bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanical Behavior Simulation of PMMA for Nano Imprint Lithography Using Molecular Dynamics
Authors: Kim Jung Yup , Kim Jae Hyun , Choi Byung Ik
Published: March 2009

NIL(Nano Imprint Lithography) is one of the most promising lithography techniques.
There are many variants of NIL, and two major techniques of them are thermal NIL and UV NIL.
Here, we focus ourselves on the thermal NIL. During the thermal NIL, the polymeric patterns
experience large mechanical strain and high temperature, and this often leads to malformation of
polymeric patterns. So it is needed to improve the pattern fidelity and contrast, and these are believed
to be closely related to the process condition and mechanical properties. In thermal NIL, PMMA is
widely used and chosen as target polymer. Generally, mechanical properties in nano scale are really
hard to acquire.
In this study, we estimate the mechanical properties of PMMA by molecular dynamic simulation.
These properties will be used as input of continuum simulation. We will estimate stress-strain
relationship of PMMA. This stress-strain relationship depends on strain rate and temperature. So we
will study about strain rate and temperature effect.
Rim Stress Analysis of Thin-Rimmed Gear
Authors: Marunić Gordana
Published: March 2009

The research into the stress state of gear rim has been based on the developed model of
pinion-wheel system and the finite element application. For a spur gear structure of middle web
position, the assumption of load distribution in the contact area that reflects, first of all, the tooth
support deformation, has been not required for the imposed boundary conditions.
To study the influence of web thickness stiffening effect on the inner rim surface stress, the ranges
of rim and web thickness values have been considered.
The area of stress along the rim circle and tooth facewidth has been shaped and discussed in relation
to maximum rim stress appearance.
Repair of Cracked Structures under Dynamic Load Using Electromechanical Admittance Approach
Authors: Providakis Costas P.
Published: March 2009

In the present paper, the repair of a cracked structure under dynamic load using the
electromechanical admittance (EMA) approach is investigated. Conceptually, appropriate electrical
field are applied on the outer surfaces of piezoelectric (PZT) patches to effect closure of the crack.
This has the effect of altering the electromechnaical (E/M) admittance signature, extracted at the
electrical terminals of a specific PZT patch, considered as an admittance calculating sensor (ACS)
patch, towards that of the healthy structure, which is the criterion concept used for the repair in this
paper. To demonstrate the present repair methodology, a cantilever 3D beam numerical example is
considered in combination with a FEM-based minimization of the difference between the healthy
and cracked structure’s (E/M) admittance signature, for specific frequency ranges.
Novel High-Rate Lithium Intercalation Electrode Materials Prepared by LiOH Solution Treatment of TiO2/Carbon Composites
Authors: Morimoto Hideyuki , Kurita Kenji , Matsuda Tetsuya , Tobishima Shinichi
Published: March 2009

Anatase-type TiO2-based oxide gel /carbon composites were treated chemically with LiOH aqueous
solution at 60 °C. The crystalline phase of treated powder was examined by powder x-ray diffraction
using CuKα radiation. The main diffraction peaks may be detected as belonging to cubic LiTiO2.
High-rate lithium intercalation properties of the samples were estimated in nonaqueous electrolyte
including lithium ions. The composite electrodes exhibited high coulombic efficiency over 90% at
first cycle and high capacities over 200 mAh g-1 after 200 cycle at large charge-discharge current
density of 5.0 mA cm-2 (3.7 A g-1). The composite materials are one of the promising candidates as
electrode materials for energy storage devices, such as hybrid capacitor, that require high-power
operations.
Morphology Control of ZnO Particles in Liquid Phase
Authors: Masuda Yoshitake , Kato Kazumi
Published: March 2009

We realized morphology control of ZnO crystals and prepared ZnO particles with variety of shapes such as hexagonal, ellipse, two large needles with small needles and multi-needles. The morphology control was achieved by the control of super saturation degree of aqueous solutions. All of the particles showed X-ray diffraction of single ZnO phase. The control of crystal growth and particle morphology in this system would contribute to the development of future crystalline materials and devices.
Structures of Ceramics/Metal and Ceramics/Ceramics Core/Shell Particles by Hybridization
Authors: Fu Zheng Yi , Fan Z. , Tang W.J. , Zhang Jin Yong , Wang Wei Min , Wang H. , Wang Yu Cheng , Zhang Qing Jie
Published: March 2009

Hybridization is a promising method for core/shell particles by a mechanical shock process
involving dry blending and dry impact blending. In this paper, hybridization was used to prepare
TiB2/Ni ceramics/metal and TiB2/Al2O3 ceramics/ceramics core/shell particles. The mechanism of
the formation and the features of the core/shell particles were analyzed. The nano- Al2O3 particles
can be coated on the surface of micron TiB2 particles directly by hybridization, The sub-micron
Al2O3 particles can be coated on the surface of micron TiB2 particles, only with the introducing of
PE-wax as transition layer. The mechanical properties of cermet sintered from TiB2/Ni core/shell
ceramics/metal particles were compared with that from TiB2/Ni blended particles.
Prediction of the Effect of Alloying Elements on In Situ Reaction in Synthesizing (AlN+Mg2Si)/Mg Composites
Authors: Zhang Cong Fa , Cao Wei , Fan Tong Xiang , Zhang Di
Published: March 2009

