Sample records for die casting dies

  1. Materials on dies for pressure die casting

    E. Ragan


    Full Text Available In the contribution the stress of die materials of thermal fatigue is defi ned and material life is derived theoretically and compared with the measured values. The important properties of the die materials as thermal conductivity, coeffi cient of thermal expansivity, modulus of elasticity and mechanical properties are described. Binding to it single die materials as carbon steels and chrome-tungsten steels are analyzed. As the perspective die material for pressure die casting of ferrous metals appears molybdenum with regard to advantageous properties.

  2. Die Soldering in Aluminium Die Casting

    Han, Q.; Kenik, E.A.; Viswanathan, S.


    Two types of tests, dipping tests and dip-coating tests were carried out on small steel cylinders using pure aluminum and 380 alloy to investigate the mechanism of die soldering during aluminum die casting. Optical and scanning electron microscopy were used to study the morphology and composition of the phases formed during soldering. A soldering mechanism is postulated based on experimental observations. A soldering critical temperature is postulated at which iron begins to react with aluminum to form an aluminum-rich liquid phase and solid intermetallic compounds. When the temperature at the die surface is higher than this critical temperature, the aluminum-rich phase is liquid and joins the die with the casting during the subsequent solidification. The paper discusses the mechanism of soldering for the case of pure aluminum and 380 alloy casting in a steel mold, the factors that promote soldering, and the strength of the bond formed when soldering occurs. conditions, an aluminum-rich soldering layer may also form over the intermetallic layer. Although a significant amount of research has been conducted on the nature of these intermetallics, little is known about the conditions under which soldering occurs.

  3. Improvement of die life in high speed injection die casting

    Yasuhiro Arisuda; Akihito Hasuno; Junji Yoshida; Kazunari Tanii


    High-speed injection die casting is an efficient manufacturing technology for upgrading aluminum die-cast products. However, deficiencies (such as die damage in eady period) due to larger load on the molding die compared with conventional technology have brought new challenges. In this study, the cause of damage generated in super high-speed injection was investigated by the combination of experimental observation of the dies and CAE simulation (e.g. die temperature analysis, flow analysis and thermal stress analysis). The potential countermeasures to solve the above problems were also proposed.

  4. Improvement of die life in high speed injection die casting

    Akihito Hasuno


    Full Text Available High-speed injection die casting is an effi cient manufacturing technology for upgrading aluminum die-cast products. However, defi ciencies (such as die damage in early period due to larger load on the molding die compared with conventional technology have brought new challenges. In this study, the cause of damage generated in super high-speed injection was investigated by the combination of experimental observation of the dies and CAE simulation (e.g. die emperature analysis, fl ow analysis and thermal stress analysis. The potential countermeasures to solve the above problems were also proposed.

  5. Modeling the Mechanical Performance of Die Casting Dies

    R. Allen Miller


    The following report covers work performed at Ohio State on modeling the mechanical performance of dies. The focus of the project was development and particularly verification of finite element techniques used to model and predict displacements and stresses in die casting dies. The work entails a major case study performed with and industrial partner on a production die and laboratory experiments performed at Ohio State.

  6. Development of vacuum die-casting process

    Masashi Uchida


    The vacuum die-casting process, started 25 years ago in Japan, has been widely applied. This technology contributes very much to improvement of castings quality. The main factor causing the defects of die castings is the trapped air in the mold cavity, while the key technology of vacuum die-casting process is to avoid the trapped air effectively by evacuating the cavity before casting. At the same time, due to the shot speed and the casting pressure reduced in half, the service life of the die is prolonged and the productivity is enhanced, as well. Vacuum die-casting process is of great significance in improving the die castings quality and making up the shortcomings of super-high-speed shot casting.

  7. Simulating a high pressure die casting

    Goldak, J.; Zhou, J.; Downey, D.; Aldea, V.; Li, G.; Mocanita, M. [Carleton Univ., Ottawa, Ontario (Canada)


    High pressure die casting is simulated for parts with complex geometry such as a large automotive transmission case. The closed die is filled in approximately 40 ms, the casting cools in the closed die for approximately 40s, to open the die, eject the casting and spray the die cavity surface requires another 40s. This 3D cyclic process is simulated using the following coupled composite solvers: the energy equation in the die and in the casting with solidification; filling of the casting by a droplet or a Navier-Stokes solver, and thermal stress analysis of the casting machine, casting and die during the cycle. This thermal analysis can be done for both starting and stopping transients and for the cyclic steady state. The software enables this analysis to be done almost automatically by designers. (author)

  8. Casting Characteristics of Aluminum Die Casting Alloys

    Makhlouf M. Makhlouf; Diran Apelian


    The research program investigates the casting characteristics of selected aluminum die casting alloys. Specifically, the alloys' tendencies towards die soldering and sludge formation, and the alloys' fluidity and machinability are evaluated. It was found that: When the Fe and Mn contents of the alloy are low; caution has to be taken against possible die soldering. When the alloy has a high sludge factor, particularly a high level of Fe, measures must be taken to prevent the formation of large hardspots. For this kind of alloy, the Fe content should be kept at its lowest allowable level and the Mn content should be at its highest possible level. If there are problems in die filling, measures other than changing the alloy chemistry need to be considered first. In terms of alloy chemistry, the elements that form high temperature compounds must be kept at their lowest allowable levels. The alloys should not have machining problems when appropriate machining techniques and machining parameters are used.

  9. Energy Consumption of Die Casting Operations

    Jerald Brevick; clark Mount-Campbell; Carroll Mobley


    Molten metal processing is inherently energy intensive and roughly 25% of the cost of die-cast products can be traced to some form of energy consumption [1]. The obvious major energy requirements are for melting and holding molten alloy in preparation for casting. The proper selection and maintenance of melting and holding equipment are clearly important factors in minimizing energy consumption in die-casting operations [2]. In addition to energy consumption, furnace selection also influences metal loss due to oxidation, metal quality, and maintenance requirements. Other important factors influencing energy consumption in a die-casting facility include geographic location, alloy(s) cast, starting form of alloy (solid or liquid), overall process flow, casting yield, scrap rate, cycle times, number of shifts per day, days of operation per month, type and size of die-casting form of alloy (solid or liquid), overall process flow, casting yield, scrap rate, cycle times, number of shifts per day, days of operation per month, type and size of die-casting machine, related equipment (robots, trim presses), and downstream processing (machining, plating, assembly, etc.). Each of these factors also may influence the casting quality and productivity of a die-casting enterprise. In a die-casting enterprise, decisions regarding these issues are made frequently and are based on a large number of factors. Therefore, it is not surprising that energy consumption can vary significantly from one die-casting enterprise to the next, and within a single enterprise as function of time.

  10. Prediction of Part Distortion in Die Casting

    R. Allen Miller


    The die casting process is one of the net shape manufacturing techniques and is widely used to produce high production castings with tight tolerances for many industries. An understanding of the stress distribution and the deformation pattern of parts produced by die casting will result in less deviation from the part design specification, a better die design and eventually more productivity and cost savings. This report presents methods that can be used to simulate the die casting process in order to predict the deformation and stresses in the produced part and assesses the degree to which distortion modeling is practical for die casting at the current time. A coupled thermal-mechanical finite elements model was used to simulate the die casting process. The simulation models the effect of thermal and mechanical interaction between the casting and the die. It also includes the temperature dependant material properties of the casting. Based on a designed experiment, a sensitivity analysis was conducted on the model to investigate the effect of key factors. These factors include the casting material model, material properties and thermal interaction between casting and dies. To verify the casting distortion predictions, it was compared against the measured dimensions of produced parts. The comparison included dimensions along and across the parting plane and the flatness of one surface.

  11. Homogenity of Die Casting and Returning Material

    J. Malik


    Full Text Available Homogeneity of die castings is influenced by wide range of technological parameters as piston velocity in filling chamber of die casting machine, filling time of mould cavity, temperature of cast alloy, temperature of the mould, temperature of filling chamber, surface pressure on alloy during mould filling, final pressure and others. Based on stated parameters it is clear, that main parameters of die casting are filling time of die mould cavity and velocity of the melt in the ingates. Filling time must ensure the complete filling of the mould cavity before solidification process can negatively influence it. Among technological parameters also belong the returning material, which ratio in charge must be constrained according to requirement on final homogeneity of die castings. With the ratio of returning material influenced are the mechanical properties of castings, inner homogeneity and chemical composition.

  12. An Integrated Die Casting Design System

    Y; K; Woon; K; S; Lee


    Die casting process is one of the prime options for m anufacturing precisely dimensioned, sharply defined metal parts. The design of d ie casting dies comprises several stages and entails a large amount of time. Tra ditionally, the different stages of the die design were not integrated but exist as separate entities. Moreover, recurring modifications or even redesigns are r equired due to the complexity in achieving an accurate initial die design. As a result, die design is usually time-consuming and cos...

  13. Thermal Fatigue of Die-Casting Dies: An Overview

    Abdulhadi Hassan A.


    Full Text Available Coupled studies by experimental and numerical simulations are necessary for an increased understanding of the material behaviour as related to the interaction between the thermal and mechanical conditions. This paper focus on the mechanisms of thermal fatigue in the failure of dies and cores used in the die casting of aluminum alloys. The thermal fatigue resistance is expressed by two crack parameters which are the average maximum crack and the average cracked area. Samples of various types of H13 steel were compared with a standard H13 steel by testing under identical thermal fatigue cycles. To determine the thermal constraint developed in the sample during the test, a finite difference technique was used to obtain the temperature distribution, based on temperature measurements at the boundaries. The resulting stresses and strains were computed, and the strain calculated at the edge or weakest point of the sample was used to correlate the number of cycles to crack initiation. As the strain at the edge increased, the number of cycles to failure decreased. The influence of various factors on thermal fatigue behavior was studied including austenitizing temperature, surface condition, stress relieving, casting, vacuum melting, and resulfurization. The thermal fatigue resistance improved as the austenitizing temperature increased from 1750 to 2050ºF.

  14. Opportunities and challenges of Chinese die-casting market


    The present status and perspectives of Chinese die-casting market were commented. In 2003, the total output of die castings in the whole country was 708 000 tons, in which the outputs of Al-alloy, Zn-alloy, Mg-alloy, Cu-alloy die castings were 474 600 tons, 222 000 tons, 5 800 tons, 5 600 tons, respectively, each accounted for 67%, 31.35%, 0.85%,0.8% of the total. The annual sale volume of die-casting machines was approximately 1 800. And the gross output value of dies approached RMB 38 billion, in which die-casting dies accounted for about 10%. In the die-casting industry of the entire country, the foreign capital enterprises, public-run enterprises, township and village enterprises, private enterprises accounted for over 80% of the total die-casting enterprises. Super huge die-casting groups are forming.

  15. Modeling of high temperature- and diffusion-controlled die soldering in aluminum high pressure die casting

    Domkin, Konstantin; Hattel, Jesper Henri; Thorborg, Jesper


    Soldering of cast alloys to the dies has been a continuing source of die surface damage in the aluminum die-casting industry. To reduce the repair and maintenance costs, an approach to modeling the damage and predicting the die lifetime is required. The aim of the present study is the estimation...... of the die lifetime based on a quantitative analysis of die soldering in the framework of the numerical simulations of the die-casting process. Full 3D simulations of the process, including the filling. solidification, and the die cooling, are carried out using the casting simulation software MAGMAsoft....... The resulting transient temperature fields on the die surface and in the casting are then post-processed to estimate the die soldering. The present work deals only with the metallurgical/chemical kind of soldering which occurs at high temperatures and involves formation and growth of intermetallic layers...

  16. Die casting process otimization using Taguchi method

    Denilson Jose Viana


    Full Text Available The aluminum die casting process has developed significantly in recent decades, occupying a prominent place for producing innovative engineering components. Among quality problems of this process is porosity due to several factors, including the process parameters that are difficult to determine, and are commonly selected by trial and error approach. This paper sought to answer the question: How to determine the best set of parameters of the aluminum die casting process to minimize porosity in the parts produced? Aiming to improve die casting aluminum parts quality through reducing of porosity. The main contribution of this paper focuses on the application of Taguchi method using ordinal categorical data (porosity classes as a quality characteristic, by analyzing the weighted signal-to-noise ratio. The experimental results were analyzed from the average effect of factors and analysis of variance (ANOVA.  In conclusion parameters metal temperature and speed of the first and second injection phase were the most significant in reducing the porosity of the part studied. Also, the Taguchi method achieved the expected result, bringing significant reduction of porosity in the part studied by optimizing the process parameters.

  17. National Metal Casting Research Institute final report. Volume 2, Die casting research

    Jensen, D. [University of Northern Iowa, Cedar Falls, IA (United States). Dept. of Industrial Technology] [comp.


    Four subprojects were completed: development and evaluation of die coatings, accelerated die life characterization of die materials, evaluation of fluid flow and solidification modeling programs, selection and characterization of Al-based die casting alloys, and influence of die materials and coatings on die casting quality.

  18. Thermo-mechanical cracking of a new and laser repair welded die casting die

    D. Klobčar


    Full Text Available The paper presents the analysis of thermo-mechanical fatigue cracking of die casting die during industrial use. An innovative, production friendly approach to monitor the surface crack dimensions was introduced, which is based on measuring defect-fin on the casting part. A new four moulds die casting die was monitored 40 000 cycles in order to complete the production series. The production was stopped three times for laser repair welding of cracks since the defect-fins were not acceptable. The defect-fin heights were measured every 1 000 cycles on the castings before and after repair welding of die surface cracks. The in-service die life can be prolonged with laser repair welding for several times, even thought that in-service die life for a particular repair varies.

  19. Enhancements in Magnesium Die Casting Impact Properties

    David Schwam; John F. Wallace; Yulong Zhu; Srinath Viswanathan; Shafik Iskander


    % in AM50 to over 9% in AZ91, more of the intermetallic Mg17Al12 is formed in the microstructure. For instance, for 15 increase in the aluminum content from AM50 to AM60, the volume fraction of eutectic present in the microstructure increases by 35%! Eventually, the brittle Mg17Al12 compound forms an interconnected network that reduces ductility and impact resistance. The lower aluminum in AM50 and AM60 are therefore a desirable feature in applications that call for higher impact resistance. Further improvement in impact resistance depends on the processing condition of the casting. Sound castings without porosity and impurities will have better mechanical properties. Since magnesium oxidizes readily, good melting and metal transfer practices are essential. The liquid metal has to be protected from oxidation at all times and entrainment of oxide films in the casting needs to be prevented. In this regard, there is evidence that us of vacuum to evacuate air from the die casting cavity can improve the quality of the castings. Fast cooling rates, leading to smaller grain size are beneficial and promote superior mechanical properties. Micro-segregation and banding are two additional defect types often encountered in magnesium alloys, in particular in AZ91D. While difficult to eliminate, segregation can be minimized by careful thermal management of the dies and the shot sleeve. A major source of segregation is the premature solidification in the shot sleeve. The primary solid dendrites are carried into the casting and form a heterogeneous structure. Furthermore, during the shot, segregation banding can occur. The remedies for this kind of defects include a hotter shot sleeve, use of insulating coatings on the shot sleeve and a short lag time between pouring into the shot sleeve and the shot.

  20. Die design and process optimization of die cast V6 engine blocks


    The use of aluminum, particularly for engine blocks, has grown considerably in the past ten years, and continues to rise in the automotive industry. In order to enhance the quality and engineering functionality of die cast engine blocks, die design and processes have to be optimized. In this study, a computer simulation software,MAGMAsoft, as an advanced tool for optimizing die design and casting process, was employed to virtually visualize cavity filling and patterns of a V6 engine block. The original die design and process was simulated first to establish a baseline.A reality check was used to verifythe predicted results. Then, the die modification with a different runner system was made by using a CAD software, Unigraphics (UG). The simulation on combinations of the modified die design and revised process was performed to examine the effect of die modification and process change on flow filling of V6 engine blocks. The simulated prediction indicates that the enhancement of cavity filling due to the die and process modification minimizes the occurrence of defects during casting, and consequently improves the quality of blocks. The results of mechanical testing show a significant increase in fatigue strengths, and a moderately improvement on tensile properties for the blocks die cast with the new die design and process in comparison with those produced by the original ones.

  1. Evaluation of permanent die coatings to improve the wear resistance of die casting dies. Final project report, January 1, 1995--April 30, 1997

    Shivpuri, R.


    Die Casting dies are subject to severe service conditions during the die casting operation. While these severe conditions are necessary to achieve high production rates, they cause the dies which are commonly made of H13 die steel, to suffer frequent failures. The major die failure mechanisms are erosion or washout, Heat checking, soldering and corrosion. Due to their geometrical complexity, die casting dies are very expensive (some dies cost over a million dollars), and thus a large number of parts have to be produced by a die, to justify this cost and leverage the advantages of the die casting process (high production rates, low manpower costs). A potential increase in the die service life, thus has a significant impact on the economics of the die; casting operation. There are many ways to extend die life: developing new wear resistant die materials, developing new surface treatments including coatings, improving heat treatment of existing H13 dies, using better lubricants that can protect the die material, or modifying the die geometry and process parameters to reduce the intensity of wear. Of these the use of coatings to improve the wear resistance of the die surface has shown a lot of promise. Consequently, use of coatings in the die casting industry and their wide use to decrease die wear can improve significantly the productivity of shop operations resulting in large savings in material and energy usage.

  2. New trends in cold-chamber die casting machine design

    R. Dańko


    Full Text Available Larger and larger proportions of aluminium castings, especially those produced by the die casting process, can be observed during recent years in the automotive industry, house-hold articles and others. In case of the automotive industry, apart from the traditional elements produced by the die pressure method such as engine blocks or crank shaft bedplates, aluminium is displacing steel from structural parts of cars (‘body in white’. The current state and development directions of the structural solutions of cold-chamber die castings are analysed in this paper. These solutions drive the prospective development of these machines and die casting technology. The focus is mainly on essential functional systems such as: hydraulic drives of closing and locking units, as well as pressing in die machines of known companies present on the European market.

  3. New trends in cold-chamber die casting machine design

    R. Dańko; W. Kowalczyk


    Larger and larger proportions of aluminium castings, especial y those produced by the die casting process, can be observed during recent years in the automotive industry, house-hold articles and others. In case of the automotive industry, apart from the traditional elements produced by the die pressure method such as engine blocks or crank shaft bedplates, aluminium is displacing steel from structural parts of cars (‘body in white’). The current state and development directions of the structural solutions of cold-chamber die castings are analysed in this paper. These solutions drive the prospective development of these machines and die casting technology. The focus is mainly on essential functional systems such as:hydraulic drives of closing and locking units, as wel as pressing in die machines of known companies present on the European market.

  4. Evaluation of porosity in Al alloy die castings

    M. Říhová


    Full Text Available Mechanical properties of an Al-alloy die casting depend significantly on its structural properties. Porosity in Al-alloy castings is one of the most frequent causes of waste castings. Gas pores are responsible for impaired mechanical-technological properties of cast materials. On the basis of a complex evaluation of experiments conducted on AlSi9Cu3 alloy samples taken from the upper engine block which was die- cast with and without local squeeze casting it can be said that castings manufactured without squeeze casting exhibit maximum porosity in the longitudinal section. The area without local squeeze casting exhibits a certain reduction in mechanical properties and porosity increased to as much as 5%. However, this still meets the norms set by SKODA AUTO a.s.

  5. Die casting die deflections: Prediction and attenuation. Final report, July 1, 1995--September 30, 1997

    Miller, R.A.; Ahuett-Garza, H.; Choudhury, A.K.; Dedhia, S.


    This report summarizes two years of research intended to develop methods to model and predict the deflection patterns in die casting dies. No comprehensive analysis of this type had previously been completed. The die casting process is complex and involves numerous mechanical and thermal phenomena that effect the mechanical behavior of the die. A critical activity in this work was sorting out and evaluating the relative contributions of the various mechanisms to die deflections. This evaluation was accomplished through a series of simple engineering analyses based primarily on the order of magnitude of the influence of each load considered on die deflections. A modeling approach incorporating commercially available finite element analysis software was developed and tested. The model evolved by testing simple models against more comprehensive models and against the limited experimental data that is available. The development of the modeling approach lead to consideration of the die casting machine in more detail than was originally anticipated. The machine is critical and cannot be ignored. A simplified model described as a spring/platen model was developed to account for the machine platens, tie bars, and toggles. The characteristics of this model are described and predictions based on this model are compared against full machine models and measured deflections of machine platens. Details of the modeling approach and the various case studies are provided in the report and in several publications that have resulted from the work.

  6. Die casting process assessment using single minute exchange of dies (SMED method

    M. Perinić


    Full Text Available Die casting process uses high productive level machines. Machine capacity utilization is a key goal in achieving minimum time consumption. Changeover procedure during die casting process is recognized as possible area for reducing time consumption. The SMED method has been improved by additional procedures simultaneously applying the 5S method. Their contribution is evident in recognition of internal and external activities, particularly while transferring internal activities into external ones in as many numbers as possible, by minimizing at the same moment the internal ones. The validity of the method and procedures are verified by an example application of die casting foundry for casting automobile parts. Significant time savings have been achieved with minimum investment.


    M.F.V.T. Pereira


    Full Text Available

    ENGLISH ABSTRACT: A number of laser additive manufacturing (LAM technologies can produce fully-dense metal components that potentially offer opportunities to apply the technology in die or mould making (known as rapid tooling. From these LAM technologies, three were selected for evaluation of their suitability as die cavity inserts in the manufacture of high pressure die-casting (HPDC dies. Apart from comparing the different LAM inserts with one another, their performance was also compared with components manufactured in a standard hot work steel. In the HPDC process, the die is unique to each component to be produced. Die cavities in particular are subjected to demanding conditions, such as cyclic heating caused by the introduction of molten aluminium at over 650°C, followed by cooling in water-based die release medium at temperatures around 25°C. Besides cyclic heating, the die cavities are also exposed to pressures exceeding 1500 MPa during the injection of molten aluminium into the cavities. This application of LAM, therefore, poses extreme challenges to the technology. The results of this study confirmed that the metals used in some of the LAM technologies did indeed meet the demanding requirements of the current application, and can lead to significant time- and cost-saving during product or process developments. Based on these findings, a number of recommendations are made for users interested in the application of LAM to produce die cavities.

    AFRIKAANSE OPSOMMING: ’n Aantal laser laagvervaardigingstegnologieë (LLV tegnolgieë is in staat om volledig digte metaalkomponente te lewer, wat tot gevolg het dat hierdie tegnologie potensieel vir vormingsmatrys- of gietmatrysvervaardiging gebruik kan word (bekend as snelgereedskap. Drie van hierdie LLV tegnologieë is gekies vir evaluasie van hulle geskiktheid as gietvorminsetsels tydens die vervaardiging van gietmatryse vir hoë druk matrysgiet (HDMG. Benewens die onderlinge

  8. Microstructures and properties of aluminum die casting alloys

    M. M. Makhlouf; D. Apelian; L. Wang


    This document provides descriptions of the microstructure of different aluminum die casting alloys and to relate the various microstructures to the alloy chemistry. It relates the microstructures of the alloys to their main engineering properties such as ultimate tensile strength, yield strength, elongation, fatigue life, impact resistance, wear resistance, hardness, thermal conductivity and electrical conductivity. Finally, it serves as a reference source for aluminum die casting alloys.

  9. Successful Asia-Pacific Die Casting Industry Exhibition'2005


    @@ Upon the expectation of practitioners in the die casting industry, the Asia-Pacific Die Casting Industry Exhibition'2005, sponsored by Chinese Mechanical Engineering Society (CMES) and China Productivity Promotion Center of Machinery Industry, organized by Foundry Institution of Chinese Mechanical Engineering Society (FICMES) and Productivity Promotion Center of Foundry Industry of China, was successfully held in INTEX Shanghai, China on August 13-17,2005.

  10. Optimization of die filling in high pressure die cast part using MAGMAsoft®

    Kotas, Petr; Hattel, Jesper Henri


    using the commercial software code MAGMAsoft®. The first process analysis revealed problems and defects of the casting which were cold shuts and out-of plane distortions. Secondly adjustment in the geometry of the casting and the gating system were carried out and evaluated. Last, modifications...... in the process and machine parameters were done and assessed. All simulations revealed that, the main causes of the problems were: a poor geometry of the casting leading to an improper filling pattern, and a massive gating system bringing thermal imbalance into the solidification process. Thus deformations due......Integrated modeling of an entire casting process has become a tool which favors design and optimization of manufactured parts. The aim of this project was to examine and optimize a high-pressure die cast part and its production process with respect to die filling and issues of residual stresses...

  11. Effect of Some Parameters on the Cast Component Properties in Hot Chamber Die Casting

    Singh, Rupinder; Singh, Harvir


    Hot chamber die casting process is designed to achieve high dimensional accuracy for small products by forcing molten metal under high pressure into reusable moulds, called dies. The present research work is aimed at study of some parameters (as a case study of spring adjuster) on cast component properties in hot chamber die casting process. Three controllable factors of the hot chamber die casting process (namely: pressure at second phase, metal pouring temperature and die opening time) were studied at three levels each by Taguchi's parametric approach and single-response optimization was conducted to identify the main factors controlling surface hardness, dimensional accuracy and weight of the casting. Castings were produced using aluminium alloy, at recommended parameters through hot chamber die casting process. Analysis shows that in hot chamber die casting process the percentage contribution of second phase pressure, die opening time, metal pouring temperature for surface hardness is 82.48, 9.24 and 6.78 % respectively. While in the case of weight of cast component the contribution of second phase pressure is 94.03 %, followed by metal pouring temperature and die opening time (4.58 and 0.35 % respectively). Further for dimensional accuracy contribution of die opening time is 76.97 %, metal pouring temperature is 20.05 % and second phase pressure is 1.56 %. Confirmation experiments were conducted at an optimal condition showed that the surface hardness, dimensional accuracy and weight of the castings were improved significantly.

  12. Technological parameters of die casting and quality of casting from EN AC46500 alloy


    Die casting represents the highest technological level of metal mold casting. This technology enables production of almost all final products without necessity of further processing. The important aspect of efficiency and production is a proper casting parameters setting. In the submitted paper following die casting parameters are analyzed: plunger pressing speed and pressure. The studied parameters most significantly affect a qualitative of castings from EN AC46500 alloy and they influence t...

  13. Strength Estimation of Die Cast Beams Considering Equivalent Porous Defects

    Park, Moon Shik [Hannam Univ., Daejeon (Korea, Republic of)


    As a shop practice, a strength estimation method for die cast parts is suggested, in which various defects such as pores can be allowed. The equivalent porosity is evaluated by combining the stiffness data from a simple elastic test at the part level during the shop practice and the theoretical stiffness data, which are defect free. A porosity equation is derived from Eshelby's inclusion theory. Then, using the Mori-Tanaka method, the porosity value is used to draw a stress-strain curve for the porous material. In this paper, the Hollomon equation is used to capture the strain hardening effect. This stress-strain curve can be used to estimate the strength of a die cast part with porous defects. An elastoplastic theoretical solution is derived for the three-point bending of a die cast beam by using the plastic hinge method as a reference solution for a part with porous defects.

  14. Die Casting Mold Design for Aluminum Alloy Shell of Instrument

    Li Yuanyuan


    Full Text Available This paper is about die casting mold design for aluminum alloy shell of instrument. Three-dimensional model of the casting and mold are designed by using Pro/Engineer and AutoCad which can analyze forming quality. Digital design and theoretical calculation can greatly shorten product development cycle and mold design cycle, improve the accuracy of product design and mold design, and reduce the cost of mold design.

  15. Die casting die deflections: Prediction and attenuation. Final report, July 1, 1995--September 30, 1997

    Miller, R.Allen; Ahuett-Garza, Horacio; Choudhury, Aswin K.; Dedhia, Sanjay


    The objective of this work was to develop and test die casting design evaluation techniques based on the visualization of geometric data that is related to potential defects or problems. Specifically, thickness information is used to provide insight into potential thermal problems in the part and die. Distance from the gate and a special type of animation of the fill pattern is used to provide an assessment of gate, vent and overflow locations. Techniques have been developed to convert part design information in the form of STL files to a volume-based representation called a voxel model. The use of STL files makes the process CAD system independent. Once in voxel form, methods that were developed in this work are used to identify thick regions in the part, thin regions in the part and/or die, distance from user specified entry locations (gates), and the qualitative depiction of the fill pattern. The methods were tested with a prototype implementation on the UNIX platform. The results of comparisons with numerical simulation and field reported defects were surprisingly good. The fill-related methods were also compared against short-shots and a water analog study using high speed video. The report contains the results of the testing plus detailed background material on the construction of voxel models, the methods used for displaying results, and the computational geometric reasoning methods used to create die casting-related information from the voxel model for display to the user.

  16. Temperature change and stress distribution analysis of die surface in Al-alloy die casting process and experimental study on die heat check

    Hu Xinping; Zhao Guoqun; Wu Bingyao


    The temperature change of the die surface in practical aluminum alloy die casting process was analyzed,and a 2D model was formulated on the basis of a deep concave round cavity without sliding core to analyze the stress distributions along the die surface in detail. Equipment was designed to test the thermal state of the die steel in different thermal loading conditions. The results of stress analysis showed that, the value of thermal stress (maximum 1.5 GPa) caused in the die filling and die spraying stages was larger than the mechanical stress (maximum 85 MPa)caused in the die locking stage. The results of the thermal check experiment showed that there were three stages of die dissolving, and that the stress distribution shown by the samples' cracking routine was close to the die surface stress analysis.

  17. Determination of the metal/die interfacial heat transfer coefficient of high pressure die cast B390 alloy

    Cao, Yongyou; Guo, Zhipeng; Xiong, Shoumei


    High-pressure die cast B390 alloy was prepared on a 350 ton cold chamber die casting machine. The metal/die interfacial heat transfer coefficient of the alloy was investigated. Considering the filling process, a "finger"-shaped casting was designed for the experiments. This casting consisted of five plates with different thicknesses (0.05 inch or 1.27 mm to 0.25 inch or 6.35 mm) as well as individual ingates and overflows. Experiments under various operation conditions were conducted, and temperatures were measured at various specific locations inside the die. Based on the results, the interfacial heat transfer coefficient and heat flux were determined by solving the inverse heat transfer problem. The influence of the mold-filling sequence, sensor locations, as well as processing parameters including the casting pressure, die temperature, and fast/slow shot speeds on the heat transfer coefficient were discussed.

  18. Technological parameters of die casting and quality of casting from EN AC46500 alloy

    Š. Gašpár


    Full Text Available Die casting represents the highest technological level of metal mold casting. This technology enables production of almost all final products without necessity of further processing. The important aspect of efficiency and production is a proper casting parameters setting. In the submitted paper following die casting parameters are analyzed: plunger pressing speed and pressure. The studied parameters most significantly affect a qualitative of castings from EN AC46500 alloy and they influence the most a gained porosity level as well as basic mechanical properties represented by permanent deformations.

  19. An optimization of injecting system in die casting


    After many years of development, die casting technology of metallic materials has been matured. In this paper,the lower-support and its injecting system were created with commercial software. And then the simulation software FLOW3D was applied to study the flow behavior of the melt during injection filling process. Both temperature field and defect distribution were simulated. Based on these results, the better injecting system with two additional overflows was adopted.

  20. Energy and resource efficiency in aluminium die casting

    Heinemann, Tim


    This monograph provides a field-proven approach to analyze industrial production with a cross-company scope as well as regarding all hierarchical system levels of manufacturing enterprises. The book exemplifies this approach in the context of aluminum  die casting, and presents a set of measures which allow a 30 percent energy reduction along the value chain. The target audience primarily comprises researchers and experts in the field but the book may also be beneficial for graduate students.

  1. An optimization of injecting system in die casting

    Wei WU


    Full Text Available After many years of development, die casting technology of metallic materials has been matured. In this paper,the lower-support and its injecting system were created with commercial software. And then the simulation software FLOW3D was applied to study the flow behavior of the melt during injection filling process. Both temperature field and defect distribution were simulated. Based on these results, the better injecting system with two additional overflows wasadopted.

  2. Processing Technology and Mechanical Properties of Die-Cast Magnesium Alloy AZ91D

    LIU Yan'gai(刘艳改); LIU Wenhui(刘文辉); XIONG Shoumei(熊守美); LIU Baicheng(柳百成); Wang Gang (王罡); MATSUMOTO Yoshihide; MURAKAMI Masayuki


    The mechanical properties of magnesium die-casting components can be improved with improved die-casting processing technology. An orthogonal experiment with four factors and three levels (Lq, 34) was used to evaluate the effect of various die-casting processing parameters on the quality and mechanical properties of an AZ91D magnesium alloy cylinder head cover component. The results show that the injection speed and casting and die temperatures all influence the component quality, with the influence of the casting pressure being the smallest. The injection speed and casting pressure are the two most important factors influencing the tensile strength. The best die-casting parameters for the magnesium alloy cylinder head cover component were determined to be a casting temperature of 660℃, a die temperature of 200℃, an injection speed of 70 ms(1, and a casting pressure of 65 MPa. The porosity is one of the most important parameters influencing the casting strength.

  3. High pressure die casting of Fe-based metallic glass

    Ramasamy, Parthiban; Szabo, Attila; Borzel, Stefan; Eckert, Jürgen; Stoica, Mihai; Bárdos, András


    Soft ferromagnetic Fe-based bulk metallic glass key-shaped specimens with a maximum and minimum width of 25.4 and 5 mm, respectively, were successfully produced using a high pressure die casting (HPDC) method, The influence of die material, alloy temperature and flow rate on the microstructure, thermal stability and soft ferromagnetic properties has been studied. The results suggest that a steel die in which the molten metal flows at low rate and high temperature can be used to produce completely glassy samples. This can be attributed to the laminar filling of the mold and to a lower heat transfer coefficient, which avoids the skin effect in the steel mold. In addition, magnetic measurements reveal that the amorphous structure of the material is maintained throughout the key-shaped samples. Although it is difficult to control the flow and cooling rate of the molten metal in the corners of the key due to different cross sections, this can be overcome by proper tool geometry. The present results confirm that HPDC is a suitable method for the casting of Fe-based bulk glassy alloys even with complex geometries for a broad range of applications.

  4. Numerical simulation of low pressure die-casting aluminum wheel

    Mi Guofa; Liu Xiangyu; Wang Kuangfei; Fu Hengzhi


    The FDM numerical simulation software, ViewCast system, was employed to simulate the low pressure die casting (LPDC) of an aluminum wheel. By analyzing the mold-filling and solidification stage of the LPDC process, the distribution of liquid fraction, temperature field and solidification pattern of castings were studied. The potential shrinkage defects were predicted to be formed at the rim/spoke junctions, which is in consistence with the X-ray detection result. The distribution pattern of the defects has also been studied. A solution towards reducing such defects has been presented. The cooling capacity of the mold was improved by installing water pipes both in the side mold and the top mold. Analysis on the shrinkage defects under forced cooling mode proved that adding the cooling system in the mold is an effective method for reduction of shrinkage defects.

  5. Development of Thin Section Zinc Die Casting Technology

    Goodwin, Frank [International Lead Zinc Research Org., Inc., Durham, NC (United States)


    A new high fluidity zinc high pressure die casting alloy, termed the HF alloy, was developed during laboratory trials and proven in industrial production. The HF alloy permits castings to be achieved with section thicknesses of 0.3 mm or less. Technology transfer activities were conducted to develop usage of the HF high fluidity alloy. These included production of a brochure and a one-hour webinar on the HF alloy. The brochure was then sent to 1,184 product designers in the Interzinc database. There was excellent reception to this mailing, and from this initial contact 5 technology transfer seminars were conducted for 81 participants from 30 companies across a wide range of business sectors. Many of the successful applications to date involve high quality surface finishes. Design and manufacturing assistance was given for development of selected applications.

  6. The Effects of Externally Solidified Product on Wave Celerity and Quality of Die Cast Products

    Carroll Mobley; Yogeshwar Sahai; Jerry Brevick


    The cold chamber die casting process is used to produce essentially all the die cast aluminum products and about 50% of the die cast magnesium products made today. Modeling of the cold chamber die casting process and metallographic observations of cold chamber die cast products indicate that typically 5 to 20% of the shot weight is solidified in the shot sleeve before or during cavity filling. The protion of the resulting die casting which is solidified in the shot sleeve is referred to as externally solidified product, or, when identified as a casting defect, as cold flakes. This project was directed to extending the understanding of the effects of externally solidified product on the cold chamber die casting process and products to enable the production of defect-free die castings and reduce the energy associated with these products. The projected energy savings from controlling the fraction of externally solidified product in die cast components is 40 x 10 Btu through the year 2025.

  7. A comparison of the accuracy of two removable die systems with intact working casts.

    Aramouni, P; Millstein, P


    This study evaluated the reproducibility of die position using two removable die systems and two die stones. Poly(vinyl siloxane) impressions were made of a stainless steel, U-shaped arch with four evenly spaced abutments. Six groups were evaluated: Zeiser system/Fuji Rock; Zeiser system/Die Keen; solid cast/Fuji Rock; solid cast/Die Keen; Fuji Rock/Pindex; and Die Keen/Pindex. An optical comparator was used to measure the height of each abutment, the distance between the anterior abutments, and the distance between the posterior abutments. The Zeiser system with either Fuji Rock or Die Keen yielded the greatest accuracy. Die Keen exhibited more linear expansion than Fuji Rock, and solid casts had less distortion than the Pindex system.

  8. Die binding van die konfessie

    P. J. Coetzee


    Full Text Available Ons moet waak teen twee uiterstes. Aan die een kant het die dogma as onversoenlike vyand die dogmatisme en aan die ander kant die antidogmatisme — dit hou enersyds die gevaar in van verabsolutering (oorskatting, en ander- syds die gevaar van relativisme (onderskatting.

  9. Die instelling van die doop

    J. L. Venter


    Full Text Available Die eerste plek in die evangeliebeskrywings waar daar van die doop as ’n opdrag van Jesus Christus gepraat word en waar die betekenis die duidelikste uitkristalliseer, staan in Matteus 28 : 16 - 20. Heilshistories gesien, is dit die begin van kerklike inlywing van die wat gehoor het hoedat Jesus sy koninkryk proklameer, die evangelie aanvaar en tot bekering kom. Vir die doel van hierdie artikel word hierdie gedeelte ondersoek om te sien hoe die instelling geskied het, wat die plek en betekenis van die Christelike doop is.

  10. Application of laser additive manufacturing to produce dies for aluminium high pressure die casting

    Pereira, MFVT


    Full Text Available to significant time- and cost-saving during product or process developments. Based on these findings, a number of recommendations are made for users interested in the application of LAM to produce die cavities....

  11. Reducing non value adding aluminium alloy in production of parts through high pressure die casting

    Pereira, MFVT


    Full Text Available The difficulties and issues associated with the economics of the process and die life in casting Aluminium alloys, as experienced by the high pressure die casting industry, were reasons behind undertaking this research project. The use of a tungsten...

  12. Die topkwark

    R. Tegen


    Full Text Available ’n Oorsig van die belangrikheid van die onlangs ontdekte topkwark by Fermilab in Chicago word gegee. Daar word aangetnon dat die topkwark belangrik is in fisika van die Oerknal, oftewel "Big Bang", en in die Standaard Model van Elementêredeeltjie-fisika. Toepaslike literatuur vir verdere studie kan van die lys van verwysings in hierdie kort, nietegniese artikel, nagegaan word.

  13. Simple visualization techniques for die casting part and die design. Final report, July 1, 1995--September 30, 1997

    Miller, R.A.; Lu, S.C.; Rebello, A.B.


    The objective of this work was to develop and test die casting design evaluation techniques based on the visualization of geometric data that is related to potential defects of problems. Specifically, thickness information is used to provide insight into potential thermal problems in the part and die. Distance from the gate and a special type of animation of the fill pattern is used to provide an assessment of gate, vent and overflow locations. Techniques have been developed to convert part design information in the form of STL files to a volume-based representation called a voxel model. The use of STL files makes the process CAD system independent. Once in voxel form, methods that were developed in this work are used to identify thick regions in the part, thin regions in the part and/or die, distance from user specified entry locations (gates), and the qualitative depiction of the fill pattern. The methods were tested with a prototype implementation on the UNIX platform. The results of comparisons with numerical simulation and field reported defects were surprisingly good. The fill-related methods were also compared against short-shots and a water analog study using high speed video. The report contains the results of the testing plus detailed background material on the construction of voxel models, the methods used for displaying results, and the computational geometric reasoning methods used to create die casting-related information form the voxel model for display to the user.

  14. Simple visualization techniques for die casting part and die design. Final report, July 1, 1995--September 30, 1997

    Miller, R.A.; Lu, S.C.; Rebello, A.B.


    The objective of this work was to develop and test die casting design evaluation techniques based on the visualization of geometric data that is related to potential defects of problems. Specifically, thickness information is used to provide insight into potential thermal problems in the part and die. Distance from the gate and a special type of animation of the fill pattern is used to provide an assessment of gate, vent and overflow locations. Techniques have been developed to convert part design information in the form of STL files to a volume-based representation called a voxel model. The use of STL files makes the process CAD system independent. Once in voxel form, methods that were developed in this work are used to identify thick regions in the part, thin regions in the part and/or die, distance from user specified entry locations (gates), and the qualitative depiction of the fill pattern. The methods were tested with a prototype implementation on the UNIX platform. The results of comparisons with numerical simulation and field reported defects were surprisingly good. The fill-related methods were also compared against short-shots and a water analog study using high speed video. The report contains the results of the testing plus detailed background material on the construction of voxel models, the methods used for displaying results, and the computational geometric reasoning methods used to create die casting-related information from the voxel model for display to the user.

  15. Application of High-Temperature Mold Materials to Die Cast Copper Motor Rotor for Improved Efficiency

    John G. Cowie; Edwin F. Brush, Jr.; Dale T. Peters; Stephen P. Midson; Darryl J. Van Son


    The objective of the study, Application of High-Temperature Mold Materials to Die Cast Copper Motor Rotor for Improved Efficiency, was to support the Copper Development Association (CDA) in its effort to design, fabricate and demonstrate mold technologies designed to withstand the copper motor rotor die casting environment for an economically acceptable life. The anticipated result from the compiled data and tests were to: (1) identify materials suitable for die casting copper, (2) fabricate motor rotor molds and (3) supply copper rotor motors for testing in actual compressor systems. Compressor manufacturers can apply the results to assess the technical and economical viability of copper rotor motors.

  16. Understanding the Relationship Between Filling Pattern and Part Quality in Die Casting

    Jerald Brevick; R. Allen Miller


    The overall objective of this research project was to investigate phenomena involved in the filling of die cavities with molten alloy in the cold chamber die-casting process. It has long been recognized that the filling pattern of molten metal entering a die cavity influences the quality of die-cast parts. Filling pattern may be described as the progression of molten metal filling the die cavity geometry as a function of time. The location, size and geometric configuration of points of metal entry (gates), as well as the geometry of the casting cavity itself, have great influence on filling patterns. Knowledge of the anticipated filling patterns in die-castings is important for designers. Locating gates to avoid undesirable flow patterns that may entrap air in the casting is critical to casting quality - as locating vents to allow air to escape from the cavity (last places to fill). Casting quality attributes that are commonly flow related are non-fills, poor surface finish, internal porosity due to trapped air, cold shuts, cold laps, flow lines, casting skin delamination (flaking), and blistering during thermal treatment.


    A. A. Pivovarchyk


    Full Text Available The paper presents the results of a study on the effect of a method for dispersing the size of the component of the dispersed phase separation coatings used in high pressure die casting aluminum alloys.


    A. Pivovarchik


    Full Text Available The paper presents the results of research on the study of the possibility of accumulation of the lubricating layer coating on the surface of the separation process of foundry equipment with high pressure die casting aluminum alloys.

  19. Aluminium Foam and Magnesium Compound Casting Produced by High-Pressure Die Casting

    Iban Vicario


    Full Text Available Nowadays, fuel consumption and carbon dioxide emissions are two of the main focal points in vehicle design, promoting the reduction in the weight of vehicles by using lighter materials. The aim of the work is to evaluate the influence of different aluminium foams and injection parameters in order to obtain compound castings with a compromise between the obtained properties and weight by high-pressure die cast (HPDC using aluminium foams as cores into a magnesium cast part. To evaluate the influence of the different aluminium foams and injection parameters on the final casting products quality, the type and density of the aluminium foam, metal temperature, plunger speed, and multiplication pressure have been varied within a range of suitable values. The obtained compound HPDC castings have been studied by performing visual and RX inspections, obtaining sound composite castings with aluminium foam cores. The presence of an external continuous layer on the foam surface and the correct placement of the foam to support injection conditions permit obtaining good quality parts. A HPDC processed magnesium-aluminium foam composite has been developed for a bicycle application obtaining a suitable combination of mechanical properties and, especially, a reduced weight in the demonstration part.

  20. Heat Transfer between Casting and Dieduring High Pressure Die Casting Process of AM50 Alloy-Modeling and Experimental Results


    A method based on die casting experiments and mathematic modeling is presented for the determination of the heat flow density (HFD) and interfacial heat transfer coefficient (IHTC) during the high pressure die casting (HPDC) process. Experiments were carried out using step shape casting and a commercial magnesium alloy, AM50. Temperature profiles were measured and recorded using thermocouples embedded inside the die.Based on these temperature readings, the HFD and IHTC were successfully determined and the calculation results show that the HFD and IHTC at the metal-die interface increases sharply right after the fast phase injection process until approaching their maximum values, after which their values decrease to a much lower level until the dies are opened. Different patterns of heat transler behavior were found between the die and the castingat different thicknesses. The thinner the casting was, the more quickly the HFD and IHTC reached their steady states. Also, the values for both the HFD and IHTC values were different between die and casting at different thicknesses.

  1. Study on interfacial heat transfer coefficient at metal/die interface during high pressure die casting process of AZ91D alloy

    GUO Zhi-peng


    Full Text Available The high pressure die casting (HPDC process is one of the fastest growing and most efficient methods for the production of complex shape castings of magnesium and aluminum alloys in today’s manufacturing industry.In this study, a high pressure die casting experiment using AZ91D magnesium alloy was conducted, and the temperature profiles inside the die were Measured. By using a computer program based on solving the inverse heat problem, the metal/die interfacial heat transfer coefficient (IHTC was calculated and studied. The results show that the IHTC between the metal and die increases right after the liquid metal is brought into the cavity by the plunger,and decreases as the solidification process of the liquid metal proceeds until the liquid metal is completely solidified,when the IHTC tends to be stable. The interfacial heat transfer coefficient shows different characteristics under different casting wall thicknesses and varies with the change of solidification behavior.

  2. Focusing on Technology and Services, Competing in China Die Casting Market Report on visits with five companies participating in the Asia-Pacific Die Casting Industry Exhibition 2005


    @@ The Asia-Pacific Die Casting Industry Exhibition 2005, organized by Foundry Institution of Chinese Mechanical Engineering Society (FICMES), was held in INTEX Shanghai, China on August 14-17, 2005. On August 16th, the journalists of CHINA FOUNDRY journal visited five exhibitors on the spot of exhibition.

  3. New Trends of Die Casting Market in China——A Commentary on the 5th China International Die Casting Exhibition

    QU Xue-liang


    @@ The 5th China International Die Casting Exhibition, sponsored by Chinese Mechanical Engineering Society (CMES) and China Productivity Promotion Center of Machinery Industry, organized by Foundry Institution of Chinese Mechanical Engineering Society (FICMES) and China Productivity Promotion Center of Foundry Industry, was successfully held on June 28 to July 1,2006 in INTEX Shanghai, China.

  4. Design of Semi-Solid Die Casting Die for Box Shell and its Die Casting%盒体铸件半固态压铸模及压铸工艺研究

    赵艳红; 姚国海; 王淼


    设计并制造出盒体半固态压铸模,利用Flow-3D模拟软件对盒体半固态流变压铸充型及凝固过程进行了数值模拟,并进行了试验验证.结果表明,半固态压铸过程中,模具温度对半固态压铸影响较大.经过模拟优化的半固态压铸工艺参数:压射速度为1 m/s,模具预热温度为260℃,浆料温度为590℃.%The semi-solid die casting die for box shell was designed and manufactured.By using Flow-3D software,the filling and solidification process of semi-solid rheological die-casting was simulated,and verification experiment was conducted.The results show that the temperature of die has the obvious effects on semi-solid die casting process.The optimized parameters for semi-solid die casting were presented as follows:injection velocity of 1 m/s,pre-heating temperature of mould at 260 ℃ and slurry temperature of 590 ℃.

  5. Modelling the Cast Component Weight in Hot Chamber Die Casting using Combined Taguchi and Buckingham's π Approach

    Singh, Rupinder


    Hot chamber (HC) die casting process is one of the most widely used commercial processes for the casting of low temperature metals and alloys. This process gives near-net shape product with high dimensional accuracy. However in actual field environment the best settings of input parameters is often conflicting as the shape and size of the casting changes and one have to trade off among various output parameters like hardness, dimensional accuracy, casting defects, microstructure etc. So for online inspection of the cast components properties (without affecting the production line) the weight measurement has been established as one of the cost effective method (as the difference in weight of sound and unsound casting reflects the possible casting defects) in field environment. In the present work at first stage the effect of three input process parameters (namely: pressure at 2nd phase in HC die casting; metal pouring temperature and die opening time) has been studied for optimizing the cast component weight `W' as output parameter in form of macro model based upon Taguchi L9 OA. After this Buckingham's π approach has been applied on Taguchi based macro model for the development of micro model. This study highlights the Taguchi-Buckingham based combined approach as a case study (for conversion of macro model into micro model) by identification of optimum levels of input parameters (based on Taguchi approach) and development of mathematical model (based on Buckingham's π approach). Finally developed mathematical model can be used for predicting W in HC die casting process with more flexibility. The results of study highlights second degree polynomial equation for predicting cast component weight in HC die casting and suggest that pressure at 2nd stage is one of the most contributing factors for controlling the casting defect/weight of casting.

  6. Study on Numerical Simulation of Mold Filling and HeatTransfer in Die Casting Process


    A 3-D mathematical model considering turbulence phenomena has been established basedon a computational fluid dynamics technique, so called 3-D SOLA-VOF (Solution Algorithm-Volume of Fluid), to simulate the fluid flow of mold filling process of die casting. In addition, the mathematical model for simulating the heat transfer in die casting process has also been established.The computation program has been developed by the authors with the finite difference method (FDM) recently. As verification, the mold filling process of a S-shaped die casting has been simulated and the simulation results coincide with that of the benchmark test. Finally, as a practical application, the gating design of a motorcycle component was modified by the mold filling simulation and the dies design of another motorcycle component was optimized by theheat transfer simulation. All the optimized designs were verified by the production practice.

  7. Die menswaardigheid van die menslike embrio : die debat tot dusver

    Vorster, J.M


    ...), "Stem cell research: the ethical issues". Rakende die gebruik van menslike embrio's in stamselnavorsing, behandel hierdie artikels die potensiaal van die menslike embrio, die morele status (menswaardigheid...

  8. Die Casting Mold Design of the Thin-walled Aluminum Case by Computational Solidification Simulation

    Young-Chan Kim; Chang-Seog Kang; Jae-Ik Cho; Chang-Yeol Jeong; Se-Weon Choi; Sung-Kil Hong


    Recently, demand for the lightweight alloy in electric/electronic housings has been greatly increased. However, among the lightweight alloys, aluminum alloy thin-walled die casting is problematic because it is quite difficult to achieve sufficient fluidity and feedability to fill the thin cavity as the wall thickness becomes less than 1 mm. Therefore, in this study, thin-walled die casting of aluminum (Al-Si-Cu alloy: ALDC 12) in size of notebook computer housing and thickness of 0.8 mm was investigated by solidification simulation (MAGMA soft) and actual casting experiment (Buhler Evolution B 53D). Three different types of gating design, finger, tangential and split type with 6 vertical runners, were simulated and the results showed that sound thin-walled die casting was possible with tangential and split type gating design because those gates allowed aluminum melt to flow into the thin cavity uniformly and split type gating system was preferable gating design comparing to tangential type gating system at the point of view of soundness of casting and distortion generated after solidification. Also, the solidification simulation agreed well with the actual die-casting and the casting showed no casting defects and distortion.

  9. Design of Die-casting Die and Analysis of Die Distortion%压铸模具设计及其变形分析

    潘宏歌; 魏家鹏


    The port plate was technologically analysed and the its die-casting mold was designed. By using Pro/Mechanic, which was the structural analysis module of Pro/E, the distortion induced by multi-stress in the working of the dies was analyzed. The results show that the die distortion is caused by the dilating force and thermal stress generated by the temperature load, and temperature load is the dominant factor leading to the mold deformation.%以配流盘为例,对其进行工艺分析,并设计压铸模具.同时,利用Pro/E软件的结构分析模块Pro/Mechanic,对模具在工作中承受的多方应力所产生的变形情况进行了分析.结果表明,胀型力和温度载荷所产生的热应力均会引起模具变形,其中,温度载荷是导致模具变形的主导因索.

  10. High Density Die Casting (HDDC): new frontiers in the manufacturing of heat sinks

    Sce, Andrea; Caporale, Lorenzo


    Finding a good solution for thermal management problems is every day more complex. due to the power density and the required performances. When a solution suitable for high volumes is needed. die-casting and extrusion are the most convenient technologies. However designers have to face the well-known limitations for those processes. High Density Die Casting (HDDC) is a process under advanced development. in order to overcome the extrusion and traditional die casting limits by working with alloys having much better thermal performances than the traditional die-casting process. while keeping the advantages of a flexible 3D design and a low cost for high volumes. HDDC offers the opportunity to design combining different materials (aluminium and copper. aluminium and stainless steel) obtaining a structure with zero porosity and overcoming some of die-casting limits. as shown in this paper. A dedicated process involving embedded heat pipes is currently under development in order to offer the possibility to dramatically improve the heat spreading.

  11. Understanding of the influence of process parameters on the heat transfer behavior at the metal/die inter-face in high pressure die casting process

    GUO ZhiPeng; XIONG ShouMei; LIU BaiCheng; LI Mei; Allison John


    The current paper focuses on the influence of the process parameters on the peak values of the inter-facial heat transfer coefficient (IHTC) at metal/die interface during high pressure die casting (HPDC) process. A "step shape" casting and AM50 alloy were used during the experiment. The IHTC was de-termined by solving the inverse thermal problem based on the measured temperature inside the die. Results show that the initial die surface temperature (IDST, TDI) has a dominant influence while the casting pressure and fast shot velocity have a secondary influence on the IHTC peak values. By curve fitting, it was found that the IHTC peak value (hmax) changes as a function of the IDST in a manner of hmax=eαTγDI. Such relationship between the IHTC peak value and the IDST can also be found when the casting alloy is ADC12, indicating that this phenomenon is a common characteristic in the HPDC process.

  12. Evolution of Intermetallic Phases in Soldering of the Die Casting of Aluminum Alloys

    Song, Jie; Wang, Xiaoming; DenOuden, Tony; Han, Qingyou


    Most die failures are resulted from chemical reactions of dies and molten aluminum in the die casting of aluminum. The formation of intermetallic phases between a steel die and molten aluminum is investigated by stationary immersion tests and compared to a real die casting process. Three intermetallic phases are identified in the stationary immersion tests: a composite layer and two compact layers. The composite layer is a mixture of α bcc, Al, and Si phases. The α bcc phase changes in morphology from rod-like to spherical shape, while the growth rate of the layer changes from parabolic to linear pattern with immersion time. The first compact layer forms rapidly after immersion and maintains a relatively constant thickness. The second compact layer forms after 4 hours of immersion and exhibits parabolic growth with immersion time. In comparison, only a composite layer and the first compact layer are observed in a real die casting process. The fresh molten aluminum of high growth rate washes away the second intermetallic layer easily.

  13. Die posisie van die Helper in die sending

    I. J. van der Walt


    Full Text Available Gedurende die aanvangsjare van die sending het die helper ’n onmisbare funksie vervul. Hulle het die onherbergsame binnelande geken, waardevolle kontakpunte vir die sendelinge geopen en hulle mense geestelik help voorlig en voorberei.

  14. Effect of mold designs on molten metal behaviour in high-pressure die casting

    Ibrahim, M. D.; Rahman, M. R. A.; Khan, A. A.; Mohamad, M. R.; Suffian, M. S. Z. M.; Yunos, Y. S.; Wong, L. K.; Mohtar, M. Z.


    This paper presents a research study conducted in a local automotive component manufacturer that produces aluminium alloy steering housing local and global markets. This study is to investigate the effect of design modification of mold in die casting as to improve the production rate. Design modification is carried out on the casting shot of the mold. Computer flow simulation was carried out to study the flow of molten metal in the mold with respect to the mold design modification. The design parameters of injection speed, die temperature and clamping force has been included in the study. The result of the simulation showed that modifications of casting shot give significant impact towards the molten flow behaviour in casting process. The capabilities and limitations of die casting process simulation to conduct defect analysis had been optimized. This research will enhance the efficiency of the mass production of the industry of die casting with the understanding of defect analysis, which lies on the modification of the mold design, a way early in its stages of production.

  15. Recycling of Al-Si die casting scraps for solar Si feedstock

    Seo, Kum-Hee; Jeon, Je-Beom; Youn, Ji-Won; Kim, Suk Jun; Kim, Ki-Young


    Recycling of aluminum die-casting scraps for solar-grade silicon (SOG-Si) feedstock was performed successfully. 3 N purity Si was extracted from A383 die-casting scrap by using the combined process of solvent refining and an advanced centrifugal separation technique. The efficiency of separating Si from scrap alloys depended on both impurity level of scraps and the starting temperature of centrifugation. Impurities in melt and processing temperature governed the microstructure of the primary Si. The purity of Si extracted from the scrap melt was 99.963%, which was comparable to that of Si extracted from a commercial Al-30 wt% Si alloy, 99.980%. The initial purity of the scrap was 2.2% lower than that of the commercial alloy. This result confirmed that die-casting scrap is a potential source of high-purity Si for solar cells.


    L. R. Dudetskaja


    Full Text Available The paper discusses distinctive design features of casting molds and technological aspects of producing cast inserts from 5ХНМЛ pressed steel. The designs of long-life metal shell molds are described. They ensure saving of molding material, increase of accepted material and improvement of quality of castings.

  17. Influences of Casting Pressure Conditions on the Quality and Properties of a Magnesium Cylinder Head Cover Die Casting

    Wenhui LIU; Yangai LIU; Shoumei XIONG; Baicheng LIU; Y. Matsumoto; M. Murakami


    Casting pressure conditions have great influences on the casting defects, such as gas porosity, shrinkage porosity and gas holes. A Mg cylinder head cover die casting was used to experimentally study the influences of casting pressure,the loading time and the piston position of pressure intensification on the variation of pressure and the quality of casting. The results show that casting pressure, the loading time and the piston position of pressure intensification have great influences on the pressure variations in the mold, the quality and performance of casting. The external quality, the density and the tensile strength of casting were improved with the increase of casting pressure and the piston position of pressure intensification and the decrease of the loading time of pressure intensification.

  18. Optimization design for gating system in die-casting die%压铸模浇注系统的优化设计



      应用CAE软件对压铸件的成型过程进行模拟,根据模拟的结果,对压铸模浇注系统进行优化,改善模具的浇注系统结构,提高了压铸件品质。%The forming process for a die-casting part was simulated by applying CAE soft⁃ware. The gating system in die-casting die was optimized in accordance with the simula⁃tion results and the structure of gating system was improved and the quality of die-casting parts was enhanced.

