bluuebunny/crossref_metadata_2025 huggingface dataset:
System Development of a Simulated Annealing Algorithm for Job-Shop Scheduling Problem Based on Delphi
Authors: Cao Yan , Cao Sen , Lei Lei , Bai Yu , Shi Lei
Published: December 2011

The job-shop scheduling is the key element of a manufacturing execution system (MES). It is significant for enterprises to utilize resources rationally, enhance product quality, shorten production cycle, reduce production cost, and improve its market competitiveness. In the paper, Simulated Annealing (SA) algorithm is adopted to solve the job-shop scheduling problem. SA algorithm is a random search method proposed to solve large-scale combinatorial optimization problems. As an efficient and general method, the optimization and convergence performance of SA algorithm is mainly affected by the problem and several factors. In order to facilitate use’s employment, a job-shop scheduling system based on SA algorithm is developed using Delphi. The system developed is verified by an example. The results show that it is an effective solution to the job-shop scheduling problems.
Mechanism and Effect of Charges Accumulation on Differential Capacitance Detector Diodes in MEMS Accelerometer
Authors: Xiao Peng , Wang Xiao Bin , Yan Zhao Bing , Yang Jie
Published: December 2011

Detector diodes have been successfully used in differential capacitive MEMS accelerometer for capacitance-to-voltage conversion. During capacitances’ charging and discharging, charge accumulation makes test results disagree with the calculated values based on its differential equations simply and finally has a great influence on circuit’s optimization. A model of charges accumulation process is built to describe the real conversion relationship between the value of capacitance variations and the output voltage. Experiments show that the model not only meets the test result well but also provides a foundation for circuit’s optimization.
Fabrication of Fine-Line Pattern with Image Reversal Process
Authors: Bao Shuai , Gao Ai Hua , Liu Huan , Liu Wei Guo
Published: December 2011

This paper describes a simple and effective lift-off method that relies upon a single layer of positive photoresist and lithography technology. We have succeeded in patterning narrow lines in a photoresist film by image reversal process. Image reversal with AZ 5214-E resist is characterized by contact lithography. A process of patterning different line widths was developed based on image reversal technology, using AZ5214-E, followed by pre-bake, exposure, reversal bake, flood exposure and development. We could obtain very neat patterns with 2-5μm dimensions and their relative features have been supported by scanning electron microscope (SEM) pictures. The application of the proposed process is suitable for the electrode fabrication in MEMS SAW devices.
Research on the Tool Images Evaluation Based on Auto-Focus Technology
Authors: Lai Yue Shen , Shi Meng , Tian Jun Wei , Cheng Gang
Published: December 2011

Accurate and efficient image-clarity evaluation function which adopts digital image processing technology is the key to achieving automatic focusing. The different evaluation functions are adopted for different images. By converting color images to grayscale, and comparing them with the green component which extract from the color images, it is found that using the gray image can get a much better results and an evaluation function is built which is used for tool images. Experiments prove that the used algorithm has a good single peak, accuracy, stability, and fast speed.
Application of Response Surface Methodology to Optimize Quenching Process Parameters of 17Cr2Ni2Mo Steel
Authors: Liu Chun Jing , Tang Dun Bing , He Hua
Published: December 2011

With fast development of output, light-weighting and high performance of automobile, 17Cr2Ni2Mo steel, as an important vehicle-used gear steel, has to improve properties to fulfill the development. The performance of 17Cr2Ni2Mo steel is affected by quenching process parameters. In order to investigate the effect of austenitizing temperature and holding time on the quenching hardness and tensile strength, the central composite design (CCD) and response surface method (RSM) are applied to optimize the operating variables viz. austenitizing temperature and holding time. Multi-objective optimization developed for the two responses (quenching hardness and tensile strength) indicates the optimum conditions to be 920.46°C of austenitizing temperature and 0 h of holding time, while the values of quenching hardness, tensile strength are not less than 43.47 HRC and 1616.42 MPa. The gear has advantages with mechanical strength and abrasion resistance energy when 17Cr2Ni2Mo steel is produced using the optimum parameters.
Data-Driven Approach for Equipment Reliability Prediction Using Neural Network
Authors: Ding Feng , Han Xing Ben
Published: December 2011

BP neural network based data-driven method is proposed to predict reliability in this paper. The BP neural network prediction using Gradient Descent Method (GDM), Additional Momentum Gradient Descent Method (AMGDM) and Levenberg-Marquardt Method(L-M) based on numerical optimization theory of training algorithm are compared with different neuron number. The proposed approach is validated via age data collected from computer numerical control (CNC) machine tool in the field. The results from the proposed method show that perfect predicting performance is achieved under considering selecting suitable number of the hidden neurons and training algorithm. Remarks are outlined regarding the fact that BP neural network based on data-driven method is feasible, effective and adequate predicting accuracy can be obtained.
Machinery Fault Detection Using Geodesic Distance Based on Genetic Clustering Algorithm
Authors: Li Gang , Wang Hong Xi , Zhuang Jian
Published: December 2011

