bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigations on Residual Stress Distribution for 2A02 Aluminum Forgings
Authors: Cao Jiang , Li Chun Fu , Wang Yan , Sun Xing , Wang Shu Yun , Zhang Mai Cang
Published: December 2013

High strength aluminum alloys have been widely used in aviation manufacturing due to their favorable combination of intensity, stress corrosion resistance and toughness. However, the research and control of residual stress distribution in aluminum components have become a key issue to be solved during the heat treatment and subsequent processes. By means of the analysis of micro-indentation method and ANSYS finite element method, the residual stress distribution in 2A02 aluminum components after water quenching were systematically investigated, mainly considering two factors of the symmetry of structure and the variation of surface constraint. This study may give great help to the technology of relieving forgings residual stress of two alloys.The results of micro-indentation method show that the absolute value of the residual stress within the sample tends to decrease as the condition of constraint increase at the location of the same thickness; the absolute value of the surface residual stress also tends to decrease as the thickness of the sample increase with the same constraint conditions. The tested results by micro-indentation method are in consistent with the results of finite element simulation to a great extent.The results of finite element simulation are as follows: for these two aluminum alloy, the stress field distribution during the process of quenching is mainly influenced by the thickness of the samples. In general, at the initial stage of the quenching process, the stress state at the components surface are controlled by tensile stress in the direction of both thickness and width, while the residual stress within the samples is dominated by compressive stress; at the end of the quenching process, the stress field distribution just turn to the opposite. These results are in great agreement with the corresponding results of the indentation method.
Effect of Process Parameters on Porosity of Intermetallic NbCr2 Porous Materials
Authors: Liu Xian Li , Fang Chao , Wang Xiao , Zheng Hai Zhong
Published: December 2013

Laves phase NbCr2 intermetallics porous materials were in-situ synthesized by mechanical alloying followed by hot pressing. The influence of the process parameters of pressing pressure and sintering temperature on porosity of intermetallic NbCr2 porous materials was studied. The results show that in a certain range of pressing pressure from 135MPa to 405 MPa, with the pressure increasing, the porosity of NbCr2 intermetallics porous materials decrease. With the sintering temperature increasing from 1500°C to 1600°C, the porosity decrease.
Numerical Simulation Study on the Cement-Based Absorbing Material
Authors: Chen Rong Jun , Zhang Yong , Wang Bo
Published: December 2013

The absorbing performance have been tested and analyzed by taking cement as matrix, blending material silica fume and culver zed fuel ash, graphite and carbon fibers, nanoTiO2 and steel fibers for absorbing agent trial Sample, in the 8 ~ 18 GHz frequency band. By using ANSYS software for computer simulation of the specimen to test experimental data and found the issue to be cement-based composite absorbing material in design, the electrical conductivity, complex permittivity, complex permeability, Dielectric loss tangent, etc of the material are all the main parameters of evaluate absorbing materials. When blending material as a composite wave-absorbing agent applications, two kinds of materials dielectric loss played a attenuation role in common, it can significantly improve the absorbing properties of the specimen, and also broaden the band, it's more advantage than adding a single wave-absorbing agent.
Experimental Research on Aluminum Foam Dynamics Performance
Authors: Wang Bo , Zhang Yong , Chen Rong Jun
Published: December 2013

This paper chooses the remit foam aluminum by Shanghai co., LTD provides high pressure filtration method is used to make the opening of aluminum foam material. System research of relative density and strain rate changes on the relative density is high (> = 0.255) of aluminum foam materials shock stress - strain behavior, deformation failure mechanism and the influence law of energy absorption characteristics. These studies can not only expand the awareness of foam metal mechanical behavior, but also on the domestic industrial production of the performance of the foam aluminum material design, optimization and production preparation plays a guiding role.
Bulk Permanent Magnet with Enhanced Anisotropy Fabricated by Magnetic Annealing from Fe-B-Nd-Nb Bulk Metallic Glass Precursor
Authors: Cao Yang , Chen Guang
Published: December 2013

Fe68.16B20.16Nd7.68Nb4bulk metallic glass was annealed at 973 K for 15 min with or without external magnetic fields. The maximum energy product (BH)maxmeasured along the axial direction of a rod sample after annealed with a magnetic field parallel to the axis is 10.9 % higher than that annealed with a perpendicular field. The intrinsic coercivityiHcof the sample annealed with the parallel magnetic field reached 1014 kA/m. The induced magnetic anisotropy is attributed to the formation of preferred crystallographic orientation of ferromagnetic phases under the external magnetic field.
New-Type Biosensor Based on Multiple Total-Internal Reflections in Heterodyne Interferometry
Authors: Wang Shinn Fwu , Hsieh Chin Hsiang , Chu Yi , Liao Yu Pin , Lay Shyh Rong , Kao Fu Hsi , Liu An Li
Published: December 2013

