bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal Analysis of Heat Recovery Unit to Recover Exhaust Energy for Using in Organic Rankine Cycle
Authors: bin Mamat Aman M.I. , Wan Mohamed Wan Ahmad Najmi
Published: September 2013

Heat engines convert only approximately 20% to 50% of the supplied energy into mechanical work whereas the remaining energy is lost as rejected heat. Although some of the energy lost is intrinsic to the nature of an engine and cannot be fully overcome (such as energy lost due to friction of moving parts), a large amount of energy can potentially be recovered. This paper presents a heat transfer analysis of a WHE for recovering wasted exhaust energy whilst transferring energy to different organic working fluid used in the OrganicRankine Cycle. The types of considered fluids are R-134a, Propane and Ammonia. The results show that the Ammonia has the highesteffectiveness of 0.25. The maximum heat transferrate of 48.5 kW was recovered using the Ammonia at the exhaust gas temperature of 700°C.
A Case Study on Indoor Comfort of Lecture Rooms in University Buildings
Authors: Harun H.A. , Buyamin Norsheila , Othman Mohamad Asyraf , Sulaiman Shaharin Anwar
Published: September 2013

The indoor environment of lecture rooms in universities can affect the learning of students. Nevertheless, study on the actual conditions of air in relation to indoor air quality is rare. This paper presents a case study on the indoor comfort of selected lecture rooms in a university. Two rooms of different sizes and ventilation rates were selected, in which the indoors air temperature, CO2 content and relative humidity were measured both when occupied and unoccupied. The study revealed that occupancy by students did not directly affect the relative humidity in the lecture rooms, probably due to the dominating influence of the outdoor air. It was found from the study that under high occupancy, the room temperature and CO2 content would be higher than the recommended level and thus affected the comfort level of students and consequently their learning ability during the lecture.
Microstructure and XRD of Ductile Iron Using Annealing-Tempering Heat Treatment Process
Authors: Idham M. F. , Abdullah B. , Syarif Junaidi , Jaffar Ahmed , Alias Siti Khadijah , Saad Nor Hayati
Published: September 2013

In this present study, the effect of tempering temperature of annealing-tempering combination processes, on microstructure as well as exploring the phase constituents of ductile iron through XRD analysis were performed. Ductile iron produced through conventional CO2 sand casting method was performed annealing-tempering heat treatment processes by using change furnace method. Three different temperatures were investigated ranging from (i) 250 °C, (ii) 300 °C and (iii) 350 °C for 1.5 hours respectively. Standard metallographic observation and XRD analysis were done to characterize the microstructure and the constituents respectively. It is found that the graphite structure exist in both treated and untreated samples. Pearlitic structure was formed in the microstructure for heat treated samples. Ferritic-pearlitic matrix structure surrounding the graphite nodule has been shown in as-cast sample. Annealing-tempering process does not change the BCC ferrite peak in (200), (211), (220) and (310) planes shown in as-cast.
The Influence of Alumina Filler on Impact Properties of Short Glass Fiber Reinforced Epoxy
Authors: Saharudin Mohd Shahneel , Jumahat Aidah , Kahar Amir Z.A. , Ahmad Shaharudin
Published: September 2013

mpact resistance is one of the main consideration in measuring service life, liability and safety of polymer composite structures or products. Impact resistance of a composite material can be measured in terms of energy absorption, depth of penetration and total impact time. In this study, the influence of alumina Al2O3 on impact properties of short glass fiber reinforced polymer was investigated. The drop weight impact tests were performed in accordance to ASTM D7136 standard using Dynatup impact tester. Based on the results, the incorporation of micronsize alumina filler enhanced the energy absorbed during crushing, reduced the depth of penetration of the impactor and expanded the total impact time hence improved the impact properties of the composites.
Effect of Bearing Mobility on the Kinetics Performance of TKA during Deep Flexion: A Computational Simulation
Authors: Mohd Afzan Mohd Anuar , Todo Mitsugu , Nagamine Ryuji , Hirokawa Shunji
Published: September 2013

Characterizing the relative performance between mobile bearing and fixed bearing knee prosthesis remains seen as a difficult task as the previous short-term and mid-term clinical studies disable to observe any evidence of superiority of one design over another. The aim of the present study is to characterize the mechanics comparison between both designs of prosthesis during deep flexional motion with tibial rotation. Three dimensional (3D) FE model of clinically used mobile bearing posterior stabilized (PS) prosthesis was developed from its CAD data. Explicit finite element model was used to simulate the dynamic loaded deep flexional motion from 0 to 135° with neutral and 10° tibial rotation. Fixed bearing prosthesis was represented by fixing the tibial insert to the tibial component. The fixed bearing design was found relatively sensitive to flexion motion and tibial rotation in terms of contact area and maximum shear stress as compared to the mobile bearing design. Tibial rotation increased the peak value of maximum shear stress up to 58 MPa for the fixed bearing, on the contrary, the mobile bearing maintained the peak value of maximum shear stress at 31 MPa even with tibial axial rotation. The influence of post-cam design was also discussed in this study. The mobile bearing has an ability to maintain conformity and relatively low shear stress during very deep flexion with tibial axial rotation in comparison to the fixed bearing.
Sensitivity Study of Surface Curvature in Characterisation of Cartilage Mechanical Properties
Authors: Abd Latif Mohd Juzaila , Ismail Noor Rizan Adzwa , Ramlan Roszaidi , Mahmud Jamaluddin , Kadir Mohammed Rafiq Abdul
Published: September 2013

