bluuebunny/crossref_metadata_2025 huggingface dataset:
Nonlinear Dynamics of Mechanical Systems with Sectional Frictions
Authors: Wen Bang Chun , Ren Zhao Hui , Han Qing Kai , Li Xiao Peng , Mao Ju Quan
Published: March 2009

This paper presents mainly the nonlinear dynamics of the mechanical system with
sectional frictions and combination friction coefficients. It is clear that the nonlinear dynamic
characteristics of mechanical systems with sectional frictions are quite different from those of
classical machinery, and have more precise and valuable in many practical projects. The
expressions of various nonlinear forces are given firstly and the approximation solutions of the
system are found with asymptotic method in nonlinear theory, and the combination friction
coefficients and damping coefficients of the materials are obtained. Then some nonlinear dynamic
characteristics of the system with sectional frictions are also discussed. The results are very
important for designers of these machines.
Temperature Effect on the Friction Behavior of NiTi Shape Memory Alloy
Authors: Gong Lei , Qian Lin Mao , Zhou Zhong Rong
Published: March 2009

By using an atomic force microscopy, the friction behavior of a NiTi shape memory alloy is
investigated under various temperatures in vacuum environment. Under wearless condition at low
loads, the adhesion-dominated friction of NiTi is almost temperature independent. However, while
scratch mark appears after friction at high loads, the plough-dominated friction force is found to
decrease with the increaase in temperature. Based on a simple contact analysis, the temperature
dependent friction behavior of NiTi at high loads may be mainly attributed to the thermoelastic phase
transition in NiTi. While temperature increases from 26~100°C, the tensile phase transition stress of
NiTi increases from 412~964 MPa, which induces ~27% magnitude decrease in the contact area
between the diamond tip and NiTi. It further results in the decrease in the plough-dominated friction
force on NiTi.
The Evaluation of Fretting Fatigue Behavior in Room Temperature for INCOLOY Alloy 800
Authors: Park Dae Kyu , Woo Seung Wan , Bae Yong Tak , Chung Il Sup , Chai Young Suck , Kwon Jae Do
Published: March 2009

Mechanical breakdown often comes from the fatigue in many structural parts and nuclear
power plants. Among the fatigue phenomenon, especially fretting fatigue occurs in mechanical joints
showing small relative movements between contact surfaces. Although the research was developed
for one hundred years, occurrence mechanism is not clearly identified yet. INCOLOY alloy 800 is a
iron-nickel-chromium alloy having excellent resistance to many corrosive aqueous media and
high-temperature atmospheres. This alloy is used extensively in the nuclear power plants industry, the
chemical industry, the heat-treating industry and the electronic industry. In this paper, the effect of
fretting damage on fatigue behavior for INCOLOY alloy 800 was studied. Also, various kinds of
mechanical tests such as tension and plain fatigue tests are performed. Fretting fatigue tests were
carried out with flat-flat contact configuration using a bridge type contact pad and plate type
specimen. Through these experiments, it is found that the fretting fatigue strength decreased about
50% compared to the plain fatigue strength. In fretting fatigue, the oblique micro-cracks at an earlier
stage are initiated. These results can be used as basic data in a structural integrity evaluation of heat
and corrosion resisting alloy considering fretting damages.
Compared Study on Laser Cladding and Plasma Spraying of Nuclear Valve Clacks
Authors: Zhang Chun Liang , Chen Li Ping , He Bin
Published: March 2009

Laser cladding of Co-base alloy on the sealing surfaces of nuclear valve clacks has been
performed with a 5KW CO2 transverse flowing laser. The laser cladding was compared with plasma
spraying. Both laser cladded and plasma sprayed zones were characterized by optical and scanning
electron microscopes. The high temperature impact-slide wear resistance of laser cladded and
plasma sprayed coatings were studied. The experimental results showed that compared with that of
plasma sprayed coating, the laser cladded coating has higher microhardness, more uniform
microstructure, smaller grain size, lower dilution rate, and fewer pores and impurities. The
experimental results also showed that the weight loss of plasma sprayed coating during the high
temperature impact-slide wear is two times larger than that of laser cladded coating.
Numerical Analysis on Surface Fractures in Two-Layered Materials Subjected to Thermal Loading
Authors: Li Lian Chong , Tang Chun An , Xing Jun , Liang Zheng Zhao , Jiang Wei , Yang Tian Hong , Zhao Xing Dong
Published: March 2009

With the knowledge of heterogeneous characteristics of thermal barrier coating materials
at mesoscopic level, a coupled thermo-mechanical-damage (TMD Model) model was introduced and
used to numerically quantify the thermal stresses and crack development of in thermal barrier coatings
(TBCs) composite subjected to decreased temperatures. The effect of different surface precrack
morphologies, such as precrack length and precrack density, on an interface crack subjected to
thermal loading caused by a temperature change is presented. It provides us with a more sensible
physical intuition and a more accurate mathematical for optimizing the design and the processing of
ceramic coatings subjected to the coupled thermal-mechanical loading.
Numerical Simulation of 3-D Failure Process of Reinforced Concrete Specimen under Uniaxial Tension
Authors: Zhang Juan Xia , Tang Chun An , Zhou Xiu Yan , Hui Xing Jie , Liang Zheng Zhao , Wang Shu Hong , Guo Xian Zhang
Published: March 2009

