bluuebunny/crossref_metadata_2025 huggingface dataset:
Structure and Properties of Hydrogenated Nitrile-Butadiene Rubber/Organo Montmorillonite Nanocomposites
Authors: Wang Xiao Ping , Jia De Min , Huang An Min
Published: October 2011

Organo-montmorillonite (OMMT) was compounded with Hydrogenated Nitrile-Butadiene Rubber （HNBR）(50% epoxidation) to prepare nanocomposites by melt mixing method. The nanometer scales of organoclays in rubber matrix were determined by X-ray diffraction testing, the exfoliated/intercalated structures of OMMT in HNBR were confirmed by transmission elector microscopy. The increases in tensile module and strength of HNBR/OMMT nanocomposites vulcanizaters were caused by the better interactions between rubber macromolecule chains and organoclay layers. The air-aging properties of nanocomposites enhanced by the increasing content of OMMT, which was leaded by the barrier characterize of nanodisperse OMMT layers. DMA test showed that the Tgs of HNBR/OMMT shifted to a higher temperature, as verified by the crosslinking density determination.
A Study on the Nanotechnology Researchers’ Information Needs and Information Retrieval Behavior
Authors: Hasoomi Tahereh , Mehraban Sahar
Published: October 2011

The purpose of this project is to study the nanotechnology researchers’ information needs and information retrieval behavior. Its Methodology is questionnaire survey. Research instrument was a researcher-made questionnaire whose reliability was calculated through Cronbach α (α= 0,914) and whose content validity was analyzed and approved through expert opinions.1225 researchers in nanotechnology are included as the research population out of whom 291 researchers, based on Krejcie and Morgan table, were selected using cluster random sampling method. Out of distributed questionnaires (500), 243 of them (84% of the sample) were returned completed. Statistical analyses were carried out in SPSS and Excel environments. The results of research indicate that, 69.7 % researchers mainly use articles, 58.8 % of them e-journals, and a few of them use bibliographies as formal sources. Their ideal type of resource is e-resources. Their motives to use information are mainly conducting research projects and updating their field-related information. Academic centers are where they usually refer to address their information needs. The major problems to access information are inappropriate internet services and lack of access to certain data bases due to subscription issues.
Nanocomputational Observation of Interaction of Two Cytotoxins and Nanobio Membrane: Molecular Dynamics Simulation Study
Authors: Maftouni N. , Amininassab M. , Kowsari F.
Published: October 2011

Experimental observations have shown that cardio toxins (cobra cytotoxins), small proteins of three-fingered cytotoxin group, damage nanobiomembranes in different cells and vesicles. However, the molecular mechanism of this damage is not yet completely cleared. Molecular dynamics simulations have been used here to study the interaction of cardiotoxins A3 and A4 from Naja atra cobra venom with hydrated 1-palmitoyl-2-oleoyl-1-sn-3-phosphatidylcholine (POPC) lipid bilayer in two separate systems. Each of studied systems included one cytotoxin molecule, 128 lipid molecules (64 molecules in each monolayer) and 11817 water molecules. It has been found that the toxin interacts with zwitterionic bilayer formed by POPC. At the beginning of simulation the cytotoxins have been oriented toward nanobiomembrane surface by their loops’ tips. This orientation has changed during first 50 ns of classical molecular dynamics simulation for both of studied cytotoxins. The A3 toxin finally meets POPC nanobiomembrane with sides of loops near tips including cytotoxin region THR148 and VAL155. The A4 cytotoxin molecule has been finally oriented toward surface of nanobiomembrane with base and one of loop's tip including THR184, ARG186 and LEU158 amino acids, after 50 ns molecular dynamics simulation. Then 25 ns steered molecular dynamics simulation has been done for both of systems. The obtained data suggest that cytotoxin A3 meets the nanobiomembrane with sides of loops near tips and A4 meets POPC nanobiomembrane with base and one of loop's tips. The difference between final orientations of these two cytotoxins comes from the difference in the structure of them.
Hybrid Flow Shop Scheduling Problems with Multiprocessor Tasks
Authors: Wang Hui Mei , Chou Fuh Der , Wu Ful Chiang , Ku Meei Yuh
Published: October 2011

Hybrid flow shop scheduling problems with multiprocessor tasks to minimize the makespan have been addressed and solved efficiently. Several approaches were used, including greedy methods and metaheuristics. In this paper, we proposed a mixed integer programming (MIP) model that can define explicitly and precisely the nature of a given problem. We also addressed a modified lower bound to obtain tighter bounds. Additionally, we propose different decoding methods and emphasize their importance in hybrid flow shop scheduling problems with multiprocessor tasks. By using existing test problems with n=5 in examining the proposed methods, many optimal solutions can be obtained as benchmarks for reference by the MIP model. Accordingly, the results are indicative of the influence of the decoding methods on the solutions to the hybrid flow shop problems with multiprocessor tasks.
Boiling and Convective Heat Transfer Characteristics of Nanofluids
Authors: Murshed S.M. Sohel , de Castro C.A. Nieto , Lourenço M.J.V. , Lopes M.L.M. , Santos F.J.V.
Published: October 2011