The mechanical properties of articular cartilage serve as important measures of tissue function or degeneration, and are known to change significantly with asteoarthritis. In previous computational studies, the cartilage surface of axisymmetric models was assumed to be flat in order to evaluate the cartilage behaviour. This assumption was inappropriate since the synovial joint possessed curvature geometrical shape and may contribute to the inaccurate in characterising the cartilage properties. Therefore, this study aims to examine the sensitivity of cartilage surface curvature of characterized cartilage biphasic properties using a combination of experimental and computational methods. Axisymmetric biphasic poroelastic finite element models were generated to measure cartilage surface radius and thickness. Based on the results, the smaller cartilage surface of 20 mm radius produced higher difference of the characterised properties where its generate 9% difference in the permeability and 5% difference in the elastic modulus, compared to the flat cartilage. Based on these results, it may indicate that the cartilage curvature will affect the characterised cartilage biphasic properties of elastic modulus and permeability.
Application of Wavelet Analysis in Blade Faults Diagnosis for Multi-Stages Rotor System
Authors: Abdelrhman Ahmed M. , Leong M. Salman , Hee Lim Meng , Ngui Wai Keng
Published: September 2013

Blade fault is one of the most common faults in turbomachinery. In this article, a rotor system which consists of multiple stages of blades was developed. A variety of blade fault conditions were investigated and its vibration responses were measured. The feasibility of wavelet analysis for multi-stages blade fault diagnosis was tested using simulated signals as well as experimental data. The use of wavelet analysis as the tool to detect multi stages blade faults was studied. Some probable solutions to improve multi stages blade fault diagnosis by wavelet analysis were also suggested.
Slippery Motion between the Limbs of a Double Tendon Graft
Authors: Cheung William , Mahmud Jamaluddin , Snow Martyn , Wang Bin , Chizari Mahmoud
Published: September 2013

Relative motion of tendon limbs of a double tendon graft for the application of anterior cruciate ligament (ACL) reconstruction may affect the mechanical behaviour of a tendon graft structure. The biomechanical data derived from the standard tensile testing machines may not be able to show the relative motion of the graft limbs. This paper uses the non-destructive digital stereo imaging recording system, synchronized with the standard test machine, to precisely determine the biomechanical properties of 10 bovine flexor tendon grafts which hanged from the loop side to the rig and the other end was fixed in a bone block. The study showed there is a relative motion between graft limbs.
Reanalysis of Modified Dynamic System in the Frequency Domain
Authors: Eun Hee Chang , Park Su Yong , Lee Seung Guk
Published: September 2013

The reanalysis approach consists in determining the effect of already established modifications. This study presents the dynamic reanalysis method to describe the dynamic response of modified system by combining the theoretically calculated receptances of the original system and the information on the modified substructure. The proposed formulation includes dynamic reanalysis where there are and are not additional dofs due to structural modification without any numerical iteration. A numerical example is given to illustrate the applications of the proposed method. And the numerical results raise the application limit of the proposed method.
Numerical Study on Combustion Performance Comparison of Premixed Methane-Air in Micro-Combustors with and without Heat Recirculating Channel
Authors: Tang Ai Kun , Pan Jian Feng , Shao Xia , Liu Yang Xian
Published: September 2013

Recently£¬research interests of micro-power generation devices which are based on micro-combustion process have been stimulated by the persistent breakthrough of MEMS techniques. A new type micro-heat recirculating combustor was presented in this paper, and the computation model for premixed methane-air was established which adopting a skeletal reaction mechanism. Combustion characteristics both in heat recirculating combustor and single-channel combustor are analyzed which containing the flame shape, location and temperature at the same simulation conditions. It is found that not only the flame location can be better fixed by heat recirculation measure, but although the flame temperature can be raised for some degrees when compared to the single channel combustor. These results provide some useful information for the design of micro-scale combustors.
Development and Implementation of a Method for Chatter Control in Turning Applying Magnet from below the Tool
Authors: Nurul Amin A.K.M. , Abdullah Fawaz Mohsen , Mohammad Ummu Atiqah Khairiyah B. , Arif Muammer Din
Published: September 2013

Chatter is a self-excited and violent form of vibration which is almost unavoidable in all machining processes. It affects surface roughness, machining accuracy, cutting tool and machine tool life, metal removal rate; and consequently operation cost. This research work focuses on investigation of the influence of the cutting parameters on chatter and implementation of a method based on application of permanent magnet for controlling chatter during turning of stainless steel AISI 304 using coated carbide tool. For this purpose, a powerful permanent bar magnet (of strength 1250-1350 Gauss) was placed inside a specially developed fixture mounted on the lathe machine carriage, to apply magnetic field to the base of the tool holder in the Z direction. The effectiveness of the application of the magnet on chatter suppression was measured in terms of reduction of amplitude of chatter compared to conventional turning. To achieve this, a small central composite design (CCD) of the Response Surface Methodology (RSM) with five levels and an alpha value of 1.4142, was used in the design of the experiments (DoE). Design-Expert 6.0 software was utilized in the model development process. Vibration monitoring was done using an online vibration monitoring system. FFT analysis of the recorded vibration signals was conducted using DASYLab software to evaluate the peak chatter amplitudes and their corresponding excited frequencies. The acceleration amplitude was found to be reduced by a maximum of 73.43% and an average of 31.58% due to the effect of damping on the resonant amplitude offered by the magnetic field created by the permanent magnet.
Aluminum Mold Machining Process Research
Authors: Zhang De Qiang , Cheng Jie , Meng Xiao Xin , Zhao Shuai
Published: September 2013

