bluuebunny/crossref_metadata_2025 huggingface dataset:
A Critical Analysis on the Cyclic Fatigue Testing of Rotary Endodontic Instrument
Authors: Shin Chow Shing , Chang Q.M. , Lin Chun Pin
Published: October 2013

Cyclic fatigue of rotary endodontic instruments has been tested using different techniques while the results were normally compared in terms of a canal curvature radiusRand an angular extent of instrument insertionθ. In this work, the effects of canal geometry and analysis method have been investigated by finite element (FE) analysis. A highly simplified FE model has been proposed and verified experimentally. Results from a detailed finite element (FE) model and a simple geometric model are discussed in the light of the simplified model results. It was found that the commonly used (R,θ) alone cannot quantify the severity of bending. The diameters and taper development of the canal and the instrument also played important roles. The simple geometric model can give unacceptable errors and cannot only be employed forensically. The detailed finite element model is much more resource consuming than the current simplified model and the extra effort is not worthwhile if only the bending strain is needed for correlation and prediction of instrument fatigue life.
Corporate Social Responsibility Research among Manufacturing Enterprises: Taiwanese Electronic Material Manufacturing Enterprises
Authors: Tsai Sang Bing , Xue You Zhi
Published: October 2013

Importance-performance analysis (IPA) is a method commonly used to measure satisfaction and enhance competitive strategies. Corporate social responsibility (CSR) refers to the economic, legal, ethical, and philanthropic responsibility that enterprises bear during their operations for all stakeholders. By combining the hierarchy of CSR with stakeholder theory, we conducted importance-performance analysis (IPA) and used a Taiwanese manufacturer of copper-clad laminate electronic materials, referred to as Company A, as the subject to investigate the evaluations of stakeholders toward the CSR of the company. This analysis could serve as a basis for future improvements.
A Novel Small-Size Coupled-Line Wilkinson Power Divider for Dual-Band Applications
Authors: Wang Wei Min , Liu Yuan An
Published: October 2013

A novel coupled-line circuit configuration is proposed to design small-size dual-band Wilkinson power dividers. This proposed power divider consists of three sections of coupled lines and two isolation resistors. The analytical design theory is given and the electrical parameters analysis is provided. Six numerical examples are presented to demonstrate the flexible dual-band applications. To avoid a negative isolation resistor, a practical power divider operating at 1GHz and 2.2GHz with two positive-value resistors is designed. The calculated and full-wave simulated results verify our proposed idea. Keywords: Coupled-line, dual-band, power divider.
The Influence of Different Kinds of Surfactants on Rheology in Polymer/Surfactant Complex Flooding
Authors: Cui Wei Lin , Xu Wu Ju , Song Ling Jian
Published: October 2013

Because of alkaline declining the sweep efficiency, causing scale formation problem in the reservoir and the well bottom and the tubular pipes, so polymer/surfactant compound flooding technology is the emphasis in the research of enhanced recovery. So the articles study the regulation of different kinds of surface active agents at different temperature by MARS Rheometer. The testing result showed that the variation of viscocity under the interaction between the surface active agent and association polymer according to “three stage” model .The linear viscoelastic region of stress decrease when different surface active agents are put into polymer liquor, and the higher frequency, the better elasticity of polymer liquor. The hydrophobic association between the surface active agents and polymer decrease with a higher temperature, but the ionic surfactant is aggravate. The systematic study of binary system rheology can contribute to correctly understand and apply binary system.
Modal Analysis for the Powertrain of Electric Vehicle by Finite Element Method
Authors: Chen Fei Fei , Yu Peng , Zhang Tong
Published: October 2013

The finite element model of an electric automotive powertrain is the basis of the research on its vibration and noise. In this paper, the vibration properties of dynamically-loaded housing are first obtained based on finite element calculation,which is testified by the modal test .It provides the reference for the establishing of electric automotive powertrain.
Modeling and Simulation on Transformer Computer Protection in Wind Farm
Authors: Tian De , Song Hai Hui
Published: October 2013

This paper studies a single machine infinite bus system with two-winding transformer and access 110KV power system after improveing voltage. We established a system model of transformer based on MATLAB/Simulink, and established the computer protection data acquisition system model in wind farm, studied second harmonic ratio brake differential protection. Setted calculation combined with actual differential protection for a given parameter transformer, and use the simulink to simulate test of short-circuit. By the simulation study, we investigated the performance of transformer differential protection.
A Study of the Simulation of a Light Trapping Module for Increasing the Absorption Efficiency of Solar Cells
Authors: Liu Wang Lin , Lin Guan Yu , Yang Hsiharng
Published: October 2013