  19. 3D scanning based mold correction for planar and cylindrical parts in aluminum die casting

    Takashi Seno


    Full Text Available Aluminum die casting is an important manufacturing process for mechanical components. Die casting is known to be more accurate than other types of casting; however, post-machining is usually necessary to achieve the required accuracy. The goal of this investigation is to develop machining- free aluminum die casting. Improvement of the accuracy of planar and cylindrical parts is expected by correcting metal molds. In the proposed method, the shape of cast aluminum made with the initial metal molds is measured by 3D scanning. The 3D scan data includes information about deformations that occur during casting. Therefore, it is possible to estimate the deformation and correction amounts by comparing 3D scan data with product computer-aided design (CAD data. We corrected planar and cylindrical parts of the CAD data for the mold. In addition, we corrected the planar part of the metal mold using the corrected mold data. The effectiveness of the proposed method is demonstrated by evaluating the accuracy improvement of the cast aluminum made with the corrected mold.

  20. Numerical simulation and optimization of Al alloy cylinder body by low pressure die casting

    Mi Guofa


    Full Text Available Shrinkage defects can be formed easily at Critical location during low pressure die casting (LPDC of aluminum alloy cylinder body. It has harmful effect on the products. Mold fi lling and solidifi cation process of a cylinder body was simulated by using of Z-CAST software. The casting method was improved based on the simulation results. In order to create effective feeding passage, the structure of casting was modifi ed by changing the location of strengthening ribs at the bottom, without causing any adverse effect on the part’s performance. Inserting copper billet at suitable location of the die is a valid way to create suitable solidifi cation sequence that is benefi cial to the feeding. Using these methods, the shrinkage defect was completely eliminated at the critical location.

  1. Pressure die cast graphite dispersed Al-Si-Mg alloy matrix composites

    Pillai, U.T.S. (Regional Research Lab. (CSIR), Trivandrum (India)); Pai, B.C. (Regional Research Lab. (CSIR), Trivandrum (India)); Kelukutty, V.S. (Regional Research Lab. (CSIR), Trivandrum (India)); Satyanarayana, K.G. (Regional Research Lab. (CSIR), Trivandrum (India))


    An improvement in casting of aluminium alloy graphite particulate composite synthesized by stir casting is discussed. About 15 wt.% graphite particles were dispersed in Al-Si-Mg (LM 25) alloy by the rheocasting technique. The composite ingots were used as a master alloy and diluted further with LM 25 alloy to obtain a 5 wt.% dispersion of graphite in the matrix. The composite ingots thus processed were subsequently remelted and pressure die cast into plates. Macroscopic and microscopic examination of the plates revealed fewer defects and a fine distribution of particles. The ultimate tensile strength evaluated in this composite was superior (132-136 MPa) to that of gravity die cast (85-95 MPa) composites. The fracture toughness of the composites was in the range 8-10 MPa m[sup 1/2]. (orig.)

  2. Numerical simulation and optimization of Al alloy cylinder body by low pressure die casting

    Mi Guofa; Liu Yanlei; Zhao Hengtao; Fu Hengzhi


    Shrinkage defects can be formed easily at critical location during low pressure die casting(LPDC)of aluminum alloy cylinder body.It has harmful effect on the products.Mold filling and solidification process of a cylinder body was simulated by using of Z-CAST software.The casting method was Improved based on the simulation results.In order to create eriective feeding passage,the structure of casting was modified by changing the location of strengthening ribs at the bottom,without causing any adverse effect on the part's performance.Inserting copper billet at suitable Iocation of the die is a valid way to create suitable solidification sequence that is beneficial to the feeding.Using these methods.the shrinkage defect was completely eliminated at the critical location.

  3. Influence of physical data and cooling conditions on the solidification of magnesium die castings


    As the simulation quality increases, the determination of hot spots is not enough to foundry engineers anymore. The simulation results have to fit in a quality way into the real foundry world. More and more results of the simulation will be used to optimise the casting process. Here it is necessary to have a very precise knowledge of the physical data. as well as the description of the geometry. To make use of the simulation in especially the magnesium-casting development it is necessary to work with precise geometrical, physical and numerical models. In this paper we describe the development of physical data concerning the heat transfer during filling and solidification by different casting methods. The low pressure as well as the gravity die casting method are used to get real data to find out the right conditions in the simulation in order to simulate the real behaviour during production. Practical tests are done under different test conditions to develop the right physical data as well as the right conditions in the metal-mould interface. The different surface conditions and the influence of the die and the molten metal temperatures are important for the layout of the die casting process. Three different shapes were applied to different mould materials and casting methods. The cooling conditions are tested on specific items. The cooling shape is not restricted by the drilling conditions. The effect of different cooling conditions are generated and measured. The results form the basis for the heat transfer conditions. These results are applied to real castings, cellular phone housings by low-pressure die casting process. The use of the new conditions leads to a good process description.

  4. Microstructure Characteristics of the Eutectics of Die Cast AM60B Magnesium Alloy

    Mengwu Wu; Shoumei Xiong


    Under the cold-chamber high pressure die casting (HPDC) process, samples were produced with AM60B magnesium alloy to investigate the microstructure characteristics of the eutectics, especially focusing on the constitution, morphology and distribution of the eutectics over cross section of the castings. Attentions were also paid to study the effect of heat treatment on the eutectics in the die castings. Based on experimental analysis using optical microscopy (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS), it was determined that fully divorced eutectics consisting of a-Mg and β-Mg17Al12 appeared at the grain boundary of the primary α-Mg in the as-cast microstructure. Islands and networks of β-Mg17Al12 phase were observed in the central region of the castings, while the β-Mg17Al12 phase revealed a more dispersed and granular morphology on the surface layer. The two phases ratio β/α in the central region of the castings was approximately 10%, which was higher than that on the surface layer. Besides, the defect bands contained a higher percentage of the eutectics than the adjacent regions. After aging treatment (T6), only a-Mg phase was detected by XRD in the AM60B magnesium alloy, though a small amount of precipitated β-Mg17Al12 phase was observed at the grain boundary. In contrast to the microstructure of die cast AZ91D magnesium alloy under the same T6 heat treatment, no discontinuous precipitation of the β-Mg17Al12 phase was observed in AM60B magnesium alloy die castings.


    V. N. Kuzmich


    Full Text Available The main details of foundry equipment are developed. Analysis of the process of filling and hardening of casting “Transducer case” is carried out on the basis of methods of mathematic modeling of foundry processes.

  6. Energy Saving Melting and Revert Reduction Technology (E-SMARRT): Development of Surface Engineered Coating Systems for Aluminum Pressure Die Casting Dies: Towards a 'Smart' Die Coating

    Dr. John J. Moore; Dr. Jianliang Lin,


    The main objective of this research program was to design and develop an optimal coating system that extends die life by minimizing premature die failure. In high-pressure aluminum die-casting, the die, core pins and inserts must withstand severe processing conditions. Many of the dies and tools in the industry are being coated to improve wear-resistance and decrease down-time for maintenance. However, thermal fatigue in metal itself can still be a major problem, especially since it often leads to catastrophic failure (i.e. die breakage) as opposed to a wear-based failure (parts begin to go out of tolerance). Tooling costs remain the largest portion of production costs for many of these parts, so the ability prevent catastrophic failures would be transformative for the manufacturing industry.The technology offers energy savings through reduced energy use in the die casting process from several factors, including increased life of the tools and dies, reuse of the dies and die components, reduction/elimination of lubricants, and reduced machine down time, and reduction of Al solder sticking on the die. The use of the optimized die coating system will also reduce environmental wastes and scrap parts. Current (2012) annual energy saving estimates, based on initial dissemination to the casting industry in 2010 and market penetration of 80% by 2020, is 3.1 trillion BTU's/year. The average annual estimate of CO2 reduction per year through 2020 is 0.63 Million Metric Tons of Carbon Equivalent (MM TCE).

  7. Strategies to reduce the environmental impact of an aluminium pressure die casting plant: A scenario analysis

    Neto, B.; Kroeze, C.; Hordijk, L.; Costa, C.; Pulles, M.P.J.


    This study explores a model (MIKADO) to analyse scenarios for the reduction of the environmental impact of an aluminium die casting plant. Our model calculates the potential to reduce emissions, and the costs associated with implementation of reduction options. In an earlier paper [Neto, B., Kroeze,

  8. Strategies to reduce the environmental impact of an aluminium pressure die casting plant: A scenario analysis

    Neto, B.; Kroeze, C.; Hordijk, L.; Costa, C.; Pulles, M.P.J.


    This study explores a model (MIKADO) to analyse scenarios for the reduction of the environmental impact of an aluminium die casting plant. Our model calculates the potential to reduce emissions, and the costs associated with implementation of reduction options. In an earlier paper [Neto, B., Kroeze,

  9. Thin-Wall Aluminum Die-Casting Technology for Development of Notebook Computer Housing


    Silicon-based aluminum casting alloys are known to be one of the most widely used alloy systems mainly due to their superior casting characteristics and unique combination of mechanical and physical properties.However, manufacturing of thin-walled aluminum die-casting components, less than 1.0 mm in thickness, is generally known to be very difficult task to achieve aluminum casting alloys with high fluidity. Therefore, in this study, the optimal die-casting conditions for producing 297 mm×210 mm×0.7 mm thin-walled aluminum component was examined experimentally by using 2 different gating systems, tangential and split type, and vent design. Furthermore, computational solidification simulation was also conducted. The results showed that split type gating system was preferable gating design than tangential type gating system at the point of view of soundness of casting and distortion generated after solidification. It was also found that proper vent design was one of the most important factors for producing thin-wall casting components because it was important for the fulfillment of the thin-wall cavity and the minimization of the casting distortion.

  10. Numerical simulation of mold-filling capability for a thin- walled aluminum die casting

    Sun, L.; Subasic, E.; Jakumeit, J.


    Mold-filling capability is an important property of casting materials. Especially in thin-walled die casting, fast cooling of the melt by contact to the die makes complete filling difficult to ensure. Simulation is an important tool enabling investigation of filling problems, even before the die is manufactured. However, the prediction of misruns is challenging. Flow and solidification have to be computed as closely coupled. The effects of surface tension, the wetting angle and reduced melt flow due to solidification must be modeled with high precision. To meet these requirements, a finite-volume method using arbitrary polyhedral control volumes is used to solve flow and solidification as closely coupled. The Volume-of-Fluid approach is used to capture the phase separation between gas, melt and solid in connection with a High-Resolution Interface-Capturing scheme to obtain sharp interfaces between phases. To model the resistance of the dendrite network to the melt flow, an additional source term in the momentum equation was implemented. The Bolt test was performed for A356 alloys at a range of different casting temperatures. Numerical prediction of incomplete filling in the bottleneck regions agreed well with experimental findings using 3D camera scanning. The simulation enables derivation of the dependence of critical wall-thickness, i.e. the thickness which is fillable, on casting temperature and metallostatic pressure. This could prove useful in predicting filling problems ahead of casting.

  11. Advanced metrology of surface defects measurement for aluminum die casting

    D. Myszka


    Full Text Available The scientific objective of the research is to develop a strategy to build computer based vision systems for inspection of surface defects inproducts, especially discontinuities which appear in castings after machining. In addition to the proposed vision inspection method theauthors demonstrates the development of the advanced computer techniques based on the methods of scanning to measure topography ofsurface defect in offline process control. This method allow to identify a mechanism responsible for the formation of casting defects. Also,the method allow investigating if the, developed vision inspection system for identification of surface defects have been correctlyimplemented for an online inspection. Finally, in order to make casting samples with gas and shrinkage porosity defects type, the LGT gas meter was used . For this task a special camera for a semi-quantitative assessment of the gas content in aluminum alloy melts, using a Straube-Pfeiffer method was used. The results demonstrate that applied solution is excellent tool in preparing for various aluminum alloysthe reference porosity samples, identified next by the computer inspection system.

  12. Energy Saving Melting and Revert Reduction Technology: Improved Die Casting Process to Preserve the Life of the Inserts

    David Schwam, PI; Xuejun Zhu, Sr. Research Associate


    The goal of this project was to study the combined effects of die design, proper internal cooling and efficient die lubricants on die life. The project targeted improvements in die casting insert life by: Optomized Die Design for Reduced Surface Temperature: The life of die casting dies is significantly shorter when the die is exposed to elevated temperature for significant periods of time. Any die operated under conditions leading to surface temperature in excess of 1050oF undergoes structural changes that reduce its strength. Optimized die design can improve die life significantly. This improvement can be accomplished by means of cooling lines, baffles and bubblers in the die. A key objective of the project was to establish criteria for the minimal distance of the cooling lines from the surface. This effort was supported with alloys and machining by BohlerUddeholm, Dunn Steel, HH Stark and Rex Buckeye. In plant testing and evaluation was conducted as in-kind cost share at St. Clair Die Casting. The Uddeholm Dievar steel evaluated in this program showed superior resistance to thermal fatigue resistance. Based on the experimental evidence, cooling lines could be placed as close as 0.5" from the surface. Die Life Extension by Optimized Die Lubrication: The life of die casting dies is affected by additions made to its surface with the proper lubricants. These lubricants will protect the surface from the considerable temperature peaks that occur when the molten melt enters the die. Dies will reach a significantly higher temperature without this lubricant being applied. The amount and type of the lubricant are critical variables in the die casting process. However, these lubricants must not corrode the die surface. This effort was supported with alloys and machining by BohlerUddeholm, Dunn Steel, HH Stark and Rex Buckeye. In plant testing and evaluation was conducted as in-kind cost share at St. Clair Die Casting. Chem- Trend participated in the program with die

  13. Energy Saving Melting and Revert Reduction Technology: Melting Efficiency in Die Casting Operations

    David Schwam


    This project addressed multiple aspects of the aluminum melting and handling in die casting operations, with the objective of increasing the energy efficiency while improving the quality of the molten metal. The efficiency of melting has always played an important role in the profitability of aluminum die casting operations. Consequently, die casters need to make careful choices in selecting and operating melting equipment and procedures. The capital cost of new melting equipment with higher efficiency can sometimes be recovered relatively fast when it replaces old melting equipment with lower efficiency. Upgrades designed to improve energy efficiency of existing equipment may be well justified. Energy efficiency is however not the only factor in optimizing melting operations. Melt losses and metal quality are also very important. Selection of melting equipment has to take into consideration the specific conditions at the die casting shop such as availability of floor space, average quantity of metal used as well as the ability to supply more metal during peaks in demand. In all these cases, it is essential to make informed decisions based on the best available data.

  14. Assessment of Computer Simulation Software and Process Data for High Pressure Die Casting of Magnesium

    Sabau, Adrian S [ORNL; Hatfield, Edward C [ORNL; Dinwiddie, Ralph Barton [ORNL; Kuwana, Kazunori [University of Kentucky; Viti, Valerio [University of Kentucky, Lexington; Hassan, Mohamed I [University of Kentucky, Lexington; Saito, Kozo [University of Kentucky


    Computer software for the numerical simulation of solidification and mold filling is an effective design tool for cast structural automotive magnesium components. A review of commercial software capabilities and their validation procedures was conducted. Aside form the software assessment, the program addressed five main areas: lubricant degradation, lubricant application, gate atomization, and heat transfer at metal mold interfaces. A test stand for lubricant application was designed. A sensor was used for the direct measurement of heat fluxes during lubricant application and casting solidification in graphite molds. Spray experiments were conducted using pure deionized water and commercial die lubricants. The results show that the sensor can be used with confidence for measuring heat fluxes under conditions specific to the die lube application. The data on heat flux was presented in forms suitable for use in HPDC simulation software. Severe jet breakup and atomization phenomena are likely to occur due to high gate velocities in HPDC. As a result of gate atomization, droplet flow affects the mold filling pattern, air entrapment, skin formation, and ensuing defects. Warm water analogue dies were designed for obtaining experimental data on mold filling phenomena. Data on break-up jet length, break-up pattern, velocities, and droplet size distribution were obtained experimentally and was used to develop correlations for jet break-up phenomena specific to die casting gate configurations.

  15. Die regsposisie van die gemolesteerde kind 1

    P.J. Schabort


    Full Text Available Hoe reik die reg uit na die seksueel gemolesteerde kind? As na die reg in wye verband gekyk word, sou dit alie wetgewing en alle gemeneregsbeginsels en alle regsprosedures insluit waardeur die Staat poog om molestering te voorkom en die gemolesteerde kind in beskerming te neem. Dit le baie wyd en sou byvoorbeeld die maatreels insluit van die Kindenvet 33 van 1960; die Wet op Egskeiding 70 van 1979; die Wet op Kindersorg 74 van 1983; die Wet op die Status van Kinders 82 van 1987 en die Wet op Bemiddeling in Sekere Egskeidingsaangeleenthede 24 van 1987. Eersdaags sal dit moontlik ook ’n Manifes vir die Regte van Kinders insluit wat vermoedelik geskoei sal wees op die W O se Konvensie vir die Regte van die Kind (1989 w a arv an die RSA tan s nog nie ’n ondertekenaar is nie.

  16. Effect of Alloying Elements on Thermal Wear of Cast Hot-Forging Die Steels

    WANG Shu-qi; CHEN Kang-min; CUI Xiang-hong; JIANG Qi-chuan; HONG Bian


    The effect of main alloying elements on thermal wear of cast hot-forging die steels was studied. The wear mechanism was discussed. The results show that alloying elements have significant influences on the thermal wear of cast hot-forging die steels. The wear rates decrease with an increase in chromium content from 3% to 4% and molybdenum content from 2% to 3%, respectively. With further increase of chromium and molybdenum contents, chromium slightly reduces the wear resistance and molybdenum severely deteriorates the wear resistance with high wear rate. Lower vanadium/carbon ratio (1.5-2.5) leads to a lower wear resistance with higher wear rate. With an increase in vanadium/carbon ratio, the wear resistance of the cast steel substantially increases. When vanadium/carbon ratio is 3, the wear rate reaches the lowest value. The predominant mechanism of thermal wear of cast hot-forging die steels are oxidation wear and fatigue delamination. The Fe2O3 and Fe3O4 or lumps of brittle wear debris are formed on the wear surface.

  17. High cycle fatigue properties of die-cast magnesium alloy AZ91D-1%MM


    The high cycle fatigue properties of the die-cast magnesium alloy AZ91D containing 1%mischmetal(mass fraction)at a fatigue ratio of 0.1 were investigated.The difference in the microstructure between the skin and core region of the die-cast magnesium alloy was analyzed by optical microscopy.The mechanical property tests indicate that the values of the tensile strength,elongation and hardness are 185 MPa,1.5%and HBS 70±3 at room temperature,respectively.The p-S-N curve(p=50%)of the die-cast magnesium alloy AZ91D-1%MM is determined and the mean fatigue strength corresponding to 3.8×105cycles is 70 MPa.A linear relation between S and Np in log scale between 103 and 106 cycles is written with a equation.The mechanical properties are influenced by the casting defects.The fatigue life of the samples with minor defects is near to the upper limit of the fatigue life data.The fatigue fracture surface of the samples with minor defects possesses the mixed characteristics of quasi-cleavage,lacerated ridge and dimple and it is briule fracture mode as a whole.

  18. Analog Studies of Thermomechanical Fatigue and Abrasive Wear of Cast and Forged Steels for "Autoforge" Dies

    Kolesnikov, M. S.; Mironova, Yu. S.; Mukhametzyanova, G. F.; Novikova, I. E.; Novikov, V. Yu.


    Processes of thermomechanical fatigue and abrasive wear of suspension-cast precipitation-hardening ferrite-carbide steel 30T6NTiC-1.5 and standard steel 4Kh5MFS are studied. The dominant kinds of fracture typical for dies for semisolid stamping are determined. The factors and parameters of cyclic temperature and force loading are shown to produce a selective action on the competing kinds of damage of the die steels. A comparative analysis of the properties of the steels is performed. Steel 30T6NTiC-1.5 is shown to have substantial advantages over steel 4Kh5FMS traditionally used for making "Autoforge" dies.

  19. Tool Steels in Die-Casting Utilization and Increased Mold Life

    Sepanta Naimi


    Full Text Available In die-casting molds, heat-checking is the typical failure mechanism. Optimizing the parameters that decrease this failure venture should be considered when designing and heat treating steels. The quality of die steels and their treatment continue to improve. This research investigated properties of the traditional materials 1.2343 and 1.2344 and the new steels (Dievar and TOOLOX 44 when applied to the die-casting mold specimens, after different experimental cycles. Also microstructures of the mentioned materials were analyzed by scanning electron microscopy (SEM test. Chrome-molybdenum-silicon-vanadium steels have good hardening ability in oil and in air. Therefore, the hot-work steels have considerable toughness and plastic attributes through both regular and higher temperatures. So, it is a good traditional die-casting material. However, another special die steel, such as Dievar, is a particularly developed steel grade; its exclusivity profile is exceptional due to its chemical composition and the use of the latest production techniques. Dievar has good heat-checking and gross-cracking resistance as a result of both high toughness and good hot strength. An additional material, a new prehardened tool steel known as TOOLOX 44, exhibits control of the failure described above by optimizing the parameters of impact toughness that could reduce the heat-checking failures. A variety of heat treatment parameters exist for various reasons because the heat treatment operation is performed by a variety of companies. This issue of the diversity in heat treatments is resolved by TOOLOX 44; this steel is quenched and tempered in delivered state.

  20. Metallic Reinforcement of Direct Squeeze Die Casting Aluminum Alloys for Improved Strength and Fracture Resistance

    D. Schwam: J.F. Wallace: Y. Zhu: J.W. Ki


    The utilization of aluminum die casting as enclosures where internal equipment is rotating inside of the casting and could fracture requires a strong housing to restrain the fractured parts. A typical example would be a supercharger. In case of a failure, unless adequately contained, fractured parts could injure people operating the equipment. A number of potential reinforcement materials were investigated. The initial work was conducted in sand molds to create experimental conditions that promote prolonged contact of the reinforcing material with molten aluminum. Bonding of Aluminum bronze, Cast iron, and Ni-resist inserts with various electroplated coatings and surface treatments were analyzed. Also toughening of A354 aluminum cast alloy by steel and stainless steel wire mesh with various conditions was analyzed. A practical approach to reinforcement of die cast aluminum components is to use a reinforcing steel preform. Such performs can be fabricated from steel wire mesh or perforated metal sheet by stamping or deep drawing. A hemispherical, dome shaped casting was selected in this investigation. A deep drawing die was used to fabricate the reinforcing performs. The tendency of aluminum cast enclosures to fracture could be significantly reduced by installing a wire mesh of austenitic stainless steel or a punched austenitic stainless steel sheet within the casting. The use of reinforcements made of austenitic stainless steel wire mesh or punched austenitic stainless steel sheet provided marked improvement in reducing the fragmentation of the casting. The best strengthening was obtained with austenitic stainless steel wire and with a punched stainless steel sheet without annealing this material. Somewhat lower results were obtained with the annealed punched stainless steel sheet. When the annealed 1020 steel wire mesh was used, the results were only slightly improved because of the lower mechanical properties of this unalloyed steel. The lowest results were

  1. Die Heimkunft

    Stephen Romer


    Full Text Available En hommage amical à René Gallet.Die HeimkunftRuhig glänzen indes die silberen Höhen darüber,Voll mit Rosen ist schon droben der leuchtende Schnee.- HölderlinAnd then one day the young master returnsfrom a dark placeand birdsong leads the wanderer inand the cat yawns and curls againin the headiness of this instantthe house is fragrantwith woodsmoke and honeysucklewhich is a kind of accomplishment.Returning from dogmahome to the humanehe lays asideknapsack, alpenstock and hat,goes straight to t...

  2. Study of Nozzle and Vent Locations on Die Casting Filling Process


    The casting nozzle location plays an important role in die casting. Improper location results in defects, such as cold shut, air cavity, shrinkage, etc. Therefore, it's sure that the molten metal full fills the mould cavity before it solidifies. And, it's to be wished that no vortex occur during the filling process, because the vortex is a main source that induces gas entrapment. To get the high quality and performance product, the inlet and outlet locations must be set properly. This paper, an optimal desi...

  3. The effect of equipment efficiency on occurrence of non-conforming products in die casting

    S. Borkowski


    Full Text Available This study focuses on determination of the relationships between equipment efficiency in casting machines and the level of quality. The determination was made based on coefficients of Total Productive Maintenance and r correlation coefficient. The degree at which break-downs and downtime affect the occurrence of non-conforming products was also evaluated. The goal of further investigations is to deter-mine the structure of downtime and finding which downtime types have greatest impact on the quality of die-casting products.

  4. Structure of Water Mist Stream and its Impact on Cooling Efficiency of Casting Die

    R. Władysiak


    Full Text Available The work is a continuation of research on the use water mist cooling in order to increase efficiency of die-casting aluminum alloys. The paper presents results of research and analysis process, spraying water and generated a stream of water mist, the effect of the type of nozzle, the nozzle size and shape of the emitting of the water mist on the wall surface of casting die on the microstructure and geometry of water mist stream and cooling efficiency. Tests were used to perform high-speed camera to record video in the visible and infrared camera. Results were used to develop a computerized image analysis and statistical analysis. The study showed that there are statistical relationships between water and air flow and geometry of the nozzle and nozzle emitting a stream of microstructure parameters of water mist and heat the incoming stream. These relationships are described mathematical models that allow you to control the generating of adequate stream of water mist and a further consequence, the cooling efficiency of casting die.

  5. Experimental Damage Criterion for Static and Fatigue Life Assessment of Commercial Aluminum Alloy Die Castings

    Battaglia, Eleonora; Bonollo, Franco; Ferro, Paolo


    Defects, particularly porosity and oxides, in high-pressure die casting can seriously compromise the in-service behavior and durability of products subjected to static or cyclic loadings. In this study, the influence of dimension, orientation, and position of casting defects on the mechanical properties of an AlSi12(b) (EN-AC 44100) aluminum alloy commercial component has been studied. A finite element model has been carried out in order to calculate the stress distribution induced by service loads and identify the crack initiation zones. Castings were qualitatively classified on the basis of porosities distribution detected by X-ray technique and oxides observed on fracture surfaces of specimens coming from fatigue and tensile tests. A damage criterion has been formulated which considers the influence of defects position and orientation on the mechanical strength of the components. Using the proposed damage criterion, it was possible to describe the mechanical behavior of the castings with good accuracy.

  6. Microstructure and properties of cast iron by semi-solid die casting process; Hangyoko diecast shita chutetsu no soshiki to seishitsu

    Yoshida, C.; Kitamura, K.; Ando, Y.; Hironaka, K.


    In the semi-solid die casting process, products are made by processing metals in the liquid and solid coexistence region. Die casting experiments were conducted using flaky graphite cast iron by means of the rheocasting method in which semi-solid slurry is directly die cast and the thixocasting method in which raw material billet is heated up to the semi-solid temperature and then die cast. In both the methods, flat plates were produced. In the rheocasting with the solid ratio of 0.2, flat plates of 6 mm thick were obtained. The surface temperature of die was lower than that in the case of melt die casting, which reduced the heat load of die. The macro segregation was also reduced. In the thixocasting, flat plates of 3 mm thick were obtained. Using general flaky graphite cast iron, the microstructure was observed where solid phase austenite is uniformly dispersed in the solid-liquid coexistence region. Austenite and austenite/cementite eutectic was observed in the specimens without treatment after casting. Cementite easily changed into fine graphite spheres through the heat treatment, which has excellent tensile strength of 400 MPa and elongation of 3%. 7 refs., 12 figs., 5 tabs.

  7. Calvyn en die Skrifgesag

    L. F. Schulze


    Full Text Available Die probleem van die Skrifgesag het die (teologiese geeste nog altyd in beroering — vandag (ná die Aufklarung! nog meer as gedurende die sestiende eeu. Gedurende die laaste paar jaar is ons in Suid-Afrika hardhandig uit ons isolement geruk en skielik lewensgroot gekonfronteer met die probleem van die Skrifgesag.

  8. Aspekte van die siekepastoraat

    H. J. C. Pieterse


    Full Text Available Die siekepastoraat vra ons aandag in hierdie tyd omdat die versorging van siekes ’n kenmerk is van die koms van die koninkryk van God. God se barmhartigheid het in sy volheid tot gelding gekom in die optrede van Jesus Christus. Die volle seën van die heil van die Ryk van God hou ook die versorging van die siekes in. Deur die heilswerk van Christus sien die blindes weer, loop die kreupeles, word melaatses gereinig, hoor die dowes, word dooies opgewek (Luk. 7:22.

  9. Study on the microstructure and mechanical properties of medium carbon Cr-Si-Mn-Mo-V steel for cast inserted dies

    HAO Xiao-yan


    Full Text Available The microstructure and mechanical properties of cast inserted dies for automobile covering components were studied. The results show that the as-cast microstructures of cast inserted dies are composed of pearlite, martensite,bainite, and austenite; and that the annealed microstructure is granular pearlite. The mechanical properties of cast inserted dies approach that of forged inserted dies. The tensile strength is 855 MPa, the elongation is 16%, the impact toughness is 177 J/cm2, and the hardness after annealing and quenching are HRC 19 and HRC 60-62. In addition, the cast inserted dies have good hardenability. The depth of the hardening zone and the hardness after flame quenching satisfy the operating requirements. The cast inserted dies could completely replace the forged inserted dies for making the dies of automobile covering components.

  10. Die prediking oor die historiese stof van die Ou Testament

    F. N. Lion-Cachet


    Full Text Available Uit ’n steekproef wat gedoen is uit die preke wat in Die Kerkblad (1986- 1987 verskyn het, blyk dit dat 40% van hierdie preke historiese stof uit die Ou Testament as teks gebruik het.

  11. Influence of samarium content on microstructure and mechanical properties of recycled die-cast YL112 aluminum alloys

    Zhi Hu


    Full Text Available The influence of Sm (Samarium content on microstructure and mechanical properties of recycled die-cast YL112 aluminum alloys was investigated. The results show that many small Sm-rich particles form in the recycled die-cast YL112 alloys with Sm addition. At the same time, the secondary dendrite arm spacing in the YL112 alloys modified with Sm is smaller than that of the unmodified alloy. The eutectic Si of recycled die-cast YL112-xSm alloys transforms from coarse acicular morphology to fine fibres. Mechanical properties of the investigated recycled die-cast YL112 aluminum alloys are enhanced with Sm addition, and a maximal ultimate tensile strength value (276 MPa and elongation (3.76% are achieved at a Sm content of 0.6wt.%. Due to the modification of eutectic Si by Sm, numerous tearing ridges and tiny dimples on the fractures of tensile samples are observed.

  12. Die gesag van die Heilige Skrif

    S.C.W. Duvenage


    Full Text Available Dit geld nie maar t.o.v. ’n ongeloofsbeskouing soos dié van Karl Jaspers nie wat beweer: „Die Bibel ist das Depositum eines Jahrtausends menschlicher Grenzerfahrung” of van die Rooms-Katolieke skrifbeskouing nie wat die kerklike leertradisie, soos dogmaties op die konsilie van Trente vasgelê is, beskou as die enigste gesaghebbende kriterium vir die kanonisering en interpretasie van die Skrif.

  13. Polymer melt rheology and flow simulations applied to cast film extrusion die design: An industrial perspective

    Catherine, Olivier


    This article is an overview of the techniques used today in the area of rheology and flow simulation, on the industrial level, for cast film extrusion die design. This industry has made significant progress over the past three decades and die and feedblock design and optimization certainly have been instrumental in the overall improvement. Dies and coextrusion feedblocks are a critical aspect of the process due to the layering and forming function, which drive the final product economics and properties. Polymer melt rheology is a key aspect to consider when optimizing the flow patterns in the extrusion equipment. Not only is rheology critical for the flow channel design when aiming at obtaining a uniform flow distribution at the die exit, but also it is playing a major role in the thermal aspect of the flow due to the strong mechanical and thermal coupling. This coupling comes, on one hand, from the occurrence of viscous dissipation in the flow and on the other hand from the significant temperature dependency of melt viscosity. Viscous dissipation is due to relatively high melt viscosities and strain rates, especially with today's processes which involve formidable extrusion speeds. The third aspect discussed in this paper is the complexity of residence time distribution in modern flow channels, which is evaluated with advanced three-dimensional flow simulation and particle tracking.

  14. Water mist effect on cooling range and efficiency of casting die

    R. Władysiak


    Full Text Available This project is showing investigation results of cooling process of casting die in the temperature range 570÷100 °C with 0.40 MPa compressed air and water mist streamed under pressure 0.25÷0.45 MPa in air jet 0.25÷0.50 MPa using open cooling system.The character and the speed of changes of temperature, forming of the temperture’s gradient along parallel layer to cooled surface of die is shawing with thermal and derivative curves. The effect of kind of cooling factor on the temperature and time and distance from cooling nozzle is presented in the paper. A designed device for generating the water mist cooling the die and the view of sprying water stream is shown here. It’s proved that using of the water mist together with the change of heat transfer interface increases intensity of cooling in the zone and makes less the range cooling zone and reduces the porosity of cast microstructure.

  15. Improvement of quality of a gravity die casting made from aluminum bronze be application of numerical simulation

    A. Fajkiel


    Full Text Available The paper describes the possibility of improving the quality of gravity die cast connectors for overhead power transmission lines. The castings were made from aluminum bronze, grade CuAl9Fe1Ni1. A MAGMAsoft computer programme was used for simulation of the process of die filling and casting solidification to avoid defects, like shrinkage depression and gas porosities. The results of the simulation have finally led to redesigning of the metal feeding and cooling system and to reduced level of defects in castings.

  16. Improved Life of Die Casting Dies of H13 Steel by Attaining Improved Mechanical Properties and Distortion Control During Heat Treatment

    J. F. Wallace; D. Schwam


    The ultimate goal of this project is to increase die casting die life by using fast enough quenching rates to obtain good toughness and fatigue resistance in premium grade H-13 steel dies. The main tasks of the project were to compile a database on physical and mechanical properties of H-13; conduct gas quenching experiments to determine cooling rates of dies in difference vacuum furnaces; measure the as-quenched distortion of dies and the residual stresses; generate finite element analysis models to predict cooling rates, distortion, and residual stress of gas quenched dies; and establish rules and create PC-based expert system for prediction of cooling rates, distortion, and residual stress in vacuum/gas quenched H-13 dies. Cooling curves during gas quenching of H-13 blocks and die shapes have been measured under a variety of gas pressure. Dimensional changes caused by the gas quenching processes have been determined by accurate mapping of all surfaces with coordinate measuring machines before and after the quench. Residual stresses were determined by the ASTM E837 hole-drilling strain gage method. To facilitate the computer modeling work, a comprehensive database of H-13 mechanical and physical properties has been compiled. Finite element analysis of the heat treated shapes has been conducted using the TRAST/ABAQUS codes. There is a good fit between the predicted and measured distortion contours. However, the magnitude of the predicted distortion and residual stresses does not match well the measured values. Further fine tuning of the model is required before it can be used to predict distortion and residual stress in a quantitative manner. This last step is a prerequisite to generating rules for a reliable expert system.

  17. Development and Application of Die-Casting High Speed Steel Rolls

    JIANG Zhi-qiang; FU Han-guang; DING Yu-cheng


    Due to its high hardness, good red hardness and excellent wear resistance at high temperature, high speed steel (HSS) is fit for the roll manufacture. In order to overcome the segregation of centrifugal casting of HSS roll, die-cast processes were developed and its effects on the properties of the HSS roll were investigated. It was found that pressure, pressing time and speed are three important factors affecting shrinkage cavity. For pouring temperature of 1 400-1 450 ℃, pressure of 150-160 MPa, pressing time of 120-150 s and pressing speed of 14-16 mm/s, a compact HSS roll was obtained, which has no segregation and small working allowance. In the high speed wire rod rolling mill, service life of the HSS roll is 5 to 8 times longer than that of high nickel chromium infinite chilled cast iron roll.

  18. Die ontwrigting van die Afrikanervolk en volkseenheid

    H. du Plessis


    Full Text Available Die gevare wat ons Afrikanerdom voor die deur staan, is baie en ernstig. Daar is die gevaar van immigrasie van buitelanders, daar is die al driester geroep om gelykstelling tussen blank en gekleurd, daar is die dreigende oorheersing van ’n oppervlakkige Amerikaanse „jazz”-gees.

  19. Die Nasionale Vakterminologiediens (NVD

    L. A. Genis


    Full Text Available Die Nasionale Vakterminologiediens (NVD ressorteer onder die Hoofdirektoraat Kultuur en Vakkundige Hulp- dienste van die Departement van Nasionale Opvoeding. Die hoofdoelwit van die NVD is die skepping van ’n fijnksionele vakwoordeskat in veral Afrikaans, parallel met die inter- nasionaal gebruikte terminologieë.

  20. Sand, die and investment cast parts via the SLS selective laser sintering process

    van de Crommert, Simon; Seitz, Sandra; Esser, Klaus K.; McAlea, Kevin


    Complex three-dimensional parts can be manufactured directly from CAD data using rapid prototyping processes. SLS selective laser sintering is a rapid prototyping process developed at the University of Texas at Austin and commercialized by DTM Corporation. SLS parts are constructed layer by layer from powdered materials using laser energy to melt CAD specified cross sections. Polymer, metal, and ceramic powders are all potential candidate materials for this process. In this paper the fabrication of complex metal parts rapidly using the investment, die and sand casting technologies in conjunction with the selective laser sintering process are being explained and discussed. TrueForm and polycarbonate were used for investment casting, while RapidSteel metal mould inserts were used for the die casting trials. Two different SandForm materials, zircon and silica sand, are currently available for the direct production of sand moulds and cores. The flexible and versatile selective laser sintering process all these materials on one single sinterstation. Material can be changed fast and easily between two different builds.

  1. Effect of Multipoint Sequential Water Mist Cooling of Casting Die on Microstructure and Mechanical Properties of AlSi11 Alloy

    Władysiak R.


    Full Text Available The work is a continuation of research on the use of water mist cooling in order to increase efficiency of the die-casting process for aluminum alloys. The paper describes the multipoint sequential cooling system of the casting die and its computer control and monitoring. It also includes results of the tests and analysis of cooling methods during making of the casting. These methods differ from each other in the sequence of casting die cooling and cause effective changes in microstructure and mechanical properties of castings made of AlSi11 alloy. The study demonstrated that the use of multipoint sequential cooling with water mist affects the microstructure refinement and reduces the segregation in the cast as well as more than by 20% increases the mechanical properties of castings in the rough state. The study also demonstrates that the sequential cooling of casting die accelerates the cooling of the casting and shortens die-casting cycle.

  2. Effect of Multipoint Sequential Water Mist Cooling of Casting Die on Microstructure and Mechanical Properties of AlSi11 Alloy

    R. Władysiak


    Full Text Available The work is a continuation of research on the use of water mist cooling in order to increase efficiency of the die-casting process for aluminum alloys. The paper describes the multipoint sequential cooling system of the casting die and its computer control and monitoring.It also includes results of the tests and analysis of cooling methods during making of the casting. These methods differ from each other in the sequence of casting die cooling and cause effective changes in microstructure and mechanical properties of castings made of AlSi11 alloy. The study demonstrated that the use of multipoint sequential cooling with water mist affects the microstructure refinement and reduces the segregation in the cast as well as more than by 20% increases the mechanical properties of castings in the rough state. The study also demonstrates that the sequential cooling of casting die accelerates the cooling of the casting and shortens die-casting cycle.

  3. Influence of neodymium on high cycle fatigue behavior of die cast AZ91D magnesium alloy

    杨友; 李雪松


    High cycle fatigue behavior of die cast AZ91D magnesium alloy with different Nd contents was investigated.Axial mechanical fatigue tests were conducted at the stress ratio R=0.1 and the fatigue strength was evaluated using up-to-down load method on specimens of AZ91D with different Nd contents.The results showed that the grain of AZ91D alloy was refined,the size and amount of β-Mg17Al12 phase decreased and distributed uniformly with increasing Nd content.At the number of cycles to failure,Nf=107,the fatigue...

  4. Die kritiese taak van die literator

    A. L. Combrink


    Full Text Available Die beoefening van die literêre kritiek was aanvanklik slegs ’n deeltydse aktiwiteit. Die vroegste literêre kritici was nie as sodanig kritici nie maar het as deel van hulle totale intellektuele aktiwiteit hulle ook uitgelaat oor die letterkunde. Die motivering wat hulle hiertoe gehad het sou in ons dag heeltemal verdag voorkom: ’n uitgesproke didaktiese of moraliserende houding was die reel.

  5. Tribological Properties of AlSi11-SiCp Composite Castings Produced by Pressure Die Casting Method

    Konopka Z.


    Full Text Available The measurement results concerning the abrasive wear of AlSi11-SiC particles composites are presented in paper. The method of preparing a composite slurry composed of AlSi11 alloy matrix and 10, 20% vol.% of SiC particles, as well as the method of its high-pressure die casting was described. Composite slurry was injected into metal mould of cold chamber pressure die cast machine and castings were produced at various values of the piston velocity in the second stage of injection, diverse intensification pressure values, and various injection gate width values. Very good uniform arrangement of SiC particles in volume composite matrix was observed and these results were publicated early in this journal. The kinetics of abrasive wear and correlation with SiC particles arrangement in composite matrix were presented. Better wear resistance of composite was observed in comparison with aluminium alloy. Very strong linear correlation between abrasive wear and particle arrangement was observed. The conclusion gives the analysis and the interpretation of the obtained results.

  6. Grain refinement of ASTM A356 aluminum alloy using sloping plate process through gravity die casting

    Adnan Mehmood


    Full Text Available Sloping plate flow is used for enhancement of material properties through grain refinement in gravity die casting of Aluminum alloy ASTM A356. The castings are prepared with different slope angles of an 800 mm long, naturally cooled stainless steel plate. The specimens obtained are then tested for tensile strength and elongation. Microstructure of the cast specimens is observed and conclusions drawn on the grain size and precipitate morphology as a function of angle of sloping plate. Analysis is presented for the boundary layer created while the material flows over the plate. An indication of the boundary layer thickness is determined by measuring the thickness of the residual metal layer on the plate after casting. An analytical solution of the boundary layer thickness is also presented. It is shown that the calculated boundary layer thickness and the thickness of the layer of material left in the channel after casting are in good agreement. Moreover, microstructure examination and tensile tests show that best properties are achieved with a 60° sloping plate.

  7. Determining the optimal index of heat stress in foundry, die casting and road construction industries using FAHP_Topsis

    Maryam Dehghanipoor


    Full Text Available Introduction: Heat stress is one of the harmful risks in casting and die casting industries, which can not only cause work-related diseases but also can impair the performance and safety of workers. Since the indicators that are used to evaluate heat stress are very different, it is very difficult to choose a suitable index. The aim of this study was to determine the optimum heat stress index in foundry, die-cast, and road construction industries using FAHP and Topsis methods. Material and Method: In order to determine optimum heat stress index in foundry, die-cast, and road construction industries, first, the prioritization criteria were defined by experts (including ease of measurement, measurement accuracy, comprehensiveness, time, cost, and correlation. Then, considering these criteria, the best heat stress index was determined based on experts’ opinions and using FAHP and Topsis methods. Result: The results of this study suggest that given the current conditions and criteria, WBGT and P4SR is the best indices for foundry, die casting and construction. Conclusion: The results showed that according to comprehensiveness, accuracy and correlation criteria, the WBGT index is considered as the best indicator of heat stress assessment in foundry, die-cast and road construction industries. Moreover, the HSI ranked in the last place due to the complexity and cost of its calculation.

  8. Die ideaal van die spreker in die satiriese gedig: M.M. Walters

    S. M. Cameron


    Full Text Available Wanneer van die satirikus gepraat word, word eintlik die spreker in die satiriese gedig veronderstel. “For the Muse ought always to be our reminder that it is not the author as man who casts these shadows on our printed page, but the author as poet” (Mack, 1971:193.

  9. Die Via Dolorosa

    W. J. van der Merwe


    Full Text Available In die hartjie van Jerusalem, die heilige stad vir Jood, Mohammedaan en Christen staan daar ’n boog, die ,,Ecce Homoboog” genaamd, en 'n klein endjie daarvandaan, die Heilige Grafkerk.

  10. Neuro-Knowledge-Based Expert System (NKBES)for Optimal Scheming of Die Casting Process

    Qiaodan HU; Peng LUO; Yi YANG; Liliang CHEN


    We develop a neuro-knowledge-based expert system (NKBES) frame in this work. The system mainly concerns with decision of gating system and die casting machine based on a neuro-inference engine launched under the MATLAB software environment. For enhancement of reasoning agility, an error back-propagation neural network was applied.A rapidly convergent adaptive learning rate (ALR) and a momentum-based error back-propagation algorithm was used to conduct neuro-reasoning. The working effect of the system was compared to a conventional expert system that is based on a two-way (forward and backward) chaining inference mechanism. As the reference, the present paper provided the neural networks sum-squared error (SSE) and ALR vs iterative epoch curves of process planning case mentioned above. The study suggests that the neuro-modeling optimization application to die casting process design has good feasibility, and based on that a novel and effective intelligent expert system can be launched at low cost.

  11. Luther die prediker

    J. J. van der Walt


    Full Text Available ’n Prediker moet ’n getroue herder wees wat magtig is in die Heilige Skrif, want die Woord bring die kerk voort. Daarom moet die prediker in sy bediening aan mense ’n woord van sekerheid hê deur seker te wees hy het die Woord van God. Met hierdie gedagtegang het Luther se pastorale besorgdheid vaste bodem vir die prediking in die gesag van die Woord van God.

  12. Influence of the casting material on the dimensional accuracy of dental dies

    Daher Antonio Queiroz


    Full Text Available The purpose of this study was to evaluate the dimensional accuracy of different materials used in the confection of dies. Two stainless steel standard models were confected. One of the models, which was 2 mm larger than the other model, was used to provide a uniform relief for the two-step putty-wash impression technique. Thirty impressions were obtained using a polyvinyl siloxane impression material and randomly divided into three groups (n = 10 according to the type of casting material: type IV dental stone, commercially available epoxy resin (Tri-Epoxy, and industrial epoxy resin (Sikadur. After the setting/polymerization of the casting material, the dimensional stability was measured in terms of the height, diameter of the base and diameter of the top from the obtained dies and from the standard metal model using a profile projector. Results were analyzed by ANOVA and Dunnet test (α = 0.05. In the height values, no significant difference was observed between the groups, except for Sikadur casts, which showed lower mean values. The Tri-Epoxi group showed statistically lower mean base diameter values, compared with the other groups, and both epoxy resin groups showed statistically lower mean top diameter values, compared with that for the type IV dental stone group. We concluded that type IV gypsum and the commercially available epoxy resin showed similar behavior in most areas. The industrial epoxy resin did not show the same characteristics, although the diameter of the base obtained with it was similar to that obtained with type IV dental stone.

  13. A process chain for integrating piezoelectric transducers into aluminum die castings to generate smart lightweight structures

    Stein, Stefan; Wedler, Jonathan; Rhein, Sebastian; Schmidt, Michael; Körner, Carolin; Michaelis, Alexander; Gebhardt, Sylvia

    The application of piezoelectric transducers to structural body parts of machines or vehicles enables the combination of passive mechanical components with sensor and actuator functions in one single structure. According to Herold et al. [1] and Staeves [2] this approach indicates significant potential regarding smart lightweight construction. To obtain the highest yield, the piezoelectric transducers need to be integrated into the flux of forces (load path) of load bearing structures. Application in a downstream process reduces yield and process efficiency during manufacturing and operation, due to the necessity of a subsequent process step of sensor/actuator application. The die casting process offers the possibility for integration of piezoelectric transducers into metal structures. Aluminum castings are particularly favorable due to their high quality and feasibility for high unit production at low cost (Brunhuber [3], Nogowizin [4]). Such molded aluminum parts with integrated piezoelectric transducers enable functions like active vibration damping, structural health monitoring or energy harvesting resulting in significant possibilities of weight reduction, which is an increasingly important driving force of automotive and aerospace industry (Klein [5], Siebenpfeiffer [6]) due to increasingly stringent environmental protection laws. In the scope of those developments, this paper focuses on the entire process chain enabling the generation of lightweight metal structures with sensor and actuator function, starting from the manufacturing of piezoelectric modules over electrical and mechanical bonding to the integration of such modules into aluminum (Al) matrices by die casting. To achieve this challenging goal, piezoceramic sensors/actuator modules, so-called LTCC/PZT modules (LPM) were developed, since ceramic based piezoelectric modules are more likely to withstand the thermal stress of about 700 °C introduced by the casting process (Flössel et al., [7]). The

  14. Development of a high creep strength hot-chamber die-casting zinc alloy

    Goodwin, F.E. (International Lead Zinc Research Organization, Inc., Research Triangle Park, NC (United States))


    Alloys of Zn-0.3% Al-1.3% Cu-0.3% Mn-0.01% Mg were pressure die cast with Li levels of 0, 0.07, 0.13, and 0.19% Li. The creep properties of these alloys were between those of Zamak 5. and ILZRO 16. Immersion testing of die steel coupons in one of the Li-containing alloys showed rates of erosion similar to those known for Zamak alloys 3 and 5. The mechanism of impoved creep values in the Li-containing alloys appears to be Li-Zn compounds which at first are located on grain boundaries. After aging at 100deg C, they are found predominantly within the grains. Shortterm tensile properties of the Li-containing alloys are 75-85 percent of the properties of Zamak 5, except for the alloy containing the lowest amount of lithium. Elongation and impact values are low. The latter attribute may be caused by the high levels of Mn in these alloys, which form Al-Mn particles on grain boundaries. (orig.).

  15. Case study of lean manufacturing application in a die casting manufacturing company

    Ching, Ng Tan; Hoe, Clarence Chan Kok; Hong, Tang Sai; Ghobakhloo, Morteza; Pin, Chen Kah


    The case study of lean manufacturing aims to study the application of lean manufacturing in a die casting manufacturing company located in Pulau Penang, Malaysia. This case study describes mainly about the important concepts and applications of lean manufacturing which could gradually help the company in increasing the profit by studying and analyzing their current manufacturing process and company culture. Many approaches of lean manufacturing are studied in this project which includes: 5S housekeeping, Kaizen, and Takt Time. Besides, the lean tools mentioned, quality tool such as the House of Quality is being used as an analysis tool to continuously improve the product quality. In short, the existing lean culture in the company is studied and analyzed, with recommendations written at the end of this paper.

  16. A Numerical and Experimental Study of Flow Behavior in High Pressure Die Casting

    Saeedipour, Mahdi; Schneiderbauer, Simon; Pirker, Stefan; Bozorgi, Salar

    High pressure die casting (HPDC) is one of the most important and yet little known manufacturing methods especially during liquid metal injection and filling phase. During its application different problems can arise: on the one hand, wavy disintegration of the jet might result in cold shut defect in the final product, on the other hand a high degree of atomization may strongly increase the porosity defect. A numerical simulation using volume of fluid approach (VOF), is carried out to model the global spreading of liquid metal jet. The formation of droplets, which are usually smaller than the grid spacing in computational domain, is determined by a surface energy-based criterion. An Eulerian-Lagrangian framework is introduced to track and model the droplets after formation. Since liquid metal is hardly to access, we performed experiments based on water analogy to capture the flow regime changes and drop formation. The comparison between numerical results and experiments shows a very good agreement.

  17. Barium phosphate conversion coating on die-cast AZ91D magnesium alloy


    Poor corrosion resistance limits the application of magnesium alloys.Conversion coating is widely used to protect magnesium alloys because of easy operation and low cost.A novel conversion coating on die.cast AZ91D magnesium alloy containing barium salts was studied.The optimum concentrations of Ba(NO3)2,Mn(NO3)2 and NH4H2PO4 are 25 g/L,15 mL/L and 20 g/L,respectively,based on orthogonal test resulm.The treating time,solution temperature and PH value are settled to be 5-30 min,50-70℃and 2.35-3.0.respectively.The corrosion resistance of barium conversion coating is better than that of manganese-based phosphate conversion coating by immersion test.The coating is composed of Ba,P, O,Mg,Zn,Mn and Al by EDX analysis.

  18. The ‘full sleeve’ application in the horizontal cold-chamber machine for pressure die casting of aluminium alloys

    Z. Konopka


    Full Text Available The ‘full sleeve’ construction has been designed and accomplished in the horizontal cold-chamber pressure die casting machine. Main part of this solution is a counter plunger placed in a movable die half which allows for full filling of the shot sleeve and precisely fixes the metal quantity needed for casting. The purpose of this new construction solution is mainly the reduction of the casting porosity caused by air entrapment and the improvement of both castability and accuracy of the die cavity reproduction. For such a redesigned machine there have been performed examinations consisting in pressure casting of AlSi9Cu alloy (EN AC-46000 at varying plunger velocity in the second stage of injection and varying intensification pressure. The alloy castability (the die filling ability has been measured for each parameter setting. For the purpose of comparison, similar measurements have been performed also for the conventional system without a counter plunger. The castability examination has been done by means of a specially designed die with an impression of a trial casting of variable wall thickness. The experiments have been held according to the assumed factor design 22, what allowed for determining the mathematical models describing the influence of die filling parameters on the castability and the die cavity reproduction level. Both alternatives of the experiment confirmed the positive influence of plunger velocity and intensification pressure increase on the improvement of castability, the measure of the latter being the filled length of the impression. Applying of the new ‘full sleeve’ solution has improved castability for each experiment by about 20% as compared with conventional alternative. Castability in the ‘full sleeve’ system has been increased even for low values of plunger velocity and intensification pressure. For both alternative systems the influence of plunger velocity has been found, as an average, by four times

  19. Wêreldmededingendheid en die tegnologie

    C. W. I. Pistorius


    Full Text Available Afgesien van die interne uitdagings wat die Heropbou- en Ontwikkelingsprogram (HOP aan Suid-Afrika bied, moet die land ook tred hou met die veranderende globale omgewing, spesifiek die toenemende belangrikheid van ekonomiese sekuriteit as komponent van nasionale sekuriteit. Die konsep van mededingendheid vergestalt die doelwit wat nagestreef moet word ten einde die ontluikende globale ekonomiese stryd aan te durf. As ’n belangrike drywer van ekonomiese welvaart is tegnologie een van die belangrikste sleutels tot internasionale mededingendheid. Tegnologiese innovasie is die proses wat as hefboom hiervoor gebruik moet word. Dit is egter nodig dat tegnologie, en spesifiek die proses van tegnologiese innovasie, formeel en gestruktureerd bestuur moet word, sowel op nasionale as firmavlak. Op nasionale vlak is die voorsiene Nasionale Innovasiestelsel beslis ’n stap in die regte rigting.

  20. Modification of Magnesium Alloys by Ceramic Particles in Gravity Die Casting

    Urs Haßlinger


    Full Text Available A critical drawback for the application of magnesium wrought alloys is the limited formability of semifinished products that arises from a strong texture formation during thermomechanical treatment. The ability of second phase particles embedded into the metal matrix to alter this texture evolution is of great interest. Therefore, the fabrication of particle modified magnesium alloys (particle content 0.5–1 wt.-% by gravity die casting has been studied. Five different types of micron sized ceramic powders (AlN, MgB2, MgO, SiC, and ZrB2 have been investigated to identify applicable particles for the modification. Agglomeration of the particles is revealed to be the central problem for the fabrication process. The main factors that influence the agglomerate size are the particle size and the intensity of melt stirring. Concerning handling, chemical stability in the Mg-Al-Zn alloy system, settling and wetting in the melt, and formation of the microstructure in most cases, the investigated powders show satisfying properties. However, SiC is chemically unstable in aluminum containing alloys. The high density of ZrB2 causes large particles to settle subsequent to stirring resulting in an inhomogeneous distribution of the particles over the cast billet.

  1. Quantitative characterization of processing-microstructure-properties relationships in pressure die-cast magnesium alloys

    Lee, Soon Gi

    The central goal of this research is to quantitatively characterize the relationships between processing, microstructure, and mechanical properties of important high-pressure die-cast (HPDC) Mg-alloys. For this purpose, a new digital image processing technique for automatic detection and segmentation of gas and shrinkage pores in the cast microstructure is developed and it is applied to quantitatively characterize the effects of HPDC process parameters on the size distribution and spatial arrangement of porosity. To get better insights into detailed geometry and distribution of porosity and other microstructural features, an efficient and unbiased montage based serial sectioning technique is applied for reconstruction of three-dimensional microstructures. The quantitative microstructural data have been correlated to the HPDC process parameters and the mechanical properties. The analysis has led to hypothesis of formation of new type of shrinkage porosity called, "gas induced shrinkage porosity" that has been substantiated via simple heat transfer simulations. The presence of inverse surface macrosegregation has been also shown for the first time in the HPDC Mg-alloys. An image analysis based technique has been proposed for simulations of realistic virtual microstructures that have realistic complex pore morphologies. These virtual microstructures can be implemented in the object oriented finite elements framework to model the variability in the fracture sensitive mechanical properties of the HPDC alloys.

  2. Failure behavior of high pressure die casting AZ91D magnesium alloy

    Li, X.; Xiong, S.M. [School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Tsinghua University, Beijing 100084 (China); Guo, Z., E-mail: [School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Tsinghua University, Beijing 100084 (China)


    The failure behavior of high pressure die casting AZ91D magnesium alloy during both tensile and fatigue tests was studied in situ by using scanning electron microscope. Attention was focused on the role of microstructure played in crack initiation and propagation. Results showed that the defects in castings, including gas pore, shrinkage pore and defect band, were the crack initiation sources. In tensile test, the crack propagated in a combination of intergranular and transgranular modes, and the specimen fractured by connecting defects at the section with minimum effective force bearing area. In fatigue test, the crack propagated in a transgranular mode at specific crystalline planes. When the crack was in contact with the β-phase, the crack would pass through, and fracture the network β-phase, whereas bypass the island β-phase by detaching it from the surrounding α-Mg grains. Besides, defects in front of the crack would act as the secondary crack initiation sources, from which new cracks would initiate and propagate. With the propagation of the fatigue crack, the actual maximum cyclic stress would increase to the fracture stress of the left cross section and lead to the final fracture of the specimen.

  3. Adhesive Bonding and Corrosion Protection of a Die Cast Magnesium Automotive Door

    Bretz, G. T.; Lazarz, K. A.; Hill, D. J.; Blanchard, P. J.

    It is well known that magnesium alloys, in close proximity to other alloys, are susceptible to galvanic corrosion. Combined with this fact, in automotive applications, it is rare that magnesium will be present in the absence of other alloys such as steel or aluminum. Therefore, in wet applications, where the galvanic cell is completed, it is necessary to isolate the magnesium in order to prevent accelerated corrosion. There are numerous commercial pre-treatments available for magnesium, however this paper focuses on conversion coatings in conjunction with a spray powder coat. By means of example, results for a hem flange joint on an AM50 die cast magnesium door structure will be presented. The outer door skin is an aluminum alloy hemmed around a cast magnesium flange. An adhesive is used between the inner and outer to help with stiffness and NVH (Noise, Vibration and Harshness). Results from bonded lap-shear coupon tests that have been exposed to accelerated corrosion cycles are presented. A second phase of this work considered a surrogate hem flange coupon, which was similarly exposed to the same accelerated corrosion cycle. Results from both of these tests are presented within this paper along with a discussion as to their suitability for use within automotive applications.

  4. Die rol van die blanke werker in die motivering van die swart werker

    G. J. Oosthuizen


    Full Text Available The motivation of the Black worker can not be studied in isolation since the White worker still holds many executive positions and therefore has an influence on the Black workers' motivation. The role of the White worker in motivating the Black worker in a specific organisation and the attitude and leadership approach of the White worker on the existence/nonexistence and relative satisfaction of the needs of Black workers are discussed.Opsomming Die motivering van die Swart werker kan nie in die huidige situasie in isolasie bestudeer word nie, omdat die Blanke werker steeds in die bestuursposisie is en daarom die motivering van die Swart werker kan beïnvloed. Hierdie ondersoek was daarop gerig om die rol van die Blanke werker in die motivering van die Swart werker nader te ondersoek. Die houding en die leierskapsbenadering van die Blanke werker teenoor die Swart werker is gemeet, asook die behoeftes wat volgens die Blanke werker by die Swart werker bestaan, bevredig is, of nie bestaan nie. Die behoeftes van Swart werkers, soos deur hulleself gesien, is ook ondersoek. Ten opsigte van sekere aspekte is beduidende verskille gevind.