Aim at the problem that there is an irregular data distribution when using multi-sensor to monitor machine conditions, a genetic clustering algorithm using geodesic distance metric (GCGD) is adopted to perform machine fault detection. In GCGD, a geodesic distance based proximity measure is employed replacing Euclidean distance that cannot correctly describe the relationship between data lying in a manifold, and GCGD determines partitioning of the feature vectors from a combinatorial optimization viewpoint. Fault detection experiments of inlet valve leakage in a two-stage reciprocating compressor reveal that GCGD achieves a better performance of fault detection than the K-means algorithm and a genetic algorithm based clustering technique.
Wear Trend Prediction of Gearbox Based on Oil Monitoring Technology
Authors: Cao Wei , Wang Wen Juan , Wang Rui
Published: December 2011

In this paper, an on-line ferrograph sensor was used to monitor the wear condition of a gearbox in mechanical equipment. A Grey-Markov model was studied to predict its wear trend, and simulation results proved the effectiveness of the model. It provides a reliable method for wear condition monitoring and remaining life prediction of mechanical transmission systems.
Research on Relationship between Weight Filter Function and Stiffness Filter Function
Authors: Shang Zhen , Sui Yun Kang
Published: December 2011

Combined with the homogenization method and the least squares method, the filter function with the form of power function is studied in the Independent Continuum Map (ICM) method. Then, the numerical simulation method is used to study the relationship between a weight filter function and a stiffness filter function. Finally, the impact of the filtration function on the efficiency of topology optimization is showed by examples. It is important to further research structural topology optimization.
Analysis and Implementation of TrueFFS Based on VxWorks System
Authors: Han Gai Ning , Li Yong Feng
Published: December 2011

In an embedded system, a large amount of high real-time data processing is required. A TrueFFS method on the embedded VxWorks system is put forward to improve the data access speed and saving storage space of the embedded system. In this paper, the TrueFFS structure is analyzed, its establishing process is realized based on VxWorks. As an embedded operating system's main storage medium to build the TrueFFS, flash can improve system access speed and facilitate the upgrade of follow-up procedures.
Implementation of an Intelligent CO2 Meter via RS-485 with Modbus Protocol
Authors: Chen Zhen , Chen Xin Ya
Published: December 2011

An intelligent CO2 meter via RS-485 with Modbus Protocol are presented in the paper. The CO2 meter can determine the concentration of CO2 in air and can control the ventilation device to the control center.
Analysis of Degree of Depolarization of Atmospheric Scatter
Authors: Liu Jian , Lei Yi Yan , Yi Kang
Published: December 2011

When laser is transmitting through the atmosphere, both the light intensity and the polarized properties of laser can be changed because of the scattering of the gaseous molecules and suspended motes. In order to study the polarized properties of atmospheric scatter, we designed an experiment to measure the degree of depolarization of atmospheric scatter and did the experimental measurement in line-of-sight laser link under different weather conditions. Then, we analyzed and discussed the experimental results in detail. We found that fog can influence the polarized properties of laser seriously and the other weathers only have a little influence. During the experiment we obtained a great quantity of data which could present strong reliance to improve the atmospheric random channel model.
Research on Capsule Filling Machine Based on Virtual Prototype
Authors: Wang Gui He , Xiao Feng , Wang Wan Shan
Published: December 2011

Automatic capsule filling machine was key equipment in medicine enterprise. Based on the NJP3400, the working principle and the characteristic of capsule filling machine were analyzed. The 3-D model was built with the software of Pro/E. The dynamic of capsule filling machine was researched based the soft of ADAMS, and then, dynamic simulation of the model was done. The limited position and correlation parameter of force, length, velocity and acceleration was studied. The results indicated that the locomotion parameter of capsule filling machine could be optimized effectively by using ADAMS.
Triangular Mesh Simplification Based on Bounded Error
Authors: Qian Xue Ming , Cao Yan , Lin Xiao Ping
Published: December 2011

The author proposed a triangular mesh simplification algorithm with the methodology of vertex culling, which is based on bounded error. The algorithm includes several steps as follow. Firstly, the algorithm arrays the vertex according to the curvature. The curvature of local area around one vertex reduces in the array. Secondly, for one vertex to be deleted, the bounding box’s height of the local area will be calculated. And the reduction of the bounding box’s height is controlled as restraint of vertex culling. After the vertex culling, triangular mesh reconstruction is conducted on polygon to fill up the hollows formed in the above steps. This algorithm well balanced the deletion rate and deletion error in the experiment.
Study on Nozzle Burning for Engineering Ceramics Machining with Micro-Detonation of Striking Arc
Authors: Tian Xin Li , Zhang Bao Guo , Lin Ke Ling , Li Fu Qiang , Guo Fang
Published: December 2011