HSS cutting tools are used for aluminum mold milling experiments, different sets of milling parameters are taken to do comparative experiments, the impact of law of the respective milling parameters on the processing quality is Learned about, process improvements and best milling parameters are proposed, suggestions for improvement methods in effectively reduce the vibration of the mold processing, deformation, and improve processing efficiency and workpiece surface quality and other aspects are put forward.
Design and Application of Embedded Intelligent Power Consumption Terminal
Authors: Li Fang , Wang Li Fang , Liao Cheng Lin
Published: September 2013

ntelligent power consumption system is an important mean to improve the energy efficiency. An embedded terminal was designed in the system, which can achieve intelligent control and management for devices, and reduce power and energy consumption. The terminal in the system was designed and implemented based on ARM platform, using B/S structure to communicate with the remote server through Internet. It has several wired and wireless communication interfaces, which can be connected with various electric equipments. For extensibility, the software of the terminal uses a hierarchical and modular approach which includes communication layer, device layer, interface layer and intelligent power consumption layer. Meanwhile, the communication protocol and the unified interface design in the terminal make sure that the terminal can interact with the remote server reliably and timely. Through experiments in the demonstration operation region, it concludes that the terminals work stable and reliable, and equipment intelligent control and management are fulfilled. The system has many advantages such as modularity and scalability, which can be widely used in many fields like smart grid and smart home, etc.
Preparation and Characterization of Magnetically Responsive Biosorbents from Coffee Industry Residues
Authors: Zuorro Antonio , Lavecchia Roberto
Published: September 2013

Spent coffee grounds (SCG) and coffee silverskin (CS), the two main coffee industry residues, were magnetically modified by contact with an aqueous ferrofluid containing magnetite nanoparticles. The materials were characterized by SEMEDX analysis, X-ray diffraction and FTIR spectroscopy. Batch adsorption experiments were performed to assess their suitability as biosorbents, using methylene blue as a model pollutant. Adsorption equilibrium data were analysed by the Langmuir model, which allowed estimation of the maximum adsorption capacity. The magnetic biosorbents were easily regenerated by treatment with hydrochloric acid.
Application of Finite Element Method for Dry Masonry Overflow Dam Analysis
Authors: Tan Min
Published: September 2013

Through analyzing dry masonry overflow dam structures mechanical characteristics in construction process and operational process, this paper adopts finite element method to carry out simulation analysis for dry masonry overflow dam of Daxilong reservoir. Deducing distribution law of the dams stress and displacement in construction process and operational process. Analysis results show that, dry masonry overflow dam of Daxilong reservoir construction is reasonable, it meets the requirements for design.
An Improved Response Surface Method for Reliability Analysis of Plate on Elastic Foundation
Authors: Kong Xu Guang , Liu Jun Qing , Cao Cai Qing
Published: September 2013

Using an improved response surface method analyzed the board of reliability on the elastic half space model. Considered the random of the larger variability parameters, such as foundation, board, load, the paper studied the reliability of this issue application of the response surface method of quadratic polynomials. This paper analyzed the influence of the random parameter variability on the reliability index β and failure probability. Comparison result shows that the convergence of the iteration of this paper is improved than the general response surface method , structural analysis to further reduce the number and improve the computational efficiency, obtained some useful conclusions and had some engineering referencing.
Simulation of Fallen-Column Geological Structure Detection of Tunnel Face and Parameters Analysis
Authors: Zhang Wei Jie , Zhao Qi Feng , Hao Ming Rui , Liu Zhi Min , Wu Miao
Published: September 2013

In order to study on the advanced detection technology and the sensitivity of the fallen geological structure based on induce polarization method, the hazards of the fallen geological structure before the driving face of coal roadway are analysed. A simplified physical model of the structure is established, which is converted to an equivalent circuit easy to study. Then an induce polarization model of the fallen geological structure is established. And the induce polarization (IP) model is connected with the simulation detection model of geological abnormal mass and the variation curves of the apparent resistivity and value of the fallen geological structure under the induce polarization mode are obtained. The curves obtained show that the parameters of simulation detection results and the electrical parameters pre-set by the induce polarization model would be the same basically. Therefore the basic idea of the electric method detection is verified and the feasibility presupposition could be provided for the development of the coal (rock) excited polarization effect base on the advanced detection instruments with the electric method.
The Natural Frequency Calculation Method of Simply-Supported Beam in the Sunshine Temperature Field
Authors: Cheng Yong Chun , Shi Yu Ping , Tan Guo Jin
Published: September 2013

