bluuebunny/crossref_metadata_2025 huggingface dataset:
Applying and Practicing of MATLAB Programing for Voronoi Tessellation
Authors: Xu Yong , Fan Xiao Hong , Liu Ke Gao , Shi Lei , Xu Bin , Wang Fu Ming , Lin Jun Pin
Published: June 2013

Three-dimensional (3D) Voronoi tessellation diagrams are generated by compiling program in MATLAB software. According to these 3D Voronoi cells, crystal structure, even the disorder structure, can be geometrically described and tessellated into the regular object, reflecting the atomic structural parameters, such as the coordination numbers (CN) and the atomic separation. Studying the characteristic of these tessellations, we can find the rule of atomic packing in real space. This Voronoi diagram is also useful in materials structure teaching curriculum and it is the significant basis to realized the atomic structure of the materials. By programing with MATLAB, the abstract concept of Voronoi tessellation are transformed into the lively and understandable computer animation, which can be easily recognized and mastered.
Energy Level Width of 2DEG in Different Well in Mesoscopic System
Authors: Xu Gang , He Ye Lu
Published: June 2013

Applying theories on quasi-classical particles and the uncertainty relation of quantum mechanics, we get the formula of uncertainty and energy level width in triangular well and parabolic well of two dimension electron gas (2DEG).Based on these ,we find energy width will increase along with the increasing of electronic field intensity and quantum number at the same electronic field, the energy width of parabolic well is more narrow than width of triangular well. At the same time, the result of this paper is agreement with the experiment.
Chiral Separation of R,S 3-(4-Fluorophenyl) -2,2-Dimethylcyclopane Carboxamide with Monolithic Molecularly Imprinted Polymers
Authors: Xu Chun Mei , Li Zhi Wei , Liu Lei
Published: June 2013

A monolithic column of molecularly imprinted polymer was prepared by an in situ polymerization method with a new compound R, S 3-(4-Fluorophenyl) -2, 2-Dimethylcyclopane Carboxamide which has fluorin organic compound as the template. The molecular recognition capabilities of the prepared monolithic MIP were evaluated by separating the enantiomers. The characteristics of the column and the influences of mobile phases were studied. The results showed that the monolithic column has chiral recognition capability for the template and the enantiomers were baseline separated even in aqueous solution.
The Micro-Pits Image Design Method with Direction-Uniformity Distribution Based on Minimum Interval Area Scrambling
Authors: Wang Hong Cai , Wang Yang
Published: June 2013

It is bigger that SRadcv of the micro-pits image based on square area scrambling, and the uniformity of micro-pits distribution is not very good. An improved method is presented that presetting the minimum interval of the micro-pits, and setting positions of these micro-pits randomly, then optimizing the positions of the micro-pits by area scrambling. SRadcv of the micro-pits image generated in this method will be much smaller, and the uniformity of the micro-pits distribution will be very good.
The Practice and Cognition of Hydraulic Fracturing Technique for Shale Gas Reservoir in Southeast Chongqing
Authors: Cheng Li Jun , Du Hong Yu , Xie Zhi Guo , Liu Pei Wu , Huang Shuai
Published: June 2013

Shale gas is an important unconventional energy resource. However its only achieved successful commercial exploitation in the United States and Canada. Shale gas well QY1 was carried out in southeast Chongqing.Taking this well as a case, the fracturing design optimization workflow and its practice are described in this paper. The fracturing feasibility of well QY1 was firstly determined by referencing all the physical parameters of target formation. Then the reservoir stress model was revised and reservoir stress profile was established as well. The reservoir simulation software (Eclipse) was applied to build reservoir geological model for predicting the gas production and determine the optimized permeability enhanced area (PEA). The unconventional fracturing model (UFM) was used to optimize the fluid volume and fracturing scale. And the final fracturing plan was made based on the optimized conclusions. This optimization workflow and the good result provide reliable technique support for the development of the shale gas reservoir in this area.
Key Words: Shale gas, PEA, Fracture propagation model, UFM, Production predicting model, Optimization
An Experimental Study on the Clearance Design of Fine Blanking Tool for High-Strength Steel Special Parts with Various Inner Corner Shapes
Authors: Kim Jong Deok , Heo Young Moo , Kang Ho Keun , Won Si Tae
Published: June 2013

The clearance between the punch and die of a fine blanking tool is an important design factor that affects the sheared surface of a product. In a fine blanking process, the clearance is typically assigned a 0.5% material thickness. If the clearance is too big, a fractured surface would occur in the product while if it is too small, bulging would occur.In this study, a setting for optimum clearance was proposed for inner corner shapes by checking shear characteristics and bulging effects according to various clearances. After designing a special part with various corner shapes possessing SPFH590 (thickness: 4 mm), a high-strength steel material, a fine blanking tool was constructed and fine blanking experiments were conducted. The result could be usefully applied in fine blanking processes for high-strength steel automobile parts with corner shapes in the future.
Comparison on Antimicrobial Activity of Different Solvent Extracts from Aerial Stem and Rhizome of Douttuynia cordata
Authors: Jiang Shao Juan
Published: June 2013

