bluuebunny/crossref_metadata_2025 huggingface dataset:
A Method for Simulation of a Cryogenic Liquid Propellant Engine
Authors: Chitsaz Mahzad , Tahmasebi Ehsan A. , Karimi M. Hasan
Published: October 2011

The purpose of this paper is developing a method for simulation of a cryogenic staged combustion-closed cycle engine. Since, aerospace systems are usually complicated and important; the simulation task becomes extremely important. If the propulsion system of space vehicle is not successfully simulated, then designers must rely on huge tests which are time and money consuming and also dangerous. The mathematical model of the engine includes a set of equations which describe all the system's elements operation. These equations correspond to mass, momentum and energy conservation principles and are simplified to make easy the process of calculations. A Fortran 90 code is developed for this simulation. Comparison of the simulation code with the actual values, demonstrates that the model can accurately predict the behavior of the real engine
Simultaneous Optimization of Multiple Quality Characteristics in Electrical Discharge Diamond Cut-Off Grinding (EDDCG)
Authors: Yadav S. K. S. , Yadava Vinod
Published: October 2011

This paper presents the simultaneous optimization of multiple quality characteristics (Material removal rate and Average surface roughness) using Taguchi method for electrical discharge diamond cut-off grinding (EDDCG) during machining of cemented carbides material. The experiments are carried out on a self-developed electrical discharge diamond grinding setup in cut-off mode, In the present work four input parameters ( current, pulse on-time, duty factor and wheel RPM ) were selected in which each parameter was at three levels. The total degree of freedom (dof) has been calculated without considering the effects of interaction among the different control factors. Based on design of experiments (DOE), a standard L9 orthogonal array (OA) was taken for experimentation. The result shows the considerable improvement of 13.999dB in multiple S/N ratio as compared to initial condition. Also, the comparison of results from single and multi-objective optimization has been presented.
Flow Maldistribution in a Simplified Plate Heat Exchanger Model - A Numerical Study
Authors: Pawar Nityanand , Maurya R.S.
Published: October 2011

The performance of a plate heat exchanger (PHE) is severely influenced by non-uniform distribution of flow among its channels. Not only the PHEs, but many other process equipment needs uniform flow distribution for their optimum performance. Flow maldistribution (non-uniform distribution) is a common design problem which always puzzles process equipment designers. Being important design parameters, it has been investigated by several researchers and case based solution has been proposed and documented. Present numerical work is intended to target this aspect of the problem of PHEs but starts with a general investigation with simple multichannel geometry. The numerical setup consists of two headers having multiple channels for U-and Z-turn flow configuration under multichannel geometry and a simplified PHE for plate heat exchanger simulation. The problem has been investigated from hydrodynamic and thermodynamic view point. For hydrodynamic study, flow has been varied for Reynolds number 120 to 17600. It has been found that channel flow goes on reducing along downstream side. In thermal study the effect of wall temperature on air flow mal distribution has been investigated. Numerical results have been validated with the experimental results. Investigation reveals new features of flow mal-distribution which is helpful in better understanding of associated mal-distribution physics.
Improved Air Turbo Rocket for Space Applications Application to Orbital Vehicles and Reentry
Authors: Dimri Ankit , Matai Racheet
Published: October 2011

An Air Turbo Rocket (ATR) is a propulsion system which combines a turbo jet with a rocket engine. Currently it is being touted as a propulsion system for future missile systems, as these engines have a higher thrust density when compared to other air breathing engines. This paper explores the possibility of modifying the ATR for use in space application as well as during spacecraft re-entry. Such modified ATR’s could be used to power space vehicles up to the Low Earth Orbit (LEO) to dock with the International Space Station (ISS). In addition, thrust reversal techniques on the ATR systems could be used to improve the accuracy of Ballistic Missiles and hypersonic space planes upon Re-entry. Challenges faced would be in this type of air breathing engine would be operating at different atmospheric conditions. This paper will explore an ATR design, which will operate at different modes namely conventional mode, which will be used during below absolute ceiling, and the mission mode, which will be employed during flight in vacuum. Lastly, the reentry mode, which can be used for lessening the entry velocity of a vehicle to reduce the risks associated with reentry. The paper will try to emphasize the advantages of ATR as an affordable launch system for space shuttles and satellites with high maneuverability.
Simulation of the Mathematical Model of a Quad Rotor Control System Using Matlab Simulink
Authors: Akhil M. , Anand M. Krishna , Sreekumar Aditya , Hithesan P.
Published: October 2011

Quad rotor vehicles are gaining prominence as Unmanned Aerial Vehicles (UAVs) owing to their simplicity in construction and ease of maintenance. They are being widely developed for applications relating to reconnaissance, security, mapping of terrains and buildings, etc. The control of the quad rotor is a complex problem. As a precursor to developing a model based design, the simulation of the mathematical model of the quad rotor is implemented. This will facilitate easier implementation of the model based design using Matlab Simulink©.
Models for Component Commonality in Multistage Production
Authors: Wazed M. A. , Ahmed S. , bin Yusoff Nukman , Ale Ebrahim Nader
Published: October 2011