This study proposed a light trapping module to improve the light path in a solar cell in order to increase its light absorption efficiency. The microlens on a transparent substrate concentrates incident light into several light beams, which it leads into the optical channel on the back side. The optical channel is designed by coating highly reflective metals on the same transparent substrate, then an optical channel opening is made at the light beam focus so the light beams can pass through the optical channel and irradiate the solar cell. The light reflected by the solar cell is reflected again by the metal surface to the upper film of the solar cell, thus, increasing the absorption efficiency of the solar cell and reducing the film thickness of the solar cell to obtain better electrical properties. In this simulation the refractive index of the microlens was set as 1.43, the optical channel was 25 μm and the spacing was 0.27 mm, thus, the simulated absorption efficiency reached over 80%. The feasibility of this study was thus proved.
Safety Performance Evaluation of Wind Power Tower under Wind Load
Authors: Liu Wen Jian
Published: October 2013

The 3d finite element model of wind power tower is established, and strain, displacement, bending moment and shearing forcing were calculated under different angle of wind blade and opening direction of wind power tower. Finally, the mechanical performance of wind power tower in different wind directions were analyzed with limited element method. The results show that the maximum strain appeared at the opening position under 180° between wind blade and opening direction, while the maximum strain value appeared at the upper position of the wind power tower under 0° and 90°. Shearing force and bending moment under 180° are greatest while shearing force and bending moment under 0° are the least. The force of wind power tower facing wind direction is greater than that 90°sidewind, and the strength design of wind power tower under 50 years design wind loads satisfies the requirement.
Research on Form Design of Electric Bicycle Charging Station According to Kansei Engineering
Authors: Ding Yuan Yuan
Published: October 2013

According to the preliminary market research, to explore people's emotional appeal preferably for the design of electric bicycle charging station, the method of Kansei Engineering is applied to the research of its form design. Based on the existing theory of Kansei Engineering, this paper applies quantitative deductive method of Kansei Engineering, transform people’s kansei needs and image of electric bicycle charging station into formative elements of detailed design, for the sake of establishing the congruent relationship between customers’ kansei appeals and design elements of charging station, and providing reference value to form design of electric bicycle charging station.
Analysis of a New Mechanical Anti-Lock Brake System for Two-Wheeled Vehicles
Authors: Yang Cheng Ping , Liu Tyng
Published: October 2013

This study aims to present an analysis on a new type of mechanical anti-lock brake system (ABS) and the device is suitable for two-wheeled vehicles, such as bicycles. Firstly, the structure of the mechanism, the principle of operation and operating stages of the device are discussed. Secondly, the force models of the system and the force equations with parameters are developed. Then, a numerical program for simulating the operation of the system is developed, and the relationship between operating force and braking force, as well as the efficiency of ABS in different situations (e.g. road friction coefficient, loading) are analyzed. Finally, the results of how each parameter affects the braking performance are discussed. In this paper, we present a complete analysis on this new mechanical ABS systematically. Through the simulation of various operating conditions, the characteristics of the system are investigated and clearly verified. It is shown that this type of mechanical ABS could be useful in some situations. However, the overall braking performance will be reduced. This new mechanical ABS might be useful with some possible modifications, and could be applied in other areas.
A Subdomain Method for the Aeroacoustic Simulation of a Generic Side View Mirror
Authors: Huang Li Na , Xue Ming Xin , Dong Hao , Yang Bo
Published: October 2013

The aerodynamic noise caused by the flow field around a generic side view mirror (SVM) was simulated using a subdomain large eddy simulation (LES) method. In this method, the LES solution could be run only in the subdomain, which can be the flow field near the SVM. The subdomain LES results show good agreement with the cited experimental data in some related works. With the principal advantage of saving CFD cell numbers, the subdomain LES method would be a perspective way to simulate the aerodynamic noise of complex geometries such as the real automobiles.
Tension Prediction Model of Ice-Coated Transmission Line Based on YULE-WALK Auto-Regressive Model and Support Vector Machine
Authors: Yang Lei , Wang Da Da , Wu Xin , Li Lin , Rui Xiao Ming , Peng Qing Jun
Published: October 2013

Large tension of ice-coated transmission line will cause line overload and conductor galloping, accidents such as break line and tower collapse will be caused, it bring great threat to safety and stability of power systems. Therefore, there is an important physical meaning for preventing above accidents to in-depth study tension prediction model of ice-coated transmission line.In this paper,we establishes a tension prediction model of ice-coated transmission line based on the Yule-Wake auto-regressive model and support vector machine, the model contains the micrometeorological and tension historical data, etc. Through studying the tension prediction of Gan-Zhen 155# transmission line in Zhaotong area of Yunnan province,it shows the prediction obtained by this model in the next eight hours is in accord with the actual monitoring data pretty well, the absolute maximum error is less than 5.86%, and the maximum absolute mean error is less than 2.74%.So, the feasibility and accuracy of this model is verified.
FEA of Thermal Characteristic of Motorized Spindle Based on ANSYS Workbench
Authors: Chen Kai Kang , Li Fu Ping , Zhao Yong Sheng
Published: October 2013

Thermal deformation of high-speed motorized spindle has an important effect on improving the machining accuracy. In this paper the thermal boundary conditions of thermal deformation, including the heat generation of the motor and bearing and heat transfer coefficient, are calculated to simulate the steady-state temperature field distribution, transient thermal analysis and thermal deformation in ANSYS Workbench. They provide theoretically the data for the thermal error compensation of the spindle system.
The System Research on Automatic Defect Detection of Glasses
Authors: Yao Hong Bing , Ping Jie , Ma Gui Dian , Li Liang Wan , Gu Ji Nan
Published: October 2013