Alloying additions have an important effect on in-situ chemical reaction 4Al+Si3N4=4AlN+3Si to synthesis (AlN+Mg2Si)/Mg composites. Using the Wilson equation and an extended Miedema model, the activity in a multiple-component system can be calculated，and then the Gibbs free energy can be calculated. In final, the influence of alloying element additions on the in-situ chemical reaction at high temperature is investigated from a thermodynamic viewpoint.
Microstructure and Properties of Vacuum Hot-Pressing SiC/ Ti-Cu-Ni-Sn Bulk Metallic Glass Composites
Authors: Lin Hong Ming , Chen Giin Shan , Lee Pee Yew
Published: March 2009

In the present study, Ti50Cu28Ni15Sn7 metallic glass and its composite powders reinforced with 4~12 vol% of SiC additions were successfully prepared by mechanical alloying. The as-milled Ti50Cu28Ni15Sn7 and composite powders were then consolidated by vacuum hot pressing into disc compacts with a 10 mm diameter and thickness of 2 mm. The structure of the as-milled powders and consolidated compacts was characterized by X-ray diffraction. While the thermal stability was examined by differential scanning calorimeter. In addition, the mechanical property of the consolidated bulk metallic glass and its composite was evaluated by Vickers microhardness tests. In the ball-milled composites, initial SiC particles were homogeneously dispersed in the Ti-based alloy glassy matrix. The presence of SiC particles did not dramatically change the thermal stability of Ti50Cu28Ni15Sn7 glassy powders. BMG composite with submicron SiC particles homogeneously embedded in a highly dense nanocrystalline/amorphous matrix was successfully prepared. A significant hardness increase with SiC additions was noticed for consolidated composite compacts.
Seeds Innovation and Bearing Applications of Silicon Nitride Ceramics
Authors: Komeya Katsutoshi , Tatami Junichi
Published: March 2009

Silicon nitride (Si3N4) is one of the most attractive materials for wear applications because it has excellent wear resistance and offers advantages such as light weight, higher strength and toughness, and good corrosion resistance. In 1984, Materials Div., Toshiba Corp. (today, Toshiba Materials Co., Ltd.) and Koyo Seiko Co. Ltd. (today JTEKT Corp.) successfully utilized high-strength silicon nitride for anti-friction bearings for the first time in the world.1-3 This ceramic bearing was a most successful product and has expanded in area and volume through key innovations such as pioneered compositions, further improvement of durability against a steel ball and the development of a conventional fabrication process. Since 1989, Yokohama National University group has investigated new materials development in silicon nitride ceramics, densification/strengthening mechanisms in an optimized sintering aids system, powder processing for reliable components and tribological evaluation for bearing applications. Subsequently it was confirmed that the addition of TiO2 and AlN to an Si3N4-Y2O3-Al2O3 system promoted densification at low temperatures.4 During firing, the TiO2 changed into TiN at the grain boundary, causing grain boundary strengthening.5,6 Most recently, it has developed a carbon nanotube (CNT) dispersed silicon nitride with high strength and high electrical conductivity that is expected to open up new applications as a new functional silicon nitride.7 However, there are many items to be overcome toward the future, which are the development of cost reduction processes with higher material reliability, and the opening up of new applications supported by validated evaluation techniques including tribology, flaw detection and life prediction, raw powder problems related to cost and production volume, and the classification of silicon nitride bearings for various graded applications.
Development of SiAlON - From Mechanical to Optical Applications
Authors: Yamada Tetsuo , Yamao Takeshi , Sakata Shinichi
Published: March 2009

Various rare-earth-doped α-SiAlON powders with high purity were prepared to study mechanical and optical properties of SiAlON-based functional materials in connection with ionic radius and electronic structure of rare-earth elements. Single phase rare-earth-doped α-SiAlON powders were obtained at a temperature as low as 1873 K by heating powder mixtures of rare-earth oxide, AlN and highly active ultrafine amorphous Si3N4. Bending strength of highly dense rare-earth-doped α/β-SiAlON-based ceramics was increased with decreasing radii of rare-earth ions, i.e., Yb-SiAlON-based ceramics exhibited excellent high-temperature strength and oxidation resistance caused by the small ionic radius of ytterbium. As for optical application, α-SiAlON is an excellent host lattice with good thermal and chemical stability for doping rare-earth element which activates photoluminescence. Europium-doped Ca-α-SiAlON phosphor formulated as CaxEuy(Si,Al)12(O,N)16 (where 0<x+y<2) was prepared to obtain high quality phosphor with high brightness and desired emission characteristics. Photoluminescence spectra of the resultant Europium-doped Ca-α-SiAlON exhibited high emission intensity at peak wavelength of 580-600 nm giving the better yellow color tone than Cerium-doped yttrium aluminum garnet for applying white LED. It was demonstrated that nitrides or oxynitrides were the innovative materials for the diverse range of high performance specialty applications.
Measurement of Indentation Fracture Toughness of Silicon Nitride Ceramics: I, Effect of Microstructure of Materials
Authors: Miyazaki Hiroyuki , Hyuga Hideki , Yoshizawa Yuichi , Hirao Kiyoshi , Ohji Tatsuki
Published: March 2009

Effect of microstructure of silicon nitride on the fracture toughness, KIc evaluated by the IF
method was studied with various indentation loads ranging from 49 N to 490 N, since practical
assessment of fracture toughness of small Si3N4 parts is needed in the ceramic ball bearing market.
The plot of KIc against the as-indented crack length revealed the rising R-curve behavior for the coarse
Si3N4 and slight R-curve for the fine Si3N4. By comparing KIc estimated from the SEPB and IF
methods using 4 different equations, it was revealed that the IF equation which gave the nearest value
to KIc from SEPB was different depending on the microstructures. These results were discussed in
conjunction with their R-curve behavior and the effective crack length in the SEPB specimens.
Nonlinear Dynamics of a Spur Gear Pair with Fault
Authors: Shen Yong Jun , Yang Shao Pu , Xing Hai Jun , Wang Xi Ying
Published: March 2009

