated by surface activated bonding for the first time. Their electrical characteristics were measured
at raised ambient temperatures. The common-base current gain α increased as the temperature was raised in
the both E-up and C-up structures. In the E-up structure, α reached to ≈ 0.99 at 573 K. Improvements in bothdevice structures and surface activated bonding conditions should provide further improvements in device
performance.
MOCVD Growth of Thick (~1 µm) InGaN on AlN/Si Substrates for InGaN/Si Tandem Solar Cells
Akio YAMAMOTO (Univ. of Fukui), Kazuki KODAMA (Univ. of Fukui), Md. Tanvir HASAN (Univ. of
Fukui), Naoteru SHIGEKAWA and Masaaki KUZUHARA (Univ. of Fukui)
Jpn. J. Appl. Phys., Vol. 54, 08KA12 (4 pages) (2015)
In order to develop key technologies for InGaN/Si two-junction tandem solar cells, MOVPE growth of thick
InGaN on Si p-on-n cell structures has been studied. By clarifying the phase separation behavior of MOVPE
InGaN, a thick (~1 μm) InxGa1-xN (x ~ 0.5) without phase separation is successfully grown on AlN/Si(111)
wafers. A sufficient current flow for the operation of the tandem cell is obtained through n-InGaN/AlN/p-Si
structures by employing the annealing of AlN/Si wafer at around 1000 °C in NH3 flow just before InGaN
growth. The annealing of AlN/Si wafers also brings about the degradation of the underlying Si pn junction.
The optimization of the annealing conditions is required to balance such favorable and unfavorable effects.
Current-Voltage and Spectral-Response Characteristics of Surface-Activated-Bonding-Based
InGaP/GaAs/Si Hybrid Triple-Junction Cells
Naoteru SHIGEKAWA, Jianbo LIANG, Ryusuke ONITSUKA (Sharp Co.), Takaaki AGUI (Sharp Co.),
Hiroyuki JUSO (Sharp Co.) and Tatsuya TAKAMOTO (Sharp Co.)
Jpn. J. Appl. Phys., Vol. 54, 08KE03 (5 pages) (2015)
We measured the current–voltage (I–V) and spectral-response characteristics of InGaP/GaAs/Si hybrid
triple-junction cells that were fabricated by using surface-activated bonding methods. We found by spectral
response measurements that the current generated in the Si-based bottom cell was lower than those in the top
and middle cells under the conditions of an air mass of 1.5G and one sun. Furthermore we observed a
discrepancy between the short-circuit current, which was obtained by subtracting the estimated contributionof Si ledges surrounding InGaP/GaAs mesas to the I–V characteristics, and the results of spectral response
measurements. One possible model for explaining the discrepancy was discussed on the basis of theelectrical coupling scheme between subcells. The intrinsic conversion efficiency of a 55mm2 triple-junction
cell was crudely estimated to be >26% by compensating for the shadow loss as well as subtracting thecontribution of Si ledges.
Growth Temperature Dependent Critical Thickness for Phase Separation in Thick(~1 µm) InxGa1-xN (x= 0.2-0.4)
Akio YAMAMOTO (Univ. of Fukui), Tanvir Md HASAN (Univ. of Fukui), Kazuki KODAMA (Univ. of
Fukui), Naoteru SHIGEKAWA and Masaaki KUZUHARA (Univ. of Fukui)
J. Crystal Growth, Vol. 419, pp. 64-68 (2015)
This paper reports phase separation in thick(~1 μm) MOVPE InxGa1-xN (x=0.2–0.4) films grown by MOVPE
at 570–750 ºC on AlN/Si(111), α-Al2O3(0001) and GaN/α-Al2O3(0001) substrates. Phase separation occurs
when InGaN thickness exceeds a critical value. Critical thickness for phase separation is markedly increased
with decreasing growth temperature. It is around 0.2 μm for a film grown at 750 ºC, while it is more than 1
μm for that grown at 570 ºC. No substrate dependencies are found in critical thickness. The cross-sectional
SEM views of phase-separated films grown at 650 ºC show that phase separation is initiated at parts far morethan 0.2 μm from the substrate and extended to the area near the substrate. SIMS analysis shows a possibility
that phase separation is initiated at a part with relatively large In/Ga ratio fluctuations in InGaN films.

−67−

Thick (~1 µm) p-type InxGa1-xN (x~0.36) Grown by MOVPE at a Low Temperature (~570 ºC)
Akio YAMAMOTO (Univ. of Fukui), Tanvir Md HASAN (Univ. of Fukui), Kazuki KODAMA (Univ. of
Fukui), Naoteru SHIGEKAWA and Masaaki KUZUHARA (Univ. of Fukui)
Physica Stat. Solidi B, Vol. 1-4, pp. 909-912 (2015)
This paper reports the post-growth annealing effects of low temperature grown Mg-doped InGaN. By using
MOVPE, 1 m-thick Mg-doped InxGa1–xN (x ~ 0.36) films are grown at 570 ºC. In order to activate the Mg
acceptors, grown samples are treated by the conventional furnace annealing (FA) or the rapid thermal
annealing (RTA). In the case of the FA at 650 ºC for 20 min, the InGaN film is phase-separated. On the other
hand, the RTA at a temperature higher than 700 ºC enables us to get p-type samples. By using the RTA at 850
for 20 s, p-type samples with a hole concentration 1018–1019 cm- 3 are successfully obtained without phaseseparation.
Investigation on the Interface Resistance of Si/GaAs Heterojunctions Fabricated by Surface-ActivatedBonding
Jianbo LIANG, Li CHAI, Shota NISHIDA, Masashi MORIMOTO and Naoteru SHIGEKAWA
Jpn. J. Appl. Phys., Vol. 54, 030211 (5 pages) (2015)
The electrical properties of p-GaAs/n+-Si, p+-Si/n-GaAs, p+-GaAs/n+-Si, p+-Si/n+-GaAs, n+-Si/n+-GaAs, andp+-Si/p+-GaAs junctions fabricated by surface-activated bonding (SAB) were investigated. An amorphouslayer with a thickness of 3nm was found across the bonding interface without annealing. The current–voltage(I–V) characteristics of p+-GaAs/n+-Si, p+-Si/n+-GaAs, n+-Si/n+-GaAs, and p+-Si/p+-GaAs junctions showed
excellent linearity. The interface resistance of n+-Si/n+-GaAs junctions was found to be 0.112Ω·cm2, which isthe smallest value observed in all the samples. The resistance decreased with increasing annealing
temperature and decreased to 0.074Ω·cm2 after the junction annealing at 400 °C. These results demonstratethat n+-Si/n+-GaAs junctions are suitable for the connection of subcells in the fabrication of tandem solar
cells.
Effects of Annealing on Electrical Properties of Si/Si Junctions by Surface-Activated Bonding
Masashi MORIMOTO, Jianbo LIANG, Shota NISHIDA and Naoteru SHIGEKAWA
Jpn. J. Appl. Phys., Vol. 54, 030212 (5 pages) (2015)
Effects of annealing on surface-activated bonding (SAB)-based Si/Si junctions were investigated bytransmission electron microscopy (TEM) observations and current–voltage (I–V) measurements. We
observed an amorphous-like layer at the bonding interface, which was recrystallized by annealing. We
extracted the potential barrier heights at Si/Si interfaces annealed at different temperatures from the results of
I–V measurements at various ambient temperatures. For p-Si/p-Si junctions, the barrier height increased as
the annealing temperature increased from 200 to 400 °C and decreased from 400 to 1000 °C. For n-Si/n-Si
junctions, the barrier height increased as the annealing temperature increased from 200 to 600 °C anddecreased from 600 to 1000 °C. By using the charge neutral level (CNL) model, we estimated the energy of
CNL, ECNL, and the density of interface states, Dit, at each annealing temperature. Dit decreased as theannealing temperature increased from 400 to 1000 °C. ECNL showed values larger than the reported ones.
Correlation between the Electrical Properties of p-Si/n-4H-SiC Junctions and Concentrations ofAcceptors in Si
Shota NISHIDA, Jianbo LIANG, Tomohiro HAYASHI, Manabu ARAI (New Japan Radio Co. Ltd.) andNaoteru SHIGEKAWA
Jpn. J. Appl. Phys., Vol. 54, 030210 (4 pages) (2015)
We fabricated p+-, p-, and p--Si/n-4H-SiC junctions by surface activated bonding (SAB). We investigatedtheir electrical properties by measuring their current–voltage (I–V) characteristics at raised ambient
temperatures, capacitance–voltage (C–V) characteristics at various frequencies, and capacitance–frequency(C–f) characteristics at room temperature. The activation energy of their reverse-bias current and theflat-band voltage in their C–V characteristics, which were estimated to be 0.97–1.01 eV and 0.83–0.84V,
respectively, were insensitive to the concentrations of acceptors in Si substrates. The relaxation times
estimated from the C–f characteristics were 0.8 and 1.5 μs for the p-Si/n-4H-SiC and p--Si/n-4H-SiC
junctions, respectively. The results are explained by a scheme wherein Fermi level pinning occurs at the
Si/4H-SiC interfaces fabricated by SAB.
Influence of InGaN/GaN Multiple Quantum Well Structure on Photovoltaic Characteristics of Solar
Cell

−68−

Noriyuki WATANABE (NTT Laboratories), Manabu MITSUHARA (NTT Laboratories), Haruki
YOKOYAMA (NTT Laboratories), Jianbo LIANG and Naoteru SHIGEKAWA
Jpn. J. Appl. Phys., Vol. 53, 112301 (9 pages) (2014)
We have investigated InGaN/GaN multiple quantum well (MQW) solar cells in terms of the relationshipbetween the short-circuit current and the MQW structure. We previously reported that higher short-circuitcurrent is obtained in solar cells with thinner GaN barrier layers, and in this investigation, we also obtained
higher short-circuit current in solar cells with higher numbers of InGaN/GaN periodic layers. These results
can be explained by the hypothesis that the transport characteristics of photoinduced carriers arecharacterized by the specific length within which carriers photoinduced in the InGaN well layer can move
before recombination. The carrier collection efficiency is improved by the drift in the barrier layer due to theforward internal electric field and degraded by the carrier accumulation in the well layer caused by the
inverse internal electric field and the potential barrier between layers, which well describes the influence ofthe MQW structure on the specific length. Using this model, we discuss how we can determine the MQWstructure that yields higher short-circuit current, and conclude that the optimum thickness of the InGaN welllayer is about 2–3 nm when the thickness of the GaN barrier layer is 3–8 nm.
Effects of Interface State Charges on the Electrical Properties of Si/SiC Heterojunctions
Jianbo LIANG, Shota NISHIDA, Tomohiro HAYASHI, Manabu ARAI (New Japan Radio Co. Ltd.) andNaoteru SHIGEKAWA
Appl. Phys. Lett., 105, 151607 (4 pages) (2014)
Electrical properties of p+-Si/n--SiC, p-Si/n--SiC, p--Si/n--SiC, and n+-Si/n--SiC heterojunctions fabricated byusing surface-activated bonding are investigated. Their flat-band voltages obtained from capacitance-voltage(C-V) measurements are found to be ~0.92 eV, which suggests that the Fermi level should be pinned at thebonding interface. An analysis by using the charge neutral level model reveals that the C-V characteristics
are sensitive to the density of interface states. The measured C-V characteristics of p+-Si/n--SiC andn+-Si/n--SiC junctions are in quantitative agreement with modeled ones obtained for the interface states
density and the conduction-band discontinuity of 2.31013 cm-2eV-1 and 0.3 eV, respectively.
Hybrid Triple-Junction Solar Cells by Surface Activate Bonding of III-V Double-Junction-Cell
Heterostructures to Ion-Implantation-Based Si Cells
Naoteru SHIGEKAWA, Li CHAI, Masashi MORIMOTO , Jianbo LIANG, Ryusuke ONITSUKA (SharpCo.), Takaaki AGUI (Sharp Co.), Hiroyuki JUSO (Sharp Co.) and Tatsuya TAKAMOTO (Sharp Co.)
Proc. 40th IEEE Photovoltaic Specialists Conference, pp. 534-537 (2014)
A hybrid triple-junction cell was fabricated by surface activated bonding of a lattice-matchedinvertedly-grown InGaP/GaAs double-junction cell to an ion-implantation-based Si bottom cell. An n+-doped layer on the top of bottom cell due to the ion implantation worked as its emitter and bonding layer forthe tunnel junction. The bonding interface was found to be stable after the annealing at 400 °C. An efficiencyof 24.4% was achieved at air mass 1.5G and one sun at room temperature.
Type-II Band Profile of GaAs/Si Hetero Junctions by Surface Activated Bonding for Hybrid Tandem
Cells
Naoteru SHIGEKAWA, Jianbo LIANG, Masashi MORIMOTO and Shota NISHIDAECS Trans., Vol. 64, pp. 235-242 (2014)
We fabricated p+-GaAs/n-Si and n+-GaAs/p-Si junctions by using surface activated bonding and measured
their current-voltage and capacitance-voltage characteristics at room temperature. Their conduction band
offset, which was extracted from the capacitance-voltage characteristics, was 0.57-0.84 eV. The results
suggested that the band profiles of junctions had type-II features, which was likely to be preferable forfabricating low-resistance tunnelling junctions in hybrid tandem cells. The influence of possible interface
states on the electrical properties of junctions was also discussed using the charge neutral level model.
Photoemission Spectroscopy Measurements of p+-Si/n-SiC and n+-Si/n-SiC Junctions by Surface
Activated Bonding
Naoteru SHIGEKAWA, Jianbo LIANG, Masato SHINGO (Univ. of Fukui), Manabu ARAI (New Japan
Radio Co. Ltd.) and Kenji SHIOJIMA (Univ. of Fukui)
Extended Abstracts of the 2015 International Conference on Solid State Devices and Materials, Sapporo,
PS-14-12, pp. 508-509 (2015)
Photoemission spectroscopy measurements were performed for p+-Si/n-SiC and n+-Si/n-SiC junctions that−69−

had been fabricated using the surface activated bonding. The optical absorption edge was estimated to be
1.36-1.4 and 1.6 eV for the p+ -Si/n-SiC and n+ -Si/n-SiC junctions, respectively. The difference in the
optical absorption edges as well as that in the responses to bias voltages were discussed in conjunction withthe potential profile across the bonding interfaces.
Mapping of Si/SiC Hetero p-n Junctions Using Scanning Internal Photoemission Microscopy
Masato SHINGO (Univ. of Fukui), Jianbo LIANG (Univ. of Fukui), Naoteru SHIGEKAWA, Manabu ARAI
(New Japan Radio Co. Ltd.) and Kenji SHIOJIMA (Univ. of Fukui)
Extended Abstracts of the 2015 International Conference on Solid State Devices and Materials, Sapporo,
PS-14-11, pp. 506-507 (2015)
We have demonstrated scanning internal photoemission microscopy (SIPM) to map p+ -Si/n-SiC hetero p-njunctions. By focusing and scanning a laser beam over the junction, a photocurrent map was clearly obtained,
and nm-deep scratches were visualized as a pattern. We found that this method is a powerful tool toinvestigate inhomogeneity of the heterojunctions.
Transport Characteristics of Minority Carriers in 4H-SiC/Si Heterojunction bipolar transistor
structures fabricated by surface activated bonding
Jianbo LIANG, Sae SHIMIZU, Shota NISHIDA, Naoteru SHIGEKAWA and Manabu ARAI (New Japan
Radio Co. Ltd.)
Extended Abstracts of the 2015 International Conference on Solid State Devices and Materials, Sapporo,
PS-14-5, pp. 494-495 (2015)
4H-SiC/Si heterojunction bipolar transistor structures with emitter-up (E-up) and collector-up (C-up)
configurations were fabricated by surface activated bonding. Their electrical characteristics were measured atraised ambient temperatures. The common-based current gain α increased as the temperature was raised. The
activation energy of α was found to be 0.05 and 0.18 eV for the E-up and C-up structures, respectively. In the
E-up structures, α reached to 0.99 at 573 K.
MOVPE Growth and Device Fabrication of Thick n+-p InGaN with in Composition of 0.3 and No
Phase Separation at 600 ºC
Kazuki KODAMA (Univ. of Fukui), Hiroyuki NOMURA (Univ. of Fukui), Naoteru SHIGEKAWA, Akio
YAMAMOTO (Univ. of Fukui), and Masaaki KUZUHARA (Univ. of Fukui)
Abstracts of the 11th International Conference on Nitride Semiconductors, Beijing, 2015, TuGP84 (2 pages)(2015)
Electrical Properties of Room Temperature Bonded Si/GaN Heterojunctions without Buffer Layers
Jianbo LIANG, Takuya NISHIMURA, Noriyuki WATANABE (NTT Laboratories) and Naoteru
SHIGEKAWA
Abstracts of the 11th International Conference on Nitride Semiconductors, Beijing, WeEP6 (2 pages) (2015)
The electrical properties of n+-Si/n-GaN and p+-Si/n-GaN heterojunctions without buffer layers fabricated byroom temperature bonding were investigated. The current-voltage (I-V) characteristics of n+-Si/n-GaN andp+-Si/n-GaN heterojunctions showed excellent linearity and rectifying properties, respectively. The flat-band
voltage of p+-Si/n-GaN heterojunctions was found to be 1.2 V from capacitance-voltage (C-V) measurements,
which determines that the valence and conduction band discontinuities are 2.15 and 0.15 eV, respectively,
which indicates a type -I band alignment.
Band Lineups in GaAs/GaN Junctions Using Surface-Activated Bonding
Syoji YAMAJO, Jianbo LIANG, Noriyuki. WATANABE (NTT Laboratories) and Naoteru SHIGEKAWA
Abstracts of 11th Topical Workshop on Heterostructure Microelectronics (TWHM 2015), Takayama, pp.
41-42 (2015).
Impacts of Annealing in N2/H2 Ambient on Electrical Properties of Si/GaN Junctions
Takuya NISHIMURA, Jianbo LIANG, Noriyuki WATANABE (NTT Laboratories) and Naoteru
SHIGEKAWA
Abstracts of 11th Topical Workshop on Heterostructure Microelectronics (TWHM 2015), Takayama, pp.
39-40 (2015)
Fabrication and Characterization of GaAs/4H-SiC Junctions by Using SAB−70−