In this paper, a novel biosensor based on multiple total-internal reflections (MTIRs) in heterodyne interferometry (HI) is proposed. The biosensor is made of an elongated prism. As a heterodyne optical light source transmits through the new-type biosensor, it will undergo multiple total-internal reflections (MTIRs). Thus we can obtain the text signal at the output. The phase difference variation due to the different refractive indices of the tested media can be obtained by a Lock-In-amplifier (LIA). By some numerical calculations, we can achieve the related parameters of the tested medium. The resolution of the sensor can reach 4×10-7 refractive index unit (RIU). The electro-optical biosensor has some merits, easy operation, in real-time measurement, and high stability, etc.
Heat Treated and As-Plated Electroless Duplex Ni-P/Ni-B Coatings: Evaluation of Hardness and Wear Resistance
Authors: Dil Gökce , Göksenli Ali , Calli Cagdas , Muhaffel Faiz , Aydeniz Ali I. , Yildiz Ahmed , Yüksel Behiye
Published: December 2013

The present work deals with the formation of NiP/NiB duplex coatings by electroless plating and evaluation of their hardness and wear resistance. The duplex coatings were prepared with Ni-P as the inner layer. To analyze the structure of the coatings, XRD analysis was carried out. According to the results, NiP and NiB coatings are amorphous in their as-plated condition and after applying heat-treatment at 450 °C for 1 h, both NiP and NiB coatings crystallize and produce nickel, nickel phosphide and nickel borides in the coatings. To determine the surface morphology and cross-section characteristics of the coatings, SEM observations were carried out and concluded that duplex coatings are uniform and good coherent exists between the duplex layers and the coatings are also connected closely to the substrate. The hardness of electroless nickel duplex coatings increased with applying heat treatment and reached maximum value at coatings annealed at 400 °C. To analyze the tribological properties, pin-on-disc tests were carried out. The wear track patterns on the coatings and on Al2O3balls were then examined by optical microscopy and EDS. The friction coefficient and wear rate of the coatings were lower than the substrate steel. Friction coefficient decreased from 0.43 to 0.36 and wear resistance decreased from 11.3 to 6.4 by applying heat treatment at 450 °C for 1 h to duplex coatings.
The Effects of Chemical Resistance for Nanocomposite Materials via Nano-Silica Addition into Glass Fiber/Epoxy
Authors: Chang Huey Ling , Chen Chih Ming , Lin Kung Liang , Chang Bor Kae
Published: December 2013

Nanocomposite samples containing epoxy resin, glass fiber and 0~2 wt.% SiO2 nanopowder are prepared. The effects of SiO2 addition on the chemical resistance, glass transition temperature (Tg) and dynamic mechanical properties of the various samples are then observed. The chemical resistance of the nanocomposite specimens is compared with that of pure glass fiber/epoxy composite specimens when tested in acetone. The results show that the addition of 2 wt.% SiO2 increases the value of storage modulus by 1646MPa compared to that of the sample containing no silica nanopowder. Following immersion in acetone, all the nanocomposite specimen storage modulus decreased, but the addition of SiO2 reduced the decline, where the 2 wt. % samples decrease from 11.76% reduction to 0.84% and no significant change in the Tg compared to that of the sample with no silica nanopowder. Therefore, the experimental results indicate that 2 wt.% SiO2 addition is beneficial in improving chemical resistance, glass transition temperature, and dynamic mechanical properties of epoxy resin / glass fiber nanocomposites.
Ecotoxicity of Nanomaterials on the Basis of Clay Minerals
Authors: Pjurova Barbora , Raclavska Helena , Skrobankova Hana
Published: December 2013

This article deals with the verification of ecotoxicity of nanomaterials on the basis of selected clay minerals (montmorillonite, kaolinite) and quartz as a reference substance. The ecotoxicity was determined by the inhibition of marine bacteria Vibrio fischeri, with relationship to the particle size and concentration of minerals in water leachate prepared according to Council Decision 2003/33/EC. Statistically significant dependence between inhibition of Vibrio fischeri and the concentration of minerals in water leachate was found for montmorillonite.
Solid-State Dye-Sensitized Solar Cells Using Mesoporous TiO2 Films Fabricated with Amphiphilic Rubbery Random Copolymer
Authors: Kim Dong Jun , Ahn Sung Hoon , Roh Dong Kyu , Kim Jong Hak
Published: December 2013

An amphiphilic copolymer, PLMA-POEM, was synthesized with hydrophobic poly (lauryl methacrylate) (PLMA) and hydrophilic poly (oxyethylene methacrylate) (POEM), which is cheap and rubbery state. The copolymers were characterized by using Fourier transform infra-red spectroscopy (FT-IR),1H-nuclear magnetic resonance (1H-NMR) and gel permeation spectroscopy (GPC). The copolymers were used as sacrificial agent to fabricate anatase mesoporous TiO2films and, by varying amounts of TiO2particles, polymer molecular weight (MW), concentration of the copolymers, various mesoporous TiO2films were fabricated. With a low MW polymer, the TiO2formed a worm-like structure with smaller pores, whereas an aggregated honeycomb-like TiO2with bimodal pores was obtained for the high MW system, characterized by scanning electron microscopy (SEM), grazing incidence small-angle X-ray scattering (GI-SAXS) and N2adsorptiondesorption measurement. With 2μm-thick TiO2film, efficiency was 4.2% due to better pore filling of the solid electrolyte and improved light scattering properties. By using a layer-by-layer method, the efficiency was further improved to 5.0% at 7μm thickness.
Research on Anti-Interference of Measurement-Control Device in Substation Automation System
Authors: Gao Qiang , Du Jing Jing , Li Quan Yang
Published: December 2013