The related researches show that , the sunshine temperature field can cause the changes of the natural frequencies of the simply-supported beam. In order to recover the influence law of the temperature field on the natural frequencies, the calculation method of the natural frequencies of the simply-supported beam bridge is formed. First, according to the principles of stress equivalence, transform the sunshine temperature field to the partiality axis forces. Based on the Bernoulli model, the calculation method of the natural frequencies of the simply-supported beam under the partiality axis forces at both ends is formed. At last, take one simply-supported T beam as the object of numerical modeling and verify the validity and the reliability of this method.
2D Anisotropic Photonic Crystals of Hollow Semiconductor Nanorod with Liquid Crystals
Authors: Karaomerlioglu Filiz , Simsek Sevket , Mamedov Amirullah M. , Ozbay Ekmel
Published: September 2013

Photonic crystals (PCs) have many applications in order to control light-wave propagation. A novel type of two-dimensional anisotropic PC is investigated band gap and optical properties as a hollow semiconductor nanorod with nematicliquid crystals (LC). The PC structure composed of an anisotropic nematicLC in semiconductor square hollow nanorod is designed using the plane wave expansion (PWE) method and finite-difference time-domain (FDTD) method. It has been used 5CB (4-pentyl-4`-cyanobiphenyl) as LC core, and Tellurium (Te) as square hollow nanorod material.The PC with hollow Tenanorod with nematicLC is compared with the PC with solid Tenanorodand the PC with hollow Tenanorod.
Experimental Study on a Gyromagnetic Piezo-Cantilever Generator
Authors: Chen Yi Feng , Kan Jun Wu , Wang Shu Yun , Huang Fang Sheng , Zeng Ping
Published: September 2013

To meet the demands of the rotating structure for self-power, a novel gyromagnetic piezo-cantilever generator (GPCG) excited by the coupling between rotating magnets and those fixed on piezo-cantilever was presented. The influence of magnetic force (number and configuration of the magnets) and rotating speed on energy generation of the GPCG was investigated experimentally. The research results show that there are 9 optimal rotating speeds for the GPCG to achieve peak voltage at speed range of 0-1390r/min. With 1 magnet (ø12x2mm3) fixed on piezo-cantilever, the increasing number of rotating magnets (ø12x4mm3) in the same place (ns) of the rotator exerts no influence on the optimal rotating speeds, but leads to rising output voltage. At 1042.5r/min, the achieved peak voltages from the GPCG in the case ofns=1/2/4/6 are 13.2/16.6/23.8/27.8V respectively. The optimal speeds decrease and the peak voltage rises with the increasing number of magnets evenly distributed on the rotator (nd). In the case of 1 magnet fixed on piezo-cantilever andnd=1/2/4/8, the optimal rotating speeds and the peek voltages from the GPCG are 708.9/528.2/528.2/264.1r/min and 13.2/16.6/23.8/27.8V respectively.
Learning from Demonstration with State Based Obstacle Avoidance for Mobile Service Robots
Authors: Nippun Kumaar A.A. , Sudarshan T.S.B.
Published: September 2013

Learning from Demonstration (LfD) is a technique for teaching a system through demonstration. In areas like service robotics the robot should be user friendly in terms of coding, so LfD techniques will be of greater advantage in this domain. In this paper two novel approaches, counter based technique and encoder based technique is proposed for teaching a mobile service robot to navigate from one point to another with a novel state based obstacle avoidance technique. The main aim of the work is to develop an LfD Algorithm which is less complex in terms of hardware and software. Both the proposed methods along with obstacle avoidance have been implemented and tested using Player/Stage robotics simulator.
An Improved Particle Swarm Optimization Algorithm
Authors: Zhang Guan Yu , Wang Xiao Ming , Guo Rui , Wang Guo Qiang
Published: September 2013

This paper presents an improved particle swarm optimization (PSO) algorithm based on genetic algorithm (GA) and Tabu algorithm. The improved PSO algorithm adds the characteristics of genetic, mutation, and tabu search into the standard PSO to help it overcome the weaknesses of falling into the local optimum and avoids the repeat of the optimum path. By contrasting the improved and standard PSO algorithms through testing classic functions, the improved PSO is found to have better global search characteristics.
Design and Implementation of Regional LS Factor Computing Tool Based on GIS and Array Operation
Authors: Zhang Hong Ming , Yang Qin Ke , Li Shu Qin , Wang Mei Li , Ying Ming , Lang Huan , Dong Xue Wen
Published: September 2013

For over 40 years, the universal soil loss equation (USLE) and its revised version the revised universal soil loss equation (RUSLE) have been used all over the world for soil mean annual loss per area unit. Because of the watershed erosion models are under developing, many researchers applied the USLE and RUSLE to estimate soil loss in watershed estimations. However, a major limitation is the difficulty in extracting the LS factor. The geographic information system-based (GIS-based) methods which have been developed for estimating the slope length for USLE and RUSLE model also have limitations. A series of ARC/INFO AML program was created that can calculate LS factor for the USLE, however the program need a very long time to run in wide-ranging areas. The flowpath and cumulative cell length-based method (FCL) overcomes this disadvantage but does not consider the following questions: (1) Some original AML program functions are not achieved, so results are different. (2) Using USLE to calculate LS factor that do not adapt to the erosion environment of China. (3) There isnt a friendly graphic user interface. The purpose of this research was to overcome these limitations and extend the FCL method through Integrating CSLE equation. We developed a LS calculation tool (LS-TOOL) in Microsofts .NET environment using C# with a user-friendly interface. Comparing the LS factor calculated with the FCL method and AML method, LS factor values generated by using LS-TOOL method delivers improved results. The LS-TOOL algorithm can automatically calculate slope length, slope steepness, L factor, S factor, and LS factors, providing the results as ASCII files which can be easily used in some GIS software. This study is an important step forward in conducting fast large-scale erosion evaluation.
Chatter Prediction Based on NC Physical Simulation in Machining Ti6Al4V Thin-Walled Components
Authors: Li Yu , Sun Chao
Published: September 2013