The 95% of ethanol crude extract of aerial stem and rhizome of houttuynia cordata was sequentially extracted with petroleum ether, ethyl acetate, n-butyl alcohol and water. Antimicrobial activity and minimum inhibitory concentration (MIC) of the different extracts against Staphylococlus aureus, Escherichia coli, Bacillus subtilis, Aspergillus niger and Saccharomycetes were examined with filter paper method. And antimicrobial activity between aerial stem and rhizome was compared. The result showed that, among the extracts of aerial stem and rhizome of houttuynia cordata, with regard to antimicrobial activity, water extract was strongest against Staphylococlus aureus, and ethyl acetate extract was strongest against Escherichia coli, and n-butyl alcohol extract was strongest against Bacillus subtilis and Saccharomycetes, while each extract had no significant antimicrobial activity against Aspergillus niger. Moreover, the antimicrobial activity of rhizome was stronger than that of the aerial stem.
The Microscopic Study on the Basis of Finite Element Johnson-Cook Model to Powder Compacting Mechanism
Authors: Yang Yong , Liu Jun
Published: June 2013

Powder high speed compaction mechanism is still a controversial issue.In order to study the densification mechanism of powder in the high speed compaction process,the article aims to study the powder densification mechanism by using the discrete density volleyball accumulation model that MSC.MARC to Ti6A14V and to describe the microscopic deformation and temperature changes of powder with Johnson-cook model. By analyzing the speed and temperature changes of particles in different position node,we found that powder particles start to deform a lot within microsecond and fill the holes and gaps of the powder in the flow,so that the air in the particles will form high-pressure and high-energy in a relatively adiabatic environment and make the temperature high and partial melting of the particle surface. It proves that the consolidation is the major mechanism of particles’large deformation,heat and soften hot-melt process in a short time.
Design and Simulation Analysis for Power Plant Coal Storage Bunker Girder Structure
Authors: Fan Hong Mei , Shi Yun Xu
Published: June 2013

The structure of the closed square storage bunker main, secondary beam are designed in detail, and has carried on the simulation using finite element analysis software ANSYS, results show that the main structure of the design to meet the design requirements.
Study on Long-Term Performance of Concrete Based on Seawater, Sea Sand and Coral Sand
Authors: Li Ying Tao , Zhou Ling , Zhang Yu , Cui Jing Wei , Shao Jun
Published: June 2013

Experimental studies of the long-term performance such have been done in this paper for sea water and sea-sand concrete and sea water and coral sand concrete, such as the elastic modulus, frost resistance and corrosion of reinforcement behavior. The test results show that the compressive elastic modulus of the sea water and sea sand concrete and the sea water and coral sand concrete are slightly lower than that of ordinary concrete, while the adding of fly ash or ground slag in them lead the late compressive elastic modulus slight increase. Compared with the ordinary concrete after freeze-thaw cycle, the mass loss rate and the compressive strength loss rate of the sea water and sea sand concrete and coral sand concrete are slightly larger, but slightly reduced by mixing with ground slag in the concrete, while a little high by mixing with fly ash. Due to the presence of Cl- in the saltwater and sea sand concrete and coral sand concrete, [Cl-] / [OH-] values will be larger, which leads to corrosion of internal reinforced, so it is necessary to adopt appropriate ways to modification for the concrete and reinforced.
The Fractal Properties of Scale Effect on the Density of Rock-Fill Materials
Authors: Wu Li Qiang , Zhu Sheng , Wei Kuang Min , Lu Chuan Yin
Published: June 2013

to study scale effect on the density of rock-fill materials, the relative density tests were carried out by physical tests and numerical tests. Fractal geometry theory was drawn into the gradation of rock-fill materials. Then, the fractal properties of scale effect on the density were investigated. There are close relations between fractal dimension D and densities of rock-fill materials. The densities are maximal when D is the critical value Dc. Furthermore, Dc is independent of the relative density Dr and the maximal diameter dmax. Truncation error is one of the main factors of scale effect of densities of rock-fill materials. The achievements in the paper lay a good foundation for further studying scale effect of rock-fill materials with fractal geometry theory.
Effect of Flow Characteristics of Polymer Flooding Produced Liquid on Attrition of Sucker Rob and Tube
Authors: Guo Li Ping , Wang Lei
Published: June 2013

Because of complex flow characteristics, polymer flooding produced liquid can bring many problems such as serious eccentric wear of rod and tube, breaking and divorcing of rod, and shortened cycle of pump-check. Flow resistance experiment was carried out aimed at these problems. Experimental results show that on-way resistance that sucker rod acts on polymer flooding produced liquid mainly depends on the viscosity of liquid and its elasticity can be ignored; Local resistance caused by couplers and centralizers is mainly related to the velocity of produced liquid, while the effect brought by mass concentration can be neglected; Resistance that pump valve endued and rate of flow agree to the exponential law; Total resistance of pump valves is generated mainly by down-valve and the law of resistance that water and polymer solution act on valves are similar. The problems that eccentric wear of rods and tubes is serious and the cycle of pump-check is shortened are not completely caused by up stress increasing after polymer flooding.
Experiment on Mechanical Properties of Steel Fiber Concrete under Dynamic Load
Authors: Wang Qi Sheng , Wan Guo Xiang , Chen Qin Rong
Published: June 2013

