ISSNMEMOIRS OF THE FACULTY OF ENGINEERING OSAKA CITY UNIVERSITY
VOL. 59.
2018

1812-0584 大阪市立大学 工学部
1-4
工学部英文紀要VOL.59（2018）

0078－6659

MEMOIRSOF THEFACULTY OF ENGINEERINGOSAKA CITY UNIVERSITY

VOL. 59
DECEMBER 2018

PUBLISHED BY THE
GRADUATE SCHOOL OF ENGINEERINGOSAKA CITY UNIVERSITY

見本

スミ

This series of Memoirs is issued annually. Selected original works of the membersof the Faculty of Engineering are compiled in the first part of the volume.

Abstracts ofpapers presented elsewhere during the current year are compiled in the second part.

Listof conference presentations delivered during the same period is appended in the last part.
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
Akira TERAIHayato NAKATANIKai CAI
Eriko SATO
Tetsu TOKUONO
Nagahiro YOSHIDA

1812-0584 大阪市立大学 工学部2-3
工学部英文紀要VOL.59（2018）

スミMEMOIRS OF THE FACULTY OF ENGINEERINGOSAKA CITY UNIVERSITY
VOL. 59

DECEMBER 2018

CONTENTS
Regular Articles ·························································································· 1Applied Chemistry and Bioengineering
Applied Chemistry and Bioengineering
Elemental analysis of three kinds of teas by tabletop XRF analyzer
Jingyuan ZHU, Haruna TAKAHASHI and Kouichi TSUJI·································

1

Urban Engineering
Urban Design and Engineering
Micro Traffic Simulation to Examine Congestion-control Measures Using Pace Maker Lights
Takahiro IGAKI and Takashi UCHIDA·······················································

7

A Study on the effect of Motorcycle Traffic Safety Workshop using Travel Speed and Vehicle
Density in Phnom Penh, Cambodia
Toshiki KOYANAGI and Nagahiro YOSHIDA ······················· ······················

19

Latent Opportunities for the Use of Two-Rider Bicycles and Associated Challenges by Welfare
Service Providers
Takuya KONISHI and Nagahiro YOSHIDA ·················································

27

Abstracts of Papers Published in Other Journals ············································ 31
Mechanical and Physical Engineering
Mechanical Engineering ······································································· 33

Electronics and Informatics
Applied Physics and Electronics ······························································ 45
Electrical and Information Engineering ····················································· 52
Applied Chemistry and Bioengineering
Applied Chemistry and Bioengineering······················································ 55

Urban Engineering
Architecture and Building Engineering ······················································ 72
Urban Design and Engineering ······························································· 75

List of Presentations at International Conferences ·········································· 87
Mechanical and Physical Engineering
Mechanical Engineering ······································································· 89
Electronics and Informatics
Applied Physics and Electronics ······························································

90

Applied Chemistry and Bioengineering
Applied Chemistry and Bioengineering······················································

93·······························································

98

Urban Engineering
Urban Design and EngineeringISSN

MEMOIRSOF THEFACULTY OF ENGINEERINGOSAKA CITY UNIVERSITY――――――――
VOL. 59――――――――DECEMBER 2018

PUBLISHED BY THE
GRADUATE SCHOOL OF ENGINEERINGOSAKA CITY UNIVERSITY

0078－6659

Elemental analysis of three kinds of teas by tabletop XRF analyzer
Jingyuan ZHU*, Haruna TAKAHASHI** and Kouichi TSUJI***(Received October 31, 2018)
Synopsis
In this research, we investigated three kinds of tea samples by using tabletop XRF analyzer JSX-1000S (JEOL
Company, Japan). Each tea sample was tested in original state, powder state and tablet state with different mass
values. We could show the minimum mass for quantitative XRF analysis. By analyzing the X-ray spectrum recorded
for these samples, we found the possibility of XRF analysis as a method of tea quality control and detecting tea
producing area.
KEYWORDS: Tabletop XRF analyzer, EDXRF, Quantitative XRF analysis
1. Introduction
With the growth of the global economy, food trade is becoming more frequent than ever before. Consumers arewilling to pay a high price for organic and non-polluting foods. Especially in tea industry, the price of famous brandtea made from specific regions is much higher than that of the ordinary brand. Therefore, the certification of the tea
origin is commercially important. In addition, depending on elemental composition of tea, drinking it has risk ofside effect to human organism. Therefore, it is very necessary to qualitatively and quantitatively analyze theelemental composition of teas.
According to Salvador’s research1), Fe, Ni and Cu have been successfully characterized in tea samples using
energy-dispersive X-ray fluorescence (EDXRF) technique. This paper shows that EDXRF method is useful for
quality control to obtain ‘chemical fingerprints’ of tea products. Meanwhile, in Rajapaksha’s research2), X-ray
fluorescence spectrometry (XRF) technique effectively gave us the concentrations of 13 elements (Mg, P, S, Cl, K,
Ca, Mn, Fe, Cu, Zn, Br, Rb and Sr) in tea samples. This result helps to confirm the origin of 58 tea samples fromfour production districts in Sri Lanka.
These two research groups mentioned above inspired us to consider the possibility of use a tabletop XRF analyzer
to acquire element composition and concentration of tea products. This XRF analyzer provides quick, easy
elemental analysis that is non-destructive and available for different kinds of solid and liquid samples3). By the
analysis of the XRF intensity and the comparison with standard sample, we can obtain the concentrations of several
elements detected in tea samples, leading to certification of the origin of tea products.
2. Experimental
We measured three kinds of tea products-green tea (ITOEN Company, Japan), roasted tea (ITOEN Company, Japan)
and barley tea (Top Value Company, Japan). Every tea product was tested in original state, powder state and tablet
state. In each state, we tested samples mass values of 0.3 g, 0.5 g, 0.7 g and 0.9 g. Therefore, we prepared 36 piecesof tea samples for investigation. To prepare the powder samples, we smashed the tea and then sieved the powder tohave a diameter less than 0.46 mm particles. To prepare tablet samples, we put tea powder (same material as powder
samples) into a tableting machine and put it in the pressure pump for 5 minutes under a pressure of 10 MPa. Fig.1
shows the grinder for preparing powder samples and the tableting machine for preparing tablet samples.

*
**
***

Student, Master Course of Department of Applied Chemistry & Bioengineering
Engineer, JEOL Ltd.
Professor, Department of Applied Chemistry & Bioengineering－1－(a) M20 (IKA Company, Germany)(b) PT-20 (JASCO Corporation, Japan)

Fig.1 (a) Grinder for making powder state samples and (b) tableting machine for making tablet state samples.
We used a tabletop EDXRF instrument: JSX-1000S (JEOL Company, Japan) as an XRF analyzer. Fig.2 shows theappearance and internal structure of JSX-1000S. As an EDXRF instrument, an X-ray tube and an X-ray detector are
installed below a sample chamber. This EDXRF analyzer enables a quick and easy elemental analysis with an easy
software for operation. The functions for conventional qualitative and quantitative analysis are equipped. Including
solution-based applications, the desired analysis can be executed automatically according to pre-recorded recipes.
The new smart fundamental parameter (FP) method makes it possible to obtain high accurate quantitative results
without preparing a standard sample. This FP method includes automatic correction for thickness and residual
ingredient balance.

Fig.2 Tabletop EDXRF instrument, JSX-1000S (JEOL Company, Japan)
Samples were put into a holder (a white plastic hollow tube with transparency film covered under bottom, shownin Fig. 3(a)) and set in sample chamber shown in Fig. 3(b). By using an auto sample changer (Fig. 3 (b)), up to
twelve samples can be analyzed at one time. For EDXRF analysis, an X-ray tube (Rh target) was operated with avoltage of 30 kV, and a current of 0.030 mA. EDXRF measurement was performed for an acquisition time of 1000
second with a collimator size of 9.0 mm.

－2－

(a)

(b)

Fig.3 (a) Sample holder and (b) auto sample changer.

3. Results and Discussion
3.1. X-ray spectrum
Fig.4 shows the X-ray spectrum of three kinds of tea products tested in powder status with a mass of 0.5 g. Elementsof P, S, K, Ca, Mn, Fe, Cu, and Zn were detected. Same elements were also detected in other samples with different
status and mass. The peak originated from Rh was mainly observed, because it is the primary X-rays emitted fromthe X-ray tube. Although we set an acquisition time in 1000 seconds for each sample, a clear X-ray spectrum
appeared very quickly in less than 200 seconds.

Intensity/Counts

500000K

Green tea

400000

Roast tea

300000Rh Ca

200000100000
0

P
0

2

S

Fe
4

Barley tea

Mn

6

Cu Zn
8

Energy/keV

10

12

14

16

Fig.4 X-ray spectrum of three kinds of tea products (0.5g samples in powder status)
3.2. Green tea
Fig.5 shows the XRF intensities of K, Fe and Zn detected for green tea samples (original status). There is significant
increase of these three elements when sample mass increased from 0.3 g to 0.5 g. However, XRF intensities of P, S,
Ca, Mn and Cu did not show so much change by the increase of mass in original status. We considered that theminimum mass of green tea samples would be more than 0.5 g. As for powder and tablet status, the XRF intensities
of elements were almost the same for different mass samples. Therefore, the concentration of elements in green tea
would be evaluated for the mass more than 0.5 g by using calibration curve.

－3－

K

x105
50

x104
35
30
25
20
15
10
5
0

Intensity/Counts

40
30
20
10
0

0.3g

0.5g

Fe

0.3g

x103
70
60
50
40
30
20
10
0
0.5g

Zn

0.3g

0.5g

Fig.5 XRF intensities of K, Fe and Zn detected in green samples (original status)
3.3. Roasted tea
Fig.6 shows XRF intensities of elements detected for the roasted tea samples (powder status) in different mass
samples. Except Mn, XRF intensities for all other elements were almost the same for different mass samples.
Besides powder status samples, XRF intensities of original status and tablet status samples almost has no changewith the change of mass. All roasted tea samples were dry, and this may be the reason why the same XRF intensities
were detected for different mass and status of samples. Because of no significant change in XRF intensities,
therefore, the concentration of elements in roasted tea would be evaluated by using calibration curve.
5,000,000
Intensity/Counts

0.3g

4,000,000

0.5g

0.7g

0.9g

3,000,000
2,000,000
1,000,000
0

P

S

K

Ca

Mn

Fe

Cu

Zn

Fig.6 XRF intensities of several elements detected in roasted tea samples (powder status)
3.4. Barley tea
Fig.7 shows XRF intensities of K and Ca element detected in 0.3 g barley tea samples. Concerning K and Ca
element, original status showed a highest XRF intensity. This may be because these two elements existed in theshell of barley tea seed and therefore could be easily detected in original status samples. This phenomenon does notshow up in 0.5 g, 0.7 g and 0.9 g samples. In three status of barley tea samples, as the mass increases, the XRF
intensities does not increase proportionally concerning the mass. Therefore, the quantitative XRF analysis would bepossible for elements in barley tea by using calibration curve.

－4－Intensity/Counts① Original status sample
3,000,000①② Powder status sample

2,500,000② ③

2,000,000
1,500,000① ② ③

1,000,000
500,000
0③ Tablet status sample

K

Ca

Fig.7 XRF intensities of K and Ca elements detected in 0.3 g barley tea samples.

4. Conclusions and future works
Using JSX-1000S XRF analyzer, it was possible to detect elements in tea products. We measured tea samples withdifferent sample conditions. It was found that the minimum sample mass depended on the element (energy of X-ray
fluorescence) analyzed. The qualitative analysis of tea products would be possible by applying a calibration curvewith standard tea sample. The EDXRF spectrometer can be applied not only for solid samples but also for liquidsamples4). Thus, a drinking tea solutions will be the next sample using a tabletop EDXRF spectrometer. After thetea leaves are put into boiling water, the liquid tea samples would be measured by the same XRF spectrometer at aroom temperature. Comparison of both solid and liquid samples will be helpful for safety and tea quality control.
5. Acknowledgement
This work was supported by JSPS KAKENHI (17H03080, 18H01755, 171000132).
6. References
1) M. Salvador, G. Lopes, V. Filho, O. Zucchi, X-ray Spectrometry, 31, 141 (2002).
2) D. Rajapaksha, V. Waduge, R. Alvarez, M. Kalpage, R. Rathnayake, A. Migliori, R. Frew, S. Abeysinghe, A.
Abrahim, T. Amarakoon, X-ray Spectrometry, 46, 220 (2017).
3) R.Van Grieken and A.A Markowiez, Handbook of X-ray Spectrometry, Marcel Dekker Inc., New York (2002).
4) K.Tsutsumimoto and K.Tsuji, BUNSEKI KAGAKU, 56, 499 (2007).

－5－

Micro Traffic Simulation to Examine Congestion-control Measures
Using Pace Maker Lights
Takahiro IGAKI  and Takashi UCHIDA (Received October 31, 2018)
Synopsis
One cause of congestion on highways is “sag”: a section where the road gradient changes gradually fromdownward to upward. Drivers unconsciously reduce speed without anticipating the uphill part of this section.
That speed reduction is imitated by other drivers, creating congestion. Some attempts to use pace maker lights
have been undertaken as measures against traffic congestion occurring at a sag. Some trial operations are being
conducted on various highways.
For this study, a micro traffic simulation using a car-following model with pace maker lights installed. Thena simulation was conducted of traffic conditions at the sag using time–space diagrams. Results confirmed thecharacteristics of the car-following model. Results demonstrated that different driving behaviors among drivers
affect congestion.
KEYWORDS: expressway, numerical experiments, sag, Time–space diagram, traffic capacity
1. Research Background and Objectives(1) Research backgroundA sag, a section at which the vertical gradient changes gradually from downward to upward, is a major causeof traffic congestion. As one example, the section of the Hanshin Expressway including the Hukae sag accounts
for the worst (down line) and second worst (up line) in rankings of traffic congestion among Japan urban
expressways 1).
The mechanism by which congestion at sag occurs is the following (Fig. 1).
1. A car approaches uphill of the sag. The driver decelerates without noticing the uphill section.
2. The driver of the following car notices slowing of the lead car and slows the vehicle by applying thebrakes.
3. Subsequently, the following car driver slows by applying the brakes. Eventually, a group of cars moving
at reduced speed is formed and congested. At the head of the congestion that passes the sag, the congestion
gradually gets resolved.
The Hanshin Expressway is carrying out measures using pace maker lights (PMLs) for traffic congestion that
occurs at sags (Fig. 2). The PMLs produce a pattern suggesting forward light flow by switching LEDs on andoff sequentially at the road side or at a tunnel wall. The apparatus uses driver consciousness of driving alongwith the flow. It is hoped that PMLs can restrain speed reduction and support prompt speed restoration.
Past studies have assessed PMLs on actual highways. They have also measured speed and traffic capacity 2),
with follow-up experiments using the simulator and the actual road to measure distances between vehicles.
They have confirmed the effects of PML for improving congestion 3). Nevertheless, these experiments havenot addressed individual driver characteristics and their effects on traffic flow.

Student, Master Course of Department of Urban Engineering
Professor, Department of Urban Engineering



－7－

(1)

(2)

(3)

Figure 1

Mechanism of congestion occurring at a sag.

350 mm

120 mmFigure 2

Pace maker lights (illustration).

(2) Research objectives
This study uses time–space diagrams to assess traffic flow and individuals’ driving characteristics on ahighway.

－8－

2. Micro Traffic Simulation(1) Examination car following model
To produce a traffic simulation incorporating PML effects, a car-following model for assessment from a
micro viewpoint particularly addressing each car’s behavior was examined as a basic model. The target
intervehicle distance of the driver is incorporated as a parameter in the Koshi model. The formula structure isreadily comprehensible. Therefore, the Koshi model 4) was adopted as the basic formula used for this study.
The Koshi model is shown as (1) below. The target intervehicle distance function �[�(� + �� )] makes it easy
to examine the intervehicle distance specifically. Another benefit is that the meanings of terms are easy tounderstand. However, an important shortcoming is that no desired speed parameter exists, although it isnecessary to express the PML speed.
�� (�) =���(� + �� ) � ��(� + �� ) � �[�(� + �� )]�
+� ��in��(� + �� )�
�(� + �� )�

(1)

In the equation above, the following variables are used.
�: Following car speed�� � �� : Reaction delay time (�� � �� )�: Longitudinal gradient difference�� �: Parameters
�: Intervehicle distance�[�(� + �� )]: Target intervehicle distance function of following car driver�� �� �: Constants

Therefore, the modified version of the Koshi model can be expressed as shown below in (2).
min[�� (�)� � ∗ ] � �� (�)(�� (�) � �� (�) � � ∗ )��� (� + �)=�+�� ��in�|�� (�) � �� (�)|�|�� (�) � �� (�)|���

(2)Therein, the following variables are used.
�� , �� : Leading car speed [m / s], Leading car position [m]�� , �� : Following car speed [m / s], Following car position [m]�: Speed difference parameter
�: Intervehicle distance parameter
�: Gradient parameter�� �: Distance attenuation parameter� ∗ : Desired intervehicle distance [m]� ∗ : Desired speed [m / s]
�: Reaction delay time [s]�: Longitudinal gradient difference [rad]The salient difference from the Koshi model is introduction of the desired speed � ∗ to the numerator of thefirst term. Originally, the desired speed is the speed that the driver desires when traveling alone, but in (2), thedesired speed is replaced with the setting speed of the PML light flow. This result is based on the assumptionthat all drivers are influenced by the PML light flow and that they drive at the same speed as the PML setting
speed. By combining the desired speed parameter � ∗ and the speed difference parameter � representing thesensitivity to the speed difference from the leading car, one can set the degree of influence of PML of eachdriver.
(2) Basic Characteristics of the following car model
To ascertain the influence of the speed difference parameter � and the intervehicle distance parameter � on
the following car, simulations were conducted by changing the values of � and � (Table 1). At this time, thelongitudinal gradient difference � = 0, the desired intervehicle distance � ∗ = 30 m. The desired speed � ∗ =－9－

60 km / h. The larger parameter � becomes, the more sensitive it is to the speed difference from the leading
car and the earlier it reaches the same speed as the leading car. The larger parameter � becomes, the moresensitive it becomes to the intervehicle distance. When the intervehicle distance is large, the following car tries
to catch up quickly and increases its speed. Results of simulations demonstrate that the larger value � is, thefaster the convergence of the expansion and contraction of the intervehicle distance becomes. The larger value� is, the smaller the wavelength of the expansion and contraction of the intervehicle distance becomes.
Moreover, the larger the gradient parameter � becomes, the stronger the influence of the longitudinal gradientis, and the slower acceleration becomes. Smaller distance attenuation parameters � and � suggest a greater
influence of the preceding vehicle with greater intervehicle distance, the desired speed, and the desiredintervehicle distance when trying to approach the distance.
Table 1 Time–space diagrams showing parameter � and � effects on the tracking situation:
longitudinal gradient difference � = 0, desired intervehicle distance � ∗ = 30 m, and desired speed� ∗ = 60 km / h.

－10－

3. Numerical Experiments(1) Summary
Experiments were conducted to reproduce the sag traffic conditions by characterizing the driver parameters.
Using results of the car following experiment for the Hanshin Expressway conducted on 20 subjects shown in
Tabira et al.3), parameters in the car following model formula are determined. The average and variance ofintervehicle distances for respective road segments and respective subjects in a following car were found fromexperiments conducted without PML, at 60 km / h, and at 80 km / h. Reading the driver characteristics fromthese data and setting parameters �, �, �, �, � ∗ , each driving behavior is characterized.
For example, the desired intervehicle distances � ∗ are 20 m, 30 m, and 40 m because the average intervehicle
distance of all drivers was about 11–44 m. For speed difference parameter � and intervehicle distanceparameter �, reference was made to the actually observed variances and variances in the simulation. Someextreme cases were also presumed.
Table 2 presents parameters: Nos. 1-1 to 2-3 show susceptibility to PML; Nos. 3 and 4 are set to theintervehicle distance; Nos. 5-1 to 6-3 are set to the gradient; Nos. 7 and 8 are set for the response delay time
(Table 2).
Table 2

Driver Parameters
Parameters
DesiredReactionintervehicle
delay time
distanceT [s]s* [m]

Driver No.

Characteristic

Characteristic
Intervehicle0Standard

Standard

10

0.5

0.5

0.1

30

Long

15

0.5

0.5

0.1

40

Standard

15

0.5

0.5

0.1

30

1-3

Short

15

0.5

0.5

0.1

20

2-1

Long

9

0.5

0.5

0.1

40

Standard

9

0.5

0.5

0.1

30

Short

9

0.5

0.5

0.1

20

1-1
1-2

2-2

Sensitivity to PML: HighSensitivity to PML: Low

2-3

Speed
Intervehicle
difference distanceab

Gradientc3

Sensitivity to leading car: HighStandard

10

0.6

0.5

0.1

30

4

Sensitivity to leading car: Low

Standard

10

0.25

0.5

0.1

30

Long

10

0.5

1

0.1

40

Standard

10

0.5

1

0.1

30

5-3

Short

10

0.5

1

0.1

20

6-1

Long

10

0.5

0.1

0.1

40

Standard

10

0.5

0.1

0.1

30

Short

10

0.5

0.1

0.1

20

5-1
5-2

6-2

Effect of gradient: Large

Effect of gradient: Small

6-3
7

Reaction delay time: Large

Standard

10

0.5

0.5

0.2

30

8

Reaction delay time: Small

Standard

10

0.5

0.5

0

30

－11－

(2) Method
The experiment was conducted for each driver to produce time–space diagrams. Using those time–space
diagrams, one can calculate the congestion amount (congestion duration) and traffic capacity (number of units
passing a certain point / unit time). For this study, they were calculated as follows, Figs. 3 and 4. Congestion
often refers to a condition in which the speed is 20–30 km / h or less. For simplicity, congestion is defined as
the condition of 0 km / h in this study. When several vehicles have a speed of 0 km / h, the time and section
appear as a trapezoid on the time–space diagram. The trapezoid area is calculated and is taken as the congestion
amount. The traffic capacity was obtained by dividing the number of follower cars (20 units) by time, which
took the leading vehicle (0th) to the 20th follower as the distance at which the 20th follower arrived at thesimulation end time.
a) Experiment 1
A case in which the same 20 drivers follow in 20 units was simulated. The drivers were classified into fourgroups by cluster analysis from results of the congestion amount and the traffic capacity. The classification isdone hierarchically. The standardized Euclidean distance is used for distance calculation between individuals.
The group average method is used to calculate distance between clusters.

Congestion in Figure 3＝Congestion length
A (21.9 s, 0.189 km)

B (24.6 s, 0.189 km)

C (41.5 s, 0.013 km)

D (71.3 s, 0.013 km)

×Congestion duration= trapezoid ABCD=1
� �(24.6 − 21.9) + (71.3 − 41.5)�
2

� (0.189 − 0.013)= 2.86 [km・s]

Figure 3

Calculation of congestion.

Traffic capacity in Figure 4

Lead car (139.3 s)E

20th car (180 s)
F==

Number of following cars
� 60
Length of Line EF20� 60
180 − 139.3= 29.48 [units/min]Figure 4

Calculation of the traffic capacity.

－12－b) Experiment 2
Cases were simulated in which 20 drivers belonging to the same group followed in 20 units. We calculated
the congestion amount and traffic capacity as in experiment 1. For example, if drivers belonging to the samegroup are Nos. 1, 2, and 3, the order of following up is 1, 2, 3, 1, ..., 2.
c) Experiment 3
Drivers belonging to different groups were mixed and simulated. For example, for driver Nos. 1, 2, and 3 inGroup A and Nos. 4, 5 in Group B, the order of following is 1, 2, 3, 4, 5, …, 1.
(3) Conditions
The conditions and assumptions of the numerical experiments we conducted are presented as shown below.
・All drivers drive at the PML setting speed.
・The PML set speed is 80 km / h (optimum speed).
・Distance attenuation parameters ݈ = ݉ = 1.
・Longitudinal gradient difference is 3.0%.
・Leading car speed is always 60 km / h.
・Simulation time is 180 s.
・Following cars are located every 50 m at the start time.
・Initial speed of the following cars is 60 km / h.
The optimal PML setting speed is expected to be greater than the actual driving speed by 10–20 km / h 5), sothat the PML speed was set to 80 km / h for the Hanshin Expressway, where the speed limit is 60 km / h.
(4) Resultsa) Experiment 1
Using the simulation results in the case in which 20 vehicles of the driver with the same characterizing
parameter follow the vehicles continuously, the congestion amount and the traffic capacity were calculated.
Then, the drivers were classified into four groups using cluster analysis (Tables 3, 4; Fig. 5). Fig. 6 showssome simulation results.
Table 3Congestion amount and traffic capacity in experiment 1.
Driver No.

Congestion[km・s]

Traffic capacity[unit/min]

0

2.86

29.48

1-1

0.18

24.24

1-2

0.00

32.35

1-3

0.00

48.58

2-1

4.20

14.89

2-2

3.50

25.92

2-3

0.91

48.58

3

3.45

27.97

4

0.00

31.33

5-1

5.57

19.20

5-2

2.89

29.13

5-3

0.66

47.06

6-1

5.59

18.49

6-2

2.78

31.91

6-3

0.57

49.79

7

2.91

28.24

8

2.83

30.38

－13－

Table 4

Characteristics of groups using experiment 1.

Group

Congestion

Traffic capacity

Drivers

A

Standard

Standard

0, 2-2, 3, 5-2, 6-2, 7, 8

B

Small

Large

1-3, 2-3, 5-3, 6-3

C

Small

Standard

1-1, 1-2, 4

D

Large

Small

2-1, 5-1, 6-1

Good

60.00
Traffic capacity [unit/min]Bad

Figure 5

50.00
40.00
30.00
20.00
10.00
0.00
6.00
Bad

4.00
2.00
Congestion amount [km・s]

0.00
Good

Congestion amount and traffic capacity in experiment 1.

(a) Driver's No.3 (Group A)(b) Driver's No.5-3 (Group B)(c) Driver's No.1-2 (Group C)(d) Driver's No.6-1 (Group D)

Figure 6

Four time–space diagrams in experiment 1.

－14－

We specifically examined the driver numbers of respective groups (Table 4). Group B includes all drivers
with small intervehicle distance. Group D includes drivers with large intervehicle distance. It is noteworthy
that all drivers with small intervehicle distances belong to group B. These results demonstrate that the desiredintervehicle distance of each driver strongly affects the traffic capacity. In addition, there are many drivers
who have standard intervehicle distance in groups A and C.
b) Experiment 2
When simulations were conducted in which 20 drivers belonging to the same group were run successively,
the congestion amount and traffic capacity were average values within the respective driver groups (Fig. 7,
Table 5). Circles designate the values of the respective drivers. Squares represent values of the respective
groups.
In Group D, only one driver (No. 2-1) with a small congestion amount as compared with the other two
vehicles is mixed, but it apparently does not strongly affect the traffic congestion of the whole group.

60.00
50.00

Traffic capacity [unit/min]■Value of the respective

groups (in experiment 2)

40.00● Value of the respective○

drivers (in experiment 1)

30.00
20.00
10.00
0.00
6.00

4.00

2.00

0.00

Congestion amount [km・s]

Figure 7

Congestion amount and traffic capacity in experiment 2.

Table 5Congestion amount and traffic capacity in experiment 2.
Group

Congestion[km・s]

Traffic capacity[unit/min]

A

3.44

29.2

B

0.36

48.39

C

0

28.71

D

5.69

18.35

－15－

c) Experiment 3
Drivers were chosen from multiple groups and were simulated to make 20 followers run successively. Results
show that the congestion amount and traffic capacity were concentrated on the overall average values (Fig. 8,
Table 6).
60.00
50.00
Traffic capacity [unit/min]

40.00
30.00
20.00
10.00
0.00
6.00

4.00

2.00

0.00

Congestion amount [km・s]

Figure 8

Congestion amount and traffic capacity in experiment 3.

Table 6

Congestion amount and traffic capacity in experiment 3.
GroupCongestion[km・s]

Traffic capacity[unit/min]

AB

1.86

38.59

AC

1.76

32.35

AD

4.46

25

BC

0.22

38.22

BD

2.6

29.7

CD

2.47

27.91

ABC

1.36

36.36

ABD

2.65

32.26

ACD

2.68

28.71

BCD

1.66

32.7

ABCD

2.17

32.26

d) Summary of Experiment results
The main points of experimentally obtained results are summarized as the following three points:(1) The traffic capacity is affected strongly by the desired intervehicle distance. Smaller intervehicle distancesreflect greater capacity to accommodate traffic volume.
(2) When the influence of PML is large or the influence of the leading vehicle is small, then the congestion
amount is lower.
(3) When following drivers having similar characteristics or different characteristics, the congestion amountand the traffic capacity are the average value of the combined drivers.

－16－

4. Conclusion
Results of numerical experiments used for this study demonstrated that drivers with a strong influence of
PML contributed to a reduction in the congestion amount. Drivers with a small intervehicle distancecontributed to an increase in the traffic capacity. Therefore, a good traffic condition (low congestion and hightraffic capacity) is achieved when the desired intervehicle distance � ∗ is small.
Future research should use time–space diagrams and other analytical methods to assess the observed traffic
flow, to check reproducibility of these results, and to reexamine the simulation model.

1)
2)
3)
4)
5)

References
The traffic situation ranking for urban expressway (2016),
http://www.mlit.go.jp/road/ir/ir-data/pdf/ranking_6.pdf (in Japanese).
T. Ueda et al.: THE MOVING LIGHT GUIDE SYSTEM ON HANSHIN EXPRESSWAY, Proceedingsof Infrastructure Planning of Japan Society of Civil Engineers, 53, 2825–2829, (2016) (in Japanese).
Y. Tabira and Y. Shiomi: A study on effect of pace maker light on car-following behavior, Proceedings ofInfrastructure Planning of Japan Society of Civil Engineers, 55, 16–03 (2017) (in Japanese).
M. Koshi: CAPACITY OF MOTORWAY BOTTLENECKS, Journal of Japan Society of Civil Engineers,
No.371/IV-5., pp. 1–7 (1986) (in Japanese).
M. Endo et al.: The measures against traffic congestion in Tokyo Wan Aqua-Line EXPWY, Proceedingsof Conference of the Japan Society of Traffic Engineers, 34, 255–261 (2014) (in Japanese).

－17－

A Study on the effect of Motorcycle Traffic Safety Workshop using Travel Speed and Vehicle
Density in Phnom Penh, Cambodia
Toshiki KOYANAGI* and Nagahiro YOSHIDA**(Received October 31, 2018)
Synopsis
In Cambodia, motorcycle use has spread rapidly in recent years, and serious accidents involving motorcycles
have increased. In particular, many young motorcyclists have been involved in traffic accidents, and various
issues in traffic safety are remained. To understand the current situations related to these issues in Phnom Penh,
Cambodia, a video observation survey on driving situations of motorcycle users in high school and university
were conducted. Based on the results, a traffic safety workshop was held to improve their risk perception ability
and basic riding skills. In this study, a statistical analysis was conducted to compare travel speed with vehicle
density on arterial roads before and after the workshop. The results showed that travelling speed decreased tobe effects of the traffic safety workshop, and the vehicle density could be an explanatory variable to represent
various driving conditions of motorcycles including psychological effects.
KEYWORDS: Motorcycles, Hazard perception, Traffic behavior, Traffic safety, Traffic education

1. Introduction

In Cambodia, motorcycle use has spread rapidly in recent years, and the proportion of accidents involving
motorcycles has also increased. According to an OECD report, the number of traffic fatality in 2016 was 1852
(11.8 per 100 thousand people), and 73% of these fatalities were riders of "motorized two wheelers" 1).
Motorcycle accidents have accounted for more than 90% in the 15-24 age group, and main factors wereidentified as excessive speed, drink driving, and dangerous overtaking. In response to these situations, a review
of driving license system for motorcycles was underway, while a mandatory helmet law for motorcycle drivers
was passed when riding a motorcycle of 49cc or above in 2007, and in 2015, it was made compulsory for
motorcycle passengers to wear a helmet and the law regarding traffic violations was toughened. Regarding
road infrastructure, the Asian Highway Network including arterial roads in Cambodia are being improved, andtraffic signals and a traffic control center are introduced in the capital city, Phnom Penh. With regard to traffic
safety education, some activities are supported by NGOs, and the content of the education has been includedin the compulsory education curriculum. However, judging from the current situation regarding traffic
accidents occurring among young people, both the quantity and the quality of this education are consideredinsufficient and some advanced knowledge concerning the necessity of additional road safety education andthe concrete educational effect are required.
As described above, to understand current situations about driving behaviors and related traffic safety
education, the following three activities were described below were carried out. The first, an observation
survey using video cameras attached to motorcycles was conducted to understand some insights from actual
traffic condition. Next, based on these results, a traffic safety workshop (WS) for the participants in the
behavior survey was held. The workshop consisted of two parts: a classroom portion, and a driving portion. In
classroom learning, after explaining the situation of traffic accidents in Cambodia, a training aimed at
improving hazard prediction ability was carried out using dangerous driving scenarios extracted from the video
observation of driving behavior. In driving portion, a basic driving training was given by an instructor. Finally,a video observation of driving behavior was carried out again to examine the impact of the traffic safety
workshop. In this study, with the aim of clarifying issues relating to fundamental driving behaviors that
contribute to motorcycle traffic safety, such as travel speed. A comparative analysis of driving behavior before*Student, Master Course of Dept. of Urban Design and Engineering**Associate Professor, Dept. of Urban Design and Engineering－19－and after the workshop were conducted by using travel speed and vehicle density. In addition, the motorcyclein this research is an automatic scooter used in Cambodia, not including auto rickshaw.

2. Literature review

Many studies on motorcycle traffic safety examined including analysis of risk behavior in Thailand 2), andvarious issues have been identified such as helmet use, alcohol, training, daytime running lights, driving
licenses, and risk taking behaviors 3).
With regard to driver education, there are many studies on hierarchical models for driving behavior 4), 5) andtheir extension 6).
In research on motorcycle use and the effects of education, there are studies on the relationship between
education and traffic safety behavior 7), educational content and license system 8), and educational methods andchildren’s developmental stage 9). In particular, to improve traffic safety performance among young people,
dealing with risk-taking behavior 10) and the importance of move advanced driving skill training in addition to
the conventional training have been identified 11).
On the other hand, in order to better understand these driving behaviors, the importance of evidence-based
traffic safety measures 12) such as naturalistic driving observation studies 13), have been pointed out.
As mentioned above, there are various research results regarding traffic safety education of motorcycle, but
information about current situation of motorcycle driving behavior in young people in Cambodia is limited. In
addition, there are rarely evaluated the effects of traffic safety education based on actual driving behavior. So
we focused on driver behavioral changes in young people and the possibility of future introduction of morepractical traffic safety education and we analyzed traffic safety education and naturalistic driving data inassociation with each other.
Still more, the content of traffic safety education presented in the project is to improve so-called hazard
perception ability, and although there are studies relating to similar objectives 14), 15) this study focus on analyzing
whether hazard perception education training affects the development of more defensive driving behavior inyoung people, based on the comparative observation of actual driving behavior.

3. Methodology
3.1 Video observations of actual driving behavior

To confirm the actual situation regarding driving behaviors, video cameras were attached on the motorcycles(50 ~ 125 cc) of students who commute to high school or university within the city of Phnom Penh, and an
observation survey was conducted. In the survey, the routine route between their home and school was recorded
during two different periods: one from December 2015 to January 2016 and one at the end of July 2017 after
the safety workshop described below. The subjects were a total of 27 people who responded to an appeal forcooperation in the survey through a local university. Four of 27 people were common samples before and after
the workshop. In the analysis, driving behavior of travelling non-intersection link was compared by separating
the 27 people into two groups: one is subjects who had not attended the workshop (before workshop) andanother one is subjects who had attended the workshop (after workshop). Individual attributes weresummarized in TABLE 1. The equipment used for video observation is the action camera GARMIN VIRB
Elite with built-in GPS function. The measured viewing angle was 123°, which is roughly the same as theangle of view of a human being (120°). Using the video data, average speed were measured as driving
behaviors indicating driving conditions. As a result, data of for 1014 links totaling 160.5 km was extracted(TABLE 2).

