bluuebunny/crossref_metadata_2025 huggingface dataset:
Virtual Simulation Applications in Manufacturing Process of High-Speed Trains
Authors: Wang Wei , Wu Bo , Hu You Min , Li Ming Yu , Liu Qing Yun , He Chun
Published: December 2012

Process of high-speed trains manufacturing is a complicated task requiring strong professional background and practical experience. However, in China, the production mode is staying at the step that explore in actual production constantly, continue to discover and solve problems, low productivity but high manufacturing costs. In order to try to solve above problems, applications of virtual simulation in manufacturing process of high-speed trains is applied for the goals. According to the workshop’s two-dimensional (2D) designing, a digital factory is constructed using simulation software based on production manufacturing process of high-speed trains. Then production model is disaggregated analysis. When virtual simulation environment is accomplished, an assembly process turns to be run. An example of plug-door assembly process is presented to illustrate the effect and feasibility of the application of virtual simulation.
Modeling, Analysis and Rapid Manufacturing of Customised Tibia Bone Scaffold
Authors: Rashia Begum S. , Arumaikkannu G. , Ashiq B.
Published: December 2012

Bio Additive Manufacturing (BAM), an interdisciplinary field of Rapid Manufacturing (RM) and Tissue Engineering (TE), aims to manufacture the customised bone scaffold for bone replacement. The hydrodynamic stress induced in cells will depend not only on the culture medium flow rate, but also on the scaffold three- dimensional micro-architecture. This paper presents, the patient’s CT scan data in DICOM format is exported into MIMICS software to convert the 2D images into 3D IGES data. The customised bone scaffolds with pore size of 0.7mm and distance between adjacent edges of pores from 0.6mm to 1mm are created in modeling software (SOLIDWORKS 2011) and porosities of five customised bone scaffolds are determined. The above customised bone scaffolds are analysed in CFD software (ANSYS CFX) for the fluid density 1000 kg/m3 and viscosity 8.2 ×10-4 kgm-1 s-1. The estimated Wall Shear Stress (WSS) at fluid velocities from 0.2mm/s to 1mm/s lies in the range of 7.05 x 10 -4 Pa to 43.4 x 10 -4 Pa., and these scaffolds are fabricated in Rapid Prototyping (RP) technique.
Optimization of Cellular Manufacturing Systems Using Genetic Algorithm: A Review
Authors: Arora Pawan Kumar , Haleem Abid , Singh M.K. , Kumar Harish
Published: December 2012

Though Cellular Manufacturing System (CMS) has been an active area of research for past few decades, but, still it has not received the requisite attention so far. Despite of a useful manufacturing strategy based on the group technology (GT), it is yet to be established on a larger scale. The CMS allows the grouping of the facilities on the basis of similarity in manufacturing processes and design considerations of the products to be manufactured. A lot of researchers have worked for various developments related to various issues of CMS, but for last decades, the modern optimization tools like genetic algorithm (GA), artificial neural networks (ANN) have changed the scenario and research work has been accelerated related to CMS. The present paper is an attempt to discuss the GA related research work by various researchers for CMS. Research work along with their impact of past researchers has been discussed and reported here.
An Analytical Model to Determine Fundamental Frequency of Free Vibration of Perforated Plate by Using Greatest Integer Functions to Express Non Homogeneity
Authors: Mali Kiran D. , Singru Pravin M.
Published: December 2012

This paper aims at determining the fundamental frequency of square perforated plate with square perforation pattern of square holes. Rayleigh’s method is used for the solution of this problem. Non homogeneity in Young’s modulus and density at the perforation is expressed by using greatest integer function i.e. floor function. Boundary condition considered is clamped on all edges. Perforated plate is considered as plate with uniformly distributed mass and holes are considered as non homogeneous patches. The deflected surface of the plate is approximated by a function which satisfies the boundary conditions. Finite Element Method (FEM) modal analysis is carried out to validate the results of the proposed approach.
Modeling of Fluid Flow and Heat Transfer in Laser Welding with a Moving Heat Source
Authors: Karimipour Arash , Abedini Ehsan , Ajam Hossein , Sarvari S.M.H.
Published: December 2012

In the present study, a numerical simulation is performed for the detailed prediction of heat transfer, phase change and fluid flow in welding process with moving heat source. This process may be considered steady with respect to the reference frame attached to the heat source for a long metal block. The problem is formulated by considering the three-dimensional equations of continuity, momentum and energy based on enthalpy model. The equations is solved using a fully implicit, control-volume-based computational method for fixed grids. The calculation domain including solid and liquid phases is solved together as a continuous region. Solid phase velocity is corrected using suitable source terms in the momentum equations. Phase change is considered based on the latent heat of evolution as a source term in the energy equation.The effects of thermal buoyancy and Marangoni flow on melting process are analyzed.
Study of Smart Substation Hardware-in-Loop Simulation Training System Structure
Authors: Xu Zhi Heng , Han Jia Bing , Wang Qing Ping , Zhang Tian Yi , Wang Wu Guan
Published: December 2012

This paper introduces the smart substation hardware-in-loop simulation training system structure based on the analysis of the smart substation simulation training requirements. The training system scheme has been designed according to the different training requirements to support training of staffs in smart substation for operating and maintenance in all possible ways. Combining with the practical solutions, the application of the training system will be introduced. This design scheme will take important effect in the development of smart substation and its operating and maintenance training.
Simulation of Biomass Gasification with Oxygen/Air as Gasifying Agent by ASPEN Plus
Authors: Raibhole N. Vaijanath , Sapali S.N.
Published: December 2012

