bluuebunny/crossref_metadata_2025 huggingface dataset:
Early Cost Estimate of Product during Design Stage Using Design for Manufacturing and Assembly (DFMA) Principles
Authors: Annamalai K. , Naiju C.D. , Karthik S. , Prashanth M. Mohan
Published: December 2012

Application of Design for Manufacturing (DFM) and Design for Assembly (DFA) methodologies can be beneficial to industries involved in the design and development of products. Improper design decisions are responsible for higher manufacturing cost for a product. Thus it is important to include DFMA by combining principles of both DFM and DFA principle early in the design process. This paper presents a case study of manufacture and assembly costs estimation during the design phase of washing machine and which is to be manufactured in company located in India, and intends to make this economically feasible. Solidworks and Solidview software tool were used to generate CAD models which were further analysed using DFMA software tool. The result obtained was accepted by industry and match with the market value of washing machine.
A Novel Quantum-Dot Cellular Automata XOR Design
Authors: Shahidinejad Ali , Farrokhtala Ali , Asadi Saman , Mofarrahi Maryam , Anwar Toni
Published: December 2012

Quantum-dot cellular automata (QCA) is an emerging nanotechnology that promises faster speed, smaller size, and lower power consumption compared to the transistor-based technology. Moreover, XOR is a useful component for the design of many logical and functional circuits. This paper proposes a novel and efficient QCA XOR design. The proposed XOR design has been compared to a few recent designs in terms of area, speed and complexity. Comparison of results illustrates significant improvements in our design as compared to traditional approaches. Also simulation proves that the proposed XOR design is completely robust and more sustainable to high input frequency as compared to other designs. This robustness is highly significant when this component is applied for realizing larger designs.
Quantification of Phase Transformation Kinetics under Thermomechanical Conditions Using Dilatometry Data
Authors: Salari Sina , Naderi Malek , Prahl Ulrich , Bleck Wolfgang
Published: December 2012

Using dilatometric technique, it is the purpose of present research to quantify the kinetics of austenite decomposition during cooling after isothermal hot compression. To reach this aim, based on lattice parameters and thermal expansion coefficients of different phases, a new model was proposed. In this model, the contributions of both isotropic and non-isotropic dilatations were considered. The model was applied to 22MnB5 steel to predict formation of bainite and martensite. Furthermore, the model was developed in order to determine the final fraction of deformation induced ferrite (DIF).
Modeling and Optimization of Micro Electro Discharge Machining Process: A Review
Authors: Sivaprakasam P. , Hariharen P. , Kathikheyen S. , Balusamy S.
Published: December 2012

Micro Electrical discharge machining (µEDM) is an electro thermal process, the cutting force is negligibly small and material removal occurs irrespective of hardness of work piece material .Micro electrical discharge machining process is capable of machining of complex shape, which is difficult to machine in conventional machining process. Last decade, the EDM process involved demand for machining requirements with short period. Since the major risk of wire breakage, deflections of electrodes were affecting the performance accuracy of EDM operation. This paper describe about a comprehensive review of micro electro discharge machining process and its process optimization techniques used for last 10 years. Micro electro discharge machining has more important given to difficult to machine materials. In order to improve the surface integrity and performance of process, need to select proper process parameters. It reports on the Micro EDM research involving the optimization of the process parameters surveying the influence of the various factors affecting the machining performance and productivity.
Fatigue Failure Analysis of a Minitype Straight Bevel Driven Gear
Authors: Liu Bao Long , Hong Jie , Zhang Da Yi , Ma Yan Hong
Published: December 2012

In the presented paper, the failure mechanism of 12Cr2Ni4A minitype straight bevel gear was analyzed by means of both experimental characterizations and numerical simulation techniques. Fractography and simulation were conducted to find the failure mechanism. 3D finite element models (FEMs) of the driven gear with different structure parameters were constructed and used to simulate the inherent characteristic and stress field in the tooth root. Fractography indicated that teeth of the straight bevel driven gear failed because of high cycle fatigue (HCF). Simulation results showed no resonance but stress concentration in the tooth root. It was concluded that this failure occurred due to high cycle fatigue (HCF) and high stress concentration caused by small tooth root fillet radius.
3D Simulation on Flow Behavior and Heat Transfer in a Circular Tube with Inclined Different Arrangement of Thin Rib
Authors: Boonloi Amnart , Jedsadaratanachai Withada , Promvonge Pongjet
Published: December 2012

This work deals with periodic flow, friction loss and heat transfer characteristics in a constant temperature-surfaced circular tube fitted with rib vortex generators (RVG). The computations are based on the finite volume method with the SIMPLE algorithm implemented. The fluid flow and heat transfer behaviors are presented for Reynolds numbers ranging from 100 to 1000. To generate two main vortex flows through the tested section, the 45o RVGs are mounted repeatedly in in-line arrangements on the top and bottom walls and in the central area of the tested section. Effects of different RVG heights, BR in a range from 0.1D to 0.3D with a single pitch of 1.5D on heat transfer and friction losses in the test section are examined. It is apparent that the vortex flows created by the RVG exist and help to induce periodically impinging flows on a sidewall leading to drastic increase in the heat transfer rate over the test section. The computational results reveal that the optimum thermal performance is about 2.38 for using the RVG height of 0.2D for the RVG placed on the tube walls at the highest Re value.
Polymer Core BGA Stress Analysis at Minimal Vertical Loading
Authors: Sauli Z. , Retnasamy V. , Taniselass S. , Rahman N.A.Z. , Aziz M.H.A.
Published: December 2012