Use of common parts for different products (commonality) is important methods for managing product variety and preserving competitiveness in the age of mass customization and supply chain competition. In literature, the advantages of inclusion of common components in a product family are well established. Unfortunately, most of the works have been conducted via simulation or conceptual thinking. The mathematical models in the premises are not adequate for production, planning and control in multistage production. This paper focuses on the advancement of venerable manufacturing resources planning models by incorporating the part commonality concept in a multiproduct, multi-period and multistage manufacturing system under a deterministic situation. The models are validated with established MRPII models. The material requirement schedule for the basic MRP II and proposed models are compared. It is really a good matching shown between the two schedules. The later bearing additional information of the location where to be available the parts in a time frame. The effects of commonality on cost, capacity and requirement schedule are discussed based on the outcomes of the mathematical models executed with the available live data.
Computational Aero Elastic Modelling of Airframes and Turbo Machinery
Authors: Prasanth L. Hari , Vivek S.
Published: October 2011

Computational analyses such as computational fluid dynamics and computational structural dynamics have made major advances towards maturity as engineering tools. Computational aero elasticity (CAE) is the integration of these disciplines. As CAE matures, it also finds an increasing role in the design and analysis of aerospace vehicles. This paper presents a survey of the current state of CAE with a discussion of recent research, success and continuing challenges in its progressive integration into multidisciplinary aerospace design. It approaches CAE from the perspective of the two main areas of application: airframe and turbo machinery design. An overview will be presented of the different prediction methods used for each field of application. Differing levels of nonlinear modelling will be discussed with insight into accuracy versus complexity and computational requirements. Subjects will include current advanced methods (linear and nonlinear), nonlinear flow models, use of order reduction techniques and future trends in incorporating structural nonlinearity. Examples in which CAE is currently being integrated into the design of airframes and turbo machinery will be presented.
FEA of Residual Stresses in Butt Welded Type Low Carbon Steel Using MMAW Technique
Authors: Brar Gurinder Singh , Singh Gurdeep
Published: October 2011

Welding is a reliable and efficient joining process in which the coalescence of metals is achieved by fusion. Welding is widely employed in diverse structures such as ships, aircraft, marine structures, bridges, ground vehicles, pipelines and pressure vessels. When two dissimilar plates are joined by welding process, a very complex thermal cycle is applied to the weldment, which further causes inhomogeneous plastic deformation and residual stress in and around fusion zone and heat affected zone (HAZ). Presence of residual stresses may be beneficial or harmful for the structural components depending on the nature and magnitude of residual stresses. In this study, a finite element analysis has been carried out to analyze the thermo-mechanical behaviour and effect of residual stress state in butt-welded in low carbon steel plates. A coupled thermal mechanical three dimension finite element model was developed. Finite element method based software SolidWorks Simulation, was then used to evaluate transient temperature and residual stress during butt welding of two plates. Plate thickness of 8 mm were used which are normally joined by multi-pass operation by Manual Metal Arc Welding (MMAW) process. During each pass, attained peak temperature and variation of residual stresses in plates has also been studied. The results obtained by finite element method agree well with those from X-ray diffraction method as published by Murugan et al. for the prediction of residual stresses.
Sedimentation Load Analysis Using ANN and GA
Authors: Ghose Dillip Kumar , Swain P.C. , Panda Sudhansu Sekhar
Published: October 2011

Artificial Neural Network (ANN) model is used to predict the suspended sediment load for the survey data collected on daily basis in the river Mahanadi. Genetic algorithm has been used to find the optimal level of process parameters such as water discharge and temperature for a minimum sedimentation load condition. Optimal level of process parameters obtained from the GA has been used in a trained neural network to obtain the sedimentation load condition. A comparative analysis is then made between GA and ANN for achieving minimum sedimentation load with the given process parameters.
Heat Transfer Approach to Modelling and Analysis of Reverse Logistics Inventory Models
Authors: Nahavandi Nasim , Rad Farzad Haghighi , Farokhi Saeed
Published: October 2011

Modeling and analysis of inventory systems in reverse logistics is more complex than in forwards logistics, because in reverse logistics not only amount of demand is not clear, but also uncertainty of product return is appeared in the system. In this paper, an inventory system with the possibility of product return is modeled by means of simulation tools and then thermal equivalent of inventory model, using laws of heat transfer is developed. In order to provide the thermal equivalent, components of the inventory system are known and for each component the thermal equivalent is introduced and then sensitivity analysis is used to show the similar behavior of the two models. Hence, analyzing the thermal model can lead us to know the effect of different policies and parameters on inventory system performance. Thermal equivalent model presented in this paper is a strong base for inventory system analysis with more complex structures in future studies.
Statistical Modeling Approach for Optimization of a Stationary Hook Hopper
Authors: Kukreja Astha , Chopra Pankaj , Aggarwal Akshay , Khanna Pradeep
Published: October 2011