A glasses defect inspection system is researched and developed according to the principle of light scattering and visual inspection method, which is based on the machine vision. In order to achieve the classification of glasses, the functions of image acquisition, simple image processing, grading and sorting of glasses are designed in this system. Operation of parallel structure is adopted in this system. Forwardlighting by low-angled-ring-LED is used to get the clear images of the defects in or on the surface of the glasses, such as speckles, impurities, feathers and so on. Image processing and glasses grading based on normalization algorithms are used to acquire the identifying information of various defects of glasses. Experiment results show that the detection system, which can detect all the kinds of defects of the glasses, has high processing speed and strong anti-interference capacity. The size of the smallest defect that can be detected by the system is 0.03mm, and the average detection time of each glass is less than 2s.
Damage Identification Method of Simply Supported Beam Bridge with Multiple Girders
Authors: Sun Ping Yi , Wang Yan Hua , Niu Yan Feng , Liu Han Bing , Tan Guo Jin
Published: October 2013

Considering the complexity of the simply supported beam with multiple girders, a two-step damage identification algorithm for this kind of bridge is presented. This algorithm first locates the damage by means of curvature of flexibility change, and then utilizes the PSO-SVM algorithm to identify the damage extent. At last, a numerical simulation calculation is conducted to identify the damage state of a simply supported T-beam bridge with five girders. The numerical simulation results show that the algorithm proposed is valid, reliable and with high recognition precision.
The Design and Kinematic Simulation of the Return System in Ball Screw Pairs Used in Special Circumstance
Authors: Zhao Guo Ping , Fan Yuan Xun , Yang Feng , Li Li Yi
Published: October 2013

Base on analyzing the design demand of the return system in the ball screws, combining the sine curve and the quintic parabola curve, this paper introduces a new type of curve for steel balls used in heavy load bearings. By computing and programming in Matlab, this paper gets the sine-quintic parabola curve and conducts the kinematic simulation based on it. The results show that the balls can get in and out of the return system continuously and cause low impulse force on the return system. The highest impulse force happens when the balls access the return system. All this results can contribute for the later design and research of the internal circulation return system.
Electric Car Styling Design and Aerodynamic Drag Optimization
Authors: Li Yan Long , Zhang Chen Ming , Yang Zhi Gang
Published: October 2013

The paper takes a research on low-drag electric cars, and set a technical route that design with ideal aerodynamic shapes and then developed into car-like shape. At last, both design refinement and aerodynamics optimization are given, finally comes out a successful concept electric car design with a nice aerodynamic of Cd=0.19.
Design an Autonomous Excavation System for Hydraulic Excavators
Authors: Wu Zhuo , Sun Ke Yi , Song Ming , Zheng Min
Published: October 2013

Shortages of skilled labor,extensive dangerous work,and technological advances are forcing rapid change in the construction industry, thus motivating construction automation,research and development of unmanned execution technologies for use to enhance safety has been undertaken.This paper presents an outline of research and development concerning automation of hydraulic excavator performed by applying a 3D vision system,3D information control system, a safety system, a 3D measurement system,and an operator interface communication system.As a result of the verification of the excavation motion suggest the technical possibility of achieving autonomous robotic excavation in moving toward construction automation.
Effect of Filter Media Structure on Fine Particle Filtration
Authors: Zheng Yan , Mao Ning , Lin Zhi Ke , Chang De Qiang , Liu Jing Xian , Sun Xi
Published: October 2013

Particles come in a wide range of sizes. Fabric filter with different structure shows different filtration performances on fine particle. In the paper, two types of filter media structure, i.e. non-woven structure and membrane structure are compared and studied. It can be seen that the pressure drop of membrane filter is apparently much higher than that of non-woven structure for it owns a density membrane. Membrane structure gives apparently higher efficiency for fine particle than non-woven structure.
Milling Stability Lobe Diagram Construction on FV520B Stainless Steel and Experimental Testing Investigation
Authors: Li Hong Kun , Zhao Peng Shi
Published: October 2013

This paper investigates the zero-order analytical method to construct milling stability lobe diagram to improve the impeller milling efficiency. It is used to determine FV520B material milling parameters optimization. This method can select the appropriate number of revolutions and the cutting depth processing avoiding chatter occurrence. It can keep the required accuracy and surface quality for the workpiece. At the same time, it improves the safety of the tool and machine reliability. Through experiments data analysis, parameters constructing lobe diagram can be obtained. Different testing points in the constructed lobes are used to verify the correctness of the method. The results show that this method has great significance in the actual impellers manufacturing process.
Research on the Oxygen-Enriched Combustion Technology Used for Ceramic Roller Kiln
Authors: Luo Ai Jun , Chen Jing , He Feng , Wen Jin
Published: October 2013

