bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimal Design of Supercavitating Underwater Vehicles for Mass Distribution
Authors: Ma Zhen Yu , Hu Fan , Lin Ming Dong , Zhang Wei Hua
Published: October 2011

A finite element model for supercavitating underwater vehicles is developed considering the effects of the connection surfaces of cabins and the non-structural mass distribution on the structural dynamic characteristics. The frequency response of supercavitating underwater vehicles is investigated, and the performance of the configuration with flanged connections is compared to those of the configuration with sleeve connections. The flanged and sleeve configurations are then optimized while minimizing the mass of the shells and the centre-of-gravity coordinate in the axial direction respectively. The computational results indicate that at high frequencies the optimal sleeve configuration is advantageous to minimize the mass of the shells, while the optimal flanged configuration is beneficial to minimize the centroid coordinate in the axial direction, and at the same time determining the appropriate connection configuration depends on the confinement of the constraint conditions at low frequencies.
Single Board Computer Based Building Security Management System: Contactless Smart Card for Automatic Door Access Control System
Authors: Atmojo Udayanto Dwi , Litasari Litasari , Irfansyah Astria Nur
Published: October 2011

A building security management system based on single board computer is currently under development. In this paper, a part of the system which is an automatic door access system using contactless smart card for identification is discussed. Running test shows that the system is working as expected. The system can identify multiple users each with different card. More specific access such as access by day, hour, even minute can be implemented. Alarm is used as indicator if the door is unlocked or any forced intrusion is happening. The corresponding system is going to be integrated in a building security management system to provide safer work environment.
Medical Image Segmentation and Reconstruction Based on Bayesian Level Set Method and Marching Cubes Algorithm
Authors: Chen Yao Tien
Published: October 2011

We propose an approach, integrating Bayesian level set method with modified marching cubes algorithm for brain tissue and tumor segmentation and surface reconstruction. First, we extend the level set method based on the Bayesian risk to three-dimensional segmentation. Then, the three-dimensional Bayesian level set method is used to segment solid three-dimensional targets (e.g., tissue, whole brain, or tumor) from serial slice of medical images. Finally, the modified marching cubes algorithm is used to continuously reconstruct the surface of targets. Since each step can definitely obtain an appropriate treatment by statistical tests, the tissue and tumor segmentation and surface reconstruction are expected to be satisfied.
Fuzzy Logic Controller Designing of an Active Roll Control System for Medium and Large Size Vehicles
Authors: Hajishafieiha Peiman
Published: October 2011

The roll / ride trade-off is a long-standing challenge to vehicle dynamicists. Achieving better ride performance almost inevitably leads to increased roll of the vehicle. This roll motion, mostly induced by maneuvering, leads to undesirable handling characteristics and subsequently higher risk of rollover. This paper analyses the use of an Active Roll Control (ARC) system with a Fuzzy Logic Controller (FLC) for improving the handling without sacrificing the ride comfort. The logic for reducing the roll angle of the vehicle is to have some forces exerted by linear actuators on the suspension system, depending on the velocity and steering angle of the vehicle. These forces create a moment about the roll axis which decreases the roll angle. The proposed Fuzzy logic controller is a feedback controller which outputs the correcting roll moment about the roll axis. The effects of employing such a control system are evaluated through computer simulation. Torsional stiffness of the chassis is then taken into consideration to account for unique properties of large-size vehicles. Simulation results with Fuzzy logic controller are very promising and show that the roll performance is significantly improved compared to the vehicle without ARC.
Extraction Method of Version Number in Engineering Drawing
Authors: Amran Mohd. Fahmi Mohamad , Sulaiman Riza , Marjudi Suziyanti , Kahar Saliyah , Adnan Zuraidy
Published: October 2011

In manufacturing industry, engineering drawing is used to facilitate the process of designing a product. In real situations, engineering drawing is usually in large quantities and not in order. In the process of designing a product, it produced many drawing. This paper describes a research and development of an extraction technique in the field of engineering drawing. Non-geometry information that will be emphasis in this research is version number.
Design Optimization Method about the Spring Stiffness Used in Active Engine Hood of Pedestrian Protection
Authors: Ye Hui , Zhu Min , Hu Ping
Published: October 2011

Among the car accident casualties, Pedestrian occupied a large proportion of the injuries. Pedestrian protection became a key problem of vehicle safety. The engine hood was the most possible zone impacted by the head of pedestrian. The pedestrian protection of engine hood was an important performance of vehicle. The active engine hood was used to improve the pedestrian protection performance of vehicle and to meet the regulations. In the lifting system of active engine hood, springs were used to improve the pedestrian protection performance. A design optimization method about the spring stiffness used in active engine hood was developed in this research. The spring stiffness of K was set as design variable, and its interval was set 1~50 N/mm. The impacting zones of engine hood where HIC values of original engine hood were higher than the mean values of corresponding child and adult zones were selected as the cases of optimization. The objective was to minimize the sum of HIC values of those selected zones. The first type of constraints was that the HIC values of child zones were less than the mean HIC value of child zones. The second type of constraints was that the HIC values of adult zones were less than the mean HIC value of adult zones. The spring stiffness optimization model about active hood based on pedestrian protection was constructed and solved. The results of optimization indicated that the obtained spring stiffness by this method improved the pedestrian protection performance of engine hood.
Design and Construction of a High Speed Inter-Row Cultivator
Authors: Abbaspour-Gilandeh Yousef , Fazel-Niari Zargham , Shahgoli Gholamhosein , Bavafa Malek
Published: October 2011

