WorldWideScience

Sample records for cast in place structures

  1. A development of numerical analysis model for tensile capacity evaluation of cast-in-place anchor

    International Nuclear Information System (INIS)

    Numerical analysis is carried out to identify the appropriateness of the design codes that is available for the tensile design of fastening system at Nuclear Power Plant (NPP) in this study. This study is intended for the cast-in-place anchor that is widely used for the fastening of equipment in Korean NPPs. The microplane model and the elastic-perfectly plastic model are employed for the quasi-brittle material like concrete and for the ductile material like anchor bolt as constitutive model for numerical analysis and smeared crack model is employed for the crack and damage phenomena. The developed numerical model is verified on a basis of the various test data of cast-in-place anchor. The appropriateness of both ACI 349 Code and CCD approach of CEB-FIP Code is evaluated for the tensile design of cast-in-place anchor and it is proved that both design codes give a conservative results compared with real tensile capacity of cast-in-place anchor

  2. Optimum design of one way concrete slabs cast against Textile Reinforced Concrete Stay-in-Place Formwork Elements

    OpenAIRE

    Papantoniou, Ioannis; Papanicolaou, Catherine; Triantafillou, Thanasis

    2009-01-01

    This study presents a conceptual design process for one-way reinforced concrete slabs cast over Textile Reinforced Concrete (TRC) Stay-in-Place (SiP) formwork elements, aiming at the minimization of the composite slab cost satisfying Ultimate Limit State (ULS) and Serviceability Limit State (SLS) design criteria. The thin-walled TRC element is considered to participate in the structural behaviour of the composite slab. This distinct function of the TRC element (as formwork and as a part of a ...

  3. Fundamental study on pull-out strength of cast-in-place anchor bolt in concrete subjected to high temperature

    International Nuclear Information System (INIS)

    Some recent research on high temperature behavior of concrete shows that its strength will decrease with further increase of temperature, and other mechanical properties also get worse, due to drying shrinkage, thermal stress and so on. Cast-in place anchor bolts are used in many structural applications. There is possibility that these anchor bolts will be exposed to high temperature in a short time by some accident, and that the pull-out strength will decrease. This paper describes a study on the pull-out strength of a cast-in-place anchor bolt installed in concrete which is subjected to high temperatures up to 500degC to obtain basic experimental data and to examine the response of cast-in-place anchor bolts to high temperature exposure. Tests results show that the pull-out strength under high temperature decreases significantly. The pull-out strength during heating and after heating up to 500degC was 20% and 50% of it in normal temperature, respectively. (author)

  4. Experimental Research on Large Diameter Cast-in-Place Piles Embedded in Rock

    Institute of Scientific and Technical Information of China (English)

    衡朝阳; 何满潮; 姚爱军

    2001-01-01

    This paper expatiated the field test of large diameter cast-in-place piles embedded in soft rock, including static loading test, high or low strain dynamic test, measurement of stresses and strains of pile body, and pressure measurements between pile tip and soft rock. The relative in-situ test problems are discussed. Based on the limit equilibrium theory and the load transfer equation, a synthesis method of analyzing the ultimate carrying capacity of single large diameter pile is put forward. The research results show that the key to determining the ultimate carrying capacity of single pile with a large diameter is the analysis of the intensity of soft rock.

  5. Fractal structures in casting films from chlorophyll

    Science.gov (United States)

    Pedro, G. C.; Gorza, F. D. S.; de Souza, N. C.; Silva, J. R.

    2014-04-01

    Chlorophyll (Chl) molecules are important because they can act as natural light-harvesting devices during the photosynthesis. In addition, they have potential for application as component of solar cell. In this work, we have prepared casting films from chlorophyll (Chl) and demonstrated the occurrence of fractal structures when the films were submitted to different concentrations. By using optical microscopy and the box-count method, we have found that the fractal dimension is Df = 1.55. This value is close to predicted by the diffusion-limited aggregation (DLA) model. This suggests that the major mechanism - which determines the growth of the fractal structures from Chl molecules - is the molecular diffusion. Since the efficiencies of solar cells depend on the morphology of their interfaces, these finds can be useful to improve this kind of device.

  6. STRUCTURAL VIOLENCE: A STUDY OF CASTE IN GUJARAT

    Directory of Open Access Journals (Sweden)

    Arif Rasheed

    2015-10-01

    Full Text Available Indian democracy is more than six decades old but a large number of its citizens are still yearning for equal treatment. Identity based discrimination is practiced in different visible and invisible forms across the country. Gujarat is certainly one of the most developed States of India but a large number of cases involving structural violence are found in this State as well. The caste identity is a major factor discriminating dalit community from other hindus and they are not permitted to freely enter the house of upper caste, religious places and donot have access to community drinking water. The act of keeping a particular section of the society out of touch is an example of structural violence. The present paper focuses on the instances of discrimination faced by people of lower strata in administrative, social and economic spheres in this techno advance State of India.

  7. Field study of plastic tube cast-in-place concrete pile

    Institute of Scientific and Technical Information of China (English)

    陈永辉; 曹德洪; 王新泉; 杜海伟; 张霆

    2008-01-01

    The compositions, technical principles and construction equipments of a new piling method used for ground improvement plastic tube cast-in-place concrete pile were introduced. The results from static load tests on single piles with different forms of pile shoes and on their composite foundations were analyzed. The distribution patterns of axial force, shaft friction and toe resistance were studied based on the measurements taken from buried strain gauges. From the point of engineering application, the pile has merits in convenient quality control, high bearing capacity and reliable quality, showing higher reasonability, advancement and suitability than other ground improvement methods. The pile can be adopted properly to take place of ordinary ground improvement method, achieving greater economical and social benefits.

  8. Probabilistic modeling of solidification grain structure in investment castings

    Energy Technology Data Exchange (ETDEWEB)

    Upadhya, G.K.; Yu, K.O.; Layton, M.A.; Paul, A.J. [Concurrent Technologies Corp., Johnstown, PA (United States)

    1995-12-31

    A probabilistic approach for modeling the evolution of grain structure in investment castings has been developed. The approach differs from the classical Monte Carlo simulations of microstructural evolution in that it uses the results from a heat transfer simulation of the investment casting process for determining the probabilities of nucleation and growth. The model was used to predict the solidification grain structure in castings. The model is quasi-3D, since it uses the information from a 3D simulation of heat transfer to predict the grain structure developed in any 2D-section of the casting. Structural transitions such as columnar/equiaxed transition can also be predicted, using suitable transition criteria. Results from the model have been validated by comparison with actual micrographs from experimental investment castings. In the first case, simulations were performed for a simple plate shaped casting of superalloy Rene 77. The effects of mold insulation as well as metal pour and mold preheat temperatures on the grain size of the casting were studied. In the second example, the casting of a complex-shaped jet engine component made of superalloy IN718 was simulated. Simulation results were seen to match very well with experiments.

  9. An improvement of design criteria for cast-in place anchor

    International Nuclear Information System (INIS)

    Actual model tests are carried out to examine the appropriateness of design criteria that is available for the anchorage design in this study. These tests are intended for the cast-in-place anchor that is widely used for the fastening of equipment in Korean NPPs. 35 test specimens taking account of 7 test conditions are manufactured on a basis of ASTM E488 under non-cracked and plain concrete for these actual model tests. As principal test variables, effective anchor embedment depth, anchor with edge effects, and anchor with overlapping failure volume etc. are chosen. In order to apply the tensile force, 100 tonf-capacity actuator is used with displacement control of 0.5 mm/min. It is proved that ACI 349-01 and CCD procedure of CEB- FIP Code are very conservative against test results through these actual model tests and the improved design criterion is proposed on a basis of test results in order to better the economical efficiency of NPPs in this study

  10. An evaluation of tensile capacity of cast-in-place anchor with crack

    International Nuclear Information System (INIS)

    Actual model tests are carried out to develop the model that can accurately incorporate the effect of the various types of cracks in this study. These tests are intended for the cast-in-place anchor that is widely used for the fastening of equipment in Korean NPPs. 115 test specimens with single anchor are constructed on a basis of ASTM E488 under 23 cracked conditions and plain concrete for these actual model tests. As principal test variables related to crack, the crack width, the crack depth, and the distance between crack and anchor etc. are chosen. In order to apply the tensile force, 100 tonf-capacity actuator is used with displacement control of 0.5 mm/min. Through these test results, the model incorporating the effect of various types of cracks accurately, is developed and will be available for the an chorage capacity evaluation for seismic qualification of equipment in USI A -46 NPPs and anchorage design of new NPPs

  11. BETWEEN THE DENDRITE STRUCTURE QUALITY, THE CASTING TECHNOLOGY AND THE DEFECTS IN CONTINUOUSLY CAST SLABS

    Directory of Open Access Journals (Sweden)

    Slavomír Peľák

    2009-11-01

    Full Text Available The paper presents the results of analysis of surface defects of continuously cast slabs. Longitudinal central cracks of type II, accompanied by local depression, were found. The local depressions were formed in areas with the thinnest slab chill zone. We suppose that they were caused by heterogeneous contraction of solidified shell. The second part of the paper analyzes the relationships between the chemical composition, the dendrite structure parameters, the casting technology parameters and the occurrence of defects in continuously cast slabs. To determine the susceptibility of the steel to longitudinal cracking, we analyzed the relationships between a large variety of data (slab chemical composition, casting speed, casting and overheating temperatures, primary and secondary dendrite arm spacing, etc.. The longitudinal defects were more frequent in overheated steel, with a small central zone, great dendrite arm spacing and with a higher than recommended sulphur and phosphorus content. Numerically expressed, cracking developed at the segregation index values IS bigger/same 100, with the surface cracking index IPT bigger/same 60.

  12. Structure and mechanical properties of vermicular cast iron in cylinder head casting

    OpenAIRE

    Guzik, E.; S. Dzik

    2009-01-01

    The paper discusses the problem of grain density and ferrite content in microstructure of vermicular graphite iron cast in bars of different section diameters and cylinder head casting. The experimental results regarding the section effect demonstrate that the nodule count, grain density and ferrite content are all function of the cast bar diameter in this particular case ranging from 0.6 to 8.0 cm and microstructure and mechanical properties in the cylinder head. The nodule count (or grain d...

  13. Structure fields in the solidifying cast iron roll

    Directory of Open Access Journals (Sweden)

    W.S. Wołczyński

    2010-01-01

    Full Text Available Some properties of the rolls depend on the ratio of columnar structure area to equiaxed structure area created during roll solidification. The transition is fundamental phenomenon that can be apply to characterize massive cast iron rolls produced by the casting house. As the first step of simulation, a temperature field for solidifying cast iron roll was created. The convection in the liquid is not comprised since in the first approximation, the convection does not influence the studied occurrence of the (columnar to equiaxed grains transition in the roll. The obtained temperature field allows to study the dynamics of its behavior observed in the middle of the mould thickness. This midpoint of the mould thickness was treated as an operating point for the transition. A full accumulation of the heat in the mould was postulated for the transition. Thus, a plateau at the curve was observed at the midpoint. The range of the plateau existence corresponded to the incubation period , that appeared before fully equiaxed grains formation. At the second step of simulation, behavior of the thermal gradients field was studied. Three ranges within the filed were visible: EC→EC→EC→EC→(tTECtt↔RERCtt↔a/ for the formation of columnar structure (the C – zone: ( and 0>>T&0>>=−>−=REREttGttG.The columnar structure formation was significantly slowed down during incubation period. It resulted from a competition between columnar growth and equiaxed growth expected at that period of time. The 0≈=−=RERCttGttG relationship was postulated to correspond well with the critical thermal gradient, known in the Hunt’s theory. A simulation was performed for the cast iron rolls solidifying as if in industrial condition. Since the incubation divides the roll into two zones: C and E; (the first with columnar structure and the second with fully equiaxed structure some experiments dealing with solidification were made on semi-industrial scale.

  14. Early-age durability assessment of cast-in-place RC bridge deck

    Science.gov (United States)

    Aktan, Haluk M.; Yaman, Ismail O.; Udegbunam, Oge; Hearn, Nataliya

    2000-06-01

    A novel method for evaluating concrete permeability at an early age is being developed for use in performance-related specifications where the material durability is specified as a performance parameter. In developing the method, the fundamental relationship between ultrasonic pulse velocity (UPV) and permeability of a porous medium is derived. An experimental relationship between UPV and concrete permeability is also established which strongly correlates with its theoretical counterpart. This experimental relationship is developed from UPV and permeability tests conducted on specimens made from a series of concrete grades. The experimental relation utilized the data collected from specimens made from a total of 20 bridge deck normal concrete mixes corresponding to five w/c (water-cement ratio) groups of 0.35, 0.40, 0.45, 0.50 and 0.55. The implementation procedure developed is the application of the 'paste efficiency' principle. In implementing 'paste efficiency' principle during the casting of a bridge deck, standard specimens are prepared in the field and cured in the laboratory. UPV measurements are obtained at an early age both from the deck and the standard specimens. The decrease in UPV from standard specimens indicates paste quality loss (PQL) and is proportional to the increase in permeability of deck concrete.

  15. Structure and mechanical properties of vermicular cast iron in cylinder head casting

    Directory of Open Access Journals (Sweden)

    E. Guzik

    2009-01-01

    Full Text Available The paper discusses the problem of grain density and ferrite content in microstructure of vermicular graphite iron cast in bars of different section diameters and cylinder head casting. The experimental results regarding the section effect demonstrate that the nodule count, grain density and ferrite content are all function of the cast bar diameter in this particular case ranging from 0.6 to 8.0 cm and microstructure and mechanical properties in the cylinder head. The nodule count (or grain density has been reported to increase, while ferrite content was decreasing with decreasing casting diameter. The density number of the grains Nv has been related (by regression analysis to the undercooling degree

  16. Model of Primary Austenite Dendrite Structure in Hypoeutectic Cast Iron

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The solidification of primary austenite in hypoeutectic gray cast iron was studied by stepped grinding and quantitative metallography. The dendrite structure of primary austenite can be described by three models: typical dendrite crystal model, metamorphic dendrite crystal model and network dendrite crystal model. The dendrite crystals formed according to 3rd model is much more than those formed according to other models in this experiment. The primary austenites are connected each other, and the primary stems of austenite could be regarded as secondary arms and vice versa.

  17. Cast in place temperature 5 influence on fresh concrete made with limestone filler and blended cement

    Directory of Open Access Journals (Sweden)

    Soria, E. A.

    2003-12-01

    Full Text Available Properties of fresh concrete play a relevant role on placing and consolidation; and its design strength and durability depends on them. It is well known too that the concrete temperature during placing affects all its properties in different ways and extent. This paper presents the influence of placing temperature of concretes made with portland cement, limestone filer cement and blended cement, commercially available, on slump, slump loss, setting time and bleeding. The results show that generally when concrete temperature rises, the bleeding and slump fall down and the slump loss and setting time are accelerated. However, regardless of the strength class the type of cement affects the value of these variations

    Las propiedades de los hormigones en estado fresco desempeñan un papel fundamental durante las operaciones de colocación y compactación de los mismos y de ellas depende, en gran medida, que se alcance en el estado endurecido la resistencia y la durabilidad de diseño. Es sabido, además, que la temperatura que alcanza un hormigón durante dichas operaciones, afecta en mayor o menor grado a todas sus propiedades, de manera diferente. En el presente trabajo se analizó la influencia de la temperatura de colocación sobre el asentamiento, la pérdida del asentamiento en el tiempo, los tiempos de fraguado y la exudación, en hormigones elaborados con cemento portland normal, fillerizado y compuesto, de procedencia comercial. Los resultados han mostrado, en general, que con el aumento de la temperatura de colocación disminuyen la exudación y el asentamiento; mientras que la pérdida de asentamiento y los tiempos de fraguado se aceleran. Sin embargo, las magnitudes de dichas variaciones resultan a su vez muy influenciadas por el tipo de cemento utilizado, aun siendo de la misma clase resistente.

  18. Static and cyclic pullout behavior of cast-in-place headed and bonded anchors with large embedment depths in cracked concrete

    International Nuclear Information System (INIS)

    Highlights: • Optimizing the design and identifying margin of the headed fasteners used in French nuclear power plants. • Static and cyclic pullout tests on cast in place anchorage composed of an anchor plate welded to four headed or bonded rods. • Experimental data base on tests on anchor plates. • Anchor with large embedment depths in cracked concrete. • Edge effects. - Abstract: The equipment of French nuclear power plants is fixed on reinforced concrete structures with base plate with headed fasteners. EDF decided to carry out an experimental research program in partnership with LGCIE in order to optimize the design of the headed fasteners and identify margin. This article introduces the results of pullout tests on anchors with large embedment cast in place in a reinforced concrete block. The anchorage are composed of an anchor plate welded to four ribbed bars or headed smooth studs. The studied parameters are: the type of loading (static or cyclic), the edge distance, the state of cracking of the concrete block. The anchors with headed rods or ribbed bars have a steel rod failure mode in agreement with their initial design. However, an optimization of the size on the headed anchors seems to be expected in order to improve their installation. This experimental campaign will provide a data base enabling the development of numerical models in order to improve the design

  19. Static and cyclic pullout behavior of cast-in-place headed and bonded anchors with large embedment depths in cracked concrete

    Energy Technology Data Exchange (ETDEWEB)

    Delhomme, F., E-mail: fabien.delhomme@insa-lyon.fr [University of Lyon, INSA-Lyon, LGCIE, F-69621 Villeurbanne (France); Roure, T.; Arrieta, B. [EDF SEPTEN Compagny, Civil Engineering, Villeurbanne (France); Limam, A. [University of Lyon, INSA-Lyon, LGCIE, F-69621 Villeurbanne (France)

    2015-06-15

    Highlights: • Optimizing the design and identifying margin of the headed fasteners used in French nuclear power plants. • Static and cyclic pullout tests on cast in place anchorage composed of an anchor plate welded to four headed or bonded rods. • Experimental data base on tests on anchor plates. • Anchor with large embedment depths in cracked concrete. • Edge effects. - Abstract: The equipment of French nuclear power plants is fixed on reinforced concrete structures with base plate with headed fasteners. EDF decided to carry out an experimental research program in partnership with LGCIE in order to optimize the design of the headed fasteners and identify margin. This article introduces the results of pullout tests on anchors with large embedment cast in place in a reinforced concrete block. The anchorage are composed of an anchor plate welded to four ribbed bars or headed smooth studs. The studied parameters are: the type of loading (static or cyclic), the edge distance, the state of cracking of the concrete block. The anchors with headed rods or ribbed bars have a steel rod failure mode in agreement with their initial design. However, an optimization of the size on the headed anchors seems to be expected in order to improve their installation. This experimental campaign will provide a data base enabling the development of numerical models in order to improve the design.

  20. The formation of the structure of cast composites in different solidification conditions

    Directory of Open Access Journals (Sweden)

    A. Dolata-Grosz

    2008-05-01

    Full Text Available Purpose: In the research work the result of the reinforcement displacement and solidification analysis foraluminium cast composite with ceramic particles in different solidification conditions have been presented. Theresults of research on the solidification process for heterophase composite have been shown.Design/methodology/approach: : The solidification process of the AK12/ SiC+C composite suspension invarious heat abstraction conditions was recorded using the ThermaCAMTME25 photometer system for temperaturecontrol and measurement. The system, equipped with a thermovision camera, LCD display and a laser pointer, wasconnected to a SPIDER 8 recorder and used to monitor, record and, simultaneously, to visualize the temperaturechanges which take place during composites’ solidification. The structure analysis for composite casts wasperformed by means of optical microscopy.Findings: As the research has shown, moulds which abstract heat quickly, like a graphite or permanent mould,ensure obtaining a uniform distribution of ceramic particles in the matrix. A longer time of composite suspensionsolidification facilitates floatation and segregation of the reinforcing particles. Therefore, application of materialswhich prolong the solidification process, e.g. a sand mould, enables obtaining a gradient or laminar structure inheterophase composites.Practical implications: The mould’s material changes the nature of composite crystallization.Originality/value: It was found that the has a significant influence on the distribution of heterophasereinforcement in the matrix. By applying an appropriate mould material it is possible to shape the cast structureand the distribution of particles in the cast.

  1. [Casting faults and structural studies on bonded alloys comparing centrifugal castings and vacuum pressure castings].

    Science.gov (United States)

    Fuchs, P; Küfmann, W

    1978-07-01

    The casting processes in use today such as centrifugal casting and vacuum pressure casting were compared with one another. An effort was made to answer the question whether the occurrence of shrink cavities and the mean diameter of the grain of the alloy is dependent on the method of casting. 80 crowns were made by both processes from the baked alloys Degudent Universal, Degudent N and the trial alloy 4437 of the firm Degusa. Slice sections were examined for macro and micro-porosity and the structural appearance was evaluated by linear analysis. Statistical analysis showed that casting faults and casting structure is independent of the method used and their causes must be found in the conditions of casting and the composition of the alloy. PMID:352670

  2. Integrated Modeling of Process, Structures and Performance in Cast Parts

    DEFF Research Database (Denmark)

    Kotas, Petr

    This thesis deals with numerical simulations of gravity sand casting processes for the production of large steel parts. The entire manufacturing process is numerically modeled and evaluated, taking into consideration mould filling, solidification, solid state cooling and the subsequent stress build...... the importance of a good gating system design. Hence, it is common to see, especially in gravity sand casting, “traditional gating systems” which are known for a straight tapered down runner a well base and 90º bends in the runner system. There are theories supported by experimental results claiming that flow...... of these defects depend on thermal gradients, cooling rate, pressure drop over the mushy zone and solidification pattern. It is not a standard procedure in daily foundry practice to run convection, macrosegregation and stressstrain calculations on all projects to identify macrosegregation and hot tearing, because...

  3. Structure of ductile iron in thin walled castings

    Directory of Open Access Journals (Sweden)

    M. Górny

    2007-12-01

    Full Text Available It this work it has been shown that it is possible to produce thin wall ductile iron (TWDI castings with considerably length using Archimedes spiral with wall thickness of 1, 2 and 3 mm. Inmould technique was used to produce TWDI. It has been estimated castability and metallographic investigations were made using different moulding materials. From castability measurements result that it is possible to obtain thin wall ductile iron castings with wall thickness down to 1 mm with castability of 200 mm. Using mould with small ability to absorb heat castability increases twice. At wall thickness equal 3 mm castability reaches 1000 mm and using LDASC sand its value increases to over 1500 mm. Structure parameters for different wall thickness and moulding materials (graphite nodule count, ferrite and cementite fraction are plotted versus distance from the beginning of spiral. It is shown strong influence of LDASC sand (material with small ability to absorb heat on structure parameters (NF, Vf i VC revealing gradient character of TWDI.

  4. Computational modeling of structure of metal matrix composite in centrifugal casting process

    Science.gov (United States)

    Zagórski, Roman

    2007-04-01

    The structure of alumina matrix composite reinforced with crystalline particles obtained during centrifugal casting process are studied. Several parameters of cast process like pouring temperature, temperature, rotating speed and size of casting mould which influent on structure of composite are examined. Segregation of crystalline particles depended on other factors such as: the gradient of density of the liquid matrix and reinforcement, thermal processes connected with solidifying of the cast, processes leading to changes in physical and structural properties of liquid composite are also investigated. All simulation are carried out by CFD program Fluent. Numerical simulations are performed using the FLUENT two-phase free surface (air and matrix) unsteady flow model (volume of fluid model — VOF) and discrete phase model (DPM).

  5. Computational modeling of structure of metal matrix composite in centrifugal casting process

    International Nuclear Information System (INIS)

    The structure of alumina matrix composite reinforced with crystalline particles obtained during centrifugal casting process are studied. Several parameters of cast process like pouring temperature, temperature, rotating speed and size of casting mould which influent on structure of composite are examined. Segregation of crystalline particles depended on other factors such as: the gradient of density of the liquid matrix and reinforcement, thermal processes connected with solidifying of the cast, processes leading to changes in physical and structural properties of liquid composite are also investigated. All simulation are carried out by CFD program Fluent. Numerical simulations are performed using the FLUENT two-phase free surface (air and matrix) unsteady flow model (volume of fluid model - VOF) and discrete phase model (DPM)

  6. Structure analysis of Al cast alloy

    Directory of Open Access Journals (Sweden)

    L.A. Dobrzański

    2008-03-01

    Full Text Available Purpose: The developed design methodologies both the material and technological ones will make it possible to improve shortly the quality of materials from the light alloys in the technological process, and the automatic process flow correction will make the production cost reduction possible, and - first of all - to reduce the amount of the waste products.Design/methodology/approach: Castings were analysed in the paper of car engine blocks and heads from the Al-Si-Cu alloys of the AC-AlSi7Cu3Mg type fabricated with the “Cosworth” technological process. In this work the AC-AlSi7Cu3Mg alloy structure was investigated, of this alloy samples were cut of for structure analysis of the cylinder part as well of crankshaft of a fuel engine. The investigation show a difference in the (phase structure morphology as a result of cast cooling rate.Findings: On the quality of casting has influence the walls thickness of car engine elements’.Practical implications: In the metal casting industry, an improvement of component quality depends mainly on better control over the production parameters.Originality/value: The value of the applied methodology was to correct identify the casting effects that occurred during the casting process.

  7. Influence of Al addition on structure of magnesium casting alloys

    Directory of Open Access Journals (Sweden)

    L.A. Dobrzański

    2006-04-01

    Full Text Available Purpose: In the following paper there have been the structure and properties of the MCMgAl9Zn1 magnesium cast alloy as-cast state and after a heat treatment presented.Design/methodology/approach: A casting cycle of alloys has been carried out in an induction crucible furnace using a protective salt bath Flux 12 equipped with two ceramic filters at the melting temperature of 750±10ºC, suitable for the manufactured material. The following results concern transmission and scanning microscopy, X-ray qualitative and quantitative microanalysis.Findings: The analysis of the thin foils after the ageing process has confirmed that the structure of the magnesium cast alloy consists of the solid solution α – Mg (matrix of the secondary phase β – Mg17Al12 evenly located in the structure. The structure creates agglomerates in the form of needle precipitations, partially coherent with the matrix placed mostly at the grain boundaries.Research limitations/implications: According to the alloys characteristic, the applied cooling rate and alloy additions seems to be a good compromise for mechanical properties and microstructures, nevertheless further tests should be carried out in order to examine different cooling rates and parameters of solution treatment process and aging process.Practical implications: A desire to create as light vehicle constructions as possible and connected with it low fuel consumption have made it possible to make use of magnesium alloys as a constructional material in automotive industry.Originality/value: The undertaken examinations aim at defining the influence of a chemical composition and precipitation processes on the structure and casting magnesium alloy properties in its as-cast state and after heat treatment with a different content of alloy components.