The work aims at the optimization of the output feed rate of a Stationary Hook Hopper Feeder so that the best possible set of parameters affecting it can be selected to get the desired output. For this purpose the effect of various parameters on the feeder output is studied. To facilitate the study and detailed analysis, a statistical model is constructed which is used to predict and optimize the performance of the system. Efficient feed rate optimization determines the input variable settings to adjust the feed rate of the feeder according to the consumption of the parts in the next phase of production. The Stationary Hook Hopper Feeder, whose performance is to be studied, consists of a rotating circular plate and a guiding hook fixed at the centre and running up to the periphery of the plate. As the plate rotates, the parts follow the trajectory of the hook, orient themselves and then eventually are delivered through the delivery chute, tangentially to the plate. The factors influencing the feeder’s performance include the speed of rotation of the disc, the population of the parts in the hopper and the size of parts to be fed. A series of experiments is performed on the three process parameters to investigate their effect on the feed rate. To study the interaction among the factors a full 23 factorial experiment approach has been adopted using the two basic principles of experimental design-replication and randomization. The process model was formulated based on Analysis of variance (ANOVA) using Minitab® statistical package. The outcome is represented graphically and in the form of empirical model which defines the performance characteristics of the Stationary Hook Hopper Feeder.
RETRACTED: Studies of Asymmetric Hysteresis Loops and Leakage Current Behaviors in Pt/Al2O3/SiO2/Si /PZT/Au Structures Prepared by MOCVD Method
Authors: Masruroh A. , Toda Masayuki
Published: October 2011

The polarization-voltage (P-V) and leakage currents density (J-V) characteristics were investigated on the ferroelectric PZT films deposited on Pt/Al2O3/SiO2/Si substrate with a vapor-deposited gold top electrode. The P-V hysteresis loops and the J-V characteristics were measured after performing a rapid thermal annealing (RTA) process. A ferroelectric test system (Precision LC Radiant Technology) was used to measure their electrical properties with a 90-nm PZT thickness and an area of 7.85 x10-5 cm2. The measurements were taken by connecting a Pt bottom electrode to the drive of the precision LC and the Au top electrode to the drive of the precision LC. The P-V hysteresis and J-V characteristics of PZT samples showed the asymmetry for both measurements. The asymmetric hysteresis loops and leakage current behavior were shifted in the positive direction when the drive was applied to the Pt electrode, while being negatively shifted in the converse case. The asymmetric behavior of the polarized state in the hysteresis loops due to the electrode configuration resulted from different work function between the Pt and Au electrodes, further influencing the leakage current behavior.
Combustion and Performance Analysis of Single Cylinder DI Diesel Engine Using Jatropha Biodiesel and its Blends
Authors: Prasath B. Rajendra , Tamil Porai P. , Shabir Mohd. F. , Devan P. K. , Vigneshvaran S.
Published: October 2011

Use of biodiesel in diesel engine is becoming popular due to its advantages such as eco friendly, green fuel, low cost and most importantly it is a renewable fuel. In the recent scenario of increased diesel fuel cost and environmental issues, the use of biodiesel in internal combustion engines in transport sector provides energy security along with environmental protection. The chemically treated vegetable oil called biodiesel can be produced from either edible or non edible oils through commonly known transesterification process. In this investigation, biodiesel produced from non edible jatropha oil has been used in a single cylinder water cooled stationary diesel engine to assess the performance and emission characteristics of the engine. The performance characteristics of biodiesel are similar to that of diesel fuel operation and emission levels are lower than the diesel fuel. The use of low cost biodiesel in diesel engines leads to same power output with lower emission levels which in turn leads to a global revolution in possessing a renewable fuel at stake and also assures energy security and environmental cleanliness.
An Insight into Combustion Process in a Spark Ignition Engine Using Three Dimensional Modeling
Authors: Yousefi Moslem , Ommi F. , Farajpour Mehdi
Published: October 2011

In this paper a three dimensional model of a spark ignition engine is presented using KIVA-3V code to investigate the combustion process of engine and gain a better understanding of what happens during this stage. The Whole engine cycle is simulated and the validity of the model is examined by experimental result of in-cylinder bulk pressure. the effect of ignition timing, spark plug location on the engine performance and pollutants of this engine has been investigated .The numerical results show that Relocating the spark plug near to the exhaust valves in order of taking advantage of higher temperature does not have the desired results. Using lean excessive air results in decreasing advancing the ignition results in an increase in the maximum bulk pressure and power of engine. Due to increase in maximum temperature of the combustion chamber the amount of NOx rises, too.
Numerical Simulation for Part Effect of Ventilation of Extra-Long Road Tunnel
Authors: Liu Sheng , Zhang Guang Long , Liu Xiao Wei
Published: October 2011

Er Lang Shan tunnel is the most absolute altitude constructed highway tunnel in china, which is firstly used the semi-transverse ventilation system, is characteristic of extensive length, higher absolute altitude, multivariate climate, two-way traffic and complex wind stream. Based on FEM software CFDesign, the distributed losses, the conflux losses and the shoot of jet fans in the semi-transverse ventilation system of Er Lang Shan highway tunnel are studied by numerical simulation. Part resistance coefficients that numerical simulation of the semi-transverse Ventilation under various work condition needs are obtained.
Reduced Master Equation for Modeling of Ferromagnetic Single-Electron Transistor
Authors: Asgari Sommayeh , Faez Rahim
Published: October 2011