In today`s scenario of depleting conventional fossil fuels biomass provides an alternate source of energy. Gasification is a chemical process that converts carbonaceous materials like biomass into useful convenient gaseous fuels or chemical feedstock. The gasification process uses an agent air or oxygen, hydrogen or steam to convert carbonaceous materials into gaseous products. As air gasification produces poor quality syngas, oxygen is used as gasifying agent for biomass gasification. Biomass gasification with oxygen as gasifying agent has great potential in applications like IGCC (Integrated Gasification combined cycle), Chemical Production and Fischer-tropsch products. In this paper the simulation model of a biomass gasifier for different biomass like charcoal, rice husk and wood pellets with oxygen and air as a gasifying agent is developed using ASPEN Plus. The model predicts syngas composition, heating value, temperature, pressure and quantity of gas produced. These results are obtained for various feedstocks like wood pallets, rice husk, and Indian coal on the basis of proximate and ultimate analysis.
A Performance Study of Real Coded Genetic Algorithm on Gear Design Optimization
Authors: Padmanabhan Sambandam , Chandrasekaran M. , Asokan P. , Raman V. Srinivasa
Published: December 2012

he major problem that deals with practical engineers is the mechanical design and creativeness. Mechanical design can be defined as the choice of materials and geometry, which satisfies, specified functional requirements of that design. A good design has to minimize the most significant adverse result and to maximize the most significant desirable result. An evolutionary algorithm offers efficient ways of creating and comparing a new design solution in order to complete an optimal design. In this paper a type of Genetic Algorithm, Real Coded Genetic Algorithm (RCGA) is used to optimize the design of helical gear pair and a combined objective function with maximizes the Power, Efficiency and minimizes the overall Weight, Centre distance. The performance of the proposed algorithms is validated through LINGO Software and the comparative results are analyzed.
Wire Bond Shear Test Simulation on Sharp Groove Surface Bond Pad
Authors: Sauli Z. , Retnasamy V. , Taniselass S. , Shapri A.H.M. , Vairavan R.
Published: December 2012

Wire bonding process is first level interconnection technology used in the semiconductor packaging industry. The wire bond shear tests are used in the industry to examine the bond strength and reliability of the bonded wires. Hence, in this study thesimulation on wire bond shear test is performed on a sharp groove surface bond pad. ANSYS ver 11 was used to perform the simulation. The stress response of the bonded wires are investigated.The effects of three wire materials gold(Au), aluminum(Al) and copper(Cu) on the stress response during shear test were examined. The simulation results showed that copper wire bond induces highest stress and gold wire exhibits the least stress response.
Flow Stress Determination of Steel Tube for Hydroformability Evaluation
Authors: Boonpuek P. , Jirathearanat S. , Depaiwa N.
Published: December 2012

This study aims to determine flow stress of a steel tube by using hydraulic bulge test. A new proposed analytical model for analyzing bulge shapes of hydroformed tubes is postulated. Bulge test apparatus designed using FEA simulation of hydroforming and STKM 11A steel tubes are used in the hydraulic bulge test. Bulge heights and internal pressures are measured during bulge testing. Tube thicknesses at vertex of a bulge shape are measured by a dial caliper gauge. Bulge curvatures and contact points are measured by taking digital photos of bulge shapes combined with measurement methods in CAD software. Effective stress - strain relationships are obtained from the newly developed analytical model using those measured values. Flow stress curves obtained from the effective stress – strain relationships are compared with those by other researchers and tensile test. Finite element analysis methods are used to conduct simulation of tube hydroforming using the flow stress curves. Predicted internal pressures versus bulge heights and tube thicknesses are compared with experimental results. Verification of the developed analytical model is presented. The flow stress at neck point of formed tube is determined.
Effect of Process Parameters on Microstructure and Mechanical Properties on Severe Plastic Deformation Process of Aa7075-T6 Aluminum Alloy
Authors: Iqbal U. Mohammed , Kumar V.S. Senthil
Published: December 2012

Severe plastic deformation is one of the emerging and promising techniques applied to bulk materials to produce fine grain structure with attractive properties. This study aims to investigate the effect of extrusion parameters like extrusion temperature, number of passes on the equal channel angular pressing and twist extrusion forming behavior of AA7075-T6 Aluminum alloy by hot extrusion process. AA7075-T6 samples of 70x28x18 mm cross sections extruded by equal channel angular pressing and twist extrusion process was subjected to microstructure analysis, hardness and tensile tests in order to determine their mechanical properties. As a result of the experiments, it was determined that twist extrusion leads to more grain refinement at high temperatures with more number of passes compared to equal channel angular pressing. SEM micrographs show that there is severe orientation of the grains facilitated by the extrusion process which enhances the strength. The dense banding of the grains had effected in marginal hardness enhancement in the matrix of the specimens processed by twist extrusion and equal channel angular extrusion process.
Thermoelectric Module of P-Type Ca-Co-O/N-Type ZnO Thin Films
Authors: Somkhunthot Weerasak , Pimpabute Nuwat , Seetawan Tosawat
Published: December 2012

Thin films thermoelectric module fabricated by pulsed-dc magnetron sputtering system using Ca3Co4O9 (p-type) and ZnO (n-type) targets of 60 mm diameter and 2.5 mm thickness, which were made from powder precursor, and obtained by solid state reaction. Thin films of p-Ca-Co-O (Seebeck coefficient = 143.85 µV/K, electrical resistivity = 4.80 mΩm, power factor = 4.31 µW/m K2) and n-ZnO (Seebeck coefficient =229.24 µV/K, electrical resistivity = 5.93 mΩm, power factor = 8.86 µW/m K2) were used to make a thermoelectric module, which consist of four pairs of legs connected by copper electrodes (0.5 mm thickness, 3.0 mm width, and 3.0-8.0 mm length). Each leg is 3.0 mm width, 20.0 mm length, and 0.44 µm thickness on a glass substrate of 1.0 mm thickness in dimension 25.0x50.0 mm2. For preliminary test, a module was used to thermoelectric power generation. It was found that the open circuit voltage increased with increasing temperature difference from 3 mV at 5 K up to 20 mV at 78 K. The internal resistance of a module reached a value of 14.52 MΩ. This test indicated that a module can be generated the electrical power. Therefore, it can be used as an important platform for further thin films thermoelectric module research.
The Interaction of the Convective Flow with the Interface Evolution of the Particle Growing in the Undercooled Melt
Authors: Chen Ming Wen , Zuo Long Fei , Jiang Han , Lin Guo Biao , Zhang Hong , Wang Zi Dong
Published: December 2012

