bluuebunny/crossref_metadata_2025 huggingface dataset:
Syntactic Foams Consolidated with Starch: Modelling for Pre-Mould Processing
Authors: Islam M.M. , Kim Ho Sung
Published: March 2009

Various manufacturing parameters involved in the ‘buoyancy method’ were inter-related.
An equation based on unit cell models for a relation between volume expansion ratio (VER) of bulk
microspheres in aqueous starch and microsphere size was derived. A good agreement between the
equation and experimental data was found. The inter-microsphere distance (MID) concept was
introduced and it was demonstrated that the MID can be calculated numerically for microspheres
with known statistical data.
Triethanolamine Molybdate, a New Polymeric Precursor for Molybdenum Nitride
Authors: Mondal S. , Banthia A.K.
Published: March 2009

Nitrides remain a relatively unexplored class of materials primarily due to the difficulties associated with their synthesis and characterization. Several synthetic routes, including high temperature reactions, microwave assisted synthesis, and the use of plasmas, to prepare binary and ternary nitrides have been explored. Transition metal nitrides form a class of materials with unique physical properties, which give them varied applications, as high temperature ceramics, magnetic materials, superconductors or catalysts. They are commonly prepared by high temperature conventional processes, but alternative synthetic approaches have also been explored, more recently, which utilize moderate temperature condition. Transition metal nitrides particularly, molybdenum nitride, niobium nitride, and tungsten nitride have important applications as catalyst in hydrodenitridation reactions. These nitrides have been traditionally synthesized using high temperature nitridation treatments of the oxides. The nitridation temperatures are very high (> 800- 1000 oC). The aim of our work is to synthesize molybdenum nitride by a simple, low-temperature route. The method involves pyrolysis of a polymeric precursor, which was prepared from the condensation reaction between triethanolamine and molybdic acid. The melting point of the product is 180oC. The polymeric precursor and its pyrolyzed products are characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). X-ray diffraction shows that molybdenum nitride (MoN) obtained from this method has hexagonal crystal structure. MoN is obtained by this method at very low temperature (~ 400 oC).
Tensile Deformation and Fracture in a Bulk Nanostructured Al-5083/SiCp Composite at Elevated Temperatures
Authors: Tang F. , Han B.Q. , Hagiwara Masuo , Schoenung Julie M.
Published: March 2009

An ultrafine-grained Al-5083 alloy reinforced with 5 vol.% nano-sized β-SiC particles was
fabricated with a powder cryomilling and consolidation technique. Tensile tests were conducted at
temperatures from 298 to 773 K for this composite. The mechanisms for deformation and fracture of
this nanostructured composite at various temperatures are discussed.
Preparation and Characterization of Alumina/TZP Particulate Composites
Authors: Cho Y. Ki , Yang Tae Young , Lee Jae Myung , Yoon Seog Young , Park Hong Chae
Published: March 2009

Particulate composites prepared by sintering compacts of Al2O3 and TZP powders, in air at 1500 and 1600 oC have been characterized in terms of microstructure and mechanical properties. The mechanical properties of the composites appear to be controlled by three main factors: the grain size of major phase, type of intergranular TZP, and presence of residual stress.
Deformation Behaviour of Composites Reinforced with Four Different Linen Flax Yarn Structures
Authors: Carpenter James E.P. , Miao Meng He , Brorens Peter
Published: March 2009

Four types of yarns were made from flax sliver (Linum usitatissimum) as reinforcements in composites: (1) twist-less, (2) two-fold, (3) high-twist singles and (4) medium-twist singles yarns. Flexural, compressive and tensile properties of the epoxy composites were compared.
Fabrication and Characterization of Polypropylene/Ethylene-Octene Copolymer Blend Nanocomposites
Authors: Samal S.K. , Mohanty S. , Nayak S.K.
Published: March 2009

PP/EOC thermoplastic blend nanocomposites were prepared by melt intercalation
technique using an intermeshing co-rotating twin screw extruder. The organoclay (Na+ MMT,
Cloisite 20A, Cloisite 30B) content was varied between 0-5wt. % whereas the blend composition
was kept constant (70PP: 30EOC) as optimized in our previous work. The effects of clays on the
mechanical and rheological properties have been studied. Mechanical studies of PP/EOC
nanocomposites reveal a significant increase in the impact strength upto a clay content of 3%. X-ray
diffraction (XRD) analysis showed a significant increase in the interlayer gallery space with
increase in clay loading. The rheological characterization made employing parallel plate rheometer
revealed a maximum increase in storage modulus (G’) and loss modulus (G”) in case of modified
clay indicating higher stiffness of the nanocomposites as compared to unmodified nanocomposites.
Time Temperature superposition (TTS) was employed to generate various viscoelastic
mastercurves.
Fabrication and Characterization of Sisal/Glass and Polypropylene Hybrid Composites
Authors: Samal S.K. , Mohanty S. , Nayak S.K.
Published: March 2009