In this paper, the reduced master equation which is a fast simulation method of spin dependent transport in ferromagnetic single electron transistors is presented, for first time. This simulation method follows steady state master equation in which all charge states of the system are considered, whereas charge states are decreased in reduced master equation. This method is based on two degrees of electron freedom which are charge and spin. This is applied in the condition that orthodox tunneling theory is applicable to calculate the tunneling rate of electrons through barriers. The comparison between the I-V characteristics of a ferromagnetic single-electron transistor by following the reduced and full master equation methods for different main parameters of these transistors show that the results are exactly the same at low bias voltages. Consequently, the reduced master equation method is not only more simplified and improves the speed of numerical simulation, but also the modeling results are as accurate as the results of the full maser equation method at low bias conditions.
Fabrication of High Aspect Ratio SU-8 Microstructures on Piezoelectric Transducers
Authors: Ramakrishnan N. , Nemade Harshal B. , Palathinkal Roy Paily
Published: October 2011

A methodology to fabricate high aspect ratio (HAR) SU-8 micro structures on piezoelectric and metallic substrates is presented. In this work, several fabrication trials were carried out to optimize the SU-8 fabrication process. The fabrication recipe mentioned in the SU-8 (Microchem, USA) datasheet is employed for the initial fabrication trials. The SU-8 structures (micropillars) fabricated during these trials resulted in poor bonding with the surface of piezoelectric substrate. In the later trials a thin film of OmniCoat (Microchem, USA) is coated over the substrate before coating the SU-8 film to improve the adhesion quality of the SU-8 micropillars to the substrate. The fabrication methodology used during the trails and results on the quality of the fabricated HAR SU-8 pillars are discussed in the paper.
Synthesis of some New Lariat Ethers as Molecular Motors
Authors: Ebadi Abdol Ghaffar , Alami Somayeh
Published: October 2011

the term "nanomotors" refers macromolecules that consume energy in order to perform certain specific cations. nanomachines could play a major role in the future of electronics, medicine and communications. The sulfoxide (1) was prepared by reaction p-cresol with SOCl2 in 65%, bisphonle (2) was prepared with reduction compound (1). Treatment of bisphenole (2) with methyl chloroacetate at refluxed gave dimethyl ester (3) in 98% yield. Macrocycle (4) in 70% yield was prepared by diamidation of diester (3) with diethylentriamine, Lariat ethers (5) and (6) were synthesized by reaction of macrocyle (4) with decasanoylechloride and ecasonoylechloride in 49% and 45% yield.
Nonlinear Elasto-Plastic Analysis of Axisymmetric Spherical Shell by Chebyshev Spectral Collocation Method under the Pulsating Forces
Authors: Barzegar Mohamadreza Salehi , Oskooe Alireza Nadaf , Najafi Kaveh , Khodarahmi Hossein , Mohamadi Mohamadreza
Published: October 2011

This paper investigates nonlinear elasto-plastic analysis of the dynamic response of composite spherical shells base on the isotropic hardening and flow rule theorem. elasto-plastic strain-hardening is expressed at this stage and the plastic strain obtains to combine with elastic strain to present the elasto-plastic constitutive relation of composite spherical shells. Analytical solutions of the governing equations are based on the Chebyshev spectral collocation methods and then compare results with ABAQUS FEM. In numerical example, the effective of different external loads on the nonlinear elastic and nonlinear elasto-plastic of composite spherical shell are discussed in details.
Generalized Early Voltage Model of Bipolar Transistors for Linearly Graded Germanium in Base
Authors: Xu Xiao Bo , Zhang He Ming , Hu Hui Yong , Ma Jian Li , Xu Li Jun
Published: October 2011

The standard Early voltage of the SPICE Gummel-Poon model (SGP) is generalized for SiGe npn heterojunction bipolar transistors (HBTs). An accurate model for Early effects compatible with the SGP model is obtained considering graded germanium induced bandgap narrowing effect in the base in modern SiGe HBTs and simplified to a compact model which is consistent with ISE TCAD simulation results. The presentation of the Early effect model is significant for the design and simulation of the high performance SiGe BiCMOS technology.
An Analytical Model for the Subthreshold Current of Fully Depleted Strained-SOI MOSFET
Authors: Qin Shan Shan , Zhang He Ming , Hu Hui Yong , Xu Xiao Bo , Wang Xiao Yan
Published: October 2011

A subthreshold current model for fully depleted strained Si on insulator (FD SSOI) MOSFET is developed by solving the two-dimensional (2D) Poisson equation and the conventional drift-diffusion theory. Model verification is carried out using device simulator ISE. Good agreement is obtained between the model’s calculations and the simulated results. This subthreshold current model provides valuable reference to the FD-SSOI MOSFET design.
Unsteady Flow past a Combined Pitching and Plunging Aerofoil Using an Implicit RANS Solver
Authors: Kumar K. Siva , Sajjan Sharanappa V.
Published: October 2011