This paper investigates the interaction between the convective flow induced by the straining flow and the interface morphology of a particle growing in the convective undercooled melt. The resulting approximate solution of the particle shape shows that the convection makes the growing particle enhance its growth velocity and protrude near the surface where the flow is incoming, but decreases its growth near the surface where the flow is outgoing, and both the incoming flow and the anisotropic surface tension make the velocity of the particle have a superposition effect along the favorite crystalline direction. The convection makes the particles growing in the undercooled melt evolve into various shapes of the interface morphology which have high strength/weight ratio and specific surface fraction and then help to form the final material of excellent mechanical and physical properties.
Sintering of Hydroxyapatite-Bioglass Ceramics Composite from Submicrometer Powder
Authors: Chankachang Phanlob , Punyanitya Sittiporn , Raksujarit Anirut
Published: December 2012

The mechanical properties of hydroxyapatite ceramics was improved by adding 5 wt% of Ca-P-Na-based-glass to be as sintering aid and were made their powder to submicron sized. The powders are uniaxially compact and then sintering at 1300°C in air.Microstructure and mechanical properties of the ceramic composite products were investigated. It was found that the strength of hydroxyapatite composite was increased about 42% that of the sample which fabricated by micron sized HA composite powder having the same porosity and this values are in rang of values of the strength of the cortical human bone. Moreover, Young modulus values of 16.4 1.8 GPa matched well with the Young modulus values of human bone, so it will not cause interfacial stress between implant and bone leading to good fixation of the materials.
Nonlinear Optical Properties of Controlled Fabrication of Copper Nanowires by a Shadow Deposition
Authors: Locharoenrat Kitsakorn
Published: December 2012

The strongly geometrical shape, high aspect ratios, and nanoscale cross-section of nanowires is expected to affect optical properties through confinement effects. Herein we have investigated optical properties of Cu nanowires with studies of second harmonic generation (SHG) spectra. These optical properties of Cu nanowires will be one of the most important issues when considering the types of materials used in current applications and development of new applications.
A Comparison of the Effect of Hydroxyl Modified Carbon Nanotubes and Graphenes on the Electrical and Mechanical Properties of Their Polyurethane Composites
Authors: Swain Sarojini , Bhattacharya Subhendu , Sharma Ram Avatar , Chaudhari Lokesh
Published: December 2012

Hydroxyl modified multi-walled carbon nanotubes (OH-MWCNT)/ polyurethane (PU) and graphene nanosheets (GNS)/PU composites were prepared by dispersing the OH-MWCNT and GNS at different wt % in to the PU matrix. It was found that the electrical percolation threshold of the GNS/PU composite is much higher compared to that of OH-MWCNT/PU and also the electrical conductivity of the OH-MWCNT/PU composite is higher than the GNS/PU composite in the same level of filler content. This may be due to the two composites having different electrical conduction mechanisms: The OH-MWCNT/PU composite represents a three dimensional conduction system while, the GNS/PU composite represents a two dimensional conduction system. The improvement in the electrical conductivity with the incorporation of GNS as a filler in the composite is far lower than what theoretically expected. It is also observed that the tensile strength of the OH-MWCNT/PU composite is higher compared to the GNS/PU in the same level filler content.
Pressure Drop and Heat Transfer Characteristics of MWCNT/Heat Transfer Oil Nanofluid Flow inside Microfinned Helical Tubes with Constant Wall Temperature
Authors: Kazemi M.H. , Akhavan-Behabadi M.A. , Pakdaman M. Fakoor
Published: December 2012

Experiments are performed to investigate the single-phase flow heat transfer augmentation of MWCNT/HT-B oil in both smooth and microfinned helical tubes with constant wall temperature. The tests in laminar regime were carried out in helical tubes with three curvature ratios of 2R/d=25, 30 and 35. Flow Reynolds number varied from 170 to 1800 resulting in laminar flow regime. The effect of some parameters such as the nanoparticles concentration, the dimensionless curvature radius (2R/d) and the Reynolds number on heat transfer was investigated for the laminar flow regime. The weight fraction of nanoparticles in base fluid was less than 0.4%. within the applied range of Reynolds number; results indicated that for smooth helical tube the addition of nanoparticles to the base fluid enhanced heat transfer remarkably. However, compared to the smooth helical tube, the average heat transfer augmentation ratio due to nanoparticle addition for finned tube was small, about 17%. Also, by increasing the weight fraction of nanoparticles in microfinned helical tubes, no substantial changes were observed in the rate of heat transfer enhancement. For the pressure drop, the results show that the pressure drop of nanofluids was slightly higher than the base fluid and increase as the volume concentrations go up.
Growth Behaviour and Electrical Resistivity Relationship of Silver Nanoparticle Thin Film
Authors: Mandal Kankan Prosad , Oh Yong Taeg
Published: December 2012