For the presence of high energy consumption and high emission in ceramic production, combining with the energy-saving and emission reduction targets of the National Twelfth Five-Year Plan, the advantages of oxygen-enriched combustion relative to normal combustion are analyzed. Concerning the new scheme of the internal burner distribution and new requirements made by combustion control method, the application of oxygen-enriched combustion technology in ceramic roller kiln is studied. The architecture and internal burner distribution scheme of ceramic roller kiln are improved in this study, and a novel combustion control method for oxygen-enriched combustion is used in the combustion experiment. Experimental results show that, with oxygen-enriched combustion, it can achieve complete combustion of the fuel, the flame characteristics conform the firing process requirements, and reduction of NOx emissions with proper O2 concentration.
Decentralized Robust Control over Robot Manipulator
Authors: Lezhnina Yuliya A. , Ternovaya Galina N. , Galyauv Elena R. , Kvyatkovskaya Irina Y.
Published: October 2013

The problem of control of systems with structural and parametric uncertainty for the case when derivatives of input and output parameters cannot be measured is solved. The operability of the designed control systems is modeled for anthropomorphic robots manipulator. Selected example demonstrates the compensation of effect of bounded structure and parametric disturbances. As in the control action organization the effect on subsystem is not allowed, i.e. obtained control system is completely decentralized.
Structural Design of Robot Applied in Post-Earthquake Relief
Authors: Ye Chuan Qi , Shang Wei Yan , Xu Zhao Peng , Liu Jian Jun , Huang Quan Rong , An Bao
Published: October 2013

In order to enhance the ability of the rescue robot, and to accomplish a rescue mission in special environment, variable pitch crawler-type robot is designed. The structural concept of the new type of variable pitch has been proposed and designed, and this can help to improve the robot's adaptive capacity to complex environment. Then the varying pitch structure has been designed using pneumatic devices, it can ensure simultaneous operation of the right and left wheel at constant speed, and enable the robot to move nimbly through a tight space. The new crawler-type running gear strengthens the security and the stability of the complete system.
Intelligent Access Control and Monitoring System
Authors: Shen Yi Jun , Zhong Bo Cheng
Published: October 2013

Based on the RFID technology, we developed an intelligent building access control and mornitoring system, with which you can effectively control access to the special zone, and monitor the people entering the restricted zone timely and accurately, and helpfully monitor and deal with abnormal situation. Instead of the passive monitoring and alarming in the traditional security system, this system uses the active control. Thus it will provide a more effective way for safety management of enterprises.
Near-Infrared Spectrometer Optical Sensor Driving and Peripheral Circuit Design
Authors: Deng Xiao Qing , Liu Jie , Wang Zhi Hong
Published: October 2013

In order to achieve Near-infrared spectrometer the feature of real-time capture and analysis in real time, CCD is used on the optical sensors. It has done a software simulation and hardware implementation.This paper presents the method of using VHDL for the solution of the linear CCD driving. Then, the external circuit is designed and the differential amplification processing to the output of the liner CCD is done in this paper. The results show that the system can correct drive,and the signal is displayed correctly. It needs only 2.5ms to complete a scany period in the 16MHZ crystal. The greater frequency of crystal,the shorter a scany period. The design is easy to understand. It has a great space to the behind application.
Effects of Bearing Configuration on Spindle Dynamic Characteristics
Authors: An Guo Ping , Zhang Bing Bing , Zhao Yong Sheng , Cai Li Gang
Published: October 2013

This article investigates the effects of bearing configuration on the spindle dynamic characteristics. First, an analytical model of spindle is proposed and the bearing sets radial stiffness is calculated. Second, the spindle analytical model is developed to perform modal analysis and harmonic response analysis with ANSYS, and then obtain the natural frequency and FRF under different bearing configurations. The result suggests that bearing configuration has little effect on the natural frequency of spindle system and the FRF amplitude corresponding to the 1st natural frequency under back to back configuration or face to face configuration is relatively small. Finally, the proposed model is validated by modal experiment.
Power Plant Performance Optimization Experiment on Primary Frequency Regulation
Authors: Chen Li , Hu Nian Su , Li Qin Gang
Published: October 2013

As the increment of the power grid scale and the requirement of high power quality, the requirement of the primary frequency regulation (PFR) of large power plant i becomes more and more strictly. In order to improve the PFR performance and to ensure the safety and stability of power plant operation, an experimental analysis was carried out to optimize the control model and parameters of the CCS, DEH and primary frequency.
Image-Based Parking Guiding Using Ackermann Steering Geometry
Authors: Tseng Din Chang , Chao Tat Wa , Chang Jiun Wei
Published: October 2013

An image-based parking guiding system is proposed to help drivers to park their cars into parking space. The proposed system only relies on an embedded hardware and a wide-angle camera to capture images for analysis. The proposed system needs no steering sensor; itis a money-saved technique; moreover, it is suitable for used cars and after-market usage. The input image is first transformed into a top-view image by a transformation matrix of homography. Then corner feature points on two continuous images are extracted to match each other. The feature-point pairs are further pruned by a least-square error metrics. The remained feature-point pairs are then used to estimate the vehicle motion parameters, where a coordinate transformation model is used to model and simulate the Ackermann steering geometry to describe the vehicle motion. At last, the vehicle trajectory is generated based on the vehicle motion parameters and the parking guiding lines are drawn according to the vehicle trajectory.
Computational Fluid Dynamics Simulation of the Exterior Flow Field around an Aerodynamic Reference Model
Authors: Wu De Jiu , Hu Xing Jun , Yang Bo
Published: October 2013