Sae SHIMIZU, Jianbo LIANG, Manabu ARAI (New Japan Radio Co., Ltd.) and Naoteru SHIGEKAWA
Abstracts of 11th Topical Workshop on Heterostructure Microelectronics (TWHM 2015), Takayama, pp.
37-38 (2015)
Fabrication and Characterization of Si-Based Bipolar Transistor Structures Using Low-Temperature
Bonding
Sae SHIMIZU, Shota NISHIDA, Jianbo LIANG, Masashi MORIMOTO and Naoteru SHIGEKAWA
Extended Abstracts of 2015 IEEE International Meeting for Future of Electron Devices, Kansai (IMFEDK),
pp. 64-65 (2015)
We applied the low-temperature bonding for fabricating base/collector junctions of Si-based bipolartransistor structures. The common-base current gain of fabricated bipolar transistors increased as the ambient
temperature was raised up to 165°C, which suggests that the low-temperature bounding might be useful for
fabricating high-performance heterojunction devices.
Interface Characteristics of Si/Si Junctions by Using Surface-Activated Bonding
Syoji YAMAJO, Masashi MORIMOTO, Jianbo LIANG and Naoteru SHIGEKAWA
Extended Abstracts of 2015 IEEE International Meeting for Future of Electron Devices, Kansai (IMFEDK),
pp. 62-63 (2015)
We investigated the electrical properties of highly-doped n-Si/n-Si and p-Si/p-Si junctions fabricated byusing the surface activated bonding. Heights of potential barrier formed at the respective bonding interface
were estimated by measuring dependence of their current-voltage characteristics on the ambient temperature.
The heights of barrier were found to be varied due to annealing often the bonding process. An analysis using
the charge neutral level model suggested that the density of interface states that were likely to be formed
during the surface activation process was lowered to ~1012cm-2eV-1 due to the annealing, similarly to results
for more heavily doped Si/Si junctions.
Electrical Properties of n+-Si/n-GaN Junctions by Room Temperature Bonding
Takuya NISHIMURA, Jianbo LIANG, Naoteru SHIGEKAWA and Noriyuki WATANABE (NTTLaboratories)
Extended Abstracts of 2015 IEEE International Meeting for Future of Electron Devices, Kansai (IMFEDK),
pp. 46-47 (2015)
The electrical properties of n+-Si/n-GaN junctions by room-temperature bonding were investigated. The
n+-Si/n-GaN junctions exhibited linear current-voltage characteristics.
Electrical Characterization of GaAs/GaAs Bonding Interfaces
Li CHAI, Jianbo LIANG, Shota NISHIDA, Masashi MORIMOTO and Naoteru SHIGEKAWA
Extended Abstracts of 2015 IEEE International Meeting for Future of Electron Devices, Kansai (IMFEDK),
pp. 44-45 (2015)
The electrical properties of GaAs/GaAs junctions fabricated by using surface-activated bonding (SAB) were
investigated. We extracted the potential barrier heights at 300-°C-annealed GaAs/GaAs interfaces from theircurrent-voltage characteristics measured at varied ambient temperatures and estimated the energy of charge
neutral level ECNL and the density of interface states Dit.
Response of Piezoelectric Lead Zirconate Titanate to High-energy Xenon Ion Beam Pulse
Seiji TAKECHI, Yoshinori MIURA, Tomoaki MITSUHASHI, Takashi MIYACHI (Chiba Institute ofTechnology), Masanori KOBAYASHI (Chiba Institute of Technology), Osamu OKUDAIRA (JAXA),
Hiromi SHIBATA (Osaka University), Masayuki FUJII (Famscience), Nagaya OKADA (Honda Electronics),
Takeshi MURAKAMI (NIRS) and Yukio UCHIHORI (NIRS)
Jpn. J. Appl. Phys. Vol. 53, pp. 118005-118007 (2014)
To develop a new radiation detector, the characteristics of piezoelectric lead zirconate titanate (PZT) arecurrently being studied using a 400MeV/n xenon (Xe) beam. In this study, the response of the PZTelement to
the pulsed beam was investigated by changing the beam intensity. It was found that the time distribution of
the Xe ions in the pulse duration must be taken into account to understand the formation of the output signalthat appeared on the PZT element.
Present Situation of Plasma Simulation in And in Contact with LiquidFumiyoshi TOCHIKUBO and Tatsuru SHIRAFUJI−71−

J. Plasma Fusion Res., Vol. 91, pp. 307-313 (2015) (in Japanese)
This paper describes present situation of plasma simulation in and in contact with liquid, in which we focus
on the two topics. The first topic is spatiotemporal evolution of electrical discharges in a gas bubble
surrounded with liquid. The second topic is transport and reaction processes at plasma/liquid interface and inliquid. Regarding the second topic, we briefly describes recent research results on the plasma/liquid interface,especially on the fact that pH and concentration of chemical species show extremely steep gradient at theactive layer just beneath the liquid surface in contact with plasma.
On the Contribution of Electrons, Ar(3P0,2), H2O+, And H3O+ to Production of OH(A2Σ+) in a MicroDielectric Barrier Discharge of Ar/H2O
Tatsuru SHIRAFUJI and Tomoyuki MURAKAMI
Jpn. J. Appl. Phys., Vol. 54, 01AC03 (5 pages) (2015)
The numerical simulation of a micro-dielectric barrier discharge of an Ar/H2O gas mixture has been
performed to understand the behavior of OH (A) in three-dimensionally integrated micro-solution plasma.
During the discharge ignition sequence in the period of 0–200 ns, the major OH (A) production reactions are
the dissociation of H2O by high-electron-temperature electrons and metastable excited Ar (3P). After themain discharge, OH (A) production is dominated by the dissociative recombination of H3O+ andlow-electron-temperature electrons.
3D Integrated Micro-Solution Plasma for the Treatment of Water - Effects of Discharge Gases Ayano NOMURA, Yuta HIMENO, Kenji TANAKA and Tatsuru SHIRAFUJI
Plasma Phys. Technol., Vol. 1, pp. 147-149 (2015)
Methylene blue molecules in aqueous solution have been decomposed by using a novel 3D integrated
micro-solution plasma reactor operated with Ar and He gases. Energy efficiency for methylene-blue
decomposition in the case of Ar is relatively higher than that in the case of He. This result suggests thatcheaper Ar gas has brought about superior performance in water purification. In both cases of Ar and He,
methylene-blue decomposition efficiency is one order of magnitude higher than that of conventional solution
plasma.
Time-Resolved Optical Emission Spectroscopy on Three-Dimensionally Integrated Micro Solution
Plasma in He/H2O Mixture
Yuta HIMENO, Yuhei OGURA and Tatsuru SHIRAFUJI
J. Phys. Conf. Ser., Vol. 518, 021021 (6 pages) (2014)
We have performed time-averaged and time-resolved optical emission spectroscopy (OES) on
three-dimensionally integrated micro solution plasma (3D IMSP) in He/H2O mixture. The results oftime-resolved OES on 3D IMSP in He/H2O mixture have shown that duration of the optical emission ofOH(A2Σ+ → X2Π around 309 nm) is shorter than that in Ar/H2O mixture. Possible causes of this difference
are discussed by means of difference in the energy of metastable states of Ar and He.
Integrated Multi-Phase-Media Plasma Source
Tatsuru SHIRAFUJI
J. Plasma Fusion Res., Vol. 90, pp. 392-397 (2014) (in Japanese)
This paper describes electrochemical aspects of a plasma/liquid interface, which involves nano-scale electric
double layer formed just beneath the liquid surface in contact with plasma. A novel three-dimensionallyintegrated micro-solution plasma (3D IMSP) is proposed as a method for efficient production of theplasma/liquid interfaces for large scale industrial applications. The process performances of the 3D IMSP arebriefly described together with experimental results on the methylene blue degradation and gold
nano-particles synthesis
Generation of Micro-Solution Plasmas in Artificial Porous Dielectric Materials Fabricated Using 3DPrinter Technology
Tatsuru SHIRAFUJI, Yuhei OGURA, Naoya SOTODA and Kenji TANAKA
Proc. 22nd International Symposium on Plasma Chemistry (ISPC 22), P-I-3-25 (2 pages), Jul. 5-10, Antwerp,
Belgium (2015)
We have fabricated a three-dimensionally integrated micro-solution plasma (3D IMSP) reactor using an
artificial porous dielectric material using 3D printer technology for generating a large number ofmicroplasmas in contact with a liquid medium. While our previous 3D IMSP reactors are fabricated with−72−

silica pumices which consist of random-size pores, this new 3D IMSP reactor is fabricated with 3D-printed
lattice structure in which the same-size pores are arranged regularly. We have successfully obtained
microplasmas in this reactor by feeding the gas-liquid mixed medium of Ar and water. Methylene-bluedegradation experiments have revealed that pore-size design is very important for achieving higher process
performance.
Systematic investigation of effects of exciton–acoustic-phonon scattering on photoluminescence risetimes of free excitons in GaAs/Al0.3Ga0.7As single quantum wells
Masaaki NAKAYAMA, Tatsuya OHNO and Yohiaki FURUKAWA
J. Appl. Physics, Vol. 117, 134306 (6 pages) (2015)
We have systematically investigated the photoluminescence (PL) dynamics of free excitons in
GaAs/Al0.3Ga0.7As single quantum wells, focusing on the energy relaxation process due to exciton–
acoustic-phonon scattering under non-resonant and weak excitation conditions as a function of GaAs-layer
thickness from 3.6 to 12.0 nm and temperature from 30 to 50 K. The free exciton characteristics wereconfirmed by observation that the PL decay time has a linear dependence with temperature. We found thatthe free exciton PL rise rate, which is the reciprocal of the rise time, is inversely linear with the GaAs-layer
thickness and linear with temperature. This is consistent with a reported theoretical study of the exciton–
acoustic-phonon scattering rate in the energy relaxation process in quantum wells. Consequently, it isconclusively verified that the PL rise rate is dominated by the exciton-acoustic-phonon scattering rate. In
addition, from quantitative analysis of the GaAs-layer thickness and temperature dependences, we suggestthat the PL rise rate reflects the number of exciton–acoustic-phonon scattering events.
Photoluminescence observation of electron-hole droplets in a GaAs/AlAs type-II superlattice
Yoshiaki FURUKAWA and Masaaki NAKAYAMA
J. Phys. Conf. Ser., Vol. 619, 012005 (4 pages) (2015)
We have investigated the photoluminescence (PL) properties of a (GaAs)12/(AlAs)12 type-II superlattice (SL)at 10 K from the viewpoint of the formation of electron-hole droplets (EHDs). In the type-II SL, thelowest-energy exciton consists of an X-electron and a Γ-heavy- hole confined in the AlAs and GaAs layers,respectively; namely, the optical transition is indirect in momentum and real space. The excitation-power
density was widely changed from ~1 mW/cm2 to ~1 kW/cm2 for precisely observing changes of PL spectra.
It was found that a broad PL band appears with a threshold-like nature in the energy region lower than thebiexciton. This suggests the occurrence of the Mott transition. The prominent feature of the broad PL band is
the fact that the spectral profile hardly depends on the excitation-power density, which is one of typical
properties of EHDs. From the line-shape analysis of the PL spectra, we estimated the stability energy of theEHD to be ~2.9 meV relative to the biexciton energy. The above results consistently demonstrate theformation of the EHD.
Unique properties of photoluminescence excitation spectra in a Eu-doped GaN epitaxial film
Masaaki NAKAYAMA, Satoshi NAKAMURA, Hideo TAKEUCHI, Atsushi KOIZUMI and Yasufumi
FUJIWARA
Appl. Phys. Lett., Vol. 106, 012102 (4 pages) (2015)
We have investigated the temperature dependence of photoluminescence-excitation (PLE) spectra of Eu3+
emission due to the intra-4f shell transitions in a Eu-doped GaN epitaxial film from the viewpoint of theenergy transfer process by carriers and excitons from the host GaN to Eu3þ ions. It was found that theexcitonic band of the PLE spectrum disappears in a low temperature region below 140 K in spite of the factthat the optical transitions of the A and B excitons are clearly observed in a reflectance spectrum. The
excitonic PLE band becomes remarkable with an increase in temperature. This fact indicates that carriers
originating from the thermal dissociation of photogenerated excitons contribute to the Eu3+ emission. In otherwords, excitons play no role in the energy transfer process. Furthermore, the PLE spectrum at room
temperature exhibits an oscillatory structure resulting from longitudinal-optical phonon emission in a hot
carrier relaxation process.
Polariton-condensation effects on photoluminescence properties in a CuBr microcavity
Masaaki NAKAYAMA, Katsuya MURAKAMI, Yoshiaki FURUKAWA and Daegwi KIM
J. Phys. Conf. Ser., Vol. 619, 012015 (4 pages) (2015)
We have investigated the photoluminescence (PL) properties in a CuBr microcavity with HfO2/SiO2
distributed Bragg reflectors at 10 K from the viewpoint of cavity-polariton condensation. From the−73−

excitation-power dependence of PL spectra detected at an in-plane wave vector of k//=0, we found that the PL
characteristics of the lower polariton branch markedly change with a threshold nature: a drastic increase(decrease) in the intensity (band width). In addition, the PL energy exhibits a large blueshift, ~10 meV,around the threshold excitation power, reflecting strong polariton-polariton interactions. The blueshifted PLenergy is far below the bottom energy of the cavity photon. In addition, the estimated density ofphotogenerated electron-hole pairs at the threshold excitation power is two orders lower than the
Mott-transition density for the formation of electron-hole plasma. The above results consistently demonstrate
the occurrence of the cavity-polariton condensation.
Theory of the lifetime of an exciton incoherently created below its resonance frequency by inelastic
scattering
Motoaki BAMBA, Shuji WAKAIKI, Hideki ICHIDA, Kohji MIZOGUCHI, Daegwi KIM, Masaaki
NAKAYAMA and Yasuo KANEMATSU
Phys. Rev. B, Vol. 91, 235205 (13 pages) (2015)
When an exciton in semiconductor is scattered and its energy is decreased far below the resonance energy ofthe bare exciton state, it has been considered that an exciton-polariton is created immediately by thescattering process because there is no exciton level at that energy. However, according to the recent
time-resolved measurements of P emission originating from inelastic exciton-exciton scattering, it looks
rather natural to consider that the exciton-polariton is created in a finite time scale which is restricted by acoherence volume of the exciton after the scattering. In this interpretation, the exciton remains in this timescale far below its resonance energy as a transient state in a series of processes. We propose an expression of
the P-emission lifetime depending on the coherence volume of the scattered excitons through the conversion
process from them to the polaritons. The coherence volume of the scattered excitons appears in thecalculation of the inelastic scattering process on the assumption of a finite coherence volume of thebottleneck excitons. Time-resolved optical-gain measurements could be a way for investigating the validityof our interpretation.
Hydrothermal Synthesis of N-Acetyl-L-cysteine-Capped CuInS2 Nanoparticles
Hang-Beom BU, Hiroki YOKOTA, Kunio SHIMURA, Kohji TAKAHASHI, Taichi TANIGUCHI and
DaeGwi KIM
Chem. Lett., Vol. 44, pp. 200-202 (2015)
CuInS2 (CIS) nanoparticles (NPs) were hydrothermally prepared by the reaction of Cu2+, In2+, and Na2S inthe presence of N-acetyl-L-cysteine as a stabilizer. The X-ray diffraction pattern of the resultant CIS NPs
indicated that the chalcopyrite NPs could be obtained. The X-ray photoelectron spectroscopy data suggested
that Cu2+ is reduced to Cu+ during the reaction process. The absorption and photoluminescence peaks of theNPs were clearly red-shifted with increasing size of the particles. Our method will aid in the synthesis ofother I-III-VI ternary compounds.
Preparation of Highly Luminescent Hybrid Gel Incorporating NAC-Capped CdTe Quantum Dotsthrough Sol–Gel Processing
Hang-Beom BU, Taichi WATANABE, Masayuki HIZUME, Tomomi TAKAGI, Susumu SOBUE, Shoichi
KAWAI, Eiichi OKUNO and DaeGwi KIM
Mater. Res. Express, Vol. 2, 036202 (9 pages) (2015)
Highly photoluminescent gel was prepared by embedding water soluble quantum dots (QDs) in an
inorganic–organic hybrid gel matrix using a conventional sol–gel process. Aminopropyltrimethoxysilane(APS) and citric acid (CA) were found to be the best combination for the gel preparation. 13C-NMRand
FT-IR studies indicated hydrogen bond formation between the amine group of APS and the carboxyl groupof CA. IR-light radiation curing was comparable to thermal curing and reduced the gelation time to aconsiderable extent (71%). The resulting composite formed a hybrid gel phosphor with excellent
transparency by embedding CdTe QDs into the matrix and emitted light of various colors with highphotoluminescence efficiency (40%). The gel phosphor retained the PL properties after storage in air for one
year. In addition, the strength of the hybrid phosphor was demonstrated by a coin-flipping test.
Effects of Surface Modification on Photoluminescence Properties of Self-Assembled Monolayer of
CdSe Quantum DotsTaichi WATANABE, Hiroki YOKOTA, Masaaki NAKAYAMA and DaeGwi KIM
J. Phys. Conf. Ser., Vol. 619, 012024 (4 pages) (2015)−74−

We have investigated surface-modification effects on photoluminescence (PL) properties of the self-assemblemonolayer of CdSe quantum dots from the viewpoint of the temperature dependence of PL properties. The
band-edge PL band is strongly activated by the surface modification and is observed as the main PL band,
contrary to the fact that the defect-related PL band is dominant in the as-grown sample. From the analysis of
PL decay dynamics, it is demonstrated that the contribution of a bound exciton state to PL processes would
suppress a trapping process to defects.
Evidence of Quantum Resonance in Periodically-Ordered Three-Dimensional Superlattice of CdTe
Quantum Dots
DaeGwi KIM, Shogo TOMITA, Kazuma OHSHIRO, Taichi WATANABE, Takenobu SAKAI, I-Ya CHANG
and KIM Hyeon-DeukNano Lett., Vol. 15, pp. 4343−4347 (2015)
Semiconductor quantum dot (QD) superlattices, which are periodically ordered three-dimensional (3D) arraystructures of QDs, are expected to exhibit novel photo-optical properties arising from the resonantinteractions between adjacent QDs. Since the resonant interactions such as long-range dipole−dipole
Coulomb coupling and short-range quantum resonance strongly depend on inter-QD nano space, precise
control of the nano space is essential for physical understanding of the superlattice, which includes both ofnano and bulk scales. Here, we study the pure quantum resonance in the 3D CdTe QD superlattice depositedby a layer-by-layer assembly of positively charged polyelectrolytes and negatively charged CdTe QDs. FromXRD measurements, existence of the periodical ordering of QDs both in the lamination and in-plane
directions, that is, the formation of the 3D periodic QD superlattice, was confirmed. The lowest excitationenergy decreases exponentially with decreasing the nano space between the CdTe QD layers and also withdecreasing the QD size, which is apparently indicative of the quantum resonance between the QDs rather
than a dipole−dipole Coulomb coupling. The quantum resonance was also computationally demonstrated andrationalized by the orbital delocalization to neighboring CdTe QDs in the superlattice.
Control of Localized Surface Plasmon Resonance Energy in Monolayer Structures of Gold and Silver
Nanoparticles
Hiroki YOKOTA, Taichi TANIGUCHI, Taichi WATANABE and DaeGwi KIM
Phys. Chem. Chem. Phys., Vol. 17, 27077-27081 (2015)
Monolayer structures of Au and Ag nanoparticles (NPs) were fabricated by a dipping method to realize thecontrol of localized surface plasmon resonance (LSPR) energy. The mean inter-particle distance in themonolayer was controlled by changing the concentration of NPs in the colloidal solution used for monolayer
assembly. The extinction-peak energy of the monolayer structure was red-shifted with decreasing
inter-particle distance, reflecting plasmon coupling between NPs.
Domain Wall in Multimode Peierls State
Yuki MATSUMOTO and Akira TERAIJ. Phys. Soc. Jpn., Vol. 83, 114705 (9 pages) (2014)
The domain wall as a one-dimensional discommensuration of the multimode Peierls (MMP) lattice distortionis investigated numerically based on the Su–Schrieffer–Heeger model generalized to the square lattice withthe half-filled electronic band. In order to create the domain wall, we consider a spin excitation where thetotal number of spin-up electrons is larger than that of spin-down electrons by the linear dimension of thesquare lattice. The extra spins are localized at the domain wall, and the localized wave functions form a
mid-gap band with zero energy. The localized wave functions are analytically constructed in the same way as
the edge states in the graphene nanoribbon. The properties of the localized states for the domain walls withvarious orientations to the MMP distortion pattern are elucidated. The number of the zero-energy states forevery orientation satisfies the index theorem established in the Dirac electron system. Furthermore, thecorrelation effects on the domain wall are studied by introducing the on-site and nearest-neighbor Coulombinteractions to the electron–lattice model. It is revealed that the creation energy of the domain wall decreases
due to the electron–electron interactions.
Fractionally Charged Solitons in “1100” Charge Order Backgrounds
Kenichi HIROKAWA, Akira TERAI and Yoshiyuki Ono
J. Phys. Soc. Jpn. Vol. 84, 034707 (7 pages) (2015)
We reconsider the problem of “binding” of a pair of fractionally charged solitons in “1100” charge orderbackgrounds, using the variational Monte Carlo method based on the matrix-product state. In the “1100”−75−

charge order ground state of the one-dimensional extended Peierls–Hubbard model, the 2kF bond order wave
(BOW) coexists with the 4kF BOW. We have found that the fractionally charged soliton with −e/2, −e being
an electronic charge, is accompanied with not only a kink in the 2kF BOW but also a kink in the 4kF BOW,
which was not allowed to exist in the dimer model used in the previous study. Calculating the total energy ofa pair of fractionally charged solitons with the same charge as a function of the soliton–soliton distance, wehave found that the soliton–soliton interaction is repulsive. Therefore the “binding” of the solitons does notoccur and the elementary charge excitation from the “1100” charge order ground state is a fractionallycharged soliton.
A Perturbative Method for Nonequilibrium Steady State of Open Quantum Systems
Tatsuro YUGE and Ayumu SUGITA
J. Phys. Soc. Jpn. Vol. 84, 014001 (7 Pages) (2015)
We develop a method of calculating the nonequilibrium steady state (NESS) of an open quantum system thatis weakly coupled to reservoirs in different equilibrium states. We describe the system using a Redfield-type
quantum master equation (QME). We decompose the Redfield QME into a Lindblad-type QME and theremaining part R. Regarding the steady state of the Lindblad QME as the unperturbed solution, we perform a
perturbative calculation with respect to R. to obtain the NESS of the Redfield QME. The NESS thus
determined is exact up to the first order in the system-reservoir coupling strength (pump/loss rate), which isthe same as the order of validity of the QME. An advantage of the proposed method in numericalcomputation is its applicability to systems larger than those in methods of directly solving the original
Redfield QME. We apply the method to a noninteracting fermion system to obtain an analytical expression of
the NESS density matrix. We also numerically demonstrate the method in a nonequilibrium quantum spin
chain.