The present work summarizes an experimental study on the dynamic mechanical
behaviour of sisal – glass fiber reinforced PP composites (SGRP). Variation in mechanical strength,
storage modulus (E’), loss modulus (E’’) and damping parameters (tan δ) with the addition of fibers
and MAPP were investigated. Mechanical tests revealed an increase in the tensile, flexural and
impact strength in the SFRP composites with an increase in the fiber loading from 10% to 30%.
Further the SGRP composites prepared using 15 wt% of glass and 15 wt % of sisal fiber, exhibited
improved mechanical performance as compared with the virgin matrix as well as 30% SFRP
composites. The fiber matrix morphology of the interface region in the composites was examined
employing SEM analysis of the tensile fracture specimens. Thermal stability in the composites was
studied using TGA/DTG thermo grams. Dynamic mechanical analysis data showed an increase in
the storage modulus of the treated composite. The tanδ spectra presented a strong influence of fiber
content and coupling agent on the α and γ relaxation process of PP. FTIR spectra of the treated and
untreated sisal fibers was also studied to ascertain the existence of the type of interfacial bonds.
Electrical Spectroscopy Studies of Organic/Inorganic Nano Composites
Authors: Anis Arfat , Banthia A.K.
Published: March 2009

The electrical conductivity studies of chemically crosslinked nano composite membranes consisting
of poly (vinyl alcohol) (PVA) and phosphomolybdic acid (PMA) with different blending
composition and crosslinking density has been conducted over a wide frequency regime. The
conductivity of the systems has been studied within the temperature range 25 oC ø T oe 100 oC for
the hydrated membranes. The proton conductivity of the membranes was generally of the order of
10-3 S/cm. The conductivity of these membranes shows a temperature dependence of Arrhenius
type. The activation energies for the membranes were calculated from the conductivity
measurements. Both the pristine and hydrated membranes were also characterized by X-Ray
diffraction studies to observe the effects of blending and hydration on the crystallinity of the
composite membranes. The membranes showed comparable proton conductivity and better
resistance to methanol permeability than that of Nafion 112 under the same measurement
conditions. These properties make them good candidates as polymer electrolyte membranes for
direct methanol fuel cell application.
Compaction of Ti-6Al-4V Powder by ECAE with Back-Pressure
Authors: Lapovok Rimma , Tomus Dacian , Muddle Barry C.
Published: March 2009

Powder metallurgy is widely used to produce alloys with low cost of production. The main drawback using powders is the level of residual porosity of final product which often implies the application of a complicated and costly hot isostatic pressing process. However, this issue can be overcome by using equal channel angular pressing (ECAE) with back pressure (BP). The use of severe shear deformation, with imposed hydrostatic pressure, allows a reduction in the range of compaction temperatures compare to those used in conventional practice. The compaction of Ti-6Al-4V powder by the ECAE method has been investigated. The compaction has been performed at temperatures starting from room temperature (RT) and increasing up to 400°C with various back pressures ranging from 0 to 350MPa. A billet processed by ECAE with 43MPa back-pressure at 400°C was found to have improved relative density of 97.5% and increased Vickers hardness of 369HV, compared to values of 96.7% and 325HV respectively obtained at RT. A relative density of 98.2% and 426HV hardness were measured for billets processed with BP = 262MPa at 400°C. A fully compact billet was obtained by applying 350 MPa of BP at 400°C.
Comparative Study of Copper Diffusion in Plasma Treated Low-k Dielectric Thin Film Using XPS and SIMS
Authors: Aw K.C. , Salim N.T. , Gao Wei , Li Zheng Wei , Prince K.
Published: March 2009

Low-k dielectric improves the switching speed by reducing the parasitic capacitance in
integrated circuits. However it suffers the problem of copper diffusion. Forming gas (H2 + N2)
plasma treatment on the surface of HSG-7000 low-k dielectric thin film has demonstrated to
improve copper diffusion resistance. Two techniques using X-ray Photoelectron Spectroscopy
(XPS) and Secondary Ion Mass Spectroscopy (SIMS) have been used to examine the copper
diffusion on this thin film. A thin layer of 10 nm with C-N bonds near the HSG-7000 surface were
believed to be created by the plasma treatment and confirmed with XPS and SIMS and acts as
barrier.
Mechanical Properties of Directionally Arrayed Dendrites in the Ni3Al Matrix Alloy
Authors: Lu Y. , Lee Je Hyun , Jang Y.H. , Kim S.S. , Oh Myung Hoon , Wee Dang Moon
Published: March 2009

Ni3Al shows the unique feature of increasing strength with increasing temperature. However, it is too brittle to use as a structural material due to grain boundary weakness. Ductility could be enhanced by controlling grains using directional solidification. In order to increase the ductility or strength of Ni3Al alloys, a ductile γ (Ni-rich) phase of dendrite fibers or a strong β (NiAl) phase of dendrite fibers were arrayed in the γ´ (Ni3Al) matrix by directional solidification. The dendrite spacing could be controlled by varying the solidification rates, and the volume fraction of the γ or β phase could be changed by using alloy compositions, from 23 to 27 at. % Al-Ni alloy. With increasing solidification rates, the dendrite spacing decreased, which caused the tensile strength to be enhanced and the elongation to decrease, evidently due to the phase boundary augmentation. With increasing Al content, the γ dendritic microstructure changed to β dendrites in the γ´ matrix, which resulted in a decrease in elongation as a result of an increase in the volume fraction of the brittle β dendrites in the γ´ matrix.
Mechanical Properties of Micro-Porous Metals Produced by Space-Holding Sintering
Authors: Banno Takumi , Li Yun Cang , Wen Cui E , Yamada Yasuo
Published: March 2009