With the wide adoption of relay protection, power grid control and communication equipments in power system based on micro-circuit and micro-processor, the electromagnetic compatibility (EMC) of measurement-control devices has become an urgent and necessary consideration in substation automation system. In this paper, the electromagnetic environment and electromagnetic interference (EMI) problem in substation is presented, and several typical anti-interference methods regarding measurement-control devices are explored based on the analysis of unique characteristics and work environment of this kind of devices. Furthermore, anti-interference application in actual substation site is demonstrated, with the example of CSI-200 series devices.
Performance of Bi-Facial PV Modules in Urban Settlements in Tropical Regions
Authors: Pisigan Carlo , Jiang Fan
Published: December 2013

This paper studies the performance of bifacial Heterojunction with Intrinsic Thin-layer (HIT) PV modules through a one-year experiment in Singapore. Two 1.2kWp (front side)/0.84kWp (rear side) PV systems were installed vertically, facing the N-S and E-W directions respectively. The operational data of two systems were monitored and collected to analyze their performance under different weather conditions. This paper will presentthe change of irradiation, energy yield and the AC energy output of the bifacial PV systems. The results help to understand the impacts of system installation on the energy yield of vertically-installedbifacial HIT PV systems, to find out its advantages in applications over monofacial PV modules and to explore the potential of bifacial PV modules in tropical regions, especially in urban areas like Singapore.
Thermo-Hydraulic Performance Evaluation of Inclined Vortex Generators
Authors: Akcayoglu Azize , Cebeci Halil , Nazli Celal
Published: December 2013

In the present study, a commercial finite volume package ANSYS FLUENT 14.5 has been used to determine thermo-hydraulic performance of two different vortex generator (VG) configurations, namely, flow-up and flow-down, located in triangular ducts. A comprehensive literature survey on flow-up and flow-down configurations has shown that there are completely opposite results obtained in terms of performance of the two configurations. In some studies, flow-up configuration showed better performance characteristics over flow-down configuration while in other studies flow-down configuration was found better. This has been motivated the present authors to make a study covering the two VG configurations to find out which one has a better performance over the other one. Therefore flow and thermal fields together with the secondary flow induced by the two VG configurations have been analyzed extensively. The geometry comprised of double row of VGs located on the slant surfaces of equilateral triangular ducts. The angle of inclination of the VGs made with the flow direction is 30°. The results show that flow-down configuration has a 40.65% higher thermo-hydraulic performance over the flow-up configuration for Re=5000. It is also shown that the heat is transferred at a further downstream distance allowing in a reduction in the number of VGs to be used in of flow down case.
Garbage Incineration and Intelligent Fusion Strategy of Secondary Pollution Control
Authors: Ni Yuan Min , Li Lei
Published: December 2013

To control the secondary atmosphere pollution produced by exhaust gas in process of garbage incineration, the paper presented a sort of intelligence fusion control strategy in city garbage incineration. In the paper, aimed at the running properties of garbage incinerator and combined the mechanism of garbage combustion and contamination generation, it studied the characteristic of controlled combustion process, proposed a sort of fusion control strategy based on human simulated intelligence for controlled process, constructed the corresponding control algorithm. Finally it took a two order model of combustion process with large lag as an example that is very nearly similar to controlled process characteristic of garbage incineration, and made the contrast experiment of digital simulation respectively by the Smith optimal controller and the presented fusion control algorithm by means of the platform of MATLAB. The response curve of simulation shows that the fusion control algorithm is better than by Smith optimal controller in control effect of anti-jamming performance and control index obviously. The experiment results show that the proposed fusion control strategy is reasonable, feasible and effective for secondary pollution control, and it is high in control precision, better in dynamical and steady quality, and very strong in robustness.
Influences of Nano-Silica Addition on Diluent/Epoxy Mechanical Properties
Authors: Chang Huey Ling , Chen Chih Ming , Chen Cheng Ho
Published: December 2013

In this paper, epoxy, diluents, nanosilica powders and hardeners are mixed and cured form nanocomposites under different production conditions such as the amount of added nanopowders, diluents, etc. Through the use of an impact tester and a Shore durometer, the influences of the amount of added diluents and silica on mechanical properties are investigated. The results show that adding nanopowers has little effect on increasing the Shore D hardness. However, adding diluents will reduce the Shore D hardness of the composites. Without diluents, the composite added 1 wt.% of nanopowders has a maximum impact value of 6.63 KJ/m2. Adding 3.2 wt.% of diluents, the nanocomposite has a maximum impact value of 5.50 KJ/m2, also happens when the amount of added nanopowders is 1 wt.% of. Adding nanopowders more than 1 wt.% will reduce the impact strength. Nevertheless, adding nanopowders to 3 wt.%, the value is still higher than the composites without nanopowders.
Upon Power Loses due to Current Harmonics in a Fotovoltaic System, Opperating at Maximum Power Point
Authors: Chioreanu Calin
Published: December 2013

