bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Thermal Barrier Coating on Piston Crown for Compressed Natural Gas with Direct Injection Engine
Authors: Helmisyah A.J. , Abdullah Shahrir , Ghazali Mariyam Jameelah
Published: March 2011

The top land of a piston normally known as the piston crown is an engine part that is continuously exposed to extreme temperature and pressure during combustion. For a compression ratio level, the compressed natural gas with a direct injection system (CNGDI) typically uses a range of compression ratio between gasoline and diesel engines, producing extremely high temperature and pressure which lead to high thermal stresses. Consequently, the piston crown is exposed to direct combustion due to the vertical movement of the piston, leading to various possible damages of thermal stresses. In contrast to a petrol fuelled internal combustion engine, natural gas combustion creates a dry condition in the combustion chamber, inducing cooling difficulties in the engine. Without good heat transfer, the piston crown materials will soon fail to withstand high temperature and operate effectively. Alternatively, any sort of insulation inside the combustion chamber such as applying ceramic coatings may protect the piston crown surface and affect the overall combustion process, as well as improving the engine performance and the exhaust emissions. By reducing the heat loss of a cylinder bore, a higher thermal efficiency of an engine can also be improved by applying a surface thermal insulation, namely; thermal barrier coating (TBC). Thus, in this study, a ceramic based TBC, yttria partially stabilised zirconia (YPSZ) coating was used to compare with conventional tin coated (Na2SnO3) and uncoated piston crown in terms of heat concentration. Moreover, a set of average value of combustion temperature of a CNGDI engine was selected. Detailed analyses using a finite element analysis (FEA) technique was utilised in order to determine the location of hotspots via distribution profiles of temperature. It was noted that the maximum heat flux of the uncoated piston crown was much higher than that of tin coated and YPSZ coated piston crown. Heat flux value reached about 62% of decrement due to lower conductivity levels of piston crown.
Research on the Shear Strength and Microstructure Change Regulation of Cement-Mixed Soil under Erosion Environment
Authors: Zhu Lei , Zhang Hua Jie
Published: March 2011

In order to research the mechanical properties and microstructure change regulation of cement-mixed soil under erosion environment, several experiments are carried out in laboratory. The changes of shear strength of cement-mixed soil are recorded under different erosion environments and in different erosion periods. Their corresponding photomicrographs are also shot to reveal the damage on cement-mixed soil under erosion environment. The results indicate that the shear strength of cement-mixed soil in erosion solutions is worse than the strength by the natural curing in the corresponding period. As erosion time increases the strength of cement-mixed soil dipped in , and solutions keeps on downtrend, whereas the strength of that dipped in unpolluted water and solution presents upward trend. The erosive effects of cement-mixed soil are mainly caused by and , meantime has more prominent erosive effect on cement-mixed soil than . Accompanying with stadium increasing quantitative parameters of microstructures are all varying markedly and have certain regulation which testifies the notable relativity between the shear strength and microstructural parameters. Liner regression methods are set up to indicate the relationship of shear strength indexes and microstructural parameters in the erosion environment.
Hazard of Vibration and Healthy Risk Assessment for Domestic Dump Truck Driver in Taiwan
Authors: Chang Ming Kuen , Li Yu Fong , Huang Hong Wen
Published: March 2011

This research expects to investigate yet at domestic-dump truck driver, carry on the preliminary vibration determination. This research studies ten dump trucks in Yunlin County and precede questionnaire at the sandstone field. The ISO 2631-1:1997 and Article 301 in Taiwan’s regulation “Rules of Equipment and Measures for Protecting Labors’ Safety and Health” are used to evaluate tolerable exposure time per day for drivers. And in accordance with ISO 2631-5:2004 to assessment healthy risk for dump truck driver. In accordance with Article 301 of Labor Safety and Health regulation in Taiwan’s to estimate tolerable exposure time. A half tolerable exposure time present lower than 8 hours. In accordance with ISO 2631-1:1997 to estimate tolerable exposure time, no matter use equation B.1 or B.2 to calculate tri-axis compose acceleration. All tolerable exposure time present lower than 8 hours. If basis of ISO 2631-5:2004 to evaluation healthy risk for driver.
An Optimal Soft Landing Control for Moon Lander by Means of Measures
Authors: Fakharzadeh J.A. , Salehi Sajad
Published: March 2011

Designing a new control strategy for a moon lander to achieve an optimal soft landing, is the main purpose of this paper. For the dynamical system of the propeller to achieve the lowest level of fuel consumption, the problem of soft landing is presented as an optimal control one. Representing this into a variational form, transferring to an optimization problem on a measure space and then determining the optimal solution via a linear programming problem is the new solution path. This method has some important advantages in compare with the other, which are explain within a numerical simulation.
Bearing Capacity Prediction of Building Pile in Soft Soil Region in China by Using Support Vector Regression
Authors: Hua Xin Ruo
Published: March 2011