Nanofluids have attracted great interest from researchers worldwide because of their reported superior thermal performance and many potential applications. However, there are many controversies and inconsistencies in reported experimental results of thermal conductivity, convective heat transfer coefficient and critical heat flux of nanofluids. In this paper, two major features of nanofluids, which are boiling and convective heat transfer characteristics are presented besides critically reviewing recent research and development on these areas of nanofluids.
Hybrid System Model Simulation Framework for Cyber-Physical Systems
Authors: Moon Soo Young , Park Hyuk , Cho Tae Ho , Kim Won Tae
Published: October 2011

Most of existing frameworks for modeling and simulation of hybrid systems represent continuous behavior of systems using ordinary differential equations (ODEs). ODE models can be represented as discrete event system specification (DEVS) models through discretization and simulated in the DEVS simulation framework. However, in cyber-physical systems (CPS), it is difficult to represent the continuous behavior of a system using an ODE because it can have unknown, unpredictable variables. In that case, it is needed to predict the model’s next event time by inference to embed the model in a DEVS model. We propose the simulation framework in which a fuzzy inference module is added to each simulation model to determine its next event time. The proposed method enables simulation of hybrid system models which can or cannot be represented using an ODE.
An Investigation of Lean Implementation Status in Thai Manufacturing
Authors: Pradabwong Jiraporn , Sriariyawat Nantawut , Temiyasathit Chivalai
Published: October 2011

Lean Manufacturing has been widely adopted in various business and industries worldwide. To determine the current stage of Lean implementation in Thailand and the barrier Lean implementation, the qualitative research involving interview with 10 industrial companies practicing Lean manufacturing was conducted. The result from this study shows that most Lean practitioners understand the principal of Lean manufacturing. Different organization functions adopt different types of Lean tools and techniques as well as the performance measures depending on their business characteristics. However, there are three performance measures, which are manufacturing cost per unit, total sales and part per million (PPM) in defective products shipped to customers, that were adopted by all 10 companies. The most important barrier in Lean implementation is the cultural change since it requires the entire company participation. Finally, the companies participated in this study confirmed that they are satisfy with the result of Lean manufacturing though some companies have not completely adopted the Lean approach into their manufacturing process. To excellent the Lean manufacturing, companies are required to satisfy customer needs, improve the manufacturing process, and increase their flexibility. Furthermore, it is necessary for the top management to provide a clear policies as well as plan and direction. If Lean implementation is to be successful, the communication and human resource department are also the main keys.
Study of End Surfaces’ Deformation and Thermal Stress in Solid State Laser
Authors: Firoozeh Karimi Moghadam
Published: October 2011

High power solid state lasers have wide applications; they have extensively attracted many attentions. When laser pumped, a lot of heat produces in it causes thermal effects such as stresses end effect and variations of refraction index. In this paper, we analytically study the thermal effects in an Nd: YAG solid state laser crystal which is pumped in longitude with a second order Gaussian (super Gaussian) profile. In this survey we neglect z derivatives of temperature distribution and also consider a statement in which thermal condition of cooler system is much more than thermal condition of laser crystal. Then we apply proper boundary conditions to probe thermal distribution function and related thermal effects. It will be shown that use of second order Gaussian profile for output beam of diode lasers is a better approximation for calculating the thermal distribution and estimating the thermal lensing than the Gaussian profile.
A Ray Transfer Matrix Model for an Elastomeric Lens
Authors: Indias Johanna Mae M. , Go Clark Kendrick C.
Published: October 2011

A Ray Transfer Matrix (RTM) of a variable-focus elastomeric fluidic lens is explored and modeled in this paper. A HeNe (543.45nm wavelength) laser is incident on the tunable lens and the effective focal length changes are explored based on this model. Results show that there are two possible focal lengths and that focal lengths are independent of the elastomer thickness.
Study of Heat Transfer and Hydrodynamics in a Gas-Solid Fluidized Bed Reactor Experimentally and Numerically
Authors: Hamzehei Mahdi , Rahimzadeh Hassan , Ahmadi Goodarz
Published: October 2011

—In this research, the heat transfer and hydrodynamics of a gas–solid fluidized bed reactor were studied experimentally and computationally. A multi-fluid Eulerian computational model incorporating the kinetic theory for solid particles was developed and used to simulate the heat conducting gas–solid flows in a fluidized bed configuration. Momentum exchange coefficients were evaluated using the Syamlal–O’Brien drag functions. Temperature distributions of different phases in the reactor were also computed. Good agreement was found between the model predictions and the experimentally obtained data for the bed expansion ratio as well as the qualitative gas–solid flow patterns. The simulation and experimental results showed that the gas temperature decreases as it moves upward in the reactor, while the solid particle temperature increases. Pressure drop and temperature distribution predicted by the simulations were in good agreement with the experimental measurements at superficial gas velocities higher than the minimum fluidization velocity. Also, the predicted time-average local voidage profiles were in reasonable agreement with the experimental results. The study showed that the computational model was capable of predicting the heat transfer and the hydrodynamic behavior of gas-solid fluidized bed flows with reasonable accuracy.
Optimization of Shrinkage in Plastic Injection Molding Process Using Statistical Methods and SA Algorithm
Authors: Akbarzadeh Alireza , Sadeghi Mohammad
Published: October 2011