Photovoltaic panels (PF), combined with lead-acid battery (AE), are increasingly used, to produce electricity. To work in maximum power points, between (PF) and (AE) is interposed a static converter (DC-DC), which is a harmonic pollution source. Within the paper there are calculated the power losses, due to current harmonics, of a photovoltaic system working at its maximum power. Photovoltaic system works at its maximum power, if in the electronic system there is permanently voltage control among solar battery terminals.
Dump Load Shedding and Slope Angle of Optimization Design
Authors: Sun S.G. , He Y.Y. , Xin X.P.
Published: December 2013

In view of the local conditions of Xingshan Iron Mine North Dump, an economically safe load shedding scheme was determined. Based on critical sliding field technology, the most dangerous slip surface can be searched of different waste-dump slope angles. Once the most dangerous slip surface is fixed, limit equilibrium methods can be used to analyze the stability of the slope. The corresponding slope angle of minimum allowable safety coefficient under the most unfavorable condition was defined as the optimal slope angle of this section, and the minimum optimal slope angle of all the sections of dump was determined as the final optimal slope angel of the whole dump. This method was not any practical but also extremely economical, which can ensure the absolute safety of dump and its surroundings.
Theoretical Calculation of the Detonation Parameters of Nitropyrazoles Explosives
Authors: Li Ya Jin , Li Yong Xiang , Wang Yan Hong , Cao Duan Lin , Jiang Zhen Ming , Wang Xiao Jun , Su Qiang
Published: December 2013

A series of new nitropyrazole explosive molecules were designed with N-nitropyrazole as structural unit, The detonation parameters of nitropyrazoles explosives, such as detonation velocity, detonation pressure, detonation temperature, detonation volume, were estimated theoretically in different methods, The calculated detonation pressure was corresponded with high energy density material (HEDM). Their detonation velocity and detonation pressure are between those of TATB and HMX. These compounds have higher detonation temperature and heat of detonation compared with HMX and TATB. It was predicted that these explosives are of favorable stability.
Numerical Simulation and Analysis of Thermal Energy Generated by Friction on Explosion-Proof Elevator
Authors: Zhang Qing Peng , Wan Jian Ru
Published: December 2013

In petroleum, chemical, metallurgical and other industries, a special kind of elevator, the explosion-proof elevator, is applied due to the existence of flammable and explosive substances in the environment. Explosion-proof elevator has adopted various approaches to meet the requirements of explosion-proof areas levels in the design stage, such as explosion isolation and intrinsically safe circuits. However, in normal working process, thermal energy will be generated by the friction occurring between different components of an elevator, which is very dangerous if the temperature of the assembly exceeds the limited value of related standards. Frictions always occur between guide shoes and guide rails when the elevator operates .Similarly, there are also frictions between safety clamp blocks and guide rails when the safety gear works. In this article, a finite element method is used to simulate and analyze the thermal energy generated in those two parts with a purpose to examine the performance of explosion-proof.
Control of Hybrid Stepping Motor Drive Using Computational Verb PID Controllers
Authors: Zheng Xue Qin
Published: December 2013

Thanks to the development of microprocessors, hybrid stepping motors have been widely used in many areas where they perform positioning operations. However, the stepping motor suffers from system variations, low performance and lack of adaptability to load variations, which slow down their responding speed of high-precision positioning operations. In this paper, a computational verb PID controller is proposed to control the position of a stepping motor drive. The simulation results show that the computational verb PID controller has better performances than conventional and fuzzy PID controllers. The simulation results also show that the responding speed and positioning accuracy of the controlled hybrid stepping motor were greatly improved. Computational verb PID controller has much less computational complexity than fuzzy PID controller.
The Design of the Footrest for the Auto Seat Based on Theergonomics
Authors: Zhan Lei , Sun Ji Guo , He Jin Guang
Published: December 2013

The design of the footrest used in the auto seat was investigated based on the ergonomics. According to the results, the design path along with the type of the footrest could be described as: i) an adjustment mechanism is necessary for the footrest to meet the requirements of the different groups; ii) the adjustor of the footrest could be realized by using a ratchet mechanism and iii) the hand-operating should be avoided for the using of the footrest and the footrest should be self-closing when it was free of use to realize the passenger protection.
Discussion the Re-Use Precision Locknut of the Machine Tools Spindle in the Vertical Assembly Characteristics
Authors: Chen Chih Ming , Chen Cheng Ho
Published: December 2013

This paper is to investigate the characteristics of re-use precision locknuts of the machine tools spindles in the vertical assembly under different effective diameters, locking axial forces and clasp screw locking torques in the static tests for the axial force change rates. The results with the new flank locking precision locknuts are compared to the re-use nuts with different values; we obtain the decline of axial force change rates from predetermined equations using regress analysis to conduct experimental forecasts. In the experimental results, plastic deformation has occurred in re-use nuts structure in the vertical spindle assembly. The decline of the axial force will be increased along with the nut size; and those of the re-use nuts decline more than the new nuts. Therefore, repetitive uses of the reuse nuts are not recommended.
Friction Characteristics of Clasp Locked Precision Locknuts under Different Conditions
Authors: Chen Chih Ming , Chen Cheng Ho
Published: December 2013