  8. Fracture Mechanisms in Steel Castings

    Directory of Open Access Journals (Sweden)

    Z. Stradomski

    2013-07-01

    Full Text Available The investigations were inspired with the problem of cracking of steel castings during the production process. A single mechanism of decohesion - the intergranular one - occurs in the case of hot cracking, while a variety of structural factors is decisive for hot cracking initiation, depending on chemical composition of the cast steel. The low-carbon and low-alloyed steel castings crack due to the presence of the type II sulphides, the cause of cracking of the high-carbon tool cast steels is the net of secondary cementite and/or ledeburite precipitated along the boundaries of solidified grains. Also the brittle phosphor and carbide eutectics precipitated in the final stage solidification are responsible for cracking of castings made of Hadfield steel. The examination of mechanical properties at 1050°C revealed low or very low strength of high-carbon cast steels.

  9. Studies of the transition zone in steel – chromium cast iron bimetallic casting

    Directory of Open Access Journals (Sweden)

    S. Tenerowicz

    2010-01-01

    Full Text Available In this work authors presented the results of transition zone studies on steel – cast iron interface in bimetallic casting. During the investigations cylindrical castings with different diameter were prepared of cast iron with steel rods placed in the center. From each bimetallic casting a microsection was prepared for microhardness tests and metalographic analysis, consisting of transition zone measurement, point and linear analysis as well as quantitative analysis.

  10. Niobium in gray cast iron

    International Nuclear Information System (INIS)

    The potential for utilization of niobium in gray cast iron is appraised and reviewed. Experiments described in literature indicate that niobium provides structural refinement of the eutectic cells and also promotes pearlite formation. (Author)

  11. Casting in Sport

    OpenAIRE

    DeCarlo, Mark; Malone, Kathy; Darmelio, John; Rettig, Arthur

    1994-01-01

    Attempts by sports medicine professionals to return high school athletes with hand and wrist injuries to competition quickly and safely have been the source of confusion and debate on many playing fields around the country. In addition to the differing views regarding the appropriateness of playing cast usage in high school football, a debate exists among sports medicine professionals as to which material is best suited for playing cast construction. Materials used in playing cast constructio...

  12. Research progress on squeeze casting in China

    Institute of Scientific and Technical Information of China (English)

    Li Yuanyuan; Zhang Weiwen; Zhao Haidong; You Dongdong; Zhang Datong; Shao Ming; Zhang Wen

    2014-01-01

    Squeeze casting is a technology with short route, high efficiency and precise forming, possessing features of casting and plastic processing. It is widely used to produce high performance metallic structural parts. As energy conservation and environmental protection concerns have risen, lightweight and high performance metal parts are urgently needed, which accelerated the development of squeeze casting technology over the past two decades in China. In this paper, research progress on squeeze casting aloys, typical parts manufacturing and development of squeeze casting equipment in China are introduced. The future trend and development priorities of squeeze casting are discussed.

  13. Structure-property relationships in centrifugally cast IMI 550 (Ti4Al-4Mo-2Sn-0.5Si)

    International Nuclear Information System (INIS)

    Centrifugal casting technology has been used to produce test pieces and hard-point bracket components for a determination of the structure-property relationships in the age-hardenable titanium alloy IMI 550. Tensile, high cycle fatigue, fracture toughness and elevated temperature creep results have shown that an attractive combination of property levels can be achieved in this alloy. It has been established that the tensile, fatigue and creep performance of cast plus Hot Isostatically Pressed (HIP) IMI 550 approaches that of conventionally wrought material while fracture toughness is superior. The improvement obtained in fracture toughness is a direct result of the presence of the highly acicular Widmanstatten or transformed beta microstructure produced by casting compared with the more traditional equiaxed alpha + beta structure exhibited by wrought products. HIP'ing has been shown to eliminate all traces of as cast internal shrinkage porosity and to thus yield a dramatic improvement in high cycle fatigue performance. HIP'ing was accompanied by general coarsening of the acicular alpha phases present in the micro-structure after casting. Macro and microstructural analysis of the castings indicated a refined and uniform beta grain size which it is believed is due to the presence of silicon in the alloy. 16 references

  14. Analysis of the structure of castings made from chromium white cast iron resistant to abrasive wear

    Directory of Open Access Journals (Sweden)

    D. Kopyciński

    2009-10-01

    Full Text Available It has been proved that an addition of boron carbide and disintegrated steel scrap introduced as an inoculant to the chromium white cast iron changes the structure of castings. The said operation increases the number of crystallization nuclei for dendrites of the primary austenite. In this case, the iron particles act as substrates for the nucleation of primary austenite due to a similar crystallographic lattice. The more numerous are the dendrites of primary austenite and the structure more refined and the mechanical properties higher. Castings after B4C inoculation revealed a different structure of fine grained fracture. Primary precipitates of chromium carbide also appeared, reducing the mechanical properties of as-cast parts. Properly established heat treatment regime makes chromium iron castings regain their, originally high, mechanical properties.

  15. Casting defects in low-pressure die-cast aluminum alloy wheels

    Science.gov (United States)

    Zhang, B.; Cockcroft, S. L.; Maijer, D. M.; Zhu, J. D.; Phillion, A. B.

    2005-11-01

    Defects in automotive aluminum alloy casting continue to challenge metallurgists and production engineers as greater emphasis is placed on product quality and production cost. A range of casting-related defects found in low-pressure die-cast aluminum wheels were examined metallographically in samples taken from several industrial wheel-casting facilities. The defects examined include macro- and micro- porosity, entrained oxide films, and exogenous oxide inclusions. Particular emphasis is placed on the impact of these defects with respect to the three main casting-related criteria by which automotive wheel quality are judged: wheel cosmetics, air-tightness, and wheel mechanical performance.

  16. 声波透射法在灌注桩检测中的应用研究%Explore the Application of Acoustic Wave Transmission Method in the Cast-in-place Pile Detection

    Institute of Scientific and Technical Information of China (English)

    郑育成

    2014-01-01

    The acoustic wave transmission method use the acoustic principle, which means through the spread of acoustic wave at enuation degree in concrete to determine if the cast-i-n-place pile is complete or not, so as to determine the constr-uction quality of cast-in-place pile. Therefore, this article carr-ies on the detailed research and analysis of the application of acoustic wave transmission method in the cast-in-place pile de-tection.%声波透射法利用声学原理,也就是通过声波在混凝土这种介质中传播的衰减程度来确定灌注桩的桩身是否完整,从而确定灌注桩的施工质量。因此,本文就对声波透射法在灌注桩检测中的应用进行了详细的研究和分析。

  17. Casting in sport.

    Science.gov (United States)

    Decarlo, M; Malone, K; Darmelio, J; Rettig, A

    1994-03-01

    Attempts by sports medicine professionals to return high school athletes with hand and wrist injuries to competition quickly and safely have been the source of confusion and debate on many playing fields around the country. In addition to the differing views regarding the appropriateness of playing cast usage in high school football, a debate exists among sports medicine professionals as to which material is best suited for playing cast construction. Materials used in playing cast construction should be hard enough to provide sufficient stabilization to the injured area and include adequate padding to absorb blunt impact forces. The purpose of the biomechanical portion of this investigation was to attempt to determine the most appropriate materials for use in constructing playing casts for the hand and wrist by assessing different materials for: 1) hardness using a Shore durometer, and 2) ability to absorb impact using a force platform. Results revealed that RTV11 and Scotchcast were the "least hard" of the underlying casting materials and that Temper Stick foam greatly increased the ability of RTV11 to absorb impact. Assessment of the mechanical properties of playing cast materials and review of current developments in high school football rules are used to aid practitioners in choosing the most appropriate materials for playing cast construction. PMID:16558257

  18. Structure formation of AlMg2-AlN composite cast in electromagnetic field

    OpenAIRE

    M. Cholewa; M. Staszewski; M. Sozańska; B. Formanek

    2007-01-01

    Purpose: Basic material concept, technology and some results of studies on aluminum matrix composite with dispersive aluminum nitride reinforcement was shown. Studied composites were manufactured with use f ex-situ technique and powder metallurgy.Design/methodology/approach: Aluminum nitride powder was manufactured in process of self-evolving high-temperature synthesis SHS. Composite powder Al-AlN was obtained using mechanical alloying. Composite castings were manufactured in stir casting pro...

  19. 3D structures of liquid-phase GaIn alloy embedded in PDMS with freeze casting.

    Science.gov (United States)

    Fassler, Andrew; Majidi, Carmel

    2013-11-21

    Liquid phase electronic circuits are created by freeze casting gallium-indium (GaIn) alloys, such as eutectic gallium-indium (EGaIn), and encapsulating these frozen components within an elastomer. These metal alloys are liquid at room temperature, and can be cast using either injection or a vacuum to fill a PDMS mold and placing the mold in a freezer. Once solidified, a GaIn alloy segment can be manipulated, altered, or bonded to other circuit elements. A stretchable circuit can be fabricated by placing frozen components onto an elastomer substrate, which can be either patterned or flat, and sealing with an additional layer of elastomer. Circuits produced in this fashion are soft, stretchable, and can have complex 3D channel geometries. In contrast, current fabrication techniques, including needle injection, mask deposition, and microcontact printing, are limited to 2D planar designs. Additionally, freeze casting fabrication can create closed loops, multi-terminal circuits with branching features, and large area geometries. PMID:24067934

  20. Impacts of the structure and processing conditions on the voltage arise in machining of gray cast irons

    Directory of Open Access Journals (Sweden)

    M. Aksoy

    2007-12-01

    Full Text Available Purpose: Machining is one of the most widely used manufacturing processes. The machining of gray cast iron is important because of wide application of these materials in various industries. The machinability studies have been carried out for these materials and it was reported that the amount of graphite in cast irons was one of the influential factor in tool wear during machining. This study is aimed to provide new approach to examine tool life by considering voltage arise during machining of gray cast irons.Design/methodology/approach: The experimental study carried out to measure voltage values during various machining conditions such as cutting speeds, feed rates and depth of cut. Chemical compositions of the four different gray cast irons were machined and the experimental results were compared to the machining of brass and steel. The selected machining conditions were 0.16, 0.32 and 0.48 mm feed rates, 0.5, 1 and 1.5 mm depths of cut and 125, 250 and 355 rpm spindle speeds, respectively.Findings: It was observed that the voltage difference was detected during the machining of cast iron specimens. This was due to increase of graphite particles within total intersections. This would lead to conclusion that high graphite particles would increase voltage and this would provide information about tool wear.Research limitations/implications: Because of being cheap, the usage of cast iron with lamella graphite particles in specific electric circuits to be used in industrial applications need to be further investigated. Also whether or not the cost iron with lamella graphite particles can be used as voltage storage under intensive stress needs to be investigated.Originality/value: Impacts of the structure and processing conditions on the voltage arise in machining of gray cast irons.

  1. Effect of Ni on eutectic structural evolution in hypereutectic Al-Mg2Si cast alloys

    International Nuclear Information System (INIS)

    Research highlights: → By the injection of rod-like NiAl3 phase in Al-Mg2Si alloys, Al-Mg2Si binary eutectic structure gradually evolves into Al-Mg2Si-NiAl3 ternary eutectic. → The ternary eutectic presents a unique double rod structure that rod-like NiAl3 and Mg2Si uniformly distribute in Al matrix. → The mechanism of structural evolution was analyzed in terms of the detailed microstructural observations. → The high temperature (350 deg. C) tensile strength of the alloy increases by 23% due to the eutectic structural evolution. - Abstract: The aim of this work is to investigate the eutectic structural evolution of hypereutectic Al-20% Mg2Si with Ni addition under a gravity casting process. Three-dimensional morphologies of eutectic phases were observed in detail using field emission scanning electron microscopy, after Al matrix was removed by deep etching or extraction. The results show that Al-Mg2Si binary eutectic gradually evolves into Al-Mg2Si-NiAl3 ternary eutectic with the increase of Ni content, and flake-like eutectic Mg2Si transforms into rods. The ternary eutectic presents a unique double rod structure that rod-like NiAl3 and Mg2Si uniformly distribute in Al matrix. Further, the high temperature (350 deg. C) tensile strength of the alloy increases by 23% due to the eutectic structure evolution, and the mechanism of structural evolution was discussed and analyzed in terms of the detailed microstructural observations.

  2. Stability of Spatial Structure of Urban Agglomeration in China Based on Central Place Theory

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper brings forward the concept of stability of the spatial structure of urban agglomeration (UA) based on Central Place Theory by introducing centrality index and fractal theory. Before assessment, K=4 is selected as parameter to calculate centrality index and fractal dimension (K represents the quantitive relationship between city and the counties in Central Place Theory), and then found the number of nodes, the type of spatial structure, the spatial allocation of nodes with different hierarchy affecting the stability of spatial structure. According to spatial contact direction and the level of stability, UAs in China are classified into five types. Finally, it is posed as a further question that how to use hierarchical relation K=6 and K=7 in central place system to coordinate with the assessment of stability of spatial structure is brought forward.

  3. Bainite obtaining in cast iron with carbides castings

    Directory of Open Access Journals (Sweden)

    S. Pietrowski

    2010-01-01

    Full Text Available In these paper the possibility of upper and lower bainite obtaining in cast iron with carbides castings are presented. Conditions, when in cast iron with carbides castings during continuous free air cooling austenite transformation to upper bainite or its mixture with lower bainte proceeds, have been given. A mechanism of this transformation has been given, Si, Ni, Mn and Mo distribution in the eutectic cell has been tested and hardness of tested castings has been determined.

  4. The structure of high-quality aluminium cast iron

    Directory of Open Access Journals (Sweden)

    D. Kopyciński

    2012-01-01

    Full Text Available In this study presents the analyse of aluminium iron cast structure (as-cast condition which are used in high temperature. While producing the casts of aluminium iron major influence has been preserve the structure of technological process parameters. The addition to Fe-C-Al alloy V, Ti, Cr leads to the improvement of functional and mechanical cast qualities. In this study, a method was investigated to eliminate the presence of undesirable Al4C3 phases in a aluminium cast iron structure and thus improve the production process. V and Ti additions in aluminium cast iron allows to development of FeAl - VC or TiC alloys. In particular, V or Ti contents above 5 wt.% were found to totally eliminate the presence of Al4C3. In addition, preliminary work indicates that the alloy with the FeAl - VC or TiC structure reveals high oxidation resistance. The introduction of 5 wt.% chromium to aluminium cast iron strengthened Al4C3 precipitate. Thus, the resultant alloy can be considered an intermetallic FeAl matrix strengthened by VC and TiC or modified Al4C3 reinforcements.

  5. The temperature gradient on section of casting in process of primary crystallization of chromium cast iron

    Directory of Open Access Journals (Sweden)

    A. Studnicki

    2008-08-01

    Full Text Available The methodology of defining in article was introduced the temperature gradient in process of primary crystallization during cooling the casting from chromium cast iron on basis of measurements of thermal field in test DTA-K3. Insert also the preliminary results of investigations of influence temperature gradient on structure of studied wear resistance chromium cast iron.

  6. Investigation on Structure and Properties of Brass Casting

    Institute of Scientific and Technical Information of China (English)

    M.M.Haque; A.A.Khan

    2008-01-01

    In this work, alpha (α) brass was poured in green sand mould and metallic chill mould at about 1050℃. Sand casting method and metallic chill casting method are representing the slow and fast cooling rates of the castings, respectively. The slow cooling rate in the sand mould produces larger grains, while the metallic chill mould produces smaller grains in the castings. As the grain size decreases, the strength of the cast brass increases; micro-porosity in the casting decreases and the tendency for the casting to fracture during solidification decreases. Thus, the faster cooling rate casting offers higher strength, density and hardness compared to the slow cooling rate casting.

  7. Effect of Grain Refinement on Structure Evolution, “Floating” Grains, and Centerline Macrosegregation in Direct-Chill Cast AA2024 Alloy Billets

    NARCIS (Netherlands)

    Nadella, R.; Eskin, D.G.; Katgerman, L.

    2007-01-01

    Direct-chill (DC) cast billets 192 mm in diameter of an Al-Cu-Mg alloy were examined in detail with the aim to reveal the effects of grain refining (GR) and casting speed on structure, “floating” grains, and centerline macrosegregation. Experimental results show that grain size and dendrite arm spac

  8. Effect of electromagnetic stirring on solidification structure of austenitic stainless steel in horizontal continuous casting

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    An investigation on the influence of low frequency rotary electromagnetic stirring on solidification structure of austenitic stainless steel in horizontal continuous casting was experimentally conducted and carried out on an industrial trial basis. The results show that application of appropriate electromagnetic stirring parameters can obviously improve the macrostructure of austenitic stainless steel, in which both columnar and equiaxed grains can be greatly refined and shrinkage porosity or cavity zone along centerline can be remarkably decreased due to eliminating intracrystalline and enlarging equiaxed grains zone. The industrial trials verify that the electromagnetic stirring intensity of austenitic stainless steel should be higher than that of plain carbon steel. Electromagnetic stirring has somewhat affected the macrostructure of austenitic stainless steel even if the magnetic flux density of the electromagnetic stirring reaches 90 mT (amplitude reaches 141 mT ) in average at frequency f=3-4Hz, which provides a reference for the optimization of design and process parameters when applying the rotary electromagnetic stirrer

  9. Effect of electromagnetic stirring on solidification structure of austenitic stainless steel in horizontal continuous casting

    Directory of Open Access Journals (Sweden)

    ZHOU Shu-cai

    2007-08-01

    Full Text Available An investigation on the influence of low frequency rotary electromagnetic stirring on solidification structure of austenitic stainless steel in horizontal continuous casting was experimentally conducted and carried out on an industrial trial basis. The results show that application of appropriate electromagnetic stirring parameters can obviously improve the macrostructure of austenitic stainless steel, in which both columnar and equiaxed grains can be greatly refined and shrinkage porosity or cavity zone along centerline can be remarkably decreased due to eliminating intracrystalline and enlarging equiaxed grains zone. The industrial trials verify that the electromagnetic stirring intensity of austenitic stainless steel should be higher than that of plain carbon steel. Electromagnetic stirring has somewhat affected the macrostructure of austenitic stainless steel even if the magnetic flux density of the electromagnetic stirring reaches 90 mT (amplitude reaches 141 mT in average at frequency f=3-4Hz, which provides a reference for the optimization of design and process parameters when applying the rotary electromagnetic stirrer.

  10. Solidification and casting

    CERN Document Server

    Cantor, Brian

    2002-01-01

    INDUSTRIAL PERSPECTIVEDirect chillcasting of aluminium alloysContinuous casting of aluminium alloysContinuous casting of steelsCastings in the automotive industryCast aluminium-silicon piston alloysMODELLING AND SIMULATIONModelling direct chill castingMold filling simulation of die castingThe ten casting rulesGrain selection in single crystal superalloy castingsDefects in aluminium shape castingPattern formation during solidificationPeritectic solidificationSTRUCTURE AND DEFECTSHetergeneous nucleation in aluminium alloysCo

  11. Comparison of Design Bearing Capacity and Site Static Load Test of the Cast-in-place Piles in Caohe Aqueduct%漕河渡槽灌注桩承载力与静载试验比较

    Institute of Scientific and Technical Information of China (English)

    杨胜慧

    2013-01-01

    The cast-in-place piles foundation is adopted in the Caohe aqueduct body. There is 0.5 meter of the piles foun-dation entering into the weak weathered rock, the bearing capacity of the piles foundation is calculated according to point bearing pile . The static load test is adopted to check the the bearing capacity of the cast-in-place pile foundation, the test results show that the bearing capacity of pile foundation in Caohe aqueduct meet the design requirements.%漕河渡槽槽身段采用灌注桩基础,桩基进入弱风化岩石0.5m,按纯端承桩计算桩基承载力。采用桩基静载试验检测桩基承载力,试验结果表明,漕河渡槽桩基承载力达到设计要求。

  12. The formation of the structure of cast composites in different solidification conditions

    OpenAIRE

    A. Dolata-Grosz; M. Dyzia; J. Śleziona

    2008-01-01

    Purpose: In the research work the result of the reinforcement displacement and solidification analysis foraluminium cast composite with ceramic particles in different solidification conditions have been presented. Theresults of research on the solidification process for heterophase composite have been shown.Design/methodology/approach: : The solidification process of the AK12/ SiC+C composite suspension invarious heat abstraction conditions was recorded using the ThermaCAMTME25 photometer sys...

  13. The Application of the Midas/Civil Software to the Simulation Calculation of Supporting Brackets for Cast-in-Place Beams%Midas/Civil软件在现浇梁支架模拟计算中的应用

    Institute of Scientific and Technical Information of China (English)

    陶友海

    2012-01-01

    The Tangxun Lake Mega Bridge of the newly-built Wuhan-to-Xianning Inter-city Railway, the upper structure of which,in design,is a dual-unit continuous beam,the lower structure of which is made up of five road-spanning piers,is to span the Jiangxia Avenue at a small angle, and in the process of the construction of which the road-spanning portal pier brackets for capping beams and road-spanning supporting brackets for cast-in-place continuous curved beams have to be built. The establish- ment of a space model by means of the Midas/Civil Software and the process of accurately simulating the calculation of the brackets for cast in-place beams under stress, including the setting of the boundary conditions, handling of loads, structural cluster approach and so on, are dealt with in detail in the paper. The calculated results show that the stability of the supporting brackets along the longitudinal direction of the capping beam is poor, in which case they have to be strengthened ~ the shear force at the bottom chord bar of the beam body bracket for the horizontal Bailey Beam is too large,and thus it has to be reinforced. The thinking ways and thinking processes to solve such problems described in the paper may serve as a useful reference for oth- er similar projects.%新建武汉至咸宁城际铁路汤逊湖特大桥小角度跨越江夏大道,上部结构设计为2联连续梁,下部设计为5座跨路门式墩,施工中搭设跨路门式墩盖梁支架和跨路现浇连续弯梁支架。详细介绍了使用Midas/Civ-il软件建立空间模型、准确模拟受力进行现浇支架计算的过程,包括边界条件的设定、荷载的处理和结构分组办法等。计算结果表明:支架门式墩盖梁梁体长度方向稳定性较差,需要加固处理;梁体支架横向贝雷梁下弦杆剪力偏大,改为加强型。文中的考虑解决问题的方法思路和过程可以为类似的工程提供借鉴。

  14. Basic properties of 3D cast skeleton structures

    Directory of Open Access Journals (Sweden)

    M. Cholewa

    2011-12-01

    Full Text Available Purpose: of this paper is to present recent achievements in field of skeleton structures. The aim of this work is to show results of searching for mechanically and technologically advantageous micro- and macrostructures. Methods of microstructure controlling were described. Most important parameters of the manufacturing process were identified.Design/methodology/approach: The influence of internal topology to stress distribution was described with the use of computer simulations. Simulations of the mold filling processes were also carried out. Real experiments were performed to prove the simulation results. The Qualitative and quantitative metallographic analysis were also carried out.Findings: It was found that the octahedron shape of internal cell causes best stress distribution and that the skeleton castings are a good alternative for cellular materials such as metal foams, lattice structures and sandwich panels. Their structured arranged topology allows precise design of properties.Research limitations/implications: Casting methods used to manufacture materials such as described skeleton castings confirmed their usefulness. Not well known and used yet rheological properties of liquid metals allow obtaining shape complicated structures near to metallic foams but structured arranged.Practical implications: Technological parameters of the skeleton castings manufacturing process were developed. Without use of advanced techniques there is a possibility to manufacture cheap skeleton structures in a typical foundry. With use of advanced technology like 3D printing there are almost unlimited possibilities of the skeleton castings internal topologies.Originality/value: Three dimensional cast skeleton structures with internal topology of octahedron confirmed their usefulness as elements used for energy dissipation. Obtaining the homogenous microstructure in the whole volume of complicated shape castings can be achieved.

  15. Effect of Structure Parameters on Power and Magnetic Field in Electromagnetic Soft-Contact Continuous Casting System

    Institute of Scientific and Technical Information of China (English)

    DENG An-yuan; WANG En-gang; HE Ji-cheng

    2008-01-01

    To design a power source system and mold for electromagnetic soft-contact continuous casting process and to theoretically estimate the heat losses from the charges and the system power, the effect of structure parameters on system power and magnetic flux density distribution was calculated using finite element method. The results show that as for electromagnetic soft-contact continuous casting system with partial-segment type mold, the power consumption is much more than that with a full-segment type mold; about 62% of electric power is dissipated in the mold, and the effective acting range of magnetic field is relatively narrow. Optimizing mold structure is a crucial measure of remarkably reducing mold power consumption and saving electric energy. Increasing slit number, width, and length can remarkably increase the magnetic flux density in the mold and can reduce the electric energy consumption. Among structure parameters, slit number and slit width are relatively more effective to reduce energy consumption. For a round billet electromagnetic continuous casting system with diameter of 178 mm, the reasonable slit number, width, and length are about 24-32, 0.5-1.0 mm, and 160 mm, respectively.

  16. 信息动态%Origin of delamination/adhesion in co-casting and the open structure

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    PEI and PSf polymer solutions were used for co-casting. Mechanisms for delamination/adhesion were investigated. It was found that the contribution of the coagulation values of membrane solutions is insignificant to the adhesion of two layers. Instead, membrane shrinkage appears to play a significant role because composite membranes were obtained by minimising their shrinkage difference at the thickness direction by the increase of the coagulant temperature. In addition, the PVP in PSf solution also improves the adhesion between PEI and PSf layer. The open structure formation mechanism of PSf membrane was ascribed to a solvent enriched environment caused by the presence of PEI coating layer, which was confirmed by addition of a large amount of solvent into water coagulant. Finally, the concave defects formation on PSf surface was proposed as the impact of the growth of finger-like macrovoids in PEI layer. The results provides a solid theoretical basis for the expanding the application of co-casting technique.

  17. INVESTIGATION OF ROTARY SPEED INFLUENCE ON STRUCTURE AND CHARACTERISTICS OF ZINC ALLOY ZnAl4Cu3 AT SPIN CASTING IN SILICONE MOULDS

    Directory of Open Access Journals (Sweden)

    M. Bajchichak

    2016-02-01

    Full Text Available Influence of the mould rotary speed on the structure and characteristics of zinc alloy ZnAl4Cu3 at centrifugal casting in silicone moulds using technology TEKCAST is investigated. 