The common determination method of pile point and pile bearing capacity always depends on the practical experiences. The accuracy of pile survey data should be verified in the field. To predict the pile point and pile bearing capacity, a prediction model based on support vector regression algorithms has been developed. The friction resistance around piles and the static-load settlement are the inputs. The pile point bearing capacity characteristic value and the characteristic value of pile bearing capacity are the outputs. The prediction model is trained by the data in the adjacent block and validated by the field data in the project. The calculations of 40mm settlement and the prediction of other piles in the project can then be acquired. Compared to the survey data, the predicted values has 16% surplus. This will be beneficial to reduce construction work significantly and to save about 5% foundation cost.
Effect of Turbulence Model on Simulation of Trailing Vortex around Ahmed Body
Authors: Yang Xiao Long , Hu Kai Yao , Lin Tie Ping , Yang Jia
Published: March 2011

The Realizable k-ε Reynolds averaged Navior-Stokes (RANS) turbulence models and SST k-w detached eddy simulation (DES) models are investigated for simulation of external flow and trailing vortex around Ahmed body. The 3-D N-S equations are solved with central finite volume scheme and half-implicit SIMPLE method. The time average parameters of the DES results, such as the pressure, velocity field and drag coefficient Cd, are verified by comparing with RANS and experiment data. The vortex structures of vertical, horizontal plane and cross-section, along with the turbulent kinetic energy of tail vortex are studied in details. The results show that for time averaged parameters both models can get reasonable results, while for capturing the instant flow structure, DES shows advantage over RANS model.
Equation for Predicting Shelf Life of an Apple
Authors: Bhosale A.A. , Sundaram Kalyan
Published: March 2011

The shelf-life of a Fruit is critical in determining both its quality and profitability. Everyone benefits from healthy produce. Approximately Rs.105Crores {$200million} is lost each year in India due to waste caused by post harvest diseases, poor temperature management, bruising and other factors. Shelf life is nothing but date of minimum durability. An apple is not dead at the time of harvest. It remains a living, respir¬ing organism and continues to take in oxygen and give off carbon dioxide and another gas, ethylene. Since the apple is no longer receiving nutrients from the tree but is still respiring, it must use up the food it has stored over the growing season. The low temperature, high humidity, and exchange of gases through air circulation serve to slow those natural events as much as possible. A mathematical relationship has been established for predicting the shelf life of an apple. Our study quantitatively takes in to account parameters such as firmness, colour of apple, atmospheric temperature, and respiration rate. This fundamental equation could be potentially used by farmers, food malls, and big food chains. This relationship can be extended to predict shelf life of perishable fruits.
Welding Stress Analysis of Manhole of Liquid Ammonia Storage Tank Based on Gauss Heat Source
Authors: Zhang Jin Zhou , Xiong He Gen , Shuai Yu Mei
Published: March 2011

Safety and reliability of liquid ammonia storage tank is very important. The stress of manhole is high and complex, so it is necessary to analyse welding stress of manhole of liquid ammonia storage tank. This paper ignored the complex process in the weld pool, simulated complex thermal process in weld pool by continuous conductive welding heat source, deduced the calculation formula of maximum stress by establishing Gaussian heat source model of carbon dioxide welding, and modified stress exponent k of cylindrical pressure vessel. This new method has a positive meaning for welding stress analysis of pressure vessel.
Measurement Slub Yarn Parameter by Parallel-Plate Capacitor
Authors: Liang Jun , Zhao Lian Ying , Xu Bo Jun
Published: March 2011

Process Parameter of slub yarn determine style of its fabric. A new method of measuring process parameter of slub yarn was put forward to improve precision and efficient . The basic principal of parallel-plate capacitor was introduced in this paper. And sample yarns were tested with test system of slubby yarn developed by ourselves. Time sequence for slub length and slub space of slubby yarn can be gotten. And distribution of slub length , slub space and slub scaling factor can also be obtained. The agreement can be attained compared with those original setting. Some error was analyzed also. Consequently this testing system is effectively, and can be adopted in practice.
Analysis and Improvement for K-Means Algorithm
Authors: Xiao Jing Zhong , Xiao Li
Published: March 2011

K-Means algorithm is one of the mostly used foundation algorithm in data mining, it base on a greedy clustering algorithm. This paper will introduce this algorithm and analysis. Then prove the correctness of the algorithm. And then show the productivity of this algorithm. And at last, this paper will show some improvement to K-Means algorithm, including how to choose initial center points, and how to calculate the means. This will improve the algorithm at a certain extent.
A Graph Clustering Algorithm for the Homology Detection
Authors: Xiao Li , Xiao Jing Zhong
Published: March 2011

In order to detect a large number of source program samples which are homologous files (files with plagiarism), a new graph-based cluster detection algorithm is proposed，the algorithm is divided into two phases, in the first phase, proposed algorithm based on the keyword program to calculate pairwise similarity in the detected sample program files,in the second stage,by means of graph clustering algorithm, the results of the first phase is dectected, homologous files (files with plagiarism) will form a cluster. The simulation results shows that the algorithm improved detection rate compare with the traditional homologous files detection algorithm and can determine which files are homologous.
Research about Application of Informatization Service on Tourism Economy Management
Authors: Wang Xiao Fei
Published: March 2011