Micro-porous nickel foams with an open cell structure were fabricated by the
space-holding sintering. The average pore size of the micro-porous nickel specimens ranged from 30
μm to 150 μm, and the porosity ranged from 60 % to 80 %. The porous characteristics of the nickel
specimens were observed using scanning electron microscopy (SEM). The mechanical properties
were studied using compressive tests. For comparison, macro-porous nickel foams prepared by the
chemical vapour deposition method with pore sizes of 800 μm and 1300 μm and porosity of 95 %
were also presented. Results indicated that the ratio value of 6 and higher for the specimen length to
cell size (L/d) is satisfying for obtaining stable compressive properties. The micro-porous nickel
specimens exhibited different deformation behaviour and dramatically increased mechanical
properties, compared to those of the macro-porous nickel specimens.
Mn, Cu Doping and Optical Properties of Highly Crystalline Ultralong ZnS Nanowires
Authors: Chien N.D. , Chung H.V. , Huy P.T. , Kim Do Jin , Ferrari Maurizio
Published: March 2009

Manganese (Mn) and copper (Cu) doping of ZnS nanowires was achieved by thermal evaporation of Mn, Cu doped ZnS nanopowders. Field emission scanning electron microscopy, and X-ray diffraction studies of the obtained ZnS nanowires demonstrate that the nanowires are single crystal structures and have diameters about 30-200 nm and lengths up to 1 millimeter. Room temperature photoluminescence (PL) measurements show a common PL peak around 520 nm for all ZnS nanowires samples, while impurity-related emission band are observed in doped ZnS nanowires. The dependence of the PL intensity on Mn doping concentration has also been investigated. It is shown that for high Mn doping concentration (10%) in the starting ZnS nanopowders, new emission bands (orange-red and red bands) are observed from the ZnS:Mn nanowires products. The origins of these new emission bands are discussed and brought up for further discussion.
Investigation of Electrical Properties in Chalcogenide Thin Film According to Wave Length
Authors: Choi H. , Kim H.K. , Koo Y.W. , Nam K.H. , Koo S.M. , Cho W.J. , Chung H.B.
Published: March 2009

Programmable metallization cell (PMC) memory is based on the electrochemical control of
nanoscale quantities of metal in thin films of solid electrolyte. We investigate the nature of thin films
formed by the photo-dissolution of Ag into Ge-Se-Te glasses for use in programmable metallization
cell devices. Glassy alloys of a-Ge25Se75-xTex(x = 0, 25) are prepared by well known melt-quenching
technique. Thin films of a-Ge25Se75-xTex(x = 0, 25) glassy alloys are evaporated by vacuum
evaporation technique at ~10-6 torr on glass substrate at room temperature. Optical properties in this
study concerns photo-diffusion of Ag on Ag-doped Ge-Se-Te electrolytes. With these promising
properties, the composition a-Ge25Se75-xTex(x = 0, 25) is recommended as a potential candidate for
PMC-RAM.
Luminescence Properties of ZnS:Er Quantum Dots with NIR Excitation
Authors: Zhang Xiao Song , Dong Xiao Yi , Kai Gui Yun , Dong Dong Qing , Zhang Yan Fang , Wang Zhi
Published: March 2009

ZnS:Er quantum dots were prepared in the aqueous medium from readily available
precursors. The construction, morphology and luminescence properties of the ZnS:Er quantum dots
were evaluated by XRD,TEM and photoluminescence spectra. Furthermore, the 1590 nm emission
of the ZnS:Er quantum dots excited by a 785.0 nm NIR laser were discussed.
Tuning of Energy Band Gaps in Ternary Semiconductors
Authors: John Rita
Published: March 2009

The first principle investigations on electronic structure of ABC2 (A = Cd; B = Si, Ge, Sn; C= P, As) pnictides using the Tight Binding Linear Muffin Tin Orbital (TB-LMTO) method within the Atomic Sphere Approximation (ASA) is reported. Variation of Eg with pressure reveals the direct and pseudodirect natures of these compounds. CdSiP2 shows a pseudo direct and CdGeP2, CdSnP2, CdSiAs2, CdGeAs2 and CdSnAs2 show direct band gap natures. Semiconductor to metal transition at high pressures is observed. Metallisation volumes (V/Vo) m and pressures (Pm), bulk modulus (Bo) and its pressure derivative (Bo 1) are reported. Correlation connecting Bo and the unit cell volume (Vo) is established.
Improved Carbon Counter Electrodes for Dye Sensitized Solar Cells
Authors: Lee Hyeon Seok , Lee Heon Yong , Ahn S.Y. , Kim K.H. , Kwon J.Y.
Published: March 2009

We fabricated improved carbon counter electrodes to improve conversion efficiency of dye
sensitized solar cells (DSSCs). Unlike conventional carbon counter electrodes, we added small
quantity of TiO2 nano powder and used chemical sintering methodology developed by Park’s group
to make surface morphology of the electrodes to change. Through these methods, we could observe
change of surface morphology of carbon electrodes and influences on short circuit current density
(JSC) and conversion efficiency.
DFB Waveguide All-Optical Switching Devices Employing Pump-Induced Refractive Index Change in GaInAsP
Authors: Mizumoto Tetsuya , Akano Yoichi , Tamura Kazuhiko , Yoshimura Masaki
Published: March 2009

A pump-induced refractive index change was measured in a passive GaInAsP waveguide
together with its temporal response. Also, the temporal response of distributed feedback (DFB)
waveguide transmittance modulated by the pump-induced index change was experimentally
investigated for an application to all-optical switching devices.
A Comparison of the Structural Quality of High-In Content InGaAsN Films Grown on InGaAs Pseudosubstrate and on GaAs Substrate
Authors: Sanorpim S. , Kongjaeng P. , Katayama R. , Onabe Kentaro
Published: March 2009