This paper is focused on the nonlinear dynamics of a spur gear pair with slight wear fault,
where the backlash, time-varying stiffness and wear fault are all included. The Incremental Harmonic
Balance Method (IHBM) is used in studying the periodic solution of this system. Based on the
Kronecker’s notation, step function and sign function, the general forms of the periodic solutions are
founded, which is useful to obtain the periodic solutions with arbitrary precision. Finally the typical
frequency-response diagrams are obtained to illustrate the properties of gear system with fault.
Microstructure and Hardness of the Laser Surface Treated Titanium
Authors: Zhang Jian Bin , Fan Ding , Sun Yao Ning , Zheng Yu Feng
Published: March 2009

Surface modification is a promising technique to improve wear properties of titanium and
titanium alloys by modifying either the surface composition or microstructure. Laser remelting and
laser nitriding of commercial purity titanium were carried out under pure argon and pure nitrogen
ambient, respectively. Characterization of the laser treated surface was done by optical microscopy,
scanning electron microscopy (SEM), X-ray diffraction (XRD), microhardness tester. During laser
irradiation heating, Ti exhibits a height activity and combines with N in the atmosphere of pure
nitrogen forming TiN and TiN0.3, whereas Ti only transform into martensitic Ti in pure argon. The
Vickers microhardnesses are greatly improved by laser remelting and laser nitriding.
The Crack Growth Mechanism from 3-D Surface Flaw with Strain and Acoustic Emission Measurement under Axial Compression
Authors: Wong R.H.C. , Guo Y.S.H. , Chau K.T. , Zhu Wei Shen , Li Shu Cai
Published: March 2009

This paper presents the crack growth mechanism from a 3-D surface flaw on gabbro
specimens using strain measurement and acoustic emission (AE) technique. Based on the results of
strain and AE measurement, microcracks initiated inside the rock and extend to the surface of the
specimen. With the observation from the measurements, four types of crack patterns initiate wing
crack, anti-wing crack (opposite direction of wing crack), petal crack and compressive crack. The
strain values of anti-wing cracks are larger 1 to 2 times than that of wing crack. The AE energy
release from anti-wing crack is higher 2.5 times than that of wing crack, while the energy release
form wing crack is the least but the compressive crack is the highest. Thus, the appearance of
initiation and propagation of the anti-wing crack and compressive crack are very actively than that
of the wing crack. The strain and AE measurement is not only to provide a clear concept on the
mechanisms of crack growth form a 3-D surface flaw but also to provide useful knowledge on the
AE property of the crack patterns.
Experimental Researches on Precision Grinding of KDP Crystal
Authors: Wang Qiang Guo , Gao Hang , Zhang Quan Zhong , Cao Xian Suo , Kang Ren Ke
Published: March 2009

The KDP (Potassium Dihydrogen Phosphate) crystal, used as an important photoelectron
part in the laser nuclear fusion system, is a typical kind of hard-to-machine material because of its
soft, brittle, anisotropic property and nano-scale requirement for the shape and plane precision.
Based on the experiments of the KDP crystal’s grindability, certain process parameters, such as the
wheel granularity, the grinding depth and the workpiece’s feeding speed etc., and their influences
on the grinding force and the surface roughness of KDP workpiece are analyzed. Furthermore, some
KDP crystal’s typical surface damages in grinding are analyzed and some technical approaches to
increasing the ultraprecision machining surface quality of KDP crystal are suggested as well.
Force Characteristics in Drilling of Engineering Ceramic with a Brazed Diamond Tool
Authors: Huang Hui , Huang Chong Fa , Xu Xi Peng
Published: March 2009

An experimental study was carried out to investigate the force in drilling of engineering
ceramic with a brazed diamond tool. The drilling forces and protrusion heights of diamond grains
were measured. The results showed that the variation of cutting forces, increasing with the cutting
time, was divided into three phases for a drilled hole. For each phase, the variation of cutting forces
was different. The drilling forces also increased with the numbers of drilled holes due to the wear of
diamond grits. The distance values of the cutting force between the end of first phase and the end of
second phase approximately kept constant.
Nanodiamond Modified with SHP
Authors: Zhu Yong Wei , Xu Feng , Shen Jian Liang , Wang Bai Chun , Xu Xiang Yang
Published: March 2009

A stirring mill, an ultrasonic bath and a high-speed shearing emulsifier were adopted to
modify the surface characteristics of nanodiamond (ND) respectively. The ζ-potential, size
distribution and Fourier transform infrared spectroscopy (FT-IR) of ND were measured to evaluate
its properties. Results show that the ζ-potential of ND modified with SHP (either by
Mechano-chemical Modification or Ultrasonic measurement) drops sharply. Results also show that
the rotating speed of the emulsifier exerts little influence on the size D5 but great influence on the
size D95 of ND.
Experimental Investigations on Surface Residual Stresses in the As-Sprayed and Ground Nanostructured WC/12Co Coatings
Authors: Deng Zhao Hui , Hu Zhong Wei , Jing Qi , Gong Ya Dong
Published: March 2009