Normal grain growth of silver thin film predominates above the critical transition temperature below which bimodal grain growth predominates. In this experiment silver Nano layers were prepared by spin coating on glass substrate and which were annealed at different temperature. The lowest attainable resistance was 1.23 Ohm/sq. The woulf plot of fcc silver suggests that during growth (111) family plane predominated on surface of every grain and that was true according to SEM figure. This is the reason for low resistivity of silver thin film. Not only on surface but also this stable (111) plane was present on grain boundary as singular interface. However, ADF Simulation has been done to construct 40 nm silver nano particle and to construct band structure of silver. The valance band and conduction band overlap shows the metallic characteristic property of silver.
Researches on Preparation of Photosan Loaded Magnetic Silica Anoparticles and their Anti-Tumor Effects in Photodynamic Therapy
Authors: Wen Yu , Deng Xiao Feng , Liu Liang Liang , Shi Shu Yun , Xiong Li
Published: December 2012

Photodynamic therapy (PDT) is an effective, noninvasive and nontoxic therapeutics for cancer and some other diseases. It is becoming a alternative of traditional therapeutics for cancers. But the efficacy of PDT was restricted by insufficient selectivity and low solubility. In this study, novel multifunctional silica-based magnetic nanoparticles were prepared as targeting drug delivery system to achieve higher specificity and better solubility. Haematoporphyrin derivative (photosan) was used as photosensitizer. Magnetite nanoparticles (Fe3O4) and photosan were incorporated in silica nanoparticles by microemulsion and sol-gel methods. The prepared nanoparticles were characterized by X-ray diffraction, and transmission electron microscopy. The nanoparticles possessed good biocompatibility and could cause remarkable photodynamic anti-tumor effects. These suggested that photosan-Fe3O4 nanoparticles had great potential as effective drug delivery system in targeting photodynamic therapy.
Preparation and Application of Supramolecular Assembled β-cyclodextrin/polyacrylonitrile Composite Nanofibers as a Highly Efficient Adsorbent for Dye Removal
Authors: Jadhav Arvind H. , Kim Hern
Published: December 2012

β-cyclodextrin (β-CD) incorporated polyacrylonitrile (PAN) composite nanofibers were successfully prepared by using electrospinning technique and used as a novel adsorbent for the elimination of dyes from aqueous solution. The formations of bead-free and uniform nanofibers were obtained using various compositions of homogeneous solution of β-CD and PAN in N,N-dimethylformamide (DMF). The morphology and structure of nanofibers were determined and characterized by SEM, XRD, TGA, and FTIR analysis. The adsorption performance of prepared nanofibers was examined by using methylene blue (MB) and methyl violet (MV) as adsorbate. Results showed that β-CD/PAN nanofibers were achieved equilibrium point within 2h with 96.21 % and 94.37 % adsorption of MV and MB, respectively at ambient condition. In addition, adsorption capacity of nanofibers was studied under different experimental conditions and their effects on adsorption capacity such as temperature, pH, and contact time. The regeneration of β-CD/PAN nanofibers were carried out using methanol and re used five times as an adsorbent, Results indicates that regenerated adsorbent was adsorb 89.0% and 85.22 % of MV and MB, respectively in 5th cycle.
Effect of the Compatibilizer on Clay Dispersion in Polypropylene/Clay Nanocomposites
Authors: Bagheri-Kazemabad Sedigheh , Khavandi Alireza , Fox Daniel , Chen Yan Hui , Zhang Hong Zhou , Chen Bi Qiong
Published: December 2012

Polypropylene (PP)/clay nanocomposites were prepared via a melt mixing technique. Two types of compatibilizers, namely poly (ethyleneco-octene) (EOC-g-MA) and polypropylene grafted maleic anhydride (PP-g-MA), were selected to facilitate the nanocomposite formation. X-ray diffraction and transmission electron microscopy in conjunction with rheological analysis were used for studying the dispersion state of clay layers in these nanocomposites. The results showed with the introduction of EOC-g-MA to PP/clay, clay was dispersed better than the presence of PP-g-MA.
Green Synthesis of Silver Nanoparticles Using a Vitamin C Rich Phyllanthus emblica Extract
Authors: Mookriang Sirirat , Jimtaisong Ampa , Saewan Nisakorn , Kittigowittana Krisada , Rachtanapun Pornchai , Pathawinthranond Verapon , Sarakornsri Thapanee
Published: December 2012

Silver nanoparticles were prepared by treating a solution of AgNO3 dissolved in deionized water with Emblica (Phyllanthus emblica) extract as reducing agent. The factors that affect the synthesis of silver nanoparticles (time, temperature and concentration of silver nitrate and reducing agent) were investigated. The high concentration of silver nitrate and reducing agent showed the higher in concentration of silver nanoparticles. The heating temperature help increase the yield of silver nanoparticles at shorter reaction time. Their structure, shape and size distribution were characterized by UV-vis spectrophotometer, SEM and TEM technique. The UV-vis spectrophotometer show peaks located of silver-Emblica nanoparticle at 430 nm and the particle size of silver-Emblica is 41.2 nm in average diameter determined by TEM.
Migration of Silicon from Nanocomposite Packaging Materials into Acidic Food Simulant
Authors: Farhoodi Mehdi , Mousavi Seyed Mohammad A. , Sotudeh Gharebagh Rahmat , Emam-Djomeh Zahra , Oromiehie Abdolrasul
Published: December 2012

PET/Clay nanocomposites were prepared by the melt blending of PET and 3% wt. closite20A nanoparticles. The stretch blow molding machine was used to produce bottles from neat PET and PET nanocomposite. Migration of silicon from PET nanocomposite bottles into acidic food simulnat was studied at two storage temperatures (25°C and 45°C) in different time intervals from 7 to 70 days. A specific surface of sheets (prepared from PET/clay nanocomposite) immersed in acidic food simulnat and two-sided migration of silicon investigated. Using XRD analysis and TEM micrographs displayed both intercalation and exfoliation morphology for PET/clay nanocomposites. Inductive coupled plasma (ICP) used to quantify the amount of Silicon migrated into acidic food simulnat. It was observed that the migration process is depended on the storage time and temperature as well as the morphology of nanocomposites.
Detection of Silver Nanoparticles Internalization into Petunia, Petunia hybrida, Isolated Protoplasts
Authors: Naderi Roohangiz , Rad Sarah Jafari , Yaraghi Aliakbar Saboor , Farhoodi Mehdi , Nemati Mina
Published: December 2012