Mechanical properties of steel fiber concrete under dynamic load had been obtained through dynamic loading experiments of steel fiber concrete in different volume ratios. The experimental results indicate that the dynamic load strength of steel fiber concrete is obviously more than the static load strength, the dynamic load strength increases with the increasing of the steel fiber volume ratio; and the effect of variable strain rate is obvious. When the strain is at 0 ~ 0.01 or smaller, the toughness index of plain concrete is slightly more than steel fiber concrete; the strain exceeded 0.01, the toughness of steel fiber concrete has improved greatly with the increase of the strain. When the strain rate is smaller, the elastic modulus changes little, and once the strain rate is more than 60 per second, the elastic modulus there is the more amplitude with the increase of strain rate.
Investigation of Entropy and Gray Theory in Coal and Gas Outburst Controlled Factors Assessment
Authors: Yuan Dong Sheng , Zhou Chen
Published: June 2013

Using gray theory established entropy weight and gray association model in analyzing the mostly infection factors of coal and gas outburst, entropy theory was used to calculate the weights of contamination. Analysis of sample data, in accordance with the order of gray correlative degree, it is found out the closest relations with the outstanding master factors to identify the most likely sensitive indicators to improve the accuracy of coal and gas outburst forecast prominently.
Application of Phast in the Quantitative Evaluation for the Liquefied Ammonia Leakage Accidents
Authors: Qu Fang , Hao Kun , Niu Hui Chang
Published: June 2013

In order to establish comprehensive safety management system, in-depth study about the liquefied ammonia leakage accidents and its impacts are fairly needed. The assessment model of “Leak” scenario of liquefied ammonia is established by Phast software to realize the quantitative assessment for the toxic effects of liquefied ammonia leakage accident, in which parameters setting are preliminarily studied as well. The dispersion distances and influence zones of ammonia leakage accident are analyzed, and the toxicity ranges of ammonia are classified together. Technical guidance and theoretical basis for the emergency rescue can be provided according to the simulation results, suggestion on personnel evacuation are subsequently put forward; those are helpful to minimize the loss and hazard caused by liquefied ammonia leakage accidents.
A Research on Navigation Star Catalog Selection Algorithm Based on SVM
Authors: Liu Fu Cheng , Liu Zhao Hui , Liu Wen , Liang Dong Sheng , Cui Kai , Yuan Hui
Published: June 2013

A navigation star catalog (NSC) selection algorithm via support vector machine (SVM) is proposed in this paper. The sphere spiral method is utilized to generate the sampling boresight directions by virtue of obtaining the uniform sampling data. Then the theory of regression analysis methods is adopted to extract the NSC, and an evenly distributed and small capacity NSC is obtained. Two criterions, namely a global criterion and a local criterion, are defined as the uniformity criteria to test the performance of the NSC generated. Simulations show that, compared with MFM, magnitude weighted method (MWM) and self-organizing algorithm(S-OA), the Boltzmann entropy (B.e) of SVM selection algorithm (SVM-SA) is the minimum, to 0.00207. Simultaneously, under the conditions such as the same field of view (FOV) and elimination of the hole, both the number of guide stars (NGS) and standard deviation (std) of SVM-SA is the least, respectively 7668 and 2.17. Consequently, the SVM-SA is optimal in terms of the NGS and the uniform distribution, and has also a strong adaptability.
An Adaptive KLT Algorithm for Hand Gesture Tracking
Authors: Xin Huang
Published: June 2013

With the development of human-computer interaction technology, hand gesture is widely investigated recently for its natural and convenient properties. In view of the disadvantage of the existing tracking algorithms for the hand gesture, a novel adaptive method based on KLT is proposed in this paper, in which a kind of filtering mechanism is applied to decrease the effects of noise and illumination on tracking system. In order to eliminate the error of tracking, the strategy based on confidence is utilized properly. However, because the hand is non-rigid, its shape often changes, which easily leads to tracking failure for the reduction of features. In order to solve the problem, a method for appending the feature points is introduced. Experimental results indicate that the method presented in this paper is state of the art robustness in our comparison with related work and demonstrate improved generalization over the conventional methods.
An Energy Aware Routing Based on Swarm Intelligence for Wireless Sensor Networks
Authors: Lv Yong
Published: June 2013