The use of an InGaAs buffer layer was applied to the growth of thick InxGa1-xAs1-yNy layers
with higher In contents (x > 30%). In order to obtain the lattice-matched InGaAsN layer having the
bandgap of 1.0 eV, the In0.2Ga0.8As was chosen. In this work, the In0.3Ga0.7As0.98N0.02 layers were
successfully grown on closely lattice-matched In0.2Ga0.8As buffer layers (InGaAsN/InGaAs).
Structural quality of such layers is discussed in comparison with those of the In0.3Ga0.7As0.98N0.02
layers grown directly on the GaAs substrate (InGaAsN/GaAs). Based on the results of transmission
electron microscopy, the misfit dislocations (MDs), which are located near the InGaAsN/GaAs
heteroepitaxial interface, are visible by their strain contrast. On the other hand, no generation of the
MDs is evidenced in the InGaAsN layer grown on the In0.2Ga0.8As pseudosubstrate. Our results
demonstrate that a reduction of misfit strain though the use of the pseudosubstrate made possible the
growth of high In-content InGaAsN layers with higher crystal quality to extend the wavelength of
InGaAsN material.
Annihilation of Threading Dislocations in Regrown GaN on Electrochemically Etched Nanoporous GaN Template with Optimization of Buffer Layer Growth
Authors: Soh C.B. , Hartono H. , Chow S.Y. , Chua Soo Jin
Published: March 2009

Nanoporous GaN template has been fabricated by electrochemical etching to give hexagonal pits with nano-scale pores of size 20-50 nm in the underlying grains. Electrochemical etching at The effect of GaN buffer layer grown at various temperatures from 650°C to 1015°C on these as-fabricated nano-pores templates are investigated by transmission electron microscopy. The buffer layer grown at the optimized temperature of 850°C partially fill up the pores and voids with annihilation of threading dislocations, serving as an excellent template for high-quality GaN growth. This phenomenon is, however not observed for the samples grown with other temperature buffer layers. The PL spectrum for the regrowth GaN on nanoporous GaN template also shows an enhancement of PL intensity for GaN peak compared to as-grown GaN template, which is indicative of its higher crystal quality. This makes it as a suitable template for subsequent device fabrication.
Raman Scattering from GaAs Nanowires Grown by Molecular Beam Epitaxy
Authors: Begum N. , Bhatti A.S. , Piccin M. , Bais G. , Jabeen F. , Rubini S. , Martelli F. , Franciosi A.
Published: March 2009

Self-assembled nanowires have attracted much attention due to their potential applications in electronics and optoelectronics. A recent interest in Mn catalyzed GaAs nanowires are due to their potential use in spintronic devices at nanoscale. High densities of Au- and Mncatalyzed self-assembled GaAs nanowires (NWs) with diameter in the range of 20 to 200 nm and length of few microns were synthesized by molecular beam epitaxy (MBE) on different substrates at varied substrate temperatures. These nanowires were investigated by means of μ-Raman spectroscopy at room temperature. The Raman spectra from NWs show an energy downshift and a broadening of the LO and TO phonon lines that differ from those of epitaxial GaAs. We suggest that those downshift and broadening are due to the relaxation of the q=0 selection rule in the presence of structural defects in the nanowires. The results indicate that the use of Mn instead of Au as growth catalyst does not affect the structural quality of the nanowires drastically.
Optical Nanowires for Microwave Applications
Authors: Decoster Didier , Carette Michele , Lesecq Marie , Lauvernier D. , Zegaoui Malek , Bernard Dorothee , Vilcot Jean Pierre , Chazelas Jean
Published: March 2009

In this paper, we propose to take advantage of specific properties of nanophotonics to achieve microwave functions which are difficult to get with more conventional ways. With this goal, we developed new technologies to fabricate III-V nanowaveguides. Two ways were explored: the first one by deep etching of conventional epitaxies and the second one by embedding nanowires in polymer. We show in this paper some results on first devices mainly based on nanowires embedded in polymer.
Dependence of the Absorption Spectra of III-V Semiconductor Quantum Dots on the Size Distribution
Authors: Kumar Subindu , Biswas Dipankar , Das Tapas
Published: March 2009

In recent years there have been extensive studies on III-V semiconductor quantum dots (QDs). In this paper we have formulated the absorption spectra of a realistic QD system with dot size distribution described by a Gaussian function. The dots were approximated as cubic boxes having finite potentials at the boundaries. The effects of size non uniformity on the optical absorption spectra of a realistic QD system was analyzed and the results have been compared with ideal dots having infinite potentials at the boundaries.
Fabrication and Optical Properties of ZnO Quantum Dots
Authors: Zhang X.H. , Chua Soo Jin , Yong A.M. , Chow S.Y. , Yang H.Y. , Lau S.P. , Yu S.F. , Sun X.W.
Published: March 2009

Using a simple process of the deposition of ZnO thin films on SiOx/Si substrates and subsequent thermal annealing, we fabricated ZnO quantum dots embedded in silicon oxide matrix. The ZnO quantum dots were characterized using transmission electron microscopy and timeintegrated photoluminescence. The photoluminescence of the quantum dots show a blue-shift of 47 meV due to the quantum confinement effect.
Intense Photoluminescence and Photoluminescence Enhancement of Silicon Nanocrystals by Ultraviolet Irradiation
Authors: Huy P.T. , Duong P.H.
Published: March 2009