As the machine tool industry moves towards high speed and high precision, we must have detection technology for the mechanical properties of fasteners, in order to overcome technical bottlenecks. This article is especially aimed at machine tools and special-purpose machines that commonly use clasp locking precision locknuts. In this research, the anti-loosening characteristics of precision nuts are investigated under different conditions, such as the clearances, end processing methods, nut cutting speeds, lubricants, and tightening speeds. The results can provide the precision nut manufacturers a data base for product design. The experimental results show that with the end surface machining method using concentric grinding, nut cutting speed 800rpm, 2rpm speed of tightening, and the use of lubricant 2TML, the nut has better anti-loosening characteristics.
Effects of Parameters on Flutter of a Wing with an External Store
Authors: Xu Jun , Ma Xiao Ping
Published: December 2013

The flutter analysis of a wing with an external store is presented. Because of the external store, the concentrated store mass is combined into the governing equations which are obtained using the extended Hamiltons principle. Dirac function is used to precisely consider the location and properties of the external store. The k method is used to calculate the flutter velocity. The effects of store parameters such as store mass and inertia on the flutter velocity are investigated.
A Combined Physiotherapy Ultrasound and Electrical Shock Device (COMPO) Design
Authors: Faraji Ali , Rezvani Talat
Published: December 2013

Today, savings and efficient use of materials are an integral and important component of design processes and production. The typical multi-purpose devices with portability in biomedical engineering and physiotherapy are visible. Due to high usage and importance of these features, particularly their combination in the treatment of a wide range of patients, the process of treatment for the patient and medical groups could be faster, easier and pleasurable. This article is presented a multifunctional physiotherapy device design that combines the most effective as well as commonly used therapies. In addition, savings in materials, efficient use of energy and reducing manufacturing process, simple, comfortable, pleasant and effective treatment process for both physiotherapists and for a broad class of patients may be represented.
The Discussion of Rotor Guide Channel Length of Vertical Shaft Impact Crushing Test Machine
Authors: Guo Wei , Zhao Fang , Li Shi Jian
Published: December 2013

With the aid of discrete element software EDEM simulation under the same size, the acceleration of particles under different channel model and speed, and analyze the throwing speed and force. The result show that speed is important influence factors of granular acceleration and speed of throwing, but excessive speed will not only increase grain stress, but also can make particle fluctuations increased significantly, channel length and the starting position has a significantly influence on particle acceleration levels, the smaller of the channels initial distance, the better of the particle acceleration effect, particles thrown speed as the speed rises, the level of volatility is not always to rise.
Production Capacity Allocation for Multi-Generational Products Based on Decision Tree Method
Authors: Chen Lan , Yang Hui , Song Hua Ming
Published: December 2013

In this paper, we study the problem of how to allocate capacity for multi-generational products when a manufacture makes production decision. We establish a capacity allocation model for three generations of products and obtain the optimal allocation strategy by incremental decision tree analysis. Through the numerical experiment and parameter sensitivity analysis, we analyze the influence of products price, cost and salvage on the decision results. We also provide management implications for manufactures using decision-making tools to improve revenue.
Structural Reorganization in Thin Films of High Molecular Weight Block Copolymer Self-Assembly
Authors: Park Sung Min , Ahn Hyung Ju , Kim Sang Woo , Gong Jin Sam , Ryu Du Yeol
Published: December 2013

We demonstrate the structural reorganization of microdomain arrays toward the perpendicular orientation of lamellar morphology in high-molecular-weight PS-b-PMMA films using a combinational approach by solvent-vapor and sequential thermal annealing processes. Solvent annealing with a PMMA-selective acetone vapor induced a cylindrical morphology. However, the sequential thermal annealing of block copolymer (BCP) films led to structural reorganization to an equilibrium lamellar morphology, where the lamellar microdomains were oriented to normal to the film surface. This technique suggests an efficient route for directing orientation and structural reorganization of microdomain arrays in the thin films of high-molecular-weight BCP self-assembly.
Analysis on Kinematic of Rod on Rotor with Sine Curve Revolving Speed in Twin-Rotor Cylinder-Embedded Piston Engine
Authors: Chen Hu , Pan Cun Yun , Zou Teng An
Published: December 2013

Twin-rotor cylinder-embedded piston engine are a high power density and no valve mechanism engine. Given the motion law of two rotors sine curve change, its kinematic model of rod can be established, and key parameters of rod related to engine performance, such as angular displacement, velocity and acceleration of rod are presented. And then the kinematic model of rod is imported into MATLAB, the moving law of angular displacement, velocity and acceleration of rod are analyzed by changing the value of swing amplitude k. It can be concluded that the changes of rods motion are periodic, relatively gentle, and the periodic of angular displacement, velocity and acceleration of rod are the same. For different value of k, the fluctuation of velocity and acceleration of rod are in direct proportion to k and angular displacement of rod is fixed.
Numerical Simulation of Aerodynamic Performance of Film Cooling on a Flat Plate with Surface Roughness
Authors: Wang Jian Fei , Ji Yong Bin , Zang Shu Sheng
Published: December 2013