Ball grid array is an interconnection method widely used in the electronic packaging industry. The reliability of the solder ball is being improved by introducing new materials for the solder ball. In this study, the stress response of BGA solder ball during minimum vertical loading is analyzed through simulation. The stress response between two types of solder ball, Normal BGA and Micropearl BGA are compared. The Micropearl BGA is a solder ball which contains polymer core. The vertical loading forces used were 1N and 3N. A commercial computational software ANSYS was used for the simulation. The simulation results showed that the Normal BGA exhibited higher stress response.
The Research of Electric Fields Calculation Based on Ring Current Source Model
Authors: Wang Xiang Jun , Liu Yi , Ji Dou
Published: December 2012

This paper establishes a point electrode model, and obtain the analytic equation of electric fields produced by this model using vector superposition. Then do some further research to the analytic equation using ring current source model, and obtain the analytic equation of electric fields produced by ring current source. At last do some simulation about the analytic equation of electric fields, that can obtain the value of electric fields in the air - sea - the sea-bed three-media model.
Simulation and Analysis of Hot Forging Process of Industrial Hub
Authors: Maarefdoust Mahdi
Published: December 2012

Today's, with the development of numerical analysis methods, simulation and analysis of processes of forging has witnessed a great deal of development and those methods one considered as one of the strongest ways of improving forge. In this research, the process of hub production with the finite volume method by means of superforge software is simulated and the required energy shaping of work piece was extracted. The considered work piece was produced in three stages by hot forging. The effect of coefficient of friction and temperature on process was examined. The result show that the effective stress will increase with rising of coefficient of friction and with increasing the temperature the press force decreases and effective plastic strain increases.
Empirical Model and Artificial Neural Network Model Approach for Air Dried Sheets (ADS) Rubber
Authors: Ninchuewong T. , Tirawanichakul S. , Tirawanichakul Y.
Published: December 2012

The objective of this research was to predict drying behavior of hot air drying using an empirical model (EM) and an artificial neural network model (ANN). Rubber sheet with initial moisture content ranging of 23-40% dry-basis was dried by temperature ranging of 40-70°C and air flow rate of 0.7 m/s. The desired final moisture content was set at 0.15% dry-basis. The results showed that drying rate of rubber sheet dried with hot air convection was faster than conventional natural aeration. The EM and ANN were simulated to describe the drying behavior of products. Furthermore, prediction results between EM and ANN were compared with the experimental data. In this research, it was obviously found that ANN can describe the drying behavior effectively. Additionally, it was also found that predicted results of Multilayer feed forward Levenberg-Maqurdt’s Back-propagation ANN were good agreement with the experimental results compared to those results of EM. It is the optimum architecture for prediction the evolution of moisture transfer for hot air drying.
High Temperature Performance of TiAlON Thin Films
Authors: Tuchida K. , Wathanyu K. , Auechalitanukul Chiraporn , Surinphong S.
Published: December 2012

In this paper, the thermal oxidation behavior, adhesion and tribological properties of TiAlON films coated on hastelloyX substrate, typically used for fuel nozzle in gas turbine engine application, have been studied. The uncoated and coated samples were heated to different temperatures, i.e. 950, 1050 and 1150 °C in the controlled atmosphere. The surface appearance, microstructure, chemical composition and adhesion of films were investigated. The thermal oxidations were observed in all testing conditions showing thicker oxide film at higher temperature. However, spalling of oxide scales was found in hastelloyX and TiAlON coated at 1150°C suggesting the maximum working temperature of < 1150 °C. The critical loads corresponding to the full delamination of the thermal oxidation coated specimens were found to be higher than the non-thermal oxidation specimens. The effect of thermal oxidation on damage patterns during scratch tests, i.e. less chipping and cracking for thermal oxidation specimen, were also observed. The tribological properties were also investigated under different load under room temperature and 600 and 1000°C. The results suggested significant improvement in wear resistance of coated sample especially at low load at all temperatures.
Tailoring the Hysteresis Loop of the Si/Cu(10nm)/FeMn(10-30nm)/CoFeB(10nm) Bilayer System
Authors: Prakash Chandra , Srivatsan Rajagopal , Fulara Himanshu , Chaudhary Sujeet
Published: December 2012

The dependence of hysteretic properties of FeMn/CoFeB (AF/FM) thin bilayers on AF thickness and magnetic annealing temperature is systematically investigated for possible applications in spin-valve devices. Inducement of an easy axis after magnetic annealing is established. The anisotropy is studied by investigating the coercivity along and perpendicular to the induced easy axis using Magneto-Optic Kerr Effect (MOKE) and the AF texture is ascertained by XRD. The existence of an optimum annealing temperature, for which the maximum change in coercivity occurs for a particular AF thickness, is evidenced. The maxima in HC of the bilayer with thickness of AF layer were correlated with FCC FeMn (111) texture of the sample.
The Structural Stabilities and Electronic Properties of Orthorhombic and Rhombohedral LaCrO3 — A First-Principles Study
Authors: Song Qing Gong , Song Ling Ling , Zhao Hui , Wei Tong , Kang Jian Hai
Published: December 2012