Wireless Sensor Networks consisting of nodes with limited power are deployed to collect and distribute useful information from the field to the other sensor nodes. Energy consumption is a key issue in the sensor’s communications since many use battery power, which is limited. In this paper, we describe a novel energy efficient routing approach which combines swarm intelligence, especially the ant colony based meta-heuristic, with a novel variation of reinforcement learning for sensor networks (ARNet). The main goal of our study was to maintain network lifetime at a maximum, while discovering the shortest paths from the source nodes to the sink node using an improved swarm intelligence. ARNet balances the energy consumption of nodes in the network and extends the network lifetime. Simulation results show that compared with the traditional EEABR algorithm can obviously improve adaptability and reduce the average energy consumption effectively.
Application and Research of Multi-Sensor Data Fusion for the Earlier Period Diagnosis in Induction Motors
Authors: Li Shu Ying , Tian Mu Qin , Xue Lei
Published: June 2013

The multi-sensor data fusion widely applied to military and industry areas is a new technique developed in recent years. It can avoid the limitations of a single sensor and obtain more information, improving the recognition ability. This paper analyzes the uncertainties in the traditional earlier period diagnosis in induction motors based on the single parameter and introduces the idea of using multi-sensor data fusion to handle these uncertainties. In a fusion system several parameters will be fused according to the D-S evidential fusion algorithm in order to identify accurately the earlier period faults of the induction motors. Practical diagnostic examples show that the fault diagnostic accuracy and confidence are markedly promoted by using the multi-sensor data fusion.
Design and Research of Carbon Dioxide Automatic Measuring Instrument
Authors: Liu Qiang , Wu Tao
Published: June 2013

Carbon dioxide is the very important material of plants when they are making food by means of photosynthesis. The concentration of carbon dioxide restricts photosynthesis and respiration in a dose-dependent manner. Therefore, keeping stability concentration of carbon dioxide is quite important for plant to grow rapidly. This paper mainly introduced the system composition and working principle of carbon dioxide automatic measuring instrument, the system taking Freescale MCU as control core. The instrument can collect signal, display data and reset by connecting with the PC. The experiment result states clearly this carbon dioxide automatic measuring instrument has practical value and application significance.
Design of Electric Control System of Stainless Steel Composite Plate
Authors: Chu Jian , Wang Gang
Published: June 2013

This paper mainly introduced to the PLC as the core of stainless steel composite plate electric control part of the design. The system uses the converter +PLC+ man-machine interface, as the major part of roll welding machine control, because of the use of the PLC, so that the system can improve the automatic level, electrical components is reduced, reduce failure rate, improve the reliability of equipment operation. Based on the current control and speed control, so that the welding quality and welding speed has been greatly improved. In the article, mainly from the production process, and the control system hardware and software design, and the control scheme to introduce several aspects.
Effect of Different Content of AlF3 of the Zinc Flux and Temperature on the Spreading Performance of Zn20Sn
Authors: Jiu Yong Tao , Yan Yan Fu , Shen Guang , Li Shuai , Wu Xue Xue
Published: June 2013

In this study, AlF3 was added into the Zinc flux and the spreading area of Zn20Sn of every flux formula was measured. The spreading area of Zn20Sn of different temperatures of the optimal content of the AlF3 was measured as well. The result showed that the spreading area of Zn20Sn increased with the content of AlF3 increasing when the content was below 2%. the spreading area of Zn20Sn decreased with content of AlF3 increasing when the content of AlF3 exceeded 2%. The spreading area of Zn20Sn was increased 126% than that of the matrix solder when the temperature was 470°C and the content of AlF3 was 2%.
Design of PMSM Position Servo System Based on Fuzzy Adaptive PI Control
Authors: Shi Hong Mei , Yu Zu Jun
Published: June 2013

A fuzzy adaptive PI controller for permanent magnet synchronous motor (PMSM) position servo system is proposed in this paper. Based on the analysis of PMSM mathematical model, the design of position loop controller is introduced in detail. To verify the effectiveness and accuracy of the fuzzy PI adaptive controller, an experimental system is designed using TMS320F2812 floating-point digital signal processor (DSP) as controller CPU and DR20A as integrated power drive module. The experimental results show that the designed AC position servo system has strong robustness, better speed performance and higher position precision, which can meet the requirements of high performance servo system.
Detection of Silver Jewelry with Orthogonal Double-Pulse LIBS
Authors: Lou Yang , Zhou Qi , Li Run Hua
Published: June 2013

A comparative study of single-and double-pulse laser induced breakdown spectrometry (LIBS) was carried out to detect the silver element in silver jewelry samples. One Nd:YAG was adopted in the experiment to generate two pulses which were set in an orthogonal configuration. The results show that, for double-laser LIBS, average diameter (3μm) of craters on the sample surface is much smaller and the intensity of silver emission signals are magnified by a factor of 40 compared with the single-pulse LIBS. Due to the superiority in high sensitivity and low energy consumption, double-pulse LIBS presents a bright application prospect in rapid on-site undamaged analysis of precious metal jewelry.
Development and Research of Colony Analysis System Based on Image Processing
Authors: Lu Ming Zhu
Published: June 2013