In this study, a number of experiments on surface grinding of nanostructured WC/12Co (n-WC/12Co) coatings were conducted on a precision surface grinding machine with a horizontal axis and rectangular worktable. The residual stresses in the as-sprayed and ground n-WC/12Co coatings were measured with the X-ray diffraction method. According to the experimental study and theoretical analysis, this paper investigates the influences of grinding parameters, such as depth of cut, feedrate of workpiece, abrasive grit size and wheel bond type on residual stresses precision grinding of n-WC/12Co coatings.
Experimental Investigation into Surface Integrity Finished by Abrasive Jet with Grinding Wheel as Restraint
Authors: Li Chang He , Xiu Shi Chao , Cai Guang Qi
Published: March 2009

The surface integrity finished by abrasive jet with grinding wheel as restraint was
experimentally investigated. Experiments were performed with plane grinder M7120 equiped with
abrasive jet finishing device and harded workpiece material 45 steel which was ground with the
surface roughness values of Ra=0.6μm.The machined surface morphology was studied using
Scanning Electron Microscope (SEM) and microscope and microcosmic geometry parameters were
measured with TALYSURF5 instrument. The surface hardness for ground and finished surface was
measured with HVS-1000 instrument and the phase structure was analyzed by X-ray energy
dispersive spectram and residual stresses were measured by PW3208 X-ray diffraction. The Results
show that longitudinal geometry parameter values were diminished and ripple was obviously
improved comparing with ground surface. Furthermore, the finished surface has condensible
residual stresses and high surface hardness comparability compared to grinding machining surface.
As a result, life and precision consistency of finished workpiece were improved.
The Experimental Study on Wear Performance of Brazed Diamond Grits
Authors: Chen Yan , Xu Hong Jun , Fu Yu Can
Published: March 2009

The wear resistance samples of brazed single crystal diamond with Ni-Cr filler alloy
were prepared, using high frequency induction brazing and vacuum brazing methods. By wear test
of brazed single crystal diamond, the wear performance of the samples with different brazing
processes was studied. The test result indicates that the wear performance of the high frequency
induction brazed diamond samples is better than that of the vacuum brazed diamond samples.
Because of different brazing processes, the wearing pattern of diamond varied; the wear course of
the vacuum brazed diamond samples in the initial wear period were abnormal and the failure modes
is different.
The Performance and Optimization of Slurry on the Double Sided Polishing Process of Silicon Wafer
Authors: Li Wei , Hu Gang Xiang , Hu Xiao Dong , Hu Xiao Zhen
Published: March 2009

This study compares the effectiveness of different polishing slurries for Double Sided
Polishing process of Silicon wafer in the polished surface roughness and stock removal rate,
discusses the mechanism of Double Sided Polishing for silicon wafer with different type slurries,
also the influence of the pH value, temperature and concentration of the slurries are discussed in
this paper. Furthermore, by the optimization of the process parameters, the ultra-smooth of polished
surface of silicon wafer has been got with higher efficient.
Grinding Titanium Alloy with Brazed Monolayer CBN Wheels
Authors: Yang Chang Yong , Xu Jiu Hua , Ding Wen Feng , Tong Sheng Ting
Published: March 2009

This paper deals with an investigation of the grindability of Titanium alloy Ti–6Al–4V
with brazed monolayer CBN grinding wheels, and systematically studies the effect of process
parameters on specific energy and grinding temperature. In the investigation, a groove is machined
with a brazed monolayer CBN grinding wheel, and the dimension accuracy of groove has been
proved to meet the design requirements. There is no microcrack in surface layer of the groove, and
the depth of work-hardening is less than 40 μm, which indicates that the grinding affected zone is
small. The results show that brazed monolayer CBN grinding wheels have excellent performance
during grinding titanium alloy.
Theoretic Analysis and Experimental Research on Barrel Finishing Uniformity of Crank Shafts with Larger Size
Authors: Li Wen Hui , Yang Sheng Qiang , Yang Shi Chun
Published: March 2009

At present, crankshafts with larger size are finished mostly by abrasive cloth and manual
steel brush, which is not ideal on finishing quality, efficiency and cost, especially cleanness degree
does not meet design and use request. So horizontal spindle barrel finishing has been developed and
has good finishing effects for crankshafts with small size. But this process has bad uniformity for
connecting rod journal of crankshafts with larger size by simulation experiments. Aimed at the size,
shape and weight of crankshafts with larger size, theoretic research is done, and main factors for
finishing uniformity are analyzed. Finally its finishing project is defined and experiments are done.
The research indicates that this process is very effective for crankshafts with larger size, and has
also positive influence on efficiency and auto product line.
Ultrasonic Machining Aided Tool Rotation of Sintered NdFeB Magnet
Authors: Li Li , Wang Dong , Niu Zong Wei , Li Zhi Yong , Yuan Guang Ming
Published: March 2009

A new kind of ultrasonic machining method named ultrasonic machining aided tool
rotation is proposed for sintered NdFeB permanent magnet. In the process abrasive slurry enters the
machining area through holes in the rotary tool which can assure the grains easily enter the
machining surface slurry. Its machining mechanisms are studied and material removal model is
developed. Experimental research was carried out on self-made equipment. Experimental results
were accordance with the developed model. It is proved that this new kind of ultrasonic machining
technology is suitable to machine deep hole for sintered NdFeB material.
Research on Design and Manufacture of Ultrasonic-Vibration-Based Gear-Honing Device
Authors: Lv Ming , Ma Lin , Liang Guo Xing , Zhang Yu
Published: March 2009