－20－

TABLE 1 Individual attributes of subjects fitted with cameras
Date ofobservation
No. of people
observed
Gender

Before WS

After WS

Dec. 2015-Jan. 2016

Jul. 2017

17

10

Total
27※

8 males/ 9 females
5 males/ 5 females
13 males/ 14 females
9
highschoolstudents/
85
highschoolstudents/
5
14 high school students / 13
Student category University students
University students
University students
Driving
Less than 1 year:5 people /Less than 1 year:0 people /Less than 1 year:5 people /experience
more than 1 year:12 people
more than 1 year:10 people
more than 1 year:22 people
Motorcycle
50cc：4 people / 90-125cc：13 50cc：3 people / 90-125cc：7
50cc：7 people / 90-125cc：20
category
peoplepeoplepeopleNumber of links 584
430
1014
Observation time Morning：327 links /afternoon：143 Morning：129 links /afternoon：184 Morning：456 links /afternoon：327
periodlinks / evening：114 links
links / evening：117 links
links / evening：231 links
Clear：429
links/Cloudy：155
Clear：192
links/Cloudy：238
Clear：621 links/Cloudy：393
Weather
links
links
links
* Of this total, 4 people participated both before and after the WS

TABLE 2 Overview of video observation result
No. of people observed
Observation time
Travel distance (except intersections)No. of links on arterial/non-arterial roads
Average link distance
Average link passage time

27
573 min(Average of 24.9 min per Person)
160.5 km (Average of 7.0 km per Person)594/420 (Total 1014)
0.160 km29.6 s

3.2 Summary of traffic safety workshop

The traffic safety workshop held at the Royal University of Phnom Penh on July 16, 2017 consisted of 2hours of classroom learning and 2 hours of driving learning. In classroom learning, after explaining thesituation of traffic accidents in Cambodia, hazard prediction training was carried out using dangerous driving
scenarios that were extracted from the video observation of driving behavior. Observed cased of near-misses
were used as the dangerous driving scenarios, for example, entering the blind spot of a four-wheeled vehicle
when weaving between cars, another vehicle suddenly appearing from a blind spot. The training method took
the form of stopping the video before the dangerous driving scenario and having the participants anticipate thepotential hazards, before explaining the actual dangerous driving scenario. In driving learning, approximately
two hours of basic riding skills, such as riding a figure of eight and braking was given by a motorcycle
instructor.

3.3 Introduction of average vehicle density around a subject

Although driving behavior on non-intersection links of arterial roads is thought to be influenced bysurrounding traffic conditions, measuring the traffic conditions which could be an important factor to describe
driver’s psychological situations, for each road in different time thought to be difficult. So the observable
relationship between average link speed and average vehicle density was employed in this study instead of therelationship between speed and density for each road in traffic flow theory.
First, to define the unit distance of motorcycle use on roads, non-intersection links were defined between
intersections. The boundary of intersection was set as the extension of a straight line from the end of the corner
cut-off at the intersection. The width and length of the links were measured using Google Earth. Measurement
errors may occur in the passage times because the link start and end positions were reliant on visual estimates.
As a rough guide, assuming that the error in average link passage time is ±1 s for both intersections, the error
in average link speed will be approximately -1.23 to 1.41 (km/h).

－21－

Next, with regard to vehicle density, average vehicle density around the observed vehicle was used. To
calculate this, a range with road width in front of the motorcycle was defined using traffic lane markings, andthe number of vehicles in the range was counted according to the type of vehicle as shown in FIGURE 1. Area
parameters shown in TABLE 3 for each type of vehicle were used to convert the number of vehicles into thetotal vehicle area in the range. Using Equation (1), the instantaneous vehicle density for every five seconds
was averaged over the number of observations within the same link. The coefficients used were a, b, c: numberof motorcycles, four-wheeled vehicles, auto rickshaws and others; α, β, γ: area parameters; A: area by which
the total vehicle area is divided; n: number of observations within link.
(∑nK=1 (αamn +βbmn +γcmn ))/An(1)

Excluding 136 links for which it was not possible to accurately count all of the vehicles inside the angle ofview owing to the effect of camera shaking and road congestion, etc., data for a total of 878 links was obtained
from the video analysis. The number of observations of instantaneous vehicle density found every five seconds
averaged 4.86 per link, with a standard deviation of ±4.42.
Using the calculated results, when correlation coefficients of average link speed and average link vehicle
density according to road conditions were compared, excluding the small number of one-way links, correlation
was highest for “links with median strip, and 2 or more lanes in each direction” (TABLE 4), and the scatter
diagram of vehicle density and speed confirmed that, as average link vehicle density increases, average linkspeed decreases (FIGURES 2, 3). Reasons for different correlation coefficients depending on road conditions
include the fact that, in addition to road conditions such as road surface, the situation concerning crossing thecenterline, reckless right/left turning, driving in the wrong direction on the road shoulder, etc. also varies
according to road conditions. The conditions on “links with median strip, and 2 or more lanes in each direction”
are such that driving behavior is less affected by the road and other people, and a detailed analysis of the 542“links with median strip, and 2 or more lanes in each direction” was conducted.
A: Area by which the total vehicle area is divided

Road width� � ����

FIGURE 1 Defined range in front of motorcycle

Average link Speed (km/h)

70
60
50
40
30
20
10
0

0

0.1

0.2

0.3
0.4
0.5
Average Vehicle Density

0.6

0.7

0.8

FIGURE 2 Relationship between average vehicle density and average link speed (all links)－22－

Average link Speed (km/h)

70
60
50
40
30
20
10
0

0

0.1

0.2

0.3
0.4
0.5
Average Vehicle Density

0.6

0.7

0.8

FIGURE 3 Relationship between average vehicle density and average link speed (links withmedian strip, and 2 or more lanes in each direction)

TABLE 3 Area parameters
Motorcycle
Four-wheeler
Auto rickshaw

Sample size
6
6
10

Average vehicle area (m2)
1.22
8.51
4.59

Standard deviation (m2)
0.14
0.51
0.17

TABLE 4 Correlation between average link speed and average vehicle density for each traffic lane scenario
Traffic lane scenario
Link without median strip, and 1 or 1.5 lanes in both direction
Link without median strip, and 2 or more lanes in both direction
Link with median strip, and 1 or 1.5 lanes in each direction
Link with median strip, and 2 or more lanes in each direction
One-way link
All links

4. Results

No. of links
165
126
33
542
12
878

Correlation coefficient, R
-0.27
-0.37
-0.48
-0.54
-0.65
-0.43

Simple Comparison before/after WS showed that an average traveling speed decreased from 26.67 km/h
(267links) to 25.44 km/h (275links). Also, to confirm the effect of the workshop on the travel speed, a multiple
regression analysis of the average link speed was carried out using a workshop dummy variable, average linkvehicle density, female dummy variable, university student dummy variable, lane line (white line) is drawn
dummy variable, right / left turn intersection at the end of link dummy variable, the frequency of passing a
motorcycle and being passed by a motorcycle as explanatory variables.
The results (TABLE 5) show that the average link speed decreased approximately 2km/h after participatingin the workshop. In term of the overall analysis, the average vehicle density has the greatest influence on the
speed reduction and the traffic condition is the dominant factor of the traveling speed. Among individual
attributes, the average interval speed is higher in case of male and university student. Furthermore, when laneline (white line) is drawn, average link speed would increase. This result shows excessive speed withoverconfidence may become a more serious problem in Cambodia if road surface were improved in the future.

－23－

TABLE 5 Multiple regression analysis with the average link speed as the objective variable
Coeficient t-value
32.15
45.20
-39.76-15.69
-3.79
-6.22
1.48
2.54
-2.16
-3.90
1.73
2.98
-2.70
-3.36
0.18
6.86
-0.10
-5.17
0.49
542

Constant term
Average vehicle density
Female dummy
University student dummy
WS dummy
Lane line (white line) dummyIntersection right / left turn Dummy
Passing a motorcycle / km
Being passed by a motorcycle / km
Coefficient of determination
Number of links

**
**
**
*
**
**
**
**
**

*p < 0.05, **p < 0.01

5. Conclusion

A Study on the effect of Motorcycle Traffic Safety Workshop was conducted based on the video observationsof actual driving behavior. Comparing driving behavior on arterial roads before and after the traffic safety
workshop which included practical skills and classroom learning aimed at improving hazard prediction ability
and acquiring basic driving skills, showed that an average travel speed decreased significantly after theworkshop. In the analysis, the variable of average vehicle density had a negative and statistically significant impact
on average link speed. This result implied that vehicle density could be an explanatory variable to represent
various driving conditions of motorcycles with psychological effects. Furthermore, this result showed that eventhough average vehicle density was high, some students got average link speed more than the legal limit speedof 30 km/h. These results suggested that many young motorcyclists didn't have sufficient risk awareness andhazard perception skills and the current motorcycle use among young people is not safe due to insufficient
educational opportunities. More practical and advanced driver education, such as hazard prediction andknowledge for driving safety can be expected to improve safety performance through motorcycle driving
behavior. Hereafter, to clearly demonstrate the relationship between the content of this kind of traffic safety
workshop and driving confidence, it is necessary to refine the experimental design, as in a panel study.
Regarding the contents of the safety workshop, the development of a traffic safety workshop program that
includes advanced driving skills training, such as speed awareness or hazard anticipation would be requiredfor practical implementation.

Acknowledgement

This study is a part of the project supported by the International Association of Traffic and Safety Sciences.
The video surveys in this study were conducted with substantial cooperation from the Faculty of Education of
the Royal University of Phnom Penh. We would like to take this opportunity to express our gratitude.

REFERENCES

1) International Transport Forum: Road Safety Annual Report, OECD Publishing, (2017)2) Prathurng Hongsranagon, Theerachai Khompratya, Surbpong Hongpukdee, Piyalamporn Havanond,
Nathawan Deelertyuenyong: Traffic risk behavior and perceptions of Thai motorcyclists: A case study,
IATSS Research, Volume 35, Issue 1, Pages 30-33, (2011)
3) Mau-Roung Lin, Jess F. Kraus, A review of risk factors and patterns of motorcycle injuries, Accident
Analysis & Prevention, Volume 41, Issue 4, Pages 710-722, (2009)4) Michon J.A.: The Mutual Impacts of Transportation and Human Behaviour. In: Stringer P., Wenzel H. (eds)
Transportation Planning for a Better Environment. Nato Conference Series, vol 1. Springer, Boston, MA,(1976)
5) M. Hatakka, E. Keskinen, N.P. Gregersen, A. Glad, K. Hernetkoski; From control of the vehicle to personal
self-control: broadening the perspectives to driver education, Transportation Research Part F: Traffic
Psychology and Behaviour, 5, pp. 201-215, (2002)
6) Esko Keskinen: Education for older drivers in the future, IATSS Research, Volume 38, Issue 1, Pages 1421, (2014)
7) Patarawan Woratanarat, Atiporn Ingsathit, Pornthip Chatchaipan, Paibul Suriyawongpaisal, Safety riding－24－

program and motorcycle-related injuries in Thailand, Accident Analysis & Prevention, Volume 58, Pages
115-121, (2013)8) Khuat Viet Hung, Le Thu Huyen: Education influence in traffic safety: A case study in Vietnam, IATSS
Research, Volume 34, Issue 2, Pages 87-93, (2011)
9) Barry Watson, Deborah Tunnicliff, Katy White, Cynthia Schonfeld, Darren Wishart: Psychological andsocial factors influencing motorcycle rider intentions and behavior, Australian Transport Safety Bureau,(2007)
10) Nina Dragutinovic, Divera Twisk: The effectiveness of road safety education, a literature review, R-20066, SWOV Institute for Road Safety Research, (2006)
11) Divera Twisk: Improving Safety of Young Drivers: In Search of Possible Solutions, D-93-2, SWOV
Institute for Road Safety Research, (1994)
12) Sudip Barua, Bhzad Sidawi, Shamsul Hoque: Assessment of the Role of Training and Licensing Systems
in Changing the Young Driver's Behavior, International Journal of Transportation Science and Technology,
Volume 3, Issue 1, Pages 63-78, (2014)
13) Fred Wegman, Hans-Yngve Berg, Iain Cameron, Claire Thompson, Stefan Siegrist, Wendy Weijermars:
Evidence-based and data-driven road safety management, IATSS Research, Volume 39, Issue 1, Pages 1925, (2015)14) Stéphane Espié, Abderrahmane Boubezoul, Samuel Aupetit, Samir Bouaziz: Data collection andprocessing tools for naturalistic study of powered two-wheelers users’ behaviours, Accident Analysis &Prevention, Volume 58, Pages 330-339, (2013)15) Atthapol Seedam, Thaned Satiennam, Thana Radpukdee, Wichuda Satiennam: Development of an onboard
system to measure the on-road driving pattern for developing motorcycle driving cycle in Khon Kaen city,Thailand, IATSS Research, Volume 39, Issue 1 , Pages 79-85, (2015)16) Mark A. Wetton, Andrew Hill, Mark S. Horswill: The development and validation of a hazard perception
test for use in driver licensing, Accident Analysis & Prevention, Volume 43, Issue 5, Pages 1759-1770,(2011)
17) Tova Rosenbloom, Amotz Perlman, Avihu Pereg: Hazard perception of motorcyclists and car drivers,Accident Analysis & Prevention, Volume 43, Issue 3, (2011)－25－

Latent Opportunities for the Use of Two-Rider Bicycles and Associated Challenges by Welfare
Service Providers
Takuya KONISHI* and Nagahiro YOSHIDA**(Received October 31, 2018)
Synopsis
For persons with reduced mobility (PRM), the two-rider bicycle might be a potential, practical means oftransportation, and the development of bicycles that meet these needs is in progress. While it revealed that there
were many limits imposed on their use as a private use in a previous study, the opportunities for business use or
associated challenges remain unclear. Thus, the purpose of this study is to understand the latent opportunities or
use of two-rider bicycles by welfare service providers, as well as the associated challenges. A hearing survey was
conducted on various type of welfare service providers that operate transportation services for the elderly andpeople with disabilities. Furthermore, a questionnaire survey was conducted on potential users after providing
opportunities to experience two-rider bicycles. The results confirmed that there were different types of latent
opportunities for the use of two-rider bicycles by each type of welfare service providers.
KEYWORDS: two-rider-bicycles, elderly or disabled people, welfare serves, hearing survey, questionnaire
survey1. Research Background and Objective
Persons with reduced mobility (PRM) including mothers and young children with disabilities, have expressed
an interest in a bicycle that can be ridden by two people, and the development of bicycles that meet these needs isin progress.
According to previous researches, while there were latent opportunities for the use of tandem bicycles
especially for people with visual impairment, it revealed that some trainings or experiential sessions were required
to reduce subjective fears in some unstable situations1). Regarding challenges for the use of two-rider bicycles by
PRM when they use it in daily life, the result of questionnaire survey showed that they would feel concerned
about road conditions, parking spaces, and getting a help for seeking a pilot rider 2).
There were many limits imposed on their use as a private use, the opportunities for business use or associatedchallenges remain unclear. Thus, the purpose of this study was to clarify the latent opportunities or use of
two-rider bicycles by potential providers in welfare service sector, as well as the associated challenges.
2. Research Methods
2.1 Method of Hearing Survey
A hearing survey was conducted on various type of welfare service providers (e.g., day care providers,afterschool, visiting long-term care, and guide helper services) that operate transportation services for the elderly
and people with disabilities in order to investigate the following topics: first, to research the realities with regard
to outings during service provision; and second, to investigate the opportunities of using a two-rider bicycle(Table.1). The hearing survey consisted of five items on organization characteristics, five items on user
characteristics, and six items on the presence or absence of current challenges and their details, as well as in the
scenarios of bicycle use.

* Student, Master Course of Dept. of Urban Design and Engineering** Associate Professor, Department of Urban Design and Engineering－27－

Table.1 Subjects of hearing survey
Day Care Provider

Afterschool

Service User
Place for service
Observe date
NumberTransport service
Origin-Destinationof Transportation
VehicleWheel Chair
Walk
PublicTransportation

Elderly
Institution
2017/1/20
1○Children with Disabilities
Institution
2017/1/24,26
2○

Visiting
long-term care
ElderlyHome
2016/12/12
1
×Institution-Home

Institution-Home/School

No Pick Up

○
○
○

○
○
○

×
○
○

Disabilities
Out Side2017/1/10
1×Anywhere basedon requests
×
○
○

×

○

○

○

Mode ofTransportat
ionType of Subject

Guide Helpers

2.2 Method of Evaluation by Two-Rider-Bicycles Experience
A questionnaire survey was conducted after providing opportunities to experience two-rider bicycles (i.e.,tandem bicycles and tricycles with frontal seats) for individuals with limited mobility as a passenger and theirfamilies and welfare service providers as a driver. Responses were received from a total of 77 drivers and thepassengers, who revealed the latent opportunities of using two-rider bicycles by type of difficulty for going out, as
well as the associated challenges (Table.2). The questions included four items on individual characteristics, fivequestions on daily outing-related behaviors, four questions on bicycle performance, and five questions on
intentions of using or owning a bicycle. The questionnaire was designed so that the difficulties of the passenger
could be understood from the driver’s response in cases where the passenger’s disability or other difficulty limited
his or her capacity to respond to the questionnaire.

RidingPlace
Subjects
NumberObserve
PeriodTwo-rider-bicycles

Table.2 Outline of evaluation by two-rider-bicycles experience
Ground, Park and Cycling
Cycling Road
Public Road
Stadium(Less Vehicle Traffic)(Much Vehicle Traffic)(No Vehicle Traffic)--Participants of the bicycles--Participants of the bicycles
experience event
experience event--Participants of the bicycles--Welfare service providers--Welfare service providers
experience event
and its users
and its users
27(Difficult to go out:844(Difficult to go out:21
5(Difficult to go out:4(including to answer instead)) (including to answer instead)) (including to answer instead))
2016/10 - 2018/1

2016/11 - 2018/2

2017/3

Tandem Bicycles
Tricycles with Frontal
Seats(2Types）

Tandem Bicycles
Tricycles with Frontal
Seats(2Types）

Tandem Bicycles－28－

3. Research Results
3.1 Results of Hearing Survey
The results confirmed that there are latent opportunities for the use of two-rider bicycles by welfare service
providers, as it can be used for small-scale welfare service businesses that provide transportation as part of theirservices. The results also confirmed that even welfare service providers that do not offer transportation had needs
for recreational purposes for routine outings and other uses as per users’ interests. On the other hand, there aremany systemic challenges, such as insurance and indemnity liabilities for welfare service providers, as well as
challenges associated with the environment of use, such as parking space (Table.3).
Table.3 Opportunities for the use of bicycles by welfare service provider type and associated challenges(Afterschool)
Visiting long-term
Type of provider
Guide Helpers
Day services
careTransportation,
During visits,
During accompaniedInterests in use
by welfare service providers
Routine outings
Routine outingsoutings
Recreational
Routine outings
Routine outings
Interests/purpose for use
by welfare service users
purposes
Recreational purposes Recreational purposes[Systemic][Vehicle]--Insurance system,
Common[Environment of use]--Poorweather
indemnity liabilities
challenges--Parking spaceconditions--Additions
forInterested purposetransportation
for use by welfare
service users
Limited number of
Designation of daily
peopleBicycle parking
Individual
use tools
challenges
who can beat the visit destinationand equipment
transported
3.2 Results of Evaluation by Two-Rider-Bicycles Experience
The study confirmed that there is a level of interest in using two-rider bicycles by people with difficulties forgoing out. Furthermore, people with inability or difficulty walking tend to be interested in using frontal-seat types
for routine outings, and people with visual disabilities tend to be interested in using the tandem type forrecreational purposes (Fig.1).

(routine use)

100%
80%
Not
interested in 60%
40%
using for20%
daily use0%Interested
in using fordaily use

(Total:n=17)

Visualimpairment(n=10)
Assistancerequired(n=4)
Walkingdifficulty(n=9)
Walkinginability(n=3)

Visualimpairment(n=10)
Assistancerequired(n=4)

Walkingdifficulty(n=9)

Walkinginability(n=3)

100%
80%
60%
40%
20%
0%

Not interested
in using forrecreational
purposes
Interested inusing forrecreational
purposes(Total:n=17)(Intended purpose (recreational))
Fig.1 Purposes of the use of bicycles by type of reduced mobility for going out.
4. Conclusion
In this study, the latent opportunities or use of two-rider bicycles were clarified by a hearing survey and aquestionnaire survey for potential business users based on an experiential evaluation. We obtained the following
results;･there are latent opportunities for the use of two-rider bicycles by small-scale welfare service businesses thatprovide transportation as part of their services,－29－･even welfare service providers that do not offer any transportation service had needs for recreational
purposes for routine outings and other uses as per users’ interests,･there are many systemic challenges for welfare service providers, as well as challenges associated with theenvironment of use, and･people with inability or difficulty walking tend to be interested in using frontal-seat types for routine
outings, and people with visual disabilities tend to be interested in using the tandem type for recreational
purposes.
From now on, it will be required to clarify the method of bicycle education for passengers assuming the use of a
two-rider bicycle and the benefit in daily use.
5. References
1) Y. Yoshida, N. Yoshida, Y. Hino, T. Uchida: A study of availability of Tandem Bicycle for Vision Impaired
Persons, Japan Society of Civil Engineers Kansai Branch Annual Scientific Lecture, Ⅳ-51, 2013.
2) Y. Yariyama, N. Yoshida, I. Fujie: Needs and Tasks for Daily Use of Tandem Bicycles for People Who are
Difficult to Move, The City Planning Institute of Japan Kansai Branch, Research Presentation Lecture, Vol. 14,
pp. 101-104, 2016.

－30－

Abstracts of Papers
Published in Other Journals

Mechanical and Physical Engineering
Mechanical Engineering
Improvement of Thermal Performance of a Coupling Hot Water-Driven and Gas Fired-Driven Absorption
Air Conditioning System by Both Using Solar Energy and Gas Engine Cooling Water
Nobuya NISHIMURA, Ryusuke MATSUDA, Norio UEDONO, Toru SHIBA and Tomohisa MEKATA
Proceedings of Grand Renewable Energy 2018 (GRE2018) International Conference, Yokohama, June 17-22,
P-St-8 (on CD-ROM) (2018).
This paper presents the thermal evaluation results on a solar-assisted coupling hot water-driven and gas
fired-driven absorption air conditioning system at experimental apartment housing NEXT21. The coupling air
conditioning system consist of hot water driven single effect absorption refrigerator of 31.3 kW rated cooling
capacity and gas-fired double effect absorption chiller of 105 kW rated cooling capacity. Performances of botheach two types of absorption refrigerator and whole absorption air conditioning system were evaluated by COP
and compared each other.
Characteristics and Mechanism of Bubble Formation in Plastic Packaging for Food
T. INOUE (Toyo College of Food Technology), T. SHIONO (Toyo College of Food Technology), H. IYOTA
Japan J. of Food Eng., Vol.16, No.3, pp.145-150 (2018). DOI: 10.11301/jsfe.17507
Heat-sealing technology, which is used for plastic packaging, entails laminating multiple kinds of films together toform a barrier with varying permeability and stiffness. Creating a heat seal consists of heating the heat-sealmaterial and then immediately cooling it down. However, overheating the heat-seal material can introduce defects
such as bubble formation. This study examined the effect of the moisture content on bubble formation by using
retort pouches as the sample material. The material is composed of polyester, nylon, and polypropylene as theoutermost layer, barrier layer, and heat seal material, respectively. A mechanism of bubble formation is proposedon the basis of the moisture adsorption characteristics, viscous elasticity, and barrier characteristics of the sample
material.
Measurement of Constant Drying Rate of Wet Material Placed in a Fluidized Bed of Inert Particles under
Reduced Pressure
Y. TATEMOTO (Shizuoka Univ.), R. OGAWA (Shizuoka Univ.), H. IYOTA
Drying Technology, Vol.36, No.11, pp.1380-1386 (2017). DOI: 10.1080/07373937.2017.1403926
The objective of this study is to estimate the drying characteristics of a relatively large material immersed in a
fluidized bed under reduced pressure by measuring the constant drying rate. The constant drying-rate period in a
fluidized bed under reduced pressure is difficult to measure because it is extremely short. To maintain the constantdrying-rate period, distilled water is directly supplied to the drying material. Through our experiment, the heattransfer coefficient of the material surface was also determined. The results were compared with data on hot air
drying. The constant drying rate is higher for fluidized bed drying than for hot air drying. It suggests that the heattransfer coefficient on the surface of the drying material is much larger for fluidized bed drying than for hot air
drying. For fluidized bed drying, the effect of pressure in the drying chamber on the heat transfer coefficient isslight at the same normalized mass velocity of dry air (G/Gmf). The temperature difference between the inside ofthe drying chamber and the drying material is much smaller for fluidized bed drying than for hot air drying. The
constant drying rate increases as the pressure in the drying chamber decreases.
Residual Bubble Volume Formed behind a Sphere Plunging into Liquid Bath (Meniscus Breakdown with
Finite Velocity of Sphere Penetration)
Kenji KATOH , Tatsuro WAKIMOTO, Yoshiaki UEDA (Setsunan Univ.) and Manabu IGUCHI
Physics of Fluids, Vol.30, No.8, 082106, 11 pages (2018).
The residual bubble formed from spherical particles plunging into a liquid bath has an important effect on theperformance of CaO particles used for the desulfurization of melted iron. Previous work has theoreticallyestimated the residual bubble volume resulting from quasi-static sphere immersion by applying the energy
minimization principle to the gas-liquid interface meniscus at its rupture [Katoh et al., "Residual bubble formed
behind a sphere plunging into liquid bath (in Japanese)," Jpn. J. Multiphase Flow 28, 547-553 (2015)]. Here, we
propose a method to theoretically estimate the residual bubble volume for sphere penetration with a finite velocity
from 0.05 to 30 mm/s into a liquid bath. To do so, the meniscus rupture at the sphere's critical depth was－33－calculated via a dynamic equation in which the energy gradient along the sphere surface was considered as thedriving force to move the triple-phase contact line. The bubble volume was then estimated by calculating thesystem energy at the meniscus breakpoint and by using the principle of minimum energy. The model results wereverified experimentally for a variety of liquids, showing that the proposed model can be used for estimation of theresidual bubble volume.
Control of Droplet Movement on an Inclined Wall with Sawtoothed Wettability Pattern by Applying
Uultrasonic Vibration
Kenji KATOH, Hiroki TAMURA, Eriko SATO and Tatsuro WAKIMOTO
Experiments in Fluids, Vol.59, No.9, 141, 10 pages (2018).
This study deals with the control of the movement of liquid droplets rolling down an inclined plate based on the
differences in the wettability of the plate. We used a photoreactive polymer poly(7-methacryloyloxy coumarin)(PMC) whose molecular structure can be changed reversibly to realize different wettabilities by ultraviolet
irradiation. We proposed employing sawtooth patterns at boundaries between areas with different contact angles tocontrol the droplet trajectory. Furthermore, we experimentally observed that the droplet moves along a line
inclined to the direction of gravity. The droplet behavior can be analyzed using a theoretical model based on thedroplet dynamics wherein the surface tension acting on the contact line and the gravitational force are considered.
The theoretical results suggest that inclination from the gravitational direction can be increased if the advancing
contact angle is reduced. In the experiments conducted herein, ultrasonic vibration was applied to the inclined
plate to reduce the contact angle hysteresis. The results showed that the advancing contact angle actually
decreased and that the droplet trajectory was controlled to realize motion along a line with inclination angle
almost twice of that realized without vibration.
Wetting Behavior of Falling Liquid Film Flowing on a Plate with a Side Wall
Kenji KATOH, Changing XU, Yoshiaki ISO (IHI Corp.), Ryosuke IKEDA (IHI Corp.) and Tatsuro
WAKIMOTO
Japanese Journal of Multiphase Flow, Vol.32, No.1, pp.35-42 (2018) (in Japanese).
The wettability of liquid film flowing on an inclined plate is extremely deteriorated if there is a vertical wall on
the channel side. In this study, an experimental study was conducted to investigate the influence of the side wallon the dryout of liquid film flow. The film surface forms a meniscus having a minimum film thickness near theside wall. The thin film thickness causes the dryout of film flow at lower flow rate. To avoid the appearance of theminimum thickness, the test channels of SUS-304 plate having circular side walls with various curvature radii RS
were manufactured and the surface profiles of liquid film were measured experimentally for three kinds of test
liquids. The meniscus profile was flattened at appropriate radius of curvature, i.e., RS~6 mm for θR = 20～30° (θR :receding contact angle) in this experiment. The critical Weber number at which dryout disappears is lowered
remarkably and is recovered to the value those experienced for the flat plate without side walls.
Simultaneous Determination of Micellar Structure and Drag Reduction in a Surfactant Solution Flow
Using the Fluorescence Probe Method
Tatsuro WAKIMOTO, Koichi ARAGA and Kenji KATOH
Physics of Fluids, Vol.30, No.3, No. 033103, 11 pages (2018).
As widely known, the addition of a specific type of surfactant to water reduces drag in a pipe flow. This effect isconsidered to be a result of the suppression of turbulent transition caused by the ordered structure of rod-likemicelles that is referred to as a shear-induced structure (SIS). However, it is typically difficult to determine the
SIS since it is necessary to noninvasively detect the SIS with several hundred nanometers in the actual moving
flow. In this study, we used the fluorescence probe method to locally determine the SIS in a pipe flow. Whenhydrophobic fluorescence molecules are added to the surfactant solution, the fluorescence molecules are trappedin micelles. Thus, fluorescence intensity varies based on the change in the micellar structure. We verified theapplicability of the fluorescence probe method to the SIS detection and determined the relationship between the
micellar structure and the drag reduction in the pipe flow by simultaneously measuring the fluorescence intensityand pipe friction factor. The experimental result demonstrates that the SIS formation in the near-wall region isclosely correlated with the drag reduction and suggests that the near-wall SIS suppresses the turbulent transition.
Development of a Wave Power Generation System Using a Slit Type Breakwater (Performance of Bending
Plate Type Generator in 1/5 Scale Experiment)
Tatsuro WAKIMOTO, Kenji KATOH, Takaaki SHIGEMATSU and Shin’ya YOSHIOKA
Advanced Experimental Mechanics, Vol.3, pp.98-103 (2018).

－34－

A new wave power generation system is proposed to be installed in a vertical slit type breakwater. The merits ofthe system are as follows: (i) no occupation of sea surface, (ii) low cost maintenance, and (iii) high energy
efficiency by using accelerated flow from the slit of breakwater. In this study, a new, higher efficiency generator is
proposed. 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, tension appears in a wire causes rotation of a wheel connected to a generator. To
estimate the power of the proposed system at full scale, the wave energy flowing into the breakwater was
simulated numerically. The results show that more than 60% of the wave energy is collected in the water chamber
behind the slit with a small opening ratio. Although the output power of the bending plate is rather small, thepower per unit of occupied sea area is somewhat superior to that of existing systems.
Evaluation of Gas-Lift Effect by Bubbles Rising in a Vertical Circular Pipe
Tomonori SUWA, Tatsuro WAKIMOTO, Kenji KATOH and Manabu IGUCHI
Transactions of the JSME, Vol.84, No.860, 17-00591, 12 pages (2018) (in Japanese).
The gas-lift effect appears in various types of gas-liquid two-phase flows. Information on the effect in a still liquid
however is very limited compared to that in a moving liquid. Experiments were carried out in this study on thecase that air bubbles rose in sill water contained in a vertical circular pipe made of transparent acrylic resin. The
flow pattern covered bubbly and slug flow regimes. The effect is composed of bath surface elevation effect andliquid flow induction effect. The latter effect was quantitatively evaluated in terms of the pipe friction loss in thepipe. An empirical equation on an apparent frictional coefficient was proposed for predicting the loss. The
experimental results reveal that the liquid flow induction effect is weak in the bubbly flow regime, while prevails
significantly in the slug flow regime.
Effect of Air Injection Method on the Efficiency of Oxygen Dissolution into a Cylindrical Water BathTomonori SUWA, Tatsuro WAKIMOTO, Kenji KATOH and Manabu IGUCHI
Journal of JSEM, Vol.18, No.2, pp.116-123 (2018) (in Japanese).
Experimental investigations were carried out to find out an efficient method of oxygen dissolution into water. Air
injection through a single-hole nozzle was chosen in this model study because of its good handling performanceand low running cost. First, basic three types were mentioned; bottom, top, and side gas injection into a cylindricalwater bath. The air flow rate and the height of bubble dispersion region were kept constant. The dissolved oxygen
was measured with a membrane electrode sensor. The history of dissolved oxygen concentration obeyed the firstorder reaction law. The dissolution efficiency therefore was evaluated in terms of the volumetric mass transfer
coefficient. The side gas injection was found to be most effective among the three methods under the experimental
conditions considered.
Numerical and Theoretical Analyses of the Dynamics of Droplets Driven by Electrowetting on Dielectric in
a Hele-Shaw Cell
Yasufumi YAMAMOTO (Kansai Univ.), Takahiro ITO (Nagoya Univ.), Tatsuro WAKIMOTO and Kenji
KATOH
Journal of Fluid Mechanics, Vol.839, pp.468-488 (2018).
Droplet movement by electrowetting on dielectric (EWOD) in a Hele-Shaw cell is analysed theoretically andnumerically. We propose a simple theoretical model for the motion, which describes well the voltage dependencyof droplet speed below the saturation voltage as measured experimentally. The simulation method for numericalanalyses is constructed by using the Young-Lippmann equation to represent EWOD and the generalised Navier
boundary condition to represent the moving contact line in the context of the front-tracking method. With an
adjusted slip parameter, the present full three-dimensional numerical simulation reproduces well the shapeevolution and movement speed of droplets as observed experimentally. We verify the proposed theoretical modelin numerical experiments with various shapes and voltages. Furthermore, we analyse theoretically the behaviourof the contact line at the onset of droplet motion as observed in the simulation and experiment, and we are able toestimate very well the time scale on which the contact angle changes.
Removal of Fine Particles on a Wall by High-Speed Impinging Air Jet with Enhanced Turbulence (A Studyon Optimal Nozzle Shape)
Tatsuro WAKIMOTO, Atsushi NAKAGAWA, Katsuki CHINO, Kazuhiko SOEMOTO (Shinco Co. Ltd.) andKenji KATOH
Proc. of the 6th International Conference on Jets, Wakes and Separated Flows, USB-memory, 4 pages (2017).
In this study, a cleaning device to remove micron-sized particles on a solid surface by an air jet is developed. This
device has a special nozzle containing a triangular cavity to add high intensity turbulence to the air jet, and the air－35－

jet impinges on the solid surface removing the particles. Assuming that the spherical particles are removed byrotational movement, we estimated the rotational moment induced by drag force and local pressure gradient from
calculated flow field by numerical simulation. From the moment estimation for various nozzle shapes, it isclarified that the addition of a rectangular interspace to the cavity increases the removal moment and the inlet
width of the cavity has an optimal value. Under the experimental conditions in this study, the inlet width of 1mmgives the best removal performance.
Visualization of Viscoelastic Behavior in vivo Skin using Optical Coherence Tomography-based
Straingraphy combined with Suction Device
Yusuke HARA, Daisuke FURUKAWA and Souichi SAEKI
Mechanical Engineering Letters, Vol.4, 17-00656 (2018).
Although various apparatuses have been developed to assess the skin mechanical function, the spatial viscoelastic
behavior of each skin layer including the epidermis and dermis is yet unclear. To resolve that lack of clarity, we
built a handmade system combining a suction device with optical coherence tomography (OCT). OCT canvisualize the vertical section of the skin with high spatial resolution and high acquisition speed. In addition, wedeveloped an algorithm for time-dependent strain tomography, named Dynamic Optical Coherence Straingraphy(D-OCSA), which can analyze the changes in strain distributions over time in sequential OCT images. Using thesystem, successive OCT images of volar forearm skin were obtained after the suction release, followed by
calculation of spatial distribution of creep recovery time as an index of viscoelastic behavior. As a result, werevealed that the creep recovery time in the dermis was significantly larger than that of the epidermis. This is thefirst report to provide evidence that there is a spatial difference in the viscoelastic behavior in the skin. Futureapplication of our method would be beneficial to the diagnosis of skin mechanical function and the validation of
cosmetic and medical applications.
Visualization of Visco-elastic Behavior in Skin Equivalent using Optical Coherence Tomography
Straingraphy
Yusuke HARA, Yuki OGURA, Toyonobu YAMASHITA, Daisuke FURUKAWA and Souichi SAEKI
Skin Research and Technology, Vol.24, pp.334-339, 10.1111/srt.12435 (2018).
Background/Purpose: The relationships between the skin components and these mechanical roles are still unclear.
To clarify these relationships, we investigated spatial mapping of the mechanical behavior of cultured skinequivalents (SEs) using optical coherence tomography (OCT)-based straingraphy. Methods: We built a strain
relaxation test system combined with OCT and developed an algorithm that could visualize a time-dependent
strain distribution, named dynamic-optical coherence straingraphy (D-OCSA). Using this system, we analyzed
how the spatial mechanical changes in the SEs depended on the culture duration. For quantitative analysis of
viscoelastic behavior, we defined a relaxation attenuation coefficient of strain rate, which indicates the ratio ofviscosity and elasticity in the Klevin-Voight model. Results: By culturing for 4 days in comparison to culturing for
1 day, the strain relaxation attenuation coefficient of the whole skin, especially at the region of thedermal-epidermal junction (DEJ), significantly increased in the negative direction. In tissue slices taken for
microscopy, several cracks were observed in the SEs cultured for 4 days. Conclusion: This study is the first to
provide quantified evidence that the DEJ is a dynamically specialized region. An OCT-based straingraphy system(D-OCSA) would be beneficial for evaluating the quality of SEs, as well as functional analysis of their mechanics.
Visualization of Age-related Vascular Alterations in Facial Skin using Optical Coherence
Tomography-based Angiography
Yusuke HARA, Toyonobu YAMASHITA, Kumiko KIKUCHI, Yoshihide KUBO, Chika KATAGIRI, Kentaro
KAJIYA and Souichi SAEKI
Journal of Dermatological Science, Vol.8, S0923-1811(18) (2018).
The assessment of dermal vasculature is crucial for understanding skin homeostasis, inflammation and disease.
Various methods have been used to investigate structural alterations of the dermal vasculature. Histologicalapproaches have revealed vascular alterations in aged skin, for example decreasing vessel density, and irregularand disorganized vessels. However, the complex three-dimensional arrangement of vascular plexuses cannot beseen and investigated by the examination of conventional histological tissue sections. In general, the different
horizontal vascular plexuses, which are interconnected by vertically oriented vessels, are well developed at a
specific depth, for example in the sub-epidermal and sub-dermal regions. A stereographic study of venous
plexuses, following injection of a contrast medium, showed that venous plexuses extend continuously overneighboring venous polygons in the sub-epidermal plane [3]. Non-invasive angiography is a technique for
vascular imaging that has been developed recently and continues to evolve. It allows non-invasive visualization of－36－