— Dimensional changes because of shrinkage is one of the most important problems in production of plastic part using injection molding. In this study, effect of injection molding parameters on the shrinkage in polypropylene (PP) and polystyrene (PS) has been investigated. The relationship between input and output of the process is investigated using regression analysis and ANOVA method. To do this, existing data is used. The selected input parameters are melting temperature, injection pressure, packing pressure and packing time. Effect of these parameters on the shrinkage of above mentioned materials is studied using mathematical modeling. For modeling the process, different types of regression equations including linear polynomial, Quadratic polynomial and logarithmic function, are used to interpolate experiment data. Next, using step backward elimination and 95% confidence level, insignificant parameters are eliminated from model. To check validity of the PP model, correlation coefficient of each model is calculated and the best model is selected. The same procedure is repeated for the PS model. Finally, optimum levels of the input parameters that minimize shrinkage, for both materials are determined. Simulated Annealing (SA) algorithm is applied on the developed mathematical models. The optimization results show that the proposed models and algorithm are effective in solving the mentioned problems.
Fault Detection in Tennessee Eastman Process Using Fisher’s Discriminant Analysis and Principal Component Analysis Modified by Genetic Algorithm
Authors: Nashalji Mostafa Noruzi , Razeghi Seyed Mohammad , Shoorehdeli Mahdi Aliyari , Teshnehlab Mohammad
Published: October 2011

This paper describes hybrid multivariate methods: Fisher’s Discriminant Analysis and Principal Component Analysis improved by Genetic Algorithm. These methods are good techniques that have been used to detect faults during the operation of industrial processes. In this study, score and residual space of modified PCA and modified FDA are applied to the Tennessee Eastman Process simulator and show that modified PCA and modified FDA are more proficient than PCA and FDA for detecting faults.
Determination of Complex Permittivity of Fly Ash for Potential Electronic Applications
Authors: Sreenivas V. Naren , Karthik D. , Kumar V. Aravinth , Sidharth V.D. , Sundaram T. Meenatchi , Sarkar Soumitro , Sabarish Narayanan B.
Published: October 2011

Disposal of fly ash obtained from thermal power plants is a major environmental concern. Fly ash contains large proportions of silica and ferrites. Investigation of its prospects as an electronic material provides scope for enhanced fly ash utilization. This involves measurement of relative permittivity and loss tangent. Experiments are carried out at X band frequencies in TE10 mode using standard klystron waveguide setup. Shorted Waveguide Method is used to determine the complex permittivity. The complex transcendental equation obtained is solved using Genetic Algorithm. Experimental results are compared with theoretical estimates based on Landau Lifshitz Looyenga (LLL) equation.
A New Genetic Algorithm for Designing Cellular Manufacturing Systems with Labor and Tools Issues
Authors: Gharbi Anis , Al-Ahmari Abdulrahman M. , Msakni Mohamed Kais , Al-Khalefah Hisham
Published: October 2011

This paper considers the problem of designing cellular manufacturing systems (CMS) with the presence of alternate process plans, tools and workers. The objective is to minimize the total costs of machine installation, operations, tools and workers with a number of identified practical constraints. A genetic algorithm is designed in order to efficiently solve medium and large sized problems. Preliminary numerical results show the worth of implementing the suggested procedure.
Study of close-Range Photogrammetric Method Using Ordinary Digital Camera
Authors: Mao Ying Dan
Published: October 2011

With the progressive development of photogrammetric technology, the digital photogrammetric method based on the basic principles of digital imaging and photogrammetry has replaced the traditional photogrammetric mapping method and has been widely promoted and applied. In this paper, it studies further the issues about the image processing and photogrammetric algorithms of common digital cameras based on some research results in the traditional field of close-range photogrammetry, and verifies with actual examples the application of using digital cameras to implement the close-range photogrammetric method to engineering is feasible.
Numerical Analysis of Single Phase Flow Pressure Drop in a Horizontal Rifled Tube
Authors: Lam Soo Poey , Abas Abdul Wahab , Ariffin Saparudin , Lee Woon Kiow
Published: October 2011

Numerical analysis by using Fluent® has been carried out to investigate the pressure drop of single phase flow in a 2 meter long of rifled tube and smooth tube which is placed horizontally. The rifled tube or also known as spiral internally ribbed tube that is used in this investigation has an outside diameter 45.0 mm and inside equivalent diameter1 of 33.1 mm while the smooth tube has an outside diameter 45.0 mm and inside diameter 34.1 mm. The working fluid that is used in this investigation is water. In this numerical analysis, realizable k-epsilon model has been chosen to solve the fully developed turbulence flow in both the tubes. The result of the pressure drop which is obtained from simulation shows that the pressure drop in rifled tube is about 1.69-1.77 times much higher than pressure drop in smooth tube. The high pressure drop in rifled tube comparing to smooth tube is due to the helical rib in the rifled tube which causes swirling effect near the wall. A correlation has been proposed for the single phase friction factor of the rifled tube.
Study to Improve the Computation of the Oil Spill
Authors: Nga Duongthi Thuy
Published: October 2011