In the internet age, normalization has become an important means to optimize structure of tourism and improve level of tourism services. Tourism informatization service for tourists has achieved its initial success; it has provided convenience for tourists’ trip to book tourism online and publish destination information online. So, it is necessary to carry on discussion and research on the service’s current situation, characteristic and development trend of tourism informatization service for tourists. This article has analyzed main restraining factors of informatization service in tourism economy management, and proposed corresponding management countermeasures for existing problems.
Performance of Cryogenic Machining with Nitrogen Gas in Machining of Titanium
Authors: Mon Thet Thet , Ramli J. , Abd Razak Jeefferie , Sharif Safian , Venkatesh V.C.
Published: March 2011

This research presents performance of nitrogen gas as a coolant in machining titanium. Compressed nitrogen gas stored in a cylindrical tank is supplied to the cutting zone via the stainless steel tube of 2x8x25mm (inside diameter x outside diameter x length) connected to the flexible hose and specially-designed valve with pressure controller. Machining experiments are carried out on conventional turning center. The cutting tool used is triangular insert of ISO-TPGN160308 with the holder (ISO-CTGPR3232K). The cutting insert grade is KC5010 (TiAlN3 coated carbide) as recommended by Kennametal for machining titanium. During machining, the tube is manually directed to be just-above the tool rake face and the nitrogen gas is supplied with high pressure so that the cutting zone receives an effective cooling as well as the chip brakes easily. The effectiveness of this new cooling strategy is demonstrated by the cutting edge condition and surface finish after machining at various speeds, and also by comparing with performance of conventional coolant. The result is found to be excellent in terms of relative amount of tool wear and surface finish. The cutting insert has surprisingly remained almost intact when using nitrogen gas coolant whereas severe tool wear occurred with conventional coolant even at low cutting speed. This cryogenic strategy also improved machined surface quality greatly.
Measurement and Analysis on Transient Thermal Characteristics of High Speed Motorized Spindle
Authors: Deng Gui Ling , Zhou Can
Published: March 2011

Thermal deformation is an important factor to affect the accuracy of the motorized spindle, the core component of high-speed machine tool. To understand the spindle system transient thermal characteristics of the high-speed turning center CH7516GS, some high-precision sensors and high-frequency data acquisition system is used to establish the temperature and displacement measuring system. The thermal deformation compensation model is established on the basis of the experimental test results.
Destination-Generalized Multi-Next-Hop Routing Algorithm
Authors: Tian Ming , Lan Ju Long , Yi Peng , Zhu Sheng Ping
Published: March 2011

To effectively avoid congestion and take full usage of bandwidth inside a network, an algorithm to increase the number of multi-next-hop routes: Destination-Generalized Multi-next-hop Routing Algorithm (DGMRA) is proposed. Simulation results show that through route combination, the number of next-hop is increased, and the throughput performance is improved compared with the single-next-hop algorithm and multi-next-hop algorithm based on shortest-path-tree mechanism.
The Identification Technology of Rolling Bearing Acoustic Emission Fault Pattern Based on Harmonic Wavelet Packet and SVM
Authors: Zhai Fen Lou , Gao Li Xin , Gong Neng Chun , Xu Yong Gang , Feng Ming Shi
Published: March 2011

As the energy distribution in each frequency band of rolling bearing acoustic emission (AE) signal is related to its fault type, so we can use the harmonic wavelet packet to decompose the rolling bearing AE signal of different fault into different frequency band, combine energy in each frequency band together to be a feature vector of the Support Vector Machines (SVM), then being applied to identify the fault through SVM. This paper also compared the Harmonic wavelet packet and Daubechies wavelet packet as well as the SVM and neural networks. The experimental result shows that for the fault pattern identification, the method that combines harmonic wavelet packet decomposition and SVM together can be effective.
A Numerical Study of the Effect of Injection Velocity on Fuel Droplets Sizing in a Three-Dimensional Side-Dump Combustor
Authors: Doustdar Mohammad Mahdi , Mojtahedpoor Mohammad
Published: March 2011

The effects of injection velocity on propulsive droplets sizing and efficient mass fraction in a three dimensional side-dump combustor with dual opposite curved side-inlet duct are numerically investigated in the present paper. The mass of fuel vapor inside the flammability limit is named efficient mass fraction. The air flow comes from side-inlet ducts into the cylindrical combustor and four nozzles which are located in the top of the cylinder have the duties of fuel injection. The injection velocity is varied as 20, 40, 60 and 80 [m/s] respectively to examine its effects on propulsive droplets sizing and efficient mass fraction which provides worthwhile information for the combustor design work. As well, by increasing entrance air flow velocity from 35 to 100 and 280[m/s] correspondingly, these computations are repeated. To fulfill the calculations a modified version of KIVA-3V code which is a transient, three-dimensional, multiphase, multicomponent code for the analysis of chemically reacting flows with sprays, is used.
Micromachining Process for Fiber Optic Pressure Sensor’s Tip
Authors: Mohd Said Muzalifah , Zainudin Muhammad Noorazlan Shah , Zul A.F.M. Napiah , Zarina M. Noh , Afifah M. Abd Himid , Norhidayah M. Yatim
Published: March 2011