−76−

Electric and Information Engineering
Volumetric display using rotating prism sheets arranged in a symmetrical configuration
Yuki MAEDA, Daisuke MIYAZAKI, Takaaki MUKAI and Satoshi MAEKAWA (Univ. of Hyogo)
Opt. Express Vol.21, 27074-27086 (2013).
A volumetric display that creates a distortion-free three-dimensional (3D) image in midair is described. The
proposed system consists of rotating prism sheets used as an optical scanner and a dihedral corner reflector
array (DCRA), which is a distortion-free imaging element. Two prism sheets are arranged in a symmetricalconfiguration to reduce an unnatural motion parallax caused by optical aberrations. A cross-section of the 3D
image is formed by the DCRA in midair and moved by the rotating prism sheets to create a 3D displayable
space. A 3D volume image was displayed without image distortion or unnatural motion parallax.
Floating multi-view image formation with micro-mirror array imaging element
Daisuke MIYAZAKI
The 3rd Japan-Korea Workshop on Digital Holography and Information Photonics, Session 2- 3 (2013).
A volumetric display that creates a distortion-free three-dimensional (3D) image in midair is described. The
proposed system consists of rotating prism sheets used as an optical scanner and a dihedral corner reflector
array (DCRA), which is a distortion-free imaging element. Two prism sheets are arranged in a symmetricalconfiguration to reduce an unnatural motion parallax caused by optical aberrations. A cross-section of the 3D
image is formed by the DCRA in midair and moved by the rotating prism sheets to create a 3D displayable
space. A 3D volume image was displayed without image distortion or unnatural motion parallax.
Floating volumetric display using an imaging element that consists of a 90° prism sheet and a linear
Fresnel lens
Yuki MAEDA, Daisuke MIYAZAKI, Takaaki MUKAI and Satoshi. MAEKAWA (Univ. of Hyogo)
Proc. Soc. Photo-Opt. Instrum. Eng., Vol. 9011, 90111N (2014).
We propose a floating volumetric display system using a novel imaging element whose aperture is large andcan be made easily at low cost. Diffuse rays in a horizontal direction for an observer are formed by a 90º
prism sheet, which has a shape of an array of 90º V-grooves, as a result of twice total internal reflection. On
the other hand, the diffuse rays in a longitudinal direction for the observer are formed by a linear Fresnel lens.
A formed image by the proposed imaging element does not distort in the horizontal direction because therays in the horizontal direction converge by retroreflection. The proposed imaging element can be produced
easier than a conventional distortion-free imaging element and display a larger floating image. A floating
three-dimensional image was displayed by a volumetric display system based on optical scanning of an
inclined image plane. A position of a two-dimensional real image formed by the proposed imaging element
was moved by an optical scanner at a faster rate than the duration time of persistence of vision. A stack of
moved images created the floating three-dimensional volume image.
Multi-user autostereoscopic display based on direction-controlled illumination using a slanted
cylindrical lens array
Daisuke MIYAZAKI, Yui HASHIMOTO, Takahiro TOYOTA, Kenta OKODA, Tetsuro OKUYAMA(Panasonic), Toshikazu OHTSUKI (Panasonic), Akio NISHIMURA (Panasonic), and Hiroyuki YOSHIDA(Panasonic)
Proc. Soc. Photo-Opt. Instrum. Eng., Vol. 9011, 90111G (2014).
This research aims to develop an auto-stereoscopic display, which satisfies the conditions required forpractical use, such as, high resolution and large image size comparable to ordinary display devices for
television, arbitrary viewing position, multiple viewer availability, suppression of nonuniform luminancedistribution, and compact system configuration. In the proposed system, an image display unit is illuminatedwith a direction-controlled illumination unit, which consists of a spatially modulated parallel light source anda steering optical system. The steering optical system is constructed with a slanted cylindrical array andvertical diffusers. The direction-controlled illumination unit can control output position and horizontal angleof vertically diffused light. The light from the image display unit is controlled to form narrow exit pupil. A−77−viewer can watch the image only when an eye is located at the exit pupil. Auto-stereoscopic view can beachieved by alternately switching the position of an exit pupil at viewer's both eyes, and alternately
displaying parallax images. An experimental system was constructed to verify the proposed method. The
experimental system consists of a LCD projector and Fresnel lenses for the direction-controlled illumination
unit, and a 32 inch full-HD LCD for image display.
Optical design for heterogeneous imaging based on retro reflection using parallel roof mirror arrays
Yuki MAEDA, Daisuke MIYAZAKI, and Satoshi. MAEKAWA (Univ. of Hyogo)
JSAP-OSA Joint Symposia 2014, Information Photonics, 20a-C4-3 (2014).
Floated integral imaging display viewable from surrounding area
Daisuke MIYAZAKI, Go MIYAZAKI, Yuki MAEDA, and Takaaki MUKAI
Imaging and Applied Optics 2014, OSA Technical Digest, DW2B.5 (2014).
A full-parallax auto-stereoscopic display method that enables formation of a floating three-dimensional
image viewable from a surrounding area is proposed. This method utilizes integral imaging, a rotating mirror
scanner, and a hemisphere concave mirror.
Wide-Viewing Angle Three-dimensional Display Using Multiple LCDs
Hirofumi YABU, Joji KANDA, and Hideya TAKAHASHIICIC Express Letters Part B, Vol.5, 1, pp.195-200 (2014).
We propose an omnidirectional three-dimensional (3D) display system. This is a tool for communication
around a 3D image among a small number of people. This 3D display system consists of multiple basic 3D
display units. The basic unit consists of an LCD, a lenticular lens array sheet, and a relay lens. In this basic
unit, the light rays from an LCD pass through a lenticular lens sheet and observed directly. Thus, the spatial
density distribution of projected light rays is partial. To average the spatial density of projected light rays, weuse a relay lens. To increase the viewing angle, we aligned multiple basic units in a circle, and displayed 3D
images at the center of the circle. To verify the effectiveness of the proposed 3D display, we constructed theprototype system. This prototype consists of 3 basic units. They are aligned 18.5-degree apart in a circle andthe radius is 613.2 mm. The shape of the maximum size of displayed 3D images is a cylinder and the radius
is 25 mm, the height is 50 mm. The viewing angle of a 3D image is 55.5-degree. This paper describes theprinciple of proposed 3D display system, and also describes the experimental results.
Silicone Rubber Membrane Tactile Sensor for Endoscope Based on Image Processing
Yuma KITANOUMA, Hideya TAKAHASHI, Kayo YOSHIMOTO (Osaka University), and Kenji
YAMADA (Osaka University)
ICIC Express Letters Part B, Vol.5, 1, pp.279-284 (2014).
We propose the silicone rubber membrane tactile sensor for an endoscope. The proposed system consists ofthe transparency silicon rubber membrane and the image sensor. Our proposed system can estimate thestiffness of the target object by measuring the deformation of the silicone rubber which includes markers
inside. When the silicone rubber is deformed by contacting with the target object, the position of each marker
shifts. By using the displacement information of markers measured by the imaging device, the system canmeasure the deformation of the silicone rubber. The purpose of this study is to evaluate the proposed system.
At first, we introduce the approximated models of the silicone and the object. We formulate the stiffness ofthe object, the deformation of silicone, and the whole object. To verify the effectiveness of the proposedsystem, we constructed the prototype system.
Retinal projection type super multi-view head-mounted display
Hideya TAKAHASHI, Yutaka ITO, Seigo NAKATA, and Kenji YAMADA (Osaka University)
Proc.SPIE-IS&T Electronic Imaging, Vol.9012, pp. 90120L-1-90120L-6 (2014).
We propose a retinal projection type super multi-view head-mounted display (HMD). The smooth motion
parallax provided by the super multi-view technique enables a precise superposition of virtual 3D images on
the real scene. Moreover, if a viewer focuses one’s eyes on the displayed 3D image, the stimulus for theaccommodation of the human eye is produced naturally. Therefore, although proposed HMD is a monocular
HMD, it provides observers with natural 3D images. The proposed HMD consists of an image projection−78−

optical system and a holographic optical element (HOE). The HOE is used as a combiner, and also works as
a condenser lens to implement the Maxwellian view. Some parallax images are projected onto the HOE, andconverged on the pupil, and then projected onto the retina. In order to verify the effectiveness of the
proposed HMD, we constructed the prototype HMD. In the prototype HMD, the number of parallax images
and the number of convergent points on the pupil is three. The distance between adjacent convergent points
is 2 mm. We displayed virtual images at the distance from 20 cm to 200 cm in front of the pupil, andconfirmed the accommodation. This paper describes the principle of proposed HMD, and also describes theexperimental result.
Evaluation of the three-dimensional endoscope system for assessing the gastrointestinal motility
Kayo YOSHIMOTO (Osaka University), Kenji YAMADA (Osaka University), Kenji WATABE (Osaka
University), Maki TAKEDA (Osaka University), Takahiro NISHIMURA (Osaka University), Michiko
KIDO (Osaka University), Toshiaki Nagakura (Osaka Electro-Communication University), Hideya
TAKAHASHI, Tsutomu NISHIDA (Osaka University), Hideki IIJIMA (Osaka University), Masahiko
TSUJII (Osaka University), Tetsuo TAKEHARA (Osaka University), and Yuko OHNO (Osaka University)
Proc.SPIE-BiOS2014 Advanced Biomedical and Clinical Diagnostic System XII, Vol.8935, pp.
89351G-1-89351G -6 (2014).
This paper described evaluation of the three-dimensional endoscope system for assessing the gastrointestinal
motility. Gastrointestinal diseases are mainly based on the morphological or anatomical abnormity. However,sometimes the gastrointestinal symptoms are apparent without visible abnormalities. Such diseases are called
functional gastrointestinal disorder, for example, functional dyspepsia, and irritable bowel syndrome. One of
the major factors of these diseases is the gastrointestinal dysmotility. Assessment procedures for motor
function are either invasive, or indirect. We thus propose a three-dimensional endoscope system forassessing the gastrointestinal motility. To assess the dynamic motility of the stomach, three-dimensional
endoscopic imaging of stomach lining is performed. Propagating contraction waves are detected bysubtracting estimated stomach geometry without contraction waves from one with contraction waves. After
detecting constriction waves, their frequency, amplitude, and speed of propagation can be calculated. In thisstudy, we evaluate the proposed system. First, we evaluate the developed three-dimensional endoscope
system by a flat plane. This system can measure the geometry of the flat plane with an error of less than 10
percent of the distance between endoscope tip and the object. Then we confirm the validity of a prototype
system by a wave simulated model. The detected wave is approximated by a Gaussian function. In theexperiment, the amplitude and position of the wave can be measure with 1 mm accuracy. These results
suggest that the proposed system can measure the speed and amplitude of contraction. In the future, we
evaluate the proposed system in vivo experiments.
Gastric contraction imaging system using a three-dimensional endoscope
Kayo YOSHIMOTO (Osaka University), Kenji YAMADA (Osaka University), Kenji WATABE (Osaka
University), Maki TAKEDA (Osaka University), Takahiro NISHIMURA (Osaka University), Michiko
KIDO (Osaka University), Toshiaki Nagakura (Osaka Electro-Communication University), Hideya
TAKAHASHI, Tsutomu NISHIDA (Osaka University), Hideki IIJIMA (Osaka University), Masahiko
TSUJII (Osaka University), Tetsuo TAKEHARA (Osaka University), and Yuko OHNO (Osaka University)
IEEE Journal of Translational Engineering in Health and Medicine, Vol.2, 1, pp.1-8 (2014).
Objective: This paper presents a gastric contraction imaging system for assessment of gastric motility using athree-dimensional endoscope. Gastrointestinal diseases are mainly based on morphological abnormalities.
However, gastrointestinal symptoms are sometimes apparent without visible abnormalities. One of the major
factors for these diseases is abnormal gastrointestinal motility. For assessment of gastric motility, a gastricmotility imaging system is needed. Method: To assess the dynamic motility of the stomach, the proposedsystem measures three-dimensional gastric contractions derived from a three-dimensional profile of thestomach wall obtained with a developed three-dimensional endoscope. After obtaining contraction waves,their frequency, amplitude, and speed of propagation can be calculated using a Gaussian function. Results:
The proposed system was evaluated for three-dimensional measurements of several objects with known
geometries. The results showed that the surface profiles could be obtained with an error of less than 10
percent of the distance between two different points on images. Subsequently, we evaluated the validity of a
prototype system using a wave simulated model. In the experiment, the amplitude and position of waves−79−

could be measured with 1-mm accuracy. Conclusions: The present results suggest that the proposed system
can measure the speed and amplitude of contractions. Clinical Impact: This system has low invasiveness andcan assess the motility of the stomach wall directly in a three-dimensional manner. Our method can be used
for examination of gastric morphological and functional abnormalities.

−80−Applied Chemistry and Bioengineering
Applied Chemistry and Bioengineering
High Catalytic Activity of Heteropolynuclear Cyanide Complexes Containing Co and Pt Ions for
Visible-Light Driven Water Oxidation
Yusuke YAMADA, Kohei OYAMA, Rachel GATES and Shunichi FUKUZUMIAngew. Chem. Int. Ed., Vol. 54, pp. 5613-5617 (2015)
A near-stoichiometric amount of O2 was evolved as observed in the visible-light irradiation of an aqueous
buffer (pH 8) containing [RuII(2,2’-bipyridine)3] as a photosensitizer, Na2S2O8 as a sacrificial electron
acceptor, and a heteropolynuclear cyanide complex as a water-oxidation catalyst. The heteropolynuclear
cyanide complexes exhibited higher catalytic activity than a polynuclear cyanide complex containing only
CoIII or PtIV ions as C-bound metal ions. The origin of the synergistic effect between Co and Pt ions is
discussed in relation to electronic and local atomic structures of the complexes.
High and Robust Performance of H2O2 Fuel Cells in the Presence of Scandium Ion
Yusuke YAMADA, Masaki YONEDA and Shunichi FUKUZUMIEnergy Environ. Sci., Vol. 8, pp. 1698-1701 (2015)
Hydrogen peroxide is a promising candidate as a next-generation energy carrier because it can be produced
from O2 abundant in air using photoenergy in the presence of a photocatalyst and can also generate
electricity via fuel cells. Although H2O2 is unstable during storage under ambient conditions, we reportherein remarkable suppression of H2O2 decomposition by adding Sc3+ ion to an aqueous H2O2 solution. The
resulting solution yields high and robust performance of one-compartment H2O2 fuel cells in terms of open
circuit potentials, power densities, and durability.
Bottom Up and Top Down Methods to Improve Catalytic Reactivity for Photocatalytic Production of
Hydrogen Peroxide from Water and Dioxygen with a Ruthenium Complex and Water Oxidation
Catalysts
Yusuke ISAKA, Satoshi KATO, Dachao HONG, Tomoyoshi SUENOBU, Yusuke YAMADA and Shunichi
FUKUZUMI
J. Mater. Chem. A, Vol. 3, pp. 12404-12412 (2015)
Hydrogen peroxide (H2O2) was produced from water and dioxygen using [RuII(Me2phen)3]2+ (Me2phen =4,7-dimethyl-1,10-phenanthroline)
asaphotocatalystand[Ir(Cp*)(H2O)3]2+
(Cp*
=
5
3+
 -pentamethylcyclopentadienyl) as a precursor of a water oxidation catalyst in the presence of Sc in water
under visible light irradiation. TEM and XPS measurements of residues in the resulting solution after thephotocatalytic production of H2O2indicated that [Ir(Cp*)(H2O)3]2+ was converted to Ir(OH)3 nanoparticles,
which are actual catalytic species. The Ir(OH)3 nanoparticles produced in situ during the photocatalytic
production of H2O2were smaller in size than those prepared independently from hydrogen hexachloroiridiate(H2IrCl6), and exhibited higher catalytic reactivity for the photocatalytic production of H2O2. The
photocatalytic production of H2O2 from water and dioxygen was also made possible when Ir(OH)3
nanoparticles were replaced by nickel ferrite (NiFe2O4) nanoparticles, which are composed of more earth
abundant metals than iridium. The size of NiFe2O4 nanoparticles became smaller during the photocatalytic
production of H2O2 to exhibit higher catalytic reactivity in the second run as compared with that in the firstrun. NiFe2O4 nanoparticles obtained by the treatment of NiFe2O4 in an aqueous solution of Sc3+ exhibited
33-times higher catalytic reactivity in H2O2-production rates than the as-prepared NiFe2O4. Thus, both thebottom-up method starting from a molecular complex [Ir(Cp*)(H2O)3]2+ and the top-down method startingfrom as-prepared NiFe2O4 to obtain nanoparticles with smaller size resulted in the improvement of thecatalytic reactivity for the photocatalytic production of H2O2 from water and dioxygen.
Singlet Oxygen Generation from Li+@C60 Nano-Aggregates Dispersed by Laser Irradiation in
Aqueous Solution
Kei OHKUBO, Naoki KOHNO, Yusuke YAMADA and Shunichi FUKUZUMI
Chem. Commun., Vol. 51, pp. 8082-8085 (2015)−81−