Photoluminescence (PL) from silicon nanocrystals deposited on top of silica-glass
template and from silicon nanocrystals in nc_Si/SiO2 multilayer films were studied as a function of
ultraviolet (UV) laser irradiation time in vacuum. Both the films exhibit intense visible PL at room
temperature under laser excitation. It was found that upon prolong irradiation time using a He-Cd
laser (325 nm) the PL intensity of the films was spectacularly enhanced. The process is reversible
and does not happen with excitation wavelength longer than 400 nm. Upon introducing air into the
measurement chamber, a rapid decrease of the PL intensity was recorded. This observation suggests
that the UV light may lead to modification of nonradiative recombination centers in the films and
thus improves the emission yield of silicon nanocrystals.
The Intrinsic Frictional Property of Carbon Nanotubes
Authors: Zhang Liang Chi , Mylvaganam Kausala , Xiao K.Q.
Published: March 2009

This paper aims to provide an understanding of the intrinsic frictional behaviour of CNTs
under contact sliding by eliminating the possible effects of CNT rolling and slipping. Two critical
steps towards the mechanism exploration were carried out: (1) the development of a new deposition
method for CNT film fabrication, which allows the manufacture of densely packed, highly
entangled CNT films to be firmly bonded on solid substrates for contact sliding testing; and (2) the
theoretical understanding of the frictional behaviour of CNTs using the molecular dynamics
analysis. The investigation clarified the controversial arguments in the literature and concluded that
CNT films can be used as a superior solid lubricant with an ultra-low coefficient of friction of
around 0.01.
Detonation Synthesis of TiO2 Nanoparticles in Gas Phase
Authors: Li X.J. , Ouyang Xin , Yan Hong Hao , Sun G.L. , Mo F.
Published: March 2009

In this paper, TiO2 nanopowders are produced by gas-phase detonation method. The
powders are analyzed by X-ray diffraction (XRD), transmission electron microscopy (TEM) and
specific surface area determination. The results indicate that the powders are mixed crystal of rutile
and anatase, and have good dispersibility and high specific surface area. Also, the particle sizes of
powders are between 40 to 200 nm which are spheroid and cube. The measurement data of
detonation pressures shows that the reaction took place under a deflagration to detonation transition
(DDT).
Evaluation of Dentinal Viscoelastic Properties Based on its Microstructural Characters
Authors: Wang Xin , Zhang Yi Xia , Cui Yu Hong
Published: March 2009

On the basis of the characters of dentinal microstructures, a new Three-Parameter-Solid
viscoelastic mechanics model which can predict strain creep, stress relaxation and instant elasticity
with anisotropic constitutive relation for the human dentin is developed in this paper. The porous
protein-mineral model is adopted to obtain the independent dentinal viscoelastic moduli based on
its microstructural characters. The influencing mechanisms and the viscoelastic properties of the
microstructural dentin are also evaluated by the Three-Parameter-Solid viscoelastic model. The
viscoelastic predictive results obtained from the Three-Parameter-Solid viscoelastic model agree
well with those from the experimental investigation in both wet and dry situations.
A Multiscale Deformation Analysis for Mono-Crystalline Copper under Dynamic Uniaxial Tension
Authors: Gu Yuan Tong , Yarlagadda Prasad K.D.V.
Published: March 2009

This paper presents a concurrent multiscale study for the deformation mechanism of monocrystalline
copper under dynamic uniaxial tension. The multiscale simulation is based on the coupled
meshless and molecular dynamic (MD) method. Using it, the size of computational model can be
extended to a large dimension (in micrometer) with an atomistic resolution. The pure MD simulation
is difficult to reach this microscopic dimension because the number of atoms will be too large. In this
study, it has been revealed that the deformation behavior and mechanism of the copper is sensitive to
its size, geometry, and loading strain rate. In addition, the Young’s modulus is found to be independent
of the cross-sectional size and the strain rate range considered in this study. On the other hand, the
yield stress decreases with specimen length and increases with the loading strain rate.
The Design of Functional Gradient Materials with Inverse Homogenization Method
Authors: Zhou Shi Wei , Li Qing
Published: March 2009

This study systemically presents an inverse homogenization method in the design of
functional gradient materials, which gained substantial attention recently due to their layer-by-layer
defined physical properties. Each layer of these materials is unilaterally constructed by periodically
extended microstructural elements (namely base cells), whose effective properties can be decided
by the homogenization theory in accordance with the material distribution within the base cell. The
design objective is to minimize the summation of the least squares of the difference between
corresponded entries in target and effective elasticity tensors. The method of moving asymptote
drives the minimization of this positive objective function, which forces the effective values
approach to the targets as closely as possible. The sensitivity of the effective elasticity tensors with
respect to the design variables is derived from the adjoint variable method and it guides the
minimization algorithm efficiently. To guarantee the connectivity between adjacent layers,
non-design domains occupied by solid materials acting as connective bars are fixed in the design of
base cells. Furthermore, nonlinear diffusion technique is introduced to avoid checkerboard patterns
and blur boundaries in the microstructures. A series of two-dimensional examples targeted for the
elasticity tensors with same extreme Poisson ratios but different densities in each layer are
illustrated to highlight the computational material design procedure.
A Study on the Uniaxial Tension of FCC Metals at Nano Level Using MD
Authors: Mortazavi Bohayra , Khatibi Akbar Afaghi
Published: March 2009