The equilibrium structures of orthorhombic LaCrO3 (O-LaCrO3) and rhombohedral LaCrO3 (R-LaCrO3) crystals were investigated by using the plane-wave self consistent field (PWSCF) method based on density functional theory (DFT). The optimized lattice parameters for both phases are in accordance with experimental results reported in literature, confirming the reliability of LSDA+U scheme used in the calculations. We have quantificationally investigated the binding energies and electronic properties of these two types of LaCrO3 crystals. The negative total energy and binding energies indicate the ground state property and the good structrual stability of O-LaCrO3 crystal, which is important for the preparation of nano materials, the synthesis of ceramic materials made of doped O-LaCrO3 crytals, as well as their applications in high technology fields, and predict the metastable property of R-LaCrO3 crystal. Furthermore, the band structures show that O-LaCrO3 is a direct semiconductor with wide energy gap, while R-LaCrO3 is an indirect semiconductor with narrow energy gap. The interaction between Cr and O atoms in O-LaCrO3 crystal possesses the character of covalent bonding.
The Damage Behaviour of Composite Tube with Pin Joint Holes
Authors: Sun Jiang , Xiao Qi
Published: December 2012

The present investigation deals with the damage behavior of composite tube with pinned-joint holes made by filament winding technique. The pin-loaded holes are tailored to fail mainly with bearing mode. The main objective of the paper is to investigate the stress state and damage behavior of pin-loaded holes made by filament winding. The failure load and the failure mode are analyzed numerically and experimentally. A good agreement between experimental results and numerical predictions is obtained.
Quantification Evaluation of Continuous Fiber Composite Microstructure with Assistance of Image Processing Technique
Authors: Sun Jiang , Xiao Qi
Published: December 2012

The paper first introduced the method of analyzing the micro-structural morphology, then with assistance of image processing techniques and a second-order intensity function, simulated the two-phase composite micro-structure and selected its RVE. By an object function based on the second-order intensity function and using genetic algorithm, the RVE of original composite microstructure was created and its elastic moduli were analyzed. Numerical calculations showed that the represent volume element can well represent the original composite microstructure.
Optical Band Gap of Wurtzite Zinc Sulphide Doped with Lanthanum Ions
Authors: Varughese George , Aswathy Sreeja R. , Usha K.T. , Kumar A.S.
Published: December 2012

Pure and doped Zinc Sulfide (ZnS) quantum dots have attracted increasing interest from researchers working on various scientific and engineering applications in electronics, nonlinear optical devices for communication, and optical computers. In this study, ZnS nanoparticles doped with lanthanum (ZnS:La) with approximately 11 nm size was produced at 150°C by chemical precipitation route. Zinc Sulphide is an extensively studied group II-VI semiconductor with wide application in field of Photo Luminescence (PL),Electro Luminescence(EL) and Cathodo Luminescence (CL). It is an excellent light transmission material with high refractive index 2.27. XRD, SEM, FTIR UV-Vis and EDS characterize the samples.In this study, the UV–Visible absorption spectra of ZnS:La showed a red shift in the absorption shoulder compared with the spectra of undoped samples. ZnS nanoparticles could be doped with lanthanum ions during synthesis without altering the X-ray diffraction (XRD) patterns of ZnS. Also, the XRD pattern of the powders showed cubic crystal structures for ZnS:La. The Optical band gap has been found to be 2.7 eV. It was found that energy Band gap Eg decreases with doping of La.
Supported Palladium Catalysis Using a Biguanide N-Donor Motif on Mesoporous Silica for Suzuki-Miyaura Coupling Reaction
Authors: Fallah Amirhossein , Kordestani Davood , Alizadeh Abdolhamid , Endud Salasiah
Published: December 2012

A supported Pd(II)/biguanide complex on ordered mesoporous SBA-15 material (Pd@SBA-15/Met) exhibited catalytic activity in the cross-coupling reaction. The structural and surface characteristics of the prepared catalysts were investigated by various techniques (XRD, SEM, FT-IR and AAS). The catalytic performance of the catalysts was evaluated in Suzuki-Miyaura coupling reaction and it was proved to act as a recoverable catalyst in green media with excellent reactivity combined with recyclability.
Effects of La-Doping on Phase Structure and Electrical Properties of Pb(Mg1/3Nb2/3)0.67Ti0.33O3 Ceramic
Authors: Liu Yong , Chu Rui Qing , Xu Zhi Jun , Wang Shu Ting , Chi Qing Bin , Wu Li Ming , Lv Hui Qin , Li Guo Rong
Published: December 2012

La-doped Pb(Mg1/3Nb2/3)0.67Ti0.33O3 ceramics were fabricated by a two-stage sintering method from conventional raw materials. The effects of La doping on the phase structure and electrical properties of ceramics were investigated. X-ray diffraction analysis showed that the pyrochlore phase increased with the increase of La-doping level. The effects of La doping on the dielectric, ferroelectric and piezoelectric properties of the ceramics were also investigated. The results showed that La doping seriously weakened the electrical properties of the ceramics. The ceramics possess optimum properties (d33=239pC/N, Pr=10.6μC/cm2, Ec=8.5kV/cm, tanδ=0.029, εr = 2250) when the doping level is low (x = 0.02).
Tribological Investigation of Nano Composite Coated Titanium Alloy Surfaces under Unidirectional Sliding
Authors: Muthuvel Prem Ananth , Ramesh Rajagopal
Published: December 2012