This paper presents an improved oil spill model, coupled with a current model based on a 2D finite-difference grid. The aim of this study is to make the models more accurate and faster than the old ones. The current model gives the velocity distribution on the surface of water body and in the case of transient analysis, the velocity distribution is computed at each computational time step. This velocity distribution will be taken as the input for the oil transport simulation model. The oil spill model computes and predicts the oil distribution and the spill size. There are two improvements in this research: moving boundary to get the more correct results and nested grid to help the models run fast. The computational results in the study area are agreement to experimental results and real data in Can Gio coastal zone. So they can be applied in reality.
Fossil Epitheca Measurement as a New Method: Retrieval of the Earth’s Climate 310 Million Years Ago the Oldest Weather Glass
Authors: Zhang Wei Jia , Yu Hang Jie
Published: October 2011

Research on very fine fossil corals from Shiqiantan Fm, Xinjiang (310Ma) which have very clear growth lines caused by diurnal increments of calcium carbonate deposition provides important information about ancient climate. This result breaks the record of the oldest remaining material for detailed climate analysis. Data showed distinct seasonal variations, separating ancient climate into four seasons. Storms are frequent in summer during at that time. And the sea temperature exceeded ~30°C for a month in mid-summer. Equipped with this new method, a specific day’s climate, cloudy or shining, can be studied from the diurnal patterns.
Optimization of Optical Wavelength Conversion in SOI Waveguide
Authors: Hussain Ashiq , Sang Xin Zhu , Yu Chong Xiu , Muneer Abid , Latif Abdul , Hussain Aftab , Freeha Freeha
Published: October 2011

In this paper the wavelength conversion in a 1cm long silicon-on-insulator (SOI) waveguide has been investigated numerically. The wavelength conversion efficiency is optimized by analyzing free carriers absorption (FCA) loss generated by two-photon-absorption (TPA). The free carriers life time is focused while other factors influencing noise figure are also considered.
Study on the Rubrene Emission Sensitized by a Phosphorescent Ir Compound in the Host of CBP
Authors: Xu Deng Hui , Li Xiong
Published: October 2011

To obtain the maximum luminous efficiency from an organic material, it is necessary to harness both the spin-symmetric and anti-symmetric molecular excitations (bound electron–hole pairs, or excitons) that result from electrical pumping. Here, we demonstrate that this deficiency can be overcome by using a phosphorescent sensitizer to excite a fluorescent dye. The photoluminescence and sensitization effect between tris (2-phenylpyridine) iridium (Ir (ppy) 3) and 5,6,11,12-tetraphenylnaphthacene (rubrene) in the host of 4,4'-N,N-dicarbazole-biphenyl (CBP) were investigated. The energy transfer characteristics in the electroluminescent process of the system of CBP, Ir (ppy) 3 and Rubrene has been discuss in this article. The Ir (ppy) 3 sensitizer affords an effective way to improve the device performance. In the organic light-emitting diodes based on the Ir (ppy) 3, rubrene and CBP system, both the singlet and triplet excitons can be used.
Biomechanical Research on Plantar Pressure Distribution in Different Landing Condition
Authors: Chen J.J. , Li Jian She , Gu Yao Dong
Published: October 2011

With the increase of the difficulty and intensity on competitive movement, the rate of sport injury will happen in training and competing frequently. The metatarsal is one of the most prone to injury part in the human body. The incidence of metatarsal injuries is rising in recently years. In this study, Pedar-X plantar pressure measure system and Novel emed pressure distribution measure plate were used in order to get the dynamics data in normal landing and inverted landing. The research concluded that: metatarsal peak stress had been transferred from the first metatarsal to the fifth metatarsal with increasing of varus angle. When the foot was in inverted state, stress distribution of metatarsal changed significantly. Lateral metatarsal played a major role in supporting function. Also, forefoot pressure distribution changed a lot in different functional sports shoes. The purpose is to provide the reliable correlative theoretical basis for improving sport equipments and security protection recommendations for people to engage in sports.
Solution of Free Vibration Equations of Euler-Bernoulli Cracked Beams by Using Differential Transform Method
Authors: Torabi K. , Dastgerdi J. Nafar , Marzban S.
Published: October 2011