dermal vascular anastomoses, not only vertically, but also horizontally [4–6]. In particular, angiography based on
optical coherent tomography (OCT) can be used to analyze vascular plexuses at the micron level [5,6]. The
principle of OCT angiography is to identify dynamic structural changes in the skin through a time-series of OCT
tomograms, based on the idea that movement within the skin in the absence of an external force reflects blood
flow, and so provides a good approximation of vascular plexus structure. Here, we performed a pilot study toevaluate the potential of OCT angiography for non-invasively investigating age-related vascular alterations infacial skin. This study was conducted according to the Declaration of Helsinki Principles and approved by the
Ethics Committee of Shiseido Ltd. We enrolled 61 female Japanese subjects aged 21–69 years (19, 21 and 21
subjects in the 20s, 40 s and 60 s age groups, respectively), who gave their informed consent. Dermal vascular
images were acquired by OCT angiography of their right cheeks, after a 15-min acclimatization period at 24
degree C.
In vivo Micro-tomographic Visualization of Capillary Angio-Dynamics around upper dermis undermechanical stimuli using Low Coherence Interferometer, “Optical Coherence Doppler Velocigraphy”
Daisuke FURUKAWA, Souichi SAEKI, Takafumi ITO and Yoshiaki NISHINO
American Journal of Physics and Applications, Vol.6, Issue 4, pp.89-96, (2018).
The skin aging process, e.g. wrinkles and sagging, caused by not only aging but also ultraviolet irradiation, could
be related to the depression of metabolic function. Therefore, an in vivo quantitative measurement of capillary
blood flow velocity governing skin metabolism functionally, i.e. microcirculation, is crucial to clarify the skinaging and to create skincare products. The purpose of this study is to visualize the tomographic velocity of red
blood cell in capillaries just below human epidermal skin using Optical Coherence Doppler Velocigraphy, namely
OCDV. This was constructed on a low coherence interferometer, which could provide tomographic distribution offlow-modulated Doppler frequency by developing OCDV algorithm of Hilbert transform and adjacentautocorrelation. In order to validate OCDV system, this was in vivo applied to human forearm skin underrespective mechanically stimulated conditions of control and avascularization. As a result, a cross-sectional
imaging of blood flow velocity was found to display not only morphological OCT images but also networks ofcapillary vasculature inside dermal tissue. It was confirmed that blood flow velocity further decreased in upper
dermis under avascularization than control condition. Additionally, OCDV could provide a velocity map of bloodflow having sensitivity to mechanical stimulus, so has strong efficacy to diagnose “Capillary Angio-Dynamics” ofskin tissue. In conclusions, OCDV system could be quite useful for a micro-tomographic imaging of blood flow
velocity of capillaries inside skin.
Vascular Morphology in Facial Solar Lentigo assessed by Optical Coherence Tomographic Angiography
Yusuke HARA, Toyonobu YAMASHITA, Kumiko KIKUCHI, Takako SHIBATA, Masato NINOMIYA, Chika
KATAGIRI, Kentaro KAJIYA, Souichi SAEKI and Hajime IIZUKAThe 42nd Annual Meeting of the Japanese Society for Investigative Dermatology, JSID2018 (2017).
The histological features of solar lentigo (SL), including epidermal thickening and hyperpigmentation, suggestthat altered dermal vasculature affects epidermal regulation. SLs show a significant increase in vessel density andincreased levels of vascular endothelial growth factor expression. It is known that the horizontal vascular plexuses
are well developed in the sub-epidermal region, which affects epidermal regulation. However, little is known
about the dermal vascular plexuses underlying pigmented lesions such as SL. We investigated vascularmorphology in facial solar lentigo, focusing on the horizontal vascular plexuses of the sub-epidermal region.
Eleven Japanese women aged 43–59 years with a clinical diagnosis of facial SL were enrolled. For visualassessment, we used newly-developed high-speed optical coherence tomographic (OCT) angiography, which canacquire en-face optical sections at high resolution. As a consequence of image analysis, OCT revealed that the
epidermis in SL is thicker than that of surrounding normal skin. OCT angiography allowed clear visualization of
the depth- resolved vascular plexuses image. In addition, we confirmed that there was a significant increase in thedensity of dermal blood vessels in SL. This finding extended from the papillary dermis to the upper reticulardermis at a depth of 200 μm. In conclusion, our results suggest that SL vascularity can be characterized using
OCT angiography. Future applications of OCT angiography may be beneficial in the diagnosis of
hyperpigmentary disorders.
Application Study on Micro-tomographic Visualization of Spatio-Temporal Mechanical Characteristics ofBiological Tissue
Souichi SAEKI, Daisuke FURUKAWA and Takeshi NAGASAKIThe 4th International Symposium on Multidisciplinary Computational Anatomy, A02-KB111 (2018).
Authors have developed Dynamic OCSA, which provide tomographic distribution of deformation velocity－37－

dynamically based on cross-correlation technique using OCT images. In this study, the present method was invivo applied to forearm skin tissue to evaluate viscoelastic behavior related with complicated micro-biomechanics
of superficial skin structures as tomographic distribution of creep recovery time. As a result, creep recovery timearound capillary vessels was observed to be larger, where there is fine and soft collagen and viscous effect of
microcirculation. So, it was confirmed that Dynamic OCSA can non-invasively visualize space-dependent andtime-dependent biomechanical properties as creep recovery time.
Characterization of Facial Solar Lentigo using Optical Coherence Tomographic Angiography
Yusuke HARA, Toyonobu YAMASHITA, Kumiko KIKUCHI, Takako SHIBATA, Masato NINOMIYA, Chika
KATAGIRI, Kentaro KAJIYA, Hajime IIZUKA, Daisuke FURUKAWA and Souichi SAEKISPIE Photonics West BIOS, 10467-35; The 4th International Symposium on Multidisciplinary Computational
Anatomy, on CD-rom (2018).
Chronic sun exposure causes cutaneous vascular and pigmentary changes, leading to photoaging. A solar lentigo(SL) is one of the major signs of photoaging on the face. Histological approach in SL biopsies showed asignificant increase in vessel density and increased levels of vascular endothelial growth factor expression. As adermal-vascular morphology, it is known that the horizontal vascular plexuses are well developed in the
sub-epidermal region which affects epidermal regulation. However, little is known about the alteration ofsuperficial vascular plexuses underling SL. To clarify the superficial vascular features of SL, we developed two
types of angiographies using optical coherence tomography (OCT), customized correlation-mapping OCT(cmOCT) and optical coherence doppler velocimetry (OCDV). Our cmOCT allows clearly visualization of
depth-resolved vasculature by noise removal algorithm which detected body motion in epidermal region. OCDV
could detect depth-profile of phase change in axial-scanned interference signals by the collaboration of Hilberttransform and adjacent autocorrelation. Using these techniques, we investigated vascular morphology in facial SL,
focusing on the horizontal vascular plexuses in the sub-epidermal region. Eleven Japanese women aged 43–59
years with a clinical diagnosis of facial SL were enrolled. As a consequence of OCT angiographies, there was asignificant increase in the density of dermal blood vessels in SL, comparing to that of surrounding SL. Thistendency was confirmed from the papillary dermis to the upper reticular dermis at a depth of 200 μm. Proposed
methodology can be a useful method for the examination of vascular characteristics in cutaneous pigmentary
disorders.
Micro-tomographic Diagnosis of Skin, Cartilage, Atherosclerosis, Tumor and Regenerative Tissue using
Multi-functional OCT
Souichi SAEKI
9th OCARINA International Symposium, O-4, p.14 (2018).
Water has significant influence on human body due to physiological carrier media. In addition, rheologicalbehavior of interstitial fluid in epidermal and dermal tissue, including blood micro-circulation, can vary skinmechanics in micro scale, i.e. vis. Therefore, an in vivo measurement of moisture content and capillary blood flow
velocity is necessary to clarify skin mechanics. This paper presents 2C-OCM (2-Color Optical Coherence
Moisturegraphy), which was composed of two-band light sources having different optical absorption properties ofwater respectively. These are capable of tomographically in vivo diagnosing the moisture content. Furthermore,
OCDV (Optical Coherence Doppler Velocigraphy) algorithm can visualize the tomographic flow velocity of red
blood cell in capillaries of human epidermal skin. In this experiment, 2C-OCM & OCDV were in vivo applied tohuman skin and regenerative tissue. Consequently, it was concluded that 2C-OCM & OCDV can provide micro
tomography of moisture content and capillary blood velocity inside skin tissue, which can be attributed tobiomechanical properties.
Study on in vivo 3D Micro-Tomographic Visualization of Vascular Plexuses and Capillary Blood Flow
Using Optical Coherence Doppler Velocigraphy”
Daisuke FURUKAWA, Ryohei NISHINO, Naoya KUSUMOTO, Souichi SAEKI, Yusuke HARA, Masatsugu
SHIBA, Susumu AOKI, Takafumi ITO and Yoshiaki NISHINO
9th OCARINA International Symposium, P-36, (2018).
The skin aging process, e.g. wrinkles and saggings, caused by not only aging but also ultraviolet irradiation, could
be related to the depression of metabolic function. The microcirculation system should be an important guidelineof skin care for the anti/smart-aging. Rheological behavior of interstitial in epidermal and dermal tissue, including
blood micro-circulation, can vary skin mechanics in micro scale, i.e. visco-elasticity. Therefore, an in vivo
quantitative measurement of capillary blood flow velocity is crucial to clarify their properties. The purpose of thisstudy is to visualize the tomographic flow velocity of red blood cell in capillaries below human epidermal skin－38－

using Optical Coherence Doppler Velocigraphy, i.e. OCDV [1]. This is constructed on a low coherence
interferometer [2], which is based on Hilbert transform and adjacent auto-correlation. In order to validate OCDV
system, this was in vivo applied to human cheek skin under the condition of control. As a result of skintomography obtained by OCDV, en face cross-sectional imaging of doppler velocity was found to display
networks of capillary blood vessels in upper dermal tissue around hair follicles, as well as morphological skinstructure. It was confirmed that capillary vasculature and blood velocity can be visualized tomographically even in
the upper subpapillary layer. In summary, OCDV system could be quite useful for a micro-tomographic imagingof blood flow velocity of capillary vessels inside skin.
Wall Inspection Robot with Maneuvering Assist Control System Against Crosswind
Yogo TAKADA, Yuhei TOKURA, Yodai MATSUMURA, Takahiro TANAKA and Tatsuki KANADA
Journal of Robotics and Mechatronics, Vol.30, No.3, pp.416-425 (2018). DOI:10.20965/jrm.2018.p0416
Many social infrastructures and buildings are aging. Therefore, inspections to find deteriorated parts to prevent
accidents are important. However, significant costs and inspection time are required for the current technologies.
Therefore, inspection methods using robots are attracting attention. As the most appropriate option to traverse
freely on concrete bridges and building walls is by traversing with lift force from propellers, a robot called
HORNET has been developed that can run along a wall with two rotors. However, the floating-type robot withpropellers could drop from a wall if hit by strong wind. Therefore, a gyro sensor was installed in the robot todetect its posture and adopted a simple maneuvering assist control to reduce the above-mentioned issue. In thisstudy, the motion of HORNET was analyzed and a simple control system was designed to realize the maneuvering
assist control. It was confirmed that the resistance of HORNET to the crosswind was improved by adding thecontrol system.
Development of Small Robotic Fish Equipped with FPGA and CMOS Camera for Traking Live Fish
Takuya ARITANI, Naoki KAWASAKI, and Yogo TAKADA
Proceedings of 7th International Symposium on Aero Aqua Bio-mechanisms (ISABMEC), 4 pages on USB
Memory (2018).
A robotic fish used to investigate live fish needs the ability to recognize and track the observation target. We havedeveloped an image processing system with the FPGA that processes signals from a CMOS camera to recognize
an investigation target and to locate its position. Besides, high turning ability is required to keep capturing thetarget by a camera. Therefore, we improved the turning ability by bending the body of a robotic fish greatly withmultiple joints. In this study, we have confirmed that the robot can recognize the investigation target and it has
desirable turning ability.
Investigation of Rotors Imitating Bird Wings for Reducing Electricity Consumption of Structure Inspection
Robot HORNET
Yogo TAKADA, Takahiro TANAKA, Tatsuki KANADA and Yodai MATSUMURA
Proceedings of 7th International Symposium on Aero Aqua Bio-mechanisms (ISABMEC), 5 pages on USB
Memory (2018).
As bridges and buildings have been deteriorating, we have developed a robot, HORNET to inspect the wall. This
robot travels on the wall surface with lift of propellers with contacting the wheels to the wall. Since the running
duration is short on the smooth surface, the cross-sectional shape of a rotor was obtained to reduce the power
consumption by optimizing with two-dimensional numerical analysis with genetic algorithm. Besides, wemanufactured several kinds of rotors imitating birds and experimented to confirm a good shape concerning
electricity consumption. Furthermore, we made HORNET’s dynamic model, and simulated to confirm thereduction of the electricity consumption.
Effect of Surface Roughness on Antibacterial Properties of Copper and Cupronickel
Hisashi KATO, Yoshihiro SATO, Hiroshi KAWAKAMI and Yasushi KIKUCHI
Journal of Japan Institute of Copper, 57, pp.304-306 (2018) (in Japanese).
Copper is known as an antibacterial metal. Introducing antibacterial metals into environment surface in hospitals
will decrease the number of viable bacteria on the environmental surface, and contribute to prevent hospitalacquired infection. One of well known antibacterial mechanism of copper is that copper ions inactivate respiratory
enzymes by oxidizing thiol groups, leading cell to be damaged. The amount of copper ion eluting from copper ishence an important factor in antibacterial property of copper. Increase in surface roughness will increase surface
area and, as a results, the amount of copper ion eluting from copper, resulting in higher antibacterial properties ofcopper. In this research, we investigated effects of surface roughness on antibacterial properties of oxygen–free－39－

copper (OFC) and cupronickel against Escherichia coli and on copper and nickel ions eluting from the surfaces.
The surface of specimens was finished by buff polishing with aluminum oxide or wet–grinding with emery papers.
The range of surface roughness of OFC was Ra = 0.05 (for buff polishing)〜0.93 (μm) and that of cupronickel
was Ra=0.06 (for buff polishing)〜0.50 (μm). Antibacterial property was evaluated in accordance with JIS Z 2801
except that the exposure time was set to 15 minutes. The amount of copper ion and nickel ion eluting from
specimens was measured using inductively coupled plasma–mass spectrometry (ICP–MS). For OFC, the surface
roughness had no effect on antibacterial properties. The buff polished OFC released more copper ion than the wet
grinded OFC. For cupronickel, surface roughness had no effect on antibacterial properties nor on the amount ofcopper ion and nickel ion eluting.
Effects of Protein Surface Contamination on Antibacterial Activities of Copper Alloys
Yuzo TODA, Yuta TAKASHIMA, Hiroshi KAWAKAMI, Yoshihiro SATO and Yasushi KIKUCHI
Journal of Japan Institute of Copper, 57, pp.307-312 (2018) (in Japanese).
Copper alloys are known as antibacterial metallic materials. Introducing such copper alloys into frequently hand–touched places has been considered to reduce risks of outbreaks of illnesses caused by pathogens onenvironmental surfaces. When copper alloys are used in environmental surfaces, surfaces of copper alloys are
exposed to the surrounding environment and become contaminated by various substances in the surroundings. As
surface contamination can reduce the antibacterial activity of copper alloys, cleaning henceforth must be carriedout periodically on the contaminated surfaces. In this study, the antibacterial activities of copper alloys
contaminated with protein were evaluated using bovine serum albumin (BSA) as a model protein contaminant.
Also, in this study, we prepared specimens which were firstly contaminated with 0.80 μg/mm2 of BSA and thensubjected to wipe–cleaning loaded with the sodium hypochlorite aqueous solution. For those specimens, we
carried out antibacterial tests and measurements of the amount of BSA remaing of the cleaned surfaces. The
antibacterial activities of the copper alloys was equal to the antibacterial activities of the clean copper alloys. The
antibacterial activities of the copper alloys decreased with the increase in the amount of surface contaminant.
However, when the amount of the BSA surface contaminant was 0.016 μg/mm2 and 0.16 μg/mm2, in those cases
the surface of the specimen was completely covered with BSA molecules, the bacterial counts recovered from thecopper alloys were one to two orders lower than those from the stainless steel specimens. The bacterial counts
recovered from specimens contaminated with 0.80 μg/mm2 of BSA were not different from those from stainlesssteel specimens which don’t have antibacterial activities. The bacterial counts recovered from the copper alloys
after wipe–cleaning was more than the bacterial counts recovered from the clean copper alloys. When the amountof residual surface contaminants was reduced to 0.0016 μg/mm2, the surfaces of the copper alloys regained
antibacterial activities to the same level as those in a clean surface condition. Hence, it is necessary to findcleaning conditions such that the amount of BSA decreases to 0.0016 μg/mm2 or less.
First-Principles Calculations of Ionic Conduction in Olivine-Type LixFePO4
Ippei KISHIDA, Shota KOYAMA and Yoshiyuki YOKOGAWA
Materials Transactions, 59 (7), pp.1062-1067 (2018).
Super ionic conductors are required for all solid Li ion batteries. Conduction mechanism of LixFePO4 has been
revealed by first-principles calculations using plane-wave basis. Crystal structures were constructed using a unit
cell and a 1 × 2 × 1 super cell. Transition of Li site occupation with the smallest energy fluctuation was searchedthrough graph theory. Trajectories of Li ions and migration energies were obtained by Nudged Elastic Band
Method. Results show the migrating atoms pass through faces of O polyhedra. At dilute limit of Li, a single ion
migrated and had very low migration energy of 0.14 eV. Increasing the carrier concentration resulted in pairing of
Li atoms and raised the migration energy. At higher concentration region, cooperative ionic conduction
mechanisms of two Li ions occurred. Low migration energies were obtained to be 0.20 and 0.22 eV for x = 0.25
and 0.5 of LixFePO4, respectively. Considering the migration energy and carrier concentration, LixFePO4 with theconcentration region 0.25 ≤ x ≤ 0.5 should have high ionic conductivity. These mechanisms would be applied todevelop new superionic conductors.
First-Principles Study of Silicon-Embedded Ni(110)Tsuneo FUKUDA and Ippei KISHIDA
E-Journal of Surface Science and Nanotechnology, 15, pp.96-101 (2017).
First-principles total energy calculations were performed to investigate stable atomic structures for the displacive
adsorption of silicon on the Ni(110) surface. Gibbs free energies were compared for 0-4 silicon atoms embedded
into the top layer in a 2×2 unit for the Ni(110) surface. When a half monolayer of Si was embedded, the p(1×2)
structure had the lowest energy, and the c(2×2) structure had only 13 meV/1×1 higher energy than the p(1×2)－40－structure. By extending to a 4×2 unit, the c(4×2) structures had almost the same energy with the p(1×2) structure.
Alternating Si-Ni chains along the close-packed [1-10] row play an essential role to stabilize these structures. Si
and Ni are alternatively aligned in separate [1-10] rows forming a p(2×1) structure, which had 276 meV/1×1
higher energy than the p(1×2) structure. For the p(2×1) structure, unique one-dimensional electronic bands
derived by the Si-3s states were formed along the [1-10] direction. (This is identical to the abstract that will appear
in the section of Applied Physics and Electronics Engineering).
Initial surface silicidation on Ni(110)Tsuneo FUKUDA, Ippei KISHIDA and Kenji UMEZAWA
Surface Science, 659, pp.1-4 (2017).
Initial silicide formation on a Ni(110) surface was studied by scanning tunneling microscopy (STM) in an
ultrahigh vacuum. Less than 0.5 ML of Si deposition initiated a Si-Ni mixed layer by displacing substrate Ni, anddark sites were formed in the STM images. A 0.5 ML-Si deposited surface showed that Si and Ni were alternatelyaligned in a close-packed row whereas Si pairs aligned along the direction forming p(1×2), obliquely aligned
forming c(2×2), or even straightly-and-obliquely aligned forming c(4×2) superstructures. A first-principles totalenergy calculation showed that the p(1×2) and c(4×2) structures had almost the same energy while the c(2×2)
structure gave 13 meV/1×1 higher energy. Because a Si-Si bond in the close-packed row is energeticallyunfavorable, Si deposition of more than 0.5 ML did not further replace the substrate Ni, but silicide islands were
nucleated along with a trench structure. (This is identical to the abstract that will appear in the section of Applied
Physics and Electronics Engineering).
Effects of Ultrasonic Waves during Resin Impregnation on the Mechanical Properties of Unidirectional
Composite Materials
Yasunari KURATANI, Aya MIKI, Norimichi NANAMI, Hayato NAKATANI and Hiroyuki HAMADAOpen Journal of Composite Materials, Vol.8, No.1, pp.1-10 (2018).
Effects of ultrasonic vibrations on mechanical properties of fiber reinforced plastics were investigated duringmolding resin impregnation process in vacuum assisted resin transfer molding. The vacuum bag including the
preformed each non-crimp fabrics (carbon and glass fibers) was placed in a water bath of an ultrasonic wave
generator during resin impregnation. The mechanical properties of the laminates were evaluated through themechanical strength tests and scanning electron microscope (SEM) observation. The results revealed thatultrasonic waves improved transverse tensile, flexural, interlaminar shear, and compressive strengths of the carbon
fiber (CF) laminates and interlaminar shear and compressive strengths of the glass fiber (GF) laminates. It was
found from SEM observation that the fracture modes of the CF and GF laminates processed using ultrasonicwaves were resin fracture. Accordingly, the adhesion of the fiber/resin interface was improved by oscillating
ultrasonic vibration during resin impregnation, leading to an increase of the interface strength.
Evaluation of Flexural Properties of the U-shape Composite Spring
Katsuyuki HARA, Toshikazu UCHIDA, Yosuke WATANABE, Norimichi NANAMI, Hayato NAKATANI and
Hiroyuki HAMADA
Procedia Manufacturing, Vol.26, pp.530-536 (2018).
CFRP (carbon fiber reinforced plastics) which provides high specific strength/stiffness is adopted in assistive
products such as orthosis for relieving the physical burden of patients. The orthosis needs the flexible
configuration of articulations like walking of normal subjects. Since the CFRP autoclave method is suitable formolding complex shape parts, a structural component containing a partially curved region such as U-shape can be
integrally molded by the method. Flexibility characteristics are added to a structural component without anincrease in the number of parts. In this study, the flexibility of CFRP was evaluated for embedded light anddurable springs into orthosis. First, three-point bending tests of the flat laminate were performed to assess theadvantage of CFRP used as spring materials. Second, the flexural properties and fracture mechanism of a U-shapespring were investigated in comparison with the results of the flat laminate. The study confirmed the advantage of
CFRP employed as a spring material.
Large Deformation Behavior of Angle-Plied CFRP Laminates by inserting PA Mesh as Interlayer
Kazuki UEDA, Hayato NAKATANI and Katsuhiko OSAKA
Proc. 12th Canada-Japan Workshop on Composites, Takayama, Japan, July 4-7, paper ID: 024 (2018).
When angle-plied CFRP laminates which do not contain 0° fibers are loaded in tension, intralaminar matrix cracks
are developed in all plies and followed by interlaminar delamination, and then this leads to rupture of laminates atrelatively low strain. Some studies found that greater fracture strain can be achieved by using thin plies since－41－matrix crack is suppressed by the constraint effect. However using thin plies is costly because stacking number
increases. The present study applies polyamide (PA) mesh which can improve interlaminar fracture toughness byinserting them between plies. This study aims greater fracture strain in angle-plied laminates by suppressing
interlaminar delamination between plies by inserting PA mesh. Damage behavior in two kinds of angle-plied
CFRP laminates such as [452/-452]S and [452/PA/-452]S are evaluated by tensile tests. It is found that by inserting
PA mesh strength and maximum strain improved compared to the laminates without PA mesh. An X-ray
observation for the specimen just before tensile rupture reveals that interlaminar delamination is not induced
though there are many intralaminar matrix cracks in the laminates with PA mesh. From these experimental results,
it is assumed that even if matrix cracking occurred, it does not progress to interlaminar delamination by inserting
PA mesh and these phenomena lead to greater fracture strain due to accumulation of damage.
Estimation of R-curve for Mode II Interlaminar Fracture Toughness by using CFRP Laminates with Fibre
Discontinuities
Takaaki WARABINO, Hayato NAKATANI and Katsuhiko OSAKA
Proc. 12th Canada-Japan Workshop on Composites, Takayama, Japan, July 4-7, paper ID: 025 (2018).
When CFRP plates of structures with complicated geometry are fabricated by using prepregs, fiber discontinuities
remain in the laminates since some slits or cuts are introduced in prepregs before lamination. The CFRP laminateswith fibre discontinuities show tensile failure at much lower stress due to crack originated from the discontinuities.
Previous studies have shown that the stress at which crack propagation from fiber discontinuity occurs can bepredicted by using mode II interlaminar fracture toughness GII. The present study aims to reverse thismethodology in order to estimate the R curve of mode II interlaminar fracture toughness GII from tensile test of
CFRP laminates with fiber discontinuity. In the technique we suggest here there is no need to perform stabilized
ENF tests that require a variety of controls. Tensile tests for CFRP laminates that contain fiber discontinuous
dispersed at an arbitrary interval are carried out. Relations between the obtained fracture stress and the interval areconverted into that between critical energy release rate (CERR) in mode II and crack extension that can becompared with R-curve obtained by ENF tests. As a result, although mismatch are found in the initial region of
R-curve a.k.a. GIIC , CERR matched with R-curve during crack propagation, which is the region where the change
of GII converges as GIIR.
Electroless Copper Plating Process by Applying Alternating One-Side Air Stirring Method forHigh-Aspect-Ratio Through-Holes
H. KANEMOTO, T. KAWAMURA, H. SUZUKI, T. MIYAZAKI, H. MOZUMI and Y. KANEKO
J. Electrochem. Soc., 164 (12), pp.D771-D777 (2017).
A new electroless copper plating process, namely, an alternating one-side air stirring method, was studied to
improve the throwing power of high-aspect-ratio through-holes in multilayer printed wiring boards. The throwing
power can even be improved for through-holes of a 40-aspect ratio under an appropriate flow velocity of thesolution because the generation of differential-pressure between the front and the back of the board enhances
supplying the solution into the through-holes. The necessary flow velocity can be estimated by considering theconsumption rate of copper ions in a through-hole and calculating it on the basis of Bernoulli's andHagen-Poiseuille's equation.
Evaluation of Microscopically Anisotropic Deformation Fields of Polycrystalline Pure Copper using Digital
Image Correlation Method
M. UCHIDA, A. TANIGUCHI and Y. KANEKO
Proc. ISEM12, Paper No. 035, 5pages (2017).
Microscopic deformation of the polycrystalline metal is characterized by anisotropic deformation depending on
the crystalline orientation of grains and the interaction with adjacent grain. The estimation of the slip deformation
under the complex stress state in the polycrystalline structure can provide an important information to understandthe deformation mechanisms of crystalline material. In the present study, the evaluation method of slip
deformation in the microscopic local region is proposed by coupling the Digital Image Correlation (DIC) Method
and the crystalline plasticity theory. Microscopic strain field and slip deformation of the polycrystalline purecopper under uniaxial tension were evaluated using the proposed method. The nonuniform deformation in the
crystal grain was firstly evaluated by DIC. Then, the slip deformation for all grains and all slip systems were
estimated using proposed method. Series of the experimental result clarified that the multiple slip deformation
occurred for almost crystal grain regardless of the degree of the total slip in FCC metal.
Evaluation of Deformation Behavior of Hydrogel on Uniaxial Tensile Test using Digital Image Correlation－42－

K. SUZUKI, M. UCHIDA, Y. KANEKO, D. OKUMURA, H. TANAKA and S. IDA
Proc. ISEM12, Paper No. 059, 5pages (2017).
Hydrogel materials, which have been employed for a wide range of biomedical applications, contain water withina three-dimensional network of polymer chains. Since this material is extremely soft as compared with otherengineering materials, it is necessary to establish a mechanical test method suitable to accurately evaluate thedeformation behavior of such soft materials. In this study, we evaluated the development of strain field and therelationships between true stress and true strain using digital image correlation (DIC) method. It was confirmedthat tensile strain was uniformly distributed, and tensile strength and elongation of hydrogel specimens decrease
with increasing the amount of cross-linking.
Basic Verification of an Extended Flory-Rehner Model using Polyacrylamide Hydrogels
D. OKUMURA, S. SHIMIZU, S. IDA, M. UCHIDA and H. TANAKA
J. JSCME, 17, pp.53-58 (2017) (in Japanese).
In this study, we perform the basic verification of an extended Flory-Rehner (F-R) model using experimental dataof polyacrylamide hydrogels. The equilibrium free swelling and subsequent uniaxial tensile tests areexperimentally performed to determine two scaling exponents characterizing the extended F-R free energyfunction for polymeric gels. To show the ability of the two scaling exponents, the Ogden model is compared as thedifferent strain energy in the F-R model. The parameter set in the Ogden model cannot uniquely be determined torepresent the swelling effects on stress-stretch responses while the extended F-R model can predict them well onlywith one scaling exponent. In addition, the other scaling exponent has a strong interaction with the Flory-Huggins
interaction parameter.
Experimental Modeling of Nonuniform Deformation in Finite Volume Evaluation Region of HeterogeneousMaterial
M. UCHIDA and Y. KANEKOHeliyon, 4, e00578, 21pp., (2018).
The objective of the present study is to establish the experimental modeling process of the nonuniform
deformation behavior of heterogeneous materials. For this purpose, the constant stress moment, which is the work
conjugate quantity of the constant strain gradient for the finite volume evaluation region, is introduced. The
proposed stress moment can be evaluated from the stress field. The extended constitutive equation that relates thestrain, stress, strain gradient, and stress moment is then formulated to predict the nonuniform deformation
behavior of heterogeneous materials. In order to confirm that the proposed method is appropriate to represent thenonuniform deformation, finite element method (FEM) simulations of bending of macroscopically andmicroscopically heterogeneous materials were performed. The proposed method could predict the bending
deformation of macroscopically heterogeneous material as precisely as the homogeneous case because the
distribution of the heterogeneity is introduced in the extended constitutive equation. A bending simulation of alaminated cantilever was then performed using the extended constitutive equation for the microscopicallyheterogeneous material. The proposed method was capable of representing the analytically verified size-dependent
bending deformation of the laminated cantilever.
Estimation of Slip Deformation of Polycrystalline Pure Copper using Digital Image Correlation Method
and Crystalline Plasticity Theory
M. UCHIDA, A. TANIGUCHI and Y. KANEKO
Advanced Experimental Mechanics, 3, pp.135-140, (2018).
The estimation of the slip deformation under the multiaxial stress state in the polycrystalline structure, which is
caused by highly anisotropic deformation in microscopic scale of material, can provide an important information
to understand the deformation mechanisms of crystalline material. In the present study, an evaluation method ofslip deformation in the microscopic local region is proposed by coupling the Digital Image Correlation (DIC)
Method and the crystalline plasticity theory. Microscopic strain field and slip deformation of the polycrystalline
pure copper under uniaxial tension were evaluated using the proposed method. The nonuniform deformation in the
crystal grain was firstly evaluated by DIC. Then, the slip deformation for all grains and all slip systems were
estimated using the proposed method. Although the initial crystalline orientations were similar for different grains,
the active slip systems for the grains did not coincide due to the interaction with surrounding grains. The multiple
slip deformation occurred for almost crystal grain regardless of the degree of the total slip in the FCC metal.
Effects of Two Scaling Exponents on Biaxial Deformation and Mass Transport of Swollen Elastomers
D. OKUMURA, M. MIZUTANI, H. TANAKA and M. UCHIDA－43－

Int. J. Mech. Sci., 146-147, pp.507-516, (2018).
In this study, we investigate the effects of two scaling exponents on the biaxial deformation and mass transport ofswollen elastomers. Two scaling exponents are included in an extended version of the Flory–Rehner model(Okumura et al., J. Mech. Phys. Solids, 2016); two scaling exponents are used to adjust the swelling effects on the
Young's modulus and osmotic pressure of swollen elastomers, resulting in the ability to predict swelling-induced
strain softening under uniaxial tensile loading. It is found that when biaxial tensile loading is given under stresscontrol, strain softening is accelerated by increasing the biaxial stress ratio, while under strain control, theresponses become more complicated, which can be interpreted by considering that Poisson's ratio at equilibrium
free swelling can take negative values depending on the two scaling exponents. Further, the effect of the two
scaling exponents on mass transport is discussed by analyzing the swelling kinetics of a gel layer constrained on arigid substrate.
Transient Mechanical Relaxation Behavior of Glassy Polymers Subjected to A Stepwise Change ofCompression Rate
Shin’ya YOSHIOKA and Ryuki MASUDA
Nihon Reoroji Gakkaishi (J. Soc. Rheol., Jpn), Vol.45, pp.235-241 (2017) (in Japanese).
Transient single relaxation time τSS of glassy polymers was evaluated by using a nonlinear single relaxation model
during uniaxial compression processes in which the compression rate changed stepwise from ߝ௡ଵሶ to ߝ௡ଶሶ . Afterthe change of compression rate, stress showed an undershoot (ߝ௡ଵሶ > ߝ௡ଶሶ ) or an overshoot (ߝ௡ଵሶ < ߝ௡ଶሶ ) before
reaching the same value as the constant-rate compression at ߝ௡ଶሶ . After a decrease of compression rate, τSS
increased monotonously to the steady value at ߝ௡ଶሶ . When the compression rate increased, τSS showed adiscontinuous increase right after the acceleration, then steeply decreased to the steady value at ߝ௡ଶሶ . Transient
values of τSS after a decrease of compression rate as a function of the nonlinear flow rate ߝఎഥሶ of the dashpot in themodel were almost the same function as the steady value of τSS, which was almost inversely proportional to ߝఎഥሶ .
After an increase of compression rate and also in the transient state under the constant rate compression, τSS (ߝఎഥሶ )showed a higher value than those in the steady flow state. This observation indicates that, when glassy structures
are getting unstable due to deformation, the nonlinear flow requires larger stress than the steady flow.
Transient Variation of Dynamic Viscoelasticity of Uniaxially Stretched Glassy Poly(methyl methacrylate)after Abrupt Change of Tensile Rate
Shin’ya YOSHIOKA and Hiroaki MATSUMOTO
Nihon Reoroji Gakkaishi (J. Soc. Rheol., Jpn), Vol.46, pp.185-187 (2018) (in Japanese).
Variation of dynamic shear modulus, G*=G´+iG, was measured for glassy poly(methyl methacrylate) (PMMA)
during uniaxial stretching processes where the tensile rate changed stepwise. Under the condition of constant-rate
stretching, it is known that G´ and G gradually change to their steady values in the post-yield range of strain, andthat the change occurs strongly at a higher tensile rate, indicating strain-induced changes in glassy structures.
After a change of tensile rate, G´ as well as G varied monotonously from their values at the initial tensile rate tothose at the final rate in a strain range where the uniaxial stress σ exhibited transient responses to the tensile ratechange. The observed variation of G´ and G simply indicates that, after an abrupt change of tensile rate,
structures of the glass successively change from those corresponding to initial tensile rate to final rate.