  18. The quality of the joint between alloy steel and unalloyed cast steel in bimetallic layered castings

    Directory of Open Access Journals (Sweden)

    T. Wróbel

    2012-01-01

    Full Text Available In paper is presented technology of bimetallic layered castings based on founding method of layer coating directly in cast process so-called method of mould cavity preparation. Prepared castings consist two fundamental parts i.e. bearing part and working part (layer. The bearing part of bimetallic layered casting is typical foundry material i.e. ferritic-pearlitic unalloyed cast steel, whereas working part (layer is plate of austenitic alloy steel sort X2CrNi 18-9. The ratio of thickness between bearing and working part is 8:1. The aim of paper was assessed the quality of the joint between bearing and working part in dependence of pouring temperature and carbon concentration in cast steel. The quality of the joint in bimetallic layered castings was evaluated on the basis of ultrasonic non-destructive testing, structure and microhardness researches.

  19. The Application of F ine-aggregate Concrete in the Cast-in-place Prestressed Concrete Hollow Slab%细石混凝土在现浇预应力空心楼板结构中的应用

    Institute of Scientific and Technical Information of China (English)

    刘维忠

    2015-01-01

    本文主要介绍了 C40细石混凝土在现浇预应力空心楼板工程实例中的应用,有效解决了预应力空心楼板结构浇筑时泵送难度大、钢筋间距小、填充困难等施工难点,并且通过原材料控制、混凝土生产过程控制、施工现场控制等措施保证 C40细石混凝土的顺利浇筑。经后期检测,满足预应力张拉要求,应用效果理想。%This paper mainly introduced the application of C40 fine-aggregate concrete in the Cast-in-place prestressed concrete hollow slab, the application effectively solved a series of construction difficulties such as small bar spacing, difficult pumping and filling. By taking measures of controlling the quality of materials, concrete production process and the construction site to realize the smooth casting of C40 fine-aggregate concrete. After the later detection, this concrete met the requirements of prestressed tensioning and the application effect proved to be ideal.

  20. Mitochondrial structure and dynamics as critical factors in honey bee (Apis mellifera L.) caste development.

    Science.gov (United States)

    Santos, Douglas Elias; Alberici, Luciane Carla; Hartfelder, Klaus

    2016-06-01

    The relationship between nutrition and phenotype is an especially challenging question in cases of facultative polyphenism, like the castes of social insects. In the honey bee, Apis mellifera, unexpected modifications in conserved signaling pathways revealed the hypoxia response as a possible mechanism underlying the regulation of body size and organ growth. Hence, the current study was designed to investigate possible causes of why the three hypoxia core genes are overexpressed in worker larvae. Parting from the hypothesis that this has an endogenous cause and is not due to differences in external oxygen levels we investigated mitochondrial numbers and distribution, as well as mitochondrial oxygen consumption rates in fat body cells of queen and worker larvae during the caste fate-critical larval stages. By immunofluorescence and electron microscopy we found higher densities of mitochondria in queen larval fat body, a finding further confirmed by a citrate synthase assay quantifying mitochondrial functional units. Oxygen consumption measurements by high-resolution respirometry revealed that queen larvae have higher maximum capacities of ATP production at lower physiological demand. Finally, the expression analysis of mitogenesis-related factors showed that the honey bee TFB1 and TFB2 homologs, and a nutritional regulator, ERR, are overexpressed in queen larvae. These results are strong evidence that the differential nutrition of queen and worker larvae by nurse bees affects mitochondrial dynamics and functionality in the fat body of these larvae, hence explaining their differential hypoxia response. PMID:27058771

  1. Metallographic and autoradiographic investigation of the structure of centrifugally cast steel

    International Nuclear Information System (INIS)

    Metallographic and autoradiographic investigations were carried out on the structure of steel tubes cast in a horizontal axis centrifugal casting machine. In chill castings the chill and columnar zones showed significantly lower sulphur contents than the equiaxed zone. Mould rotational speed was found to have an important influence on sulphur segregation. Sulphur-depleted bands, which were often observed in the castings were found to arise due to minor variations in the mould rotational speed. (auth.)

  2. Place Branding in Systems of Place

    DEFF Research Database (Denmark)

    Zenker, Sebastian; Andéhn, Mikael

    2015-01-01

    The pervasive managerial logic of branding has established a stable foothold in the context of place management. Yet the question of whether places, such as cities, regions and nations, can be effectively managed using marketing techniques remains elusive, as place brands and company brands have...... – like a city, region or nation brand – is per definition attached to a system of geographical abstractions in quasi-cartographic form in which each city, region or nation is understood in relation and contrast to other geographical entities. For those who seek to alter perceptions about a place.......g. the European Union or Africa). Using the example of nation branding for Sudan and Slovenia, one can identify supranational places such as “sub-Saharan Africa” or “Eastern Europe”, carrying their own highly salient and often negative meaning in much of the Western world. We explore how association to a system...

  3. Evaluation of porosity in Al alloy die castings

    Directory of Open Access Journals (Sweden)

    M. Říhová

    2012-01-01

    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.

  4. PLACE AND ROLE OF THE STRUCTURAL FUNDS IN THE LOCAL BUDGET REVENUES

    Directory of Open Access Journals (Sweden)

    CRISTINEL ICHIM

    2016-06-01

    Full Text Available In this study we aim to analyse the place and role manifested within local budgets of Romania by a new category of revenues available to local authorities namely those from the Structural and Cohesion Funds of the EU. At the beginning of our scientific approach we have outlined the scope of local government revenues highlighting that in the section development of local budgets are also set off funds from the European Union. The research continues with a characterization of the structural funds in which, on the one hand, we have emphasized their importance to the development of territorial administrative units in Romania and on the other hand we showed some difficulties arising in the process of absorption of European funds. The analysis of financial resources from the EU funds within the local budgets from Romania is the last part of the article and is based on the quantitative analysis of the budget indicator, "amounts of the EU in the payments made and pre-financing" from existing data in the Statistical Yearbook of Romania, and highlights the place occupied by such income within local public revenues. This analysis shows that local public authorities from Romania have made significant progress in terms of accessing European funds, their share in total revenues of local budgets increased during 2008-2014.

  5. Comparative study: sensitization development in hot-isostatic-pressed cast and wrought structures type 316L(N)-IG stainless steel under isothermal heat treatment

    International Nuclear Information System (INIS)

    This work focuses on the relative sensitization resistance of type 316L(N)-IG stainless steel (SS). Cast and wrought structures SS after solid hot-isostatic pressing (solid-HIP) operation are investigated under isothermal heat treatment. Wrought SS/SS solid-HIP joint sensitization is taken also into consideration. These experiments employed the quantitative double-loop electrochemical potentiokinetic reactivation (DL-EPR) and oxalic acid etch screening tests. A copper-copper sulfate-16% sulfuric acid test applied for strongly sensitized cast SS to reinforce the results were received by the methods mentioned above. Results from all employed methods correlate well. Sensitization was detected neither in cast nor in wrought SS in as-HIPed condition excluding wrought SS/SS solid-HIP joints. Significant difference between sensitization development rates was determined in cast and wrought SS structures when annealing at 675 deg. C for a duration up to 50 h

  6. Segregation in cast products

    Indian Academy of Sciences (India)

    A Ghosh

    2001-02-01

    Microsegregation gets eliminated significantly if subsequent hot working and/or annealing are done on cast products. Macrosegregation however persists, causing problems in quality, and hence, has to be attended to. Microsegregation is a consequence of rejection of solutes by the solid into the interdendritic liquid. Scheil’s equation is mostly employed. However, other equations have been proposed, which take into account diffusion in solid phase and/or incomplete mixing in liquid. Macrosegregation results from movements of microsegregated regions over macroscopic distances due to motion of liquid and free crystals. Motion of impure interdendritic liquid causes regions of positive macrosegregation, whereas purer solid crystals yield negative macrosegregation. Flow of interdendritic liquid is primarily natural convection due to thermal and solutal buoyancy, and partly forced convection due to suction by shrinkage cavity formation etc. The present paper briefly deals with fundamentals of the above and contains some recent studies as well. Experimental investigations in molten alloys do not allow visualization of the complex flow pattern as well as other phenomena, such as dendrite-tip detachment. Experiments with room temperature analogues, and mathematical modelling have supplemented these efforts. However, the complexity of the phenomena demands simplifying assumptions. The agreement with experimental data is mostly qualitative. The paper also briefly discusses centreline macrosegregation during continuous casting of steel, methods to avoid it, and the, importance of early columnar-to-equiaxed transition (CET) as well as the fundamentals of CET.

  7. Effect of liquid volume on the evolution of solidified structure in horizontal centrifugal casting

    Science.gov (United States)

    Esaka, H.; Kataoka, Y.; Shinozuka, K.

    2015-06-01

    Horizontal centrifugal casting process is widely applied for long products. However, it often has macro-segregation problems, such as band segregation. In order to understand solidification process in this process, in-situ observation using transparent substances has been performed. Here, the effect of liquid volume in the mold was investigated. Succinonitrile-water alloy was introduced in the glass cell and filling ratio of organic alloy was varied from 70 to 100 vol. % and the rotation rate was set to be 250 rpm. Equiaxed grains formed in case of low filling ratio. On the other hand, no equiaxed grain formed when the filling ratio was 100 vol. %. Strong fluid flow may be induced by the fluctuation of free surface and this may form equiaxed grains. However, when the area of free surface decreased with increasing filling ratio, the influence of free surface diminished and fluid flow was stabilized. Therefore, well-developed columnar zone grew and no equiaxed grains formed.

  8. Place in Transition

    DEFF Research Database (Denmark)

    Mikkelsen, Jacob Bjerre; Lange, Ida Sofie Gøtzsche

    redefinition of oil rigs from an urban design perspective. The paper constitutes a theoretical basis for future design scenarios - exemplified through visionary urban design proposals for a specific site in the city of Esbjerg, Denmark. Relocating rigs to an urban context initiates discussions of conception of...... 'Place' questioning the fixity of 'Place' (Jensen 2010). Scoped through a relational sense of place (Massey 1993) and the potential of exploring new relations between places (Burns & Kahn 2005), the paper challenges the notion of 'Place as God' (Hvattum 2010). These places in transition contest the...

  9. Complex Doping of Uranium under Centrifugal Casting in Zirconium Mold

    International Nuclear Information System (INIS)

    The paper presents the results of the investigation on the structure and distribution pattern of the doping elements in uranium casting, produced by the centrifugal casting in a sealed zirconium mold. It is investigated the possibility of complex zirconium and iron doping of uranium. The values of the zirconium mold dissolution rate against the centrifugal casting time are provided. The mechanism is suggested for doping uranium with the elements included in the mold material during the fuel rod fabrication by the centrifugal casting

  10. THE IMPACT OF STRUCTURAL, PETROGRAPHIC AND CLIMATIC FACTORS ON THE SLOPE STABILITY IN THE OPEN CAST MINE OF GRADNA

    Directory of Open Access Journals (Sweden)

    Ivan Tomašić

    1992-12-01

    Full Text Available This paper presents an analysis of a complexity of interrelated structural, petrologic and climatic factors that considerably affect the instabilities in the open cast mine of Gradna, near Samobor. The instabilities provoke the slope failures such as slides and slumps of rock material. During the protracted periodical investigations, the relationship among the factors of regional geology, tectonics, structural geology, petrography, engineering geology, rock mechanics and the rock mining technology was observed in the area. The local control of hydrogeologic properties, as well as climatic fluctuations of temperature and precipitation on the slope stability, was also recognized. It turned out that the structural relationships, characteristic of the manifold cataclased dolomite, stimulated the development of local instabilities, particularly during the period of low temperatures affecting the process of ground-water accumulation. When the temperatures are worm, the ground-water circulation is slow, exerting only the small-scale influence on the local instabilities (the paper is published in Croatian.

  11. Synthesis and structural evaluation of freeze-cast porous alumina

    International Nuclear Information System (INIS)

    In this work we fabricated alumina samples by the freeze-casting technique using tert-butanol as the solvent. The prepared materials were examined by scanning electron microscopy and X-ray microtomography. Next, they were coated with sol–gel silica films by dip-coating. Permeability tests were carried out in order to assess the permeation behavior of the materials processed in this study. We observed that the sintering time and alumina loading showed a remarkable effect on both the structural properties and flexural strength of the freeze-cast samples. Nitrogen adsorption tests revealed that the silica prepared in this study exhibited a microporous structure. It was observed that the presence of silica coatings on the alumina surface decreased the CO2 permeance by about one order of magnitude. Because of the similar kinetic diameters of nitrogen and carbon dioxide, the CO2/N2 system showed a separation efficiency that was lower than that observed for the He/CO2 and He/N2 systems. We noticed that increasing the feed pressure improved the separation capacity of the obtained materials. - Highlights: • Porous alumina samples obtained by the freeze-casting technique • Microporous silica coating prepared by a simple sol–gel dip-coating methodology • Samples examined by SEM, μ-CT, and nitrogen sorption tests • Mechanical tests were carried out in the freeze-cast samples. • The presence of silica coatings on the alumina surface decreased the CO2 permeance

  12. As-cast structure of DC casting 7075 aluminum alloy obtained under dual-frequency electromagnetic field

    Institute of Scientific and Technical Information of China (English)

    Zhi-hao Zhao; Zhen Xu; Gao-song Wang; Qing-feng Zhu; Jian-zhong Cui

    2014-01-01

    We have experimentally determined the as-cast structures of semi-continuous casting 7075 aluminum alloy obtained in the pres-ence of dual-frequency electromagnetic field. Results suggest that the use of dual-frequency electromagnetic field during the semi-continuous casting process of 7075 aluminum alloy ingots reduces the thickness of the surface segregation layer, increases the height of the melt menis-cus, enhances the surface quality of the ingot, and changes the surface morphology of the melt pool. Moreover, low-frequency electromag-netic field was found to show the most obvious influence on improving the as-cast structure because of its high permeability in conductors.

  13. Simulation of Heat Flow in Computational Method and Its Verification on the Structure and Property of Gray Cast Iron

    Directory of Open Access Journals (Sweden)

    S. K. Shaha

    2010-01-01

    Full Text Available Problem statement: The solidification of materials depends on the cooling rate of the materials which is governed by heat flow in the mould and alloy composition. Solidification rate also affects the structure and properties of the materials. Approach: In the present study, the heat flow of cold set resin bonded sand mould was simulated using JL Analyzer FEM analysis software. To verify the model, the gray cast iron was melted at 1350°C temperature and poured into a resin bonded sand mould at 1300°C. Results: It showed that most of the heat-reserve at the junction of the mould which was nearer to the source of liquid metal and the lowest heat-reserve at the end of the mould. So, the solidification rate was very high at the end of the mould wall whereas it was comparatively low near the sprue of the mould. Conclusion: Finally, depending on the heat-flow through the mould, the solidification rate changed the microstructure from chill, mottled and gray cast iron and hardness changed from 95.1 HRB-78.78 HRB.

  14. 铸造铝合金叶轮嵌铸铸铁轮芯结构设计及工艺要点%Structural Design and Process Essentials of Inlay Casting Iron Core in Cast Aluminum Impeller

    Institute of Scientific and Technical Information of China (English)

    洪美琴; 尹社新

    2011-01-01

    Inlay casting iron core sometimes looses in axial direction from the running cast aluminum impeller, then the fan will cause fault such as vibration and abnormal voice etc. The effects of the two different configurations of the cast aluminum iron core on the quality of the impeller were analyzed in this paper. Structural design of inlay core and casting technology of impeller were briefly explained.%采用嵌铸铸铁轮芯的铸造铝合金叶轮在运行中有时出现轴向松动的现象,使运转中的风机产生振动、异音等故障.文中对铸造铝合金叶轮中嵌铸铸铁轮芯的两种不同结构对叶轮质量的影响进行了分析,阐述了铸造铝合金叶轮中嵌铸铸铁轮芯的结构设计和工艺要点.

  15. Structuring virtual spaces as television places

    DEFF Research Database (Denmark)

    Reinhard, CarrieLynn D.

    As all major American broadcast and cable networks now provide some form and amount of online distribution of their television programming, we are beginning to see more interactive features being attached to this distribution to remediate the conditions of television consumption in the physical...... studies of virtual places are analyzed in terms of how interactivity is being managed.  Two types of interactivity are used to compare these case studies: social interaction and narrative interaction.  Broadcast networks CBS and NBC separately created virtual places to imitate “living room” conditions of...... considering how these Internet-based interactive television examples demonstrate the remediation of conventional conceptualizations of television distribution structures and consumption practices, which then indicate the power dynamics of the producer-consumer relationship.  The form in which the...

  16. Teaching Bodies in Place

    Science.gov (United States)

    Jones, Stephanie; Woglom, James F.

    2013-01-01

    Background/Context: This piece draws on literature in justice-oriented teacher education, feminist pedagogy, and postmodern notions of bodies and place to make sense of data generated from a three-year study of an undergraduate teacher education course. A feminist lens was used to engage a body- and place-focused pedagogy that aimed to engage…

  17. Prediction of useful casting structure applying Cellular Automaton method

    Directory of Open Access Journals (Sweden)

    Z. Ignaszak

    2009-07-01

    Full Text Available The results of simulation investigations of primary casting’s structure made of hypoeutectic Al-Si alloy using the Calcosoft system with CAFE 3D (Cellular Automaton Finite Element module are presented. CAFE 3-D module let to predict the structure formation of complete castings indicating the spatial distribution of columnar and equiaxed grains. That simplified model concerns only hypoeutectic phase. Simulation investigations of structure concern the useful casting of camshaft which solidified in high-insulation mould with properly chills distribution. These conditions let to apply the expedient locally different simplified the grains blocs geometry which are called by the authors as pseudo-crystals. The mechanical properties in selected cross-sections of casing are estimated.

  18. Mathematical Modelling of the Thermical Regime in the Continous Casting Process

    OpenAIRE

    Monika Erika POPA; Kiss, Imre

    2005-01-01

    Continuous casting is one of the prominent methods of production of casts. Effective design and operation of continuous casting machines needs complete analysis of the continuous casting process. In this paper the basic principles of continuous casting and its heat transfer analysis using the finite element method are presented. In the analysis phase change is assumed to take place at constant temperature. A front tracking algorithm has been developed to predict the position of the solidifica...

  19. Structure dependence of the dynamic Young modulus, G modulus and the attenuation in high temperature forged alloys and cast alloys

    International Nuclear Information System (INIS)

    This work consists of two parts. The first part reports on the measurement of the elastic properties and the thermal expansion coefficients of selected, technically important high temperature alloys (as e.g. cast alloys and forged alloys, directionally solidified alloys, single crystals) in the temperature range of 20deg C to 1200deg C. The orientation dependence and the structure dependence of these characteristics are of special interest especially in this study. The second part reports on investigations of selected materials with regard to the quantitative relationships between the elastic properties of single-phase single crystals and multiphase single crystals, directionally solidified alloys as well as polycrystals without und with texture, in the temperature range of 20deg C to 1200deg C. The limiting value concept and the phase mixing rules are used for the evaluation. (orig./MM) With 133 figs., 18 tabs., 322 refs

  20. Effect of partial remelting time on the initial carbide in semisolid structure of hypereutectic hih Cr cast iron

    Directory of Open Access Journals (Sweden)

    Zhifu HUANG

    2004-11-01

    Full Text Available In order to review the effect of partial remelting time on the morphology of initial carbides, semisolid ingots of hypereutectic high Cr17 cast iron were remelted at 1 270 ℃ for four different times, and the changing characteristics of shape factor an the equivalent diameter of initial carbides were analyzed quantitatively using a Leica image analyzer. The results indicate that firstly, the evolution process of the initial carbides' morphology undergoes melting, sheroidization and refining during the partial remelting; secondly, the solute diffusion and interface tension take dominant roles at the primary and the middle-final stages respectively in the process of initial carbde evolution; finally, a perfect structure can be obtained by remeltin semisolid ingots at 1 270 ℃ for 15 min.

  1. Undercooling and nodule count in thin walled ductile iron castings

    DEFF Research Database (Denmark)

    Pedersen, Karl Martin; Tiedje, Niels Skat

    2007-01-01

    Casting experiments have been performed with eutectic and hypereutectic castings with plate thick¬nesses from 2 to 8 mm involving both temperature measurements during solidification and micro¬structural examination afterwards. The nodule count was the same for the eutectic and hypereutectic...... castings in the thin plates ( 4.3 mm) while in the 8 mm plate the nodule count was higher in the hypereutectic than in the eutectic castings. The minimum temperature prior to the eutectic recalescence (Tmin) was 15 to 20C lower for the eutectic than the hypereutectic castings. This is due to nucleation...... of graphite nodules which begins at a lover temperature in the eutectic than in the hypereutectic castings The recalescence (Trec) was however also larger for the eutectic casting and in the thin plates the maximum temperature after recalescence (Tmax) was the same in the eutectic and hypereutectic...

  2. Structure and properties of metal of commercial steam pipes produced by centrifugal casting

    International Nuclear Information System (INIS)

    Structure and properties of metal of large diameter pipes produced by centrifugal casting of 15Kh1M1FL steel are investigated. It is shown that the structure of centrifugally cast pipe metal is much more in homogeneous than that of hot-rolled pipes

  3. Effect of Ni on eutectic structural evolution in hypereutectic Al-Mg{sub 2}Si cast alloys

    Energy Technology Data Exchange (ETDEWEB)

    Li Chong; Wu Yaping; Li Hui; Wu Yuying [Key Laboratory of Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, 17923 Jingshi Road, Jinan 250061 (China); Liu Xiangfa, E-mail: xfliu@sdu.edu.cn [Key Laboratory of Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, 17923 Jingshi Road, Jinan 250061 (China)

    2010-12-15

    Research highlights: {yields} By the injection of rod-like NiAl{sub 3} phase in Al-Mg{sub 2}Si alloys, Al-Mg{sub 2}Si binary eutectic structure gradually evolves into Al-Mg{sub 2}Si-NiAl{sub 3} ternary eutectic. {yields} The ternary eutectic presents a unique double rod structure that rod-like NiAl{sub 3} and Mg{sub 2}Si uniformly distribute in Al matrix. {yields} The mechanism of structural evolution was analyzed in terms of the detailed microstructural observations. {yields} The high temperature (350 deg. C) tensile strength of the alloy increases by 23% due to the eutectic structural evolution. - Abstract: The aim of this work is to investigate the eutectic structural evolution of hypereutectic Al-20% Mg{sub 2}Si with Ni addition under a gravity casting process. Three-dimensional morphologies of eutectic phases were observed in detail using field emission scanning electron microscopy, after Al matrix was removed by deep etching or extraction. The results show that Al-Mg{sub 2}Si binary eutectic gradually evolves into Al-Mg{sub 2}Si-NiAl{sub 3} ternary eutectic with the increase of Ni content, and flake-like eutectic Mg{sub 2}Si transforms into rods. The ternary eutectic presents a unique double rod structure that rod-like NiAl{sub 3} and Mg{sub 2}Si uniformly distribute in Al matrix. Further, the high temperature (350 deg. C) tensile strength of the alloy increases by 23% due to the eutectic structure evolution, and the mechanism of structural evolution was discussed and analyzed in terms of the detailed microstructural observations.

  4. Ductile fracture behavior of cast structure containing voids

    International Nuclear Information System (INIS)

    In pressurized water reactors, the primary loop contains cast-piping components made of duplex stainless steel. Due to the presence of ferrite, such steels are susceptible to thermal aging embrittlement, which decrease their fracture resistance. The cast process induces shrinkage cavities, therefore all these components are submitted to liquid penetrant examination and all surface defects are repaired. EDF, CEA and Framatome have conducted experimental and analytical analysis of fatigue and fracture behavior of aged cast stainless steel structures containing shrinkage cavities. The present study considers only ductile tearing and is based on specimen test results and a fracture mechanics model of the interaction between shrinkage cavities. The experimental results presented here show that large groups of shrinkage cavities have almost no influence on the global behavior of the structure. Only for the specimen with the largest reduction of area, a significant reduction of strength has been registered. Using elementary fracture mechanics models, it has been evidenced that failure mechanism of structures containing shrinkage cavities consists in 3 phases: local initiation, macro-crack formation by coalescence and failure by crack instability or collapse depending if J resistance is low or not. No significant changes in global behavior appear in the first phase. (A.C.)

  5. Solidified structure of thin-walled titanium parts by vertical centrifugal casting

    OpenAIRE

    Wu Shiping; Xu Qin; Zhang Jun

    2011-01-01

    The solidified structure of the thin-walled and complicated Ti-6Al-4V castings produced by the vertical centrifugal casting process was studied in the present work. The results show that the wall thickness of the section is featured with homogeneously distributed fine equiaxial grains, compared with the microstructure of the thick-walled section. The grain size of the castings has a tendency to decrease gradually with the increasing of the centrifugal radius. The inter-lamellar space in thick...

  6. Context in place

    DEFF Research Database (Denmark)

    Nordentoft, Helle Merete; Thomsen, Rie

    The purpose of this paper is to provide a theoretical framework - i.e. a vocabulary - for understanding the importance of integrating context in analyses of guidance practices. The paper delineates a conceptual landscape of context based on social practice and interactional theories on context. We...... studies on interdisciplinary clinical supervision and work place guidance in which there appears to be a mismatch between intended outcomes and actual events. The analyses demonstrate and support that 'the place' seems - to influence partipants' responses in the guidance sessions and, therefore, must be...... specifically argue for a more grounded approach to the conception of context - a topographic approach - in which the physical setting - i.e. 'the place' becomes an inevitable part of analyses of guidance practices in order to understand participants' sense-making processes. In the paper we draw on two case...

  7. Ageing in Communal Place

    DEFF Research Database (Denmark)

    Aarhus, Rikke; Ballegaard, Stinne Aaløkke; Grönvall, Erik;

    2009-01-01

    In this paper we adopt the position that design of social media for the elderly and virtual senior communities may be informed by studying ‘real’ senior communities. Since current research efforts target the role of social media and virtual communities for supporting seniors ageing in place, i...... how these findings apply to designers of social media technologies. .......e. in their homes, housing communities seem a natural place to begin this enquiry. We conducted observations and informal interviews in six different senior dwellings. In this paper we present the key findings from these visits related to social interaction and the formation of communities and explicate...