In this paper, free vibration differential equations of cracked beam are solved by using differential transform method (DTM) that is one of the numerical methods for ordinary and partial differential equations. The Euler–Bernoulli beam model is proposed to study the frequency factors for bending vibration of cracked beam with ant symmetric boundary conditions (as one end is clamped and the other is simply supported). The beam is modeled as two segments connected by a rotational spring located at the cracked section. This model promotes discontinuities in both vertical displacement and rotational due to bending. The differential equations for the free bending vibrations are established and then solved individually for each segment with the corresponding boundary conditions and the appropriated compatibility conditions at the cracked section by using DTM and analytical solution. The results show that DTM provides simple method for solving equations and the results obtained by DTM converge to the analytical solution with much more accurate for both shallow and deep cracks. This study demonstrates that the differential transform is a feasible tool for obtaining the analytical form solution of free vibration differential equation of cracked beam with simple expression.
Active Stabilization of a Two-Satellite Tether in Elliptic Orbits Using Coulomb Forces
Authors: Zhang Hao , Zhao Yu Shan , Shi Peng
Published: October 2011

This paper investigates the dynamics and control of a charged two-craft tether formation in elliptical orbit. Due to the fact that the inter-spacecraft Coulomb forces are not sufficient to stabilize the tether, a method of hybrid control is proposed which uses conventional thrusts and Coulomb forces. A feedback control law is developed which could asymptotically stabilize the tether size and attitude while mitigating plume impingement issues. The equations governing this system are periodic in time, thus a feedback control using constant gains can not work. A periodic control law is suggested basing on Floquet theory. The control law consists of two main parts. First Floquet transformation is utilized to transform the system into a new linear system with a constant state matrix but a periodic control matrix. Then a feedback control is used to stabilize the new system. Numerical examples are provided to demonstrate the performance of the control law.
Efficiency Improvement of an Axial Flux Permanent Magnet Brushless DC Motor for LVAD Application
Authors: Neethu S. , Shinoy K.S. , Shajilal A.S.
Published: October 2011

This paper presents the Finite Element Analysis (FEA) based design, optimization and development of an axial flux permanent magnet brushless DC motor for Left Ventricular Assist Device (LVAD). With the design objective of improving the existing motor's efficiency , different topologies of AFPM machine has been examined. Selection of optimal magnet frac-tion, Halbach arrangement of rotor magnets and the use of Soft Magnetic Composite (SMC) material for the stator core results in a novel motor with improved efficiency and torque profile. The results of the 3D Finite element analysis for the novel motor have been shown.Thermal analysis for the existing motor has also been done and the FEA results are compared with the analytical and experimental results.Finally the test results for the novel motor and the general conclusions are also discussed.
Exact Elasticity Solution for the Density Functionally Gradient Beam by Using Airy Stress Function
Authors: Daneshmehr Alireza R. , Momeni Saeed , Akhloumadi Mahdi Reza
Published: October 2011

In this paper the problem of a density-functionally gradient beam subjected to uniform load is studied. Airy stress function methodology is used to obtain a set of analytical solutions for simply supported and clamped beams subjected to uniform load. A stress function in the form of polynomial is proposed and determined. The treatment for fixed-end boundary conditions is the same as that presented by Timoshenko and Goodier (1970). By this method all of the analytical plane-stress solutions can be obtained for a uniformly loaded isotropic beam with rectangular cross section under different types of classical boundary conditions.
Product Design Aspects for Design of Accurate Mass Properties Measurement System for Aerospace Vehicles
Authors: Gopinath K. , Raghavendra K. , Behera M.K. , Rao E.V.Subba , Umakanth M. , Gopinath S.
Published: October 2011

Mass properties of aerospace vehicle viz Weight, Center of Gravity (Xcg, Ycg, Zcg) & Mass Moment of Inertia (Ixx, Iyy & Izz) are critical inertial parameters which are vital to meet the intended mission objectives. Accurate mass properties measurement is needed for fast maneuvering aerospace vehicles to meet the Control and Guidance requirements within the tolerable limits generated by the System Designer. Mass properties estimation is vital during the configuration design phase of an aerospace vehicle. Assumptions and Constraints during the configuration design, limits the accuracy of estimations making the mass properties measurement mandatory. The mass properties of the aerospace vehicle can be measured by numerous methods, but for achieving high accuracies within the tolerable limits, the measurement system should have advanced technologies and measurement methodologies. Based on the experience, mass properties measurement systems were designed using Load Cells and Cross-Flexural Pivots in two different systems (Weight and CG in System-1, MOI in System-2), which have limited accuracy and also involves tedious external measurements. Adopting Air-Bearing (T / H / Spherical shape) supported with accurate sensors using Inverted Torsion Pendulum method, Multiple Point Weighing method and a proper measurement methodology, enhances the accuracy of the measurement system. Usage of spherical bearing yields a better accurate system but has the difficulty in realization of the system indigenously, whereas use of T or H-shape bearing is a feasible solution for achieving the desired accurate mass properties specifications. This paper gives an insight into to the product design aspects to be considered for realization of accurate mass properties measurement system.
Comparative Dynamic Response of a Optimized Single Link Flexible Manipulator
Authors: Mahto S. , Dixit U.S.
Published: October 2011

—In this work, comparative study for dynamic response is carried out for optimized single link flexible robotic manipulator under various types of excitations. Manipulator is considered as an Euler-Bernoulli beam and shape is optimized for circular area of cross-section. Finite element method is used to obtain fundamental frequency and sequential quadratic programming (SQP) is used for its maximization.
Control System Development of Grating Ruling Engine Based on MATLAB/Simulink
Authors: Liu Dong Cai , Shen Yuan , Zhong Jun , Lian Guo Fu , Zhu Chang An
Published: October 2011