Fiber optic interferometry pressure sensor is an excellent diaphragm-base measurement system. It is in-vivo medical device to measure local blood pressure by using endoscopic procedures via the blood vessels and the heart. The sensor must smaller than the size of human artery. This paper has concentrated on the MEMS technology in order to build the sensor tip using micromachining process to the proposed Fabry-Perot Interferometry (FPI) micro-pressure sensor. The feasibility of bulk, surface and hybrid micro-machining as viable proposition for sensor fabrication are reviewed. This paper will address the various factors involved in the manufacturing of FPI sensors, which gives high yield with a specific level of performance. The reliability of the sensor tip has been discussed.
The Position Analysis of Drilling Fluid Retention in Horizontal Well
Authors: He Jun , Ren Shuai Qin , Feng Fu Ping , Liu Guo Yong
Published: March 2011

The driving force caused by density difference of slurry and drilling fluid is a function of circumference angle and radius in horizontal well displacing. The closer to annulus bottom, the larger is the driving force, which leads to the displacing interface more easily to extend downward annulus. Based on the mechanics analysis of annular fluid displacing infinitesimal in horizontal well, this paper sets up the calculation model of drilling fluid layer dynamic shearing stress in displacing process. According to the equilibrium condition of displacing interface stability, the boundary position of drilling fluid retention layer at casing and sidewall with different circumference angles for horizontal well is acquired, which will enhance the pertinence of displacing techniques in horizontal well.Calculation results show that with the same circumference angle, the thickness of drilling fluid retention layer at sidewall is far larger than at casing. For this reason, the cement bond quality of the second cementing interface should be used as one of criterions for evaluating horizontal well cementing quality. And the retention at sidewall and casing gradually increases from the lower annulus to the upper part. The retention layer at upper sidewall is thickest. So the oil/gas/water channeling-path is easy to form and special attention should be given to cleaning the upper sidewall drilling fluid . Low permeable horizontal wells generally take subsection fracturing method for exploitation , requirements of cementing quality is higher. The guarantee of higher displacing efficiency is the premise of obtaining high quality of cement quality , in the horizontal well because of dirlling fluid retention and free water precipitation , the oil/gas/water channeling-path is easy to form at the upper wellbore , seriously restricted the implementation[1-2] of the horizontal well stimulation measures. At present technology about improving the displacing efficiency develope rapidly[3-6],but because of drilling fluid retention laws and the retention position is uncleared in horizontal well,which lead to these measures are not well targeted. Analysed by displacing interface dynamic extension process in the process of slurry displace drilling fluid , this article establishes dynamic shearing stress calculation model of horizontal well annular fluid displacing infinitesimal , according to the condition of displacing interface stability, the drilling fluid retention law and retention position in horizontal well is acquired.
Tensile and Impact Properties Evaluation for Enviro-Recycled Wood Plastic Composite of PP/r-WF
Authors: Abd Razak Jeefferie , Toibah A.R. , Yuhazri M.Yaakob , Rashid Mohd Warikh Abdul , Binti Omar Nooririnah , Haidir M.M. , Sihombing Haeryip , Ramli J.
Published: March 2011

The potential of recycled wood flour (r-WF) addition to the thermoplastics polypropylene (PP) matrix for the composites in structural application is evaluated. The effects of different r-WF loading to the tensile and impact mechanical structural properties are analyzed. Two types of polypropylene resin which are the virgin and the recycled resin and recycled wood flour as reinforcement materials are utilized as raw materials in the composites fabrication. Various mechanical testing was conducted in accordance to ASTM standard, to study the behavior of the composites mechanical properties to the applied load. The best compounding formulation of enviro-recycled composite was found at 60wt% of PP matrix and 40wt% of the wood flour addition for both of virgin and recycle matrix. Overall experimental results showed that, the increasing of r-WF loading had significantly increased the mechanical properties of produced composite which is suitable to be applied in the application of structural engineering, through the advantage of mechanical properties performance in tensile and impact behavior. Conclusively, this finding is hoped to lead for contribution in the development of newly advanced material that is environmental friendly for the use of structural application.
Synthesis, Characterization and Visible Light Photocatalytic Properties of BiOCl0.2Br0.1I0.7
Authors: Huang Kai Jin , Liu Hou Guang , Xie Chang Sheng
Published: March 2011

The ternary solid solution BiOCl0.2Br0.1I0.7 was successfully synthesized using a wet chemical method. The visible light photocatalytic properties of BiOCl0.2Br0.1I0.7 were investigated for the first time. Powder samples were characterized by XRD, SEM, UV-vis spectrophotometry and nitrogen sorption. BiOCl0.2Br0.1I0.7 absorbs intensely in the visible light region and the optical bandgap is 1.82eV. The chlorine and the bromine elements have an obvious effect in changing the bandgap energy and the particle size of the catalysts. The deep valance band edge position, the internal electric ﬁelds and the morphology give the BiOCl0.2Br0.1I0.7 best visible light photocatalytic properties.
Gear Shifting Control for Medium Truck without Clutch
Authors: Chen Yong Dan , Xi Jun Qiang , Xu Chun Guang
Published: March 2011

Traditionally a gear shift with clutch control makes the synchronisation phase unnecessarily long torque gap time. Gear shifting by engine control realizes fast gear shifts by controlling the engine instead of sliding the clutch to a torque-free state in the transmission. Detailed mathematical models of different driveline states are presented and to improve driving comfortable. Theoretical analysis results are compared with experimental ones from the road experience in equal conditions in order to prove the validity of the gear shifting control strategy.
Shop Floor Control Mechanism of Aerospace Machine Shop
Authors: Chang Hsien Ming , Huang Chi Kong , Torng Chau Chen
Published: March 2011