Industrial application of sliding components required to improve the tribological properties by increasing the surface hardness, friction and wear resistance. Modern modification of surface layers for friction applications combines surface texturing and filling of textured layers by wear resistant coatings of various compositions to improve its functional aspect and enhanced service life. Texturing of contact surfaces has a remarkable influence on their tribological properties, especially in the effect of wear and friction. This work proposes the coating of nano sized Titanium Aluminum Nitride (TiAlN) by Magnetron Sputtering-Physical Vapour Deposition (PVD) on the Titanium alloy (6Al-4V) substrate and study the performance of the coated surfaces by pin on disc tribometer. Two kinds of substrates were prepared one is the lapped surface and the other one is the textured surface by Laser beam machining. The Tribological performance of the wear resistant coatings on lapped and textured surfaces was experimentally investigated under various normal load conditions and the results were compared. Critical parameters such as friction coefficient, wear rate, wear volume, wear morphology and micro wear mechanism were investigated in this work. The coating surfaces and wear scars were evaluated by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDAX). The results showed that the TiAlN coating on textured surfaces exhibited lower friction coefficient and wear rate than the TiAlN coating on lapped surfaces under same testing conditions.
The Influence of Rutile Nano-TiO2 on Paint Ultraviolet Resistance
Authors: Wu Jian Chun
Published: December 2012

Rutile nano-TiO2 was modified with surfactant to improve its dispersion in organic solvents. The modified nano- TiO2 was used in furniture paint, anticorrosive paint and automotive paint. The ultraviolet resistance of the paint was knowed by detecting the color difference and gloss loss rate of the paint. The results show that: the nano-TiO2 which is modified with B/C surfactant has excellent dispersion in paint. And it shows excellent ultravioleting performance in paint applications. The paint color and gloss can be maintained for a longer time.
Experimental Investigation on Heat Transfer and Pressure Drop of CNT-Base Oil Nano-Fluid Flow in Rectangular Channels under Constant Wall Temperature
Authors: Naghavi M.R. , Akhavan-Behabadi M.A. , Pakdaman M. Fakoor
Published: December 2012

An experimental investigation has been carried out to study the heat transfer and pressure drop characteristics of MWCNT-Base oil nano-fluid flow inside horizontal rectangular channels under constant wall temperature. The temperature of the tube wall was kept constant at around 95 °C to have isothermal boundary condition. The required data were acquired for laminar fully developed flow inside round and rectangular channels. The effect of different parameters such as mass velocity, aspect ratio of rectangular channels and nano-particles concentration on heat transfer coefficient and pressure drop of the flow is studied. Observations show that the heat transfer performance is improved as the aspect ratio is increased. Also, increasing the aspect ratio will result in the pressure drop increasing. In addition, the heat transfer coefficient as well as pressure drop is increased by using nano-fluid instead of base fluid. Furthermore, the performance evaluation of the two enhanced heat transfer techniques studied in this investigation showed that applying rectangular channels instead of the round tube is a more effective way to enhance the convective heat transfer compared to the second method which is using nano-fluids instead of the base fluid.
Controlled Synthesis of CeO2 Nanostructure via Electrospinning and Chemical Etching
Authors: Li Qi Ming , Zhang Hong Liang , Li Fang , Kim Hern
Published: December 2012

Combining the versatility of electrospinning and chemical etching technique enables selective controlled synthesis of CeO2 nanostructure. The as-prepared CeO2 material exhibits one- or two- dimensional microstructure based on different processing conditions. XRD and EDX characterization demonstrated that SrFeO3 crystal particles as template can be introduced into the bulk of CeO2 nanofiber using co-electrospinning to optimize related nanostructures. SEM images showed that the electrospun nanofiber of ceria can be transformed into nanoparticles, nanofibers or porous films according to treatment conditions.
Antibacterial Activity of Chemogenic Copper Nanoparticles Coated Cotton Fabrics against Pyogenic Bacteria Isolated from Post Operative Patients
Authors: Namasivayam S. Karthick Raja , Rabel Arul Maximus , Abhraham Teena
Published: December 2012

In this present study, copper nanoparticles coated on the cotton fabrics was evaluated for the antibacterial property against bacterial strains isolated from post operative patients.In this study, CUNPs synthesized by chemical reduction method and the synthesized nanoparticles characterized by UV spectroscopy, energy dispersive X ray spectroscopy and further characterized for its size by SEM. CUNPs coated on the bleached cotton fabrics by pad dry cure method. Coating of CUNPs to cotton fabric conferred by SEM and FTIR. The coated fabrics were examined in the range of basic physical–mechanical parameters such as the tensile strength, the bursting strength and air permeability.Anti bacterial activity was determined against the clinical isolate of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa by agar diffusion assay. Copper nanoparticles synthesized by chemical reduction was primarly confirmed by the colour change of the reaction mixture from blue to olive green, plasmon absorption maxima at 600 nm and uniform sp
The Effect of Growth Time on the Morphology of ZnO Nanorods by Hydrothermal Method
Authors: Ren Xiu Ming , Zhang He Qiu , Hu Li Zhong , Ji Jiu Yu , Li Yang , Liu Jun Lin , Liang Hong Wei , Luo Ying Ming , Bian Ji Ming
Published: December 2012

ZnO nanorod arrays were synthesized by hydrothermal method under different growth times. The effect of growth time on nanorods morphology was investigated systematically. Results illustrate that ZnO nanorods with hexagonal wurtzite structure grow vertically on the Si substrates. The length of the ZnO nanorods increases with increasing growth time. In our experiments, quenching stage plays a key role in forming the tips of nanorods. With growth time no more than 1h, the solution is in a continuous heating state and doesn’t reach the set temperature 180oC. Therefore, longer growth time means higher solution temperature which in turn increases cooling rate during quenching stage, as a consequence, to a smaller mean crystal size in the nanorods tips.
Parametric Optimization of Electrochemical Honing of Helical Gears by Response Surface Methodology and Genetic Algorithm
Authors: Misra J.P. , Jain P.K. , Dwivedi D.K.
Published: December 2012