The use of nanoparticles has spannded many divisions of biological fields including sensors, drug delivery and clinical diagnosis. These functions all based on the most important action in cells called Endocytosis. The study of endocytosis in higher order plants remained inactive for a long period of time. In this work we use Silver Nano Particles (S.N.Ps) as a endocytosic substances were incubated by isolated protoplast of petunia .Concurrently, with the study of internalization, their appear aggregation inter and intracellular were investigated by Transmissions Electron Microscopy (TEM). Results and observations showed that the S.N.Ps crossed the cell membrane and internalized in to the cells. It can be assumed that the particles with the organic functionality – PEG coated – were internalized by the petunia protoplasts.
Surface Modification of Silver Nanoparticles in Phase Change Materials for Building Energy Application
Authors: Wei Shah Kwok
Published: December 2012

In this report, we propose a direct silica-coating technique to enhance the stability of silver nanoparticles as a doping additive to enhance the thermal conductivity phase change materials (PCM). Our experimental results show that a thin layer of silica can protect silver nanoparticles and help retain its intrinsic metallic properties, when subjected to harsh corrosive environments found in PCM media. Furthermore, PCM materials can be effectively used to cool the ambient temperature of a building room by up to ~1.2 degree Celsius. Our preliminary results demonstrate a real opportunity in air-conditioning energy-savings for buildings using enhanced PCM.
Development of Poly(dimethylsiloxane)/BaTiO3 Nanocomposites as Dielectric Material
Authors: Nayak Suryakanta , Kumar Chaki Tapan , Khastgir Dipak
Published: December 2012

Polymer-ceramic nanocomposites with controlled dielectric properties are prepared using poly(dimethylsiloxane) elastomer as base matrix and barium titanate as filler. Barium titanate (BaTiO3) used in this study is prepared by solid state reaction at high temperature. The effect of BaTiO3 nanoparticles on electrical and mechanical properties are extensively studied and found that dielectric constant of nanocomposites increases significantly with the increase in BaTiO3 concentration where as volume resistivity decreases continuously. Different mechanical properties are also studied for all the composites in order to find the effect of filler concentration. Morphology of the prepared BaTiO3 was studied by field emission scanning electron microscope (FESEM).
Nano Mechanics and Modeling of Phase Transitions of Water
Authors: Venkatesh Vijayaraghavan , How Wong Chee
Published: December 2012

The water molecule, H2O is a very simple and most stable molecule. It displays a discrete but nevertheless exceptional property that has far-reaching consequences, one of them being that without it life would not exist. At ambient conditions, water remains in liquid form, becomes ice below freezing temperatures and turns into vapor form at high temperatures. In this paper, we use molecular dynamics (MD) simulation method to study the hydrodynamic properties of water molecule. The interactions that exist in the water molecule is described using the 3 site transferable inter-molecular potential model. The properties of water molecule that occur at nano level are studied and compared with those at the bulk.
Preparation, Characterization and Phototoxicity of Photosan-Loaded Hollow Silica Nanospheres for Photodynamic Therapy
Authors: Deng Xiao Feng , Wen Yu , Lin Liang Wu , Xiong Li , Miao Xiong Ying
Published: December 2012

In this study, Photosan (PS) was loaded onto hollow silica nanospheres using one-step wet chemical-based synthetic route method. Polydispersive index of the Photosan-loaded hollow Silica Nanospheres (PS-loaded NSs) is 0.121±0.01. The photobiological activity of the PS-loaded NSs was evaluated on human cholangiocarcinoma QBC939 cells. Cells were incubated with free PS or PS-loaded NSs for 2 h and then washed with phosphate-buffered saline. Culture medium was added to the wells containing the cells. Finally, the cells were exposed to red light (630 nm) with a light dose of 10J/cm2. The cellular viability was determined after 24 h of incubation. PS-loaded NSs and free PS eliminated about 96.4%±2.0% and 54.7%±1.9% of QBC939 cells, respectively. The phototoxicity was time dependent up to 2 h and concentration dependent at 1-7.5 mg/l. The cells viability decreased with the increase of the light dose in the range of 5-15 J/cm2. In conclusion, PS-loaded NSs are the release systems that promise photodynamic therapy use.
Design of Dye-Sensitized Solar Cell by Inserting Single-Walled Carbon Nanotubes
Authors: Yadipour Reza , Abbasian Karim , Afshar Bita Azemoodeh , Rostami Ali
Published: December 2012

In this paper, a solid-state dye sensitized solar cell (DSSC) based on carbon nanotubes by inserting N719 dye molecules has been designed for operating at 300oK and 330oK temperatures. The role of carbon nanotubes as hole and electron conducting agents and dye molecules as absorber of solar radiation and hole-electron pair producing agents has been discussed. After inserting N719 dye, parameters of the cell such as absorption coefficient of both layers (ZNO+SWNT, P3HT+SWNT), current density of solar cell , internal and external quantum efficiency of P3HT+SWNT layer have been obtained at 300oK and 330oK, numerically. Then, improvement value of energy conversion efficiency of the cell has been compared after inserting carbon nanotubes.
Metal-Metal Bonding Process Using Ag2O/CuO Mixed Particles
Authors: Maeda Takafumi , Kobayashi Yoshio , Yasuda Yusuke , Morita Toshiaki
Published: December 2012