  8. Heat treatment impact on the structure of die-cast magnesium alloys

    Directory of Open Access Journals (Sweden)

    L.A. Dobrzański

    2007-01-01

    Full Text Available Purpose: In the following paper there have been the structure and properties of the MCMgAl6Zn1 magnesiumcast alloy as-cast state and after a heat treatment presented.Design/methodology/approach: A casting cycle of alloys has been carried out in an induction crucible furnaceusing a protective salt bath Flux 12 equipped with two ceramic filters at the melting temperature of 750±10ºC,suitable for the manufactured material. The following results concern light and scanning microscopy, X-rayqualitative and quantitative microanalysis.Findings: The results of the EDS chemical composition analysis confirm the presence of magnesium, aluminum,manganese, and zinc, constituting the structure of α solid solution with the Mg17Al12 placed mainly on the grainorder in the form of plates, also the phase AlMnFe with irregular shape, occurred often in the shape of blocksor needles and the Laves phase Mg2Si.Research limitations/implications: According to the alloys characteristic, the applied cooling rate and alloyadditions seems to be a good compromise for mechanical properties and microstructures, nevertheless furthertests should be carried out in order to examine different cooling rates and parameters of solution treatmentprocess and aging process.Practical implications: A desire to create as light vehicle constructions as possible and connected with itlow fuel consumption have made it possible to make use of magnesium alloys as a constructional material inautomotive industry.Originality/value: The undertaken examinations aim at defining the influence of a chemical composition andprecipitation processes on the structure and casting magnesium alloy properties in its as-cast state and after heattreatment with a different content of alloy components.

  9. Ageing in communal place

    DEFF Research Database (Denmark)

    Aarhus, Rikke; Ballegaard, Stinne Aaløkke; Grönvall, Erik;

    2009-01-01

    In this paper we adopt the position that design of social media for the elderly and virtual senior communities may be informed by studying `real´senior communities. Since current research efforts target the role of social media and virtual communities for supporting seniors ageing in place, i.e. in...

  10. Synthesis and structural evaluation of freeze-cast porous alumina

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Douglas F., E-mail: souzadf@outlook.com [Department of Metallurgical and Materials Engineering, Federal University of Minas Gerais — UFMG, Avenida Presidente Antônio Carlos, 6627, Campus UFMG, Belo Horizonte, MG CEP: 31270-901, Escola de Engenharia, bloco 2, sala 2230 (Brazil); Nunes, Eduardo H.M., E-mail: eduardohmn@gmail.com [Department of Metallurgical and Materials Engineering, Federal University of Minas Gerais — UFMG, Avenida Presidente Antônio Carlos, 6627, Campus UFMG, Belo Horizonte, MG CEP: 31270-901, Escola de Engenharia, bloco 2, sala 2230 (Brazil); Pimenta, Daiana S.; Vasconcelos, Daniela C.L. [Department of Metallurgical and Materials Engineering, Federal University of Minas Gerais — UFMG, Avenida Presidente Antônio Carlos, 6627, Campus UFMG, Belo Horizonte, MG CEP: 31270-901, Escola de Engenharia, bloco 2, sala 2230 (Brazil); Nascimento, Jailton F.; Grava, Wilson [Petrobras/CENPES, Avenida Horácio Macedo 950, Cidade Universitária, Ilha do Fundão, Rio de Janeiro, RJ CEP:21941-915 (Brazil); Houmard, Manuel [Department of Materials Engineering and Civil Construction, Federal University of Minas Gerais — UFMG, Avenida Presidente Antônio Carlos, 6627, Campus UFMG, Belo Horizonte, MG CEP: 31270-901, Escola de Engenharia, bloco 1, sala 3304 (Brazil); Vasconcelos, Wander L., E-mail: wlv@demet.ufmg.br [Department of Metallurgical and Materials Engineering, Federal University of Minas Gerais — UFMG, Avenida Presidente Antônio Carlos, 6627, Campus UFMG, Belo Horizonte, MG CEP: 31270-901, Escola de Engenharia, bloco 2, sala 2230 (Brazil)

    2014-10-15

    In this work we fabricated alumina samples by the freeze-casting technique using tert-butanol as the solvent. The prepared materials were examined by scanning electron microscopy and X-ray microtomography. Next, they were coated with sol–gel silica films by dip-coating. Permeability tests were carried out in order to assess the permeation behavior of the materials processed in this study. We observed that the sintering time and alumina loading showed a remarkable effect on both the structural properties and flexural strength of the freeze-cast samples. Nitrogen adsorption tests revealed that the silica prepared in this study exhibited a microporous structure. It was observed that the presence of silica coatings on the alumina surface decreased the CO{sub 2} permeance by about one order of magnitude. Because of the similar kinetic diameters of nitrogen and carbon dioxide, the CO{sub 2}/N{sub 2} system showed a separation efficiency that was lower than that observed for the He/CO{sub 2} and He/N{sub 2} systems. We noticed that increasing the feed pressure improved the separation capacity of the obtained materials. - Highlights: • Porous alumina samples obtained by the freeze-casting technique • Microporous silica coating prepared by a simple sol–gel dip-coating methodology • Samples examined by SEM, μ-CT, and nitrogen sorption tests • Mechanical tests were carried out in the freeze-cast samples. • The presence of silica coatings on the alumina surface decreased the CO{sub 2} permeance.

  11. Cementite Solidification in Cast Iron

    Science.gov (United States)

    Coronado, J. J.; Sinatora, A.; Albertin, E.

    2014-06-01

    Two hypereutectic cast irons (5.01 pct Cr and 5.19 pct V) were cast and the polished surfaces of test pieces were deep-etched and analyzed via scanning electron microscopy. The results show that graphite lamellae intersect the cementite and a thin austenite film nucleates and grows on the cementite plates. For both compositions, graphite and cementite can coexist as equilibrium phases, with the former always nucleating and growing first. The eutectic carbides grow from the austenite dendrites in a direction perpendicular to the primary plates.

  12. Do attitudes toward societal structure predict beliefs about free will and achievement? Evidence from the Indian caste system.

    Science.gov (United States)

    Srinivasan, Mahesh; Dunham, Yarrow; Hicks, Catherine M; Barner, David

    2016-01-01

    Intuitive theories about the malleability of intellectual ability affect our motivation and achievement in life. But how are such theories shaped by the culture in which an individual is raised? We addressed this question by exploring how Indian children's and adults' attitudes toward the Hindu caste system--and its deterministic worldview--are related to differences in their intuitive theories. Strikingly, we found that, beginning at least in middle school and continuing into adulthood, individuals who placed more importance on caste were more likely to adopt deterministic intuitive theories. We also found a developmental change in the scope of this relationship, such that in children, caste attitudes were linked only to abstract beliefs about personal freedom, but that by adulthood, caste attitudes were also linked to beliefs about the potential achievement of members of different castes, personal intellectual ability, and personality attributes. These results are the first to directly relate the societal structure in which a person is raised to the specific intuitive theories they adopt. PMID:25754516

  13. Structure, castability and mechanical properties of commercially pure and alloyed titanium cast in graphite mould.

    Science.gov (United States)

    Cheng, W W; Ju, C P; Lin, J H Chern

    2007-07-01

    This report is a study of structure, castability, mechanical properties as well as corrosion behaviour of titanium doped with up to 5 weight percentage (wt%) of a series of alloy elements, including Ta, Mo, Nb, Hf, Zr, Sn, Bi and Ag. The results indicate that, with addition of 1 wt% alloy element, Bi and Mo were most effective in enhancing the castability of titanium. With more alloy elements added, the castability values of most alloys more or less decreased. Except Ti-Mo system, all Ti alloys with a fine acicular morphology had the same crystal structure (hcp) as that of c.p. Ti with a typical lath type morphology. When 3 wt% or more Mo was added, a finer orthorhombic alpha'' phase was formed. The microhardness and bending strength values of Ti alloys were all higher than those of c.p. Ti. Among all alloys, Ti-Mo system exhibited the highest hardness and strength level. For a certain alloy, the bending strength did not necessarily increase with its alloy content. Except Ti-5Zr and Ti-Mo alloys, the bending moduli of most alloy systems were not much different from that of c.p. Ti. All alloys showed an excellent resistance to corrosion in Hanks' solution at 37 degrees C. PMID:17559621

  14. Some characteristics properties of structure of stainless steel pipe blanks produced by vacuum centrifugal casting for nuclear power

    International Nuclear Information System (INIS)

    Results of studies macro- and microstructures of centrifugal castings and distributions of inclusions and alloying elements and impurities are presented. It was established that distribution of components of steels in castings is uniform. The macro structure is band and the microstructure is dendritic. Principal feature of centrifugal castings is redistribution of inclusions, main part of casting being free from conclusions. 1 refs.; 4 figs.; 3 tabs. (author)

  15. Numerical Simulation System for Casting Process in Concurrent Engineering

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    According to the implementing principle and application background of the Concurrent Engineering (CE) project, studies on the integration of numerical simulation system for casting process with CE, simulation of turbulent phenomena in filling process of casting by Algebraic Stress Model (ASM), computation efficiency of filling process and quantitative prediction of shrinkage cavity and porosity under feeding condition of several risers are discussed. After the simulation of casting process of typical magnesium-based alloy casting with complicated structure, remarkable success in assuring the quality is also presented.

  16. Examples of material solutions in bimetallic layered castings

    Directory of Open Access Journals (Sweden)

    S. Tenerowicz

    2011-07-01

    Full Text Available In paper is presented technology of bimetallic layered castings based on founding method of layer coating directly in cast process so-called method of mould cavity preparation. Prepared castings consist two fundamental parts i.e. bearing part and working part (layer. The bearing part of bimetallic layered casting is typical foundry material i.e. pearlitic grey cast iron, whereas working part (layer is depending on accepted variant plates of alloy steels sort X6Cr13, X12Cr13, X10CrNi18-8 and X2CrNiMoN22-5-3. The ratio of thickness between bearing and working part is 8:1. The verification of the bimetallic layered castings was evaluated on the basis of ultrasonic NDT (non-destructive testing, structure and macro- and microhardness researches.

  17. In Place of Fishing

    DEFF Research Database (Denmark)

    Ounanian, Kristen

    2016-01-01

    the imposition of transferable catch shares, this research takes a holistic approach to studying coastal communities. This study focuses on instances of transition from a greater presence of the fishing industry to new configurations of fisheries, maritime sectors, and tourism. Situated in places in......, affecting certain segments of the community more severely than others. In addition, the transition to tourism dependence holds a somewhat precarious future for coastal communities in temperate areas. In some cases, heritage and community identity remain strongly connected to the surviving fishing industry...

  18. Acoustic contributions of a sound absorbing blanket placed in a double panel structure: Absorption Versus Transmission

    CERN Document Server

    Doutres, Olivier; 10.1121/1.3458845

    2010-01-01

    The objective of this paper is to propose a simple tool to estimate the absorption vs. transmission loss contributions of a multilayered blanket unbounded in a double panel structure and thus guide its optimization. The normal incidence airborne sound transmission loss of the double panel structure, without structure-borne connections, is written in terms of three main contributions; (i) sound transmission loss of the panels, (ii) sound transmission loss of the blanket and (iii) sound absorption due to multiple reflections inside the cavity. The method is applied to four different blankets frequently used in automotive and aeronautic applications: a non-symmetric multilayer made of a screen in sandwich between two porous layers and three symmetric porous layers having different pore geometries. It is shown that the absorption behavior of the blanket controls the acoustic behavior of the treatment at low and medium frequencies and its transmission loss at high frequencies. Acoustic treatment having poor sound ...

  19. Where is 'place' in Aging in place?

    DEFF Research Database (Denmark)

    Blaakilde, Anne Leonora

    2015-01-01

    article builds on a qualitative study among Danish retirement migrants regarding their experiences with the need for care or support while living abroad. Denmark is a welfare state with a long history of public nursing homes and in-home care for frail elderly persons. This system of governance is...... in-home help. It is argued that we should consider public solutions to the problems faced by frail Danish citizens in transnational settings, enhancing their opportunities to live abroad....

  20. Craft in Unexpected Places

    OpenAIRE

    Barber, Claire; Macbeth, Penny

    2015-01-01

    Within the shifting territories of craft practice, the handmade has become a relational form of contemporary activity that transforms our understanding of place through a hands-on minds-on process of collective making. The conceptual significance of craft is activated through a chance encounter with the hand-made in daily life The point of departure for this paper was a conference Outside: Activating Cloth to Enhance the Way We Live held in the winter of 2012 at the University of Hudders...

  1. Pressure distribution in centrifugal dental casting.

    Science.gov (United States)

    Nielsen, J P

    1978-02-01

    Equations are developed for liquid metal pressure in centrifugal dental casting, given the instantaneous rotational velocity, density, and certain dimensions of the casting machine and casting pattern. A "reference parabola" is introduced making the fluid pressure concept more understandable. A specially designed specimen demonstrates experimentally the reference parabola at freezing. PMID:355283

  2. Casting behavior of titanium alloys in a centrifugal casting machine.

    Science.gov (United States)

    Watanabe, K; Miyakawa, O; Takada, Y; Okuno, O; Okabe, T

    2003-05-01

    Since dental casting requires replication of complex shapes with great accuracy, this study examined how well some commercial titanium alloys and experimental titanium-copper alloys filled a mold cavity. The metals examined were three types of commercial dental titanium [commercially pure titanium (hereinafter noted as CP-Ti), Ti-6Al-4V (T64) and Ti-6Al-7Nb (T67)], and experimental titanium-copper alloys [3%, 5% and 10% Cu (mass %)]. The volume percentage filling the cavity was evaluated in castings prepared in a very thin perforated sheet pattern and cast in a centrifugal casting machine. The flow behavior of the molten metal was also examined using a so-called "tracer element technique." The amounts of CP-Ti and all the Ti-Cu alloys filling the cavity were similar; less T64 and T67 filled the cavity. However, the Ti-Cu alloys failed to reach the end of the cavities due to a lower fluidity compared to the other metals. A mold prepared with specially designed perforated sheets was effective at differentiating the flow behavior of the metals tested. The present technique also revealed that the more viscous Ti-Cu alloys with a wide freezing range failed to sequentially flow to the end of the cavity. PMID:12593955

  3. Effect of Nb on Structure and Mechanical Properties of Chilled Cast Iron at Room and Elevated Temperatures

    Institute of Scientific and Technical Information of China (English)

    Qijie ZHAI; Li FU; Huaying ZHAI

    2004-01-01

    Effect of Nb on microstructure and mechanical properties of chilled cast iron at room and elevated temperatures is studied in this research. The results demonstrate that the cast structure and mechanical properties of chilled cast iron at room and elevated temperatures are improved with the addition of trace amount of Nb. However, if Nb was added too much, the cast structure and mechanical properties of chilled cast iron would deteriorate. The suitable content of Nb in chilled cast iron is about 0.05% (mass fraction). Except the dissolution in the matrix of cast iron the excessive Nb will form Nb-rich phases in three morphologies. Those are lumpy NbC, complicated strip-like phase and compound with pearlite structure.

  4. Enhancements in Magnesium Die Casting Impact Properties

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-06-30

    % 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.

  5. The ecology of unhealthy places: violence, birthweight, and the importance of territoriality in structurally disadvantaged communities.

    Science.gov (United States)

    Kane, Robert J

    2011-12-01

    The present study tested the relationships between macro-level violence and birthweight in structurally disadvantaged communities in the District of Columbia. The study hypothesized that both rates of violence and violence "uncertainty" (the latter was operationalized as within-census tract residual change scores in violence), should be inversely associated with birthweight among all live singleton births in DC from 2000 to 2002. Using mixed models, the study found that (1) patterns of violence and violence uncertainty were significantly associated with birthweight among mothers residing in structurally disadvantaged communities, and (2) these findings held for Black and Hispanic, but not white, mothers. The study argues that urban ecological researchers should begin to consider not just how rates (or levels) of violence influence health and other social outcomes in communities, but also the effects of violence uncertainty as a source of unpredictable risk and territorial disruption. PMID:22001230

  6. StatsCasts: screencasts for complementing lectures in statistics classes

    Science.gov (United States)

    Dunn, Peter K.; McDonald, Christine; Loch, Birgit

    2015-05-01

    Students who are studying introductory statistics units but are enrolled in non-statistics majors often struggle with the content, and do not stay engaged. Support structures are in place at many Australian universities to help these students. Most of these are face-to-face support centres that the students can visit during opening hours. To provide additional assistance to these students any time, and from anywhere, online media are increasingly used by students - either provided by support centres, or sought independently by students. Little research has been undertaken on the effectiveness of such resources to support student learning. This paper investigates whether students will embrace StatsCasts - short screen-capture videos on key statistical topics that students have struggled with in the past, with narrator explanation provided by the lecturer - as part of their learning strategy and if they will actively engage with the videos. Students enrolled in a large first-year statistics class at an Australian university who had been provided with StatsCasts responded to a survey at the end of the semester. Volunteering students also participated in a focus group to probe deeper into students' perceptions of and motivations for watching the videos. Analysis of the data shows that students do actively engage with the StatsCasts and they appear to become an important component of their study and revision strategy.

  7. Numerical simulation on the solidification structure of Ø600mm continuous casting round bloom

    Science.gov (United States)

    Fang, Q.; Ni, H. W.; Wang, S. J.; Zang, H.

    2016-03-01

    A FE (Finite Element)—CA (Cellular Automation) coupling model was developed for the simulation of solidification structure formation during the Ø600mm round bloom continuous casting process of Q345E steel. The simulation result of the temperature field was consistent with the nail-shooting experimental result, and the simulated solidification structure of the bloom was in great agreement with corrosion testing under the same casting condition. The simulation results showed that the centre equiaxed crystal ratio increased slightly with the increase of secondary cooling water rate and decreased with the increase of casting temperature and casting speed. When the secondary cooling water rate was over 0.08L/kg, it had less effect on the solidification structure. As the casting temperature increased by 1°C or the casting speed increased by 0.01m/min, the centre equiaxed crystal ratio would decrease by 0.4%∼1.2% and 3%∼0.8% respectively. According to the simulation results, the optimized continuous casting process of Ø600mm round bloom should be the secondary cooling water rate of 0.08L/kg, the casting temperature of 1532°C∼1539°C and the casting speed of 0.20m/min∼0.22m/min. It was found that the solidification structure of Ø600mm Q345E steel round bloom was much improved after the optimized continuous casting process was adopted in practical production.

  8. A method for the realization of complex concrete gridshell structures in pre-cast concrete

    DEFF Research Database (Denmark)

    Larsen, Niels Martin; Egholm Pedersen, Ole; Pigram, Dave

    2012-01-01

    This paper describes a method for the design and fabrication of complex funicular structures from discrete precast concrete elements. The research proposes that through the integration of digital form finding techniques, computational file-to-fabrication workflows and innovative sustainable concr...

  9. Effect of partial remelting time on the initial carbide in semisolid structure of hypereutectic hih Cr cast iron

    OpenAIRE

    Huang, Zhifu; Jiandong XING; He, Wei

    2004-01-01

    In order to review the effect of partial remelting time on the morphology of initial carbides, semisolid ingots of hypereutectic high Cr17 cast iron were remelted at 1 270 ℃ for four different times, and the changing characteristics of shape factor an the equivalent diameter of initial carbides were analyzed quantitatively using a Leica image analyzer. The results indicate that firstly, the evolution process of the initial carbides' morphology undergoes melting, sheroidization and refining d...

  10. Solidification Structure of Continuous Casting Large Round Billets under Mold Electromagnetic Stirring

    Institute of Scientific and Technical Information of China (English)

    Tao SUN; Feng YUE; Hua-jie WU; Chun GUO; Ying LI; Zhong-cun MA

    2016-01-01

    The solidification structure of a continuous casting large round billet was analyzed by a cellular-automaton-finite-element coupling model using the ProCAST software.The actual and simulated solidification structures were compared under mold electromagnetic stirring (MEMS)conditions (current of 300 A and frequency of 3 Hz).There-after,the solidification structures of the large round billet were investigated under different superheats,casting speeds,and secondary cooling intensities.Finally,the effect of the MEMS current on the solidification structures was obtained under fixed superheat,casting speed,secondary cooling intensity,and MEMS frequency.The model accurately simulated the actual solidification structures of any steel,regardless of its size and the parameters used in the continuous casting process.The ratio of the central equiaxed grain zone was found to increase with decreasing su-perheat,increasing casting speed,decreasing secondary cooling intensity,and increasing MEMS current.The grain size obviously decreased with decreasing superheat and increasing MEMS current but was less sensitive to the casting speed and secondary cooling intensity.

  11. Strangers in Familiar Places

    DEFF Research Database (Denmark)

    Muhr, Sara Louise

    2012-01-01

    are important. These spaces appear culturally generic to the Western traveler, but are highly Westernized to bring comfort to Western employees traveling in foreign cultures. This paper argues that these spaces are important in cross-cultural identity work in the sense that international workers......Employees working across multiple cultures are exposed to a vast number of different norms and values, and consequentially work is often a struggle to retain a coherent sense of self. However, when international workers travel, they also encounter more bland spaces where familiarity and similarity...... – professional strangers – need these places to belong and relate to familiarity and to regain a sense of identity. Drawing on an illustrative empirical vignette of an international consultant, I demonstrate how culturally generic spaces can be used in identity work of an international relations consultant....

  12. A super-ductile alloy for the die-casting of aluminium automotive body structural components

    OpenAIRE

    Watson, D.; Ji, S; Fan, Z.

    2014-01-01

    Super-ductile die-cast aluminium alloys are critical to future light-weighting of automotive body structures. This paper introduces a die-cast aluminium alloy that can satisfy the requirements of these applications. After a review of currently available alloys, the requirement of a die-cast aluminium alloy for automotive body structural parts is proposed and an Al-Mg-Si system is suggested. The effect of the alloying elements, in the composition, has been investigated on the microstructure an...

  13. Prediction of Part Distortion in Die Casting

    Energy Technology Data Exchange (ETDEWEB)

    R. Allen Miller

    2005-03-30

    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.

  14. The right friends in the right places: Understanding network structure as a predictor of voluntary turnover.

    Science.gov (United States)

    Ballinger, Gary A; Cross, Rob; Holtom, Brooks C

    2016-04-01

    Research examining the relationship between social networks and employee retention has focused almost exclusively on the number of direct links and generally found that having more ties decreases the likelihood of turnover. The present research moves beyond simple measures of network centrality to investigate the relationship between 2 additional, and theoretically distinct, facets of social capital and voluntary turnover. In 2 organizations, we found consistent evidence of a negative relationship between reputation, as measured by relationships with highly sought-out others (incoming eigenvector centrality) and voluntary turnover. Further, we found that the negative relationship between brokerage (structural holes) and turnover is significant, but only for higher-level employees. The theoretical and practical implications of expanding the suite of social capital measures to understand voluntary turnover are discussed. (PsycINFO Database Record PMID:26595755

  15. Thin wall ductile iron casting as a substitute for aluminum alloy casting in automotive industry

    Directory of Open Access Journals (Sweden)

    M. Górny

    2009-01-01

    Full Text Available In paper it is presented thin wall ductile iron casting (TWDI as a substitute of aluminium alloy casting. Upper control arm made of ductile iron with wall thickness ranging from 2 – 3.7 mm was produced by inmold process. Structure, mechanical properties and computer simulations were investigated. Structural analysis of TWDI shows pearlitic-ferritic matrix free from chills and porosity. Mechanical testing disclose superior ultimate tensile strength (Rm, yield strength (Rp0,2 and slightly lower elongation (E of TWDI in comparison with forged control arm made of aluminium alloy (6061-T6. Moreover results of computer simulation of static loading for tested control arms are presented. Analysis show that the light-weight ductile iron casting can be loaded to similar working conditions as the forged Al alloy without any potential failures.

  16. Prediction of the solidification structure of casting and heterogeneous nucleation

    Institute of Scientific and Technical Information of China (English)

    K. Ohsasa; H. Shirosawa; T. Narita

    2003-01-01

    The frequency of heterogeneous nucleation during the solidification of Al-Si binary alloy was estimated by comparing ex-perimentally obtained macrostructures of castings with numerically simulated ones. A molten alloy was unidirectionally solidifiedfrom a water-cooled copper chill in an adiabatic mold. The location of colunmar to equiaxed transition (CET) in the solidified alloyingot was measured. A numerical simulation for grain structure formation based on the Monte Carlo method was carried out, and thefrequency of heterogeneous nucleation in the alloy was evaluated by producing similar structure with the experimental one. The fre-quency of heterogeneous nucleation was expressed as a probabilistic function with an exponential form of undercooling that deter-mines the probability of nucleation event in the simulation. The value of the exponent is regarded as the nucleation parameter. Thenucleation parameter of Al-Si binary alloy varied with initial Sicontent.

  17. Field test study of pile-soil load transfer characteristics of X-shaped cast-in-place pile%现浇X形桩桩-土荷载传递规律现场试验研究

    Institute of Scientific and Technical Information of China (English)

    丁选明; 孔纲强; 刘汉龙; 吕亚茹

    2012-01-01

    A new pile type, X-shaped cast-in-place concrete pile (XCC pile) was developed for coast or river soft soils treatment. XCC piles have many technical and economic advantages, such as large surface area, high shaft friction, conveniently construction, and high economic effects. But there were relative little studies focused on- the pile-soil load transfer characteristics of XCC pile composite foundation. Based on a sewage treatment plant soft ground improvement engineering, field tests for the pile-soil load transfer of XCC pile composite foundation were carried out. The load-settlement, pile-soil load sharing, pile-soil stress ratio, and the distributions of axial force of pile shaft were measured. Then the pile-soil interaction and neutral plane of XCC pile under different conditions were analyzed. In order to do comparative analysis, the static load tests for circular pile which has the same concrete amount with that of XCC pile were carried out. The results show that, the neutral plane of XCC pile in composite foundation is mainly occurred in 0.2 times of pile depth. The maximum value of positive skin friction is about 140 % of those of negative skin friction. The pile-soil stress ratio of XCC pile in composite foundation is increased with the decreasing of pile spacing under the same pile length.%现浇X形混凝土桩(简称X形桩)是为了更好地满足沿海、沿江软土地基处理应用而开发的一种新桩型.该新型桩具有比表面积大、侧向摩阻力高,施工便捷,经济效益高等技术经济优势;但针对其在复合地基中桩-土荷载传递规律特性的研究却相对较少.结合某污水处理厂软基处理工程,开展了X形桩复合地基中桩-土荷载传递规律的现场试验,测得了荷载-沉降关系,桩-土荷载分担比、桩-土应力比,以及桩身轴力等发展情况,分析了不同工况下复合地基中桩-土协调相互作用和中性点位置规律;并将等混凝土用量圆形桩和X形桩

  18. Obtaining Martensitic Structures during Thixoforming of Hypoeutectic Gray Cast Iron

    Directory of Open Access Journals (Sweden)

    Lucas Bertolino Ragazzo

    2015-01-01

    Full Text Available The control of parameters such as liquid fraction, holding time, and cooling rate during thixoforming can help control the final microstructure of the thixoformed part, thus improving its mechanical properties. This study intended to investigate conditions required to obtain martensite in hypoeutectic gray cast iron at 3.1% CE (carbon equivalent deformed in the semisolid state. Samples heated up to 1130, 1135, and 1145°C (liquid fractions of 10, 30, and 45% were compressed into platens without any holding time (0 s. If a sample presented a martensitic structure for 0 s holding time, new samples were retested at the same temperature for 30, 60, and 90 s holding times. The die casting process was simulated by allowing the platens to become locked after hot compression. Samples that cooled in the locked platens were submitted to higher cooling rates than samples that cooled with the platens open and presented martensite instead of the conventional ferrite and pearlite. Thus, the factor that had the greatest influence on the formation of martensite was the cooling rate rather than stress. The thixoforming process presented good morphological stability, which is highly desirable for industrial applications.