Finishing is crucial for maximizing the service life and overall in-service performance of gears. This paper presents the parametric optimization of Electrochemical Honing (ECH) of helical gears using Response Surface Methodology (RSM) and Genetic Algorithm (GA) to predict the surface quality of gear teeth profile. A three factors three levels Box Behnken Design (BBD) of Response Surface Methodology (RSM) has been designed to investigate and analyze the effects of input variables: voltage, rotating speed and electrolyte concentration on measures of process performances: percentage improvement in average and maximum surface roughness (PIRa / PIRtm) value. Typical ranges of input parameters were investigated and regression models were developed and used respectively as constraints and objective function for parametric optimization using GA. The results established the feasibility of using the process to improve the surface quality of gear teeth profile.
Synthesis and Characterization of Porous Nano-Crystalline Barium Hexaferrite
Authors: Hamidizadeh S. , Ataie A. , Nozari Amin
Published: December 2012

Barium hexaferrite/high density polyethylene composite was prepared from synthesized barium hexaferrite as matrix with 0, 10, 20, 30, 40 wt.% of high density polyethylene via a high energy planetary ball milling for 10 h. The milling products were isostatically pressed and finally sintered at 1250 °C for 1 h. Effect of HDPE content on morphology of the products were investigated using scanning electron microscope (SEM). Vibrating samplemagnetometer (VSM) analysis of single phase BaFe12O19 indicates saturation magnetization and coercivity of 52 emu/g and 4300 Oe, respectively. Visually, as the weight percent of the HDPE increases, more porous structure was observed. Moreover, the density of the sintered sampleslinearly decreased from 4.16 to 1.41 g/cm3 by increasing the amount of HDPE from 0 to 40 wt.%.
Flow Characteristics for High-Speed Scanning in Immersion Lithography
Authors: Chen Hui , Du Heng , Chen Su Mei
Published: December 2012

High-speed scanning is an effective way to improve the throughput of immersion lithography with double patterning, especially when the critical dimension is less than 32-nm. But it makes more complex characteristics of immersion flow. In this paper, considering the extreme speed of wafer scanning, the model is developed to investigate the characteristics of immersion flow, including the velocity vector, pressure distribution, renovation efficiency and so on. Finally, the optimized parameters and methods to effective liquid renovation are proposed when the wafer scans at high-speed.
N-Loaded TiO2 for Photocatalytic Degradation of Methyl Orange under Visible Light Irradiation
Authors: Boonprakob Natkritta , Wetchakun Natda , Phanichphant Sukon , Chen Jun , Inceesungvorn Burapat
Published: December 2012

Nitrogen-loaded TiO2 (N-loaded TiO2), a visible-light driven catalyst, was successfully synthesized by the modified sol-gel method. Physical characterizations of the as-prepared catalysts have been performed by using X-ray diffraction (XRD), Diffuse reflectance UVvisspectroscopy(DRUVvis), Raman spectroscopyand BETspecific surface areain order to obtain structure-activity relationship. Results from Raman spectroscopy clearly suggested that N atoms were incorporated into the TiO2 crystal lattice as evidenced by the vibrational peak of TiN in TiO2-xNx.DR UVvis results also suggested that the nitrogen dopant might be responsible for narrowing the TiO2band gap energy, thus resulting in a shift towards the visiblelight region. Photocatalytic activity of N-loaded TiO2 evaluated through the degradation of methyl orange (MO)under visible light irradiation (l> 400 nm) indicated that all N-loaded photocatalysts exhibited significantly higher activities than the unloaded TiO2 and Degussa P25 TiO2. According to the results from DR UV-vis, XRD and BET studies, the enhanced photoactivity observed from N-loaded samples might be due to a decrease in TiO2 band gap energy and/or changes in chemical and physical properties of the materials upon loading with nitrogen.
Synthesis and Characterization of Bone Cement (Hydroxyapatite Base) Calcinated at 900°C and Loading the Silver Nanoparticles on it
Authors: Ebrahimi H.R. , Eslami M.
Published: December 2012

The bioceramics, calcium hydroxyapatite (HA), is a material which is biocompatible to the human body and is well suited to be used in hyperthermia applications for the treatment of bone cancer. We synthesis hydroxyapatite in modified synthetic body fluid (SBF) solutions at 37°C and pH of 7.4 using a novel chemical precipitation technique. Then after heat operation, on filtered precipitated result HA were produced. For loading the silver nanoparticles (Ag NPs) on the hydroxyapatite we use AgNO3 solution. And for reducing Ag+ ions apply sodium borohydrate solution. The formations of the silver nanoparticles on the HAP structure were confirmed by X-ray diffraction, transmission electron microscopy (TEM). TEM image show the nanostructure of silver particles, being formed on hydroxyapatite texture.
Supplier Score Prediction Using Hybrid Neural Network Model Based on Simple Exponential Smoothing
Authors: Priya P. , Iyakutti K. , Devi S. Prasanna
Published: December 2012

This paper proposes a hybrid model combining artificial neural networks (ANN) and simple average exponential smoothing (SES) forecasting models, termed as the ANNSES model. The proposed model attempts to incorporate the linear characteristics of SES and nonlinear patterns of ANN for predicting the score of suppliers in an e-procurement system of an automobile industry. The MAPE and RMSE errors obtained indicate that predictions upto a month ahead was accurate using the hybrid model compared to those obtained using ANN and SES forecasting models individually.
Wear Behavior of Diamond-Like Carbon Film Coated by Filtered Cathodic Arc
Authors: Khamnaulthong Nattaporn , Siangchaew Krisda , Limsuwan Pichet
Published: December 2012