  5. Die verbondeling in verband

    J. A.L. Taljaard


    Full Text Available Daar is dikwels en deur groot outoriteite al geskryf oor die mens in die samelewing. Hier wil ons egter die saak probeer aanraak uit ’n nuwe hoek, veral om die Skrifbeligting van die siening te benader. Vanselfsprekend verg hierdie benaming ’n skrifmatige mensbeskouing, maar ook ’n skrifmatige verbandsbeskouing. Die mens staan egter nie slegs in verhouding tot sy medemens nie maar ook in verhou­ ding tot stof, plant en dier. Boweal staan die mens in verhouding tot God, en hierdie verhouding is deurslaggewend vir al die ander verhoudinge waarin die mens hom bevind. Tog staan die mens ook in verhouding tot homself; wie kan die diepere roersele van die menslike siel peil, wie weet van die wroeginge, vreugde, leed en genot van die mens beter as hyself? Ook hierdie aspek verdien ons aandag. Op volledigheid kan nie aanspraak gemaak word nie, dit is ook nie my bedoeling nie. Die bedoeling is maar om die omvang van die tema aan te dui, die gedagtes te prikkel en veral om aan te spoor tot nuwe denkoriëntering waarin ook terminologies gebreek behoort te word met die neo-skolastiek binne reformatoriese lyn.

  6. A 1-D Analytical Model for the Thermally Induced Stresses in the Mould Surface During Die Casting

    Hattel, Jesper; Hansen, Preben


    This paper presents an anlytically based method for predicting the normal stresses in a die mold surface exposed to a thermal load. A example of application of the method is the high-pressure di casting process where the surface stresses in critical cases lead to cracks. Expressions for the normal...

  7. Wege in die Zukunft

    Kauermann, Göran; Mosler, Karl

    Die Zukunft stellt große Herausforderungen an die Arbeit der Deutschen Statistischen Gesellschaft. Sie betreffen die gestiegenen Anforderungen der Nutzer von Statistik, die Kommunikationsmöglichkeiten des Internets sowie die Dynamik der statistischen Wissenschaften und ihrer Anwendungsgebiete. Das Kapitel 5 beschreibt, wie sich die Gesellschaft diesen Herausforderungen stellt und welche Ziele sie sich in der wissenschaftlichen Zusammenarbeit und im Kampf gegen das Innumeratentum gesetzt hat.

  8. Die Gewalt der Frauen

    Angelika Ebrecht


    Full Text Available Anhand historischer Beispiele aus der Zeit der letzten Jahrhundertwende in Europa stellt die Autorin den Zusammenhang von Transgression, Aggression und Inversion dar. Gegen die gängige Auffassung, Gewalt sei männlich, setzt sie Selbst- und Fremdentwürfe von Frauen, die als Duellantinnen, Soldatinnen und Mörderinnen die gesellschaftlich festgelegten Grenzen der Gewalt verletzten. Sie interpretiert dies als Versuch, die Geschlechtergrenzen zu überschreiten und sich eine Subjektposition anzueignen.

  9. Antiglobalisierung die Andere Globalisierung

    Ljiljana Croce


    Das Ziel der Arbeit ist, ein je größeres Interesse an diesem Thema zu erwecken und auf die Gefahren hinzuweisen, denen wir alle verlaufen, wie die Armen, sowie auch die Reichen und die kleine Gruppe der zum mittleren Stand gehörenden, die immer mehr in die offene Armut versinken. Es wäre zu viel, in einer Welt solcher Globalisierung, die soziale Empfi ndlichkeit der Menschen zueinander zu erwarten. In Wirklichkeit geht sie immer mehr verloren. Der Mensch als Einzelperson, sowie auch die Völke...

  10. Modelling of Filling, Microstructure Formation, Local Mechanical Properties and Stress – Strain Development in High-Pressure Die Cast Aluminium Castings

    Kotas, Petr; Hattel, Jesper Henri; Thorborg, Jesper


    inherently affects the component’s properties depending on design, metallurgy and casting technique. The wall thickness influences the coarseness of the microstructure and the material will have properties depending on the local metallurgical and thermal histories. This is independent on the material, i.......e. whether the casting is based on cast iron- or aluminium-alloys. The distribution of local properties in a casting might vary substantially which makes it complex to optimize the casting with good accuracy. Often, mechanical simulations of the load situation are based on the assumption that the cast...... product has constant material properties throughout the entire casting. Thus, if the microstructure is determined or predicted at a given point, it gives the possibility to calculate the local material behavior more realistically. In the present work, a test case of a complex high-pressure die cast part...

  11. Verrekening van die kragveld van die verbond in die inkleding van die kommunikatiewe driehoeksverhouding tussen teks, hoorder en prediker


    In hierdie artikel word die kommunikatiewe driehoeksverhouding tussen die Bybelse teks, die hoorders en die prediker homileties verken. Die probleemstelling waarmee gewerk word handel oor potensiële versteurings wat kan plaasvind in hierdie driehoeksverhouding wanneer die hoorders en die prediker in hulle menslike beperktheid in verbinding gebring word met die ewige Woord van God soos dit in die Bybelse teks na vore kom. In die loop van die artikel word die volgende aspekte verken: ’n Ideale...

  12. A three-die cast technique for duplicating free gingival form in zirconia crowns: two case reports.

    Nozawa, Takeshi; Tanaka, Koji; Tsurumaki, Shunzo; Ookame, Yasuhisa; Enomoto, Hiroaki; Ito, Koichi


    This report describes a duplication technique of free gingival form from a provisional restoration to a zirconia crown. Three die casts were manufactured from a silicone impression with an acrylic resin ring tray. The first die cast was for the zirconia framework, the second for the provisionalized transfer coping, and the third for relining the provisional restoration. A free gingival impression was taken using a provisionalized transfer coping, and a soft gingival cast was manufactured. The depth of free gingival transparency was measured using a zirconia shade plate. Then, the zirconia framework was customized to allow for subgingival porcelain space. This technique seems to contribute to the clinical-laboratory interface in computer-aided design/computer-assisted manufacture restorations.

  13. Die voorspellingswaarde van die takseersentrum: 'n Oorsig

    H. J. Pietersen


    Full Text Available The assessment centre: a brief review of predictive value. Factors such as the rise of the professional manager, industrialization and worker expectations have, over the last few decades, increasingly placed managers in the limelight as a key occupational group. In this regard the assessment centre has become prominent as a method for the identification of managerial potential. However, a brief review of the relevant research literature indicates low predictive variances for the managerial assessment centre. This fact, together with the limited scope of the assessment centre, therefore necessitates, amongst other things, a wider research perspective which will include other work and non-work related factors as well. Opsomming Verskynsels soos die opkoms van die professionele bestuurder, industrialisering en stygende werkerverwagtinge het meegebring dat die kollig die afgelope paar dekades al hoe meer op bestuurders as sleutelberoepskategone geplaas is. In hierdie verband het veral die takseersentrum aandag gekry as 'n metode vir die identifisering van bestuurs- potensiaal 'n Kort oorsig van die betrokke navorsingsliteratuur toon egter lae voorspellingsvariansiesyfers vir die takseersentrum aan. Hierdie feit, tesame met die beperkte fokus van die takseersentrum, noodsaak, onder andere, 'n wyer navorsingsperspektief wat ook ander relevante werk- en nie-werkverwante faktore msluit.

  14. Die ontwikkeling van die bestuursmotiveringsvraelys (BMV

    A. S. Engelbrecht


    Full Text Available The development of the Managerial Motivation Questionnaire (MMQ: Several criticisms of the psychometric suitability of existing measures of managerial motivation are reported in the literature. This study aimed at developing a new psychometrically sound instrument, the Managerial Motivation Questionnaire (MMQ. This was done on the basis of a comprehensive study of the literature on managerial motivation and the role-motivation theory. The preliminary MMQ was systematically shortened and refined until the final MMQ of 98 items was composed. This was based on social desirability and semantic appraisal, item analysis and factor analysis of the questionnaire. The results indicate that it was possible to develop a final MMQ that was relatively free of social desirability. It further demonstrated satsifactory internal consistencies on two samples (a = 0/90, N = 360; a = 0/91, N = 535, where all subscale items were found to be relatively pure measures of the isolated factors. Although some evidence was found providing support for the reliability of the MMQ, a need for further research on the construct validity of managerial motivation still exists. Opsomming In die literatuur word verskeie punte van kritiek teen die psigometriese geskiktheid van bestaande meetinstrumente van bestuursmotivering gerapporteer. Die doelstelling van hierdie studie was dus om aan die hand van die konseptuele omiyning van bestuursmotivering, en die rolmotiveringsteorie as algemene verwysingsraamwerk, 'n nuwe psigometries aanvaarbare meetinstrument, die Bestuursmotiveringsvraelys (BMV, te ontwikkel. Op grond van sosiale wenslikheids- en semantiese beoordeling, itemontleding en faktorontleding van die voorlopige BMV is die vraelys stelselmatig verkort en verfyn totdat die finale BMV van 98 items saamgestel is. Die resultate dui daarop dat hierdie studie wel daarin geslaag het om 'n finale BMV te ontwikkel wat relatief vry van sosiale wenslikheid is, bevredigende interne

  15. Online industrial thermography of die casting tooling using dual-wavelength IR imaging

    Kourous, Helen E.; Shabestari, Behrouz N.; Luster, Spencer D.; Sacha, Jaroslaw P.


    Recent advances in IR system technology coupled with significant reduction sin cost are making thermography a viable tool for on-line monitoring of industrial processes. This paper describes the implementation of a novel rugged thermal imaging system based on a dual-wavelength technique for a large intelligent process monitoring project. The objective of the portion described herein is to deploy a non-contact means of monitoring die cast tooling surface thermal conditions and analyzing the data in the context of the process monitor. The technical and practical challenges of developing such a non-contact thermal measurement system for continuous inspection in an industrial environment are discussed, and methods of resolving them are presented. These challenges include implementation of a wavelength filter system for quantitative determination of the surface temperature. Additionally, emissivity variations of the tooling surface as well as IR reflections are discussed. The primary issues that are addressed, however, are compensation for ambient temperature conditions and optimization of the calibration process. Other issues center on remote camera control, image acquisition, data synchronization, and data interpretation. An example application of this system, along with in-plant images and thermal data, is described.

  16. Microstructural effects of phosphorus on pressure die cast Al-12Si components

    Suárez-Peña, B.


    Full Text Available The refinement of cuboidal silicon in eutectic Al-Si alloys by phosphorus additions used to manufacture pressure die cast components was studied. The results show that the addition of phosphorus in the form of AlFeP mother alloy before process degassing, leads to the best refinement of the size of the Si-cuboids phase, among several phosphorus additions analysed in the present research.

    Se ha estudiado el afino del silicio cuboidal en aleaciones eutécticas Al-Si por acción del fósforo, en piezas obtenidas mediante la técnica de fundición a presión. Tras la adición de fósforo en pruebas industriales, en las que dicho elemento se incorpora al baño con diversas composiciones, los mejores resultados se obtienen con la adición de la aleación madre AlFeP, previa al desgasificado industrial.

  17. Machining studies of die cast aluminum alloy-silicon carbide composites

    Sornakumar, Thambu; Kathiresan, Marimuthu


    Metal matrix composites (MMCs) with high specific stiffness, high strength, improved wear resistance, and thermal properties are being increasingly used in advanced structural, aerospace, automotive, electronics, and wear applications. Aluminum alloy-silicon carbide composites were developed using a new combination of the vortex method and the pressure die-casting technique in the present work. Machining studies were conducted on the aluminum alloy-silicon carbide (SiC) composite work pieces using high speed steel (HSS) end-mill tools in a milling machine at different speeds and feeds. The quantitative studies on the machined work piece show that the surface finish is better for higher speeds and lower feeds. The surface roughness of the plain aluminum alloy is better than that of the aluminum alloy-silicon carbide composites. The studies on tool wear show that flank wear increases with speed and feed. The end-mill tool wear is higher on machining the aluminum alloy-silicon carbide composites than on machining the plain aluminum alloy.

  18. Microstructure and property of zinc phosphate coating on die-casting magnesium alloy AZ91D

    LI Guang-yu; LIAN Jian-she; NIU Li-yuan; JIANG Zhong-hao


    A surface treatment method was described, which can form a uniform and dense phosphate conversion coating on the die -casting magnesium alloy AZ91D in a non-chromate and non-nitrite bath. The coating consists of Zn3(PO4)2-4H2O, Zn, AlPO4 and MgZn2(PO4)2 analyzed by XRD. The SEM results show that the microstructure of the zinc phosphate coating transfers from flower-like to slab-like crystals with the increase of immersion time of magnesium alloy samples in the phosphating bath. The zinc phosphate coating formed in the bath with immersion time of 1 min is denser because metallic Zn and insoluble phosphate crystals co-deposit on the magnesium alloy surface and the growth of the crystals are restricted by each others. The zinc phosphate coating on the magnesium alloy is used as the base layer for further cataphoric and powder paintings. The cataphoric painting on AZ91D alloy based on phosphate coating has similar adhesion and corrosion-resistance to that based on the chromate conversion coating. But for powder painting, the former exhibits better adhesion property than the latter, due to the uneven microstructure and the enough thickness of the phosphate coating.

  19. Galvanic corrosion behavior of die cast AZ91D magnesium alloy in chloride solution

    Zhensong Tong; Wei Zhang; Jiuqing Li; Jin Gao; Jiquan He; Ji Zhou


    The galvanic corrosion behavior of die cast AZ91D magnesium alloy coupled with H62 brass, 316L stainless steel, A3steel and LY12 aluminum alloy of different areas in 3.5% NaC1 solution was studied. The free corrosion potentials, galvanic potentials and currents of these galvanic couples were measured. The galvanic effects were determined by the mass loss and regression method using three points. The results show that: (1) In these four kinds of couples AZ91D acts as the anode, whose galvanic corrosion behavior is mainly controlled by the cathodic polarization; (2) The free corrosion potentials of these four kinds of couples change a liffle with time and cathodic/anodic area ratio (CAAR); (3) The galvanic potential of AZ91D/LY12 moves positively with the increase of time and CAAR; (4) The galvanic currents increase with CAAR, but there is difference in the current change between different couples; (5) The anodic dissolution rate of the magnesium alloy increases by 2-3 orders after being coupled with these four kinds of metals and the galvanic effects of these couples have such a relation as γH62>γ316LS.S>γLY12 >γA3.

  20. Die sestienpersoonlikheidsfaktorvraelys as hulpmiddel by die takseersentrum

    J. C. D. Augustyn


    Full Text Available The 16PF Personality Test as an aid to the assessment centre Assessment centres still remains costly and thime consuming. This study investigates the reduction of time and costs by the use of the 16 PF Personality Test as a method for measuring management dimensions. Promising results were obtained with a relatively small sample for the prediction of initiative and perseverance. Significant multiple correlations were also found for three criteria of management success. Further research may establish the use of the 16 PF as an aid to management assessment and thereby reduce the costs and time involved in assessment centres. Opsomming Takseersentrums se grootste probleem is gelee in die koste en tyd wat dit behels. Hierdie studie ondersoek die moontlikheid om beide te verminder deur die aanwending van die 16 PF Persoonlikheidsvraelys vir die meting van bestuursdimensies. Belowende resultate is met 'n relatiewe klein steekproef bevind ten opsigte van die voorspelling van inisiatiefen deursettingsvermoe. Beduidende meervoudige korrelasies is ook ten opsigte van drie kriteria van bestuursukses bevind. Verdere navorsing kan die gebruik van die 16 PF as hulpmiddel by bestuursevaluering vestig en sodoende die tydsduur en koste van takseersentrums verminder.


    norm aan die een kant en deur die S^^eeksnorm aan die ander." (ibid. 384). ...... grondslag, hoewel die groot aantal voorbeelde uit die werke van Thomas Mann ...... Mentrup, W., & P. Kuhn, (1980) "Deutsche Sprache in Osterreich und in der.

  2. Cradle-to-Gate Impact Assessment of a High-Pressure Die-Casting Safety-Relevant Automotive Component

    Cecchel, Silvia; Cornacchia, Giovanna; Panvini, Andrea


    The mass of automotive components has a direct influence on several aspects of vehicle performance, including both fuel consumption and tailpipe emissions, but the real environmental benefit has to be evaluated considering the entire life of the products with a proper life cycle assessment. In this context, the present paper analyzes the environmental burden connected to the production of a safety-relevant aluminum high-pressure die-casting component for commercial vehicles (a suspension cross-beam) considering all the phases connected to its manufacture. The focus on aluminum high-pressure die casting reflects the current trend of the industry and its high energy consumption. This work shows a new method that deeply analyzes every single step of the component's production through the implementation of a wide database of primary data collected thanks to collaborations of some automotive supplier companies. This energy analysis shows significant environmental benefits of aluminum recycling.

  3. The fuzzy algorithm in the die casting mould for the application of multi-channel temperature control

    Sun, Jin-gen; Chen, Yi; Zhang, Jia-nan


    Mould manufacturing is one of the most basic elements in the production chain of China. The mould manufacturing technology has become an important symbol to measure the level of a country's manufacturing industry. The die-casting mould multichannel intelligent temperature control method is studied by cooling water circulation, which uses fuzzy control to realize, aiming at solving the shortcomings of slow speed and big energy consumption during the cooling process of current die-casting mould. At present, the traditional PID control method is used to control the temperature, but it is difficult to ensure the control precision. While , the fuzzy algorithm is used to realize precise control of mould temperature in cooling process. The design is simple, fast response, strong anti-interference ability and good robustness. Simulation results show that the control method is completely feasible, which has higher control precision.

  4. An establish attempt of reasons of machining splinter formation in AC47000 alloy high pressure die castings

    J. Mutwil


    Full Text Available A problem of splinter formation during machining the AC47000 alloy high pressure die casting has been experimental investigated. Inorder to establish the reason of this occurrence a set of 200 high pressure die casting of the tensile strength samples have been prepared. The tensile tests were carried out using a Zwick Z050 universal testing machine. JM-SPC program has been used for statistical analysis of test results. A large variability of tensile strength results has been found. In order to find the reason of this variability the fracture surfaceinvestigations (macrographs for all of samples and SEM micrographs for chosen samples have been carried out. It has been establish thatin all cases a significant decrease of tensile strength was caused by presence of inclusions or porosity.

  5. An establish attempt of reasons of machining splinter formation in AC44200 alloy high pressure die castings

    J. Mutwil


    Full Text Available A problem of splinter formation during machining the AC44200 alloy high pressure die casting has been experimental investigated. Inorder to establish the reason of this occurrence a set of 200 high pressure die casting of the tensile strength samples have been prepared. The tensile tests were carried out using a Zwick Z050 universal testing machine. JM-SPC program has been used for statistical analysis of test results. A large variability of tensile strength results has been found. In order to find the reason of this variability the fracture surface investigations (macrographs for all of samples and SEM micrographs for chosen samples have been carried out. It has been establish that in all cases a significant decrease of tensile strength was caused by presence of inclusions or porosity. In lot of cases the inclusions have a form of oxide film.

  6. Development of a 3D Filling Model of Low-Pressure Die-Cast Aluminum Alloy Wheels

    Duan, Jianglan; Maijer, Daan; Cockcroft, Steve; Reilly, Carl


    A two-phase computational fluid dynamics model of the low-pressure die-cast process for the production of A356 aluminum alloy wheels has been developed to predict the flow conditions during die filling. The filling model represents a 36-deg section of a production wheel, and was developed within the commercial finite-volume package, ANSYS CFX, assuming isothermal conditions. To fully understand the behavior of the free surface, a novel technique was developed to approximate the vent resistances as they impact on the development of a backpressure within the die cavity. The filling model was first validated against experimental data, and then was used to investigate the effects of venting conditions and pressure curves during die filling. It was found that vent resistance and vent location strongly affected die filling time, free surface topography, and air entrainment for a given pressure fill-curve. With regard to the pressure curve, the model revealed a strong relation between the pressure curve and the flow behavior in the hub, which is an area prone to defect formation.

  7. Die etiek van Luther

    J. H. van Wyk


    Full Text Available Dink ons aan die etiek van Luther dan spring onmiddellik ’n paar boeiende uitsprake van hom na vore soos o.a. dat Christene vanuit die gemeenskap met Christus nuwe dekaloë moet maak wat helderder as die van Moses kan wees, of dat ons in bepaalde sin vir ons naaste ’n Christus moet word. Die bydrae van Luther 'tot die Christelike etiek is sonder twyfel van groot betekenis en die bestudering daarvan die moeite werd. Luther is geprys as rewolusionêr en verguis as konserwatis, hy is geëer as iemand wat weer die ware be­tekenis van godsdiens ontdek het toe die lewe vervloei het in etiek. Of dit egter korrek is om sy etiek as konserwatief te tipeer, soos White doen, moet betwyfel word.

  8. Development of a new metal casting technique for micromechanical systems; Entwicklung einer neuen Metallgiesstechnik fuer die Mikromechanik

    Bach, F.W.; Moehwald, K.; Hollaender, U.; Nakhosteen, B. [Dortmund Univ. (Germany). Lehrstuhl fuer Werkstofftechnologie


    The effect that metallic molten masses can flow into deep and narrow gaps by capillary action forms the basis of the mould filling mechanism of the micro casting process presented here. Potential applications of ''Capillary Action Microcasting'' are the minimal invasive surgery (e. g. micromechanical endoscope items, grippers and cutting tools), magnetic actuators and the micro-electromechanical system (MEMS) technique (e. g. magnetic cores for micromechanical drive components and sensors) as well as the technology of mechanism design. Castings of a eutectic silver-copper alloy prove that both a definition and a guaranteed withdrawal of the cast part are achieved. The procedure is suitable and promising for the production of magnetic components, e. g. Fe47Sb53 for micro-electric motors. (orig.) [German] Der Effekt, dass metallische Schmelzen durch Kapillardruck in enge, tiefe Spalte einfliessen koennen, bildet die Basis fuer den Formfuellungsmechanismus des hier vorgestellten Mikro-Giessverfahrens, des ''Metall-Kapillardruckgiessens''. Potentielle Anwendungen werden in der minimalinvasiven Chirurgie (z. B. mikromechanische Endoskopelemente, Greiferzangen und Schneidwerkzeuge), der Magnetoaktorik und der mikro-elektromechanischen System (MEMS)-Technik, z. B. magnetische Kerne fuer mikromechanische Antriebselemente und Sensoren, sowie der Getriebetechnik erwartet. Abguesse, die mit Ag72Cu28-Schmelzen kapillardruckgegossen wurden, belegen, dass sowohl eine hohe Konturentreue als auch eine sichergestellte Entnahme des Gussteils realisiert wird. Das Verfahren ist geeignet und aussichtsreich fuer die Herstellung magnetischer Bauteile aus Fe47Sb53, wie z. B. fuer Mikro-Elektromotoren. (orig.)

  9. Ambrosius en die virginitas

    C. J. Malan


    Full Text Available Ambrosius het met reg die benaming “Leraar van Maagdelikheid” ontvang (Dooley, 1948:119. Die opmerking van Thamin: “C’est une vertu proprement chrétienne que la vertu de virginité, proclame tout d’abord saint Ambroise” (1895:344, gee dadelik aanleiding tot die vraag of Ambrosius dan geen waardering vir die huwelik gehad het nie. Hierdie vraag word nog meer dringend as sy beskrywing van die kruis van die getroude lewe nagegaan word.

  10. Numerical optimization of die geometry in open die forging

    Christiansen, Peter; Hattel, Jesper Henri; Bay, Niels


    This paper deals with numerical optimization of open die forging of large metallic ingots made by casting implying risk of defects, e.g. central pores. Different material hardening properties and die geometries are combined in order to investigate, which geometry gives rise to maximum closure...... of a centreline hole in a single compression operation. Friction is also taken into account. The numerical analysis indicates that a lower die angle of approximately 140o results in the largest centreline hole closure for a wide range of material hardening. The value of optimum die angle is not influenced...... by friction, which was found only to change the degree of centreline porosity closure in case of small lower die angle....

  11. Navorsing op die gebied van die sosiale wetenskappe*

    P. M. Robbertse


    Full Text Available In Hollands is die woord scientia vertaal met wetenskap, wat sowel die natuur- as die geesteswetenskappe insluit, waardeur die woordsy oorspronklike betekenis behou. Die neiging bestaan om die Engels science met wetenskap in Afrikaans te vertaal, waarmee dan eintlik die natuurwetenskap bedoel word.

  12. Foute in die meting van die aarde se magneetveld met die protonmagnetometer

    G. P. Hancke


    Full Text Available Die tipiese foute wat voorkom wanneer die metode van periode-meting gebruik word vir die bepaling van die presessiefrekwensie van die magnetiese moment van protone, word bespreek, en metodes om dit teen te werk word voorgestel. Belangrike gevolgtrekkings wat sal lei tot die optimale funksionering van die periodemeter, word gemaak — veral ten opsigte van die meettyd, polarisasietyd en die eienskappe van die sensorvloeistof.

  13. Wake up and Die

    Schubart, Rikke


    Anmeldelse af den colombianske gyserfilm Volver a morir (eng. titel Wake Up and Die) af Miguel Urrutia......Anmeldelse af den colombianske gyserfilm Volver a morir (eng. titel Wake Up and Die) af Miguel Urrutia...

  14. Die radio in Afrika

    S. de Villiers


    Full Text Available Omvang van radio-uitsendings in en na Afrika. — Redes vir die versnelde tempo van uitbreiding. — Radio as die geskikste massa-kommunikasiemiddel vir Afrika. — Faktore wat die verspreiding bemoeilik. — Skouspelagtige toename in luistertalle.Toe Plinius, wat in die jaar 79 oorlede is, in sy „Historia Naturalis” verklaar het dat daar altyd iets nuuts uit Afrika afkomstig is, kon hy nouliks voorsien het dat die „iets" negentien eeue later in die lug sou setel wat hierdie reuse-vasteland oorspan — ’n Babelse spraakverwarring en ’n ongekende, verbete woorde-oorlog in die etergolwe, onder meer daarop bereken om die harte en hoofde van derduisendes te verower.

  15. Die verhouding doop en geloof

    L. Floor


    Full Text Available By die aanvalle wat op die kinderdoop geloods word, kom telkens die verhouding doop en geloof ter sprake. Die geloof is so wesentlik met die doop verbonde, sodat daar nie gedoop mag word waar die geloof nie aanwesig is nie. 0ns lees inderdaad dwarsdeur die Nuwe Testament van ’n innige samehang wat daar tussen geloof en doop beslaan.

  16. Die gebruik van parallelplaatreologie vir die bepaling van die intrinsieke viskositeit van poli-etileentereftalaat

    O. C. Vorster


    Full Text Available Die bepaling van die intrinsieke viskositeit van poli-etileentereftalaat word bemoeilik deur die feit dat daar tans slegs twee metodes in gebruik is. In die eerste metode word die bepaling deur middel van oplossingsviskometrie gedoen, maar die toksisiteit van die oplosmiddel, asook die tydperk wat dit neem om die bepaling te doen, is ’n probleem. Die tweede metode word beperk deur die kompleksiteit en beskikbaarheid van die apparatuur in Suid-Afrika. In hierdie studie word ’n alternatiewe metode, gebaseer op parallelplaatreologie, voorgestel wat albei hierdie probleme oorkom en die resultate sodoende verkry, word vergelyk met dié wat met bestaande metodes verkry is.

  17. Die invloed van die neo-marxistiese kultuuranalise op die Wêreldraad van Kerke en die Gereformeerde Kerke van Nederland

    J. M. Vorster


    Full Text Available Toe die studente dwarsoor die VSA en Europa in die laat sestigerjare ’n plotselinge en radikale verset openbaar het teen die bestaande orde, het hulle die deur geopen vir ’n nuwe mededinger om die hart van die Westerse kultuur. Dit is die nou reeds bekende neo-Marxisme. Sedertdien het hierdie jongeling sy voetspore op vele vlakke van die Westerse kultuur gelaat.

  18. Die lebensvision des semonides

    Milivoj Sironić


    Full Text Available Der Autor analysiert die Weibersatire des Semonides und andere seiner kurzen Fragmente. Dabei kommt er zu der Schlussfolgerung, dass sich die Verse der Satire durch eine gute Technik auszeich­ nen, dass aber auch eine unnötige Weitschweifigkeit nicht zu Ubersehen ist. Trotzdem kann man jedoch dem Dichter nicht die künstlerische Überzeugungskraft absprechen, wie auch die Ten­ denz nach Detailschilderungen und die Feinheit geistreicher Charakterisierungen. Die Aussage beinhaltet manchmal eine be­ stimmte innere Ironie in der Einfachheit der Wörter.In kurzen Fragmenten wird die Fähigkeit des Semonides sichtbar, sich sehr präzise auszudrücken. Seine ironisch-epische Sprache ist sehr reich  und verdient vom linguistischen Standpunkt aus Auf­ merksamkeit wegen ihres reichhaltigen lexischen und termino­ logischen Materials, insbesondere was die Bereiche der Tier­ welt und des Essens anbelangt.Die Weltanschauung des Dichters ist in dem ersten Fragment recht deutlich erkennbar. Da sieht man, dass er düster und pessimistisch auf das Leben blickt. Das Fehlen jeglicher positiven Einstellung hat dann den Sar­ kasmus zur Folge, mit dem der Dichter die Darstellung der Weiber einkleidet, ihn aber auch auf die Menschen schlechthin ausweitet.

  19. Verskuiwing in die moraal?

    S.P. van der Walt


    Full Text Available Modewoorde het ons deesdae oorgenoeg in die Christelike sedeleer en hulle kan nogal verwarring stig. U moet my vergun om met u te spreek oor een so ’n modewoord nl „verskuiwing’’ in die moraal. Dis nogal ’n mooi woord, wat so dikwels gebruik word op baie terreine en tog meer wil aandui as maar net ’n veranderde sienswyse, ’n wysiging in opvattinge of nuwe riglyne wat al gangbaar geword het in die praktyk. Die begrip wil eintlik die ewolusionêre gang beklemtoon, want dit is dan eintlik net die ou norme wat effens anders bekyk word of nie meer so nou geneem of dik onderstreep word nie. Die verskuiwing beteken dan dat alles nog dieselfde bly, net die posisie of plek het verander. Verskuiwing beteken tog plekverandering of plekwisseling en dan sekerlik nie in die sin dat die plekke ver uitmekaar lê nie. Verskuiwing beteken net maar vlak langs die vorige te staan kom. As dit dan ’n beter plek is, is dit ewolusie, ontwikkeling, verbetering.

  20. Effect of Injection Velocity on Structure Part Characteristic in AZ50 Die Casting Process with High Vacuum System


    When diecasting large and thin Mg alloy parts, material defects occur, which include porosity, nonuniform mechanical properties, irregular surfaces, and incomplete filling. To resolve these problems, it is necessary to have uniform injection velocities and temperatures as well as control the melt. This study investigated the feasibility of producing large and thin components using a die caster by attaching a high vacuum system. In particular, the effects of injection velocity on surface quality and the mechanical properties of the products were investigated. Hence, an injection velocity scheme and a die structure capable of casting in a vacuum were proposed. As a result, it was found that the critical low injection velocity was 0.2 m/s to produce large thin Mg alloy structures having good mechanical properties.

  1. Die karst-ekologie van die Bakwenagrot (Gauteng

    François Durand


    Full Text Available Die Bakwenagrot huisves ’n verskeidenheid organismes wat ’n ingewikkelde en verweefde voedselweb vorm. ’n Kolonie Natalse langvingervlermuise gebruik hierdie grot regdeur die jaar as blyplek. Die vlermuisguano en dooie plantmateriaal wat van buite in die grot inval, vorm die basis van die ekologie in die grot wat ook as ’n tipiese detritus-gedrewe ekostelsel beskryf kan word. Afbrekers soos bakterieë en swamme wat vir die afbraak van die guano en plantreste verantwoordelik is, word deur ’n verskeidenheid organismes, insluitend nematode en myte, as voedselbron benut. Hierdie organismes wat die volgende trofiese vlak vorm, word deur predatoriese artropode as voedselbron benut. Die Bakwenagrot is een van die weinige dolomietiese grotte in Suid-Afrika wat dit vir ‘n mens moontlik maak om tot by die grondwatervlak te kom. Die grondwater huisves verskeie tipes organismes waaronder bakterieë, swamme en diere – hoofsaaklik nematode en krustaseë. Die Bakwenagrot is ook die hoofvindplek waar varswater-amfipode in Suider-Afrika gevind is. Hierdie besondere en sensitiewe ekostelsel is hoofsaaklik van guano van die vlermuiskolonie afhanklik. Die grasveld in die gebied rondom die grot, wat as voedingsarea vir die vlermuiskolonie dien, word tans deur voorstedelike ontwikkeling en die gevolglike habitatfragmentasie en -vernietiging bedreig. Indien die vlermuise die grot sou verlaat, sal dit ’n hele domino-effek van uitsterwing van die grotbewonende organismes tot gevolg hê.

  2. Die voorgeskiedenis van kwantumberekening

    P. H. Potgieter


    Full Text Available

    Die hoofidees wat tans gestalte vind in die teorie en tegnologie van kwantumberekening is in die laat 1970’s en vroeg 1980’s deur fisici in die Weste en ’n wiskundige in die voormalige Sowjetunie neergelˆ e. Dat di´ e teorie ook wortels in die Russiestalige vakliteratuur het, is nie algemeen bekend in die Weste nie. Daar word kortliks gekyk na die idee soos deur Benioff en (veral Feynman in die Weste versprei, asook die voorstel van di´ e rekengrondslag deur Manin in die Russiese literatuur. Die outeur hoop om hiermee so ’n onpartydig moontlike sintese van die vroe ¨ e gedagtegeskiedenis rondom kwantumberekening aan te bied. Die rol van omkeerbare en onomkeerbare berekeningsprosesse word vlugtig bekyk soos dit verband hou met die ontstaan van kwantumberekening, asook die sogenaamde Inligtingsparadoks in die fisika. Die inligtingsteorie en die fisika het heelwat met mekaar te kommunikeer, soos hierdie paradoks uitwys.


    The pre-history of quantum computation

    The main ideas behind developments in the theory and technology of quantum computation were formulated in the late 1970s and early 1980s by two physicists in the West and a mathematician in the former Soviet Union. It is not generally known in the West that the subject has roots in the Russian technical literature. The idea, as propagated by Benioff and (especially Feynman, is reviewed along with the proposition of a foundation for this kind of computation by Manin in the Russian literature. The author hopes to present as impartial a synthesis as possible of the early history of thought on this subject. The role of reversible and irreversible computational processes will be examined briefly as it relates to the origins of quantum computing and the so-called Information Paradox in physics. Information theory and physics, as this paradox shows, have much to communicate to each other.

  3. Die benutting van water in die landbou: strategie vir die toekoms

    D. S. van der Merwe


    Full Text Available ’n Uiteensetting word gegee van die faktore wat die hoofrol in die toekomstige waterbenutting in die landbou gaan speel. Hierdie faktore is die hoeveelheid water beskikbaar vir landboudoeleindes; die toenemende mineraiisasie van besproeiingswater; en die invloed wat energiebehoeftes op besproeiing sal hê. Navorsing is nodig om die situasie na wense te hanteer, en die aanbevelings van besproeiingsnavorsingswerksessies in hierdie verband word kortliks aangedui en bespreek.

  4. Improved life of die casting dies of H13 steel by attaining improved mechanical properties and distortion control during heat treatment. Year 1 report, October 1994--September 1995

    Wallace, J.F.; Schwam, D. [Case Western Reserve Univ., Cleveland, OH (United States)


    Optimum heat treatment of dies (quenching) is critical in ensuring satisfactory service performance: rapid cooling rates increase the thermal fatigue/heat checking resistance of the steel, although very fast cooling rates can also lead to distortion and lower fracture toughness, increasing the danger of catastrophic fracture. Goal of this project is to increase die life by using fast enough quenching rates (> 30 F/min ave cooling rate from 1750 to 550 F, 1/2 in. below working surfaces) to obtain good toughness and fatigue resistance in Premium grade H-13 steel dies. An iterative approach of computer modeling validated by experiment was taken. Cooling curves during gas quenching of H-13 blocks and die shapes were measured under 2, 5, and 7.5 bar N2 and 4 bar Ar. Resulting dimensional changes and residual stresses were determined. To facilitate the computer modeling work, a database of H-13 mechanical and physical properties was compiled. Finite element analysis of the heat treated shapes was conducted. Good fit of modeled vs measured quenched rates was demonstrated for simple die shapes. The models predict well the phase transformation products from the quench. There is good fit between predicted and measured distortion contours; however magnitude of predicted distortion and residual stresses does not match well the measured values. Further fine tuning of the model is required.

  5. Openbaring, teologie en die regswetenskap

    S. Postma


    Full Text Available In die jongste tyd is telkens en weer gewaarsku teen die gevare van oorspesialisasie en die hipertrofie van professionalisme. Die gemis aan ’n totaliteitsvisie wat hiermee gepaard gaan, word dan ook tereg teengegaan en wel deur aan die Wysbegeerte as die Wetenskap van die totaliteit van die kosmos in toenemende mate sy regmatige plek as wetenskapsintegreerder te gun. Hierdie grootmoedige gun van ’n plek in die son van geleerdheid kan egter ook uit bedenklike motiewe plaasvind. Die vakwetenskaplike kan nie of wil nie die plek en betekenis van sy spesifieke vak bepaal en bepeins nie en vind dit in elk geval moeilik om die verband tussen Gods Woord en sy besondere vak in duidelike perspektief te sien; vandaar dan ’n grootmoedige toelaat dat die wysbegeerte die „veritas” dien terwyl die eie ek tevrede is om die „utilitas” onderdanig te wees.

  6. Die tug oor ampsdraers tydens die doleansie van 1886

    J. Visser


    Full Text Available In art 29 van die Nederlandse Geloofsbelydenis word bely: “Die merktekens om die ware Kerk te ken is die volgende: As die Kerk die suiwere prediking van die evangelie uitoefen, as dit die suiwer bediening van die sakramente gebruik soos Christus dit ingestel het, as die kerklike tug gebruik word om die sondes te straf.” Dit spreek vanself dat wanneer ampsdraers, aan wie Christus sy kudde toevertrou het (Hand 20 : 28, met leer en /of lewenswandel in sonde volhard en nie daarin met tug gestuit word nie, word die ware kerk nie gebou nie maar afgebreek. 0ns sal later in hierdie artikel aantoon hoedanig die suiwer tug oor ampsdraers, veral leertug, tydens die Doleansie tot skade van die kerk van Christus agterweë gebly het.

  7. Spray-formed tooling for injection molding and die casting applications

    K. M. McHugh; B. R. Wickham


    Rapid Solidification Process (RSP) Tooling{trademark} is a spray forming technology tailored for producing molds and dies. The approach combines rapid solidification processing and net-shape materials processing in a single step. The ability of the sprayed deposit to capture features of the tool pattern eliminates costly machining operations in conventional mold making and reduces turnaround time. Moreover, rapid solidification suppresses carbide precipitation and growth, allowing many ferritic tool steels to be artificially aged, an alternative to conventional heat treatment that offers unique benefits. Material properties and microstructure transformation during heat treatment of spray-formed H13 tool steel are described.

  8. Spray-formed Tooling for Injection Molding and Die Casting Applications

    Mc Hugh, Kevin Matthew


    Rapid Solidification Process (RSP) ToolingTM is a spray forming technology tailored for producing molds and dies. The approach combines rapid solidification processing and net-shape materials processing in a single step. The ability of the sprayed deposit to capture features of the tool pattern eliminates costly machining operations in conventional mold making and reduces turnaround time. Moreover, rapid solidification suppresses carbide precipitation and growth, allowing many ferritic tool steels to be artificially aged, an alternative to conventional heat treatment that offers unique benefits. Material properties and microstructure transformation during heat treatment of spray-formed H13 tool steel are described.

  9. Die sterwende kindjie

    J.T. De Jongh van Arkel


    Full Text Available The thought of a child dying appears as an antithesis and thus the feelings evoked by the dying child are stronger than when older persons are dying. Around the child’s death bed there is no place for detached spectators and all become involved in caring for and supporting him. Caregivers also have a supporting responsibility towards the members of the child’s family.

  10. Ontsporing van die regstaatsbegrip en sy konsekwensies vir die afrikanervolk

    N. G.S. Van der Walt


    Full Text Available Die opvatting van die suiwere regstaat bring sy vraagstukke mee wanneer dit in verband gebring word met die leer van die soewereiniteit in eie kring. Laasgenoemde leer wortel in die geloof dat God die mens roep tot diens aan Hom, en dat die mens vry moet wees om ten opsigte van alle lewensaspekte God na die hoogste mate te kan dien. Hierdie verskeidenheid van aspekte is deur dr. A. Kuyper en sy volgelinge gesistemati- seer tot menslike verbande en lewenskringe, elk met ’n be- paalde sfeer waarin ander kringe nie mag inmeng nie. Elkeen is dan soewerein binne sy eie kring. Met verwysing na die staat is dan gespreek van die staatstaak as synde die hand- hawing van die reg, en omdat die staat in toenemende mate hom veral in die latere tyd ook besig gehou het met bedrywig- hede wat nouliks as van juridiese aard beskou kan word, is daar die onderskeid gemaak tussen die primêre en sekundêre taak van die staat. Die sistematiek van die wetsidee, deur prof. Dooyeweerd ontwikkel, waar die staat sy bestemmingsfunksie in die regsaspek vind, het vanselfsprekend geen plek vir so 'n dualistiese staatstaak nie, en die oplossing is deur sommige daarin gesoek om sulke staatsoptrede te vertolk as hebbende wel betrekking op die regsgemeenskap of die regsverkeer. Staatsondernemings soos paaie, spoorweë, spellingreëling, ens. word dan beskou as noodsaaklik vir die instandhouding van die regsgemeenskap en regsverkeer. Tereg wys A. M. Donner1 daarop dat so ’n vertolking eintlik neerkom op ’n oorspanning van die regsbegrip. Hy self sien dan die staatstaak in vrede- of orde-handhawing, wat in die eerste plaas wel regshandha- wing veronderstel. Onder orde word dan alles verstaan wat noodsaaklik is vir die gladde verkeer in die ontwikkelingsgang van die regsgemeenskap. Die wese van die staat het dan vol- gens hom te doen met reg, maar sy taak is meer as suiwere regshandhawing. Wat onrus verwek en die orde versteur, moet uit die openbare lewe verwyder word, en die

  11. Mensuration and simulation of mold filling process in semi-solid die-cast of aluminum alloy

    YANG Yi-tao; WANG Jian-fu; ZHANG Heng-hua; SHAO Guang-jie


    To understand the flow trace of semi-solid slurry in mold cavity, some thermocouples were inserted in mold cavity, and the reaction timing of thermocouples showed the arrival of fluid. The filling time and rate were estimated by comparison between the experiment and calculation. The introduction of computer simulation technique based on ADSTEFAN was to predict injectionforming process and to prevent defects during trial manufacture of various parts. By comparing the formed appearance of parts in experiment and in simulation, and observing the relationship between internal defects inspected by X-ray or microscope and the flow field obtained in simulation, it was indicated that both have quite good agreement in simulation and experiment. Right predictions for cast defects resulted from mold filling can be carried out and proper direction was also proposed. The realization of numerical visualization for filling process during semi-solid die-cast process will play an important role in optimizing technology plan.

  12. Analise van die Tswanaraaisel

    S. A. Swanepoel


    Full Text Available ’n Strukturele, stilistiese en funksionele bcskrywing van die Twanaraaisel bring mee dat daar aan die volgende aspekte aandag gegee moet word: •\tWat is ’n raaisel en lioe word dit in Tswana genoem. •\tTot watter studiegebied en literere genre hoort die raaisel en watter subvorme kan vir Tswana onderskei word. •\tHoe sien die struktuur van Tswanaraaisels daar uit. •\tDeur wie, waar, wanneer en hoe word Tswanaraaisels voorgedra. •\tWatter stilistiese kenmcrke kan in Tswanaraaisels onderskei word. •\tWatter funksies vervul raaisels in ’n Tswanagcmeenskap.

  13. Die brein soos beskou deur die Grieke en Romeine

    Francois P. Retief


    Full Text Available In Ou Egipte is mummifikasie met uitgebreide reseksie of uitsnyding van organe geassosieer, maar geen kennis is geneem van die morfologie van die brein nie. Griekse skrywers van die sesde en vyfde eeue v.C. het die brein aanvanklik gesien as die setel van intelligensie, die orgaan van sensoriese waarneming en gedeeltelik die oorsprong van sperma. Pneuma het ’n belangrike rol in breinfunksie gespeel. Hippokrates was die eerste om die brein te beskryf as ’n dubbele orgaan, wat met harsingvlies (meninges bedek, funksioneel van pneuma afhanklik en vertolker van begrip is. Tydgenote soos Plato, Aristoteles en Diokles het tot die beskrywing bygedra, maar laasgenoemde twee het beweer dat die hart die middelpunt van intelligensie is en nie die brein nie. Gedurende die laaste helfte van die vierde eeu v.C. is disseksie van die menslike liggaam tydelik aan die mediese skool van Alexandrië toegelaat en het dit tot merkwaardige vooruitgang in die begrip van die menslike anatomie en fisiologie gelei. Herofilus en Erasistratus het uitstekende beskrywings van die struktuur en funksie van die brein gegee wat eers in die tweede eeu n.C. deur Galenus geëwenaar is.

  14. Prediking oor die poëtiese stof van die Ou Testament - Die Psalms

    E. J. Smit


    Full Text Available ’n Belangrike rede waarom die prediking uit die Psalms ’n aparte bespreking regverdig, is die feit dat die Psalms die omvangrykste verteenwoordiging van poetiese stof in die Ou Testament be vat. Dit is nie vir almal ewe maklik om poesie te lees en te verklaar nie.

  15. Die hebsugtige seekoei en Rooikappie: Die groteske in sprokies

    Dineke van der Walt


    Full Text Available Hierdie artikel bied ’n vergelykende lees van twee volksverhale wat ook as kinderverhale getipeer kan word (een vanuit Venda-folklore en die ander ’n populêre Europese narratief met die oog daarop om spesifieke ooreenkomste uit te lig – soos die eet van mensvleis, goedgelowige mense wat deur ‘n maskerspel om die bos gelei word en ander ‘onetiese’ en ‘immorele’ aktiwiteite. In Die hebsugtige seekoei boots die monster byvoorbeeld die stem van die jong seun na om sy suster te flous en toegang tot hulle hut te verkry, terwyl die wolf in Rooikappie op sy beurt die ouma flous om die huis te kan betree sodat hy later ook vir Rooikappie kan mislei. In albei stories word die jong meisies (asook Rooikappie se ouma deur ’n seekoei óf ’n wolf opgeëet. Soos gewoonlik in sprokies, word die slagoffers gered of ontsnap en die verhale het ’n gelukkige einde. Alhoewel dit absurd mag voorkom dat kinderverhale elemente van die groteske bevat, argumenteer ek dat dit inderdaad ’n bruikbare doel dien. Hierdie verhale betrek kinders nie net op ’n emosionele vlak nie (as gevolg van die skokwaarde van die groteske; die groteske dien ook as objek van fassinasie. Sodoende word die waarskuwingsboodskap in die verhale beter oorgedra en onthou deur die kinders.

  16. Casting dimensional control and fatigue life prediction for permanent mold casting dies. Technical progress report, September 29, 1993-- September 30, 1994



    First year efforts as part of a three year program to address metal casting dimensional control and fatigue life prediction for permanent mold casting dies are described. Procedures have been developed and implemented to collect dimensional variability data from production steel castings. The influence of process variation and casting geometry variables on dimensional tolerances have been investigated. Preliminary results have shown that these factors have a significant influence on dimensional variability, although this variability is considerably less than the variability indicated in current tolerance standards. Gage repeatability and reproducibility testing must precede dimensional studies to insure that measurement system errors are acceptably small. Also initial efforts leading to the development and validation of a CAD/CAE model to predict the thermal fatigue life of permanent molds for aluminum castings are described. An appropriate thermomechanical property database for metal, mold and coating materials has been constructed. A finite element model has been developed to simulate the mold temperature distribution during repeated casting cycles. Initial validation trials have indicated the validity of the temperature distribution model developed.

  17. Die entwicklung, die metamorphose, die entstehung: Die konzepte des organismus von Aristoteles bis Darwin

    Kamerer Eva


    Full Text Available (nemački In diesem Aufsatz versuche ich, die Elemente verschiedener Konzepte des Organismus in der Philosophie und in der Wissenschaft zu analysieren. Die Deutungen des Organismus und der Einheit der Natur bei Aristoteles, Kant und Goethe werden als ein Beispiel der Bewegung von einem finalistischen zum antifinalistischen Bild der Natur verstanden.

  18. Die Gattung Oerstedia

    Stiasny-Wijnhoff, G.


    Die vorliegenden Individuen von Oerstedia dorsalis (Abildg.) wurden in den Helder an der holländischen Küste gesammelt; die Art war in frühern Jahren im Hafen sehr allgemein. Sie lebte zwischen Tubularien und Muschelbrut, welche in der Gezeitenzone den Schiffsrümpfen angewachsen sind und enthielt im

  19. Die Mollusken der Njalindungschichten

    Martin, K.


    Die Versteinerungen, welche im folgenden behandelt sind, sammelten meine Frau und ich im Jahre 1910 in den Preanger-Regentschappen von Java, in der Gegend von Njalindung ¹). Sie stammen aus Sedimenten, für welche ich den Namen Njalindungschichten einführte, und für die Gastropoden wurde bereits eine

  20. Die oorsake vir die ontstaan en besondere aard van die Zion Christian Church

    M. A. Kruger


    Full Text Available Aanvanklik het die Z.C.C. geen opsienbarende groei getoon nie, maar veral sedert die veertigerjare het hulle getalle skerp toegeneem en versprei oor die hele land. In 1963 is Edward Lekganyane toegelaat tot die Stofberg Teologiese Skool van die N.G. Kerk. Sedert die stigting van die Z.C.C. het die groep al verder van die Woord af weg beweeg, maar met hierdie toetrede tot die skool het daar by Edward self ’n mate van verandering gekom.

  1. Tweedetaalteorie vir die eerstetaalonderwyser

    Ludolph Botha


    Full Text Available In hierdie artikel word die eerstetaalonderwyser se aandag op tweedetaalteorie gevestig. Krashen se tweedetaalteorie word uitgesonder en die implikasies van sy werk vir eerstetaalonderwysersword ondersoek. Die oordrewe beklemtoning van vormen struktuur in moedertaalklasse ( oor die taal praatl lees/ skryf word vanuit die gesigspunt van Krashen se taalverwerwingsteorie beskou en die gevolgtrekking word gemaak dat daar veel meer klem op gebruiksvaardigheid behoort te val (in die taal praat!lees!skryf. In this article the first language teacher is made aware of second language teaching theory. Particularly Krashen' s second language theory is referred to and implications of his work for mother tongue teachers are discussed. The over-emphasis on form and structure in first language classes (talking/reading/writing about the language is looked at in terms of Krashen' s theory and it is concluded that the emphasis in first language classes should be far more on the functional use of the language (talking/reading/writing in the language.

  2. Die kairos van die New Age: 'n Kultuurhistoriese skets

    the whole universe, manifesting the two aspects of spirit and matter, .... vestiging van die Christendom het hierdie leer uit die Westerse kultuur verdwyn tot- ... Hegel (1770-1831) het die Simboliste aangespreek (Mathews 1986:30-31, 33). Sy.

  3. Oor die einders van die bladsy as konseptuele kuns

    Rita M.C. Swanepoel


    Full Text Available Hierdie artikel bied ’n filosofies-besinnende oorsig oor konseptuele kuns. Ek argumenteer dat, soos wat die projek Oor die einders van die bladsy die grense van boekwees oorskry en konseptueel uitbrei, dit in geheel ’n konseptuele en taalgebaseerde kunsinstallasie is wat uit verskeie komponente, naamlik kunstenaarsboeke,bestaan. Hierdie saamgestelde konseptuele kunsinstallasie daag vanweë die interdissiplinêre aard daarvan, die grense van konseptuele kuns uit. Hierdie projek en uitstallings bevestig dat kunstenaarsboeke ’n ideale medium is om kunstenaars uit verskillende dissiplines by die spel met en ontdekking van die moontlikhede van die boek te betrek. Die projek kan in die geheel as konseptuele kuns getipeer word omdat die konsep boek herdink, herskep en oor gefilosofeer word.

  4. Structure and properties of Fe-Cr-Mo-C bulk metallic glasses obtained by die casting method

    W. Pilarczyk


    Full Text Available urpose: The goal of this work is to investigate structure and properties of Fe54Cr16Mo12C18 alloy rods with different diameters obtained by the pressure die casting method.Design/methodology/approach: Master alloy ingot with compositions of Fe54Cr16Mo12C18 was prepared by induction melting of pure Fe, Cr, Mo, C elements in argon atmosphere. The investigated material were cast in form of rods with different diameters. Glassy and crystalline structures were examined by X-ray diffraction. The microscopic observation of the fracture morphology was carried out by the SEM with different magnification. The thermal properties of the studied alloy were examined by DTA and DSC method.Findings: These materials exhibit high glass-forming ability, excellent mechanical properties and corrosion resistance.Research limitations/implications: It is difficult to obtain a metallic glass of Fe54Cr16Mo12C18 alloy. The investigations carried out on the different samples of Fe54Cr16Mo12C18 bulk metallic alloy allowed to state that the studied ribbon was amorphous whereas rods were amorphous – crystalline.Originality/value: The formation and investigation of the casted Fe-Cr-Mo-C bulk materials and the study of glass-forming ability of this alloy.

  5. Predicting Stress vs. Strain Behaviors of Thin-Walled High Pressure Die Cast Magnesium Alloy with Actual Pore Distribution

    Choi, Kyoo Sil; Barker, Erin; Cheng, Guang; Sun, Xin; Forsmark, Joy; Li, Mei


    In this paper, a three-dimensional (3D) microstructure-based finite element modeling method (i.e., extrinsic modeling method) is developed, which can be used in examining the effects of porosity on the ductility/fracture of Mg castings. For this purpose, AM60 Mg tensile samples were generated under high-pressure die-casting in a specially-designed mold. Before the tensile test, the samples were CT-scanned to obtain the pore distributions within the samples. 3D microstructure-based finite element models were then developed based on the obtained actual pore distributions of the gauge area. The input properties for the matrix material were determined by fitting the simulation result to the experimental result of a selected sample, and then used for all the other samples’ simulation. The results show that the ductility and fracture locations predicted from simulations agree well with the experimental results. This indicates that the developed 3D extrinsic modeling method may be used to examine the influence of various aspects of pore sizes/distributions as well as intrinsic properties (i.e., matrix properties) on the ductility/fracture of Mg castings.

  6. Die owerheidsinmenging met betrekking tot kerklike tughandelinge.

    L. Roeleveld


    Full Text Available Volgens art 29 NGB is die merktekens van die ware kerk die suiwere prediking van die Evangelie, die suiwere bediening van die Sakramente en die gebruik van die kerklike tug. Art. 32 NGB spreek uit dat die Kerkorde nie mag afwyk van wat Christus ingestel het nie. Menslike vindinge en wette om die gewetens te bind en te dwing, moet daarom verwerp word. Die ekskommunikasie of die ban moet toegepas word volgens die Woord van God.

  7. Microstructural stability of heat-resistant high-pressure die-cast Mg-4Al-4Ce alloy

    Wang, Wei; Zhang, Jinghuai; Li, Guoqiang; Feng, Yan; Su, Minliang; Wu, Ruizhi; Zhang, Zhongwu [Harbin Engineering Univ. (China). Key Laboratory of Superlight Material and Surface Technology; Jiao, Yufeng [Jiamusi Univ. (China). College of Materials Science and Engineering


    The thermal stability of Al-RE (rare earth) intermetallic phases with individual RE for heat-resistant high-pressure die-casting Mg-Al-RE alloys is investigated. The results of this study show that the main strengthening phase of Mg-4Al-4Ce alloy is Al{sub 11}Ce{sub 3}, whose content is about 5 wt.% according to quantitative X-ray diffraction phase analysis. The Al{sub 11}Ce{sub 3} phase appears to have high thermal stability at 200 C and 300 C, while phase morphology change with no phase structure transition could occur for Al{sub 11}Ce{sub 3} when the temperature reaches 400 C. Furthermore, besides the kinds of rare earths and temperature, stress is also an influencing factor in the microstructural stability of Mg-4Al-4Ce alloy.

  8. Self-sealing anodization approach to enhance micro-Vickers hardness and corrosion protection of a die cast Al alloy

    Lee, Chulho; Oh, Kiseok; Lee, Dongeun; Kim, Yelim; Yoon, Hyungsop; Park, Dong-Wha; Gab Kim, Moon; Lee, Kiyoung; Choi, Jinsub


    Die cast, high-Si content ADC12 Al alloy samples were successfully anodized without surface cracks. This was accomplished with a 0.3 M sulfuric acid electrolyte with a high concentration of sodium aluminate. During anodization, the AlO2- anions were attracted to the positively-charged Al substrate and deposited in the cracks formed by un-oxidized Si islands within the ADC12. Anodic films prepared in electrolytes with a high concentration of AlO2- drastically enhanced surface morphology, thickness uniformity, Vickers hardness, and corrosion behavior in comparison with anodic film prepared without AlO2- concentration. The simultaneous sealing mechanism by AlO2- anions during anodization is reported in detail.

  9. An improved mathematical model to simulate mold filling process in high pressure die casting using CLSVOF method and CSF model

    Cheng Bi


    Full Text Available A 3D mathematical model was proposed to simulate the mold filling process in high-pressure die casting (HPDC to improve accuracy considering the surface tension. Piecewise liner interface calculation (PLIC and volume of fluid (VOF methods were used to construct the pattern of the liquid interface. A coupled level-set and VOF method (CLSVOF was proposed to capture the interface pattern and obtain its normal vector. A continuum surface force (CSF model was used to consider the surface tension. Two water analogy experiments were carried out using the proposed model. Simulation and experimental results were analyzed and compared; and the effects of surface tension were also discussed. The simulation results agreed well with the experiments and the simulation accuracy was an improvement on interface geometries, liquid flows, and gas entrapments.

  10. Fabrication of ZnO Nanowires Arrays by Anodization and High-Vacuum Die Casting Technique, and Their Piezoelectric Properties.

    Kuo, Chin-Guo; Chang, Ho; Wang, Jian-Hao


    In this investigation, anodic aluminum oxide (AAO) with arrayed and regularly arranged nanopores is used as a template in the high-vacuum die casting of molten zinc metal (Zn) into the nanopores. The proposed technique yields arrayed Zn nanowires with an aspect ratio of over 600. After annealing, arrayed zinc oxide (ZnO) nanowires are obtained. Varying the anodizing time yields AAO templates with thicknesses of approximately 50 μm, 60 μm, and 70 μm that can be used in the fabrication of nanowires of three lengths with high aspect ratios. Experimental results reveal that a longer nanowire generates a greater measured piezoelectric current. The ZnO nanowires that are fabricated using an alumina template are anodized for 7 h and produce higher piezoelectric current of up to 69 pA.