Unsteady Reynolds-averaged Navier-Stokes (RANS) computations are presented for low Mach number flow past a combined pitching and plunging NACA 0012 aerofoil. The Implicit RANS solver used for obtaining time-accurate solutions is based on a finite volume nodal point spatial discretization scheme with dual time stepping. The aim is to validate the unsteady solver for flapping motion of the aerofoil. Results are presented in the form of aerodynamic coefficients and compared with available literature, thus demonstrating the capability of the solver to provide useful unsteady input data for aeroelastic and aeroacoustic analysis.
The Determination of Efficient Super Finishing Conditions for the Mirror Surface Finishing of Titanium
Authors: Kim J. S. , Hwang J. D. , Jung Y.G. , Shin O. C.
Published: October 2011

Recently, the demands for superfinishing machines have increased, but the development of superfinishing devices and superfinishing technology remain insufficient. And titanium, with its infinite potential, is widely known as a highly ideal material. It is therefore used in various industries that require precision-machined parts, such as the automobile, chemistry and aerospace industries, due to its outstanding specific strength and corrosion resistance compared to any other alloys. In this study, a series of experiments was performed to determine the mirror surface finishing conditions of titanium as well as efficient superfinishing conditions that can be utilized practically and economically at production sites. The applied conditions were the workpiece rotation speed, the oscillation speed, the contact pressure, the roller hardness and the type of abrasive film used when superfinishing was performed using an abrasive film for titanium-based materials such as pure titanium and titanium alloy. From the experiments, it was confirmed that efficient superfinishing conditions and mirror surface finishing conditions were determined for pure titanium and titanium alloy.
Optimal Control for Combined Energy Storage and Attitude Control System (CEACS) in Small Satellites
Authors: Siang Ban Ying , Varatharajoo Renuganth
Published: October 2011

The combined energy storage and attitude control system (CEACS) combines both energy storage and attitude control modules via the flywheel technology. Previously only the conventional control methods were tested for CEACS. In this paper, H2 and H-infinity control methods are implemented in CEACS. The satellite attitude control performances show that both control options can be employed for a good attitude pointing accuracy. (Abstract)
Effect of Nanoparticle Concentration on Thermo-Hydraulic Behavior of a Nanofluid in a Horizontal Tube with Constant Heat Flux and Mass Flow Rate
Authors: Mirmasoumi S. , Behzadmehr A.
Published: October 2011

How nanoparticle concentration affects on thermal and hydrodynamic parameters of a nanofluid (water+Al2O3) is numerically investigated in a horizontal tube while these parameters are impressed by buoyancy force under constant heat flux and mass flow rate. Comparisons with previously published experimental and numerical works on mixed convection in horizontal tubes show good agreements between the results. Results which are obtained using the two – phase mixture model indicate that adding the nanoparticles causes changes in the properties of nanofluid and finally increases the temperature of the flow. Whereas, dimensionless pressure drop along the tube length could increase with the nanoparticle concentration.
Numerical Study of Laminar Mixed Convection of a Nanofluid in a Horizontal Curved Tube with Constant Heat Flux and Mass Flow Rate
Authors: Alikhani S. , Behzadmehr A. , Mirmasoumi S.
Published: October 2011

Fully developed laminar mixed convection of a nanofluid (water/Al2O3) in a horizontal curved tube is numerically investigated. Three-dimensional elliptic governing equations have been solved to show how nanoparticle concentration affects on thermal and hydrodynamic parameters while these parameters are impressed by centrifugal and buoyancy forces under constant mass flow rate and heat flux. Comparisons with previously published experimental works on horizontal curved tubes show good agreements between the results. Results which are obtained using the two – phase mixture model indicate that adding the nanoparticles causes changes in the properties of nanofluid and finally increases the temperature of the flow. Furthermore, increasing nanoparticles volume fraction at first augments the heat transfer coefficient of nanofluid and then, for higher concentration of particles, decreases this thermal parameter of nanofluid.
Fluidization of Geldart Type-D Particles in a Swirling Fluidized Bed
Authors: Mohideen Mohd Faizal , Seri Suzairin Md , Raghavan Vijay Raj
Published: October 2011

Geldart Type-D particles are often associated with poor fluidization characteristics due to their large sizes and higher densities. This paper reports the hydrodynamics of various Geldart Type-D particles when fluidized in a swirling fluidized bed (SFB). Four different sizes of particles ranging from 3.85 mm to 9.84 mm with respective densities ranging from 840 kg/m3 to 1200 kg/m3 were used as bed material to study the effect of various bed weights (500 gram to 2000 gram) and centre bodies (cone and cylinder) for superficial velocities up to 6 m/s. The performance of the SFB was assessed in terms of pressure drop values, minimum fluidization velocity, Umf and fluidization quality by physical observation on regimes of operation. The swirling fluidized bed showed excellent capability in fluidizing Geldart Type-D particles in contrast to the conventional fluidized beds. The bed pressure drop of increased with superficial velocity after minimum fluidization as a result of increasing centrifugal bed weight. It was also found that the particle size and centre body strongly influence the bed hydrodynamics.
Research of the Technological Parameters Importance for Plasma Arc Thermal Cutting
Authors: Hatala Michal , Zajac Jozef , Čep Róbert , Orlovský Imrich
Published: October 2011