－44－

Electronics and Informatics
Applied Physics and Electronics
Ultrafast Dynamics of Coherent Optical Phonon Correlated with the Antiferromagnetic Transition in a
Hexagonal YMnO3 Epitaxial Film
Takayuki HASEGAWA, Norifumi FUJIMURA and Masaaki NAKAYAMA
Applied Physics Letters, Vol. 111, 192901 (5 pages) (2017)
We report on the observation of the coherent optical phonon in a hexagonal YMnO3 epitaxial film using areflection-type pump-probe technique at various temperatures, excitation powers, and energies. We detected an
oscillatory structure with a frequency of ∼5.1 THz, which is assigned to the coherent optical phonon with A1
symmetry, in a time-domain signal. It was found that the coherent optical phonon can be observed at temperaturesfrom 10 K to room temperature, while the oscillation amplitude markedly decreases with an increase intemperature around ∼70 K corresponding to the Néel temperature. The temperature dependence of the oscillation
amplitude indicates that the coherent optical phonon is sensitive to the spin-lattice coupling connected with theantiferromagnetic transition.
DOI: 10.1063/1.5003269
Screening Effects of Photogenerated Carriers on Terahertz Radiation from Coherent GaAs-like
Longitudinal Optical Phonons in (11n)-Oriented GaAs/In0.1Al0.9As Strained Multiple Quantum Wells
Hideo TAKEUCHI, Souta ASAI and Masaaki NAKAYAMA
Journal of Physics: Conference Series, Vol. 906, 012020 (4 pages) (2017)
We investigated terahertz radiation from coherent GaAs-like longitudinal optical (LO) phonons in (11n)-oriented
GaAs/In0.1Al0.9As strained multiple quantum wells for clarifying the screening effects of photogenerated carriers.
We observed the intense quasi-monochromatic terahertz wave from the coherent GaAs-like LO phonon, which
originates from the initial polarization enhanced by the strong piezoelectric field. The intensity of the coherent
GaAs-like LO-phonon band exhibited a saturation behavior as the pump power was increased. We evaluated thesaturation behavior in terms of excitation efficiency of the terahertz wave from the coherent GaAs-like LO
phonon using the parameter of unit-power intensity. From the pump-power dependence of the unit-power intensity,
we conclude that the screening effect of high density photogenerated carriers on the piezoelectric field causes
saturation of the terahertz-wave intensity from the coherent GaAs-like LO phonon.
DOI: 10.1088/1742-6596/906/1/012020
Bayesian Spectroscopy of Admixed Photoluminescence Spectra with Exciton, Biexciton and Electron Hole
Droplet States in a GaAs/AlAs Type-II Superlattice
Kazunori IWAMITSUA, Yoshiaki FURUKAWA, Masaaki NAKAYAMA, Masato OKADA and Ichiro AKAI
Journal of Luminescence, Vol. 197, pp. 18-22 (2018)
We have analyzed a photoluminescence (PL) spectrum in a GaAs/AlAs type-II superlattice and have statisticallyconfirmed stable existence of an electron-hole droplet (EHD) state. Although the PL spectrum consists of spectral
components of the EHD, exciton and biexciton states, we have succeeded in decomposing the admixed spectrum
into the respective components. In addition, posterior probability distributions of spectral parameters have beenobtained in all spectral components from 30,000 times samplings through a replica exchange Monte Carlo method.
By using mean values of their posterior probabilities, the PL spectrum can be completely reproduced by the sumof these spectral components. The stability energy of the EHD state has a sharp distribution in its posterior
probability and has been confirmed to be enough larger than the ambient thermal energy. This fact is a strong
evidence for the stable formation of the EHD state in the GaAs/AlAs type-II superlattice.
DOI: 10.1016/j.jlumin.2018.01.002
Quantitative Evaluation of Light-Matter Interaction Parameters in Organic Single-Crystal Microcavities
Takumi NISHIMURA, Kenichi YAMASHITA, Shun TAKAHASHI, Takeshi YAMAO, Shu HOTTA, Hisao
YANAGI and Masaaki NAKAYAMA
Optics Letters, Vol. 43, pp. 1047-1050 (2018)
Investigation of physics on light-matter interaction and strong coupling formation in organic microcavities isimportant to characterize the device structure enabling efficient room-temperature polariton condensation. In thisstudy, we evaluate quantitatively the light-matter interaction parameters for three types of organic single-crystal
microcavities and discuss the effects of microcavity structures on the strong coupling formation. We found that－45－

improvement in cavity quality factor causes a reduction in the photon damping constant, which results in an
increase in the Rabi splitting energy. Moreover, when we used a metal thin film as the cavity mirror, it was
revealed that the exciton damping became 30 times stronger than that in a dielectric mirror cavity. Theseexperimental findings are very intriguing to achieve low-threshold or electrically pumped organic polariton
devices.
DOI: 10.1364/OL.43.001047
Temperature Effect on the Dispersion Relation of Nonequilibrium Exciton-Polariton Condensates in a
CuBr Microcavity
Masaaki NAKAYAMA and Kazuki TAMURA
Journal of the Physical Society of Japan, Vol. 87, 053701 (4 pages) (2018)
We observed the dispersion relation of nonequilibrium exciton-polariton condensates at 10 and 80 K in a CuBr
microcavity using angle-resolved photoluminescence spectroscopy. The dispersion relation consists ofdispersionless and dispersive parts in small and large in-plane wave vector regions, respectively. It was found thatthe cutoff wave vector of the dispersionless region at 80 K is larger than that at 10 K. From quantitative analysisof the dispersion relation based on a theory for nonequilibrium condensation, we show that the larger cutoff wave
vector results from an increase in the effective relaxation rate of the Bogoliubov mode in equilibrium
condensation; namely, a degree of nonequilibrium at 80 K is higher than that at 10 K.
DOI: 10.7566/JPSJ.87.053701
Biexciton Relaxation Associated with Dissociation into a Surface Polariton Pair in Semiconductor Films
Yasuyoshi MITSUMORI, Shimpei MATSUURA, Shoichi UCHIYAMA, Kentarao SAITO, Keiichi EDAMATSU,
Masaaki NAKAYAMA and Hiroshi AJIKI
Physical Review B, Vol. 97, 155303 (6 pages) (2018)
We study the biexciton relaxation process in CuCl films ranging from 6 to 200 nm. The relaxation time ismeasured as the dephasing time and the lifetime. We observe a unique thickness dependence of the biexciton
relaxation time and also obtain an ultrafast relaxation time with a timescale as short as 100 fs, while the exciton
lifetime monotonically decreases with increasing thickness. By analyzing the exciton-photon coupling energy fora surface polariton, we theoretically calculate the biexciton relaxation time as a function of the thickness. The
calculated dependence qualitatively reproduces the observed relaxation time, indicating that the biexciton
dissociation into a surface polariton pair is one of the major biexciton relaxation processes.
DOI: 10.1103/PhysRevB.97.155303
Ultrafast Dynamics of Polariton Cooling and Renormalization in an Organic Single-Crystal Microcavity
under Nonresonant Pumping
Kenichi YAMASHITA, Uyen HUYNH, Johannes RICHTER, Lissa EYRE, Felix DESCHLER, Akshay RAO,
Kaname GOTO, Takumi NISHIMURA, Takeshi YAMAO, Shu HOTTA, Hisao YANAGI, Masaaki NAKAYAMA
and Richard H. FRIENDACS Photonics, Vol. 5, pp. 2182-2188 (2018)
Microcavity systems with organic luminescent materials have a hot prospect for room-temperaturecavity-polariton devices. The polariton dispersion relation of organic microcavities is significantly different fromthat of inorganic microcavities due to the strong localization of Frenkel excitons. Also photoexcited particles will
undergo a different cooling mechanism until they reach the polariton ground state. In the characterization ofefficient polariton condensates, therefore, the polariton cooling dynamics as well as the kinetics of the polariton
eigenstate should be measured. Here we present experimental studies on ultrafast dynamics of cavity polaritons inan organic single-crystal microcavity under nonresonant pumping. In time-resolved photoluminescencemeasurements we observed, for the first time, an ultrafast dynamics of stimulated cooling of the organic cavity
polariton. Transient transmission measurement enabled us to investigate the detailed renormalization dynamics ofthe polariton eigenstate. The results clearly demonstrated the prospect of organic microcavities forroom-temperature polaritonic devices.
DOI: 10.1021/acsphotonics.8b00041
Evidence for Spatial Propagation of Photon-like Polaritons Generated by Exciton-Exciton Scattering in a
GaAs/AlAs Multiple-Quantum-Well Structure
Yoshiaki FURUKAWA and Masaaki NAKAYAMA
Journal of the Physical Society of Japan, Vol. 87, 094718 (6 pages) (2018)
We have investigated the polariton characteristics of the photoluminescence (PL) due to exciton–exciton－46－

scattering at 10 K in a GaAs/AlAs multiple-quantum-well structure with the use of spatially-resolved PL
spectroscopy. We found that the PL band from the exciton–exciton scattering, the so-called P emission, is detected
only at spots along a sample edge which is spatially separated from an excitation spot. In contrast, the PL bands
attributed to the exciton and biexciton were observed only at the excitation spot. Because the exciton–exciton
scattering occurs at the excitation spot, the appearance of the spatially-separated P-emission spot demonstrates
that the photon-like lower polariton, which is the nal state of the exciton–exciton scattering process, propagatesalong the interface, leading to conversion to a photon. The spectral shape of the P-PL band detected at the
spatially-separated spot exhibits a fringe pattern, which is quantitatively explained by the Fabry–Pérot interference
originating from the spatial separation of the P-emission and excitation spots.
DOI: 10.7566/JPSJ.87.094718
Quick Synthesis of Water-Soluble, Luminescent ZnTe Nanoparticles by Hydrothermal TechniqueHang-Beom BU and DaeGwi KIM
Chem. Lett. Vol. 47, pp. 152–155 (2018).
We first report the successful quick synthesis of water-soluble ZnTe nanoparticles (NPs) by a hydrothermal
technique. The use of N-acetyl-L-cysteine as a ligand and adjustment of the precursor solution’s pH to 10.3±0.2
are believed to play key roles in the quick synthesis of ZnTe NPs with a high photoluminescence quantum
efficiency of 15%. The reaction time is at least 140-fold quicker than the previous works.
DOI:10.1246/cl.170917
Experimental Verification of Förster Energy Transfer and Quantum Resonance Between Semiconductor
Quantum Dots
DaeGwi Kim, TaeGi Lee, Yong-Shin Lee, and Taichi Watanabe
Current Appl. Phys. Vol. 18, pp. S14-S20 (2018).
Quantum dot (QD) superlattices have the potential to provide new optical properties and functions based oninteractions between adjacent QDs. Two types of interactions occur between the QDs: energy transfer (ET) fromsmall-sized QDs to large QDs and resonant coupling between QDs with equal eigenenergies. Since ET andresonant coupling strongly depend on the distance between QDs, it is critical to precisely control the distance tounderstand the interaction mechanism. In this review, we describe that the distance between QDs can becontrolled with an accuracy of 1 nm by a layer-by-layer method and further explain the mechanisms of ET andresonant coupling between adjacent QDs.
DOI:10.1016/j.cap.2017.11.012
Surface Modification Effects on Defect-Related Photoluminescence in Colloidal CdS Quantum Dots
TaeGi Lee, Kunio SHIMURA, and DaeGwi KIM
Phys. Chem. Chem Phys. Vol. 20, pp. 11954-11958 (2018).
We investigated the effects of surface modification on the defect-related photoluminescence (PL) band in colloidal
CdS quantum dots (QDs). A size-selective photoetching process and a surface modification technique with aCd(OH)2 layer enabled the preparation of size-controlled CdS QDs with high PL efficiency. The Stokes shift ofthe defect-related PL band before and after the surface modification was ~1.0 eV and ~0.63 eV, respectively. Thisdifference in the Stokes shifts suggests that the origin of the defect-related PL band was changed by the surface
modification. Analysis by X-ray photoelectron spectroscopy revealed that the surface of the CdS QDs before andafter the surface modification was S rich and Cd rich, respectively. These results suggest that Cd-vacancy
acceptors and S-vacancy donors affect PL processes in CdS QDs before and after the surface modification,
respectively.
DOI:10.1039/C7CP07812A
Linear stability of periodic three-body orbits with zero angular momentum and topological dependence of
Kepler’s third law: a numerical test
Veljko DMITRASINOVIC, Ana HUDOMAL, Mitsuru SHIBAYAMA and Ayumu SUGITA
Journal of Physics A: Mathematical and Theoretical, 51, 315101 (2018)
We test numerically the recently proposed linear relationship between the scale-invariant period Ts.i.=T|E|3/2, andthe topology of an orbit, on several hundred planar Newtonian periodic three-body orbits. Here T is the period ofan orbit, E is its energy, so that Ts.i. is the scale-invariant period, or, equivalently, the period at unit energy |E|=1.
All of these orbits have vanishing angular momentum and pass through a linear, equidistant configuration at least
once. Such orbits are classified in ten algebraically well-defined sequences. Orbits in each sequence follow anapproximate linear dependence of Ts.i., albeit with slightly different slopes and intercepts. The orbit with the－47－shortest period in its sequence is called the 'progenitor': six distinct orbits are the progenitors of these ten
sequences. We have studied linear stability of these orbits, with the result that 21 orbits are linearly stable, which
includes all of the progenitors. This is consistent with the Birkhoff–Lewis theorem, which implies existence of
infinitely many periodic orbits for each stable progenitor, and in this way explains the existence and ensures
infinite extension of each sequence.
Electrical Characteristics of Solder-Free SiC Die/Metal Foil/AlN Plate Junctions Fabricated Using Surface
Activated Bonding
Sho MORITA, Jianbo LIANG, and Naoteru SHIGEKAWA
Extended Abstracts of Americas International Meeting on Electrochemistry and Solid State Science (AiMES), 961(2018).
Atomistic Structure of Low-Resistance Si/GaAs Heterointerfaces Fabricated By Surface-Activated Bondingat Room Temperature
Yutaka OHNO (Univ. of Tohoku), Hideto YOSHIDA (Univ. of Osaka), Seiji TAKEDA (Univ. of Osaka), LiangJIANBO, and Naoteru SHIGEKAWA
Extended Abstracts of Americas International Meeting on Electrochemistry and Solid State Science (AiMES), 968(2018).
Investigation of Residual Strain in 4H-SiC/Si Heterostructures Fabricated By Surface Activated Bonding
Jianbo LIANG, Yan ZHOU (Univ. of Bristol), Shoji YAMAJO, Martin KUBALL (Univ. of Bristol), Manabu
ARAI (New Japan Radio Co. Ltd.), and Naoteru SHIGEKAWA
Extended Abstracts of Americas International Meeting on Electrochemistry and Solid State Science (AiMES), 975(2018).
Room-temperature Direct Bonding of Diamond and Al
Jianbo LIANG, Shoji YAMAJO, Martin KUBALL (Univ. of Bristol), and Naoteru SHIGEKAWA
Scripta Materialia 159, 58 [4 pages] (2018)
The direct bonding of diamond and Al substrates was achieved by surface activated bonding at room temperature.
The interfacial structure of the diamond/Al bonding interface with annealing at different temperatures wasinvestigated under in-situ annealing in a transmission electron microscope (TEM). An amorphous layer with athickness of about 4 nm was present at the bonding interface without annealing, the thickness of the amorphouslayer decreased with increasing annealing temperature, the amorphous layer vanished after annealing at 600 °C.
No structural defects were observed at the bonding interface with annealing at different temperatures. The
sp2/(sp2 + sp3) ratio in the diamond near the interface estimated from the X-ray photoemission spectra increased
from 3.4 % to 26.6 % after the irradiation of Ar fast beam that is an essential process to activate the surface of thebonding materials, and decreased from 26.6 % to 1.2 % after annealing at 600 °C, which should be predominantly
attributable to the diamond-graphite conversion.
The combination of Diamond devices with Si LSI by surface activated bonding
Jianbo LIANG, Satoshi Masuya (Univ. of Saga), Makoto Kasu (Univ. of Saga), and Naoteru SHIGEKAWA
Extended Abstracts of 12h New Diamond and Nano Carbons Conference, pp. 36 (2018).
Room-temperature direct bonding of diamond to aluminum
Jianbo LIANG, Shoji YAMAJO, Martin KUBALL (Univ. of Bristol), and Naoteru SHIGEKAWA
Extended Abstracts of 29h International Conference on Diamond and Carbon Materials, O4.1 (2018).
GaAs/indium tin oxide/Si bonding junctions for III-V-on-Si hybrid multijunction cells with low series
resistance
Naoteru SHIGEKAWA, Tomoya HARA, Tomoki OGAWA, Jianbo LIANG, Takefumi KAMIOKA (Toyota
Technological Institute), Kenji ARAKI (Toyota Technological Institute), and Masafumi YAMAGUCHI (Toyota
Technological Institute)
IEEE J. Photovoltaics 8, 579 [8 pages] (2018)
Effects of GaAs/indium tin oxide (ITO)/Si junctions on III-V-on-Si multijunction solar cells are examined byfabricating and characterizing InGaP/GaAs/ITO/Si triple-junction (3J) solar cells. The 3J cells are fabricated byevaporating ≈ 100-nm-thick ITO films on the surfaces of Si bottom cells and bonding the InGaP/GaAs
double-junction (2J) subcells and the ITO films using surface activated bonding technologies at room temperature.

－48－

The current-voltage characteristics of 3J cells with p+-GaAs/ITO/n+-Si and n+-GaAs/ITO/n+-Si junctions arecompared with those of an InGaP/GaAs/Si 3J cell. The parasitic resistance of the respective 3J cells is estimatedby analyzing their characteristics in the dark. We find that the 3J cell with an n+-GaAs/ITO/n+-Si junction shows
the lowest parasitic resistance, which is the origin of its lowest differential resistance at the open-circuit voltage
and highest fill factor. This means that n+-GaAs/ITO/n+-Si junctions are promising for improving theperformances of III-V-on-Si hybrid multijunction cells. The spectral response characteristics of these cells indicatethat the thickness of the ITO films must be optimized.
Electrical properties of Al foil/n-4H-SiC Schottky junctions fabricated by surface-activated bonding
Sho MORITA, Jianbo LIANG, Moeko MATSUBARA (Toyo Aluminum K. K.), Marwan DHAMRIN (ToyoAluminum K. K.), Yositaka NISHIO (Toyo Aluminum K. K.), and Naoteru SHIGEKAWA
Jpn. J. Appl. Phys. 57, 02BE01 [5 pages] (2018)
We fabricate 17-μm-thick Al foil/n-4H-SiC Schottky junctions by surface-activated bonding. Their current–
voltage and capacitance–voltage characteristics are compared with those of Schottky junctions fabricated byevaporating Al layers on n-4H-SiC epilayers. We find that the ideality factor of Al foil/SiC junctions is larger thanthat of conventional junctions, which is due to the irradiation of the fast atom beam (FAB) of Ar. The ideality
factor of Al foil/SiC junctions is improved by annealing at 400 °C. We also find that the Schottky barrier height isincreased by FAB irradiation, which is likely to be due to the negative charges formed at SiC surfaces.
Electrical properties of GaAs//indium tin oxide/Si junctions for III–V-on-Si hybrid multijunction cells
Tomoya HARA, Tomoki OGAWA, Jianbo LIANG, Kenji ARAKI (Toyota Technological Institute), Takefumi
KAMIOKA (Toyota Technological Institute), and Naoteru SHIGEKAWA
Jpn. J. Appl. Phys. 57, 08RD05 [6 pages] (2018)
The electrical properties of GaAs//indium tin oxide (ITO)/Si junctions fabricated by surface-activated bonding(SAB) are investigated with emphasis on their dependence on the temperature of postbonding annealing. The
current–voltage (I–V) characteristics of n+-GaAs//ITO/p+-Si and n+-GaAs//ITO/n+-Si junctions without annealing
are linear. Those of p+-GaAs//ITO/p+-Si and p+-GaAs//ITO/n+-Si junctions without annealing are nonlinear.
Although the interface resistance of all the junctions increases with increasing annealing temperature, theresistances of the respective junctions after the annealing at 400 °C are still smaller than the series resistance of
the actual SAB-based InGaP/GaAs//Si hybrid triple-junction cells (̴4Ωcm2). The n+-GaAs//ITO/n+-Si junction
reveals the lowest resistance among the investigated junctions after annealing. These results demonstrate that
GaAs//ITO/Si junctions with an ITO intermediate layer could be effective for reducing series resistance in hybrid
multijunction cells.
Intrinsic microstructure of Si/GaAs heterointerfaces fabricated by surface-activated bonding at room
temperature
Yutaka OHNO (Univ. of Tohoku), Hideto YOSHIDA (Univ. of Osaka), Seiji TAKEDA (Univ. of Osaka), LiangJIANBO, and Naoteru SHIGEKAWA
Jpn. J. Appl. Phys. 57, 02BA01 [3 pages] (2018)
The intrinsic microstructure of Si/GaAs heterointerfaces fabricated by surface-activated bonding at room
temperature is examined by plane-view transmission electron microscopy (TEM) and cross-sectional scanning
TEM using damage-free TEM specimens prepared only by mechanochemical etching. The bonded
heterointerfaces include an As-deficient crystalline GaAs layer with a thickness of less than 1 nm and an
amorphous Si layer with a thickness of approximately 3 nm, introduced by the irradiation of an Ar atom beam forsurface activation before bonding. It is speculated that the interface resistance mainly originates from the
As-deficient defects in the former layer.
Analysis of effects of interface-state charges on the electrical characteristics in GaAs/GaN heterojunctions
Shoji Yamajo, Jianbo LIANG, and Naoteru SHIGEKAWA
Jpn. J. Appl. Phys. 57, 02BE02 [5 pages] (2018)
Electrical properties of p+-GaAs/n-GaN and n+-GaAs/n-GaN junctions fabricated by surface-activated bonding areinvestigated by measuring their capacitance–voltage (C–V) and current–voltage (I–V) characteristics. The
difference between their flat-band voltages (0.17 eV), which are extracted from C–V measurements, disagrees
with the ideal value (1.52 V), suggesting that the Fermi level should be pinned at the bonding interface. The C–V
characteristics of the two junctions are calculated by assuming that the Fermi level is pinned at the interface. The
measured C–V characteristics quantitatively agree with modeled ones obtained by assuming that the interface－49－

state density and conduction band discontinuity are 1.5×1014cm-2 eV-1 and 0.63 eV, respectively. The effective
heights of barriers at interfaces, which we estimate by analyzing dependences of I–V characteristics on theambient temperature, are ̴10–20 meV for the two junctions at room temperature. This suggests that the transportof carriers is dominated by tunneling through interface states.
Transport characteristics of minority electrons across surface-activated-bonding based p-Si/n-4H-SiC
heterointerfaces
Naoteru SHIGEKAWA, Sae SHIMIZU, Jianbo LIANG, Masato SHINGO (Univ. of Fukui), Kenji SHIOJIMA(Univ. of Fukui), and Manabu ARAI (New Japan Radio Co. Ltd.)
Jpn. J. Appl. Phys. 57, 02BA04 [5 pages] (2018)
We investigate the transport properties of minority electrons across p-Si/n-4H-SiC interfaces fabricated using
surface activated bonding. The transport properties along each direction are examined by measuring thephotoresponse (PR) of p-Si/n-4H-SiC heterojunctions and characterizing 4H-SiC/Si heterojunction bipolartransistors (HBTs). The photoyield obtained in PR measurements is sensitive to the concentration of acceptors in
p-Si and reverse-bias voltages, which indicates that the energy of optically excited electrons in p-Si is first relaxed
and then they are driven to n-SiC through the tunneling process. By the postprocess annealing of HBTs, theproperties of emitter/base interfaces are improved so that the current gain is drastically increased, which meansthat the Si/4H-SiC interfaces are in metastable states when the device process is completed. A maximum current
gain of >10 is demonstrated.
Electrical conduction of Si/indium thin oxide/Si junctions fabricated by surface activated bonding
Jianbo LIANG, Tomoki OGAWA, Kenji ARAKI (Toyota Technological Institute), Takefumi KAMIOKA (Toyota
Technological Institute), and Naoteru SHIGEKAWA
Jpn. J. Appl. Phys. 57, 02BA03 [5 pages] (2018)
The electrical properties of n+-Si//indium tin oxide (ITO)/n+-Si, n+-Si//ITO/p+-Si, and p+-Si//ITO/n+-Si junctions
fabricated by surface activated bonding (SAB) were investigated. The current–voltage (I–V) characteristics ofn+-Si//ITO/n+-Si, n+-Si//ITO/p+-Si, and p+-Si//ITO/n+-Si junctions showed excellent linear properties. Theinterface resistances of n+-Si//ITO/n+-Si, n+-Si//ITO/p+-Si, and p+-Si//ITO/n+-Si junctions were found to be 0.030,
0.025, and 0.029Ω‧cm2, respectively, which are lower than required for concentrator photovoltaics. The interface
resistances of all the junctions increased with increasing annealing temperature. The degradation of the interface
resistance is lower in n+-Si//ITO/n+-Si junctions than in n+-Si//ITO/p+-Si and p+-Si//ITO/n+-Si junctions, when
the annealing temperature is higher than 100 °C. These results demonstrate that the ITO thin film as anintermediate layer has high potential application for the connection of subcells in the fabrication of tandem solar
cells.
Semi-analytical Model for a Static Sheath Including a Weakly Collisional Presheath
Tatsuru SHIRAFUJI and Kazuki DENPO (Tokyo Electron Technology Solutions Ltd.)
Jpn. J. Appl. Phys., Vol. 57, 06JG02 (8 pages) (2018)
A semi-analytical static sheath (SASS) model can provide a spatial potential profile on a biased surface withmicrostructures, which can be used for predicting ion trajectories on the surface. However, two- or
three-dimensional SASS models require a search procedure for a sheath edge equipotential profile, at which ionshave the Bohm velocity, as the starting positions for calculating ion trajectories. This procedure can betroublesome when surface microstructures have complex structures. This difficulty is due to the fact that the SASS
model cannot handle a presheath region. In this work, we propose a modified SASS model that can handle apresheath region. By using the modified SASS model, ion trajectories can be calculated from edges with arbitrarygeometry without searching for the equipotential profile corresponding to sheath edges.
DOI: 10.7567/JJAP.57.06JG02
Effects of Ambient Air on the Characteristics of an Atmospheric-pressure Plasma Jet of a Gas Mixture ofHighly N2-diluted O2 on a Sliding Substrate
Tatsuru SHIRAFUJI and Yasushi SAWADA (Air Water R&D Co., Ltd.)
Jpn. J. Appl. Phys., Vol. 57, 01AA06 (10 pages) (2018)
We have performed numerical simulations of reaction kinetics and flow dynamics of an atmospheric-pressureplasma jet (APPJ) of a gas mixture of 99.9% N2 and 0.1% O2 in a two-dimensional flow channel with a height of
5 mm and investigated the effects of a sliding substrate and the substitution of the ambient gas. The sliding
substrate in the flow channel produces the gas-drag effect, which results in not only the bending of the APPJ

－50－

trajectory but also significant loss of atomic oxygen when the ambient gas is air. The flux of atomic oxygen
integrated on the substrate is reduced to 19% of that integrated on the fixed substrate. We discuss the mechanismsof the reduction in the atomic oxygen flux through the analysis of spatial distributions of atomic oxygen loss
reactions and show that the reduction in the atomic oxygen flux can be suppressed by substituting the ambient gas(air) with N2.
DOI: 10.7567/JJAP.57.01AA06
Au-nanoparticle-embedded Cross-linked Gelatin Films Synthesized on Aqueous Solution in Contact with
Dielectric Barrier Discharge
Tatsuru SHIRAFUJI, Yusuke NAKAMURA, Shiori AZUMA, Naoya SOTODA and Toshiyuki ISSHIKI (Kyoto
Inst. Technol.)
Jpn. J. Appl. Phys., Vol. 57, 0102BE (8 pages) (2018)
A wine-red free-standing thin film has been formed by irradiating dielectric barrier discharge plasma on an
aqueous solution containing HAuCl4 and gelatin. The film has a fibrous structure with an inhomogeneous
thickness profile and is composed of cross-linked gelatin, as confirmed by optical microscopy and infraredabsorption spectroscopy. The film has embedded Au nanoparticles (GNPs), as confirmed by transmission electron
microscopy. In the region with a relatively small film thickness, the number density of GNPs is relatively low, andthe sizes of GNPs range from 5.3 to 34.3 nm. In the region with a relatively large film thickness, on the other hand,
GNPs are highly accumulated, and the sizes of GNPs range from 10.0 to 26.7 nm. The aqueous solution remains
transparent even after the film growth process, which indicates that the plasma-induced processes involving GNP
formation and film growth are confined near the surface of the aqueous solution. A possible film growthmechanism is discussed on the basis of the experimental results of this study.
DOI: 10.7567/JJAP.57.0102BE
Simultaneous Generation of Acidic and Alkaline Water Using Atmospheric Air Plasma Formed in Water
Shin-ichi IMAI (Panasonic Corp.), Yoshihiro SAKAGUCHI (Panasonic Corp.) and Tatsuru SHIRAFUJI
Jpn. J. Appl. Phys., Vol. 57, 0102BC (6 pages) (2018)
Plasmas on water surfaces and in water can be generated at atmosphere pressure using several kinds of gases,
including helium, argon, oxygen, and air. Nitrates are generated in water through the interaction between waterand atmospheric plasma that uses ambient air. Water that has been made acidic by the generation of nitric acid andthe acidic water can be used for the sterilization of medical instruments, toilet bowls, and washing machines.
Dishwashers are another potential application, as alkaline water is needed to remove grease from tableware. To
investigate the production of alkaline water and its mechanism, gas component analysis was performed using an
atmospheric quadrupole mass spectrometer. It was found that hydrogen gas evolves from the water surrounding
both the positive and negative electrodes. The gas and water analyses carried out in this study revealed that acidic
water of pH 2.5 and alkaline water of pH 10 can be simultaneously generated by our ambient air plasma device,
which has been altered from our original model. The alterative plasma device has a partition wall, which is madeof conductive resin, between the positive and negative electrodes.
DOI: 10.7567/JJAP.57.0102BC
Plasma Materials Processing Involving Liquid
Tatsuru SHIRAFUJI
Vac. Surf. Sci., Vol. 61, 119-130 (2018) (in Japanese)
In materials processing using plasma in contact with liquid, plasma plays an important role as a trigger to promote
primary processes at the plasma/liquid interface. However, direct effects such as radicals from plasma vanish after
traveling a few or a few 10 nm from the plasma/liquid interface. The rest of the processes in liquid proceed only
deep inside the liquid where the direct effects of plasma are no longer expected. This situation can be regarded as
robustness in the process. However, at the same time, it has a negative aspect of poor controllability by plasma. In
other words, the factor of “the unique to plasm” governs only the limited part of a whole process. In this paper, wesurvey recent research activities on materials processing using plasma in contact with liquid from the view point
mentioned above and discuss why we use plasma.
DOI: 10.1380/vss.61.119－51－

Electrical and Information Engineering
Retinal projection type super multi-view 3D head-mounted display using the time division projection
optical system
Tadayuki KONDA, Katsuhisa TANAKA, Kayo YOSHIMOTO, and Hideya TAKAHASHI
Proc.SPIE Advanced in Display Technologies VIII, San Francisco, Feb. 19, Vol.10556, CD-ROM (2018).
We have previously proposed the see-through 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 real scene. Moreover, if a viewer focuses one’s eyes on the displayed
3D image, the stimulus for the accommodation of human eye is reproduced naturally. To realize the super
multi-view condition, multiple parallax images must be projected onto the retina. However, in the previous
proposed HMD, since the respective parallax images were spatially divided and were projected onto theretina, the image resolution was low and the optical system was complicated. In order to overcome these
problems, we propose the improved see-through retinal projection type super multi-view HMD by using thetime division projection optical system. The proposed HMD consists of a multiple exposure holographic lenswith multi-convergence points, a high frame rate display device, and a high-speed optical shutter. Multiple
parallax images are displayed by time division and are converged on respective points by the holographic
lens. The optical shutter which synchronized to the display device passes only one convergence lightcorresponding to the right parallax image. Therefore, proposed HMD realizes the pseudo super multi-view
condition and displays the virtual image at the distance within ability for focusing on the human eye. To
verify the effectiveness of the proposed HMD, we confirmed the depth range of the 3D image by the
prototype of the proposed HMD was more than 250 mm in front of the pupil.
3D registration method for assessing the gastrointestinal motility using spectral reflectance estimation
Kazuki NOBE, Kayo YOSHIMOTO, Kenji YAMADA (Osaka University), and Hideya TAKAHASHI
Proc.SPIE Advanced Biomedical and Clinical Diagnostic and Surgical Guidance Systems XVI, San
Francisco, Feb. 12, Vol.10484, CD-ROM (2018).
Functional gastrointestinal disorders (FGID) are the most common gastrointestinal disorders. The term
"functional" is generally applied to disorders where there are no structural abnormalities. One of the major
factors for FGID is abnormal gastrointestinal motility. We have proposed a system for assessing the functionof gastric motility using a 3D endoscope. In this previous study, we established a method for estimating
characteristics of contraction wave extracted from a 3D shape include contraction wave obtained from stereo
endoscope. Because it is difficult to fix the tip position of the endoscope during the examination, estimationof the 3D position between the endoscope and the gastric wall is necessary for the accurate assessment. Then,
we have proposed a motion compensation method using 3D scene flow. However, since mucosa has few
feature points, it is difficult to obtain 3D scene flow from RGB images. So, we focused on spectral imaging
that can enhance visualization of mucosal structure. Spectral image can be obtained without switching
optical filters by using technique to estimate spectral reflectance by image processing. In this paper, we
propose registration method of measured 3D shape in time series using estimated spectral image. The
spectral image is estimated from the RGB image for each frame. 3D scene flow of feature points, that is,enhanced mucosal structure calculated by spectral images in a time series. The position change between theendoscope and gastric wall is estimated by 3D scene flow. We experimented to confirm the validity of the
proposed method using papers with a grid of colors close to the background color.
Development of pulse wave sensing textile using conductive fiber
Kayo YOSHIMOTO, Katsuhisa TANAKA, Hideya TAKAHASHI, and Atsuji MASUDA (Industrial
Technology Center of Fukui Prefecture)
Journal of Fiber Science and Technology, vol.73, no.11, pp.294-299 (2017).
This paper describes a pulse wave sensing textile to measure pulse wave continuously without stress. Due toaging population, the attention is focused on measurement of vital signs during daily life. Blood pressure(BP) is widely used as an index representing the state of the circulatory system. BP can be estimated fromelectrocardiogram (ECG) and photoplethysmogram (PPG). PPG can be obtained by a combination of a lightemitting diode (LED) and a phototransistor (PT). The textile measured PPG has not been realized although
there are fabric electrodes for measuring ECG. Therefore we developed the pulse wave sensing textile for－52－

using underwear aiming to continuously BP estimation. By using conductive fibers woven into the textile as
wiring, the pulse wave sensing textile is realized. In order to improve the stability of pulse wave
measurement, LEDs and PTs were arranged in array on the textile. We designed the textile circuit under theconsideration that circuit lines on the textile must be straight. We showed that arranging LEDs and PTs in anarray improve the stability of pulse detection and evaluated that the proposed sensing textile can be measured
pulse wave on the waist even if a person attached the proposed sensing textile is moving. These results
suggest that the proposed sensing textile could be built into underwear and used as a part of BP estimation
system. Unconscious continuous BP monitoring underwear could be realized by combining the proposed
textile with fabric electrodes.
Dynamic hand gesture recognition on 3D virtual cultural heritage ancient collection objects using knearest neighbor
Adri Gabriel Sooai (ITS), Khamid (ITS), Kayo YOSHIMOTO, Hideya TAKAHASHI, Surya Sumpeno(ITS), and Mauridhi Hery Purnomo (ITS)Engineering Letters, vol.26, no.3, EL_26_3_09 (2017).
This paper discusses on how to prepare a specific dynamic hand gesture, modeling and testing it to interact
with 3D virtual objects of cultural heritage ancient collection. Those virtual objects prepared to avoid
damage on the original one. Several kinds of research work for recreation or reactivating ancient heritage foreducational purposes can take place using it. The dynamic hand gesture detected using hand movement
sensor. We recorded ten specific dynamic hand gesture that stands for the interaction between museum
visitors and the ancient collection chosen for the test. All ten gestures consist of fingers tips coordinates,
palm, and wrist movement. A total of 14474 rows in 30 features forming fingers and palm movements
information. Those gestures namely: pickup , sweep from right to left, sweep from left to right, grab fromabove, grab from the right side, pinch from above, pointing, scooping, push and picking. We train ten
dynamic hand gestures using K-NN classifier and using different distance metric namely Cosine, Euclidean
and Cubic. The best result of trained model reaches 99.3% accuracy. Later, we use the new hand gesture to
test the trained model. It consists of 15000 rows of fingers coordinates in 30 features. The results show thatfrom all ten gestures, there are four gestures reach recognition accuracy more than 92%. One gesture reaches
100%, two gestures on 82% and 89% and three gestures below 64%. The gesture which reaches highaccuracy in training and testing consider selected for default model.
Application of online supervisory control of discrete-event systems to multi-robot warehouseautomation
Yuta TATSUMOTO, Masahiro SHIRAISHI, Kai CAI, and Zhiyun LIN (Hangzhou Dianzi University)
Control Engineering Practice, vol. 81, pp. 97-104 (2018).
In this paper we present an online supervisory control approach, based on limited lookahead policy, that is
amenable for the control of multi-agent discrete-event systems. We then apply this online control scheme tomodel and control a warehouse automation system served by multiple mobile robots; the effectiveness of thisscheme is demonstrated through a case study. Moreover, we build an experiment testbed for testing thevalidity of our proposed method with implementation on real robots.
Application of supervisory control theory with warehouse automation case study
Yuta TATSUMOTO, Masahiro SHIRAISHI, and Kai CAI
Transactions of the Institute of Systems, Control and Information Engineers, vol. 62, pp. 203-208 (2018).
In this paper we provide a tutorial on supervisory control theory, and introduce a new application on
warehouse automation using mobile robots. In presenting supervisory control theory, we demonstrate theprocedure of supervisory control design by using an easy-to-use software package TCT. Our purpose is forcontrol scientists and engineers who may not be familiar with the theory to still carry out the design ofsupervisory controllers step-by-step in TCT.
On algebraic connectivity of directed scale-free networks
Takanobu IMAE and Kai CAI
Journal of the Franklin Institute, vol. 355, pp. 8065–807 (2018).
In this paper, we study the algebraic connectivity of directed complex networks with scale-free property.