The exterior flow field around a Ford notchback automobile aerodynamic reference model was investigated using a commercial Computational Fluid Dynamics (CFD) code, Ansys Fluent. Two computational domains were set up in order to represent different model mounting conditions. According to the comparisons, good simulation accuracy could be obtained using the steady state k-ω SST model with small size near wall mesh (y+<5) simulations. The comparatively large prediction errors of the surface pressure coefficient of the model centerline happened in two positions. One is the roof trailing edge, where the flow separation begins. The other is the saddle point on the deck lid centerline, where the reverse flow emerges. These differences between the CFD and experiment were possibly due to the unstable wake. This wake instability would be the reason of the differences between the Ford notchback model transverse vortices and the typical notchback car wake structures.
Information Technology Risk Management Using Frap (A Case of Insurance Company)
Authors: Gui Anderes , Haron Hasnah , Sabrina Cecilia , Timoti Jerom , Yusuf Mochamad , Pratiwi Septy Debby
Published: October 2013

The purpose of this study was to determine how the application of information technology and the risks of what might happen. Research methods used include literature studies, field studies by conducting observations, interview and study documentation. The approach used to conduct risk management of information technology is a method of Facilitated Risk Analysis Process (FRAP). The results are the discovery of the risks of using information technology. The conclusions of this study demonstrate the application of information technology is good enough because it takes only a little improvement in information technology risk management.
Insider Forgery Cryptanalysis of Two Post-Quantum Multi-Signature Schemes
Authors: Kong Fan Yu , Diao Lu Hong , Yu Jia , Jiang Ya Li , Zhou Da Shui
Published: October 2013

In 2010, M. Meziani and P.-L. Cayrel presented two post-quantum multi-signature schemes based on the syndrome decoding hard problem and error correcting codes. In this paper, we propose the insider forgery cryptanalysis of M. Meziani et al.s post-quantum multi-signature schemes. In M. Meziani et al.s schemes, the verifier only verifies the final multi-signature and does not check the validity of the partial signatures generated by other signers. Thus the malicious last signer can forge a valid multi-signature by himself/herself on behalf of the group of signers, which can pass the verification of the verifier. Therefore, M. Meziani et al.s post-quantum multi-signature schemes do not meet the security requirements of multi-signature schemes.
Route Length, Curve Radius and Layout of Evacuated Tube Maglev Space Launch System
Authors: Zhang Yao Ping
Published: October 2013

Current space launch is expensive and low-efficient because the invalid load----rocket and fuel in it occupies over 80% of the total launch weight. A solution to reduce the space launch cost and increase the launch efficiency is to construct the evacuated tube, pump air out from the tube and have the maglev vehicle loaded with the spacecraft run in it; the spacecraft fly out the tube when the maglev is accelerated to ultra-speed, e.g. 5km/s even 8km/s in the tube. By this way, the first class of the rocket could be saved, so that the launch cost would be low and lead the large scale space exploitation to become reality in the soon future. As for the tube construction, the route layout should be concerned on at first. Because of the engineering restriction, the height at the tube end wouldnt be very high, and the embedding depth wouldnt be very deep, practically about 8km. However, the tube length will be 700km at least, a completely straight tube or a completely curve tube (on a single circle) would lead a too small launch angle. Thus both of them are not feasible. Reasonable tube routes in vertical section will include two or more than two segments, for example, a straight tube segment and a curve tube segment, or two or more than two curve segments in different radius or different curve direction.
Study on Cost Accounting of Special Steel Enterprises Based on Multi-Factor Resource Allocation Model
Authors: Wang Ya Jun , Wang De Quan , Li Jia Liang
Published: October 2013

To deal with the problems of data inaccuracy and incorrect fee allocation, an activity based costing model for the special steel enterprises based upon multi-factor resource model was proposed. The model was built to combine the cost factors of consumption, operation, and cost drivers with resource, process and machining parameters and to realize the information integration of finance, production and inventory, which improve the accuracy, consistency and integrality of the product effective cost. Finally, the cost management system framework based on the model was realized and the application is illustrated by an example.
Research on the Construction of Brand Identity System in the Exterior Design of Machine Tool Products
Authors: Xu Gang , Yu Hong , Zhang Jiu Mei , Yang Xian Chao
Published: October 2013

Explains the significance and function of brand identity system for machine tool manufacturing enterprises, meanwhile, it converts theories to visual elements based on the theories of industrial design, discusses the design elements for realizing the brand identity system of machine tool products from the perspective of practical application, and analyzes and explores the implementation methods of various design elements including color matching, form, details and so on one by one. It provides a new method and a new idea for the innovative design of machine tool products in China, with very great theoretical and practical significance.
How to Get Information in the Process of Way-Finding, the Research of the Effectiveness of Signage System Design
Authors: Yang Xiao Yang
Published: October 2013