In many parts of the world, row crops are treated with herbicides. Because of environmental concerns, crop cultivation is suggested as an excellent method of weed control. The object of this study was to design and construct a high speed inter-row cultivator. The speed of plowing has a significant effect not only on the depth of plowing but on factors which affect the quality of soil preparation such as loosening of the upper soil layer, cutting roots of the previous crops, covering and plowing in of weeds, leveling the finished surface of the field, displacement of the son layer and so on. In this study, the designed and constructed cultivator has a toolbar, unit frame, disk coulter and a flat sweep. The unit frame is attached to a tractor mounted tool bar by a suspension linkage. The suspension linkage allows the unit frame to move up and down relative to a tool bar that the cultivator unit is attached to. The numerical analysis was performed with COSMOS/M 1.71 FEM software (Structural Research and Analysis Corporation, CA).
Enhancing the Starting Torque of Turbocharged SI Engine Using 1-D CFD Simulation
Authors: Sajedin Azadeh , Jazayeri Seyed Ali , Ahmadi Mahdi , Marandi Omid Farhangian
Published: October 2011

Turbo lag and low starting torque is the challenges of turbochargers. These challenges can be met with the implementation of an additional boosting device which can significantly boost the starting torque of the engine. the goal of this study is to show how the steady-state performance of a turbocharged SI engine can be improved by supercharging turbocharged engine. A one dimensional model for a turbocharged V type, four cylinder CNG engine has been developed and studied in detail using GT-POWER software. For validation purposes the model results are compared with experimental data available where acceptable results with good accuracy has been observed.
Error Recovery System Encoder/Decoder Method and VHDL Design for Saving Memory of Embedded System
Authors: Kim Byung Joon , Sung Rae Cho , Jin Sung Ho
Published: October 2011

Unexpected errors may occur in any embedded systems. An error correction circuitry is used to prevent system errors. Parity bits generated from an encoder are needed to perform an error recovery process. Therefore, to be stored in the memory space should be added. In this paper, Parity bits to be stored without a memory space that can be used to error correction circuitry are proposed. The proposed method was designed in VHDL. The proposed design used the Reed-Solomon (RS) code of an error correction method. Then, 8 bits of information symbols and a symbol error correcting RS code were designed based on the design.
A New Hybrid Design of Experiments Approach for Optimization in Structural Acoustics
Authors: Ranjbar Mostafa , Marburg Steffen , Hardtke Hans Jürgen
Published: October 2011

a new hybrid optimization method including of simplex method and method of design of experiments is developed. The objective of the optimization includes the minimization of the root mean square level of structure borne sound. Application of this new hybrid optimization method is experienced on a square plate. The shape modification concept is considered. The structure’s local geometry modification values at the selected surface key-points are considered as design variables. It is shown that the presented hybrid optimization method is able to reduce the value of objective function with a few number of objective function evaluations.
Electrical Characteristics Investigation of Transient Plasma Ignition
Authors: Lan Yu Dan , He Li Ming
Published: October 2011

A pseudo-spark based high repetition pulse generator is used, and a rapid charger (3μF) is used for repetitive discharge, and the frequency of typical discharge is 10 kHz. The pulse generator can provide pulse with duration of 1~2μs, which can be generated at 10~100 kHz maximum repetition rate in burst mode, with amplitudes up to 140 kV and 7 J of energy per ignition pulse. This paper studies the changing laws of voltage and current in TPI under different electrodes and discharge voltages. The result indicates that the use of screw thread electrode can increase the discharge times of TPI, reduce applied voltage without reducing the peak burst power. With the same time, TPI can raise the pulse energy and reduce pulse time by increasing voltage.
Design of Quaternary Half Adder Using Hybrid SETMOS Cell
Authors: Feizi Khadijeh , Shahhoseini Ali
Published: October 2011

Adder is one of the important arithmetic units in computers. In this paper, we investigate the implementation of quaternary half adder based on multiple-valued (MV) logic gates using single electron transistor (SET) and metal-oxide-semiconductor (MOS) transistor. We use hybrid SETMOS universal literal gate which has been proposed by Mahapatra and Ionesco. We apply two 4-radix inputs to the proposed quaternary half adder and obtain sum and carry outputs. The logic operation of the proposed quaternary half adder is verified by using HSPICE simulator. Moreover we compare the performance of our proposed quaternary half adder with the performance of a quaternary half adder based on MOS technology.
Research on TCAM Match Algorithm in High-Speed DPI System
Authors: Chen Zheng Hu , Lan Ju Long
Published: October 2011