Molecular Dynamics (MD) are now having orthodox means for simulation of matter in
nano-scale. It can be regarded as an accurate alternative for experimental work in nano-science. In
this paper, Molecular Dynamics simulation of uniaxial tension of some face centered cubic (FCC)
metals (namely Au, Ag, Cu and Ni) at nano-level have been carried out. Sutton-Chen potential
functions and velocity Verlet formulation of Noise-Hoover dynamic as well as periodic boundary
conditions were applied. MD simulations at different loading rates and temperatures were
conducted, and it was concluded that by increasing the temperature, maximum engineering stress
decreases while engineering strain at failure is increasing. On the other hand, by increasing the
loading rate both maximum engineering stress and strain at failure are increasing.
A Study on the Nanoindentation Behaviour of Single Crystal Silicon Using Hybrid MD-FE Method
Authors: Khatibi Akbar Afaghi , Mortazavi Bohayra
Published: March 2009

Developing new techniques for the prediction of materials behaviors in nano-scales has
been an attractive and challenging area for many researches. Molecular Dynamics (MD) is the
popular method that is usually used to simulate the behavior of nano-scale material. Considering
high computational costs of MD, however, has made this technique inapplicable as well as
inflexible in various situations. To overcome these difficulties, alternative procedures are thought.
Considering its capabilities, Finite Element Analysis (FEA) seems to be the most appropriate
substitute for MD simulations in most cases. But since the material properties in nano, micro, and
macro scales are different, therefore to use FEA methods in nano-scale modeling one must use
material properties appropriate to that scale. To this end, a previously developed Hybrid Molecular
Dynamics-Finite Element (HMDFE) approach was used to investigate the nanoindentation behavior
of single crystal silicon with Berkovich indenter. In this study, a FEA model was developed based
on the material properties extracted from molecular dynamics simulation of uniaxial tension test on
single crystal Silicon. Eventually, by comparison of FEA results with experimental data, the validity
of this new technique for the prediction of nanoindentation behavior of Silicon was concluded.
Solidification Microstructure Modelling Using Cellular Automaton Method
Authors: Wang H. , Li Q.
Published: March 2009

A model based on the cellular automaton (CA) technique for the simulation of
solidification microstructure has been developed. An improved solid fraction calculating method is
used, in which the solid fraction of the interface unit is calculated by temperature compensation
method combined with local equilibrium phase diagram. And then, a quadratic equation of solid
fraction can be calculated according to the local temperature, solute concentration and curvature.
The method avoids the assumption of the position and shape of solid/liquid interface. By using this
model on A356 aluminium alloy, a dendrite growth process is simulated. The model can predict the
final microstructure both grain size and grain morphology. It also predicts the Si concentration
distribution in both solid and liquid phases.
The Role of Al2O3 Buffer Layer in the Growth of Aligned CNTs
Authors: Lai M.K. , Mohamed Norani Muti , Begam K.M.
Published: March 2009

Carbon nanotube (CNT) can be thought of as a hexagonal network of carbon atoms that
has been rolled up to make a seamless cylinder. If they are consisting of one layer, they are termed
singled-walled CNTs (SWNTs) while if there are multiple walls, they are called multi-walled CNTs
(MWNTs). For most functional devices application, an aligned arrangement of CNTs is desired.
Aligned multiwalled carbon nanotubes (MWNTs) have been successfully grown by the inclusion of
a buffer layer of oxidized Al. An Al2O3 layer has been proven to be an important contributing factor
towards obtaining good quality aligned CNTs. In this work, Al is deposited onto the Si wafer using
electron beam evaporation and later oxidized by heating in air. A thin layer of iron catalyst is then
deposited on top of the oxidized Al layer and annealed at 400oC. The result shows an improvement
in the intensity of the graphitization peak (G-band) in the Raman spectra and aligned MWNTs is
observed in these samples compared to the ones that have undergone the same process parameter
except the Al2O3 layer.
Improved Fabrication of PMMA/Ag Core-Shell Nanostructures with Two Steps
Authors: Chen Zhi Hua , Wu Zheng , Bao Jian Jun , Lu Gao Qing Max , Zhang Qi Qing , Wang Lian Zhou , Zhu Xian Fang
Published: March 2009

An improved technique to fabricate PMMA/Ag core-shell nanocomposite via a two-step
procedure is reported. The procedure includes an improved particle surface treatment and an
improved, subsequent Ag reduction reaction strategy. Well-dispersed PMMA/Ag core-shell
nanoparticles with uniform particle size distribution were successfully fabricated using this
improved technique. Different functional group treatment on the PMMA particle surface led to an
electronically graded transition from the covalent bond of PMMA core to the metallic bond of silver
shell. The improved fabrication technique thus allows a highly tailorable size of PMMA core and
controllable thickness of Ag shell, which is crucial to producing a tunable plasmon resonance signal
to different bio-/chem-environments.
Simulation on Optical Properties of Gold and Silver Coated Nano Coreshell
Authors: Chen Xin Yi , Li Qiang , Wu Zheng , Zhu Xian Fang
Published: March 2009

Fabrication, optical property of nano coreshells and their potential applications in
chemical and biological sensors have attracted much research interest. In this paper, we simulated
the effect of size, structure, and dielectric properties as well embedding medium on the optical
properties of gold or silver coated coreshell nanoparticle and the corresponding effects both of
phase-retardation and of electron interface scattering as well as the nansize effect were discussed.
Intriguing transition of the optical properties was simulated when a two-phase core-shell
nanoparticle changes gradually into the single phase nanoparticle. We also obtained a good
correlation of the simulation to the experimental results. Thus, the simulation has many implications
and can guide further core-shell nanostructure fabrication with optimization of its optical properties.
Bovine Serum Albumin Adhesion Force Measurements Using an Atomic Force Microscopy
Authors: Lai Chun Chih , Bell John M. , Motta Nunzio
Published: March 2009