Chatter has been a problem in CNC machining process especially during machining thin-walled components with low stiffness. For accurately predicting chatter stability in machining Ti6Al4V thin-walled components, this paper establishes a chatter prediction method considering of cutting parameters and tool path. The fast chatter prediction method for thin-walled components is based on physical simulation software. Cutting parameters and tool path is achieved through the chatter stability lobes test and finite element simulation. Machining process is simulated by the physical simulation software using generated NC code. This proposed method transforms the NC physical simulation toward the practical methodology for the stability prediction over the multi-pocket structure milling.
Theoretical Studies on Structures and Properties of Pentazine,1,2,4,5-Tetrazine and s-Triazine Derivatives with Nitrogen - Containing Substitutents
Authors: Liang Xiao Qin , Zheng Yan , Wang Bi Qin , Pu Xue Mei
Published: September 2013

B3LYP /aug-cc-pvdz level of theory, combined with NBO and G3 methods, is applied to study substituent effects on the geometries, bond dissociation energies and high energetic density material properties of 27 kinds of derivatives designed by substituted hydrogen atoms of pentazine, 1,2,4,5-tetrazine and s-triazine, of which the hydrogen atoms are substituted by CN, -NO2, -NH2, -N3, -N2H, -NHNH2, -N4H and-N4H3 groups. The relatively small heats of formation are observed for the derivatives substituted by-NH2, -H, -NO2 and-NHNH2. The order of heats of formation for the derivatives containing the same substituent is: pentazine > 1,2,4,5-tetrazine >s-triazine. For the derivatives substituted by-CN, -N2H and-N4H3, heats of formation are 860~1124 kJ/mol,in which heats of formation of 1,2,4,5-tetrazine derivatives are larger. For derivatives substituted by-N3 and-N4H, their heats of formation are 974 1735 kJ/mol, which are the highest in all derivatives. The order of heats of formation is: s-triazine derivative > 1,2,4,5-tetrazine derivative > pentazine derivative. The normalized heats of formation of these pentazine derivatives substituted by-CN-N3 ,- N2H and N4H and 1,2,4,5-tetrazine derivatives substituted by-CN-N3 and N4H are 93 109 kJ, which is higher than that of triazido-s-triazine and diazido-s-tetrazine derived from Hiskey. Our observations indicate that the higher heats of formation of substituent molecules have, the higher ones the substitutive derivatives. By means of the data of dissociation energy, it can be found that the heats of formation of derivatives substituted by N3, -N2H and CN are greater, and they are also more stable. It is possile for them to become energetic materials with high-energy and low sensitivity.
Fractal Analysis of Laser Cutting Heavy Plate Surface Topography
Authors: Zhao Lin , Zhang Yang , Ma Da Guo , Li Wei
Published: September 2013

The estimation and characterization of laser cutting heavy plate surface topography is very significant to the study on the formation mechanism of laser cutting surface and the relationship between machined surface formation and the processing parameters. The article characterizes the surface topography of the laser cutting heavy plate based on the fractal geometry theory, use box-counting method to calculate the fractal dimension of the laser cutting heavy plate surface. The results show the laser cutting heavy plate surface of low carbon steel has a obvious fractal feature, the fractal dimension of laser cutting surface range from 1.283 to 1.395 in a certain scale, the laser cutting surface topography is relatively complex, the relation between Fractal dimension D and surface roughness Ra are not linear correspondence, and then the surface topography of laser cutting heavy plate can be comprehensively estimated in accordance with D and Ra.
Study on Micro Electrochemical Machining Technology and its Influencing Factors
Authors: Li Xiao Hai , Zhao Li Ping , Shi Ying Chun , Zhao Li Jie
Published: September 2013

Electrochemical machining (ECM) is an anodic dissolution process of metal as anode ion by ion, and micro-ECM is a promising micromachining method at micro to meso-scale. Thus, a micro-ECM setup was developed to fabricate micro parts and explore the feasibility of micro-ECM at micro to meso-scale, including the design of high-frequency micro-energy pulse power supply. By using the detection unit of machining state and optical encoder, a closed loop control system for micro-ECM was developed. Under low concentration of passivating electrolyte, low machining voltage, micro rotating electrode and high-frequency short-pulse current, the machining gap can be reduced to about 10μm. The influence factors of the additives and the rotation of micro electrode on micro ECM were analysed by experiments. A micro-hole about 30μm in diameter was drilled by the rotating micro electrode.
Research on Cu-Fe Solid Solution and Plastic Deformation Properties of Explosively Welded T2/DT4C Laminate
Authors: Liu Peng , Jiang Jian Ping , Sun Bai Lian
Published: September 2013