The backbone network throughput has climbed up to 40Gbps, it demands a high-speed pattern matching algorithm. In this paper, we apply Half byte matching and SRAM-based Expansion into the traditional TCAM lookup algorithm, to meet accuracy requirements. Theoretical analysis and experimental results show that, the HBS-TCAM algorithms can significantly improve the service identification accuracy, thus enhancing the performance of TCAM lookup system.
The FPGA Implementation of Digital Correlator in PCS
Authors: Jiang Hai Ying , Ma Yu Liang
Published: October 2011

Digital correlator play an important role for Photon Correlation Spectorscopy. In this paper, the theory of Photon Correlation Spectorscopy (PCS) and the internal structure of digital correlator are described, and by increasing the number of channels to improve the precision. The digital correlator with 256 channels is implemented by FPGA, effectively raising the real-time and precision.
Computer-Aided Process Planning of Strip Layout in Progressive Dies
Authors: Lin Alan C. , Sheu Dean K.
Published: October 2011

This paper proposes a two-step process which uses the knowledge gathered in sheet-metal manufacturing practice as the basis to find proper layouts of strip in progressive dies. In the first step, manufacturing knowledge is used to formulate various rules to cluster the punches into five categories for reducing the searching space of feasible layouts. Evaluation functions are then applied to find the better ones from the feasible layouts. This two-step process provides a new approach to solving the problem of “explosive combinations” in strip layout design
An Adaptive Surrogate Model Applied to the Design Optimizations of Waverider-Based Hypersonic Vehicle
Authors: Li Ping , Chen Wan Chun
Published: October 2011

The primary objective of this work is to optimize the lift-to-drag ratio of a waverider-based configuration by a new global optimization method — the adaptive surrogate model (ASM), which is based on latin hypercube computer experiment and kriging surrogate model. Additional design points will be added in experiment set of points during iterative process. Design spaces of each variable are reduced by an adaptive reduction radius, which is improved gradually by the adaptive inconsistency of optimum solutions during the optimization process. Also the search efficiency and the accuracy of the optimization are compared with another global optimization scheme. At last, this paper gives maximum L/D optimization with restrictions of actual volumetric efficiency and the total mass, which shows that the adaptive surrogate model is quite suitable for the design optimization of waveriders.
Analytical Modeling for Short Channel SOI-MOSFET and to Study its Performance
Authors: Kumar K. Senthil , Ghosh Saptarsi , Sarkar Anup , Bhattacharya S. , Sarkar Subir Kumar
Published: October 2011

With the emergence of mobile computing and communication, low power device design and implementation have got a significant role to play in VLSI circuit design. Conventional silicon (bulk CMOS) technology couldn‘t overcome the fundamental physical limitations belonging to sub-micro or nanometer region which leads to alternative device technology like Silicon-on-Insulator (SOI) technology. In a fully-depleted FDSOI structure the electrostatic coupling of channel with source/drain and substrate through the buried layer (BL) is reduced. This allows in turn to reduce the minimal channel length of transistors or to relax the requirements on Si film thickness. A generalized compact threshold voltage model for SOI-MOSFET is developed by solving 2-D Poisson‘s equation in the channel region and analytical expressions are also developed for the same. The performance of the device is evaluated after incorporating the short channel effects. It is observed that in SOI, presence of the oxide layer resists the short channel effects and reduces device anomalies such as substrate leakage by a great factor than bulk-MOS. The threshold voltage and current drive make SOI the ultimate candidate for low power application. Thus SOI-MOSFET technology could very well be the solution for further ultra scale integration of devices and improvised performance.
Telerobot Arm (TRA)
Authors: Pornpanomchai Chomtip , Sukklay Phichate
Published: October 2011

The objective of this research is to operate a robot arm via the Internet network, which is called “Telerobot Arm or (TRA)”. The robot arm is connected with a server computer via a parallel port and it is controlled by a client computer via the Internet network by the webcam guidance. The server and client computers are located at different campuses with distance of around 20 kilometers. The whole robot arm is made of plastic. Therefore, it has some limitation to hold a heavy object. The experiments are conducted on three different tasks, which are 1) hold a small box and put it into a small basket, 2) push a bottle of water, and 3) hold a bottle of water. The experiments have given a very attractive result.
Determining the Optimal Capacity and Place of DGs in Distribution Systems
Authors: Hosseini Seyed Amir , Karami Mohsen , Madahi Seyed Siavash Karimi , Razavi Farzad , Ghadimi Ali Asghar
Published: October 2011

Increasing application of distributed generation on distribution networks is the direct impact of development of technology and the energy disasters that the world is encountering. Using these resources in distribution network is one of the most influential solutions to reduce losses, improve voltage profile and improve power quality. To obtain these goals the resources capacity and the installation place are of a crucial importance. In this paper a new method is proposed to find the optimal and simultaneous place and capacity of these resources to reduce losses, improve voltage profile and reduce network harmonics. The proposed method is also capable of identifying the appropriate number of resources. The method is tested on actual power network of Zanjan Province, Iran and the simulation results are presented and discussed. Genetic algorithm is used to obtain the best answers.
Optimisation Design of Six-Bar Double Dwell Mechanisms: A New Approach
Authors: Jagannath Mohan
Published: October 2011