The production environment of aerospace industry is make-to-order. The life cycle of aircraft is more than 20 years. Aircraft parts should have higher precision and lightweight to achieve the requirements of safety, payload, and controllability. Machine parts are the important portion of aero-structures. Base on the strength, function, contour of machine parts, then assign to suitable machine center for machining. This study construct the shop floor control mechanism of aerospace machine shop which combine the concept of order release control, gateway control, queue level control, color code control, cycle time control, and apply the on-time dispatch and on-time completion as an indicator to monitor the performance of shop floor control. Thus, we can improve the weakness and increase the competitive advantages of machine shop in the global competitive aerospace market.
Analysis on PLA Textile Fiber Production Technology and Properties
Authors: Chang Tao
Published: March 2011

PLA fiber is a green eco-fiber of excellent properties and sustainable development, with adequate sources of raw materials, low energy consumption, good biodegradability, and excellent physical and mechanical properties, thus the development of this product not only has considerable economic benefits, and also has excellent social benefits. In this paper, through comprehensively testing the properties of PLA fiber, it carries out the systematical analysis and research on the Tests of PLA fiber length, fineness, over length, double length, and defects, combustion property, heat resistance, and hydrolysis property, etc. several aspects.
Study on No-Diving Running Mode of Submersible Pump
Authors: Feng Li Jie , Wang Jin Feng , Li Zhao Hui , Zhong Hua Ke
Published: March 2011

The paper describes a type of serial running mode that boost pump provides water floating and the main submersible pump runs in a no-diving mode. The practice show that this mode can effectively solve the drainage problem at the inclined shaft under the condition of large water inflow and no track, and overcome the drainage problem under the coal slime silting condition. This mode also expands the application of high-power submersible pump theoretically.
Finite Element Simulation and Dynamic Test of the Bridge Structure
Authors: Liu Yu Qing , Wu Yan Xiang , Huo Hai Bo
Published: March 2011

In this paper, we established a bridge three-dimensional finite element model for the structural dynamic analysis according to the geometry and material properties of a bridge Li Gong Yi Qiao at Wuhan University of Technology. On the other hand, we tested the dynamic characteristics of the bridge under environmental excitation by means of bridge sensors arranged at different points. The modal parameters of the bridge were identified through fitting the admittance circle. The comparison between the measured results and the theoretical studies has shown that the low-order vibration frequency and mode obtained from finite element analysis generally consistent with those from test. The finite element model provides a scientific basis for condition monitoring of the bridge in actual operations.
Microstructure and Mechanical Properties of Nanocrystalline FeCr Alloy Prepared by Spark Plasma Sintering
Authors: Sebayang Darwin , Khaerudini Deni S. , Saryanto Hendi , Othman M.A. , Saleh Mat Husin , Fredrick D. , Untoro Pudji
Published: March 2011

This paper investigates the efficiency of two consolidation processing techniques prepared by spark plasma sintering (SPS) and hot pressing (HP) which allow obtaining fully dense nanostructured materials. FeCr powders were sintered by using spark plasma sintering (SPS) and hot pressing (HP) sintering techniques over sintering temperature up to 1000oC. The microstructures of the sintered end-products were characterized by Scanning Electron Microscopy (SEM). X-rays diffraction line profile analysis was adopted to analyze the crystallite size of starting and sintered FeCr using Williamson–Hall method. The density of the sintered specimens was measured by using the Archimedes method. The result indicated that the dense specimen with relative similar density and approaching the equilibrium state obtained in shorter time and lower sintering temperature by spark plasma sintering compared to conventional hot pressing. The FeCr specimen prepared by SPS showed more effective to retain nanocrystalline and better mechanical properties than those prepared by HP. The diffraction investigation revealed that the grain growth was not significant in SPS process compared to HP, which would enhance the mechanical properties of the SPS sintered FeCr.
Rheological Analysis of Microminiature Powder Injection Molding (μPIM) Feedstock
Authors: Li Haw Pei , Muhamad Norhamidi
Published: March 2011

A rheological analysis has been performed to evaluate the characteristics and behaviors of Microminiature Powder Injection Molding (μPIM) feedstocks. The feedstocks comprised of 316L stainless steel powder and water-based binder components. Feedstocks formulations with powder loading of 59% to 63% were prepared and investigated. In these formulations, the binder system consists of 65% Polyethelena Glycol (PEG), 25% Polymethyl Methacrilate (PMMA) and 10% Cellulose Acetate Butyrate (CAB) based on the weight fraction. The influences of rheological behaviors such as flow activation energy (E), Power-Law exponent (n), viscosity (η) and temperature (T) of the SS316L/PEG/PMMA/CAB feedstocks are analyzed and discussed. Results show that all of the feedstocks exhibited the pseudo-plastic flow behavior. The homogenous feedstock at 61 vol. % demonstrated the most satisfactory rheological properties for μPIM with the lowest flow activation energy, Power-Law exponent, n < 1 and moderate viscosity values. It was chosen to perform the injection molding process. Micro components have been replicated successfully by using this selected feedstock.
Application of Taguchi Method for Parameters Optimization in Micro Metal Injection Molding
Authors: Li Haw Pei , Muhamad Norhamidi , Sulong Abu Bakar , Yunn Heng Shye , Abolhasani Hooman
Published: March 2011