In this paper, after the simple and practical hardware is connected with the host, the software system is used to count the colony of bacteria, the results are statistically analyzed, and the obtained data can be displayed, saved and printed. The software is developed with VC++, using digital image processing knowledge to do some research on automatic analyzing the count of colony.
Fault Diagnosis of Rolling Bearing Based on S Transform and Image of Invariant Moments
Authors: Guo Jun Feng , Wang Bao Zeng , Wei Peng , Wei Xing Chun
Published: June 2013

According the characteristics of rolling bearing fault information are nonlinear and non-stationary, the method of time-frequency is often used to make the one dimensional time signal map into two dimensional time and frequency function, and describe the energy density of signal at different times and frequency simultaneously. A method of fault diagnosis based on S transformation and image Hu of invariant moments was put forward in this paper. First of all the measured rolling bearing signals have been S transformed, and time-frequency spectrum which is got is expressed as two dimensional image, then Hu geometric moment invariant of the S transformation spectrum is calculated and the simulation research is carried out using invariant moment principle in image processing. The results show that this method can distinguish the inner ring, outer ring and bearing roller fault intuitively and accurately and measure rolling bearing fault diagnosis efficiently.
Fault Diagnosis System of Rolling Bearing Based on Ultrasonic Signal
Authors: Wang Shi Long , Wang Li Na
Published: June 2013

The bearing of rotating machinery often fails due to the frictional forces of rolling element, in the early stages of the faults, a series of ultrasound can be generated in short time intervals, which occur at bearing characteristic frequencies. Since the frequencies of ultrasonic signal are very high, they will lead to much higher computing burden when using the common technique of Fast Fourier Transforms (FFT) directly. In this paper, envelope detection technology and heterodyne technology which integrated in an ultrasonic data collection system are used to reduce the frequency effectively. To allow for the easier detection of the bearing faults, these two techniques has been used together with FFT. A verification research with respect to vibration analysis is carried out to analyze the effectiveness and superiority of ultrasonic data collection in time domain and frequency domain aspects respectively. Extensive experiments have been performed in an Alternating Current (AC) motor system, and the results indicated that this ultrasonic data collection system is as useful as vibration analysis system in diagnosing the faults of bearings. In addition, it is more sensitive in fault diagnosis in the early stages of the bearing faults than vibration acquisition system.
Integrative Control of Regenerative Braking System and Anti-Lock Braking System
Authors: Chu Liang , Wang Xiang , Zhang Lei , Yao Liang , Zhang Yong Sheng
Published: June 2013

For Electric Vehicle (EV), energy saving and endurance mileage prolonging are very important. Regenerative Braking System (RBS) is a key point in this respect. At the same time, braking safety is a rigid demand of EV. In this respect, the Anti-lock Braking System (ABS) has an excellent performance. As a result, the integration of RBS and ABS plays an important role in the development of the EV control. In this paper, a dynamic adaptive threshold theory decides when RBS should exist will be studied, and when the states of vehicle reach the adaptive threshold, a sliding mode control method will be used to meet the total braking force and the system will reduce the motor braking force. Before slip rate of vehicle reaches the ABS threshold, the regenerative braking force will be reduced to 0. The braking safety will be improved in this way.
Magnetic Field Intensity Gradient Method on the Detection of a Remote Target
Authors: Huan Ying Chun , Lin Chun Sheng
Published: June 2013

Based on the spheroid and magnetic dipole mixed array model, the magnetic field intensity gradient of ship is measured by using buoys and optically pumped magnetometers in order to achieve the purpose of eliminating the interference of the background magnetic field, thereby effectively improving magnetic detection of remote targets.
Performance Study and Structure Control of Carbon Aerogel
Authors: He Rui , Liu Xuan , Liu Zhen Fa , Zhang Li Hui
Published: June 2013

In this research the fabrication of carbon aerogel is reported. nanopore carbon aerogels were prepared via a sol-gel process with resorcinol and formaldehyde (RF) aerogels,which were cost-effectively manufacture form Rf wet gels by an ambient drying technique instead of conventional supercritical drying. The key of the work is to fabricate carbon aerogels with controllable nanopore structure, which means sharp pore size distribution and extremely high surface area.The influence of preparation condition of carbon aerogels was studied by scanning electron microscope and Micropore Physisorption Analyzer. The BET surface of the carbon aerogels are from 749m2/g to 1156m2/g .The size of the carbon nanoparticles are in the range of 20nm~40nm. The micro-pore volume and bore diameter can be controlled by gelation conditions such as RF mass fraction.
Effects of Load on the Wear Behaviors of Cu-Based Composite under Different Electrical Currents
Authors: Zheng Run Guo , Zhan Zai Ji
Published: June 2013

A new type Cu-La2O3 composite was fabricated by internal oxidation method using powder metallurgy. The sliding behavior of the Cu-La2O3 composites was studied using a pin-on-disk wear tester under different electrical currents and different applied loads. The worn surfaces were examined using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) to determine the wear mechanisms. The results showed that the wear rate and friction coefficient of the La2O3 composites pins increased with the increase of the applied load at low electrical current, while at high electrical current the wear rate and friction coefficient decreased firstly and then increased as the applied load increased. The main wear mechanisms of the Cu-La2O3 composites were found to be adhesive wear, abrasive wear, oxidation wear and arc erosion.
Research of the Electronics Definite Direction Technology
Authors: Wang Jun Feng , Zhong Tao , Yang Yan Rong
Published: June 2013