This paper introduces a new approach for me-chanical design of planar six-bar linkages with rotary joints which produce two dwells in each cycle of the input crank. The approach builds on the concept of function generation in a simple manner. The synthesis problem is posed as a single-objective constrained optimisation problem. A genetic algorithm-based optimisation scheme, namely the Non-dominated Sorting Genetic Algorithm-II (NSGA-II) has been used for solving the optimisation problem. The proposed method has been illustrated by means of an example problem from a recent contribution to literature. It is seen that the results compare favourably with the existing work.
Micro-Hydro Power Generation Design and Fabrication of Micro-Hydro Turbine for Water Treatement Plant
Authors: Patrike Nikhil P. , Patro Sanmaya
Published: October 2011

Micro hydro is that form of alternative source which refers to hydro power systems with a power rating of 100Kw. A 100kW system will produce 100 standard units of electricity in one hour. Micro hydro systems differ from large hydro power since the flows of water required are much smaller. This paper will give the details of our research on micro-hydro turbine. It also includes designing, fabricating and testing of a model for the prototype. The whole project has been done at the Pimpri Chinchwad municipal corporation’s water treatment plant. A complete model analysis report, with CAD design will be illustrated in the report. The details of model like its specifications, significance, figures, advantages and various forms of application will be documented. The flow in between various processes is utilised to generate electricity. The plus point of our project is that we design according to available conditions, not recondition according to available design
Simulation of Solid Particles in Combined Conduction, Convection and Radiation Gas Flow over a Backward-Facing Step in a Duct
Authors: Golkarfard Vahid , Nassab Seyyed Abdolreza Gandjalikhan , Ansari Amir Babak
Published: October 2011

A numerical simulation procedure for studying deposition of aerosol particles in a laminar convection flow of radiating gas over a backward-facing step including the effect of thermal force is developed. In the gas flow, all of the heat transfer mechanisms consisting of conduction, convection and radiation take place simultaneously. Behavior of solid particles is studied numerically based on an Eulerian–Lagrangian method. Two dimensional Navier-Stokes and energy equations are solved using CFD techniques, while the radiating transfer equation (RTE) is solved by discrete ordinate method (DOM) for calculating radiative heat flux distribution. The objective of this research is to study the effect of Reynolds number variation and also radiation on thermophoretic deposition of particles. Numerical results show a decrease in deposition percent by increasing in Reynolds number and the radiation effect is negligible. The results are compared with the existing experimental and numerical data and good agreement is found.
Computational Analysis and Studies on Differential Ejector
Authors: Tyagi Ankit , Gudwani Bhisham , Singhal Gaurav
Published: October 2011

Studies on differential ejector configuration have been carried out with a view to obtain the optimal entrainment of low pressure gas flow by injecting the motive gas at an appropriate pressure and angle of injection. The length of mixing has been kept constant in one case and varied in another to get results for optimal angle of ejection (between 0 to 90 degrees) for varying mass flow rates between 0.02kg/s and 0.08kg/s, stagnation pressures between 200kPa to 2500kPa and conduit diameter being 50mm. The predictions made are validated employing a versatile code Fluent in 2-d, viscous, turbulent flow formulation. Since the flow is supersonic, compressible form of SIMPLE algorithm is used along with a first order upwinding scheme for correctly predicting the properties inside the flow domain. Various curves have been plotted depicting variation of Mach number with angle of ejection and Mach number with mass flow rate for various pressures and angles of ejection.
Semi Active Control of Chaos in Systems Excited by Non-Ideal DC Motor
Authors: Farokhi Saeed , Komma Aghil Yosefi , Bayat Zohreh
Published: October 2011

In this paper, semi active control of non-ideal mechanical system with Magneto-Rheological (MR) damper is presented. The setup composed of a motor operating on a structure with mass M connected to a fixed frame by a non-linear spring and with a linear viscous damper. From the investigations carried out it is possible to observe the DC motor influence on the vibrating system along with non-periodic motions with chaotic characteristic. To control this system linear viscose damper is substituted by MR damper. A semi-active control method, sky-hook control is used in this study. Our results suggest that the addition of a MR damper turns the phase space smoother and it is so effective to suppress chaos.
Characterization of Capacitively Coupled Radio-Frequency Argon Plasma by Electrical Circuit Simulation
Authors: Bora B. , Bhuyan H. , Favre M. , Wyndham E. , Chuaqui H.
Published: October 2011

Low temperature radio frequency plasma is widely used in low temperature plasma processing medium for material processing in many fields including microelectronics, aerospace, and the biology. For proper utilization of the process, it is very much important to know the plasma parameters. In this paper a novel technique is used to determine the plasma parameters from the electrical discharge characteristic and the power balance method. The homogeneous discharge model is used to evaluate the relation between the plasma parameters with the discharge characteristics. The electron density and temperature is found to be well agree with the Langmuir probe data in the range of 0.5x1016 to 45x1016 cm-3 and 1.4 to 1.6 ev for wide range of rf power.
Nanostructured Mesoporous Thick Films of Titania for Dye-Sensitized Solar Cells
Authors: Wang John , Zhang Yu
Published: October 2011