Micro-detonation of striking arc machining (MDSAM) is a new machining technology for engineering ceramics rough machining. In the paper, the constituent part and principle of machine system are introduced. In addition, the characteristics of corresponding technology are summarized, and nozzle burning law of micro-detonation generator is also analyzed. Lastly, the reasonable machining quality and efficiency can be achieved by controlling nozzle diameter between 2.4 mm and 2.8 mm.
Preparation and Mechanical Properties of a Bulk Icosahedral Quasicrystalline Ti-Zr-Sc-Ni Alloy
Authors: Wang Xin Lu , Liu Wan Qiang , Zhang Shan Shan , Wang Li Min
Published: December 2011

The discovery of the icosahedral quasicrystalline phase (i-phase) in as-cast Ti40.83Zr40.83-xScxNi18.34(x = 0~2.0) alloys is described herein. The effect of Sc on the structure and mechanical properties of the bulk quasicrystalline alloys is investigated. The results show that the phase structure of the as-cast alloys are mainly composed of icosahedral phase accompanied by minor C14 Laves phase (L-phase), and the mechanical properties of the bulk quasicrystalline alloys have been examined at room temperature, the compressive fracture strength first increased and then decreased with increasing x from 0.4 to 2.0, and the highest strength is near 1400 MPa when x =1.2, it was 380 MPa higher than the without Sc alloy. The bulk quasicrystalline alloy exhibits the elastic deformation by the compressive test, and the fracture mode was brittle cleavage fracture.
The Effect of Thai Compost on Biodegradability of Polylactic Acid Based on ISO 14855-2 Method
Authors: Timbuntam Walaiporn , Pongsomnam Sirinthon , Vanichsriratana Wirat , Sukyai Prakit
Published: December 2011

The plastic requirements of earth inhabitant are enormous and have environment impacts of such consumption. An average person consumes many tons of those materials which ultimately disposed as wastes. Therefore, the trend of environmental awareness increases the demanding of biodegradable plastic. Presently, the biodegradability test has been reported in various kinds of standards. However, the biodegradation in aerobic condition under controlled composting system is the main focus of this research. As we have known that microorganisms in compost are the key player of biodegradation which differ from country to country. Therefore, our own compost was fermented from rice straw together with cow dropping and urea for 60 days. It was found that the properties of compost were acceptable the requirements of ISO 14855-2. Such that the compost was utilized for testing the biodegradation of cellulose and polylactic acid powder which operated by Microbial Oxidative Degradation Analyzer (MODA). The compost was designed to control the humidity, aeration ratio and temperature at 58oC. It was discovered that the percentage of biodegradability of cellulose and polylactic acid powder were 80 and 98, respectively after 60 days testing. Thus, from this report, we have confirmed that our compost attain the criterion of standard requirement.
Strain Characteristic of Filament Wound Composite Cylinder under Axial Loading
Authors: Wen Wei Dong , Li Jian , Cui Hai Tao , Xu Ying , Zhang Hong Jian
Published: December 2011

Experimental investigations were performed on strain characteristic of filament wound composite cylinder. Cylinders are wound with S-1 glass fiber and epoxy resin, and then subjected to an axial tension. During loading, strains at three fiber crossing position and one laminate region on cylinder’s surface are measured by gauges for better understanding strain field. For all specimens, strains at fiber crossing positions are larger than that of laminate region. This indicates that fiber undulation caused by winding process affects mechanical response of filament wound composites.
Experimental study and Parameters Optimization of Laser Milling on Al2O3 Ceramics
Authors: Xu Zhao Mei , Zhou Jian Zhong , Zhu Yin Bo
Published: December 2011

The theory of laser milling ceramics was analyzed. Experiments of laser milling were done on Al2O3 ceramics with Nd:YAG laser. The influence law on the amounts of laser milling and milling surface quality with different parameters were studied systematically and the micro-morphology of the milling surface was analyzed. The optimal parameters were obtained according to the experimental results.
Evolution Characteristics of Primary Phase in A356 Al Alloy during Isothermal Holding in Solid-Liquid Phase Region
Authors: Liu Zheng , Cao Kai , Xu Hong Biao , Huang Mei Yan
Published: December 2011

Evolution characteristics of primary phase in A356 alloy at the different isothermal holding temperatures and time were investigated. The results showed that there were the effects of the isothermal holding temperature and time on the evolution of primary phase, and microstructure changed from dendritic-like to rosette-like, and then to particle- or globular-like with the decrease of holding temperature. The suitable technology in the test was obtained, in which when being held at 600°C for 5min, the roundness and size of primary became better.
Application Research of Data Warehouse Technology in Integrated Drilling Engineering Design
Authors: Liu Zhi Kun , Bai Yan Wei , Li Qi
Published: December 2011

In the process of drilling engineering design, in order to meet the needs of different departments and designers of different levels, using data warehouse technique, this paper proposes to build a integrated design system of drilling engineering. Through the establishment of data warehouse system, realize the integrated management and application of geological design, drilling design and real time information of drilling. In the process of collaborative design under network environment, provide a convenient and unified data analysis platform for specialists and designers in different fields. This paper describes the design and implementation of data warehouse system in detail.
Design Method of Measuring Rheogeniometer System Precision
Authors: Liu Chun Li , Yan Feng
Published: December 2011