Explosive welding experiment of T2 red copper plate and DT4C electrical pure iron plate was carried out. Microcosmic analysis and plastic deformation test of the bonding interface were also studied. Results indicate that the welded zone presents periodical wavy metallurgical interface and Cu-Fe Solid solution is distributed on the wave interface. Moreover, large amplitude variation of the ratio of Cu to Fe in the Cu-Fe Solid solution is found. No separation happens after flattening test and bending test, which shows that Cu-Fe Solid solution does no harm to the bonding properties and the welding quality of T2/DT4C laminates can meet the needs of plastic working of complicated shape workpieces.
A Method to Predict the Sheet Metal Deformation under Different Locator Layout
Authors: Zhao Hong Wang , Lu Cong , Li Wan Yu
Published: September 2013

"N-2-1" principle is widely recognized in the fixture design for deformable sheet metal workpieces, where N, the locators on primary datum, is the key to sheet metal fixture design. However, little research is done on how to determine the positions of N locators when considering normal deviation. This paper, concerning the low efficiency of the locating point optimization method using the finite element model, proposes a GA-BP neural network to predict the sheet metal deformation under different locator layout, by which to calculate the clamp normal deviation. Finally, a case is used to illustrate the flowchart of GA-BP network. Results show that the method has good performance and prediction ability.
Optimum Design and Analysis of Metal Delivery System for Magnesium Alloy Plates with Twin-Roll Casting Process
Authors: Yu Qun , Hu Xiao Dong , Huang Long Huan , Lin Yue
Published: September 2013

Using physical and numerical simulation method，metal delivery system of twin-roll casting magnesium alloy process was researched. The Anycasting software was used to simulate different flow systems by VOF method. And based on similar principles, an acrylic experimental model with the ratio of 1:1 was designed. The dam’s size and position were optimized by simulations and experiments. The flow distribution is uniform along the horizontal of the casting roller. Numerical simulation and physical simulation are in good coincidence.
Unified Multi-Error Model for Four Types CNC Machining Center
Authors: Fan Kai Guo , Yang Jian Guo , Yang Li Yan
Published: September 2013

The error modeling compensation method for improvement the machine tools accuracy has been extensively used in the past decades. To unify the multi-error model for four types CNC machining center, the comprehensive multi-error model of TXYZ type machining center was established based on the homogenous coordinate transformation. According to the analysis of the transmission chain, a unified multi-error model for four types machining center was established based on the Singular Function. Using the unified multi-error model, the mathematical model of four types machining center can be standardized. It is very important for unceasing development of error compensation technology.
The Preparation and Tribological Property Investigation of Chrysotile Nanotubes on the Grease
Authors: He Kai Ji , Liu Jia , Lv Hao , Zheng Shu Min , Wang Kai Ming
Published: September 2013

The nanoMgO and active nanoSiO2 were prepared by the special liquid-phase precipitation method. Subsequently, Chrysotile nanotube was prepared of by hydrothermal method using the nanoMgO and active nanoSiO2 as precursors at 220°C under 23atm in basic solution. The surface topographies and composition of the Chrysotile nanotube were characterized by XRD and TEM. Then, the dispersive property of particles modified by oleic acid was analyzed by IR. The tribological properties) were explored by adding the modified nanomagnesium silicate hydroxide to 2# lithic-grease after dispersing uniformly. Compared with the blank sample, it can significantly reduce the friction traces of the metal surface, improve extreme pressure performance. The friction coefficient is still stable when the temperature is raised during the friction. Nanotube power can be adhered and spread on the worn metal surface. Thus self-repairing coating forms on the worn surface.
Electroless Plating of Cu on Multi-Walled Carbon Nanotubes
Authors: Dai Rong Rong , Huang Xin Min , Fei Zhang Ping
Published: September 2013

A layer of densely distributed copper particles has been deposited on the surface of multi-walled carbon nanotubes (MWCNTs) by pretreatment including oxidation, sensitization and activation and electroless plating methods. Due to our experiments, the rate of deposition will increase by increasing the PH value and temperature of the solution bath properly. Different morphologies of coatings have been obtained with different PH values and temperatures. The most suitable PH value and temperature of the plating bath were 11.5 and 20°C, respectively.
Synthesis and Characterization of N-Doped Meso/Macroporous Carbon
Authors: Liu Chao , Chen Ai Bing , Hu Yong Qi , Yu Yi Feng
Published: September 2013

N-doped meso/macroporous carbon materials were synthesized by using melamine-formaldehyde resin as carbon precursor and silica spheres as a removable template. Scanning electron microscopy images reveal that the macropores of carbon materials can be modulated by changing the diameter of template. While the BET results verify that the template had no obvious effect to the mesopores of the materials. The as-synthesized carbon materials with a bimodal pores structure display a high surface nitrogen content of 30wt%. XPS analysis reveals that N atoms are mostly bound to the graphitic network in two forms, i.e. pyridinic and pyrrolic nitrogen.
Electrical Erosion Characteristics of Pt-Ir-Zr Alloy Contact under DC Load
Authors: Wang Sai Bei , Wang Song , Xie Ming , Zhang Ji Ming , Yang You Cai , Chen Yong Tai , Liu Man Men , Hu Jie Qiong
Published: September 2013