The present study describes metal-metal bonding process using mixture of CuO nanoparticles and Ag2O nanoparticles (Ag2O/CuO mixed particles). The leaf-like aggregates with a longitudinal size of 1116 nm and a lateral size of 460 nm composed of CuO nanoparticles with a size of ca. 10 nm and the Ag2O nanoparticles with a size of 20.6 nm were fabricated with a salt-base reaction. Metal-metal bonding could be successfully performed by using the mixed particles as a filler sandwiched between metallic discs and pressurizing the discs at 1.2 MPa for 5 min under annealing in H2 gas at 400oC. The mixed particles bonded not only metallic Cu discs but also metallic Ag discs strongly; The shear strengths were as large as 17.3 and 22.4 MPa for the Cu discs and the Ag discs, respectively.
Preparation of Nano-Particles of Transition Metal Oxides Using Ball-Milling and its Application for Lithium Battery
Authors: Kotobuki Masashi
Published: December 2012

Lithium ion battery prefers an electrode consist of small particles so as to allow giving short Li+ diffusion pathway. In order to obtain small particles of LiCoO2, which has been commonly used as cathode for lithium battery, the ball-milling is applied to LiCoO2 prepared through a sol-gel method. By the ball-milling, the particle size of LiCoO2 can be reduced from 400 to 250 nm. The discharge capacity of milled LiCoO2 under high current density of 5C is about 100 mA h g-1, that is much higher than non-milled LiCoO2 (60 mA h g-1). It is concluded that the small LiCoO2 prepared by the ball-milling possess superior performance due to short Li+ diffusion length.
Growth and Morphology of β-Si3N4 Nano-Belts by Carbothermal Reduction Nitridation of Used Silica Refractory Brick
Authors: Li Wen Juan , Pan Zi He , Huang Zhao Hui , Liu Yan Gai , Fang Ming Hao
Published: December 2012

Silicon nitride (β-Si3N4) nano-belts had been synthesized by used silica bricks and carbon powder as raw materials through carbothermal reduction nitridation. The morphology and microstructure of β-Si3N4 nano-belts were characterized by scanning electron microscopy (SEM/HRSEM), energy disperse spectrum (EDS) and X-ray diffraction (XRD). Results showed that the well-crystallized β-Si3N4 nano-beltes were grown with thinness of 50-150nm and width of 3-5μm. The relatively purer β-Si3N4 were prone to be thin films with thinness of 150nm, while the as-grown SiCN (impurityβ-Si3N4with C elements) were presented as nanorods with cross section length of 150*150nm. Orientation growth mechanism by grain dislocation and vapor-solid (VS) mechanism were both involved in the growth of nanostructures of β-Si3N4 nano-beltes and SiCN nanorods.
Synthesis of β-Sialon/Ti(C,N) Composites Using Low and Middle Grade Bauxite and Ilmenite by Carbothermal Reduction-Nitridation
Authors: Yang De Xin , Liu Yan Gai , Ye Ding Yun , Huang Zhao Hui , Fang Ming Hao , Chen Yong Bo , Shen Jian Xin , Wang Bao Chen
Published: December 2012

β-Sialon/Ti(C,N) composites were prepared using low and middle grade bauxite and ilmenite as raw material,while coke as reducing agent in high purity nitrogen atmosphere through carbothermal reducrion-nitridation(CRN).The main phases of low and middle grade bauxite are kaolinire(Al2O3•2SiO2•2H2O) and (Al2O3•H2O)2 and ilmenite mainly contain ilmenite(FeTiO3) and rutile(TiO2).The reaction products of bauxite are the β-Sialon(Z=3,Si3Al3O3N5) while those of ilmenite are TiC and Fe.The results showed that the main phases are β-Sialon,Ti(C,N),Al2O3 and Fe when the reaction temperature is at 1400°C holding for 4 hours(10wt% ilmenite and 90wt% bauxite as raw material).However,β-Sialon decomposes into 21R at 1450°C and into 15R and AlN at 1500°C.So 1400°C is selected as the proper temperature to synthesize β-Sialon/Ti(C,N) composites.At 1400°C,the β-Sialon crystals with the largest quantity grow well and show long column in shape.With the increase of the reacrion temperature β-Sialon begin to decompose,the β-Sialon crystals change to short columnar,with the number decreasing quickly.
Preparation and Characterization of β-Eucryptite Glass Ceramics
Authors: Zhai Ping , Duan Xiao Feng , Chen Da Qian , Wang Chong Hai
Published: December 2012

In this paper, β-eucryptite glass ceramics were synthesized by using solid reaction method. Phase constitution, structure and properties of the material were studied by X-ray diffraction (XRD) and differential thermal analysis (DTA). Furthermore, the effects of heat treatment temperature and preservation time on the thermal expansion coefficient were also analyzed. The results showed that the crystallization temperature of β-eucryptite glass ceramics was in the range of 810-860 °C and the content was more than 90%. With the increase of heat treatment temperature, the material expansion coefficient decreased.
Property Improvement for Microwave Absorbing Slabs by Adding Conductive Grains
Authors: Zeng Zhao Yang , Guo Yi Ming , Liu Heng
Published: December 2012

The possibility of improving microwave absorption ability for magnetic slabs by adding conductive grains was analyzed within the theory of effective medium. It was found that pure magnetic slabs cannot mediate the contradiction between high absorption ability and high reflection property. Gradient magnetic structure cannot improve the absorption either. Adding conductive grains, however, can simultaneously improve the matching effect and absorption ability of slabs. This result means some methods for fabricating high absorption slabs.
Ferroelectric Properties of Bismuth Titanate Ceramics by Er3+/V5+ Substitution
Authors: Liu Rui Fang , Sun M.B. , Ding W.P. , Mei X.A.
Published: December 2012