  19. Influence on ultrasonic incident angle and defect detection sensitivity by cast stainless steel structure

    International Nuclear Information System (INIS)

    It is well known that ultrasonic waves are affected strongly by macro-structures in cast stainless steel, as in the primary pipe or other components in pressurized water reactors (PWRs). In this work, ultrasonic refractive angles and defect detection sensitivities are investigated at different incident angles to cast stainless steel. The aims of the investigation are to clarify the transmission of ultrasonic waves in cast stainless steel and to contribute to the transducer design. The results are that ultrasonic refractive angles in cast stainless steel shift towards the 45-degree direction with respect to the direction of dendritic structures by 11.8 degrees at the maximum and that the sensitivity of transducer for inner surface breaking cracks increases with decreasing incident angle. However, in an ultrasonic inspection of actual welds at smaller incident angles, a trade-off occurs between increased defect detection sensitivity and decreased defect discrimination capability due to intense false signals produced by non-defective features. (orig.)

  20. The effect of thermohydrogen treatment on the structure and properties of casts obtained from titanium alloys

    International Nuclear Information System (INIS)

    The method based on the combination of high temperature gas-static and thermal hydrogen treatments is suggested to increase mechanical properties of cast pseudo-α and (α+β)-titanium alloys. The study is carried out using alloys VT20L, VT23L and alloy Ti-6%Al-2%Mo-4%Zr-2%Sn. It is shown that the method proposed provides the change in a cast structure, an increase in density of castings, an increase of strength properties by 10-20% and fatigue by a factor of 1.5-2 at satisfactory ductility and impact strength

  1. Microdefects in cast multicrystalline silicon

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, E.; Klinger, D.; Bergmann, S. [Inst. of Crystal Growth Berlin (Germany)

    1995-08-01

    The microdefect etching behavior of cast multicrystalline BAYSIX and SILSO samples is mainly the same as that of EFG silicon, in spite of the very different growth parameters applied to these two techniques and the different carbon contents of the investigated materials. Intentional decorating of mc silicon with copper, iron and gold did not influence the results of etching and with help of infrared transmission microscopy no metal precipitates at the assumed microdefects could be established. There are many open questions concerning the origin of the assumed, not yet doubtless proved microdefects.

  2. Managerial Competence--Its Place in the Structure of University Teachers Competencies

    Science.gov (United States)

    Turturean Monica

    2012-01-01

    Higher education in Romania is passing though an authentic crisis caused by the necessity of our society to adapt to the European Union's demands. University teachers have a huge role in satisfying these requests. They need to possess a lot of competencies, and one of the most important is the managerial competency that will help university…

  3. Development and application of titanium alloy casting technology in China

    Institute of Scientific and Technical Information of China (English)

    NAN Hai; XIE Cheng-mu; ZHAO Jia-qi

    2005-01-01

    The development and research of titanium cast alloy and its casting technology, especially its application inaeronautical industry in China are presented. The technology of molding, melting and casting of titanium alloy, casting quality control are introduced. The existing problems and development trend in titanium alloy casting technology are also discussed.

  4. THE PLACE OF FINANCIAL ACCOUNTING INFORMATION IN THE INFORMATIONAL STRUCTURE OF ECONOMIC ENTITITES

    Directory of Open Access Journals (Sweden)

    Costi Boby

    2013-06-01

    Full Text Available Accountancy deals with the measurement, registration and control of the most important parts of business. Accounting is a central activity in a business’ economical life. Even in the simplest economies, there has to be kept an evidence of the assets, the liabilities and the transactions of the entity with other entities. The role of accountancy becomes even more important in modern economy, which relies on information. Due to the fact that resources are insufficient, choosing between several alternatives is necessary, and information provided by accountancy is needed to identify the best alternatives. Considering the importance of the financial-accounting information in taking decisions, the quality of that information is vital.

  5. Kinetics of carbon distribution in uranium doping elements and its alloys at centrifugal casting

    International Nuclear Information System (INIS)

    The report presents results of the metallic Uranium and its Zirconium and Niobium alloys centrifugal cas-ting influence on the distribution mode of the alloying elements in casts,structure and carbide composition.Distribution mechanism of carbon and alloying elements in Uranium during centrifugal casting is suggested in the report

  6. Non-dendritic structural 7075 aluminum alloy byliquidus cast and its semi-solid compression behavior

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Fine, equiaxed, non-dendritic structure needed by semi-solid processing was obtained by liquidus cast, i.e.7075 wrought aluminum alloy cast from liquidus temperature. The microstructures after heat treatment at different tem-peratures and time in the semi-solid range were observed, and the compression deformation behavior at different tempera-tures (490 ~ 600 C) and strain rates (5 × 10-3 ~ 5s-1) was investigated by means of Gleeble-1500 thermal-mechenicalsimulator. Thc results show that the deformation resistance of the non-dendritic structure attained by liquidus cast in semi-solid is remarkably lower than that of conventional dendritic structure. The formability of non-dendritic structure is betterthan that of dendritic structure

  7. Yield Improvement in Steel Casting (Yield II)

    Energy Technology Data Exchange (ETDEWEB)

    Richard A. Hardin; Christoph Beckermann; Tim Hays

    2002-02-18

    This report presents work conducted on the following main projects tasks undertaken in the Yield Improvement in Steel Casting research program: Improvement of Conventional Feeding and Risering Methods, Use of Unconventional Yield Improvement Techniques, and Case Studies in Yield Improvement. Casting trials were conducted and then simulated using the precise casting conditions as recorded by the participating SFSA foundries. These results present a statistically meaningful set of experimental data on soundness versus feeding length. Comparisons between these casting trials and casting trials performed more than forty years ago by Pellini and the SFSA are quite good and appear reasonable. Comparisons between the current SFSA feeding rules and feeding rules based on the minimum Niyama criterion reveal that the Niyama-based rules are generally less conservative. The niyama-based rules also agree better with both the trials presented here, and the casting trails performed by Pellini an d the SFSA years ago. Furthermore, the use of the Niyama criterion to predict centerline shrinkage for horizontally fed plate sections has a theoretical basis according to the casting literature reviewed here. These results strongly support the use of improved feeding rules for horizontal plate sections based on the Niyama criterion, which can be tailored to the casting conditions for a given alloy and to a desired level of soundness. The reliability and repeatability of ASTM shrinkage x-ray ratings was investigated in a statistical study performed on 128 x-rays, each of which were rated seven different times. A manual ''Feeding and Risering Guidelines for Steel Castings' is given in this final report. Results of casting trials performed to test unconventional techniques for improving casting yield are presented. These use a stacked arrangement of castings and riser pressurization to increase the casting yield. Riser pressurization was demonstrated to feed a casting up to

  8. Cast iron - a predictable material

    OpenAIRE

    Jorg C. Sturm; Guido Busch

    2011-01-01

    High strength compacted graphite iron (CGI) or alloyed cast iron components are substituting previously used non-ferrous castings in automotive power train applications. The mechanical engineering industry has recognized the value in substituting forged or welded structures with stiff and light-weight cast iron castings. New products such as wind turbines have opened new markets for an entire suite of highly reliable ductile iron cast components. During the last 20 years, casting process s...

  9. Solidified structure of thin-walled titanium parts by vertical centrifugal casting

    Directory of Open Access Journals (Sweden)

    Wu Shiping

    2011-05-01

    Full Text Available The solidified structure of the thin-walled and complicated Ti-6Al-4V castings produced by the vertical centrifugal casting process was studied in the present work. The results show that the wall thickness of the section is featured with homogeneously distributed fine equiaxial grains, compared with the microstructure of the thick-walled section. The grain size of the castings has a tendency to decrease gradually with the increasing of the centrifugal radius. The inter-lamellar space in thick-walled casting parts is bigger than that of the thin-walled parts, and the profile of inter-lamellar space is not susceptible to the centrifugal radius.

  10. Formation of microstructures in the spheroidal graphite cast iron

    International Nuclear Information System (INIS)

    Pipeline systems for hydraulic networks are obtained via centrifugal casting of spheroidal graphite cast iron. The very high cooling rate that is achieved in the skin of the product can sometimes lead to carbide instead of graphite in cast iron. An experimental device has been built in the laboratory that allows reproducing the extreme thermal conditions encountered during formation of skin of centrifugally cast pipes. Liquid metal droplets fall on a cold substrate. Rapid directional solidification occurs. The temperature evolution of the lower surface of the droplet is recorded during the very first moment of the solidification (t < 200 ms) thanks to a photodiode, which is located below the substrate. The microstructures that are obtained in laboratory are characterised in both the as-cast state and the heat-treated state. They are compared to the centrifugally cast ones. A model of directional solidification of cast iron under a very large temperature gradient has been built. It allows explaining the transition from stable to metastable micro structure that was observed in the products and reproduced in the laboratory samples.

  11. Detection of Cast Shadows in Surveillance Applications

    DEFF Research Database (Denmark)

    Erbou, Søren G.; Sørensen, Helge Bjarne Dissing; Stage, Bjarne

    2005-01-01

    Cast shadows from moving objects reduce the general ability of robust classification and tracking of these objects, in outdoor surveillance applications. A method for segmentation of cast shadows is proposed, combining statistical features with a new similarity feature, derived from a physics...

  12. Acoustic energy transmission in cast iron pipelines

    Science.gov (United States)

    Kiziroglou, Michail E.; Boyle, David E.; Wright, Steven W.; Yeatman, Eric M.

    2015-12-01

    In this paper we propose acoustic power transfer as a method for the remote powering of pipeline sensor nodes. A theoretical framework of acoustic power propagation in the ceramic transducers and the metal structures is drawn, based on the Mason equivalent circuit. The effect of mounting on the electrical response of piezoelectric transducers is studied experimentally. Using two identical transducer structures, power transmission of 0.33 mW through a 1 m long, 118 mm diameter cast iron pipe, with 8 mm wall thickness is demonstrated, at 1 V received voltage amplitude. A near-linear relationship between input and output voltage is observed. These results show that it is possible to deliver significant power to sensor nodes through acoustic waves in solid structures. The proposed method may enable the implementation of acoustic - powered wireless sensor nodes for structural and operation monitoring of pipeline infrastructure.

  13. Structure of low-alloy constructional cast steel - a quantitative analysis of impurities

    Directory of Open Access Journals (Sweden)

    D. Bartocha

    2011-07-01

    Full Text Available The mechanical properties of cast steel are primarily a function of chemical composition and solidification conditions i.e. primary structure, however, a significant role also plays its quality understood as purity metallurgical i.e. as small as possible content of harmful components of the structure. In work the results of porosity and non-metallic inclusions in steel cast structure quantity analysis are presented.A function which coefficient can be treated as parameters of unwontedstructurecomponent was statistically fittedto histograms of impurities distribution. The influence of O, N, P and S content on approximation function coefficients was analyzed.

  14. Energy use in selected metal casting facilities - 2003

    Energy Technology Data Exchange (ETDEWEB)

    Eppich, Robert E. [Eppich Technologies, Syracuse, IN (United States)

    2004-05-01

    This report represents an energy benchmark for various metal casting processes. It describes process flows and energy use by fuel type and processes for selected casting operations. It also provides recommendations for improving energy efficiency in casting.

  15. Use of freeze-casting in advanced burner reactor fuel design

    Energy Technology Data Exchange (ETDEWEB)

    Lang, A. L.; Yablinsky, C. A.; Allen, T. R. [Dept. of Engineering Physics, Univ. of Wisconsin Madison, 1500 Engineering Drive, Madison, WI 53711 (United States); Burger, J.; Hunger, P. M.; Wegst, U. G. K. [Thayer School of Engineering, Dartmouth College, 8000 Cummings Hall, Hanover, NH 03755 (United States)

    2012-07-01

    This paper will detail the modeling of a fast reactor with fuel pins created using a freeze-casting process. Freeze-casting is a method of creating an inert scaffold within a fuel pin. The scaffold is created using a directional solidification process and results in open porosity for emplacement of fuel, with pores ranging in size from 300 microns to 500 microns in diameter. These pores allow multiple fuel types and enrichments to be loaded into one fuel pin. Also, each pore could be filled with varying amounts of fuel to allow for the specific volume of fission gases created by that fuel type. Currently fast reactors, including advanced burner reactors (ABR's), are not economically feasible due to the high cost of operating the reactors and of reprocessing the fuel. However, if the fuel could be very precisely placed, such as within a freeze-cast scaffold, this could increase fuel performance and result in a valid design with a much lower cost per megawatt. In addition to competitive costs, freeze-cast fuel would also allow for selective breeding or burning of actinides within specific locations in fast reactors. For example, fast flux peak locations could be utilized on a minute scale to target specific actinides for transmutation. Freeze-cast fuel is extremely flexible and has great potential in a variety of applications. This paper performs initial modeling of freeze-cast fuel, with the generic fast reactor parameters for this model based on EBR-II. The core has an assumed power of 62.5 MWt. The neutronics code used was Monte Carlo N-Particle (MCNP5) transport code. Uniform pore sizes were used in increments of 100 microns. Two different freeze-cast scaffold materials were used: ceramic (MgO-ZrO{sub 2}) and steel (SS316L). Separate models were needed for each material because the freeze-cast ceramic and metal scaffolds have different structural characteristics and overall porosities. Basic criticality results were compiled for the various models

  16. Use of freeze-casting in advanced burner reactor fuel design

    International Nuclear Information System (INIS)

    This paper will detail the modeling of a fast reactor with fuel pins created using a freeze-casting process. Freeze-casting is a method of creating an inert scaffold within a fuel pin. The scaffold is created using a directional solidification process and results in open porosity for emplacement of fuel, with pores ranging in size from 300 microns to 500 microns in diameter. These pores allow multiple fuel types and enrichments to be loaded into one fuel pin. Also, each pore could be filled with varying amounts of fuel to allow for the specific volume of fission gases created by that fuel type. Currently fast reactors, including advanced burner reactors (ABR's), are not economically feasible due to the high cost of operating the reactors and of reprocessing the fuel. However, if the fuel could be very precisely placed, such as within a freeze-cast scaffold, this could increase fuel performance and result in a valid design with a much lower cost per megawatt. In addition to competitive costs, freeze-cast fuel would also allow for selective breeding or burning of actinides within specific locations in fast reactors. For example, fast flux peak locations could be utilized on a minute scale to target specific actinides for transmutation. Freeze-cast fuel is extremely flexible and has great potential in a variety of applications. This paper performs initial modeling of freeze-cast fuel, with the generic fast reactor parameters for this model based on EBR-II. The core has an assumed power of 62.5 MWt. The neutronics code used was Monte Carlo N-Particle (MCNP5) transport code. Uniform pore sizes were used in increments of 100 microns. Two different freeze-cast scaffold materials were used: ceramic (MgO-ZrO2) and steel (SS316L). Separate models were needed for each material because the freeze-cast ceramic and metal scaffolds have different structural characteristics and overall porosities. Basic criticality results were compiled for the various models. Preliminary results

  17. Welding Tubes In Place

    Science.gov (United States)

    Meredith, R.

    1984-01-01

    Special welding equipment joins metal tubes that carry pressurized cyrogenic fluids. Equipment small enough to be used in confined spaces in which such tubes often mounted. Welded joints lighter in weight and more leak-proof than joints made with mechanical fittings.

  18. Signs in Place

    DEFF Research Database (Denmark)

    Hamid, Salmiah Binti Abdul; Jensen, Ole B.; Silva, Victor

    be an effective guidance tool. However, “signs in place” offer alternative or additional guidelines to help people with their journey. This paper firstly seeks to understand road traffic signs in terms of mobility in everyday life. It then attempts to distinguish the different perspectives of...... mobility and geosemiotic studies with regards to the road traffic signs used in urban spaces. The paper ends with a discussion on how people choreograph their movement in their everyday life from two different perspectives: above vs. below....

  19. Signs In Place

    DEFF Research Database (Denmark)

    Hamid, Salmiah Binti Abdul; Jensen, Ole B.; Silva, Victor

    2012-01-01

    an effective guidance tool. However, “signs in place” offer alternative or additional guidelines to help people with their journey. This paper, first, seeks to understand road traffic signs in terms of mobility in everyday life. It, then, attempts to distinguish the different perspectives of mobility...... and geosemiotic studies with regards to the road traffic signs used in urban spaces. The paper ends with a discussion on how people choreograph their movement in their everyday life from two different perspectives: above vs. below...

  20. Running in place

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, R.; Mohsberg, J. (Richard Hunt Associates, Annapolis, MD (United States))

    1993-04-01

    Various resource agencies are diluting FERC's authority to carry out its mandated duties. Greater assertiveness is needed to regain control of the hydropower licensing process. Allowing resource agencies this control has not resulted in a workable process or the timely processing of applications. Several examples illustrate the resulting problems.

  1. DEVELOPMENTS IN THE FIELD OF STEEL AND CAST IRON

    OpenAIRE

    Ten, E. B.; V. D. Belov

    2015-01-01

    The article describes the use of a number of promising casting technologies applied to produce the castings of steel and cast iron with special properties. Such as, technology of centrifugal casting of large-size workpieces made of steel, forecasting method composition of slag in the smelting of high-manganese steels, method of complex modifying chromium cast irons, analysis of properties of perspective high-alloy aluminium cast iron.

  2. DEVELOPMENTS IN THE FIELD OF STEEL AND CAST IRON

    Directory of Open Access Journals (Sweden)

    E. B. Ten

    2015-05-01

    Full Text Available The article describes the use of a number of promising casting technologies applied to produce the castings of steel and cast iron with special properties. Such as, technology of centrifugal casting of large-size workpieces made of steel, forecasting method composition of slag in the smelting of high-manganese steels, method of complex modifying chromium cast irons, analysis of properties of perspective high-alloy aluminium cast iron.

  3. Modelling Al-4wt.%Cu as-cast structure using equiaxed morphological parameters deduced from in-situ synchrotron X-ray radiography

    Science.gov (United States)

    Ahmadein, M.; Wu, M.; Reinhart, G.; Nguyen-Thi, H.; Ludwig, A.

    2016-03-01

    The as-cast structure of laboratory scale Al-4wt.%Cu was numerically calculated using assumed morphological parameters. Two parameters are identified: The shape factor which correlates the growth velocity of dendrite envelope to that of the tip; and the sphericity of the equiaxed envelope or the circularity of the columnar trunk envelope which is required to calculate the averaged species diffusion flux across the envelope. In the present work, the real-time radiographs of equiaxed solidification experiment carried out on Al-4wt.%Cu at the European Synchrotron Radiation Facility are used to track the development of crystal envelope with time. The growth rate of the equivalent circular envelope was correlated to dendrite tip growth velocity to deduce the shape factor. The sphericity of dendrite envelope is estimated over the time. The average of the deduced morphological parameters is applied to the model to predict the as-cast structure. The results were compared to those obtained by using morphological parameters from literature. The predicted phase quantities, columnar-to- equiaxed transition, and macrosegregation exhibited significant dependence on those parameters. The predicted macrosegregation using the experimentally deduced parameters fits better to the measurements.

  4. Estimation of primary dendrite arm spacings in continuous casting products

    Energy Technology Data Exchange (ETDEWEB)

    Cicutti, C. [Centro de Investigacion Industrial-FUDETEC, Campana (Argentina); Bilmes, P.; Boeri, R.

    1997-09-01

    The proportion of steels produced by continuous casting has grown drastically during the last two decades, increasing to such an extent that in some countries, several grades of steel are exclusively made by this process. Many investigations recognized the significant influence of the solidification structure on the quality of cast products, and pointed out the importance of the development of appropriate tools to predict the microstructure as a function of thermal and physical parameters. The estimation of secondary dendrite arm spacings in continuously cast steel products has received some attention. However, very little effort has been focused on the prediction of primary dendrite arm spacings, to the best of the authors` knowledge. The main objective of this study is to develop simple expressions to estimate the variation of primary dendrite arm spacings through the section of continuous casting steel products.

  5. Characterization of Technetium Speciation in Cast Stone

    Energy Technology Data Exchange (ETDEWEB)

    Um, Wooyong; Jung, Hun Bok; Wang, Guohui; Westsik, Joseph H.; Peterson, Reid A.

    2013-11-11

    This report describes the results from laboratory tests performed at Pacific Northwest National Laboratory (PNNL) for the U.S. Department of Energy (DOE) EM-31 Support Program (EMSP) subtask, “Production and Long-Term Performance of Low Temperature Waste Forms” to provide additional information on technetium (Tc) speciation characterization in the Cast Stone waste form. To support the use of Cast Stone as an alternative to vitrification for solidifying low-activity waste (LAW) and as the current baseline waste form for secondary waste streams at the Hanford Site, additional understanding of Tc speciation in Cast Stone is needed to predict the long-term Tc leachability from Cast Stone and to meet the regulatory disposal-facility performance requirements for the Integrated Disposal Facility (IDF). Characterizations of the Tc speciation within the Cast Stone after leaching under various conditions provide insights into how the Tc is retained and released. The data generated by the laboratory tests described in this report provide both empirical and more scientific information to increase our understanding of Tc speciation in Cast Stone and its release mechanism under relevant leaching processes for the purpose of filling data gaps and to support the long-term risk and performance assessments of Cast Stone in the IDF at the Hanford Site.

  6. Cracks in high-manganese cast steel

    Directory of Open Access Journals (Sweden)

    A. Chojecki

    2009-10-01

    Full Text Available The reasons which account for the formation of in service cracks in castings made from Hadfield steel were discussed. To explain the source of existence of the nuclei of brittle fractures, the properties of cast steel were examined within the range of solidification temperatures, remembering that feeding of this material is specially difficult, causing microporosity in hot spots. This creates conditions promoting the formation of microcracks which tend to propagate during service conditions involving high dynamic stresses, and explains why the cracks are mainly characterized by a brittle nature. The reason for crack formation in service are micro-porosities formed during casting solidification.

  7. Modification of the Cast Structure in a Cu-12.6 Wt Pct Sn Alloy by Heat Treatment in the Semisolid State

    Science.gov (United States)

    Bandyopadhyay, Biswarup; Mishra, Dewika; Bhattacharyya, Ashish; Mallik, Manab

    2015-10-01

    The dendritic structure in a cast Cu-12.6 wt pct Sn alloy can be transformed to a globular structure if the alloy is heat treated in the semisolid range. A Cu-12.6 wt pct Sn alloy has a wide solidification range which encourages the development of a cored dendritic structure during solidification. In order to transform it into a globular structure, heat treatment was carried out separately at three temperatures in the semisolid range, namely 1183 K, 1153 K, and 1123 K (910 °C, 880 °C, and 850 °C) with corresponding liquid volume fractions of 50, 40, and 20 pct, respectively. An attempt was made to optimize the temperature and vol pct of liquid combination. It was observed that microstructural modification proceeded mainly through coarsening, fragmentation, and spheroidization of the dendrite arms. Semisolid heat treatment at 1123 K (850 °C) for 2 hours with 20 vol pct liquid yielded the best result. This microstructure was compared with the microstructure developed by solid-state heat treatment at 1023 K (750 °C) for 2 hours. Assessment of the structure-property co-relation demonstrated that hardness, yield stress, ultimate tensile stress, and toughness of the semisolid heat-treated samples were superior to those of subcritically annealed samples.

  8. SOLUBILITY OF SILICON IN CAST ALUMINIUM ALLOY AFTER ELECTROHYDROPULSE TREATMENT

    OpenAIRE

    Dyachenko, S.; Fedchenko, N.

    2006-01-01

    The structure of cast aluminium alloy AЛ9 exposed to electrohydropulse treatment (EHPT) was studied. It has been shown that after EHPT solubility of silicon in alloy matrix was increased. With the help of thermodynemic analysis the structural changes in metal after EHPT were explained.

  9. Low Background Micromegas in CAST

    CERN Document Server

    Garza, J G; Aznar, F.; Calvet, D.; Castel, J.F.; Christensen, F.E.; Dafni, T.; Davenport, M.; Decker, T.; Ferrer-Ribas, E.; Galán, J.; García, J.A.; Giomataris, I.; Hill, R.M.; Iguaz, F.J.; Irastorza, I.G.; Jakobsen, A.C.; Jourde, D.; Mirallas, H.; Ortega, I.; Papaevangelou, T.; Pivovaroff, M.J.; Ruz, J.; Tomás, A.; Vafeiadis, T.; Vogel, J.K.

    2015-01-01

    Solar axions could be converted into x-rays inside the strong magnetic field of an axion helioscope, triggering the detection of this elusive particle. Low background x-ray detectors are an essential component for the sensitivity of these searches. We report on the latest developments of the Micromegas detectors for the CERN Axion Solar Telescope (CAST), including technological pathfinder activities for the future International Axion Observatory (IAXO). The use of low background techniques and the application of discrimination algorithms based on the high granularity of the readout have led to background levels below 10$^{-6}$ counts/keV/cm$^2$/s, more than a factor 100 lower than the first generation of Micromegas detectors. The best levels achieved at the Canfranc Underground Laboratory (LSC) are as low as 10$^{-7}$ counts/keV/cm$^2$/s, showing good prospects for the application of this technology in IAXO. The current background model, based on underground and surface measurements, is presented, as well as ...

  10. Privileged Girls: The Place of Femininity and Femininity in Place

    Science.gov (United States)

    Fahey, Johannah

    2014-01-01

    Constructions of femininity and attendant notions of feminism are being produced in different ways in different places around the world. This is a complicated global process that cannot be reduced to analyses that take place in nation states. This paper seeks to respond to and enhance Angela McRobbie's compelling argument about understandings…

  11. Modelling of Level Fluctuation in Continuous Casting

    Institute of Scientific and Technical Information of China (English)

    Xiao LIU; Huanxin ZHANG; Rongjun XU; Yongquan LI; Houfa SHEN; Baicheng LIU

    2003-01-01

    The free surface profile and fluid flow in the mold of continuous casting have been calculated by the VOF method couplingthe SIMPLER algorithm. The SIMPLER-VOF model developed is validated by solving a classical experiment, broken damproblem. The calculat

  12. CONTRIBUTION OF CAST STRUCTURE TO THE LEVEL OF HARDENING OF THE TOOL STEEL FOR HOT FORMING, RECEIVED AT INDUCTION MELTING

    Directory of Open Access Journals (Sweden)

    V. N. Fedulov

    2015-05-01

    Full Text Available The matters of influence of cast structure on level of hardening of tool steel of type 4X2BMC with various proportions of elements in their structure are considered. It is shown that presence of cast structure can provide hardness increase up to 5-15% of the experience value that is especially necessary at tempering temperatures of 600 ° C and over.