The analysis of electrical erosion characteristics of contacts under DC load is conducive to the in-depth study of the arc erosion mechanism. Through the electrical contact experiment, the electrical erosion status of the Pt-Ir-Zr alloy under DC load of 25V/15A is studied in this paper. The results show that: the contacts have excellent anti-welding behavior and lower loss on arc ablation. The separation acceleration of the breaking process between the movable and static contacts is 154.32μm/ms2. The arc erosion surfaces of the material show a large number of paste-like coagulum and bubbles. There are some micro-cracks existing on the surface of the Pt-Ir-Zr alloy contacts. The obvious material transfer phenomenon occurs between the movable and static contacts under DC load.
Effect of the Ratio of Zn/Y on Microstructure and Mechanical Properties of As-Cast Mg-4Zn-xY Alloys
Authors: Wang Feng , Li Ji Bao , Mao Ping Li , Liu Zheng
Published: September 2013

In order to investigate the ratio of Zn/Y on as-cast Mg-4Zn-xY (x=1, 2, 3 in wt. %), microstructure and mechanical properties are analyzed by scanning electronic microscopy (SEM), X-ray diffraction (XRD), energy dispersive spectrum (EDS) and tensile testing. The results indicate that with the decrease of the ratio of Zn/Y, microstructures are refined more greatly and the spheroidization and uniformity coefficient are improved obviously, and the morphologies of second phases are changed from diversity to unity, resulting in an improvement of mechanical properties of alloys.
Methods for Determining the Physical Property Cutoffs of the Effective Reservoirs of the Yaoyi Formation in Cha 48 Zone
Authors: Zhang Qing Guo , Sun Lu Lu , Chen Xi
Published: September 2013

The determination of the physical property cutoffs of the effective reservoirs is a major factor that affects the result of the reserve calculation and is a difficult problem in the research of the reservoir evaluation. It is related to the exploration, development and decision-making. This paper used the empirical statistical method, the minimum pore throat radius method, the oil attitude method and the porosity permeability cross plot method to exploratorily strike the physical property cutoffs of the effective reservoirs of Yaoyi Formation in Cha 48 zone. It was based on the actual situation of the data of cores, the well testing and the well logging and combined with the applicability of various methods. The results achieve the attest of the data from the well testing and the producing test and provide the basis for the reservoir calculation.
Effect of Cooling Rate on Oxidation Behaviour of Microalloyed Steel
Authors: Yu Xiang Long , Jiang Zheng Yi , Zhao Jing Wei , Wei Dong Bin , Zhou Cun Long
Published: September 2013

Oxidation characteristics of a microalloyed low carbon steel were investigated by a hot rolling mill combined with acceleration cooling system over the cooling rate range from 20 to 70°C/s. The effects of cooling rate after hot rolling on microstructure and phase composition of oxide scale were examined. The results showed that the increase of the cooling rate has a significant influence on the decrease of the grain size and surface roughness of oxide scale. A higher cooling rate promotes the formation of retain wustite and primary magnetite precipitation while suppression of eutectoid α-iron precipitates. This provides the possibility to enhance potential contribution of magnetite precipitates with preferable ductility, and hence fabricates a desired oxide-scale structure under continuous post cooling conditions considering a suitable cooling rate.
Effects of Aging Precipitates on the Mechanical and Corrosion Resistance Properties of 18Cr-18Mn-2Mo-0.96N Super High Nitrogen Austenitic Stainless Steel
Authors: Zhang Zu Rui , Zhao Zhen Ye , Li Chun Zhi , Jiang Zhou Hua , Li Hua Bing
Published: September 2013

This paper investigates the effects of aging precipitates on the mechanical and corrosion resistance properties of 18Cr-18Mn-2Mo-0.96N super high nitrogen austenitic stainless steel (HNS) through Vickers hardness, Charpy impact, tensile and electrical chemical methods. The probable affected mechanism is discussed by optical microscope (OM) and transmission electron microscopy (TEM). The results are presented as follow: the initial TTP curve with 0.05% precipitates volume fraction presents C type which has a nose temperature at 850°C with an incubation period for 60s. The precipitates increase with prolonging aging time to 40%. The HV results of aged HNS present firstly decrease then increase, the relevant yield strength firstly increase then decrease with increasing the aging time. Meanwhile, the impact energy, ultimate tensile strength and elongation are deteriorated significantly because of the formation and growth of cellular Cr2N and χ phase with concomitant increased amount of intergranular Cr2N. The IGC susceptibility increases and the pitting corrosion potentials decrease because of the Cr, N and Mo depletion through the formation of intergranular, cellular Cr2N and intermetallic χ precipitates by aging treatments.
Effect of Magnesium Addition on the Cast Microstructure of a Kind of HSLA Steel
Authors: Liu Yan , Wang Jian Ming , Liu Yang , He Chun Lin
Published: September 2013

A new technology to obtain a fine-structured and high-toughness HAZ of HSLA steel for high heat input welding is developed using metallurgical thermodynamics, physical chemistry of metallurgy and material processing methods synthetically in this study. A kind of HSLA steel is designed in this experiment. The thermal stability second phase particles which would not be dissolved or aggregated at high temperature will be expected by means of adding magnesium into the steel in the form of Mg-Zr alloy. The effect of magnesium addition on the cast microstructure of HSLA steel was analysed. The results show that The cast microstructure is mainly consist of lamellar and acicular ferrite, a small amount of pearlite and bainite. Compared with the original steel, there are acicular ferrites presenting in the experimental steel after adding 3 wt% Mg and 5 wt% Mg, which are the microstructure that we hope to get. The acicular ferrite will have a positive impact on the mechanical properties of the subsequent rolled steel.
Effect of the Continuous Annealing Process on Microstructure and Mechanical Properties of DP590 Steel
Authors: Wang Hong Bin , Xing Rui , Yu Yi Yao , Li Ji Guang , Yang Ji Hong , Long Ping
Published: September 2013