  11. Fabrication of ZnO Nanowires Arrays by Anodization and High-Vacuum Die Casting Technique, and Their Piezoelectric Properties

    Chin-Guo Kuo


    Full Text Available In this investigation, anodic aluminum oxide (AAO with arrayed and regularly arranged nanopores is used as a template in the high-vacuum die casting of molten zinc metal (Zn into the nanopores. The proposed technique yields arrayed Zn nanowires with an aspect ratio of over 600. After annealing, arrayed zinc oxide (ZnO nanowires are obtained. Varying the anodizing time yields AAO templates with thicknesses of approximately 50 μm, 60 μm, and 70 μm that can be used in the fabrication of nanowires of three lengths with high aspect ratios. Experimental results reveal that a longer nanowire generates a greater measured piezoelectric current. The ZnO nanowires that are fabricated using an alumina template are anodized for 7 h and produce higher piezoelectric current of up to 69 pA.


    Javedhusen Malek


    Full Text Available In today's ever-changing customer driven market, industries are needed to improve their products and processes to satisfy customer requirements. The Six Sigma approach has set a new paradigm of business excellence. Six Sigma as a process driven improvement methodology has been adopted successfully by many industries. From the review of various literatures, it is revealed that Six Sigma is well adopted in large scale enterprise but having less evidence of adoption in Indian SMEs. This paper is focused on providing path to Indian SMEs for initiating Six Sigma approach in their industries. The paper discusses the real life case where Six Sigma has been successfully applied at one of the Indian small-scale unit to improve rejection/rework rate in manufacturing products by pressure die casting process. This paper describes phase wise application of all the phases of define-measure-analyse-improve-control (DMAIC which also shows impact of Six Sigma in quality improvement.

  13. Die verband tussen die sielkundige kontrak en organisasieverbondenheid

    K. J. Stanz


    Full Text Available The relationship between the psychological contract and organisational commitment. The aim of this study is to design a measuring instrument with acceptable metric characteristics for the strength of the psychological contract within the South African context, and to determine empirically the relation between the strength of the psychological contract and organisational commitment. The Dhammanungune Model served as foundation for the design of the Strength of the Psychological Contract Questionnaire which consists of two scales namely, a needs expectation scale and a needs fulfilment expectation scale. The items of each scale have been formulated in the manner that ensures that the respondent reacts consecutively to two instructions namely, (a the level of the expectation and (b the importance of the expectation. This questionnaire was administered together with the Organisational Commitment Questionnaire to two population groups within the military environment. The Pearson Product Moment Correlation was calculated between the strength of the psychological contract and organisational commitment and the significance of the correlations was evaluated. Opsomming Die doel van die studie is om 'n meetinstrument met aanvaarbare metriese eienskappe vir die sterkte van die sielkundige kontrak vir Suid-Afrikaanse omstandighede te ontwerp en om empirics die verband tussen die sterkte van die sielkundige kontrak en organisasieverbondenheid te bepaal. Die sterkte van die sielkundige kontrak vraelys is op grond van die Dhammanungune-model ontwerp en het uit twee skale naamlik, die behoefteverwagting- en vervullingsverwagtingskale bestaan. Items vir eike skaal is sodanig geformuleer dat die respondent agteropeenvolgens op twee instruksies naamlik (a die vlak van die verwagting en (b die belangrikheid van die verwagting moet reageer. Die vraelys is saam met die organisasieverbondenheidsvraelys op twee populasies uit 'n militere omgewing toegepas. Die Pearson

  14. Die postpolitische Stadt

    Erik Swyngedouw


    Full Text Available Die Polis ist tot, es lebe die kreative Stadt! Während die Stadt, zumindest in Teilen des städtischen Raums, blüht und gedeiht, scheint die Polis im idealisierten griechischen Sinn dem Untergang geweiht; in diesem Verständnis ist sie der Ort der öffentlichen politischen Auseinandersetzung und demokratischen Unterhandlung und somit eine Stätte (oft radikaler Abweichung und Unstimmigkeit, an der die politische Subjektivierung buchstäblich ihren Platz hat. Diese Figur einer entpolitisierten (oder postpolitischen und postdemokratischen Stadt im Spätkapitalismus bildet das Leitmotiv des vorliegenden Beitrags. Ich lehne mich dabei an Jacques Rancière, Slavoj Žižek, Chantal Mouffe, Mustafa Dikeç, Alain Badiou und andere Kritiker jenes zynischen Radikalismus an, der dafür gesorgt hat, dass eine kritische Theorie und eine radikale politische Praxis ohnmächtig und unfruchtbar vor jenen entpolitisierenden Gesten stehen, die in der polizeilichen Ordnung des zeitgenössischen neoliberalen Spätkapitalismus als Stadtentwicklungspolitik [urban policy] und städtische Politik [urban politics] gelten. Ziel meiner Intervention ist es, das Politische wieder in den Mittelpunkt der zeitgenössischen Debatten über das Urbane zu stellen. [...

  15. Die Anima in Eschenbachs Parzival

    Kitunen, S. (Sakari)


    In meiner Pro-Gradu -Arbeit untersuche ich die Darstellung und Entwicklung des Jungschen Animabegriffes im Parzival von Wolfram von Eschenbach. Ich werde die in Parzival vorkommenden Charaktere als Anima- und Animus-Figuren analysieren und untersuchen, wie die Interaktion zwischen ihnen die Entwicklung des Helden beeinflusst. Viele Werke, die das Thema Frauen bzw. Weiblichkeit im Mittelalter behandeln, gehen oft davon aus, dass die Frauen in der mittelalterlichen Literatur als Objekte behande...

  16. Die liefde wat die son beweeg en die ander sterre: Digterlike transendering – tot die vermenigvuldigde lewe ontroer

    A.S. (Rensia Robinson


    Full Text Available T.T. Cloete se oeuvre word onder andere gekenmerk deur fyn waarneming van ’n mistieke vervlegtheid in die skepping. Dit word op vele maniere ontgin en geïnterpreteer. Die poëtiese potensiaal van die vrou, in uiteenlopende gestaltes, is een van die sentrale temas waardeur die digter hieraan vorm gee. In die kunstige, bibliofiele uitgawe Uit die wit lig van my land gesny val die lig op die vrou se kreatiewe rol in die groter skepping wat haar onder andere identifiseer as haarveer vir digterlike insig en vormgewing. Vrou (alternatief Anna Perenna, universele moeder, is nie slegs draer van die lewenskiem wat tot gees transendeer nie, maar sy funksioneer as ligbron (’sonvrou’ wat selfs kosmiese insig verwesenlik. Dit raak meervoudige vorms en patrone waarin die mens ingeweef is in die universele hologram van lewe. Vir die digter is hierdie patroonvorming vergelykbaar met die maak van Persiese tapyte waarvan die patrone vasgelê is in die geheue van voorouers, en oorgedra word na opeenvolgende geslagte. In dié verkenning word digterlike transendering ontgin as ’n proses waarin die kleurvolheid van lewe en dood in en deur individuele sowel as universele vroulikheid geïnspireer word.

  17. Die liefde wat die son beweeg en die ander sterre: Digterlike transendering – tot die vermenigvuldigde lewe ontroer

    A.S. (Rensia Robinson


    Full Text Available T.T. Cloete se oeuvre word onder andere gekenmerk deur fyn waarneming van ’n mistieke vervlegtheid in die skepping. Dit word op vele maniere ontgin en geïnterpreteer. Die poëtiese potensiaal van die vrou, in uiteenlopende gestaltes, is een van die sentrale temas waardeur die digter hieraan vorm gee. In die kunstige, bibliofiele uitgawe Uit die wit lig van my land gesny val die lig op die vrou se kreatiewe rol in die groter skepping wat haar onder andere identifiseer as haarveer vir digterlike insig en vormgewing. Vrou (alternatief Anna Perenna, universele moeder, is nie slegs draer van die lewenskiem wat tot gees transendeer nie, maar sy funksioneer as ligbron (’sonvrou’ wat selfs kosmiese insig verwesenlik. Dit raak meervoudige vorms en patrone waarin die mens ingeweef is in die universele hologram van lewe. Vir die digter is hierdie patroonvorming vergelykbaar met die maak van Persiese tapyte waarvan die patrone vasgelê is in die geheue van voorouers, en oorgedra word na opeenvolgende geslagte. In dié verkenning word digterlike transendering ontgin as ’n proses waarin die kleurvolheid van lewe en dood in en deur individuele sowel as universele vroulikheid geïnspireer word.

  18. Die histologie en ultrastruktuur van die hepatopankreas van die bloukurper Oreochromis mossambicus

    M. M. Nel


    Full Text Available Die histologie en ultrastruktuur van die hepatopankreas van die bloukurper Oreochromis mossambicus word beskryf. ’n Dun bindweefselkapsel omring die lewer. Die hepatosietrangskikking vertoon as lobules, met die koorde van hepatosiete wat vanaf ’n sentrale vene uitradieer en met mekaar anastomaseer. Indiwiduele lewerlohules vertoon nie duidelike grense nie, maar enkele duidelike triades word wel in die lewer van O. mossambicus aangetref. Die hepatosiete bevat ’n enkele ronde kern met ’n duidelike nukleolus en die growwe endoplasmiese retikula kom in twee of meer rye om die kerne en teen die selgrense van die hepatosiete voor. Die ander sitoplasmiese organelle kom verspreid in die hepatosietsitoplasma voor. Die eksokriene pankreasselle is om die portale venes gesetel. Die kerne van hierdie selle is rond en is hasaal in die kubies- tot silindervormige selle gelee. ’n Goedontwikkelde growwe endoplasmiese retikulum — vesikulêr, tubulêr en sirkulêr in vorm — en sektretoriese granules wat apikaal in die sel gelee is, kom voor.

  19. The effect of natural pre-ageing on the mechanical properties of Rheo-High pressure die cast aluminium alloy 2139

    Chauke, L


    Full Text Available -high pressure die casting process (R-HPDC). Alloy 2139 is a Ag-containing aluminium alloy from the Al-Cu-Mg 2xxx series family. The addition of Ag enhances the age hardening response through the formation of co-clusters that act as precursors to the formation...

  20. Technological Superiority and Application of Real-Time Control Die Casting Machine%实时控制压铸机的技术优势及应用*

    张新华; 孔晓武


    This article introduces the development of die casting machine controlling theory, concept and feature of die casting machine embedded real time operating system,with drawing conclusions that contain electro-hydraulic schematic diagram for die casting machine injection system, configuration scheme of embedded real time controlling, analysis of real time control curve and comparison with traditional controlling technique. The real time control die casting machine which referred in this article has been to the stage of application,and won quite considerable market share and high praise.%介绍了压铸机控制理论的发展和压铸机嵌入式实时控制技术的概念及其特点优势,给出了压铸机压射系统的电液原理图,嵌入式实时控制的配置方案,实时控制曲线的分析及与传统控制技术的对比。介绍的实时控制压铸机已经进入应用环节,并取得了较大的市场份额和较好的评价。

  1. Process Modeling of Low-Pressure Die Casting of Aluminum Alloy Automotive Wheels

    Reilly, C.; Duan, J.; Yao, L.; Maijer, D. M.; Cockcroft, S. L.


    Although on initial inspection, the aluminum alloy automotive wheel seems to be a relatively simple component to cast based on its shape, further insight reveals that this is not the case. Automotive wheels are in a select group of cast components that have strict specifications for both mechanical and aesthetic characteristics due to their important structural requirements and their visibility on a vehicle. The modern aluminum alloy automotive wheel continues to experience tightened tolerances relating to defects to improve mechanical performance and/or the physical appearance. Automotive aluminum alloy wheels are assessed against three main criteria: wheel cosmetics, mechanical performance, and air tightness. Failure to achieve the required standards in any one of these categories will lead to the wheel either requiring costly repair or being rejected and remelted. Manufacturers are becoming more reliant on computational process modeling as a design tool for the wheel casting process. This article discusses and details examples of the use of computational process modeling as a predictive tool to optimize the casting process from the standpoint of defect minimization with the emphasis on those defects that lead to failure of aluminum automotive wheels, namely, macroporosity, microporosity, and oxide films. The current state of applied computational process modeling and its limitations with regard to wheel casting are discussed.

  2. Diskussie oor die millenium en die herstel van Israel

    J. J. Engelbrecht van Waverley


    Full Text Available Dit verheug my dat daar eindelik gereageer word op my boekie. Behalwe telefoonoproepe en briewe van medechiliaste was daar tot dusver geen kommentaar van anti-chiliastiese kant. Ek het die boekie aan ongeveer 1800 predikante en professore gestuur en vriendelik uitgenooi tot nuwe besinning. Net soos oor die soteriologie, is die Bybel nêrens in teëspraak met homself oor die eskatologie nie. God gee in sy Woord nie vir ons drie verskillende toekomsbeelde om uit te kies nie. God is een en sy profetiese Woord is deurgaans eenstemmig m.b.t. die raad van God oor Israel, die nasies en die kerk.

  3. Application of TPM indicators for analyzing work time of machines used in the pressure die casting

    Borkowski, Stanisław; Czajkowska, Agnieszka; Stasiak-Betlejewska, Renata; Borade, Atul B.


    The article presents the application of total productive maintenance (TPM) to analyze the working time indicators of casting machines with particular emphasis on failures and unplanned downtime to reduce the proportion of emergency operation for preventive maintenance and diagnostics. The article presents that the influence of individual factors of complex machinery maintenance (TPM) is different and depends on the machines' modernity level. In an original way, by using correlation graphs, research findings on the impact of individual TPM factors on the castings quality were presented and interpreted. The examination results conducted for machines with varying modernity degrees allowed to determine changes within the impact of individual TPM factors depending on machine parameters. These results provide a rich source of information for the improvement processes on casting quality of the foundry industry that satisfies the automotive industry demand.

  4. Die kerk en die kommunisme, uitgangspunt en perspektief

    A. H. Murray


    Full Text Available Waar ons onmiddellike opdrag is om die konkrete taak van die kerk in die bestryding van Kommunisme en Marxisme te beskrywe, is ons gedwing om terug te dink aan die eerste grondslae van die vyandelike aanslag — die grondslae waarop sy leer en sy beleid van gewelddadige optrede berus. Want ons het nie te doen met ’n opportunistiese onderneming of ’n imperialistiese waagstuk as dit oor die Kommunisme gaan nie, en ook nie met die blinde opbruising van laere en agterlike volksklasse nie, maar wel met ’n deurdagte en afgeronde heelal-filosofie wat oor die aardbol versprei is en wat op sistematiese wyse en met wetenskaplike strategie ’n aanval op die bestaande Christelike orde maak.

  5. Rapid die manufacturing - high pressure casting of low volume non ferrous metals components

    Pereira, MFV


    Full Text Available Pressure Casting of Low Volume Non Ferrous Metals Components Date: 2 November 2006 Slide 2 © CSIR 2006 Introduction to RPT • Rapid Prototyping Techniques (RPT) generally used for non functional prototypes • RPT...

  6. Die Psychosen bei Epilepsie

    Glauninger G


    Full Text Available In einer Übersicht werden die verschiedenen Formen psychotischer Zustandsbilder bei Epilepsiepatienten, deren Ätiopathogenese und Möglichkeiten der Behandlung dieser Störungen beschrieben. Risikofaktoren finden sich durch neurobiologische Gegebenheiten - besonders bei Mitbeteiligung des Temporallappens, durch psychosoziale Einflüsse und manchmal auch durch medikamentöse Behandlung. Anhand von Fallbeispielen sollen dem Leser typische Krankheitsverläufe von psychotischen Episoden bei Epilepsiepatienten, die zumeist erst bei einer schon länger dauernden Epilepsie auftreten, nähergebracht werden. Es wird deutlich, daß sich die Beschwerden von Patienten mit Epilepsie nicht auf iktale Phänomene beschränken. Bei der Behandlung dieser Patienten kommt einer guten interdisziplinären Zusammenarbeit besondere Bedeutung zu.

  7. Wêreldgebeure gedurende die jaar 1954.

    S. du Toit


    Full Text Available Die jaar 1954 het begin sonder Stalin, die magtigste diktator van die modeme tyd, en dit wa s nog onseker hoe die nuwe regime sou optree.Teen die einde van die ja a r weet ons nou dat hulle oënskynlik meer toeskietlik is maar in wese nog net so geheimsinnig en nog net so geslepe. Die Petrof-gesjriedenis in Australië het weereens laat blyk dat daar oordie hele aarde ’n netwerk van spioene is.

  8. Elasto-Plastic-Creep Constitutive Equation of an Al-Si-Cu High-Pressure Die Casting Alloy for Thermal Stress Analysis

    Motoyama, Yuichi; Shiga, Hidetoshi; Sato, Takeshi; Kambe, Hiroshi; Yoshida, Makoto


    Accurate simulation of residual stress and deformation is necessary to optimize the design and lifetime of casting components. Therefore, the recovery and strain-rate dependence of the stress-strain curve have been incorporated into empirical constitutive equations to improve the thermal stress analysis accuracy. Nevertheless, these equations present several difficulties related to the determination of material constants and their physical bases. This study suggested an empirical elasto-plastic-creep constitutive equation incorporating these phenomena. To determine the material parameters used in this constitutive equation, this study investigated tensile test methods to obtain stress-strain curves that most closely resemble those during or immediately after casting for the Al-Si-Cu high-pressure die-casting alloy JIS ADC 12 (A383.0), which exhibits natural aging. Results show that solution heat treatment with subsequent cooling to the test temperature should be applied to obtain stress-strain curves used for the thermal stress analysis of high-pressure die casting process of this alloy. The yield stresses obtained using the conventional heating method were 50-64 pct higher than those of the method described above. Therefore, the conventional method is expected to overestimate the overestimation of the predicted residual stress in die castings. Evaluation of the developed equation revealed that it can represent alloy recovery and strain-rate dependence.

  9. The Influence of Pressure Die Casting Parameters on Distribution of Reinforcing Particles in the AlSi11/10% SiC Composite

    A. Pasieka


    Full Text Available The method of pressure die casting of composites with AlSi11 alloy matrix reinforced with 10 vol. % of SiC particles and the analysis of the distribution of particles within the matrix is presented. The composite castings were produced at various values of the piston velocity in the second stage of injection, at diverse intensification pressure values, and various injection gate width values. The distribution of particles over the entire cross-section of the tensile specimen is shown. The index of distribution was determined on the basis of particle count in elementary measuring fields. The regression equation describing the change of the considered index was found as a function of the pressure die casting parameters. The conclusion presents an analysis of the obtained results and their interpretation.

  10. Die voorspelling van akademiese prestasie na die eerste universiteitsjaar

    G. K. Huysamen


    Full Text Available The prediction of academic performance after the first year at university. In agreement with findings elsewhere, the correlations of high school performance (Swedish Formula Point and the verbal and nonverbal GSAT scores with the mean percentage marks (MPMs gradually decreased from the first through sixth semester at university, whereas the decrease in the corresponding correlations with the cumulative mean percentage marks (CMPMs was less pronounced. The later the semester for which either an MPM or a CMPM was used as a predictor, the higher the latter tended to correlate with the MPMs of subsequent semesters but these correlations also decreased in size over the ensuing semesters. The best predictor of the MPM of any given semester was either the MPM of the immediately preceding semester or the CMPM of all the preceding semesters. Opsomming In ooreenstemming met bevindings elders, het die korrelasies van hoërskoolprestasie (Sweedse Formulepunt en verbale en nie-verbale ASAT-tellings met die gemiddelde persentasiepunte (GPP's geleidelik van die eerste tot die sesde semester op Universiteit afgeneem, terwyl die afname in die ooreenstemmende korrelasies met die kumulatiewe gemiddelde persentasiepunte (KGP's minder opvallend was. Hoe later die semester waarvan die GGP of KGP as voorspeller gebruik is, hoe hoër was dit geneig om met die GGP's van die daaropvolgende semesters te korreleer, maar die korrelasies het: eweneens met die toename in laasgenoemde semesters in grootte afgeneem. Die beste voorspeller van die GPP van enige gegewe semester was of die GPP van die pas afgelope semester, of die KGP van al die voorafgaande semesters.

  11. Discussion on Reducing Costs of Die-Cast Automotive Starter-Generator Cover Die Casting%压铸汽车起动机-发电机端盖压铸件降本初探



    主要介绍了铝压铸件企业通过对原材料牌号进行分类和归纳,在对比了原材料的力学性能和化学成分,得出具有通用性的材料牌号,将3种材料牌号统一成一个牌号,实现单一牌号的采购和生产。在确保产品质量的前提下,降低原材料的采购成本、生产成本和管理成本,最终实现了产品成本降低的目标。%The aluminum die casting enterprises through classification and induction of raw material grades, and by comparing the mechanical properties and chemical composition of raw materials, obtained the universal material grades, three kinds of material grades have been uniifed into a single grade, so that a single brand of procurement and production has been achieved. In the premise of ensuring the quality of products, the raw materials procurement costs, production costs and management costs have been achieved, finally the product cost reduction target has been realized.

  12. Die-cast heterophase composites with AlSi13Mg1CuNi matrix

    M. Dyzia


    Full Text Available On the basis of the performed tests, an advantageous interaction of glassy carbon particles in a couple consisting of a heterophase composite and a spheroidal cast iron has been corroborated. It was found that, the presence of glassy carbon in the heterophase composite (SiC+C affects the stabilization of the friction coefficient value as a function of the friction distance and reduces the intensity of the wearing-in stage of the interacting surfaces. Both a decrease of the friction coefficient and the wear of the heterophase composites may be connected with the carbon particles' chipping effect and the deposition of its fragments on the surface of the interacting components of the friction couple, which forms a kind of a solid lubricating agent in the system. This should allow applying of this material to the composite piston - cylinder sleeve system in piston air-compressors. Further works will concern the selection of the matrix alloy composition with the purpose of reducing the phenomenon of particles chipping during machining. It seems that one of the possibilities is the application of a more plastic matrix and optimizing the fraction of reinforcing phases and their gradient distribution in the casting.

  13. Die Kunst des Scheiterns

    Juul, Jesper


    Menschen haben von Kindesbeinen an das Verlangen, Erfolge zu erzielen und Kompetenz zu erreichen. Computerspieler entscheiden sich jedoch fortlaufend für eine Aktivität, die oft und wiederholt zum Verlieren führen muss und ein taubes Gefühl der Unfähigkeit erzeugt. Im Kino, im Theatersaal und bei...

  14. Die skool en die onderwyser as faktore in die geestesgesondheid van die kind*

    B. C. Schutte


    Full Text Available Ons hou geestesgesondheidsweke, stig beroepsentrums, samel geld in om mense wat geestelik siek is te genees, klae oor die tekort aan psigiaters, kliniese sielkundiges, bedryfsielkundiges, voorligters, skoolpsigoloë,ens. ’n Karige kwarteeu gelede het ons aan al hierdie dinge slegs akademiese aandag gewy. In hierdie kursus wordverskeie tipes kinders bespreek en geleer hoe om hulle probleme te benader.

  15. Die Kunst des Scheiterns

    Juul, Jesper


    Menschen haben von Kindesbeinen an das Verlangen, Erfolge zu erzielen und Kompetenz zu erreichen. Computerspieler entscheiden sich jedoch fortlaufend für eine Aktivität, die oft und wiederholt zum Verlieren führen muss und ein taubes Gefühl der Unfähigkeit erzeugt. Im Kino, im Theatersaal und bei...

  16. Die Creol Taal

    Rossem, van Cefas; Voort, van der Hein


    Negerhollands is the original creole language, lexically closely related to Dutch, of the Virgin Islands. It emerged as a separate language around 1700 and died out completely only a few years ago, having gradually been replaced by English in the course of the nineteenth century. Apart from giving i

  17. Die andere Revolution

    Kippenhahn, Rudolf


    War Kopernikus der größte Revolutionär des naturwissenschaftlichen Weltbildes? Seine Erkenntnisse waren der Beginn eines jahrhundertelangen Denkprozesses, welcher zur Einsicht führte, dass im Weltall die gleichen physikalischen Gesetze gelten wie auf der Erde.

  18. Die Kosmologie der Griechen.

    Mittelstraß, J.

    Contents: 1. Mythische Eier. 2. Thales-Welten. 3. "Alles ist voller Götter". 4. Griechische Astronomie. 5. "Rettung der Phänomene". 6. Aristotelische Kosmololgie. 7. Aristoteles-Welt und Platon-Welt. 8. Noch einmal: die Göttlichkeit der Welt. 9. Griechischer Idealismus.

  19. Die ontwikkeling van 'n instrument vir die meting van die konstruk sielkundige diepte-orientasie

    L. C. De Jager


    Full Text Available The development of an instrument (the RD-Depth Questionnaire, Form B for measuring the construct psychological depth orientation is discussed. Results show that the questionnaire has satisfactory internal consistency and that the items of the questionnaire in general measure the same characteristic. Further research is needed to refine and improve the questionnaire until it meets all the psychometric requirements of a good measuring instrument.OpsommingDie ontwikkeling van 'n instrument (die RD-Diepte Vraelys, Vorm B vir die meting van die konstruk sielkundige diepteoriëntasie word bespreek. Resultate dui daarop dat die vraelys bevredigende interne bestendigheid toon en dat die items van die vraelys oor die algemeen dieselfde eienskap meet. Verdere navorsing word egter nog vereis om die vraelys te verfyn en te verbeter sodat dit aan al die psigometriese vereistes van 'n goeie meetinstrument sal voldoen.

  20. Die Wiege stand doch in Africka


    Kaum ein Forschungsgebiet ist so umstritten wie die Palaeoanthropologie, die Lehre yore Ursprung der Menschheit. Nicht nur die Vorgeschichte, ouch die unmittelbare Entstebung des Homo sapiens entzweit die Experten: Die einen verrnuten die Wiege in Afrika,die anderen gehen davon aus, dass sich tier moderne Mensch auf mehreren Kontinenten gleichzeifig aus Vorfahren eatwickelte,

  1. High Cycle Fatigue Properties of Die-Cast Magnesium Alloy AZ91D with Addition of Different Concentrations of Cerium


    The effect of addition of different concentrations of Ce on high-cycle fatigue behavior of die-cast magnesium al-loy AZ91D was investigated. Mechanical fatigue tests were conducted at the stress ratio of R = 0.1, and fatigue strength was evaluated using up-and-down loading method. The results show that the grain size of AZ91D alloy is remarkably refined, and the amount of porosity decreases and evenly distributes with the addition of Ce. The fatigue strength of AZ91D alloy at room temperature increases from 96.7 up to 116.3 MPa (1% Ce) and 105.5 MPa (2% Ce), respectively, at the number of cycles to failure, Nf = 1 × 107. The fatigue crack of AZ91D alloy initiates at porosities and inclusions, and propagates along grain boundaries. The fatigue striations on fractured surface appear with Ce addition. The fatigue fracture surface of test specimens shows mixed-fracture characteristics of quasi-cleavage and dimple.

  2. Vacuum Die Casting Process and Simulation for Manufacturing 0.8 mm-Thick Aluminum Plate with Four Maze Shapes

    Chul Kyu Jin


    Full Text Available Using vacuum die casting, 0.8 mm-thick plates in complicated shapes are manufactured with the highly castable aluminum alloy Silafont-36 (AlSi9MgMn. The sizes and shapes of the cavities, made of thin plates, feature four different mazes. To investigate formability and mechanical properties by shot condition, a total of six parameters (melt temperatures of 730 °C and 710 °C; plunger speeds of 3.0 m/s and 2.5 m/s; vacuum pressure of 250 mbar and no vacuum are varied in experiments, and corresponding simulations are performed. Simulation results obtained through MAGMA software show similar tendencies to those of the experiments. When the melt pouring temperature is set to 730 °C rather than 710 °C, formability and mechanical properties are superior, and when the plunger speed is set to 3.0 m/s rather than to 2.5 m/s, a fine, even structure is obtained with better mechanical properties. The non-vacuumed sample is half unfilled. The tensile strength and elongation of the sample fabricated under a melt temperature of 730 °C, plunger speed of 3.0 m/s, and vacuum pressure of 250 mbar are 265 MPa and 8.5%, respectively.

  3. Die spel van assosiasies in en om 'Die verlossing van die beeld' van Breyten Breytenbach

    P.A. du Toit


    Full Text Available The play of association in and around 'The liberation of the image' by Breyten Breytenbach This analysis focuses on the conjunction of memory and imagination, which is an important impulse in, and key to, Breytenbach’s work. The play with language and with associations, the foregrounding, in the short story, “Die verlossing van die beeld” (Breytenbach, 1983 with its metafictional title and apparently divergent motifs (rain/water, watch, onion, the death and burial of a grandfather acts, as it were, as an invitation to the reader to become a co-player. The reader ventures on a search for traces, intertextual links within the Breytenbach oeuvre and for already acknowledged influences such as Surrealism (which in turn casts some light on the strange title of the story and the Eastern philosophies such as Zen and the even older Taoism. The analysis also takes into account the context in which “Mouroir” was written, namely Breytenbach’s term in prison (1975-1982. Seeing that the writer had to hand in his manuscripts to the jail authorities regularly, he might have decided, consciously or by intuition, to hide some thoughts and feelings behind a screen or a mask, in, for example in “Die verlossing van die beeld”, a lighter tone and irony.

  4. On the Structure Optimization and Design System Development of Die Casting Mould%压铸模具结构优选与设计系统开发



    介绍了压力铸造成形原理及其工艺过程、剖析了压力铸造成形工艺的优点和存在的缺陷;总结了压力铸造技术的发展历史、应用范围及中国压力铸造生产产品应用领域的多元性,展示了中国压力铸造业发展的广阔前景。%This paper introduces the principle and forming process of the pressure casting and analyzes the advantages and disadvantages of pressure casting forming technology. It summarizes the development history and application range of the pressure casting technology and Chinese pressure casting product diversity,and shows the prospect of the development of Chinese die casting industry.

  5. Die Tambaniprojek: ’n rekenaaranimasie van Die hebsugtige seekoei

    Rita M.C. Swanepoel


    Full Text Available Hierdie artikel bied ’n ondersoek na en refleksie op die tegnieke en die produksieprosesse wat gebruik is in die omskakeling van ’n tradisionele Ngano-Venda-volksverhaal, Die hebsugtige seekoei, vanaf borduurwerk in ’n digitale animasiefilm. Die artikel word gerig deur ’n metode wat afgelei is uit ’n praktykgebaseerde navorsingsmodel vir skeppende uitsette. Hierdie navorsingsmodel omskryf wyses waarvolgens skeppende uitsette as geldige navorsingsopsies gereken kan word. Die metode bestaan uit die dokumentering van en refleksie ten opsigte van die projek in drie fases, naamlik pre-produksie, produksie en post-produksie. Die Tambani-borduurwerkprojek is ’n gemeenskapsuitreikingsinisiatief wat deur Ina le Roux van stapel laat loop is. Ngano is die versamelwoord vir tradisionele Vendavolksverhale. In hierdie artikel argumenteer ons dat rekenaaranimasietegnieke wel suksesvol geïmplementeer word in die digitale omskakeling van ’n Venda-volksverhaal wat oorspronklik uit ’n mondelinge tradisie stam. Ons demonstreer hierdie argument aan die hand van Christiaan van der Westhuizen se omskakeling van Die hebsugtige seekoei in ’n rekenaaranimasie.

  6. Die historiese betroubaarheid van die aartsvadervertellinge. 'n Beknopte bespreking van die huidige debat na aanleiding van die jongste publikasie

    W. Vosloo


    Full Text Available Die afgelope twintig jaar was daar �n toenemende belangstelling in die aartsvadervertellinge in Genesis. Benewens die talle tydskrifartikels het skrywers soos die volgende ook boeke oor die onderwerp die lig laat sien: A. Parrot (1962, W. M. Clark (1964, R. Kilian (1966, R. E. Clements (1967, N. Lohfink (1967, H. Weidemann (1968, R. Martin-Achard (1969, T. L. Thompson (1974, J. van Seters (1975, J. P. Fokkelman (1975, C. Westermann (1976, R. Rendtorff (1977, J. Bright (1977, W. McKane (1979 en A. R. Millard en D. J. Wiseman (1980.

  7. Herausforderungen durch die deutsche Wiedervereinigung

    Stäglin, Reiner

    Die Wiedervereinigung stellte auch die Statistik vor große Aufgaben. Die als Organ der staatlichen Planung staatsnah orientierte Statistik der DDR musste auf das zur Neutralität und wissenschaftlichen Unabhängigkeit verpflichtete System der Bundesrepublik umgestellt werden. Ebenso verlangten die Universitäten eine Neuorientierung. Die Deutsche Statistische Gesellschaft hat sich vor allem dreier Aufgaben mit großem Engagement, aber auch mit Bedachtsamkeit angenommen: Aufnahme und Integration der Statistiker aus den neuen Bundesländern in die Gesellschaft, Begleitung der Neuausrichtung des Faches Statistik an deren Hochschulen und Sicherung sowie Nutzung von Datenbeständen der ehemaligen DDR.

  8. Gedagtes oor die begin van die kerk - 'n geskiedenis van ...

    seriously, affirm, and thankfully acknowledge Christendom, the. Church. We must ... In all this we at least approached the theology and practice of a spiritual partisan ..... Hegel se geskiedsfilosofie hou juis 'sintese' voor as die eindpunt van die.

  9. Film Presentation: Die Urknallmaschine

    Carolyn Lee


    Die Urknallmaschine, an Austrian film by Gerd Baldauf, narrated by Norbert Frischauf (Alpha Österreich - ORF, 2009).  In CERN’s gigantic complex particles are accelerated to almost the speed of light, brought to collision and made to divide into even smaller particles. Public opinion of CERN’s research is also divided. Sceptics fear that black holes may be created. Might the goal to study the origin of the world lead to its destruction? The Austrian researcher Norbert Frischauf worked at CERN for many years. With his guidance it is possible to explore the world’s largest research centre, get a glimpse of the fascinating work the scientists do there and take a crash course in particle physics. Die Urknallmaschine will be presented on Friday, 25 June from 13:00 to 14:00 in the Main Auditorium. Language: German

  10. Dying for security

    Buchan, Bruce


    Full Text Available If political statements and media coverage are any guide, it seems Australians today are dying for security. At no other moment in our history has the spectre of war and terrorism so haunted popular, political and scholarly perceptions of Australia’s colonial past and of its geopolitical future. And yet, debates over colonial war or genocide and contemporary terrorism have been conducted in more or less complete isolation. In this article I argue that our contemporary obsession with ‘security’ is premised on the perennial threat of ‘insecurity’. This is the problem of in/security, and it has played a central role in the development of Western political thought. More importantly, its formulation in Western political thought provided a powerful justification for the violence of the early decades of Australia’s colonisation during which Indigenous Australians could also be said to have been dying for security.

  11. Dying for Security

    Bruce Buchan


    Full Text Available If political statements and media coverage are any guide, it seems Australians today are dying for security. At no other moment in our history has the spectre of war and terrorism so haunted popular, political and scholarly perceptions of Australia’s colonial past and of its geopolitical future. And yet, debates over colonial war or genocide and contemporary terrorism have been conducted in more or less complete isolation. In this article I argue that our contemporary obsession with ‘security’ is premised on the perennial threat of ‘insecurity’. This is the problem of in/security, and it has played a central role in the development of Western political thought. More importantly, its formulation in Western political thought provided a powerful justification for the violence of the early decades of Australia’s colonisation during which Indigenous Australians could also be said to have been dying for security.

  12. Safety-relevant components made of low-iron, Al-base die-casting alloys; Sicherheitsbauteile aus eisenarmen Aluminium-Druckgusslegierungen

    Hielscher, U. [Aluminium Rheinfelden GmbH, Rheinfelden (Germany)


    The modern automotive engineering requirements to be met by die-casting aluminium alloys with respect to the microstructure, casting process, compatibility with operating media, and weldability are such that they cannot be met by conventional alloys. Therefore, there was a quest for novel alloys, which at the Aluminium Rheinfelden company has led to the development of two low-iron alloys: Silafont-36 (AlSi9MgMnSr), and Magsimal-59 (AlMg5Si2Mn). The materials properties and some applications are explained. (orig./MM) [German] Von der Automobilindustrie werden an die Aluminiumguss-Legierungen folgende Anforderungen gestellt: 1. sehr duktiles Gefuege, 2. gute Giessbarkeit fuer das Druckgiessverfahren, 3. Vertraeglichkeit mit den Eisenwerkstoffen der Giesswerkzeuge sowie Trenn- und Schmierstoffen, 4. gute Schweissbarkeit und gute Boerdelbarkeit. Die herkoemmlichen Gusslegierungen erfuellen diese Anforderungen nicht; der Aluminium Rheinfelden gelang die Entwicklung von zwei eisenarmen Legierungen: Silafont-36 (AlSi9MgMnSr) und Magsimal-59 (AlMg5Si2Mn). (orig.)

  13. Dying from cardiac tamponade

    Powari Manish


    Full Text Available Abstract Background To determine the causes of cardiac tamponade (CT, focussing especially on haemopericardium (HP, as a terminal mode of death, within a 430,000 rural English population. Methods Our hospital mortuary register and, all postmortem reports between 1995 and 2004 inclusive, were interrogated for patients dying of CT or HP. The causes of CT/HP and selected morphological characteristics were then determined. Results 14,368 postmortems were performed in this period: of these, 461 patients died of CT. Three cases were due to non-haemorrhagic pericardial effusion. HP accounted for the remaining 458 cases of which, five were post-traumatic, 311 followed rupture of an acute myocardial infarction (RAMI, 138 after intra-pericardial rupture of dissecting ascending aortic aneurysms (RD3A and four were due to miscellaneous causes. HP was more commonly due to RAMI. Men tended to die from RAMI or RD3A earlier than women. RAMI or RD3A were commoner in men Two thirds of RAMI were associated with coronary artery thrombosis. Anterior free wall rupture was commonest overall, and in women, but posterior free wall rupture was commoner in men. The volume of intrapericardial blood in RAMI (mean = 440 ml and RD3A (mean = 498 ml varied between 150 and 1000 ml: intrapericardial blood volume was greater in men than in women dying from either RAMI or RD3A. Conclusion At postmortem, CT is most often related to HP, attributable to either RAMI or intrapericardial RD3A. Post-traumatic and other causes of CT are infrequent.

  14. Die medizinische Diskussion um die Fettleibigkeit 1800-1914

    Holstermann, Inga Kristine


    Gegenstand der Untersuchung ist die medizinische Diskussion um die Fettleibigkeit von 1800 bis 1914. Dargestellt werden die unterschiedlichen Betrachtungsweisen der Fettleibigkeit beeinflusst durch gesellschaftliche, industrielle und medizinische Entwicklungen im Untersuchungszeitraum unter den Aspekten der Ursachen (Lebensführung, erbliche Veranlagung, Geschlecht, Alter, Stoffwechselstörungen) und Folgen (Gesundheitsgefahren, Ästhetik, psychische Auswirkungen). Des weiteren werden Konzepte z...

  15. Die Leben Einsteins eine Reise durch die Geschichte der Physik



    Jeder kennt die Namen Einstein, Newton oder Galilei. aber was weiss man über sie? Hier ein Porträt Einsteins anhand von sechs Meilensteinen aus der Geschichte der Physik. Einstein tritt auf als Protagonist in verschiedenen Epochen und bei verschiedenen Entdeckungen, die die Welt verändert haben.

  16. Geslagsverskille in die ouditiewe ontlokte potensiaal van die brein

    Anita D Stuart


    Full Text Available Gender differences in the auditory evoked potential of the brain. Based on literature indications of an association between temperament characteristics and the evoked potential of the brain, and indications of gender differences in certain temperament traits, the purpose of this study was to ascertain whether evoked responses also differentiated between the genders. A sample of 81 male and 210 female students was randomly selected. Two auditory evoked potential procedures were applied. The results indicated statistically significant differences in evoked potential responses between the genders. The results are interpreted against the background of sensory and neurological sources of the evoked potential responses and linked to the neurophysiological foundations of temperament. Opsomming: Gegrond op aanduidings in die literatuur van ’n assosiasie tussen temperamentskenmerke en die ontlokte potensiaal van die brein, sowel as aanduidings van geslagsverskille in sekere temperamentstrekke, was die doel van die huidige studie om te bepaal of ontloktepotensiaal-response ook tussen die geslagte onderskei. ’n Steekproef van 81 manlike en 210 vroulike studente is ewekansig geselekteer. Twee ouditiewe ontloktepotensiaal- prosedures is toegepas. Die resultate het op statisties beduidende verskille tussen die geslagte gedui. Die bevindinge word teen die agtergrond van die sensoriese en neurologiese oorsprong van ontloktepotensiaal–response geïnterpreteer en verbind aan die neurofisiologiese verankering van temperament.

  17. Effect of T4 and T6 treatment on corrosion of die cast AZ91D magnesium alloys in 3.5% NaCl

    ZHOU Wan-qiu; SHAN Da-yong; HAN En-hou; KE Wei


    The effect of heat treatment on microstructure and corrosion behavior of die-cast AZ91D magnesium alloys in 3.5% NaCl solution was investigated by SEM, EDX, XRD and electrochemical technique. It is found that the distribution of β phase influences the corrosion morphology. Corrosion occurs preferentially in primary α phase and presents pitting corrosion feature in die-cast AZ91D. After homogenization of T4 treatment, β phase dissolves in α phase and forms a single phase with α matrix, and the corrosion form turns to localized corrosion. The attack initiates at local site, expands towards deep direction and produces "digging effect". After artificial aging of T6 treatment, β phase is produced in abundance and provides a great deal of effective micro-cathode for anodic dissolution, and the corrosion form exhibits in general corrosion.

  18. J1140型压铸机增压蓄能器设计%Design of Booster Accumulator for J1140 Type Die Casting Machine



    According to the design requirements of injection system of J1140 type die casting machine,the hydraulic principle of die casting machine injection system booster was analyzed,the volume of the accumulator was calculated. Combining with practical ap-plication,the choice and application methods of accumulator was introduced.%根据J1140型压铸机压射系统的设计要求,分析压铸机压射系统增压液压原理,对增压蓄能器的容积进行计算;结合实践应用,介绍蓄能器的选择及应用方法。

  19. Verrekening van die kragveld van die verbond in die inkleding van die kommunikatiewe driehoeksverhouding tussen teks, hoorder en prediker

    Friedrich W. de Wet


    Full Text Available In hierdie artikel word die kommunikatiewe driehoeksverhouding tussen die Bybelse teks, die hoorders en die prediker homileties verken. Die probleemstelling waarmee gewerk word handel oor potensiële versteurings wat kan plaasvind in hierdie driehoeksverhouding wanneer die hoorders en die prediker in hulle menslike beperktheid in verbinding gebring word met die ewige Woord van God soos dit in die Bybelse teks na vore kom. In die loop van die artikel word die volgende aspekte verken: ’n Ideale tipering van die verhouding tussen die teks, hoorders en prediker waarin al drie faktore ’n regmatige plek het; die maniere waarop die kommunikatiewe driehoek in die spanningsveld tussen teks, hoorders en prediker kan skeeftrek; en pneumatologiese verankering van die kommunikatiewe driehoek in die kragveld van die verbondsruimte, waarin Jesus Christus versoenend (integrerend teenwoordig is. Die gevolgtrekking waartoe gekom word, is dat die prediker in die kragveld van die verbond in staat gestel word om getrou te bly aan die teks (waarin God aan die Woord kom, aan die hoorders (as mededeelgenote in die genade van God sowel as – in missionêre konteks – mense wat geroep word om deelgenote in hierdie genade te word en aan hom- of haarself (as nuwe mens in Christus sonder dat die verbintenis aan een element in die  kommunikatiewe driehoek die verbintenis aan die ander versteur of laat disintegreer.Reckoning with the force field of the covenant in aligning the communicative triangle between text, listener and preacher. In this article the communicative triangular relationship between the Biblical text, the listeners and the preacher is reflected upon from a homiletic point of view. The problem statement deals with potential distortions in this triangular relationship when the listeners and preacher (in their human finitude are brought into contact with the eternal Word of God as it proceeds from the Biblical text. In the course of the article the

  20. Die amtliche Kinder- und Jugendhilfestatistik

    Schilling, Matthias


    Unter Rückgriff auf verschiedene wissenschaftliche Methoden umfasst die Dissertation eine differenzierte Untersuchung der amtlichen Kinder- und Jugendhilfestatistik (KJH-Statistik). Da die wissenschaftliche Sozialpädagogik erst langsam und zögerlich beginnt, die amtliche Statistik der Kinder- und Jugendhilfe wahrzunehmen, liegt das Forschungsinteresse darin, dass eine grundlegende und umfassende wissenschaftliche Analyse der Möglichkeiten und Grenzen der KJH-Statistik vorgenommen wird. Die KJ...

  1. Precision die design by the die expansion method

    Ibhadode, A O Akii


    This book presents a new method for the design of the precision dies used in cold-forging, extrusion and drawing processes. The method is based upon die expansion, and attempts to provide a clear-cut theoretical basis for the selection of critical die dimensions for this group of precision dies when the tolerance on product diameter (or thickness) is specified. It also presents a procedure for selecting the minimum-production-cost die from among a set of design alternatives. The mathematical content of the book is relatively simple and will present no difficulty to those who have taken basic c

  2. The Effect of Aluminum Content and Processing on the Tensile Behavior of High Pressure Die Cast Mg Alloys

    Deda, Erin M.

    Due to their high specific strength and good castability, magnesium alloys are desirable for use in weight reduction strategies in automotive applications. However, the mechanical properties of high pressure die cast (HPDC) magnesium can be highly variable and dependent on location in the casting. To better understand the relationship between microstructure and tensile properties, the influence of alloying and section thickness on the microstructural features and tensile properties of Mg-Al and Mg-Al-Mn alloys is quantified. This investigation provides experimental input to modeling activities for the development of an Integrated Computational Materials Engineering capability, to assess and quantify the impact of microstructure on the tensile behavior of HPDC Mg AM series (magnesium-aluminum-manganese) alloys. As a result of this work, it is found that with increasing aluminum content, the yield strength increases and the ductility decreases. Increasing the plate thickness results in a decrease in both the yield strength and ductility. HPDC components have varying microstructural features through the plate thickness, developing a "skin" and "core". The grain size, beta-Mg 17Al12 phase, and solute content are all quantified through the thickness of the plates. By quantifying microstructural variations, a physics-based model has been developed which is able to predict the effects of alloying and plate thickness on yield strength. The primary factors affecting strengthening are accounted for using a linear superposition model of solid solution, grain size, and dispersion hardening. This model takes into account through-thickness microstructure gradients that exist in HPDC components by using a composite model to incorporate the skin and core changes. The yield strength in these alloys is dominated by grain boundary strengthening and solute hardening effects. In order to isolate the effects of eutectic phases, shrinkage porosity and oxide films on strength and

  3. Gods hand in die natuur

    A. Duvenage


    Full Text Available Kan ons van so iets spreek? Daaroor bestaan daar seker geen verskil nie. Die Bybel is vol daarvan van Genesis tot Openbaring. God is Skepper. ’n Ander vraag is of ons God ook kan ken uit wat daar in die natuur gebeur? Verloop alles nie maar volgens ewige natuurwette waaraan tog niks verander kan word nie? Ons bely egter dat die Here nie net in die hart van die mens gelê het wat ons noem die „saad van die religie” nie (semen religionis, maar dat ons Hom ook ken deur die skep- ping, onderhouding en regering van die hele wêreld, aangesien dit voor ons oë is soos ’n mooi boek waarin alle skepsels, groot en klein, die letters is wat ons die onsigbare dinge van God duidelik laat sien, nl. sy ewige krag en Goddelikheid ...; dinge wat almal genoegsaam is om die mense te oortuig en hulle alle verontskuldiging te ontneem (Art. 2 Ned. Gel. Bel..

  4. Die eunug in die klassieke mitologie en samelewing

    F. P. Retief


    Full Text Available Die konsep, eunug, wat na ’n gekastreerde persoon (gewoonlik manlik verwys, het sy oorsprong in die mitologie. Van hier word dit deurgevolg na die Klassieke tydperk. Kastrering vir religieuse redes was deel van godsdiensrituele gekoppel aan verering van aardgodinne en fertiliteit. Die kultusse wat aan die godinne Kubele, Hekate, Atargatis-Dea, Astarte, Artemis en Innana-Ishtar gewy was en wat deur eunugpriesters bedien was, word beskryf. Kastrering vir niereligieuse redes, oorwegend weens sosio-ekonomiese oorwegings, het waarskynlik tydens die 2de millennium v.C. sy oorsprong in Midde-Oosterse lande gehad vanwaar dit teen ongeveer die 5de eeu v.C. na Griekeland, en twee eeue later na Rome uitgebrei het. ’n Oorsig word gelewer van die invloed en rol van die eunug ten tye van die klassieke beskawing. Die sogenaamde “kongenitale eunug” waar hipogonadisme weens ’n aangebore letsel ontstaan, ’n baie seldsame verskynsel, word nie verder bespreek nie.

  5. Zinc Base Die Castings


    183 B86- 33T SAE N.J .zn Co. B86-33T 1934 SAE N.J.Zn Cc,. Zamak 3N AllO;E Cl C2 Allo~ XXI 221 Zarnak 2 .A.llo;z XXIII .Allol XXIII 202 Zamak 2 O...2 Pb ,Fe, Cd, C:’. 3 special high gra1e ?:inc. • t • • ; -J TABLE II Chemical Composition for Zinc Alloy Nuuber Zam.ak 2 Zamak 3...was alco given regarding the aging of the alloys. The a1loy3 Aupplied were: Zamak 2, Zamak 3, Zamak 3-S (Stabilized to hasten contraction which

  6. Aard, funksie en invloed van die Literatuur

    J. van der Elst


    Full Text Available Binne die raam werk van die tema van hierdie simposium gaan dit om twee komponente:die Literatuur, meer bepaald die letterkundige werk of woordkunswerk met sy drie genres endie gemeenskap, die onlvangers of belewers van die Literatuur of doodgewoon die lesers.

  7. Videobasierte Unterrichtsbeobachtung: die Quadratur des Zirkels?

    Fankhauser, Regula


    Seit einigen Jahren wird Unterrichtsforschung vermehrt videobasiert angegangen. Die methodologische Diskussion, die die Weiterentwicklung des Instrumentariums begleitet, kreist dabei zentral um die Frage der Invasivität der Aufzeichnungstechnik und möglicher Kameraeffekte. Je nach methodologischer Ausrichtung wird diesem Problem anders begegnet: So versucht die abbildtheoretische Unterrichtsvideografie, die Invasivität zu kontrollieren. Qualitative Methoden wie die Kameraethnografie dagegen m...

  8. Die wisselende rol van kontinuïteit en diskontinuïteit in die geskiedenis van die filosofie en die wiskunde

    Danie F.M. Strauss


    Full Text Available Hierdie artikel wil lig werp op die onvermydelikheid van diskreetheid en kontinuïteit as primitiewe (ondefinieerbare verklaringswyses in die geskiedenis van die filosofie en die wiskunde. Dit beliggaam die algemene uitdaging om rekenskap van die samehang van iets wat uniek is te gee. Gödel beklemtoon die samehang van ‘primitiewe begrippe’. Die Griekse filosofie het reeds die ruimtelike geheel-dele-relasie – en die oneindige verdeelbaarheid daarvan – ontdek. Gedurende en na die Middeleeue het filosowe wipplank gery tussen ’n atomistiese waardering van die kontinuum en die teenoorgestelde daarvan, wat byvoorbeeld in die denke van Leibniz aangetref word as die gepostuleerde wet van kontinuïteit (lex continui. Die ontdekking van ‘inkommensurabiliteit’ (irrasionale getalle deur die Grieke het aanleiding gegee tot die eerste grondslagkrisis van die wiskunde en die geometrisering daarvan. Leibniz en Newton kon die probleme rondom die limietbegrip nie besleg nie en spoedig sou dit tot die derde grondslagkrisis van die wiskunde aanleiding gee. Dit het Frege en die ‘kontinuum-teoretici’ daartoe gebring om prioriteit aan die kontinuum te gee – diskreetheid is ’n katastrofe. Onlangs waardeer Smooth Infinitesimal Analysis kontinuïteit as iets wat ’n ‘ongebroke en ononderbroke geheel’ daarstel. Die intuïsionistiese wiskunde het opnuut aangesluit by die klem op die ruimtelike geheel-dele-relasie. Ondanks pogings om kontinuïteit eksklusief aritmeties en ruimtelik te verstaan bevestig die geskiedenis van die filosofie en die wiskunde onmiskenbaar dat die medekondisionerende rol van hierdie twee wyses van verklaring ’n konstante metgesel in die nadenke oor kontinuïteit en diskontinuïteit sou bly. (Die rol van kontinuïteit en diskontinuïteit in die fisika en biologie sal in ’n aparte artikel ondersoek word.

  9. Effects of Dy, Sr and Die Casting on Microstructure, Mechanical and Corrosion Properties of Mg-Dy-Sr-Nd-Zr Alloys

    Liu, Dexue; Yin, Xunyan; Pang, Xin; Hu, Shiwen; Ding, Yutian


    By adding 2, 6 and 10 wt.% Dy and 0.5, 1.5 and 2 wt.% Sr elements to Mg-2.4Nd-0.5Zr alloys and adopting die-casting process for biomedical Mg-10Dy-0.5Sr-2.4Nd-0.5Zr alloys, the effects of Dy and Sr elements and die-casting process on the microstructure, mechanical properties and corrosion resistance of Mg-Dy-Sr-Nd-Zr alloys were investigated. The new biomedical Mg-10Dy-0.5Sr-2.4Nd-0.5Zr alloys were designed, and the grain size of the as-cast new alloy was refined to 70 μm and distributed equably. The ultimate tensile strength increased with increasing Dy content and decreasing Sr content. The corrosion rate decreased firstly and then increased with increasing Dy content and decreased with increasing Sr content. By adjusting the content of Sr and Dy, the ultimate tensile strength of as-cast new Mg-10Dy-0.5Sr-2.4Nd-0.5Zr alloys increased to 203 MPa, elongation was 7.4%, and the corrosion rate decreased to 0.48 mm/a. The elongation rate increased to 10.2% after the new biomedical alloys were processed by die casting with an refine-grained microstructure of 18 μm, meanwhile the ultimate tensile strength decreased to 180 MPa, and the corrosion rate was 1.29 mm/a.

  10. Effect of post-welding heat treatment on wear resistance of cast-steel die with surfacing layer

    Xu Wujiao


    Full Text Available The wear resistance capability of die surfacing layer under different Post-Welding Heat Treatments (PWHT was analysed by Finite Element (FE simulation and experiments. Taking hot forging process of a crankshaft as an example, a wear model of the hot forging die coated with surfacing layer was established using FE software DEFORM-3D. The simulation results indicated that the wear resistance capability of the die surfacing layer is optimal when tempering temperature and holding time are 550 °C and 4 h respectively. To verify the wear computational results, 16 groups of PWHT orthogonal wear tests were performed at a temperature of 400 °C, which is a similar temperature to that occurs in an actual hot forging die. The wear-test result showed a good agreement with the FE simulation. SEM observation of the wear debris on 16 specimens showed that oxidative wear is dominant when the temperature was in 400 °C. Furthermore, when tempering temperature and holding time were 550 °C and 4 h respectively, the carbide alloy dispersively distributes in the metallographic structure, which helps to improve the wear resistance of the surfacing layer.

  11. Expert Network for Die Casing Defect Analysis

    Jiadi WANG; Yongfeng JIANG; Chen LU; Wenjiang DING


    Due to the competition and high cost associated with die casting defects, it is urgent to adopt a rapid and effective method for defect analysis. In this research, a novel expert network approach was proposed to avoid some disadvantages of rulebased expert system. The main objective of the system is to assist die casting engineer in identifying defect, determining the probable causes of defect and proposing remedies to eliminate the defect. 14 common die casting defects could be identified quickly by expert system on the basis of their characteristics. BP neural network in combination with expert system was applied to map the complex relationship between causes and defects, and further explained the cause determination process.Cause determination gives due consideration to practical process conditions. Finally, corrective measures were recommended to eliminate the defect and implemented in the sequence of difficulty.

  12. Reuchlin und die Kabbala


    Auszug: Hundert Jahre nachdem Johannes Reuchlin sein wissenschaftliches Werk vollendet hatte, war der von ihm hinterlassene Eindruck auf die europäische Wissenschaft und das europäische Denken so nachdrücklich, daß er - liebe- oder vorwurfsvoll - einmal >Rabbi Capnion< genannt wurde. Und wirklich - so meint Joseph Blau in seiner Darstellung der christlichen Kabbala - habe Reuchlin der hebräischen Literatur mehr gedient als mancher ordentliche Rabbiner. Ähnlich hat Gershom Scholem, der Begründ...

  13. Die Mythosphilosophie Ernst Cassirers

    Pedersen, Esther Oluffa

    Bogen undersøger Ernst Cassirers filosofiske hovedværk - Die Philosophie der symbolischen Formen - for at finde frem til, hvilken betydning det har, at Cassirer inddrager myten som den menneskelige kulturs grundform og dermed på mange måder sidestillet med videnskab, sprog og kunst. Der...... argumenteres for, at netop arbejdet med myten muliggjorde en frugtbar åbning af erkendelsesteorien i retning af udtryksfænomenet og følelsers betydning for menneskets livsverden. Bogens anden del ser nærmere på, hvordan Cassirer bruger sin mytefilosofi fra 1920'erne til at forstå 1940'ernes fascistiske...

  14. Rapid die manufacturing using direct laser metal deposition

    Pereira, MFVT


    Full Text Available This paper highlights the work undertaken at the CSIR on the issue of rapid die manufacturing through the application and evaluation of a rapid prototyping technique and coating technologies applied to die components of a high pressure casting die...

  15. Die historiese Jesus, die Jesus-beweging en die vorming van die kerk

    Andries van Aarde


    Full Text Available The historical Jesus, the Jesus movement and the birth of the church. The article focuses on the birth of the church. The point at which the church began its existence is located within the boundaries of fonnative Judaism. The parting of the ways is explained as a movement from faction to sect, to the eventual fonnation of the church in its own right as distinct from the synagogue. The historical Jesus should therefore not be seen as the founder of the church. However, the article argues that the relation of the life and death of the historical Jesus to the resurrection belief of the post-paschal Jesus movement constitutes the cradle of the church. This continuum between Jesus and New Testament Christendom is referred to by means of the Gennan phrase die Sache Jesu. Reconsideration of this trajectory results in the conviction that the vision and program of the historical Jesus cannot be neglected when one reflects on the nature of the church in the New Testament or on the vocation of the church through history to the present day. Two thought complexes form the kernel of die Sache Jesu: God's unbounded presence and the concept that everyone has unmediated and non-hierarchical access to the grace of God.