The periodically distributed fracture spacing phenomenon exists in the failure process of
the reinforced concrete prism under uniaxial tension. In this paper, A numerical code RFPA3D (3D
Realistic Failure Process Analysis) is used to simulate the three-dimensional failure process of plain
concrete prism specimen and reinforced concrete prism specimen under uniaxial tension. The
reinforced concrete is represented by a set of elements with same size and different mechanical
properties. They are uniform cubic elements and their mechanical properties, including elastic
modulus and peak strength, are distributed through the specimens according to a certain statistical
distribution. The elastic modulus and other mechanical properties are weakened gradually when the
stresses in the elements meet the specific failure criterion. The displacement-controlled loading
scheme is used to simulate the complete failure process of reinforced concrete. The analyses focus on
the failure mechanisms of the concrete and reinforcement. The complete process of the fracture for
the plain concrete prism and the fracture initiation, infilling and saturation of the reinforced concrete
prism is reproduced. It agrees well with the theoretical analysis. Through 3D numerical tests for the
specimen, it can be investigated the interaction between the reinforcement and concrete mechanical
properties in meso-level and the numerical code is proved to be an effective way to help thoroughly
understand the rule of the reinforcement and concrete and also help the design of the structural
concrete components and systems.
Atomistic Simulation of Crack Initiation at Bi-Material Interface Edges
Authors: Shang Fu Lin , Kitamura Takayuki
Published: March 2009

Atomistic simulations using molecular dynamics (MD) method are conducted to check the
conditions of the onset of fracture at the interface edges with a variety of angles. The simulations are
facilitated with model bi-material systems interacting with Morse pair potentials. Three simulation
models are considered, i.e. the interface edges with angles 45°, 90° and 135°, respectively. The
simulation results show that, at the instant of crack initiation, the maximum stresses along the
interfaces reach the ideal strength of the interface; also, the interface energies just decrease to below
the value of the intrinsic cohesive energy of the interface. And the onset of fracture at the interface
edges with different geometries is controlled by the maximum stresses or the cohesive interfacial
energy.
Fracture-Damage Model for Anchored Discontinuous Jointed Rockmass and its Application
Authors: Wang Gang , Li Shu Cai , Wang Shu Gang , Li Jing Long , Li Xiao Jing
Published: March 2009

According to the theories of fracture mechanics and damage mechanics, the constructive
model and fracture damage mechanism of brittle discontinuous jointed rockmass are systematically
studied under the state of complex stress in this paper. By the aid of the method of equivalent strain
energy, the constitutive relation of anchored brittle discontinuous jointed rockmass is derived under
the state of compression-shearing. The constitutive relation under the state of tension-shearing is
also developed according to the theory of self-consistence. Finally, based on the above constructive
models, the three-dimensional finite element procedure has been developed to model the ground
movements that occur when underground power-houses of pumped-storage power station are
installed in discontinuous jointed rockmass. The anchor supporting is an important component of
this underground power-houses excavation work. Besides the displacement field and the secondary
state of stress induced by the excavation disturbance, the effect of anchoring and the damage
evolution around the power-houses have been particularly described during the process of
installation. The numerical results obtained by numerical simulation were compared with that of
field monitoring in order to verify the validity of the proposed models.
Research on Rubbing Fault in a Dual-Disc Overhung Rotor-Bearing System
Authors: Ren Zhao Hui , Yu Tao , Luo Yuegang , Song Nai Hui , Wen Bang Chun
Published: March 2009

Mechanical model and rubbing force model of a dual-disc overhung rotor-bearing system
are set up respectively. By using an experiment rig to simulate rubbing fault, the nonlinear dynamic
characteristics of rubbing rotor system are investigated and the dynamic characteristics of mid-disc
and overhung disc are analyzed respectively. The numerical simulation results coincide with the
experiment results and the research in this paper has practical reference value to the safe and stable
run of the practical rotating machinery.
Modelling the Behavior of Short Fatigue Cracks under Variable Amplitude Loading Using FEM
Authors: Xu Yan Hai , Zhao Yong Xiang
Published: March 2009

The behavior of short fatigue cracks under variable amplitude loading (VA) was
investigated by FEM. The crack closure induced by the crack surface roughness was taken into
consideration by using the contact between these crack surfaces. The effects of variable amplitude
loading on the performance of short cracks are demonstrated with factors such as grain orientation
and misorientation, crack length and the friction efficient between the contacted crack surfaces.
Through the two indicators, crack tip opening displacement represented by "CTOD and "CTSD
and the plastic strain range of crack tip, the characteristics of short cracks affected by loading
blocks are discussed in detail. It is shown from the numerical results that the significance of the
design of loading blocks in the fatigue experiments is evident and the performance of short cracks
from the variable amplitude loading is more effective due to the closer to practice.
Comparison of Power in CBN Grinding of Steels and Stone
Authors: Xu Xi Peng , Du Cun Ji
Published: March 2009

The present study was undertaken to compare the consumed power in surface grinding of
three different materials with a vitrified CBN wheel. High speed steel, stainless steel, and natural
granite were used as the workpiece materials in the experiments. Two different depth of cut and
workpiece velocity were combined to give different material removal rates. The spindle power was
in-process monitored in each pass of grinding. The radius wear of the grinding wheel was also
measured and the morphologies of CBN grains were observed during the grinding of high speed steel
and granite. The power for the grinding of high speed steel was found to be the lowest under any
operating parameters. For other two materials, the results became complex. At shallower depth of cut,
the power for the grinding of stainless steel was higher in most cases. However, the power for the
grinding of granite was higher under larger depth of cut. It was found that the grinding wheel failed
much earlier in the grinding of granite as compared with the grinding of high speed steel.
Experimental Study on the Ultraprecision Lapping Technology of the Copper Substrates for Alloy Films
Authors: Zhu Cong Rong , Xu Qin , Yuan Ju Long , Wen Dong Hui , Lv Bing Hai
Published: March 2009