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

    Science.gov (United States)

    Singh, Rupinder; Singh, Harvir

    2016-04-01

    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.

  14. Solidification Conditions and Microstructure in Continuously Cast Aluminum

    Science.gov (United States)

    Buxmann, K.; Gold, E.

    1982-04-01

    The well-known relationship between cell size or dendrite spacing and local solidification time gives the possibility of calculating the thermal parameters of solidification from the microstructure of the as-cast product. As a basis for such calculations, the dendrite spacing of different aluminum castings (DC cast ingots of different diameters, cast in conventional and electromagnetic molds; cast strip from roll casters, belt casters, and block casters; and Properzi cast rod) has been measured through their cross sections. Based on these measurements, a qualitative discussion of the thermal conditions during the solidification of these products is given, and the influence of a variation in the casting conditions discussed.

  15. Changes of Structure and Magnetic Properties during Crystallization in Cast Nd60Fe20Al8Co10B2 Alloy

    Institute of Scientific and Technical Information of China (English)

    谭晓华; 徐晖; 王庆; 戚楠楠; 董远达

    2004-01-01

    The Nd60Fe20Al8Co10B2 alloy was prepared by suction casting of the molten alloy into a copper mold under argon atmosphere.The micro-structural and magnetic property changes in the Nd60Fe20Al8Co10B2 alloy during crystallization were investigated by X-ray diffraction(XRD),differential scanning calorimetry(DSC),scanning electron microscope(SEM)and the vibrating sample magnetometer(VSM).The precipitation and Nd-rich and Fe-rich phases have no significant effect on the intrinsic coercitity for Nd60Fe20Al8Co10B2 alloy annealed below 723 K.However,the growth of Fe-rich phase decreases the saturate magnetization and remanence of the alloy.The hard magnetic behavior is disappeared when the alloy is fully crystallized.

  16. Experiments to study the erosive effect of oxide casting streams on structures

    International Nuclear Information System (INIS)

    The experiments performed under an activity of the Nuclear Safety Project (PSF) make a contribution to the study of the erosive effect of oxide casting streams on structures. As aluminothermically generated oxide casting stream, 20 mm in diameter, was applied from 1.0 m dropping height to 40 mm thick horizontal stainless steel plates in free air atmosphere. The test parameters were different temperatures of preheating of the plates (900 and 1200deg C). By means of thermocouples offset in depth in the plates it was possible to record and represent the temperature distribution in the plate correlated with time. Regarding the direct erosive effect of an oxide casting stream as a function of the temperature of plate preheating it appeared that a high initial temperature of the stainless steel plate (1200deg C) causes an increased erosion area at the surface only, but does not exert a macroscopically visible influence on erosion depth. (orig.)

  17. Simulation of the ingot extraction in the continuous casting process

    Directory of Open Access Journals (Sweden)

    J. Szajnar

    2011-07-01

    Full Text Available Cast ingot pulling speed is significantly affecting the nature of the resulting structure and the quality of the outer surface of the ingot. By introducing a variable algorithm for extraction of the ingot we may to some extent control the shape and location of the solid / liquid interface and temperature field in the cross-section of the ingot. The shape of the crystallization front, as well as its position relative to mold plays an important role in the process of continuous casting ingots of grey iron and affects the structure of the casting. In order to verify the impact of an algorithm on the shape and the location of solid / liquid interface, a number of simulations in ANSYS Fluent 12 were made, for determining the shape of crystallization front and temperature distribution on the cross-section of the ingot.

  18. Place and dialect levelling in Denmark

    DEFF Research Database (Denmark)

    Monka, Malene

    , informants’ languages featured substantial amounts of dialect features (Kristensen 1980; Pedersen 1986). In 2005 to 2010, researchers at the Danish National Research Center for Language Change in Real Time (LANCHART) and the University of Southern Denmark re-interviewed informants, thus providing data for......) – but also to place effects, i.e. the ensemble of sociolinguistic conditions within speech localities (Horvath and Horvath 2001; Britain 2009; Blommaert 2010). This paper examines the impact of social and structural factors of place (historic, demographic, and socio-economic) (e.g. Britain 2002) as well...... as phenomenological factors (conceptualizations of place, sense of belonging and sense of place) (Johnstone 2010; Quist 2010; Jørgensen, Fallov et al. 2011) on language change in real time. Social and structural factors of place may explain why conceptualizations of – and perceived relations between...

  19. The change of temperature gradient in solidification of hypereutectic chromium cast iron casting

    OpenAIRE

    A. Studnicki

    2010-01-01

    In article the analysis of temperature gradient of solidification in section of hypereutectic chromium cast iron model casting was introduced. On this example was presented the method (DTGA – derivative and thermal gradient analysis), which was worked out in Department of Foundry Silesian University of Technology enabling the record of indispensable data to execution of analysis the temperature gradient and its derivative after time on section of model casting. It multichanneled apparatus to ...

  20. The change of temperature gradient in solidification of hypereutectic chromium cast iron casting

    Directory of Open Access Journals (Sweden)

    A. Studnicki

    2010-01-01

    Full Text Available In article the analysis of temperature gradient of solidification in section of hypereutectic chromium cast iron model casting was introduced. On this example was presented the method (DTGA – derivative and thermal gradient analysis, which was worked out in Department of Foundry Silesian University of Technology enabling the record of indispensable data to execution of analysis the temperature gradient and its derivative after time on section of model casting. It multichanneled apparatus to registration of data was used Crystaldigraph - PC.

  1. Effect of Chemical Composition on Number of Eutectic Colonies in Ni-Mn-Cu Cast Iron

    Directory of Open Access Journals (Sweden)

    A. Janus

    2013-01-01

    Full Text Available Determined were direction and intensity of influence of alloying additions on the number of eutectic graphite colonies in austenitic cast iron Ni-Mn-Cu. Chemical composition of the cast iron was 1.7 to 3.3% C, 1.4 to 3.1% Si, 2.8 to 9.9% Ni, 0.4 to 7.7% Mn, 0 to 4.6% Cu,0.14 to 0.16% P and 0.03 to 0.04% S. Analysed were structures of mottled (20 castings and grey (20 castings cast iron. Obtained wereregression equations determining influence intensity of individual components on the number of graphite colonies per 1 cm2 (LK. It wasfound that, in spite of high total content of alloying elements in the examined cast iron, the element that mainly decides the LK value is carbon, like in a plain cast iron.

  2. Concept of Place in Novel

    Directory of Open Access Journals (Sweden)

    Mehmet Bakır ŞENGÜL

    2010-04-01

    Full Text Available Novel, as the modern time’s narration type, is a literary type which claims to surround life holistically. It expresses a perception which owns the whole emotions that people have and a perception which focuses on the story of time and individual. Whether it is real or fictional, a person or another object needs place in order to exist. It is seen that ‘place’ starts to gain meaning in people’s mind with the help of the occurrence of the humanity norms and with the help of their perception. The concept of place starts to occupy an important place in novel by following a proper route in accordance with the novel’s development process. The fact that ‘place’ is the basic element of novel has both provided the novel to get away from a character that is only based on the event and both provided its personal side that is to be discovered. The parallelism between the existence of the ‘place’ and the people’s life reflects into the novel in different types. Sometime it is a talky witness of the novel and sometimes it is in place of an actor who displays the physical and spiritual limits of the character of the novel. In this study, the ambiguities which the concept of place has had in the historical process and the forms of the expression of ‘place’ in the prenovel narrations and in the novels have been emphasized.

  3. Evaluating the effectiveness of heat-resistant cast steel filtration from the results of structure examinations

    Directory of Open Access Journals (Sweden)

    Asłanowicz M.

    2007-01-01

    Full Text Available Filtration guarantees castings characterised by high quality and free from any non-metallic inclusions, which are formed at the stage of melting and pouring of liquid metal. This article discusses the problem of the effectiveness of filtration process taking as an example heat-resistant cast steel poured into ceramic moulds. In investigations, foamed zircon filters made by FerroTerm Sp. z o.o. The effectiveness of filtration was described and examined using the results of metallographic examinations, including macro- and micro-structure examinations of metal and of cast metal/ceramic filter interface, and measurements of the content of non-metallic inclusions. The methods of investigations were presented, the obtained results were described, and relevant conclusions were drawn, all of them unmistakably indicating a very beneficial effect that filtration has on molten metal quality. Łódź, Poland, were used.

  4. Skeleton castings dynamic load resistance

    OpenAIRE

    M. Cholewa; J. Szajnar; T. Szuter

    2013-01-01

    Purpose: The article is to show selected results of research in a field of new type of cast spatial composite reinforcements. This article shows skeleton casting case as a particular approach to continuous, spatial composite reinforcement.Design/methodology/approach: The research is concerning properties of cast spatial microlattice structures called skeleton castings. In this paper results of impact test of skeleton casting with octahedron elementary cell were shown. The selection of interna...

  5. Colour Metallography of Cast Iron

    Institute of Scientific and Technical Information of China (English)

    Zhou Jiyang; Liu Jincheng

    2011-01-01

    White Cast Iron (Ⅰ) White cast iron or ‘white iron' refers to the type of cast iron in which all of the carbon exists as carbide;there is no graphite in the as-cast structure and the fractured surface shows a white colour.White cast iron can be divided in three classes:· Normal white cast iron — this iron contains only C,Si,Mn,P and S,with no other alloying elements.· Low-alloy white cast iron — the total mass fraction of alloying elements is less than 5%.

  6. Effects of Rare Earths and Al on Structure and Performance of High Chromium Cast Iron Containing Wolfram

    Institute of Scientific and Technical Information of China (English)

    Guo Erjun; Wang Liping; Huang Yongchang; Fu Yuanke

    2006-01-01

    Effects of RE and Al on the structure, impact toughness, hardness, and wear resistance of high chromium cast iron containing wolfram were investigated.The results show that without modification the volume fraction of austenite is high and the carbide appears to be thick lath and the grain size is relatively large;proper modification using RE combined with Al can reduce volume fraction of residual austenite in the as-cast structure obviously, refine grain size of primary austenite notably, and make the morphology of carbide changing from thick lath to thin lath, rosette, and feather-like modification can also increase hardness, wear resistance and impact toughness of cast iron.

  7. Microstructure and elevated temperature mechanical and creep properties of Mg–4Y–3Nd–0.5Zr alloy in the product form of a large structural casting

    International Nuclear Information System (INIS)

    Highlights: • A modified WE43 alloy, free of heavy rare earth elements, has been assessed. • The new alloy, Mg–4Y–3Nd–0.5Zr (wt.%), is stronger than WE43 up to 573 K. • The new alloy is more creep resistant than WE43 alloy at 473 K under 40–80 MPa. • It is promising to use neodymium to replace heavy rare earth elements in WE43. - Abstract: In order to save the invaluable heavy rare earth (HRE) elements for important functional applications, a modified version of the WE43 magnesium alloy, Mg–4Y–3Nd–0.5Zr (wt.%), free of the HRE elements, has been designed. As part of the alloy development program, a large complex component of the alloy (net product weight: 80 kg) was made via differential pressure casting. The large component was then subjected to the T6 treatment (solid solution and ageing) following established commercial practice for the T6 treatment of the WE43 alloy. A significant number of samples were prepared from the thickest section (58 mm) of the T6-treated component for both microstructural characterization and detailed property assessment. The alloy showed noticeably higher tensile strengths than did the HRE-containing WE43 alloy over the temperature range of 473–573 K. The creep resistance of the alloy was superior to that of the WE43 alloy at 473 K while being similar at 523 K. The microstructures of the alloy in the as-cast, solution treated and then aged states were characterized. The component-based detailed assessment suggests that the idea of using neodymium (Nd) to replace the HRE elements in the WE43 alloy is promising for structural applications at elevated temperatures

  8. The influence of casting temperature on castability and structure of AJ62 alloy

    Directory of Open Access Journals (Sweden)

    A. Kiełbus

    2007-06-01

    Full Text Available Purpose: The AJ62 magnesium alloy exhibit good elevated-temperature tensile properties, excellent creep resistance and good castability. This alloy contains approximately 6% aluminum and about 2.5% strontium. Typically, it is used in automotive industry for the engine crankcase and power-train components. The aim of this paper is to present the results of the influence of pouring temperature on the fluidity and microstructure of the AJ62 magnesium alloy.Design/methodology/approach: The study was conducted on AJ62 magnesium alloys. Sand casting was performed at 695-755°C temperatures. The spiral test of fluidity was used. The microstructure was characterized by optical microscopy (Olympus GX-70 and a scanning electron microscopy (Hitachi S3400 equipped with an X-radiation detector EDS (VOYAGER of NORAN INSTRUMENTS. The phase identification of these alloys was identified by X-ray diffraction (JDX-75. Quantitative examination was conducted using the “MET-ILO” automatic image analysis programme.Findings: In as cast condition AJ62 alloy consisted of α-Mg grains with some types of intermetallic phases: (Al,Mg4Sr , Al8Mn5 and Al3Mg13Sr. The flow length and the intermetallicphases area fraction increase with increase the pouring temperature.Research limitations/implications: Future researches should contain investigations of the influence of casting temperature and heat treatment parameters on mechanical properties of AJ62 magnesium alloy.Practical implications: The established casting parameters (mainly temperature can be useful for preparing sand and die casting technology of the AJ62 magnesium alloy.Originality/value: The relationship between the initial structure, casting temperature, castability and phase composition in AJ62 magnesium alloy was specified.

  9. A Novel Process in Semi-Solid Metal Casting

    Institute of Scientific and Technical Information of China (English)

    Bijan Abbasi-Khazaei; Saeid Ghaderi

    2012-01-01

    In this research a new process for semi-solid casting of ductile iron based on the high nucleation rate combined with locally mechanical stirring is presented. In this process at first fully liquid ductile iron was poured on the peripheral surface of a wheel rotating against pouring direction. At this stage, the solid crystals nucleated at the chilling surface were pushed to the melt by a heat resistance steel cutter and finally the semi-solid slurry was generated. Reheating treatment was done on the samples to achieve more efficiency of semi-solid casting process. The effects of the travelling distance of solid particles during casting, the reheating time and temperature were examined. The results showed that the process effectively changes the dendrite structure to globular one.

  10. Maintenance system improvement in cast iron foundry

    Directory of Open Access Journals (Sweden)

    S. Kukla

    2011-07-01

    Full Text Available The work presents the issue of technical equipment management in an iron foundry basing on the assumptions of the TPM system (Total Productive Maintenance. Exploitation analysis of automatic casting lines has been carried out and their work’s influence on the whole production system’s functioning has been researched. Within maintenance system improvement, implementation of autonomic service and planned lines’ review have been proposed in order to minimize the time of breakdown stoppages. The SMED method was used to optimize changeover time, and the OEE (Overall Equipment Effectiveness was applied to evaluate the level of resources usage before and after implementing changes. Further, the influence of the maintenance strategy of casting devices’ efficiency on own costs of casting manufac- ture was estimated.

  11. Role of the preliminary heat treatment in anisothermic eutectoid change of the cast iron

    OpenAIRE

    T. Szykowny; T. Giętka; M. Trepczyńska - Łent

    2011-01-01

    Preliminary heat treatment, preceding continuous cooling of the iron casting, assumed in the research, complies with the applied in prac- tice single normalization, double normalization or normalization with slow cooling. In each of these cases continuous cast iron cooling has been begun from the same temperature 925°C. CCT diagrams have been made with use of metallographic method. The mechanism, kinet- ics and the final structure of eutectoid change of the cast iron after such treatment have...

  12. Electron theory study on the effect of Mn on as-cast structure of Fe-C-Cr-Mn cast irons

    Institute of Scientific and Technical Information of China (English)

    SUN Zhi-ping; SHEN Bao-luo; WANG Jun; LIU Hao-huai; YANG Hong-shan; HUANG Si-jiu

    2008-01-01

    The valence electron structure of alloying austenite of 3C-15Cr high chromium White cast iron with different Mn contents from 1%to 6% is analyzed by BLD method and EET.Results shoW that the addition of Mn has major influence on the valence electron structure of the alloying austenite,especially on that of Fe-C,Fe-C-Cr and Fe-C-Cr-Mn unit cells of it.The effect becomes weak when Mn content is over 4%.Based on the effect of nA,F Dc,the weighting of each unit cell and the degree of underceoling on phase transition of the austenite,we can calculate the retained austenite content of as-cast structure of the hish chromium white cast iron.The calculation results coincide well with those of the experiment.The phase transition characters of the austenite in high chromium white cast iron can be forecasted through valence electron structure analysis of alloying austenite by BLD method and EET on the basis of Fe-C-Cr equilibrium phase diagram.

  13. High Pressure Die Casting of Aluminium and Magnesium Alloys : Grain Structure and Segregation Characteristics

    OpenAIRE

    Laukli, Hans Ivar

    2004-01-01

    Cold chamber high pressure die casting, (HPDC), is an important commercial process for the production of complex near net shape aluminium and magnesium alloy castings. The work presented in the thesis was aimed at investigating the microstructure formation in this type of casting. The solidification characteristics related to the process and the alloys control the formation of grains and defects. This again has a significant impact on the mechanical properties of the castings.The investigatio...

  14. Effect of molybdenum, vanadium, boron on mechanical properties of high chromium white cast iron in as-cast condition

    Science.gov (United States)

    Nurjaman, F.; Sumardi, S.; Shofi, A.; Aryati, M.; Suharno, B.

    2016-02-01

    In this experiment, the effect of the addition carbide forming elements on high chromium white cast iron, such as molybdenum, vanadium and boron on its mechanical properties and microstructure was investigated. The high chromium white cast iron was produced by casting process and formed in 50 mm size of grinding balls with several compositions. Characterization of these grinding balls was conducted by using some testing methods, such as: chemical and microstructure analysis, hardness, and impact test. From the results, the addition of molybdenum, vanadium, and boron on high chromium white cast iron provided a significant improvement on its hardness, but reduced its toughness. Molybdenum induced fully austenitic matrix and Mo2C formation among eutectic M7C3 carbide. Vanadium was dissolved in the matrix and carbide. While boron was played a role to form fine eutectic carbide. Grinding balls with 1.89 C-13.1 Cr-1.32 Mo-1.36 V-0.00051 B in as-cast condition had the highest hardness, which was caused by finer structure of eutectic carbide, needle like structure (upper bainite) matrix, and martensite on its carbide boundary.

  15. The deformation of wax patterns and castings in investment casting technology

    Directory of Open Access Journals (Sweden)

    A. Herman

    2012-01-01

    Full Text Available The dimensional accuracy of the final casting of Inconel alloy 738 LC is affected by many aspects. One of them is the choice of method and time of cooling wax model for precision investment casting. The main objective was to study the initial deformation of the complex shape of the casting of the rotor blades. Various approaches have been tested for cooling wax pattern. When wax models are cooling on the air, without clamping in jig for cooling, deviations from the ideal shape of the casting are very noticeable (up to 8 mm and most are in extreme positions of the model. When blade is cooled in fixing jig in water environment, the resulting deviations compared with cooling in air are significantly larger, sometimes up to 10 mm. This itself does not mean that the final shape of the casting is dimensionally more accurate with usage of wax models, which have deviations from the ideal position smaller. Another deformation occurs when shell mould is produced around wax pattern and furthermore deformations emerge while casting of blade is cooling. This paper demonstrates first steps in describing complex process of deformations of Inconel alloy blades produced with investment casting technology by comparing results from thermal imagery, simulations in foundry simulation software ProCAST 2010 and measurements from CNC scanning system Carl Zeiss MC 850. Conclusions are so far not groundbreaking, but it seems deformations of wax pattern and deformations of castings do in some cases cancel each other by having opposite directions. Describing entirely whole process of deformations will help increase precision of blade castings so that models at the beginning and blades in the end are the same.

  16. Bryce Canyon National Park: Hoodoos Cast Their Spell. Teaching with Historic Places.

    Science.gov (United States)

    Shakespear, Mala

    Surrounded by the beauty of southern Utah and panoramic views of three states, filigrees of colorful stones that erosion has shaped into a spectacular array of spires, fins, and pinnacles called "hoodoos" remind tourist viewers of church steeples, Gothic spires, castle walls, animals, and even people. In this lesson students explore why and how…

  17. METHODS OF RECEIVING OF FINE-GRAINED STRUCTURE OF CASTINGS AT CRYSTALLIZATION

    Directory of Open Access Journals (Sweden)

    N. K. Tolochko

    2012-01-01

    Full Text Available The article deals with methods for fine-grained structure of ingots during crystallization depending on the used foundry technologies. It is shown that by using modern scientific and technological advances may improve the traditional and the development of new casting processes, providing production of cast parts with over fine-grained structure and enhanced properties.

  18. Effect of Secondary Cooling Conditions on Solidification Structure and Central Macrosegregation in Continuously Cast High-Carbon Rectangular Billet

    Science.gov (United States)

    Zeng, Jie; Chen, Weiqing

    2015-10-01

    Solidification structures of high carbon rectangular billet with a size of 180 mm × 240 mm in different secondary cooling conditions were simulated using cellular automaton-finite element (CAFE) coupling model. The adequacy of the model was compared with the simulated and the actual macrostructures of 82B steel. Effects of the secondary cooling water intensity on solidification structures including the equiaxed grain ratio and the equiaxed grain compactness were discussed. It was shown that the equiaxed grain ratio and the equiaxed grain compactness changed in the opposite direction at different secondary cooling water intensities. Increasing the secondary cooling water intensity from 0.9 or 1.1 to 1.3 L/kg could improve the equiaxed grain compactness and decrease the equiaxed grain ratio. Besides, the industrial test was conducted to investigate the effect of different secondary cooling water intensities on the center carbon macrosegregation of 82B steel. The optimum secondary cooling water intensity was 0.9 L/kg, while the center carbon segregation degree was 1.10. The relationship between solidification structure and center carbon segregation was discussed based on the simulation results and the industrial test.

  19. Young People as Active Citizens: Placing Youth Participation Structures in The Republic of Ireland under Critical Scrutiny

    OpenAIRE

    Hobbs, Adrienne

    2012-01-01

    This thesis is a critical investigation into the effectiveness of the youth participation structures created by the Irish State following the passing of the National Children’s Strategy (2000). As a signatory to the United Nations Convention on the Rights of the Child, the State is obliged to extend citizenship rights, including the right to actively participate in the democratic process, to children and young people. Two structures are under review; the thirty-four youth councils, Comhairle ...

  20. Fermilab joins in global live Web cast

    CERN Multimedia

    Polansek, Tom

    2005-01-01

    From 2 to 3:30 p.m., Lederman, who won the Nobel Prize for physics in 1988, will host his own wacky, science-centered talk show at Fermi National Accelerator Laboratory as part of a lvie, 12-hour, international Web cast celebrating Albert Einstein and the world Year of Physics (2/3 page)

  1. Thermodynamic stability of austenitic Ni-Mn-Cu cast iron

    Directory of Open Access Journals (Sweden)

    A. Janus

    2014-07-01

    Full Text Available The performed research was aimed at determining thermodynamic stability of structures of Ni-Mn-Cu cast iron castings. Examined were 35 alloys. The castings were tempered at 900 °C for 2 hours. Two cooling speeds were used: furnace-cooling and water-cooling. In the alloys with the nickel equivalent value less than 20,0 %, partial transition of austenite to martensite took place. The austenite decomposition ratio and the related growth of hardness was higher for smaller nickel equivalent value and was clearly larger in annealed castings than in hardened ones. Obtaining thermodynamically stable structure of castings requires larger than 20,0 % value of the nickel equivalent.

  2. Undercooling and nodule count in thin walled ductile iron castings

    OpenAIRE

    Pedersen, Karl Martin; Tiedje, Niels Skat

    2007-01-01

    Casting experiments have been performed with eutectic and hypereutectic castings with plate thicknesses from 2 to 8 mm involving both temperature measurements during solidification and microstructural examination afterwards. The nodule count was the same for the eutectic and hypereutectic castings in the thin plates (≤4.3 mm) while in the 8 mm plate the nodule count was higher in the hypereutectic than in the eutectic castings. The minimum temperature before the eutectic recalescence (Tmin) w...

  3. Role of Titanium in Thin Wall Vermicular Graphite Iron Castings Production

    Directory of Open Access Journals (Sweden)

    M. Górny

    2013-04-01

    Full Text Available In this paper the effects of titanium addition in an amount up to 0.13 wt.% have been investigated to determine their effect on the microstructure and mechanical properties of Thin Wall Vermicular Graphite Iron Castings (TWVGI. The study was performed for thinwalled iron castings with 3-5 mm wall thickness and for the reference casting with 13 mm. Microstructural changes were evaluated by analyzing quantitative data sets obtained by image analyzer and also using scanning electron microscope (SEM. Metallographic examinations show that in thin-walled castings there is a significant impact of titanium addition to vermicular graphite formation. Thinwalled castings with vermicular graphite have a homogeneous structure, free of chills, and good mechanical properties. It may predispose them as a potential use as substitutes for aluminum alloy castings in diverse applications.

  4. Considering place in community health nursing.

    Science.gov (United States)

    Bender, Amy; Clune, Laurie; Guruge, Sepali

    2009-03-01

    When a geographic location is assigned meaning, it becomes a place. The authors argue that place matters as both geographical location and lived experience.They extend the current conceptualization of nursing geography to encompass community health nursing and address intricacies of community nursing practice and research that often go unnoticed. They do so by exploring the notion of place in home and community, including the structural/spatial dimensions of the nurse-client relationship. The authors review the health geography literatures, then discuss the implications for practice and research in community health. They invite community health nurses to critically examine their practice and research with reference to such issues as the power of the nurse, marginalized places as determinants of health, and how best to care for clients living in diverse community settings. PMID:19485049

  5. PLACE OF NUTRITION IN YOGA

    OpenAIRE

    Desai, B.P.

    1990-01-01

    Nutrition plays a very vital role in our life. Yoga and Ayurveda had laid down the foundations of dietetics. The valuable guidelines regarding various food articles and diet for Yoga Sadhaka, to achieve maximum benefits, are given in traditional yoga texts like Hatha Pradipika and Gheranda Samhitha. Now is the time to evaluate the place of nutrition in Yoga and to study how the dietetic principles in yoga will help to eradicate the national problem of Mal-nutrition and poverty which is the pr...