  16. Die hermeneutiek van gereformeerde kerkreg

    Andries le Roux du Plooy


    Full Text Available Die artikel het op die belangrikheid en noodsaaklikheid van ‘n hermeneutiek vir die gereformeerde kerkreg gefokus. Die kerkregtelike dokument wat besonderlik ter sake was, is die kerkorde van die Gereformeerde kerke in Suid-Afrika, met sy besondere band met die Dordtse kerkorde van 1618 en 1619. Agtereenvolgens is aandag gegee aan die volgende aspekte soos (1 die eiesoortige aard van ‘n kerkorde as ‘n teologiese dokument en teks, in onderskeiding van regsdokumente; (2 die aard van die hermeneutiek van kerkreg; (3 enkele teorieë oor die interpretasie of uitleg van tekste, veral regstekste en (4 normatiewe vooronderstellings en reëls vir die interpretasie en verstaan van die teks en artikels van die kerkorde asook besluite van kerklike vergaderinge. Die gevolgtrekking was dat weinig indringende navorsing gedoen is oor die saak van hermeneutiek vir kerkreg, hoewel dit noodsaaklik is. Duidelike hermeneutiese reëls is gesuggereer en verduidelik, wat sou kon meehelp dat kerke en kerklike vergaderinge die artikels van die kerkorde asook besluite en reglemente wat daarop berus het, kan interpreteer en toepas.The hermeneutics of reformed church polity. The article focused on the importance and urgency of a design for reformed hermeneutics on church polity. The Church Order referred to in the article is the Church Order of the Reformed Churches in South Africa, which are closely related to the Church Order of Dordt of 1618 and 1619. The following aspects received attention namely (1  the unique character of a Church Order, in comparison to and distinguished from legal documents and statutes; (2 the character and nature of hermeneutics of church polity; (3 theories of interpretation in the common law tradition and their relevance to church polity and (4 normative presuppositions and marks for the interpretation and understanding of the text and articles of the Church Order, as well as the resolutions of church assemblies. It was found that

  17. Is die ortodoksie se verstaan van die sondeval belemmerend vir die gesprek tussen teologie en natuurwetenskap?

    Johan Buitendag


    Full Text Available In hierdie artikel is betoog dat die Gereformeerde Ortodoksie se begrip van die sondeval ’n  belemmering  was  vir  die  gesprek  tussen  teologie  en  natuurwetenskap.  Die  rede hiervoor was dat dit ten eerste ’n bepaalde verstaan van liniêre tyd nahou en ten tweede dat dit ’n bonatuurlike ingryp veronderstel het. Albei hierdie aspekte het die debat onnodig problematiseer. Die argument is ontwikkel deur eerstens die probleem te definieer, gevolg deur ’n uiteensetting van die standpunte van Augustinus en Calvyn onderskeidelik oor die sondeval. As ’n heuristiese sleutel is die konsepte van infralapsarisme en supralapsarisme aangewend om die tema te ontleed. Die artikel is afgesluit met die oortuiging dat die imago Dei ’n beliggaamde menslike persoon is wat biologies in die geskiedenis in terme van selfbewussyn en morele verantwoordelikheid ontluik het.Is the Orthodoxy’s notion of the Fall inhibitory for the dialogue between theology and science? In this article it was argued that the Reformed Orthodoxy’s interpretation of the Fall had become an impediment in the dialogue between theology and science. The reason was that it assumed firstly a specific understanding of linear time and secondly a metaphysical intervention. Both events were unnecessarily problematising the debate. The argument was deployed by stating the problem, followed by an exposition of the views of Augustine and Calvin on the Fall. As a heuristic key, the concepts of infralapsarism and supralapsarism were applied respectively to analyse the topic. The article concluded with the conviction that the imago Dei is an embodied human person that had biologically emerged in history as a center of self-awareness, and moral responsibility.

  18. Die verband tussen lokus van beheer en die werks prestasie van swart bemarkers in die lewensversekeringsbedryf

    E. L. Coetzer


    Full Text Available The relationship between locus of control and the work performance of black marketers in the life assurance industry. The aim of the study was to establish the relationship between locus of control and the work performance of black marketers in the life assurance industry. These constructs were selected by virtue of the lack of empirical research regarding the assumed relationship between them. The Locus of Control Scale of Schepers (1995 was used for measuring locus of control. Work performance was measured by the commission earned per month by the marketer, the number of policies generated by the marketer, as well as the percentage of lapsed policies. The relevant measurements were obtained in respect of a sample of 149 black marketing personnel. The results indicated a modest but statistically significant relationship between external locus of control and the work performance of black marketers. Opsomming Die doel van die studie was om die verband tussen lokus van beheer en die werksprestasie van swart bemarkers in die lewensversekeringsbedryf te bepaal. Hierdie konstrukte is gekies op grond van die gebrek aan empiriese navorsing rakende die veronderstelde verband tussen genoemde konstrukte. Die Lokus van Beheer-vraelys van Schepers (1995 is in die meting van lokus van beheer gebruik. Werksprestasie is aan die hand van kommissie per maand verdien, aantal polisse gegenereer deur 'n bemarker en die persentasie vervalde polisse, gemeet. Die tersaaklike metinge is verkry ten opsigte van 'n steekproef van 149 swart bemarkers. Die resultate toon 'n klein, dog statisties beduidende verband tussen eksterne lokus van beheer en die werksprestasie van swart bemarkers in die lewensversekeringsbedryf.

  19. 压铸镁合金汽车方向盘骨架的工艺研究%Research Die Casting Magnesium Alloy Steering Wheel Skeleton

    安帅杰; 王峰


    FLOW-3D simulation software for die-casting process car steering wheel skeleton is designed and optimized to determine the optimum casting process parameters;using optical microscopy,scanning electron microscopy analysis of the organizational structure of the steering wheel skeleton.Determine the best framework for the die casting process parameters by orthogonal experiment method:pouring temperature 700℃,die-type temperature 220℃,injection speed 2.34m/s.Under this argument,casting good shape, and actual results and simulation results are basically consistent.Skeleton dense,with good ductility.%利用FLOW-3D模拟软件对汽车方向盘骨架的压铸工艺进行了设计与优化,确定了较优的压铸工艺参数;利用金相显微镜、扫描电镜分析了方向盘骨架的组织结构。采用正交实验法确定骨架最佳的压铸工艺参数:浇注温度700℃、压铸型温度220℃、压射速度2.34m/s。在此工艺参数下,压铸件成型良好,实际结果与模拟结果基本吻合。骨架组织致密,具有良好的塑性。

  20. Sedimentêre omgewings van die Inhaca-eilandstelsel met spesiale verwysing na die petrografiese en geochemiese eienskappe van die sedimente spesiale verwysing na die petrografiese en geochemiese eienskappe van die sedimente

    Marieke Peché


    Full Text Available Die Inhaca-eilandstelsel is geleë langs die suidooskus van Mosambiek. Die oostekant van die stelsel grens aan die Indiese Oseaan en die westekant aan die Baai van Maputo. Hierdie eilandstelsel bestaan uit Inhaca- en Portugese eiland, asook ’n groep sandbanke wat van die noordlike punt van Inhaca na Portugese eiland strek. Die doel van hierdie studie is om die verskillende moderne en oer-sedimentêre omgewings op die eilandstelsel te identifiseer en te beskryf, die invloed van getye en golfaksie op die moderne sedimentêre omgewing vas te stel en die geochemiese en petrografiese samestelling van die geologiese eenhede te bepaal.

  1. A new approach to assess the effects of Sr and Bi interaction in ADC12 Al–Si die casting alloy

    Farahany, Saeed, E-mail:; Ourdjini, Ali; Abu Bakar, Tuty Asma; Idris, Mohd Hasbullah


    Highlights: • Interactive effect between Bi and Sr has been invesitigated comprehensively. • Sequence of addition did not affect thermal and microscopical characteristics. • A new map has been established to assess the final microstructure of castings. - Abstract: In the present paper, the possible interaction between bismuth and strontium in ADC12 die casting alloy was investigated comprehensively by using in situ thermal analysis technique. The characteristic temperatures including nucleation, minimum and growth temperatures of eutectic Al–Si were also analyzed. The results show that with Bi present in the Al–Si alloy melt the efficiency of Sr in modifying the eutectic Si is reduced. A threshold Sr/Bi ratio of at least 0.5 is required for a fully modified Si structure to form. A new map based on the characteristic temperatures, Sr/Bi ratio and microstructure, was established to assess the microstructure of fully solidified Al–Si castings.

  2. Die gebruik van metode in die filosofie, spesiaal in die reformatoriese tra­disie 1

    N. T. van der Merwe


    Full Text Available Die onderw erp van my voordrag, Die gebruik van metode in die fílosofie, verg ’n paar verduidelikende opinerkings vooraf. Ek dink u verm oed alreeds dat hierdie fomulering ’n versuikerde pil is om u in so ’n mate nuuskierig te maak dat una ’n heerlike vrye filosofiese ‘onderonsie’ gedurende die teepouse darem vir ’n tw eede sessie terugkeer. Want is dit nie twee smaaklike heuningdruppels nie: filosofie en sy metode’ en ‘metode in die Reformatoriese filosofiese tradisie'?! Veral as in gedagte gehou word dat in teenstelling met wat ’n mens sou verw ag, daaroor dié onderwerp as sodanig relatief maar heel weinig geskrywe is en word, selfs as die ‘Inleidings in die Metodologie’ daarby gereken word.

  3. Die derivation der slowenischen substantive

    ]ože Toporišič


    Full Text Available Von der traditionellen slowenischen Wortbildungslehre von Substantiven mit den Suffixen (s. g. Derivation wird die betreffende Problematik so dargestellt, dass man - nach Miklošič's Vorbild - von Suffixen mit einem charakteristischen Konsonanten (oder mit eine charakteristischen Konsonantengruppe aus gehend bei verschiedenen Wortartbasen (Zeitwort, Adjektiv, Substantiv die semantischen kategorien von Wortbildungen mit »demselben« Suffix aufzählt. Aber schon bei A. Bajec (Besedotvorje slovenskega jezika, 1950 findet man auch das Kapitel »Die Suffixe nach ihren Bedeutungen, worin Suffixe für 24 Bedeutungsgruppen festgehalten sind. In der Slovenska slovnica (1956 gibt es 16, im Slovenski knjižni jezik 2 (1966 aber 13 solcher Gruppen von Suffixen. Der vorliegende Ausatz geht ebenfalls von den semantischen Kategorien aus, versucht aber die Zahl der Bedeutungskategorien, die aus verhalen, adjekvsehen oder substantiviseher Basen mit Hilfe von Suffixen gebildet werden, auf 6 grosse Gruppen zu reduzieren. Diese 6 Gruppen sind: 1. die Namen der Agenten, des Eigenschaftstragers und der Verbundenheit; 2. die Namen der Werkzeuge, 3. die Namen der Handlung, der Eigenschaft und des Zustandes, 4. die Namen der vergegenständlichten Tat oder Eigenschaft, 5. die Namen der Lokalisierung und 6. Verschiedene. Nur bei den Wortbildungen aus einer substantivischen Basis gibt es noch eine besondere, die s. g. Modifikationsbedeutungsgruppe (Feminativa und Maskulinativa, Kollektiva, Gradativa, Iuvenalia, Diminutiva, Diminutivhipokoristika, Diminutivpeirotiva und Peiorativa. - Dabei wird keine Riick­ sicht darauf genommen, ob diese Suffixe genain slowenisch oder aus anderen Sprachen übernommen sind. Die Berechtigung dafiir gibt uns nicht nur die produktive Wortbildung mit den entlehnten (nichtautochtonen Suffixen im gegenwärtigen Slowenisch, sondern (was noch wichtiger ist auch das richtige Verständnisvermögen der Sprecher für solche Wortbildungen im

  4. Die invloed van herbivorie en vuur op die oorlewing van sekere meerjarige kruide langs die Sabierivier, Kruger Nasionale Park

    H. Myburgh


    Full Text Available Die groot vloede wat in die jaar 2000 in die Kruger Nasionale Park plaasgevind het, het dierivieroewerplantegroei versteur. Dit het die geleentheid gebied om heinings op te rig langsdie Sabierivier om herbivore uit sekere gebiede uit te sluit en sodoende die herstel van die rivieroewerekosisteme te monitor.

  5. Die heelal en sy onstaan (II

    D. J. Van Rooy


    Full Text Available Ons kennis en wetenskap van die hemelliggame word volkome bepaal deur die lig wat ons van hulle ontvang, d.w.s. as ons die feite wat die Bybel daaromtrent meedeel, buite rekening laat.

  6. Spearman se G en die faktorstrukture van die senior aanlegtoetse en die algemene skolastiese aanlegtoets

    G. P. De Bruin


    Full Text Available Spearman's G and the factor structures of the Senior Aptlitude Test and the General Scholastic Aptitude Test. Scores of 1507 university students on the six subtests of the General Scholastic Aptitude Test (GSAT and on nine subtests of the Senior Aptitude Tests (SAT were subjected to a joint confirmatory factor analysis. This procedure was followed to examine (a the extent to which scores in respect of the two batteries of tests, are explained by a general factor (Spearman's g, and (b the relationship between the two general factors. Scores on the GSAT subtests were adequately explained by just one factor. With regard to the SAT three group factors could be distinguished, namely Verbal Ability, Visual-Spatial Ability and Numerical Ability. The correlations between the group factors were so high that the influence of a general factor was evident. The general factors underlying the SAT and GSAT respectively, also correlated significantly. In view of findings suggesting the general intelligence is the best single predictor of criteria such as academic success and work performance, the GSAT is recommended for selection purposes. Opsomming Tellings van 1507 universiteitstudente op die ses subtoetse van die ASAT en nege subtoetse van die SAT, is gesamentlik aan 'n bevestigende faktorontleding onderwerp. Hierdie prosedure is gevolg om ondersoek in te stel na (a die mate waartoe 'n algemene faktor (Spearman se g die tellings op die twee batterye toetse onderskeidelik onderle, en (b wat die verwantskap tussen die twee algemene faktore sou wees. Ten opsigte van die ASAT is dit duidelik dat slegs een faktor tellings op al ses subtoetse verklaar. Ten opsigte van die SAT kon drie groepsfaktore onderskei word/ naamlik Verbale Vermoe, Visueel-Ruimtelike Vermoe en Numeriese Vermoe. Die korrelasies tussen die drie groepsfaktore was egter so hoog dat dit duidelik is dat daar 'n algemene faktor onderliggend is aan die nege subtoetse. Die algemene faktore wat die

  7. Die MCI im Wandel: User Experience als die zentrale Herausforderung?

    Jetter, Christian


    Die Informationstechnologie hat heute einen Reifegrad erlangt, der stark umkämpfte Massenmärkte von interaktiven Produkten hervorgebracht hat. In diesen sind - wie auch in den herkömmlichen Konsumgütermärkten - nicht nur die pragmatische Produktqualität, sondern auch das Benutzungserlebnis und die Gesamtwirkung auf den Käufer entscheidend für den Markterfolg. Eine erfolgreiche Gestaltung dieser "User Experience" geht dabei über die reine Softwareergonomie hinaus und erfordert interdisziplinär...

  8. Optimization of Composition and Heat Treating of Die Steels for Extended Lifetime

    David Schwam; John F. Wallace; Quanyou Zhou


    An ''average'' die casting die costs fifty thousand dollars. A die used in making die cast aluminum engine blocks can cost well over one million dollars. These costs provide a strong incentive for extension of die life. While vacuum quenched Premium Grade H13 dies have become the most widely used in the United States, tool makers and die casters are constantly searching for new steels and heat treating procedures to extend die life. This project was undertaken to investigate the effects of composition and heat treating on die life and optimize these parameters.

  9. Meganisisme, vitalisme en holisme in die Biologie

    P.J. Botha


    Full Text Available Die Biologie word omskryf as die wetenskap van die lewende wesens (organismes. Die lewe staan dus in die brandpunt van die biologiese studie en ondersoek. Vra ons ons egter af wat onder „lewe” verstaan word, besef ons dadelik dat ons hier met ’n uiters moeilik definieerbare begrip te doen het. In verband met die aard van lewe het daar onder die bioloë en natuurfilosowe veral twee denkrigtings posgevat, nl. meganisisme en vitalism.

  10. Die mites rondom die val van Troje en Vergilius se uitbeelding daarvan in die tweede boek van die Aeneïs

    J. Swanepoel


    Full Text Available Die mites oor die val van Troje vertel ’n aangrypende verhaal en in die tweede boek van die Aeneïs gee Vergilius op ’n besondere wyse gestalte daaraan. Maar Vergilius se vergestalting daarvan is slegs een van die variante van die verhaal.

  11. Lady Di - Die moderne Madonna

    Steuten, Ulrich; Strasser, Hermann


    Die authentischen Bekundungen von Trauer und Wertschätzung, die der bei einem Autounfall in Paris ums Leben gekommenen Prinzessin Diana weltweit entgegengebracht und seit Jahren von mehreren Seiten instrumentalisiert werden, sind unübersehbar. Das Leben und Sterben der Prinzessin von Wales ist nach Ansicht der Autoren geeignet, einer populären Mythenbildung in der modernen Gesellschaft Substanz zu verleihen. Vor allem bietet es die Möglichkeit, einen modernen Kult zu etablieren, der sich im Z...

  12. Maintaining Low Voiding Solder Die Attach for Power Die While Minimizing Die Tilt

    Hamm, Randy; Peterson, Kenneth A.


    This paper addresses work to minimize voiding and die tilt in solder attachment of a large power die, measuring 9.0 mm X 6.5 mm X 0.1 mm (0.354” x 0.256” x 0.004”), to a heat spreader. As demands for larger high power die continue, minimizing voiding and die tilt is of interest for improved die functionality, yield, manufacturability, and reliability. High-power die generate considerable heat, which is important to dissipate effectively through control of voiding under high thermal load areas of the die while maintaining a consistent bondline (minimizing die tilt). Voiding was measured using acoustic imaging and die tilt was measured using two different optical measurement systems. 80Au-20Sn solder reflow was achieved using a batch vacuum solder system with optimized fixturing. Minimizing die tilt proved to be the more difficult of the two product requirements to meet. Process development variables included tooling, weight and solder preform thickness.

  13. Theoretic and Experimental Studies on the Casting of Large Die-Type Parts Made of Lamellar Graphite Grey Pig Irons by Using the Technology of Polystyrene Moulds Casting from Two Sprue Cups

    Constantin Marta


    Full Text Available This paper presents a comparative analysis between the practical results of pig iron die-type part casting and the results reached by simulation. The insert was made of polystyrene, and the casting was downward vertical. As after the part casting and heat treatment cracks were observed in the part, it became necessary to locate and identify these fissures and to establish some measures for eliminating the casting defects and for locating them. The research method was the comparisons of defects identified through verifications, measurements, and metallographic analyses applied to the cast part with the results of some criteria specific to simulation after simulating the casting process. In order to verify the compatibility between reality and simulation, we then simulated the part casting respecting the real conditions in which it was cast. By visualising certain sections of the cast part during solidification, relevant details occur about the possible evolution of defects. The simulation software was AnyCasting, the measurements were done through nondestructive methods.

  14. Relationship Between the 3D Porosity and β-Phase Distributions and the Mechanical Properties of a High Pressure Die Cast AZ91 Mg Alloy

    Biswas, Somjeet; Sket, Federico; Chiumenti, Michele; Gutiérrez-Urrutia, Iván; Molina-Aldareguía, Jon M.; Pérez-Prado, Maria Teresa


    Currently, most magnesium lightweight components are fabricated by casting as this process is cost effective and allows forming parts with complex geometries and weak textures. However, cast microstructures are known to be heterogeneous and contain unpredictable porosity distributions, which give rise to a large variability in the mechanical properties. This work constitutes an attempt to correlate the microstructure and the mechanical behavior of a high pressure die cast (HPDC) Mg AZ91 alloy, aimed at facilitating process optimization. We have built a stairway-shaped die to fabricate alloy sections with different thicknesses and, thus, with a range of microstructures. The grain size distributions and the content of β-phase (Mg17Al12) were characterized by optical and electron microscopy techniques as well as by electron backscatter diffraction (EBSD). The bulk porosity distribution was measured by 3D computed X-ray microtomography. It was found that the through-thickness microhardness distribution is mostly related to the local area fraction of the β-phase and to the local area fraction of the pores. We correlate the tensile yield strength to the average pore size and the fracture strength and elongation to the bulk porosity volume fraction. We propose that this empirical approach might be extended to the estimation of mechanical properties in other HPDC Mg alloys.

  15. Neurokognitiewe integrasie en die leerproses

    Johan J. Du Preez


    Full Text Available The purpose of this article, "Neuro-cognitive integration and the learning process'; is to find principles and strategies for the development of brain potential and the optimal integration of subject matter. Eight neuro-cognitive systems are identified and their importance to the integration of subject matter is emphasized. These systems are cortical energy, coding, planning and controlling, as well as the verbal sequential, non-verbal holistic, physical-motor, social effective and the subconscious. The relevant principles and strategies can serve as basis for mainstream and special education, guidance as well as psychotherapy. Die doe! met hierdie artikel is om beginsels en strategiee te vind om breinpotensiaal te ontsluit en leerstof optimaal te integreer. Aan die hand van 'n neurokognitiewe model word 'n aantal beginsels en strategiee bespreek en die verband met die leerproses word aangetoon. Agt neurokognitiewe sisteme is gei'dentifiseer en die belangrike rot wat dit speel ten opsigte van die integrasie van leerstof word beklemtoon. Genoemde sisteme sluit die volgende in: kortikale energie, kodering, beplanning en kontrolering, asook die verbaal-sekwensiele, nieverbaal- holistiese, fisiek-motoriese, sosio-affektiewe en die subbewuste. Genoemde beginsels en strategiee kan oak dien as grondslag vir hoofstroomonderwys, spesialiseringsonderwys, voorligting sowel as psigoterapie.

  16. Op die grens van vakwetenskap en filosofie

    M Elaine Botha


    Full Text Available Die begrip “grens” soos dit voorkom in die titel is vir meerdere uitleg vatbaar. Eerstens sou dit kon dui op ’n onoorskreibare punt tussen die filosofie en die vakwetenskappe, so iets soos ’n grenspaal of baken, met ander woorde ’n punt van waterdigte skeiding tussen die domein van die filosofie en die vakwetenskappe. As ’n mens soms die dramatiese grensgevegte tussen die filo­ sofie en die vakwetenskappe in die wetenskaplike literatuur beskou1 dan blyk dit kennelik noodsaaklik te wees om wel sodanige grens te stel, veral ten einde die gevaar van weten­ skaplike terrorisme van die een of die ander kant die hoof te bied.

  17. het die reformasie die leer gered en aanbidding verloor?

    B. Spoelstra, emeritusprofessor in Diakoniologiese Vakke, Fakulteit Teo- logie, P.U. vir C.H.O. (Skool vir ... Van der Leeuw sê liturgiek en leer is verwant en die geskiedenis van liturgie weerspieël die ...... VAN LEEUWEN G. 1946. Liturgiek.

  18. The Structure and Properties of Inductively Coupled Plasma Assisted Magnetron Sputtered Nanocrystalline NbN Coatings in Corrosion Protective Die Casting Molds.

    Chun, Sung-Yong


    Niobium nitride coatings for the surface modified die casting molds with various ICP powers have been prepared using ICP assisted magnetron sputtering. The applied ICP power was varied from 0 to 200 W. The deposited coatings were characterized post-deposition using X-ray diffractometry (XRD) and atomic force microscopy (AFM). Single NbN phased coatings with nano-grain sized (hardness of each coating were evaluated from potentiostat and nanoindentator. Superior corrosion protective coatings in excess of 13.9 GPa were deposited with assistance of ICP plasma during sputtering.

  19. Die wysgerige konsepsie van Thomas van Aquino

    Thomas Van Aquino


    Full Text Available Samevattend is tot dusver die volgende aangetoon: Die werklikheid vertoon volgens Thomas 'n hierargiese struktuur. Daar is verskillende grade van syn. God is die hoogste, die volheid van syn, en by die laere synsniveaus is daar steeds 'n verdere verwydering van hierdie synsvolmaaktheid in die rigting van absolute afwesigheid van syn. Hierdie synshiërargie is volgens die vorm-materieskema opgebou. Die materie in die hoëre synslaag word vorm vir die laere, of omgekeerd: die vorm van die laere is die materie vir die hoëre dinge. God is absoluut suiwer vorm of wet (essensie. Die vorme van die dinge is die goddelike wet (genoem exemplar, similitudo, ratio, verbum of imago wat deur God daarin geskape is. God druk op dié wyse sy gelykenis op wyse uit. Sy absolute volmaaktheid kan alleen tot uitdrukking gebring word deur 'n veelheid en verskeidenheid van geskape dinge. God word deur Thomas die causa effiaiens en exemplaris genoem. Die verhouding tussen Skepper en geskape werklikheid is dus dié van oorsaak en gevolg. As gevolg van sy wetsidee word daar deur Thomas dus nie duidelik tussen Skepper en skepping onderskei nie, want skepping beteken volgens hom onder andere dat God iets goddeliks (die wet in die dinge lê. Via die goddelike wet in die dinge ingeskape, is daar 'n sekere kontinuiteit tussen God en kosmos.

  20. Statues Also Die

    Pierre-Philippe Fraiture


    Full Text Available “African thinking,” “African thought,” and “African philosophy.” These phrases are often used indiscriminately to refer to intellectual activities in and/or about Africa. This large field, which sits at the crossroads between analytic philosophy, continental thought, political philosophy and even linguistics is apparently limitless in its ability to submit the object “Africa” to a multiplicity of disciplinary approaches. This absence of limits has far-reaching historical origins. Indeed it needs to be understood as a legacy of the period leading to African independence and to the context in which African philosophy emerged not so much as a discipline as a point of departure to think colonial strictures and the constraints of colonial modes of thinking. That the first (self-appointed exponents of African philosophy were Westerners speaks volumes. Placide Tempels but also some of his predecessors such as Paul Radin (Primitive Man as Philosopher, 1927 and Vernon Brelsford (Primitive Philosophy, 1935 were the first scholars to envisage this extension of philosophy into the realm of the African “primitive.” The material explored in this article – Statues Also Die (Marker, Resnais, and Cloquet, Bantu Philosophy (Tempels, The Cultural Unity of Negro Africa (Cheikh Anta Diop, and It For Others (Duncan Campbell - resonates with this initial gesture but also with the ambition on part of African philosophers such as VY Mudimbe to challenge the limits of a discipline shaped by late colonialism and then subsequently recaptured by ethnophilosophers. Statues Also Die is thus used here as a text to appraise the limitations of African philosophy at an early stage.  The term “stage,” however, is purely arbitrary and the work of African philosophers has since the 1950s often been absorbed by an effort to retrieve African philosophizing practices before, or away from, the colonial matrix. This activity has gained momentum and has been

  1. Die andersheid van Die verdwaalde land – die waarheid as storie vertel

    M. Hattingh


    Full Text Available Die verdwaalde land was written by Abraham Phillips, a so-called Coloured man from a South African working class background; someone who has no knowledge of literary conventions. The question arises: how can such a text be read without its uniqueness being affected by biased preconceptions? This article shows that post-structurally inspired theories on colonial discourse reveal perspectives on the complexity within the simplicity of this story. In this analysis of Die verdwaalde land particular emphasis is placed on identifying the framing strategies through which images and presentations of the Self and Other are created. Literary conventions are exposed as mechanisms which demarcate meaning, which in principle do not differ much from the manipulative strategies which define identity in the real world.Irrespective of nationality and time the line at which light race meets dark is the line at which human sociality is found at the lowest ebb; and wherever that line conies into existence there arc found the darkest shadows which we humans have cast by our injustice and egoism across the earth. (Olive Schreiner - Thoughts on South Africa

  2. Die Presbiter by Lukas en Paulus

    L. Floor


    Full Text Available In die jongste navorsing oor Lukas word die skrywer van die derde evangelieverhaal en die Handelinge van die Apostels aan ons bekend gestel as ’n teoloog wat uit die ‘Sitz im Leben’ (uit die situasie van sy eie tyd die boodskap aangaande Christus interpreteer . Lukas sou hom by sy interpretasie van die Christusboodskap laat lei het deur ’n bepaalde dogmatiese ‘Verstandnis’ waardeur hy homself verraai as ’n teoloog van die na-apostoliese tyd.

  3. Awareness of Dying Preface

    Barney G. Glaser, PhD, Hon. PhD


    Full Text Available Recently The New York Times reported: “VERY ILL CHILDREN TOLD OF DISEASE; Leukemia Patients at N.I.H. Not Shielded From Truth. . . . A child should always be told the truth, even when he has an incurable disease such as leukemia, according to two researchers who interviewed 51 children hospitalized at the National Cancer Institute, Bethesda, Maryland, for treat¬ment of leukemia.” This kind of news item reflects the growing concern among researchers and public about matters which touch on morality as much as on the technical aspects of medi¬cine. The rapidly increasing proportion of elderly people in the American population presents a range of personal and social questions; not the least is how they view their newly won longevity (often including anticipated years of chronic disease as well as their attitudes toward death. In consequence, many geriatric specialists are beginning to study American attitudes toward death, while others, spurred on by what seems a sense-less prolonging of life within hospital walls by medical tech¬nology run wild, are raising questions about death and dying in American life.

  4. Adapt or die?

    Visser, S S; Nel, A H


    The worldwide economic recession and the concomitant limited stock of finances have had an influence on the available money of every household and have also inhibited the improvement of socio-economic conditions and medicine. The Reconstruction and Development Programme (RDP) has the objective of improving the living conditions of the people with regard to housing, education, training and health care. The latter seems to be a major problem which has to be addressed with the emphasis on the preventive and promotional aspects of health care. A comprehensive health care system did not come into being property in the past because of the maldistribution of health care services, personnel and differences in culture and health care beliefs and values. The question that now arises, is how to render a quality health care service within the constraints of inadequate financing and resources. A comprehensive literature study has been done with reference to quality health care and financing followed by a survey of existing health services and finances. Recommendations are made about minimum requirements to be accepted if one were to adapt rather than die in terms of the provision of healthcare: the decentralization and rationalization of the administration of health care, the stress on and realization of effective and efficient primary health care, the acceptance of participative management in health providing organizations, the provision of financial management training for health care managers and the application of management accounting principles for the improvement of the efficiency and effectiveness of management.

  5. Die etiek van Karl Barth

    J. H. van Wyk


    Full Text Available Die etiek van Barth kan nie reg verstaan word sonder begrip van sy ganse teologiese agtergrond en opset, en ek wil byvoeg: sonder die besondere tydsomstandighede (oorlog! waarin hy geleef en gewerk het nie. Dit is verder bekend dat in sy teologiese ontwikkeling verskillende figure groot invloed op hom uitgeoefen het.

  6. Die Parlamentswahlen 2008 in Malaysia

    Reher, Stefanie; Knirsch, Thomas


    Nach den Parlamentswahlen vom März 2008 in Malaysia deutet manches auf einen politischen Umbruch hin: Die regierende Barisan Nasional (BN), die sich bislang einer komfortablen Zweidrittelmehrheit von 91,4 Prozent der Sitze im Parlament des Landes erfreut hatte, rutschte auf 63,1 Prozent ab und das...

  7. The Effect of Water Mist Cooling of Casting Die on the Solidification, Microstructure and Properties of AlSi20 Alloy

    Władysiak R.


    Full Text Available Unmodified AlSi20 alloy were casted at the research station, allowing for sequential multipoint cooling using a dedicated computer- controlled program. This method allows for the formation of the microstructure of hypereutectic AlSi20 alloy and also increases hardness. Primary silicon dendrites were found in the microstructure of cooled samples. Based on these dendrites, the formation of primary silicon particles is explained. Cooling of casting die with a water mist stream causes changes in solidification, which leads to expansion of the boundary layer with columnar crystals and shrinkage of the core zone with equiaxed crystals. It also causes more regular hardness distribution around pre-eutectic Si crystals, which can lead to tensile strength and machinability improvement.

  8. Leierskapstyl en die lerende organisasie

    W. G. Victor


    Full Text Available Leadership style and the learning organisation. In the present highly competitive environment, it has become increasingly important for organisational leaders to establish a learning organisation. In this study the focus was on the extent of influence that the evolution of organisations, as determined by their relative level of leadership practises (leadership style, has on the establishment of a learning organisation. Opsomming Die daarstel van ’n lerende organisasie deur bedryfsleiers word toenemend belangrik in die hedendaagse hoogskompeterende omgewing. In hierdie studie is gefokus op die mate van beinvloeding wat die evolusie van organisasies, soos deur hul relatiewe vlak van demokratiese leierskapspraktyke (leierskapstyl bepaal, op die daarstelling van’n lerende organisasie het.

  9. Montessori-skole: die ander kant

    Monica Viljoen


    Full Text Available Na aanleiding van die artikel “Die invloed van die New Age-beweging op die onderwysagenda van die toekoms” deur Lien van Niekerk en Corinne Meier van die Departement Historiese Opvoedkunde van Unisa (vgl. Koers, 59 (1 1994:69-84 wil ek graag ’n ander sy van Montessori-skole onder die aandag van Koers lesers bring.

  10. Filosofiese tendense in die wordinggeskiedenis van ons verstaan van die fisiese natuur

    D. F. M. Strauss


    Full Text Available Die ontstaan van ’n lang tradisie van natuurwetenskaplike denke is in antieke Griekeland te vind – die bakermat van die Westerse beskawing en die bron van geartikuleerde rasionele besinning. Die vroegste fases van die Griekse kultuur het reeds geboorte geskenk aan ’n teoretiese nadenke oor die heelal. Die Pythagoreërs is veral bekend vir hul klem op die verklaringskrag van getalsverhoudinge. In hul tese dat “alles getal is” het hulle egter slegs rasionale getalle (breuke erken en gevolglik uiteindelik vasgeloop in die ontdekking van irrasionale getalle wat tot die geometrisering van die Griekse wiskunde gelei het en tegelyk die bedding gevorm het van waaruit ’n magtige tradisie van ruimte-metafisika gegroei het wat die hele middeleeuse tydperk omspan het. Die vermeende statiese syn is in die mees ekstreme geval – die skool van Parmenides en die argumente van Zeno teen veelheid en beweging – tot in die uiteindelike antinomiese konsekwensies daarvan deurdink. Dit was egter eers die vroeg-moderne tyd – die voorgangers en nakomelinge van Galilei – wat naas getal en ruimte ’n waardering ontwikkel het vir die verklaringskrag van beweging (vergelyk die klassieke meganistiese wêreldbeeld van die heelal as ’n meganisme van stofdeeltjies in beweging. Maar ook hierdie meganistiese reduksie (waardeur alle fisiese verskynsels herlei is tot die beweging van al of niegelade massapunte sou uiteindelik misluk omdat dit nie van die onomkeerbaarheid van fisiese prosesse rekenskap kon gee nie. Gevolglik beliggaam eers die fisika van die 20ste eeu ’n erkenning van die deurslaggewend-stempelende rol van energie-werking (dus van die fisiese aspek in die aard van stoflike dinge en prosesse. Die artikel word afgesluit met ’n vlugtige verduideliking van die implikasies van die voorafgaande argumentasie vir ’n benadering van die misterie van die bestaan van materie.

  11. Die rym in Jukstaposisie (T.T. Cloete en die regverdiging van enkele fonologiese begrippe

    D. P. Wissing


    Full Text Available Die taalkundige hon daarvan om te kan se dat die goeie literator sonder taalkundige insigte geen volledige cn behoorlike teksanalise kan docn nie. Maar die situasic kan ook omgekeerd wees: die letterkunde (eintlik die woordkunswerk kan ook vir die taalkunde van waarde wees. In hierdie stuk wil ek meer in die besonder probeer aantoon dat en hoe die taalkundige ook ondersteuning vir die invoering van bepaalde fonologiese begrippe uit die gedig kan vind. Vir die doel beperk ek my tot die bunde Jukstaposisie van T.T. Cloete.

  12. Ekumeniese kerkreg: Die aangewese weg?

    Pieter J. Strauss


    Full Text Available Die argument word gehoor dat kerkregeringstelsels soos dié van die Rooms-Katolieke, Lutherse en gereformeerde kerke van ’n transendentale aard was en is. Daardeur word geïmpliseer dat hierdie stelsels een transendentale, unieke vaste beginsel gebruik om ’n hele stelsel van kerkregering van buite af te bepaal. Volgens Leo Koffeman, ’n voorstander van ’n ekumeniese kerkreg, plaas hierdie stelsels hulself hiermee buite die diskoers oor kerkreg en kerkregering en die beweging van die Heilige Gees. ’n Ekumeniese kerkreg, daarenteen, is ten gunste van ’n gemeenskaplike kerkreg tussen kerke. Omdat dit verskillende tradisies bymekaar bring, is dit ’n kritiese en daarom beter benadering. Die skrywer oorweeg hierdie argumente krities in die lig van ’n gereformeerde benadering tot kerkreg.The argument is used that church political systems like that of the Roman Catholic, Lutheran and reformed churches were of a transcendental character. By that it is implied that it used one transcendental and unique ‘hard principle’ from outside to direct a system of church government. Such uniqueness, according to Leo Koffeman who advocates an ecumenical church polity, places it outside the church political discourse and the way of the Holy Spirit. An ecumenical church polity seeks a combined polity between churches and is, by bringing different traditions together, a critical and therefore better undertaking. The author examines these arguments critically in the light of a reformed church polity.

  13. 'n Begronde bedieningsmodel vir die diakonia van die gemeente

    15 Feb 2012 ... This work is licensed under the ... Grobler & Van der Walt 2008; Lingenfelter 2005; Armour & Browning 2000) en daarmee saam die ...... missionary structure of the church', Swedish Missiological Themes 93(3), 433–447.

  14. Die Valenz als textgrammatische Kategorie

    Stojan Bračič


    Full Text Available Vor mehr als dreißig Jahren kam der französische Linguist Lucien Tesnière auf die geniale Idee, die gegenseitigen Relationen zwischen dem Verb eines Satzes einerseits und den anderen Satzteilen andererseits mit den chemischen Relationen in der Struktur eines Moleküls zu vergleichen. Die Eigenschaft des Verbs, andere Wörter an sich zu binden, nannte er Verbvalenz. Tesnière schreibt (schon 1959 wörtlich: "Man kann das Verb mit einem Atom vergleichen, an dem Häkchen angebracht sind, so daß es -je nach der Anzahl der Häkchen - eine wechselnde Zahl von Aktanten an sich ziehen und in Abhängigkeit halten kann. Die Anzahl der Häkchen, die ein Verb aufweist, und dementsprechend die Zahl der Aktanten, die es regieren kann, ergibt das, was man die Valenz des Verbs nennt" (Tesnière 1980: 161. Und weiter: "Aufgrund der strukturalen Konnexionen bestehen Dependenzbeziehungen (Abhängigkeitsbeziehungen zwischen den Wörtem. Jede Konnexion verbindet im Prinzip einen übergeordneten mit einem untergeordneten Term" (ibid., 27. Schematisch hat Tesnière diese Relationen bekannt­ lich in den sogenannten Stemmata (Strukturbaumen, graphischen Darstellungen von Konnexionsstrukturen; ibid., 384 wiedergegeben. Im Satz "Mon vieil ami chante cette chanson fort jolie" ist das Verb "chante" als "régissant" allen anderen Wortkonstituenten iibergeordnet, wobei die üntergeordneten Elemente "ami" und "chanson" in einer zweiten Rangstufe wiederum den untergeordneten Elementen "mon", "vieil", "cette", "jolie" übergeordnet sind. (Vgl. Greule 1982: 99.

  15. Die Dankesrede bei der Preisverleihung

    Elenmari Pletikos Olof


    Full Text Available Festliche Preisverleihungen sind Gelegenheiten, bei denen von den Preisträgerneine kurze Rede erwartet wird. Obwohl die Dankesrede eine kleinere Randgattung innerhalb des epideiktischen Genres ist, steht sie im Mittelpunkt des Ereignisses. Rhetorikhandbücher geben zahlreiche Ratschläge, wie eine gute Festrede vorbereitet werden soll, um zu unterhalten, zu bewegen und zu belehren. Ziel dieser Untersuchung ist es festzustellen, welche Eigenschaften der Dankesrede die Zuhörer als erwünscht oder unerwünscht wahrnehmen und welche Charakteristika am meisten zur Qualität festlicher Dankesreden beitragen. Das Korpus der gesprochenen Texte bilden 30 Dankesreden anlässlich kroatischer Preisverleihungen in den Bereichen Schauspiel, Sport, Musik, Fernsehen, Literatur und Wirtschaft. Die Audio-Aufnahmen der Dankesreden wurden einer Gruppe von Hörern zur Bewertung in folgenden Kategorien vorgelegt: interessant, geistreich, hoher Sprachstil, feierlich, emotiv, persönlich, originell, bescheiden, vorbereitet und spontan. Zusätzlich wurde zu jeder Rede die offene Frage gestellt, was dem Zuhörer an der Rede gefallen oder nicht gefallen habe. Die Resultate der Perzeptionsanalye lassen erkennen, dass die Interessantheit einer Rede mit der Eigenschaft des Geistreichen, des Originellen, des Emotionalen und des Persönlichen in Verbindung gebracht wird und die Eigenschaft des Festlichen im Wesentlichen nur mit dem hohen Sprachstil und der Vorbereitetheit des Textes korreliert. Einige Eigenschaften können sowohl erwünscht als auch unerwünscht sein, z. B. Dialekt, Persönliches und Kürze. Die besten Dankesreden haben Eigenschaften, die im Grunde schwer miteinander zu verbinden sind: Einerseits soll der Text vorbereitet sein (hoher Stil, Wortwahl, Figuren, Originalität der Geschichte, Humor, andererseits wird bei der Ausführung Spontaneität (Aufrichtigkeit, Emotionalität, Persönlichkeit erwartet.

  16. Die wêreld en ons

    D. W. Kruger


    Full Text Available Gedurende die jaar 1949 het Sowjet-Rusland twee groot suksesse behaal, n.l. die oorwinning van die Komniunisnie in China en die vervaardiging van die atoombom, albei gebeurtenisse wat vir sy westerse teenstanders ’n groot ontngtering was.

  17. Ueber die Neoperla-Arten aus Java

    Klapálek, Fr.


    Die Anregung zum Versuche die bisher aus Java bekannten Neoperla-Arten zusammenzustellen, gab mir die Sendung des Herrn E. Jacobson aus Semarang. Sie enthielt zwei Arten, von welchen die eine für mich neu war; ich nehme mir die Freiheit dieselbe ihrem Entdecker zu widmen. Bei dieser Gelegenheit habe

  18. Vraagstelling vir bemagtiging: die tradisionele klaskamer as ...

    Erna Kinsey

    ... loep geneem aan die hand van kwalitatiewe data wat tydens 'n empiriese studie op die voor- .... stelling in die klas opgelei, wat die hantering van die leerders se ant- ..... tent, but as part of the meta-communication in the classroom. Reasons.

  19. Afrika die Onbekende: Die Federasie van Rhodesie Njassaland (I

    J. S. van der Merwe


    Full Text Available Die grondgebied van die Federasie van Rhodesië en Njassaland strek oor 14° 15’ in ’n N.-S.-rigting (vanaf22“ 30’ S. to t 8° 15’ S. en ongeveervanaf 22° 0 to t 36° 0. Dit verteenwoordig afstande in albei gevalle van tussen 900 en 1000 myl.

  20. Decorative pleats; Falten, die schmuecken

    Marfurt, P. [Sulzer Rueti AG, Rueti (Switzerland)


    Pleated fabrics - also known as plisses - are very popular in the fashion industry. The pleats are normally created in a process which involves pressing and heat-setting. The Sulzer Ruti G6200 rapier weaving machine is now available with special equipment, which allows the pleats to be woven directly into the fabric. (orig.) [Deutsch] Im modischen Bereich sind Faltengewebe - sogenannte Plissees - sehr beliebt. Ueblicherweise entstehen die Falten in einem Press- und Thermofixiervorgang. Die Greiferwebmaschine G6200 von Sulzer Rueti ist jetzt mit einer speziellen Ausruestung lieferbar, mit deren Hilfe die Falten direkt in den Stoff gewebt werden koennen. (orig.)

  1. Die-casting Process for High-performance Thin-wall Casting of Aluminum Alloy%高性能薄壁铝合金铸件的压铸

    尹志鹏; 宋朝辉; 李义平


    采用本公司发明的专利技术制备了铝合金浆料。概述了高性能薄壁多抽芯铝合金铸件的半固态流变压铸生产过程。经半固态流变压铸生产的铝合金铸件的显微组织致密,无气孔、缩松和夹杂,T6热处理后的力学性能比普通压铸件提高了40%左右。%Aluminum alloy paste was fabricated with a patent technology invented by Cixi Alt Advanced Materials Co.. The semi-solid rheocasting process for high-performance multi-core thin-wall aluminum alloy castings was outlined. The aluminum alloy castings produced by the semi-solid rheologic die-casting technology exhibited dense structure in which there are not any pore, porosity and inclusion, and after being T6 treated its mechanical properties were 40% higher that of common die castings.

  2. Die rol van persoonlikheidstrekke in die weerstand teen stres

    Sonja V. R. van Oudtshoorn


    Full Text Available The role of personality characteristics in resistance to stress: A study was conducted to establish whether certain personality characteristics contribute to resistance to stress. Rescue brigadesmen, performing dangerous rescue operations in the goldmining industry, served as basis for the study. The sample consisted of 63 current, 56 ex- and 50 non-brigadesmen. Results indicate that brigadesmen, on the basis of their personality structure, are better equipped to cope with stress. Scores on the 16PF show that they have a lower level of interpersonal anxiety (Factor Q4 and that they are more practical (Factor I, emotionally stable (Factor C, and conscientious (Factor G. These findings support existing knowledge of the 16PF. Opsomming Ten einde vas te stel ofdaar sekere persoonlikheidstrekke bestaan wat bydra tot weerstand teen stres, is 'n studie uitgevoer met reddingspanlede, wat lewensgevaarlike reddingsdiens in die goudmynbedryf verrig, as ondersoekgroep. Die streekproefhet uit 63 huidige, 56 oud-reddingspanlede en 50 amptenare, wat nog nooit aan die span behoort het nie, bestaan. Dit blyk dat reddingspanlede, op grond van hulle persoonlikheidstruktuur, beter toegerus is om stres te hanteer. Tellings op die 16PF toon dat hulle oor 'n laervlakvan interpersoonlike angs beskik, (Faktor Q4, dat hulle meer prakties (Faktor I, emosioneel stabiel (Faktor C en konsensieus is (Faktor G. Hierdie bevindinge sluit aan by die reeds bestaande kennis oor die 16PF.

  3. Quantenfische die Stringtheorie und die Suche nach Weltformel

    Lüst, Dieter


    Lässt sich das Verhalten aller Dinge, von den kleinsten Teilchen bis zum Universum, einheitlich beschreiben? Der heißeste Kandidat für die Entwicklung einer Weltformel, die alle physikalischen Phänomene erklären kann, ist die Stringtheorie. Sollte sie sich als richtig erweisen, so würde das unser Verständnis über den Ursprung der Naturgesetze dramatisch verändern. Denn das von uns beobachtete Universum wäre dann vermutlich eine winzige Blase in einem viel größeren Gebilde, dem Multiversum. Um die Stringtheorie und die Idee des Multiversums plausibel zu machen, greift der international bekannte theoretische Physiker Dieter Lüst auf ein Modell zurück: das Leben von Fischen in einem Teich. Eines Tages gelingt es den Fischen, die kleinsten Teilchen zu identifizieren, aus denen alles im Fischteich besteht - eingeschlossen sie selbst. Sie nennen diese Urbausteine Quantenfische, da ihr Verhalten nahelegt, dass sie auch eine Art von Lebewesen sind. Doch der ersten folgt eine weitere Entdeckung der Fisch...

  4. Die plek van goud in die huidige internasionale monetêre stelsel en die rol wat dit kan speel in die herstel van die internasionale monetêre orde.

    D. P. Erasmus


    Full Text Available Die vrye wêreld het sedert die oorloggedwonge opskorting van die goudstandaard in 1914, ’n groot agteruitgang in die internasionale betalingsmeganisme beleef. Hoewel die inter- nasionale goudstandaard in die laaste helfte van die twintiger- jare herstel is, was meeste lande nie langer gedwee om hulle aan die monetêre dissipline van dié stelsel te onderwerp nie en vind ons dat die een land na die ander onder die druk van die depressie in die dertigerjare die goudstandaard laat vaar het. Die Verenigde State van Amerika was die enigste uitson- dering. Geleidelik moes wisselkoersstabiliteit en die vrye inter­ nasionale betalingsverkeer vir wisselkoersmanipulasie en valu- tabeheer plek maak. Hierdie transformasie was ’n weerspieë- ling van die sterker opkoms van ekonomiese nasionalisme en die begeerte van die onderskeie lande om elkeen vir homself die beste voordeel in die internasionale ekonomiese en finan- siële terrein toe te eien. Die daarstelling van die Internasionale Monetêre Fonds te Bretton Woods in 1944, was ’n simptoom van die wêreldwye kommer oor die vooroorlogse neigings op monetêre gebied en terselfdertyd ’n poging om meer dissi­ pline in die internasionale betalingsverkeer te skep. Feit is egter dat ondanks sy positiewe resultate op sommige gebiede, die Internasionale Monetêre Fonds nie heeltemal 'n geskikte substituut vir die goudstandaard daargestel het nie. Wat meer is, die skok van die internasionale monetêre steurnisse word nog steeds deur die lande met die internasionale geldeenhede, naamlik die pond sterling en die dollar ondervind.

  5. Die verbond - van Ou Testament na Nuwe Testament

    H. F. van Rooy


    Full Text Available Die verbondsbegrip het in die Ou Testamentiese wetenskap weer ’n plek gekry op grond van die werk van Eichrodt en die studie van ooreenkomste tussen die verbond in die Ou Testament en die buite-Bybelse staatsverdrae, sedert die werk van Korosec,Mendenhall en baie ander. Natuurlik bestaan hieroor nie eenstemmigheid nie, veral omdat oor die ouderdom van die verbondsgedagte in die Ou Testament nie eenstemmigheid bestaan onder geleerdes nie. Die studie van die verbond in die Nuwe Testament het egter nie naastenby dieselfde aandag gekry nie - iets wat miskien as een van die redes vir die ontkenning van die waarde van die verbond vir Nuwe Testamentiese gelowiges beskou kan word. In hierdie studie word drie sake aangeraak, nl. die terminologie vir verbond in die Ou en Nuwe Testament, die agtergrond vir en belangrikste vorme van die verbond in die Ou Testament en enkele opmerkings oor die verbond in die Nuwe Testament.

  6. Verlossing en die verbeelding van die kinderjare: Dickens se voorstelling van kinders in A Christmas Carol

    David E. Robinson


    Full Text Available Hierdie artikel oorweeg die uitbeelding van kinders in Dickens se bekendste Kersboek. Sentraal in hierdie staan die oorweging van die historiese omstandighede waarin hierdie boek geskryf is, asook Dickens se eie kinderjare en die moontlikheid van verlossing, deur die mag van die verbeelding, uit die negatiewe gevolge van sosiale omstandighede en persoonlike keuses. Die veranderende opvatting van die Victoriaanse kind, van die idee dat kinders van nature sondig is tot die idee dat hulle suiwer en onskuldig is, plaas hierdie literêre werk histories en teoreties. Die rol van Dickens se herinneringe aan sy kinderdae en die invloed daarvan op sy werk word bespreek. Die werk van Edmund Wilson en die kenner van kinderliteratuur, Adrienne Gavin, word ingesluit in hierdie oorweging van die kort roman.

  7. Die Last mit der Lust

    Lutz Sauerteig


    Full Text Available Robert Jütte legt mit Lust ohne Last eine umfassende, allgemeinverständliche und spannend zu lesende Geschichte der Empfängnisverhütung von der Antike bis in die unmittelbare Gegenwart vor.

  8. Nuwe patogene in die voedselbedryf

    M. M. Ehlers


    Full Text Available ’n “Nuwe generasie” voedselpatogene het die afgelope jare hul verskyning gemaak en kan 'n ernstige gevaar vir die voedselbedryf inhou. Hierdie organismes is uiters aanpasbaar en bestaande voedselprosesseringstegnieke, veral die verkoeling van voedsel, is nie altyd volkome effektief om hul groei te voorkom nie. Clostridium botulinum tipe E, enterotoksigeniese Eschsrichia coli. Listeria monocytogenes en Aeromonas hydrophila is in staat om in voedsel by 5 °C te groei. Campylobacter jejuni en Brucella kan weer by 5 °C oorleef en 'n derde groep organismes, naamlik Salmonella, Staphylococcus aureus, Vibrio parahaemolyticus en Vibrio vulnificus kan by temperature tussen 5 °C en 12 °C groei en hul teenwoordigheid is ’n aanduiding dat die koueketting verbreek is.

  9. Die gesetzliche Frauenquote in Deutschland

    Amling, Svenja


    In der vorliegenden Arbeit wird auf eine per Gesetz vorgeschriebene Frauenquote in Deutschland eingegangen. Im Fokus steht die Frage, ob Frauendiskriminierung durch eine solche Vorschrift tatsächlich bekämpft werden kann oder ob vielmehr die Männer diskriminiert würden. Zudem werden mögliche Unterschiede in den Führungsstilen zwischen Frauen und Männern untersucht sowie einige bereits vorhandene Frauenquoten in Politik und Wirtschaft vorgestellt.

  10. Dies irae ~Acta est Fabula~


    从2007年11月的Diesirae Also sprach Zarathstra到2009年的7月的Dies irae Also sprach Zarathustra—die Wieder kunfl-,Light社的Diesirae的完全版可说是时隔两年的大坑,发行了两个非完全版的游戏吊足玩家们的胃口后。

  11. Gedagtes oor die onbepaaldheidsbeginsel van Heisenberg

    P. H. Stoker


    Full Text Available Van filosofiesc syde en ook deur populariserende skrywers is daar al baie geskryf oor die onbepaaldheidsbeginsel in die Fisika, wat deur Heisenberg in die twintiger jare na vore gebring is.

  12. Videobasierte Unterrichtsbeobachtung: die Quadratur des Zirkels?

    Regula Fankhauser


    Full Text Available Seit einigen Jahren wird Unterrichtsforschung vermehrt videobasiert angegangen. Die methodologische Diskussion, die die Weiterentwicklung des Instrumentariums begleitet, kreist dabei zentral um die Frage der Invasivität der Aufzeichnungstechnik und möglicher Kameraeffekte. Je nach methodologischer Ausrichtung wird diesem Problem anders begegnet: So versucht die abbildtheoretische Unterrichtsvideografie, die Invasivität zu kontrollieren. Qualitative Methoden wie die Kameraethnografie dagegen machen mögliche Kameraeffekte wie die Performanz vor der Kamera oder die Blickrichtung, die durch das Kameraauge fixiert wird, zum Ausgangspunkt neuer, ästhetischer Verfahrensweisen. Der vorliegende Artikel geht einen dritten Weg: Anhand eines Rückgriffs auf den Wissenschaftssoziologen LATOUR und anhand der methodologischen Reflexion eines forschungspraktischen Beispiels sollen grundsätzliche Probleme der Unterrichtsforschung herausgearbeitet werden, die sich mit dem Einsatz der Videografie besonders deutlich zeigen und mit der sich die Unterrichtsforschung vermehrt auseinandersetzen müsste. URN:

  13. Dying at the best time.

    Seale, C; Addington-Hall, J


    These are the results of two surveys of relatives, and others who knew people who had died, describing events in the year before death and their views on the time of the person's death. Those surveyed were identified from death certificates in England. The main focus is on a sample of 3696 people dying in 1990 in 20 health authorities, with supporting analysis from an earlier national sample of 639 people dying in 1987. Variation in peoples' views about whether an earlier death would have been better is reported, in the context of debate about euthanasia. Spouses were less likely than others to feel that it would have been better if the person had died earlier, and this held true even when controlling for the deceaseds' levels of pain, distress, dependency and age. Spouses were more likely than others to say that a later death would have been better, though not in cases where the deceased was reported as having said they wanted to die sooner. Spouses were influenced by the loss which the death of the person represented for them, being more likely than others to say they missed the person who died a great deal, and feel loneliness was a big problem. Non spouses (children and other relatives of the deceased, friends, neighbours and a few officials) on the other hand were more likely than spouses to say an earlier death would have been better, even when levels of pain, distress, dependency and age were controlled for.(ABSTRACT TRUNCATED AT 250 WORDS)

  14. CAE模拟分析在水龙头手柄压铸模设计中的应用%Application of CAE Simulation Analysis to the Design of Die Casting Mold for Faucet Handle



    针对传统压铸模具浇注系统设计采用试错法存在的缺陷,本文通过水龙头手柄压铸模设计,提出利用ProCAST铸造模拟分析功能,先确定内浇道合理位置,再进行浇注系统详细设计及模具设计,避免浇注系统对铸件成形过程不利影响,提高铸件质量,缩短模具制造周期.可为类似铸件浇注系统及压铸模具设计提供参考.%Aimed at the existing defects of traditional die casting mold gating system design by trial-and-error method, first the reasonable location of the ingate was determined and then the gating system and mold were designed in detail through designing the faucet handle die-casting mold, utilizing ProCAST casting simulation analysis capabilities, which avoid the adverse effects of the gating system for casting formation process, improve casting quality, and reduce mold manufacturing period. It can provide a reference for similar casting gating system and die casting mold design.

  15. Uitdagings in die onderrig van evolusie in die lewenswetenskappeklaskamer

    Josef J. de Beer


    Full Text Available In hierdie artikel skryf die outeurs oor navorsing wat hulle gedoen het oor onderwysers se siening van die onderrig van evolusie, wat in 2008 as ’n tema in lewenswetenskappe in Suid-Afrikaanse skole ingesluit is. Hierdie vernuwing in die kurrikulum is met gemengde reaksies begroet. Terwyl sommige onderwysers dit met entoesiasme onderrig, is baie gekant teen die onderrig van evolusie. Die artikel is gebaseer op ’n navorsingsprojek waarby 255 onderwysers betrek is. Vraelyste is gebruik om kwalitatiewe data, wat vir diskoers ontleed is, in te samel. Die diskoers van die onderwysers het getoon dat ’n groot getal van hulle nie hul onderrigopdrag kan versoen met hul geloof nie en konsepte oor evolusie as ‘feite’ verduidelik, maar seker maak dat evolusie as ’n teorie gediskrediteer word. Dit het verreikende implikasies vir sowel onderwyseropleiding as kurrikulumontwikkeling. Konseptuele veranderingsteorie word as ’n lens gebruik om na hierdie problematiek te kyk. Challenges in the teaching of evolution in the life sciences classroom. In this article the authors report on research that was conducted about teachers’ views on evolution, which was introduced as a theme in the school life sciences curriculum in 2008. This innovation in the curriculum has been met with mixed reactions. Whereas some teachers embrace this new theme, many teachers are opposed to the teaching of evolution. The article reports on an inquiry that was conducted amongst 255 teachers and in which survey questionnaires were used to collect qualitative data, which was analysed for its discourse. The discourse of the teachers shows that many of them cannot reconcile their religious faith with their teaching and that they may teach the ‘facts’ of evolution, but make sure that they discredit evolution as a theory. This raises serious concerns about teacher education and curriculum development. The authors examine these issues through the lens of conceptual change

  16. Microstructural and mechanical properties of gravity-die-cast A356 alloy inoculated with yttrium and Al-Ti-B grain refiner simultaneously

    Y.P. Lim


    Full Text Available In the present work, the effect of inoculating yttrium and Al-5Ti-1B simultaneously on A356 aluminum alloy has been studied. Gravity die casting process is used to cast the ASTM tensile test specimens for analysis. In each experiment, the Ti and B contents were maintained constantly at 0.1 and 0.02 wt% respectively. The addition of yttrium was manipulated at the amount of 0, 0.1, 0.2, 0.3, 0.4 and 0.5 wt%. Microstructural characterization of the as-cast A356 alloy was investigated by means of optical microscope and its phases are detected by XRD. The mechanical properties tested are tensile strength and hardness. The inoculation of yttrium was found to enhance the grain refinement effect of Al-5Ti-1B grain refiner and improve the mechanical properties. The optimal weight percentage of yttrium was found to be 0.3. The grain refining efficiency of combining yttrium and Al-5Ti-1B on A356 aluminum alloy was mainly attributed to the heterogeneous nucleation of TiB2 and TiAl3 particles which were dispersed more evenly in the presence of yttrium and the grain growth restriction effected by the accumulation of Al-Y compound at grain boundaries.