To obtain the amorphous alloy films with superior properties by method of
electrochemical deposition, the accuracy requirement for the copper substrates for Alloy Films is
extraordinarily strict. The ultraprecision lapping technology for the copper substrate employing
polyurethane polishing pad and flannel pad is studied in this paper, surface roughness, material
removal rate and change process of surface construction of copper substrates are discussed. The
influences of the different lapping parameters on the surface roughness, material removal rate and
the influences of lapping load on copper substrate surface formation in the ultraprecision lapping
process of copper substrate are both discussed. Experiment results show that the surface scratch will
disappear by employing polyurethane polishing pad and flannel pad, and an extremely smooth
surface of copper substrate with roughness 6nm Ra is obtained in the final finishing lapping
process.
Study on the Performances of the Ferromagnetic Poles Based on the Curved Surface Magnetic Abrasive Finishing
Authors: Ding Yan Hong , Yao Xin Gai , Wang Xing Xiang , Yang Shi Chun
Published: March 2009

Magnetic abrasive finishing (MAF) is a kind of method for polishing the surfaces and the
edges. The investigation for the technique of MAF and the development of the ferromagnetic poles
lay a theoretical foundation for developing a new method for finishing the curved surfaces
automatically under the numerical control. In the paper, the performance parameters of the developed
magneto poles, which are used for finishing the plane surfaces and the curved ones, have been tested.
The curvature of the finished surface, the sloping angle of the machined surface and the rotation
speed of the poles, which affect the surface roughness, are studied theoretically. What mentioned
above supply references to the practical uses of the MAF, especially in the mould manufacturing.
Laser Brazing of Diamond Grits with a Ni-Based Brazing Alloy
Authors: Yang Zhi Bo , Xu Jiu Hua , Fu Yu Can , Xu Hong Jun
Published: March 2009

Brazing diamond grits onto steel substrate using a Ni-based filler alloy was carried out by
laser beam in an argon atmosphere. The microstructure of the interfacial region among the Diamond
grits, the filler layer and the steel substrate, were investigated by means of scanning electron
microscopes (SEM), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDS).
Meanwhile, the formation mechanism of carbide layers was discussed. All the results indicated that
the active element chromium in the Ni-based alloy concentrated preferentially to the surface of the
grits to form a chromium-rich layer, and the hard joint between the alloy and the steel substrate is
established through a cross-diffusion of iron and Ni-based alloy.
The Numerical Analysis on Action Mechanism of Slurry in Free Abrasive Wiresaw Slicing
Authors: Ge Pei Qi , Sang Bo , Gao Yu Fei
Published: March 2009

Free abrasive wiresaw technology is the main method in slicing monocrystalline silicon
wafers. The mathematical model of hydrodynamic action in the process of the free abrasive
wiresaw slicing was founded, displacement caused under distributed radial load of every node on
the wire is embodimented through self-compliance influence coefficient, which is beneficial to
found the film thickness equation. The distributions of hydrodynamic pressure and film thickness in
the free abrasive wiresaw slicing process are yielded by using the finite difference numerical
methods to solve the two-dimension Reynolds equation. The results show that the minimum film
thickness increases with the increase of wire speed, and slurry viscosity, while decreases with the
increase of wire bow angle. The film thickness is greater than the average abrasive size so that the
abrasives float in the slurry when the size of abrasive is small enough.
On Programming for NC Grinding of Grooved Cam with Discretional Plane Curve Profile
Authors: Zhang Zi Qiang , Ge Yong Chao , Zheng Zhi Dan , Chen Shao Bo
Published: March 2009

In grinding of grooved cam, the programming for NC machining can’t directly be accomplished according to track curve of roller center in working drawing because the diameter of wheel becomes smaller than diameter of cam’s follower roller after wheel dressing. Track curves of wheel center are equidistant curves of the track curve of roller center and they can be gained by equidistant offset. But track curves of wheel center can’t be gained by equidistant offset for grooved cam with discretional plane curve profile, due to the profile including aspheric curves whose equations are usually unknown. To solve above problem, circular arc approximation for the aspheric curve part was realized by using Approximate Double Circular Arc Interpolated Method (ADCAIM), then equidistant offset of circular arcs was carried out by “offset” way, and consequently track curves designed for wheel center of any diameter can expediently be gained on AutoCAD platform. Validation experiment of simulation grinding was fulfilled on a NC milling machine. The experiment results indicate: it is feasible to NC grind grooved cam with discretional plane curve profile using the method introduced in this paper for the example.
The Differences between the Direct and Sol-Gel Syntheses of Silicon-Contained Calcium Phosphates
Authors: Dorozhkin Sergey V. , Gunduz Oguzhan , Oktar Faik N.
Published: March 2009