The microstructure and mechanical properties of the continuous annealing DP590 steel produced by a cold rolled plant were studied by utilizing a Gleeble thermal simulator tested machine. The results show that, increasing annealing temperature can not effectively improve the martensite content in the steel and annealing temperature be set at 780 °C and 800 °C is rational. Martensite decomposition at high overaging temperature will decrease tensile strength of the samples. As the overaging temperature sets at 250 °C ~ 300 °C, the samples could achieve tensile strength more than 600 MPa, which meet the requirements of DP590.
The Influence of the Electromagnetic Field Power on the Solidification of the Casting
Authors: Li Ji Guang , Li An Hong , Xu Chang Jun , Sheng Xing Xing , Sun Xing Long , Hu Lin
Published: September 2013

The electromagnetic stirring technique was used in the experiment to prepare the ingot casting. After comparing the conventional production by the means of ingot casting through electromagnetic field production, the results showed that the solidification of crystal was significantly influenced by the electromagnetic power. As the powers of the agitator increasesed from 0 KW to 20 KW, the refined grain size could be easily detected. That means, the length of the columnar crystal had shortened and isometric crystal had increased dramatically. From the phase transformation we can see that the pearlite and ferrite were distributed much more uniform than the original specimens. The results of the test showed that strengthening electromagnetic field is one of the most important methods to modify the internal crystal morphology. In conclusion, the electromagnetic stirring played a key role in ingot casting.
Electron Microscopic Analysis of 30CrMnSi Steel Surface Layers after Hot Deformation
Authors: Skakov Мazhyn , Uazyrkhanova Gulzhaz , Popova Natalya
Published: September 2013

Using electron microscopy were investigated character of change microdiffraction pattern of fragmented substructure, the relationship between average size micrograins, which forming the diffraction pattern, and the point reflections number on the ring. Also the integrated degree of plastic deformation was assessed in the roll surface layers, made of steel 30CrMnSi during hot deformation. It was shown that the fragments generated during steel deformation considerably disoriented with respect to each other. Formed by heat treatment steel fragments practically is not disoriented. Found that average size of fragments to be achieved in layer at distance of 2 mm from roll surface, for anisotropic fragments amounts to 0.27×0.66 μm, for isotropic - 0.43 μm, average size of fragments - 0.44 μm. Here plastic deformation degree ε0.70. Found that in layer located at distance of 0.5 mm from roll surface, anisotropic fragments have size 0.25×0.56 μm value, for isotropic - 0.39 μm, average fragment size - 0.40 μm. Here plastic deformation degree achieved value ε0.75. It is shown that on roll surface are present only isotropic fragments with average size 0.22 μm. Corresponds to it plastic deformation degree ε0.85.
Microstructure Evolution in Nb-Ti Micro-Alloyed Steel during Hot Compression and Hot Rolling Simulation
Authors: Shen Bin , Zhu Song He , Zhang Heng Hua
Published: September 2013

Based on a improved mathematic model of predicting austenite grain size of hot rolled Nb-Ti micro-alloyed steel, a module for calculating microstructure evolution in the steel during hot-forming process was developed. To evaluate the recrystallization behavior according to the proposed model during plate multi-pass hot rolling, the multi-pass hot compression and its FE analysis in couple with the newly determined model were conducted. It indicated that the present models were capable of simulating the multi-pass hot compression and the actual multi-pass rolling process. After simulating an actual rolling process in factory by using the above models, evolution laws of microstructure were analyzed. Simulation results of microstructure had a good agreement with the measured ones.
The Study on the Synthesis of Polyfluoroacrylate
Authors: Yang Qin Huan
Published: September 2013

Cationic polyfluoroacrylate has been synthesized in the dual presence of cationic and non-ionic emulsifiers. Optimization studies indicated that the optimal proportions of cationic emulsifier 1631 and non-ionic emulsifiers FSA and AEO-9 were 1.75%, 1.25%, and 0.08%, respectively. Under these conditions, the conversion to the polymer was 92.5%, the particle size was 142 nm, and the water contact angle on a polymer film surface was 94.0°. With increasing dosage of hydrocarbon emulsifier, the water contact angles of copolymer films decreased dramatically. The magnitude of this decrease for a polymer with low fluoride content was greater than that for a polymer with high fluoride content. The fluorinated emulsifier FSA behaved similarly to the hydrocarbon emulsifier.
Study on Acrylic Emulsion Adhesive Modified by Double Siloxane
Authors: Gao Cai Hua , Guo Wen Lu , Jin Zhi Ming
Published: September 2013

The acrylic emulsion adhesive was modified by D4 and KH570 with chemical process, and we can get the modified product successfully via the best technology parameter which was confirmed by orthogonal experiment. The structure of acrylic was characterized by FTIR, while there was a comparative study on the macroscopic properties and thermal stability of the unmodified and modified product. The results showed that when m(D4):m(KH570) was 2:1, the dosage of emulsifier was 3.0%, the dosage of KPS was 4.0%, the monomer(soft and hard) ratio was 1:1, the stability of the acrylic emulsion adhesive modified by double siloxane was good, and its viscosity, water resistance, heat resistance were improved greatly.