With the development of electronic resist technology, the wireless definite direction technology becomes more and more important. By comparing the same external signal amplitudes which are received from two channel or more than two channels, ratio amplitude method realize the direction function. This paper analyzes and studies the influence of various system errors, and analyzes the multi-beam direction finding technology at the same time. The orientation of radar emitter which falls into different beam can also be measured.
Research of Ultrahigh Vehicle Detection System Based on Infrared Sensor
Authors: Chen Jian Hong , Cao Hong , Su Qing Lie , Liu Rui
Published: June 2013

Ultrahigh vehicle detection system has been designed which is based on infrared sensor. In application of optical modulation & demodulation, the hardware-circuit is successfully designed by sunlight interference concern. Because of scattering properties of infrared light, software design which is applied of overlapping interference uses algorithm of pulse delay& separation. The later algorithm can well solve the measurement errors of hollow objects, which is basically opposite to the former one, but it costs scan time much more while gets lower efficiency in dynamic measurements of vehicle. The accuracy of this system is 5cm which ranges from 4m to 6m in actual test. The velocity of vehicle can reach 30km/h on the basis of the pulse delay algorithm and 18km/h with the pulse separation algorithm.
Research on Method of Coal Shearer States Monitoring
Authors: Zhang Jun
Published: June 2013

According to the requirements of states monitoring and detection to shearer, it is an urgent need to develop a new states signal collection method, which can solve the current problem in signal collection. In this paper we collect shearer’s states signal by using self-developed portable intrinsically safe mining vibration recorder, which has solved the data acquisition problem of vibration-based shearer fault diagnosis research. This has laid the foundation for states monitoring and detection to shearer, and also for remote monitoring and fault diagnosis to shearer. At the same time, this will provide theoretic reference and basis for design improvement and performance improvement of shearer in future through analyzing the data.
Research on Parametric Digital Model Form Based on 3-Dimensional Body Measurement
Authors: Yang Li Na , Zhang Tong , Zhang An Fen
Published: June 2013

The modeling method of 3-dimensional garment model form is the key for the 3-dimensional garment design system. The modeling method of model form will directly have effects on the complexity and presentation effects of the latter design of garment styles. It is also closely related to the garment 3-dimensional al imitation and simulation as well as the transformation relation between 3-dimension and 2-dimension. Therefore, the modeling method of 3-dimensional garment model form is much worthy to study and has a good application prospect.
Inclusion of Tapered Tubes in Enhancing the Crash Performance of Automotive Frontal Structures
Authors: Ahmad Zaini , Nagel Greg , Thambiratnam David
Published: June 2013

This paper treats the design and analysis of an energy absorbing system. Experimental tests were conducted on a prototype, and these tests were used to validate a finite element model of the system. The model was then used to analyze the response of the system under dynamic impact loading. The response was compared with that of a similar system consisting of straight circular tubes, empty and foam-filled conical tubes. Three types of such supplementary devices were included in the energy absorbing system to examine the crush behavior and energy absorption capacity when subjected to axial and oblique impact loadings. The findings were used to develop design guidelines and recommendations for the implementation of tapered tubes in energy absorbing systems. To this end, the system was conceptual in form such that it could be adopted for a variety of applications. Nevertheless, for convenience, the approach in this study is to treat the system as a demonstrator car bumper system used to absorb impact energy during minor frontal collisions.
Extreme Modal Combinations for Pushover Analysis of RC Buildings
Authors: Mihanović Ante , Trogrlić Boris , Balić Ivan
Published: June 2013

The pushover method is a practical procedure for comprehensive nonlinear analysis of structures subjected to seismic action. Application of this method, in accordance with the Eurocode 8 rules and due to engineering simplicity, favours application utilizing the first mode. The aim of the presented research in this paper was to find the influence of multi modal combinations in assessing the bearing capacity of reinforced concrete (RC) frames and walls. This paper presents a procedure in which the most extreme state is defined by the lowest ground acceleration caused by a predetermined shape of an elastic spectrum. The extreme bearing value is obtained by the envelope principle. Mode shapes and period sizes are determined on a linear elastic model while the limit state of the load bearing system is evaluated in a nonlinear state of structures. Results of the analysis show that influences of higher modes are significantly higher and that the safety/reliability, indicated by the criteria for the target displacement, in accordance with Eurocode 8 (Annex B), is not achieved. Inclusion of higher modes, in some presented examples, decreases the peak ground acceleration by more than two times, which is significantly less favourable than the target displacement criteria.
The Study of Microstructures and Tensile Properties of an In Situ A356-ZrB2 Metal Matrix Composite
Authors: Moosavian H. , Emamy Masoud , Arani M. Mansouri , Mahboubi S.
Published: June 2013