Comparison of two experimental techniques of silicon-contained and/or silica-substituted
calcium phosphate preparation from Ca(NO3)2·4H2O, NH4H2PO4, fumed silica and aqueous
solution of NH4OH was performed. The first technique was a traditional one, in which the final
product was synthesized in an aqueous solution by the well-known sol-gel process, followed by
phase separation, washing off, drying and high-temperature sintering. An environmentally friendly
direct preparation route was the second technique, in which the initial chemicals were mixed in the
necessary proportions inside a crucible, followed by a high-temperature sintering of the entire
mixture. The sintered powders were analyzed by the standard measurement techniques. Intentional
variations from the stoichiometry within ±10% of the amounts of the mixed chemicals were
employed to compare the vulnerability of both preparation techniques to random fluctuations of the
processing parameters. The results revealed a better reproducibility and a higher yield of the direct
preparation technique but the traditional sol-gel technique was found to be able to compensate
accidental technological imperfections.
Changes in Osteogenic Activity of MG63 Cells on Hydroxyapatite/Collagen Nanocomposite Sponge under Pressure/Perfusion Culture
Authors: Yoshida Teruaki , Mizuno Ikko , Kikuchi Masanori , Koyama Yoshihisa , Takakuda Kazuo
Published: March 2009

The bone-like self-organized hydroxyapatite/collagen (HAp/Col) nanocomposite sponge
was prepared from HAp/Col nanocomposite fibers. We analyzed osteogenic activity of human
osteoblastic MG63 cells in the HAp/Col sponge under pressure/perfusion culture. Collagen (Col)
sponge was used as a control. The MG63 cells were attached well and showed good proliferation in
the HAp/Col sponge. The total DNA content in the HAp/Col sponge was approximately 1.8 times
greater than that in the Col sponge at 21 days. The MG63 cells showed good osteogenic gene
expression in the HAp/Col sponge by reverse transcription-polymerase chain reaction analysis.
These result suggested that HAp/Col sponge can be useful for bone tissue engineering scaffold
materials.
Preliminary Study for Evaluating Bone Forming Ability of Porous Bioceramics Using Rat Mesenchymal Stem Cells to be Used for International Standard
Authors: Tadokoro Mika , Hirose Motohiro , Ohgushi Hajime
Published: March 2009

In the field of tissue engineering for bone regeneration, there have been many studies that
examined in the bone forming ability of the porous biomaterials with mesenchymal stem cells
(MSCs). To promote the tissue engineering approach in clinical situation, there is a need for the
establishment and standardization of evaluation methods for measuring the in vivo bone forming
ability. In this study, we examined the seeding process using rat MSCs to ascertain whether it is a
valid protocol for various materials. Our results showed that the cell seeding process for the
fabrication method of MSCs/materials composite influenced the number and distribution of the
MSCs in the materials, therefore the process is a key to show new bone formation which derived from
the seeded MSCs. Here, we describe the detailed process which can show consistent new bone
formation in pores of the materials.
Effect of Synthetic β-TCP and Bovine-Derived Hydroxyapatite Grafting on Bone Regeneration in Rats
Authors: Lim C.S. , Kim S.G. , Lim Sung Chul
Published: March 2009

We evaluated the bone healing effect of grafting with synthetic β-tricalcium phosphate
(β-TCP; Cerasorb®), bovine-derived hydroxyapatite (HA; Bio-Oss®), and a mixture of β-TCP and
HA in rats. Each material was grafted in prepared 8-mm frontal bone defects in 15 rats. The control
group underwent surgery without any grafting materials and was examined after 4 weeks, whereas
the experimental groups received grafting materials and were examined after 1, 2, and 4 weeks.
After implantation, the rats were sacrificed for histomorphometric studies using light microscopy,
and the data were analyzed using analysis of variance. Considerable inflammation and fibrosis were
observed after 1 and 2 weeks in all experimental groups, whereas the inflammation was reduced and
fibrosis was stabilized after 4 weeks. New bone formation was observed at the defect margin.
Statistically, there was no difference in new bone formation among the three experimental groups.
In conclusion, there was no difference in new bone formation using Bio-Oss®, Cerasorb®, and a
mixture of Bio-Oss® and Cerasorb®.
Human Dentin Transplantation for Bone Engineering
Authors: Murata Masaru , Hino J. , Akazawa Toshiyuki , Ito Katsutoshi , Hirose Yukito , Ochi Morio , Arisue Makoto
Published: March 2009

The aims of this study are to confirm the capacity of hard tissue induction by human demineralized
dentin matrics (DDM) and calcified dentin matrics (CDM) in subcutaneous tissues of nude mice,
and to report a human pioneering trial following the autotransplantation of DDM for bone
augmentation in a case of the atrophied upper jaw. Human DDM and CDM particles were prepared
from adult, extracted vital teeth, and were implanted into the subcutaneous tissues of 4-week-old
nude mice. DDM induced bone and cartilage independently at 4 weeks after implantation, while
CDM did not induce a hard tissue formation. Autogenous DDM prepared from the non-functional
second molar of a 58-year-old female were grafted on the atrophied jaw and received to the host.
Human dentin can be recycled as autogenous biomaterials for local bone engineering.
Five Years Clinical Follow Up Bone Regeneration with CaP Bioceramics
Authors: Rodríguez Clemencia , Jean Alain , Mitja Sylvia , Daculsi G.
Published: March 2009