Optimization of injection parameters in Micro Metal Injection Molding (μMIM) was described in this study. Stainless steel powder was mixed with Polyethelena Glycol (PEG), Polymethyl Methacrilate (PMMA) and Cellulose Acetate Butyrate (CAB) to produce feedstock. Design of Experiments (DOE) of Taguchi L-27 (313) orthogonal array technique has been used to investigate the significance and optimal injection molding parameters. The signal-to-noise ratio and analysis of variance (ANOVA) are applied to study the optimum levels and effects of process parameters. Simultaneous optimization to obtain the highest green density and excellent surface appearance was discussed. The result concluded that the mold temperature (D) is the most statistically significant process parameter and its contribution to the best appearance and density is the highest.
Influences of Binary Mixtures on the Regenerator of VM Cycle Heat Pump
Authors: Xie Ying Bai , Wang Shao Heng , Li Bing , Liu Yun
Published: March 2011

To improve the overall performance of the VM cycle pump. Based on the mixture with nitrogen (including N2 - Ne, N2 - Ar, and N2 - Kr) by working in the regenerator of flow and heat transfer in performance is analyzed and calculated, different mix of refrigerant regenerator performance impact. To enhance the VM cycle pump overall performance study provides new ideas.
Web Caching Replacement Based on User's Visiting Action
Authors: Wang Bo , Wu Yong Wei , Zheng Wei Min
Published: March 2011

Web server aims to service clients sensitively and clients wish to explore web sites at fast bandwidth. Nevertheless, sometimes users can only get the web content at a slow response due to the slow communication. Using data buffering technique, web cache provides clients an alternative way to acquire the web content from web server at low cost and high bandwidth. Using web cache technique, users can get fast response at low communication cost. When quantities of data are buffered to the cache server, cache policy becomes an important factor which can clearly affect the performance efficiency. Our contribution is that we take full account of the user's visiting action and redesign the cache policy. Based on this, we compare our policy (UVA) with existing method (LFU) through series of experiments. The results show that our method can efficiently improve cache hit rate.
Research on the Phase Distribution of White Blood Cells with Nucleus Model under VirtualLab Technique
Authors: Wang Ya Wei , Yue Qu Wei , Bu Min , Han Guang Cai
Published: March 2011

Focusing on the application technique of the phase testing techniques in cell identification, the analysis to the morphological structures of the leucocytes is done, and the physical models with nucleus of white blood cells are built. Based on the VirtualLab and numerical simulation techniques to systematic study on the distribution of the phase of the the leucocytes, the inside and outside morphological structures of the leucocytes and the main characteristics of the models are found. Thus, the phase testing application has been expanded. The light phase distribution analysis of biological cell is expected to become a new tool to detect the biological cell.
Conceptual Design of a 16-Speed Bicycle Drive Hub
Authors: Wu Yi Chang , Lin Shi Liang
Published: March 2011

This paper presents a design approach for the conceptual design of a novel 16-speed bicycle drive hub. First, a distributed-flow type planetary gear train, which consists of two parallel- connected transmission units and one differential unit, for the power transmission mechanism of a bicycle drive hub is proposed. Based on the kinematic analysis of the presented gear mechanism, a feasible clutching sequence is synthesized to provide 16 forward speeds. Then, the numbers of teeth of all gears are determined according to the desired velocity ratio of each speed. As a result, a schematic diagram of the embodiment of the proposed 16-speed drive hub is presented.
Modeling Study of Long-Stroke Valve-Controlled Asymmetrical Cylinder
Authors: Xiao Zhi Quan
Published: March 2011

With the consideration of compressibility flow and the redefined load flow and load pressure, the mathematical model of long-stroke valve-controlled asymmetrical cylinder system is presented. The equivalent volume functions, the functions of equivalent volume functions of cylinder's two chambers are introduced, which reflects the influence of piston's positions in its long stroke on the dynamic performance of valve-controlled cylinder. Simulation results show that there exists obvious differences between forward and backward directions of long-stroke valve-controlled asymmetrical cylinder system, and its dynamic performance varies along the whole stroke, where the middle-stroke position may not always be the so-called most dangerous position.
Nonlinear Characteristics of Two-Span Rotor-Bearing System with Three-Coupling Faults
Authors: Luo Yue Gang , Zhang Song He , Ren Zhao Hui , Wen Bang Chun
Published: March 2011

The dynamic model of two-span rotor-bearing system with three-coupling faults of rub-impact, crack and pedestal looseness faults was set up, and the influences of faults to nonlinear dynamic characteristics of the system were studied by mapping and continuation comprehensive method. There are many harmonic elements of 1/3, 1/2, 2/3, 1, 3/2 and 2 et al within the sub-critical rotate speed range. But the 3/2 and 2-harmonic elements decrease within the super-critical rotate speed range. It may the main characteristics of the system with three-coupling faults of rub-impact, crack and pedestal looseness. It should notice to diagnosis the three-coupling faults of the system when running within the super-critical rotate speed range.
Optimization Mixing Parameters on the Electrical Conductivity of Polymer Nanocomposites Based on the Taguchi Method
Authors: Suherman Hendra , Sahari Jaafar , Sulong Abu Bakar
Published: March 2011