This study is aimed at researching surface roughness effect on the performance of blades in terms of aerodynamics. Numerical simulation on a rough flat plate with a row of 35°round film holes under different roughness heights, Reynolds numbers and blowing ratios is conducted to see how they affect film cooling on a flat plate. In terms of aerodynamics, the increase of surface roughness height, Reynolds number and blow ratio will result in the increase of skin friction coefficient. Besides, roughness has combined effects with Reynolds number and blowing ratio So the effect of surface roughness on blades performance is too big to ignore.
Applying Support Vector Machines in Rebound Hammer Test
Authors: Wang Yu Ren , Kuo Wen Ten , Lu Shian Shien , Shih Yi Fan , Wei Shih Shian
Published: December 2013

There are several nondestructive testing techniques available to test the compressive strength of the concrete and the Rebound Hammer Test is among one of the fast and economical methods. Nevertheless, it is found that the prediction results from Rebound Hammer Test are not satisfying (over 20% mean absolute percentage error). In view of this, this research intends to develop a concrete compressive strength prediction model for the SilverSchmidt test hammer, using data collected from 838 lab tests. The Q-values yield from the concrete test hammer SilverSchmidt is set as the input variable and the concrete compressive strength is set as the output variable for the prediction model. For the non-linear relationships, artificial intelligence technique, Support Vector Machines (SVMs), are adopted to develop the prediction models. The results show that the mean absolute percentage errors for SVMs prediction model, 6.76%, improves a lot when comparing to SilverSchmidt predictions. It is recommended that the artificial intelligence prediction models can be applied in the SilverSchmidt tests to improve the prediction accuracy.
Effect of Blank Shape and Size on the Forming Quality of Thread Shaft Rolling in Cross Wedge Rolling
Authors: Yan Hua Jun , Mao Hao En , Li Guo Chang , He Xiao Xi , Liu Jin Ping , Hu Zheng Huan
Published: December 2013

The defects of the lower tooth height and of larger pitch in thread portion of rolled pieces are prone to appearing when rolling thread shaft in cross wedge rolling. To solve this problem, changing the blank shape and size were tried. Two types of concave conical and round blanks are designed with concave conical blanks obtained by rolling in the cross wedge rolling. Because the design of the rolling die is simple, good precision of blank can be ensured. Multiple size types of blanks were designed and the rolling experiment was made in the rolling mill of model H630. By measuring the values of the tooth height and pitch, the effect of blank shape on thread shafts rolled in the wedge rolling were investigated carefully. The reasonable size range of the blank shape was obtained. The conclusions above pave the theoretical foundation for the in-depth study on this technology.
Design and Realization of Robot Workplaces with Virtual and Augmented Reality Application
Authors: Novak-Marcincin Jozef , Janak Miroslav
Published: December 2013

Virtual reality provides an easy, powerful, intuitive way of human-computer interaction. The user can watch and manipulate the simulated environment in the same way we act in the real world, without any need to learn how the complicated user interface works. Therefore many applications like flight simulators, architectural walkthrough or data visualization systems were developed relatively fast. Later on, virtual reality has was applied as a teleoperating and collaborative medium, and in the entertainment area. Augmented reality system generates a complex view where the virtual areas are covered by real environment and offers the basic working place for the user. It is a reciprocal combination of the real scene observed by the camera and virtual scene generated by the computer logical core that mixture the both scenes. It is easy to say that possibilities of augmented reality find the utilization in many industrial spheres like as aeronautics, automobile industry, manufacturing etc.
Algorithms for Dynamic Hardness Measurements by Scratch Testing in the Submicron and Nanometer Scale
Authors: Lvova Natalia , Kravchuk K. , Shirokov I.
Published: December 2013

The automatic scratch geometrical parameters analysis algorithms based on the images obtained by scanning probe microscopy have been developed. We provide a description of the technique to determine the contact area and the scratch volume with and without account of the pile-ups. The developed algorithms are applied to measure the dynamic hardness by sclerometry on the submicron and nanometer scale.
Formation of Thermally Induced Defects in Silica Optical Material
Authors: Xiao Zhong Yin , Wen Jian Xiang , Luo Wen Yun , Wu Wen Kai , Gong Ren Xiang , Yin Jian Chong , Wang Ting Yun
Published: December 2013

Characteristics of silica optical material largely depend on its thermal history. In this paper, formation of thermally induced defects in silica optical material is studied. The formation process of defect is analyzed in detail. The results show that there is an obvious difference in defect formation induced by heating treatment when the composition of silica optical material changes. Defect formation mainly displays as the produce process when the initial defects of the silica material are zero. However, defect formation expresses as the produce and annealing process when the initial defects of the silica material are not zero. The initial defect concentration can be decreased significantly when the silica material is heated in high temperature. At the same time, the new defect is also produced. These theoretic results are consistent with the previous experimental ones.
Design of Automatic Scraping System
Authors: Tong Hui Fen , Liu Wei , Chi Yan , Wang Wei
Published: December 2013