To overcome autograft use for dental implantation, it is important to prevent bone loss
after tooth extraction or to restore alveolar bone level after pathological diseases. Biphasic calcium
phosphate (BCP), mixture of HA and ß-TCP, have proven its performance in orthopaedic, while
few studies have been reported in dentistry. We reported 5 years clinical follow up on bone
regeneration after immediate dental root filling. MBCP 60/40 and MBCP 20/80 are biphasic CaP
intimate mixture of HA/TCP 60/40 and 20/80; with interconnected macroporosity and
microporosity. Forty cases have been distributed in two groups for alveolar pocket filling. Seven
cases without filling are used as control. X-Ray at 0, 3, 6, 12 months and 5 years follow up for some
patients were performed. In all the 40 cases, radio-opacity of the implantation area decreases on
time, indicating resorption and bone ingrowths at the expense of the two bioceramics. No difference
in the resorption kinetics appeared on X-Ray. After 1 year, the implantation area looks as
physiological bone and is maintained on time. The newly formed bone is preserved after 5 years
contrarily to the controls cases (without filling)where we observed decrease of 2 to 5 mm. This
study demonstrated that immediate filling of alveolar pocket after tooth extraction is a preventive
method of the jaw bone resorption. After long term (other one year) resorption and bone ingrowth
were demonstrated for both micro and macroporous biphasic calcium phosphate with two different
HA/TCP ratio.
TEM Study of the Reaction Interface between an Apatite-Mullite Glass-Ceramic and Ti6Al4V
Authors: Stanton Kenneth T. , O’Flynn Kevin P. , Newcomb Simon
Published: March 2009

Apatite-mullite glass-ceramics have been developed as an alternative to hydroxyapatite for use in vivo as a bioactive, osseoconductive biomedical alloy coating. In the cerammed state, they present a number of advantages including control over dissolution rates and mechanical properties by altering the composition of the parent glass or heat treatment regime. In the present study, a simple sedimentation route was used to coat a biomedical titanium alloy, commonly used for orthopaedic applications. The material was deposited as a glass and cerammed in situ to create a well adheared coating that resisted delamination or cracking. To investigate the nature of the coating-substrate reaction, a number of characterization techniques were used to examine the crystallization behaviour of the glass, the glass-ceramic microstructure, and the interfacial reaction region composition. The presence of products such as titanium silicides and unexpected pores are explained by proposed reaction routes between the titanium and glass coating.
Vertebroplasty in Goat Model Using Macroporous Calcium Phosphate Cement (MCPC®)
Authors: Bourges Xavier , Baroth Serge , Goyenvalle Eric , Cognet Ronan , Moreau Françoise , Pilet Paul , Aguado Eric , Daculsi G.
Published: March 2009

We performed vertebroplasty on goat model by injecting a new macroporous calcium phosphate cement MCPC®. The mechanical property of the cement is about 12MPa after 24 hours (compression test). The cement matrix is totally transformed into poorly crystallized apatite in 48 hours. This study demonstrates that MCPC cement was suitable and efficient for a spine application. Its injectability allows to be used in mini invasive surgery and its mechanical properties are compatible to support spine strength. In addition, a bone ingrowth onto the BCP granules occurred with time.
Bioactive Hydroxyapatite/Calcium Silicate Composites Obtained by Fast Hot Pressing: Structure and Flexural Strength
Authors: Sprio Simone , Tampieri Anna , Landi Elena , Celotti Gian Carlo , Dalle Fabbriche Daniele
Published: March 2009

The present work deals with the preparation and characterization of ceramic composites
for the substitution of load-bearing bone portions, made of hydroxyapatite (HA) and bioactive β-
calcium silicate (β-Ca2SiO4) as a reinforcing phase. The composite materials were prepared by Fast
Hot-Pressing technique (FHP), which allowed the rapid sintering of monolithic ceramics at
temperatures up to 1500 °C, well above the commonly adopted temperatures for sintering of
hydroxyapatite (1200-1300 °C), in order to achieve the densification of the reinforcing phase also.
XRD analysis reported no formation of secondary phases other than HA and β-Ca2SiO4, after FHP
cycles. Flexural strength tests were performed on selected samples sintered at different
temperatures: the composite materials exhibited increased mechanical resistance compared to
samples constituted of HA only. These preliminary results confirmed that composites of HA and β-
Ca2SiO4 are promising for the development of bioactive load-bearing ceramic bone substitutes.
Kinetic of the Phase Transformation of ATZ Compared to Biograde Y-TZP
Authors: Begand Sabine , Oberbach Thomas , Glien Wilfried , Schneider J.
Published: March 2009

Alumina and zirconia ceramics have been successfully used as materials for joint
endoprostheses. The present study has been aimed at combining the advantages of the two singlephase
materials, Al2O3 and ZrO2 while avoiding their disadvantages, by producing a composite
ceramic.
Within the scope of a study of an ATZ ceramic we tested the influence of aging by a hydrothermal
treatment on strength, phase composition and surface properties. We found that the hydrothermal
treatment of the ATZ ceramic did not significantly influence these parameters, unlike those of a
single-phase ZrO2 ceramic.
Microscopic Mechanisms behind the Toughening Behavior of Ceria Stabilized Tetragonal Zirconia/Alumina Nanocomposite for Biomedical Applications
Authors: Nawa Masahiro , Yamada Kiyotaka , Pezzotti Giuseppe
Published: March 2009