－53－

Algebraic connectivity of a directed graph is the eigenvalue of its Laplacian matrix whose real part is thesecond smallest. This is known as an important measure for the diffusion speed of many diffusion processes
over networks (e.g. consensus, information spreading, epidemics). We propose an algorithm, extending thatof Barabasi and Albert, to generate directed scale-free networks, and show by simulations the relations
between algebraic connectivity and network size, exponents of in/out-degree distributions, and minimum
in/out degrees. The results are moreover compared to directed small-world networks, and demonstrated on a
specific diffusion process, reaching consensus.
Supervisory control of discrete-event systems: a brief history
W.Murray WONHAM (University of Toronto), Kai CAI, and Karen RUDIE (Queen’s University)
Annual Reviews in Control, vol. 45, pp. 250-256 (2018).
This brief history summarizes the ‘supervisory control of discrete-event systems’ as it has evolved in the
period 1980–2017. Overall, the trend has been from centralized or ‘monolithic’ control to more structured
architectures, and from ‘naive’ to symbolic computation. Like any ‘history’ this one represents theperspective of the authors; in consequence some important contributions may have been overlooked or shortchanged.

－54－

Applied Chemistry and Bioengineering
Quantitative Analysis of Large Voltage Hysteresis of Lithium Excess Materials by “Backstitch Charge andDischarge” Method
Kingo ARIYOSHI, Takayuki INOUE, Yusuke YAMADA
J. Electrochem. Soc., Vol. 165, pp. A2675-A2681 (2018)
Lithium-excess (LEX) materials (LiMO2·Li2MnO3; M = Co, Ni, etc.) are attractive as potential positive electrodesof high-capacity lithium-ion batteries, however, large voltage hysteresis of LEX materials in charge and discharge
disturbs real application. Thus, the large voltage hysteresis was investigated by a novel electrochemical method
termed as a “backstitch charge and discharge” (backstitch CD) method, in which unsymmetrical charge anddischarge with a small capacity were continuously repeated. The backstitch CD method was applied to
Li[Li1/5Co2/5Mn2/5]O2(0.5LCoO2·0.5Li2MnO3) known as an LEX material for the first time.
Li[Li1/5Co2/5Mn2/5]O2 showed different reversible potentials during the backstitch CD processes in spite ofsymmetrical polarization behavior at each process. The voltage hysteresis in Li[Li1/5Co2/5Mn2/5]O2 resulted fromelectrochemically reversible but different reactions occurring during charging and discharging processes.
Contributions of overpotential and difference in reversible potential to the voltage hysteresis can be evaluatedquantitatively by the backstitch CD method.
Effect of Surface Acidity of Cyano-bridged Polynuclear Metal Complexes on Catalytic Activity for
Hydrolysis of Organophosphates
Hiroyasu TABE, Chihiro TERASHIMA, Yusuke YAMADA
Catal. Sci. Technol., Vol. 8, pp. 4747-4756 (2018)
Heterogeneous catalysis of cyano-bridged polynuclear metal complexes, which were prepared by systematic replacementof C-bound metal ions (MC) and/or N-bound metal ions (MN) of Prussian blue ([MN(H2O)x]y[FeII/III(CN)6]; MN = FeIII,
GaIII, MnII, ZnII or CoII: [FeII/III(H2O)x]y[MC(CN)6]; MC = FeII, PtIV, CoIII, IrIII or RuII), was examined for the hydrolysisof p-nitrophenol phosphate (p-NPP) as a model compound of insecticides. The catalytic activity of the complexes wasenhanced by employing metal ions in higher oxidation states at the C- and N-bound sites, although only N-bound metal
ions act as active sites. The dependence of the initial reaction rates for the hydrolysis on the initial concentrationof p-NPP suggested that the rate determining step is the adsorption of p-NPP onto catalyst surfaces. The surface acidityof each complex estimated by the heat of pyridine desorption is strongly correlated with catalytic activity.
Photocatalytic Hydrogen Evolution Systems Constructed in Cross-linked Porous Protein Crystals
Hiroyasu TABE, Hikaru TAKAHASHI, Takuya SHIMOI, Satoshi ABE, Takafumi UENO, Yusuke YAMADA
Appl. Catal. B, Vol. 237, pp. 1124-1129 (2018)
Cross-linked hen egg white lysozyme crystals (CL-HEWL) have been employed as supports to construct
heterogeneous catalysts for photocatalytic hydrogen (H2) evolution, where rose bengal (RB) and Pt nanoparticles(PtNPs) acted as a photosensitizer and H2-evolution catalysts, respectively. Single-crystal X-ray structure analysesof the CL-HEWL immobilizing a precursor for PtNPs suggested that a coordination site of the precursor locates in
immediate proximity to potential adsorption sites for RB. The accumulation of the components facilitatedphoto-induced electron transfer, resulting in efficient H2 evolution. These results suggest that porous protein
crystals are promising platforms to periodically and rationally accumulate catalytic components by using
molecular interactions.
High Dimensional Stability of LiCoMnO4 as Positive Electrodes Operating at High Voltage for Lithium-ion
Batteries with a Long Cycle Life
Kingo ARIYOSHI, Hiroya YAMAMOTO, Yusuke YAMADAElectrochim. Acta, Vol. 260, pp. 498-503 (2018)－55－

Dimensionally stable LiCoMnO4 having a spinel-framework structure was developed as a positive electrodeof lithium-ion batteries with a long cycle life. Well-crystallized LiCoMnO4 prepared by a two-step solid-state
reaction shows large rechargeable capacity of 120 mAh g−1 at high operating voltage of 5 V. Ex-situ XRD
measurements of the LiCoMnO4 revealed small change in the cubic lattice parameter (ca. 0.7%) during charge
and discharge. Change in electrode thickness of LiCoMnO4 measured by using a precision dilatometer isaccordance with the change in the cubic lattice parameter. The LiCoMnO4 electrode showed high dimensional
stability compared with other LiMn2O4-based materials having a spinel-framework structure.
Cobalt-copper Nanoparticles Catalyzed Selective Oxidation Reactions: Efficient Catalysis at Room
Temperature
Biraj Jyoti BORAH, Abhijit MAHANTA, Manoj MNDAL, Hemen GOGOI, Yusuke YAMADA, Pankaj
BHARALI
Chem. Select, Vol. 3, pp. 9826-9832 (2018)
Bimetallic nanoparticles (NPs) play a pivotal role in promoting high activity and selectivity towards various
industrially important reactions in comparison to single metal NPs due to their modulated electronic and surface
properties. Herein, we report the synthesis of non-precious CoCu NPs, which serve as an excellent catalyst for theselective oxidation of a wide range of electronically diverse benzyl alcohols to benzaldehydes, in the presenceof tert‐butyl hydroperoxide (TBHP) as an oxidant at room temperature. The excellent catalytic activity of CoCu
NPs is ascribed to a two‐fold synergistic effect arising from the combination of enhanced peroxide decomposition,
active Co2+ catalyst regeneration driven by the faster redox processes (between Co3+ and Cu+), and a feasible
cobalt dimerisation‐regeneration process. The recoverability and reusability of CoCu NPs are also demonstrated.
With the merits of low‐cost and recyclable catalysis under mild conditions, the present catalyst represents anefficient and potential alternative to precious metal catalysts.
Construction of Assemblies for Photocatalytic Hydrogen Evolution Using Various Supports
Yusuke YAMADA, Hiroyasu TABEJXTG Technical Review, Vol. 60, pp. 8-14 (2018) (in Japanese)
The review discloses how to construct photocatalytic assemblies for hydrogen evolution on various supports. The
assemblies involve a photosensitizer and a hydrogen evolution catalyst in the presence of a sacrificial electron
donor. The supports are chosen from conventional mesoporous silica-alumina, assembly of silica-alumina
nanoparticles, porous protein crystals, and a layered metal oxide semiconductor.
Electrocatalysts for Hydrogen Peroxide Reduction Used in Fuel Cells
Yusuke YAMADA
Anion Exchange Membrane Fuel Cells, Principles, Materials and Systems (Eds. Liang AN, T. S. ZHAO), pp.
141-168, Springer (ISBN: 978-3-319-71370-0)
Hydrogen peroxide is a strong oxidant, which enables to enhance the output power of fuel cells. Thus,
electrocatalysts for hydrogen peroxide reduction have been investigated with various materials such as metals,
metal oxides and metal complexes. This review focuses on cathode materials utilized in hydrogen peroxide fuelcells.
X-Ray Technology
Kouichi TSUJI
Encyclopedia of Analytical Chemistry:, Kirk-Othmer Encyclopedia of Chemical Technology, John Wiley & Sons,
Inc.(2018) DOI: 10.1002/0471238961.2418012519160118.pub3
Analytical X-ray instruments are used to characterize materials in several ways. There are analytical instrumentsthat can produce images of the internal structure of objects that are opaque to visible light. There are instruments
used to determine chemical composition of an object, the crystalline phases of solids, and the complete atomic and－56－molecular structure of a single crystal. The determination of particle size, structural information for fibers andpolymers and the study of stress, texture, and thin films are applications that are growing in importance and can be
examined with X-ray instruments. This article gives information on the characterization, generation, andproperties of X-Rays, and principles of X-ray diffraction. Small molecule and macromolecule single-crystal
structure determinations are discussed. These techniques are compared with powder diffraction. X-ray
reflectometers, position sensitive detectors, and area detectors are some of the special instruments designed tomeasure properties of the new and exotic materials being manufactured. Details on X-ray fluorescence
spectrometry and X-ray radiography are also given.
X-Ray Spectrometry
Kouichi TSUJI, Yasuji MURAMATSU
Kodansha Ltd., total page 352 (2018) (in Japanese)
Fundamentals and applications of X-ray fluorescence (XRF), Electron microprobe analysis (EPMA), x-ray
absorption (XAS) including EXAFS and XANES, total reflection XRF (TXRF), soft x-ray XRF, XRF imagining,and scanning transmission x-ray microscope (STXM) are described in details. In chapter 2, x-ray tube,
synchrotron radiation, x-ray detectors are explained. In chapter 3, quantitative XRF analysis using fundamental
parameter (FP) method and principle of XRF technique are explained. In chapter 4, EPMA are introduced withintroduction of wavelength dispersive spectrometer. In chapter 5, fundamental of XAS and applications are shown.
Finally, in chapter 6, applications of x-ray techniques to metals, inorganic materials, plastic materials, soils,
aerosol particles, catalyst materials, battery materials, and biological and food samples are shown as well as
sample preparation techniques.
Large-area Imaging by WD-XRF Analysis and Elemental Monitoring of the Dissolution Process of a Solid
SampleShota AIDA, Yuki TAKIMOTO, Takuto SAKUMURA, Kazuyuki MATSUSHITA, Takashi SHOJI, Naoki
KAWAHARA
Bunseki Kagaku, Vol. 66, pp. 885-892 (2017) (in Japanese)A wavelength-dispersive X-ray fluorescence (WD-XRF) imaging spectrometer gives XRF images more rapidly
than energy-dispersive X-ray fluorescence (ED-XRF). The analyzing area by this method is dependent on the
diameter of the used 2D collimator. We considered large-area imaging while scanning a sample, to enlarge theanalyzing area. Then, the analyzing object was measured at each segment, and obtained XRF images werecombined. As the result, Cu and Br elemental whole images were constructed for an electronic circuit card (30mm × 54 mm), with a total exposure time of 54 s. In addition, WD-XRF imaging rapidly provides specificelemental images. Therefore, this method was applied for the monitoring of chemical reactions in liquid samples.
WD-XRF imaging was repeated in an exposure time of 60 s/frame for observing the dissolution process of metals
in solutions. Consequently, the dissolution process of a Zn piece in hydrochloric acid was visualized from Zn Kαintensity distributions.
Fundamental Study on Quantitative Full Field XRF Imaging with X-ray CCD Camera
Masaki YAMANASHI, Aoi YAMAUCHI, Kouichi TSUJI
Bunseki Kagaku, Vol. 66, pp. 901-907 (2017) (in Japanese)A full field energy-dispersive X-ray imaging apparatus (FF-EDXRF) using photon counting technique wasproposed by our group and confirmed its performance. The energy resolution was 142 eV for Fe Kα line, thespatial resolution was 52 µm. These values are equally of the energy-dispersive X-ray detector and micro-XRF
imaging apparatus. X-ray fluorescence images of multi elements was obtained at the same time for the print color
board sample. The quantitative method of full field X-ray imaging apparatus has not established. The calibration
curve created by Ni standard materials (FXS 326 - 331) are evaluated by R2 value. The accuracy of calibration－57－

curve and R2 value was satisfied and one calibration curve created by summarized all calibration curve are applied
for all effective pixels.
Cross Sectional Elemental Mapping of Under Film Corrosion of Galvanized Steel Sheets by Confocal XRF
Analysis
Koji AKIOKA, Takashi DOI, Ryota YAGI, Tsuyoshi MATSUNO, Kouichi TSUJI
Proc. of the 11th Int. Conf. on Zinc and Zinc Alloy Coated Steel Sheet Galvatech2017, Tokyo, Japan, ISIJ, pp.
161-168 (2017)
For the understanding of the under film corrosion behavior of the painting steel sheet, grasp of the element
behavior in the solid - liquid interface is important. Because the XRF analysis technique using fluorescence
X-rays can get element distribution information in nondestructiveness, it is thought that it is effective analysis
technique. Above all, as for the micro-XRF technique using the confocal optical system, the section observationof test specimens is possible in nondestructiveness. This time, the process of under film corrosion of painted
galvanized steel sheet was investigated by confocal micro-XRF method. To reduce the attenuation of fluorescent
x-ray by air, the area of analysis was placed in a vacuum chamber. L-line of Rh target of X-ray was used tomeasure the signal from light element sensitively. Painted galvanized steel sheet was prepared byelectro-deposition coating with zinc phosphate conversion coating. Moving test specimens to depth direction with
confocal optical placement, the cross sectional element map was measured. The depth profiles of light element
were broad compare to those of heavy element. The thickness of each layer was estimated by comparing the peak
distance of the profile of each element.
To investigate the under film corrosion process, the dipping type acceleration corrosion test was applied. The
painted galvanized steel sheet was scratched to reach Fe substrate, and then, it was immersed to a 5 mass %sodium chloride solution at 55 °centigrade. The cross section maps of the same field of vision were observed
every 48 hours to make use of the merit of the non-destructive analysis. The obtained element map of Ti revealed
that blister type corrosion around the scratch. From the depth maps of P and Zn, these were observed that thecross sectional elemental maps were changed and the intensity of P and Zn signal were decreased near the blister.
It was suggested that some Zn and P atoms in the zinc phosphate coating layer dissolved into the NaCl solution.
After 240 hours, the cross sectional elemental maps obtained by this XRF non-destructive method were compare
to the cross sectional SEM/EDS images obtained by destructive method.
The 17th International Conference on Total Reflection X-Ray Fluorescence Analysis and Related Methods(TXRF2017)
Kouichi TSUJI
Adv. X-Ray. Chem. Anal., Japan, Vol. 49, pp. 71-76 (2018) (in Japanese)
The 17th International Conference on Total Reflection X-Ray Fluorescence Analysis and Related Methods(TXRF2017) was held in the period from 19 Sept. to 22 Sept. 2017 at “Centro Pastorale Paolo VI” ConferenceCentre in Brescia Italy. Details of this international conference were reported as well as VAMAS (Versailles
Project on Advanced Materials and Standards) course, which was held during TXRF2017. In addition, ISO
TC201/ SC10 meeting was held before TXRF2017. The activity of SC10 was also described.
Elemental Distribution Analysis in the Hair by Confocal Micro XRF
Naoya YOMOGITA, Kouichi TSUJI
Adv. X-Ray. Chem. Anal., Japan, Vol. 49, pp. 209-218 (2018) (in Japanese)
Confocal micro X-ray fluorescence is an effective method for obtaining information about elemental distribution
inside the sample. A hair has trace elements such as Ca and Zn, so it is possible to examine deficiency of theseelements and whether we take harmful metal by scanning one’s hair. Then, we tried obtaining elemental map at
any position and revealing information about elemental distribution from the hair root to top by applying confocal
micro XRF. We also investigated the possibility about invasion of element from outside by analyzing fluorescent－58－

X-ray intensity of hair on surface and at center in specific cross section. In the hair applied a permanent wave, it
became clear that it receives strong contamination from the outside.
Elemental Analysis of Teas, Herbs and Their Infusions by Means of Total Reflection X-Ray Fluorescence
Rogerta DALIPI, Laura BORGESE, Kouichi TSUJI, Elza BONTEMPI, Laura E. DEPERO
Journal of Food Composition and Analysis, Vol. 67, pp. 128-134 (2018)
This work shows that total reflection X-ray fluorescence (TXRF) is a suitable tool for multi-elemental analysis ofteas, herbs and their infusion. A low power benchtop TXRF spectrometer was used. Safety of infusion
consumption was evaluated. Many commercially available teas,herbs and roots samples were analyzed. Total
concentrations of thirteen elements K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Rb, Sr, Ba and Pb as well as their extraction
efficiencies into infusion were determined. The content of Pb is highlighted in all teas and herbs, in theconcentration range between 0.5 and 4.8 mg/g, but only in infusions of herbs. Chemometry was applied forclassification purposes. Elemental daily intakes with respect to infusion drinking was calculated and comparedwith dietary reference intake values. Results show that TXRF is a fast and simple technique for safety check of tea
and herb infusions on a routine basis.
Corrosion Process Analysis of Steel Samples by Confocal Micro 3D X-Ray Fluorescence Analysis
Kouichi TSUJI
NSST Communication Bulletin, Vol. 99, pp. 2-3 (2018) (in Japanese)
Fundamental of confocal micro-XRF technique was introduced. A few applications of this technique to steel
samples were introduced.
X-Ray Fluorescence Elemental Imaging of Liquid Samples Near Solid Surface.
Kouichi TSUJI
Transactions of The Research Institute of Oceanochemistry, Vol. 31, No. 1, Apr., pp. 27-30 (2018) (in Japanese)
Fundamental of confocal micro-XRF technique was introduced. A few applications of this technique tosolid-liquid interface analysis were shown.
Sample Preparation for Total Reflection X-ray Fluorescence Analysis Using Resist Pattern Technique
Kouichi TSUJI, Naoya YOMOGITA, Yuji KONYUBA
Spectrochim. Acta Part B, Vol. 144, pp. 68-74 (2018)
A circular resist pattern layer with a diameter of 9 mm was prepared on a glass substrate (26 mm × 76 mm; 1.5mm thick) for total reflection X-ray fluorescence (TXRF) analysis. The parallel cross pattern was designed with awall thickness of 10 μm, an interval of 20 μm, and a height of 1.4 or 0.8 μm. This additional resist layer did not
significantly increase background intensity on the XRF peaks in TXRF spectra. Dotted residue was obtained froma standard solution (10 μL) containing Ti, Cr, Ni, Pb, and Ga, each at a final concentration of 10 ppm, on a normal
glass substrate with a silicone coating layer. The height of the residue was more than 100 μm,whereself-absorption in the large residue affected TXRF quantification (intensity relative standard deviation (RSD): 12–20%). In contrast, froma droplet composed of a small volume of solution dropped and cast on the resist pattern
structure, the obtained residue was not completely film but a film-like residue with a thickness less than 1 μm,
where self-absorption was not a serious problem. In the end, this sample preparationwas demonstrated to improve
TXRF quantification (intensity RSD: 2–4%).
Comparison of Multiple X-Ray Fluorescence Techniques for Elemental Analysis of Particulate Matter
Collected on Air Filters
Fabjola BILO, Laura BORGESE, Anne WAMBUI, Ahmad ASSI, Annalisa ZACCO, Stefania FEDERICI,
Diane EICHERT, Kouichi TSUJI, Roberto LUCCHINI, Donatella PLACIDI, Elza BONTEMPI, Laura
Eleonora DEPERO－59－

Journal of Aerosol Science, Vol. 122, pp. 1-10 (2018)
This work reports on qualitative and semi-quantitative elemental analysis of particulate matter (PM) collected on
PTFE membrane filters, for a source apportionment study conducted in Brescia (Italy). Sampling was undertaken
in a residential area where an increase in Mn emissions has been highlighted by previous studies. Filters aremeasured by means of X-ray Fluorescence (XRF) based techniques such as micro-XRF and grazing incidence
XRF using synchrotron radiation, Mo or W excitation sources, after applying an automatized sample preparation
method. A heterogeneous distribution in PM shape, size and composition was observed, with features typical ofanthropogenic sources. XRF measurements performed at various incidence angle, on large areas and different
experimental setup were reproducible. The results demonstrate a successful comparison of the various XRF
instrumentation, and the decrease in Mn content with the distance away from the identified emission source. This
work highlights the potentialities of the presented approach to provide a full quantitative analysis, and ascertain its
suitability for providing a direct, fast, simple and sensitive elemental analysis of filters in source apportionment
studies and screening purposes.
Wavelength-Dispersive XRF Imaging Using Soller Slits and 2D Detector
Shota AIDA, Masaki YAMANASHI, Takuko SAKUMURA, Kazuyuki MATSUSHITA, Takashi SHOJI, Naoki
KAWAHARA, Kouichi TSUJI
Advances in X-ray Analysis, Vol. 61, pp. 180-187 (2018)
A new wavelength-dispersive X-ray fluorescence (WD-XRF) imaging spectrometer equipped with a highly
sensitive two-dimensional detector was developed in our laboratory. In this spectrometer, a straight typepolycapillary optic was applied instead of a Soller slit which is used in conventional WD-XRF spectrometers. The
straight type polycapillary optic worked as a 2D collimator for fluorescent X-rays to keep the information of theelemental distribution in the sample. However, the analyzing area of this technique is limited by the outer
diameter of the polycapillary optic, because it is practically difficult to make a polycapillary with a large diameter.
Therefore, we attempted the use the Soller slits for 2D collimator. Two Soller slits were orthogonally arranged
between the sample and the analyzing crystal (LiF). Elemental images of Cu and Pb were clearly obtained withimproved spatial resolution compared to the elemental images with the polycapillary optic.
Photocatalytic Reduction of CO2 by Pt-Loaded TiO2 in the Mixture of Sub- and Supercritical Water and
CO2
Noritsugu KOMETANI, Shoutarou HIRATA, Masaaki CHIKADA
Journal of Supercritical Fluids, Vol. 120, pp. 443-447 (2017)
Photocatalytic reduction of CO2 by Pt-loaded TiO2 in the mixture of CO2 and water has been examined as afunction of temperature and pressure up to 400 °C and 30 MPa. The abrupt increase in the yields of CO, CH4,HCOOH and HCHO was observed as temperature was elevated from 300 to 400 °C at a constant pressure of 30
MPa. This is attributed to the formation of uniform single phase mixture of water and CO2 under supercriticalcondition, leading to the enhanced efficiency of CO2 reduction. In contrast, the yield of H2 produced by water
reduction showed a monotonous increase with temperature because of the thermal acceleration of photocatalytic
reaction. It is suggested that the control of the phase state of reaction medium has a key role in the determinationof conversion efficiency for the photocatalytic reduction of CO2 with water.
Development of Cu/Ni Binary Catalyst for Hydrothermal Oxidation of Refractory Compounds
Noritsugu KOMETANI, Masaaki NARITA
Proceedings of 12th International Symposium on Supercritical Fluids, Paper ID: OI04 (2018)
We have reported that Cu-based materials show a remarkable catalytic effect for the treatment of refractoryorganic compounds such as chlorophenol and trichloroethylene by catalytic hydrothermal oxidation, because ofenhanced generation of hydroxyl radicals through Fenton-like reaction catalyzed by Cu(I) ion under hydrothermal
condition. Here, we report that Cu/Ni binary catalyst exhibits a higher activity than Cu for the hydrothermal－60－oxidation of 3,4-dichlorophenol. It is indicated by EXAFS data that the atomic interaction between Cu andzero-valent Ni may accelerate Fenton-like reaction, resulting in enhanced degradation and mineralization of
3,4-dichlorophenol.
Development of Dissolution Inhibitor in Chemically Amplified Positive Tone Thick Film Resist
Yusuke SOTOKAWA, Takashi NISHIYAMA, Eriko SATO, Hideo HORIBE
J. Photopolym. Sci. Technol., Vol. 31(3), pp. 399-402 (2018)
Thick film resist is applied to a template for microelectrode used in semiconductor device integration. Utilizationof positive type resist in chemically amplified system for thick film is expected to improve production efficiencyof semiconductor device integration, but improvement of resolution is required. In order to improve the resolutionof chemically amplified positive tone thick film resist, chemical structure of the dissolution inhibitor (DI) was
designed for the control of solubility in resist polymer. The increase of molecular size in DI improved thedissolution inhibiting ability for the resist polymer in the unexposed area and the high acidity of the deprotected
DI having carboxyl group improved dissolution promoting ability for the resist polymer in the exposed area. The
resist containing DI possessing a large molecular size and high acidity improved its sensitivity and resolution.
Time-Resolved Analysis of Resist Stripping Phenomenon Using Laser Irradiation
Tomosumi KAMIMURA, Yuji UMEDA, Hiroyuki KURAMAE, Kosuke NUNO, Ryosuke NAKAMURA, Hideo
HORIBE
J. Photopolym. Sci. Technol., Vol. 31(3), pp. 413-418 (2018)
Resist stripping phenomenon with laser irradiation was observed by using a time-resolved analysis. The timechange of the resist stripping phenomenon by a probe laser irradiation was observed from the viewpoint of theintensity change of the probe laser. As for the laser irradiation in the water, the probe laser intensity arrived at the
maximum after around 40 μs. During the pump laser irradiation of 8 ns, a large compressive stress of -10 MPa
was confirmed inside the resist from the FE analysis results. The generation of this compression stress isimportant for starting the resist stripping process, and is thought to improve the resist removal efficiency.
Fabrication of Mesoscopic Structure on PMMA Surface by Atomic Hydrogen and Evaluation of the
Surface Functionality
Akari MATSUO, Seiji TAKAGI, Takashi NISHIYAMA, Masashi YAMAMOTO, Eriko SATO, Hideo HORIBE
J. Photopolym. Sci. Technol., Vol. 31(3), pp. 369-372 (2018)
Surface properties of polymers such as wettability and adhesiveness play an important role in industrial
applications. The properties can be enhanced by fabricating a mesoscopic structure to the surface. In this study,
we examined a chemical etching which is a simple and direct technique for the surface profile control, using
atomic hydrogen generated by hot-wire catalytic method. Several tens of nanoscale structures were fabricated onpoly(methyl methacrylate) (PMMA) surface by atomic hydrogen irradiation, and the size and pitch of thestructure could be controlled by reaction temperature and time. The wettability of PMMA film surface changed
from hydrophilicity to hydrophobicity by formation of mesoscopic structures.
Degradation of Poly(acrylic acid) in Aqueous Solution by Using O3 Microbubble
Terumi MIYAZAKI, Takashi NISHIYAMA, Eriko SATO, Hideo HORIBE
J. Photopolym. Sci. Technol., Vol. 31(3), pp. 409-412 (2018)
Polyacrylic acid (PAA) aqueous solution was treated with O3 microbubbles and O3 water, there was no difference
in decrease in molecular weight of PAA due to the presence or absence of microbubbles. Regardless of dissolved
O3 concentration, O3 microbubbles alone did not cause reduction in TOC and mineralization did not proceed. In
the advanced oxidation proses with hydrogen peroxide added, the molecular weight and TOC decreased. It isconsidered that active oxygen is generated from hydrogen peroxide by advanced oxidation and PAA is－61－decomposed. From these results, it is no considered generation of reactive oxygen species by microbubbles in thedecomposition of PAA.
Removal of Polymers for KrF and ArF Photoresist Using Hydrogen Radicals Containing a Small Amountof Oxidizing Radicals
Masashi YAMAMOTO, Tomohiro TAKI, Takuto SUNADA, Tomokazu SHIKAMA, Shiro NAGAOKA,
Hironobu UMEMOTO, Hideo HORIBE
J. Photopolym. Sci. Technol., Vol. 31(3), pp. 419-424 (2018)
Photoresist removal method using hydrogen radicals, which are produced on a tungsten hot-wire catalyst, iseffective to resolve some environmental and industrial problems in conventional methods for the fabrication ofelectronic devices. However, its removal rate is not as good as that of the conventional ones. We have previously
described that the removal rate of a positive-tone novolac photoresist is enhanced by the addition of a small
amount of oxygen gas to the atmosphere, in which hydrogen radicals are produced. Oxidizing radicals, such as
OH and O radicals, can be produced together with H radicals. In present study, we examined the effects of oxygen
addition on base polymers of KrF and ArF photoresists: the former is poly(vinyl phenol) (PVP), and the latter ispoly(methyl methacrylate) (PMMA). Effects of oxygen addition on PVP was confirmed, as was found for the
novolac photoresist. On the other hand, the effects on PMMA were different from the cases of the novolac
photoresist and PVP. Results were ascribed to the presence or absence of benzene rings, the properties ofpolymers and the reactivity of oxidizing radicals.
Chemical Structure of the Ion Beam Irradiated Polymer
Hideo HORIBE
RADIOISOTOPES, Vol. 66(11), pp. 567-577 (2017) (in Japanese)
We investigated the chemical structure of positive-tone novolak photoresists into which B, P, and As ions were
implanted with doses of 5×1012 to 5×1015 atoms/cm2. The thickness of the surface-hardened layer of
ion-implanted photoresists increased in the order As–P–B. The energy supplied from the ions to the photoresist
concentrated on the surface side in the increasing order of B–P–As. The photoresists are exhibitting carbonization
and/or crosslinkage attributable to the decrease in OH, CH, and O1s and the increase in C=C, C1s, andπ-conjugated systems.
Material Design of the Chemically Amplified Positive Type Electron Beam Resist
Hideo HORIBE
RADIOISOTOPES, Vol. 66(11), pp. 557-566 (2017) (in Japanese)
The dissolution characteristics of a chemically amplified electron beam (EB) resist composed of partiallytert-butoxycarbonyl group (tBOC) protected poly(p-vinylphenol) (PVP), a dissolution inhibitor, and an acidgenerator were investigated. The resist sensitivity was improved with decreasing tBOC ratio of the matrix resin.
As the tBOC ratio increased, the resolution of the resist was better. SEM observation of the pattern profile wascarried out to investigate the sensitivity and the resolution of the resist. The optimum tBOC ratio was 23.8%. As
dissolution inhibitors, hydroquinone protected by a tert-butoxycarbonyl group(B-HQ) and isophthalic acidprotected by a tert-butyl group(B-IP) are used. Dissolution inhibitors (B-HQ and B-IP) become dissolution
promoters (HQ and IP) after exposure. The dissolution rate of the resist consisting of B-IP was faster than that of
B-HQ in the exposed area. Pka of IP is smaller than that of HQ, and the acidity of IP is higher than that of HQ.
Therefore IP enhances the solubility of the matrix resin in the alkaline developer. We evaluated the dependence ofsensitivity of the resist upon acid generators. Triphenylsulfonium triflate, Diphenyliodonium triflate,
Triphenylsulfonium antimonate, and Diphenyliodonium antimonite were used. When iodonium ion was used as
cation, the sensitivity of the resist was better. When antimonate ion as anion was used, the sensitivity of the resist
was better.