Laser pulse irradiation of a deaerated aqueous solution containing the solid state lithium ion-encapsulated
fullerene resulted in the formation of highly dispersed nano-aggregates (Li+@C60)n. Photoirradiation of an
O2-saturated D2O solution containing (Li+@C60)n gave singlet oxygen with 55% quantum yield, leading toefficient double-stranded DNA cleavage.
Ni–Cu Alloy Nanoparticles Loaded on Various Metal Oxides Acting as Efficient Catalysts for
Photocatalytic H2 Evolution
Yusuke YAMADA, Shinya SHIKANO and Shunichi FUKUZUMIRSC Adv., Vol. 5, pp. 44912-44919 (2015)
Catalysis of Al2O3–SiO2, TiO2, SiO2 and CeO2 (MOx) impregnated with pre-formed Ni–Cu alloy
nanoparticles (Ni–CuNPs/MOx) for photocatalytic hydrogen (H2) evolution was compared with that of MOx
impregnated with Ni2+ and Cu2+ ions followed by calcination and reduction (Ni–Cu/MOx). The
photocatalytic H2 evolution was conducted by photoirradiation ( > 340 nm) of a deaerated mixed solution ofa phthalate buffer (pH 4.5) and acetonitrile [1:1 (v/v)] containing -dihydronicotinamide adenine
dinucleotide (NADH), 2-phenyl-4-(1-naphthyl)quinolinium ion (QuPh+–NA), and Ni–CuNPs/MOx or Ni–
Cu/MOx as an electron donor, a photosensitiser and an H2-evolution catalyst, respectively. Ni–
CuNPs/Al2O3–SiO2 exhibited activity for the photocatalytic H2 evolution, whereas Ni–Cu/Al2O3–SiO2
showed no activity. Such precursor dependent catalysis can be elucidated by the ion-exchangeable nature andhigh surface area of Al2O3–SiO2, on which Ni–Cu alloy particles hardly form from metal salts. On the other
hand, Ni–Cu/TiO2 and Ni–Cu/SiO2 exhibited higher activity than Ni–CuNPs/TiO2 and Ni–CuNPs/SiO2,
respectively, resulting from formation of smaller Ni–Cu alloy nanoparticles on TiO2 and SiO2 by reducing
Ni2+ and Cu2+ on the surfaces. When CeO2 was used as the support, no catalytic activity was observed for
either Ni–CuNPs/CeO2 or Ni–Cu/CeO2. Kinetic study for thermal H2 evolution suggested that Ni–CuNPs
were severely deactivated for H2 evolution by being loaded on CeO2.
Characterization of Lithium Insertion Electrodes and Its Verification: Prototype 18650 Batteries
Consisting of LTO and LAMO
Kensuke NAKURA, Kingo ARIYOSHI, Hiroshi YOSHIZAWA and Tsutomu OHZUKU
J. Electrochem. Soc., Vol. 162, pp. A622-A628 (2015)
The insertion electrodes of lithium titanium oxide (LTO) and lithium aluminum manganese oxide (LAMO)
are characterized in terms of the area-specific capacity (ASC) in mAh cm–2, area-specific impedance (ASI) inΩ cm2, and area-specific deformation (ASD) in µm/(mAh cm–2). The prototype 18650-batteries consisting of
LTO and LAMO electrodes characterized in this way are fabricated and examined in their performance inorder to verify the basic concepts of the characterization of the lithium insertion electrodes. The rechargeable
capacity, 1.05 Ah, calculated from ASC and the active electrode area agrees with the nominal capacity of 1.0
Ah determined at the 5-h rate of discharge. The impedance estimated from ASI and the active electrode area
also agrees well with the observed impedance spectra for a prototype battery except a high frequency region
due to inductance derived from a spirally wounded electrode configuration. The internal resistance of thebattery is calculated to be ca. 30 mΩ from the results on the rate capability tests at 1/5, 1/2, 1, 2, 3, 4, and 5
C-rate for both charge and discharge, and an understanding on the internal resistance of a battery is discussed
in relation to ASI and ASD.
Secondary Excitation Process for Quantitative Confocal 3D-XRF Analysis
Kouichi TSUJI, Atsushi TABE, Peter WOBRAUSCHECK and Christina STRELI
Advances in X-ray Analysis, Vol.58, pp. 191-199 (2015)
X-ray fluorescence (XRF) is a well-established method for quantitative elemental analysis. For accuratequantification, secondary excitation has to be taken into account. In this paper, the secondary excitation
process was discussed for analysis by confocal micro-XRF. Experimental depth profiles were shown for alayered sample of Co and Cu. An additional peak was observed in the depth profile of Co, and it was
explained by secondary excitation process. Additionally, a Mosaic model was proposed for quantification ofconfocal micro- XRF analysis.
Confocal Micro-XRF Analysis of Light Elements with Rh X-Ray Tube and Its Application for Painted
Steel Sheet−82−

Ryota YAGI and Kouichi TSUJI
X-Ray Spectrom., Vol.44, pp. 186-189 (2015)
A confocal micro-X-ray fluorescence (XRF) instrument with a vacuum chamber was applied for analysis oflight elements for painted steel sheet. Because this instrument is equipped with a Rh-anode X-ray tube, lightelements are excited more effectively by the Rh-L lines. However, it was difficult to analyze Cl, because theenergies of the Cl-K lines are close to those of the Rh-L lines. Thus, we applied an Al thin film as a primary
X-ray filter to eliminate the Rh-L lines and confirmed the feasibility of Cl analysis using a Rh X-ray tube.
Rh-L scattered X-rays were observed by using an acrylic plate as a sample. The Rh-L scattered X-rays werecompletely absorbed by a 24 µm thick Al filter. A calibration curve of Cl was prepared by using certified
reference materials with different Cl concentrations. The limit of detection for Cl was 11.9 ppm as estimatedfrom the calibration curve. Confocal micro-XRF with a Rh X-ray tube enables the analysis of low Z
elements including Cl by applying an Al filter. This technique was applied for a practical painted steel sheet
sample. The elemental image of Cl was successfully observed after corrosion in NaCl solution as well asother light elemental maps.
Confocal Micro XRF Monitoring of Displacement Plating Process
Yuta KITADO, Shintaro HIRANO, Noritsugu KOMETANI and Kouichi TSUJI
Adv. X-ray. Chem. Anal., Japan, Vol. 46, pp.269-276 (2015) (in Japanese)
X-ray fluorescence analysis (XRF) is a non-destructive method. There is a lot of applications like analysis ofindustrial material. By assembling the polycapillary X-ray lens (PCXL) in the point part of X ray tube and a
detector, the micro-area analysis has been possible. The depth resolution of the confocal micro XRF
instrument which had been developed in our laboratory is about 44 μm at the confocal point at Au Lβ (11.4
keV). The confocal micro XRF instrument was applied to in situ analysis of displacement plating process.
Time dependent profiles were acquired by repeated point analysis on the surface of the steel sheet andrepeated line scan near a solidliquid interface. Inhomogeneous nature of displacement plating was observedby 2D mapping of the steel sheet after the chemical reaction.
On X-Ray Channeling in a Vibrating Capillary
Andrea LIEDL Sultan B. DABAGOV, Dariush HAMPAI, Claudia POLESE and Kouichi TSUJI
Nucl. Instrum. Methods Phys. Res., B, Vol. 355, pp. 289-292 (2015)
A novel study on a different use of polycapillary optics is presented. The scope of this study is to achieve an
efficient radiation collimation due to handled beam profiling that avoids the typical one based on total
external reflection into the capillary channel. For this purpose a vibration is applied to a monocapillary inorder to emulate a “virtual roughness” on the channel internal wall surface. The transmission properties ofsuch a system for different vibrational states are discussed.
Preliminary Experiment of X-Ray Diffraction Imaging
Masaki YAMANASHI, Noritsugu KOMETANI and Kouichi TSUJI
Nucl. Instrum. Methods Phys. Res., Sect. B, Vol. 355 pp. 272–275 (2015)
X-ray diffraction (XRD) techniques have been used in various fields, such as, material science, medical
science, etc. XRD gives the structure information of materials. An XRD imaging spectrometer equipped witha 2D X-ray detector for obtaining the information of a large observation area was developed in this study. A
polycapillary half lens was applied as a 2D collimator to have an X-rays with a large collimated area of
8 mm. The 2D diffracted X-rays were detected by a 2D X-ray detector.
Analytical Technique for Monitoring Trace Heavy Elements Eluted from Surface of Toys
Kouichi Tsuji
In Trace analysis of metals and sample preparation techniques, Technical Information Institute Co., Ltd. pp.
423-429 (2015) (in Japanese)
Total reflection X-ray fluorescence (TXRF) is well known as a trace analysis method. There are many
applications of trace elemental analysis by TXRF. Sample preparation technique has been developed
depending on the type of the samples to be analyzed. In the case of solution samples, a normal sample
preparation is to drop a small amount of solution on a flat sample carrier, then a dried residue is measured by
TXRF. We have studied how to measure the metals in surface layers of plastics by TXRF. In some cases, the−83−surface of the plastic products will be dissolved by acid solutions such as acid rain, leading that harmful
elements are also dissolved into the solutions or soils. In this study, we have studied dissolving and leachingprocesses of plastic products for TXRF analysis. A droplet of solutions dissolved by organic solutions was
prepared in thin films by spin coating techniques. This sample was analyzed by TXRF with an internal
standard solution. In addition, a actual plastic toy (minicar) was dissolved in acid solution. The leachingsolution was sampled in the time range from 0.5 min. to 180 min., then they were measured by TXRF. The
time-dependent curves of TXRF intensities showed specific shapes depending on the elements. This result
indicates that TXRF is useful for monitoring the leaching process of metals from plastic toys.
Determination of Trace Elements in Italian Wines by Means of Total Reflection X-Ray Fluorescence
Spectroscopy
Rogerta DALIPI, Laura BORGESE, Annalisa ZACCO, Kouichi TSUJI, Emanuele SANGIORGI, Roberto
PIRO, Elza BONTEMPI and Laura E. DEPERO
Intern. J. Environ. Anal. Chem., in press (DOI:10.1080/03067319.2015.1036861)
This work was performed to highlight the advantages of total reflection X-ray fluorescence spectroscopy(TXRF) for multi-elemental qualitative and quantitative analysis of wine. Indeed the International
Organization of Vine and Wine (OIV) selected some potentially toxic elements and proposed limit values fortheir concentration in wines. Direct TXRF analysis of nine wine samples from Emilia Romagna region of
Italy was performed in two different laboratories: Italy and Japan. Wine dehydration was also evaluated as
sample conservation mean. Traces of Fe, Cu, Zn and Pb are present in all the analysed samples, withconcentrations lower than the limits established by the OIV. The target hazard quotients (THQs) were also
calculated for seven elements (Cl, Mn, Fe, Ni, Cu, Zn and Sr) to determine their potential detrimental effects.
The results show that TXRF is a fast, simple and accurate analytical technique for trace element analysis ofwine. Moreover, dehydration is an effective way to store wine samples for further elemental analysis.
Secondary Excitation Process for Quantitative Confocal 3D-XRF Analysis
Kouichi TSUJI, Atsushi TABE, Peter WOBRAUSCHECK and Christina STRELI
Powder Diffraction, Vol. 30, pp. 109-112 (2015)
X-ray fluorescence (XRF) is a well-established method for quantitative elemental analysis. For accuratequantification, secondary excitation has to be taken into account. In this paper, the secondary excitation
process was discussed for analysis by confocal micro-XRF. Experimental depth profiles were shown for alayered sample of Co and Cu. An additional peak was observed in the depth profile of Co, and it was
explained by secondary excitation process. Additionally, a Mosaic model was proposed for quantification ofconfocal micro- XRF analysis.
Analytical Characteristics of Wavelength Dispersive XRF Imaging with Straight Polycapillary and 2D
Detector
Seiji EMOTO, Kouichi TSUJI, Shuichi KATO, Takashi YAMADA and Takashi SHOJI
Advances in X-Ray Chemical Analysis, Japan, Vol.45, pp.129-138 (2014) (in Japanese)
XRF imaging is analytical method to obtain 2D elemental distribution by using XRF. One of the typicalmethods of XRF imaging is scanning XRF imaging using micro X-ray beam. For this method, energy
dispersive detector is used. However, in energy dispersive scanning XRF imaging, since the sample isscanned with a fixed micro X-ray beam, this method needs long measurement time to obtain elemental
images of a wide area. The alternative method for performing XRF imaging in a shorter time is a projection
XRF imaging. For this method, incident X-ray is irradiated to a sample in a wide area and fluorescence
X-ray is detected by 2D detector. However, since 2D detector has no energy resolution, there is a problem
that the identification of the elements can not be performed. Therefore, we proposed the projection XRF
imaging combined with wavelength dispersive spectroscopy (WDS). In this paper, we discuss WD-XRF
imaging using straight polycapillary and X-ray CCD camera.
3D-XRF Analysis of Electrodes of Li-ion Battery
Ryota YAGI, Shintaro HIRANO, Kouichi TSUJI, Mareike FALK, Jurgen JANEK and Ursula FITTSCHEN
Advances in X-Ray Chemical Analysis, Japan, Vol.45, pp.241-250 (2014) (in Japanese)
X-ray fluorescence analysis (XRF) is a non-destructive method. Using polycapillary X-ray lens (PCXL), the−84−micro-area analysis has been possible. In confocal setup, foci of both X-ray focusing PCXL and collecting
PCXL are adjusted to the identical point, therefore depth elemental profiling and three dimensional elemental
analysis are possible by scanning sample in three dimensions. In our laboratory, confocal 3D micro-XRF
instrument which provides a vacuum chamber was developed. Under vacuum condition, it becomes possible
to detect soft X-rays from light elements because of the absence of atmosphere which absorb soft X-rays.
The depth resolution of the confocal 3D-XRF instrument which had been developed in our laboratory is
about 11 μm at the confocal point at Mo-Kα (17.4 keV). The confocal 3D-XRF instruments were applied toanalysis the electrode materials of Li-ion secondary battery under atmospheric and vacuum conditions.
Depth-dependent elemental mapping was performed for a positive-electrode material, which consists of
LiMn1.5Ni0.5O4, after charge-discharge processes. On the negative electrode material (graphite), Ni and Mn
were observed.
Visualization of Elemental Distributions near Steel Sample Surface by Confocal Micro X-Ray
Fluorescence
Kouichi TSUJI, Shintaro HIRANO, Ryota YAGI, Takashi NAKAZAWA, Koji AKIOKA, Masahiro ARAI
and Takashi DOI
Tetsu-to-Hagané, Vol. 100, pp.897-904 (2014) (in Japanese)
Details of corrosion process under the coating layer of the steel sheet have not been understood well.
Therefore, it is required to develop a nondestructive analytical method for the near surface of the steel sheet.
It is also required to have analytical tool for observing the corrosion process in the solution. The authors
developed a confocal 3D-XRF analytical instrument, which enables a nondestructive elemental analysis near
the surface of the material. This technique was applied for analyzing the corrosion process under the coating
layer of the steel sheet. Depth elemental images showing elemental distributions were nondestructively
obtained. 3D-XRF method was also applied for observing Fe distribution in the NaCl solution duringcorrosion of Fe from the steel sheet. Dissolution, migration, and deposition processes were successfully
monitored. It is expected that this confocal 3D-XRF technique will be applied for in-situ analysis of thesteels under various environments.
Comparison of Two Confocal Micro-XRF Spectrometers with Different Design Aspects
Stephan SMOLEK, Takashi NAKAZAWA, Atsushi TABE, Kazuhiko NAKANO, Kouichi TSUJI, Christina
STRELI and Peter WOBRAUSCHEK
X-Ray Spectrom., Vol. 43, pp. 93-101 (2014)
Two different confocal micro X-ray fluorescence spectrometers have been developed and installed at Osaka
City University and the Vienna University of Technology Atominstitut. The Osaka City University system isa high resolution spectrometer operating in air. The Vienna University of Technology Atominstitut
spectrometer has a lower spatial resolution but is optimized for light element detection and operates undervacuum condition. The performance of both spectrometers was compared. In order to characterize the spatial
resolution, a set of nine specially prepared single element thin film reference samples (500nm in thickness,
Al, Ti, Cr, Fe, Ni, Cu, Zr, Mo, and Au) was used. Lower limits of detection were determined using the
National Institute of Standards and Technology standard reference material glass standard 1412. A paint layer
sample (cultural heritage application) and paint on automotive steel samples were analyzed with both
instruments. The depth profile information was acquired by scanning the sample perpendicular to the surface.
Elemental Depth Imaging of Solutions for Monitoring Corrosion Process of Steel Sheet by Confocal
Micro-XRF
Shintaro HIRANO, Koji AKIOKA, Takashi DOI, Masahiro ARAI and Kouichi TSUJI
X-Ray Spectrom., Vol. 43, pp. 216-220 (2014)
Non-destructive and non-contact analysis has been in demand on numerous occasions. Confocal micro X-ray
fluorescence analysis enables depth-selective elemental analysis of solid samples in the laboratory. In thispaper, we applied this technique for imaging elemental distributions in solutions. A low-carbon steel sheet
was placed in artificial seawater (NaCl: 3.5 mass%), and the corrosion process in the solution was observed.
A depth image of Fe Kα intensity in the NaCl solution was obtained by using this technique. The Fe Kα
intensity in the solution was measured with corrosion time by sequential line analysis at a fixed lateralposition. The corrosion of Fe from the steel sheet, the migration of Fe ions in solution, and their−85−condensation near a polymer window were successfully monitored.
An Estimation of the Number of Upstream Migration of Juvenile Ayu Plecoglossus Altivelis Altivelis in
the Urbanized Yamato River by the Method of Micro-X-Ray Fluorescence Analysis
Mayu NAMITA, Hiromitsu ONCHI, Tenma ITAYA, Takashi NAKAZAWA, Kouichi TSUJI and Susumu
YAMOCHIKankyo Asesumento Gakkaishi Japan Society for Impact Assessment, Vol. 12, pp.101-108 (2014) (inJapanese)
Strontium or strontium calcium ratios in otoliths were determined employing the method of micro-X-ray
fluorescence analysis along with the microscopic observation of daily growth rings of the otoliths. This
enabled us to distinguish natural Ayu from artificially released ones, and to estimate the number of upstream
migrating Ayu in the Yamato River. As a result, of the Captured Ayu, 20 individuals of the 27 individuals in
2010, 41 individuals of the 44 individuals in 2011, and 29 individuals of the 32 individuals in 2012 were
thought to be natural and the remaining individuals were artificially released ones. A total of 14,000 to
33,000 individuals of the natural Ayu were expected to ascend the lower areas of the Yamato River from2010 to 2012.
Underfilm Corrosion of Steel Sheets Observed by Confocal 3D-XRF Technique
Koji AKIOKA, Takashi NAKAZAWA, Takashi DOI, Masahiro ARAI and Kouichi TSUJI
Powder Diffraction, Vol. 29, pp. 151-154 (2014)
A confocal micro-X-ray fluorescence (XRF) method with a vacuum chamber was used for investigation ofunderfilm corrosion that occurs on a painted steel sheet used for automotive applications. A painted steel
sheet was prepared by applying electrodeposition coating onto an electro-galvanized steel sheet with a zinc
phosphate conversion coating. The spatial resolution of the confocal micro-XRF was about 10.9 μm at anenergy of 17.4 keV. The phosphorus signal from the zinc phosphate layer was able to be observed
nondestructively by measuring under the vacuum condition. Each layer of the painted steel sheet wasobserved from the depth profile analysis of the characteristic elements of each layer. The painted steel sheet
was scratched to expose the substrate surface, and then the sheet was then immersed in a NaCl solution for
10 days. The in-depth elemental map of Ti of the corroded steel sheet revealed blister-type corrosion aroundthe scratch. The in-depth elemental maps of Zn and P suggested that the zinc phosphate layer dissolved fromthe scratched part into the NaCl solution.
First Total Reflection X-Ray Fluorescence Round-Robin Test of Water Samples: Preliminary Results
Laura BORGESE, Fabjola BILO, Kouichi TSUJI, Ramón FERNÁNDEZ-RUIZ, Eva MARGUI, Christina
STRELI, Giancarlo PEPPONI, Hagen STOSNACH, Takashi YAMADA, Peter VANDENABEELE, David M.
MAINA, Michael GATARI, Keith D. SHEPHERD, Erick K. TOWETT, Leonardo BENNUN, Graciela
CUSTO, Cristina VASQUEZ and Laura E. DEPERO
Spectrochimica Acta Part B, Vol. 101, pp. 6-14 (2014)
Total Reflection X-Ray Fluorescence (TXRF) is a mature technique to evaluate quantitatively the elemental
composition of liquid samples deposited on clean and well polished reflectors. In this paper the results of thefirst worldwide TXRF round-robin test of water samples, involving 18 laboratories in 10 countries arepresented and discussed. The test was performed within the framework of the VAMAS project,interlaboratory comparison of TXRF spectroscopy for environmental analysis, whose aim is to develop
guidelines and a standard methodology for biological and environmental analysis by means of the TXRF
analytical technique.
Development of a Compact Grazing Exit X-Ray Fluorescence Spectrometer for Fast Trace Elemental
AnalysisTakafumi ASHIDA and Kouichi TSUJI
Spectrochimica Acta Part B, Vol. 101, pp. 200-203 (2014)
A compact grazing exit X-ray fluorescence (GE-XRF) spectrometer was developed in the laboratory. An Al
cylindrical collimator for the primary X-rays was placed just above the sample stage. This collimator also
played the role of an exit slit to detect fluorescent X-rays at small grazing exit angles. Therefore, noadditional exit slit was used in this setup, leading to a compact design. The entire size of the analysis−86−equipment was 80 mm × 200 mm × 170 mm (horizontal × vertical × height). The maximum exit angle wasadjusted to the height of the sample stage. The background was drastically reduced at grazing exit angles,
enabling trace elemental analysis. A calibration curve was obtained using 10 μL Ga solutions. Accordingly,
the detection limit for Ga was evaluated to be 20 ppb.
In Situ Observations of Thermoreversible Gelation and Phase Separation of Agarose andMethylcellulose Solutions under High Pressure
Noritsugu KOMETANI, Masahiro TANABE, Lei SU, Kun YANG, and Katsuyoshi NISHINARI
J. Phys. Chem. B, Vol. 119, pp. 6878–6883 (2015)
Thermoreversible sol–gel transitions of agarose and methylcellulose (MC) aqueous solutions on isobaric
cooling or heating under high pressure up to 400 MPa have been investigated by in situ observations of
optical transmittance and falling-ball experiments. For agarose, which undergoes the gelation on cooling, theapplication of pressure caused a gradual rise in the cloud-point temperature over the whole pressure range
examined, which is almost consistent with the pressure dependence of gelling temperature estimated byfalling-ball experiments, suggesting that agarose gel is stabilized by compression and that the gelation occurs
nearly in parallel with phase separation under ambient and high-pressure conditions. For MC, which
undergoes the gelation on heating, the cloud-point temperature showed a slight rise with an initial elevationof pressure up to 150 MPa, whereas it showed a marked depression above 200 MPa. In contrast, the gelling
temperature of MC, which is nearly identical to the cloud-point temperature at ambient pressure, showed amonotonous rise with increasing pressure up to 350 MPa, which means that MC undergoes phase separation
prior to gelation on heating under high pressure above 200 MPa. Similar results were obtained for themelting process of MC gel on cooling. The unique behavior of the sol–gel transition of MC under highpressure has been interpreted in terms of the destruction of hydrophobic hydration by compression.
High Pressure Study of Rotational Dynamics of Perylene and Sodium 8-Methoxypyrene-1,3,6triulonate in Imidazolium-Based Ionic Liquids
Noritsugu KOMETANI and Atsuko TAI
J. Solution Chem., Vol. 43, pp.1529-1538 (2014)
Rotation times of perylene and 8-methoxypyrene-1,3,6-trisulfonate (MPTS) in 1-alkyl-3-methylimidazolium
tetrafluoroborate and 1-alkyl-3-methylimidazolium hexafluorophosphate under high pressure have been
examined by means of the time-resolved fluorescence anisotropy measurements. The isothermal compressionof sample solutions by the application of high pressure could change the solvent viscosity alone over a wide
range, allowing for an observation of the pure viscosity dependence of rotation times at a constanttemperature (45°C). Rotation times of both perylene and MPTS show a considerably nonlinear dependence
on the solvent viscosity and a substantial deviation from the predictions of hydrodynamic andquasihydrodynamic theories particularly at high pressures.
Catalytic Effects of Copper Oxides on the Decomposition of Chlorophenol by the Hydrothermal
Oxidation
Noritsugu KOMETANI, Kyohei NAKAO and Hiroki HONDA
J. Soc. Mater. Sci. Jpn., Vol. 63, pp. 674-678 (2014) (in Japanese)
It has been revealed that hydrothermal oxidation of persistent organochlorine substances is dramaticallyfacilitated with the aid of Cu-based catalysts such as Cu-supported WO3, because the Fenton-type reaction
catalyzed by Cu ions undergoes substantial acceleration under subcritical conditions of water at around200~300°C, leading to the increased formation of hydroxyl radicals which possess a strong oxidative power.
In this study, the catalytic hydrothermal oxidation of 4-chlorophenol with CuO or Cu2O has been examinedusing the slurry flow and catalyst packed-bed reactor systems. It is found that Cu2O has a remarkable
catalytic activity for the hydrothermal oxidation of 4-chlorophenol compared with those of CuO andCu-supported TiO2. The conversion of 4-chlorophenol reached nearly 100% at reaction temperatures around
130°C when Cu2O was used as catalyst, indicating that it is possible to substantially reduce the reaction
condition required for the complete decomposition of persistent organochlorine substances by thehydrothermal oxidation. The continuous treatment of 4-chlorophenol has been also conducted using thepacked-bed reactor system with Cu2O. The results demonstrated that 4-chlorophenol could be degraded for
up to 22 hours without significant loss of the catalytic activity.