Ultrasonic-vibration-based hardened-gear honing is creativity technique in the domain of
gear finishing. The honing technique is improved by introducing ultrasonic machining to improve
the accuracy and surface quality of hardened-gear. With respect to the design and manufacture of
ultrasonic-vibration-based gear honing machine, the paper refers to reasonable project and
trial-manufacture. The electroforming technique of spur gear CBN honing-wheel is helpful to
improve the comprehensive performance of honing-wheel. Finally the characteristic and advantage
of ultrasonic vibration based gear-honing technique is described.
Apply Image Registration to the Wear Measurement and Analysis of Different PVD-Coating Drills
Authors: Chiou Yih Chih , Liang Yu Teng
Published: March 2009

PVD (Physical Vapour Deposition) multilayer coatings were extensively used in cutting
tools because of their relatively high wear and corrosion resistance, adhesion strength, hot hardness,
and low coefficient of friction. The object of this study is to measure flank wear of dry cutting drills
of different PVD coatings, including TiN, TiCN, and TiAlN by using drilling force experiments and
machine vision technique incorporated with image registration technique. To obtain an optimal
combination of cutting parameters quickly, we applied Taguchi method to plan the drilling
experiment. The experimental results show that coating layer is the most important control factor for
cutting and the TiAlN-coating drills generate least wear and thus has the longest tool life.
A Fundamental Study on the Digital Recognition of Grinding Wheel
Authors: Gong Jun Feng , Xu Xi Peng
Published: March 2009

In this paper, the 3D morphology of a grinding wheel was modeled by the depth from focus. Firstly, the picture information of different heights was extracted by the up-down moving of the microscope. The operator Laplacian was adopted to distinguish the distinct and fuzzy areas in a picture. Then, the distinct image and height information was obtained. The information of height was distorted due to the occurrence of noise. In order to reconstruct 3D surface, a method based on Min/Max curvature flow was developed to remove noises. In the end, an abrasive grain in the image of a grinding wheel was segmented by the Mumford-Shah model. The results could be further developed to evaluate the worn status of grinding wheels. Introduction The examination of the wear of abrasive grain in the grinding wheel is very important for evaluation of performance of diamond grinding wheel. The three-dimensional (3D) reconstruction of grinding wheel topography can provide more information about wear of abrasive grains than common ways such as observation by optical microscope. Nowadays, there have been many techniques to be considered to obtain 3D data, for example, profilometry, the scanning electron microscope (SEM), the scanning laser microscope (SLM), stereo vision and so on. SEM is a powerful measuring tool, but the time needed for sample coating process and chamber air pumping is considerable. SLM is promising tool for 3D shape modeling, but still expensive for most of users. Stereo vision is simple and quick method to obtain the height information, but only the height of points which match in two corresponding images could been obtained. In this paper, a new method based on depth from focus (DFF) [1] is presented for 3D modeling. Compared with SEM and SLM, it is easy and not very expensive equipments are needed. Meanwhile, it can provide more real 3D model than stereo vision method. In order to measure the abrasive grains, a segmentation Algorithms based on Mumford-Shah model [4] is introduced to divide the grains from image of grinding wheel.
Vibration Characteristic Analysis of Diamond Saw Blade with Multitude Holes Structure for Vibration and Noise Reduction
Authors: Hu Shan Shan , Hu Ying Ning , Wang Cheng Yong , Chen Chang Xiong
Published: March 2009

Finite element mode analysis and structure optimization of several multitude holes
structure diamond saw blades are conducted to study vibration and noise of saw blade. Result shows
multitude holes structure saw blade has lower natural frequency than conventional saw blade, which
conduces decreasing of noise radiant efficiency. Through configuration optimization, it is clear that
hole diameter, hole arrange group number and average displacement DMX of Z axes have great
effects on saw blade vibration target function. Finally, the analysis to characters of sawing force and
vibration by experiment helps to find out optimum structure of diamond saw blade with multitude
holes, more rational sawing parameter and its adaptability to work piece material.
Comparison of Hydroxyapatite with Carbonate Apatite in Osteoclastic Cell Resorptive Activity
Authors: Ohashi Natalie , Nakamura Miho , Nagai Akiko , Tanaka Yumi , Sekijima Yasutaka , Yamashita Kimihiro
Published: March 2009

Various bioactive calcium phosphates such as hydroxyapatite (HA) and carbonate apatite (CA) bone substitutes have been studied because of the biocompatibility and osteoconductivity when implanted into bone defects. In this study, the interaction between bioceramics and osteoclast-like cell using the cell-line such a RAW264 was examined for the investigation of the important factors of the osteoclastic responses. From the results, the possibility of effectiveness by surface geometry and chemical property means solubility was suggested. Moreover, it was considerable that the CA induced much stronger responses to osteoclast-like cells than the HA.
Proliferation of Osteoblast-Like Cells on Zirconia/Alumina Nanocomposite
Authors: Yamashita Daisuke , Kanbara Kenji , Machigashira Miho , Miyamoto Motoharu , Sato Hideo , Izumi Yuichi , Ban Seiji
Published: March 2009

The aim of this study was to evaluate the biocompatibility with the proliferation of osteoblast-like cell (MC3T3-E1) on zirconia/alumina nanocomposite (NANOZR) in comparison to yttria stabilized zirconia (3Y-TZP) and titanium (Ti). Cellular proliferations after 1-, 3-, 6-, and 9-day incubation were calculated from the measurement of the MTT activities of the proliferated cell and were analyzed by two-way ANOVA. Time-dependent proliferation of MC3T3-E1 in all the sample was observed in all three materials with culture days. However, these were no significant differences in the proliferation between three kinds of material, indicating all the materials have a similar-good biocompatibility.
Rat Bone Marrow Cell Responses on the Surface of Hydroxyapatite with Different Topography
Authors: Chen Xue Ning , Zhu Xiang Dong , Fan Hong Song , Zhang Xing Dong
Published: March 2009