This paper presents the control system development of a diffraction grating ruling engine. The grating ruling engine which consists of a ruling subsystem and a indexing subsystem including a outside stage (coarse stage) and a inside stage (fine stage) and which realize groove densities of 6000 grooves/mm, maximum ruled area of 300 (groove length) × 300 (width) and nanometer level positioning error has been designed. The ultra-precision requirement demands not only precision mechanical structure but also advanced control system, both of whose development take long time. To shorten development period and reduce the costs, concurrent control system development combined with MATLAB/Simulink is implemented. The control software constructs graphic user interface to show the virtual grating ruling engine and provides interface with Simulink module. Various control algorithms, which are written in C language to facilitate future code porting, is verified in Simulink. Finally, single neuron PID control algorithm is adopted. The control software starts Simulink simulation and emulated data which is transferred from Simulink to software is used to control virtual engine to move corresponding. After the completion of simulation, the algorithm is ported into software to control the real ruling engine. The simulation and experimental results demonstrate that combined simulation is an effective approach and that the positional accuracy has been readily achieved within 9.2 nm.
An Implementation of Lean Technology in an in-Plant Manufacturing System, a Funiture Company
Authors: Le Ngoc Quynh Lam , Do Ngoc Hien , Nam Ki Chan
Published: October 2011

The development of the Toyota Production System (TPS) based on principles of lean technology has especially impressed numerous manufacturers around the world. It attaches remarkable importance to reducing and then eliminating waste and focusing on added-value activities. Lean technology is growing in important and scope because they help companies become more competitive and streamlined at a time when competitive and cost reduction pressures have intensified. Accordingly, a studied furniture company intends to transform its shop floor first to lean system. It is really an interesting and practical case study, so this paper presents an implementation of lean technology in an in-plant manufacturing system through a systematic way, step by step. It could be considered as a reference of an implementation of the lean technology.
Increasing the Image Contrast of Atomic Force Microscope by Using Improved Rectangular Micro Cantilever
Authors: Sadeghi Ali
Published: October 2011

The resonant frequency of flexural vibrations for an atomic force microscope (AFM) cantilever has been investigated using the Euler-Bernoulli beam theory. The results show that for flexural vibration the frequency is sensitive to the contact position, the first frequency is sensitive only to the lower contact stiffness, but high order modes are sensitive in a larger range of contact stiffness. By increasing the height H, for a limited range of contact stiffness the sensitivity to the contact stiffness increases. This sensitivity controls the image contrast, or image quality. Furthermore, by increasing the angle between the cantilever and sample surface, the frequency decreases.
Automatic Global Registration of 3D Point Clouds for Reverse Engineering and Inspection Processes
Authors: Imbert Mariano , Li Xiao Xing
Published: October 2011

Registration of 3D point clouds is one of the most fundamental phases during the process of reverse engineering and most challenging at the same time. This phase consists on matching two or more different point clouds into one data set in order to have them share the same global coordinate system. In this paper we present a new approach for automatic registration of 3D point clouds that uses the genetic algorithm (GA) as a global optimization method. We introduce a trips extraction technique for rough registration, which extracts important geometric information from a point cloud. Another contribution in this paper is the introduction of the Interpenetration Fraction Measure (IFM), which maximizes the number of points that overlap two different point clouds. The algorithm we present also takes advantage of the parallel computing power of today’s multi-core processors, and other techniques for further efficiency. Finally, we present some experimental data with comparisons for analysis and further discussion about the algorithm’s performance.
Library Structure of Dynamic Simulation for Combined Heat and Power Plant in Modelica Language
Authors: Razak Amir A.
Published: October 2011

The most common form of energy recycling system is Combined Heat and Power (CHP) plants. The CHP plant is a complex system and still under intensive development by many researchers. The system needs to be developed in quick and efficient manners with low resources based on modeling and simulation method. With the development of CHP library in open source Modelica language, it could be used as a base for further advancement of CHP technology. The aim of this work is to design a structure of initial version of a model library for the dynamic simulation of Combined Heat and Power plants (CHP). Modular approach and top-down design have been implemented in the model library development. A solid base for this work is defined which includes rules in modeling the components (e.g. robustness and reusability), default library structure arrangement and model documentation. By strictly follow the rules and concepts introduced in this work, the mistakes in modeling is minimized. The designed library in Modelica language will provide an organized environment in modeling a CHP plant.
Design and Prototyping of a Linear Electromechanical Actuator
Authors: Figueroa Alexis , Lin Yan
Published: October 2011

This paper presents the design and prototype of an electromechanical actuator with some constraints that allow creating a feasible prototype with reasonably accuracy. Also, was consider the variation of friction forces due to changes in load conditions to obtain the mathematical relation between the maximum load, the required motor torque and the maximum angular acceleration of the payload; important parameters that contribute to determine the suitable motor.
Station-Keeping Control Law Design of Near-Space Airship with Wind Interferences Based on Control Allocation Strategy
Authors: Di Xiao Guang , Yang Ya Fei , Han Xue , Ma Ke Mao
Published: October 2011