−87−Advanced Treatment Technique of Polluted Water by the Combination of Fenton and Hydrothermal
Oxidation Methods using Copper Oxide Catalysts
Noritsugu KOMETANI
Chemical Engineering, Vol.6, pp. 504-508 (2015) (in Japanese)
Catalytic Activity of Epi-Quinine-Derived 3,5-Bis(trifluoro-methyl)benzamide in Asymmetric
Nitro-Michael Reaction of Furanones
Tohru SEKIKAWA, Takayuki KITAGUCHI, Hayato KITAURA, Tatsuya MINAMI and Yasuo
HATANAKA
Org. Lett., Vol. 17, pp. 3026–3029 (2015)
High catalytic activity of novel epi-quinine-derived 3,5-bis(CF3)benzamide in the asymmetric nitro-Michael
reaction is described. With 0.1-5 mol % loadings of this catalyst, the addition of 5-substituted2(3-H)-furanones to a wide range of nitroalkenes involving challenging substrates, β-alkyl-nitroalkenes
smoothly proceeded, giving the Michael adducts in high yields (> 90%) with excellent diastereo- andenantioselectivity (> 98:2 dr, syn major; 88-98% ee). DFT calculation was carried out to account for thehigh catalytic activity.
Development of Environmental Harmony Resist Removal System using Cryogenic Particulate SprayJun ISHIMOTO and Hideo HORIBE
J. Photopolym. Sci. Tech., Vol. 28, pp. 285-288 (2015)
It is numerically found that the atomization of LN2 droplet is induced by shear flow between LN2 andgaseous nitrogen (GN2) flow. Sequentially, liquid to solid phase change is enhanced and solid nitrogen(SN2) particle is continuously created by LN2 droplet freezing. By using ToF-SIMS and XPS analysis forresist removal experiment, the obtained C film thickness of resist removal section is 0.2 nm. Therefore, thephoto resist can be successfully removed by using cryogenic solid particulate spray method.
Effect of Microbubbles on Ozonized Water for Photoresist Removal
Masayoshi TAKAHASHI, Hideo HORIBE, Kouhei MATSUURA and Katsumi TATERA
J. Photopolym. Sci. Tech., Vol. 28, pp. 293-298 (2015)
The existence of microbubbles in ozonized water has been shown to significantly enhance the photoresist
removal rate due to an elevated dissolved ozone concentration and a direct effect of the microbubbles
relating to the radical generation. Additionally, the ozone microbubble solution was able to effectively
remove a high-dose ion-implanted photoresist, which is extremely resistant to removal by ozonized waterand other wet chemicals because of its amorphous carbon-like layer, or "crust". Electron spin resonanceexperiments were also performed without the influence of serious metal contamination and indicated thepresence of hydroxyl radicals, which are thought to be formed by interaction of ozone with hydroxide ionsadsorbed at the gas-water interface upon collapse of the microbubbles.
Degradation of Polymers for Resist using Microbubbles on Ozonized Water
Kohei MATSUURA, Takashi NISHIYAMA, Eriko SATO, Masashi YAMAMOTO, Masayoshi
TAKAHASHI, Kunihiko KOIKE and Hideo HORIBE
J. Photopolym. Sci. Tech., Vol. 28, pp. 299-301 (2015)
A significant effect of microbubbles on degradation of novolak resin could not be confirmed. Microbubbles
efficiently dissolved ozone in solution, enhancing dissolved ozone concentration. By using ozone
microbubbles, removal rate of novolak resin was enhanced. We expect that the effect of polymer degradation
by microbubbles would be made more obvious by setting suitable conditions such as pH, ionic strength, andremoval process.
Enhancement of Photoresist Removal Rate by Using Atomic Hydrogen Generated under Low-Pressure
Conditions
Masashi YAMAMOTO, Hironobu UMEMOTO, Keisuke OHDAIRA, Shiro NAGAOKA, Tomokazu
SHIKAMA, Takashi NISHIYAMA and Hideo HORIBE
J. Photopolym. Sci. Tech., Vol. 28, pp. 303-306 (2015)−88−

Instead of photoresist removal methods using chemicals, we investigated a novel, environmentally friendly
removal method using atomic hydrogen generated on a tungsten hot-wire catalyst. We revealed that thephotoresist removal rate is remarkably enhanced under low hydrogen pressure conditions. This enhancement
may be ascribed to the high kinetic energy of H atoms. If we optimize the removal conditions, the removal
rate may become comparable to that achieved when chemicals are used.
Dependence on Resist Stripping Efficiency to Irradiating Beam Size in Advanced Laser Resist
Stripping Method
Tomosumi KAMIMURA, Yuta KUROKI, Takuma MURAKAMI, Kosuke NUNO, Masaya AKIMOTO,
Yoshiyuki HARADA, Takashi NISHIYAMA and Hideo HORIBE
J. Photopolym. Sci. Tech., Vol. 28, pp. 307-311 (2015)
Dependence on the stripping efficiency to irradiating beam size was investigated in an advanced laser resist
stripping method. The beam size on the resist surface was changed from 0.3 mm to 3.0 mm. An intensity
shape of the laser beam was Gaussian shape. At a beam diameter of 0.3mm, the stripped resist area in a beam
was 15 % of 0.01 mm2. In the case of beam diameter of 3.0 mm, the stripped resist area in a beam was 5 %of 0.38 mm2. The stripped area improves 38 times for scale-up of the beam area of 100 times. The resist
stripping efficiency was thought to depend on the heat stress due to a temperature gradient between the beam
center and the regions without laser irradiation. Irradiation with multiple laser beams by small beam diameter
was confirmed as one of the methods for improvement of a resist stripping rate with high efficiency.
Estimation of Activation Energies for Decomposition Reaction of Polymer by Hydrogen Radicals
Generated Using Hot-Wire Catalyzer
Akihiko KONO, Yu ARAI, Yousuke GOTO, Masashi YAMAMOTO, Seiji TAKAHASHI, Tadaaki
YAMAGISHI, Kenji ISHIKAWA, Masaru HORI and Hideo HORIBE
Thin Solid Films, Vol. 575, pp. 17-20 (2015)
This paper discusses the decomposition processes of polymer thin films coated on silicon (Si) substrates byhydrogen radicals generated from H2 on hot-wire catalyst surfaces. N2 buffer was used to relax thetranslational motion of hydrogen radicals. It is shown that H atoms react to polymer films under thermal
equilibrium conditions when the total pressure is 21.3 Pa and the distance between the catalyst and thesubstrate is 100 mm. Polymers with benzene ring such as phenol resin, polystyrene, poly(vinylphenol), andpoly(α-methylstyrene) exhibited both low removal rate and high activation energy of decomposition
compared to those polymers without benzene ring such as poly(methylmethacrylate) and poly(isobutylene).
We concluded that benzene ring with CC bond and resonance structure is resistant to decomposition byhydrogen radicals.
Study of the Decomposition Mechanism of PMMA-Type Polymers by Hydrogen Radicals
Yu ARAI, Yusuke NOTO, Yousuke GOTO, Seiji TAKAHASHI, Masashi YAMAMOTO, Takashi
NISHIYAMA, Akihiko KONO, Tatsuo ISHIJIMA, Kenji ISHIKAWA, Masaru HORI and Hideo HORIBE
Thin Solid Films, Vol. 575, pp. 12-16 (2015)
The relationship between the chemical structure of PMMA-type polymers and the removal rate by hydrogenradicals was examined. Hydrogen radicals are known to have superior reduction ability and can be generated
by decomposing H2 on hot-wire surfaces. PMMA-type polymers, which are widely used as base polymers
for ArF resist, have many variations with the difference in the substituents. The removal rate of the main
chain scission type polymers was faster than that of the main chain cross-linking type polymers. In the main
chain cross-linking type polymers, it is considered that reduction decomposition of polymer was inhibitedapparently according to occurrence to simultaneously reduce decomposition by hydrogen radicals and main
chain cross-link. The removal rate was slow in the case of the main chain scission type polymers with abenzene ring. We guessed that the polymer with a benzene ring was a stable structure by resonancestabilization of a benzene ring. We found that the removal rate was slow according to increasing bulkiness of
α-side chain in the main chain scission type polymers. It is considered that etching resistance increases withincreasing bulkiness of α-side chain of polymer.

−89−

The Effect of the Structural Order of Isotactic Polypropylene Containing Magnetically Aligned Nickel
Particles on Its Electrical Resistivity
Masafumi YAMATO, Shuhei OBAYASHI, Takashi NISHIYAMA, Hideo HORIBE, Kohki TAKAHASHI
and Kazuo WATANABE
Polymer, Vol. 55, pp. 6546-6551 (2014)
The effect of the high order structure of an isotactic polypropylene (PP) composite on the resistivity ofcomposites containing magnetically aligned Ni particles was studied. Only a small amount of particles
needed to be added for the composite material to become conducting after heating while in a magnetic field.
The Ni columns formed on applying the field were distorted by the formation of large PP spherulites.
Changes to the crystallization process due to the addition of a nucleating agent gave rise to changes in thecolumnar structure, resulting in large changes in the resistivity of the composite material. Controlling thehigh order structure of the polymer matrix including its morphology is very important in order to be able tocontrol the magnetically aligned Ni structure.
Synthesis, Thermal, Optical, and Mechanical Properties of Sequence-Controlled Poly(1-adamantyl
acrylate)-block-Poly(n-butyl acrylate) Containing Polar Side Group
Yoshinori NAKANO, Eriko SATO and Akikazu MATSUMOTO
J. Polym. Sci., Part A: Polym. Chem., Vol. 52, pp. 2899-2910 (2014)
We prepared the sequence-controlled block copolymers including poly(1-adamantyl acrylate) (PAdA) andpoly(n-butyl acrylate) sequences as the hard and soft segments, respectively, by theorganotellurium-mediated living radical polymerization. The thermal, optical, and mechanical properties of
the adamantane-containing block copolymers with polar 2-hydroxyethyl acrylate (HEA) and acrylic acid(AA) repeating units were investigated. The microphase-separated structures of the block copolymers wereconfirmed by the differential scanning calorimetry and atomic force microscopy observations as well as
dynamic mechanical measurements. The - and -dispersions due to the main-chain and side groupmolecular motions, respectively, of the hard and soft segments were observed. Their transition temperatures
and activation energies increased due to the formation of intermolecular hydrogen bonding by the
introduction of the HEA and AA repeating units. The effects of the hydrogen bonding on their tensile
elasticity, strength, and strain were also evaluated.
Acetal-Protected Acrylic Copolymers for Dismantlable Adhesives with Spontaneous and Complete
Removability
Eriko SATO, Keisuke YAMANISHI, Tadashi INUI, Hideo HORIBE and Akikazu MATSUMOTO
Polymer, Vol. 64, pp. 260-267 (2015)
Acetal-protected acrylic copolymers consisting of 1-isobutoxyethyl acrylate (iBEA), 2-ethylhexyl acrylate(2EHA), and 2-hydroxyethyl acrylate (HEA) repeating units were applied to the pressure-sensitive adhesive(PSA) types of dismantlable adhesives. The random and block copolymers with a relatively high HEA
content showed good PSA properties before dismantling treatment. The deprotection of the acetal protectedgroup of the iBEA unit took place in response to individual external stimuli, soaking in boiling water and UV
irradiation in the presence of a photoacid generator. The random copolymers containing an HEA unit ofmore than 10 mol% and an iBEA unit of more than 70 mol% achieved spontaneous debonding withinterfacial failures at both the stainless steel and polyethylene terephthalate support film sides by soaking inboiling water within 10 min, whereas the corresponding block copolymer did not achieve interfacial failure
even after a 20-min soaking. Photoirradiation of the random copolymers containing N-hydroxynaphthalimide
triflate as a photoacid generator resulted in interfacial failures at both sides with a sufficiently reduced peelstrength, where cross-linking arose due to the transacetalization and transesterification of a hydroxy group in
the HEA unit along with deprotection.
Dual Stimuli-Responsive Homopolymers: Thermo- and Photo-responsive Properties of
Coumarin-Containing Polymers in Organic Solvents
Eriko SATO, Yuki MASUDA, Joji KADOTA, Takashi NISHIYAMA and Hideo HORIBE
Eur. Polym. J., Vol. 69, pp. 605-615 (2015)
Thermoresponsive properties of poly(7-methacryloyloxycoumarin) (P1a) and its derivatives as
homopolymers containing a photoreactive coumarin unit were systematically investigated. P1a showed a−90−lower critical solution temperature (LCST)-type phase separation in dichloromethane, chloroform, and1,1,2-trichloroethane. The temperature producing a 50% transmittance (Tc) of 0.1 wt% P1a in distilledchloroform was 26 °C, while the Tc value decreased to 21 °C in deuterated chloroform i.e., the deuterium
isotope effect. The Tc values in chloroform were adjustable from 28 to 57 °C by the introduction of theethyleneoxy spacer and -methyl group to P1a. While the polymers containing 4-substituted coumarins
were soluble in chloroform and dichloromethane from 0 °C to their boiling points. In the distilledchloroform solution, the coumarin units in P1a underwent a [2+2] cycloaddition and the transmittance at 500
nm decreased from 98 to 29 % at 25 °C by a 180-sec photoirradiation (326 mJ/cm2, emission band at 365
nm).
Analysis of Initiation Mechanism for Thermal Curing of Multifunctional Hyperbranched Polymers by
Radical Trapping
Eriko SATO, Izumi UEHARA, Takashi NISHIYAMA and Hideo HORIBE
Journal of Network Polymer, Japan, Vol. 36, pp. 186-191 (2015) (in Japanese)
We have reported that multifunctional hyperbranched polymers are synthesized by radical
homopolymerization of ethylene glycol dimethacrylate in the presence of methyl (2-bromomethyl)acrylate as
an addition-fragmentation chain transfer agent. The hyperbranched polymers contain the pendant vinylgroups and the ω-end vinyl groups, and exhibit thermosetting properties in the absence of any catalyst. In
this study, the initiation mechanisms for the thermal curing of the hyperbranched polymer were investigatedby radical trapping using a nitroxide free radical.
The hyperbranched polymer reacted with
4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxy benzoate by heating at 150 °C showing that the curing
proceeded by radical mechanism. The 1H NMR analysis of the product revealed that the cleavage of
Br-CH2 bond and C-C bond adjacent to a vinyl group having relatively low bond dissociation energies has
minor contribution to the radical formation and thermal curing proceeds by spontaneous polymerization ofvinyl groups.
Precise Synthesis of Reactive Polymers and Their Application to Functional Adhesive Materials
Eriko SATOThe 8th Symposium on Precisely Designed Network Polymer for Young Researcher, Invited Lecture,
Higashiosaka, March 6, 2015 (in Japanese)
Design and Precise Synthesis of Reactive Acrylic Polymers
Eriko SATOKOBUNSHI-DOYUKAI Kansai Workshop, Invited Lecture, Osaka, April 7, 2015 (in Japanese)
Design and Precise Synthesis of Functional Polymers
Eriko SATO
Colour Material Seminar, Invited Lecture, Osaka, May 20, 2015 (in Japanese)
Precise Synthesis of Multifunctional Hyperbranched Polymers by Metal-Free and One-Pot Reactions
Eriko SATO
Malaysian Scientific Association (MSA) International Symposium on Organic Chemistry (ISOC) in
Conjunction with MSA 60th Anniversary 2015, Invited Lecture, Kuala Lumpur, Malaysia, September 22,
2015, Abstract Books, p. 138
Photochromism of Diarylethene Molecules and Crystals: Memories, Switches, and Actuators
Masahiro IRIE, Tuyoshi FUKAMINATO, Kenji MATSUDA and Seiya KOBATAKE
Chem. Rev., Vol. 114, pp. 12174−12277 (2014)
A new class of thermally irreversible photochromic molecules, named “diarylethene”, was serendipitously
discovered a quarter of a century ago. The dithienylperfluorocyclopentene derivatives undergo thermallyirreversible, fatigue resistant, ultrafast and highly sensitive photochromic reactions. The outstanding
photochromic performance attracts considerable attention from both scientific and technological points ofview, and stimulates researches on the diarylethenes from fundamental 33ft he-chemical aspects to various
applications in optical memories, switches and molecular machines. In this review development of studies on−91−