The objective of this paper is optimization mixing parameters in terms of mixing process of polymer nanocomposites using Taguchi method. Considering the mixing parameters such as rotational speed, mixing temperature and mixing time were performed to reveal the electrical conductivity data. Taguchi method was used by electrical conductivity analyses based on three level factorial designs. Orthogonal arrays of Taguchi, the signal-to-noise (S/N) ratio, and the analysis of variance (ANOVA) were utilized to find the optimal levels and the effect of mixing parameters on electrical conductivity. Confirmation analysis measurements with the optimal levels of mixing parameters were carried out in order to show the optimum electrical conductivity of Taguchi method. The result shows that Taguchi method is effective in solving the quality problem occurred on the mixing parameters of the polymer nanocomposites.
Optimization of Surface Properties and Performances for HVOF Sprayed WC-Co Coatings on Mild Steel
Authors: Jean Ming Der , Chien Tzu Hsuan
Published: March 2011

This study presented the application of Taguchi designed experiments to optimize the tungsten carbide/cobalt (WC-Co) deposited quality properties of the high-velocity oxygen-fuel (HVOF) process. The eight control factors were designed in a L18 factorial orthogonal array experiment, and the effects of control parameters on the surface properties were critically evaluated in the experiments. The surface anti-wear properties by optimal design have been studied comparatively. By optimization from Taguchi S/N ratios and analysis of variance, the surface wear volume values are decreased by 37%. It was clear that anti-wear performance estimations of HVOF sprayed WC-Co coatings are greatly improved by way of the optimal experiment, and these findings achieved the desired values in the WC-CO coatings. The experimental results indicated that the proposal method offers an effective and efficient approach for developing a robust and highly quality HVOF sprayed WC-Co coating.
Design and Analysis of Enhanced Chromium Nitride Film Performance by Tuning Sputtering Magnetic Systems
Authors: Jean Ming Der , Huang Wesley , Fang Jium
Published: March 2011

This paper presents the optimal chromium nitride (CrN) deposited performance by tuning magnetic systems on die steel in PVD. The strength of magnetic fields was controlled by adjusting the gap distance between magnet sets and target surfaces of the unbalanced magnetic field of sputtering systems. In L18 orthogonal experiments, the effect of control factors were explored such as gap distance between magnet set and target surface (GDMT), target current, argon and nitrogen flow rate, DC pulse frequency, and work distance. Hardness and wear behavior of the CrN films were analyzed using a statistical method. The wear rate was estimated by Pappus’s theorem. Among the results, the Cr2N phase with the mixture crystallographic orientations of (111) and (002) exhibited better wear resistance than CrN(200) with a single preferential orientation. In addition, variance analysis exhibited the largest percentage contribution to friction coefficient in comparison with the other two properties of friction coefficient and GDMT, which showed that GDMT is extremely sensitive to friction coefficient.
The Preparations and Characterization of Water-Based TiO2 Nano-Coating
Authors: Chang Ho , Chen Tien Li , Wu Yan Chyuan , Cho Kung Ching , Peng He Jun
Published: March 2011

This study proposes a new method—the ultrasonic vibration-assisted arc-submerged nanofluid synthesis system (VANSS). This method prepares for water-based TiO2 woodenware nano-coating and applies the nano-coating to medium density fiberboard (MDF) to measure the characteristics of the coatings on the woodenwares. For VANSS, water-based coating serves as dielectric fluid and anodes, while cathode electrodes use titanium rods (editor’s note: please check carefully and consider revising the above sentence. I’m confused by the multiple use of ‘and’ in this case). Electrodes soon vaporize under the influence of a high-temperature plasma arc and instantly condense into nanoparticles under the cool effect of low-temperature dielectric fluid to form Ti nano-coating with good suspension. Placed for two weeks, Ti nano-coating has transformed into TiO2 nano-coating. TiO2 nano-coating is applied to MDF to compare the coating with and without the addition of TiO2 nanoparticles. The results show that TiO2 nanoparticles have an average particle size of 20 nm. For the coating properties test, the results show that lightness rises from 49.7 to 69.32, increasing 39.5 % after the coating is added to the TiO2 nanoparticles. Chroma lowers from 37.1 to 33.3, decreasing 11.3 % after the coating is added to the TiO2 nanoparticles. However, hue difference is within 3 %, having little influence on vision. Adhesion enhances from 1B to 5B, increasing 4 grades when the aqueous polyurethane, AE-418, is added to the TiO2 nanoparticles; solvent resistance elevates from 46.3 % to 56.8 %, increasing 10.5 % after the coating is added to the TiO2 nanoparticles.
Vibration Control of an Engine Mount for UAV Activated by Piezostack Actuator
Authors: Oh Jong Seok , Choi Seung Bok
Published: March 2011