With elongation of average human life, problem such as bone embrittlement and
osteoporosis call for quick solution and the expectation for artificial biomaterials heightens. Many
ceramics widely used as artificial biomaterials are limited by their poor reliability characteristics. A
CeO2 stabilized tetragonal zirconia polycrystalline (Ce-TZP) matrix incorporating nanometer sized
Al2O3 particles within the zirconia grains (Ce-TZP/Al2O3) was recently developed. This material
experienced significant improvements in both fracture toughness and strength above the standard
mechanical performance of monolithic zirconia. In this paper, we performed a macro/microscopic
fracture mechanics assessment of this developed Ce-TZP/Al2O3 nanocomposite, in comparison with
a 3 mol% Y-TZP according to advanced in situ confocal Raman spectroscopy techniques.
Morphologic Change of Implant Surfaces Conditioned with Tetracycline-HCl
Authors: Herr Y. , An S.H. , Kwon Y.H. , Park J.B. , Chung J.H.
Published: March 2009

The purpose of treatment for peri-implantitis is to achieve structural and functional
restoration of the lost supporting tissues around implants, including re-osseointegration. Both
surgical and non-surgical approaches in combination with a variety of anti-microbial treatment
regimens have been applied depending on the size and shape of the bone defect. Tetracycline-HCl
(Tc) treatment has been considered as a effective chemical modality for decontamination and
detoxification of contaminated implant surfaces. The aim of this study was to examine if Tc
conditioning changes the microstructures of the modified surface of dental implants. Dental
implants with (1) hydroxyapatite-coated surface (HAS) (Replace® select HA, Nobel Biocare AB,
Göthenburg, Sweden), (2) TiO2-blasted surface (TBS) (Astra TiOblast®, ASTRA Tech AB,
Mölndal, Sweden) were used in this study. Tc treatment noticeably altered the surface of HAS and
TBS. HAS and TBS were partially removed from the implant surface as early as 90 and 60 sec,
respectively.
Flexural Strength Measurement of Ceramic Dental Restorative Materials
Authors: Hermansson Leif , Kraft Lars , Lindqvist Karin , Ahnfelt Nils Otto , Engqvist Hakan
Published: March 2009

Flexural strength of a dental material reflects its ability to withstand tensile stresses and
thus the fracture risk of a filling. The flexural strength of an experimental bioceramic Calcium
aluminate-based (CA) dental restorative material was measured using three different methods with a
composite (Tetric Ceram), a glass ionomer cement (Fuji II) and a phosphate cement (Harward) as
references. The three test methods were: a) ISO 4049 for dental composites, 3-point bend test b) EN
843-1 for ceramic materials, 3-point bend test and c) ASTM F-394, biaxial ball-on-disc for ceramic
materials. The strength of the CA-material, tested in the ball-on-disc method, is close to the
theoretical strength based on the microstructure of the material (max. grain size of 15 μm). The
composite material and the phosphate cement were rather insensitive to the test method, while the
glass ionomer cement as the CA-material showed sensitivity towards the test method. A modified
biaxial test method for evaluation of strength of dental materials in a close to real-life component is
proposed.
Enhancement of the Mechanical Property of Apatite-Fiber Scaffold Using Type I-Collagen
Authors: Motojima S. , Igeta N. , Honda Michiyo , Kanzawa Nobuyuki , Aizawa Mamoru
Published: March 2009

We have successfully fabricated apatite-fiber scaffolds (AFSs) that enable
three-dimensional cell culture. The AFSs possessing large pores of 100~250 μm and micro pores
of about 5 μm were fabricated by firing the green compacts consisting of the single-crystal apatite
fibers and the carbon beads with a size of 150 μm. In order to enhance the mechanical properties
of the AFSs, we have improved the process of AFS fabrication: Collagen gel (type I) solutions were
introduced into the pores in the scaffolds; in addition, the resulting apatite/collagen scaffolds were
chemically modified by thermally dehydrated cross-linking. Actually, the results of compressive
strength tests show that the value of the AFS with chemically cross-linked I-collagen was about
twice as high as that of the conventional AFS without I-collagen. We conclude that combination
of I-collagen and thermal dehydrated cross-linking is effective for enhancement of the mechanical
properties of AFSs.
Preliminary Study on Novel Bone Tissue Engineering Scaffold with Stacking Hollow Hydroxyapatite Microspheres
Authors: Li Y.F. , Peng Qian , Bao C.Y. , Qiu Y.L. , Wei X. , Weng Jie
Published: March 2009

This study was aimed to estimate the cell-activity after culture of the cell-material
composite and to evaluate the feasibility of constructing tissue-engineered bone using this novel
material. Hollow HA mcirospheres (H-HAMs), porous PLA\HA tube，polyurethane plunger were
prepared respectively. Mesenchymal stem cells (MSCs), which were derived from rat bone marrow
were utilized as seed cells.Two different methods were used to integrate the seed cells and scaffold
materials. Group A: H-HAMs were filled into porous HA tube, and porous polyurethane plungers
were used to cover onto the ends of HA/PLA tubes as a whole, Then MSCs were cultured on the
composite scaffolds; Group B: MSCs were compounded with H-HAMs completely first, then the
pre-seeded composite of H-HAMs and cells was put into the porous PLA\HA tube which was then
sealed with the polyurethane plunger. 1,3,5,7 and 9 days after cell-material composites were cultured,
the growing status and adhesions of seed cells were observed. The viability of cells was quantified and
increased over time in different methods, but was significantly higher in Group B after 9 days of
culture. SEM detection revealed that more cells were detected on the PLA\HA tube and the outer layer
of H-HAMs; growth of cells was more widespread and more cells were detected on H-HAMs in
Group B. However, cells on H-HAMs seem to diminish over time in both groups. As a novel 3-D
Hydroxyapatite scaffold, its H-HAMs are more easy to be integrated with seed cells, to be shaped
according to clinical needs because of its semi-liquidity. However, the growth of cells especially in
the inner core of the integrated material needs further research.
High Brightness White Organic Light Emitting Devices Employing Phosphorescent Iridium Complex as RGB Dopants
Authors: Song Rui Li , Duan Yu
Published: March 2009