diarylethene molecules and crystals over the past 10 years is described.
Synthesis and Characterization of Amphiphilic Silica Nanoparticles Covered by Block Copolymers
Branching Photochromic Diarylethene Moieties on Side Chain
Ryuta SENO and Seiya KOBATAKE
Dyes Pigm., Vol. 114, pp. 166−174 (2015)
Silica nanoparticles covered with polystyrene branching diarylethene moieties to the side chains aresynthesized by reversible addition-fragmentation chain transfer polymerization on silica nanoparticles. The
resulting nanoparticles are soluble in toluene and tetrahydrofuran and show reversible photoisomerization
upon alternating irradiation with ultraviolet and visible light. The photoreversible isomerization follows color
change, which is called photochromism. During the photochromic reactions, the nanoparticles are dispersedin solutions such as tetrahydrofuran. The modification by further block copolymerization of
N-isopropylacrylamide results in fabrication of photochromic silica nanoparticles soluble in bothtetrahydrofuran and water.
Photoreversible Current ON/OFF Switching by Photoinduced Bending of Gold-Coated Diarylethene
Crystals
Daichi KITAGAWA and Seiya KOBATAKE
Chem. Commun., Vol. 51, pp. 4421−4424 (2015)
We investigated the photoinduced crystal bending behavior of 1a before and after gold deposition. The
crystals of 1a showed photoreversible crystal bending upon irradiation with alternating UV and visible light
before and after gold deposition. It was revealed that the relationship between the initial speed of thecurvature change and the crystal thickness was well explained by Timoshenko’s bimetal model and theextended bimetal model before and after gold deposition, respectively. Moreover, we have demonstrated thephotoreversible ON/OFF switching of the electric circuit using the gold-coated diarylethene crystal. The
current could be flowed in the gold layer on the surface of diarylethene crystal without any resistance.
Furthermore, the photoreversible current switching by the photoinduced bending of the gold-coateddiarylethene crystal could be repeated over 10 cycles upon alternating irradiation with UV and visible light.
These findings bring about not only a new strategy to design for photomechanical actuators but also a newpractical use of photomechanical crystals.
Polymorphic Crystallization and Thermodynamic Phase Transition between the Polymorphs of a
Photochromic Diarylethene
Chika IWAIHARA, Daichi KITAGAWA and Seiya KOBATAKE
Cryst. Growth Des., Vol. 15, pp. 2017−2023 (2015)
We synthesized a photochromic diarylethene, 1,2-bis(2-methyl-5-(4-hexyloxyphenyl)-3-thienyl)perfluorocyclopentene (1a), and found that it has two types of crystals, a needle-like α-crystal and aplate-like β-crystal._ From X-ray crystallographic analysis, the space groups of the α- and β-crystals were
determined to be P1 and C2/c, respectively. The molecular conformation and packing of two crystal forms
are quite different. The α- and β-crystals can be obtained individually by recrystallization from acetone atdifferent temperatures. The solvent-mediated phase transition from the α-crystal to the β-crystal was found tooccur in the acetone solution at room temperature. Moreover, the thermodynamic phase transition from
α-form to β-form was found to take place above 88 °C, as confirmed by differential scanning calorimetry
measurement, optical microscopic observation under crossed Nicols, and powder X-ray diffraction
measurement. The phase transition from α-form to β-form was also observed at 78 °C by photochromic
reaction of 1a, and the phase transition proceeded from the UV irradiated part to the nonirradiated part.
Synthesis and Optical Properties of Gold Nanoparticle Networks Cross-Linked with
Chain-Length-Controlled Polymers
Emi SUGATA and Seiya KOBATAKERSC Adv., Vol. 5, pp. 34704−34708 (2015)
In order to control the absorption band ascribed to localized surface plasmon resonance (LSPR) of gold
nanoparticles (AuNPs) in solution, we newly synthesized a gold nanoparticle network (AuNP-NW)
crosslinked with chain-length-controlled polymers. The chain-length-controlled polystyrene (poly(St))−92−having dithiobenzoate groups at both termini was synthesized by reversible addition-fragmentation chaintransfer (RAFT) polymerization with a novel RAFT agent which enables the precise control of the chain
length of the polymers. Both terminal groups of poly(St) were reduced from dithiobenzoate groups to thiolgroups. The AuNP-NW was prepared by the self-organized cross-linking of individual AuNPs with poly(St)having thiol groups at both termini. Transmission electron microscopy images and absorption spectra of the
AuNP-NW indicate the presence of a network structure. The absorption band due to LSPR of the AuNP-NW
could be changed by the precise control of the distance between the AuNPs.
Restricted Diffusion of Guest Molecules in Polymer Thin Films on Solid Substrates as Revealed byThree-Dimensional Single-Molecule Tracking
Syoji ITO, Yuhei TAGA, Kengo HIRATSUKA, Satoshi TAKEI, Daichi KITAGAWA, Seiya KOBATAKE,
and Hiroshi MIYASAKA
Chem. Commun., Vol. 51, pp. 13756−13759 (2015)
Single-molecule tracking (SMT) of fluorescent guest dyes can provide information on microscopic
inhomogeneity in host polymer materials through the dynamics of individual guests depending on the local
environment. In the conventional SMT, two-dimensional motions of guests were analyzed for the evaluationand it was difficult to extract the depth-dependent properties. In the present work, we applied
three-dimensional (3D) SMT to the elucidation of anomalous motions of guest dyes in poly(2-hydroxyethyl
acrylate) thin films on glass substrates by using so-called astigmatism imaging method. The 3D-SMT
revealed that hydrophobic guest dyes did not approach the surface of glass substrate and typical distancefrom the surface was longer than 300 nm. In spite of the long distance from the surface, 5-10% of guest dyes
still showed anomalous diffusion, which was attributed to the intrinsic inhomogeneity of the polymer film.
Dependence of Photoinduced Bending Behavior of Diarylethene Crystals on Irradiation Wavelength of
Ultraviolet Light
Daichi KITAGAWA, Rika Tanaka and Seiya KOBATAKE
Phys. Chem. Chem. Phys., Vol. 17, pp. 27300−27305 (2015)
When irradiated with 365 nm light, a crystal of 1,2-bis(5-methyl-2-phenyl-4-thiazolyl)perfluorocyclopentene
bends toward the incident light. In contrast, when irradiated with 380 nm light, the crystal first bends awayfrom the light source and then bends toward the incident light. This bending behavior can be explained by acomprehensive mechanism based on the depth of the photochromic reaction from the crystal surface. Thismechanism is successfully supported by the change of cell parameters associated with the photochromic
reaction upon irradiation with 380 nm light, which was determined by in situ X-ray crystallographic analysis.
Photoinduced Mechanical Motion of Photochromic Crystalline Materials
Seiya KOBATAKE and Daichi KITAGAWA
In Advances in Organic Crystal Chemistry, Comprehensive Reviews 2015, Eds.: R. Tamura, M. Miyata,
Springer, Chapter 27, pp. 533-547 (2015)
Photochromic compounds undergo a photochemically reversible transformation reaction between two
isomers. Such molecules in organic crystals, which are regularly oriented and fixed in the crystal lattice, may
be potentially useful for optoelectronic devices, such as optical memory, photoswitchable color filter,photoswitchable polarizer, photomechanical actuator, and so on. This chapter has focused on photochromismof the diarylethene crystals and their photomechanical phenomena, such as crystal bending and twisting.
Photoreversible Current ON/OFF Switching by Photoinduced Bending of Gold-Coated Diarylethene
Crystals
Daichi KITAGAWA and Seiya KOBATAKE
22nd International Conference on the Chemistry of the Organic Solid State (ICCOSS 2015), Young Scientist
Award Presentation, O16, Toki Messe, Niigata, Japan, July 12−17 (2015)
Photomechanical motions of photoresponsive molecular crystals have attracted much attention because they
enable us to convert light energy into mechanical energy in direct without any contact and electric wires.
Among various compounds which show photomechanical motions, diarylethene derivatives are the mostpromising compounds functioned as photomechanical actuators because of their rapid response, fatigue
resistance, and thermal stability. Previously, we have reported the photoinduced crystal shape changes of−93−

diarylethene crystals such as contraction, expansion, bending, fragmentation, and twisting. For further
development of this research field, both theoretical and practical studies are required. Here, we have focusedon the photoinduced bending behavior of gold-coated diarylethene crystals. The gold-coated rod-like crystals
show photoreversible bending upon alternating irradiation with ultraviolet and visible light. The initial speedof bending depends on the crystal thickness and the relationship between the speed and the thickness can bewell explained by using Timoshenko’s bimetal model for the non-coated diarylethene crystals. Moreover, thebending behavior of the gold-coated diarylethene crystals can also be explained by the extended bimetalmodel which we propose here. The gold-coated layer on the crystal cannot be broken during thephotoreversible bending. Thus, the photoreversible bending behavior can be used as actual electrical circuit
switching which is very small size. These results provide not only a new useful strategy to design forphotomechanical actuators but also a new practical use of photomechanical crystals.
Evaluation of the Relationship between Preparation Method and Photoinduced Bending Behavior of
Diarylethene Microfibers
Hajime TSUJIOKA and Seiya KOBATAKE
22nd International Conference on the Chemistry of the Organic Solid State (ICCOSS 2015), Poster
Presentation, P29, Toki Messe, Niigata, Japan, July 12−17 (2015)
Photochromic diarylethenes have drawn much attention because the chemical and physical properties can bechanged by photoirradiation. Photomechanical effect of diarylethene crystals such as bending is an attractive
property for the light-driven actuator. However, it is not easy to control the crystal shape and size in themolecular crystals. A simple preparation method of the light-driven actuator is required. We evaluatedbirefringence of microfibers and examined the relationship between molecular orientation and bending
behavior. When the microfiber was irradiated with ultraviolet light, the microfiber was found to be bent in
the direction towards the incident light. The bent fibers did not return to the initial-shaped fibers upon
irradiation with visible light. When the microfiber was observed by polarizing microscopy under crossed
Nicols, birefringence was confirmed. The birefringence means that the diarylethene molecules were oriented
in the microfiber. To examine the relationship between birefringence and bending behavior of diarylethene
microfibers, the microfibers having constant thickness and different birefringence were prepared undervarious conditions. Birefringence values of the microfibers were measured by Senarmont method. It was
found that microfibers having high birefringence showed large bending curvature under the same
photoirradiated conditions. These results suggest that the orientation of molecules relates to photoinduced
bending behavior of microfibers.
Photochemistry and Solid State Property Changes of photoresponsive Organic Crystals
Seiya KOBATAKE
Annual Meeting on Photochemistry 2015, Award Lecture, AL04, Osaka City University, Japan, September
9−11 (2015)
Photochromic compounds undergo photochemically reversible transformation between two isomers. Suchmolecules in organic crystals, which are regularly oriented and fixed in the crystal lattice, may be potentially
useful for optoelectronic devices. To apply photochromic crystals to photonics, electronics, mechanics, andmedical fields, materials are required to change large physical property by photoirradiation. In most cases,
compounds that exhibit photochromism in the crystalline phase are rare. Diarylethene derivatives exhibit
thermally stable (P-type) photochromic reactions even in the crystalline phase. The P-type photochromic
compounds have the potential to be used as optical memory, photoswitching, display, photomechanicalactuator, and so on. This paper has focused on photochromism of the diarylethene crystals and theirphotomechanical phenomena.
Anti-Inflammatory Effect of Water-Soluble Complex of 1’-Acetoxychavicol Acetate with Highly
Branched β-1,3-Glucan on Contact Dermatitis
Jiawei LI, Yui AIZAWA, Keiichi HIRAMOTO, Emiko KASAHARA, Daisuke TSURUTA, Toshio
SUZUKI, Atsushi IKEDA, Hideki AZUMA and Takeshi NAGASAKI
Biomed. Pharmacother., Vol. 69, pp. 201-207 (2015)
The anti-inflammatory effect on contact dermatitis of the water solubilized 1’-Acetoxychavicol Acetate(ACA) by complexation with β-1,3-glucan isolated form Aureobasidium pullulans black yeast is reported. It−94−

is well known that ACA possesses a function to inhibit the activation of NF-κB by which genes encoding
proinflammatory cytokines, chemokines, and growth factors are regulated. However, because ACA is quite
insoluble in water, its usefulness has been extremely limited. On the other hand, a triple-helicalpolysaccharide β-1,3-glucan can include hydrophobic compounds into intra-strand hydrophobic cavity andsolubilize poorly-water-soluble compounds. In this study, solubilization of ACA by complexation withhighly branched β-1,3-glucan was achieved. The effect of anti-inflammatory response of water-soluble ACA
complex with β-1,3-glucan was confirmed in vitro and in vivo.
Kojic Acid-Appended Carborane/Hydroxypropyl--Cyclodextrin Complex: A Novel Boron Carrierfor Melanoma Targeting
Takeshi NAGASAKI, Junki KAWAGUCHI, Riku KAWASAKI, Masashi Sakuramoto, Mitsunori
KIRIHATA, Yoshihide HATTORI, Shin-ichiro MASUNAGA and Yoshinori SAKURAIKURRI Progress Report 2014, p. 7 (2015)
Although melanoma boron neutron capture therapy (BNCT) with L-10B-p-boronophenyl alanine has beentreated for melanoma patient, the enhancement of 10B accumulation in melanoma cells would lead to
improved efficacy of malignant melanoma BNCT. Recently, we have evaluated the inclusion complex of
kojic acid-appended carborane (CKA) with hydroxypro-pyl-β-cyclodextrin (HP-β-CD) as a novel boron
agent for BNCT toward melanoma. CKA/HP-β-CD complex showed melanoma cells selectivity, uniquenuclear localization, and high tumor-suppression effect on BNCT to-ward melanoma-bearing mice.
Furthermore, CKA/HP-β-CD complex was found to be the potent inhibitor of hypoxia-induced HIF-1α andto have a strong effect on tumor metastasis. Herein, in order to evaluate quantitatively metastasis-suppression,
TaqMan RT-PCR assay of melanoma gene GP100 was carried out toward melanoma B16BL6 cells
metastasis from thigh subcutaneous to lung in melanoma-bearing mice. TaqMan RT-PCR Assay toward
GP100 is potent to estimate quantitatively the metastasis of melanoma cells to lung. The quantitativeevaluation of metastasis-suppression effect of CKA/HP-β-CD complex is proceeding in our laboratory.
Evaluation of Boron-containig Rare Earth Oxides Nanoparticles as an Agent for Boron Neutron
Capture Therapy
Takeshi NAGASAKI, Riku KAWASAKI, Shunsuke Iizuka, Hiroko YUKAWA, Yusuke TSUJIMOTO,
Mitsunori KIRIHATA, Koji Tomita, Kiyofumi KATAGIRI, Koji ONO, Shin-ichiro MASUNAGA andYoshinori SAKURAIKURRI Progress Report 2014, p. 132 (2015)
Boron Neutron Capture Therapy (BNCT) is a highly selective cancer therapy that can target single tumor cellwithout causing excessive radiation damage around normal cells. The success of BNCT depends on thedelivery that 10B compounds accumulate effectively inside the tumor cells. Clinically, boronophenylalanine(BPA) and borocaptate sodium (BSH) are currently used for BNCT as boron delivery agents but these agents
have some disadvantages on accumulation or selectivity toward tumor tissue. In addition, the efficacy ofboron neutron capture reaction is suppressed due to low neutron fluence. In this study, in order to improvethe efficiency of neutron capture reaction, we used boron containing rare earth oxides nanoparticle (SmBO3,
GdBO3, YBO3). When their diameter is suitable sizes, these nanoparticles could be significantly accumulated
in tumor tissue with EPR effect. Moreover, the particle doped with europium can possess the fluorescence.
This fluorescent nanoparticles are expected as novel boron delivery drugs that can diagnose and treat cancer
simultaneously and efficiently.
Development of Efficient Boron Delivery System Using Enhanced Permeability and Retention Effectin Boron Neutron Capture Therapy
Masashi SAKURAMOTO, Yoshinori SAKURAI, Hiroki TANAKA, Shin-ichiro MASUNAGA, Koji ONO,
Mitsunori KIRIHATA and Takeshi NAGASAKIThe 2nd International Symposium on Fusion Materials, Tokyoto, Japan, November 2-4 (2014); Preprints
Cyclodextrin Complex of Kojic Acid Modified o-Carborane as a Novel BNCT Drug for Melanoma
Takeshi NAGASAKI, Riku KAWASAKI, S Yoshinori SAKURAI, Hiroki TANAKA, Shin-ichiro
MASUNAGA, Koji ONO and Mitsunori KIRIHATA
The 2nd International Symposium on Fusion Materials, Tokyoto, Japan, November 2-4 (2014); Preprints−95−