  17. Microstructure, Mechanical and Surface Morphological Properties of Al5Ti5Cr Master Alloy as Friction Material Prepared by Stir Die Casting

    Ahmed, Syed Faisal; Srivastava, Sanjay; Agarwal, Alka Bani


    Metal matrix composite offers outstanding properties for better performance of disc brakes. In the present study, the composite of AlTiCr master alloy was prepared by stir die casting method. The developed material was reinforced with (0-10 wt%) silicon carbide (SiC) and boron carbide (B4C). The effects of SiC reinforcement from 0 to 10 wt% on mechanical, microstructure and surface morphological properties of Al MMC was investigated and compared with B4C reinforcement. Physical properties like density and micro Vickers hardness number show an increasing trend with an increase in the percentage of SiC and B4C reinforcement. Mechanical properties viz. UTS, yield strength and percentage of elongation are improved with increasing the fraction of reinforcement. The surface morphology and phase were identified from scanning electron microscopy (SEM) and X-ray diffraction analysis and the oxidized product formed during the casting was investigated by Fourier transformation infrared spectroscopy. This confirms the presence of crystallization of corundum (α-Al2O3) in small traces as one of the alumina phases, within casting sample. Micro-structural characterization by SEM depicted that the particles tend to be more agglomerated more and more with the percentage of the reinforcement. The AFM results reveal that the surface roughness value shows a decreasing trend with SiC reinforcement while roughness increases with increase the percentage of B4C.

  18. Die Departement Godsdiens- en Sending- wetenskap (Afd A ...

    van die teologiese leergang aan die Transvaalse Universiteitskollege (TUK). Die. ISSN 0259 9422 = m s 4 ... Die Universiteit van Pretoria neem in 1916 'n eerste tree met die onderrig van teo- logie. In die TUK ...... Van Leeuwen, A T 1966.

  19. Kantaantekeninge by die formele en materiële beginsels van die Suid-Afrikaanse kerkgeskiedskrywing

    E. Brown


    Full Text Available Die totstandkoming van ons Kerkhistoriese Werkgemeenskap staan sekerlik in die teken van ’n ‘geschichtliche Bevifusstsein’ met betrekking tot die kerkgeskiedenis in ons land. In die geskiedenis van die ecclesia patria val dit nie sonder rede met die toenemende pleitredes vir ’n krities (teologiese beoefening van hierdie vakgebied saam nie.

  20. Die Energiesicherheit Europas in Bezug auf Erdgas und die Auswirkungen einer Kartellbildung im Gassektor

    Krämer, Luis-Martín


    Die Dissertation untersucht die aktuelle Sicherheit der europaeischen Erdgasversorgung. Sie beruecksichtigt zudem die moeglichen Auswirkungen einer Kartellbildung auf die europaeische Gasversorgungssicherheit. Die Arbeit besteht aus einer detaillierten empirischen Studie und darauf aufbauender Szenarioanalyse. Hierzu wird auf den Interdependenzansatz von Robert O. Keohane und Joseph Nye zurueckgegriffen. Zur Darstellung des komplexen Themenbereichs wird auf die Darstellungspraxis der Dichten ...

  1. Die Literêre Sisteem Van Dertig

    H. Viljoen


    Full Text Available In die literatuurgeskiedenis is daar onteenseglik ’n behoefte aan sistematiek. ’n Vinnige oorsig oor byvoorbeeld die geskiedenis v an die Afrikaanse poesie kan die leser erg verward laat. Daar is verskeie redes daarvoor. Eerstens word verskillende kategorieë gebruik om die verskillende generasies mee te beskryf — as dit al hoegenaamd duidelik is waar die grense tussen generasies nou eintlik lê. Die leser word as belangrike kategorie beskou by die poësie voor 1900, bewuste kunstenaarskap by Dertig, stad en oorlog (tematiese dinge by Veertig. Standaardbegrippe is nodig waarmee verskillende generasies vergelyk kan word.

  2. Die filosofie van Smuts en Boodin.

    J. M. de Wet


    Full Text Available Die werk van generaal Smuts, baie goed bekend omder die titel ,,Holism and Evolution” , en sy artikel oor ,,Some recent scientificadvances in their bearing on philosophy” in ,,Our Changing worldview”, as ook die werke van J. E. Boodin, professor in die wysbegeerteaan die Universiteit van California, Los Angeles, ,,Cosmic Evolution 1925, ,,Three interpretations of the Universe” 1934 en ,,God” 1934, toon die besondere en kenmerkende gedagtegamg vandie filosofie van die laaste tiental jare aan. Die kenmerkende is dit dat dit ’in filosofie is van sintese of, soos Whitehead

  3. Strategieë om die implementering van die Suid-Afrikaanse professionele leergemeenskapmodel te bevorder

    Christina J. van Staden


    Full Text Available Die Geïntegreerde Strategiese Beplanningsraamwerk vir Onderwyseropleiding en -ontwikkeling in Suid-Afrika 2011–2025 vereis dat vakverwante professionele leergemeenskappe tussen 2011 en 2017 op skool- en distriksvlak gevestig word. Die doel daarvan is om onderwysers van geleenthede te voorsien om hul eie leerbehoeftes te identifiseer en te vervul. Slegs sommige van die Distriksonderwysersontwikkelingsentra wat as vergaderplekke moet dien, hoef egter teen 2025 gereed te wees. Die gaping tussen beleid en die implemetering daarvan kan die vestiging van professionele leergemeenskappe rem en selfs verhoed. Drie implementeringsprobleme wat die professionele leergemeenskapmodel op die berugte onderwyshervormingsiklus kan stuur, word geïdentifiseer ten einde strategieë aan die hand te doen om die probleme op te los. Die ondersoek het tot die voorstel gelei dat ’n gekoördineerde benadering noodsaaklik geword het ten einde te verhoed dat die professionele leergemeenskapmodel die prooi van die berugte onderwyshervormingsiklus word.

  4. Die rol van die onderwys in die handhawing en uitbouing van ons volkskultuur

    G.J. Jordaan


    Full Text Available Op die oog af lyk dit ’n baie maklike onderwerp, maar hoe meer 'n mens daaroor nadink hoe ingewikkelder en omvangryker word die implikasies wat verband hou. Dit is veral so omdat dit hier voor alles gaan om eerste fundamentele uitgangspunte, dit wil sê, om lewens- en wêreldbeskouing. Dit geld van albei komponente — van onderwys sowel as van kultuur.

  5. Effects of deformation temperature and rate on compressive deformation behaviour of Y 112 die cast aluminum alloy in semi-solid state

    YANG Ming-bo; HU Hong-jun; TANG Li-wen; DAI Bing


    The semi-solid compression deformation behaviour of Y112 die casting aluminum alloy with nondendritic structure obtained under the semi-solid isothermal treatment condition of 570 ℃ and 120 min, was investigated by means of Gleeble-1500 thermal-mechanical simulator. The results show that, when the strain is lower than 0.8, along with the compression strain increasing,the compression stress firstly increases rapidly, then decreases gradually. Under the condition of different deformation temperatures and deformation rates, the maximium compression stress is obtained simultaneously when the strain is 0.07 approximately.Furthermore, when the deformation rate keeps a constant, the compression stress decreases along with the deformation temperature increasing, and when the deformation temperature keeps a constant, the compression stress increases along with the deformation rate increasing.

  6. Die-cast of a hypo-eutectic AL-SI alloy: influence of injection temperature on microstructure and mechanical properties; Fundicao sob pressao das ligas de AL-SI: influencia da temperatura de injecao nas microestruturas e propriedades mecanicas

    Santos, Silvano Leal dos; Santos, Sydney Ferreira, E-mail: [Universidade Federal do ABC (UFABC), SP (Brazil)


    Die-casting is widely used for manufacturing light alloy components for automotive industry. Among others, hypo-eutectic Al-Si alloys are currently processed by die-casting. To obtain high quality die-cast components, a better understanding on the correlations between processing parameters, microstructures, and mechanical properties are of utmost importance. In this study, we investigate the effect of injection temperature of liquid metal on the microstructure and mechanical properties of Al-Si alloy EN AC 46000 (DIN designation). The injection temperatures were 579, 589, 643, and 709 deg C. As-cast components had their microstructures analyzed by X-ray diffraction, optical and scanning electron microscopy, and X-ray energy dispersive spectroscopy. The mechanical properties were examined by micro-hardness and tensile tests. It was observed that the ultimate tensile strength slightly increased with the increase of injection temperature. The same trend was observed for micro-hardness. The amount of porosity in the samples varies in a small amount for different injection temperatures. On the other hand, the microstructure of the alloys seems more refined for higher temperatures of injection. This refinement in microstructure might play a major role on the mechanical properties of the Al-Si die-cast alloy. (author)

  7. 双螺旋流变压铸AZ91D镁合金的研究%Rheo-Die Casting of AZ91D Magnesium Alloy by Twin-Screw Stirring

    马跃宇; 杨必成; 王亚宝; 徐骏


    液态压铸是镁合金最主要的成形方式,但液态压铸件存在气孔等缺陷,限制了镁合金的进一步推广使用.介绍了采用双螺旋流变制浆技术,对镁合金AZ91D进行了流变压铸研究.首先,将镁合金AZ91D熔体浇入到双螺旋流变制浆机中,然后根据不同工艺参数制备流变镁合金浆料,待制浆结束后,将半固态浆料转移到压铸机内,制得半固态压铸件.采用Micro-Image Analysis&Process(MIAP)软件分析了双螺旋流变制浆工艺参数(搅拌温度、搅拌时间和转速)对镁合金AZ91D的初生相晶粒大小的影响,并研究了镁合金压铸成形性.结果表明:随着搅拌温度的降低,晶粒尺寸变化不是很大;随着搅拌时间延长,镁合金晶粒尺寸逐渐增大;随着搅拌速度的增加,镁合金平均晶粒尺寸减少.镁合金流变压铸件中的初生α相由搅拌中形成的球状晶及压铸过程中二次凝固形成的更为细小的球状晶组成.对比了普通压铸件与流变压铸件热处理后的力学性能,流变压铸件的力学性能得到大幅提高,其原因归结为铸态组织的细小和均匀化.%The liquid die casting is the main forming technique of magnesium alloys. However, in die cast components, some defects such as pores and so on restrained further applications of magnesium alloys. In this paper, rheo-die casting of AZ91D magnesium alloy prepared by twin-screw stirring technique was studied. Firstly, AZ91D magnesium alloy melt was put into a twin-screw stirring machine ; then, rheo-slurries were fabricated by twin-screw stirring according to different parameters. Lastly, the slurries were transferred into a die casting machine and rheo-die casting components were made. Effects of rheo-slurries processing parameters (temperature, time and speed) on the sizes of primary phase and performances of the die cast components were researched. The results showed that the grains changed little with the temperatures decreasing. When

  8. Die anderen Ausdrucksweisen: subtile Offensiven

    Ella Jasiowka


    Full Text Available Was passiert, wenn der „Herrscher des filmischen Blickes“ eine Frau ist? Anhand zweier jeweils sehr unterschiedlicher Beispiele „weiblicher“ Filmkunst zeigt die Autorin, dass es nötig ist, herkömmliche Interpretationsmuster zu überwinden, um dem Filmschaffen einzelner Künstler und Künstlerinnen auf den Grund zu gehen. Da es nicht die „feministische Kunst“ an sich gibt, muß man für das Werk so unterschiedlicher Künstlerinnen wie Sally Potter und Jane Campion jeweils unterschiedliche Schlüssel suchen, um ihnen gerecht zu werden. Dies tut Radkiewicz in ihrem Werk – aus feministischer Perspektive. Sie holt jeweils verschieden weit aus, wenn es darum geht, künstlerische Herkunft, Biographie, Vorbilder und Ziele der Künstlerinnen zu deren Werk in Bezug zu setzten. Ohne zu bahnbrechend neuen Erkenntnissen zu kommen, gelingt es ihr doch, ein komplexes Bild der von ihr behandelten Filmemacherinnen und den Filmen zu entwerfen, das einen umfassenden Gesamteindruck vermittelt. Die Kürze des Buches bringt dabei eine Konzentration mit sich, die zu einer Weiterbeschäftigung und Vertiefung einlädt.

  9. Tweedimensionele generatorfunksie vir die vektorkardiogram vir gebruik in volume-geleidingsmodelle van die toraks

    T. A. Geldenhuys


    Full Text Available ’n Elektrokardiogram (EKG meet die elektriese aktiwiteit van die hart op die veloppervlak. Volumegeleidingsmodelle van die toraks kan ontwerp word om hierdie metings te simuleer. ’n Generatorfunksie, wat die elektriese aktiwiteit van die hart beskryf, word benodig om hierdie simulasies aan te dryf. Hoewel soortgelyke simulasies van variërende kompleksiteit in die literatuur bespreek word, is daar ’n behoefte aan ’n vereenvoudigde, dog omvattende benadering wat kan dien as inleiding tot die onderwerp of vir gevalle waar ’n eerste-orde-benadering tot die probleem voldoende is. In hierdie artikel word ’n oorsig gegee oor die vektorinterpretasie van die EKG, ook bekend as ’n vektorkardiogram (VKG, in die tweedimensionele menslike frontale vlak. Die afleiding van die ekwivalente elektriese dipool (met ander woorde die kardiale vektor vanaf die VKG, wat gebruik kan word as ’n stroombron-generatorfunksie vir volumegeleidingsmodelle wat die EKG simuleer, word bespreek. ’n Prosedure om so ’n volume-geleidingsmodel met die eindige-element-tegniek te implementeer en die vereenvoudigde tweedimensionele generatorfunksie te gebruik, sowel as die resultate daarvan, word bespreek. Die algemene kenmerke van gemete EKG-afleidings stem ooreen met dié wat deur die eenvoudige model voorspel word.

  10. 基于神经网络与遗传算法的压铸工艺参数优化%Optimization of die casting processing parameters based on BP neural network and GA algorithm

    王成勇; 朱汝城; 王婉璐; 李亨; 刘全坤; 周慧杰


    According to the feature of high pressure die casting of A356 coffee machine dome, the die casting process of coffee machine dome was simulated by finite element simulate software.The L16 (45 )-orthogonal experiments and six complementary experiments were chosen as the trained samples of Back Propagation Neural Network.The major processing parameters of die casting were pouring temperature, mould pre-heated temperature, injection pressure and injection speed.The non-linear mapping between these processing parameters and thermal stress of die casting mould were built up.In order to get the minimum heat stress of die casting mould, the die casting processing parameters were optimized by GA algorithm.The best combination processing parameters of pouring temperature, mould pre-heated temperature, injection pressure, injection speed were found.Under these process parameters, the experimental index (σ)max became low, the trend of mold fatigue was reduced and the quality of casting was improved.The experiment results validate the feasibility of this optimization on reducing the thermal fatigue of mould and provide guidance on producing similar die casting parts.%依据A356咖啡机顶盖高压铸造特点,采用FEM仿真软件对铸件成型工艺进行数值模拟,以L16(45)正交试验和6个补充试验作为BP神经网络的训练样本,建立模具热应力与浇注温度、模具预热温度、压射比压、压铸速度4个压铸工艺参数的非线性映射关系;以模具热应力θmax的最小值为优化目标,运用遗传算法进行工艺参数优化.最终得出浇注温度、模具预热温度、压射比压、压铸速度等4个参数最佳的一组组合,使试验指标θmax最小,模具的热疲劳趋势最低,零件的成型质量最佳.试验结果证明,该减少模具热疲劳趋势的优化方案具有可行性,同时对相近结构压铸件的生产也具有一定的指导意义.

  11. Die Meting van die verband tussen geslag en konformiteit as groepdinamiese veranderlikes.

    W. S. de Villiers


    Full Text Available The amount and kind of conformity induced by group pressure depend upon the nature of the situation. The nature of the group and the characteristics of the individual. In this particular study the experimental measurement of conformity developed by Asch and Crutchfield was repeated. Confirmation was found that sex operates as one of the determinants of conformity. OpsommingIn die sosiale bedryfsielkunde is die invloed van die groep op die individu een van die vernaamste studieterreine. Die mate waarin ‘n individu konformeer tot groepsdruk hang af van die aard van die situasie, die aard van die groep en die eienskappe van die individu. In hierdie studie is die eksperimentele meting van konformiteit soos ontwikkel deur Asch en Crutchfield herhaal en bevestiging is gevind dat geslag een van die individuele determinante van konformiteit is.

  12. Leerteoretiese basis van die andragogie

    C. J. A. Simpson


    Full Text Available Learning theory basis of andragogy. A cursory glance at andragogy creates the impression that humanistic learning theory plays an all encompassing role in the learner centered approach andragogy espouses. A closer look, however, reveals that Knowles (1973, after having made an intensive study of learning theory, created an extensive framework within which human resource development can take place. The fact that Knowles attracted critique from different areas, led to a need to ascertain the role different learning theories, if any, played in the emergence of andragogy. Having looked at the assumptions displayed by the andragogical approach, as well as a comparison of different learning theories and their connection with andragogy, it became clear that andragogy contains elements of various learning theories in an adapted way. These adaptations resulted in an approach to adult education in which learners are given the opportunity to be part of the learning process in such a way that they themselves contribute to the development which takes place. Opsomming Met 'n eerste oogopslag wil dit voorkom asof humanistiese leerteorie 'n oorheersende rol in die leerdergesentreerde benadering van andragogie speel. By nadere ondersoek blyk dit egter dat Knowles (1973, na 'n deeglike studie van verskillende leerteoretiese beginsels, 'n omvangryke raamwerk geskep het waarbinne, aan die hand van verskeie aangepaste leerteoretiese beginsels, menslike hulpbronontwikkeling kan plaasvind. As gevolg van die feit dat Knowles vanuit verskillende oorde kritiek op die lyf geloop het, is besluit om die rol wat verskillende leerteorieë in andragogie speel, te bestudeer. Dit blyk dat andragogie nie net elemente van verskillende leerteorieë bevat nie, maar dat toepaslike aspekte van die teoriee wat ondersoek is, benut en aangepas is om 'n geintegreerde benadering te bewerkstellig waarin veral volwassene-leerders by leergeleenthede en hulle selfontwikkeling betrek word.

  13. Die resepsie van die Heidelbergse Kategismus (Sondag 17 en 22 insake die opstanding in die Nederduitse Gereformeerde Kerk sedert 2000 (Deel 2

    Johannes W. Hofmeyr


    Full Text Available Met die 450e herdenking van die Heidelbergse Kategismus as vertrekpunt, word met die huidige en die vorige artikel gepoog om lig te werp op die plek, die rol en die interpretasie van die opstanding van Jesus Christus in veral Sondag 17 en 22, spesifiek in die konteks van twee besondere eras in die Nederduitse Gereformeerde (NG Kerk. In die vorige artikel is allereers ’n bespreking gevoer oor die Heidelbergse Kategismus (HK. Daar is gekyk na die resepsie van die betrokke HK-geloofsartikels in die era van Andrew Murray, spesifiek teen die agtergrond van die negentiende-eeuse liberale teologie in Nederland. In die huidige artikel word soortgelyk gekyk na die resepsie van die betrokke HK-geloofsartikels in die NG Kerk na 2000, teen die agtergrond van die herverskyning van die negentiende-eeuse liberale teologie in die vorm van die Jesus Seminaar, die Nuwe Hervorming en ondersteuners daarvan binne die NG Kerk. Sowel die negentiende-eeuse liberale stryd in die NG Kerk asook die stryd oor die opstanding in die NG Kerk van die eerste dekade van die een-en-twintigste eeu, soos verder in hierdie artikel sal blyk, was gekenmerk deur kontekstueelbepaalde uniekhede. Die gemene deler was dat albei deel was van tye van teologiese vrysinnigheid. In die lig van hierdie bespreking word tot die gevolgtrekking gekom dat die NG Kerk tans, betreffende haar identiteit as gereformeerde kerk waarskynlik in ’n kritieke geloofs- en toekomskrisis verkeer. Dit impliseer kommerwekkende gevolge vir haar Skrifverstaan en getuienis as belydenis en belydende kerk van Jesus Christus en haar toekoms. Alleen duidelike visie, verantwoordelike leierskap en ’n herontdekking van die verlossingskrag van Christus se kruis en opstanding sal herstellende, positiewe en dinamiese oplossings kan bied om sodoende die NG Kerk te red van ’n snelwentelende afwaartse spiraal.With the 450th celebrations of the origin of the Heidelberg Catechism (HC in mind, the main aim of this and the

  14. Die «ASEAN-Wirtschaftsgemeinschaft»

    Juego, Bonn


    Entwicklungsstufen, wie sie unterschiedlicher kaum sein können. Der Autor, Bonn Juego, nimmt die ASEAN Vision 2020 sowie die Debatten, die diesbezüglich in den einzelnen Ländern geführt werden, unter die Lupe. Er geht dem Potenzial des ASEANAnsatzes zu sozialer Teilhabe und wirtschaftlicher Verteilungsgerechtigkeit...

  15. Moderne diskoerse in die teologie vandag

    J.H. van Wyk


    Full Text Available In hierdie artikel word aandag gevra vir enkele moderne diskoerse in die teologie vandag. Volgens die outeur staan die vrae oor God, Jesus, die mens en die aarde in die sentrum van belangstelling en oorheers dit in ’n groot mate die teologiese debat. Die opkoms van die moderne aggressiewe ateïsme, die wetenskaplike navorsing oor die historiese Jesus, die groeiende vrae oor die mens en die menslike samelewing, asook die dreigende ekologiese krisis op aarde, sorg vir nuwe debatte van ongekende omvang. Die outeur bespreek hierdie debatte oorsigtelik, met kritiek waar nodig, en sluit af met enkele rigtingwysers van wat hy as ‘goeie teologie’ verstaan.In this article attention is paid to some modern discourses in theology today. According to the author the questions about God, Jesus, man and the earth are in the centre of interest and to a large extent dominate the theological debate. The rise of modern aggressive atheism, the scientific research on the historic Jesus, the growing questions about man and human society as well as the threatening ecological crisis on earth, provide new discourses of unparalleled magnitude. The author provides a broad summary of these discourses, with criticism where necessary, and concludes with some indicators of his view what can be called ‘good theology’.

  16. Die Ökonomik der Reputation

    Tegtmeyer, Jan C.


    Gegenstand dieser Arbeit ist die Betrachtung der Reputation eines Unternehmens aus ökonomischer Sicht. Die Zusammenfassung von Beurteilungen der Unternehmensaktivitäten durch wirtschaftlich relevante Interessengruppen bildet eine Unternehmensreputation. Die Reputation wird hier mit einem betriebswirtschaftlichen Kosten-Nutzen Kalkül betrachtet. Nur mit einer Reputation, die durch eine vorteilhafte Beurteilung der Unternehmensleistung entsteht, kann ein Unternehmen wirtschaftliche Vorteile gen...

  17. Die Ökonomik der Reputation

    Tegtmeyer, Jan C.


    Gegenstand dieser Arbeit ist die Betrachtung der Reputation eines Unternehmens aus ökonomischer Sicht. Die Zusammenfassung von Beurteilungen der Unternehmensaktivitäten durch wirtschaftlich relevante Interessengruppen bildet eine Unternehmensreputation. Die Reputation wird hier mit einem betriebswirtschaftlichen Kosten-Nutzen Kalkül betrachtet. Nur mit einer Reputation, die durch eine vorteilhafte Beurteilung der Unternehmensleistung entsteht, kann ein Unternehmen wirtschaftliche Vorteile gen...

  18. Die Welt als Fassade : kosmischer Schrecken als Angriff auf die Wirklichkeit

    Zuch, Rainer


    "The oldest and strongest emotion of mankind is fear, and the oldest and strongest kind of fear is fear of the unknown." Mit diesem Satz eröffnet Howard Phillips Lovecraft 1927 seinen berühmten Essay "Supernatural Horror in Literature". In der Phantastik wird oft die Demontage der Erfahrungswirklichkeit durch die Kontaminierung mit dem Wunderbaren thematisiert; die bekannte Welt bekommt Risse, durch die das Unbekannte eindringt. Radikalisiert wird dies in Konzepten, die die gesamte vertrau...

  19. How Tycho Brahe really died

    Jacobsen, Aase Roland; Petersen, Lars


    In 2001 we commemorate the 4th centenary of the death of Tycho Brahe, perhaps the first great scientists in a modern sense.This famous Danish astronomer died in Prague on the 24th of October 1601, eleven days after he had attended a banquet at the Bohemian count of Rosenberg. Tycho was too...... courteous to obey the calls of nature during the hour-long dinner and finally his bladder burst, which led to his death. Or so the story goes. But is this the real cause of Tycho's death? Is it at all possible to die from a burst bladder? Or are there more likely explanations of his death?...

  20. Ein Blick hinter die Kulissen

    Michaela Kempter


    Full Text Available In den Games-Workshops der wienXtra-spielebox lernen Kinder zwischen 7 und 12 Jahren empfehlenswerte Computer- und Konsolenspiele kennen und reflektieren nebenbei ihren Spielkonsum. Dieser Beitrag lässt die Leserinnen und Leser einen Blick hinter die Kulissen der Arbeit von wienXtra werfen.wienXtra-spielebox offers gaming workshops for young people between 7 and 12 years. The objective of these workshops is to explore new games that are evaluated as suited for the target group and to let the girls and boys reflect their playing habits. This article describes the work of wienXtra-spielebox.

  1. [Dying with cancer: Hollywood lessons].

    Niemeyer, Fernanda; Kruse, Maria Henriqueta Luce


    The study attempts to understand how dying from cancer is portrayed by five movies produced in Hollywood between 1993 and 2006. Based on the cultural studies and their post-structuralism version and supported by the notions of discourse and subjectivity, as proposed by philosopher Michel Foucault, we suggest one of the possible readings of the movie picture corpus. We assess how the movie picture discourse acts as a cultural pedagogy that produces ways of seeing dying with cancer: immortalizing the healthy body image, silencing death, taking care of the dead body and, finally, accepting death. Our proposal is intended to stimulate reflections that may contribute to care and education in nursing.

  2. ’n Etiek van liefde: Die etiese perspektiewe van die Heidelbergse Kategismus

    Koos Vorster


    Full Text Available Hierdie artikel behandel die etiese perspektiewe van die Heidelbergse Kategismus – een van die prominente belydenisskrifte in die gereformeerde tradisie. Die etiese relevansie is ingebed in die konfessie se verklaring van die tien gebooie. Die artikel verduidelik dat die etiek van die Heidelbergse Kategismus ten diepste ’n karakteretiek is en dat dit gelowiges oproep tot ’n etiek van liefde. Hierdie liefde sluit in liefde vir die verbondsgemeenskap, die bediening van die Woord, die heiligheid van God en die waardigheid van mense, die gemeenskap van die gelowiges, gesag, die lewe, die huwelik, privaatbesit en arbeid asook waarheid en geregtigheid. As gevolg van die sinekdogeekarakter van die wet is hierdie etiek van liefde vandag baie relevant.This article deals with the ethical relevance of one of the prominent confessions in the reformed tradition, namely the Heidelberg Cathechism. The ethical relevance lies in the confession’s elucidation of the ten commandments and its application to moral conduct. The article explains that the ethics of the Heidelberg Catechism is essentially a virtue ethics calling for an ethics of love. This love should include love for the covenantal communion, ministry of the Word, the holiness of God and the dignity of people, the communion of the saints, authority, life, marriage, private property and labour, and truth and justice. Due to the synecdochical character of the ten commandments this ethics of love is highy relevant in the present times.

  3. Chirurgie in die Grieks-Romeinse era

    François P. Retief


    Full Text Available In die Grieks-Romeinse era het mediese behandeling kenmerkend uit drie elemente bestaan, naamlik regimen (dieet en gesonde leefwyse, geneesmiddels en chirurgie – laasgenoemde alleen toegepas indien regimen en geneesmiddels onsuksesvol was. Bewyse van primitiewe chirurgie dateer terug na die Bronstydperk, en in Homerus se eposse is heelwat vermelding van die chirurgiese hantering van oorlogswonde, met tussenkoms van die gode. Met die koms van empiriese geneeskunde in die 5de eeu v.C. het chirurgie in die Hippokratiese Corpus prominent gefigureer met beduidende bydraes in veral die ortopediese veld en hoofbeserings. Uitbouing van anatomiese en fisiologiese kennis, gebaseer op disseksie van menslike kadawers in Alexandrië vanaf die laat 4de eeu v.C., het chirurgie ’n hupstoot gegee. Teen die Romeinse era vanaf die 2de eeu v.C. het snykundetegnieke (en -instrumente beduidend verbeter, maar is steeds oorwegend deur Griekse geneeshere beoefen. Van geneeshere is steeds verwag om al drie bovermelde terapeutiese modaliteite te bemeester, maar chirurgie het meer aansien verwerf en daar is al meer in onderafdelings van chirurgie soos oogheelkunde, vrouesiektes en verloskunde, blaaskwale en mond- en keelsnykunde gespesialiseer. Militêre geneeskunde was in die Romeinse Ryk ’n belangrike aktiwiteit, en het veral traumachirurgie uitgebou. Betreding van die buik- en toraksholtes was nie meer noodwendig fataal nie, en veeartsenykunde het tot stand gekom. Die eerste beduidende chirurgiehandboek ná die Hippokratiese Corpus is in die 1ste eeu n.C. deur Celsus opgestel. Vanaf die 3de eeu het die chirurgieberoep min vordering gemaak, die beroepstaal het mettertyd van Grieks na Latyn verander en kundigheid is later veral deur Islam-geneeshere na die Middeleeue en later oorgedra.

  4. The Cape Gunsmith / Die Kaapse Geweersmid

    W. Otto


    Full Text Available In die Verslag van die Kommissie van Ondersoek na die Koordinering van Museums op 'n Nasionale Vlak (RP 113/1975, word vyf kolomme gewy aan historiese vuurwapens. Die kommissie wys op die belangrike plek wat vuurwapens in Suid-Afrika se wordingsgeskiedenis inneem en voeg daaraan toe dat geen museum in Suid-Afrika hierdie belangrike veld in sy uitstallings dek nie.

  5. Bevordering van transformerende leer: Die skryf van ’n reflektiewe joernaal in die Natuurwetenskappe

    Erna R. du Toit


    Full Text Available Die doel van die artikel is om aan te toon hoe die skryf van ’n reflektiewe joernaal in die Natuurwetenskappe die perspektiewe en denke van onderwysstudente kan transformeer en/of leer kan bevorder. Die studie maak voorspraak vir die gebruik van ’n reflektiewe joernaal as ’n instrument vir studente om betekenis te gee aan die leeromgewing vanuit verskillende perspektiewe deur te leer in praktyk. ’n Kwalitatiewe navorsingsmetode is gevolg om die inskrywings in ’n joernaal te analiseer aan die hand van bepaalde indikatore. Die bevindinge toon dat die meeste studente na die praktykervaring positief was en sommiges het tot ander perspektiewe vanweë hul ervaring gekom.

  6. Die invloed van drie kruisbestuiwers op die saadinhoud van Minneola tangelo (Citrus parodist x C reticulata

    H. J. Esterhuizen


    Full Text Available Die invloed van verskillende kruisbestuiwers (Clementine, Empress en Valencia op die gemiddelde saadinhoud van Minneo­la tangelo is ondersoek. Clementine en Empress as kruisbestuiwers het die grootste invloed op die gemiddelde saadinhoud van die vrugte gehad, terwyl dié van Valencia nie noemenswaardig was nie. Die gemiddelde saadinhoud van die vrugte het afgeneem met toename in afstand vanaf die kruisbestuiwer. Indien ’n beperking op die afstand tussen kultivar en kruisbestuiwer geplaas word, sal ’n groter persentasie vrugte aan uitvoerstandaarde ten opsigte van saadinhoud voldoen.

  7. MOOCs; vanwaar al die ophef?

    Henderikx, Maartje; Kreijns, Karel


    MOOCs; vanwaar die ophef? Het nog maar zeer recente fenomeen MOOCs (massive open online courses) heeft zich in korte tijd al een onwrikbare positie weten in te nemen in het open online onderwijs. De hype rondom deze nieuwe manier van onderwijs geven bereikte zijn hoogtepunt in 2012, dat prompt werd

  8. Die Suche nach den Gottesteilchen


    2008 wird der größte jemals gebaute Teilchenbeschleuniger in Betrieb genommen Anlässlich des Mathematik-Jahres 2008 hat der Experimentalphysiker der Universität Hamburg und der designierte Generaldirektor des europäischen Zentrums für Teilchenphysik CERN in Genf, Rolf-Dieter Heuer, die Bedeutung des Dialogs zwischen Naturwissenschaftlern und Philosophen hervorgehoben.

  9. Robert Merton Dies at 92

    Snell, Joel C.


    This article features Robert Merton, who died recently at age 92. Merton came into this world as a Jewish baby named Meyer Schkolnick. He lived in South Philly where his parents wrenched a living as blue-collar workers. Merton chose an Anglicized name to move into the Yankee dominated America of the 20's and 30's. At Harvard, he studied under…

  10. 77 FR 6587 - PHB Die Casting a Subsidiary of PHB, Inc., Including On-Site Leased Workers From Career Concepts...


    ... Workers From Career Concepts and Volt Services, Including a Contract Worker From Burns Industrial Group... subsidiary of PHB, Inc., including on-site leased workers from Career Concepts and Volt Services, Fairview... Casting, a subsidiary of PHB, Inc., Fairview, Pennsylvania, including on-site leased workers from...

  11. Die Wissensgesellschaft und die Bildung des Subjekts - ein Widerspruch?

    Sebastian Hacke


    Full Text Available Der Beitrag untersucht, inwiefern sich medienpädagogisch relevante Diskrepanzen zwischen dem Diskurs der Wissensgesellschaft und jugendlichem Medienhandeln nachzeichnen lassen. Dazu werden zunächst einige Aspekte des Konstrukts Wissensgesellschaft skizziert, das in seiner gegenwärtig populären Form ins Fahrwasser an volkswirtschaftlichen Verwertungskalkülen orientierter Denkformen geraten ist. Dies wird in Bezug auf die sich daran gekoppelte Programmatik von Kompetenz diskutiert, welche den «homo oeconomicus» beschwört und sich darin konträr zu klassisch bildungstheoretischen Kategorien verhält. Weitergeführt werden diese Überlegungen anhand der Problematisierung des Medienkompetenztheorems, das sich bis heute damit schwer tut, sich von der Vereinnahmung durch zweckrationale und restringierende Tendenzen zu befreien. Argumentiert wird, dass mit Medienkompetenz zu wenig einer milieuspezifischen Differenzierung Rechnung getragen werden kann, die eine wichtige Prämisse für eine soziale Ungleichheiten ernst nehmende Medienpädagogik ist. Als eine Alternative diskutieren wir, inwieweit sich hier praxeologische Perspektiven zum Verständnis jugendlichen Handelns anbieten. Der Beitrag mündet in einige medienpädagogisch fruchtbare Ideen, in deren Zentrum eine reflexivere, stärker am Habitus von Jugendlichen orientierte Praxis steht.

  12. Die impak van tutoriale op die wiskundeprestasie van eerstejaarstudente

    J. G. Maree


    Full Text Available

    Studente uit histories-agtergeblewe gemeenskappe in Suid-Afrika onderpresteer dikwels in wiskunde vanweë ’n verskeidenheid faktore. Aksienavorsing wat aan die (voormalige Technikon Noord-Gauteng uitgevoer is, om ondersoek in te stel na wyses waarop hierdie studente se wiskundeprestasie verbeter kan word, het die implementering van ’n tutoriaalstelsel behels. Kwantitatiewe en kwalitatiewe data is deur middel van ’n verskeidenheid instrumente ingesamel. Die resultate het sekere tendense in tersiêre wiskundeonderrig, wat in ’n tweede of derde taal geskied, uitgewys.


    The impact of tutorials on achievement in mathematics of first year students

    Historically disadvantaged students in South Africa often underachieve in mathematics due to a number of factors. Action research that was conducted at the (former Technikon Northern Gauteng to investigate ways in which these students’ achievements in mathematics could be improved comprised the implementation of tutorial sessions. Quantitative and qualitative data were gathered by means of a variety of instruments. The results revealed certain trends in tertiary mathematics education where learning takes place in a second or third language.

  13. Die aard en problematiek van vertaling

    J. Swanepoel


    Full Text Available George Steiner (1975 se onlangse werk oor vertaling dra die treffende titel: After Babel. Dit is met hierdie dilemma wat die mens in sy na-babelse bestaan in sy strewe na sinvolle kommunikasie te kampe het: die bestaan van ’n magdom van tale wat geen individu, hoe begaafd ookal, eers kan droom om te beheers nie. Vandaar die strewe na die totstandbrenging van ’n eenvoudige en universele wereldtaal, Esperanto, of — meer algemeen — die behoefte aan vertaling. Maar vertaling is nie net ’n dilemma nie, dit is ook ’n uitdaging.

  14. Die Felsfassadengräber von Kyrene

    Greve, Anika


    Die griechische Kolonie Kyrene wurde im letzten Drittel des 7. Jhs. v. Chr. einige Kilometer vom Mittelmeer entfernt im libyschen Innenland gegründet. Die Siedler waren dorische Griechen aus Thera im Süden der Kykladen. Nicht nur die erhaltenen innerstädtischen Gebäude zeugen von einem einstigen Wohlstand, auch die Nekropole nahm im Laufe der Zeit gewaltige Ausmaße mit aufwendig gestalteten Grabanlagen an, die sich rund um die urbane Bebauung entlang der Ausfallstraßen ausbreitete. Viele Ruhe...

  15. The skin effect and the yielding behavior of cold chamber high pressure die cast Mg-Al alloys

    Yang, K. Vanna [ARC Centre of Excellence for Design in Light Metals, Materials Engineering School of Engineering, University of Queensland, Brisbane, QLD, 4072 (Australia); Caceres, C.H., E-mail: [ARC Centre of Excellence for Design in Light Metals, Materials Engineering School of Engineering, University of Queensland, Brisbane, QLD, 4072 (Australia); Nagasekhar, A.V. [ARC Centre of Excellence for Design in Light Metals, Materials Engineering School of Engineering, University of Queensland, Brisbane, QLD, 4072 (Australia); Easton, M.A. [CAST Co-operative Research Centre, Department of Materials Engineering Monash University, Melbourne, VIC, 3800 (Australia)


    Highlights: Black-Right-Pointing-Pointer The area fraction of elastic skin was calculated for a range of Mg-Al alloys. Black-Right-Pointing-Pointer The skin was defined using micro mechanistic concepts and tensile testing data. Black-Right-Pointing-Pointer The elastic constraint imposed by the skin on the core is discussed. Black-Right-Pointing-Pointer The skin covers {approx}30% of the cross section of the most concentrated alloy. - Abstract: The volume fraction of material that remained elastic as yielding developed in cast-to-shape tensile specimens of binary alloys with Al contents between 0.47 and 11.6 mass% was calculated using the Kocks-Mecking method of analysis. In the most dilute alloys the elastic fraction decreased rapidly to zero at a well-defined stress, suggesting that yielding was uniform across the specimen, whereas in the concentrated ones it decreased gradually over a wide range of stresses, suggesting that yielding developed first in the softer core of the casting while the harder outer layer, or skin, remained elastic. Comparison with specimens of the concentrated alloys which had a surface layer removed showed that the strain hardening behavior of the core resembled that of full specimens of the most dilute alloy. The maximum amount of elastic material in comparison with the most dilute alloy was used to define the area fraction covered by the skin, for each alloy. The skin covered between {approx}10% and {approx}30% of the cross section, the greater values for the concentrated alloys. The skin imposed an elastic constraint that delayed the development of full plasticity at the core.

  16. Psychotherapy of the dying patient.

    Stedeford, A


    The psychotherapeutic aspects of the care of the 49 terminally ill patients described in the preceeding paper are discussed. Their differing ways of coping with the stress of dying and the range of psychotherapeutic strategies used in treatment are described. The work suggests that the therapist's use of psychological insights can improve his understanding of the emotional pain of terminal illness, and well-aimed psychotherapy can contribute to its relief.

  17. Skrifberoep in die vorming van etiese uitsprake, Deel 1: ’n Etiese verstaan van die vrou in die Bybel

    Adriaan L. Rheeder


    Full Text Available Na 30 jaar kon die grammaties-historiese metode van Skrifondersoek nie daarin slaag om die etiese probleem van die vrou in die kerklike ampte (en homoseksualiteit in die GKSA op te los nie. Hierdie metode kan na alle waarskynlikheid nie meer as die enigste verklaringsmetode gebruik word nie en moet deur ander uitgangspunte aangevul word. In hierdie artikel word twee hermeneutiese uitgangspunte bespreek wat saam met die grammaties-historiese metode in die vertolking van die Skrif gebruik kan word. Hierdie hermeneutiese uitgangspunte sal gedemonstreer word in ‘n bespreking oor die etiese verstaan van die vrou in die Bybel, spesifiek soos dit op die vrou in kerklike ampte toegepas word. In aansluiting by laasgenoemde twee vertrekpunte word in ’n opvolgartikel ’n verdere drie hermeneutiese vertrekpunte behandel. Die twee hermeneutiese vertrekpunte wat in hierdie artikel behandel word, staan as reëldoelwit en analogie bekend. Die eerste hermeneutiese vertrekpunt gaan uit van die veronderstelling dat die reëldoelwit van ’n teks swaarder weeg as die teks self, terwyl analogie van die veronderstelling uitgaan dat analogie as beredenering ’n aanvaarbare en noodsaaklike vertrekpunt is. Bogenoemde hermeneutiese vertrekpunte (vyf in totaal is op twee aannames gegrond. Ten eerste word aanvaar dat die Bybel, alhoewel ’n goddelike boek, ’n besliste kreatuurlike kant het wat in die vertolking daarvan in ag geneem moet word. Tweedens word geredeneer dat die Skrif nie ’n  teologiese boek is nie, wat beteken dat gelowiges in etiese sake waaroor daar twee verstaansmoontlikhede bestaan, die reg gegun moet word om self die Skrif te vertolk. Daar word tot die  gevolgtrekking gekom dat ’n etiese verstaan van die vrou daartoe moet lei dat die vrou as gelykwaardig aan die man beskou en behandel moet word, met die gevolg dat die vrou tot alle ampte in die kerk toegelaat moet word.Appeal to Scripture in the formation of ethical judgments, Part 1: An

  18. Mechanisms of fatigue-crack initiation and their impact on fatigue life of AlSi7 die-cast components

    Redik Sabine


    Full Text Available In the course of the present study, in-situ observations of crack initiation and crack growth of naturally induced cracks in cyclically loaded specimens along with conventional fatigue tests and fracture surface analyses were performed. The specimens used were taken from different sampling positions of standard and HIPed aluminum-die-cast engine blocks, with different cooling conditions. In one sampling position within the standard engine block microporosity was able to form, acting as a source for fatigue-crack initiation. While in the absence of microporosity, as observed in specimens taken from HIPed components, crack initiation occured via slip band mechanism. If material defects such as pores were present, premature crack initiation reduced the fatigue life yielding a lower fatigue life and fatigue strength than specimens where cracks formed by slip band mechanism. For cracks formed at pores, the pore size is the determining factor for fatigue behavior. While for cracks initiated via slip band mechanism fatigue strength is a function of the local material strength.

  19. Numerical simulation of the interface molten metal air in the shot sleeve chambre and mold cavity of a die casting machine

    Korti, Abdel Illah Nabil; Abboudi, Said


    The objective of this study relates to the numerical simulation of the free surface during the two-dimensional flow and solidification of aluminum in the horizontal cylinder and mold cavity of the high pressure die casting HPDC machine with cold chamber. The flow is governed by the Navier-Stokes equations (the mass and the momentum conservations) and solved in the two phase's liquid aluminum and air. The tracking of the free surface is ensured by the VOF method. The equivalent specific heat method is used to solve the phase change heat transfer problem in the solidification process. Considering the displacement of the plunger, the geometry of the problem is variable and the numerical resolution uses a dynamic grid. The study examines the influence of the plunger speed on the evolution of the interface aluminum liquid-air profile, the mass of air imprisoned and the stream function contours versus time. Filling of a mold is an essential part of HPDC process and affects significantly the heat transfer and solidification of the melt. For this reason, accurate prediction of the temperature field in the system can be achieved only by including simulation of filling in the analysis.

  20. 压铸建压过程与建压时间浅析%Relationship between Pressure-Establishment and Time-Establishment during Die Casting

    卢宏远; 赵希文; 董亚明; 邹宪福; 丁晔平


    With the increasingly improvement of function and control of pressurization mechanism in the die casting machine, time-establishment , which has been as a controllable factors, was paid attention to. Through analyzing the working mechanism of accumulator, pressure-increment process of injection and pressurization mechanism, pressurization control mode and time-establishment, the minimum time-establishment and key factors influencing time-establishment were presented.%随着压铸机增压机构功能和控制的不断完善,建压时间已成为压铸工艺中的可控因素而受到普遍重视.通过对蓄能器的工作原理、压射及增压机构的升压过程、增压控制模式及建压时间等内容的简要分析,说明了在正常的三段建压过程模式下,目前压铸机能够达到的最短建压时间大约为30 ms,而内浇口厚度、铸件几何特征、合金凝固特性及工艺条件等是确定最短建压时间的主要因素.

  1. 压铸模具产品FDM快速成型工艺设计%Process design for die casting products with FDM rapid prototyping



    Analyzing die casting products FDM rapid prototyping process, using processing software to fine STL data, choosing excellent moulding material, optimizing forming parameters reasonablely, determining optimum forming direction and using ultrasonic removal of water soluble machine to remove supporting materials, advantages of FDM rapid prototyping was brought into full play. Practices had proven that the developed cycle was shortened and the manufacture speed was improved with FDM rapid prototyping and thus product development efficiency was improved by 42 percent to 58 percent.%对压铸模具产品FDM快速成型的工艺进行分析,应用处理软件精细化STL数据,通过选择优良的成型材料,合理优化成型参数,确定最佳成型方向,采取超声波水溶机去除支撑材料等手段来充分发挥FDM快速成型工艺的优势.实践证明,FDM快速成型技术在产品开发中缩短了产品开发周期,提高了制造速度,使产品开发效率提高42%~58%.

  2. Effects of silicon contents on formation of abnormal structures of aluminum alloy die castings; Aruminiumu gokin daikasuto no ijo soshiki keisei ni oyobosu keisoryo no eikyo

    Komazaki, T.; Maruyama, Y.; Nishi, N. [Ryobi Ltd., Hiroshima (Japan)


    In this study, Al-5-11mass%Si binary alloys and commercial alloys with equivalent amount of silicon contents (AC2A, ADC10, ADC12) were fabricated into die castings with changed shot-time-lag, and effects of alloy structures on formation of abnormal structures were investigated. The results show the following discoveries. With the increasing of silicon contents in Al-Si binary alloys from 5 mass% to 11 mass%, the abnormal structures caused by the cooling and solidification of the molten metal in the injection sleeve will change from mainly coarse {alpha} phase to mainly breaking chill crystals as the solidification state is changing form porridge state to solid surface forming state. The abnormal structure of the commercial alloy AC2A mainly consists of coarse {alpha} phases and that of ADC12 mainly consists of breaking chill crystals. The ADC10 alloy is an intermediate alloy between them. The amount of dispersion for values of tensile strength of ADC12 alloy is larger than that of AC2A and ADC10 alloys because ADC12 alloy contains many breaking chill crystals. 12 refs., 11 figs., 4 tabs.

  3. Killing, letting die and euthanasia.

    Husak, D N


    Medical ethicists debate whether or not the moral assessment of cases of euthanasia should depend on whether the patient is 'killed' or 'allowed to die'. The usual presupposition is that a clear distinction between killing and letting die can be drawn so that this substantive question is not begged. I contend that the categorisation of cases of instances of killing rather than as instances of letting die depends in part on a prior moral assessment of the case. Hence is it trivially rather than substantively true that the distinction has moral significance. But even if a morally neutral (ie non-question begging) distinction could be drawn, its application to the euthanasia controversy is problematic. I illustrate the difficulties of employing this distinction to reach moral conclusions by critically discussing Philippa Foot's recent treatment of euthanasia. I conclude that even if an act of euthanasia is an instance of killing, and there exists a prima facie moral duty not to kill, and no more stringent duty overrides this duty, one still cannot determine such an act to be morally impermissible.

  4. Letting die and mercy killing.

    Narbekovas, Andrius; Meilius, Kazimieras


    We are all called to make moral decisions, not only about preserving life and health, but also about accepting our death and dying. There are situations, when it is morally right, and indeed obligatory, to allow a dying person to die in peace and dignity. But there is a world of difference between allowing a peaceful death, and deliberately setting out to bring death of the person either by acts of commission (s.c. 'active euthanasia'), or by acts of omission (s.c. 'passive euthanasia'). The word "killing" seems proper for euthanasia, because "to kill" does mean " to intentionally cause the death of someone." It can be morally acceptable to withhold or withdraw a treatment precisely because it is reasonably judged as inefficacious (futile), or excessively burdensome for the patient. One's reason for withholding such treatment must not be a judgement about the desirability of putting an end to the patient's life, but a judgement about the desirability of putting an end to the treatment, which is futile or burdensome.

  5. Ethnographische Filme und die Darstellung von Frauen

    Judith Keilbach


    Full Text Available In dieser Filmographie werden ethnographische und koloniale Filme aus dem Bestand des Nederlands Filmmuseum kommentiert, die für die Frage nach der Darstellung von Frauen und Geschlechterverhältnissen von Interesse sind.

  6. [Die Gründung...] / Anders Henriksson

    Henriksson, Anders


    Rets.: Karsten Brüggemann. Die Gründung der Republik Estland und das Ende des "Einen und unteilbaren Russland" : die Petrograder Front des Russischen Bürgerkrieges, 1918-1920. Wiesbaden : Harrassowitz, 2002

  7. Die ausbildung von wertbedeutungen im schuljugendalter*

    Siegfried Heusinger


    Full Text Available Die folgenden Darlegungen stützen sich auf Untersuchungsergebnisse des Verlassers zur Sprachentwicklung in der Ontogenese. Angeregt wurde die UnterSuchung durch die besonders in den letzten Jahren in mehreren Ländern verstärkt erhobenen Forderungen, nicht nur die Sprache des Klein­ kindes, sondern vornehmlich den Entwicklungsstand der Schülersprache auf den einzelnen Klassenstufen zu erforschen und den Prozeß der Sprachentwicklung des Schülers genauer zu bestimmen. Die Forderungen sind (so z. B. in der DDR durch das Bestreben motiviert, weitere wissenschaftliche Voraussetzungen für die Verbesserung der muttersprachlichen Bildung und Erzliehung zu schaffen. Es geht also vor allem um Bedürfnisse des Muttersprachunterrichts, die aus der gesellschaftlichen Bedeutung der Sprache überhaupt und den steigenden Anforderungen an die gesellschaftliche Kommunikation insbesondere erwachsen.

  8. Die invloed van verpoeiering op die kwikinhoud van verskeie gesertifiseerde verwysingsmateriale

    Frederick Roelofse


    Full Text Available Die meeste analitiese tegnieke wat gebruik word vir die bepaling van die kwikinhoud van aardmateriale benodig komminusie van monsters voor analise. Dit word gewoonlik bewerkstellig deur die vergruising van die monsters, gevolg deur die verpoeiering daarvan. Dit is bekend dat in konvensionele meule hitte tydens verpoeiering vrygestel word, en dit volg dat kwikverlies verwag kan word weens die element se vlugtigheid. Om kwikverlies tydens verpoeiering te bestudeer het ons nege gesertifiseerde verwysingsmateriale van stolrotse geanaliseer voor verpoeiering, asook na 3 en weer na 10 minute van verpoeiering, met behulp van ’n direkte kwikanaliseerder. Die resultate van die eksperimente dui daarop dat: (1 kwikverlies onbeduidend is na 3 minute van verpoeiering, (2 kwikverlies beduidend raak indien monsters oormatige verpoeiering ondergaan, (3 kwikverlies klaarblyklik nie deur mineralogie beheer word nie en (4 vir monsters met ’n lae kwikinhoud, kontaminasie tydens verpoeiering ’n baie meer beduidende invloed op die geanaliseerde kwikinhoud het as die duur van verpoeiering.

  9. Die tätigkeitstheoretische Perspektive

    Stroh, Wolfgang Martin


    Die Perspektive, die der Autor entwickelt, ist die der dialektischen Tätigkeitstheorie. Gemäß dieser Theorie ist Musik eine spezifische Art der Aneignung von Wirklichkeit. SchülerInnen sollten im Musikunterricht lernen, bewusst, selbstbestimmt und sozial zu handeln, wenn sie sich durch Musizieren Wirklichkeit aneignen. Wenn SchülerInnen im Unterricht Musik machen, müssen sie sich daher auch des kulturellen Kontextes bewusst sein, dem die Musik entstammt. Sie sollten auch selbstbestimmt handel...

  10. Aanspreekvorme in die poësie

    D. M. Wybenga


    Full Text Available By die deurblaai van die Groot Verseboek (hierna GV is dit opvallend dat daar so baie keer van aanspreekvorme in gedigte gebruik gemaak word. Van die heel eerste gedig wat daarin opgeneem is, naamlik Klaas Geswind en sy perd (p. 1 tot ’n gedig van die laaste opgenome digter, André le Roux, (struisbaai-blues, p. 506, gebruik digters telkens hierdie taalmiddel om een of ander spesifieke effek te verkry.

  11. “Ruik die verderf in die kieliebakke”: Breyten Breytenbach se blik op die lyk

    M. Crous


    Full Text Available “Smell the rot in the armpits”: Breyten Breytenbach’s perspectives on the corpse The purpose of this article is to analyse Breyten Breytenbach’s so-called corpse poem, “bekommernis”, taken from his debut album “die ysterkoei moet sweet” (1964. The theoretical point of departure is the theories of Kristeva, in particular her essay on abjection. Not only does the article focus on Breytenbach’s portrayal of the abject, but also shows to what extent his use of language describing death, decay and the cadaver illustrates what Kristeva calls “a revolution in poetic language”. Given the fact that the poem is situated in a Zen Buddhist context, the Zen philosophy on death and dying is also taken into consideration when analysing aspects such as the dissolution of the ego, the bardos of death, et cetera.

  12. Die waarde van voorafopleiding deur die ouer vir pedo-oudiometrie by drie- en vierjarige kleuters

    Merisa Lodewyckx


    Full Text Available Die verkryging van akkurate, betroubare inligting aangaande die gehoorvermoë van jong kinders is van besondere belang vir die oudioloog, maar word dikwels bemoeilik aangesien die kleuter nie goeie samewerking bied in die vreemde pedo-oudiometriese situasie nie. Die oplossing hiervoor is grootliks geleë in die opleiding van die kind voor formele  gehoortoetsing en meer spesifiek  opleiding tuis deur die ouer. Die doel van hierdie studie was om 'n voorbereidende program op te stel wat die ouer tuis met die kind kan uitvoer, voordat formele  toetsing plaasvind. Die waarde en effek van hierdie program in die pedo-oudiometriese situasie is geevalueer by 'n groep drie- en vierjarige kleuters. Resultate dui daarop dat laer en meer akkurate drempels, 'n korter toetstydperk, verminderde angs en beter samewerking verkry is by die kleuters wat vooraf  opleiding ontvang het. Die opleidingsprogram kan dus in die kliniese praktyk benut word as voorafopleiding  vir pedo-oudiometrie.

  13. Die persoonlikheidseienskappe en bestuurspotensiaal van bestuursgemotiveerde persone

    A. S. Engelbrecht


    Full Text Available The personality traits and managerial potential of managerial motivated persons: In the ligth of criticisms of the psychometric suitability of existing measures of managerial motivation a new scale, the Managerial Motivation Questionnaire (MMQ, was developed. This was done on the basis of a comprehensive study of the literature on managerial motivation and the role-motivation theory of Miner. The MMQ demonstrated adequate internal consistency. The aim of this study is to clarify the construct validity of the MMQ. Significant and positive correlations were found between managerial motivation, overall managerial potential, and nine managerial dimensions. The construct validity of the MMQ was further supported by correlations between sixteen personality traits and managerial motivation. Opsomming In die lig van kritiek teen die psigometriese geskiktheid van bestaande meetinstrumente van bestuursmotivering is 'n nuwe skaal, die Bestuursmotiveringsvraelys (BMV/ ontwikkel. Dit is gedoen op grond van die konseptuele omiyning van bestuursmotivering en die rolmotiveringsteorie van Miner. Die BMV vertoon toereikende interne konsekwentheid. Die doel van hierdie studie is om die konstrukgeldigheid van die BMV verder op te klaar. Beduidend positiewe korrelasies is tussen bestuursmotivering/ globale bestuurspotensiaal en nege bestuursdimensies gevind. Hierbenewens het die korrelasies tussen sestien persoonlikheidseienskappe en bestuursmotivering verdere ondersteunende bewyse gelewer van die konstrukgeldigheid van die BMV.

  14. Die Prozessionsspinner Mitteleuropas - Ein Überblick

    Bräsicke, Nadine


    Full Text Available Die Auswirkungen des Klimawandels lassen sich bereits auch in Deutschland beobachten. Dabei werden die Waldökosysteme in besonderer Weise betroffen. Waldstandorte sind stärker trockenen Bedingungen ausgesetzt, die zusammen mit höheren Vegetationszeittemperaturen eine erhöhte Stressanfälligkeit der Bäume verursachen. Bei den Insekten beeinflusst eine erhöhte Temperatur u. a. die Entwicklungsdauer, die Populationsdichte und die Verwertbarkeit der Wirtspflanzen als Nahrung (BMLFUW 2003, Petercord et al. 2008. Es ist zu erwarten, dass die Wachstumsrate und die Entwicklung der Insektenarten beeinflusst wird (Netherer & Schopf 2009, die aufgrund eines relativ hohen Populationswachstums und hoher Mobilität durch Migration oder Adaption auf veränderte Klimabedingungen rascher reagieren (Harrington et al. 2001. Bei einigen Schädlingen zeichnet sich eine solche Entwicklung bereits ab. Unter ihnen befinden sich humanpathogene Arten, die zunehmend auch zum Forstschädling avancieren und die Waldbestände existenziell gefährden. Der Eichenprozessionsspinner gehört zu diesen Arten. Ebenfalls relevant für Mitteleuropa sind Thaumetopoea pinivora und Th. pityocampa, die mit dem Beitrag näher betrachtet werden.

  15. Die kuns van Maggie Laubser . 1

    G. Dekker


    Full Text Available Dis vir my ’n groot genoeë om iets te mag sê oor die kuns van 'n vrouw at jare lank haar pad eensaam gegaan het, trou gebly het aan haar kunstenaarsoortuiging en nie toegegee het aan die smaak van die publiek, geenkompromieë daarmee gesluit het terwille van populariteit of stoflike gewin nie.

  16. Eenheid en differensiasie in die onderwys

    B. C. Schutte


    Full Text Available Hierdie tenia van die interíakultêre lesings sny in werkliklieid oor alle fakulteite lieen en is ’11 probleem wal by elke dissipliiie ontstaan, sonder twyfel by almal wat met die mens en met levve te doen het, maar ook by die fisiese wetenskappe waar met die lewelosc skepping gewerk word. Waar ons in ons land en veral in Transvaal deesdae voortdurend te doen het met differensiasie in die onderwys, met A-, B- en C-bane, is hierdie beginsel van eenheid en verskeidenheid, van eeridersheid en ver- skillendbeid, van integrasie en differensiasie, van verdeelde beheer in die onderwys en van ’11 eenheidsheleid en -beheer, van nasionale en inter- nasionale onderwys, van verskillende skooltipes en van komprehensiewe skole e.d.m., voortdurend in die nuus. Saam met die eenheid en differen­ siasie in die volkewêreld van Afrika, is die probleem in die onderwys seker die popnlêrste; dis byna reeds gemeen|laas.