The key problems of designing rheogeniometer product are divided into two aspects: one is the method of designing the hardware and measuring the shear rate; another is how to compute the viscosity accurately by the data of the shear rate, both are necessity. Since making plans, the connection of the mechanisms, the electric elements and the software is considered comprehensively. In order to solve the key problem that the rotate speeds of turntable in the rheogeniometer make error often, a method called Precision Design is built up, which could improved the detecting precision of the rheogeniometer.
Study of the Parametric Design and Experiment of a Single Unit Integrated Laser Photo-Interrupter
Authors: Lin Samuel I. En , Wang Jhih Hung , Chang Yu Chi , Huang Jian Fu
Published: December 2011

High-power lasers (>+21dBm), because of their ability to transmit long distance signals, have gradually become the common solution for signal transmission systems including regional cable television, Fiber To The Home (FTTH), and gigabit passive optical networks (GPON). However, if protective design is not implemented at the client-side facility, users may be exposed to health hazards caused by the high-power laser, e.g. direct eye exposure to laser beams. High-power optical adapters with photo-interrupters use metal shutter to prevent direct laser beam exposure to the eyes. They have progressively replaced conventional optical adapters and have entered the market mainstream. Our study uses the elastic-plastic theory together with parametric design to investigate the effect of geometry on the initial photo-interrupter spring-back angle. Once the metal spring-back stabilizes after several attempts of insertion and extraction, the initial springing-back angles are found to be the same as the simulated results. In our study, it is observed that factors including the ratio of the notch width to the total width of the metal shutter plate and the relationship with the boundary conditions have significant influence on the springing-back angle. These can be used as references in design control.
Study of Microstructures in Single Crystalline Chemical Vapor Deposited Diamond Thin Films
Authors: Jain Lokendra , Mohapatra D.R. , Bajpai R. , Basu Ritwik , Misra D.S. , Samajdar Indradev
Published: December 2011

Homo-epitaxial (100) single crystal diamond films of different isotopic (13C) composition were synthesized by micro-wave plasma chemical vapor deposition (MPCVD). Undoped 12C (100) films were also synthesized at different thicknesses. The growth surface of 13C doped showed a sequential morphological change from flat surface to stepped or ledge surface and coarsening of the steps/ledges with the increase of 13C-isotope concentration. As the growth proceeds via surface steps/ledges and coarsening of these steps/ledges, further increase in imperfection of the grown CVD single crystal diamonds observed with the development of non-(100) orientations. In case of undoped 12C samples, as the thickness increased the in-grain misorientation got reduced.
Texture Evolution of Armco Iron during Accumulative Roll Bonding Process
Authors: Bonnot Erell , Brisset François , Helbert Anne Laure , Baudin Thierry
Published: December 2011

The Armco iron is one of the purest commercial iron with very low levels of carbon, oxygen and nitrogen. In order to improve the mechanical properties, it is worth applying severe plastic deformation to obtain ultrafine-grained bulk materials, with grain size <1µm. In this study, samples of Armco iron were subjected to a technique of severe plastic deformation named Accumulative Roll Bonding (ARB). The important parameter of ARB is the number of cycles and then the von Mises equivalent strain. By means of the Electron BackScattered Diffraction (EBSD) technique, the texture evolution with the number of cycles was studied. The microhardness was also measured in function of the equivalent strain. Finally, the mean grain size and the fraction of high angle grain boundaries were determined as a function of the number of cycles.
Practical Aspects of Texture Analysis in the Aluminum Industry
Authors: Weiland Hasso
Published: December 2011

Crystallographic texture analysis is a microstructure characterization technique essential for relating microstructure attributes to the anisotropy of properties in crystalline matter. As such, it is widely used in research as well as in industrial materials and process design. Additionally, texture analysis is also used in industrial applications to monitor the consistency of a process for e.g. the anisotropy in mechanical properties from product to product. This overview outlines the reduction of quantitative texture data for the use in industrial settings.
Texture Evolution in Titanium and Aluminum Sheets Subjected to Friction Roll Surface Processing and Subsequent Annealing
Authors: Takayama Yoshimasa , Shi Mei Qin , Ougiya Yoshihiro , Nonaka Kenta , Watanabe Hideo
Published: December 2011

Titanium and aluminum sheets were directionally strained by friction roll surface processing (FRSP). Severe shear strain was imposed into the surface layer and strain gradient was formed through the thickness of the sheet. The microstructure and texture in as-strained state were investigated by optical microscopy and X-ray diffraction technique. Ultra-fine grains in the surface layer of the titanium sheet were found to have a sharp texture with a preferred orientation strongly related to the FRSP direction. The evolution of microstructure and crystallographic texture of FRSPed samples during annealing were studied by electron back-scattered diffraction (EBSD) technique. Obvious preferred orientations of shear straining were obtained in the surface layer of both materials as a result from FRSP and subsequent annealing.
Recrystallization Textures in Aluminum Alloys: Experimental Study and Modelling
Authors: Sidor Jurij J. , Petrov Roumen H. , Kestens Leo A.I.
Published: December 2011