Many clients and plasma arc thermal cutting devices providers deal with the question which technological factor in adjustment process of cutting has the greatest influence on the final product quality. Many researchers and teachers deal with this issue during lecturing these knowledges for university students. The article presents the design and evaluation of plasma arc cutting technological process. Influence of technological factors on roughness parameters Ra of the steel surface ISO Fe510 have been evaluated using planned experiments. Using factor experiment, the significance of the four process factors: plasma burner feed speed, plasma gas pressure, nozzle diameter, distance between nozzle mouth and material have been observed. Regression models obtained by multiple linear regression indicates the quality level as observed factors function.
One-Dimensional Harmonic Oscillator in Quantum Phase Space
Authors: Lu Jun , Wang Xue Mei , Wu Ping
Published: October 2011

Within the framework of the quantum phase space representation established by Torres-Vega and Frederick, we solve the rigorous solutions of the stationary Schrödinger equations for the one-dimensional harmonic oscillator by means of the quantum wave-mechanics method. The result shows that the wave mechanics and the matrix mechanics are equivalent in phase space, just as in position or momentum space.
Synthesis of NanoTiO2/CTMAB-Expanded Perlite Applied to the Degradation of Methyl Orange
Authors: Wang Xiao Zhi , Gao Qian Qian , Zhao Hai Tao , Feng Ke , Guo Rong
Published: October 2011

Different environmental remediation materials were prepared by using Cetyltrimethylammonium Bromide (CTMAB) and/or TiO2 to surface-modify expanded perlite (EP). Photocatalytic degradation of Methyl Orange in polluted water by these materials (CTMAB-EP, TiO2/CTMAB-EP, TiO2-EP and EP), adsorption/ degradation kinetics and relevant factors affecting degradation effects were studied. The results showed that EP had little ability to remove Methyl Orange in water, while EP modified with CTMAB and/or TiO2 could remove Methyl Orange (MO) significantly, and TiO2/CTMAB-EP treatment showed the highest removal rate in all treatments. Removal effects of the materials were influenced by dosage of material, shaking time and initial concentration of MO in water. These results indicated that nanoTiO2/CTMAB-Expanded perlite can be used as a new and promising environmental remediation material in efficient removal of organic pollutant from environment.
Synthesis of Nano Machines Based on Catenanes and Rotaxanes
Authors: Ebadi Abdol Ghaffar , Alami Somayeh
Published: October 2011

A nanomachine is an assembly of a discrete number of supramolecular components designed to perform mechanical like movements as a consequence of appropriate external stimuli. In this research work we wish report synthesis of a part of nanomachines are based on interlocked macrocycle named rotaxanes, catenanes, pseudorataxane and knots, that Bis aza thiacrown compound (5) was synthesized by macrocyclic diamide (4) and 2, 6-dicarbonyldicholoride pyridine in dry CH2Cl2 and was refluxed in presence of Et3N in good yield. The structures of these compounds were confirmed by IR, 1H NMR, 13C NMR and elemental analysis.
The Study of Nano Optical Antenna Based on Surface Plasmon Resonance
Authors: Yuan Zong Heng , Zhu Dong Dong , Wang Peng
Published: October 2011

The strong local property of surface plasmon polaritons can break through the diffraction limit, and reduce the propagation of corner scattering on nanoscale. The nanoantenna structure based on the plasmon resonant effect can collect the light energy effectively, and the local field enhancement effects of the structure have extensive application prospect. The field distribution and field enhancement effects of optical antenna under nanoscale are calculated with finite-difference time-domain (FDTD) method. Several different structures of nanooptical antenna are studied, and their enhancement properties are compared in this paper.
A Novel Method of Developing ZnO-Based Nano Hetero Strucutre on Flexible Substrate for UV Photo Detecting Application
Authors: Chen Tron Min , Uang Kai Ming , Chen Hao Xiang , Lin Shu Kuo
Published: October 2011

In this study, we report the fabrication and characterization of a novel nanohetero junction structure (NHJ) UV photodetectors (PDs) on flexible polyethylene terephthalate (PET). The ZnO nanowires (NWs) were grown by 2-step hydrothermal growth (HTG) onto p-type nickel oxide (p-NiO) film deposited PET flexible substrate. For enhancing the quality and reliability of the fabricated UV PDs, the PET substrate was treated with a beforehand thermosetting process to refine its toughness and flatness. By switching the illumination UV light “on” and “off”, the fabricated UV PDs biased under-5 V have an on-off current ratio of 16. After over 100 times 90o bend, the transient measurement almost has the same reversibility but on-off current ratio reducing to 10. These results suggest that the proposed n-ZnO-NWs/p-NiO NHJs on PET flexible PET substrate not only have a fairly good response to UV light but also have good endurance within suitable bend. The present optoelectronic UV sensor would provide an effective and simple way for future developments of flexible optoelectronic devices.
Nanosize Beta-Spodumene Glass-Ceramic Powders Synthesized by Sol–Gel Route
Authors: Xiao Zhuo Hao , Luo Wen Yan
Published: October 2011