  6. On Peritectic Reactions and Transformations and Hot Forming of Cast Structures

    OpenAIRE

    Nassar, Hani

    2009-01-01

    This thesis deals with peritectic reactions and transformations that occur during the solidification of many alloys. Peritectics are believed to be a major cause of crack-formation in many steels, thus, good knowledge of the mechanisms by which these phenomena occur is essential for preventing such defects. The thesis also handles the behaviour of metals, in particular cast structures, during hot forming. Grain size and microstructure are of most importance in determining the strength, toughn...

  7. Microanatomical Structure and Physical Characteristics of Thin Tail Hogget with Calpastatin (CAST-1) Genotype Differences

    OpenAIRE

    B. W. Putra; C Sumantri; Nurhidayat .

    2013-01-01

    Thin tail sheep has good adaptation in tropics condition, but they have low meat quality. Quality of thin tail hogget can be improved by selection. Calpastatin (CAST) gene is an indigenous inhibitor of calpain that involved in regulation of protein turn over and growth. The objective of this research was to determine the effect of calpastatin-genotype on microanatomical structure and physical characteristics of thin tail hodget. Nine thin tail sheep from Jonggol were used for this research. ...

  8. Study of the as-cast structures of tool steels with niobium

    International Nuclear Information System (INIS)

    The as-cast structures of modified M-2 type of tool steels, in which W was partially or totally substituted by Nb, were examined. Inspite of the emphasis given to the observations related to carbide type, morphology and distribution, quantitative analysis of the matrix revealed essentially the same contents in W, Mo, Cr and V. Niobium, on the other hand, was always found as NbC. (Author)

  9. Rate of solidification of aluminium casting in varying wall thickness of cylindrical metallic moulds

    Directory of Open Access Journals (Sweden)

    Katsina Christopher BALA

    2014-02-01

    Full Text Available The quality of final casting mainly depends on the rate of solidification as rapid solidification produces fine grains structures with better mechanical properties. The analysis of heat transfer during the casting and solidification of aluminium alloy as well as the experimental investigation of the rate of solidification in varying thicknesses of cylindrical metallic mould was carried out. The temperature variation with time of the casting was recorded from which cooling curves were obtained for the determination of solidification time of the cast. The results showed that as the cylindrical mould thickness increases the solidification time decreases due to the chilling effect of the mould.

  10. Development Of Pallan Caste In Tamil Nadu - Hindrance And Contributive Factors

    OpenAIRE

    B. Jawaharlal Nehru

    2013-01-01

    Pallan caste is sub – sect of scheduled castes in Tamil Nadu. Pallan caste people possess their own cultural heritage among the scheduled caste. This paper narrates about the hindrance contributive and factors for development of Pallan in Tamil Nadu.

  11. COMPARATIVE RESEARCHES OF FRACTURES OF HIGH-STRENGTH CAST IRON IN THE AS-CAST AND DEFORMED STATE

    Directory of Open Access Journals (Sweden)

    A. I. Pokrovsky

    2016-01-01

    Full Text Available The results of comparative studies of fracture surfaces of high-strength cast iron in the as-cast state and after hot direct extrusion through an aperture of a conical die are presented.The shape change of graphite inclusions and components of the metal matrix is examined with increasing the reduction ratio from 0 (as-cast state to 80%.For the fist time, using the electrochemical etching of the metal matrix of the cast iron, it is demonstrated experimentally that at plastic deformation the ductile flow of graphite inclusions occurs without fracturing of the latter. The surface morphology of a deformed graphite inclusion is revealed. It is shown that inside the inclusion the strain is distributed non-uniformly: the peripheral zones are deformed to a larger extent while the central part may retain its original radial structure.The fact that the most part of graphite inclusions on the fracture surface of the deformed cast iron appeared undamaged (very small amount of fractured inclusions was observed testifies against the common opinion that graphite acts as a crack nucleation site. A hypothesis is put forward that the crack nucleates in the metal matrix, presumably at the pearlite/ferrite interface, and propagates from one graphite inclusion to another rounding but not damaging the latter.

  12. Microstructural characterization of second phase regions in cast stainless steels

    International Nuclear Information System (INIS)

    Full text of publication follows: Cast austenitic stainless steels offer the possibility of directly producing large and/or relatively complex structures, such as the first wall shield modules or the divertor cassette for the International Tokamak Experimental Reactor (ITER). Unfortunately, one of the inherent problems associated with casting stainless steel, especially large castings, is the formation of coarse dendrites with possibly inhomogeneously distributed second phases separated by up to several hundred microns in the microstructure. These microstructural features result from temperature and composition gradients that develop during solidification and subsequent cooling. However, detailed characterization of the second phase regions in the cast microstructures can be quite challenging to techniques such as transmission electron microscopy (TEM), which is useful for phase identification. furthermore, the information about the phases that may be present in the cast microstructures, both equilibrium and nonequilibrium, is important as input as well as for confirming predictions made by computational thermodynamics and solidification modeling. In this study, the investigation of second phase regions that formed in a large cast of a 316 stainless steel (equivalent to CF3M) will be presented and compared to simulations of the phases predicted by computational thermodynamic modeling of the solidification process. The preliminary TEM investigation of the cast microstructure was performed with specimens that were prepared by jet-polishing of 3 mm diameter discs. Although this approach allowed for the identification of the sigma and chi phases, which was consistent with the simulations, it was not suitable for detailed analysis of the second phase regions since these specimens often contained only grains of the gamma austenite phase. A better approach for preparing TEM specimens consisted of strategically lifting small sections of material from second phase regions

  13. Unusually well preserved casts of halite crystals: A case from the Upper Frasnian of northern Lithuania

    Science.gov (United States)

    Rychliński, Tomasz; Jaglarz, Piotr; Uchman, Alfred; Vainorius, Julius

    2014-07-01

    Upper Frasnian carbonate-siliciclastics of the Stipinai Formation (northern Lithuania) comprise a bed of calcareous silty arenite with casts of halite crystals, including hopper crystals. Unusually well-preserved casts occur on the lower surface of the bed, while poorly-preserved casts are present on the upper bedding surface. The casts originated as the result of the dissolution of halite crystals which grew in the sediment. The dissolution took place during early stages of diagenesis, when host sediment was soft. Unstable cavities after crystal dissolution were filled by overlying sediment forming their casts. The collapsing sediment form sink-hole deformation structures which disturb wave-ripple cross lamination from the upper part of the bed. Dewatering pipe structures are also present. The casts and accompanying sink-hole and dewatering pipes are classified as the postdepositional deformation structures caused by haloturbation.

  14. Development of fabrication technology for copper canisters with cast inserts. Status report in August 2001

    International Nuclear Information System (INIS)

    This report contains an account of the results of trial fabrication of copper canisters with cast inserts carried out during the period 1998 - 2001. The work of testing of fabrication methods is being focused on a copper thickness of 50 mm. Occasional canisters with 30 mm copper thickness are being fabricated for the purpose of gaining experience and evaluating fabrication and inspection methods for such canisters. For the fabrication of copper tubes, SKB has concentrated its efforts on seamless tubes made by extrusion and pierce and draw processing. Five tubes have been extruded and two have been pierced and drawn during the period. Materials testing has shown that the resultant structure and mechanical properties of these tubes are good. Despite certain problems with dimensional accuracy, it can be concluded that both of these methods can be developed for use in the serial production of SKB' copper tubes. No new trial fabrication with roll forming of copper plate and longitudinal welding has been done. This method is nevertheless regarded as a potential alternative. Copper lids and bottoms are made by forging of continuous-cast bars. The forged blanks are machined to the desired dimensions. Due to the Canister Laboratory's need for lids to develop the technique for sealing welding, a relatively large number of forged blanks have been fabricated. It is noted in the report that the grain size obtained in lids and bottoms is much coarser than in fabricated copper tubes. Development work has been commenced for the purpose of optimizing the forging process. Nine cast inserts have been cast during the three-year period. The results of completed material testing of test pieces taken at different places along the length of the inserts have in several cases shown an unacceptable range of variation in strength properties and structure. In the continued work, insert fabrication will be developed in terms of both casting technique and iron composition. Development work on

  15. The degradation processes in high loaded casts

    Directory of Open Access Journals (Sweden)

    E. Ďuriníková

    2010-01-01

    Full Text Available In this work are described structural changes of jet engine DV – 2 turbine blades and effect of degradation process. Turbine blades work in aggressively environs and because of that there are rate among high loaded cast stock. As an experimental material we have chose nickel superalloy ŽS6K with surface heat - resisting alitize layer. Evaluation is slant on largeness wearing over work of certain number of hour in operation. Effect working environs and overrun working temperatures is show changes measures as well as changes macrostructure of basic material blades. Evaluate is advance quantitative metallography through the medium metallographic software NIS element. Quantitative analysis evaluate thickness measures, quality control outer look and lack mixture in the seat, which is not splash, is precede by lack of near another applied protective layer. Allowance is knot on last examination in the area ratings protective heat-resisting layers and gives records for others possible ratings and experiments in this area.

  16. Structural analysis of heat treated automotive cast alloy

    Directory of Open Access Journals (Sweden)

    E. Tillová

    2011-07-01

    Full Text Available Purpose: The present study is conducted to investigate and to provide a better understanding of the heat treatment T4 (solution treatment at 505, 515 and 525°C, holding time 2, 4, 8,16 and 32 hours, then quenching in warm water in the range from 40°C and natural aging at room temperature during 24 hours on the microstructure (morphology of eutectic Si, morphology of intermetallic Fe- and Cu-rich phases and on mechanical properties (tensile strength and Brinell hardness of recycled (secondary AlSi9Cu3 cast alloy.Design/methodology/approach: Metallographic samples were selected from tensile specimens (after testing and prepared by standard metallographic procedures (wet ground, polished with diamond pastes, finally polished with commercial fine silica slurry (STRUERS OP-U and etched by Dix-Keller, HNO3 or H2SO4 (standard etching or HCl (deep etching in order to reveal the three-dimensional morphology of phases. The microstructure was studied using an optical microscope Neophot 32 and SEM observation with EDX analysis using scanning electron microscope VEGA LMU II linked to the energy dispersive X-ray spectroscopy (EDX analyser Brucker Quantax. Hardness measurement was performed by a Brinell hardness tester with a load of 62.5 kp (1 kp = 9.807 N, 2.5 mm diameter ball and a dwell time of 15 s.Findings: The results indicate that increasing solution treatment temperature results in spheroidization of eutectic Si, gradual disintegration of iron rich intermetallic phases on base Al15(FeMn3Si2, dissolution but also melting of intermetallic phases on base Al-Al2Cu-Si. Optimal solution treatment (515°C/4 hours most improves mechanical properties. Further increases of solution time, leads to alloy elongations, while both, the tensile strength continuously drop.Practical implications: The present study is a part of larger research project, which was conducted to investigate and to provide a better understanding microstructure, heat treatment and

  17. Effects of slope plate variable and reheating on semi-solid structure of ductile cast iron

    Institute of Scientific and Technical Information of China (English)

    M. Nili-Ahmadabadi; F. Pahlevani; P. Babaghorbani

    2008-01-01

    Semi-solid metal casting and forming are known as a promising process for a wide range of metal alloys production. In spite of growing application of semi-solid processed light alloys, a few works have been reported about semi-solid processing of iron and steel. In this research inclined plate was used to change dendritic structure of iron to globular one. The effects of length and slope of plate on the casting structure were examined. The results show that the process can effectively change the dendritic structure to globular. In the slope plate angle of 7.5°and length of 560 mm with cooling rate of 67K·s-1 the optimum nodular graphite and solid globular particle were achieved.The results also show that by using slope plate inoculant fading can be prevented more easily since the total time of process is rather short.In addition, the semi-solid ductile cast iron prepared by inclined plate method, was reheated to examine the effect of reheating conditions on the microstructure and coarsening kinetics of the alloy. Solid fraction at different reheating temperatures and holding time was obtained and based on these results the optimum reheating temperature range was determined.

  18. Structure changes and mechanical properties of laser alloyed magnesium cast alloys

    Directory of Open Access Journals (Sweden)

    W. Kwaśny

    2009-02-01

    Full Text Available Purpose: The aim of this work was to investigate structure and mechanical properties of the MCMgAl12Zn1 casting magnesium alloys after laser treatment. The laser treatment was carried out using a high power diode laser (HPDL.Design/methodology/approach: The laser processing of TiC, WC, SiC particles in MCMgAl12Zn1 and the resulted microstructures and properties are discussed in this paper. The resulting microstructure in the modified surface layer was examined. Phase composition was determined by the X-ray diffraction method using XPert device. The measurements of hardness after laser melt injection was also studied.Findings: Structure of the solidyifying material after laser alloying is characteristic with occurrences of areas with the diversified morphology, dependent on solidification rate of the magnesium alloys, is characteristic of structure of the solidified material after laser alloying. The MCMgAl12Zn1 casting magnesium alloys after laser alloying demonstrate similar hardness tests results, in reference to hardness of the alloys before their laser treatment.Research limitations/implications: In this research three powders (titanium carbide, tungsten carbide and silicon carbide were used to reinforcing the surface of the MCMgAl12Zn1 casting magnesium alloys.Practical implications: High power diode laser can be used as an economical substitute for CO2 and Nd:YAG lasers to modify the surface magnesium alloy by feeding the carbide particles.Originality/value: The originality of this work is applying of High Power Diode Laser for laser treatment of cast magnesium alloy consisting in fusion penetration of the hard particles of titanium, tungsten, and silicon carbides into the remelted surface layer of the alloy.

  19. THE INFLUENCE OF THE INGOT MOLD COOLING ON THE STRUCTURE OF SILUMINA CASTINGS AK15M3 AT VERTICAL CENTRIFUGAL CASTING

    Directory of Open Access Journals (Sweden)

    V. Yu. Stecenko

    2015-05-01

    Full Text Available Influence of ways of the mold cooling on structure of castings with diameter of 135 mm from AK15M3 silumin at vertical centrifugal casting is investigated. It is established that for production of castings with diameter 135 mm from AK15M3 silumin with high mechanical and tribotechnical properties it is necessary to apply a shaped mould with water-spray cooling at expense of cooler of 0,42 m3/h.

  20. THE INFLUENCE OF THE INGOT MOLD COOLING ON THE STRUCTURE OF SILUMINA CASTINGS AK15M3 AT VERTICAL CENTRIFUGAL CASTING

    OpenAIRE

    V. Yu. Stecenko; K. N. Baranov; R. V. Konovalov

    2015-01-01

    Influence of ways of the mold cooling on structure of castings with diameter of 135 mm from AK15M3 silumin at vertical centrifugal casting is investigated. It is established that for production of castings with diameter 135 mm from AK15M3 silumin with high mechanical and tribotechnical properties it is necessary to apply a shaped mould with water-spray cooling at expense of cooler of 0,42 m3/h.

  1. Undercooling and nodule count in thin walled ductile iron castings

    DEFF Research Database (Denmark)

    Pedersen, Karl Martin; Tiedje, Niels Skat

    2007-01-01

    Casting experiments have been performed with eutectic and hypereutectic castings with plate thicknesses from 2 to 8 mm involving both temperature measurements during solidification and microstructural examination afterwards. The nodule count was the same for the eutectic and hypereutectic castings...... in the thin plates (≤4.3 mm) while in the 8 mm plate the nodule count was higher in the hypereutectic than in the eutectic castings. The minimum temperature before the eutectic recalescence (Tmin) was 15 to 20ºC lower for the eutectic than for the hypereutectic castings. This is due to nucleation of...... graphite nodules which begins at a lower temperature in the eutectic than in the hypereutectic castings. The recalescence ∆Trec was however also larger for the eutectic casting and in the thin plates the maximum temperature after recalescence (Tmax) was the same in the eutectic and hypereutectic plates...

  2. Recent development of ductile cast iron production technology in China

    Directory of Open Access Journals (Sweden)

    Cai Qizhou

    2008-05-01

    Full Text Available Recent progress in the production and technology of ductile cast iron castings in China is reviewed. The manufacture and process control of as-cast ductile iron are discussed. The microstructure, properties and application of partial austenitization normalizing ductile iron and austempered ductile iron (ADI are briefl y depicted. The new development of ductile iron production techniques, such as cored-wire injection (wire-feeding nodularization process, tundish cover ladle nodularizing process, horizontal continuous casting, and EPC process (lost foam for ductile iron castings, etc., are summarized.

  3. Recent development of ductile cast iron production technology in China

    Institute of Scientific and Technical Information of China (English)

    Cai Qizhou; Wei Bokang

    2008-01-01

    Recent progress in the production and technology of ductile cast iron castings in China is reviewed.The manufacture and process control of as-cast ductile iron are discussed.The microstructure.properties and application of partial austenitization normalizing ductile iron and austempered duclile iron(ADI)are briefly depicted.The new development of duclile iron production techniques,such as cored-wire injection(wire-feeding nodularization)process,tundish cover ladle nodularizing process,horizontal continuous casting,and EPC process (lost foam)for ductile iron castings,etc.,are summarized.

  4. Niobium alloying effect in high carbon equivalent grey cast iron

    OpenAIRE

    Zhou Wenbin; Zhu Hongbo; Zheng Dengke

    2011-01-01

    The effect of niobium on the formation of NbC phase and solidification structure in high carbon equivalent grey cast iron was investigated. The experimental results indicated that an increase in the niobium content is favorable to refining the graphite and eutectic cell; and the pearlite lamellar spacing is reduced. Based on the thermodynamic calculation the formation of NbC is prior to the eutectic reaction. The reduction in the pearlite lamellar spacing is mainly attributed to the decrease ...

  5. The lost foam process in pilot castings plattes

    Directory of Open Access Journals (Sweden)

    Z. Żółkiewicz

    2009-04-01

    Full Text Available The paper discusses the process of thermal evaporation of a foundry pattern. At several research-development centres, studies have beencarried out to examine the physico-chemical phenomena that take place in foundry mould filled with polystyrene pattern when it is pouredwith molten metal. In the technique of evaporative patterns, the process of mould filling with molten metal (the said mould holding inside a polystyrene pattern is interrelated with the process of thermal decomposition of this pattern. The process of polystyrene pattern evaporation in foundry mould under the effect of molten metal is of a very complex nature and depends on many different factors, still not fully investigated. The technology of evaporative patterns was used in manufacture of pilot castings of the high abrasion resistance plates. The material and the properties of the resultant castings were determined by the customer (patent protection. At the beginning of the studies, the properties of the pattern material were determined, patterns were assembled, the properties of the ceramic layer were determined as well as the technique of its preparation and application. The technique of molten metal feeding to the mould cavity was examined along with the parameters of the gating and feeding system, and casting cooling and solidification conditions (large contraction, shrinkage cavities and depressions.

  6. CASTING OF DETAILS OF WEAR-RESISTANT CHROME CAST IRONS FOR CHROMIC MILLS IN COMBINED MOLDS AND CHILLS

    Directory of Open Access Journals (Sweden)

    K. E. Baranovskij

    2009-01-01

    Full Text Available Relative wear resistance of chrome cast irons of eutectic composition is determined in laboratory and industry conditions. Complex alloyed eutectic cast iron with increased wear resistance and mechanical characteristics is developed.

  7. The prediction of bubble defects in castings

    OpenAIRE

    Lawrence, James Andrew

    2004-01-01

    Objective of this research was to develop models that capture the entrainment, breakup and transport of gas bubbles in solidifying TiAl castings. The candidate has reviewed the literature, programmed in FORTRAN code, and validated a number of competing techniques for two phase flow relevant to the filling of moulds. He has developed a hybrid (Donor-acceptor/ Level Set) method, which captures the characteristics of gas bubbles based on the surface tension —fluid inertia balance on the free sur...

  8. Maintenance system improvement in cast iron foundry

    OpenAIRE

    S. Kukla

    2011-01-01

    The work presents the issue of technical equipment management in an iron foundry basing on the assumptions of the TPM system (Total Productive Maintenance). Exploitation analysis of automatic casting lines has been carried out and their work’s influence on the whole production system’s functioning has been researched. Within maintenance system improvement, implementation of autonomic service and planned lines’ review have been proposed in order to minimize the time of breakdown stoppages. The...

  9. Effect of quenching temperature on structure and properties of centrifugal casting high speed steel roll

    Directory of Open Access Journals (Sweden)

    Fu Hanguang

    2009-02-01

    Full Text Available The critical points and time-temperature-transformation (TTT curves of the isothermal transformation diagrams for a high-speed steel casting on a horizontal centrifugal casting machine had been determined experimentally in the study. The effects of quenching temperature on the microstructures and properties of centrifugal casting high speed steel (HSS roll has been investigated using scanning electron microscopy (SEM, light optical microscopy (LOM and X-ray diffraction (XRD as well as using tensile, impact, and hardness tests. The results show that the HSS roll has excellent hardenability and its matrix structure can be transformed into the martensite after being quenched in the sodium silicate solution. The retained austenite in the quenching structure increases and the hardness decreases when the quenching temperature exceeds 1,040℃. The tensile strength and impact toughness of HSS roll increase once the quenching temperature is raised from 980℃ to 1,040℃. However, the tensile strength and impact toughness have no signifi cant change when the quenching temperature exceeds 1,040℃. The HSS roll quenched at 1,040℃ exhibits excellent comprehensive mechanical properties.

  10. Phase Transformation in Cast Superaustenitic Stainless Steels

    Energy Technology Data Exchange (ETDEWEB)

    Nathaniel Steven Lee Phillips

    2006-12-12

    Superaustenitic stainless steels constitute a group of Fe-based alloys that are compositionally balanced to have a purely austenitic matrix and exhibit favorable pitting and crevice corrosion resistant properties and mechanical strength. However, intermetallic precipitates such as sigma and Laves can form during casting or exposure to high-temperature processing, which degrade the corrosion and mechanical properties of the material. The goal of this study was to accurately characterize the solid-solid phase transformations seen in cast superaustenitic stainless steels. Heat treatments were performed to understand the time and temperature ranges for intermetallic phase formations in alloys CN3MN and CK3MCuN. Microstructures were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy and wavelength dispersive spectroscopy (EDS, WDS). The equilibrium microstructures, composed primarily of sigma and Laves within purely austenitic matrices, showed slow transformation kinetics. Factors that determine the extent of transformation, including diffusion, nucleation, and growth, are discussed.

  11. Solidification control in continuous casting of steel

    Indian Academy of Sciences (India)

    S Mazumdar; S K Ray

    2001-02-01

    An integrated understanding of heat transfer during solidification, friction/lubrication at solid-liquid interface, high temperature properties of the solidifying shell etc. is necessary to control the continuous casting process. The present paper elaborates upon the knowledge developed in the areas of initial shell formation, mode of mould oscillation, and lubrication mechanism. The effect of these issues on the caster productivity and the quality of the product has been discussed. The influence of steel chemistry on solidification dynamics, particularly with respect to mode of solidification and its consequence on strength and ductility of the solidifying shell, has been dealt with in detail. The application of these basic principles for casting of stainless steel slabs and processing to obtain good quality products have been covered.

  12. Level measurement in electromagnetic continuous casting

    International Nuclear Information System (INIS)

    Level measurement method of molten metal have been investigated to apply in the electromagnetic continuous casting. The level measuring principle was based on the electromagnetic induction and search coil type of magnetic sensor was chosen as a level sensor, Before construct the level meter, the artificial cold charges was used to characterize the sensor output according to the level, the coil current, and the aging. Considering the results of basic experiments, we constructed a level measurement system and applied it to electromagnetic continuous casting at a billet caster of POSCO works. The developed level meter showed that the resolution of the level was within ±0.3 mm, the dynamic range of sensing was from the top of the mold to 300 mm below the top of the mold. It worked well with the existing control device in supplying the molten steel to the mold.

  13. Preferential dissolution behaviour in Ni–Cr dental cast alloy

    Indian Academy of Sciences (India)

    Viswanathan S Saji; Han Cheol Choe

    2010-08-01

    A Ni–Cr–Mo dental alloy was fabricated by three different casting methods, viz. centrifugal casting, high frequency induction casting and vacuum pressure casting. The dependence of cast microstructure on the electrochemical corrosion behaviour was investigated using potentiodynamic cyclic and potentiostatic polarization techniques, impedance spectroscopy and scanning electron microscopy. The experimental results were compared and discussed with those obtained for a Co–Cr–Mo counterpart. The results of the study showed that the variation in casting morphologies with casting methods has only marginal influence in the overall corrosion resistance of Ni–Cr and Co–Cr dental alloys. There was severe preferential dissolution of Ni rich, Cr and Mo depleted zones from the Ni–Cr–Mo alloy. The overall corrosion resistance property of the Co–Cr base alloy was better than that of the Ni–Cr base alloy.

  14. Myoglobin casts in renal biopsies: immunohistochemistry and morphologic spectrum.

    Science.gov (United States)

    Liapis, Helen; Boils, Christie; Hennigar, Randolph; Silva, Fred

    2016-08-01

    Five hundred eighty renal biopsies from a pool of 27850 archived cases were identified in which a myoglobin stain was performed because of atypical casts. Two hundred and thirty-eight (41%) of these biopsies were found to be positive for myoglobin casts. The morphology of the myoglobin casts ranged from light, almost translucent and refractile, to pink, to dark red and slightly brown granular casts by hematoxylin and eosin, to beaded globular casts that stained brightly fuchsinophilic with Masson trichrome and partially argyrophilic with silver methenamine. All biopsies displayed acute tubular injury associated with intratubular debris and thinning and vacuolization of tubular epithelium. Approximately 20% of myoglobin-positive biopsies showed calcium oxalate or phosphate deposition. Positive myoglobin staining was present in casts, proximal tubular epithelial cells without casts, and also dehisced epithelial cells. Collecting ducts and occasionally the distal tubular epithelium also stained positive. One case showed concurrent myeloma cast nephropathy with "fractured" casts and translucent myoglobin-positive casts. Herein, we describe the morphologic spectrum of myoglobin-positive casts. We conclude that utilization of myoglobin immunohistochemistry is advantageous and, when not available, knowledge of the morphologic spectrum is important. PMID:27038680

  15. CHANGE OF CONNECTION BETWEEN MAGNETIC PARAMETERS OF CAST IRON IN COMPARISON WITH STEEL UNDER INFLUENCE OF INTERNAL DEMAGNETIZATION

    Directory of Open Access Journals (Sweden)

    S. G. Sandomirsky

    2014-01-01

    Full Text Available Connection of maximum magnetic permeability µm of cast irons with coercive force Нс and residual magnetism Мr is established in all size of changing of the magnetic characteristics of cast iron. Differences of this connection for steels and cast irons are revealed. Formula for calculation µm of steels by Нс and Мr is corrected for calculation µm of cast irons. As a result of correction the calculation error of cast irons µm is diminished. The results can be used in magnetic structural analysis instead of labor-consuming measurement µm.