A composite containing A356 Al alloy as matrix and ZrB2 particles was made in an induction furnace by mixing Al-15Zr and Al-8B master alloys with Zr:B weight ratio of 9:2. The microstructures and tensile properties of the extruded composite were studied by scanning electron microscopy (SEM) and x-ray diffraction (XRD) analysis before and after T6 heat treatment. XRD results showed the presence of ZrB2 phase in the microstructure. Tensile test results showed an increase in ultimate tensile strength (UTS) and elongation values of the extruded composite in comparison with the matrix alloy. Further investigation showed an increase in UTS, but reduction in elongation values of the composite after T6 heat treatment.
New Developed Formula to Calculate the Permittivity of Ferrite-Polymer Composite
Authors: Al-Habashi Ramadan , Abbas Zulkifly
Published: June 2013

A new developed formula named theHabashi-Zul formula, based on the Maxwell-Garnett (MG) formula was fabricated and used to calculate the complex permittivity of the Sm-YIG in PVDF composite samples in the frequency range of 10 MHz to 1 GHz. The calculated permittivities results were compared with the measured values of each sample of Sm-YIG in PVDF composite samples and, with calculated results from various theoretical models including the MG, Looyenga, Bruggeman and, Sen Scala and Cohen. TheHabashi-Zule formulapresented higher accuracy as compared to other models.
Effects of the SIMA Process on the Microstructure of 6061 Al Alloy Refined by Al-5Ti-1B
Authors: Khorshidi R. , Emamy M. , Amuei M.
Published: June 2013

In current research the effect of the strain-induced melt activation (SIMA) process on the microstructure of 6061 Al alloy has been investigated. The optimum amount of Ti for proper grain refining was found to be 0.03 wt.% in the alloy. In SIMA process, after hydraulic pressing, recrystallization and partial melting (RAP) were employed to obtain a fine globular microstructure. Certain amount of strain (40%), heat treatment time (30 min) and temperatures (605-645°C) were employed to find an optimized fine globular microstructure of the alloy. A microstructural study which was carried out by optical microscopy, exhibited the uniform equiaxed recrystallized grain structure.
Study of the Forces Generated during Nonlinear Friction Stir Welding: Circular Trajectory
Authors: Jemal Nejah , Chevert Sandra , Langlois Laurent , Abba Gabriel
Published: June 2013

Friction stir welding is known for his capability to achieve a linear weld. However, more investigation on a curved friction stir weld trajectory is still required to industrialize this promising process. In the same perspective, this study is aimed at analyzing the influence of nonlinear tool trajectory in friction stir welding. The study considers a variety of circular trajectories on the plane plate and uses them for experimentation while considering different welding parameters of rotation speed feed speed, axial force and tilt angle.In FSW, the tool is generally needed to be tilted with a constant angle in the travel direction during welding process. Therefore, for circular trajectory, an adequate roll and pitch angle are assigned to the spindle in all tool positions. The paper presents the effect of circular trajectory on longitudinal and transversal forces generated during circular welding. The results are then compared with the experimental results which are obtained using linear FSW. Furthermore, the experimental investigation includes relationship between tool trajectory and weld quality.
A Numerical and Experimental Analysis of Microstructural Aspects in AA2024-T3 Friction Stir Welding
Authors: Carlone Pierpaolo , Palazzo Gaetano S.
Published: June 2013

In recent years, remarkable interest has been focused on the Friction Stir Welding (FSW) process, by academic as well as industrial research groups. Conceptually, the FSW process is quite simple: a non-consumable rotating tool is plunged between the adjoining edges of the parts to be welded and moved along the desired weld line. Frictional and viscous heat generation increases the work piece temperature, softening the processing material and forcing it to flow around the pin. Although FSW has been effectively applied in welding of several materials, such as copper, steel, magnesium, and titanium, considerable attention is still focused on aluminum welding, in particular for transport applications. Recent literature clearly evidenced microstructural variations in the stir zone, imputable to continuous dynamic recrystallization phenomena, leading to the formation of a finer equiaxed grains. Moreover, depending on the specific alloy, thermal cycles can induce coarsening or dissolution of precipitates in the thermo-mechanically affected zone (TMAZ) and in the heat affected zone (HAZ). The influence of the aforementioned microstructural aspects on mechanical properties and formability of FSWed assemblies is also well recognized. The aim of this paper is to numerically and experimentally investigate the influence of process parameters, namely rotating speed and welding speed, on microstructural aspects in AA2024-T3 friction stir butt welds. A three-dimensional Computational Fluid Dynamic (CFD) model has been implemented to simulate the process. A viscoplastic material model, based on Wright and Sheppard modification of the constitutive model initially proposed by Sellars and Tegart has been implemented in the commercial package ANSYS CFX, considering an Eulerian framework. Tool-workpiece interaction has been modeled assuming partial sticking/sliding condition, and incorporating both frictional and viscous contributions to the heat generation. Microstructural aspects have been numerically predicted using the Zenner-Holloman parameter and experimentally measured by means of conventional metallographic techniques. Satisfactory agreement has been found between simulated and experimental results. The influence of process parameters on mechanical properties has also been highlighted.
Numerical Study of a Crimped Assembly Mechanical Strength
Authors: Petitprez Matthieu , Mocellin Katia
Published: June 2013