Beta-spodumene glass-ceramic powder was prepared by Sol–gel route. Tetraethyl orthosilicate (TOES), aluminum nitrate, lithium carbonate were used as starting materials. X-ray powder diffraction (XRD), thermal expansion coefficient (TEC), scanning electron microscope (SEM) and transmission electron microscope (TEM) were utilized to characterize the dried LAS gels and glass-ceramic blocks. The results suggest beta-spodumene is the only crystals phase in the prepared LAS glass-ceramics powder when sintering temperature is 950 °C. The average particle size of the beta-spodumene crystal is about 30 nm with a narrow size distribution both in prepared LAS glass-ceramics powder and block. The thermal expansion coefficient of moulding pressed blocky LAS glass-ceramics is lower than 0.6×10-6 oC-1.
Optimum Design of Guide Positions for Decreasing the Permanent Deformation of a Cockpit Module
Authors: Kim Bae Young , Jeong Choong Min , Suh Myung Won , Kim Hae Ryong , Kim Hae Kyung
Published: October 2011

The noise of interior plastic parts has been one of the major driving factors in the design of automotive interior assemblies. This phenomenon is one of the major contributors to the perceived quality in a vehicle. The noise is caused by interior plastic parts and other parts as a result of permanent deformation. Traditionally, noise issues have been identified and rectified through extensive hardware testing. However, to reduce the product development cycle and minimize the number of costly hardware builds, hardware testing must rely on engineering analysis and upfront simulation in the design cycle. In this paper, an analytical study to reduce permanent deformation in a cockpit module is presented. The analytical investigation utilizes a novel and practical methodology, which is implemented through the software tools, ABAQUS and iSight, for the identification and minimization of permanent deformation. Here, the emphasis is on evaluating the software for issues relating to the prediction of permanent deformation. The analytical results are compared with the experimental findings for two types of deformation location and the qualitative correlation is found to be very good. In this study, we also develop a methodology to design the guide and mount location of cockpit module for minimizing the permanent deformation. Nonlinear finite element analysis has been implemented and integrated with sensitivity-analysis techniques to minimize the permanent deformation at the areas of interest. Finally, we find the optimal guide and mount locations that reduce the permanent deformation.
The Comprehensive Utilizing Method for Urban Rain-Flood Based on Nanotechnology
Authors: Yan Jun , Zhang Ju , Zhang Yu Hua , Yang Xian Bo
Published: October 2011

The urban rain-flood disaster occurs more ordinary and more serious recently. Summing up the characters of urban rain-floods, the mechanism of urban rain-flood disasters is analyzed. More ever, the main countermeasures to prevent urban rain-flood disasters are stated. Finally, the method to use urban rain-flood comprehensively based on nanotechnology is put forward.
Turbulent Convective Heat Transfer of Nanofluids
Authors: Hosseini Seyyed Hossein , Javadi Seyyed Mohammad , Ebrahimnia-Bajestan Ehsan
Published: October 2011

In this paper, the convective heat transfer of nanofluid flow in a turbulent boundary layer of a flat plate is simulated numerically. Turbulent flow equations with RNG K-ε turbulence model are solved employing Fluent software. Furthermore, the effects of nanoparticle concentration on the heat transfer characteristics are studied. The results show that nanofluids enhance the heat transfer coefficient dramatically with little change in pressure drop.
A Study of Relationship between Competency Program and Mold and Die Occupation
Authors: Thong-u-thai S. , Kaewkuekool S.
Published: October 2011

The research aim was to determine the course outline and study of relationship between conpetency program and Mold & Die occupation. The research tools used to collect the data were questionnaires and focus groups. The sampling group was chosen by purposive random sampling, which included experts related to the development of personnel in the molding industry. Results for this is that the course competencies are defined by the enterprises themselves to be divided into three levels of personnel: operators, experts and management. Role of performance standards can be devided for operating level out of 6 role include skill drawing mechanical works, mechanical works, material, english in industry, math in industry and safety in industry. An analysis of competency courses, by Delphi technique, found that experts, educational institute representatives, related mold personnel development institute representatives and enterprise representatives agreed both times. The difference was that it was higher for the second time although most medians were at ‘agree-the-most’ level. And average correlation is high. Relationship every competence has significant at .01.
Application of Statistical Process Control Tools to Improve Product Quality in Manufacturing Processes
Authors: Bataineh Omar , Al-Dwairi Abdullah
Published: October 2011

Quality control and improvement at the process level is a vital activity for the achievement of defect-free products in various manufacturing processes. This study employs statistical process control (SPC) tools such as control charts and process capability ratio for quality control and improvement. The control charts employed are , R and the cumulative-sum (CUSUM). The process capability ratio used is the so called process capability index (PCI). These tools have been implemented with the aid of Minitab® statistical software. In this study, the manufacturing process of gelatin capsules is investigated in terms of quality of the capsules, which are produced and shipped for use by various drug companies. As a result of implementation of SPC tools, an expected reduction in the number of defective capsules by 29% relative to the stage before implementation was achieved.
Research on Intelligent Variable Frequency of Air-Conditioner Control System Based on Fuzzy Control
Authors: Du Hai Cun
Published: October 2011