The changes in crystallographic texture are investigated during recrystallization in 5182 and 6016 aluminum alloys, which were subjected to various cold rolling reductions. In the current study, the texture varieties in the recrystallized materials are conditioned by both the material’s chemistry and the applied rolling strain. The presence of large constituent particles produces strain heterogeneities during cold rolling which causes a specific texture development. The development of recrystallization textures is discussed based on experimental data and results of crystal plasticity simulations. A recrystallization model based on nucleation and growth selection is presented. The driving force for nucleation was accounted for by applying continuum mechanics crystal plasticity models. For the modeling of the strain heterogeneities around hard undeformable particle a FE-code was used.
Recrystallization Behavior Immediately after Hot-Rolling in Ferrite Region in Ultra Low Carbon Sheet Steels
Authors: Okuda Kaneharu , Seto Kazuhiro
Published: December 2011

One-pass hot rolling in the ferrite region was conducted at higher temperatures, using various rolling temperatures and rolling reductions, with two types of ULC steels, 0.016% Nb and 0.023% Ti, and recrystallization behaviors immediately after hot rolling were investigated. The γ-fiber strength reached its maximum at around 50% rolling reduction at 1273K with the Nb-added steel and 1323K with the Ti-added steel. On the other hand, in high temperature rolling of the Ti-added steel, the γ-fiber did not develop, independent of rolling reduction. These changes corresponded to the recrystallized fraction, in that the strength of the γ-fiber decreased when recrystallization occurred immediately after rolling. New recrystallized-like grains were produced in the domain where distortions were particularly concentrated. Recrystallization seemed to be the result of various mechanisms, as some recrystallized grains were formed by a bulging mechanism, whilst others were surrounded by high angle grain boundaries.
Grrain Orientations and their Influence on Precipitation in Hot Compressed Columnar Grains in Electrical Steel
Authors: Qian H. , Yang Ping , Zheng G.H. , Mao Wei Min
Published: December 2011

To identify the relationship between grain orientation and precipitation of MnS/AlN particles during hot deformation, cylinder samples containing columnar grains in electrical steels were prepared with different angles between columnar grain axis and sample axis. They were heated at 1360°C and compressed at 1100°C for 50%. Grain orientations and the precipitation states are determined using XRD, EBSD, EDS and SEM. Results indicate a general behavior of less precipitates in <100> and more precipitates in <111> grains. In addition, more precipitates were observed in samples with grain boundaries perpendicular to compression axis.
Development of Microstructure and Texture in Al5052 Alloy Processed at Room and Cryogenic Temperatures in an ECAP Die
Authors: Singh Jung B. , Sarkar Apu , Sharma Garima , Basavaraj V. , Chakravartty J.K.
Published: December 2011

Development of microstructure and texture in alloy Al5052 deformed at room and cryogenic temperatures in an equal channel angular pressing (ECAP) die has been investigated. Billets were deformed using the Bc route up to 14 passes. Billets pressed at room temperature showed almost a 4 fold increase in the yield strength, which increased to about 320 MPa from about 90 MPa, while it increased to about 230 MPa in billets deformed at cryogenic temperature. At two deformation temperatures, grains were refined at more or less similar size reduction rate as a function of number of passes. However, for a given amount of strain, billets pressed at the two temperatures showed subtle differences in their microstructures and texture.
Influence of Additives on Texture Development of Submicro- and Nanocrystalline Nickel
Authors: Klement Uta , Oikonomou C. , Chulist Robert , Beausir Benoit , Hollang L. , Skrotzki Werner
Published: December 2011

Organic additives such as saccharin have been frequently used in electroplating operations to moderate deposit growth rates and to control film quality. In this study, texture development upon annealing of pulse-electroplated Nickel produced without additives is analyzed by use of electron backscatter diffraction technique. Plating without additives results in a microstructure with slightly elongated grains and a fibre texture in growth direction and this texture is conserved upon annealing up to 600°C. Structural units in form of groups of elongated grains possessing a common zone axis in growth direction and twin relationships between themselves are found in the microstructure. For revealing the influence of additives, the observations are compared with results obtained for Ni and Ni-Fe plated in the presence of additives where during abnormal grain growth the initial fibre texture changes to an energetically more favourable texture by twinning. The lack of additives is assumed to be responsible for the observed differences in texture and microstructure development.
Microstructural Analysis of Type 304 Metal Sleeve
Authors: Ohtani Shintaro , Morooka Satoshi , Umezawa Osamu
Published: December 2011

In order to form thin metal sleeve with the thickness of 0.03 mm, type 304 austenitic steel sheet was deeply drawn to a cup and spinning method applied to its body. The sleeve shows high strength with a dual-phase microstructure of fine austenite and transformed martensite. Pancaked austenite and martensite grains were highly elongated along RD (drawing direction) in the layer structure, and their grain width was about 100 nm. Dynamically recovered austenite grains were highly aligned from {101} to {101}. The strain-induced martensite grains mainly showed two components of {001} and {111}. Recover and recrystallization of the sleeve appeared at the temperature from 873 K to 1073 K. Annealed at 1073 K the austenite grains were mostly recrystallized with intensifying {101}, and the martensite grains were also reverse-transformed to austenite.
A Cross-Sectional TEM Study of Abrasive Water Jet Cut Surface
Authors: Gouthama  , Yugesh Bollineni
Published: December 2011