Diamond-like carbon (DLC films were deposited on NiFe coupon by Filtered Cathodic Arc (FCA) technique. Two different DLC thicknesses were selected to compare thickness dependency on film properties change. The mechanical property as wear resistance under cyclic heating condition was investigated by nanoindenter (Hysitron). The detail of DLC film composition change was also studied using X-ray Photoelectron Spectroscopy (XPS). The roles of heating in material composition and wear behavior of DLC films are discussed. The effect of DLC film thickness is also considered. The results showed that thinner DLC (2 nm) has higher carbon oxidation resulting that deteriorate in wear resistance as compare to thicker one (5 nm). The heating accelerates these oxidation and wear in this study. .
Flow Stress Optimization for Machining Simulations
Authors: Sekar K.S. Vijay , Pradeep Kumar M.
Published: December 2012

Flow stress is a vital input data for machining simulations, which is experimentally measured from Split Hopkinson pressure bar (SHPB) tests. However such flow stress does not fit machining conditions of strain, strain rate and temperatures and lead to serious simulation errors. In this research work an integrated Taguchi – Finite element (FE) methodology is adopted to optimize the flow stress of AISI 1045 steel material for orthogonal machining. The flow stress computed from the optimization approach along with thermo physical material properties are input into the FE code. The FE cutting forces and chip thickness ratio (CTR) showed an improvement of 6-8% and 2-4% over conventional Johnson – Cook (JC) models. An optimum set of JC model parameters were found from the study. The JC parametric analysis indicated high cutting force sensitivity to yield strength and CTR sensitivity to yield strength, strain hardening and thermal softening.
Treatment of Agricultural Wastewater Using Porous Ceramics Composite of Hydroxyapatite and Silica
Authors: Intapong Supansa , Raksudjarit Anirut
Published: December 2012

Porous ceramics filter was prepared by sintering of hydroxyapatite (HA) and silica composite nanopowder. Silica nanopowder of 50 wt% are incorporated into HA nanopowder. The mixing powders are uniaxially compact and then sintering at 900°C-1050°C in air. The characterization of the porous was carried out by scanning electron microscopy (SEM). Filtration studies using porous ceramic were performed for agricultural wastewater. The studies of the water filtration and flow through these porous showed that the sintered ceramic filter at all temperatures reduced the TDS, TS, conductivity, and arsenic (As) content. The water permeated through porous ceramic composites could be compared to drinking water quality.
Synthesis and Characterization of ZnO Nanorods Using Molecular Beam Epitaxy
Authors: Asghar M. , Mahmood Khalid , Raja M. Yasin , Hasan M.A.
Published: December 2012

We present the study of the growth of ZnO nanorods on p-Si (100) using MBE. Various characterization techniques such as Fourier transform infra-red (FTIR), scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), Raman spectroscopy and capacitance – voltage (C-V) measurements were employed to analyze and assess the grown ZnO nanorods. AFM clearly demonstrated the growth of vertically aligned nanorods, however, they get diffused as the thickness of the layer is increased beyond 1 µm. C-V measurements in particular, justified p-n junction between Si/ZnO nanorods. The junction showed n-type conductivity with carrier concentration 1×1015 cm-3. The source of this n-type conductivity was Zn-interstitials and the presence of Zn-interstitials was confirmed by EDAX and Raman spectroscopy. Experimental detail and results were presented that help in furtherance of our understanding of the material issues and its potential as required for the practical devices.
Effects of Surface Elasticity on 3D Micromechanical Modeling of Short Fiber Nanocomposites
Authors: Saboori M.A. , Naghdabadi R.
Published: December 2012

Recent studies have shown that the surface/interface free energy plays an important role in the effective mechanical properties of solids with nanosized inhomogeneity. In the present study, an analytical model is developed for 3D axisymmetric analysis of short fiber nanocomposites including the fiber end region, subjected to an applied axial load considering surface effects. Closed form expressions are obtained for 3D stress filed in the fiber and matrix. Moreover, performing numerical examples, it is shown that the elastic stress field is size dependent in both the fiber and matrix especially for fiber radii less than 50 nm.
Effect of Sintering Aid on Synthesis and Magnetic Properties of Nanocrystalline BaFe12O19 Ceramic Foam
Authors: Jafari Saeed , Ataie A. , Nozari Amin
Published: December 2012

BaFe12O19 ceramic foam was synthesized from the mixture of Fe2O3 and BaCO3 using polymeric sponge replication technique. Effect of 1, 1.5, 2, 2.5, and 3 wt.% of SiO2 addition on foam lattice shape and magnetic properties of foams were investigated. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating samplemagnetometer (VSM) and Brunauer–Emmett–Teller (BET) techniques.Addition of 3 wt.% SiO2 can completely maintain the foam lattice shape at lower calcination temperature of 1075 °C. It resulted in higher values of coercivity and saturation magnetization. Moreover, BET analysis of the foam sample with 3 wt.% SiO2 demonstrate a specific surface area of 0.3 m2g-1.
One-Step Synthesis of BaCO3 Nano-Particles via Mechano-Chemical Method
Authors: Moayyer H. Akbari , Ataie A. , Nozari Amin , Jafari Saeed
Published: December 2012