It is well known that the cellular responses are related with both physical and chemical characteristics of substrate, including surface topography. In the present study，the effect of surface topography of hydroxyapatite (HA) on rat bone marrow cell (rBMCs) response was investigated. HA disc-shaped pellets with various topography were manufactured by single-axis pressing methods. The rBMCs responses on materials including cell morphology and proliferation were evaluated by SEM and MTT methods respectively, and the differentiation potential was assessed by total protein content and alkaline phosphatase (ALP) activity testing. The results showed that the cell porliferation was higher on HA surfaces with macropore structure, while ALP activity was lower. No significant difference in the cellular responses on the pore distribution and orietation was observed. However, the pore structure had a potential to guide cell orientation by gathering the cells inside the pores rather than on the ridges. Since ALP served as an indicator of early osteoblast differentiation, in this study its higher expression on HA surface with micropores suggested that surface microtopograhy exhibited an important effect on early osteoblast differentiation process.
Effect of Amine Additives on the Morphology of Hydroxyapatite
Authors: Zhang Hong Quan , Darvell Brian W.
Published: March 2009

Long HA whiskers with uniform morphology, high aspect ratio, and good crystallinity
could be prepared using a hydrothermal technique at 180 oC for 10 h. Whisker morphology was
sensitively-dependent on preparation conditions. Compared with formamide and urea, acetamide
showed a low hydrolysis rate; it was found to be an appropriate additive to synthesize HA whiskers.
Length and aspect ratio could be controlled by selecting solution conditions with the Ca/P ratio at
1.67 in the range 42 - 84 mmol/L calcium and 25 - 50 mmol/L phosphate and 0.75 – 1.25 mol/L
additive concentration (as amide, -NH2).
Mechanical Properties of Living Cells: Interaction of the Adherent Endothelial Cell and the Fluid Shear Flow
Authors: Liu Xiao Heng , Yin Hong Mei , Lai Yi , Xue Long Juan
Published: March 2009

In present study a theoretical model was established to simulate the interaction between
the adherent endothelial cell and fluid shear flow. A two-dimensional computational fluid dynamics
(CFD) was conducted to solve the model equations. The results showed that the model cell was
deformed under steady shear flow. It spread along the flow direction, and decreased its height. The
deformation index (DI) increased with Reynolds number of applied fluid flow. The DI of the cell
increased greatly when the initial contact angle (α) was smaller than 130°, and then it was less
important with the increase of α. These results suggest that the fluid shear flow may play a
particular role in the mechanism of cell activation and in the regulation of endothelial cells
functions.
Techniques for Manufacturing FGM Bioceramics
Authors: Hsu Y.H. , Turner I.G. , Miles A.W.
Published: March 2009

Several novel methods for the production of calcium phosphate based functional gradient materials have been explored. The processes involved the use of polyurethane foams with a different number of pores per inch which were joined together in a variety of ways to form unique templates prior to vacuum impregnation with a ceramic slip. Before processing, rectangular blocks of foam were joined by stitching or trapezoidal blocks were compressed into rectangular shapes to produce a gradient of porosity along the length of the template. Four-point bend testing of the sintered samples which combined two porous structures showed them to have comparable mechanical properties to homogeneous ceramics based on foam templates with uniform pore sizes, with no evidence of weakness at the interface. The method was further developed to make a cylindrical sample with two diverse porous structures which more closely mimic the natural bone morphology. The two very different areas, which represented cortical and cancellous bone, had good structural integrity at the interface.
Quantitative Micro-Radiography of New Bones Formed around the Implant Using Parametrics X-Ray
Authors: Suwa Taketoshi , Sakae Toshiro , Nakada Hiroshi , Numata Yasuko , LeGeros Racquel Z. , Sato Isamu
Published: March 2009

To clarify new bone tissues, radiography with a newly developed tunable wavelength and
highly parallel Parametric X-ray, PXR, was applied. Methods: PXR was generated by a LINAC at
LEBRA, Nihon University (Hayakawa et al., 2005). X-ray wavelength was tuned from 7 KeV, 0.177
nm, to 16 KeV, 0.0775 nm. Coated or grit-blasted Ti-alloy implants modified with coating or blasting
were implanted in surgically created defects in rabbit tibia. Undecalcified polished thin sections were
prepared from the implant/bone areas 1 and 4 weeks after implantation. Results: PXR radiography
showed a distinct difference between the newly formed bone and the compact bone. Color-mapping
of the images showed an increase in the total amount of bone formation with time. Conclusion:
Application of LEBRA-PXR, a high-powered, highly monochromatized and highly parallel oriented
X-ray allowed easy and accurate radiographic analysis of new bone formation around the implant.
Fast and Simultaneous Determination of Calcium and Phosphorous in Calcium Phosphate Based Bioceramics by ICP-AES
Authors: Lin Kai Li , Wang Zheng , Chang Jiang , Zou Hui Jun , Lu Jian Xi
Published: March 2009

Calcium is generally determined by EDTA titration after separation of phosphate radicals,
and the phosphorus is determined by weigh method. This traditional analytical process is time
consuming and unfavourable for quality controlling. In contrast, the ICP-AES is simple and fast,
and can simultaneously determine multielements. In this paper, the ICP-AES method was used to
simultaneously determine calcium and phosphorous in calcium phosphate based bioceramics, and
wavelengths of 317.933 nm and 213.618 nm were selected for the measuring of the calcium and
phosphorus, respectively. The results obtained by ICP-AES are well consistent with the results
determined by the traditional EDTA titration and weigh method, and suggest that the ICP-AES
analysis is a simple, fast and accurate method for simultaneous determination of calcium and
phosphorous in calcium phosphate based bioceramics.
Advanced Mechanical Properties of Porous Hydroxyapatite Ceramics Prepared Using Hydroxyapatite Slip and its Slurry Synthesis
Authors: Zhang Yin , Yokogawa Yoshiyuki , Kameyama Tetsuya
Published: March 2009