This paper analyzes the process of way-finding, summarizes the features of this process, and studies the problems of Chinese public signage system status. And the Beijing Subway is taken as an example to analyze the effectiveness of the design. Finally, proposed four scientific points to improve the effectiveness of the signage system design.
Numerical Investigation of the Effect of Sprue Base Design on the Flow Pattern of Aluminum Gravity Casting
Authors: Baghani Amir , Bahmani Ahmad , Davami Parviz , Varahram Naser , Shabani Mohsen Ostad
Published: October 2013

Effects of sprue base size and design on flow pattern during aluminum gravity casting have been investigated by employing different sprue base sizes and using computational fluid dynamics (CFD). Calculations was carried out using SUTCAST simulation software based on solving Navier-Stokes equation and tracing the free surface using SOLA-VOF algorithm. Flow pattern was analyzed with focusing on streamlines and velocity distribution in sprue base, runner and in-gate. Increasing well size was produced a vortex flow at the bottom of sprue base which increased the urface velocity of liquid metal in runner. Using a rather big sprue well could eliminatevena contracta, but in-gate velocity was observed independent from well size. It assumes that in-gate velocity may be more influenced by other casting considerations. Using a curved sprue base could remove vortex flow at the bottom of sprue while keeping a nearly full contact between liquid metal and runner wall.
Theoretical Studies of the Local Structures and Spin Hamiltonian Parameters for the Cu2+ Centers in Alkali Barium Borate Glasses
Authors: Wei Wang He , Lu Min , Hou Chun Ju
Published: October 2013

The spin Hamiltonian parameters (g factors g||, g and the hyperfine structure constants A||, A) for the Cu2+centers in alkali barium borate glasses were theoretically studied based on the high-order perturbation formulas of these parameters for a 3d9ion in a tetragonally elongated octahedron. From the calculations, the ligand octahedra around Cu2+are suggested to suffer about 9.4%, 10.7%, and 11.1% relative elongation along C4 axis for the alkali barium borate glasses (Li-Ba-B, Na-Ba-B and K-Ba-B, respectively), the results are in good agreement with the observed values. In addition, the negative signs for A|| and A of the studied Cu2+centers were also suggested in the discussion.
Energy Diagnosis of the Structure of the Demolition Hammer with WoSSo Vibroisolation of a Biomechanical System
Authors: Dobry Marian Witalis
Published: October 2013

The article presents the results of energy diagnosis of the structure of an innovative, mechanized, hand-held demolition tool with application of the Constant Interaction Force Vibroisolation (abbreviated as WoSSO) of a biomechanical system. Sample results refer to the demolition hammer of the weight of 15,6 kg and the frequency of working shocks of 20 Hz. The diagnostic research was to recognise and evaluate the energy and spatial impact of the innovative structure of the hammer provided with anti-vibration system upon human. 3D energy physical and mathematical models of the entire system human demolition hammer with vibroisolation of 18 degrees of freedom were designed and the problem was solved with the digital simulation method. The forces enforcing three directions of vibrations were identified via experiments at the research stand on the model base compliant with the ISO standard and then entered in the simulation program. The obtained results of the energy diagnosis of the structure explained the phenomenon of the energy flow in the examined biomechanical system and confirmed the efficiency of the flow reduction of the energy of vibrations into the human body at all the reduction points in the three directions of vibrations.
Influence of the Indicator Channel and Indicator Valve on the Heat Release Characteristics of Medium Speed Marine Diesel Engines
Authors: Polanowski Stanisław , Pawletko Rafał , Witkowski Kazimierz
Published: October 2013

Analysis of the indicator diagram is the basis of technical state evaluation of marine diesel engines. The indicator diagram contains a large amount of diagnostic information. A major problem for the diagnostic use of the indicator diagram is the pressure sensor location. Indicator channel and valve may introduce significant distortions in the resulting pressure. The paper presents results of research conducted on the medium speed laboratory engine Al 25/30. Pressure measurement (indication) was made by the sensor placed directly in the cylinder (instead of starting air valve), before the indicator valve (with special Kistler adapter) and on the indicator valve. Distortion of heat release characteristics for the sensor placed on the indicator valve is important, but it is estimated that diagnostic information is not erased. For medium speed engines is to be expected the use of a portable pressure sensors placed on the indicator valve. For this reason, further research is needed to assess the impact of channels and valves on different cylinders. During the research the course of heat release rate q and the heat released Q were determined. The curve of heat release rate q is a full equivalent to fuel injection pressure curve in the fuel pipes. It allows identification of the failure of the injection system. The curve of Q allows such determination and assessment of internal efficiency of the cylinder.
Recent Research on Thermal Fatigue of Composite Elements of Transport Means
Authors: Katunin Andrzej , Moczulski Wojciech
Published: October 2013