－62－

Effect of Glass Transition Temperature on Heat-Responsive Gas Bubbles Formation from Polymers
Containing tert-Butoxycarbonyl Moiety
Masashi ISEKI, Yuta HIRAOKA, Chu JING, Haruyuki OKAMURA, Eriko SATO and Akikazu MATSUMOTO
J. Appl. Polym. Sci., Vol. 135(19), Article No. 46252 (7 pages) (2018)
Various types of polymers containing tert-butoxycarbonyl (BOC) moiety as the typical protecting group offunctional moieties have been used for the design of stimuli-responsive polymer materials. In this study, weinvestigated the heat-responsive deprotection behavior of BOC-containing polymers obtained by radical
polymerization of 4-(tert-butoxycarbonyloxy)styrene (BSt) and copolymerizations of BSt with styrene and methyl
acrylate. The deprotection of BOC groups accompanying the evolution of isobutene and carbon dioxide asgaseous products was monitored by thermogravimetric analyses at different temperature circumstances; that is, on
heating at a rate of 10 ºC/min and under isothermal conditions at various temperatures. The deprotection resulted
in a significant decrease in the transmittance of visible light due to the formation of a large number of gas bubbles,that is, foaming, in the polymer films when a heating temperature was close to the glass transition temperature of
the used polymer. The potential of BOC-containing polymers was also evaluated as the heat-responsive adhesivepolymers for dismantlable adhesion.
Cross-Linked Polyperoxides for Photoremovable Adhesives
Eriko SATO, Chisato OMORI, Takashi NISHIYAMA and Hideo HORIBE
J. Photopolym. Sci. Technol., Vol. 31(4), pp. 511-515 (2018)
Photoremovability of cross-linked polyperoxides was investigated considering the application to dismantlable
adhesives. Applying lap-shear stress on the glass joints bonded by the cross-linked polyperoxides, i.e., thealternating copolymer of 2-hydroxyethyl sorbate and oxygen cross-linked by tolylene 2,4-diisocyanate, resulted in
the failure of the glass adherend. UV irradiation on the bonded glass joints more than 19 J/cm2 resulted in asignificant decrease in the lap-shear adhesion strength due to the photodegradation of the cross-linked
polyperoxides, and the bonded glass joints were successfully debonded without breaking the glass adherends. The
failure mode was the cohesive failure of the adhesive and the residue of the cross-linked polyperoxides heavily
adhered on the both debonded glass adherends. The additional photoirradiation on the debonded glass adherends
in tetrahydrofuran resulted in the significant removal of the adhered cross-linked polyperoxide due to the further
photodegradation. After 150 J/cm2 irradiation, the adhesive residues were completely wiped off from the glass
adherends.
Control of Droplet Movement on an Inclined Wall with Saw-Toothed Wettability Pattern by Adding
Ultrasonic Vibration
Kenji KATOH, Hiroki TAMURA, Eriko SATO and Tatsuro WAKIMOTO
Exp. Fluid., Vol. 59(9), Article ID. 141 (10 pages) (2018)
This study deals with the control of the movement of liquid droplets rolling down an inclined plate based on the
differences in the wettability of the plate. We used a photoreactive polymer poly(7-methacryloyloxy coumarin)(PMC) whose molecular structure can be changed reversibly to realize different wettabilities by ultraviolet
irradiation. We proposed employing sawtooth patterns at boundaries between areas with different contact angles
to control the droplet trajectory. Furthermore, we experimentally observed that the droplet moves along a line
inclined to the direction of gravity. The droplet behavior can be analyzed using a theoretical model based on thedroplet dynamics wherein the surface tension acting on the contact line and the gravitational force are considered.
The theoretical results suggest that inclination from the gravitational direction can be increased if the advancing
contact angle is reduced. In the experiments conducted herein, ultrasonic vibration was applied to the inclined
plate to reduce the contact angle hysteresis. The results showed that the advancing contact angle actually
decreased and that the droplet trajectory was controlled to realize motion along a line with inclination angle
almost twice of that realized without vibration.
(This is identical to the abstract that appeared in the section of Mechanical and Physical Engineering)－63－

Design of Pressure-Sensitive Dismantlable Adhesives Utilizing Living Radical Polymerization
Eriko SATO
In Living Radical Polymerization: Recent Development of Synthesis and Application of Functional Polymers,
Edited by Akikazu MATSUMOTO, CMC Publishing, pp. 261-267 (323 pages in total) (2018) (in Japanese)
Reactive Polymers for the Design of Dismantlable Adhesives: From the Perspective of Dismantling
Mechanisms
Eriko SATO and Akikazu MATSUMOTO
Kagaku To Kogyo, Vol. 92(1), pp. 7-12 (2018) (in Japanese)
Dismantlable Adhesives Using Light Irradiation
Eriko SATOThe Technical Association of Photopolymers, Japan, Newsletter, Vol. 82, pp. 5-7 (2018) (in Japanese)
Synthesis of Well-Defined Reactive Polymers and Their Application to Dismantlable Adhesives
Eriko SATO
Function & Materials (Kinou Zairyou), Vol. 38(9), pp. 37-44 (2018) (in Japanese)
Development of Thermal Latent Reductants and Their Application to Accelerated Degradation of
Polyperoxides (Hot Topics)
Chisato OMORI, Michihiro YURI, Eriko SATO, Takashi NISHIYAMA and Hideo HORIBE, Kobunshi (HighPolymers, Japan), Vol. 61(4), p. 180 (2018)
Cycloreversion Reaction of a Diarylethene Derivative at Higher Excited States Attained by Two-color
Two-photon Femtosecond Pulsed Excitation
Hikaru SOTOME, Tatsuhiro NAGASAKA, Kanako UNE, Soichiro MORIKAWA, Tetsuro KATAYAMA, Seiya
KOBATAKE, Masahiro IRIE, Hiroshi MIYASAKA
J. Am. Chem. Soc., Vol. 139(47), pp. 17159-17167 (2017)
Two-color, two-pulse femtosecond pulsed excitation was applied to the elucidation of the dynamics andmechanism of cycloreversion reaction of a diarylethene derivative in the higher excited states. Transientabsorption spectroscopy under one-photon visible excitation revealed that the 1B state produced by the excitation
undergoes the internal conversion into the 2A state with a time constant of 200 fs. Geometrical rearrangement of
the 2A state takes place concomitantly with the vibrational cooling with a time constant of 3 ps. The resultant 2A
state undergoes the transition into the conical intersection point in competition with nonradiative as well asradiative deactivation into the ground state with a time constant of 12 ps. The second pulse excitation of the 2A
state, especially the geometrically relaxed 2A state, led to the significant enhancement of the cycloreversion
reaction through the large reaction quantum yield of ca. 50−90% in the higher excited state (Sn state), while theexcitation of the 1B state, leading to the Sn’ state, did not induce such enhancement. By integrating with theexcitation wavelength dependence of the second pump laser pulse, we discussed the chemical reactivity of
diarylethene derivatives in terms of the symmetry of the electronic states.
Solid-state Fluorescence Behavior Induced by Photochemical Ring-opening Reaction of 1,2-Bis(3-methyl5-phenyl-2-thienyl)perfluorocyclopentene
Tatsumoto NAKAHAMA, Daichi KITAGAWA, Hikaru SOTOME, Syoji ITO, Hiroshi MIYASAKA, Seiya
KOBATAKE
Bull. Chem. Soc. Jpn., Vol. 91(2), pp. 153-157 (2018)－64－

Crystals consisting of the closed-ring form of 1,2-bis(3-methyl-5-phenyl-2-thienyl)perfluorocyclopentene
underwent a photochemical ring-opening reaction accompanying crystal fragmentation upon irradiation withvisible light. The open-ring form crystal produced by the ring-opening reaction exhibited green fluorescence,
whereas open-ring form crystals produced by recrystallization exhibit orange or yellow fluorescence depending on
the polymorphic forms. The fluorescence quantum yield of the photogenerated open-ring form crystal was larger
than that in n-hexane. The open-ring form exhibits different fluorescence colors depending on the intermolecularinteraction in different states.
Photomechanical Motion of Diarylethene Molecular Crystal Nanowires
Fei TONG, Daichi KITAGAWA, Xinning DONG, Seiya KOBATAKE, Christopher J. BARDEEN
Nanoscale, Vol. 10(7), pp. 3393-3398 (2018)
Crystalline nanowires composed of the photochromic diarylethene derivative 1,2-bis(2,4-dimethyl-5-phenyl3-thienyl)perfluorocyclopentene are prepared and characterized. 200 nanometer diameter wires with a length of
60 microns are grown by slow solvent annealing in a porous anodic aluminum oxide template. The nanowires areoriented crystals, as determined by X-ray diffraction measurements, and can be liberated by dissolving thetemplate in acid. They exhibit pronounced bending when exposed to ultraviolet light that can be reversed byvisible light irradiation. The bending–unbending sequence can be repeated for more than 10 cycles without fatigue.
This robustness results from the ability of the nanowires to maintain their crystallinity during the forward andreverse reactions. The small diameter of these nanowires allows them to achieve curvatures that are at least 40
times greater (200 mm−1 versus 5 mm−1) than those observed for micron-thick diarylethene needles. This first
demonstration of photomechanical nanostructures based on diarylethene photochromism opens up the possibilityof making more complicated structures composed of this high-performance photochrome.
Fluorescence On/Off Switching in Nanoparticles Consisting of Two Types of Diarylethenes
Tatsumoto NAKAHAMA, Daichi KITAGAWA, Hikaru SOTOME, Tuyoshi FUKAMINATO, Syoji ITO, Hiroshi
MIYASAKA, Seiya KOBATAKEACS Omega, Vol. 3(2), pp. 2374-2382 (2018)
Singleanddouble-component
nanoparticles
consisting
of
two
types
of
diarylethenes,
1,2-bis(3-methyl-5-phenyl-2-thienyl)perfluorocyclopentene (1a) and 1,2-bis(2-methyl-5-phenyl-3-thienyl)perfluorocyclopentene (2a), were fabricated by a reprecipitation method. Nanoparticles consisting of 1a exhibitedorange or green fluorescence depending on the fabrication condition and did not undergo any photocyclization
reaction. In contrast, nanoparticles consisting of 2a underwent photoreversible photochromic reactions uponalternating irradiation with ultraviolet and visible light. Nanoparticles composed of 1a and 2a exhibited
fluorescence on/off switching with rapid switching speed and high on/off contrast, accompanying thephotochromic reactions of 2a. The dependence of fluorescence on/off switching properties on Förster distance andmolar fraction was observed and quantitatively evaluated by a simplified model.
Control of Photomechanical Crystal Twisting by Illumination Direction
Daichi KITAGAWA, Hajime TSUJIOKA, Fei TONG, Xinning DONG, Christopher J. BARDEEN, Seiya
KOBATAKE
J. Am. Chem. Soc., Vol. 140(12), pp. 4208-4212 (2018)
Photomechanical molecular crystals have been investigated as mesoscopic photoactuators. Here, we report how
the photomechanical twisting of 1,2-bis(2-methyl-5-phenyl-3-thienyl)perfluorocyclopentene crystals depends onillumination direction. The ribbon-like crystal could be successfully prepared by a sublimation method. The
crystal exhibited reversible photomechanical twisting upon alternating irradiation with UV and visible light.
Moreover, changing the UV illumination direction with respect to the crystal resulted in different twisting modes,
ranging from helicoid to cylindrical. Control of photomechanical crystal deformation by illumination direction
provides a convenient and useful way to generate a variety of photomechanical motions from a single crystal.

－65－

Photomechanically Induced Magnetic Field Response by Controlling Molecular Orientation in
9-Methylanthracene Microcrystals
Fei TONG, Wenjing XU, Maram AL-HAIDAR, Daichi KITAGAWA, Rabih O. AL-KAYSI, Christopher J.
BARDEEN
Angew. Chem. Int. Ed., Vol. 57(24), pp. 7080-7084 (2018)
A surfactant-assisted seeded-growth method is used to form single-crystal platelets composed of
9-methylanthracene with two different internal molecular orientations. The more stable form exhibits aphotoinduced twisting, as observed previously for 9-methylanthracene microribbons grown by the floating drop
method. However, the newly discovered elongated hexagonal platelets undergo a photoinduced rolling-up andunrolling. The ability of the rolled-up cylindrical shape to trap superparamagnetic nanoparticles enables it to be
carried along in a magnetic field gradient. The new photoinduced shape change, made possible by a novelsurfactant-assisted crystal growth method, opens up the possibility of using light to modulate the crystal
translational motion.
Photoinduced Crystal Shape Change Accompanying Thermodynamic Phase Transition (Division Topics,
Division of Organic Crystals)
Seiya KOBATAKE
Chemistry & Chemical Industry (Kagaku To Kogyo), Vol. 71(1), p. 25 (2018) (in Japanese)
An unusual photomechanical behavior of a molecular crystal induced by combination of a photochromic reaction
and a reversible single-crystal-to-single-crystal phase transition has been introduced in Japanese.
Organic Crystal that Changes its Shape in Response to Light and Heat
Daichi KITAGAWA, Seiya KOBATAKE
Chemical Industry (Kagaku Kogyo), Vol. 69(4), pp. 251-257 (2018) (in Japanese)
The thermodynamic phase transition and photomechanical behavior of diarylethene crystals have been reviewed
in Japanese.
Soluble Expression in Escherichia coli of a Single-Domain Antibody–Tumor Necrosis Factor α Fusion
Protein Specific for Epidermal Growth Factor Receptor
Tomohiro OSAKI, Takeshi NAKANISHI, Motoshi AOKI, Takahiro OMIZU, Daisuke NISHIURA, Masaya
KITAMURA
Monoclon. Antib. Immunodiagn. Immunother., Vol. 37, pp. 20–25 (2018)
Tumor-targeted antibody-cytokine fusion proteins, called immunocytokines, are expected to be a useful platform
for the development of effective antitumor therapeutic agents; however, their design and cost-efficient production
remain as challenges. In this study, we constructed an antibody-cytokine fusion protein (Ia1-TNFα) comprising
the single-domain antibody Ia1, which targets epidermal growth factor receptor (EGFR) overexpressed inepithelial tumors and a tumor necrosis factor α (TNFα) domain, which has antitumor activity. Ia1-TNFα wasproduced in a soluble form by using an Escherichia coli expression system, and after affinity purification of theculture supernatant, an yield of ~2 mg/L of cell culture was obtained. Gel filtration analysis showed that Ia1-TNFα
existed predominantly as a trimer, which is consistent with the multimerization state of TNFα. Ia1-TNFα
exhibited approximately 7-fold lower TNFα biological activity than that of TNFα itself. Flow cytometric analysis
revealed that Ia1-TNFα specifically bound to EGFR-expressing tumor cells and that its binding activity was
higher than that of monovalent Ia1, suggesting that the fusion protein bound to the tumor cells multivalently.
Altogether, these results show that fusion of TNFα with a single-domain antibody could be a cost-efficient meansof producing antitumor therapeutic agents.
Affinity Maturation of Humanized Anti-Epidermal Growth Factor Receptor Antibody Using a Modified－66－

Phage-Based Open Sandwich Selection Method
Hideaki SANADA, Kazuki KOBAYASHI, Takamitsu MARU, Takeshi NAKANISHI, Mitsuo UMETSU, Ryutaro
ASANO, Izumi KUMAGAI
Sci. Rep., Vol. 8, Article No. 5414 (9 pages) (2018)
Affinity maturation is one of the cardinal strategies for improving antibody function using in vitro evolutionary
methods; one such well-established method is phage display. To minimise gene deletion, we previously developed
an open sandwich (OS) method wherein selection was performed using only phage-displaying VH fragments after
mixing with soluble VL fragments. The decrease in anti-EGFR antibody 528 affinity through humanization was
successfully recovered by selecting VH mutants using this OS method. However, the affinity was not similar tothat of parental 528. For further affinity maturation, we aimed to isolate VL mutants that act in synergy with VH
mutants. However, the OS method could not be applied for selecting VL fragments because the preparation ofsoluble VH fragments was hampered by their instability and insolubility. Therefore, we initially designed amodified OS method based on domain-swapping of VH fragments, from added soluble Fv fragments tophage-displaying VL fragments. Using this novel Fv-added OS selection method, we successfully isolated VL
mutants, and one of the Fv comprising VH and VL mutants showed affinity almost equivalent to that of parental
528. This method is applicable for engineering other VL fragments for affinity maturation.
Pharmaceutical Microcrystal Formation by Supersaturation Control with an Electrolyte
Muneki KISHIDA, Koichi IGARASHI, Masayuki AZUMA, Hiroshi OOSHIMA
Journal of Chemical Engineering of Japan, Vol. 51, pp. 1-6 (2018)
Methods to control the particle sizes of active pharmaceutical ingredients were investigated using sodium ecabet(Na-ECA) hydrate, which tends to generate large plate-like crystals, as a model compound. In batch-coolingcrystallization in H2O, the particle size decreased as the cooling rate was increased. Although the particle size
reached 97 µm at a cooling rate of 40 °C/h, this may be too large for formulation without further physicalprocessing. A series of semi-batch crystallization experiments was conducted by adding aqueous Na-ECA
solution to aqueous NaCl. In these experiments, the particle sizes decreased to less than 7 μm as the NaCl
concentration was increased to >1.2% w/w. The particles yielded by semi-batch crystallization showed improved
particle size distributions compared to those obtained by the batch-cooling crystallization method. The solubilityof Na-ECA hydrate decreased to less than 10% of that in pure water as the NaCl concentration was increased to
3.0% w/w. This solubility change enabled the production of a highly supersaturated environment, allowing facile
generation of microcrystals with a narrow particle size distribution.
Behavior of t-Butoxycarbonyl-L-asparagine (Boc-Asn) during the Initial Stage of Crystallization
Koichi IGARASHI, Masako AOKI, Yoshiko MASUDA, Masayuki AZUMA, Hiroshi OOSHIMA
Journal of Chemical Engineering of Japan, Vol. 51, pp. 111-115 (2018)
The crystallization mechanism of amino acid derivative t-butoxycarbonyl-L-asparagine (Boc-Asn) wasinvestigated. NMR spectroscopy was used to observe the behavior of Boc-Asn molecules in under- andsupersaturated solution. Nuclear Overhauser effect (NOE) NMR measurements were performed to provide
information concerning the intra- or intermolecular access of a particular hydrogen atom to other hydrogen atoms
in solution. We compared the interactions identified by NOE measurements for under- and supersaturated
solutions of Boc-Asn with those in the crystal, as determined by X-ray analysis. According to the X-ray analysis,
intramolecular NOE should not be observed, but intermolecular NOE might be observed between the methyl
protons of the t-butoxycarbonyl group and the protons belonging to other functional groups. The time course of
the NOE intensity was followed for three solutions with different saturation ratios S (= concentration ofsolute/solubility). For undersaturated and nearly saturated conditions (S = 0.8 and 1.12 at 0 °C), the NOE intensity
did not change for at least for 250 h. However, for the supersaturated solution (S = 1.62 at 10 °C), the NOE
intensity increased suddenly and rapidly after about 120 h, and no crystals were observed during the NOE
measurements. As the observed NOEs agreed with those expected from the arrangement of molecules in the－67－

crystal, it was suggested that Boc-Asn molecules aggregated after about 120 h with the same structure as that in
the crystal. In addition to the behavior of the Boc-Asn solution before nucleation, we also investigated the effectof aggregation on the crystallization process. Solutions that were preincubated at 10 °C for various periods were
further cooled and crystallized at -30 °C. It was found that when the solution was preincubated under thesupersaturated condition for a long time before crystallization, nucleation was enhanced, and consequently, thecrystal size distribution became homogeneous.

S-allyl-glutathione improves experimental liver fibrosis by regulating Kupffer cell activation in rats
Shigekazu TAKEMURA, Hideki AZUMA, Mayuko OSADA-OKA, Shoji KUBO, Toshihiko SHIBATA, Yukiko
MINAMIYAMA
Am. J. Physiol Gastrointest. Liver Physiol., Vol. 314(2), pp. G150-G163 (2018)
S-allyl-glutathione (SAG) is one of the metabolites of diallyl sulfide (DAS), a component of garlic. DAS has
shown preventative effects on carcinogenesis in animal models. However, whether synthetic SAG can
improve liver fibrosis has not been investigated. We examined the potential preventive effects of SAG on acuteand chronic models of liver fibrosis by chronic carbon tetrachloride (CCl4) administration. SAG
inhibited liver fibrogenesis induced by CCl4 in a dose-dependent manner and reduced heat shock protein-47(HSP47), a collagen-specific chaperone, and other fibrosis markers. In fibrosis regression models, afteradministration of either CCl4 for 9 wk or dimethyl nitrosamine (DMN) for 6 wk, SAG markedly accelerated
fibrolysis in both models. In the regression stage of DMN-treated liver, SAG normalized the ratio of M2
phenotype (expression of mannose receptor) in Kupffer cells (KCs). Consistent with these results, the culture
supernatants of SAG-treated M2-phenotype KCs inhibited collagen-α1(I) chain (COL1A1) mRNA expression inprimary culture-activated rat hepatic stellate cells (HSCs). However, SAG did not directly inhibit HSC activation.
In an acute model of CCl4 single injection, SAG inhibited hepatic injury dose dependently consistent with the
inhibited the elevation of the bilirubin and ALT levels. These findings suggest that SAG could improve thefibrogenic and fibrolysis cascade via the regulation of excess activated and polarized KCs. SAG may also serve asa preventive and therapeutic agent in fibrosis of other organs for which current clinical therapy is unavailable.
NEW & NOTEWORTHY S-allyl-glutathione (SAG) is a metabolite of diallyl sulfide, a component of garlic. SAG
increased hepatic glutathione levels and GSH-to-GSSG ratio in normal rats. SAG treatment before orafter liver fibrosis from chronic CCl4 administration improved liver fibrosis and regression. SAG decreased heatshock protein-47 (HSP47), a collagen-specific chaperone, and other fibrosis markers in CCl4-treated livers.
SAG-treated Kupffer cellconditioned medium also inhibited collagen-α1(I) chain (COL1A1) mRNA expression
and other markers in primary culture hepatic stellate cells.
A new method to purify poly-γ-glutamic acid using gemini quaternary ammonium salts andcharacterization of its ionic complex.
Tao LIU, Hirobumi NOBESHIMA, Yoshihiro OJIMA, Masayuki AZUMA,
J. Chem. Eng. Jpn., Vol. 51(5), pp. 431-437 (2018)
Poly-gamma-glutamic acid (γ-PGA) is a water-soluble, nontoxic biodegradable polymer. It is extensively utilized
in medicines, foodstuffs, and cosmetics, as well as in water treatment. Highly pure γ-PGA is required for various
purposes. In many cases, γ-PGA is produced by microbes of Bacillus sp. However, an increase in the viscosity of
the culture broth is one of the major problems of γ-PGA production as higher viscosity makes the separation andpurification steps difficult. Herein we propose a novel method to obtain pure γ-PGA using gemini quaternaryammonium salts (GQASs). The quaternary ammonium cation of GQASs binds to the carboxylic acid group of
γ-PGA via an ionic bond, following which water-insoluble and antimicrobial complexes are formed. These
complexes are obtained in the aqueous solution, which were resolved in ethanol solution. With an increase in theadded amount of GQAS, the negative charge of the complex decreased in the aqueous solution. Subsequently, the
GQAS within the complexes was dissociated by the addition of NaCl, affording pure γ-PGA in a high yield.

－68－Moreover, the complexes were shown to have antibacterial activity and adhered to glass, indicating that thecomplex itself has a utility value.
Characterization of D-succinylase from Cupriavidus sp. P4-10-C and its application in D-amino acidsynthesis.
Yosuke SUMIDA, Sachio IWAI, Yoshiaki NISHIYA, Shinya KUMAGAI, Toshihide YAMADA, Masayuki
AZUMA,
J. Biosci. Bioeng., Vol. 125(3), pp. 282-286 (2018)
D-amino acids are important building blocks for various compounds, such as pharmaceuticals and agrochemicals.
A more cost-effective enzymatic method for D-amino acid production is needed in the industry. We improved aone-pot enzymatic method for D-amino acid production by the dynamic kinetic resolution of N-succinyl aminoacids using two enzymes: D-succinylase (DSA) from Cupriavidus sp. P4-10-C, which hydrolyzes
N-succinyl-D-amino acids enantioselectively to their corresponding D-amino acid, and N-succinyl amino acidracemase (NSAR, EC.4.2.1.113) from Geobacillus stearothermophilus NCA1503. In this study, DSA and NSAR
were purified and their properties were investigated. The optimum temperature of DSA was 50°C and it was
stable up to 55°C. The optimum pH of DSA and NSAR was around 7.5. In D-phenylalanine production, theoptical purity of product was improved to 91.6% ee from the examination about enzyme concentration. Moreover,
100 mM N-succinyl-DL-tryptophan was converted to D-tryptophan at 81.8% yield with 94.7% ee. This enzymatic
method could be useful for the industrial production of various D-amino acids.
Large-scale culture of a megakaryocytic progenitor cell line with a single-use bioreactor system.
Retno W. NURHAYATI, Yoshihiro OJIMA, Takeaki DOHDA, Masahiro KINO-OKA,
Biotechnol. Prog., Vol. 34(2), pp. 362-369 (2018)
The increasing application of regenerative medicine has generated a growing demand for stem cells and theirderivatives. Single-use bioreactors offer an attractive platform for stem cell expansion owing to their scalability
for large-scale production and feasibility of meeting clinical-grade standards. The current work evaluated thecapacity of a single-use bioreactor system (1 L working volume) for expanding Meg01 cells, a megakaryocytic(MK) progenitor cell line. Oxygen supply was provided by surface aeration to minimize foaming and orbital
shaking was used to promote oxygen transfer. Oxygen transfer rates (kLa) of shaking speeds 50, 100, and 125 rpm
were estimated to be 0.39, 1.12, and 10.45 h-1, respectively. Shaking speed was a critical factor for optimizing cell
growth. At 50 rpm, Meg01 cells exhibited restricted growth due to insufficient mixing. A negative effect occurred
when the shaking speed was increased to 125 rpm, likely caused by high hydrodynamic shear stress. The
bioreactor culture achieved the highest growth profile when shaken at 100 rpm, achieving a total expansion rate
up to 5.7-fold with a total cell number of 1.2±0.2 × 109 cells L-1. In addition, cells expanded using the bioreactor
system could maintain their potency to differentiate following the MK lineage, as analyzed from specific surface
protein and morphological similarity with the cells grown in the conventional culturing system. Our study reports
the impact of operational variables such as shaking speed for growth profile and MK differentiation potential of aprogenitor cell line in a single-use bioreactor.
Metabolic Engineering of Escherichia coli KO11 with NADH regeneration system for enhancing ethanol
production.
Fernanda M. KASHIWAGI, Yoshihiro OJIMA, Masahito TAYA,
J. Chem. Eng. Jpn., Vol. 51(3), pp. 264-268 (2018)
Cofactor regulation for the production of reduced metabolites, such as ethanol, plays an important role regarding
the metabolic pathways of microorganisms. In this study, intracellular NADH/NAD+ ratio in the ethanologenic
strain Escherichia coli KO11 was increased by overexpression of formate dehydrogenase from Mycobacterium
vaccae. In order to avoid the generation of pyruvate-derived byproducts, genes coding for lactate and acetateproducing pathways were successfully deleted using the genome editing based on a CRISPR-Cas9 system. In the－69－culture of constructed strain, NADH regeneration system caused an increase in intracellular NADH/NAD+ ratio in
the presence of formate, leading to enhanced ethanol production 36% more than the original KO11 strain in
culture for 24 h. The detailed investigation revealed that the transient pyruvate accumulation plays a key role forthe enhanced ethanol production by NADH regeneration system.
EB1-binding-myomegalin protein complex promotes centrosomal microtubules functions
Habib BOUGUENINA, Daniele SALAUN, Aurelie MANGON, Leslie MULLER, Emilie BAUDELET, Luc
CAMOIN, Taro TACHIBANA, Sarah CIANFERANI, Stephane AUDEBERT, Pascal VERDIER-PINARD, Ali
BADACHE
Proc. Natl. Acad. Sci. USA., Vol. 114(50), pp. E10687-E10696 (2017)
Control of microtubule dynamics underlies several fundamental processes such as cell polarity, cell division, andcell motility. To gain insights into the mechanisms that control microtubule dynamics during cell motility, weinvestigated the interactome of the microtubule plus-end-binding protein end-binding 1 (EB1). Via molecularmapping and cross-linking mass spectrometry we identified and characterized a large complex associating a
specific isoform of myomegalin termed "SMYLE" (for short myomegalin-like EB1 binding protein), the PKA
scaffolding protein AKAP9, and the pericentrosomal protein CDK5RAP2. SMYLE was associated through an
evolutionarily conserved N-terminal domain with AKAP9, which in turn was anchored at the centrosome via
CDK5RAP2. SMYLE connected the pericentrosomal complex to the microtubule-nucleating complex (γ-TuRC)
via Galectin-3-binding protein. SMYLE associated with nascent centrosomal microtubules to promote
microtubule assembly and acetylation. Disruption of SMYLE interaction with EB1 or AKAP9 prevented
microtubule nucleation and their stabilization at the leading edge of migrating cells. In addition, SMYLE
depletion led to defective astral microtubules and abnormal orientation of the mitotic spindle and triggered G1cell-cycle arrest, which might be due to defective centrosome integrity. As a consequence, SMYLE loss offunction had a profound impact on tumor cell motility and proliferation, suggesting that SMYLE might be an
important player in tumor progression.
A statistical image analysis framework for pore-free islands derived from heterogeneity distribution of
nuclear pore complexes
Yasuhiro MIURA, Satoko TAKEMOTO, Taro TACHIBANA, Yutaka OGAWA, Masaomi NISHIMURA, Hideo
YOKOTA, Naoko IMAMOTO
Sci. Rep., Vol. 7, Article No. 16315 (14 pages) (2017)
Nuclear pore complexes (NPCs) maintain cellular homeostasis by mediating nucleocytoplasmic transport.
Although cyclin-dependent kinases (CDKs) regulate NPC assembly in interphase, the location of NPC assemblyon the nuclear envelope is not clear. CDKs also regulate the disappearance of pore-free islands, which
are nuclear envelope subdomains; this subdomain gradually disappears with increase in homogeneity of the NPC
in response to CDK activity. However, a causal relationship between pore-free islands and NPC assembly remains
unclear. Here, we elucidated mechanisms underlying NPC assembly from a new perspective by focusing
on pore-free islands. We proposed a novel framework for image-based analysis to automatically determine thedetailed 'landscape' of pore-free islands from a large quantity of images, leading to the identification of NPC
intermediates that appear in pore-free islands with increased frequency in response to CDK activity. Comparisonof the spatial distribution between simulated and the observed NPC intermediates within pore-free islands showedthat their distribution was spatially biased. These results suggested that the disappearance of pore-free islands ishighly related to de novo NPC assembly and indicated the existence of specific regulatory mechanisms for the
spatial arrangement of NPC assembly on nuclear envelopes.
The STK35 locus contributes to normal gametogenesis and encodes a lncRNA responsive to oxidative stress
Yoichi MIYMOTO, Penny AF WHILEY, Hoey Y GOH, Chin WONG, Gavin HIGGINS, Taro TACHIBANA,
Paul MCMENAMIN, Lynne MAYNE, Kate L LOVELAND－70－

Biol. Open., Vol. 7(8), pii: bio032631. doi: 10.1242/bio.032631. (2018)
Serine/threonine kinase 35 (STK35) is a recently identified human kinase with an autophosphorylation function,linked functionally to actin stress fibers, cell cycle progression and survival. STK35 has previously been shown tobe highly expressed in human testis, and we demonstrated its regulation by nuclear-localized importin α2 in HeLa
cells. The present study identifies progressive expression from the STK35 locus of two coding mRNA isoforms
and one long non-coding RNA (lncRNA) in mouse testis during spermatogenesis, indicating their tightly
controlled synthesis. Additionally, lncRNA transcripts are increased by exposure to oxidative stress in mouse
GC-1 germ cell line. STK35 knockout (KO) mice lacking all three RNAs are born at sub-Mendelian frequency,
and adults manifest both male and female germline deficiency. KO males exhibit no or partial spermatogenesis in
most testis tubule cross-sections; KO ovaries are smaller and contain fewer follicles. Eyes of KO mice display
phenotypes ranging from gross deformity to mild goniodysgenesis or iridocorneal angle malformation, toovertly normal. These findings demonstrate the tight regulation of transcription from the STK35 locus and its
central importance to fertility, eye development and cell responses to oxidative stress.

－71－

Urban Engineering
Architecture and Building Engineering
COMPARISON STUDY OF ELASTO-PLASTIC BEHAVIOR ON STATIC AND DYNAMIC RESPONSESFOR SINGLE LAYER LATTICE DOMES UNDER VERTICAL LOADING
Yoshiya TANIGUCHI, Tomoya MATSUI and Susumu YOSHINAKA
J. Struct. Constr. Eng., AIJ, Vol. 83 No. 747, 709-716, May, 2018
This paper focuses on the elasto - plastic behavior of static and dynamic responses for single layer lattice domes,
which are subjected to vertical loads. The purpose is to make clear the relationship between seismic responses andstatic responses from the view point of input strain energy properties after and before yielding, and to estimate
bearable seismic levels with the information of static elasto - plastic behaviors. The static response compared is therelationships between equivalent velocities of strain energies and displacements. The dynamic response comparedis that between earthquake input acceleration PGA and equivalent velocities of strain energies.
Impact test of an arch model using TMDs with initial displacement
Susumu YOSHINAKA and Yoshiya TANIGUCHI
Proceedings of the IASS Annual Symposium 2017, “Interfaces: architecture. engineering. science”, September 25- 28th, 2017, Hamburg, Germany, Session #27, ID 9205, pp.1-10, (2017)
TMDs (Tuned Mass Dampers) show superior control performance for harmonic responses, but have limited capacity
for transient responses. To control transient responses effectively, we propose TMDs with initial displacement. In
our previous study, we formulated an equation for initial conditions to release initial TMD displacement. Thisequation is based on the principle that, under a specific structural initial condition, by giving specific initialdisplacement to a TMD, the first modal response with low modal damping is eliminated while the second modal
response with high modal damping is only oscillated on a two-degree-of-freedom system. This paper describes a
vibration test using an arch model under impulse loading to verify the control performance of the proposed method
experimentally. From test results, we can see that the TMD model showed high control performance. On the other
hand, the control performance is very sensitive to the length and the release moment of the TMD’s initialdisplacement.
Examination of failure wind speed for roof structure of wooden houses in the Enhanced-Fujita scale
Eri GAVANSKI, Gregory A. KOPP (Univ. of Western Ontario)
Proc. of 9th Asia-Pacific Conference on Wind Engineering, (3-7 December 2017, Auckland, New Zealand)
Under tornadic wind events, residential houses are frequently damaged and one of the components of houses which
commonly fail are roof-to-wall-connections (RTWC). RTWC failure needs to be mitigated because of its significant
damage on insured loss. The Enhanced-Fujita (EF) scale, which is utilized to identify the tornado scale, has only asingle damage indicator (DI) for residential houses with little description of structural details of the houses. Since itis well known that building shape and dimensions affect wind pressure acting on the house, more structuraldescription of houses may need to be specified for the Degrees-of-Damage (DOD) in the EF-Scale. In order toexamine this point, the present study performed fragility analysis for RTWC failure of residential house considering
a wide variety of parameters believed to affect failure wind speeds, which include parameters of roof slope, shapeand height, surrounding terrain, neighbouring houses and the presence of dominant opening on a wall.
Surrounding effect on internal wind pressure and correlation between external-internal pressures on lowrise buildings
Eri GAVANSKI, Daisuke KONNO (National Institute of Technology, Hachinohe College), Yasushi Uematsu(Tohoku Univ.)
International Workshop on Wind-Related Disasters and Mitigation, (11-14 March 2018, Sendai, Japan)
The effect of surrounding buildings on internal pressure coefficient, Cpi, and the correlation between Cpi andexternal pressure coefficient, γ, were examined by performing wind tunnel tests using a flat-roofed low-risebuilding model. It is found that its effect is mainly shielding and is significant especially on Cpi. Simple fragility
analysis was performed in order to understand its effect more clearly. This result indicates that the use of Cpi andγ obtained from the isolated building underestimates the roof panel failure wind speed for surrounded building by
the degree that it can affect the tornado rating using the EF-scale.

－72－

Numerical investigation and accuracy verification of indoor environment for an impinging jet ventilatedroom using computational fluid dynamics
Tomohiro KOBAYASHI, Kazuki SUGITA, Noriko UMEMIYA, Takashi KISHIMOTO (Kinden Corporation),Mats SANDBERG (University of Gavle, Sweden)
Building and Environment, Vol.115, 251-268, (2017)
The impinging jet ventilation (IJV) system has been proposed as an air distribution strategy to provide a better
thermal environment with a medium supply momentum than displacement ventilation (DV) system. However, nosimplified prediction method that is practically applicable has been established to date. The ultimate goal of thisstudy is to establish a calculation model to predict the vertical temperature profile in an IJV system. The authors
aim to propose a one-dimensional model, where the room is divided into several control volumes. To perform this,the turbulent thermal diffusion between control volumes needs to be well understood. Therefore, a knowledge about
the effect of each design factor such as the supply air velocity on the turbulent thermal diffusivity needs to beacquired through a parametric study. Computational Fluid Dynamics (CFD) is effective for this purpose. As firststep, the accuracy of CFD simulations is verified by conducting a full-scale experiment. The velocity profiles inside
the impinging jet and the indoor temperatures are measured and compared with the CFD results. It is shown that theshear-stress transportκ-ω model has a sufficient accuracy to analyse the target room, and an appropriate grid layout
is established as well. The convection–radiation coupling CDF prediction where the external temperature is used asa boundary condition is adopted as the best method for numerical study in this research. Finally, a parametric study
on the supply air velocity is performed based on this setting and its effect on the thermal stratification is presented.
Light environment evaluation under different orders and speeds of illuminance change
Noriko UMEMIYA, Tetsuro ARAI, Tamami SUZUKI and Tomohiro KOBAYASHI
Proceedings of the 10th Asia Lighting Conference, 72-77, Shanghai, (2017)
For this study, the light environment and subjective impressions of observers are evaluated and compared as theilluminance level of an experimental room is changed between light and dark with different orders and speeds.
Effects of mood states on the evaluation were also assessed. Results of statistical analyses indicated the following
results. 1) In darkening experiments, deterioration of comfort, preference and sense of coziness are less by
instantaneous change than by gradual change. 2) In brightening experiments, improvement of comfort, preference,
sense of coziness and clearness are greater by instantaneous change than by gradual change. 3) When changed
gradually, comfort and preference deteriorate after darkening. The sense of brightness decreases and the sense ofglare increases after lightening for subjects of high vigour in mood states. 4) When changed instantaneously, a moodstate does not affect the light environment
Light evaluation in high and low mood states
Noriko UMEMIYA and Tamami SUZUKI
Proceedings of the Midterm Conference of CIE, 687-693, Jeju, (2017)
Effects of mood states on evaluation of light environment evaluation were inspected in this study. Light conditions
were set in two levels, light (2200 lux) and dark（340 lux). Light level was changed from light to dark or dark tolight in an experiment and effects of change order were also considered. Mood states were calculated by Profile ofMood States score which was developed for clinical use. Subjects were classified into high and low mood states bylimits of 25, 50 and 75 percentile values of mood score. As a results, tension–anxiety mood was related to theevaluation of glare and comfort. Vigour mood was related to the brightness, comfort, preference and performance.
Anger-hostility mood was related to the glare and performance. Depression mood was related to the brightness andglare. However, fatigue and confusion mood were not related to the evaluation of light environment at all.
Comparison of thermal environment, thermal sensation and sleep quality among thermal control patterns
in summer sleeping rooms
Noriko UEMIYA, Yoshiki TACHIBANA, Tomohiro KOBAYASHI, Yusuke NAKAYAMA and Hirona BESSHOAbstract book of the 17th International Conference on Environmental Engineering, 131, Kobe, (2017)
This survey, with 75 respondents on a total of 343 peak summer days for three years in apartments in Osaka, Japan,
compared sleep quality for three thermal control patterns: air-conditioning through the night, window opening
through the night, and partial air-conditioning using a timer. Results revealed the following: 1) The outdoor
temperature was higher in PA than in WO (p<0.01) and higher in AC than WO (p<0.05). 2) The indoor SET*_total
was higher in WO than in PA (p<0.01) and higher in PA than in AC (p<0.01). Nevertheless, no significant difference
was found among thermal sensations associated with the three conditions. Moreover, sleep quality measured by
OSA test was higher, it means that the sleep quality was better, in WO than in AC (p<0.01). 3) As Figure 1 shows,
OSA score was low and unrelated to the indoor SET*_total in AC. It worsened as the indoor thermal environment－73－

became hotter in WO. But it became better in PA when indoor SET*_total exceeded 31°C. 4) Sleep quality wasbetter in PA than in WO and AC when the outdoor temperature exceeded 27.9°C.