Abrasive Water jet cutting (AWJ) is a process used to cut materials using a jet of pressurized water. These water jets are capable of cutting a variety of materials like superalloys, titanium alloys, stainless steel, tool steels, ceramics, armor tool and granite. In the present study an attempt has been made to investigate microstructural changes taking place in the sub-surface as a result of AWJ cutting using cross-sectional Transmission Electron Microscopy (TEM). TEM analysis shows that the sub-surface of the AWJ machined sample surface experienced severe deformations. The surface microstructure is observed to contain extremely fine sized grains, going down from sub-micrometer to nanometer range. The selected area diffraction pattern analysis also confirms the presence of extremely fine grained microstructure.
Tribological Characteristics on the Helical Gear in Cold Forging Mold
Authors: Choi Won Sik , Son Jae Hwan , Lee Inh , Jin Eun Young , Kwon Ju Ri , Lee Young Moon , Umehara Noritsugu
Published: December 2011

The purpose of this study is to find out the tribological characteristics of the various lubricants in cold forging of helical gear, which is used in mobile auto-transmission. Five kinds of lubricant were used in this study, i.e. L1, L2, L3, L4 and L5. The pin-on-disk type of friction wear test system has been adopted here. The normal load of 20, 40, 60, 80 and 100N has been applied to the test specimen. The sliding velocities were 0.06, 0.10, 0.14, 0.18, 0.22, 0.26, 0.30 and 0.34m/s. Experimental results show that the friction coefficients of oils having higher kinematic viscosity such as L1, L2, L4 and L5 tend to increase gradually as the sliding velocity increases. The increasing rate of the friction coefficient is relatively high in lower sliding velocity range. However in case of L3 which has low kinematic viscosity the friction coefficient tends to decrease as the sliding velocity increases. The friction coefficients of Bondelube and Bondelite were 3 times higher than those of L1 and L5. The Stribeck curve indicates that L1, L2, L4 and L5 were in hydrodynamic lubrication condition and L3 was in boundary lubrication condition. SEM micrographs revealed that there were some scratch, adhesive wear, adhesion wear and scuffing on the worn surface.
Rudolf Bultmann: Sy mees invloedryke bydrae in die 20ste eeu: ‘Urchristentum’, ‘Jesus’, ‘Johannes’-kommentaar?
Authors: Van Aarde Andries G.
Published: December 2011

Rudolf Bultmann: His most influential contribution in the 20th century: ‘Urchristentum’, ‘Jesus’, ‘Commentary on John’s gospel’? This article pays tribute to Rudolf Bultmann as a scholar of faith who fulfilled the most influential role in the interpretation of Jesus and the New Testament during the twentieth century. In the article Bultmann’s leading publications are discussed against the background of the question of which one has been the most significant. Three important publications are identified, namely his book on the socio-cultural environment of the earliest followers of Jesus in first-century Semitic-Hellenistic world, his book on the historical Jesus, and his commentary on the Gospel of John. Various criteria are applied to value the significance of these three publications. They are Bultmann’s understanding of what the scientific nature of the theological discourse principally would entail; how modern-day believers could adhere to an ancient mythological discourse; the way in which today a historical discourse could existentially been engaged with and why Jesus of Nazareth would be regarded as theologically significant. Both the depth of Bultmann’s understanding of the substance of the theological discourse found in John’s gospel and the quality of Bultmann’s historical-critical analysis of John’s gospel lead to the finding that this commentary should be considered to be not only the most significant for the twentieth century but beyond that time even into the current phase of biblical and theological interpretation.
‘n Prakties Teologiese ondersoek na die betrokkenheid van gemeentes in die gemeenskap waarbinne hul bestaan
Authors: Ungerer André
Published: December 2011

A Practical Theological research on the involvement of congregations in the community where they exist The study deals with the question about the involvement of congregations of the two traditional Reformational churches in South Africa, namely the Dutch Reformed Church (DRC) and the Netherdutch Reformed Church of Africa (NRCA) in their communities. The question posed is whether the love of God is kept for the benefit of the congregation or whether it is also for the well-being of the community. The study comprises two parts, an introduction that deals with the theory of mission and service to the community. The second part is an empirical study where 12 projects were given as examples and congregations were asked about their involvement.
Homoseksualiteit: Die standpunte van die Nederduitse Gereformeerde Kerk en die Nederduitsch Hervormde Kerk van Afrika in 2007
Authors: Strauss Piet J.
Published: December 2011