A new, direct method has been developed to measure the adhesion forces of bovine
serum albumin (BSA) on surfaces by using Atomic Force Microscopy (AFM) in liquid environment.
We were able to measure interactions between proteins and substrate surface in PBS solution
directly without any modification to the substrate or the AFM tip. Two different surfaces have been
used in the experiments: mica (hydrophilic surface) and polystyrene (hydrophobic surface). The
results show that a polystyrene surface is more adhesive to BSA than a mica surface. This is
consistent with previous research, which assessed that hydrophobic surfaces enhance protein
adhesion but hydrophilic surfaces do not, demonstrating the effectiveness of the technique.
Analytic Prediction of Structural Stress-Strain Relations of Microstructured Metal
Authors: Yang Chun Hui , Sabirov Ilchat , Mullins Jonathan , Hodgson Peter
Published: March 2009

Nanostructured and ultra-fine grained metals have higher strength but extremely limited
ductility compared to coarse grained metals. However, their ductility can be greatly improved by
introducing a specific range of grain sizes in the microstructures. In the paper, multiscale unit cell
approach (UCA) is developed and applied to predict the averaged stress-strain relations of the multiscale
microstructure metals. The unit cell models are three-phase structured at different scale
lengths of 100 nm, 1 μm and 10 μm with different volume fractions and periodic boundary
conditions. The contributions of multi-scale microstructures to the macroscopic structural properties
of metals are also studied using a analytic approach—two-step mean-field method (TSMF), where
three microstructural parameters are introduced and thus mechanical properties such as strength and
ductility are presented as a function of these parameters. For verification of these proposed
numerical and theoretical algorithms, the structural properties of the pure nickel with three-grain
microstructures are studied and the results from FEA and the proposed theory have good agreement.
Stress Field Near a Nanosized Spheroidal Cavity under Bi-Axial Tension Perpendicular to the Revolution Axis
Authors: Ou Zhi Ying , Wang Gang Feng , Wang Tie Jun
Published: March 2009

The elastic field around a nanosized spheroidal cavity is derived on the basis of surface
elasticity theory. The effects of surface energy, shape and size of the cavity are discussed. It is seen
that the stress field near the nanosized cavity depends on the shape and the size of the cavity as well as
the properties of the surface. These new characteristics are different from those predicted by the
classical elasticity and may illuminate some new mechanisms at nanoscale.
The Experimental Study of Mechanics-Heating Effect to Sand-Therapy in the Uyghur Medicine
Authors: Mahemuti Dilinaer , Maitirouzi Julaiti , Kong Chun Yuan
Published: March 2009

Purpose: Experiment research and theory analysis to the heat transmission and mechanics
property about organism tissue. Method: Heat transmission and the dynamic change of temperature
should be survey in the course of sand-therapy, then compare it with simulative result; workpieces
were made, buried in different temperature and buried in the sand for 30 minutes, to test its
biomechanics property and compare to group without buried in sand. Result: (1) The initial
temperature field of the sand was not well mixed. (2) The test spot of the electric thermocouple was
inaccuracies when test the temperature. (3) Every parameter of the mathematical model is taken from
the bibliography, it may not fix actually to the parameter of the patient. (4) In the model, we did not
consider several factors such as sweat transit in the sand. (5) There was some differentiation between
parameter of the experiment such as temperature, humidity, wind speed in the natural environment.
The very common disease such as rheumarthritis, lumbag and cervical vertebra degeneration
brings huge pain to the patients. Medical treatments which are often used by the medical institutions
can not obtain efficient results. But sand-therapy, a great part of Uyghur medicine, has obviously
effects to these diseases [1, 2].
The sand-therapy provides positive effects in such diseases taking place in the hot sand in Turfan in
Xingjiang where special climate, special environment and strong sunshine have. But this treatment is
greatly effected by environment and climate and only can take place between July to September.
Nowadays, there is little research about the sand-therapy both domestically and internationally,
among them concentrated on influence of medical parameter of the human body and exploration to
cure the disease mechanism. The sand-therapy is effected by calorific, magnetic and mechanics, etc.,
involving a lot of disciplines. Some scholars have carried on qualitative analysis to sand-therapy and
other heat-therapy in terms of biomechanics [3,4], others have carried on thermal effects by experiment
manner and analysis [5,6], still others analysis sand-therapy deeply by animal experiment[7,8,9].
This paper has carried on experiment and theoretical analysis to part of hot-strength effect of
Uyghur medicine[10,11] and mechanics of bone tissue by temperature of sand-therapy[12,13], based on
thermal-physical model of thermal transmitting among human body and sand and numerical
simulation of temperature change in human body and sand in the course of sand-therapy[14].
In Vitro Study on Branch Flows with a Cerebral Aneurysm
Authors: Osao Atsushi , Wahap Gulbahar , Takakura Yoko , Arai Norio , Konishi Yoshifumi , Fukasaku Kazuaki , Kikuchi Nobumasa
Published: March 2009

The purpose of this study is to accumulate data to predict the ruptures of aneurysms on the
bifurcation of the middle cerebral arteries at the base of the brain. Particular stress is laid on
understanding the elemental nature of branch flows with/without an aneurysm. Therefore, “flow
patterns” and “wall shear stress”, which are important factors for the causes of ruptures, are
investigated by the three-dimensional experiments in vitro and the two-dimensional numerical
simulations with simplified models. In the branch arteries without an aneurysm, there is a possibility
of growing aneurysms at the location slightly away from a stagnation point. If an aneurysm forms into
a centrosymmetric shape for the inlet axis, it is considered that they tend to grow further in a
symmetrical plane. From the viewpoint of the risk of ruptures, recirculation flows become
problematic with the lower Reynolds number, while the influence of wall shear stress becomes larger
with the higher Reynolds number.
Numerical Simulation of Sand Cover Phenomenon on the Desert Highway Using SPH Method
Authors: Jin A Fang , Gheni Mamtimin , Yang Zhi Chun
Published: March 2009