This paper presents a method for solving the station-keeping problem of near-space airship (NSA) at an altitude of 22km above sea level with wind influence. Firstly, according to the system overall configuration, the nonlinear mathematical model of NSA is established. Secondly, considering the steady wind and turbulence influences, the station-keeping control law of NSA longitudinal plane which divided into forward control loop and vertical control loop is designed. The vertical position control loop adopts the dual PID control method. In order to improve attitude response performance and decrease energy consumption of actuators, attitude control allocation strategy between fins and vectored thruster is provided. At last, the simulation experiment proves the validity of the proposed station-keeping control method of NSA.
Nanoimprint Photonic Crystal Film Enhanced Light-Trapping in a-Si Thin Film Solar Cells
Authors: Chu Wei Ping , Juang Fuh Shyang , Lin Jian Shian , Lin Tien Chai , Kuo Chen Wei
Published: October 2011

We utilize photonic crystals to enhanced lighttrapping in a-Si:H thin film solar cells. The photonic crystals effectively increase Haze ratio of glass and decrease reflectance of a-Si:H solar cells. Therefore, increase the photon path length to obtain maximum absorption of the absorber layer. The photonic crystals can effective in harvesting weakly absorbing photons with energies just above the band edge. We were spin coated UV glue on the glass, and then nanoimprint of photonic crystals pattern. Finally, used UV lamp was curing of UV glue on the glass. When the 45∘composite photonic crystals structures, the haze was increase to 87.9 %, resulting the short circuit current density and efficiency increasing to 13.96 mA/cm2 and 7.39 %, respectively. Because 45∘composite photonic crystals easy to focus on the point of light lead to the effect of scattering can’t achieve. So, we designs 90∘V-shaped photonic crystals structures to increase scattering. When the 90∘V-shaped photonic crystals structures, the Haze was increase to 93.9 %. Therefore, the short circuit current density and Efficiency increasing to 15.62 mA/cm2 and 8.09 %, respectively. We observed ~35 % enhancement of the short-circuit current density and ~31 % enhancement of the conversion efficiency.
Design of Neural Network for Satellite’s Attitude Control Systems
Authors: Montenegro Salomon , Luna Lenin
Published: October 2011

The objective of this paper is to design a neural network-based residual generator to detect the fault in the actuators for a specific communication satellite in its attitude control system (ACS). First, a design of dynamic neural network with dynamic neurons is done, those neurons corresponds a second order linear Infinite Impulse Response (IIR) filter and a nonlinear activation function with adjustable parameters. Second, the parameters from the network are adjusted to minimize a performance index specified by the output estimated error, with the given input-output data collected from the specific ACS. Then, the designed dynamic neural network is trained and applied for detecting the faults injected to the wheel, which is the main actuator in the normal mode for the communication satellite. Then the performance and capabilities of the designed network were tested and compared with a conventional model-based observer residual, showing the differences between these two methods, and indicating the benefit of the proposed design to know the real status of the momentum wheel. Finally, the application of the methods in a satellite ground station is discussed.
Two Output OTA Biquad Filter
Authors: Qadir Abdul
Published: October 2011

This paper presents a current mode biquad filter, which uses multiple output OTAs. The proposed filter design has electronic tunability because of the use of OTAs and is suitable for implementation in CMOS technology because of the use of grounded capacitors.
Solving Problems in Chaos Control though an Differential Evolution Algorithm with Region Zooming
Authors: Gao Fei , Qi Yi Bo , Yin Qiang , Xiao Jia Qing
Published: October 2011

In this paper, a novel scheme is propose to solve the problems in chaos control via a nonnegative multi–modal nonlinear optimization, which finds the unstable periodic orbits and best parameters of chaos system such that the objective function is minimized. The novel scheme embeds with a differential evolution algorithm consisting of techniques in three aspects: uniform design to the initial population, deflection and stretching to the objective functions, and the region zooming self–adaptively, which result in a much more effective searching mechanism with fine equilibrium between exploitation and exploration. To exhibit the new scheme’s performance, the experiments done to Hénon, Chen and Lü system are given, and the simulations done show that the method has better adaptability, dependability and robustness.
Silver Nanoparticles Supported on Ordered Mesoporous Carbon for Formaldehyde Electrooxidation
Authors: Kong Ling Bin , Wang Ru Tao , Wang Xiao Wei , Yang Zhen Sheng , Luo Yong Chun , Kang Long
Published: October 2011