In this paper, we determine the fuzzy control strategy of inverter air conditioner, the fuzzy control model structure, the neural network and fuzzy control technology, structural design of the fuzzy neural network controller as well as the neural network predictor FNNC NNP. Simulation results show that the fuzzy neural network controller can control the accuracy greatly improved the compressor, and the control system has strong adaptability to achieve a truly intelligent; model of the controller design and implementation of technology are mainly from the practical point of view, which is practical and feasible.
Steady Hydrodynamics and Thermal Behaviors of Fluid Flows in Micro – Parallel Plates (Couette Flows)
Authors: Al-Shyyab Ahmad , Al-Lubani Suleiman E. , Kwafha Muhammad M. , Khadrawi A. F.
Published: October 2011

The hydrodynamics and thermal behaviors of fluid in micro - Couette flows is investigated numerically. The model that combines both the continuum approach and the possibility of slip at the boundary is adopted in the study. The Effects of Knudsen number Kn, Brinkman number and the pressure gradient on the Couette microchannel hydrodynamics and thermal behaviors are investigated. It is found that as Kn increases the slip in the hydrodynamic and thermal boundary condition increases. Also, it is found that the slip velocity and the temperature jump at the boundaries increases as the Brinkman number and the pressure gradient increases.
A New Fuzzy Approach for Minimizing Conveyer Stoppages in Mixed-Model Assembly Lines
Authors: Radmehr Farzad , Manavizadeh Neda , Rafiei Hamed , Rabbani Masoud
Published: October 2011

Mixed model production is the practice of assembling different and distinct models in a line without changeovers with responding to sudden demand changes for a variety of models. In this paper, we specify sequence of models to minimize the conveyer stoppages. We assume our lines are fixed and we can not change the balance of the lines. When the condition of lines like setup cost, demand of each models change, it is important to specify the sequence for minimizing the conveyer stoppages without balancing the line again, because the main lines are fixed. We consider three objective functions, simultaneously: minimizing the variation in actual and required production capacity of the line, minimizing the objectives which increase the chance of conveyer stoppage including: a) minimizing the total setup time, b) minimizing the total production variation cost, and minimizing the total utility work cost. We use a new fuzzy programming for this problem; it can present us an estimator for nearness of conveyer stoppages. We study about sub lines and conveyer velocity and its affect on stoppages.
The Use of Laser Scanning Technology to Improve the Design Process
Authors: Kiraci Ercihan , Attridge Alex , Williams Mark. A.
Published: October 2011

Benchmarking competitor products helps a company to identify opportunities to improve their product relative to their competitors. This allows a company to determine the basic requirements of a new product, and target potential areas for improvement, particularly within the automotive industry where there is considerable growth and competition. Automotive firms have been increasingly focusing on development processes. Reducing time to market and improving quality whilst minimising cost. Laser scanning technology enables companies to make design and engineering improvements through the ability to analyse a competitor’s design. A case study of this generic process will be presented in this paper. The results have revealed that a company can create significant value-added activity, reduce the need for physical prototype costs and time, improve quality in new product development introduction.
Study of Atmospheric Channel Charateristics in Space Laser Communication System
Authors: Sun Jing , Li Dong Guang , Cui Xue Jun
Published: October 2011

Laser light beam transmit efficiency and accuracy in atmosphere channel is important parts in space laser communication system. The atmosphere channel effects to laser light beam mainly have two aspects, atmospheric attenuation and atmospheric turbulence. After doing related experiments, we figure that the speed of wind has little effect to atmospheric turbulence and the altitude is portional to structure parameter. And bad weather has much influence with energy transmission efficiency. In practical situation, we should consider two ways working at the same time refer to our conclusions.
Extracting Modal Parameters of Constrained Structure from Free Test Data
Authors: Wu Bin , He Yun , Feng Song
Published: October 2011

This study explores the method of extracting modal parameters of constrained structure from test data. The normal mode spectrum matrix constituted of low order frequencies of the structure can be derived from the free test data, while the normal mode shapes and the extra high order modes can be obtained through FEM analysis; The boundary constrains are equivalent as a kind of sub-structure, and the modal synthesis is used to extract the constrained modal parameters. Experiment and simulation are conducted and the results show that the extraction method based on the modal synthesis and which combines the experiment model and the analytical model is feasible.
Computational Fluid Dynamic Analysis for Modified Steam Duct in Air Cooled Condenser
Authors: Salehi Fatemehsadat , Khoshkho Ramin Haghighi
Published: October 2011

Cooling system is a subsystem of a power plan that has an indispensable effect on efficiency of power plant. Air Cooled Condenser (ACC) system as a cooling system, is usually used in many power plants. Steam duct as a part of ACC conveys the steam flow with high velocity form steam turbine exhaust to head of tube bundle which is located at height of 25 to 30 meters. In this paper, pressure drop in steam duct is calculated using computational fluid dynamic method. Then, in order decrease pressure drop and consequently increase ACC efficiency, steam duct configuration is modified. The steam flow is modeled as an incompressible, turbulent and single phase flow. The solution strategy is based on SIMPLE and Segregated Implicit algorithm and the k-ε RNG model for turbulence are employed. The second order upwind differencing scheme are applied to discrete governing equations. Numerical results confirm reducing of total pressure drop in modified diffuser comparing with primary geometry.