In this paper, vibration control performance of piezostack active engine mount system for unmanned aero vehicle (UAV) is evaluated via computer simulation. As a first step, the dynamic model of engine mount system which is supported at three points is derived. In the configuration of engine mount system, the inertia type of piezostack based active mount is installed for active vibration control. Then, the vibration level of UAV engine is measured. To attenuate the vibration which is transmitted from engine, a sliding mode controller which is robust to uncertain parameters is designed. Vibration control performances of active engine mount system are evaluated at each mount and center of gravity. Effective Control results are presented in both time and frequency domains.
J-Integral Analysis of Surface Cracks in Round Bars under Tension Loadings
Authors: Ismail Al Emran , Ariffin Ahmad Kamal , Abdullah Shahrum , Ghazali Mariyam Jameelah , Daud Ruslizam , Razzaq M. Abdul , Zulkifli A.
Published: March 2011

This paper presents a non-linear numerical investigation of surface cracks in round bars under tension stresses by using ANSYS finite element analysis (FEA). Due to the symmetrical analysis, only quarter finite element (FE) model was constructed and special attention was given at the crack tip of the cracks. The surface cracks were characterized by the dimensionless crack aspect ratio, a/b = 0.6, 0.8, 1.0 and 1.2, while the dimensionless relative crack depth, a/D = 0.1, 0.2 and 0.3. The square-root singularity of stresses and strains were modeled by shifting the mid-point nodes to the quarter-point locations in the region around the crack front. The proposed model was validated with the existing model before any further analysis. The elastic-plastic analysis under tension loading was assumed to follow the Ramberg-Osgood relation with n = 5 and 10. J values were determined for all positions along the crack front and then, the limit load was predicted using the J values obtained from FEA through the reference stress method.
Equilibrium State of a Binary Granular Solids Mixture
Authors: Buonsanti Michele , Leonardi Giovanni , Scoppelliti Francesco
Published: March 2011

We consider a possible equilibrium configuration under dead load of a vertical cylindrical specimen which is composed of a mixture of two elastic materials. An energetic approach in the mixture evolution is performed and this particular approach can be utilized to describe the bi-phase characterization of the mixture material. Our final aim is to build a theoretical simple model to determine the decrease load bearing capacity of mixture.
Model Optimization and Wavenumbers Selection for FTIR/ATR Spectroscopy Analysis of Glucose Aqueous Solution
Authors: Pan Tao , Wu Ling Ling , Chen Hua Zhou
Published: March 2011

The rapid quantification method of glucose aqueous solution was established by using the Fourier transform infrared spectroscopy (FTIR) and attenuated total reflection (ATR). Model optimization and wavenumbers selection was investigated based on Savitzky-Golay (SG) smoothing. For the whole spectral collecting region 4500-600 cm-1 and the fingerprint region 1600-900 cm-1, Partial least squares (PLS) models without and with SG smoothing were established respectively. The optimal model was on the fingerprint region with SG smoothing of 1st order derivative, 2nd degree polynomial and 73 smoothing points, PLS factor, RMSEP, RP, were 4, 0.331 mmol/L, 0.999 respectively. Based on 19 absorption peaks of the subtracted spectra of glucose aqueous solution for de-ionized water, all possible wavenumber combinations were used to establish discrete multiple linear regression (MLR) models respectively, the optimal wavenumbers combination was 3084, 1034, 991 (cm-1), RMSEP and RP were 0.459 mmol/L, 0.997 respectively. It could provide valuable references for designing spectrophotometer system in special spectrometer and further for glucose analysis of the complex system. To get the stable prediction results, all models and results here were obtained based on the average data on 50 different divisions of calibration set and prediction set.
Estuary Geometric Feature ’s Effecting on Salt-Fresh Water Mixing
Authors: Yuan Li Rong , Cheng Xiang Ju , Guo Zhen Ren
Published: March 2011

A three dimensional unstructured model was established and estuaries with different cross sectional divergence rates and different bed form were designed to study the estuary geometric feature effecting on salt-fresh water mixing in estuary. The model dispersing 3d domain into unstructured triangular and/or quadrangular elements, has good flexibility to simulate complex bank. By analyzing the horizontal and longitudinal distribution attributes of velocity and salinity field, the effects of cross section divergence rate, the bottom elevation of mouth and the slope inside estuary on salt water intrusion in estuary are studied. The result could act as design basis for the engineering projects which will change estuary’s bank shape or bed form such as estuary regulation and channel dredging.
Preliminary Study of Dry Sliding Wear in Kenaf Epoxy and Carbon Epoxy Composites
Authors: Kasolang Salmiah , Ahmad Mohamad Ali , Ghazali Farizah Adliza , Azmi Azlin Mohd
Published: March 2011

This paper presents an experimental investigation carried out to compare specific wear rate and surface morphology between Kenaf Epoxy Composite (KEC) and Carbon Fiber Reinforced Plastic (CFRP). Wear tests were carried out using Abrasion Resistance Tester (TR-600) in dry sliding conditions. These tests were performed at room temperature with different applied loads (5, 20 and 30N) and sliding velocity of 1.4m/s. Surface morphology of both materials was also examined before and after each test using an optical 3D surface measurement device. From the wear test, it was observed that the wear characteristics of KEC are comparative to those of CFRP. It was also found that the morphology of worn material composites in both cases exhibits a similar trend. This is a preliminary test for a future work on the enhancement of Kenaf Composites and the application.