An efficient phosphorescent white organic light-emitting diode (WOLED) was realized
by using a bright blue-emitting layer, iridium (III) bis [(4, 6-di-fluoropheny)-pyridinato-N, C2’]
picolinate doped 4.4’-bis (9-carbazolyl)-2, 2’-dimethyl-biphenyl, together with tris (2-
Phenylpyridine) iridium and bis (1-phenyl-isoquinoline) acetylacetonate iridium (III) were codoped
into 4,4’-N,N’-dicarbazole-biphenyl layer to provide blue, green, and red emission for color mixing.
The device emission color was controlled by varying dopant concentrations and the thickness of
blue and green-red layers as well as tuning the thickness of exciton-blocking layer. The maximum
luminance and power efficiency of the WOLED were 37100cd/m2 at 17 V and 7.37lm/W at 5V,
respectively. The Commission Internationale de 1’Eclairage (CIE) chromaticity coordinate changes
from (0.41, 0.42) to (0.37, 0.39) when the luminance rangeed from 1000cd/m2 to 30000cd/m2.
Thermal-Hygro-Mechanical Design for CMOS Image Sensor
Authors: Hsu Hsiang Chen , Lee Hui Yu , Hsu Yu Cha
Published: March 2009

The characteristic of overall structure for CMOS image sensor has been studied in this
research. A three-dimensional solid model of CMOS image sensor based on finite element ANSYS
software is developed to predict the thermo-induced strain and the stress induced by moisture
absorption. The predicted thermal-induced displacements were found to be very good agreement
with the Moiré interferometer experimental in-plane deformation. The developed finite element 3D
model, therefore, is applied to simulate the mechanism of thermal and hygroscopic stresses based
on JEDEC pre-condition standard JESD22-A120. A series of comprehensive parametric studies
were conducted in this research. The design rules for thermal optimization of CMOS image senor
are summarized.
A Study of Two-Stage Micro Injection Compression Molding Process for Diffractive Optical Lens
Authors: Chen Chao Chang Arthur , Kao Shi Chi
Published: March 2009

This research aimed to develop a novel two-stage micro injection compression molding
(μ-ICM) process for fabrication of plastic diffractive optic elements (DOE). The DOE was designed
with the spherical coefficients and the Fresnel lens. A piezo actuator was installed inside the mold
plate for activating the mold insert for the second compression motion for micro ICM of the DOE
lens. The first experiment proceeded to find the operation window of Fresnel lens and then compare
the product weight of flat spherical lens by injection molding (IM), injection compression molding
(ICM) and μ-ICM. The second experiment was to investigate the effectiveness of micro
compression activated by the piezo actuator by the transfer ratio of grooves (TRG) of the DOE lens
with spherical lens and Fresnel lens. Results showed that the μ-ICM of the DOE can obtain the
highest TRG than that of IM and conventional ICM processes. Therefore, results of this research
can be explored to related aspheric optical elements with micro features, such as fine lens used in
the zoom lens of camera.
Package for Side Emitting LED
Authors: Pao Yu Nan , Yao Po Hung , Sun Yi Ting , Tien Chung Hao
Published: March 2009

A wide angle light-deflected lens combining collimation and total internal reflection
(TIR) optical mechanics for LED package is proposed. Utilizing angle-dividing method the angle of
emitting distribution of LED chip was cut into several angular zones and then a light-collimating
curve surface with corresponding declined plane performing TIR for the collimated incident ray
was designed. Thereby, the light-deflected lens, consisting of multi pairs of collimating curve
surfaces and declined planes, can achieve wide-angle deflection of light emitting from LED chip.
The design rule and experiment results of the lens with optimization optical design are
demonstrated and discussed in this paper.
Novel Approach to Fabrication of 3D Micro-Structures by Laser Machining
Authors: Young Hong Tsu , Lin Fang Fei , Hong Shu Bin
Published: March 2009

Miniaturization is a worldwide trend in manufacturing industry. Though lithography has
been introduced to meet the basic needs, the technology is limited by its process complexity and the
parts geometry to be produced. This research attempted to overcome the above obstacles by
applying laser machining approaches on general 3D micro-parts. The machining model is based on
a layer-by-layer concept. Experimental verification was made on a 1mm stainless steel sheet by
applying a diode-pumped Nd:YVO4 laser with Q-switch option. Three main parameters: power,
repetition rate and the speed of laser process were set to optimize the process quality. In the
research round holes with the diameter ranging from 10 μm to 30 μm were drilled. The following
step was the machining of a sloped groove with the area size of 100 μm × 100 μm for validation.
Profiles Detection in Ring Convex Forming by ACLN with Sub-Pixel Accuracy
Authors: Wang Jang Ping , Huang Guo Ming , Yurs Sheng Hua
Published: March 2009