Melanoma-Targeting Boron Delivery System Using Kojic Acid-Carborane Conjugate
Takeshi NAGASAKI, Riku KAWASAKI, Yoshihide HATTORI, Yoshinori SAKURAI, Hiroki TANAKA,
Shin-ichiro MASUNAGA, Koji ONO and Mitsunori KIRIHATA
2nd International Workshop on BNCT – Basic Science and Technology for BNCT -, Invited Lecture, Kyoto,
Japan, December 8-9 (2014); Preprints
Kojic Acid-Appended Carborane/Hydroxypropyl-β-Cyclodextrin Complex for Melanoma-Targeted
Boron Neutron Capture Therapy
Takeshi NAGASAKI, Riku KAWASAKI, Yoshihide HATTORI, Shin-ichiro MASUNAGA, Yoshinori
SAKURAI, Hiroki TANAKA, Koji ONO and Mitsunori KIRIHATA
8th Young Researcher BNCT Meeting, Pavia, Italy, September 13-17 (2015); Preprints
Development of Functional Food Materials Based on -1,3-Glucan: from Food to Medical Materials
Toshio SUZUKI, Takeshi NAGASAKI and Hideaki IDOGAKI
Design of Supermolecular Structures and Development (ed. A. Harada), CMC Books, Tokyo, Japan (2014)(in Japanese)
Boron-Containing Rare Earth Oxides Nano-Particles for Boron Neutron Capture Therapy
Takeshi NAGASAKI and Koji TOMITA
Chemical Industry, Vol. 65, pp. 512-517 (2014) (in Japanese).
Development of a Bispecific Antibody Tetramerized through Hetero-Associating Peptides
Tomohiro OSAKI, Shingo FUJISAWA, Masahiro KITAGUCHI, Masaya KITAMURA and Takeshi
NAKANISHI
FEBS J., Vol. 282, pp. 4389-4401 (2015)
The specific assembly of self-associating peptides can be useful in building a functional antibody complex
from small antibody fragments. We have focused on the exceedingly specific heterotetrameric assembly of
Lin-2 and Lin-7 (L27) domains, which work as protein–protein interaction modules in many scaffold
proteins. Here, we describe a novel method for constructing a highly functional antibody based on thehetero-association of L27 domains. In this study, we used a bacterial expression system to produce abispecific antibody that was heterotetramerized through L27 domains and that targeted both epidermal
growth factor receptor (EGFR) and Fcγ receptor III (FcγRIII or CD16). Gel electrophoresis, mass
spectrometry and gel filtration analyses revealed that the constructed recombinant antibody was adisulfide-linked heterotetramer. The tetramerized antibody bound to EGFR and CD16 simultaneously,according to results from flow cytometry and surface plasmon resonance spectroscopy, respectively.
Furthermore, we demonstrated that the bispecific antibody showed cytotoxic activity against
EGFR-expressing tumor cells by using CD16-positive lymphocytes as effectors, and its cytotoxicity wascomparable to that of a commercial therapeutic antibody. Taken together, the results show that our method
has high potential for the cost-efficient production of highly active therapeutic antibodies.
Preparation of Keratin and Chemically Modified Keratin Hydrogels and Their Evaluation as a Cell
Substrate with Drug Releasing Ability
Ryo NAKATA, Yu OSUMI, Shoko MIYAGAWA, Akira TACHIBANA and Toshizumi TANABE
J. Biosci. Bioeng., Vol. 120, pp. 111-116 (2015)
Keratin (K) was extracted as a reduced form from wool, which was then subjected to acetoamidation,
carboxymethylation or aminoethylation at abundant free cysteine residues to give acetoamidated keratin(AAK), carboxymethylated keratin (CMK) and aminoethylated keratin (AEK). Hydrogels were preparedfrom intact and three chemically modified keratins simply by concentrating their aqueous solution andsubsequent cooling. The lowest concentration to form a hydrogel without fluidity was 110 mg/ml for AAK,
120 mg/ml for AEK, 130 mg/ml for K and 180 mg/ml for CMK. Comparing with a hydrogel just prepared(swelling ratio: 600-700), each hydrogel slightly shrank in an acidic solution. While AAK hydrogel little
swelled in neutral and basic solutions, other hydrogels became swelled and CMK hydrogel reached todissolution. Hydrogels of K, AAK and AEK were found to support cell proliferation, although cell
elongation on AAK and AEK hydrogel was a little suppressed. On the other hand, CMK hydrogel did not−96−seem to be suitable for a cell substrate because of its high swelling in culture medium. Evaluation of thehydrogels as a drug carrier showed that K and AAK hydrogels were good sustained drug release carriers,
which showed the drug release for more than three days, while the release from AEK and CMK hydrogels
completed within one day. Thus, keratin and chemically modified keratin hydrogels, especially K and AAKhydrogels, were promising biomaterials as a cell substrate and a sustained drug release carrier.
Characterization of a Thermostable Glucose Dehydrogenase with Strict Substrate Specificity from a
Hyperthermophilic Archaeon Thermoproteus sp. GDH-1
Hiroshi AIBA, Yoshiaki NISHIYA, Masayuki AZUMA, Yuusuke YOKOOJI, Haruyuki ATOMI andTadayuki IMANAKA
Biosci. Biotechnol. Biochem., Vol. 79, pp. 1094-1102 (2015)
A hyperthermophilic archaeon was isolated from a terrestrial hot spring on Kodakara Island, Japan anddesignated as Thermoproteus sp. glucose dehydrogenase (GDH-1). Cell extracts from cells grown in medium
supplemented with glucose exhibited NAD(P)-dependent glucose dehydrogenase activity. The enzyme(TgGDH) was purified and found to display a strict preference for D-glucose. The gene was cloned andexpressed in Escherichia coli, resulting in the production of a soluble and active protein. Recombinant
TgGDH displayed extremely high thermostability and an optimal temperature higher than 85 °C, in addition
to its strict specificity for D-glucose. Despite its thermophilic nature, TgGDH still exhibited activity at 25 °C.
We confirmed that the enzyme could be applied for glucose measurements at ambient temperatures,
suggesting a potential of the enzyme for use in measurements in blood samples.
Development of Catalyst Suitable for Microbial Fuel Cell which Deprives Cells of Electrons
Masayuki AZUMADivision of Biochemical Engineering, The Society of Chemical Engineering. Newsletter. No.39, p11-14,(2015) (in Japanese)
Phosphorylation of Myosin II Regulatory Light Chain by ZIP Kinase is Responsible for Cleavage
Furrow Ingression During Cell Division in Mammalian Cultured Cells
Kosuke HOSOBA, Satoshi KOMATSU, Mitsuo IKEBE, Manato KOTANI, Xiao WENQIN, Taro
TACHIBANA, Hiroshi HOSOYA and Kozue HAMAO
Biochem. Biophys. Res. Commun., Vol. 459, pp. 686-691 (2015)
Zipper-interacting protein kinase (ZIPK) is known to regulate several functions such as apoptosis, smoothmuscle contraction, and cell migration. While exogenously expressed GFP-ZIPK localizes to the cleavage
furrow, role of ZIPK in cytokinesis is obscure. Here, we show that ZIPK is a major MRLC kinase duringmitosis. Moreover, ZIPK siRNA-mediated knockdown causes delay of cytokinesis. The delay in cytokinesis
of ZIPK-knockdown cells was rescued by the exogenous diphosphorylation-mimicking MRLC mutant.
Taken together, these findings suggest that ZIPK plays a role in the progression and completion ofcytokinesis through MRLC phosphorylation.
A Novel Marker for Undifferentiated Human Embryonic Stem Cells
Kiyoshi HIGASHI, Masaki YAGI, Tatsuhiko ARAKAWA, Kouji ASANO, Kumiko KOBAYASHI, Taro
TACHIBANA and Koichi SAITO
Monoclon. Antib. Immunodiagn. Immunother., Vol. 34, pp. 7-11 (2015)
Human embryonic stem cells (hESCs) are pluripotent stem cells from early embryos, and their self-renewal
capacity depends on the sustained expression of hESC-specific molecules and the suppressed expression ofdifferentiation-associated genes. To discover novel molecules expressed on hESCs, we generated a panel ofmonoclonal antibodies against undifferentiated hESCs. The antigen recognized by Mab2 is expressed on thecell surface of undifferentiated hESCs; three diffused bands with molecular mass between 30 and 60 kDa in
the lysates of hESCs were diminished during hESC differentiation into neural cells. The expression of Mab2
antigen was also observed on the plasma membrane of lung cancer cells, and Mab2 detected 55, 50, and35 kDa protein bands in the cell lysates. Immunoprecipitation followed by proteomics analyses identified
CD147/basigin as a Mab2 antigen. Finally, the positive expression of CD147/basigin protein
in undifferentiated hESCs was confirmed. These results suggested that CD147/basigin could be
another undifferentiated hESC marker.

−97−

DBZ Regulates Cortical Cell Positioning and Neurite Development by Sustaining the AnterogradeTransport of Lis1 and DISC1 through Control of Ndel1 Dual-Phosphorylation
Masayuki OKAMOTO, Tokuichi IGUCHI, Tsuyoshi HATTORI, Shinsuke MATSUZAKI, Yoshihisa
KOYAMA, Manabu TANIGUCHI, Munekazu KOMADA, Min-Jue XIE, Hideshi YAGI, Shoko SHIMIZU,
Yoshiyuki KONISHI, Minoru OMI, Tomohiko YOSHIMI, Taro TACHIBANA, Shigeharu FUJIEDA, Taiichi
KATAYAMA, Akira ITO, Shinji HIROTSUNE, Masaya TOHYAMA and Makoto SATO
J. Neurosci., Vol. 35, pp. 2942-2958 (2015)
Cell positioning and neuronal network formation are crucial for proper brain function.
Disrupted-in-Schizophrenia 1 (DISC1) is anterogradely transported to the neurite tips, together with Lis1,
and functions in neurite extension via suppression of GSK3β activity. Then, transported Lis1 is retrogradelytransported and functions in cell migration. Here, we show that DISC1-binding zinc finger protein (DBZ),
togetherwith DISC1, regulatesmouse cortical cell positioning and neurite development invivo.
DBZ hindered Ndel1 phosphorylation at threonine 219 and serine 251. DBZ depletion or expression of adouble-phosphorylated mimetic form of Ndel1 impaired the transport of Lis1 and DISC1 to the neurite tips
and hampered microtubule elongation. Moreover, application of DISC1 or a GSK3β inhibitor rescued the
impairments caused by DBZ insufficiency or double-phosphorylated Ndel1 expression. We concluded
that DBZ controls cell positioning and neurite development by interfering with Ndel1 from disproportionate
phosphorylation, which is critical for appropriate anterograde transport of the DISC1-complex.
Incorporation of Histone H3.1 Suppresses the Lineage Potential of Skeletal Muscle
Akihito HARADA, Kazumitsu MAEHARA, Yuko SATO, Daijiro KONNO, Taro TACHIBANA, Hiroshi
KIMURA and Yasuyuki OHKAWA
Nucleic Acids Res., Vol. 43, pp. 775-786 (2015)
Lineage potential is triggered by lineage-specific transcription factors in association with changes in thechromatin structure. Histone H3.3 variant is thought to play an important role in the regulationof lineage-specific genes. To elucidate the function of H3.3 in myogenic differentiation, we forced theexpression of GFP-H3.1 to alter the balance between H3.1 and H3.3 in mouse C2C12 cells that could be
differentiated into myotubes. GFP-H3.1replaced H3.3 in the regulatory regions of skeletal muscle (SKM)
genes and induced a decrease of H3K4 trimethylation (H3K4me3) and increase of H3K27 trimethylation(H3K27me3).
Similarresults
wereobtainedby H3.3
knockdown.
In
contrast,
MyoD-dependent H3.3 incorporation into SKM genes in fibroblasts induced an increase of H3K4me3 andH3K27me3. In mouse embryos, a bivalent modification of H3K4me3 and H3K27me3 was formedon H3.3-incorporated SKM genes before embryonic skeletal muscle differentiation. These results suggestthat lineage potential is established through a selective incorporation of specific H3 variants that governs thebalance of histone modifications.
KRAS Mutation Confers Resistance to Antibody-Dependent Cellular Cytotoxicity of Cetuximab
against Human Colorectal Cancer Cells
Yusuke NAKADATE, Yasuo KODERA, Yuka KITAMURA, Senji SHIRASAWA, Taro TACHIBANA,
Tomohide TAMURA and Fumiaki KOIZUMIInt. J. Cancer, Vol. 134, pp. 2146-2155 (2014)
Cetuximab is a chimeric IgG1 monoclonal antibody (mAb) that targets the extracellular domain of epidermal
growth factor receptor (EGFR). Oncogenic KRAS mutations in tumors have been shown to be a negative
predictor of the response of colorectal cancer (CRC) to cetuximabtreatment. Cetuximab exerts its therapeutic
effects through several mechanisms including antibody-dependent cellular cytotoxicity (ADCC). However,
the influence of KRAS mutations on cetuximab-mediated ADCC is not fully understood. Here, weinvestigated cetuximab-mediated ADCC in two pairs of isogenic CRC cells with or without
a KRAS mutation. Peripheral blood mononuclear cells (PBMCs) from healthy volunteers and NK92, anatural killer (NK) cell line that exogenously expresses FcγRIIIa (CD16a), were used as effector cells. In an
ADCC assay, perforin-dependent target cell lysis was not affected by the KRAS mutation status. On theother hand, perforin-independent ADCC was observed only in CRC cells with wild-type KRAS, but notin cells with mutant KRAS. Neutralizing experiments revealed that the Fas-Fas ligand (FasL) interaction was
responsible for the induction of apoptosis and perforin-independent ADCC. Furthermore, the presence of−98−

effector cells clearly enhanced the growth-inhibitory effect of cetuximab only in CRC cells withwild-type KRAS, but not in those with mutant KRAS. These findings suggest that ADCC is an importantmode of action of cetuximab and that KRAS mutation impairs the therapeutic effect exerted
by cetuximab-mediated ADCC.
Retraction
The following article information appeared in Page 104 of Vol. 55 of this memoirs is retracted.
Amazing Catalytic Activity of Epi-Quinine-Derived 3,5-Bis(trifluoromethyl)-benzamide in Asymmetric
Nitro-Michael Reaction of Furanones
Tohru SEKIKAWA, Takayuki KITAGUCHI, Hayato KITAURA, Tatsuya MINAMI, and Yasuo HATANAKA
J. Am. Chem. Soc., accepted−99−Urban Engineering
Architecture and Building Engineering
Load-displacement Behavior of Deployment of DCMS Basic Unit
Junichi KATO and Yoshiya TANIGUCHI
Proceedings of the International Association for Shell and Spatial Structures (IASS) Symposium 2015„Future
Visions” 17-20 August, Amsterdam, The Netherlands (2015)
DCMS (Deployable Closed-Membrane Structure) is a deployable structure consisting of membranes and arod frame. This paper reports load-displacement behavior of a basic unit of DCMS on pressing and stretching
test in 2 directions of the deployment of the unit. Pressing and stretching test are performed in the directionof axial deployment and pressing test is performed in the direction of nonaxial deployment. Test models areconstructed of aluminum pipes, elastic cords, banding bands and 3 kinds of fabric membrane. At the test in
the direction of axial deployment, stretching test shows that the self-equilibrium system of the unit generates
restoring force against stretched deformation. Pressing test shows that snap through action may happen in therange of folding. At the test in the direction of non-axial deployment, pressing test shows the apparent
rigidity of the unit is softening.
Stochastic Optimization Method for Tuned Mass Damper Systems of Spatial Structures Based on
Order Statistics
Makoto YAMAKAWA (Tokyo Denki University) and Susumu YOSHINAKA
Journal of Structural Engineering, AIJ, Vol. 61B, pp. 531-536 (2015) (in Japanese)
In design of passive tuned mass damper (TMD) on the vibration control performance of the spatial structure,
we have to decide the both of a spatial arrangement and characteristics of TMDs. To find an optimal designof the systems is formulated as Mixed-Integer Programming (MLP) problem. It is difficult to obtain the exact
global optimum solution in general. However, such global solution might not be required. To find a good
local solution of the TMD systems, we propose a stochastic optimization method. We investigate thebehavior of the method through a numerical example.
Cross-Correlations among Daily Variations of Thermal Control Use, Thermal Sensation, Clothing
Insulation and Outdoor Temperature during Cooling Season in Japan
Noriko UMEMIYA and Tomohiro TANIGUCHI
Proceedings of the 8th Windsor Conference: Counting the Cost of Comfort in a Changing World, 7-4, pp.1-8(2014)
This survey was designed to investigate university student rooms to realize energy savings related to thermal
control use and the relations among thermal sensation, clothing insulation, and outdoor air temperature inpre-cooling and post-cooling seasons. Results revealed the following: 1) Phase shifts to the outdoor air
temperature mutually differ in pre-cooling and post-cooling seasons. 2) For neutral temperatures, although
the effect of pre-cooling makes the act of opening a window less likely, that is not true in the post-coolingseason. 3) For thermal sensations, the section rates of thermal control use vary in the pre-cooling season, but
do not vary in the post-cooling season. 4) The clothing amount varies more during the pre-cooling season
than during the post-cooling season.
Resident Evaluation of Soccer and Music Concert Noise Near a Soccer Stadium
Noriko UMEMIYA and Ken MURAMOTO
Proceedings of the 11th International Congress on Noise as a Public Health Problem (ICBEN) 2014, 6-20
(2014)
Large-scale popular music concerts attracting several tens of thousands of spectators have been held in Japan
often during the last decade. Nagai Athletic Stadium in Osaka, an official FIFA soccer stadium that canaccommodate 50 thousand spectators, has hosted more than 20 professional games annually since 1994 as
the home stadium of a Japanese soccer league team: Serezo Osaka. It has also hosted a few popular music
concerts since summer 2007. Surveys of soccer and concert noise were administered to residents near thestadium. Results show the following. 1) The degrees of noise annoyance and living disturbance are notsignificantly different for soccer and concert noise, although the noise level is reportedly higher for concerts.
2) Concert noise creates greater discomfort than soccer noise. 3) Noise annoyance is higher for residences−100−with high resistance to noise. 4) The visibility of the stadium is not strongly related to noise annoyance. 5)
Consideration of the park and the stadium when they selected the living area is not strongly related to thenoise annoyance. 6) The relation between living disturbance and noise annoyance is similar for soccer andconcert noise. 7) Soccer noise annoyance is lower for residents who like playing soccer. Concert noise
annoyance is lower for residents who pass the park and who take a walk in the park.
Relation Between Noise Evaluation and Daily Noise Exposure to Road Traffic Noise and Railway Noise
Naohiro KATADA, Noriko UMEMIYA and Tomohiro KOBAYASHI
Proceedings of the 11th International Congress on Noise as a Public Health Problem (ICBEN) 2014, 6-16
(2014)
This study examines the relation between daily noise exposure and noise sensitivity, effects of noise
exposure on the relation between sensitivity and noise evaluation and the differences attributable to noise
types. Some study showed that railway noise is more annoying than road traffic noise, but others
demonstrated that road traffic noise is more annoying than railway noise. This study examined road traffic
noise and railway noise as usual daily noises and investigates the relation between daily noise exposure tothese noises and evaluation of noise. Building construction noise at the actual spot of building construction
was selected as an object of evaluation. Conclusions are the following. 1) Respondents exposed to railway
noise evaluated construction noise as annoying. However, no relation was found between road traffic noise
and annoyance. 2) No relation was found between daily exposure and sensitivity to sound. 3) Amongrespondents not exposed to any noise in daily life, sensitive people answered that construction was annoying.
Change of Summer Thermal Control Use in Homes After Electricity Shortage Caused by 3.11 Disasterin Japan
Xiaoyong LIN and Noriko UMEMIYA
Proceedings of the 20th International Congress of Biometeorology, Cleveland, 5D.4, pp.1-12 (2014)
Electricity shortages prevailed in many areas of Japan after the earthquake that occurred in Tohoku on March
11, 2011. Almost all electricity generation by nuclear plants was halted in Japan after the disaster. Electricity
conservation was requested by government in the national interest. Excessive air-conditioning andillumination were discouraged. Circumstances were most severe in the Kansai area, where half of theelectricity generation capacity was done by nuclear power generation. In summer 2011, electric utilities in
Kansai asked businesses and households to reduce electricity consumption by up to 15 percent. This study
examined summer thermal control use in apartments in Osaka in Japan in 2004 and 2011. 1) Electricity
charges were lower in 2011 by 6.0% in May and by 23.7% in August. The cooling charge was lower by
43.8%. The mean setting temperature was 26.0°C in 2004 and 27.5°C in 2011. 2) Degrees of air
conditioner use and window opening and habits of ‘saving electricity’ did not differ. 3) Cooling charges
related to the degree of window opening stronger when asleep than when awake. Habits of ‘saving
electricity’ showed only slight effects on electric charges and cooling charges in 2011. 4) Relations
between temperature settings and the degree of thermal control use were stronger in 2004 than in 2011.
Temperature settings did not differ by living environment evaluation or habits of saving electricity either in2004 or in 2011.