The sand cover is the main form of sand disaster for the desert highway induced by the
wind-blown-sand flow over the highway. As a kind of two-phase flow of air and sand, it is necessary
to study the physical principle and the mode of its migration. The Smoothing Particle Hydrodynamic
(SPH) method is adopted to simulate the movement of the wind-blown-sand flow. A two dimensional
model of the sand cover for desert highway with embankment is built with SPH method. The
numerical simulations are carried for different embankment height to investigate the sand cover
distribution on the road surface of desert highway. The results show that the migration of sand with
wind blow can be well simulated using SPH method and the embankment height is an important
factor for controlling sand cover disaster of desert highway.
Flow and Dynamic Characteristics between FPD and Contact-Free Handler Nozzles
Authors: Chang Yoon Suk , Chang Hyuk Soo , Choi Jae Boong , Kim Young Jin , Chun Poong Hwan , Kong Jae Youn
Published: March 2009

The purpose of this paper is to investigate fluid characteristics and flat panel display
behaviours on contact-free flat panel display handler nozzles. Since air force distributions streaming
bottom surface of a flat panel display highly dependent on operating as well as design conditions and
configuration of contact-free handler nozzle, influences of various parameters such as flow rate,
supply air pressure, floating height are examined through a series of computational fluid dynamics
analyses. Moreover, dynamic finite element analyses of the flat panel display are carried out to assure
that an oscillation effect caused by disturbances is not significant. Key findings from the both
computational fluid dynamics and structural integrity analysis results are presented and discussed,
which can be figured out an optimized operating condition of contact-free handler nozzles.
Fatigue Analysis for CNG Storage Gas Pressure Vessel Based on ANSYS
Authors: Zhang Ya Xin , Du Jun Ge , Shi Chuan Mei
Published: March 2009

The fatigue destruction is one way of expiration of pressure vessels, In order to avoid the
accident occurring, it is extremely important to carry on the fatigue analysis to the pressure vessels.
First, this article introduces the definition of fatigue destruction, the primary factors of affecting the
fatigue expiration, and the advantages the analysis principle when the ANSYS finite element is
applied to fatigue analysis; Then, this article carries on the stress analysis based on ANSYS software
to the CNG storage gas pressure vessel, produces the stress distributed cloud chart, and gets the node
number where is the maximum stress; Finally, This article carries on the fatigue analysis based on
stress analysis result, the fatigue analysis demonstrates the CNG pressure vessel is effective in the
establishment service life, Its fatigue accumulative damage coefficient is smaller than 1,Which
explain it can satisfy the fatigue strength request.
One Method of Fluid-Solid Coupled Interaction Simulation
Authors: Lin Yong Wen , You Xiao Chuan , Zhuang Zhuo
Published: March 2009

In this article we presented a method of Fluid-Solid coupled simulation via FLUNET and
ABAQUS in problems such as Aero/Hydro-Elasticity problems. UDF (user define function) script
file in the Fluent software was utilized as the ‘Connecting File’ between FLUENT and ABAQUS for
Aero-Elastic computations. Firstly, the fluid field was computed by Navier-Stokes Equation and the
structure movement was directly integrated by the dynamics Equation, respectively. Then, the
‘Connecting File’ exchanged the computed data through the fluid and structure’s interface. The next
analysis step continued. Analysis of the computed results showed that this coupling method designed
for aero-elastic system was feasible and can be also used for other Fluid-Structure Coupling
problems.
Kinematical Analysis of Slope Stability Using Triangular Slices Method
Authors: Zhu Yong Jian
Published: March 2009

Conventional stability analysis of slopes is established on vertical slices with a linear
Mohr-Coulomb (MC) failure criterion. In this paper, the soil mass of slopes is assumed to follow
linear and nonlinear failure criteria. A new procedure is proposed for determination of stability factors
of slopes using triangular slices within the framework of limit analysis method under plane strain
condition. The potential sliding mass is divided into a series of triangular slices, rather than vertical
slices as usual. Using a generalized tangential technique, the nonlinear failure criterion is simplified
as a set of straight lines according to the linear MC failure criterion. The straight line is tangential to
the curve of the nonlinear failure criterion. With a linear MC failure criterion, solutions to stability
factors are determined by limit analysis theory, which agree well with the published solutions. With
triangular slices method, a study is carried out to investigate the influences of nonlinear parameter on
stability of the soil slope.
Study on Dynamic Characteristics of the 3-Dimensional Parachute-Like Body with Consideration of Virtual Mass
Authors: Houzu Hiroyuki , Arai Norio , Takakura Yoko
Published: March 2009

In this article the freely oscillating 3-dimensional parachute-like body sustained at one
point is focused. To catch the real phenomenon by numerical simulation, the virtual mass is
considered in this study. The flow field is calculated by using the MAC method applying third order
upwind scheme for the convex term, and applying central difference for the other terms. ALE method
is applied in order to consider a moving boundary problem. The virtual mass is calculated by using a
potential flow at every time step. As a result, it has been made clear that the virtual mass has influence
on the freely oscillating rigid concave body motion. And the flow structure around the freely
oscillating parachute-like body is made clear.