For energy harvesting, such as in dye-sensitized solar cells, thick films of nanostructured mesoporous titania are inevitably required. Although various mesoporous thin films, i.e., film thickness below 300 nm, such as those of TiO2 and SiO2, have been widely investigated via a supramolecular templating approach in the past decade, little progress has been made with thick films, i.e., film thickness of at least several micrometers. In order to develop the desperately wanted thick films of mesoporous nanostructure for titania, we have successfully modified the supramolecular templating approach, where the highly crystallized mesoporous titania thick films of varying thicknesses and different morphologies are realized, resulting in the formation of highly ordered body-centered orthorhombic and disordered wormlike mesostructures. The performance of these mesoporous films in dye-sensitized solar cells has been investigated, achieving a maximum efficiency of ~7% at the film thickness of ~6 μm. The highly ordered mesoporous titania film outperforms the disordered counterpart of the same thickness in both short circuit current and efficiency. The improved cell performance of the ordered mesoporous film is shown to arise from the enhanced electron transport in the regularly packed titania network due to the enhanced crystalline grain connectivity.
The Research of Micro-Satellite Attitude Determination Based on Predictive Filter
Authors: Cao Lu , Yang Wei Wei , Chen Xiao Qian , Huang Yi Yong
Published: October 2011

— An extended predictive filter is presented for attitude determination of Micro-satellite based on the basic theory of predictive filter. This algorithm enhances the precision of kinematics equation, accurately estimates satellite attitude angle and angular velocity using measurement vectors from magnetometer and sun sensors by predicting model errors and angular velocity errors one step ahead. In addition, a new measurement model is derived about angular velocity, which improved the efficiency of the use of measurement vectors. Simulation results show both the high reliability and precision of this method.
The Study of Direct Tunneling Current in Strained MOS Device with Silicon Nitride Stack Gate Dielectric
Authors: Xu Li Jun , Zhang He Ming , Hu Hui Yong , Xu Xiao Bo , Ma Jian Li
Published: October 2011

As the size of MOS device scaled down to sub 100nm, the direct tunneling current of gate oxide increases more and more. Using silicon nitride as gate dielectric can solve this problem effectively in some time due to the dielectric constant of silicon nitride is larger than silica’s.This paper derived the dielectric constant of silicon nitride stack gate dielectric,and simulated the direct tunneling current of strained MOS device with silica and silicon nitride gate dielectric through device simulation software ISE TCAD10.0,studied the direct tunneling current of strained MOS device with silicon nitride stack gate dielectric change with the variation of some parameters and the application limit of silicon nitride material.
Detemining the Thickness of Barriers and Well of Resonance Tunneling Diodes by Specified I-V Characteristic
Authors: Shahhoseini Ali , Ghorbanalipour Samane , Faez Rahim
Published: October 2011

In this paper, a method of determining physical dimension of Double Barrier Quantum Well (DBQW) of Resonance Tunneling Diodes (RTDs) is presented by using I-V characteristic governing on them. In this procedure, first we have used performance metrics related to RTDs I-V characteristic such as Peak to Valley Current Ratio (PVCR), peak current density (JP), valley current density (JV) and Voltage Swing (VS), and by some other arbitrary points, we have fitted a curve to the RTD current-voltage equation by MATLAB software. Then we have obtained the physical parameter of I-V equation and adjusted some of them with modification coefficients. Next, by choosing the material of barriers and the well and amount of doping, we have calculated the thicknesses of both. To review the mentioned method, the experimental result of I-V characteristic of the sample structure DBQW is considered and we have come to this idea that the dimensions gained out of this method are highly correlated with those of the experimental sample.
Synthesis of ZnO with Different Morphology and its Photocatalytic Property
Authors: Wang Yu Xin , Xu Jing , Cheng Xing Guo , Xu Hong Fang , Liu Li Jun
Published: October 2011

ZnO nanostructures with different morphology have been successfully fabricated by a simple relative low temperature approach at 90 °C for 5 h without surfactant assistance. These structures can be easily tailed using varied concentrations of sodium hydroxide (NaOH) and different amounts of the hydrazine hydrate (N2H4·H2O). X-ray diffraction (XRD) result proves the formation of ZnO with wurtzite structure. Microstructure as revealed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) indicates that the rod-like and chrysanthemum-like ZnO nanostructures contain many radial nanorods, which grow along the [0001] direction. Furthermore, the as-prepared ZnO nanomaterials exhibit high activity on the photo-catalytic degradation of typical persistent organic pollutants (POPs), indicating that they are promising as semiconductor photo-catalysts.
Studies on the Preparation and Characterization of Ferroelectric PLZT Film Capacitors
Authors: Liu Li , Wang Hua , Xu Ji Wen , Ren Ming Fang , Yang Ling
Published: October 2011