  17. 不锈钢管镶嵌件在压铸中的应用研究%Research and Application of Inserts of Stainless Steel Tube in Die Casting



    阐述了汽车发动机电控冷却器压铸件不锈钢油管内镶嵌件的结构、定位及工艺过程控制.其要点是,在油管接头上预先按图纸尺寸要求钻攻底孔、攻牙及铣面,同时做出与之配合的镀锌螺栓接头,装配后(将螺栓接头旋入油管接头内,成为油管总成,再放到压铸模上)通过与模具上的限位镶块精确定位,从而实现铸件压铸后油管接头位置度及接头端面的距离尺寸不变的目的.压铸结束后拆除可循环利用的螺栓接头,镀锌接头涂层防止了高温下因油污引起的生锈,满足了产品的清洁度要求.%According to the product assembly requirements, first pre-drilling thread bottom hole, tapping and milling surface in the tube union required by the drawing, and make the galvanized thread plug at the same time, the thread plug is screwed into the tube union as a tube assembly, and then put it into the casting mold . The tube dimensions of the casting would be achieved directly by the die casting process through die-casting mould precision limit insert . When the die casting is complete, remove the recyclable thread plug . The galvanized thread plug can prevent effectively metal from rust caused by the high temperature and oil of the fitting surface between the tube union and the thread plug to ensure the cleanliness requirement, and protect the tube surface against damage . The internal thread of the tube u-nion ensure the tooth shape in the thread plug force in the die casting process, so as to achieve the purpose of directly by the die-casting process. Reduce the cost under the precondition to satisfy the production requirements.

  18. Missionale kerkwees en die elektroniese sosiale media

    Martin J. Lazenby


    Full Text Available Die geweldige toename in die benutting van die sosiale media as interaktiewe kommunikasiemiddel wêreldwyd, bied aan die Christelike kerk groot missionale geleenthede, maar stel ook groot uitdagings en eise. Hierdie geleentheid moet benut word om missionaal ’n verskil ten gunste van God se koninkryk te maak. Die inhoud en die kommunikasiestyl kom onder die vergrootglas. Hierdie artikel poog om ’n paar bybels-etiese beginsels aan te dui wat as basis vir die missionale styl van kommunikasie moet dien. As uitgangspunt word die Bybel as die Woord van God gebruik. Daar word geredeneer dat die moreel-etiese beginsels wat in die Bybel aan die gelowige voorgeskryf word, van die grootste belang is om gestalte te gee aan die koninkryk van God in hierdie wêreld wanneer via die sosiale media op horisontale vlak met mense gekommunikeer word. Dit gaan dus vir die gelowige nooit net om humanistiese, sosiale kommunikasie nie, maar altyd dat die beeld van God in hierdie wêreld geëer en sy koninkryk daardeur uitgebou word. Vir die Christen-gelowige gaan dit nooit om die mens nie, maar altyd om God se eer en die manifestasie van sy koninkryk.Being a missional church and the social media. The tremendous increase in using the social media as interactive communication medium worldwide creates the opportunity for the Christian church to make a missional difference in favour of God’s kingdom on earth. It also brings great challenges with it. This means that the way communication via the mass social media is done, becomes of the utmost importance. The content as well as the manner in which the communication is conducted must be considered. This article aims at providing certain basic biblical-ethical principles for communicating in the mass social media that will serve the missional calling of the church. The point of departure is the Word of God. The basic focus of the argument is that the moral-ethical principles given to the believer in the Bible are of the

  19. Straatsburg en artikel 2 van die dordtse kerkorde

    L. F. Schulze


    Full Text Available In art. 2 K.O. word daar vier soorte kerklike dienste on dcrskei, nl. „dié van die bedienaars van die Woord, dié van die professore aan die teologiese skool, die van die ouderlinge, en dié van die diakens”.

  20. Application of Using Ultra-Low-Speed Die Casting the Support Bracket of Automobile Engine Transmission%汽车发动机变速箱支架类零件的超低速压铸工艺

    刘春生; 苏建强; 罗金祺


    针对传统压铸工艺在生产超厚型产品时存在的气孔率高、强度低等问题,研究开发了某发动机支架零件的超低速压铸工艺,讨论了不同压射速度、内浇口厚度、浇注温度以及模具结构和模温控制等因素对压铸产品质量的影响.结果表明,当低速压射速度为0.25 m/s,高速压射速度为0.5 m/s,内浇口厚度为5.2 mm,浇注温度为680~690℃时,获得的铸件质量最好.通过对超低速压铸模具结构进行改进,并采用顺序凝固模温控制方法,满足了对铸件进行T6热处理的要求,使产品性能有较大提升.%aiming at problems existed in the traditional die casting super-thickness product, such as high porosity, low strength, the ultra-low-speed die casting engine support bracket was conducted, and effects of different injection speed, the thickness of ingate, pouring temperature of liquid metal, the mould structure and the control methods of the mould temperature on the quality of die casting support bracket were discussed. The results show that the support bracket exhibits acceptable quality with low injection speed of 0. 25 m/s and high injection speed of 0. 5 m/s, thickness of ingate of 5. 2 mm as well as pouring temperature of 680~690 ℃. Through modifying die casting die structure and adopting the sequential solidification mould temperature, the support bracket ca be treated by T6 heat treatment, improving greatly the performance of the die castings.

  1. Die effekvan punttoekenningstandaarde op die korrelasie tussen matriek- en universiteitsprestasie

    G. K. Huysamen


    Full Text Available The effect of marking standards on the correlation between matriculation and university performance. Marking standards differ between courses in the sense that the same group of students shows different course means in different courses. Goldman andWidawski (1976 proposed a within-persons procedure to adjust for such differences between university departments and Elliott and Strenta (1988 adjusted this procedure to perform such corrections between courses within departments. In this study the correlation between matriculation performance and university performance has been increased by applying this adjustment not only to university courses but also to matriculation subjects. Opsomming Punttoekenningstandaarde verskil tussen kursusse in die opsig dat dieselfde groep studente verskillende kursusgemiddeldes in verskillende kursusse toon. Goldman en Widawski (1976 het 'n tussenproefpersoonprosedure voorgestel om vir sodanige verskille tussen universiteitsdepartemente te korrigeer en Elliott en Strenta (1988 het dit aangepas om sodanige korreksies tussen kursusse binne departemente uit te voer. In hierdie ondersoek is die korrelasie tussen matriekprestasie en universiteitsprestasie verhoog deur hierdie aanpassing nie slegs op universiteit-kursusse nie, maar ook op matriekvakke toe te pas.

  2. Artikel 2 van die Nederlandse Geloofsbelydenis as geloofsvooronderstelling in die gesprek tussen wetenskap en geloof

    Jan A. Erasmus


    Full Text Available Artikel 2 van die Nederlandse Geloofsbelydenis bely dat God deur twee middele geken word, te wete deur middel van die skepping, onderhouding en regering van die wêreld (waaronder die wetenskap en deur die heilige en goddelike Woord (die Bybel. Hierdie belydenis is van groot belang vir die gesprek tussen Wetenskap en Teologie. In hierdie artikel word gepoog om die verskille, maar ook die ooreenkomste tussen hierdie twee middele van openbaring uit te lig, elkeen tot sy reg te laat kom, maar hulle ook in balans met mekaar te stel. Die wyse waarop te werk gegaan word, is die volgende: eers word gestel wat vooronderstellings is, asook die plek wat vooronderstellings in die beoefening van wetenskap sowel as geloof inneem. Daarna word nagevors watter perspektiewe artikel 2 van die Nederlandse Geloofsbelydenis as geloofsvooronderstelling vir die wetenskaps- en teologiebeoefening respektiewelik bied. Hieruit word ’n aantal gevolgtrekkings gemaak wat kan help om die problematiek in die wetenskap-geloofsgesprek op te los. Die kernbevinding van hierdie artikel is die volgende: Vanweë die verskil in die aard en die doel tussen Bybelfeite en wetenskaplike navorsingsresultate kan en sal klaarblyklike harmonieprobleme tussen die Skrif en die wetenskap ontstaan. Hierdie is egter slegs klaarblyklike probleme, omdat ’n verrekening van die verskil in die aard en die bedoeling van die wetenskapresultate en die Bybelfeite hierdie probleem sal oplos.Article 2 of the Belgic Confession as faith presupposition in the science-faith debate. Article 2 of the Belgic Confession confesses that God can be known by two means: firstly by studying the creation, preservation and government of the universe (i.e. science and secondly by studying the Word of God (the Bible. This confession is very important for the discussion between science and faith. In this article the similarities, but also the differences between these two means of revelation are researched. The aim is to

  3. Die Welt des Herrn Kuhn

    Kern, Daniela

    Eines Morgens erwachte Herr Kuhn fröstelnd und staunte darüber, dass es in seinerWohnung eiskalt war. Dennoch quälte er sich aus seiner kuscheligen Bettdecke heraus und schlurfte ins Bad. "Hoffentlich wird wenigstens das Wasser warm", dachte er sich, als er den Wasserhahn betätigte - aber es kam nicht nur kein warmesWasser, außer einem unheilvollen Gluckser kam gar nichts aus der Leitung. "Dann werde ich wohl mal den Klempner anrufen", sprach er sich leise in den Bart und griff zu seinem Handy - doch das Netz war tot! Herr Kuhn begann nun, sich ernsthaft Sorgen zu machen, "Oje, was ist denn heute nur los? Ist irgendetwas Schlimmes passiert?" Um einen besseren Überblick über die Lage zu bekommen und sich austauschen zu können, brannte er nun förmlich darauf, rauszugehen und zur Arbeit zu fahren. An anderen Tagen, die er frisch geduscht und mit Kaffee und Marmeladen-Brot begann, war er selten so motiviert. So ging er also nun mit leerem Magen aus dem Haus. Hätte er den Versuch unternommen, sein tägliches Marmeladenbrot zuzubereiten, und dafür den Kühlschrank geöffnet, um das Marmeladenglas herauszunehmen, wäre ihm aufgefallen, dass auch die Stromversorgung Störungen unterworfen war, unschön zu erkennen an den ersten grünen, felligen Inseln auf seinem Lieblingskäse.

  4. Die rol van kapitaal in die ekonomiese groei en ontwikkeling van onderontwikkelde gebiede*

    F. J. du Plessis


    Full Text Available In die teorie oor ekonomiese groei speel kapitaal ’n besonder prominente rol. Kapitaal met die daarby behorende tegnologiese ontwikkeling, word beskou as die belangrikste enkele faktor verantwoordelik vir die bereiking en instandhouding van ’n „ten voile ontwikkelde” volkshuishouding.

  5. Die persoonlikheidsoriëntasieprofiel van die saluto-genies-funksionerende mens

    A. M. Viviers


    Full Text Available The aim of this research is to integrate the theoretical personality profile of the salutogenic functioning person, drawn from the literature on Salutogenesis, with the personality orientation profile of the optimal functioning employee, as documented in the literature on Organisational and Personnel psychology. The integration is done according to intra- (cognitive affective, conative and physical characteristics and interpersonal characteristics. The two profiles could be integrated, according to these characteristics, into a profile of the salutogenic functioning person who handles life and work stressors effectively and functions optimally in his daily existence. This integration shows a theoretical relationship between the two constructs and confirms a meaningful relationship found in empirical research. Opsomming Die doel van hierdie navorsing is om die teoretiese persoonlikheidsprofiel van die salutogenies-funksionerende mens vanuit die literatuur oor Salutogenese met die persoonlikheidsorientasieprofiel van die optimaal- funksionerende werknemer soos deur die Organisasie- en Personeelsielkunde-literatuur voorgehou, te integreer. Die integrasie word volgens intra- (kognitiewe, affektiewe, konatiewe en fisiese eienskappe en interpersoonlike eienskappe gedoen. Daar is bevind dat die twee profiele volgens die eienskappe geïntegreer kan word tot 'n profiel van die salutogenies-funksionerende mens wat die stressors van die lewe en werk effektief kan hanteer en sodoende optimaal in sy daaglikse bestaan funksioneer. Die integrasie bevind 'n teoretiese verband tussen die twee konstrukte. Dit bevestig empiriese navorsing wat 'n beduidende verband tussen die twee konstrukte bevind het.

  6. Was die neuen Frauen wollen

    Wilhelm, Hannah; Meyen, Michael


    Seit Mitte der 90er Jahre hat sich eine neue Generation von Frauenzeitschriften auf einem als übersättigt geltenden Markt etabliert. Diese Blätter richten sich an Frauen zwischen 20 und 35 Jahren. Glamour aus dem Condé Nast Verlag scheint die Perfektion dieses neuen Zeitschriftentypus zu sein. Das Magazin im Pocket-Format wurde sofort nach seiner Einführung im Februar 2001 Marktführer im Segment der monatlich erscheinenden Frauenzeitschriften. Der Beitrag geht der Frage nach, wie dieser Erfol...



    Logic components are used to support the conceptual design. Taking the stamping die structure as the research object,several logic components are defined for the conceptual die construction design. A new method-logic assembly modeling is presented to satisfy the characteristic of the top-down die design process. Representing shapes and spatial relations in logic can provide a natural,intuitive method of developing complete computer systems for reasoning about die construction design at the conceptual stage. This method can reflect the designer's thought clearly and provide the designer with a test bed for generating alternatives and performing reasoning work at the conceptual die design stage.

  8. Genl. Koos De La Rey, die krygsman.

    J. S. du Plessis


    Full Text Available 22 Oktober is die geboortedag van genl. Koos de la Rey, wat van dag tot ons heldeverlede behoort. Vanjaargedenk ons ook op 11 Oktober die uitbreek van die Tweede Vryheidsoorlog, sestig jaar gelede. Daarom wil ek graag by hierdie geleentheid die persoon van Koos de la Rey in herinnering roepen by wyse van hierdie artikel huldebring aan hom wat God aan ons volkgegee het op ’n tydstip toe sulke mannedringend noodsaaklik was; ’n man wat in die ure van dood en benoudheid leidingkon gee; ’n man sonder wie onsvolksgeskiedenis beslis armer sou gewees het. Aangesien hy by uitstek krygsmanen veldheer.

  9. Anforderungen an die Detektoren von DIVA.

    Wagner, S. J.

    Neben dem optischen System sind die Detektoren in der Fokalebene die wichtigste Komponente des Instruments eines astrometrischen Minisatelliten. Einer möglichst optimalen Auswahl des Detektorsystems und seiner Operationsmodi kommt daher eine entscheidende Bedeutung zu. In diesem Beitrag werden die Anforderungen vorgestellt, die sich zum gegenwärtigen Stand der Planung eines Interferometrie-Minisatelliten für astrometrische und photometrische Untersuchungen ergeben. Sie basieren auf dem grundlegenden Missionskonzept für die DIVA Mission (Bastian et al., 1996) und dem an der Landessternwarte Heidelberg zusammen mit dem ARI Heidelberg und DSS Ottobrunn erarbeiteten optischen Konzept des Instruments.

  10. Die resepsie van die Heidelbergse Kategismus (Sondag 17 en 22 insake die opstanding in die negentiende-eeuse Nederduitse Gereformeerde Kerk (Deel 1

    Johannes W. Hofmeyr


    Full Text Available Met die 450e herdenking van die Heidelbergse Kategismus (HK as vertrekpunt word in twee artikels gepoog om lig te werp op die plek, die rol en die interpretasie van die opstanding van Jesus Christus uit veral Sondag 17 en 22, spesifiek in die konteks van twee besondere eras in die Nederduitse Gereformeerde (NG Kerk. Na ’n kort bespreking van die Heidelbergse Kategismus , word in hierdie eerste artikel uitgebreid gekyk na die resepsie van die betrokke HK-geloofsartikels in die era van Andrew Murray, spesifiek teen die agtergrond van die negentiende-eeuse liberale teologie in Nederland. In ’n tweede artikel word soortgelyk gekyk na die resepsie van die betrokke HK-geloofsartikels in die NG Kerk na 2000, veral teen die agtergrond van die herverskyning van die liberale teologie in die vorm van die Jesus Seminaar, die Nuwe Hervorming en die aanhangers daarvan se standpunte binne die NG Kerk. Sowel die negentiende-eeuse liberale stryd in die NG Kerk as die stryd rondom die opstanding in die NG Kerk van die eerste dekade van die een-en-twintigste eeu, soos in die tweede artikel duidelik sal blyk, was gekenmerk deur kontekstueelbepaalde uniekhede. Die gemene deler is dat albei deel was van tye van teologiese vrysinnigheid. In die lig van hierdie bespreking, ook ten opsigte van die negentiende eeu, sal tot die gevolgtrekking gekom word dat die NG Kerk, wat sy identiteit as gereformeerde kerk betref, tans waarskynlik in ’n kritieke geloofs- en toekomskrisis verkeer wat kommerwekkende gevolge vir sy Skrifverstaan en getuienis as belydenis en belydende kerk van Jesus Christus en sy toekoms inhou. Alleen ’n duidelike visie, verantwoordelike leierskap en die herontdekking van die kruis en die opstanding as ononderhandelbare heilsgebeure, wat ook deur die HK gehandhaaf word, sal die NG Kerk kan red van ’n snelwentelende afwaartse spiraal. Slegs die pasgenoemde faktore kan ’n herstellende, positiewe en dinamiese oplossing vir hierdie proses bied wat

  11. The Nonlinear Predictive Control of Die Casting Machine for Multivariable Injection Process%压铸机多变量压射过程非线性预测控制

    陈伟华; 彭继慎; 赵忠建


    In the electric hydraulic servo control system during injection process of die casting machine,this paper presents a nonlinear-predictive-control method of die casting machine for multivariable injection process based on adaptive differential chaotic evolutional algorithm.The tent map is embedded into the adaptive differential evolution algorithm (DE),which has improved the generating process of DE algorithm for the crossover factor and compiling factor.The results of simulation experiment show that by using the intelligent algorithm to optimize injection parameters of die-casting PID controller,we can achieve fast optimization of die-casting machine injection speed and make the dynamic characteristics of nonlinear predictive control better,and the control precision more higher,so as to achieve the optimal-control purpose for the system.%在压铸机压射过程的电液压伺服控制系统中,提出了一种基于混沌自适应差分进化算法(CADE)的压铸机多变量压射过程非线性预测控制方法.该方法将帐篷映射嵌入到自适应差分进化算法(DE)中,改进了DE算法中交叉因子及编译因子的产生过程.通过仿真实验结果表明,利用该智能算法对压射控制PID控制器进行参数优化,能实现压铸机压射速度的快速寻优,使其非线性预测控制动态特性更好,控制精度更高,从而达到系统的最优控制目的.

  12. Ouditiewe aandag by die voorskoolse kind

    Elmarie Niemand


    Full Text Available Daar is met hierdie navorsingsprojek gepoog om 'n duidelike beeld te vorm van ouditiewe aandagsprosessering by die voorskoolse kind. Aangesien ouditiewe aandagsprosessering van groot belang is vir die kind wat skool toe gaan is daar op die groep wat in die daaropvolgende jaar skool toe gaan besluit. 'n Groep van 64 kinders is geselekteer. Daar is gebruik gemaak van 'n gegradeerde ouditiefgerigte  ondersoekprogram wat so saamgestel is dat dit wetenskaplik verantwoordbaar is. In sy geheel gesien dui die navorsingsresultate daarop dat die basiese ontwikkelingsproses van ouditiewe aandagsprosessering op hierdie ouderdom (5;2 tot 5;8 voltooi is. 'n Verdere evaluering van die resultate in terme van die uiteengesette doelstellings van die navorsingsprojek dui daarop dat kinders in hierdie ouderdomsgroep nog soms moeite ondervind om aan 'n ouditiewe sei binne omgewingslawaai aandag te skenk. Bekende seine verhoog die vermoë om aandag te skenk. Daar kon egter nie vir alle aannames wat in die literatuur gemaak word, bewys gevind word nie.

  13. J1140型压铸机增压控制油路设计特点与应用%Design Features and Application of Booster Pressure Control Circuit for J1140 Type Die-casting Machine



    According to the requirements of J1140 type die-casting machine injection system, boost pressure control circuit was designed. The problem for the change of injection process parameters due to artificial pouring amount different was solved. So the qual-ity stability of die-casting machine parts production is improved, injection force can be adjusted in a wide range, the process-range of die-casting machine is expanded.%根据J1140型压铸机压射系统的要求, 设计增压控制油路, 解决了由于人工浇筑量的不同而造成的压铸工艺参数变化的问题, 提高了压铸机生产零件质量的稳定性, 压射力可在较大范围内进行调整, 扩大了压铸机的工艺范围.

  14. Tensile Properties and Fracture Behavior of Aluminum Alloy Foam Fabricated from Die Castings without Using Blowing Agent by Friction Stir Processing Route

    Yoshihiko Hangai


    Full Text Available Al foam has been used in a wide range of applications owing to its light weight, high energy absorption and high sound insulation. One of the promising processes for fabricating Al foam involves the use of a foamable precursor. In this study, ADC12 Al foams with porosities of 67%–78% were fabricated from Al alloy die castings without using a blowing agent by the friction stir processing route. The pore structure and tensile properties of the ADC12 foams were investigated and compared with those of commercially available ALPORAS. From X-ray computed tomography (X-ray CT observations of the pore structure of ADC12 foams, it was found that they have smaller pores with a narrower distribution than those in ALPORAS. Tensile tests on the ADC12 foams indicated that as their porosity increased, the tensile strength and tensile strain decreased, with strong relation between the porosity, tensile strength, and tensile strain. ADC12 foams exhibited brittle fracture, whereas ALPORAS exhibited ductile fracture, which is due to the nature of the Al alloy used as the base material of the foams. By image-based finite element (FE analysis using X-ray CT images corresponding to the tensile tests on ADC12 foams, it was shown that the fracture path of ADC12 foams observed in tensile tests and the regions of high stress obtained from FE analysis correspond to each other. Therefore, it is considered that the fracture behavior of ADC12 foams in relation to their pore structure distribution can be investigated by image-based FE analysis.

  15. 某缸体铝合金金属型低压铸造工艺研究%Study on Low Pressure Die Casting Process of A356 Aluminum Alloy Cylinder

    王狂飞; 王凯; 王有超; 米国发


    利用ViewCast软件对低压金属型铝合金A356铸造过程进行了计算机模拟,预测了产生缩孔、缩松缺陷的位置.通过计算机模拟以及对铸件表面缺陷进行分析,提出了生产工艺方案,铸造出了满足质量要求的铸件.所铸的铸件表面质量好、无缩松等铸造缺陷.这为铝合金金属型低压铸造模具设计及工艺研究提供了有价值的参考.%The low pressure die casting process of A356 aluminum alloy was simulated by ViewCast software, and the location of the shrinkage defects was forecasted. The producing process was proposed by computer simulating and analyzing the surface defect of the aluminum alloy castings. Regular castings were produced, the surface quality was obviously improved and no defects such as shrinkage were found. It provides the valuable reference for the research of low pressure die casting process and mold design of aluminum alloy permanent mold.

  16. Die effek van intelligensie op die verhouding tussen lokus van kontrole en taakkompleksiteit

    F. G. de Kock


    Full Text Available The effect of intelligence on the relationship between locus of control and task complexity. The aim of the study was to establish the effects of intelligence on the relationship between locus of control and task complexity. These constructs were selected by virtue of their importance in the literature, as well as the lack of empirical research regarding the assumed relationship which exists between them. The Human Sciences Research Council's (HSRC General Scholastic Aptitude Test (ASAT was used for measuring intelligence, Duttweiler's Internal Control Index (ICI was used for determining locus of control and the Raven's Advanced Progressive Matrices (APM was used as a criterion for coping with task complexity. These instruments were administered to 292 subjects to determine whether the relationship between locus of control and task complexity was effected when the effect of intelligence was controlled. The results indicated a significant relationship between locus of control and task complexity, however the relationship was no longer significant after the effect of intelligence was controlled. Opsomming Die doel van die studie was om die effek van intelligensie op die verhouding tussen lokus van kontrole en taak-kompleksiteit te ondersoek. Hierdie konstrukte is gekies na aanleiding van hulle belangrikheid in die literatuur asook die leemte in empiric se navorsing rakende die veronderstelde verband wat tussen hulle bestaan. Die Algemene Skolastiese Aanlegtoets (ASAT van die Raad vir Geesteswetenskaplike Navorsing (RGN is gebruik vir die meting van intelligensie, die Internal Control Index (ICI van Duttweiler is gebruik vir die meting van lokus van kontrole en die Advanced Progressive Matrices (APM van Raven is gebruik as maatstaf vir die bantering van taakkompleksiteit. Die genoemde meetinstrumente is op 292 proefpersone toegepas om te bepaal of die verband tussen lokus van kontrole en taakkompleksiteit geaffekteer word wanneer daar vir die effek

  17. Die invloed van ‘n intensiewe opleidingsprogram op die Kardio Stres-indeks

    Tammy Claassen


    Full Text Available Mense ondervind baie stressors in hul alledaagse lewe, wat ‘n groot uitwerking het op daagliksefunksionering. Kardio Stres-indeks (KSI is ‘n nie-indringende mate van die stres wat die hartervaar. KSI (uitgedruk as ‘n persentasie berekeninge word gebaseer op die duur van die QRSkompleks, hart tempo, ritme en standaardafwyking van die RR-interval (RRSD spesifieke parameters.

  18. Task 7: Die soldering during host site testing. Final report, January1--December 31, 1997

    Goodwin, F.E. [International Lead Zinc Research Organization, Inc., Research Triangle Park, NC (United States); Walkington, W.G. [Walkington (William G.), Cottage Grove, WI (United States)


    To provide industrial confirmation of laboratory results produced in Task 6 of this project, five industrial trials were organized with cooperative die casters in the USA. Components cast during these trials ranged from functional electronic heat sinks to decorative household plumbing components. Whereas laboratory work indicated that die temperature and draft angle were the most important process factors influencing solder accumulation, it was not possible to vary draft angle on the established production dies used for these trials. Substantial variations in die temperature were realized however and also die surface conditions were varied, confirming the influence of a secondary variable in the laboratory investigation. Substantial evidence from the trials indicated that die surface temperature is the most important factor for controlling solder build up. The surface roughness of the die casting die greatly influenced the number of castings that could be run before solder initially appeared. Development of careful thermal management techniques, now judged to be beyond the capabilities of most US die casters, will be necessary to control incidences of die soldering found in typical production. Thermal control will involve both control of the bulk die temperature through use of thermally controlled cooling lines, and also regulation of surface temperature by well controlled cooling lines, and also regulation of surface temperature by well controlled die spraying (lubrication) techniques. Further research, development and technology transfer to enhance thermal control capabilities of US die casters is recommended.

  19. Implikasies van ontwikkelings in die leerstelling van goddelike genesing binne die Pinksterbeweging

    Marius Nel


    Full Text Available Die Pinksterbeweging het met verloop van tyd sy begrip van die leer van goddelike genesing verander. Die veranderings is hoofsaaklik as gevolg van vorderings wat deur die mediese wetenskap gemaak is en die pinksterteologie moes opnuut die verhouding tussen versoening en heling definieer. Die veranderings word in terme van die geskiedenis van die wit afdeling van die Apostoliese Geloof Sending van Suid-Afrika (AGS, die grootste pinksterdenominasie in Suid-Afrika, beskryf. Dit dien tot ’n groot mate as verteenwoordigend van veranderings in die res van die AGS, maar ook van die Pinksterbeweging as sodanig. Die ontleding toon dat die veranderde houding teenoor die gebruik van medisyne en inenting sowel as mediese prosedures soos operasies pinksterkerke uiteindelik dwing om toegewings in sy genesingsbediening te maak wat aan sy Skrifbeskouing verwant is. Dat die kerk veranderings aanbring in ’n belangrike leerstelling soos dié van goddelike genesing, hou belangrike implikasies vir die kerk in. Die implikasies hou verband met die wyse waarop die pinkstermense die Bybel lees en benut en dit noodsaak die Pinksterbeweging om ook oor ander leerstellings na te dink wat uitdagings daaraan stel, byvoorbeeld die eskatologie en ekklesiologie.Implications of developments in die doctrine of divine healing in die Pentecostal movement. The Pentecostal movement changed over time its understanding of the doctrine of divine healing. These changes are mainly in the attitude towards the advances made by medical science and reflected in the way pentecostal theology defined the relation between atonement and healing. The changes are described in terms of the history of the white division of the Apostolic Faith Mission of South Africa (AFM, the largest pentecostal denomination within South Africa. It serves to a large extent as representative of the changes in the AFM, but also the Pentecostal movement per se. The analysis shows that the changed attitude towards the

  20. Selection of the Optimal Cooling Parameters to the Multi-Cavity Die

    Chiaming; Yen; Jui-Cheng; Lin; Wujeng; Li


    This study is subject to the finite element and abd uc tive network method application in the multi-cavity die. In order to select the optimal cooling system parameters to minimize the warp of a die-casting die, t he Taguchi's method and the abductive network are used. These methods are appli ed to create an efficient model with functional nodes for the considered problem . Once the cooling system parameters are developed, this network can be used to predict the warp for the die-casting die accurately. A ...

  1. The development of a nanostructured, graded multilayer Cr-CrxNy-Cr1-xAlxN coating produced by pulsed closed field unbalanced magnetron sputtering (P-CFUBMS) for use in aluminum pressure die casting dies.

    Lin, Jianliang; Mishra, Brajendra; Myers, Sterling; Ried, Peter; Moore, John J


    The main objective of this research is to design an optimized 'coating system' that extends die life by minimizing premature die failure. The concept of the multilayer coating system with desired combinations of different kinds of single-layer coatings was introduced. A pulsed closed field unbalanced magnetron sputtering (P-CFUBMS) deposition system has been used to deposit Cr-CrxNy-Cr1-xAlxN compositionally graded multilayer coating structures. In this study, three power law scenarios have been adopted to vary the aluminum concentration in the graded Cr1-xAlxN layer: (i) p = 1, the aluminum concentration was increased linearly in the Cr1-xAlxN layer. (ii) p = 0.2, the Cr1-xAlxN layer is an aluminum-rich graded layer, and (iii) p = 2, the Cr1-xAlxN layer is a chromium-rich graded layer. It was found that all the graded coatings exhibit lower residual stress and higher adhesion strength than the homogeneous Cr1-xAlxN (x = 0.585) film. However, different power law grading architectures have significant influence on the hardness and wear resistance of the films. When p = 2 and p = 1, the graded films exhibited relatively low hardness values (24 and 26 GPa respectively) and high COF (0.55 to 0.60). When p = 0.2 the graded film exhibited both high hardness (34 GPa) and good wear resistance (COF = 0.45) due to the structural consistency in the graded zone. The paper discusses the correlation between the pulsing parameters and coating architecture with the resulting nanostructure and tribological properties of this Cr-CrxNy-Cr1-xAlxN coating system.

  2. Dat die klip kan heers: Pieter Fourie se Die koggelaar

    J. L. Coetser


    Full Text Available Die koggelaar (The teaser, by playwright Pieter Fourie, is generally regarded as exceptional among his recent works. The purpose of this article is to discuss the title and drought as recurring themes in the drama. The teaser is Boet Cronje, but he is of the opinion that everyone teases him. In an ironic twist of events he finally believes that God teases him by not providing the rain he so desperately needs. An investigation of the text reveals the utilization of psychoanalytical theory, i.e. the theory of the collective and the personal unconscious as formulated by Jung. In this case physical drought initiates events which lead to the development of a fully-fledged psychosis in Boet. As a consequence of the interconnection of the personal and the collective unconscious the physical drought surrounding Boet additionally becomes a dramatic metaphor for the figurative drought in the community of which he is part.

  3. Verspreiding en habitats van Unio caffer Krauss, 1848 (Bivalvia: Unionoida: Unionidae in Suid-Afrika gebaseer op die rekords in die databasis van die Nasionale Varswaterslakversameling

    K. N. de Kock


    Full Text Available Die kosmopolities-verspreide Unionoida bereik hul grootste diversiteit in Noord-Amerika. In Suid-Afrika word twee genera van die familie Unionidae, naamlik Unio en Coelatura wat vier spesies insluit, aangetref. Hierdie artikel handel oor die verspreiding en habitats van Unio caffer Krauss, 1848 gebaseer op die rekords in die Nasionale Varswaterslakversameling (NVWSV van Suid-Afrika. Alhoewel dit elders in Suid-Afrika sporadies aangetref is, is die Wes-Kaap die enigste provinsie waarvan geen monster op rekord in die databasis van die NVWSV is nie. Van die 58 monsters wat op rekord is, is die meerderheid in riviere (32.8% en damme (20.7% versamel en in watertoestande wat as standhoudend, staande, helder en vars beskryf is. ’n Temperatuur-indeks wat vir hierdie spesie bereken is, het dit vyfde in rangorde geplaas van die 12 Bivalvia-spesies wat in die databasis verteenwoordig word op grond van ’n assosiasie met lae omgewingstemperature. ’n Besluitnemingsboom-analise het aangedui dat temperatuur, substratum en waterbronne die mees betekenisvolle bydrae gelewer het tot die daarstelling van die gedokumenteerde geografiese verspreiding van U. caffer. Omdat omvattende opnames van varswater Mollusca deur staatsinstansies reeds in die tagtigerjare van die vorige eeu uitgefaseer is en die meerderheid versamelpunte sedertdien nie weer gemonster is nie, is kennis oor hul huidige stand van bewaring en spesiediversiteit gebrekkig. Negatiewe resultate by drie voormalige lokaliteite van U. caffer wat wel intussen deur die outeurs besoek is, dui egter daarop dat die voortbestaan daarvan, soos van sommige verwante spesies elders in die wêreld, bedreig word. Dit word bepleit dat opnames van varswater Mollusca met die gedokumenteerde verspreiding in die databasis van die NVWSV as riglyn, beplan en uitgevoer behoort te word. Die resultate van sulke opnames behoort ’n groot bydrae te lewer om die huidige stand van die verspreiding en spesiediversiteit van

  4. Bedryf- en organisasiesielkunde - Die grondslag van personeelbestuur

    L. D. Coetzee


    Full Text Available In a recent article in People and Profits Whyte (1978 attempts to distinguish between Industrial Psychology and Personnel Management and states that Industrial Psychology is "one specific aspect" of Personnel Management. Whether such difference exists is analysed in terms of Whyte's definition and views of Personnel Management and Industrial Psychology and recent developments in the field of Industrial and Organizational Psychology. It is concluded that differences do exist but that they are not the same as those which Whyte emphasizes. In order to promote common objectives both the similarities and differences should be recognized and close co-operation between Industrial and Organizational psychologists and Personnel Mangers should be encouraged.OpsommingIn 'n onlangse artikel in People and Profits poog Whyte (1978 om 'n onderskeid te tref tussen Bedryfsielkunde en Personeelbestuur en spreek die mening uit dat die Bedryfsielkunde 'n spesifieke aspek van Personeelbestuur is. Of daar wel so 'n onderskeid bestaan word in hierdie artikel ontleed aan die hand van Whyte se definisie en beskouinge van Personeelbestuur en Bedryfsielkunde en die resente ontwikkelinge op die terrein van die Bedryf- en Organisasiesielkunde. Daar word tot die slotsom gekom dat daar wel geringe klemverskille bestaan, maar dat dit nie dieselfde is as die wat Whyte beklemtoon nie. Ten einde die gemeenskaplike doelstellings te bevorder, moet beide die ooreenkomste en verskille erken word en moet noue samewerking tussen Bedryf- en Organisasiesielkundiges en personeelbestuurders aangemoedig word.

  5. Development and Application of Hot Rectification Technology in Al Alloy Die Castings%铝合金压铸件热矫形技术的开发与应用

    黄志垣; 万里; 张百在; 陈亮; 池晓钦; 陈毅廷; 余亮; 徐飞跃


    零件变形是压铸生产中经常遇到且难以完全消除的主要缺陷之一,矫形是减轻零件变形量的有效手段.针对压铸生产中人工矫形方法存在效率低、工作量大、工作环境恶劣的缺点,开发了一种适于铝合金压铸件的热矫形技术.结果表明,在铸件出模后立即实行热矫形并辅助于水冷,可有效降低零件的变形量,产品100%满足机加工的要求.该方法具有效率高、工人劳动强度低、环境噪音低的优点,可取代人工矫形方法.%Distortion is one kind of main defects occurred in the aluminum alloy die castings, which is difficult to fully be eliminated. Rectification is a key method to relieve the distortion of aluminum alloy die castings. A new hot rectification technology suitable for aluminum alloy die castings was developed to o-vercome the problems in low efficiency, high intensity and wicked environment in manual rectification condition. The distortion of the aluminum alloy parts can be effectively decreased by hot rectification combining with water cooling after ejection from the die, fully meeting the machining demand. The technology exhibits the advantages of high efficiency, low working intensity and low environmental noise.

  6. Die sterwende kind in hospitaalvernand

    Fredrika de Villiers


    Full Text Available Illness and death of a child is a crisis situation in the family, affecting all members. Parents experience certain universal problems such as denial, feelings of guilt and withdrawal. The dying child is usually aware of his situation and experiences fear and loneliness. He has diverse physical and psychological needs as a result of his illness which must be met by parents and nurses. In caring for the terminally ill child attention must be given to providing: a physical environment conducive to well-being; a consistent emotional climate; communication which should include therapeutic play; a therapeutic program in which various measures are taken to enhance acceptability; physical care where the child is encouraged to help himself as far as possible; psycological and spiritual care to allay his fears and anxiety.

  7. Should assisted dying be legalised?


    When an individual facing intractable pain is given an estimate of a few months to live, does hastening death become a viable and legitimate alternative for willing patients? Has the time come for physicians to do away with the traditional notion of healthcare as maintaining or improving physical and mental health, and instead accept their own limitations by facilitating death when requested? The Universities of Oxford and Cambridge held the 2013 Varsity Medical Debate on the motion “This House Would Legalise Assisted Dying”. This article summarises the key arguments developed over the course of the debate. We will explore how assisted dying can affect both the patient and doctor; the nature of consent and limits of autonomy; the effects on society; the viability of a proposed model; and, perhaps most importantly, the potential need for the practice within our current medico-legal framework. PMID:24423249

  8. Lig op Satan en Satanisme vanuit die Nuwe Testament

    F. J. van Rensburg


    Full Text Available In hierdie artikel word, in aansluiting by en as voorsetting van prof. Vosloo se "Lig op Satanisme vanuit die Ou Testament" ook in die Nuwe Testament lig op die Satan en Satanisme-verskynsel gesoek. Wat die aard van die inhoud van hierdie artikel betref, probeer ek doelbewus om die stof só aan te bied dat dit gemaklik tot die gemiddelde ernstige Bybelleser kommunikeer. Derhalwe is die aanpak nie akademies-wetenskaplik nie, maar populêr-wetenskaplik.

  9. Die Casting Semi-Solid ZL101 Alloy Prepared by Inclined Slope Cooling-Transferring Method and its Properties%ZL101过流冷却转移法半固态压铸工艺及性能研究

    李璐; 周荣锋; 岑启宏; 黎振华; 蒋业华; 周荣


    Die casting semi-solid ZL101 alloy prepared by inclined slope cooling-transferring method was conducted. Effects of processing parameters on properties of semi-solid rheoforming ZL101 alloy die castings were investigated, and the change of properties of the semi-solid die casting ZL101 parts after T6 heat treatment was analyzed. Mechanical properties of semi-solid die casting parts were comparatively analyzed with those of conventional die casting parts. The results reveal that, the semi-solid die casting parts exhibit desirable mechanical properties with pouring at 595 ℃ and injecting at 1. 8 m/s, and the elongation is increased by 11% compared with that of conventional die casting parts at 630 ℃. Tensile strength and elongation of the semi-solid die casting parts after heat treatment are greatly improved. The fracture mechanism of both conventional die casting parts and semi-solid die casting parts are characterized by quasi-cleavage fracture, while semi-solid die casting parts after heat treatment are characterized by ductile fracture.%采用倾斜管过流冷却-转移法生产半固态流变压铸件,研究了压铸工艺对ZL101铝合金半固态流变压铸件性能的影响,以及半固态压铸件经T6热处理之后性能的改变.对比研究了液态与半固态压铸件的力学性能.结果表明,在浇注温度为595℃、压射速度为1.8 m/s时,压铸件性能最佳,此时较浇注温度为630℃的液态压铸件的抗拉强度提高了11%.经热处理的半固态压铸件抗拉强度与伸长率都得到改善.液态与半固态压铸件试样的拉伸断口为准解理断裂,经热处理的半固态压铸件试样的拉伸断口为韧性断裂.

  10. Amensie en demensie met verwysing na die intellek

    P. C. W. Deppe


    Full Text Available ,,Es ist der Geist der sich den Kórper baut” het Goethe gesê en hy het daardeur die monistiese begrip in die psigiatrie beklemtoon. Dwarsdeur die eeue het die ontwikkelingsgeskiedenis van die mens maar telkens getoon hoedat daar by die mens veral, nie anders gedink kan word dan as 'n psigosomatiese eenheid nie. 

  11. MIDCAB Operationen in Wien - die ersten Erfahrungen

    Czerny M


    Full Text Available Die sogenannte MIDCAB (minimal invasive direct coronary artery bypass Operation wurde als chirurgische Therapie der koronaren Eingefäßerkrankung in letzter Zeit kontroversiell diskutiert. Ihr klinischer Stellenwert ist weiterhin unklar. Im Zeitraum von April 1996 bis Mai 1998 wurde die MIDCAB-Operation an 57 Patienten an der Abteilung für Herz-Thorax Chirurgie, Universität Wien durchgeführt. Zielgefäße für eine chirurgische Revaskularisierung waren die LAD (n = 52 und die RCA (n = 5. Als arterieller Graft dienten die linke Art. mammaria interna (LAD-Bypass bzw. die Art. gastroepiploica dextra (RCA-Bypass. Als Zugänge wurden limitierte Schnittführungen gewählt, in 91% der Fälle die anterolaterale Thorakotomie und in 9% der subxyphoidale Zugang, die Anastomosierungen erfolgten am schlagenden Herzen ohne Herzlungenmaschine. In 52 Fällen wurde die LIMA (Left internal mammary artery mit der LAD anastomosiert. Bei 3 von 52 Patienten mußte wegen einer intramyokardialen LAD zu einer konventionellen Operation gewechselt werden, in 4 Fällen war eine Revision notwendig. In allen Fällen gab es keinen Todesfall und keinen perioperativen Infarkt. Bei 36 Patienten wurde eine postoperative Kontrollangiographie durchgeführt, es ergab sich eine primäre Offenheitsrate von 96%. In 5 Fällen wurde eine Anastomose zwischen GEA und RCA hergestellt. Es gab keine Konversion, keinen Todesfall und keinen Myokardinfarkt. Drei dieser Patienten wurden postoperativ nachangiographiert, die Bypässe waren gut durchgängig. Zum derzeitigen Zeitpunkt sind alle 57 Patienten klinisch symptomfrei. Nach Überwindung von anfänglichen technischen Schwierigkeiten sind die Ergebnisse mit der MIDCAB-Operation sehr gut. Als potentielles Patientenkollektiv für die Zukunft scheinen sich vor allem Patienten nach multiplen kardiologischen Interventionen an der LAD bzw. der RCA anzubieten.

  12. Hemofilie onder die nasate van koningin Victoria

    Francois P. Retief


    Full Text Available Hierdie studie bespreek die uitwerking van die sogenaamde Victoriaanse hemofilie op Europese koningshuise gedurende die negentiende en twintigste eeu. Hemofilie as molekulêre defek word verduidelik en die kliniese beeld van die siekte word aangedui. ’n Bespreking van toepaslike terapeutiese ingrepe volg. Dan word ’n historiese oorsig verskaf van die verspreiding van Victoriaanse hemofilie vanaf koningin Victoria (Britse monarg, 1837–1901 via sommige van haar dogters na ander lede van die Britse koningshuis en ook na die Duitse, Russiese en Spaanse koningshuise. Elf bevestigde gevalle van hemofilie onder lede van koningin Victoria se nageslag word vermeld, asook drie ander moontlike gevalle van die siekte. Die effek van hemofilie op die verloop van die geskiedenis word ook ondersoek.Haemophilia amongst the descendants of Queen Victoria. This study discusses the impact of ‘Victorian haemophilia’ on the royal houses of Europe during the 19th and 20th centuries. Haemophilia as a molecular defect is explained and the clinical picture of the condition is indicated. Applicable therapeutic interventions also receive attention. Next, an historical review is provided of how ‘Victorian haemophilia’ spread from Queen Victoria (British monarch, 1837–1901 via some of her daughters to other members of the British royal family and also to the royal houses of Germany, Russia and Spain. Eleven confirmed cases of haemophilia amongst the descendants of Queen Victoria are mentioned, as well as three other possible cases. The effect of haemophilia on the course of history is also investigated.


    李帅君; 熊守美; Mei Li; John Allison


    通过对压铸充型过程中卷气缺陷形成机理的分析,认为型腔中空气的流动以及与金属液之间的相互作用是形成卷气现象的主要原因.为了考虑型腔中空气的流动,采用了一种不可压缩两相流数学模型来模拟压铸充型过程的卷气现象.通过计算流体力学中的两个基准算例,较为全面地验证了该模型的准确性和可靠性.在此基础上,设计了专门针对压铸充型过程的高速水模拟实验,通过对可视化实验结果与两相流模拟结果的比较,证实二者吻合较好,说明了该模型能够较好地模拟液体的充填行为和卷入其中的气泡.%The most common defect found in high pressure die casting (HPDC) process is the gas porosity which significantly affects the mechanical properties of the final components. The generation of gas porosity is known mainly due to the air entrapment in the liquid metal during the mold filling stage. Knowing the trapped-air location and amount could allow for a more accurate and objective analysis of casting quality. In the past few decades, extensive efforts have been made to develop simulation codes of casting flow. Most of these codes solve the velocity, pressure and fluid fraction only in the liquid phase with the assumption that the effect of air in the die cavity is negligible. As a matter of fact, the air in the die cavity has significant influence on the filling pattern of the molten metal and the gas porosity distribution of the die casts. Recently, following the development of computational fluid dynamics (CFD), two-phase flow models have drawn continuous attention in the numerical simulation of casting processes, but there are still few models and further studies are needed. In this study, the mechanism of the formation of air entrapment defects in the HPDC process was discussed and it turned out that the air flow in the die cavity as well as the interaction between air and liquid metal resulted in the final air

  14. Anfangen, sich die Welt anders vorzustellen

    Sabine Fuchs


    Full Text Available Der Sammelband Butler Matters bezeugt Judith Butlers außerordentliche Bedeutung für feministische und queere Studien und Forschung. In elf Beiträgen wird Butlers (frühes Werk von Gender Trouble und Bodies That Matter über Excitable Speech bis zu The Psychic Life of Power betrachtet und sein weit reichender Einfluss quer durch die wissenschaftlichen Disziplinen nachgewiesen. Dargestellt werden auch die kontroverse Rezeption von Butlers Werk sowie die politischen Wirkungen von Butlers Denken. Besonders anregend ist ein zweiteiliges Interview mit Judith Butler, in dem sie auf ein breites Spektrum von Fragen eingeht, die auch wichtige Themen ihrer aktuelleren Werke betreffen.

  15. Die Osteonekrose des Hüftgelenks

    Meizer R


    Full Text Available Die Osteonekrose des Hüftgelenkes entsteht durch eine Ischämie des Hüftkopfes. Diese kann traumatisch bedingt sein oder durch Risikofaktoren wie Kortikosteroide, Alkohol, Blutgerinnungsstörungen, Schwangerschaft sowie entzündliche und systemische Erkrankungen begünstigt werden. Als Sonderform der avaskulären Nekrose wird das Knochenmarködemsyndrom diskutiert. In der Diagnostik hat sich die Magnetresonanztomographie insbesondere wegen der Erfassung des reversiblen Frühstadiums zur Methode der Wahl entwickelt. Die Stadieneinteilung der ARCO unterscheidet zwischen Initialstadium (Stadium 0, reversiblem und irreversiblem Frühstadium (1 und 2, Übergangsstadium (3 und Spätstadium (4. Der Erfolg der verschiedenen Behandlungsmöglichkeiten hängt sehr vom Stadium bei Diagnosestellung ab. Im Frühstadium sowie beim Knochenmarködemsyndrom hat sich die Therapie mit dem Prostazyklinanalogon Iloprost bewährt und die Behandlung durch Hüftkopfbohrung in den Hintergrund gedrängt. Erfolgversprechend sind weiters die Therapien mit Enoxaparin und Bisphosphonaten. In fortgeschrittenen Stadien sind Umstellungsosteotomien und die Verwendung von Knochentransplantaten möglich. Bei großen Läsionen im Spätstadium ist die Hüftendoprothetik die Therapie der Wahl.

  16. Goethe und die Kindsmörderin

    Ursula Künning


    Full Text Available Am 28. November 1783 wurde in Weimar die vierundzwanzigjährige Dienstmagd Johanna Catharina Höhn wegen der Tötung ihres neugeborenen Kindes hingerichtet. Maßgeblich beteiligt am Todesurteil war Johann Wolfgang von Goethe als Mitglied des Beratungsgremiums des Herzogs von Weimar Carl Gustav. Äußerst kritisch beurteilt Rüdiger Scholz in seinem Text die Goetherezeption, die bis in die Gegenwart hinein den Schriftsteller idealisiert und Rechtfertigungen für seine Mitwirkung am Schicksal der Johanna Catharina Höhn sucht.

  17. Die religieuse grondslag van ons omgewingskrisis

    M.L. Hugo


    Full Text Available Die mensdom is besig om sy habitat op so ’n wyse te misbruik en te besoedel dat sy toekoms op hierdie planet duister is. In die woorde van White “.. surely no creature other than man has ever managed to foul its nest in such short order”. Hierdie stelling is nie oordrewe nie soos blyk uit die vloedgolf van literatuur wat tans verskyn oor hierdie kwessie. Miskien die sprekendste titel onder hierdie bronne wat onlangs verskyn het, is dié onder redaksie van Anderson: “OMEGA: Murder of the Ecosystem and Suicide of Man.”

  18. Die samestelling en evaluering van 'n groepfasiliteringskursus

    S. Rothmann


    Full Text Available The development and evaluation of a group facilitation course. The personality profile of a group facilitator is conceptualised as consisting of group knowledge and skills, interpersonal effectiveness, and personality traits. A group facilitation course directed at the stimulation of this profile was developed. The course improved the skills of praticipants to respond to process issues in a group, as well as their knowledge of group facilitation. Their empathy, respect, genuineness and concreteness improved significantly. Although changes in spontaneity, time competence and existentiality were found after completing the course, these changes cannot be ascribed to the course. Organisational factors may impede the development of the personality traits of the group facilitator. Opsomming Die persoonlikheidsprofiel van die groepfasiliteerder word gekonseptualiseer as groepkennis en -vaardighede, interpersoonike effektiwiteit, en persoonlikheidskenmerke. 'n Groepfasiliteringskursus gerig op die stimulering van hierdie profiel is ontwikkel. Die kursus het daartoe bygedra om deelnemers se vaardigheid om op prosesaangeleenthede in 'n groep te reageer, asook om hul kennis van groepfasilitering te verbeter. Deelnemers se empatie, respek, egtheid en konkreetheid het beduidend toegeneem. Alhoewel veranderinge ten opsigte van spontaneïteit, tydsbewustheid en eksistensialiteit gevind is, kan hierdie veranderinge nie aan die kursus toegeskryf word nie. Organisasiefaktore kan struikelblokke wees in die weg van die ontwikkeling van die persoonliheidskenmerke van die groepfasiliteerder.


    G.E. Visser


    part of the debate. Also in dispute, was the location of the Academy at Saldanha, rather than in the military heart-land in Pretoria. By interpreting the academic training needs of the Defence Force correctly and positioning itself accordingly, the Academy survived that crisis. Thereafter, the Academy time and again adapted to the changing military and socio-political environment and strove towards ever increasing relevance to the Defence Force. In this way female and non-European students were admitted to the Military Academy, whilst the way was also paved for the admittance of students from other African states. In anticipation of the new political dispensation in South Africa, a concerted effort was launched in 1990 to make the student body more representative of the South Africa population in terms of race and sex. The Military Academy has through the years established itself as a credible military academic institution and has made a significant contribution towards military professionalism in South Africa. By 1990 it favourably positioned itself to continue that role in future. Though forming only a small percentage of the total officer corps, the Academy graduates have gradually been distributed at all levels of the' officer corps and have dominated the top posts in the SA Defence Force since the early 1970's. They were consequently well placed in 1990 to play a significant role in preparing the Defence Force for the so-called "New South Africa". ****** AFRIKAANSE OPSOMMING: Die Suid-Afrikaanse Militêre Akademie is op 1 April 1950 gestig met die doel om die militêrakademiese opleiding van kandidaatoffisiere hier te lande op dieselfde peil as in die buiteland te bring en dit terselfdertyd tot universiteitsvlak te verhef. Die Minister van Verdediging, F.C. Erasmus, wou egter ook die Akademie gebruik as instrument om die Afrikaner sy regmatige plek, naas Engelssprekendes, in die offisierskorps te laat inneem en sodoende die oorwegend Britse karakter van die

  20. Ideologiese normverplasings en die Afrikaanse handwoordeboek van die negentigerjare

    A. Carstens


    Full Text Available Ideological norm replacement and the Afrikaans desk dictionary of the ninetiesIn South Africa the past decade has been marked by extensive sociopolitical changes and by concomitant linguistic changes. These changes may be regarded as instances of norm replacement - a process during the course of which a norm or a set of norms is gradually replaced by another norm or set of norms. It is maintained that the standard synchronic dictionaries of a language not only have the obligation to reflect lexicalised norm replacements, but also to make projections with regard to future use. Two standard synchronic desk dictionaries of Afrikaans, namely the eighth edition of Verklarende Afrikaanse Woordeboek (1992 and the third edition of Verklarende Handwoordeboek van die Afrikaanse Taal (1994 are explored with special regard to their reflection of norm replacements within the domains of race and political ideology. It is shown that the compilers of these dictionaries consciously and sincerely aimed at removing all racial bias but that they failed to record the diversity of meaning within the political lexicon and the semantic shifts which have occurred within that lexicon during the past decade.

  1. Verskyningsvorme van die Simbolisme in die ouer Afrikaanse vertelkuns

    H. Roos


    Full Text Available As the Symbolist movement has primarily been linked to the poetic mode, the association of symbolism with prose writing, and particularly with traditional Afrikaans prose, raises many questions, From the writings of older critics it appears that whereas they did identify symbolic patterns in the work of contemporaries, the presence of a specific Symbolist influence is either not recognized at all, or played down and evaluated negatively. However, several of the early authors themselves, e.g. Leipoldt, Grosskopf and Marais, referred to, or admitted to being influenced by the great 19th-century Symbolist poets. The most marked example of Symbolist writing is evident in the short stories of Marais (“Die Reënbul” and Van Melle (Denker kom kyk. In all the cases where the symbolist influence can be traced, several common characteristics are evident: the authors remained outside the mainstream of traditional Afrikaans prose writing, the lyrical tone and a decadent mood dominate, and in these early works signs of the innovative “Sestiger” prose are already evident.

  2. Comment on the reported fiber attenuations in the visible regime in "Fabrication of glass photonic crystal fibers with a die-cast process".

    Feng, Xian; Loh, Wei H; Richardson, David J


    We comment on the recent paper by Zhou et al. [Appl. Opt.45, 4433 (2006)APOPAI0003-693510.1364/AO.45.004433], in which transmission losses of 0.2-0.3 dB/m were claimed across the wavelength range 420-900 nm in a high-index (n(d)=1.80518 at 587.6 nm) SF6 glass-based photonic crystal fiber fabricated by novel die-cast technique. If confirmed, these losses are at least 1 order of magnitude lower than previous reported losses of SF6 photonic crystal fibers from other fabrication approaches. Here we present a statistic survey on the relationship between the refractive index and the bulk material attenuation, based on a large number of commercial Schott optical glasses with the n(d) ranging between 1.40 and 2.05. It shows that the loss of a high-index (n(d)=1.80) glass optical fiber should be at the levels of 10-50 dB/m at 420 nm and 1-10 dB/m at 500 nm, respectively. Moreover, the material attenuation of such a high-index glass fiber should intrinsically show a large decay, from 10-50 dB/m at 420 nm to the level of 1 dB/m at 700 nm, which arises from the tail on the UV absorption edge of the high-index glass extending to the visible region. Therefore, we conclude that: (1) the low loss of 0.2-0.3 dB/m reported in the cited paper is abnormally one or two magnitudes lower than the material attenuation that a high-index (n(d)=1.80) glass optical fiber should have in the range between 420 and 500 nm and that (2) the flat loss curve between 420 and 700 nm in the cited paper deviates greatly from the intrinsic behavior of a high-index (n(d)=1.80) glass fiber.

  3. Handelinge in die erediens: Die verryking van die liturgie deur musiek

    Elsabé Kloppers


    Full Text Available Actions in the worship service: Enriching liturgy through musicThe worship service in the Reformed Churches in South Africa has of late come under pressure. On the one hand it is experienced as too rigid and “traditional”. On the other hand superficial forms of renewal create tension. In this article the worship service and the meaning of the liturgical actions in the worship service of the Afrikaans Reformed Churches are discussed, and related to world-wide ecumenical tendencies. It is argued that certain liturgical actions are a necessary part of the ritual of the worship service. The structure needs inner logic, although there should also be some degree of flexibility. Hymns and music offer the means for a more creative presentation of liturgical actions and traditional forms. Suggestions to enrich the liturgy through the use of hymns and liturgical forms in the Liedboek van die Kerk (2001 are offered.

  4. Cumulated energy consumption - fabrication of cast iron pieces. Vol. 1: Methods of evaluation and analysis of foundries. Vol. 2: Energy consumption of metal cutting processes. Vol. 3: Development of a model for material and energy consumption analysis in casting processes. Final report; Kumulierter Energieaufwand - Gussteilfertigung. Bd. 1. Teilthema: Methodik der Auswertung und Analyse von Giessereien. Bd. 2. Teilthema: Energieaufwand in der spanabhebenden Teilefertigung. Bd. 3. Teilthema: Entwicklung eines Modells zur Stoff- und Energiemengenanalyse fuer die Herstellung von Gussteilen. Abschlussbericht

    Ketscher, N.; Herfurth, K.; Kademann, R.; Wohlgemuth, H.; Huppertz, A.


    Development of materials, energy and carbon dioxide balances, acquisition and recording of data on casting and metal cutting processes, with selected examples of the 9 participating partners of the casting industry. [German] Erarbeitung von Stoff-, Energie- und CO{sub 2}-Bilanzen, Erfassung und Ermittlung von Daten fuer die Formgebung durch Giessen und die spangebende Bearbeitung an ausgewaehlten Beispielen der 9 beteiligten Firmen der Giessereiindustrie. (orig.)

  5. ‘n Vergelykende histomorfologiese assessering van die testis van twee Clarias spesies van die Okavango Delta, Botswana

    M.L. Mokae


    Full Text Available Die testis van twee Clarias species wat in die Okavango Delta voorkom, is histomorfologiesgeassesseer om die verskil in struktuur te beskryf, omdat die twee spesies se testiskleur verskilmet die Clarias ngamensis ‘n swart testis en die Clarias gariepinus ‘n roomkleurige testis.

  6. Kontekstuele bepalers by die beplanning van skoolwoordeboeke

    Herman L. Beyer


    Full Text Available

    OPSOMMING: Die doel van hierdie artikel is om tot die metaleksikografiese gesprek oor skoolwoordeboeke as 'n tipe pedagogiese woordeboek by te dra. Die fokus is op kontekstuele bepalers wat by die beplanning van skoolwoordeboeke verreken behoort te word: Binne die konteks van 'n veeltalige Namibië word enkele onderwyskundige sisteme verken wat 'n impak op die ontwerp van gedrukte skoolwoordeboeke vir die sekondêre skoolfase kan hê, naamlik skoolkurrikula, die nasionale taalbeleid vir skole en die beleid van leerdergerigte onderwys. Hierdie artikel voer ook aan dat die voor die hand liggende teikengebruiker van 'n skoolwoordeboek, naamlik die leerder, nie die enigste teikengebruiker is nie: Die onderwyser word as medeteikengebruiker gestel wanneer dit by die gebruik van woordeboeke in die onderrigleersituasie kom. Verskillende tipes gevalle van woordeboekgebruik in die mikrokonteks van die onderrigleersituasie word onderskei, naamlik woordeboekonderrig, woordeboekgeïntegreerde taalonderrig en woordeboekgeondersteunde taalonderrig. Hierdie tipes gebruik behoort komponente van 'n woordeboekpedagogie te wees, wat uiteindelik behoort te lei tot outonome woordeboekgebruik en die gepaardgaande vestiging van 'n individuele woordeboekkultuur by die leerder. Die leksikograaf moet al hierdie aspekte inreken wanneer 'n skoolwoordeboek beplan word ten einde die nodige leksikografiese vernuwing in te voer. Enkele voorstelle vir sodanige vernuwings en vir verdere navorsing word ten slotte aangebied.