Based on the principle of hand scraping a set of automatic scraping system is designed in this paper. Machine tool bed consists of supporting chassis and cast iron sidewall, which has little deformation, good rigidity and high mechanical strength. And the operating floor features 3-Degree of Freedom with high precision. Guideway adopts imported linear guideway, featuring high precision, high load - bearing redundancy and long life. Scraping tool holder is stably installed in the hole at the end of the piston rod. By the electrical control system the cylinder can control scraping tool to do reciprocal motion stably. Scraping points on the surface of workpieces are captured by a CCD camera with high detection efficiency and accurate test data. The results show that the system is designed to greatly reduce labor intensity and improve scraping efficiency under the precondition of keeping good scraping quality.
The Spectral Element Method for the Steklov Eigenvalue Problem
Authors: Li Yan Jun , Yang Yi Du , Bi Hai
Published: December 2013

This paper discusses the spectral element approximation with LGL node basis for the Steklov eigenvalue problem, and analyzes the a priori error estimates. Finally, numerical experi-ments on the square and the L-shaped domain are carried out to get very accurate approximations by the spectral element method.
A Review on the Bin Packing Capacitated Vehicle Routing Problem
Authors: Zhang Qun , Wei Li Rong , Hu Rui , Yan Rui , Li Li Hua , Zhu Xiao Ning
Published: December 2013

This paper introduced the Bin Packing Capacitated Vehicle Routing Problem. It introduced the constraints and differences between algorithms of two-dimensional and three-dimensional loading capacitated vehicle routing problem. It gave a review of models and algorithms for Bin Packing Capacitated VRP. Finally, it prospected future research orientations and possible improvement in this area.
A Novel Model for Multi-Parametric Load Balance in Grid Computing
Authors: Liu Quan Sheng
Published: December 2013

Grid computing is a computing model in which computing resources are geographically dispersed. A computing node can share these resources as well as can transfer applications at other nodes to execute it. Due to the absence of centralized authority in grid, some resources may be overloaded and others may be under loaded. To obtain high performance, load balance strategy is necessarily needed. Load balance strategy can be affected by different parameters like network parameters, application characteristics, computing node capacity etc. In this paper, we consider using three parameters namely network parameters, computation node capacity and application characteristic to obtain effective load balance. All these parameters will pass to AHP (Arithmetic hierarchy process) for automatic decision making to select better resources for high performance service.
Properties and Application of Alumina Reinforced Aluminum Composite
Authors: Li Ya Nan , Zhang Wei Zheng , Cao Yuan Fu , Zhang Ti En
Published: December 2013

Improving high-temperature strength of aluminum piston material is a core technology for diesel engines to high speed and high intensity. To figure out the influence of alumina reinforced aluminum composites to the thermal load of high intensity piston, this paper study the properties of the alumina fiber reinforced aluminum composite and its protection for piston. The research shows that, compared with the cast aluminum, the high tensile strength and fatigue limit of the composite were increased by about 25% and 26% respectively. Therefore, the alumina fiber reinforced composite could not improve the temperature distribution of the piston, but it can improve high temperature strength and the operational reliability of the piston.
Virtual Learning Technology and Materials in Malaysian Higher Education
Authors: Lam Jason M.S. , Fern Yeo Sook , Chong Venny S.W. , Huat Tan Seng , Leng Oh Yit
Published: December 2013

This study has been developed to explore the usage of virtual learning materials and its system on students experience in higher education (HE). Most virtual learning literatures were well documented in the developed country context but little in the Malaysia HE. In this study, 15 students and a prominent professor from public university were interviewed to seek their views on virtual learning between May to June, 2013. This qualitative approach identifies better knowledge sharing, cost reduction and productivity as the main benefits of using virtual learning technologies. However, the findings can only be deduced by quantitative research, comprising of larger sample size of students from local and private HE Institutions (HEIs), and seeking their views of virtual learning on usefulness and acceptance towards education satisfaction and loyalty. Hence, a conceptual model was derived for this preliminary study.
Excellent Electrochemical Performance and Thermal Stability of LiNi0.5Mn1.5O4 Thin-Film Cathode Prepared by Pulsed Laser Deposition
Authors: Wang Yan , Yang Guang , Peng Qian , Lu Pei Xiang
Published: December 2013

Lithium secondary batteries using LiNi0.5Mn1.5O4 (LNMO) films as a cathode material were prepared by pulsed laser deposition on stainless steel substrates. X-ray diffraction and Field-emission Scanning Electron Microscope results show that the film deposited at 750°C exhibits good crystallinity with well-defined grains structure. Galvanostatic charge/discharge measurement results revealed that the reversible capacity maintains 116.8mAhg-1 after 100 cycles at 0.5C. It also exhibits excellent rate capability, as the rates increase to 5 and 10 C, about 95.4% and 92.3% of its initial capacity at 0.2C can be retained. In additional, thermal stability of the Al2O3 coated LNMO thin film cathodes were also explored. The high temperature cyclic performance of LNMO thin film electrode was significantly enhanced by the coating.
The Preparation and Properties of the Conductive and Magnetic Tin-Coated Polyester Fibers for Clothing
Authors: Sun Yi Ming , Cheng Yan , Li Jiao
Published: December 2013