Metal nanocatalysts, as the anodic materials, have become increasingly important in fuel cells due to their unique physical and chemical properties. Here we report the ordered mesoporous carbon (CMK-3) supported silver nanocatalysts have been prepared through the wet chemical reduction by using the reduction of formaldehyde. The electrochemical properties of the Ag/CMK-3 nanocatalysts for formaldehyde oxidation are studied by cyclic voltammograms (CV) and chronoamperometric curves (i-t) in alkaline aqueous solutions. The results show that the peak current density (from CV) of the Ag/CMK-3 electrode is 112 mA cm-2, above 2 times higher than that of Ag/XC-72 at the same Ag loading (14.15 μg cm-2). Furthermore, the i-t curves demonstrate that the Ag/CMK-3 nanocatalysts are efficient and stable electrocatalysts for anodic oxidation of formaldehyde in alkaline solutions. Our results indicate that the application potential of Ag/CMK-3 nanocatalysts with the improved electrocatalytic activity has far reaching effects on fuel cells and sensors.
CROPS - A Decision-Making Aid Tool for Product Redesign
Authors: Romli Fairuz Izzuddin , Cheang Kian Hou , Chew Jun Xian
Published: October 2011

Change Ranking of Product Subsystems (CROPS) is a computer program that is designed to act as a decision-making aid for designers during early stages of their product redesign process. It generates a ranking of all subsystems within the existing product design architecture based on their estimated redesign risk. This information assists designers in selecting the right existing subsystems to be initially changed to satisfy the driving requirements, which have to be quickly decided. In this program, evaluation of redesign risk captures both direct and indirect change effects that potentially result from the modification of each subsystem. Designers are provided with a relative reference as to how risky and extensive it is to change one subsystem over the others, which can be useful when they have options to pick between several subsystems to modify for the same redesign requirement.
Effect of Propanetriol on the Electrochemical Behavior of Nano Fumed Silica Gel
Authors: Sun Cheng Fang , Cheng Fa Liang , Chen Mei Qiong , Zhang Min , Cai Zhi Quan
Published: October 2011

The effect of propanetriol on the electrochemical properties of nanofumed silica gel of Valve-regulated lead-acid (VRLA) batteries have been investigated by means of cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), transmission electron microscope (TEM) and linear sweep voltammetry (LSV). The results show that with the adding of propanetriol the redox peak current density of the lead electrode greatly increases and the reaction resistance reduces obviously. Additionally, the oxygen reactions take place less easily in the gels containing propanetriol. The content of the additive propanetriol also relates with the gel properties. It is proved that the electrochemical properties of gel contained excessive propanetriol (4wt. %) are not as good as that contain 1wt.%~3wt.%.
A Method of Optimizing the Scheduler for Improving the Performance of the OSEK OS
Authors: Hong Jaeseung , Kum Daehyun , Jin Sung Ho , Cho Jeong Hun
Published: October 2011

OSEK OS is a very static system. all of the functionality of the system is already defined in the design phase. During Operation, the change of the system functionalities does not occur. Thus, we propose a optimized implementation of the scheduler for OSEK OS based on predictable system features to improve the functionality of the Real-time system.
Capacitive Micromachined Ultrasonic Transducer Based Gas Sensor Modeling and Simulation
Authors: Kumar K. Senthil , Saha Saral , Pradhan P.C. , Sarkar Subir Kumar
Published: October 2011

Micro Electro Mechanical Systems (MEMS) based Ultrasonic Transducers presents several advantages for some applications such as ease of array fabrication, unique thermal manipulation capabilities. Micromachining allows us to miniaturize device dimensions and produce capacitive transducers whose performance is comparable with their piezoelectric counterpart. Computer simulation has been widely used for MEMS based system. The main advantage of computer simulation is to provide design optimization by varying geometry, layer dimension and materials of the device without actual fabrication. This systematic approach can save time and cost of device fabrication and experimentation. In this work, a model of Capacitive Micromachined Ultrasonic Transducer (CMUT) is simulated in COVENTORWARE software. The solver is used to analyze the electrical current flow, voltage and heat and stress distribution in the device. The result is used to predict the temperature and stress as a function of the applied voltage across heating layer. The displacement results are used in the mechanical analysis to predict the mechanical behaviour of the CMUT. Here two different types of dielectric materials Si3N4 and Zr02 are used. The optimization is performed mainly based on resonant frequency and collapse voltage. Then we use this model as a gas detector (Sensor) to detect gas like Methane.
Design Considerations for Electrostatic Energy Harvester
Authors: Abdulmunam Rita T. , Taha Luay Yassin , Ivey Paul
Published: October 2011

This paper presents the design considerations and the design procedure for low and medium power electrostatic energy harvester. First, the principle of electrostatic harvester is discussed then the design considerations are analyzed and assessed. Our assessments indicate that the electrostatic generator requires motion energy at low frequency to achieve higher power generation. This motion produces a higher power per unit volume in comparison to the vibration. The best material that can be used for the electrodes is silver as it has a higher conductivity, reliability, stability and it can handle high voltage up to 100 V when compared to the other common capacitor materials. The in-plane overlap realization method can be considered to be a suitable choice when applied to variable capacitor machine. With regard to the conditioning circuits, the switched capacitor regulator is the most appropriate option as it can solve the sizing problem and provides solution for the up or down conversion of voltage when comparing it with the other conditioning circuits. Finally, we propose a general electrostatic harvester design procedure according to the addressed designed considerations.