The ferroelectricity of Bi3.2Er0.8Ti3O12 (BET), and Bi3.2Er0.8Ti2.97V0.03O12 (BETV) ceramics prepared at 1100°C by a conventional ceramic technique was investigated. These ceramics possess random-oriented polycrystalline structure. The remanent polarization (Pr) and coercive field (Ec) of the BET ceramics are 18 µC/cm2 and 64kV/cm, respectively. Furthermore, V substitution improves the Pr value of the BETV ceramics up to 30 μC/cm2, which is much larger than that of the BET ceramics. Therefore, co-sustitution of Er and V in Bi4Ti3O12 (BIT) ceramic is effective for the improvement of its ferroelectricity.
Dielectric and Ferroelectric Properties of Bi2.9Pr0.9Ti2.97V0.03O12
Authors: Liu J.G. , Mei X.A. , Huang C.Q. , Liu J.
Published: December 2012

Bi2.9Pr0.9Ti2.97V0.03O12 (BPTV) ceramics were prepared by solid state reaction. These samples had polycrystalline Bi-layered perovskite structure without preferred orientation, and consisted of well developed plate-like grains with random orientation. BPTV caused a large shift of the Curie temperature ( TC ) of Bi4Ti3O12 (BIT) from 675°C to 385°C. The remanent polarization and the coercive field of the BLTV were 31μC/cm2 and 60kV/cm at an electric field of 100kV/cm, respectively. Furthermore, the dielectric permittivity and dissipation factor were 300 and 3.3×10-3 at 1MHz, at 1V and at room temperature, respectively. These ferroelectric properties of BPTV are superior to V-doped Bi4Ti3O12 (~20μC/cm2 and 80kV/cm) and (Sr, Ta)-doped Bi4Ti3O12 (~12μC/cm2 and 71kV/cm) ceramics. In addition, the dense ceramics of BPTV could be obtained by sintering at temperatures 100─200°C lower than those of the SrBi2Ta2O9 system.
Fatigue and Ferroelectric Properties of Bi3.25Gd0.75Ti2.97V0.03O12
Authors: Liu J.G. , Mei X.A. , Huang C.Q. , Liu J.
Published: December 2012

Bi3.25Gd0.75Ti2.97V0.03O12 (BGTV) ceramics were prepared by solid state reaction. These samples had polycrystalline Bi-layered perovskite structure without preferred orientation, and consisted of well developed plate-like grains with random orientation. The remanent polarization and the coercive field of the BGTV were 24μC/cm2 and 65kV/cm at an electric field of 100kV/cm, respectively. These ferroelectric properties of BGTV are superior to V-doped Bi4Ti3O12 (~20μC/cm2 and 80kV/cm) and (Sr, Ta)-doped Bi4Ti3O12 (~12μC/cm2 and 71kV/cm) ceramics. In addition, the dense ceramics of BGTV could be obtained by sintering at temperatures 100─200°C lower than those of the SrBi2Ta2O9 system.
Synthesis of Mg2+ and Al3+ Co-Doped Li3V2(PO4)3/C Powder
Authors: Yang Qian , Zhang Lei , Liu Yan Gai , Huang Zhao Hui , Fang Ming Hao
Published: December 2012

Mg2+2+,Al3+ Co-doped Li3V2(PO4)3/C powder was synthesized by sol-gel method under nitrogen. The crystal structure and micrograph ofLi3V2(PO4)3/C powder before and after doping was investigated by XRD, SEM and FT-IR. The effect of Mg2+/Al3+ Co-doping onLi3V2(PO4)3/C powder was discussed. The results indicated that Mg2+2+,Al3+ Co-doping did not change the crystal structure of Li3V2(PO4)3, but decreased the grain size of the as-synthesized powder. The FT-IR analysis indicated that weak Al-O bond was generated after doping.
Bond Strength of Veneering Ceramics to a Graded Zirconia Core
Authors: Zhou Shan Yu , Shao Long Quan , Ai Jun , Hu Chen , Wang Lin Lin , Wen Ning , Deng Bin
Published: December 2012

To evaluate bond strength of veneering ceramics to a graded zirconia core. Two zirconia core ceramics (Y-TZP and graded zirconia) were fabricated and veneered with IPS e.max Ceram. A metal ceramic system (IPS d.SIGN, Ivoclar Vivadent, Liechtenstein) was used as a control group for the two all-ceramic test groups (n=20). Shear bond strength test and microtensile bond strength test were conducted by a universal testing machine. Fracture surfaces were also evaluated to determine the failure modes. Additionally, one-way ANOVA and Tukey's HSD tests were used to analyze the data. The shear bond strength test and microtensile bond strength test showed the familiar results. Graded zirconia exhibited the highest bond strength value (SBS: 31.01±2.01 MPa, MTBS: 40.95±1.95 MPa), significantly higher than that of Y-TZP (SBS: 28.14±2.28 MPa, 37.99±2.83 MPa). No significant differences were found between the metal core group and the two zirconia core groups. All test groups demonstrated cohesive failure within the veneer, as well as adhesive failure between the core and the veneer. Glass infiltration to zirconia may affect bond strength between zirconia core and veneering ceramics. A graded zirconia glass structure exhibits a benign bond to a veneering ceramics which could be similar to that of a metal ceramic system.
Preparation and Properties of Porous β–Tricalcium Phosphate Bone Graft
Authors: Zhao Li Sheng , Wang Zheng , Mao Ke Ya , Deng Bin , Yi Yuan Fu , Shao Long Quan , Wen Ning
Published: December 2012