Thermal fatigue occurred in many engineering constructions made of polymeric composites subjected to the intensive loading and vibrations. During this process the mechanical energy is dissipated in the form of heat due to the hysteretic behaviour of the material, which introduces the self-heating effect. In some cases the self-heating effect dominates the fatigue process and intensifies much structural degradation of composite elements. The paper presented a survey of engineering applications in which the self-heating effect and thermal fatigue occurred and recent advances in theoretical and experimental research in this area. Selected results of experimental studies were presented and discussed.
Remote Monitoring of Fatigue Cracks Growth in the Aircraft Structure Based on Active Piezosensor Network during the Full Scale Fatigue Test
Authors: Dragan Krzysztof , Dziendzikowski Michal , Uhl Tadeusz , Stepinski Tadeusz
Published: October 2013

One of the major issues from a structural integrity point of view of the aircraft structure is an appropriate health monitoring technology delivery for the damage tolerant philosophy. This paper presents a development of a system for fatigue crack growth monitoring and early damage detection in the PZL 130 ORLIK TC II turbo-prop military trainer aft structure. The maintenance system of the aircraft shifts from the safe-life to the hard-time. The aircraft started Full Scale Fatigue Test (FSFT) which will continue up to 2013. In the article a built block approach for the system design, signal modeling, sensing and signal processing as well as damage detection is presented. Taking into the consideration a previous experience of AGH as well as AFIT, a network of PZT transducers was deployed in the aircraft structure hot-spots. The system components are: remote monitoring unit, signal analysis, graphical user interface, sensor self-diagnostic tools, and data classification model. Description of damage detection capabilities are delivered in the paper. In particular some issues concerning the proposed damage indices and its application to crack growth estimation models are discussed. Fishers Linear Discriminant is used as a method to obtain effective crack growth predictors and one of the self-diagnostic tools used in the system. The results of the data collected from specimen fatigue tests are delivered and cross-validation technique is used to evaluate a classification model based on the damage indices derived.
Magnitud y características de la participación laboral en el empleo temporal agrícola en Chile
Authors: Caro Molina Pamela
Published: October 2013

Dada la modernización de la agricultura y la relevancia de las exportaciones frutícolas y vitivinícolas, los/as temporeros/as agrícolas se han constituido en una “identidad laboral u ocupacional” de alta relevancia a partir de los años 1980. En la actualidad, la inexistencia de una cuantificación continua y comparable constituye un problema para la investigación como para el diseño de políticas públicas. Si bien el ciclo agrícola y estacional define el momento de inserción laboral, estudios indican que los/as temporeros/as son un contingente estable y autónomo que concurre cada ciclo agrícola. Pueden tener varios contratos con el mismo o distintos empleadores, para una única o distintas faenas, independientemente trabajen el resto del año en otra actividad. La condición temporera oscila entre regularidad (de formas y ciclos) e irregularidad (de lo inestable). Entre in y exclusión social. El problema a abordar en este trabajo es la caracterización social, económica y laboral del sector actual, haciendo un análisis por sexo, comparando formalización, cotizaciones previsionales, zona de residencia, escolaridad, lugar que ocupa en la familia, quintil de ingresos, pertenencia a Chile Solidario, acceso a capacitación laboral, tamaño de la empresa e ingresos, a partir de las encuestas de Caracterización Socioeconómica Nacional —CASEN 2006 y 2009— y del Censo Agropecuario 2007.
Descriptions of the male and queen of the north Andean ant Pheidole unicornis Wilson, 2003 (Hymenoptera: Formicidae)
Authors: Scupola Antonio
Published: October 2013

The winged reproductives of the north Andean ant Pheidole unicornis Wilson, 2003 are described for the first time.
The home range of a recently established group of Southern ground-hornbill (Bucorvus leadbeateri) in the Limpopo Valley, South Africa
Authors: Theron Nicholas , Jansen Raymond , Grobler Paul , Kotze Antoinette
Published: October 2013

Little is known about Southern ground-hornbill (SGH) population ecology outside of large, formally protected areas where the largest declines in numbers have been recorded. The SGH has started re-colonising, establishing group territories and breeding successfully in the Limpopo Valley on the northern border of South Africa, following localised extinction from the 1950s to the 1970s. A group of SGH was monitored over a period of 14 months by means of radio telemetry across privately owned land in order to investigate their seasonal habitat movements in this semi-arid, predominantly livestock-based environment. We also investigated seasonal fluctuations in invertebrate prevalence, as an indication of food availability and its influence on seasonal SGH group movements and foraging activity patterns. There was a clear increase in food availability during the summer rainfall period allowing the group to forage over a wider area, whilst winter foraging remained localised within their range. Kernel home range analysis indicated a marked difference in size between the summer (13 409 ha) and winter (5280 ha) home ranges, with an overall home range of 19 372 ha, which is approximately double that of home ranges recorded that fall within formally and informally protected reserves. In this article, we proposed that food availability is the driving force for home range size and seasonal activity patterns in a semi-arid livestock-ranching habitat.Conservation implications: The Limpopo Valley SGH population is one of the most significant outside protected areas in South Africa. This population is especially vulnerable to threats such as poisoning, persecution for window breaking and drought, as shown by their near extirpation from the area. Conservation efforts need to focus on awareness amongst local farmers, provision of artificial nests and continued monitoring of groups.
Keeping it real for the sake of my career: An exploration of teaching creative writing in the broader Afrikaans literary system (1995–2012)
Authors: Kleyn Leti
Published: October 2013