(Pb0.92La0.08)(Zr0.65Ti0.35) O3(PLZT) thin films were fabricated on indium-doped tin oxide (ITO)-coated glass substrates to create transparent capacitor by the sol-gel method following annealing process. X-ray diffraction analysis shows that the PLZT thin films are polycrystalline with a single perovskite phase at 650°C. The ferroelectric, electrical and optical properties of these films were investigated in detail as a function of annealing temperature. Measurements with the PLZT films annealed at 650°C yielded the following: relative permittivity≈775 and dielectric loss (tanδ) ≈0.054, leakage current of 7.1× 10-9A, and remanent polarization of 38 μC/cm2 and the coercive electric field of 55 kV/cm and transparency of 88%. The pure perovskite films exhibit better properties than those films which have some fraction of pyrochlore phase.
Photoluminescence and Raman Scattering of Cu-N Codoped ZnO Thin Films
Authors: Lv Zhi Yong , Zhao Yue , Li Zhao , Liang Xiao Yan , Hou Zhan Jie , Wang Lin Jun , Min Jia Hua
Published: October 2011

Polycrystalline ZnO thin films codoped with Cu and N have been obtained by chemical bath deposition. The effect of N incorporation and Cu-N incorporation on microstructure and optical properties of ZnO films has been investigated. X-ray diffraction patterns of the films indicated N incorporation deteriorated the crystalline quality while Cu-N incorporation improved the crystalline quality. The PL spectra showed that the relative intensity between the ultraviolet luminescence and the deep level-center luminescence of ZnO thin films was clearly correlated with the crystalline quality. Furthermore, the Raman spectra revealed the intensity of E2 (high) increase with Cu-N incorporation.
A New Hydrogen Peroxide Biosensor Based on Hrp/Ag Nanowires/Glassy Carbon Electrode
Authors: Zhang Min , Cheng Fa Liang , Cai Zhi Quan , Chen Mei Qiong
Published: October 2011

An amperometric biosensor for H2O2 detection was developed with immobilization of Horseradish Peroxidase (HRP) on Ag nanowires (AgNWs). Ag nanowires (AgNWs) have been prepared by the reductive deposition method and characterized by the scanning electron microscopy (SEM) and the energy dispersive X-ray (EDX). The electrochemical performance of the HRP/AgNWs/GC electrode was investigated by cyclic voltammetry (CV) and chronoamperometry and the use of Ag nanowires led to an efficient enzyme loading, and also provided an increased surface area for sensing the reaction, showing high electrocatalytic activity towards the reduction of H2O2. Under the optimized conditions, the response of the biosensor towards H2O2 was investigated by chronoamperometry. The biosensor exhibited excellent sensitivity (the detection limit was down to 0.005 mM), fast response time (15 sec). Moreover, the biosensor had long-time stability and good reproducibility.
Effect of Pressure on Structure and Properties of Lost Foam Casting of Al-11Si Cast Alloy
Authors: Niakan Ali Asghar , Idris M.H. , Karimian Majid , Ourdjini A.
Published: October 2011

The paper presents the results of an investigation on aluminum-silicon (LM6) alloy using pressurized lost foam casting process. The study investigated the effect of pressure on casting integrity-geometry, eutectic silicon spacing, particle roundness and hardness. Following air pressures: 1bar, 2bar, 3bar and 4bar were applied on the solidifying alloy. The eutectic silicon spacing and particle roundness were measured using optical microscope which was equipped with image analyzer by averaging of at least ten results as well as Vickers hardness testing machine. For casting integrity-geometry all surfaces of solidified castings were captured by digital camera for better observation. The results show that applying pressure during solidification of the LM6 alloy has significant influence on casting integrity-geometry, eutectic silicon spacing, particle roundness and hardness of the alloy. By increasing the applied pressure, solidification time decline. Consequently, silicon spacing reduces as well as increasing of hardness. Besides, rising air pressure lead to fulfilling of molten which improves the casting integrity and particle roundness.
In House Construction of an Induction Motor Rotor by Using 0.35mm Thickness of Steel Sheet for Efficiency Based Investigation
Authors: Daut I. , Nsurface Gomesh , Yanawati Y. , Irwanto Muhammad , Nor Shafiqin S.
Published: October 2011

In this paper, an in house production of a 0.5hp induction motor’s rotor is investigated. This investigation considers the induction motor’s efficiency and losses dissipation as an important aspect to determine the rotors efficiency. Through out this project, a new rotor which has 0.35mm steel sheet thickness and 10mm rotor bar slot size is constructed and compared with the existing rotor which has 0.50mm steel sheet thickness and 10mm rotor bar slot size. Once the construction phase of the rotor has been completed an in house motor experiment is done such as the no load, blocked rotor and dc resistance test. Result shows that thinner steel sheet (0.35mm) of the constructed rotor increase the efficiency up to 3.2% and reduces the losses to 17.2 watts compare to the thicker steel sheet rotor (0.5mm). An economical aspect is presented to show the amount of energy and money that can be saved from replacing the existing rotor (0.5mm) with a thinner rotor (0.35mm). As for the annual energy saving (AES) and total cost saving (TCS), the new rotor manage to save 138.7kWh per year and utility billing by RM45.51 per year per motor.
A Novel Cupped Solid-State Wave Gyroscope
Authors: Yi Tao , Wu Xue Zhong , Xiao Ding Bang , Xi Xiang , Tan Ying Qi
Published: October 2011