The need for bone repair has increased as the population ages. However, currently, the bone grafts still have some disadvantages, such as low compressive strength and porosity, which limit their use. In order to solve these disadvantages, in this study, the porous beta-tricalcium phosphate (β-TCP) anorganic bone graft were prepared from healthy bovine cancellous bone by cell-free, defat and twice calcinations. X-ray diffraction (XRD) was used to investigate the chemical composition of the bone graft. And the morphology, porosity and mechanical strength of the bone graft were also evaluated. The results showed that most constituent of the bone graft was β-TCP. In addition, the bone graft scaffold exhibited the macro and micro porous structure and the porosity was 57.63%, just as the nature cancellous bone. The compressive strength was 4.47±0.63MPa. Above all, the porous β-TCP anorganic bone graft not only has similar chemical composites as the nature cancellous bone, but also it can effectively retain the porous structure of natural cancellous bone and provides optimal channels for the ingrowth of new bone and blood vessels.Therefore, the porous β-TCP anorganic bone graft is a potential biomaterial in bone tissue engineering.
Study on a High-Temperature Delayed Cross-Linked Acid
Authors: Zhao Xiao , Song Qi , Lin Hai , Wang Yan Ling , Wang Zeng Bao , Jin Jia Feng , Xu Chao
Published: December 2012

A retarded zirconium cross-linking agent ECA-1 was prepared by using zirconium oxychloride, lactic acid， xylitol, and so on, then we got a high-temperature delayed cross-linking acid with cross-linking agent ECA-1 added to EVA-180 gelling acid, cross-linked acid performance and its influencing factors were discussed in details, such as reaction conditions of crosslinker, concentrations of crosslinker and thickener, and so on. The results showed that the obtained cross-linked acid had good temperature-tolerate and shear-tolerate properties when the mass ratio of zirconium oxychloride, lactic acid and xylitol is 1:1.25:0.0208 , the reaction temperature is 50~55°C, the reaction time is 4 hours, the delayed cross-linking time of acid system can be adjusted by changing the dosage of crosslinker and thickener.
Influence of Nucleating Agent on PLLA Crystalline and Mechanical Properties
Authors: Yang Gang , Gao Qun , Ouyang Chun Fa , Zheng Kang Sheng , Guo Yun , Li Wen Tao
Published: December 2012

This paper mainly concerned the effect of nucleating agents CAV101 on PLLA crystalline property. CAV101 was mixed with poly (L-lactic acid) (PLLA) to make PLLA/CAV101 blends, with CAV101 contents of 0, 0.1%, 0.3%, 0.5%, 0.7%, respectively. Mechanical performances, morphology and crystalline properties were investigated by tensile test, WAXD, SEM. The results demonstrated that the tensile strength and elongation of PLLA increased with the increase of CAV101 content and the maximum value at CAV101 of 0.3% and 0.5%, respectively. The crystallinity of PLLA blends CAV101 of 0.1%, 0.3%, 0.5%, 0.7% were 86.58%, 82.43%, 49.01%, 64.00% respectively.The SEM investigation found that the agglomeration of PLLA with the increasing of nucleating agents CAV101 content.
Preparation and Properties of Oligomeric Sulfonated Chitosan
Authors: Liu Ying , Wei Chang Ping , Dong Li Dan
Published: December 2012

In the homogeneous system, the low molecular weight Chitosan is obtained by H2O2 oxidation degradation method. Acetyl Sulface reacted by the mixture of Acetic Anhydride and Concentrated Sulfuric Acid at equal proportion is the reagent. low molecular weight Chitosan being as raw materials, Vulcanized Oligomer Chitosan is sulfonated with good water-solubility and high sulfur content under certain conditions. It has been tested for the influence of the usage of sulfonated reagent, reaction temperature and reaction time on Sulfer content. The best condition for preparation Vulcanized Oligomer Chitosan is 5ml of Acetyl Sulface with the reaction temperature of 25°C and time of 5 Hours. It’s a new potential heparin with around 100 nm particale size tested by spectral analysis and SEM measurements, which could be a new reagent in other fields.
Relation between Cell Density and PM Content Investgation of Three-Way Catalyst
Authors: Zhang Wei Jun , Hu Jin , Luo Hong , Shen Li , Tan Hua , Su Lin
Published: December 2012

In this paper, Pd/Rh series catalyst substrate samples were prepared at the different cell density, with different volume. The fresh catalyst aging treatment. And Catalysts test by light-off factor (LOF). The results tested demonstrated that, it can achieve equal performance levels with the cell density is 600cpsi that the catalyst sample of the cell density is 400cpsi with the precious metal content for the 1.2g/L. This is more efficient for low content of noble metal catalysts. This work is still importantly to promoted catalyst stability, that the catalyst structure is optimized. And it can be used as the interaction between cell density and noble metal content of catalysts.
A Catalytic Behavior Study of Pd/Rh-Mg-Al-O Catalysts with Different Substrate Cell Density
Authors: Zhang Wei Jun , He Xiao Kun , Shen Li , Hu Jin , Cao You Dong , Su Lin
Published: December 2012

This paper verified the relationship between the cell density of three types of substrates with different cell densities (400cpsi, 600cpsi, 900cpsi) and light-off factor (LOF). The results tested on engine bench demonstrated that, higher cell density of substrate could improve the light-off performance characteristics of catalysts. The effect of increasing cell density of substrate on air-fuel ratio characteristic of catalyst. It was effective measurement that higher cell density enlarged the operating window of catalyst.
Preparation and Characterization of Bi-Doped LaAlO3 via Sol-Gel Process
Authors: Sun Gui Fang , Qi Xi Wei , Zhang Teng , Zhang Xiao Yan , Chen Huan Huan
Published: December 2012

A series of Bi-doped BixLa1-xAlO3 (x=0.0, 0.1, 0.2, 0.3, 0.4) powders have been prepared by sol-gel method at 800°C. The influences of Bi doping content on phase, morphology, particle size, surface area, infrared absorption spectrum are discussed. XRD results show that there is no second phase in powders when x≤0.3, however, there exist impure phases when x≥0.4. The SEM analysis indicates the particle size of powder is 50-150nm. The specific surface area is 5-13 m2/g.