−101−

Urban Design and Engineering
Measurements of Driving Energy in SPT and Various Dynamic Cone Penetration Tests
Tatsunori MATSUMOTO (Kanazawa University), Le Ta PHAN (Ho Chi Minh City University), Akihiko
OSHIMA and Shinya SHIMONO (Kanazawa University)
Soils and Foundations, Vol. 55, pp. 201–212 (2015)
Driving energy was measured in a standard penetration test (SPT) and 12 types of dynamic cone penetration
tests (DCPTs) having different configurations for the hammer, driving rod, anvil and cone tip. The driving
energy transferred from the free falling hammer to the driving rod was estimated from the measurements ofstrain and acceleration below the anvil. Basically, the driving energy was estimated for 21 successive blowsin order to obtain the mean value, the standard deviation (σ) and the coefficient of variance (COV) in the
SPT and DCPTs. The dynamic cone resistance, qdyn, was estimated from the driving energy, thecorresponding set per blow, and masses of the hammer and the total rods. Thus, the estimated dynamic cone
resistance was compared with the static cone resistance, qt, from a cone penetration test (CPT). The main
objective of this report is to provide information on the driving efficiency in the SPT and each DCPT. The
mean values for ef in the tests ranged from 52% to 76%. The values of COV for ef ranged from 0.024 to
0.265. Even though the test results are limited, the dynamic cone resistance, qt, estimated from the dynamic
measurements were relatively good measures of the cone resistance from the CPT, showing the importanceof the dynamic measurement in the SPT and DCPTs. In addition, possible factors influencing the driving
efficiency, such as the hammer mass, the configuration of the driving rod (solid or hollow), the ratio of thediameter of the anvil and the diameter of the hammer, and the existence of a cushion or cushions between theanvil and the hammer, are discussed on the basis of the limited test results.
Reconsideration on Expression of Consolidation Characteristics of Clay by Logarithm Volume Ratio f－An Example of Dredged Clay－
Hirohisa OKADA (Kobe City) and Akihiko OSHIMA
J. Geotechnical Engineering, Vol. 10, pp. 187-199 (2015) (in Japanese)
Consolidation characteristics of clay, which are compressibility, permeability and consolidation velocity etc.,
are conventionally represented by relationships between the “arithmetic scaled” volume ratio f or void ratio eand the logarithmic scaled effective stress p, coefficient of permeability k and coefficient of consolidation cv
etc. However, some previous works have suggested that a relation of volume ratio f and effective stress p indouble logarithmic scale (logf-logp) is able to express compressibility of clay more reasonably than the one
in single logarithmic scale (f-logp). At the exordium of this paper, the rationale of representation of
consolidation characteristics of clay including k and cv by “logarithmic f” than “arithmetic f” was derived
from a revisional study on them. Next, experimental results of a series of centrifuge consolidation test for thevery soft clay (dredged clay) were examined. Then their results were numerically simulated for two cases ofusing “logarithmic f” or “arithmetic f”. As a consequence, consolidation curves experimentally obtained werecorrectly represented by the numerical simulation with “logarithmic f”. Moreover, it was found that morestable and faster calculation is enabled by applying “logarithmic f” instead of “arithmetic f” to the expansionof the consolidation equation.
Development of Representative Soil Profile Model of Quaternary Alluvium in Osaka Region and Its
Application to Liquefaction-Hazard Assessment
Akihiko OSHIMA, Suguru YAMADA, Teruyuki Hamada (Geo-Research Institute) and Mari KASUGAI(Geo-Research Institute)
The XIX INQUA (International Union for Quaternary Research) Congress, Nagoya, Japan (2015)
Subsurface ground in Osaka region is coated with loosely deposited alluvial sandy soil, a result of theformation of river delta which had begun since approximately 6,000 years ago at when Holocene glacial
retreat was peaking. Since the alluvial sandy layer has shallow ground water table, higher risk of liquefaction
occurrence during expected earthquake events has been pointed out. The Kansai Geo-informatics databasehas summarized and published the planar distributions of geotechnical properties, which are the thickness ofthe strata, the SPT-N value and the grain size characteristics, as mean value of each stratum. However, thedatabase contains insufficient number of data of the grain size characteristics in comparison with the SPT-N
data. Hence, it can be considered that the details of planar distributions and depth distributions or theregional characteristics of the alluvial sandy strata have not yet been necessarily comprehended.
In the present study, the regionality of grain size characteristics of alluvial sandy strata in Osaka region was
examined, as shown below. First, digital models of alluvial sandy strata were developed using “Supporting−102−system for building representative soil profile model”, in which representative soil classification and mean
SPT-N value at each 1m depth were given to each 250m × 250m mesh. Second, the value of fines content ineach 1m depth for each mesh were obtained from a correlation between SPT-N and fines content.
Additionally, based on the developed model, planar distributions of liquefaction risk were assessed for 2
cases in which the different groundwater level, current or lowered, were considered. Finally, the effect ofliquefaction countermeasure with the groundwater drawdown method was examined by comparison ofassessment results.
Comparison of Calculation on Self-Weight Consolidation of Dredged Clay Using Consolidation
Properties Expressed by “Logarithmic Volume Ratio” and “Arithmetic Volume Ratio”
Hirohisa Okada (Kobe City), Akihiko OSHIMA and Suguru YAMADA
Proc. of the 6th Japan-China Geotechnical Symposium, Sapporo Aug. 30- Sep. 1 (2015)
This paper describes the effect of the initial volume ratio f0 (or the initial water content w0) on the rate ofself-weight consolidation of dredged clay as well as the effect of the expressive form of the consolidation
characteristics, by examinations on results of the consolidation calculation by means of the finite deferential
method. The consolidation characteristics such as the compression curve were considered to express either
the arithmetic f or the logarithmic f in calculations performed with different f0 (or w0) conditions. It was
found as conclusions that the faster rate of self-weight consolidation was observed in cases of the arithmetic f
was considered, and the rate of consolidation became faster with an increase of f0. It is also found that thestable calculation can be performed if consolidation characteristics were expressed in log f form even thougha large interval of time difference was configured. In contrast, the short interval of time difference wasneeded to obtain stable results from calculations with the arithmetic f expressive form.
Inhibition of avoidance and jumping behavior in ayu Plecoglossus altivelis altivelis by free ammonia
Hiromitsu ONCHI and Susumu YAMOCHI
Journal of Japan Society for Impact Assessment, Vol.13, pp.79-85 (2015) (in Japanese)
Behavioral experiments were conducted from February to March 2011 to clarify the effect of free ammonia(range 0.055-0.33mg/L) to the activity of ayu Plecoglossus altivelis altivelis. Test of avoidance behavior
revealed that ayu tend to remain in the same place regardless of the concentration of free ammonia, and any
avoidance behavior was not clearly confirmed for free ammonia at the concentration range used in thisexperiment. However, when free ammonia concentrations exceeded, the area of distribution of the school of
ayu became significantly wider, and abnormal movement was confirmed. In the jumping experiment, thejumping rate with free ammonia concentration had a significant negative relationship with each other, andapproximately 70% of ayu were not able to jump when the free ammonia concentration was 0.33 mg/L.
A Field Investigation on CO2 Budget at a Salt Marsh Located at Coastal Urban Area
Toru ENDO, Yusuke NAKANO, Tenma ITAYA, Noriaki IKADA and Susumu YAMOCHI
Journal of Japan Society of Civil Engineers, Ser. B2 (Coastal Engineering), Vol. 70, pp. I_1196-I_1200(2014) (in Japanese)
It is thought that a salt marsh located at coastal urban area absorbs and emits large amounts of carbon dioxide(CO2). In this study, a field investigation on CO2 budget was conducted at Osaka-Nanko bird sanctuary, andCO2 fluxes were measured at tidal flat, sea surface and reed field by using chamber methods in order toestimate CO2 budgets of the salt marsh. The results of this study were as follows: (1) CO2 fluxes of tidal flatand reed field were one order larger than that of sea surface. (2) It was estimated that CO2 flux emitted fromtidal flat was 3.26 g/m2/day and CO2 flux absorbed by reed grass field was 1.53 g/m2/day in October 2013.
(3) It was suggested from the result of seasonal change of fluxes that the absorbed amount of CO2 becomeslarger on summer than on autumn.
An Analysis on Influence Factors to Use Frequency and WTP of Shopping Support Services for People
in Food Desert
Noboru ISE and Yasuo HINO
Osaka City University, Memoirs of the Faculty of Engineering, Vol. 55, pp. 19-26 (2014)
Recently, the food desert problem has been becoming serious problem in mainly rural areas of Japan,
because it must be improved by local responsibility according to local needs. Although, some applicableestimation method of the number of people in food desert (PFD) were developed by many studies, theestimations of the demand for and profit from each shopping support service will be also required. Therefore,
this paper mainly aims to gain the fundamental knowledge not only to develop the estimation model of the−103−demand for each shopping support service for PFD but also to evaluate the profit of their services at local
level, by using the factor analysis including individual attributes and area characteristics.
As a result, some important findings, concerned with influence factors to use frequency and WTP of
shopping support services, came out of this study. These results must be useful information to introduce thesuitable support services for PFD in consideration of each local need.
Approach to Improve Driving Condition on Desert highway from Viewpoint of Road Safety
Zulpikar KERAM and Yasuo HINO
Osaka City University, Memoirs of the Faculty of Engineering, Vol. 55, pp. 57-62 (2014)
Recently, the environmental problems caused by road construction and the road safety problems caused bydesert climate have been getting more and more obvious. Especially, the road safety must be the mostimportant issue against the desert weather. In this paper, the approach to improve the driving conditions ondesert roads should be proposed from viewpoint of road safety, based on reviewing major results of a seriesof studies. As a result, an appropriate idea to prevent traffic accidents caused by desert weather fromviewpoint of developing road facilities, in consideration of results of a series of studies.
Evaluation of Some Trial Bus Services to Support Elderly Persons toward the Active Town Life
Yasuo HINO，Kazuo MUKAI，Kazuya MIZUKAMI and Junichi MORITA
Japan Society of Traffic Engineers, Papers on Traffic Engineering, Vol. 1, pp. B18-B25 (2015) (in Japanese)
As population has been decreasing with both aging and declining birthrate, the activity of town with bothresidents and visitors must be required more and more. In order to realize the activity, it should be essential
to provide the opportunity of going out with accompanying person based on the improvement of theirmobility and accessibility in daily life. Therefore, three new trials of bus services, such as, “free charge foraccompanied person on Sunday”, “discount fare of regular route bus to adjust the fare of small bus of sameroute” and “getting on and off at the non-designated bus stop in the limited areas”, were introduced in
Kawachi-nagano city of Osaka prefecture, Japan. In this study, the user’s situation and evaluation for these
services were analyzed by using the site survey and questionnaire survey. As a result, some important
findings to evaluate the utility of these services and investigate the future approaches to realize the active
town planning.
A Study on “Community Bus” System Focusing on Operation Transition and Regional Characteristics
Yusuke KURASHIMA, Megumi KATAYAMA, and Takashi UCHIDA
Japan Society of Traffic Engineers, Papers on Traffic Engineering, No. 34，pp. 445-450 (2014) (in Japanese)
Study on the Effect that Recognition and Application of Use Promotion Measure Gives to Will to
Support Community Bus
Yusuke KURASHIMA and Takashi UCHIDA
Japan Society of Civil Engineers, Proceedings of Infrastructure Planning, No.50, pp. 3 (CD-ROM) (2014)(in Japanese)
Posterior Evaluation after the Development for the Nature-friendly Environment and the Water
Amenity of the Medium and Small Size River in the Built-up Area -- an approach with a questionnaire
to inhabitants -Yasumasa FUKUSHIMA and Takashi UCHIDA
Japan Society of Civil Engineers, Proceedings of Infrastructure Planning, No. 50, pp. 9 (CD-ROM) (2014)(in Japanese)
In recent years the development of the urban river has been focusing on efforts for the environment and thewater amenity besides the flood control and the water utilization. In the waterfront development various
factors such as the river itself, the development conditions the environment in every region complicatedly
connect each other, and moreover the stakeholders/agents such as local governments, inhabitants, planners,
and bodies concerned are mutually involved, in some cases however, the residents along the river have failed
to value and then water amenity have made little progress.
This paper takes a case of the waterfront development of the small size river in an emerging built-up area.
Going through several years after the project implementation, we take hold of the actual condition and theevaluation by means of questionnaire survey to the inhabitants. An analysis focusing on their involvementwith the waterfront development is conducted. This study gives basic data for the consideration on
development methods in order to promote the utilization with high evaluations from the inhabitants.

−104−Formation of Waterside Spaces with Groins
Yasumasa FUKUSHIMA and Takashi UCHIDA
Osaka City University, Memoirs of the Faculty of Engineering, Vol. 55, pp. 27-33 (2014)
River management in recent years involves measures for waterside management emphasizing theenvironment and utilization as well as river improvement and irrigation. This study addresses the formationof waterside spaces with groins as a part of waterside management emphasizing the environment andutilization, using typical groin management cases in which planning we have been engaged. This reportpresents our knowledge obtained through processes from planning, business implementation, and subsequentdegradation by aging.
Midosuji Cycle Picnic Event for Raising the Awareness of Positive Images of cycling in Osaka
Itaru FUJIE and Nagahiro YOSHIDA
Velo-city 2015 in Nantes, Speed Dating Session (2015)
While bike commuting rate of Osaka city, the third largest city in Japan, increased by 33.7 percent in 2010,
the prevailing image of cycling is still negative due to the long history of countermeasures for illegal parking
issues or undesirable behaviors. Under these situations, some interested people planned a unique cycling
demonstration event called as Midosuji Cycle Picnic for raising the awareness of positive images of cycling.
The purpose of the event is 1) to demonstrate the cultural diversity of cycling for publics, 2) to get relianceabout right-of-way from car drivers, 3) to increase the number of desirable cyclists who could use handsignals or eye contact with drivers, and 4) to make some recommendations for improving the condition of
cycling infrastructure through demonstration.
The event is held at Midosuji, where is the main street in Osaka. It has been organized at theseventh time in September 2014 since 2011. Like a critical mass event in other countries, some picnic tours
with different destinations are developed to attract people who may not have enough interest for the purposes.
More than 300 cyclists, including visually impaired people with different types of bike like recumbent ortandem bicycle were participated. Participants were divided into small group, and cycled together on the
roadway led by a group leader who could deliver proper attitudes to the member of the group. The organizerof this event is the Party of Making Cycling Town, who promotes bicycle usage in conjunction with urban
planning. They also distribute education program, leadership training course, as well as communicationmaterials for surroundings against negative images for cyclists.
The Effects of Shared Lane Pavement Markings: A New Trial of Osaka City
Nagahiro YOSHIDA, Teruyoshi TAKAHASHI, Masayuki KINUTA, and Masaaki MATSUNO
The third Asia-Pacific Cycle Congress, Spin Cycle Session (2015)
Recently safer cycling facility especially for urban area is required in the transport planning and trafficengineering to maximize environmental and health benefit in the world. In Japan, shared-use paths, which
are commonly designed for two-way travel on both sides of road, has introduced into one of the Government
Order on Road Design Standards to decrease bicycle-related accidents since 70s. However, recent research
evidences showed riding on pavement included a negative impact on their risk as well as pedestrian's safety.
In addition, the Japanese government has published the technical guideline for bicycle transport inNovember 2012. The types of bicycle lane with regulation and shared lane pavement markings on roadway
have been indicated for the first time as a part of technical guideline. In response to this, Osaka city, where is
the third largest city in Japan and bicycle commuting share has increased by 33.7 percent in 2010, decided to
introduce a bicycle lane and shared lane pavement markings on the roadway of the Honmachi-dori within thecentral business district in September 2013. The objective of the introduction on new bicycle path on
roadways is to protect pedestrian safety, which means the extra path, were expected to encourage faster
cyclists to change their path choice behavior. In order to get the effects of road markings, the before and after
observations for traffic conditions as well as some questionnaire surveys for traffic participants including
pedestrians, cyclists, and car drivers were conducted. After showing the basic comparison, the effect ofdifferent type of pavement markings on path choice behavior for cyclists using a discrete choice model werealso indicated−105−Research on Bicyclist Safety Analysis on Sight Distance and Driving Behavior at Unsignalized
Intersections along Highway
Yoshito TAKENAKA and Nagahiro YOSHIDA
Japan Society of Civil Engineers, Journal of JSCE, Division D3, Vol. 70, pp. I_1167-I_1172 (2014) (inJapanese)
Recently, using a bicycle is recommended under the growing concerns about health and environment, while
the bicycle involved collision rate tends to increase. Some remarkable researches pointed out that a sightdistance or driver’s behaviors at intersections have affected an significant influence on bicycle safety, but therelationship between these factors are not clearly described together. Therefore, the purpose of this study is
to investigate the possible factors of bicycle related accidents focused on the sight distance and driving
behavior at unsignalized intersections along highway.
Analysis of Road Traffic Conditions and Individual Knowledge and experiences on Cyclist Path
Choice Behavior
Takuya OKADA and Nagahiro YOSHIDA
Japan Society of Civil Engineers, Journal of JSCE, Division D3, Vol. 70, pp. I_655-I_661 (2014) (inJapanese)
Cycling on the sidewalks have brought some safety problems in Japan. Preceding research findings havesuggested that building bicycle lanes on roadways or providing information related with traffic law may
encourage cyclists to ride on the roadway. However, the effects of individual knowledge and experiences aswell as road traffic conditions on cyclist path choice behavior are not clearly captured. The purpose of thispaper, therefore, is to analyze these effects on path choice behavior. Multiple methods; a photomontage
experiment and on-site observations were employed to collect both stated preference data and revealed
preference data. As a result, some factors encouraging cycling on the roadways or discouraging cycling on
the sidewalks as well as future intervention effects are revealed.

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ISSN

MEMOIRS OF THE FACULTY OF ENGINEERING OSAKA CITY UNIVERSITY
VOL. 56.
2015

1511-0471 大阪市立大学 工学部
工学部英文紀要VOL.56（2015） 1-4

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MEMOIRSOF THEFACULTY OF ENGINEERINGOSAKA CITY UNIVERSITY

VOL. 56
DECEMBER 2015

PUBLISHED BY THE
GRADUATE SCHOOL OF ENGINEERINGOSAKA CITY UNIVERSITY

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