Aiming at improving the Q-factor and simplifying the fabricating process of the cupped solid-state wave Gyroscope, a novel cupped solid-state wave gyroscope based on piezoelectric effect is presented in this paper. The sensor has a novel cupped metallic resonator comprises of a cone shell and eight thin flat beams. The working principle of the gyroscope is validated by FEM. Compared with conventional solid-stated gyroscopes, the novel structural features improve the Q-factor and simplify the fabricating process of the gyroscope. The prototypal gyroscope is fabricated and tested, the work mode frequency is about 3979Hz, and the Q-factor is over 8000 in atmosphere. The side-lobes in the output signal’s FFT curve validate the novel design scheme.
Viscous Potential Flow Analysis of Rayleigh-Taylor Instability of Cylindrical Interface
Authors: Asthana Rishi , Awasthi Mukesh Kumar , Agrawal G.S.
Published: October 2011

The present paper deals with the study of Rayleigh-Taylor instability at the cylindrical interface using viscous potential flow theory. In the inviscid potential flow theory, the viscous term in Navier-Stokes equation vanishes as viscosity is zero. In viscous potential flow, the viscous term in Navier-Stokes equation vanishes as vorticity is zero but viscosity is not zero. Viscosity enters through normal stress balance in viscous potential flow theory and tangential stresses are not considered. A dispersion relation is derived and stability is discussed in terms of various parameters such as Ohnesorge number, density ratio etc. A condition for neutral stability is obtained and it is given in terms of critical value of the wave number. It is observed that the Ohnesorge number has destabilizing effect while inner fluid fraction has stabilizing effect on the stability of the system.
Numericl Analysis Supersonic Cavity Unsteady Flow
Authors: Liu Ou Zi , Cai Jin Sheng
Published: October 2011

The computational analysis was performed of self-sustained oscillatory flow over the open cavity driven by a shear layer at flight Mach 5.0 condition with the solution of the Reynolds-averaged Navier-Stokes equations with a two-equation turbulence model. The self-sustained oscillation cycle of the open ramp cavity was got by simulation. It is found that the self-sustained oscillation feature of the cavity was complex flow. The shear layer rolls up and forms a vortex that grows in strength as the fluid enters the cavity. The amplitude of the pressure oscillation on the aft wall is much higher than that at the other wall due to the mass entrainment and ejection mechanism along the aft wall. This periodic mass addition and expulsion could be critical to the fuel and air mixing and flame-holding in the scramjet engine applications.
Temperature Field of Repetitive Laser Pulse Irradiation and its Effect on Laser Surface Hardening
Authors: Gupta Aniruddha , Nath Ashish Kumar
Published: October 2011

Analytical expressions for the temperature rise in a semi-infinite workpiece due to the heating with CW and repetitive laser pulse irradiation have been derived. It has been shown that the soaking time at a temperature above the phase transformation temperature, on which the homogeneity of microstructure and the depth of hardening depend, can be increased by heating with repetitive laser pulses. Experimental results of surface hardening of high-carbon steel with repetitive laser pulses showed higher depth of hardening and better microstructure homogeneity compared to those with continuous wave laser.
The Mechanical Strength of Granular Sulphur and its Relation to Size Distribution and Storage Silo Clogging
Authors: Moradifar R. , Rahi A. , Kadivar M.H. , Eslami F. , Salimi S.
Published: October 2011

The purpose of this study was to investigate the effect of particle size distribution on the mechanical properties of granular sulphur and its relation to silo blockage at South Pars Gas Complex Phases 2 & 3. Solid elemental sulphur is a relatively hard, friable crystalline material that tends to break up into smaller particles when subjected to force or stress of any magnitude. Conglomeration of the dust so produced clogs storage silos, making truck loading difficult. Grain size selection is based on the “friability value” and “maximum entropy” for granules in a static state. The model of the behavior of confined granular sulphur is based on the principle of continuum mechanics. Granules were formed by feeding liquid sulphur and water to a rotating granulation drum. Sample granules were classified into different size fractions (300 μm – 4.75 mm) by sieve analysis, and friability tests were done by the Fines 28-inch tumbler S5-77 test. Friability and granule size data collected over four years were studied. The implication of field analysis and laboratory tests is that the granule size should be controlled during sulphur solidification while ensuring that only granular material with the correct mechanical characteristics is stored in the silo and shipped.
Alfvén Surface Waves in a Partially Ionized Resistive Medium
Authors: Kumar Nagendra , Kumar Vinod , Sikka Himanshu
Published: October 2011

We study the joint effects of viscosity, resistivity and ion-neutral collisions on Alfvén surface waves propagating along a partially ionized plasma - vacuum interface. Applying boundary conditions at plasma-vacuum interface, we obtain the dispersion relation for Alfvén surface waves and solve it numerically. For different values of resistivity and neutral gas friction parameters, the variation of real and imaginary parts of wave number with viscosity parameter are shown graphically. It is found that two-mode structure of Alfvén surface waves results due to the combined effects of resistivity, viscosity and ion-neutral collisions. These results might be useful for studying the behavior of Alfvén surface waves in laboratory and space plasmas.
Numerical Solution of an Edge Cracked 2-D Piezoelectric Media Using Extended Finite Element Method
Authors: Bhargava Rama R. , Sharma Kuldeep
Published: October 2011