By an oxidation-reduction reaction the polyester film would be coated with a layer of tin. The conductivity of polyester film was discussed under different plating time, temperature, and PH. The results showed that when the plating time was 60 minutes, the temperature was 90°C and the PH was 4, the polyester film attained the optimal conductivity. The polyester film could be protected and the combination of magnetic and electrical conduction would be achieved by coating with a layer of magnetic powder after plating.
Interface Structure of EPS and Pores Effect on Properties of EPS Lightweight Concrete
Authors: Zhang Xue Song
Published: December 2013

The weak interfacial bond strength EPS beads and large intercommunicating pores in the EPS lightweight concrete result in degradation of the mechanical properties of the concrete. The interface bond properties between EPS beads and the concrete can be improved by using the polyvinyl acetate (PVA) emulsion and silica fume. To prevent EPS beads rise up to the surface in the concrete mixing and reduce the number of larger pores in the concrete, vibrating with pressure, which can enhance the mechanical properties of the concrete, is applied. To decrease the aperture size of large pores and enhance thermal performance of the concrete, it is appropriate to decrease EPS beads size . The three-dimensional net structure formed by the polyvinyl acetate (PVA) emulsion and the hydration products of cement in the large pores of the concrete can reduce connectivity of the pores in the concrete ,thus the anti-frozen properties of the concrete is up as well.
Study on the Load Test of Variable Cross-Section Box Girder Bridge
Authors: Long Xing Hang , Su Ji Jun , Wang Lei , Han Hai Bo , Sun Yue Long
Published: December 2013

In order to study the load property of variable cross-section continuous box girder bridge, in this paper, the static and dynamic load test were carried on the main span for Xiaoqinghe super-large bridge in Shandong province. The main girder stress, deflection, impact coefficient, self-vibration frequency and the static and dynamic characteristics were analyzed, compared with the theoretical calculation to judge the safety of the bridge.
Acoustic Detection on Analysis of Rock Mass Integrality
Authors: Li Zhuang , Han Hai Bo , Zheng Yi Feng , Li Ming
Published: December 2013

This paper briefly described borehole wave velocity test and the principle and method of wave velocity test technique, by using acoustic measurement and control technology of tunnel rock mass test, integrality index of rock mass is obtained, ultimately, we evaluate the rock mass integrity. The actual application effect is good and provides an important basis for the engineering rock mass quality evaluation.
Analysis of Influence to Primary Support Forces by Stress Release in Loess Tunnel
Authors: Su Zhong Ming
Published: December 2013

Based on a certain loess tunnel in Kelan-Linxian Expressway in Shanxi province, the influence to primary support forces by different stress release is analyzed by the Ansys FE software in the step method excavation. The analysis results can reasonably reflect the actual case of primary support forces, and can offer related reference to the selection of reasonable design parameters for primary support.
The Test of Dynamic Characteristics of Concrete under Biaxial Compression State
Authors: Lei Jin Sheng , Liu Fei , Peng Gang , Lei Min
Published: December 2013

Concrete structure in reality mostly in complicated stress state, dynamic characteristics and static characteristics under earthquakes and other dynamic loads are very different. For a further understanding of the dynamic characteristics of the concrete, true triaxial testing machine system was used to the C30 concrete at different strain rates and different side of the cube concrete specimens stress biaxial dynamic compression tests. Biaxial stress state concrete elasticity modulus, peak stress, peak strain, was obtained by the experimental study, and carries on the comparative analysis. Results show that: the dynamic characteristics of concrete under biaxial compression state of concrete and uniaxial condition are very different.
Reconstruction of Key Parameters of Marine Supercharged Boiler Based on PLS-SVM
Authors: Song Fei , Cheng Gang , Sun Feng Rui , Zhu Guo Qing
Published: December 2013

A PLS-SVM method is used in order to improve the performance matching of Marine Supercharged Boiler and Turbocharged set. Value of key parameter of processing control is reconstructed through out of historical operating data. The traditional way of parameter reconstruction is theoretical calculation, which cannot solve the problem caused by performance degradation. Experiment shows that the PLA-SVM method could lead to a more accuracy and efficient results.
Research on Civil Engineering with Ecological Impact Assessment of Construction Activities
Authors: Liu Yan Min
Published: December 2013

Ecological impact assessment is revealed through quantitative the impact of human activities on economic development and on human health to determine a regional ecological or environmental load capacity. Only scientific, reasonable and practical to establish an evaluation system, it may promote the healthy development of the construction industry and emerge more green construction enterprises, so as to contribute more green building community. The paper used analytic hierarchy process (AHP). With this evaluation criterion, we can evaluate green construction level of engineering construction.
Research on Optimization Method of Extreme Learning Machine with Application of Information Technology
Authors: Zhang Zhi Feng , Gan Cheng , Ding Xiao Jian , Cai Zeng Yu
Published: December 2013

Based on the research of extreme learning machine and support vector machine, this paper does the research on the optimization method on extreme learning machine. This paper suggests an optimization model of extreme learning machine based on the improvement of the old model, and this model has obvious improvement on generalization ability and learning parameter ability. This approach can improve the development efficiency in the information technology, the experiment indicate this approach is efficient.