    ABSTRACT: Contextual Determiners in the Planning of School

  7. Die Casting Technology of Hypereutectic Al-Si Alloy Clutch Gear with High Strength and Wear Resistance%高强耐磨过共晶铝合金离合器齿轮的压铸技术

    万里; 杨剑霞; 刘后尧; 吴湛方; 陈国强; 赖沛基


    Aiming at die casting thick-walled ADC automobile clutch gear, P-Cu modification on hypereu-tectic Al-Si alloy suitable for die casting was conducted. Die casting scheme for clutch gear was designed and simulated, meanwhile, vacuum die casting and local pressurization technology were developed. The results show that with 0. 1 % P addition, ADC14 exhibits good modification effects with 6 h modification time, where primary Si phase in the alloy reaches 20~40 μm with uniform distribution, and the depth of Si particle depletion zone on surface of the castings is in the range of 0. 18~0. 20 mm. At given injecting parameters, the mechanical vacuum valve is superior to zig-zag valve in vacuum effects, and the rejected rate with gas hole is decreased by 10%. Shrinkage porosity (hole) at thick-wall of the gear can be effectively eliminated by optimized local pressurization, the quality of the gear is improved, and qualification rate of mass-production is more than 95%.%针对压铸成形的ADCl4汽车离合器齿轮厚壁部件,研究了适于压铸的过共晶Al-Si合金的P-Cu变质处理工艺.设计并模拟了齿轮的压铸工艺方案,开发了真空压铸及局部加压技术.结果表明,当P的加入量为0.1%时,ADC14的变质效果好,变质时间可达6h.铸件中初生Si尺寸为20~40 μm,分布均匀;铸件表面的Si贫乏区深度在0.18~0.20 mm范围内.在相同压射参数下,采用机械式真空阀比搓衣板式排气阀的真空效果好,铸件的气孔缺陷废品率下降10%以上.优化后的局部加压技术消除了厚壁部位的缩松缺陷,提高了铸件内部质量.批量生产合格率达95%以上.

  8. Vokaalverplasing in die Afrikaans van die Griekwas van Griekwaland-Wes

    P. J.P. Henning


    Full Text Available Afrikaans is die totaal van al sy dialekte — Griekwa-afrikaans en Standaardafrikaans is maar twee voorbeelde daarvan. Chambers (1980:3 sê baie duidelik: “… a language is a collection of mutually intelligible dialects” . Hierdie definisie het die voordeel dat dit dialekte kan karakteriseer as subslandaarvorme van ’n taal en dit kan ook weer die kriterium wees om deur middel van vergelyking die variasies op te spoor.

  9. Die Motions of New Forging Process Using IntermediateDie Assembly


    The die motions of a new forging process for automation with an intermediate die assembly called hamburger were analyzed through high-speed video pictures. The results showed that the upper die that is assembled in the hamburger and retained over the lower die collides few times with the ram and workpiece, but sound products can be obtained with less sticking in spite of the lowered impacts of hit.

  10. Goethe almost died of urosepsis.

    Gross, A J; Hummel, G


    In the year of 1805, Goethe almost died of urosepsis. His urological problems were not diseases arising from full health but a new variation in a life accompanied by illnesses. Some sources date the first colics he experienced to the year 1795 and others say 1805. The most dramatic period in the course of his illness was in February, when he suffered from fever of such an extent that one could speak of urosepsis. Recovery took place slowly and was accompanied by minor relapses. Nothing about this is written down in his work. On the advice of his doctors, Goethe undertook a cure in Lauchstädt in July and August. The report of his consultant, Professor Johann Christian Reil, on his problems in the field of urology remained undiscovered until 1937. Professor Reil recommended treatment with thermae carolinae, aqua calcis, soap soda crystallisata, herbae subastringentes, and uva ursi, among other measures. With increasing age, Goethe's colics disappeared. The passing of a stone has never been described. Whereas Goethe hinted about medical problem other than those reported herein, the urological problems discussed in this article were left unmentioned. Nonetheless, literature that deals with Goethe's diseases is interesting from the aspect of both the history of medicine and the history of culture.

  11. Bylaag 3 tot „Koer&’’, April en Junie, 1955: Die belang van toegepaste geologie en die werk van die geoloog in ons mineral afhanklike besawing

    P. B. Ackermann


    Full Text Available Die toekomstigc ontwikkeling, welvaart en sekuriteit van ons land en die handhawing en verbetering van ons huidige lewenstandaard hang tot’n groot mate af van die doeltreffendste gebruik van ons oorvloedige mineraalhulpbronne, maar beperkte watervoorrade.

  12. Metateoretiese vertrekpunte ten opsigte van wetenskaplike navorsing in die Liturgiek

    Barend J. de Klerk


    Full Text Available Om die nuwe ontwikkelings in die Liturgiek grondig te kan beoordeel, moet na die metateoretiese onderbou van die verskillende standpunte gekyk word. Wanneer ’n navorser op die terrein van die Liturgiek nie hierdie wendings in sy metateoretiese vertrekpunte verreken nie, kan sodanige navorser of meegesleur word deur hierdie denkrigtings, of aan die ander kant, impulsief reaksionêr ’n onwetenskaplike oordeel daaroor uitspreek. Die navorsingsartikel het daarom ten doel om die eie reformatoriese metateoretiese vertrekpunte ten opsigte van die Liturgiek te probeer formuleer en om vas te stel wat die invloed daarvan is in die konteks van wendings in die denkklimaat asook die leefwêreld en kultuur waarin die wetenskaplike taak uitgevoer word. Hierdie navorsingsartikel het verder ten doel om ’n voorbeeld daar te stel hoe hierdie metateoretiese beskouing ’n navorsingsprojek kan stuur. Die wyse waarop God in die doop werksaam is en die effek daarvan op vergifnis en versoening in die Suid-Afrikaanse konteks, is die voorbeeld van hoe ’n navorsingsprojek in die wetenskap van die Liturgiek aangepak kan word.

  13. Die Gattung Stenothoe (Crustacea, Amphipoda) im Mittelmeer

    Krapp-Schickel, Gertraud


    Ausgangssituation dieser Untersuchung war die Kenntnis von 11 nominellen Stenothoe-Arten im Mittelmeer. Von diesen wurde St. bosphorana Sowinski, 1898, seit der Beschreibung nicht mehr wiedergefunden, von St. dactylipotens Chevreux, 1908, kannte man nur das ♀, schließlich waren die Arten im Komplex

  14. Student Nurses' Perception of Death and Dying

    Niederriter, Joan E.


    Student nurses are involved in caring for patients who are actively dying or who have been told they have a terminal illness and are faced with the process of dying. Students encounter these patients in hospitals, nursing homes, at home or in hospice care settings. According to Robinson (2004), "nurses are the healthcare providers that are most…

  15. Killing and letting die: a defensible distinction.

    Cartwright, W


    The distinction between killing and letting die is investigated and clarified. It is then argued that in most cases, though not in all, it is worse to kill than to let die. In euthanasia the significance of the distinction is diminished, but still important.

  16. Puzzling cases about killing and letting die.

    Favor, C D


    Discussions of euthanasia often appeal to the distinction between killing people and letting them die. Favor asks whether this distinction is morally important--in particular, whether killing is worse than merely letting someone die, even when the motivations and consequences are the same. She explores our moral intuitions via a discussion of various subtly different hypothetical examples.


    31 Okt 1977 ... totstandkoming van die mediese diens is aan It- kol M,C, Roland ... mediese hulp aan verskeie regi- mente op die Rand te gee, Lt-kol D,W, Johnston. 38 .... lent work you have done with us, all of it con- structive and under the ...

  18. Abraham Kuyper en volksideologie onder die Afrikaners

    K. Smit


    Full Text Available Om die waarheid te sê, Kuyper is lank nie meer gewild in Gereformeerde geledere in Suid-Afrika nie. Deels moet dit gewyt word aan die assosiasie van apartheidsideologie met Kuyper se idee van skeppingsordeninge (’n idee wat ook verbind kan word met Hitler se regverdiging van sy uitwissingsoperasies.

  19. Die Königlich Zoologische Gesellschaft „Natura Artis Magistra” und die Tierpsychologie

    Bierens de Haan, J.A.


    Die Königlich Zoologische Gesellschaft „Natura Artis Magistra”, deren Hundertjahrfeier wir diesen Sommer feiern, hat sich von Anfang an die Aufgabe gestellt, mehr als die Eigentümerin eines Gartens zu sein, in welchem mehr oder weniger seltene und kuriose Tiere für das Publikum zur Schau gestellt si

  20. Die vraag na ’n nuwe belydenis, met besondere verwysing na die ‘Proeve’

    P. J. Coetzee


    Full Text Available Uit Matt. 16:16–18 blyk dat daar ’n allernouste verband deur Christus gelê is tussen kerk en belydenis. Die belydenis staan ook in onmiddellike verband met die bediening van die sleutelmag (vgl. vr. 84 H. Kateg..

  1. Die Kasteel "De Goede Hoop" (1921-1923 : Die verhaal van 'n reddingsdaad.

    Jan Ploeger


    Full Text Available Die Kasteel De Goede Hoop is ongetwyfeld die belangrikste historiese monument waaroor OIlS vandag beskik. Nie aileen was dit gedurende die Nederlandse en Britse koloniale tydperke in ons geskiedenis belangrik as 'n setelplaas vir siviele en militêre bestuur nie, maar ook is dieselfde vyfhoekige militêre bouwerk, militêrhistories beskou, besonder waardevol.

  2. Die koste van vrywillige, beheerbare arbeidomset

    G. Roodt


    Full Text Available The cost of voluntary, controllable labour turnover. Labour turnover for individuals can be classified as voluntary or non-voluntary, whereas labour turnover in organisations can be categorised as controllable or non-controllable. Data on total labour turnover in a particular service organisation indicated the existence of a possible problem. Voluntary, controllable labour turnover between 1 January 1988 and 31 March 1991 for technicians only within this particular organisation was closely scrutinised by calculating the direct recruitment, training, and separation costs for this period. The replacement costs of the technical population alone (N = 1594 for the last-mentioned period were approximately R94 million and could possibly increase to as high as R470 million if the hidden costs are also considered. If these costs are projected to the period 1980-1991 in which there were 60284 voluntary leavers, the total labour turnover costs for this organisation could be astronomical. It is clear from the above that preventative strategies by management could reduce the negative consequences of labour turnover and improve the prospects of a positive outcome. Opsomming Arbeidomset kan vir individue as vrywillig of nie-vrywillig geklassifiseer word; daarenteen kan arbeidomset vir organisasies as beheerbaar of nie-beheerbaar gekategoriseer word. Gegewens oor totale arbeidomset in "n bepaalde diensorganisasie het op die bestaan van 'n moontlike probleem gewys. Die koste van vrywillige, beheerbare arbeidomset van slegs tegnici is vir die periode 1 Januarie 1988 tot 31 Maart 1991 in die betrokke organisasie nader ondersoek, deur die direkte verkrygings-, opieidings- en skeidingskoste van tegniciverlaters vir hierdie tydperk te bereken. Die vervangingskoste van slegs die tegnicipopulasie (N = 1594 vir die laasgenoemde tydperk het sowat R94 miljoen beloop en kon selfs so hoog soos R470 miljoen wees as die verskuilde kostes ook verreken is. Indien hierdie kostes

  3. Etiese perspektiewe op haatspraak in die lig van die derde gebod

    Jakobus M. (Koos Vorster


    Full Text Available Hierdie artikel fokus op die implikasies van die derde gebod met betrekking tot haatspraak in Suid-Afrika (SA vandag. Die artikel gaan uit van die standpunt dat die name van God op sy wese dui. Die name van God soos dit in die bybelse openbaringsgeskiedenis ontwikkel word, druk die gemeenskapskarakter van God se verhouding met mense en die skepping uit. Die betekenis van die name kulmineer in die Nuwe-Testamentiese uitdrukkings Vader en God is liefde. Alle verbale gedrag wat hierdie gemeenskaps- en liefdesverhouding inhibeer, oortree die derde gebod. Die misbruik van die Naam van God vind onder andere plaas wanneer mense, wat na die beeld van God geskep is, gedegradeer word deur haatspraak, omdat sodanige degradering die gemeenskap en liefde tussen God en die mens skend. Ten slotte word sekere gevalle van haatspraak soos dit vandag in Suid-Afrika voorkom, teologies-eties belig teen die agtergrond van die betekenis van die derde gebod. Hierdie vorms sluit religieuse, rassistiese, xenofobiese, seksistiese en homofobiese haatspraak in.This article focuses on the implications of the third commandment for hate speech in modern-day South Africa. The article contends that the names of God are expressions of his Being. The names of God as they are developed in the biblical history of revelation express his creation of covenantal community and restored relations with humankind and creation. The meaning of the names of God culminates in the New Testament expressions Father and God is love. Verbal actions that inhibit the new community created by God or violate love transgress the third commandment. Misuse of the name of God occurs among others when people, created in the image of God, are verbally degraded by hate speech because such degradation violates the community of love between God and humankind. In conclusion, the article indicates forms of hate speech in South Africa that should be dealt with in the light of the third commandment. These are acts

  4. Die funksionaliteit van die martelaarsverhale in Victor van Vita se Historia Persecutionis (HP

    Nico P. Swartz


    Full Text Available Victor van Vita het geglo dat die Vandale se vervolging van die Christene in Noord-Afrika (429–489 n.C. ’n straf van God was. Die Christene in Noord-Afrika was volgens hom immoreel en het losbandige lewens gelei. Lyding of marteling is hiervolgens ’n natuurlike resultaat van die mens se sonde. Victor verklaar in Pauliniese konteks dat die sondige liggaam deur middel van marteling vernietig word en dat die mens nie meer slaaf van die sonde sal wees nie. Victor wil dus die persepsie by die leser tuisbring dat marteling ’n goddelike en verlossende kwaliteit behels. Die uitbeelding van die martelaars se leefwyse moet die leser aanspoor om hulle dade na te streef. Hieromtrent bied die martelaarverhale ’n vierledige funksie vir die handhawing van morele waardes in die burgerlike samelewing. Dié funksies vergestalt die etiese, eksemplariese, filosofiese en aansporende dimensies van die martelaarsverhale in die Historia Persecutionis. Op grond hiervan is die martelaarsverhale in die Historia Persecutionis nie net as ’n literêre werk nie, maar dra dit ook by tot onderrig in die sedeleer.The functionality of the martyrs’ accounts in Victor of Vita’s Historia Persecutionis (HP. Victor of Vita believed that the Vandal persecution of the Christians in North Africa (429–489 AD was a visitation of God to punish them for their immoral and dissolute life. In this context, suffering and torture are the logical results of profligacy which Victor explains in Paulinian terms as a means of destroying the human body and thus releasing mankind from bondage to sin. Victor therefore advances arguments to convince the reader that torture contains both divine and redeeming qualities. The life of the martyr is portrayed as an encouragement so that the reader may emulate this conduct. The martyr narratives provide four measures for the preservation of moral values in civil society. They embody the ethical, exemplary, philosophical and stimulant dimensions

  5. Killing, letting die, and simple conflicts.

    Malm, H M


    Proponents of the moral equivalence of killing and letting die argue that in cases of simple conflict, where one agent must either perform a positive act and kill one person, or not perform that act and allow another person to die, the agent's alternatives are clearly morally equivalent. Malm rejects this view in a three part essay. He argues that in cases of simple conflict, the acts of killing and letting die are morally different, and that killing is not in itself worse than letting die. Malm considers and rejects the suggestion that the agent should decide randomly between the two alternatives. He concludes that while simple conflict cases require us to recognize a morally significant difference between killing and letting die, they do not require us to recognize a morally significant difference between acting and refraining.

  6. Research on Forging Die Design Ontology

    ZHANG Wenlei; FAN Yushun


    Forging die design is heavily dependent on engineers' experiences. But traditional AI technologies can barely provide a standard knowledge representation style for knowledge transferring. This paper introduces ontology into forging die design. 3-layer forging die design ontology is built, which includes Meta-ontology, Domain-ontology and Bottom ontology. Further, by conceptualization, the concepts and their relations are formally addressed by primitives such as Term, Relation and Function etc, which are explicitly expressed by concept tree. Bottom ontology uses Knowledge Item and Prototype to represent and capture general knowledge for knowledge reuse and share. Forging die design ontology building approach is discussed for standard knowledge representation, knowledge mine and knowledge driven CAD design etc. And OWL language is employed for integration among different domain ontologies integration. Finally a locomotive forging die KBE system is presented to demonstrate this approach.

  7. Moyamoya disease; Die Moyamoya-Erkrankung

    Papanagiotou, P.; Grunwald, I.Q.; Politi, M.; Roth, C.; Reith, W. [Universitaetsklinikum des Saarlandes Homburg/Saar (Germany). Klinik fuer Diagnostische und Interventionelle Neuroradiologie


    Moyamoya disease is an idiopathic progressive vasculopathy characterized by slowly progressive narrowing involving the distal internal carotid artery and the proximal circle of Willis. Collateral vessels develop to compensate for the slowly progressive stenosis. These enlarged collaterals appear as a ''puff of smoke'' on angiography, which gives the disease its name. This review discusses the clinical manifestation, imaging findings, and angiographic features. (orig.) [German] Die Moyamoya-Erkrankung ist eine idiopathische progressive Vaskulopathie, die durch eine langsam progrediente Stenosierung der distalen A. carotis interna und der proximalen Arterien des Circulus arteriosus Wilisii charakterisiert wird. Kollaterale Gefaesse hypertrophieren, um die progressive Stenosierung auszugleichen. In der Angiographie zeigen diese Kollateralen ein ''nebelartiges'' Erscheinungsbild, was der Erkrankung ihren Namen gab. In diesem Review werden das klinische Bild, die Bildgebung sowie die angiographischen Eigenschaften der Erkrankung diskutiert. (orig.)

  8. Die Krakauer Kirche von Karmeliten und Karmelitaninnen

    Józef Szymon Wronski


    Full Text Available 1. Die Klosterkirche der unbeschuhten Karmelitinnen Zum Heiligen Josef. Ein glücklicher Auftakt und somit die charakteristische Einführung in das 20. Jh. für den Kirchenbau von Krakau war die Errichtung der Karmeliterinnen St. Josephs-Kirche an der Lobzowska-Straße 40, in der die Architekten (Tadeusz Stryjeński (1849-1943 - Projektant der Kirche und Franciszek Mączyński (1874-1947 - Ausführer des Bauprojektes mit eigenen Verbesserungen die historisch- eklektizistischen Formen d.h. die mittelalterlichen Formen vor allem des sog. Übergangsstils vereinfachten. Die Kirche, die in den Jahren 1903-1905 errichtet wurde, steht inmitten vom Baukomplex des Klosters, dessen Grundriss das Quadrat ist49. Der Kirchenbau ist ein dem Gesamtbau des Klosters eingefügter Längsraum. Hinter dem Chor liegt das Oratorium des Konvents. Das Material Backstein (mit Verwendung von Stein erinnert an die Baukunst eines der besten Architekten jener Zeit, nämlich Teodor Talowskis (1857-1910, der viele Kirchen in Südpolen, aber auch viele Bürgerhäuser nicht nur in Krakau im ausgehenden 19. Jh. baute. Die Architektur der Karmeliterinnen St. Josephs-Kirche ist immer noch im Malerischen begriffen. Aber die Vereinfachung der historischen Formen führt zu ihrer „Beruhigung” und dadurch zur Wuchtigkeit des Ausdrucks. Bemerkenswert ist die in dieser Zeit (in der Anlage noch seltene ausgewogene Proportionierung des Baukörpers. Das methodische Prinzip jener Zeit ist der Kontrast. Im Kontrast zu den gedrungenen und wuchtigen Formen des Baukörpers stehen z.B. die sich verjüngenden obeliskenförmigen und pylonenartigen Türmchen, die nicht nur die Eingangsfassade der Kirche flankieren, sondern auch an den Ecken des Querhauses der Kirche stehen. Die ingravierten weißen Steine an der Fassade in der Zahl von Zehn erinnern an das Gebot des Karmelterinnenordens: Bete täglich den Rosenkranz und sind zugleich ein Vanitativmotiv. 2. Die Klosterkirche der unbeschuhten

  9. Nonlinear Predictive Control for Real-time Control Injection System of Die-casting Machine Based on CADE Algorithm%基于CADE算法的压铸机实时控制压射系统的研究

    闫孝姮; 陈伟华; 彭继慎; 赵忠建


    A nonlinear predictive control algorithm was proposed for multivariable die-casting processes of die-casting machine based on chaos adaptive differential evolution model.In the adaptive differential evolution model,the tent map was embedded to improve the process of production of crossed factors and compile factor in the DE model.The simulation results show that the injection control PID controller with the intelligence algorithm can optimize the die-casting machine injection velocity and make the nonlinear predictive control possess good dynamic characteristics and high control precision to achieve the system optimal control objective in the end.%提出了一种基于混沌自适应差分进化算法(CADE)的压铸机多变量压射过程非线性预测控制.其将帐篷映射嵌入到自适应差分进化算法(DE)中,改进了DE算法中交叉因子及编译因子的产生过程.通过仿真试验,结果表明,利用该智能算法对压射控制PID控制器进行参数优化,能实现压铸机压射速度的快速寻优,使其非线性预测控制动态特性更好,控制精度更高,从而达到系统的最优控制目的.

  10. Die Verwandlung der Philosophie in eine historische Diagnostik der Differenzen

    Casale, Rita


    In diesem Beitrag versucht die Autorin, „den philosophischen Kontext darzustellen, in dem der Differenzbegriff entstand“. Die Autoren (Nietzsche, Heidegger, Derrida, Deleuze und Foucault), die die Autorin „für die Frage der begrifflichen Thematisierung der Differenz“ betrachtet, „gelten als die theoretischen Bezugspunkte der Postmoderne, wobei dieser Beitrag „die Rekonstruktion eines philosophischen Ansatzes“ ist, „dem Nietzsche den Namen ‚historisches Philosophieren’ gab“. Inhalt: 1. Nietzsc...

  11. [Dying and death in societal transformation].

    Heller, Andreas; Wegleitner, Klaus


    Dying and death in modern societies are subject to profound social, professional and cultural-religious changes. Secularization and a stronger differentiation of societies have led to a change in the way humans handle the dying process. Normatively ritualized collective behaviour has been replaced by an individual, subjectivized approach. In late modern societies there are many different views of what "successful" or "good" dying means.In the article this change is described by the following seven theses: 1. We live longer and we die longer. 2. We no longer die suddenly and unexpectedly but slowly and foreseeably. 3. Even though our biological life on earth has become longer, our life has been shortened by the loss of eternity. 4. We no longer die on the stage of ritualized relationships with our family and neighbours but behind the curtains of organizations. 5. We live and die in a society of organizations and have to get organized for the final phase of our life. 6. Living and dying are no large, state-owned enterprises but small, private enterprises. 7. The hospice movement as well as palliative medicine have created public awareness, made dying a matter of discussion and offered a new set of options.In late modernism end-of-life care requires new approaches based on individual and shared responsibility as well as cooperation between professional institutions and community-based voluntary care.A change towards community care is visible. Thus "dying" is a topic in the discussion about the future of public health and societal solidarity.

  12. Endokrinologie in der Lebensmitte: Die Perimenopause.

    Seifert-Klauss V


    Full Text Available Anhand dreier Kasuistiken aus der gynäkologischen Hormonsprechstunde werden beispielhaft besondere Situationen und eine darauf individuell abgestimmte Hormontherapie während der Perimenopause vorgestellt. Der erste Fall beschreibt eine 47-jährige Patientin mit ausgeprägter perimenopausaler Symptomatik und Östrogen-Dominanz. Die Dokumentation über 5 Jahre illustriert die Probleme, die perimenopausal durch die endogene Überstimulation der Ovarien entstehen können. Über die Unvorhersehbarkeit der perimenopausalen Hormonschwankungen, die sich in Brustspannen und Wassereinlagerungen bei hohen Östrogenspiegeln sowie Hitzewallungen und Schweißausbrüchen bei Abfall der endogenen Östrogenspiegel äußern, sollten Patientinnen aufgeklärt werden. Durch eine zyklische Gestagensubstitution kann bei Östrogendominanz unter Umständen mehr Beschwerdeerleichterung erreicht werden als durch eine hochdosierte Östrogentherapie. Fall 2 stellt eine 47-jährige Patientin mit Epilepsie vor, deren perimenopausal bedingte Hormonschwankungen zu vermehrten Anfällen führen. Hier gilt es abzuklären, ob die Anfälle durch stark erhöhte Estradiolspiegel, die zum Ende des Zyklus hin abfallen, begünstigt werden oder aber die Art und Entstehungsgeschichte der Epilepsie nicht auf eine andere Interaktion zwischen Perimenopause und Anfällen hindeuten. In der dritten Kasuistik geht es um eine 54- jährige Patientin mit Morbus Basedow, bei der die ausgeprägte Interaktion zwischen der Schilddrüseneinstellung und den steigenden FSH-, LHsowie unvorhersehbar wechselnden Östrogenspiegeln aufgezeigt und eine individuelle symptombezogene Hormontherapie erforderlich ist.

  13. Medien als Lernform und die Trimediale Redaktion

    Wolf Hilzensauer


    Full Text Available Der vorliegende Artikel beschreibt ein Konzept für eine handlungsorientierte Medienpädagogik im Bildungsbereich. Im Mittelpunkt steht dabei die SO!-Campusredaktion, die als Methode für expansives Lernen die Möglichkeit bietet, unabhängig von Thema oder Medium die Verantwortung für den Lernprozess in die Hände der Lernenden zu legen. Der Dokumentation von Reflexion über den Lernprozess wird dabei eine besondere Bedeutung zugesprochen. Gleichzeitig werden unterschiedliche mediale Gestaltungsmöglichkeiten (Audio/Radio, Video/Fernsehen und Zeitung – sowohl als Print- als auch als Onlinemedium vorgestellt, die durch das Konzept BYOD – bring your own device – auch einfach und niederschwellig im Bildungskontext umsetzbar sind. Dadurch ergeben sich innovative Möglichkeiten, einen Lernprozess sichtbar zu machen und gleichzeitig eine Grundlage für eine alternative Leistungsbeurteilung anzubieten. Die SO!-Campusredaktion wird derzeit an der Pädagogischen Hochschule Salzburg in Kooperation mit dem Communitysender FS1 und der Radiofabrik entwickelt und erprobt. Community Medien nehmen als MedienpartnerInnen eine bedeutende Stellung ein: Durch ihren offenen Zugang zu Know How und Equipment sowie durch die Möglichkeit, Medienproduktionen über die verfügbaren Distibutionskanäle (Radiofrequenz oder Sendeplatz einer breiten Bevölkerung zugänglich zu machen, gewinnt die Medienpädagogik einen wichtigen Mehrwert in ihrer schulischen und außerschulischen Arbeit. (Dieser Artikel knüpft an den Artikel "BYOD, Smartphonefilme und webbasierte Videoschnittprogramme" der Medienimpulse, Ausgabe 2/2014, an.

  14. Influence of die geometry and material selection on the behavior of protective die covers in closed-die forging

    Yu, Yingyan; Rosenstock, Dirk; Wolfgarten, Martin; Hirt, Gerhard


    Due to the fact that tooling costs make up to 30% of total costs of the final forged part, the tool life is always one main research topic in closed-die forging [1]. To improve the wear resistance of forging dies, many methods like nitriding and deposition of ceramic layers have been used. However, all these methods will lose its effect after a certain time, then tool repair or exchange is needed, which requires additional time and costs. A new method, which applies an inexpensive and changeable sheet metal on the forging die to protect it from abrasive wear, was firstly proposed in [2]. According to the first investigation, the die cover is effective for decreasing thermal and mechanical loads, but there are still several challenges to overcome in this concept, like wrinkling and thinning of the die cover. Therefore, an experimental study using different geometries and die cover materials is presented within this work. The results indicate the existence of feasible application cases of this concept, since conditions are found under which a die cover made of 22MnB5 still keeps its original shape even after 7 forging cycles.

  15. Bestuursontwikkelingsbehoeftes in die Suid-Afrikaanse lugmag: 'n Vergelykende studie van die persepsies van die vier kultuurgroepe

    J. J. Theart


    Full Text Available Management Development Needs in the South African Air Force: A comparative study of the perceptions of four cultural groups. The object of the study was to determine whether the perceptions of managers and supervisors from different cultural groups in the South African Air Force differ concerning their managerial skills, and to determine to what extent the perceptions of the superiors differ from those of their subordinates. A questionnaire of perceived management development needs was used to determine whether specific training needs exist. It was found that there are indeed statistically significant differences between the various cultural groups'perceptions of their management development needs and that training needs exist within all four cultural groups. Opsomming Die doel van die studie was om te bepaal of die persepsies van bestuurders en toesighouers mt verskillende kultuurgroepe in die Suid-Afrikaanse Lugmag, rakende hul bestuursvaardighede, onderling van mekaar verskil en om te bepaal in watter opsig die persepsies van bogeskiktes van die van hul ondergeskiktes verskil. nVraelys van waargenome bestuursontwikkelingsbehoeftes is gebruik om te bepaal of daar spesifieke opieidingsbehoeftes bestaan. Daar is bevind dat daar wel statistics beduidende verskille tussen die kultuurgroepe se persepsies van hul bestuursontwikkelingsbehoeftes bestaan en dat daar opieidingsbehoeftes by al vier groepe bestaan.

  16. ’n Voorgestelde matriks vir die pastorale berading van die verwonde geloofsvervreemde

    Wentzel C. Coetzer


    Full Text Available Hierdie artikel fokus op die rol van pastorale berading aan die emosioneel-verwonde en geloofsvervreemde persoon deur middel van die redding in Christus. Die rol van God Drie-enig en die sentrale posisie van die Skrif word ondersoek. Verder word aspekte wat ’n Skrifgefundeerde mensbeeld onderlê, gekonstrueer. Die verband tussen emosionele trauma en geloofsvervreemding, asook die aspek van reg en geregtigheid, word hierna ondersoek. Die belangrikheid van die heil in Christus in die geestelike genesingsproses word ook bespreek. Ter afsluiting word ’n pastoraal-terapeutiese matriks voorgestel vir ingrype in die huidige lewenskrisis en die bestaande geloofsvervreemding met inagneming van die traumageskiedenis. Praktiese riglyne word verder verskaf as hulpmiddel vir begeleiding in die ondersteuningsproses.A proposed matrix regarding the pastoral counselling of the wounded faith-estranged. This article focuses on the role of the pastoral counselling of the emotionally wounded and faith-estranged person through the mediation of the salvation in Christ. The role of the Triune God and the central position of Scripture in mediating the salvation in Christ are also examined and the Scriptural view of man is constructed. The role of emotional trauma in the estrangement from God as well as the importance of justice and retribution are examined as it relates to the spiritual and emotional healing of the wounded faith-estranged. The article also discusses the prominence of the salvation in Christ in the spiritual healing process. In conclusion, a pastoral-therapeutic matrix of intervention is proposed to help in addressing the present life crisis and current faith-estrangement within the context of the trauma history, with a view to find healing from the woundedness and the faith-estrangement through salvation in Christ. Practical guidelines are offered to guide this supporting process.

  17. Design of Injection Cylinder for J1170 Horizontal Cold Chamber Die-casting Machine%J1170型卧式冷室压铸机压射缸结构设计



    The injection cylinder structure of J1170 horizontal cold chamber die-casting machine was designed,and the injection cylinder structure size was calculated.Combining with practical application,the characters of the design were analyzed.%设计J1170型卧式冷室压铸机压射缸结构,对压射缸的结构尺寸进行理论计算;结合实际应用,分析其设计特点.

  18. Die identifisering van ’n geskikte vraelys vir die bepaling van lewenskwaliteit by Suid-Afrikaanse vroue met servikskanker

    George du Toit


    Full Text Available Servikskanker is een van die algemeenste kankertipes onder Suid-Afrikaanse vroue. In die afwesigheid van ’n voldoende voorkomende servikale sitologieprogram presenteer die meer derheid vroue met servikskanker in ’n gevorderde stadium. Die prognose van dié vroue, ondanks terapie, is beperk. Menslike immuniteitsgebreksvirus-infeksie (MIV-infeksie benadeel die behandeling van servikale kanker. Servikskanker, en die behandeling daarvan, het ’n impak op die lewenskwaliteit van die vroue. Die objektiewe bepaling van lewenskwaliteit kan lei tot aanpassing van behandeling, asook toepaslike ondersteuning. Hierdie studie is gedoen om die mees geskikte vraelyste vir Suid-Afrikaanse vroue met servikskanker te identifiseer. Die twee vraelyste wat internasionaal die meeste gebruik word, is die European Organisation for the Research and Treatment of Cancer (EORTC en die Functional Assessment of Chronic Illness Therapy Measurement System (FACIT. Deur die sistematiese ondersoek van gepubliseerde artikels is die twee vraelyste aan die hand van spesifieke kenmerke geëvalueer. Hierdie kenmerke sluit in: studiestruktuur (dwarssnit of prospektief, lewenskwaliteit- uitkoms (primêr of sekondêr, tydstip van gebruik tydens die siekte en die nasionaliteit van die studiebevolking. Gebaseer op hierdie kenmerke is die EORTC as die mees geskikte vraelys geïdentifiseer.

  19. Totius en die boek Openbaring

    H.A. Louw


    Full Text Available Totius and the Book of Revelation In his sermons on the book Revelation, published in 1921, the Afrikaans theologian and poet, Prof. J.D. du Toit, better known under the pseudonym Totius, took the “futurist” view as the principal way to explain this Bible book. Elements of other views like the “historicist view” were also followed, especially in the sermon on the seven churches in Asia Minor, which regarded each church as concerned with later periods in the history of Western Europe. According to Du Toit the scene of the sealing of the servants of God (7:1-8 and of the great multitude mentioned later in the chapter (7:9-17 is set at the end of time. It should, however, be better to interpret chapter 7:1-8 as the church in John's time and the vast crowd of people from every nation as an image of the redeemed in the bliss of heaven. The multitude who comes (present tense out of the great tribulation are those who died for their faith when Revelation was written. But the article describing the multitude in the original Greek text also seems to indicate the great trouble accompanying the end of things. For Du Toit the prostitute in chapter 17 symbolizes a city, namely Babylon. The harlot, however, had slain a great number of saints who believed in Jesus (17:6. Thus the harlot cannot be identified with Babylon. The city must be Rome, the contemporary representative of the cruel empires which, through the ages have enslaved people by brute force. Rome also killed saints who served Christ. Du Toit’s greatest shortcoming in his explanation of the Book of Revelation was that he did not see that the book Revelation is rooted in a given historical situation.

  20. Pastorale begeleiding van die self-mutileerder

    Wentzel C. Coetzer


    Full Text Available In hierdie artikel het  dit geblyk dat die toenemende voorkoms van self-mutilering onder jongmense in talle gevalle as uitlaatklep gedien het vir opgeboude druk en nie soseer as ‘n selfmoordpoging nie. Heel dikwels was dit ‘n uitvloeisel van mishandeling en/of seksuele misbruik en die persoon het  dan hierdie metode gebruik om van innerlike pyn ontslae te raak. Gevoelens van alleenheid, ‘n behoefte aan beheer, ‘n behoefte om net íéts te voel, asook ‘n behoefte om die self te straf, kon ook ‘n rol gespeel het. Die gesinsklimaat was oor die algemeen van besondere belang. Hierdie probleem het aan pastorale beraders en aan die kerk ‘n besondere uitdaging gebied deur onder andere veel meer op die probleem van pyn, asook die hantering daarvan te fokus. Dit het  verband gehou met die feit dat ontkenning in die verlede ‘n groot rol gespeel het in sekere kerklike kringe en ook binne sekere gesinne. As deel van ‘n pastoraal-terapeutiese strategie in die begeleiding van die self-mutileerder kon aspekte soos die identifisering van die rol van  leuens, die benutting van oplossings uit die verlede, vergifnis, nagmaal, gebed en meditasie gevolglik uiters belangrike komponente van die helingsproses gevorm het. Pastorale beraders sal hulleself ten volle op die hoogte moet bring van die verskynsel van self-mutilering ten einde in staat te wees om werklik te kan help.Pastoral guidance for the self-mutilator. In this article it seemed that the increase in the occurrence of self-mutilation among young people in many cases served as a pressure-relief valve and not a suicide attempt as such.  It was very often the outcome of ill-treatment and/or sexual abuse and the person used this method to get rid of the inner pain. Feelings of aloneness, a need to be in control, a need to feel at least something and a need to punish the self could also have played a role. The family climate was generally very important. This provided a special challenge

  1. Teologiese tipologie: 'n Homiletiese sleutel vir die prediking van die Ou Testament

    J. J. van der Walt


    Full Text Available Daar is ’n baie ‘maklike’ en daarom verleidelike manier om uit die Ou Testament te preek deur ’n mens, van wie geskrywe word, tot ’n tipe of voorbeeld aan die gemeente voor te hou. Op hierdie manier word die sentrale boodskap van so ’n preek: ‘word ’n Rut’ ; ‘wees nie ’n Esau nie’. Op dieselfde wyse sou ook oor Calvyn, Vader Kestell of Lenin gepreek kan word: Daarom is dit duidelik dat prediking oor menslike tipes nie Bybelse prediking is nie, al kom die mense in die Bybel voor.

  2. Die Entdeckung des Unteilbaren Quanten, Quarks und die Entdeckung des Higgs-Teilchens

    Resag, Jörg


    Mitten in Europa ist eine der größten und komplexesten Maschinen in Betrieb gegangen, die wir Menschen je gebaut haben: der Large Hadron Collider (kurz LHC). Mit ihm öffnet sich ein Fenster in eine neue Welt, die viele Geheimnisse birgt: Was verleiht den Teilchen der Materie ihre Masse? Gibt es verborgene Raumdimensionen? Existiert ein tiefer Zusammenhang zwischen Teilchen mit verschiedenem Spin (Supersymmetrie)? Woraus besteht die dunkle Materie, die unser Universum durchdringt? Gibt es das Higgs-Teilchen? Mit diesem Buch taucht der Leser ein in diese wunderbare Welt, die wir Menschen in der Neuzeit entdeckt haben: Atome und ihre Substruktur aus Quarks und Leptonen, die rätselhafte Quantenmechanik, Teilchen des Lichts, Einsteins Gewebe aus Raum und Zeit, die vier Wechselwirkungen und schließlich die neue Welt, in die der LHC gerade vordringt und in der wir Higgs-Teilchen, Supersymmetrie und womöglich erste Anzeichen für die String-Theorie vermuten. Die erste Vermutung konnte mittlerweile bestätigt w...

  3. Die verband van leerprosesveranderlikes met leersukses

    D. F. Lotriet


    Full Text Available The relationship between learning process variables and study success. The main objective of this study was to determine the relationship between the constructs “meaning orientation” (in-depth approach to study, “transformational conception” and “self-regulation” in the distance education context (TV– learning. A random sample of 1951 participants taken from a large financial institution yielded 263 usable questionnaires. The responses obtained to the 167 items were subjected to factor analysis and item analysis. Opsomming Die hoofdoel van die onderhawige studie was om te bepaal of daar ‘n verband tussen die konstrukte“betekenisoriëntasie"? (dieptebenadering tot leer, “transformasionele begrip"? en “selfregulering"? in die afstandsonderrigkonteks (TV-leer bestaan. ‘n Ewekansige steekproef van 1951 deelnemers geneem uit ‘n groot finansiële instelling het 263 bruikbare vraelyste opgelewer. Die response op 167 items is aan faktor- en itemontledings onderwerp. Daarna is die interver-wantskappe tussen die leerprosesveranderlikes, naamlik “benadering tot leer"?, “begrip van leer"? en regulering-strategieë"? bepaal.

  4. ’n Beoordeling van die Skrifberoep ten opsigte van die doodstraf

    De Wet Saaiman


    Full Text Available In die lig van die Christelike etiek is ’n beroep op die Skrif ’n sine qua non waar ’n standpunt in verband met ’n etiese vraagstuk ingeneem word. Met ’n beroep op die Skrif is die probleem ongelukkig nie sonder meer opgelos nie. Die verskillende vertolkings van die Skrif het tot gevolg dat etici met teenoorgestelde standpunte hul op dieselfde Skrifgedeeltes beroep. Dit is egter nie voldoende om slegs ’n goeie uiteensetting van vertrekpunte of selfs hermeneutiese reëls te gee nie. Die Christelike etikus moet ’n grondige kennis van die werklikheid hê – etiek word eenvoudig nie in ’n vakuum beoefen nie. In hierdie artikel is ’n beoordeling gedoen van die Skrifberoep ten opsigte van die doodstraf. In die artikel is aangetoon dat die Skrif ten spyte van goeie hermeneutiese vertrekpunte gemanipuleer kan word om die etikus se eie voorveronderstelling te weerspieël.An adjudication of the use of Scripture regarding capital punishment. The use (recall of Scripture is, in light of Christian ethics, a sine qua non when a position with regard to an ethical problem is assumed. A simple interpretation of Scripture does not necessarily settle the problem. Different interpretations of Scripture result in a difference of opinions even when the same Scriptural texts are used. It is therefore simply not sufficient to note a fair explanation of departure points or hermeneutical principles. The Christian ethicist should have an intimate knowledge of reality – ethics is not practised in a vacuum. In this article an adjudication of the use or interpretation of Scripture in the light of capital punishment was conducted. In this article it was shown that Scripture is most often misused despite of fair hermeneutical principles only to reflect the ethicist own preconceived ideas.

  5. Modelle van interreligieuse toleransie in die onderwys van die een-en-twintigste eeu

    Charste C. Wolhuter


    Full Text Available Vir ’n toenemend multireligieuse samelewing en globaliserende wêreld behoort die opvoedeling, net soos in die verlede, voorberei te word vir saamleef met mense wie se religieuse oortuigings anders is as hulle eie. Die doel van hierdie artikel is om die belangrikste modelle van interreligieuse toleransie in terme van hulle bruikbaarheid in die onderwys te evalueer. Hierdie evaluering geskied aan die hand van die volgende maatstawwe: die struktuur en aard van religie en die plek daarvan in die lewe van die mens; die aard, doelstellings en reikwydte van onderwys; die toenemende diverse samestelling van samelewings; en die kontemporêre samelewingstendense van toenemende individualisering en pluralisering. Die hoofmodelle van interreligieuse verhoudings, naamlik eksklusivisme (sowel die sendingywer- as die laissez faire-variasies, inklusivisme, universalisme en ook die verskillende vorms van pluralisme, insluitende positiewe of dialogiese pluralisme, word aan hierdie maatstawwe gemeet. Op grond van die tekortkomings van hierdie modelle word ’n nuwe model, te wete ’n lewensbeskoulik(e saamleef, vervolgens ontwikkel en voorgestel.Models of interreligious tolerance for education in the 21st century. For an increasingly multi-religious society and globalised world, the educand should also be prepared for living with people who embrace religious beliefs that may differ from their own. The aim of this article is to evaluate the various models of interreligious tolerance in terms of their usefulness in education. This assessment takes place according to the following parameters: the nature and structure of religion and the place thereof in the lives of people; the increasingly diverse composition of societies; the contemporary societal trends of growing individualisation and pluralisation, and also the nature, aims and extent of education. The major models of interreligious relations are weighed up against these criteria, namely

  6. Braunes Fettgewebe: Die neue Waffe gegen Adipositas?

    Fenzl A


    Full Text Available Adipositas entsteht, wenn die Energieaufnahme den Energieverbrauch übersteigt. Braunes Fett – im Gegensatz zu weißem Fett – ist darauf ausgerichtet, Energie in Form von Wärmeproduktion (Thermogenese zu verbrauchen. Bei diesem Vorgang wird die Atmungskette von der ATP-Synthese entkoppelt, was durch das Molekül „Uncoupling Protein-1“ (UCP-1 vermittelt wird, welches praktisch nur in braunem Fettgewebe vorkommt. Aufgrund seiner hohen Stoffwechselaktivität und der rezenten Entdeckung, dass aktives braunes Fett auch in Erwachsenen vorkommt, hat dieses Gewebe in den vergangenen Jahren einen hohen Stellenwert in der Adipositasforschung erlangt. In zahlreichen Tiermodellen führt die Aktivierung von braunem Fett oder die Transformation von weißem in braunes Fett (browning zu einer Erhöhung des Energieumsatzes sowie zum Schutz vor Adipositas und metabolischen Komplikationen. Zusätzlich zu klassisch braunem und weißem Fett wurde kürzlich eine neue Fettart beschrieben, die sowohl weiße als auch braune Eigenschaften aufweist – das so genannte „beige“ Fett. Beige Fettzellen kommen zwar primär im weißen Fettgewebe vor, können aber, ähnlich wie braune Adipozyten, thermogenetisch hoch aktiv sein. Es werden laufend neue Faktoren entdeckt, die die Entwicklung und/oder Funktion von beigem bzw. braunem Fett kontrollieren. Die Bemühungen, molekulare Mechanismen und Stoffwechselvorgänge in braunem Fett besser zu verstehen, haben sich noch intensiviert, als man kürzlich mittels FDG-PET-Untersuchungen entdeckte, dass aktives braunes Fettgewebe nicht nur in Erwachsenen vorkommt, sondern auch den Energieverbrauch steigert. Derzeit existieren allerdings noch keine pharmakologischen Ansätze, um die metabolischen Eigenschaften von braunem Fett therapeutisch nutzen zu können, doch das Rennen ist längst im Gange.

  7. An eco design strategy for high pressure die casting components: microstructural analysis applied to mass reducing processes; Una estrategia de ecodiseno de piezas obtenidas mediante moldeo a presion: analisis microestructrual aplicado a la desmaterializacion

    Suarez-Pena, B.; Asensio-Lozano, J.


    In this work the study focused on the possibility of use of new aluminium alloys with optimized microstructures that ensure the mechanical properties requested for cast components made by high pressure die casting. The objective was to check the possibility of manufacture of structurally sound eco-steps for escalators with reduced structural integrity. The former arises as a result of a new redesign of the traditional steps aiming at a significant weight reduction. The experimental results show that it is feasible to cut the use of materials during processing and therefore to reduce the impact of the components during its lifetime, whilst the performance and safety standards are kept identical or even improved. (Author) 17 refs.

  8. Gebed en die vorming van Christelike identiteit in Openbaring

    31 Jul 2015 ... Die tema van gebed bereik 'n hoogtepunt in die laaste hoofstuk wanneer die stem ... Die lirieke maak gebruik van tradisionele Joodse en vroeg-Christelike temas wat by die huidige literêre ...... C.J. Thornton (red.), Studien zur ...



    baie duidelik gestel word dat die Suid-Afrikaanse familiereg eers teen die einde van .... promote a particular view of social ordering? .... aangaande die verhouding was die feit dat die 18-jarige se vriend (had) a tremendous influence ..... ethnic solidarity or the kinship network, provided the framework within which individuals.

  10. Hoofstuk 2 - Die Klein Begin 1916−1933

    J.P. Oberholzer


    Full Text Available Die opleiding neem ‘n aanvang met een kerklike dosent, J.H.J.A. Greyventein, en ‘n aantal universiteitsdosente. Die studentetal groei stadig. Die vertrek van professor Paterson en die koms van S.P. Engelbrecht in 1921 bring ‘n belangrike wending. Wanneer B. Gemser in 1926 toetree, is daar drie dosente wat tegelyk ampsdraers van die Nederduitsch Hervormde Kerk is. Gemser is dosent in Teologie sowel as in Lettere en Wysbegeerte waar hy begin met die vestiging van ‘n sterk departement Semitiese Tale. Engelbrecht se kundigheid omvat Kerkgeskiedenis sowel as ‘n unieke kennis van die Voortrekker- en ou Tansvaalse geskiedenis en dit kom die Departement Geskiedenis ten goede. Die akademiese gehalte van die opleiding neem toe, en so ook die studentetal. ‘n Bedreiging vir die voortbestaan van die Fakulteit teologie is afgeweer deur die tydige optrede van S.P. Engelbrecht en die tussenkoms van die Eerste Minister. Die selfstandigwording van die Universiteit van Pretoria en die Afrikaanswording van die Universiteit bring ‘n veranderde konteks.

  11. Die taal wat nie wou doodgaan nie

    Hertzog Venter


    Full Text Available Ek ontleen die opskrif aan ’n bewering deur ’n Swartman, Justus Tshungu, van Radio Bantoe — ’n Swartman wat ’n idiomatiese Afrikaans besig wat baie hom kan beny, iemand wat geesdriftiger is as baie gebore blanke Afrikaners oor die bestaan en voortbestaan van Afrikaans. Hy het in ’n sprankelende en boeiende toespraak die pakkende beeld gebruik dat Afrikaans soos kweekgras opgekom en gegroei het en geweier het om uitgeroei te word.

  12. "Superman" Star Christopher Reeve Dies at 52

    Jim Fitzgerald; 李邦珍


    @@ Superman actor Christopher Reeve, who turned personal tragedy into a public crusade① and from his wheelchair became the nation's most recognizable spokesman for spinal cord research, has died. He was 52. Reeve died Sunday of complications② from an infection caused by a bedsore③. He went into cardiac arrest④ Saturday, while at his Pound Ridge home, then fell into a coma⑤ and died Sunday at a hospital surrounded by his family, his publicist said. His advocacy for stem cell research helped it emerge as a major campaign issue between President Bush and Sen. John Kerry. His name was even mentioned by Kerry during the second presidential debate on Friday.

  13. Evaluation of Heat Checking and Washout of Heat Resistant Superalloys and Coatings for Die inserts

    David Schwam; John F. Wallace; Yulong Zhu; Edward Courtright; Harold Adkins


    This project had two main objectives: (1) To design, fabricate and run a full size test for evaluating soldering and washout in die insert materials. This test utilizes the unique capabilities of the 350 Ton Squeeze Casting machine available in the Case Meal Casting Laboratory. Apply the test to evaluate resistance of die materials and coating, including heat resistant alloys to soldering and washout damage. (2) To evaluate materials and coatings, including heat resistant superalloys, for use as inserts in die casting of aluminum alloys.

  14. Numerical Simulation of Semi-Solid Die Casting of Barrel Shell%“筒壳”铸件半固态压铸过程数值模拟



    采用铸造模拟软件ProCAST对腔深、壁薄的A356合金的“筒壳”铸件进行模拟分析.通过对其压铸过程中的温度场进行数值模拟、分析,预测缩孔缩松所在的位置及大小.优化出最佳工艺参数:浇注温度为590℃,压射速度为5 m/s,模具温度为220℃.在此工艺条件下A356半固态浆料充型平稳,温度场分布均匀,无飞溅卷气和浇注不足等缺陷,在实际生产中获得了质量完好的铸件,验证了该工艺参数.%The die cast "barrel shell" casting with deep cavity and thin wall was simulated by casting simulation software ProCAST. By making casting simulation on casting process and temperature field, the location and sizes of shrinkage and dispersed shrinkage were forecasted. The optimized parameters are: pouring temperature 590 ℃, injection speed 5 m/s, mold temperature 220 ℃. Under this process, semi-solid slurry mold filling is stable, temperature field is uniform and there were no casting defects such as splash air entrapments and misrun. The process parameters were proved by obtaining perfect part quality in actual production.

  15. Effect of austempering temperature and time on the kinetics and microstructure of austempered compacted graphite cast irons; Einfluss von Zwischenstufenverguetungstemperatur und -zeit auf die Kinetik und die Mikrostruktur von zwischenstufenverguetetem, Gusseisen mit Vermiculargraphit

    Teymourian, Mehdi [LMI Co., Tehran (Iran, Islamic Republic of). Casting Dept.; Boutorabi, Seyed Mohammad Ali [Iran Univ. of Science and Technology, Narmak, Tehran (Iran, Islamic Republic of). Center of Excellence for Advanced Materials


    After starting the austempering nucleation of bainitic ferrite was observed within a very short time. Samples that austempered for 2 min. showed martensite in the microstructure. By increasing the austempering time from 30 min to 90 min the retained austenite decomposes and X-ray diffraction observations revealed the greatest volume fraction of retained austenite up to 17.3 and 23.8 percent when austempered for 30 min. Micro-hardness of the bainitic Verbesferrite increased up to 370 and 500 HV and micro-hardness of the retained austenite increased up to 300 and 400 HV at the austempering temperatures of 300 C and 400 C respectively. In comparison to austempered ductile iron, the austempered compacted graphite cast iron shows higher rate of bainitic reaction. Bainite formation driving force and consequently the rate of austempering process are higher in compacted graphite cast irons. (orig.)

  16. Preparation of Wax-Emulsion Releasing Agent for Aluminium Alloy Die Casting%一种铝合金压铸蜡乳液脱模剂的研制

    吴国江; 曹桂芝; 江敏


    研究了用氧化聚乙烯蜡、58#全炼蜡制备铝合金压铸蜡乳液脱模剂的方法。考查了乳化剂类型、乳化剂用量、乳化工艺对乳液稳定性的影响。实验结果表明,当复合乳化剂用量为复合蜡的30%,乳化温度为95℃,搅拌速度为500~700 r/min时,乳化时间为40~45 min,可以制取一种稳定的用于铝合金压铸蜡乳液脱模剂。%A preparation method of wax-emulsion releasing agent for aluminium alloy die casting from oxidized polyethylene wax and 58# fully refined paraffin wax was studied. Effects of emulsifier type, emulsifier dosage and emulsifying process on the emulsion stability were studied. The results show that, when the compounded emulsifier dosage is 30%of the mixed wax mass, the emulsifying-temperature is 95℃, the stirring speed is between 500~700 r/min, the emulsifying time is between 40~45min, stable wax-emulsion releasing agent for aluminium alloy die casting can be prepared.

  17. A comparative evaluation of linear dimensional accuracy of the dies obtained using three conceptually different die systems in the fabrication of implant prosthesis: An in vitro study

    Manawar Ahmad


    Purpose: The purpose of the study was to evaluate the linear dimensional accuracy between the implant master die and three conceptually different die systems such as Pindex system, Accu-trac precision die system, and Conventional brass dowel pin system. Materials and Methods: Thirty impressions of implant master die were made with polyether impression material. Ten experimental implant casts were fabricated for each of the three different die systems tested: Accu-trac precision die tray system, Pindex system, and conventional brass dowel pin system. The solid experimental casts were sectioned and then removed from the die system 30 times. Linear distances between all six possible distances were measured from one centre of the transfer coping to the other, using a co-ordinate measuring machine in millimeters up to accuracy of 0.5 microns. Data were tabulated and statistically analyzed by Binomial non parametric test using SPSS version 15. Results: Significant differences were found for distance A-B (P = 0.002, A-C ( P = 0.002, A-D (P value = 0.002, and B-D ( P = 0.021 in Conventional Dowel pin system however for Accu-trac precision die tray system, it was significant only for distance A-D (P = 0.002 but for Pindex system it was non-significant for all the distances measured. Conclusion: Within the limitations of this study, use of Pindex system is recommended when sectioned dies are needed for a multi implant retained prosthesis.

  18. Die omvang en aard van afwesigheid in die werkplek: ‘n Suid-Afrikaanse gevalstudie

    Anel Du Plessis


    Full Text Available The scope and nature of absenteeism in the workplace: A South African case study. The objective of the study was to develop quantitative measures for monitoring trends of absenteeism in a company within the meat industry and to assess qualitatively the possible existence of a collective culture of absenteeism within the organisation. The scope and frequency of absenteeism, costs incurred due to absenteeism, and individual absenteeism patterns of 145 employees, were studied over a period of one year. It was found that 2900 planned and 912 unplanned leave workdays that were lost, resulted in direct costs of R895,054.55. Five employees who were absent most often accounted for 18.60% of the unplanned leave taken. The extraordinary levels of absenteeism found in this case study were ascribed to specific employees. Opsomming Die doel van die studie was om kwantitatiewe metings vir die monitering van afwesigheidstendense vir ‘n maatskappy in die vleisbedryf te ontwikkel en om die moontlike bestaan van ‘n kollektiewe afwesigheidskultuur kwalitatief te ondersoek. Die omvang, frekwensie en koste van afwesigheid, asook individuele afwesigheidspatrone, is bestudeer vir 145 werknemers oor ‘n tydperk van een jaar. Daar is bevind dat 2900 beplande en 912 onbeplande verlofwerkdae wat verloor is, die maatskappy R895,054.55 gekos het. Vyf werknemers wat die meeste afwesig was, was verantwoordelik vir 18,60% van die onbeplande verlof geneem. Die uitsonderlike vlakke van afwesigheid in hierdie gevalstudie is toegeskryf aan spesifieke werknemers.

  19. Mathematical model of determination of die bearing length in design of aluminum profile extrusion die

    闫洪; 王高潮; 夏巨谌; 李志刚


    Based on the finite element simulation of profile extrusion process, the effect of local extrusion ratio, die bearing area and the distance between extrusion cylindrical center and local die orfice center on mental flow velocity was investigated. The laws of deformed metalflow on profile extrusion process were obtained. The smaller the local extrusion ratio, the faster the metal flow velocity; the smaller the area of die bearing, the faster the metal flow velocity; the smaller the distance of position of local die orifice(the closer the distance of position of local die orifice from extrusion cylindrical axis), the faster the metal flow velocity. The effect of main parameters of die structure on metal flow velocity was integrated and the mathematical model of determination of die bearing length in design of aluminum profile extrusion die was proposed. The calculated results with proposed model were well compared with the experimental results. The proposed model can be applied to determine die bearing length in design of aluminum profile extrusion die.

  20. Ambrosiaster se uitleg van die Filemonbrief en die retoriese analise van hierdie brief

    D. Francois Tolmie


    Full Text Available Die studie van Paulus se brief aan Filemon het gebaat by die hernude belangstelling in die retoriese analise van Nuwe-Testamentiese geskrifte, in die sin dat ’n groot aantal retoriese analises van die brief gepubliseer is. Hierdie retoriese analises is vanuit ’n verskeidenheid perspektiewe gedoen, maar tot dusver het niemand nog die manier sistematies ondersoek waarop die vierde-eeuse outeur, wat later die naam Ambrosiastergekry het, die brief in sy kommentaar op die Pauliniese briewe geïnterpreteer het nie. Hierdie artikel bied dus ’n oorsig van Ambrosiaster se interpretasie van die brief aan Filemon en dui aan watter bydrae dit tot die retoriese analise van die brief kan maak. Ambrosiaster’s exposition of the Letter to Philemon and the rhetorical analysis of the letter. In recent times, the study of Paul’s letter to Philemon benefitted from the renewed interest in the rhetorical analysis of New Testament writings, in the sense that a large number of rhetorical studies of the letter have been published. These rhetorical analyses of the letter have been done from different perspectives, but thus far, no one has systematically investigated the way in which the fourth-century author, who was later called Ambrosiaster, interpreted the letter in his commentary on the Pauline letters. Accordingly, this article offers an overview of Ambrosiaster’s interpretation of the letter to Philemon, and then outlines the contribution that his reading of the letter can make to the rhetorical interpretation of it.