There is a clinical need for synthetic scaffolds that will promote bone regeneration. Important factors include obtaining an optimal porosity and size of interconnecting macropores whilst maintaining scaffold mechanical strength, enabling complete penetration of cells and nutrients throughout the scaffold, preventing the formation of necrotic tissue in the centre of the scaffold. To address this we investigated flexural strength of bimodal porous apatite ceramics prepared using apatite slurry and its slurry synthesis was studied. Slips with different contents of HAp (K-HAp and T-HAp) and deflocculant were prepared by milling in a pot mill. The viscosity of slurries made of commercial T-HAp powder showed a drop after 3 hours’ milling, but the viscosity of slurry with high solid content of k-HAp and 2.0 wt% deflocculant increased with an increase of milling time after 2 hours’ milling. The porosity and flexural strength of the porous HAp prepared by heating the foam dipped in K-HAp slip with 2.0 wt% of deflocculant and 0.5wt% of foaming regent heated at 1200°C were 62.4 % and 14.7 MPa, and those in T-HAp were 59.7 % and 15.2 MPa with 1.5 wt% of deflocculant and 0.5wt% of foaming regent heated at 1200°C.
An Introduction of New Artificial Bone Unit “Tetra-Bone”
Authors: Teraoka Kay , Tei Yuichi , Sasaki Nobuo , Suzuki Shigeru , Takane Katsuhisa
Published: March 2009

We fabricated a small α-TCP ceramic unit having four pods, named “Tetra-bone” employing a ceramic injection molding. Tetra-bone can keep uniform concave geometry among the pods as well as immobilizing each other. Owing to the monotony of Tetra-bone, weight of Tetrabones used can be converted into the number of Tetra-bones, volume that can be filled with Tetrabones, and the number of functional structures. By using Tetra-bones, bone defects can be filled with intentional geometry that helps to discuss the relation between geometric features of pores and bone formation.
Mg-Free Precursors for the Synthesis of Pure Phase Si-Doped α-Ca3(PO4)2
Authors: Motisuke M. , García Carrodeguas R. , Zavaglia Cecília A.C.
Published: March 2009

On this paper, methods to obtain Mg-free reagents for synthesizing pure phase Sistabilized
α-TCP were established. The Mg contents of synthesized reagents were considerably
lower than those in commercially available reactants. Pure Si-doped (2.5 at.-% of P by Si
substitution) α-TCP was obtained by solid state reaction from synthetic reagents at temperature as
low as 1200°C. When commercial reagents were employed for the solid state synthesis, a mixture
of α- and β-TCP was obtained even when the solid state reaction was conducted at 1300 °C.
Cellular Activity on Siloxane-Doped Poly(Lactic Acid)/Vaterite Composite Scaffolds
Authors: Obata Akiko , Kasuga Toshihiro
Published: March 2009

Cellular activities of human mesenchymal stem cells (MSCs) and osteoblasts (HOBs) on a silicon-releasable scaffold, which is siloxane-doped poly(lactic acid) / vaterite composite coated with hydroxycarbonate apatite (SPV-H), were estimated using two types of media, with or without organic factors, dexamethasone (Dex) and β-glycerophosphate (β-GP). The culture tests using MSCs shows that the level of alkaline phosphatase (ALP) activity in the cells cultured on SPV-H increased for 21-day culturing in medium without Dex and β-GP. The proliferation of MSCs on SPV-H was significantly higher than that on a poly(lactic acid) / vaterite composite coated with hydroxyapatite (PV-H) at all time points. In the case of supplementing Dex and β-GP to the medium, the level of ALP activity in MSCs cultured on SPV-H was higher in comparison with that on PV-H at all time points. Scanning electron microscopy showed that there were some agglomerates in HOBs cultured on the SPV-H surface after 21-day culturing in the medium without the factors, while there are no agglomerates on PV-H. The agglomerates were regarded from laser Raman spectroscopy as bone nodules. This result implies stimulation to HOBs by silicon species in SPV-H. SPV-H is expected to be useful as the scaffold for bone tissue engineering.
Investigation to the Cross Microstructure of Hydroxyapatite Sheets of a Cannon Bone
Authors: Chen Bin , Peng Xiang He , Sun Shi Tao
Published: March 2009

Bone possesses excellent mechanical properties, which are closely related to its favorable
microstructures optimized by nature through many centuries. In this work, a scanning electron
microscope (SEM) was used to observe the microstructures of a cannon bone. It showed that the
bone is a kind of bioceramic composite consisting of hydroxyapatite layers and collagen protein
matrix. The hydroxyapatite layers are composed of long and thin hydroxyapatite sheets. The
hydroxyapatite sheets in different hydroxyapatite layers distribute along different orientations,
which composes a kind of cross microstructure. The maximum pullout force of the cross
microstructure was investigated and compared with that of the 0° microstructure with their
representative models. The result indicated that the maximum pullout force of the cross
microstructure is markedly larger than that of the 0° microstructure.
Novel Composite of Nano-Sized SiO2/Chitosan Induce the Growth of HAp Crystal
Authors: Huang Shao Wei , Wang Xu Dong , Zhang Weng Juan , Lu Chang , Zhu Zhi Hong , Huang Xin Tang , Zeng Yan
Published: March 2009