－74－

Urban Design and Engineering
Extending the Verbal Map Navigation System for Visually-impaired People Focusing on Byway
Information and NFC Interface
Yuki ADACHI, Takashi UCHIDA, Yoshiki SUGA and Yumie SAWADA
Japan Society of Traffic Engineers, Papers on Traffic Engineering, No. 37，pp. 367-372 (2017) (in Japanese)
A System of Assisting Verbal Map Description of Pedestrian Town Navigation for Universal Situations
Yumie SAWADA, Takashi UCHIDA and Yuki ADACHIJapan Society of Civil Engineers，Proceedings of Infrastructure Planning, No. 56，pp.125_1-7 (2017) (inJapanese)
It is very hard to use walking navigation by smartphones and AR app for visually-impaired people unlike
sighted people. Visually-impaired people can’t walk a strange land alone. They can’t enjoy walking even thewell know land because of not knowing the information of the facilities not to usually use and scene of a
town changing every day. Voice AR navigation has been studied from the point of view of safety, pace ofmind and enjoying walk in order to overcome this disparity.
This study builds a system that allows anyone to easily description Verbal Map. These are helping expansionof navigation area and make more useful AR app for visually-impaired people.
Posterior Evaluation of the Small-Size River Development for the Nature- Friendly Environment andthe Water Amenity in the Built-Up Area— Analyses Based on the Actual Use Situation
Yasumasa FUKUSHIMA and Takashi UCHIDA
Japan Society of Civil Engineers，Proceedings of Infrastructure Planning, No. 56，pp. 218_1-10 (2017) (inJapanese)
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 some cases however, the residents along
the river have failed to value and then water amenity has 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 theattitudes of residents by means of hearing survey to the inhabitants. This study performs analyses on the
results of actual condition survey towards the smooth implementation of the enterprise and the consensus
formation and in urban riverside development considering development methods in order to promote theutilization with high evaluations from the inhabitants as concrete strategies.
Method of Evaluating Dialogue Robots for Visually Impaired and Elderly People
Hiroko MATSUMOTO, Takashi UCHIDA and Kanami BESSYOOsaka City University, Memoirs of the Faculty of Engineering, Vol. 58, pp.13-24 (2017)
To support the daily living of visually impaired people, we have been conducting research on pedestriannavigation, mainly audio guidance by a “Verbal map.” In collaboration with “Verbal map,” we plan a
dialogue robot that can guide a person in a plaza space. As the first step, this study establishes an evaluation
experiment to quantify the degree of pleasant feeling a person has when talking with a robot.
This paper first presents the research background and objectives. Chapter 2 describes the evaluation
experiment method. In chapter 3, using results of the experiment conducted, we specifically examine afunction evaluation questionnaire and measurements of the psychological load. Finally, this report provides asummary of the research.
Actual Conditions and Major Issues on Basic Scheme of Public Transportation
Yusuke TAKAHASHI, Yasuo HINO, Takashi UCHIDA and Ayaka ARIMOTO
Japan Society of Traffic Engineers, Papers on Traffic Engineering, No. 37，pp.561-564 (2017) (in Japanese)
Effects and Major Issues of Arranging for Bicycle Parking Problems in Residential and Commercial
Mixed Area
Yuriko YOSHIKANE, Yasuo HINO, Takashi UCHIDA and Yurie ISHIMURA
Japan Society of Civil Engineers，Proceedings of Infrastructure Planning, No. 56，pp.217_1-4 (2017) (inJapanese)－75－Illegal parked bicycle problem near rail station area has improved by both supplying bicycle parking spaces
and removing illegal parked bicycles. On the other hand, in city center it has not still improved. In theseareas, as there are many stakeholders such as residents, shop owners, employee and visitors, it may be noteasy to improve the bicycle problems, because of differences of their needs. Therefore, it must be essential toinvestigate the possibility of public involvement among them.
As a result of a series of studies in corporation with local government and local community, an activity ofarranging parked bicycles by “cycle supporter” has introduced based on some workshop activities as a
typical public involvement. Then, in this paper, we not only investigated the awareness and effect of theactivity of arranging parked bicycles, but also made the desirable issues and presented the possibility offurther activities, in future.
Effects and Further Required Issues on Progressing Measures to Promote Safer Use of Bicycles by
Enacting the Ordinance in Local Government
Yasuyuki TAKEDA, Yasuo HINO, Takashi UCHIDA and Daiki DOUBATAJapan Society of Civil Engineers，Proceedings of Infrastructure Planning, No. 56，pp.80_1-5 (2017) (inJapanese)
Recently the movement of enacting the ordinance for promoting safer use of bicycles has been progressing in
local government, because of increasing the ration of traffic accidents and illegal parking and so on.
However, the background and purpose and effects for enacting ordinance, and further required issues infuture, according to feature of each local government, have not been yet clear. Then in this study, in
corporation with the local governments enacted the ordinance for safer use of bicycles, the background andpurpose effects for enacting ordinance, the important items, the possibility of progressing measures and so on
were investigated by questionnaire survey. As a result, it was revealed that the role of relevantorganizations and progress of road safety education were not only most important but also thy nave not beendeveloped in common. In addition, further required issues were proposed based on these findings.
A Study on Identifying Opportunities and Barriers to Use Adaptive Cycle For People with Travel
Difficulties
Takuya KONISHI and Nagahiro YOSHIDA
Japan Society of Civil Engineers，Proceedings of Infrastructure Planning, No. 56，pp. 218_1-10 (2017) (inJapanese)
In late years, a tool for traffic to be similar to a bicycle has been developed, and there are the things which
two-crew is possible, which have an electric assist, and which have three wheels. The activity in the scene
which is not usable by car including the case to go to the small place that a case and the car which do nothave a driver's license do not put is expected, and it is thought possibility as the new transportation of thepeople for with travel difficulties. However, there are few examples that is examined about the use ofadaptive cycling by the people for with travel difficulties is possible, and it is necessary to study about thepossibility. In this study, I do a hearing survey to the welfare company and experiment with using adaptive
cycling, and I decided to grasp the situation that were hard to go out, the potential use opportunity ofadaptive cycling, and the problem for using it.
Latent opportunities for the use of two-rider bicycles and associated challenges based on assessmentsof its use by people with reduced mobility
Takuya KONISHI and Nagahiro YOSHIDAThe 6th Japan Cycling Congress, Poster session, (2017) (in Japanese)
A Case Study on the Issues of Bicycle Safety Education for Children from the Comparative Views of
Responsible Organization
Syuta HOSHIRO and Nagahiro YOSHIDAThe 6th Japan Cycling Congress, Poster session, (2017) (in Japanese)
Traffic Accident Risk Analysis Along Trunk Roads using Emergency Braking Event from Floating Car
Data
Toshiki KUBOTA, Nagahiro YOSHIDAThe Annual Meeting of Traffic Science, 2 Pages, (2017) (in Japanese)－76－

A Study on Safety Education of Bicycle for Parents with Infants and Elderly People
Kumiko TANIUCHI, Itaru FUJIE, Nagahiro YOSHIDA, Takao YANAGIHARA, Noriaki FUJIMOTO, andNobuhiko MATSUMURA
Traffic Science, Vol. 48, No. 2, pp.25-29, (2017) (in Japanese)
Understanding the Nature of Walking and Cycling for Transport in Japan
Pola BERENT and Nagahiro YOSHIDA
Osaka City University, Memoirs of the Faculty of Engineering, Vol. 58, pp.25-43 (2017)
The following document is a summary of the existing academic articles available in English. The literature
review was conducted for the purpose of gaining an understanding of cycling and walking behaviors in Japan.
This was background research in order to acquire theoretical knowledge for the further study, which aimed toestablish whether people in Japan (where cyclists regularly mix with pedestrians on sidewalks) show
different attitudes and perceptions of comfort while travelling on segregated or unsegregated shared-use
paths and to identify whether it is dependable purely on technical aspects of path design (i.e. physicalcharacteristics) or/and whether the travel behavior generated by traffic law has impacts on it.
Experimental Study on Measuring Level of Stress for Bicycle Facilities using Vital Reactions
Katsumasa TATSUNO and Nagahiro YOSHIDA
Japan Society of Civil Engineers，Proceedings of the annual meeting in Kansai，2 pages (CD-ROM) (2018)(in Japanese)
Evaluation of Road Space Reallocation for Pedestrian and Cyclists using Level of Service Concept at
Midosuji Street in Osaka
Haruka KAWACHI, Takashi UCHIDA and Nagahiro YOSHIDA
Japan Society of Civil Engineers，Proceedings of the annual meeting in Kansai，2 pages (CD-ROM) (2018)(in Japanese)
A Case Study about the Impact of Traffic Signal Installation on Mixed Traffic Conditions in Phnom
Penh, Cambodia
Kazuto IMAI and Nagahiro YOSHIDA
Japan Society of Civil Engineers，Proceedings of the annual meeting in Kansai，2 pages (CD-ROM) (2018)(in Japanese)
Basic Analysis of On-Street Parking Behaviors using Floating Car Data in Osaka Central Areas
Kensuke MEGUMI and Nagahiro YOSHIDA
Japan Society of Civil Engineers，Proceedings of the annual meeting in Kansai，2 pages (CD-ROM) (2018)(in Japanese)
Evaluation of Road Space Reallocation for Pedestrian and Cyclists using level of service concept at
Midosuji Street in Osaka
Haruka KAWACHI and Nagahiro YOSHIDAThe City Planning Institute of Japan, Kansai Branch, Proceedings of The City Planning Institute of Japan,
Kansai Branch, 2018, Volume 16, Pages 29-32, (2018) (in Japanese)
The road space reallocation project in the main street of Osaka, Midosuji has started since 2017 to realize theconcept of human-centered urban space in response to the change of social trend and conditions. The initial
pilot project has been undertaken in the way of increasing the space for pedestrians and cyclists. In addition,
a comfortable space in the reallocated section has been created as an experimental study. While the Level ofService concept was widely employed to evaluate user comfort issues in the transportation field but it isunknown that the LOS concept could apply to these space differences and evaluate the reallocation effectcorrectly. Therefore the objective of this study is to evaluate the effect of space reallocation on street users
using the LOS concept through questionnaire and observational surveys. 3 different street sections including
a narrow mixed pavement, a wide shared pavement, and a wide shared pavement with comfortable space
were compared focusing on the difference between subjective and objective comfort.
Introduction of Inclusive Cycling and Cycle Training in London
Itaru FUJIE, Takao YANAGIHARA, Takuya KONISHI and Nagahiro YOSHIDA－77－

The 7th Japan Cycling Congress, Poster session, (2018) (in Japanese)
Latent opportunities for the use of two-rider bicycles and associated challenges based on assessmentsof its use by people with reduced mobility
Takuya KONISHI and Nagahiro YOSHIDAThe 7h Japan Cycling Congress, Poster session, (2018) (in Japanese)
A Study on a Numerical Model of Two-Phase Gas-Liquid Flow Induced by a Moving Solid withHigh Accuracy
Hiroshi MATSUMOTO, Takaaki SHIGEMATSU
Journal of Japan Society of Civil Engineers, Ser. B2 (Coastal Engineering), Vol. 73(2), pp. I_ 865-I_870(2017)In this study, a numerical model for calculation of fluid motion induced by an object penetrating thegas-liquid interface by combining the Immersed Boundary Method and the Level Set Method was presented.
A new method of satisfying the boundary condition at the Lagrange points near the gas-liquid interface withhigh accuracy is described. After validating of tracing method of the gas-liquid interface by calculated result
on sloshing in rectangular tank, it is presented that calculated result of the Strouhal number and distributionof time-mean velocity in wake of a circular cylinder agrees to experimental result with reasonable accuracy.
Finally, calculated results of vortex pattern induced around a horizontally-oscillating vertical circularcylinder in stationary fluid under the condition of the Keulegan-Carpenter number = 9 and the Reynolds
number = 1,000 is presented.
A Study on Splash Generated by Breaking Wave Acting on a Vertical Wall
Yuki YASUHIRA, Takaaki SHIGEMATSU, Masahide TAKEDA
Journal of Japan Society of Civil Engineers, Ser. B2 (Coastal Engineering), Vol. 73(2), pp. I_835-I_840(2017)In order to take countermeasures against salt damage of pier superstructure economically and efficiently, it isindispensable to clarify the wave conditions of splash generation at the vertical wall, and to grasp thecharacteristics of the splash. Using a series of images capturing splash generation process by a high speed
camera, characteristics of splash such as the number of droplet, diameter and splashing velocity of eachsplashing speed, and so on are measured by the PIV and PTV technique and the relationship between splash
and wave characteristics was investigated.
A Numerical Study on Effect of Inducing Slow Flow on the Bottom Sediment Environment in Closed
Water Area
Hiroaki SUKENAGA, Takaaki SHIGEMATSU, Akio SOHMA, Naotaka YOSHIMURA, Ken HIRAIJournal of Japan Society of Civil Engineers, Ser. B2 (Coastal Engineering), Vol. 73(2), pp. I_1333-I_1338(2017)
It is thought that even very slow flow may be useful for environmental improvement of closed watersheds.
This study aims to quantitatively evaluate seawater conduction to improve the environment of the Doi River,which is a part of the old moat and therefore is a river without flow. The field survey was carried out. Afterparameter tuning based on the field survey, a numerical calculation using the ecological model which cantreat circulation of nutrients, organic carbon, oxygen, oxygen demand units and so on. It is presented that theeffect of promoting slow flow and oxygen concentration on the profile of nutrient and oxygen demand units
and oxygen in the sediment material.
A Fundamental Study on the Characteristics of a Local Scour Under a Vertical Plate and Its
Countermeasure in Wave Field
Yusuke NAKAHARA, Takaaki SIGEMATSU, and Takashi YAMANO
Journal of Japan Society of Civil Engineers, Ser. B3 (Ocean Engineering), Vol. 74(2), pp. I_814-I_819(2018)
Since the local scour, which occurs at the foot of the structure for controlling the drift sand and the flow,
greatly affect the stability of the structure, the appropriate countermeasure should be taken based on theprediction of scale of the scour. In this study, the flow and sand migration phenomena formed in the vicinityof the vertical flat plate were observed in detail by using a high speed camera and the effect of the height ofthe vertical plate on the characteristics of the local scour at the foot of the plate was investigated in hydraulic－78－

experiment. On the basis of the observation the mechanisms of the occurrence of scour was inferred. Further
the countermeasures of penetration of the vertical plate into sand bed and embankment at the foot of thevertical plate were proposed and the effectiveness of them were investigated.
An Experimental Study on the Interaction between Oscillatory Flow and Idealized Porous Bed
Takaaki SHIGEMATSU, Sota NAKAJO, and Yuya OKADA
Journal of Coastal Research,: Special Issue 85 - Proceedings of the 15th International Coastal Symposium:
pp. 981 – 985 (2018)
The microscopic structures of over and inside flow of a porous medium placed in oscillatory flow wasmeasured by the Particle Tracking Velocimetry with the refractive index matching method in order toinvestigate interaction between them. The strong shear flow was observed over the surface of the porous
medium and the thickness of shear flow varied with the phase of the oscillatory flow. It was found that the
thickness of non-dimensional shear flow was almost constant and that it did not depend on the Reynolds
number. It was found that the thickness of non-dimensional shear flow was almost constant and it
independent with the Reynolds number. Besides, it was also found that the phase difference between flows
over and inside the porous bed occurred. The characteristics of the spatial variance of velocity components
were shown in detail with the time phase variance. Further, the flow properties around the particle constitutes
porous body were measured and investigated in detail.
The Future Prediction of the One-Dimensional Topography of the Estuary Delta of the Shirakawa
River
Sota NAKAJO, Kohei NAKANISHI and Hikaru OTA
Coastal Engineering Journal, Volume 59, Issue 2, Special Issue on Climate Impacts on Coastal Engineering,pp. 1740008-1-174008-24 (2018)
Predicting the long-term topographical change based on results of a time-slice experiment using a General
Circulation Model (GCM) is difficult because actual change is a result of the continuum of events occurringin succession leading from the past to the future. We developed a one-dimensional topographical model of anestuary delta as the first step of assessing climate change effects. Three major effects, i.e. tidal flow, waves
and sediment supply from the river, were included in this model. In order to estimate the sensitivity of theseeffects, simulations with virtual conditions were conducted. These simulations show equilibrium profiles thatare close to the results of Roberts et al. [2000] “Predicting the profile of intertidal mudflats formed bycross-shore tidal currents,” Proc. Marine Sci. 3, 263–285.]. The simulation results were validated withobservation data from the Shirakawa River delta. As a long-term prediction (about 37 years), the propagationof the rollover point was less than the actual data showed. The gradient of the subtidal zone was gentler thanthat observed. However, the short-term prediction (about 17 years) agrees with the observation data. These
results show that old, unreliable, observation data used as a boundary condition significantly affects the
reproducibility of the actual tidal flat profile. Finally, the effect of continuous Sea Level Rise (SLR) over 100
years from the present was investigated. As expected, the simulation results show a shift of the shorelinelandward. The water depths in the intertidal and subtidal zones increase compared to a no-SLR condition.
Therefore, the topset area grows as a consequence of SLR. Additionally, it was shown that futureaccumulation in the subtidal zone is reduced with SLR.
On the Effects of Absence of a Member of Porous Media Based on MicroscopicFlow Simulation
Sota NAKAJO, Yuya WATANABE, and Takaaki SHIGEMATSU
Journal of Japan Society of Civil Engineers, Ser. B2 (Coastal Engineering), Vol. 73(2), pp. I_877-I_882(2017)
Simulation results of microscopic flow through porous media used Immersed Boundary method have beenvalidated by comparison with previous experimental studies about the macroscopic pressure drop duringpassing porous media, the drag force acting on sphere body and so on. The constant rate of pressure drop incase of regular arrangement of porous media members shows suitability of conventional macroscopic
method. However, the heterogeneity of pores caused by absence of a member of porous media would induce
the difficulty of application of the conventional model. We discussed about the evidences of its difficulty byshowing the pressure drop distribution inside porous media, the drag coefficient acting on each porous
members, and the distribution of sectional average of intrinsic velocity in porous media.
Morphological Changes and Sediment Discharge at the Mouth of SHIRAKAWA River after－79－

Kumamoto Earthquake
Gozo TSUJIMOTO, Takaomi HOKAMURA, Kengo TABATA, Hikaru OHTA, Sota NAKAJYO, Yasuhide
TAKANO
Journal of Japan Society of Civil Engineers, Ser. B2 (Coastal Engineering), Vol. 73 (2), pp. I_601-I_606(2017)The geomorphological changes of tidal flats adjacent to Shirakawa River mouth due to flush flood after
earthquakes on April 14 and 16, 2016 were examined through field observation data. There was about 0.41m
ground subsidence around field observation site. Therefore, the cross-shore bottom profiles could not returnto the averaged profiles. The measured profiles were analyzed by the three parameters and the correlation
among them was so high. The clinoform along the water-route propagated to off-shore approximately 150m
during 2014 to 2016 after the earthquake. The estimated sediment discharge was 1.1x105m3/yr/km2, whichcorrespond to four times during 1978 to 1997.
Probabilistic Evaluation of Storm Surges in Suruga Bay Employing Stochastic Typhoon Model
Tomohiro YASUDA, Katsuhito IWAHARA, Shota HIRAI, Sota NAKAJO, Soo Youl KIM
Journal of Japan Society of Civil Engineers, Ser. B2 (Coastal Engineering), Vol. 73 (2), pp. I_253-I_258(2017)
Design procedure of coastal embankment compares tsunami height and storm surge height and employs
higher value as a crown level. Estimation of tsunami or storm surge height is usually based on the historicalmaximum record or the assumed maximum value. This study proposes probabilistic evaluation procedure ofstorm surges employing stochastic typhoon model and applies to Suruga Bay. Typhoon tracks passed thetarget area were extracted from the synthetic typhoon tracks dataset for 5000 years. Storm surge simulationand inundation simulation were conducted by nonlinear shallow water models, and occurrence probabilitiesof storm surge height were estimated along coasts in Suruga Bay. Statistical analysis estimated a return
period of the current design storm surge height at Suruga coast is about 270 years.
On the Effects of a Long-Term Yearly Variation of Tropical Cyclones on the Storm Surge Potential in
Japanese Three Major Bays
Sota NAKAJO, Hideyuki FUJIKI, Sooyoul KIM, Gozo TSUJIMOTO
Journal of Japan Society of Civil Engineers, Ser. B2 (Coastal Engineering), Vol. 73 (2), pp. I_211-I_216(2017)The different temporal trend of tropical cyclone properties by each latitude has been shown based on analysisof representative value in each latitudinal band. Some variations of tropical cyclone properties are correlated
to two oscillation indices of atmosphere and ocean interaction. The data of tropical cyclone was divided into
two groups based on these results. Then representative scenarios for boundary conditions of storm surge
simulation were estimated by using statistical approach. The phase change of tropical cyclone is not so large
around three major bay, therefore the phase change of storm surge was also small. However, the change oftropical cyclone track caused local change of storm surge event in each bay.
Sensitivity Analysis of Storm Surge Height and Inundation Area Around Tokyo Bay by Changing
Typhoon Characteristics Due to Climate Change
Yoko SHIBUTANI, Nobuhito MORI, Sooyoul KIM, Sota NAKAJYO, Hajime MASE
Journal of Japan Society of Civil Engineers, Ser. B2 (Coastal Engineering), Vol. 73 (2), pp. I_1399-I_1404(2017)
It is reported that the tropical cyclones will be strengthened and the course of tropical cyclones will bechanged. Impact assessment of storm surge on climate change due to changed tropical cyclones has been
carried out by several researchers. In this study, we have carried out a sensitivity tests of storm surge
simulations to climate change considering typhoon characteristics and sea level rises in the Tokyo bay. The
maximum surge height at Tokyo bay with worst track had been estimated. Next, relationship between
inundation area and central pressure change or sea level rise had been examined. It was found that the change
of central pressure and the surge height are in a proportional relation. And the inundation at Ota area wasconfirmed when the surge height or sea level rise is higher than 1.0 m.
Proposal of an Empirical Equation for Storm Surges Employing a Stochastic Typhoon Model in the
Sea of Aki and Iyo-Nada
Tomohiro YASUDA, Kanoto YOKOYAMA, Shota HIRAI, Sota NAKAJO, Sooyoul KIM－80－

Journal of Japan Society of Civil Engineers, Ser. B3 (Ocean Engineering), Vol. 74 (2), pp. I_581-I_586(2018)
Recently, the climate has become extreme by the influence of global warming, and frequency of strong
typhoon attack is getting increase. Particularly, storm surge disasters are influenced by intensified typhoons.
The number of observations of storm surges are limited and insufficient because hazardous storm surges are
low-frequency events. It is difficult to assess the probability of storm surges only based on observation data.
This study simulates storm surges employing a stochastic typhoon model and a non-linear shallow watermodel, and proposes an empirical equation. Analysis assesses the effect of the number of data and thetyphoon route on estimation accuracy by a proposed empirical equation targeting in Hiroshima (Aki-nadasea) and Matsuyama (Iyo-nada sea). As a result, errors and variations are reduced and the accuracy can be
improved by increasing the number of data. Also, even if tropical cyclones have the same scale, storm surge
are different by the difference of routes, which are dangerous semicircle and navigable semicircle. If
compute the coefficient after classifying the routes, the proposed method can estimate storm surges of highaccuracy at any locations.
Estimation of Characteristics of Micro-Barometric Wave and Its Effect on Longwave Propagation
Sota NAKAJO, Sooyoul KIM
Journal of Japan Society of Civil Engineers, Ser. B3 (Ocean Engineering), Vol. 74 (2), pp. I_539-I_544(2018)
The characteristics of micro-barometric waves in Kyushu island estimated from analysis of high resolution
stationary data was similar between each station. The propagation speed and direction was estimated basedon cross-correlation analysis. Even if synoptic low-pressure development was similar, micro-barometricwave propagation process was different. Numerical simulation results show the possibility of significant
meteorological tsunami caused by very small amplitude pressure waves, and importance of group wave
characteristics, e.g. number of waves or wave length.
Basic Study on Real-time Prediction of Meteotsunami Using Artificial Neural Network Model
Calibrated by Stationary Measurement Data
Sota NAKAJO, Ryuta YAMAGUCHI, Sooyoul KIM and Gozo TSUJIMOTO
Asian and Pacific Coasts 2017: Proceedings of the 9th International Conference on APAC 2017, pp.
292-232(2017)
Around the west-coastal zone of Kyushu island in Japan, the meteotsunami has been observed many times.
In previous studies, some researchers ascertained the micro-barometric wave is primary factor of thisphenomena. However, a real-time prediction of the meteotsunami is very difficult because the micro-pressure
wave is too small and quick to identify from numerical weather forecasting results. In this study, we analyzed
the meteotsunami from high time resolution measurement data and examined predictability of it by an
artificial neural network model (ANN model). We used measurement data collected by Japan Meteorological
Agency for analysis and calibration of ANN model. Target periods are three significant meteotsunami events.
(A)2009 Feb. 21st-28th, (B)2009 Jul. 14th-16th, (C)2010 Jan. 31st-Feb. 2nd. We used a hierarchical neuralnetwork model. The back propagation method and the Levenberg-Marquardt method were adopted as an
optimization algorithm and an error evaluation. Anomaly of tide was defined as difference between
observation tide and prediction tide. Micro-pressure variation was calculated from difference between an
observation atmospheric pressure and the moving average of it. We used these values and observation data as
inputs of ANN model. The output of ANN was anomaly of tide at a target point. The appropriate
combination of input data is very important factor in order to make a high-reproducible model. In addition,
the number of units of intermediate layer, training epochs and a lead-time are also notable model parameters.
We discussed about these effects based on sensitivity analysis of an ANN model. Relation between anomaly
of tide and micro-pressure wave has been confirmed from high time resolution observation data. However, it
is difficult to predict the meteotsunami from observation of atmospheric pressure at fixed point because not
all micro-pressure caused the meteotsunami. Some guidelines of appropriate parameters of ANN model havebeen estimated from sensitivity analysis, although model results are depending on the number ofintermediate units and training epochs. In a present basic model, the appropriate longest lead-time wasapproximately 2 hours. The combination of learning data and validation data was very important for model
accuracy. It would be efficient to use some ensemble models reflecting the effect of different factors for
actual prediction. Prediction result has to be considered as one sample of statistical trial.

－81－Modeling a Coastal Ecosystem to Estimate Climate Change Mitigation and a Model
Demonstration in Tokyo Bay
Akio SOHMA, Hisashi SHIBUKI (Mizuho Information and Research Inst.), Fumiyuki NAKAJIMA (The
Univ of Tokyo), Atsushi KUBO (Shizuoka Univ.), Tomohiro KUWAE (Port and Airport Research Inst.)
Ecological Modelling, 384 pp. 261-289 (2018)
An ecosystem model called the “EMAGIN-B.C. ver 1.0 (Ecosystem Model for Aquatic Geologic Integrated
Network for Blue Carbon)”, describing the Carbon-Nitrogen-Phosphorus-Oxygen-Calcium cycle wasdeveloped to estimate/predict carbon capture and storage in estuaries. EMAGIN-B.C. analyzes (1) carbon
burial, wherein carbon is captured biologically in the pelagic and benthic ecosystems and stored in deeper
sediments, (2) CO2 uptake at the ocean surface while considering the carbonate chemistry with total
alkalinity and Dissolved Inorganic Carbon (DIC) production/consumption due to biochemical processes, (3)DIC capture associated with grazing at the trophic level among phytoplankton, zooplankton, and benthic
fauna, (4) the effects of hypoxia on benthic fauna and bacteria by precise modeling of the biochemical
oxygen production/consumption and the resultant hypoxia, and (5) the carbon transport by integration withthe hydrodynamic model. EMAGIN-B.C. was applied to Tokyo Bay, a eutrophic, shallow coastal area, andreproduced the observations well. From the model outputs, it can be observed that Tokyo Bay shows
functions of climate change mitigation. In the one-year carbon budget, Tokyo Bay captured 16.6% of the
DIC from the atmosphere and river as organic matter by biological processes, and 3.9% of the total carbon
flowing from the atmosphere and river was stored in the deeper sediment layer.
Ecosystem Model Study on Long-term Dynamics of Dissolved Oxygen and Its Factors at the
Bottom Water in Tokyo Bay
Akio SOHMA and Takuro HARUTA
Journal of Japan Society of Civil Engineers, Ser. B2 (Coastal Engineering), Vol.74, No.2, pp. I_1273-I_1278,(2018) (in Japanese)
Hypoxia has been improving throughout Tokyo Bay, however, there are still seriously hypoxic areas. In thisstudy, we analyzed the secular change of dissolved oxygen (DO) and consumption mechanism of thesea-floor due to reduction of nutrients and COD inflow from the land from 1979 to 2009, using thebenthic-pelagic coupled ecosystem model, EMAGIN-H.P. As a result, the model demonstrated that there
were at least three types of areas: zone A, in which DO increases; zone B, in which DO turns from a decrease
to an increase; and zone C, where DO decreases. In addition, reduction of nutrients and COD inflow leads to(1) decrease of reduced substances (Mn2+, Fe2+, and S2-) and increase of benthic fauna due to improvementof hypoxia at zone A, (2) decrease of reduced substances due to DO increase and decrease of benthic fauna
due to food shortage at zone C, and (3) increase of benthic fauna until 1994 with the improvement of
hypoxia and then a decrease due to food shortage at zone B. These results show that the optimal amount of
nutrients and COD inflow in view of both the increase of benthic fauna and the improvement of hypoxia
differs from area to area.
Annual Variation of Air-Sea CO2 Flux at the River Mouth Area and Its Factors -Analysis of an
Ecosystem Model, EMAGIN_B.CAkio SOHMA, Mizuki NAKAI, Atsushi KUBO (Shizuoka Univ.), and Tomohiro KUWAE (Port and Airport
Research Inst.)
Journal of Japan Society of Civil Engineers, Ser. B2 (Coastal Engineering), Vol.74, No.2, pp. I_1267-I_1272,(2018) (in Japanese)
The carbon capture and storage in the coastal shallow ecosystem is a hot topic because of its high po-tential.
The release and uptake of atmospheric CO2 at the air-sea boundary is an important element con-sisting theseries of carbon capture and storage of the shallow waters. In this study, we applied an ecosys-tem model,
EMAGIN_B.C., considering carbonate chemistry, food-web, and Carbon-Nutrients-Oxygen cycling in thebenthic-pelagic coupled system to Tokyo Bay, and analyzed the dynamics of air-sea CO2 flux and its factors
especially focusing on the river mouth area. As the result of the model analysis, CO2 was released from theocean to air at the river mouth area on an annual average basis, although CO2 was taken up at other areas inTokyo Bay. In addition, the CO2 release and CO2 uptake are repeated in the pe-riod from the end of April tothe end of November. The CO2 absorption period is thought to be dominated by the consumption of DIC byphotosynthesis, and the release period is thought to be dominated by con-sumption of total alkalinity by
nitrification.