Homosexuality: The viewpoints of the Dutch Reformed Church (DRC) and the Netherdutch Reformed Church of Africa (NRCA) in 2007 These two churches, through their broadest assembly namely the General Synod and the General Church Assembly respectively, show remarkable similarities in their approach to Scripture on the matter of homosexuality, the position of gay people in church life and the time frame in which they took decisions on these matters. The point of departure for both is marriage as something only for one husband and one wife. This is explicitly complemented by the NRCA with a limitation of sexual intercourse to marriage, which rules out the possibility of homosexuality. In the DRC the same principle is tradition, thus basicly coming to the same conclusion as the NCRA. The reason for these similarities is not that the two assemblies openly copied each other, but the fact that they both are reformed churches in Southern Africa serving, mainly, Afrikaners. Perhaps these similarities supply another reason for the present increase in cooperation between the two churches.
Aktuele Bybelinterpretasie in Suid-Afrika – ’n kort oorsig en toepassing
Authors: Van Wyk Wouter C.
Published: December 2011

The current debate on Biblical interpretation – a short review and applicationThe article offers a review of important aspects of Biblical interpretation discussed in four recent books published in Afrikaans by prominent theologians Dirkie Smit, Gerrie Snyman, Gert Malan and Klaus Nürnberger. In the light of challenges to the traditional dogmas of the church and new ethical questions posed by a changing world, factors giving rise to conflict over Biblical interpretation are discussed. A number of untenable approaches to modern day Biblical interpretation are outlined, followed by a discussion of aspects of Biblical interpretation that have become more and more important. These insights are then applied to the current debate on Biblical interpretation within the Netherdutch Reformed Church of Africa. The article is concluded with a plea for continued concerted efforts to search for valid Biblical interpretation.
Gestaltegewing van geloof – Aspekte van outentieke geloofskommunikasie
Authors: Kloppers Elsabé
Published: December 2011

Faith embodied – Aspects of the authentic communication of the faith In this article a theological theory for the communication of the faith is addressed from the basic metaphor of the Church as the body of Christ, within the fields of church publications, visual communication, the worship service and church music. It is argued that words (spoken, published or sung), music, art, gestures, visual images, silences and open spaces, are all communicative actions performing on a symbolic or metaphorical level to express and communicate the faith. Through these communicative actions the corporate identity of the community of faith is shaped and the body of Christ is built up. It is argued that in the church the act of communicating should adhere to certain theological principles to be true to its essence and aim: to communicate the faith faithfully and trustworthy.
Conflict between work and nonwork roles of employees in the mining industry: Prevalence and differences between demographic groups
Authors: Steyl Betsie , Koekemoer Eileen
Published: December 2011

Orientation: International researchers have increasingly recognised the interaction between work and nonwork roles as an interesting and important topic. Research purpose: The purpose of this study was to investigate the prevalence of different work–nonwork conflict subscales and differences between demographic groups in work– nonwork conflict.Motivation for the study: Several studies have shown that demographic groups differ in their experiences of the interaction between work and family life. This may also be true of conflict between work and nonwork roles. The prevalence of work–nonwork conflict and nonwork– work conflict is also very important for organisations that may find the results very valuable for developing organisational and individual interventions and performance management in organisations.Research design, approach and method: The researchers chose a random sample of mining employees (n = 245) from a platinum mine in Rustenburg. The researchers used self-developed items similar to items developed in the Work–nonwork Interference Scale of Koekemoer, Mostert and Rothmann (2010) to measure conflict between work and various nonwork roles. The researchers used descriptive statistics, paired-sample t-tests, multivariate analysis of variance and one-way analysis of variance to analyse the data.Main findings: Work–nonwork conflict was more prevalent than nonwork–work conflict. Work–family conflict was more prevalent than work–domestic conflict and work–religion/ spirituality conflict. The researchers found significant differences for marital status and language groups about work–nonwork conflict. Results showed that participants who spoke African languages experienced higher levels of private–work conflict.Practical/managerial implications: Organisations need to recognise the negative interference or conflict between work and nonwork roles for different demographic groups and address the prevalent work–nonwork conflicts in their organisations.Contribution/value-add: Organisations are able to focus interventions and programmes that specifically address the problem of work–nonwork conflict in specific roles and for different demographic groups.
Pictorial essay: Allergic bronchopulmonary aspergillosis
Authors: Agarwal Ritesh , Khan Ajmal , Garg Mandeep , Aggarwal Ashutosh N , Gupta Dheeraj
Published: December 2011