Barium carbonate (BaCO3) nano-particles were synthesized from the mixture of Ba(OH)2.8H2O and Na2CO3 by mechano-chemical route without any subsequent heat treatment of the as-milled powders. Effects of milling time and addition of process control agents (PCA) on the phase composition and morphology of products have been investigated. The samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD results show that BaCO3 nano-particles were synthesized only after 10 minutes of mechanical milling and phase evolution was not taken place by further milling. SEM results indicated that pencil-like and globular-like were two major morphologies of the particles. Addition of stearic acid as a PCA resulted in homogenized globular-like nano-particles with a mean particle size of 54 nm.
Photocatalytic Activity of TiO2-Calcium Phosphate Nanocomposite on the Removal of Methylene Blue in Aqueous Suspension
Authors: Linh Nguyen Thi Truc , Tuan Phan Dinh , Dzung Nguyen Van
Published: December 2012

The TiO2-calcium phosphate (TiO2/CP) nanocomposites with different ratios were prepared by precipitation of calcium phosphate in the presence of nano-sized TiO2. The products were characterized by BET, XRD, SEM and EDX techniques. Photocatalytic activity of the nanocomposites was evaluated as a rate constant of decomposition reaction of methylene blue (MB) in aqueous suspensions under UVA irradiation. It was observed that all of the nanocomposites showed higher photocatalytic activity in comparison to pure TiO2 catalyst. In particular, the rate constant photodecomposition of MB on TiO2/CP composite at 9:1 ratio (w/w) was above five times higher than on pure TiO2.
Microstructure Observation and Analysis of Powders, Green Bodies Used for Sintering SiC Ceramics by SEM
Authors: Jiang Yong , Wu Lan Er , Chen Yu Hong , Lu You Jun , Huang Zhen Kun
Published: December 2012

The present work observed and analyzed the microstructures of various starting powders including SiC, AlN-R (Y / La) 2O3 as additives for LPSing (Liquid Phase Sintering), B/C additives for SSSing (Solid State Sintering), as well as the spray granulated powders as comparison, by using scanning electron microscopy SEM. The microstructure of molded green bodies was also posted. Present paper opens out the characters of the various perfect and defect of microstructures of these samples. Their effect on the processing and properties of SiC ceramics was analyzed and discussed.
Compare Study of Electronic Structure, Chemical Bonding and Elastic Properties of Ti3AC2 (A=Al, Si, Sn) by First-Principles
Authors: Zeng Fan Jun , Xia Qing Lin
Published: December 2012

The electronic structure, chemical bonding and elastic properties of Ti3AC2 (A=Al, Si, Sn) were investigated by generalized gradient approximation (GGA) based on density functional theory (DFT). The calculated lattice parameters and equilibrium volumes are in good agreement with the available experimental data. The density of state (DOS) and partial density of states (PDOS) show that the DOS at the Fermi level (EF) is located at the bottom of a valley and originate mainly from the Ti-3d electrons. Population analyses suggest that there are strong covalent bonding in Ti1-C and Ti2-C atoms in Ti3AC2 (A=Al, Si, Sn). Single-crystal elasticity constants were calculated and the polycrystalline elastic modules were estimated according to Voigt, Reuss and Hill’s approximations (VRH). The Young’s modulus Y, Poisson’s ratio ν and BH/GH are also predicted. Results conclude that the hexagonal phase Ti3AC2 (A=Al, Si, Sn) are mechanical stable and behaves in a brittle manner. Polycrystalline elastic anisotropy coefficients AB and AG are also derived from polycrystalline bulk modulus B and shear modulus G.
Effect of Sr-Doping Concentration on Structure and Phase-Separation between Ferromagnetic and Paramagnetic Phases in Lanthanum Manganite Oxide
Authors: Khoa Bao Le Van , Tang Guang Ze , Ma Xin Xin
Published: December 2012

The perovskite La1-xSrxMnO3 (LSMO) nanocrystalline compounds with the doping concentration x in the range of 0.2~0.5 have been synthesized by combustion method using the pair of citric acid and ethylene glycol as a burning fuel. It was found that the sintering temperatures at which the compounds began forming the single-phase of LSMO increased from 900 °C up to 1200 °C corresponding to the increasing of Sr-doping content. X-ray pattern investigations presented the crystalline sizes of all samples sintered at 1200 °C evidently reduced from 77.7 nm to 18.9 nm as the doping concentration x increases. The effects of Sr-doping levels on Mn4+/Mn3+ ratio as well as on their electrical resistivity are also studied by X-ray photoelectron spectroscopy and four-point probes method, respectively. By using a resistive approximation model, the role of the Sr-doping with respect to the phase-separation between ferromagnetic and paramagnetic phases with respect to colossal magnetoresistance effect of these compounds is discussed.
Reaction Synthesis of Cr2AlC Ceramics Powders
Authors: Guan Chun Long , Zhang Zi Ping , Shan Ying Chun , Wang Chun Hua
Published: December 2012

Polycrystalline Cr2AlC was fabricated by a solid reaction synthesis of a mixture of Cr, Al and graphite powders in a flowing or the atmosphere in the temperature range of 700 to 1450 °C. The products for identification and analysis were characterized by X-ray diffraction (XRD). The effects of the composition of the initial elemental powders and temperature of purity and formation of Cr2AlC were examined. It is found that the co-existence of Cr7C3 with Cr2AlC is attributed to the surplus of carbon in the starting powders at 1350 °C, selecting the starting materials with a Cr: Al: C molar ratio of 2: (1.1-1.6): 1. For sample obtained from the starting elemental powders with the Cr: Al: C molar ratio of 2: 1.2: 0.94, no other phases but Cr2AlC were detected. In addition, the effect of temperature on the formation of Cr2AlC ceramic powders was carried out.
The Electrocaloric Effect of BaTiO3 Ceramics Using Hydrothermal Synthesized Nano-Sized Starting Powders
Authors: Han Xi , Bai Yang , Qiao Li Jie
Published: December 2012