－82－

CO2 Uptake in the Shallow Coastal Ecosystems Affected by Anthropogenic Impacts
Tomohiro KUWAE (Port and Airport Research Inst.), Jota KANDA Tokyo Univ. of Marine Science andTechnology), Atsushi KUBO (Shizuoka Univ.), Fumiyuki NAKAJIMA (The Univ. of Tokyo), Hiroshi
OGAWA (The Univ. of Tokyo), Akio SOHMA, Masahiro SUZUMURA (National Inst. Of Advanced
Industrial Science and Technology)
Book Chapter In: Blue Carbon in Shallow Coastal Ecosystems: Carbon Dynamics, Policy, andImplementation (eds T. Kuwae, M. Hori), Springer Nature, Singapore, pp.295–319 (2018)
Shallow coastal ecosystems (SCEs) are generally recognized as not only significant organic carbon
reservoirs but also as sources for CO2 emission on the atmosphere, thus posing a dilemma regarding theirrole in climate change mitigation measures. However, we argue that SCEs can act as sinks for atmospheric
CO2 under a given set of biogeochemical and socioeconomic conditions. The key properties of SCEs thatshow net uptake of atmospheric CO2 are often characteristic of human-dominated systems, that is, highnutrient inputs from terrestrial systems, input of treated wastewater in which labile carbon has been mostly
removed, and the presence of hypoxic waters. We propose a new perspective on the potential of
human-dominated SCEs to contribute to climate change mitigation, both serving as carbon reservoirs andproviding direct net uptake of atmospheric CO2, in light of human systems-ecosystem interactions. Namely,
if we view the land and a SCE as an integrated system, with appropriate management of both wastewater
treatment and SCE, we will be able to not only suppress CO2 release but also capture and store carbon.
Quantification of Ecosystem Services at Tidal Flats in Osaka Bay Using Tidal Flat Health Index:
Characterization of the Tidal Flats by Comparison Between Tokyo Bay and Osaka Bay
Tomonari OKADA, Yugo MITO, Takanori SUGANO, Toshiyuki TAKAHASHI, Yoshihiro AKIYAMA, Hiroshi
KUROIWA, Toru ENDO, Sosuke OTANI, Susumu YAMOCHI, Yasunori KOZUKI, Takayuki KUSAKABE,
Koji OTSUKA, Ryoichi YAMANAKA, Takaaki SHIGEMATSU, Kazuyuki NAKANO, Makoto USHIRO andTomohiro KUWAE
Journal of Japan Society of Civil Engineers, Ser.B2 (Coastal Engineering), Vol.74, No.2, pp.1417-1422 (2018) (inJapanese)In this study, the tidal flat health index (THI) was applied to four tidal flats in Osaka Bay to confirm the versatilityof THI and understand the features in each tidal flat by comparing them with four tidal flats in Tokyo Bay. The
reference values (the best score of each health index) in the services, such as food supply and water purification,
related to the ecosystem states, in Osaka Bay were almost equal to those of Tokyo Bay. The reference values in theservices, such as tourism and recreation, influenced by the regional population, were higher in Tokyo Bay than in
Osaka Bay. However, the reference value of education was higher in Osaka Bay compared to Tokyo Bay,suggesting that environmental learning is active in Osaka. Principal component analysis of the nine services in theeight tidal flats in Osaka Bay and Tokyo Bay revealed that 74% of the THI scores could be explained by 2components: "utilization of people" and "biodiversity".
Estimation of Air-sea CO2 Fluxes in Osaka Bay, Harima-Nada and Ago Bay base on Spatial Distribution
Survey of Dissolved Inorganic Carbon
Toru ENDO, Junpei SHIMANO, Kenji IKENAGA and Hideki KOKUBU
Journal of Japan Society of Civil Engineers, Ser.B2 (Coastal Engineering), Vol.74, No.2, pp.1315-1320 (2018) (inJapanese)To evaluate the air-sea CO2 flux of Osaka Bay, Harima Nada and Ago Bay, we conducted the spatial distribution
surveys of the dissolved inorganic carbon (DIC) and pH. There are low DIC concentration in the inner part of
Osaka Bay where external load is large because DIC was consumed by photosynthesis of phytoplankton. On theother hand, there are high DIC concentration in the Ago Bay where much organic carbon was accumulated on thesea floor. We found that CO2 was absorbed basically in all seas at daytime and, especially, Osaka bay had highCO2 absorption potential compared with the other seas.
CO2 fluxes were calculated based on a chemical equilibrium model of carbonic acid from the measurement dataof DIC and pH, air to sea CO2 flux was 12.6 to 14.0 CO2/m2/hr in Osaka bay, 1.5 to 3.7 CO2/m2/hr in Harima
Nada and 0.8 mg CO2/m2/hr in Ago Bay. The CO2 Flux of Osaka Bay was larger than the averaged CO2 fluxes ofcoastal seas reported in around the world.
Effect of Fallen Leaves Supply with Sandy Sediment Layer on the Benthic Ecosystem in an Artificial Tidal
Flat
Toru ENDO, Tsukasa MORITA, Ataru TAMURA and Hiroyuki OOKA

－83－

Journal of Japan Society of Civil Engineers, Ser.B3 (Ocean Engineering), Vol.74, No.2, pp.492-297 (2018) (inJapanese)
Deterioration of ecosystem functions is concerned because the sediment layer is becoming sandy by the lack oforganic matter in an artificial tidal flat of Osaka Nanko bird sanctuary. We focused on fallen leaves supply withthe sandy sediment layer as part of preservation measures for the benthic ecosystem. In this study, we conducted
several experiments (a dissolution test, survival tests about benthic organisms and field experiment) by using theeasily decomposable fallen leaves and the humified persistent fallen leaves to confirm the efficacy of the fallen
leaves supply.
We found that the easily decomposable fallen leaves supply had a negative effect on the benthic habitat
environment because the sediment layer was kept in anaerobic condition by decomposing organic matter.
However, for the case of suppling the persistent fallen leaves, sulfide was not almost generated and survive rate ofPerinereis wilsoni was higher than that without supplying fallen leaves. On the other hand, we confirmed that
more species were inhabited in the site supplied fallen leaves with the sediment layer than the site of without
supplying fallen leaves form the results of field investigation. Therefore, it was suggested that the persistent fallen
leaves supply is effective way for the conservation of the benthic ecosystem in sandy tidal flat.
Relationship between Vertical Distribution of pCO2 in Sea and Air-sea CO2 Exchange in Inner Part of
Osaka Bay
Toru ENDO, Junpei SHIMANO, Daiki SAKAI and Ryuichi FUJIWARA
Journal of Japan Society of Civil Engineers, Ser.B2 (Coastal Engineering), Vol.73, No.2, pp.1231-1236 (2017) (inJapanese)
Vertical distribution of dissolved inorganic carbon (DIC) and water qualities and CO2 concentration of air watermeasured at an inner part of Osaka bay during one year and at around the time of approaching typhoon, in order tograsp relationship between the air-sea CO2 exchange and the vertical distribution characteristics of pCO2 in sea.
We found that CO2 was absorbed constantly from air to sea at normal condition despite pCO2 in sea was larger athigh water temperature season when biological activity is high. However, CO2 was emitted from sea to air in rainy
weather because pH of surface water becomes lower due to rain water mixing. In addition, CO2 was also emitted
when the coastal upwelling occurred, or the seawater was mixed by typhoon. Furthermore, we increased at bottom
layer at the time of high density stratified season spread to surface layer.
Evaluation of Carbon Absorption of Phytoplankton at the North Salt Marsh of Osaka Nanko Bird
Sanctuary
Toru ENDO and Taiki KAWASAKI
Journal of Japan Society of Civil Engineers, Ser.B2 (Coastal Engineering), Vol.73, No.2, pp.1369-1374 (2017) (inJapanese)
Recently, the carbon absorption process of wetland ecosystem is getting a lot of attention as a new ecosystem
function. It is important to understand the carbon cycle of salt marsh in urban coastal area for coastal managementof future. In this study, an incubation experiment on phytoplankton photosynthesis and field investigations oncarbon cycle in salt marsh were conducted at the north salt marsh in Osaka Nanko bird sanctuary in order toevaluate the effect of phytoplankton on the carbon budget of salt marsh. The carbon absorption rate perchlorophyll a was formulated as a function of temperature and photon flux density, and the carbon emission rate ofrespiration and decomposition in seawater was formulated as a function of temperature by measuring DIC
changes in the seawater under light and dark conditions. It was found that the rate of the air-sea carbon exchange
is smaller than the carbon absorption rate of phytoplankton, and there was no correlation between them, according
to estimation of the rate of air-sea carbon flux and amount of carbon absorption of phytoplankton obtained by theseasonal investigation on phytoplankton biomass and DIC of surface water. Finally, it was suggested that the ratioof photosynthesis to carbon budget of the salt marsh was from 10 to 30 % from comparing the daily variation of
the carbon cycle due to the air-sea exchange, the water exchange, the carbon absorption of phytoplankton and thecarbon emission of respiration and decomposition in sea water.
Organic pollution loads in municipal solid waste incineration fly ash derived from highly reactive
slaked lime in leachate from landfill site
Satoshi MIZUTANI, Katsunori MATOZAKI, Hirofumi SAKANAKURA and Yoshinori KANJO
Proc. of the 10th International Conference on the Environmental and Technical Implications of Construction
with Alternative Materials (WASCON2018), Tampere, 6-8 June 2018 (on USB).
High levels of total organic carbon (TOC) are often detected in leachate from landfill sites in Japan, which is－84－

problematic for proper leachate treatment. In this study, TOC and chemical oxygen demand (CODMn) of
leachate from fly ash and slaked lime in Japanese landfill sites were determined. The TOC in leachates from
13 kinds of incineration fly ash from municipal solid waste was measured. Ignition loss (IL) of each type of
fly ash was also measured to determine the content of organic matter. There was no relationship between
TOC and IL. Higher TOC levels were detected in leachate from fly ash from incinerators with dry-acid gas
treatment systems. This suggests that the TOC of the leachate from the fly ash was derived from slaked lime
for the neutralization of acid gas. Subsequently, 13 kinds of highly reactive slaked lime were obtained. The
TOC of their leachates was measured and was in the range of 600–5,680 mg/kg. In contrast, normalindustrial lime and Ca(OH)2 reagent do not contain organic materials. Generally, there was a positive
correlation between COD and TOC in slaked lime. TOC showed 60–80% of CODMn－85－

List of Presentations
atInternational Conferences
Presenters are underlined in the list of authors.
†

Undergraduate or graduate students of the Faculty of Engineering, Osaka City University

Mechanical and Physical Engineering
Mechanical Engineering
Damage Behavior of CFRP/Titanium Mesh Laminates under Three-point Bending Loading
Yoshinori SEI†, Hayato NAKATANI and Katsuhiko OSAKA
The 12th Canada-Japan Workshop on Composites, Takayama, Japan, July 4-7, 2018 (poster).
Evaluation of Resin Impregnation Behavior in Thick FRP with Corner during VaRTM Process
Kyosuke NAKAMURA†, Hayato NAKATANI and Katsuhiko OSAKA
The 12th Canada-Japan Workshop on Composites, Takayama, Japan, July 4-7, 2018 (poster).
High- and Low-Cycle Fatigue Properties of SUS304L Steel Processed by ECAP
Y. KANEKO, H. KOBAYASHI, K. TSUJIMURA, M. UCHIDA and A. VINOGRADOV
The 15th International Conference on Advanced Materials, Kyoto, Japan, Aug. 27-Sep. 1, 2017 (invited).
Fabrication and Microstructure of Electrodeposited Cu-based Alloy Films Having High Composition
Gradient
H. HAGIWARA†, Y. KANEKO and M. UCHIDA
15th International Symposium on Functionally Graded Materials, Kitakyushu, Japan, Aug. 5-8, 2018.
Nonlocal Multiscale Modeling of Deformation Behavior of Polycrystalline Copper by Second-order
Homogenization Method
M. UCHIDA, A. TANIGUCHI† and Y. KANEKO
The 9th International Conference on Multiscale Materials Modeling, Osaka, Japan, Oct. 27-Nov. 2, 2018.

－89－

Electronics and Informatics
Applied Physics and Electronics
Excitation Energy Dependence of Carrier-Induced Terahertz Wave Radiation in a GaAs Epitaxial Film
Takayuki HASEGAWA, Yuta OKUSHIMA, Masaaki NAKAYAMA and Yoshihito TANAKA
12th International Conference on Excitonic and Photonic Processes in Condensed Matter and Nano Materials,
Nara, Japan, July 8-13, 2018
Temperature Dependence of Photoluminescence Dynamics of Exciton-Exciton Inelastic Scattering in a
GaAs/AlAs Multiple-Quantum-Well Structure
Yuichiro MIYAZAKI† and Masaaki NAKAYAMA
12th International Conference on Excitonic and Photonic Processes in Condensed Matter and Nano Materials,
Nara, Japan, July 8-13, 2018 (poster)
Photoluminescence Polarization Characteristics of Self-Trapped Excitons in an Undoped β-Ga2O3 Single
CrystalSuguru YAMAOKA†, Yusuke MIKUNI† and Masaaki NAKAYAMA
12th International Conference on Excitonic and Photonic Processes in Condensed Matter and Nano Materials,
Nara, Japan, July 8-13, 2018 (poster)
Strong Coupling Formation in Organic Crystal Microcavities
Takumi NISHIMURA, Keita IMAI, Shun TAKAHASHI, Kenichi YAMASHITA, Hisao YANAGI and Masaaki
NAKAYAMA
12th International Conference on Excitonic and Photonic Processes in Condensed Matter and Nano Materials,
Nara, Japan, July 8-13, 2018 (poster)
Investigation of a Pressure Gradient Ar Plasma Sputtering for Metal Thin Film Deposition
Hiroki OOTA, Kiyomi TAKAHASHI, Jun-Seok OH, Kazunori KOGA, Tatsuyuki NAKATANI, Masafumi ITO,
Masaharu SHIRATANI, Ken YONEZAWA
16th International Conference on Plasma Surface Engineering, Garmisch-Partenkirchen, Germany, September
17-21, 2018 (poster)Developing In Vitro Models to Analyze the Metrology of Plasma-Tissue Interactions
Endre SZILI, Jun-Seok OH, Akimitsu HATTA, Masafumi ITO, Hideo FUKUHARA, Keiji INOUE, Sung-Ha
HONG, Nishtha GAUR, Rob SHORT
Plasma Processing and Science, Gordon Research Conference, Smithfield, RI, USA, August 5-10, 2018 (invited)
Assessing the Helium Plasma Jet Induction of Apoptosis in an In Vivo Tumor Model
Nishtha GAUR, Endre SZILI, Jun-Seok OH, Hideo FUKUHARA, Rishabh BHATIA, Cuong NGUYEN, Sung-Ha
HONG, Satsuki ITO, Kotaro OGAWA, Chiaki KAWADA, Taro SHUIN, Masayuki TSUDA, Mutsuo FURUHATA,
Atsushi KURABAYASHI, Hiroshi FURUTA, Masafumi ITO, Keiji INOUE, Akimitsu HATTA, Robert SHORT
Plasma Processing and Science, Gordon Research Conference, Smithfield, RI, USA, August 5-10, 2018 (poster)
Application of Multiphase Media Plasmas to Nano-material Treatment
Tatsuru SHIRAFUJI
The 7th International Conference on Microelectronics and Plasma Technology, Incheon, Korea, July 24-28, 2018(invited)
Effects of Argon Micro-bubble Assistance on the Performance of 3D Integrated Micro Solution Plasma
Reiya NAKAGAWA†, Hiroto MASUNAGA†, Jun-Seok. OH, and Tatsuru SHIRAFUJI
The 7th International Conference on Microelectronics and Plasma Technology, Incheon, Korea July 24-28, 2018
(poster)
Effects of Pulse Voltage Polarity on GNP-embedded Polymer Formation on Aqueous Solution Irradiatedwith Ar DBD Plasma－90－

Shunta HIRANO†, Shiori AZUMA†, Yusuke NAKAMURA†, Jun-Seok OH, Toshiyuki ISSHIKI, and Tatsuru
SHIRAFUJI
The 7th International Conference on Microelectronics and Plasma Technology, Incheon, Korea, July 24-28, 2018
(poster)
Effects of Grounded Electrode on the APPJ Treatment for Improving Water Permeability of a
Bone-regeneration Scaffold
Yuki HAMAMOTO†, Masato OSHIRO† , Jun-Seok OH, Kumi ORITA, Hiromitsu TOYODA, and Tatsuru
SHIRAFUJI
The 7th International Conference on Microelectronics and Plasma Technology, Incheon, Korea, July 24-28, 2018
(poster)
Generation of 3D Integrated Micro Solution Plasma in Water with Micro Bubbles
Reiya NAKAGAWA†, Hiroto MASUNAGA†, Jun-Seok. OH, and Tatsuru SHIRAFUJI
The 1st International Symposium on Water Frontier Science & Technology Research Center, Tokyo University of
Science, "Water on Materials Surface 2018", Tokyo, Japan, July 25-28, 2018 (poster)Long-term Investigation of Radical-activated Water
Jun-Seok OH, Naoyuki IWATA, Takayuki OHTA, Masaru HORI, and Masafumi ITO
The 8th International Symposium on Plasma Bioscience, Incheon, Korea, July 24-28, 2018 (invited)
Time-Dependence Monitoring of Sterilization Effects and RONS Concentrations in Radical-Activated
Water
Naoyuki IWATA, Jun-Seok OH, Takayuki OHTA, Masaru HORI, and Masafumi ITO
The 8th International Symposium on Plasma Bioscience, Incheon, Korea, July 24-28, 2018 (poster)Diagnostics of Radicals Generated from Atmospheric-Pressure Radical Source and Their Activated Water
Using Ultra-Violet Absorption Spectroscopy
Masafumi ITO, Naoyuki IWATA, Jun-Seok OH, Takayuki OHTA, Masaru HORI
24th Europhysics Conference on Atomic and Molecular Physics of Ionized Gases, Glasgow, UK, July 17-21, 2018
(poster)
Plasma Jet Treatment of Hypoxic Tumours
Endre SZILI, Jun-Seok OH, Hideo FUKUHARA, Keiji INOUE, Akimitsu HATTA, Rob SHORTThe 20th Gaseous Electronics Meeting, Queensland, Australia, June 21-24, 2018 (invited)
Investigation of How Short-Lived and Long-Lived Plasma Species Interact with DNA in Models of Tissue
Fluid, Tissue and Cells
Nishtha GAUR, Endre SZILI, Sung Ha HONG, Hirofumi KURITA, Jun-Seok OH, Masafumi ITO, Akira
MIZUNO, Akimitsu HATTA, Allison COWIN, David GRAVES, Robert SHORTThe 20th Gaseous Electronics Meeting, Queensland, Australia, June 21-24, 2018
Development of VUV Absorption Spectroscopy for Quantitative Analysis of Plasma Activated Water
Jun-Seok OH, Naoyuki IWATA, Akimitsu HATTA, Tatsuru SHIRAFUJI, and Masafumi ITO
The 6th International Workshop and the 5thrd International Mini Workshop on Solution Plasma and MolecularTechnology, Gdansk, Poland, June 4-7, 2018 (invited)
Plasma-on-Chip: An Innovative Microdevice to Direct Cell Fate using A Non-Thermal AtmosphericPressure Plasma
Shinya KUMAGAI, Mine KOBAYASHI, Jun-Seok OH, Tetsuji SHIMIZU, Minoru SASAKI
10th International Symposium on Organic Molecular Electronics, Saga, Japan, May 31-June 2, 2018
Improvement of Water Permeability of a Scaffold by Irradiating Atmospheric Pressure Plasma Jet
Masato OSHIRO†, Kumi ORITA, Yoshihiro HIRAKAWA, Hiromitsu TOYODA and Tatsuru SHIRAFUJI
The 19th anniversary International Symposium on Advanced Plasma Science and its Application for Nitrides andNanomaterials / The 11th International Conference on Plasma-Nano Technology & Science, Nagoya, Japan,
March 4-8, 2018 (poster)－91－

Time Evolution of RONS in Water Treated with Air Bubble Plasma
Shoma MIYAMOTO†, Kentaro NISHIMOTO†, Shin-ichi IMAI and Tatsuru SHIRAFUJI
The 19th anniversary International Symposium on Advanced Plasma Science and its Application for Nitrides andNanomaterials / The 11th International Conference on Plasma-Nano Technology & Science, Nagoya, Japan,
March 4-8, 2018 (poster)
Effects of Micro-bubble Assistance on the Performance of 3D Integrated Micro Solution Plasma
Hiroto MASUNAGA†, Yodai ISHIDA† and Tatsuru SHIRAFUJI
The 19th anniversary International Symposium on Advanced Plasma Science and its Application for Nitrides andNanomaterials / The 11th International Conference on Plasma-Nano Technology & Science, Nagoya, Japan,
March 4-8, 2018 (poster)
Structural Analysis of Au-Nanoparticle-Embedded Polymer Films Synthesized on HAuCl4/Gelatin Aqueous
Solution Irradiated with Ar DBD Plasma
Shiori AZUMA†, Yusuke NAKAMURA†, Toshiyuki ISSHIKI and Tatsuru SHIRAFUJI
The 19th anniversary International Symposium on Advanced Plasma Science and its Application for Nitrides andNanomaterials / The 11th International Conference on Plasma-Nano Technology & Science, Nagoya, Japan,
March 4-8, 2018 (poster)
Efficiency of OH Radical Production in 3D Integrated Micro Solution Plasma
Tatsuru SHIRAFUJI, Junpei YAMAMOTO† and Hiroto MASUNAGA†
The 19th anniversary International Symposium on Advanced Plasma Science and its Application for Nitrides andNanomaterials / The 11th International Conference on Plasma-Nano Technology & Science, Nagoya, Japan,
March 4-8, 2018 (poster)－92－

Applied Chemistry and Bioengineering
Hydrolysis of Organophosphates Catalyzed by Plussian Blue Analogs
Chihiro TERASHIMA†, Hiroyasu TABE, Yusuke YAMADAThe 9th OCARINA International Symposium, Osaka, Japan, March 7, 2018 (poster)Light-Driven Water Oxidation Reaction Catalyzed by Cyano-Bridged Metal Complexes with Core-Shell
Structure
Akira KITASE†, Hiroyasu TABE, Yusuke YAMADAThe 9th OCARINA International Symposium, Osaka, Japan, March 7, 2018 (poster)
Catalytic Activity of Thiocyanato-bridged Polynuclear Metal Complexes for
Organophosphates
Masaaki MATSUSHIMA†, Chihiro TERASHIMA†, Hiroyasu TABE, Yusuke YAMADAThe 9th OCARINA International Symposium, Osaka, Japan, March 7, 2018 (poster)HydrolysisofConstruction of Composite Photocatalysts for Water Oxidation Using Silica Nanoparticles Assembly as a
Mesoporous Support
Gentaro SAKAMOTO†, Hiroyasu TABE, Yusuke YAMADAThe 9th OCARINA International Symposium, Osaka, Japan, March 7, 2018 (poster)Synthesis and Characterization of Li2Co1.8Ni0.2O4 as Zero-Strain Lithium Insertion Material
Kensuke KAJIKAWA†, Yusuke YAMADA, Kingo ARIYOSHI
The 9th OCARINA International Symposium, Osaka, Japan, March 7, 2018 (poster)
Heterogeneous Catalysis of Cyano-Bridged Polynuclear Metal Complexes for Organophosphate Hydrolysis
Hiroyasu TABE†, Chihiro TERASHIMA, Yusuke YAMADA
43rd International Conference on Coordination Chemistry, Sendai, Japan, July 31, 2018 (poster)
Enhanced Catalysis of Prussian Blue Analogs with CN-Deficient Sites for Hydrolysis of Organophosphates
Mari YAMANE†, Chihiro TERASHIMA, Hiroyasu TABE, Yusuke YAMADA
43rd International Conference on Coordination Chemistry, Sendai, Japan, July 31, 2018 (poster)
Activity of Core-Shell Nanoparticles Composed of Cyano-Bridged Metal Complexes Containing Co Ions
for Photocatalytic Water Oxidation
Akira KITASE†, Hiroyasu TABE, Yusuke YAMADA
43rd International Conference on Coordination Chemistry, Sendai, Japan, August 1, 2018 (poster)
Catalysts Utilized for Artificial Photosynthesis with a Molecular Light Harvesting Unit
Yusuke YAMADA
OrganiX-2018, An International Conference in Chemistry, Tezpur, India, December 20, 2018 (invited)
Workshop Instructor on “Micro XRF”
K. TSUJI
67th Annual Conference on Applications of X-ray Analysis Denver X-ray Conference, Westminster, Colorado,
U.S.A., August 6-10, 2018 (invited)
Workshop Instructor on “Trace Analysis”
K. TSUJI－93－

67th Annual Conference on Applications of X-ray Analysis Denver X-ray Conference, Westminster, Colorado,
USA, August 6-10, 2018 (invited)
Recent Advances and Standardization in X-Ray Fluorescence (XRF) Analysis: Confocal 3D-XRF and Total
Reflection XRF
K. TSUJIIUPAC Analytical ChemistryWorkshop Advances in Analytical Chemistry II, Nara, Japan, April 27, 2018 (invited)
New Sample Preparation for TXRF Analysis Using Resist Pattern Layer
K. TSUJI, T. FURUSATO†, N. YOMOGITA†
67th Annual Conference on Applications of X-ray Analysis Denver X-ray Conference, Westminster, Colorado,
U.S.A., August 6-10, 2018
Observation of Crystal Structure Changes with Full Field X-ray Diffraction Imaging Instrument
M. YAMANASHI†, K. TSUJI
67th Annual Conference on Applications of X-ray Analysis Denver X-ray Conference, Westminster, Colorado,
U.S.A., August 6-10, 2018 (poster)
New Sample Carrier Modified with Low-Z Material Layer for TXRF Analysis
K. TSUJI, T. FURUSATO†, N. YOMOGITA†
European Conference on X-Ray Spectrometry (EXRS2018), Ljubljana, Slovenia, June 24-29, 2018
Elemental Analysis of Human Hair by Confocal Micro-XRF Analysis
T. FURUSATO†, N. YOMOGITA†, K. TSUJI
European Conference on X-Ray Spectrometry (EXRS2018), Ljubljana, Slovenia, June 24-29, 2018
Quantitative Elemental Analysis of Human Hairs by Using Desktop X-Ray Fluorescence Analyzer
T. FURUSATO†, F. INOUE (Nobias), K. TSUJI
European Conference on X-Ray Spectrometry (EXRS2018), Ljubljana, Slovenia, June 24-29, 2018 (poster)
In Situ Observation of the Corrosion Process of Steel Sheets under Bending Stress by Confocal Micro XRF
TechniqueM. NAKANISHI†, R. HOSOMI†, K. TSUJI
European Conference on X-Ray Spectrometry (EXRS2018), Ljubljana, Slovenia, June 24-29, 2018 (poster)Elemental Distribution Analysis of Copper-based Preservative-treated Woods by Micro XRF Method
M. NAKANISHI†, Y. FUJIWARA (Kyoto University), Y. FUJII (Kyoto University), K. TSUJI
European Conference on X-Ray Spectrometry (EXRS2018), Ljubljana, Slovenia, June 24-29, 2018 (poster)
Raman Microspectroscopic Study on an Optically Formed Poly(N-isopropylacrylamide) Rich
Microparticle: Molecular Weight Dependence of a Polymer Concentration in the Particle
Kayo FUJIWARA†, Tatsuya SHOJI, Mitsuhiro MATSUMOTO, Taka-Aki ASOH, Takashi NISHIYAMA, Hideo
HORIBE, Yasuyuki TSUBOI
Optical Manipulation Conference, SPIE Structured Light, Yokohama, Japan, April 25–27, 2018
Oxygen Additive Effects on Decomposition Rate of Poly(Vinyl Phenol)-Based Polymers Using Hydrogen
Radicals Produced by a Tungsten Hot-Wire Catalyst－94－

Masashi YAMAMOTO (Kagawa College), Shiro NAGAOKA (Kagawa College), Keisuke OHDAIRA (Japan
Advanced Institute of Science and Technology), Hironobu UMEMOTO (Shizuoka University, Osaka City
University), Hideo HORIBE
10th International Conference on Hot Wire (Cat) & Initiated Chemical Vapor Deposition, Kitakyushu, Japan,
September 3–6, 2018 (poster)
PEGylated Amphiphilic Block Copolymers as Membrane Anchors for Controlled Affinity to Lipid Bilayer
Membranes
Yuta KODA (Osaka City University, Kyoto University), Daiki TAKAHASHI (Kyoto University), Yoshihiro
SASAKI (Kyoto University), Kazunari AKIYOSHI (Kyoto University, JST-ERATO)
256th ACS National Meeting & Exposition, Boston, U.S.A., August 19–23, 2018
Coumarin Derivative Polymers for Thermo- and Light-Responsive Monofunctional Polymers
Eriko SATO
14th International Conference of Computational Methods in Science and Engineering (ICCMSE 2018),
Thessaloniki, Greece, March 14-18, 2018 (invited)
Design of Smart Adhesive Materials based on Well-Defined Reactive Polymers
Eriko SATO
The polymer society of Korea, 2018 Spring Meeting, Korea-Japan Joint Symposium, Smart Interface by
Functional Polymers, Daejeon, Korea, April 4-6, 2018 (invited)
Cross-Linked Polyperoxides for Photoremovable Adhesives
Eriko SATO, Chisato OMORI†, Takashi NISHIYAMA and Hideo HORIBE
The 35th International Conference of Photopolymer Science and Technology, Chiba, Japan, June 25-28, 2018(invited)
Degradable Polymers for Dismantlable Adhesive Materials
Eriko SATO
The 10th International Conference of Modification, Degradation and Stabilization of Polymers, Tokyo, Japan,
September 2-6, 2018 (invited)
Degradable Hyperbranched Polymers for Green Adhesive Materials
Eriko SATO, Yoji YAMASHITA†, Yuta KODA, Hideo HORIBE
The 12th SPSJ International Polymer Conference, Hiroshima, Japan, December 4-7, 2018
Development of Thermal Latent Reductants for Accelerated Decomposition of Cross-Linked Polyperoxides
Chisato OMORI†, Eriko SATO, Yuta KODA and Hideo HORIBE
The 12th SPSJ International Polymer Conference, Hiroshima, Japan, December 4-7, 2018 (poster)
Thermo- and Photo-Responsive Behavior of Monofunctional Dual Stimuli-Responsive Organogels
Seidai OKADA†, Eriko SATO, Yuta KODA and Hideo HORIBE
The 12th SPSJ International Polymer Conference, Hiroshima, Japan, December 4-7, 2018 (poster)
Facile Synthesis of Poly(dialkyl fumarate) Macromonomers by Radical Polymerization using
Addition-Fragmentation Chain Transfer Agent
Junichiro KURAHASHI†, Noboru TAMARI†, Eriko SATO, Yuta KODA and Hideo HORIBE
The 12th SPSJ International Polymer Conference, Hiroshima, Japan, December 4-7, 2018 (poster)－95－

Photoswitching of Birefringence of Diarylethene Single Crystals by Photochromic Reaction
Kohei MORIMOTO†, Hajime TSUJIOKA†, Daichi KITAGAWA, Seiya KOBATAKE
9th OCARINA International Symposium, Osaka, Japan, March 6-7, 2018 (poster)
Dependence of Fluorescence On/Off Switching Properties of Nanoparticles Consisting of Two Types ofDiarylethenes on Forster Distance and Molar Fraction
Tatsumoto NAKAHAMA†, Daichi KITAGAWA, Hikaru SOTOME (Osaka University), Syoji ITO (Osaka
University), Hiroshi MIYASAKA (Osaka University), Seiya KOBATAKE
French-Japanese International Associated Laboratory Nano-synergetics: Workshop for Young Researchers on
Photo-active materials with Cooperative and Synergetic Responses, Lille, France, March 29-30, 2018
Development of Novel Photomechanical Phenomena of Photoresponsive Molecular Crystals by High-order
Photoexcitation
Seiya KOBATAKE
2nd International Symposium on Photosynergetics and 3rd Workshop on Photo-active Materials with Cooperativeand Synergetic Responses - Nanosynergetics, International Associated Laboratory (LIA) between France andJapan, Osaka, Japan, May 21-23, 2018 (invited)
Emission Color Tuning and Efficient Emission of BODIPY Polymer in Solid State
Katsuya SHIMIZU†, Daichi KITAGAWA, Seiya KOBATAKE
27th International Symposium on Photochemistry (PhotoIUPAC 2018), Dublin, Ireland, July 8-13, 2018 (poster)
Photoinduced Crystal Shape Change of Photochromic Diarylethene Crystals
Seiya KOBATAKE
13th International Workshop on Crystal Growth of Organic Materials (CGOM13), Seoul, Korea, August 27-30,
2018 (plenary)
How Illumination Direction Affects Photomechanical Crystal Twisting
Daichi KITAGAWA, Hajime TSUJIOKA†, Fei TONG (University of California, Riverside), Xinning DONG
(University of California, Riverside), Chrostopher J. BARDEEN (University of California, Riverside), Seiya
KOBATAKE
13th International Workshop on Crystal Growth of Organic Materials (CGOM13), Seoul, Korea, August 27-30,
2018
Photo-tuning of Birefringence in Diarylethene Crystals
Kohei MORIMOTO†, Hajime TSUJIOKA†, Daichi KITAGAWA, Seiya KOBATAKE
13th International Workshop on Crystal Growth of Organic Materials (CGOM13), Seoul, Korea, August 27-30,
2018 (poster)
Crystallization-induced Emission of 1,2-Bis(3-methyl-5-(4-alkylphenyl)-2-thienyl)perfluoro- cyclopentenes
Tatsumoto NAKAHAMA†, Daichi KITAGAWA, Hikaru SOTOME (Osaka University), Syoji ITO (Osaka
University), Hiroshi MIYASAKA (Osaka University), Seiya KOBATAKE
13th International Workshop on Crystal Growth of Organic Materials (CGOM13), Seoul, Korea, August 27-30,
2018 (poster)Fluorescence On/Off Switching of Branched Polymer Consisting of Diarylethene and Fluorene Derivatives
Katsuya SHIMIZU†, Seiya KOBATAKE
Journées GDR Photo Électro Stimulation, Kick-off meeting, Rennes, France, October 2-3, 2018 (poster)－96－

Photochromic Diarylethene Crystals That Exhibit Unusual Photomechanical Behavior
Seiya KOBATAKE, Daichi KITAGAWA
10th Asian Photochemistry Conference (APC 2018), Taipei, Taiwan, December 16-20, 2018 (invited)
Fluorescence Color Tuning and On/Off Switching of BODIPY Polymers in Solid State
Katsuya SHIMIZU†, Seiya KOBATAKE
10th Asian Photochemistry Conference (APC 2018), Taipei, Taiwan, December 16-20, 2018 (poster)
Photomechanical Crystal Deformation of Diarylethenes with Polarized Light
Akira HIRANO†, Daichi KITAGAWA, Seiya KOBATAKE
10th Asian Photochemistry Conference (APC 2018), Taipei, Taiwan, December 16-20, 2018 (poster)
Change in Interference Color in Diarylethene Crystals upon Photoirradiation
Kohei MORIMOTO†, Hajime TSUJIOKA†, Daichi KITAGAWA, Seiya KOBATAKE
10th Asian Photochemistry Conference (APC 2018), Taipei, Taiwan, December 16-20, 2018 (poster)
Determination of Solubility of Extremely Poor Water Solubility Co-crystal Melamine Cyanurate
K. IGARASHI, R. YANAGITA†, J. ter HORST (Strathclyde University)
13th International Workshop of the Crystal Growth of Organic Material, Seoul, Korea, August 27-30, 2018
(poster)
Effect of Plastic Piece Moving in the Solution on Crystal Nucleation of L-alanine
K. IGARASHI, T. KOBAYASHI†, H. OOSHIMA
Asian Crystallization Technology Symposium 2018, Singapore, June 20-22, 2018 (poster)Control of Crystal Size Distribution Using a mL-Scale Continuous Crystallizer Equipped with a High
Speed Agitator
K. IGARASHI, H. OOSHIMAInternational Powder and Nanotechnology Forum 2018 in ACHEMA 2018, Frankfurt am Main, Germany, June
12-13, 2018 (invited)
Enhancement of Crystal Nucleation Rate by Reciprocating Plastic Piece in L-alanine Solution
T. KOBAYASHI†, K. IGARASHI, H. OOSHIMA
11th International Conference on Separation Science and Technology (ICSST17), Busan, Korea, November 9-11,
2017 (poster)
Crystallization of a Tripeptide from the Oil Phase
K. IGARASHI, H. OOSHIMA
11th International Conference on Separation Science and Technology (ICSST17), Busan, Korea, November 9-11,
2017
Development of Large-scale Single-use Bioreactor System for a Megakaryocytic Progenitor Cell Line
Tomohiro TOKURA (Fujimori Kogyo Co., Ltd), Retno Wahyu NURHAYATI (Universitas Indonesian), Hiroyuki
MATSUDA (Fujimori Kogyo Co., Ltd), Yoshihiro OJIMA, Takeaki DOHDA (Osaka University), Masahiro
KINO-OKA (Osaka University)
Tissue Engineering and Regenerative Medicine International Society (TERMIS) 2018, 03-P530, Kyoto, Japan,
September 4-7, 2018 (poster)－97－

Urban Engineering
Urban Design and EngineeringChildren’s Bicycle Transport Mobility, Development of Safety Education Programs and Their Adaptation
for Children with Disabilities
N. YOSHIDAThe International Workshop on Delivering Cycling Training and Activity Sessions for Disabled People, London,
The United of Kingdom, October 11, 2018
Bicycle Transportation Policy in Japan and Recent IATSS Project
N. YOSHIDA
Japanese Association of Traffic Psychology (JATP) & International Association of Traffic and Safety Sciences(IATSS), French-Japanese workshop - Present and future of traffic psychology and neighbouring, disciplines -,Tokyo, Japan, October 23-24, 2018
The estimation of CO2 flux in subtropical coastal ecosystems using a numerical model
Hirotada MOKI (Port and Airport Research Inst.), Akio SOHMA, Hisashi SHIBUKI (Mizuho Information andResearch Inst.), Kenji TOYODA (Mizuho Information and Research Inst.), Anirban AKHAND (Port andAirport Research Inst.), Kenta WATANABE (Port and Airport Research Inst.), Tatsuki TOKORO (National
Research Institute of Fisheries and Environment of Inland Sea), Tomomi INOUE (National Institute forEnvironmental Studies), Hiroya YAMANO (National Institute for Environmental Studies), Masayuki BANNO(Port and Airport Research Inst.), Yasuyuki NAKAGAWA (Kyushu Univ.), Hiroyuki MATSUDA (Yokohama
National Univ.), and Tomohiro KUAWE(Port and Airport Research Inst.)
Proc. of the Japan Geoscience Union Meeting, ACG43-P06, Chiba, JAPAN, (2018.5) (on USB).
Coastal ecosystems can play a role in climate change mitigation. One of the appropriate way to accurately
quantify and predict the role is the utilization of numerical models. The mitigation effects can be facilitated by
CO2 uptake by net primary producers such as mangroves, zooxanthella in coral reef and seagrasses. In this study,
we developed a new ecosystem model that incorporates the biogeochemical processes of mangroves, tidal flats,
seagrass meadows, lagoons, and coral reefs. We estimated CO2 fluxes between air and the ecosystems and carbon
burial rates in Yaeyama islands, Japan, which is the model site. In the future prediction, we selected two scenariosof representative concentration pathways, low emission (RCP2.6) and high emission (RCP8.5), adopted in IPCC
5th Assessment Report and compared the model results in 2010 and 2100. The output of HadGEM2-ES from
CMIP5 models were used as the boundary data. Our model results showed that the mangrove absorbed CO2 morethan other ecosystems because of direct uptake of CO2 from the air. The maximal carbon burial rate was found in
the mangrove. Additionally, the inflowing of open waters affected the air-ecosystem CO2 flux and carbon burial
rate near the open boundary. We will also present the result of comparisons between the model results andobserved data.
Ecosystem modelling to estimate blue carbon in a human-dominated estuarine and shallow coastal system
Akio SOHMA, Hisashi SHIBUKI (Mizuho Information and Research Inst.), Fumiyuki NAKAJIMA (The Univ ofTokyo), Tomohiro KUWAE (Port and Airport Research Inst.)
Proc. of the International Society for Ecological Modelling Global Conference 2017, (2017.9) (on USB).
Estuarine and shallow coastal systems (ESCS) are recognized as not only significant organic carbon reservoirs but
also emitters of CO2 to the atmosphere through air-sea CO2 gas exchange, thus posing a dilemma on ESCS’s rolein climate change mitigation measures. A ecosystem model composed of a benthic and a pelagic system wasdeveloped and applied to the Tokyo bay, ESCS, Japan with the goal of (1) understanding the “pattern andvariability” of carbon cycle of ESCS in a high CO2 world, (2) revealing the “key process and interaction” of
ESCS as the carbon reservoirs/emitters of CO2, and (3) evaluating the ideal “management” of ESCS to obtain thebest balance among the water quality, biological productivity and carbon storage. The description ofbiogeochemical processes are derivied from model components (i.e. TCO2, phytoplankton, detritus, DOM, DO,
Nutrients, pH and alkalinity). From the model analysis, Tokyo bay is capable of directly absorbed atmosphericCO2. In the presentation. we summarize key factors for coastal areas to be functioned as a sink for atmospheric
CO2.

－98－

ISSN

MEMOIRS OF THE FACULTY OF ENGINEERING OSAKA CITY UNIVERSITY
VOL. 59.
2018

1812-0584 大阪市立大学 工学部
1-4
工学部英文紀要VOL.59（2018）

0078－6659

MEMOIRSOF THEFACULTY OF ENGINEERINGOSAKA CITY UNIVERSITY

VOL. 59
DECEMBER 2018

PUBLISHED BY THE
GRADUATE SCHOOL OF ENGINEERINGOSAKA CITY UNIVERSITY

見本

スミ