Allergic bronchopulmonary aspergillosis (ABPA) is the best-known allergic manifestation of Aspergillus-related hypersensitivity pulmonary disorders. Most patients present with poorly controlled asthma, and the diagnosis can be made on the basis of a combination of clinical, immunological, and radiological findings. The chest radiographic findings are generally nonspecific, although the manifestations of mucoid impaction of the bronchi suggest a diagnosis of ABPA. High-resolution CT scan (HRCT) of the chest has replaced bronchography as the initial investigation of choice in ABPA. HRCT of the chest can be normal in almost one-third of the patients, and at this stage it is referred to as serologic ABPA (ABPA-S). The importance of central bronchiectasis (CB) as a specific finding in ABPA is debatable, as almost 40% of the lobes are involved by peripheral bronchiectasis. High-attenuation mucus (HAM), encountered in 20% of patients with ABPA, is pathognomonic of ABPA. ABPA should be classified based on the presence or absence of HAM as ABPA-S (mild), ABPA-CB (moderate), and ABPA-CB-HAM (severe), as this classification not only reflects immunological severity but also predicts the risk of recurrent relapses.
Management of empyema of gallbladder with percutaneous cholecysto-duodenal stenting in a case of hilar cholangiocarcinoma treated with common bile duct metallic stenting
Authors: Kumar Sheo , Sharma Pankaj , Muthu Ramesh , Mohakund Sudipta
Published: December 2011

Empyema of the gallbladder develops when the gallbladder neck is obstructed in the presence of infection, preventing pus from draining via the cystic duct. Treatment options include cholecystectomy or, in patients with comorbidities, drainage via percutaneous cholecystostomy, later followed by cholecystectomy. Here, we describe a 59-year-old man who presented with complaints of recurrent hiccups and was found to have cholangiocarcinoma causing obstruction to cystic duct drainage. The patient was managed successfully by percutaneous transhepatic cholecysto-duodenal self-expandable covered metal stent.
Impact of mineral dust on cloud formation in a Saharan outflow region
Authors: Smoydzin L. , Teller A. , Tost H. , Fnais M. , Lelieveld J.
Published: December 2011

Abstract. We present a numerical modelling study investigating the impact of mineral dust on cloud formation over the Eastern Mediterranean for two case studies: (i) 25 September 2008 and (ii) 28/29 January 2003. On both days dust plumes crossed the Mediterranean and interacted with clouds forming along frontal systems. For our investigation we used the fully online coupled model WRF-chem. The results show that increased aerosol concentrations due to the presence of mineral dust can enhance the formation of ice crystals. This leads to slight shifts of the spatial and temporal precipitation patterns compared to scenarios where dust was not considered to act as ice nuclei. However, the total amount of precipitation did not change significantly. The only exception occurred when dust entered into an area of orographic ascent, causing glaciation of the clouds, leading to a local enhancement of rainfall. The impact of dust particles acting as giant cloud condensation nuclei on precipitation formation was found to be small. Based on our simulations the contribution of dust to the CCN population is potentially significant only for warm phase clouds. Nevertheless, the dust-induced differences in the microphysical structure of the clouds can contribute to a significant radiative forcing.
Traditional protection ratios in FM sound broadcasting – still appropriate for interference management?
Authors: Philipp J.
Published: December 2011

Abstract. A detailed analysis of the measurement procedures recommended by the International Telecommunication Union (ITU) shows that – with proper definition of audio quality – the FM broadcasting system can provide an audio signal-to-noise ratio of no better than 40 dB, when the interference in the neighboring channels exhausts the limits established by the internationally agreed protection ratios. Thus any attempt to relax the protection, be it motivated by the desire to implement additional FM or new digital services in the FM band, would inevitably degrade reception quality of existing services to levels hardly acceptable by broadcast listeners.
Equitable access to spectrum in further development of the Geneva 2006 frequency plan
Authors: Philipp J.
Published: December 2011

Abstract. Since the frequency plan of the Regional Radiocommunication Conference Geneva 2006 has come into force, many attempts have been made towards its enhancement. The preliminary results, however, seem not to be compliant with elementary principles of distribution justice. Therefore, the planning principles which lead to the observed imbalance will be scrutinized. Furthermore it will be shown that the utilization of spectrum can be advanced in a balanced way when the same (necessary) condition for "equitable access", which has been used by a group of middle European countries for the construction of the original frequency plan, is applied to plan refinements as well. The necessary condition mentioned consists simply in the parity of the number of coverages (constituted of disjoint allotments) configured in the plan for each country. In order to be able to plan enhancements, the concept of coverage number has to be generalized to the case of incomplete coverages of potentially overlapping allotments. The computation of coverage numbers is straightforward and renders the concept of coverage number parity a useful tool to be applied as a necessary condition in testing a frequency plan variant for equitable access.
FATIGUE PROPERTIES OF NYLON 66/POLYESTER HYBRID CORDS
Authors: Aytaç Ayşe , Yilmaz Berrin , Deniz Veli
Published: December 2011

In this study, the fatigue and mechanical properties of Nylon 66/Polyester (Ny 66/PET) hybrid cords and Ny 66 and polyester reference cords which are being used in tire industry were studied. The most effective parameters and the optimum twist levels were determined for the fatigue performance of Ny 66/PET hybrid cords. Taguchi design of experiment method is used to minimize the required number of experiments. Different sets of nylon and PET reference cords were prepared in order to make a comparison of fatigue performance. The selected process parameters for Taguchi experimental analysis were Ny 66, PET, and cable ply twist levels. The effects of the selected parameters were investigated. It was found that the most effective factor was cable twist level and better fatigue resistance for hybrid cords with high cable and PET ply twist level can be obtained.