The electrocaloric effect (ECE) of barium titanate ceramics with hydrothermal synthesized nano-sized starting powders was investigated. The Curie point and latent heat of the phase transition were characterized by a differential scanning calorimeter (DSC). The P-E hysteresis loops were measured in the temperature range from 30-160oC and ECE adiabatic temperature change was obtained according to the Maxwell relation. A double hysteresis loop is observed at the temperature slightly above the Curie point, which indicates a good consistency of phase transition similar to single crystal. It is also proved by the sharp endothermic peak of phase transition in DSC curves. It exhibits a high ECE of ΔTmax=1.3K under a low applied field of 10kV/cm, which is much higher than that of the sample using micron-sized starting powders.
Electrical Characteristics and Microstructures of Bismuth Titanate Ceramics by Sm3+ Substitution
Authors: Chen Min , Mei X.A. , Liu Rui Fang , Huang C.Q. , Liu J.
Published: December 2012

The electrical properties of Sm-doped bismuth titanate，Bi4-xSmxTi3O12 (BST) ceramics prepared by a conventional electroceramic technique were investigated. XRD analyses revealed Bi-layered perovskite structure in all samples. The P-V hysteresis loops of samples with x=0.4 and 1.2 were characterized by large leakage current, whereas for samples with x=0.6 and 0.8 the P-E hysteresis loops were the saturated and undistorted hysteresis loops. The remanent polarization ( Pr ) and coercive field (Ec) of the BST ceramic with x=0.8 were above 20μC/cm2 and 60KV/cm , respectively.
Current-Voltage and Ferroelectric Characteristics of Er2O3-Doped Bi4Ti3O12 Ceramics
Authors: Huang C.Q. , Liu X.B. , Mei X.A. , Liu J.
Published: December 2012

The electrical properties of Er2O3-doped bismuth titanate，Bi4-xErxTi3O12 (BET) ceramics prepared by a conventional electroceramic technique were investigated. XRD analyses revealed Bi-layered perovskite structure in all samples. SEM micrographs showed randomly oriented and plate-like morphology. For the samples with x=0.4 and 1.0 the current-voltage characteristics exhibited negative differential resistance behaviors and their P-E hysteresis loops were characterized by large leakage current, whereas for the samples with x=0.6 and 0.8 the current-voltage characteristics showed simple ohmic behaviors and their P-E hysteresis loops were the saturated and undistorted hysteresis loops. The remanent polarization ( Pr ) and coercive field (Ec) of the BET ceramic with x=0.8 were above 20μC/cm2 and 65KV/cm , respectively.
Phase and Microstructure Evolution of Mullite Synthesized from Coal Gangue and γ-Al2O3
Authors: Ji Hai Peng , Huang Zhao Hui , Chen Kai , Fang Ming Hao , Huang Jun Tong , Liu Yan Gai
Published: December 2012

Mullite with puncheon-like grains was synthesized by sintering the mixtures of coal gangue and γ-Al2O3 at 1400 °C~1550 °C for 4 h. The phase and microstructure evolution of the mullitization behavior were investigated by XRD, SEM and EDS. Phases of the sintered specimens were mullite, corundum and cristobalite at 1400 °C to 1450 °C. Arise of temperature would enhance mullitization, and total consumption of cristobalite occurred from 1500 °C upward. The in-situ produced primary mullite from gangue upon heating may be seeds for the growth of enenly dispersed mullite puncheons. Specimen sintered at 1550 °C consists of puncheons with an aspect ratio of 2~4, regionally forming an interlocking structure.
Impedance Spectra and Ferroelectric Properties of Bismuth Titanate Ceramics by Nd3+/V5+ Substitution
Authors: Chen Min , Mei X.A. , Liu Rui Fang , Huang C.Q. , Liu J.
Published: December 2012

The ferroelectricity of Bi3.25Nd0.75Ti3O12 (BNT), and Bi3.25Nd0.75Ti2.97V0.03O12 (BNTV) 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 BNT ceramics are 16 µC/cm2 and 65kV/cm, respectively. Furthermore, V substitution improves the Pr value of the BNTV ceramics up to 23 μC/cm2, which is much larger than that of the BNT ceramics. Therefore, co-sustitution of Nd and V in Bi4Ti3O12 ceramic is effective for the improvement of its ferroelectricity.
Electrical Characteristics and Impedance Spectra of Gd2O3-Doped Bi4Ti3O12 Ceramics
Authors: Liu X.B. , Mei X.A. , Huang C.Q. , Liu J.
Published: December 2012

The electrical properties of Gd2O3-bismuth titanate (Bi4-xGdxTi3O12) prepared by a conventional ceramic technique have been investigated. At applied d.c. field below 200V/mm, the current-voltage curve of Gd-doped sample exhibits a simple ohmic behavior. The impedance spectrum of Gd-doped sample indicates that consist of semiconducting grain and moderately insulating grain boundary regions. XRD, SEM and EPMA analyses reveal crystalline phase characterized by a Bi-layered perovskite structure of Bi4Ti3O12 and the distribution of every element is uniform. Gd-doped sample exhibit randomly oriented and plate-like morphology.