The numerical solution for an edge crack problem in a two-dimensional (2-D) finite piezoelectric media has been discussed using extended finite element method. The four-fold standard enrichment functions are taken in conjugation with the interaction integral to evaluate the intensity factors (IFs). The intensity factors as well as the mechanical energy release rate and the total energy release rate has been analyzed for different electro-mechanical boundary conditions. It is observed that the IFs results are coupled and contrary to analytic solution which shows uncoupled behaviour.
Experimental Analysis of Wear and Friction Characteristics of Jatropha Oil Added Lubricants
Authors: Liaquat A.M. , Masjuki H.H. , Kalam M.A. , Rasyidi A.
Published: October 2011

This study examines the experimental results of wear and friction characteristics using normal lubricant and jatropha oil (JO) added lubricants. The experiments are performed using a four-ball tribotester with standard test method ASTM D 4172. This simple test consists of a device by means of which a ball bearing is rotated in contact with three fixed ball bearings that are immersed in the sample. Different loads are applied to the balls weights on a load lever that gives a correlative pressure act similar to the one in the piston cylinder frictional zone. The data presented to evaluate friction and wear characteristics are coefficient of friction (μ), wear scar diameter (WSD), flash temperature parameter (FTP) and viscosity index (VI). Each test was conducted for two different loads (15 kg and 40 kg) to observe the variation of above parameters. All tests were carried out at 75 °C and speed 1200 rpm respectively for one hour. The normal lubricant (0% JO) was used for comparison purposes. The test results show that 5% JO added lubricant has over all good influences in reducing wear and friction coefficient. The objective of this investigation is to develop a new lubricant based on biofuel added lubricant (such as jatropha oil), which can also be used for biofuel fueled IC engines. The promising results have been presented with discussions.
Inertial Flow Phenomenon Analysis on Piezoelectric Pump
Authors: Liu Yong , Yang Zhi Gang , Wu Yue
Published: October 2011

The author finds that there is outflow during piezoelectric pump sucking process, and a dynamic model combined with hydrodynamics and mechanical vibration is presented for the anlysis of piezoelectric pump sucking process phenomenon. The model is utilized to study the reason of sucking process outflow and the effect of the driving frequency, outlet valve rigidity, the load in inlet and outlet on the sucking process outflow. The result turns out that the flow inertia is the cause of sucking process outflow; the inertial flow also exists during draining process as the sucking process; increasing driving frequency, or outlet valve rigidity, the inertial flow decreases, increasing the load in inlet and outlet has the same effect. The research makes it clear that the pump output flow should include two parts, bulk flow and inertial flow, which will provide theory reference for the precise flow control of piezoelectric pump.
The Laminar Boundary Layer on a Moving Cylindrical Rod with an Applied Magnetic Field
Authors: Jayakumar K.R. , Eswara A.T.
Published: October 2011

The steady, nonsimilar MHD boundary layer flow over a moving cylindrical rod has been investigated. The nonlinear coupled partial differential equations governing the flow have been solved numerically using the Kellar box method. The results indicate that the magnetic field enhances the skin friction coefficient, while it reduces the velocity profile.
Investigation of Shielding Effectiveness Caused by Incident Plane Wave on Conductive Enclosure in UHF Band
Authors: Keshtkar Asghar , Maghoul Amir , Kalantarnia Ali , Sadr Negar Elmiye
Published: October 2011

Electromagnetic compatibility is achieved by reducing the interference below the level that disrupts the proper operation of the electronic system or subsystem. This compatibility is generally accomplished by means of electronic filters, and component or equipment shielding. Shielding an electromagnetic field is a complex and sometimes formidable task. The reasons are many, since the effectiveness of any strategy or technique aimed at the reduction of the electromagnetic field levels in a prescribed region depends largely upon the source (s) characteristics, the shield topology, and materials. In this paper, the effect of an incident plane wave with linear polarization on aluminum shield in UHF frequency is investigated, then, the type of shield material is changed and shielding effectiveness caused by it is investigated. Also, the linear polarization of incident wave is converted to circular polarization and shielding effectiveness variation is obtained in this stage. Slots and apertures are very important parameters to determine suitable shielding effectiveness. In following paper, slot is placed on shield, and its shielding effectiveness is evaluated. The effects of slot width variation, slot length variation and slot displacement, on shielding effectiveness are investigated. Finally, the effect of different aperture structure is evaluated and shielding factor is obtained in any stage. The whole of simulations in this paper, are done with CADFEKO.
Research on Interference of Electromagnetic Radiation on Micro-Strip Line
Authors: Wang Hong You , Li Jin Guang
Published: October 2011

Micro-strip line is a kind of transmission line that is the most widely used in microwave integrated circuit. With the development of microwave integrated circuits and the increasing work frequency of the micro-strip line, a higher requirement for its electromagnetic compatibility has been raised. Finite-Difference Time-Domain (FDTD) method has characteristics of good adaptability in the analysis of electromagnetic compatibility issues and superiority in complexity of the structure modeling. For these reasons, this Article uses FDTD method which is widely used in electromagnetic field calculation to analyze the time-domain of micro-strip line, calculates its current and voltage induced in ports and discuss the response feature under different radiation conditions.