Electrical contact crimping is a mechanical fastening process commonly used in aeronautical and aero spatial applications. In order to ensure the perfect electrical conduction and acceptable mechanical properties, the assembly have to fullfil some drastic holding force criteria. This outfit is directly dependent on the indentation depth at the end of crimping. The feedback generally reveals that an over crimping will lead to the cable breakage whereas an under crimping will be characterized by the cable sliding into the contact during pulling. The optimal behavior is a combinaison of both phenomena : the cable must become thinner before slipping into the contact. Numerical simulation is an efficient tool to limit the tedious experimental tests. It is the main topic of our work. This paper deals with prediction of the failure type and the force level required to tear out a contact crimped on multistrand cable for different indentation depths. The determination of optimal crimping condition is determined. In order to simulate the contact tensile test, crimping simulation has to be performed. The first step is then to be able to simulate accurately the crimping stage by using appropriate behavior laws and realistic conditions. One difficulty is linked to the small size of our objects. The first one is a 19 strands cable, in which each strand is about 0.15 mm diameter. The second sample is a 1 mm diameter cylindrical copper contact measuring 7 mm long. Adapted testing devices are described. Geometries and mechanical fields are obtained and then exported in the mechanical holding model to ensure realistic prediction [1]. Impact of crimping conditions on the pulling results is discussed. Pulling simulation results are compared to experimental values. The prediction of breakage mechanisms is also studied. Keywords: Crimping process, mechanical fastening operation, finite element computations, mechanical strength, breakout force, tensile test. [1] Fayolle, S., 2008, Etude de la modélisation de la pose et de la tenue mécanique des assemblages par déformation plastique : application au rivetage auto poinçonneur, Thèse de l'Ecole des Mines de Paris.
Effect of Process Parameters on the Joint Integrity in Friction Stir Welding of Ti-6Al-4V Lap Joints
Authors: Buffa Gianluca , Fratini Livan , Schneider Matthias , Merklein Marion
Published: June 2013

Friction Stir Welding (FSW) is a solid state welding process patented in 1991 by TWI; initially adopted to weld aluminum alloys, is now being successfully used also for magnesium alloys, copper and steels. The wide diffusion the process is having is due to the possibility to weld materials traditionally considered difficult to be welded or “unweldable” by traditional fusion welding processes due to peculiar thermal and chemical material properties. Additionally, the process allows welding a wide range of sheet thickness (up to 50mm) avoiding typical fusion welding processes defects, like cavities and porosities, with no shielding gas, filling material or joint preparation. Recently, research is focusing on titanium alloys thanks to the high interest that such materials are getting from the industry due to the extremely high strength-weight ratio together with good corrosion resistance properties. Welding of titanium alloys by traditional fusion welding techniques presents several difficulties due to high material reactivity resulting in bonding with oxygen, hydrogen, and nitrogen with consequent embrittlement of the joint. In this way FSW can represent a cost effective and high quality solution. A few studies have been developed on the FSW of titanium alloys butt joints, while there is a complete lack of knowledge as far as different joint morphologies are regarded (lap joints, T joints, etc.). In the paper the results of an experimental campaign on lap joints made out of thin Ti-6Al-4V sheets are presented. The effect of the main process parameters on the micro and macro mechanical properties has been investigated and related to the microstructural transformations occurring during the process because of the thermo-mechanical action of the tool.
Research into the Flow Stress of Al-Mg-Si Alloy (AD-35) during the Abrupt Change of the Strain Rate at Elevated Temperatures
Authors: Petrov Pavel A. , Voronkov Viktor , Potapenko Konstantin , Petrov Mikhail , Gamzina Olga
Published: June 2013

In industrial practice of rolling and hot forging, i.e. extrusion-type forging, abruptchanges in strain rate during the deformation of the material occur. For accurate numericalsimulation of a forging process, the experimental investigation of the effect of the transient changein strain rate on plastic flow behaviour is necessary. The present paper deals with the investigationof this effect on the flow stress of an AD-35 aluminium alloy during its deformation within thetemperature range of 350-450 °C. During continuous uniaxial compression loading of a cylindricalspecimen, the strain rate was either constant or abruptly increased or decreased from its initial valueat engineering strain of app. 26 %. The following strain-rate histories were applied: 1) constantstrain rate of 0.1, 1.0 and 10 s-1; 2) abrupt strain-rate increasing from 1.0 to 10.0 s-1; 3) abrupt strainratedecreasing from 10.0 to 1.0 s-1. The results of the experimental investigations corresponded tothe transient change in strain rate histories were used to verify the model of softening as well as themodel of hardening of the AD-35 alloy during the abrupt change of the strain rate. It allows todefine these models explicitly.