An optical measuring system for the ring test is proposed. In this approach, the machine vision inspection equipment is first built to record and capture the images of ring test from the digital camcorder.The image processing procedures to detect and locate the edge points of the inner and outer radii in ring convex forming are presented. Unlike the conventional sub-pixel estimation based on gray-level values, the quantity (8 bits) of color’s scale has been adopted. In image processing procedures, a clustering method called Adaptive Competitive Learning Network (ACLN) is first used to classify the image hues which represent the different heights of bulge profiles on the top of ring, and then the edge points can be searched by the interpolation step of subpixel accuracy. The calibration curves constructed by the mode of non-constant friction factor called F-value approach is designed to compare and check with the measurement data. The experimental results will be presented and discussed in this study.
The Application of Motif Characterizing Method in the Surface Topography Evaluation of MEMS Device
Authors: Wang Sheng Hua , Xie Tie Bang , Yang Xu Dong
Published: March 2009

The surface topography characterization of MEMS device is very important to bonding
technology of MEMS device. Motif characterizing method is a characterizing method of surface
topography by graph. Aiming at the diversity and regionality of surface topography of MEMS
device, in this study we have sampled the surface of MEMS device by 3-dimentinal grids using the
surface profiler developed by us and characterizes the surface topography of MEMS device by the
extended Motif characterizing method. The surface of MEMS device is divided into several Motif
regions; the surface topography of every divided region can be evaluated respectively; the details of
every region can be zoomed and these regions as a whole or every region can be revolved and
projected; one of these regions can be as the reference of other regions. So the height, gradient and
other characteristics of others regions of the whole MEMS device surface can be analyzed relative
to the reference region; the whole and local surface topography of whole MEMS device can be
analyzed.
Analysis on the Performance of Differential Confocal Pointing Signal
Authors: Zhang Jian Huan , Gao Xue Min
Published: March 2009

With differential confocal pointing method, the ultra-precise machined surface can be measured with high resolution. In this technology, the differential confocal pointing signal, the zero point of the output diagram, may be affected by the different response of the two detectors, the different defocus of the two detectors, the accordance of the two pinholes in front of the detectors and so on. The paper aims at discussing the effect of these elements on the measuring signal. Through theoretical analysis of the output of the differential confocal microscopy (DCM), the conclusion that the pointing signal keeps fixed after the differential confocal system has been set up, does not change with the differences mentioned above, is presented. However, the resolution of the differential confocal system is concerned with the response performance and defocus of the two detectors. This is also confirmed by experiments.
Study on Anastomosis Feature in Polishing Zone in Aspheric Optics Machining
Authors: Wang Gui Lin , Dai Yi Fan , Li Sheng Yi
Published: March 2009

In order to keep the stability of tool’s removal function, it is required that the anastomosis
be tight between the tool and workpiece surface in Computer-controlled Optical Surfacing (CCOS).
In this paper, the influence of tool’s character on anastomosis status is firstly studied. The relation
model on the ratio of radius to thickness, Young's modulus of the tool, normal asphericity and
normal arc height of workpiece surface is established, and the macroscopical condition of tight
anastomosis is derived in aspheric optics machining. According to the microcosmic distribution of
surface error, the mathematical relation between anastomosis error and removal rate is researched.
In the end, the influence rule of anastomosis status on the convergence ratio of residual error is
analyzed in machining zone. Based on the conclusion of machining instance, it is found that
workpiece material would be fast removed in middle contact zone when the peak value of tool’s
removal function locates in its center position.
A Large Measuring Range Profilometer for Three-Dimensional Surface Topography Measurement
Authors: Yang Xu Dong , Li Jia Chun , Xie Tie Bang
Published: March 2009

A novel profilometer for three-dimensional (3D) surface topography measurement is
presented. The profilometer has large measuring range, high precision and small measuring touch
force. It is composed of a two-dimensional (2D) displacement sensor, a 3D platform based on
vertical scanning, measuring and control circuits and an industrial control computer. When a
workpiece is measured, the vertical undulation of the profile at a sampling point leads to a zero
offset of the 2D displacement sensor. According to the zero offset, a piezoelectric actuator and a
servo motor drive the vertical scanning platform to move vertically to ensure that the lever returns
to its balance position. So the non-linear error caused by the rotation of the lever is very small even
if the measuring range is large. When the stylus barges up against a steep wall, the horizontal
resistance force results in another zero offset of the 2D displacement sensor. If the zero offset
exceeds a quota, the vertical scanning platform descends to make the stylus climb the steep wall
successfully. According to the theoretical and experimental analysis, the profilometer can measure
roughness, profile of sphere, step, groove and other 3D surfaces with curvature precisely.
A Laboratory Scale Equipment to Relieve Force and Pressure in Cold Extrusion of Lead Hollow Components
Authors: Filice Luigino , Gagliardi Francesco , Micari Fabrizio
Published: March 2009

Nowadays, many researchers are involved in studies aimed to the explanation of some
peculiar aspects regarding manufacturing processes. In this paper, an experimental campaign was
carried out in order to reproduce tube extrusion starting from a cylindrical billet. In particular, the
development of a proper equipment is presented: the aim was to measure both the total load, by
using the testing machine load cell, and the local pressure value on the porthole. The latter task was
carried out performing a proper system based on the use of a small load-cell. The tube was extruded
with a good surface quality and the external area does not show any welding line evidence. Pure
Lead was used for the experimental analysis; this material was chosen due to its high ductility which
allows to carry out the process at room temperature. The material was characterized by compression
tests at different strain rates and the obtained material law was used to perform a numerical analysis
using SFTC Deform 3D numerical code. The Numerical analysis was carried out to show both the
advantages and drawbacks of the modern FE codes when extrusion processes are investigated.