This article focuses on the impact which training for creative writers has had in the wider Afrikaans literary system during the period 1995–2012 with specific reference to creative writing as postgraduate qualification. Development of the subject on tertiary level and the role of mentorship in the development of creative writing talent are examined. Furthermore, the investigation covers the number of solo book publications to date by people who followed courses in creative writing, how training in writing affects packaging, as well as the reception and awarding of literary prizes. Lastly, the teaching of creative writing within the literary system (both positively and negatively) is taken into consideration.
Experimental investigation of water droplets' behavior in dielectric medium: the effect of an applied D.C. electric field
Authors: Bararnia H. , Ganji D. D.
Published: October 2013

Abstract. In this article, the behavior of water droplets which are suspended in silicon oil is qualitatively investigated and some phenomena such as liquid's burst are reported. The movement of droplet in perpendicular line is considered while many studies have considered small droplets fluctuating between two horizontal electrodes. Additionally any deformation caused by increasing voltage was observed from start to finish until short contact occurred. As can be seen two oppositely charged drops contacting each other do not necessarily result in coalescence. Repelling can be expected occasionally. By increasing the voltage, the droplets, which spread through the domain due to frequent breakups, tend to gather in a certain line.
A Package Deal? African American Men’s Perspectives on the Intersection of Marriage and Fatherhood
Authors: Perry Armon R. , Harmon Dana K. , Bright Mikia
Published: October 2013

In response to decreasing marriage rates among childbearing couples, public policy has sought to reinforce the notion that marriage and fatherhood are a package deal. However, what remains unclear is whether the ideology and values of the policymakers promoting marriage and fatherhood as a package deal represent the values of the men targeted by the policy initiatives. In an attempt to respond to this question, this preliminary study presents the findings from a qualitative analysis of 33 African American adult males’ attitudes toward marriage and romantic relationships. The findings revealed that most of the sample conceptualized marriage and fatherhood as a package deal, but many of the men’s transition to marriage was facilitated by their engaged fathering, which is contrary to the philosophy espoused in the initiatives promoted by the marriage movement. This disconnect and its implications for policy are also discussed.
Agravamento de Projetos de Sistemas de Informação: Uma Revisão da Literatura
Authors: De Souza Enock Godoy , Reinhard Nicolau
Published: October 2013

Este artigo procura identificar quais são os principais fatores que contribuem para o agravamento de projetos de Sistemas de Informação. A identificação desses fatores ocorreu por meio de uma revisão bibliográfica sobre projetos intermináveis ou em condição de agravamento, analisando essa literatura em relação ao ambiente cultural brasileiro. As principais teorias que explicam o agravamento são analisadas e comparadas. Os principais resultados da pesquisa contemplam uma série de recomendações práticas para prevenir o agravamento de projetos.DOI:10.5585/gep.v4i1.106
Lacunas e Tendências na Literatura de Sustentabilidade no Gerenciamento de Projetos: Uma Revisão Sistemática Mesclando Bibliometria e Análise de Conteúdo
Authors: Martens Mauro Luiz , Brones Fabien , De Carvalho Marly Monteiro
Published: October 2013

Este estudo tem como objetivo explorar como o tema sustentabilidade se desdobra no âmbito da gestão de projetos. Como metodologia de pesquisa foram utilizadas técnicas de revisão sistemática de literatura e análise de conteúdo para identificação e interpretação das principais publicações acerca do tema na literatura científica dos últimos vinte anos. A amostra obtida à partir da base ISI Web of Knowledge, totalizou apenas 23 artigos oriundos de setores, países e áreas de conhecimento variados, com predominância de publicações ligadas à construção civil, com maior avanço em projetos de “construções verdes” certificadas. Os resultados revelam que o conceito de sustentabilidade ainda vem carregado das perspectivas econômica e ambiental, dado que o termo é aplicado na perspectiva do Triple-Bottom Line em menos da metade da amostra e, além disso, a análise do conceito de sustentabilidade evidenciou que a dimensão social ainda apresenta lacunas em face às demais dimensões. Outra contribuição deste estudo foi a aplicação experimental do modelo generalista de 3 eixos de sustentabilidade em gestão de projeto por meio da análise de conteúdos qualitativa: esse modelo se mostrou potencialmente capaz de avaliar ou direcionar projetos de qualquer setor com duas dimensões complementares (sistema e tecnologias associados aos processos gerenciais e ao seu produto, e pessoas/governança). Tal modelo constitui uma abordagem promissora a ser aprofundada em pesquisas futuras sobre essa questão relevante da busca de gestão sustentável dos projetos.DOI:10.5585/gep.v4i1.123