A novel hybrid material of chitosan/nano-sized SiO2/hydroxyapatite (HAp) composite was prepared through a biomimetic approach. HAp deposited in situ on the surface of chitosan/ nano-sized SiO2 composite film in simulate body fluid (SBF) solution at 36.5°C. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) were performed to study composition and morphological characteristics of the HAp crystal. The results indicated that nano-sized SiO2 dispersed in the chitosan film provided initial nucleation sites for the growth of the HAp in SBF solution by adsorbing further PO4 3−, Ca2+ due to the induction of HAp formed. The strength of the composite was largely improved because of the addition of nano-sized SiO2.
Improvement of Microstructure of Bovine Hydroxyapatite (BHA) with Machineable Fluorapatite Glass (MFG)
Authors: Gunduz Oguzhan , Salman S. , Kayali S. , Goller Gultekin , Goker I. , Agathopoulos Simeon , Ozyegin L.S. , Oktar Faik N.
Published: March 2009

Composites of calcinated bovine bone derived hydroxyapatite (BHA) doped with 5 wt% and 10 wt% machineable fluorapatite glass (MFG) were prepared by sintering. Microstructure observations and measurements of density, compression strength and microhardness indicated a positive effect of MFG-doping to BHA. The highest compression strength (59.7 MPa) was achieved after sintering at 1300°C for 5% MFG. In the light of results of earlier similar studies, the paper discusses the features of the potential of BHA-MFG composites in biomedical practice.
In Vitro Calcification of Silk Fibroin Hydrogel
Authors: Nogueira Grínia M. , Aimoli Cassiano Gomes , Weska Raquel Farias , Nascimento Leandro S. , Beppu Marisa Masumi
Published: March 2009

Silk fibroin hydrogels were prepared and their potential to deposit calcium phosphates in
vitro was observed. Pristine and lyophilized samples were tested in 1xSBF and 1.5xSBF. The
results showed that silk fibroin hydrogels can induce calcium phosphate deposits both in the pristine
and lyophilized form. However, the pristine silk fibroin hydrogel after calcification presented a
fragile structure making it difficult to handle, while the lyophilized samples presented better
resistance to handling. Calcium phosphates deposits were intense in samples submitted to tests in
1.5xSBF, however, few and isolated deposits were observed on samples submitted to tests in
1xSBF. The 3-D porous structure and the ability to deposit calcium phosphates, turn silk fibroin
hydrogel a potential material suitable to use in biomimetic processes.
DNA-Coatings: Bioactive Properties and Effects on Osteoblast-Like Cells
Authors: van den Beucken Jeroen J.J.P. , Walboomers X.Frank , Leeuwenburgh Sander C.G. , Vos Matthijn F.J. , Sommerdijk Nico A.J.M. , Nolte Roeland J.M. , Jansen John A.
Published: March 2009

The aim of this study was to evaluate potential effects of DNA-coatings on calcium
phosphate (CaP) nucleation from simulated body fluids (SBF) and subsequently the effects of
DNA-coatings and SBF-immersed DNA coatings on the behavior of osteoblast-like cells. DNAcoatings
demonstrated to enhance the nucleation and deposition of CaP from SBF compared to
titanium controls. The behavior of osteoblast-like cells was affected on SBF-immersed DNAcoatings,
showing an increased deposition of the extracellular matrix protein osteocalcin compared
to titanium controls. These results indicate bone-bonding capacity of DNA-coatings, which needs to
be confirmed using future animal experiments.
Development of a Bioactive Surface on a Co-Cr-Mo Alloy during Investment Casting or Heat Treatment
Authors: Ortiz-Cuellar J. Carlos , Cortés-Hernández Dora A. , Escobedo-Bocardo José C. , Almanza Robles J.M.
Published: March 2009

Two different techniques were used to promote a bioactive surface on a cobalt base alloy: i) the cobalt alloy melt was cast into wollastonite-coated cavities of an investment mold, or ii) wollasonite-encapsulated as-cast samples were heat treated at 1220°C for 1 h, this is the typical treatment performed to this alloy for improving its mechanical behavior. In vitro bioactivity was assessed by immersing samples in a simulated body fluid for 21 days. Potentially bioactive layers were obtained in both of the cases. A thicker apatite layer was formed on the samples obtained by investment casting. However, since the heat treatment needs to be performed, the heat treatment method is also a promising technique for promoting the bone-bonding ability of this Co alloy.
In Vitro Bioactivity of Atomic Layer Deposited Titanium Dioxide on Titanium and Silicon Substrates
Authors: Heinrichs Jannica , Jarmar Tobias , Rooth Marten , Engqvist Hakan
Published: March 2009

A non-bioactive implant device can easily be changed to in vitro bioactive with a thin
coating of crystalline TiO2. This crystalline coating can be deposited very thin with great step
coverage at a low temperature with Atomic Layer Deposition (ALD). An anatase TiO2 coating was
built up atomic layer by atomic layer using TiI4 and H2O as precursors in a hot wall furnace.
Several hundreds of cycles resulted in a 10-30nm well defined TiO2 of anatase phase on both Si and
Ti substrates. These coatings were shown to be bioactive when immersed in simulated body fluid in
vitro, as hydroxyapatite (HA) formed on the surface. The surface roughness of the substrates
affected the adhesion of the HA. The adhesion was low on the smooth Si but much better on the 100
times rougher Ti. The ALD technique is promising for coating substrates of all shapes with
bioactive crystalline TiO2 at a low temperature.