  16. The Effects of Fracture Origin Size on Fatigue Properties of Ductile Cast Iron with Small Chill Structures

    Science.gov (United States)

    Sameshima, Daigo; Nakamura, Takashi; Horikawa, Noritaka; Oguma, Hiroyuki; Endo, Takeshi

    Reducing the weight of a machine structure is an increasingly important consideration both for the conservation of resources during production and for the energy saving during operation. With these objectives in mind, thin-walled ductile cast iron has recently been developed. Because rapid cooling could result in brittle microstructure of cementite (chill) in this cast iron, it is necessary to investigate the effect of cementite on the fatigue properties. Therefore, fatigue tests were carried out on a ductile cast iron of block castings which contained a relatively small amount of cementite. Fracture surface observation indicated that the fracture origins were located at graphite clusters and cast shrinkage porosity, not at cementite. It appears that when the size of the cementite is smaller than that of the graphite, the cementite does not affect the fatigue properties of ductile cast iron. Not surprisingly, the fatigue lives were found to increase with decrease in the size of the fatigue fracture origin. The threshold initial stress intensity factor range ΔKini,th for fatigue failure was found to be about 3-4MPa√m, independent of microstructure.

  17. Numerical simulation of casting process to assist in defects reduction in complex steel tidal power component

    Science.gov (United States)

    Guo, E. J.; Zhao, S. C.; Wang, L. P.; Wu, T.; Xin, B. P.; Tan, J. J.; Jia, H. L.

    2016-03-01

    In order to reduce defects and improve casting quality, ProCAST software is performed to study the solidification process of discharge bowl. Simulated results of original casting process show that the hot tearing is serious at the intersection of blades and outer or inner rings. The shrinkage porosity appears at the bottom of discharge bowl and the transition area of wall thickness. Based on the formation mechanisms of the defects, the structure of chills attached on the outer surface of discharge bowl casting is optimized. The thickness of chills ranges from 25mm to 35mm. The positions of chills corresponded to the outer surface of the T-shaped parts. Compared to the original casting design (without chills), the hot tearing and shrinkage porosity of the discharge bowl are greatly improved with addition of chills.

  18. Interactions between solidification and fluid flow. Effects on cast structures and segregations

    International Nuclear Information System (INIS)

    Natural or forced fluid flow of the bulk melt can induce several changes in the solidification history of a casting : it may change the heat transfer conditions, the as-cast grain distribution, and the segregations. On the other hand, solidification can result in intense fluid flow due to natural solutal convection and in severe local segregations. The two following practical cases illustrate the variety and complexity of interactions between the fluid flow and the solidification of alloys : a) the effects of the stirring of the bulk liquid on the formation of the equiaxed zone during the continuous casting of steels, b) the formation of freckles and related segregations during the directional solidification of nickel-base alloys. Informations are given about, either new experimental observations, or up-dated physical and numerical models related to each case chosen here as examples. In the case of the influence of stirring on the formation of the equiaxed zone, emphasis is put on the importance of the interaction of the fluid flow with the dendrites in the columnar zone and in the stirred region itself. In the case of the freckles, evidence is brought forward that the dendritic nature and structure of the mushy zone are not the only causes of the dependence of the freckling on the heat transfer conditions during directional solidification. (orig.)

  19. Effect of quenching temperature on structure and properties of centrifugal casting high speed steel roll

    OpenAIRE

    Fu Hanguang; Cheng Xiaole; Du Zhongze

    2009-01-01

    The critical points and time-temperature-transformation (TTT) curves of the isothermal transformation diagrams for a high-speed steel casting on a horizontal centrifugal casting machine had been determined experimentally in the study. The effects of quenching temperature on the microstructures and properties of centrifugal casting high speed steel (HSS) roll has been investigated using scanning electron microscopy (SEM), light optical microscopy (LOM) and X-ray diffraction (XRD) as well as us...

  20. Characterization of the structure and precipitation process in Al-Mg-Si and Al-Mg-Ge casting alloys

    OpenAIRE

    Boyko, Viktoriya

    2015-01-01

    Die Al-Mg-Si-Legierungen, welche neuerdings in der Gießerei verwendet werden, weisen eine exzellente Kombination aus Härte und Duktilität auf, aber es liegen kaum Informationen über ihre Zusammensetzung, Struktur und Phasen sowie die Ausscheidungsprozesse bei der Wärmebehandlung vor. Für das Al-Mg-Ge-System trifft dies in noch stärkere Maße zu. Das Ziel der vorliegenden Dissertation ist darum die Erweiterung des Wissensstands bezüglich Struktur, Zusammensetzung und Ausscheidungen in Al-Mg-Si-...

  1. Casting of 3-dimensional footwear prints in snow with foam blocks.

    Science.gov (United States)

    Petraco, Nicholas; Sherman, Hal; Dumitra, Aurora; Roberts, Marcel

    2016-06-01

    Commercially available foam blocks are presented as an alternative material for the casting and preservation of 3-dimensional footwear impressions located in snow. The method generates highly detailed foam casts of questioned footwear impressions. These casts can be compared to the known outsole standards made from the suspects' footwear. Modification of the commercially available foam casting blocks is simple and fast. The foam block is removed and a piece of cardboard is secured to one side of the block with painter's masking tape. The prepared foam block is then placed back into its original box, marked appropriately, closed and stored until needed. When required the foam block is carefully removed from its storage box and gently placed, foam side down, over the questioned footwear impression. Next, the crime scene technician's hands are placed on top of the cardboard and pressure is gently applied by firmly pressing down onto the impression. The foam cast is removed, dried and placed back into its original container and sealed. The resulting 3D impressions can be directly compared to the outsole of known suspected item(s) of footwear. PMID:27124876

  2. Effect of cooling rate and forced convection on as-cast structure of 2205 duplex stainless steel

    OpenAIRE

    Cheng Zhang; Hong-gang Zhong; Cong-sen Wu

    2015-01-01

    To forecast the as-cast structure and ferrite-austenite phase ratio of 2205 duplex stainless steel (DSS), the effects of cooling rate and forced convection were observed in a high-vacuum resistance furnace in which the forced convection was created by the rotation of the crucible. The as-cast structure of all 2205 DSS samples is full equiaxed grains, and the microstructure consists of a great amount of desirable intra-granular austenite inside the continuous ferrite grain matrix, besides Widm...

  3. Semi-solid thixo casting structure of aluminum alloy and relevant assistant analysis with the help of computer simulation

    Institute of Scientific and Technical Information of China (English)

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

    2008-01-01

    The relationship between structure morphology of semi-solid aluminum alloy die-casting sample and filling condition was studied. By systematical structure analysis and computer simulation of the filling process, the quant-itative relationship between microscopic morphology (such as solid fraction, grain size and shape) and formation state was studied. The results showed that the billet microstruc-ture must have fine and round grains for the die-casting of complex shapes. It is necessary to optimize injection speeds to escape the non-uniform distribution of the solid fraction in complex and changeable mold cavity.

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

    Science.gov (United States)

    Chun, Sung-Yong

    2015-07-01

    Chromium 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 300 W. The deposited coatings were characterized post-deposition using X-ray diffractometry (XRD) and atomic force microscopy (AFM). Single CrN phased coatings with nano-grain sized (< 20 nm) were identified. The corrosion resistance and hardness of each coating were evaluated from potentiost at and nanoindentator. Superior corrosion protective coatings in excess of 20 GPa were deposited with assistance of ICP plasma during sputtering. PMID:26373141

  5. The history and present of art casting in China

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    @@ A compendiary review of art casting in China: History of art casting in china has been over 5000 years. In the past few thousand years, numerous forming and decorating skills of art castings had been created, and left behind precious treasures in the world metal arts and crafts. In individual historical period and at different terrain, a unique artistic style formed,which flashed brilliant light in world artistic treasury.

  6. Comparison of residual stresses in sand- and chill casting of ductile cast iron wind turbine main shafts

    DEFF Research Database (Denmark)

    Sonne, Mads Rostgaard; Frandsen, J. O.; Hattel, Jesper Henri

    2015-01-01

    In this work, simulations of pouring, solidification and cooling, and residual stress evolution of sand and chill cast wind turbine main shafts is performed. The models are made in the commercial software MAGMAsoft. As expected, the cooling rate of the sand casting is shown to be much lower than...... for the chill casting, resulting in a very course microstructure.From the simulations the nodule count is found to be 17 nodules per mm2 and 159 nodules permm2 for the sand and chill casting, respectively, in the critical region of the main bearing seat.This is verified from nodule counts performed on...... the real cast main shafts. Residual stressevaluations show an overall increase of the maximum principal stress field for the chill casting,which is expected. However, the stresses are found to be in compression on the surface of thechill cast main shaft, which is unforeseen....

  7. Caste differences in Pseudopolybia compressa (Hymenoptera: Vespidae: Polistinae)

    OpenAIRE

    Laura Chavarría Pizarro; Noll, Fernando B; Sidnei Mateus

    2009-01-01

    Studies of morphological caste syndromes in the tribe Epiponini help us to understand the evolution of social behavior in insects. Few studies have integrated morphological syndromes of various species from the same or distinct genera. We studied morphological differences between castes from three colonies of Pseudopolybia compressa de Saussure, 1854, in order to relate their caste syndrome with those of other species in the genus. We took eight morphometric measures and females were classifi...

  8. Heat treatment effect on structure and mechanical properties of nonmagnetic high nitrogen steels produced by casting with counterpressure

    International Nuclear Information System (INIS)

    Effects of quenching temperature, aging temperature and aging duration on the structure and mechanical properties of vanadium alloyed high nitrogen Cr-Mn steels produced by casting with nitrogen counter-pressure are investigated. For studying aging kinetics apart from the investigation of the structure and mechanical properties measurements of specific electric resistance, specific heat, relative elongation of specimens in the process of heating, cooling and isothermal holding have been performed. It has been found that casting with nitrogen counterpressure permits to produce aging stainless high nitrogen (up to 1.1 % N) nickel-free steels which can be used for manufacturing heavy-loaded nonmagnetic machine parts and devices. The strength level of high nitrogen Cr-Mn steels produced by casting with nitrogen counterpressure considerably increases using vanadium as an addition ensuring hardening with precipitation of VN disperse particles

  9. Graphitization in chromium cast iron

    OpenAIRE

    LECOMTE-BECKERS, Jacqueline; Terziev, L.; Breyer, J. P.

    1998-01-01

    Some trials with graphite Hi-Cr iron rolls have been done mainly in Japan, for the rolling of stainless steel. This material could lead to good compromise between oxidation, wear and thermal behaviour. By using thermal analysis and resistometry, the conditions for secondary graphite formation have been studied. The amount and volume of free graphite may be strongly increased by a suitable heat treatment, allowing a good thermal conductivity as well as high wear and mechanical properties.

  10. Awareness Programs and Change in Taste-based Caste Prejudice

    DEFF Research Database (Denmark)

    Banerjee, Ritwik; Gupta, Nabanita Datta

    2015-01-01

    Becker's theory of taste-based discrimination predicts that relative employment of the discriminated social group will improve if there is a decrease in the level of prejudice for the marginally discriminating employer. In this paper we experimentally test this prediction offered by Garry Becker in...... his seminal work on taste based discrimination, in the context of caste in India, with management students (potential employers in the near future) as subjects. First, we measure caste prejudice and show that awareness through a TV social program reduces implicit prejudice against the lower caste and...... exhibit favorable opinion about reservation in jobs for the lower caste....

  11. Automatic inspection of surface defects in die castings after machining

    OpenAIRE

    S. J. Świłło; M. Perzyk

    2011-01-01

    A new camera based machine vision system for the automatic inspection of surface defects in aluminum die casting was developed by the authors. The problem of surface defects in aluminum die casting is widespread throughout the foundry industry and their detection is of paramount importance in maintaining product quality. The casting surfaces are the most highly loaded regions of materials and components. Mechanical and thermal loads as well as corrosion or irradiation attacks are directed pri...

  12. Phase Transformations in Cast Duplex Stainless Steels

    Energy Technology Data Exchange (ETDEWEB)

    Yoon-Jun Kim

    2004-12-19

    Duplex stainless steels (DSS) constitute both ferrite and austenite as a matrix. Such a microstructure confers a high corrosion resistance with favorable mechanical properties. However, intermetallic phases such as {sigma} and {chi} can also form during casting or high-temperature processing and can degrade the properties of the DSS. This research was initiated to develop time-temperature-transformation (TTT) and continuous-cooling-transformation (CCT) diagrams of two types of cast duplex stainless steels, CD3MN (Fe-22Cr-5Ni-Mo-N) and CD3MWCuN (Fe-25Cr-7Ni-Mo-W-Cu-N), in order to understand the time and temperature ranges for intermetallic phase formation. The alloys were heat treated isothermally or under controlled cooling conditions and then characterized using conventional metallographic methods that included tint etching, and also using electron microscopy (SEM, TEM) and wavelength dispersive spectroscopy (WDS). The kinetics of intermetallic-phase ({sigma} + {chi}) formation were analyzed using the Johnson-Mehl-Avrami (MA) equation in the case of isothermal transformations and a modified form of this equation in the case of continuous cooling transformations. The rate of intermetallic-phase formation was found to be much faster in CD3MWCuN than CD3MN due mainly to differences in the major alloying contents such as Cr, Ni and Mo. To examine in more detail the effects of these elements of the phase stabilities; a series of eight steel castings was designed with the Cr, Ni and Mo contents systematically varied with respect to the nominal composition of CD3MN. The effects of varying the contents of alloying additions on the formation of intermetallic phases were also studied computationally using the commercial thermodynamic software package, Thermo-Calc. In general, {sigma} was stabilized with increasing Cr addition and {chi} by increasing Mo addition. However, a delicate balance among Ni and other minor elements such as N and Si also exists. Phase equilibria in

  13. Phase transformations in cast duplex stainless steels

    Science.gov (United States)

    Kim, Yoon-Jun

    Duplex stainless steels (DSS) constitute both ferrite and austenite as a matrix. Such a microstructure confers a high corrosion resistance with favorable mechanical properties. However, intermetallic phases such as sigma (sigma) and chi (chi) can also form during casting or high-temperature processing and can degrade the properties of the DSS. This research was initiated to develop time-temperature-transformation (TTT) and continuous-cooling-transformation (CCT) diagrams of two types of cast duplex stainless steels, CD3MN (Fe-22Cr-5Ni-Mo-N) and CD3MWCuN (Fe-25Cr-7Ni-Mo-W-Cu-N), in order to understand the time and temperature ranges for intermetallic phase formation. The alloys were heat treated isothermally or under controlled cooling conditions and then characterized using conventional metallographic methods that included tint etching, and also using electron microscopy (SEM, TEM) and wavelength dispersive spectroscopy (WDS). The kinetics of intermetallic-phase (sigma + chi) formation were analyzed using the Johnson-Mehl-Avrami (JMA) equation in the case of isothermal transformations and a modified form of this equation in the case of continuous cooling transformations. The rate of intermetallic-phase formation was found to be much faster in CD3MWCuN than CD3MN due mainly to differences in the major alloying contents such as Cr, Ni and Mo. To examine in more detail the effects of these elements of the phase stabilities, a series of eight steel castings was designed with the Cr, Ni and Mo contents systematically varied with respect to the nominal composition of CD3MN. The effects of varying the contents of alloying additions on the formation of intermetallic phases were also studied computationally using the commercial thermodynamic software package, Thermo-Calc. In general, a was stabilized with increasing Cr addition and chi by increasing Mo addition. However, a delicate balance among Ni and other minor elements such as N and Si also exists. Phase equilibria in

  14. Structure changes and mechanical properties of laser alloyed magnesium cast alloys

    OpenAIRE

    W. Kwaśny; T. Tański,; Sz. Malara; J. Domagała; L.A. Dobrzański

    2009-01-01

    Purpose: The aim of this work was to investigate structure and mechanical properties of the MCMgAl12Zn1 casting magnesium alloys after laser treatment. The laser treatment was carried out using a high power diode laser (HPDL).Design/methodology/approach: The laser processing of TiC, WC, SiC particles in MCMgAl12Zn1 and the resulted microstructures and properties are discussed in this paper. The resulting microstructure in the modified surface layer was examined. Phase composition was...

  15. Caste Discrimination, Land Reforms and Land Market Performance in Nepal

    OpenAIRE

    Aryal, Jeetendra P.; Holden, Stein T.

    2011-01-01

    This paper assesses the implications of caste discrimination and past land reforms on the land rental market performance, land productivity and land use intensity in Nepal. The most severely discriminated group in the caste system is the Dalits, the so-called “untouchables”. Dalits faced religious, occupational and even, territorial discrimination. The study uses data from western Nepal. The low-caste households remain poorer than other households, have significantly smaller land endowments, ...

  16. LIGHT-WEIGHT LOAD-BEARING STRUCTURES REINFORCED BY CORE ELEMENTS MADE OF SEGMENTS AND A METHOD OF CASTING SUCH STRUCTURES

    DEFF Research Database (Denmark)

    2009-01-01

    The invention relates to a light-weight load-bearing structure, reinforced by core elements (2) of a strong material constituting one or more compression or tension zones in the structure to be cast, which core (2) is surrounded by or adjacent to a material of less strength compared to the core (2......), where the core (2) is constructed from segments (1) of core elements (2) assembled by means of one or more prestressing elements (4). The invention further relates to a method of casting of light-weight load-bearing structures, reinforced by core elements (2) of a strong material constituting one or...... more compression or tension zones in the structure to be cast, which core (2) is surrounded by or adjacent to a material of less strength compared to the core (2), where the core (2) is constructed from segments (1) of core elements (2) assembled and hold together by means of one or more prestressing...

  17. Investigation of the tensile properties of continuous steel wire-reinforced gray cast iron composite

    International Nuclear Information System (INIS)

    Research highlights: → Metal matrix composite (MMC) is an important structural material. → Gray cast irons as a matrix material in MMC have more advantages than other cast irons. → Interface greatly determines the mechanical properties of MMC. → Interface formed by diffusion of carbon atoms. → While decarburizing takes place in gray cast iron, carburiszing takes place in steel near the interface. - Abstract: The aim of the present study was to improve the tensile properties of gray cast iron by reinforcing the material with a steel wire. The composite was produced by sand mold casting, and the specimens were normalized by applying heat treatments at 800 deg. C, 850 deg. C, and 900 deg. C. Tension tests were conducted on gray cast iron and composite specimens, and the microstructure of the specimens was examined with an optical microscope. The fracture surface of the tension test specimens was examined with a scanning electron microscope (SEM), and graphite-free transition regions with high degrees of hardness were observed due to the diffusion of carbon from the cast iron to the steel wire. The microstructure of the transition region (fine pearlitic phase with partially dissolved graphite flakes) and the bond quality in the transition region increased the tensile properties of cast iron composites. Also, it is concluded that the tensile properties of gray cast iron increased with an increase in the normalization temperature.

  18. Structure and tensile performance of 1025 carbon steel produced by vacuum electromagnetic centrifugal casting

    International Nuclear Information System (INIS)

    The effects of magnetic induction (0, 0.052, 0.085, 0.115 T) and rotation speed (950, 1250, 1450 r/min) on microstructure and room temperature tensile property of the vacuum electromagnetic centrifugal casting 1025 carbon steel tube was studied. The results indicate that the cast structure is refined distinctly with electromagnetic density increment, and the room temperature tensile strength and ductility are improved and reached the standards of hot rolling material. (authors)

  19. Thermal analysis of ductile iron in thin walled casting

    Directory of Open Access Journals (Sweden)

    M. Górny

    2007-12-01

    Full Text Available Hypereutectic ductile iron was cast in self hardening moulding sand to produce castings with the shape of Archimedes spirals and with wall thickness of 1, 2 and 3 mm. Inmould technique was used to produce thin wall ductile iron (TWDI. In this work it has been carried out thermal analysis in spiral with 3 mm wall thickness. The present work provides results of thermal analysis, that are initial temperature of metal in mould cavity, velocity of metal stream as well as solidification time. Measurement of temperature shows that there is essential its drop during filling of mould cavity and amounts 230 oC for distance 700 mm from the beginning of spiral. On the basic on first derivative of temperature versus time characteristic solidification points were distinguish, namely solidification of primary graphite, austenite dendrite and eutectic. Experimental measurements of temperature drop during filling of mould cavity along with microscopic examinations of castings structure can be used to verify computer modeling and simulation of fluid flow and thermal field in TWDI.

  20. Influence of Low-Alloy Cast Steel Modification on Primary Structure Refinement, Type and Shape of Non-Metallic Inclusions

    Directory of Open Access Journals (Sweden)

    Bartocha D.

    2015-04-01

    Full Text Available In the article there are presented methods and results of investigation which main aim were determination of influence of melting technology (gas extraction, vacuum refining, slag refining and extraction, deoxidation and degassing and type of used modifiers on the type and shape of non-metallic inclusions and the primary structure refining. Low alloy cast steel melted in laboratory conditions, in an inductive furnace was investigated. Additions of FeNb, FeV, FeTi and FeZr modifiers were applied. The contents of oxygen and nitrogen in obtained cast steel were determined.

  1. Synergy, inteligibility and revelation in neighbourhood places

    OpenAIRE

    Dalton, N. S. C.

    2011-01-01

    In architectural and urban design the notion of place is highly desired, or in its absence, strongly criticised. Yet what is place and how might it be engendered by design? Over the last 30 years an extensive body of research on place has emerged, largely based on phenomenological approaches. This work gives rise to the question of whether place is a purely social concept completely divorced from physical space, or is linked to space and therefore amenable to design based inter...

  2. Sense of Place in Environmental Education

    Science.gov (United States)

    Kudryavtsev, Alex; Stedman, Richard C.; Krasny, Marianne E.

    2012-01-01

    Although environmental education research has embraced the idea of sense of place, it has rarely taken into account environmental psychology-based sense of place literature whose theory and empirical studies can enhance related studies in the education context. This article contributes to research on sense of place in environmental education from…

  3. Experimental validation of error in temperature measurements in thin walled ductile iron castings

    DEFF Research Database (Denmark)

    Pedersen, Karl Martin; Tiedje, Niels Skat

    2007-01-01

    thicknesses between 2 and 4.3 mm. The thermocouples were accurately placed at the same distance from the surface of the casting for different plate thicknesses. It is shown that when measuring the temperature in plates with thickness between 2 and 4.3 mm the measured temperature will be parallel shifted to a...... level about 20C lower than the actual temperature in the casting. Factors affecting the measurement error (oxide layer on the thermocouple wire, penetration into the ceramic tube and variation in placement of thermocouple) are discussed. Finally, it is shown how useful cooling curve may be obtained in...

  4. Self-assembly in casting solutions of block copolymer membranes

    KAUST Repository

    Marques, Debora S.

    2013-01-01

    Membranes with exceptional pore regularity and high porosity were obtained from block copolymer solutions. We demonstrate by small-angle X-ray scattering that the order which gives rise to the pore morphology is already incipient in the casting solution. Hexagonal order was confirmed in PS-b-P4VP 175k-b-65k solutions in DMF/THF/dioxane with concentrations as high as 24 wt%, while lamellar structures were obtained in more concentrated solutions in DMF or DMF/dioxane. The change in order has been understood with the support of dissipative particle dynamic modeling. © 2013 The Royal Society of Chemistry.

  5. Influence of formwork surface on the orientation of steel fibres within self-compacting concrete and on the mechanical properties of cast structural elements

    DEFF Research Database (Denmark)

    Svec, Oldrich; Zirgulis, Giedrius; Bolander, John E.;

    2014-01-01

    The influences of formwork surface on the final orientation of steel fibres immersed in self-compacting concrete and on the resulting mechanical response of the cast structural elements are investigated. Experimental observations of fibre orientation within cast slabs, obtained via computed...... tomography, indicate that fibres tend to orient according to the flow patterns during casting, but such tendencies are suppressed near rough formwork surfaces. Fibre orientation, in turn, affects the mechanical properties of the concrete as demonstrated by the load testing of beams extracted from the cast...... slabs. These processes and results are simulated using a computational fluid dynamics model of the casting process, in tandem with a lattice model of the fracture of the beam specimens. The computational fluid dynamics model determines the coordinates of each fibre within the concrete, which serve as...

  6. Derivative-gradient thermal analysis in casting properties forecasting

    Directory of Open Access Journals (Sweden)

    M. Dziuba

    2007-01-01

    Full Text Available Purpose: The aim of this work was to show possibilities and conception of more accurate structure andmechanical properties forecasting with use of modified derivative – gradient thermal method.Design/methodology/approach: The main restriction in standard thermal and derivative analysis is one pointmeasurement of temperature in casting with assumed geometry. In this work a modified method is describedin which restrictions present in TDA method are overcame and more accurate diagnostic of the liquid materialcan be conducted.Findings: Structural relations have been shown for local conditions of solidification defined by two derivativesdT/dt and dT/dl. Presented method incorporates up-to-date knowledge about structure influence on operatingproperties of metallic materials.Research limitations/implications: Proposed methodology can be used for cast metal matrix composite and alloysproperties diagnosis and forecasting. However accurate forecasting requires more detailed mathematical description.Originality/value: Proposed conception enables possibility of structure and operating properties forecastingbasing upon one physical measurement – temperature measurement.

  7. Places of remembrance in citizenship education

    Directory of Open Access Journals (Sweden)

    KInga Majchrzak

    2012-06-01

    Full Text Available The text starts with a short introduction. Then the concept of place is defined and its inherent characteristics are described: its symbolism, multi-sided nature and multidisciplinary connotations. Afterwards the principles of place-based pedagogy are presented and it’s eclectic character is pointed out. Then, attempt is made to explain the idea of the places of remembrance from the standpoint of history and pedagogy. In the final part the author relates to educational potential of places of remembrance and takes a stance on the role of places of remembrance in citizenship education.

  8. Caste differences in Pseudopolybia compressa (Hymenoptera: Vespidae: Polistinae

    Directory of Open Access Journals (Sweden)

    Laura Chavarría Pizarro

    2009-12-01

    Full Text Available Studies of morphological caste syndromes in the tribe Epiponini help us to understand the evolution of social behavior in insects. Few studies have integrated morphological syndromes of various species from the same or distinct genera. We studied morphological differences between castes from three colonies of Pseudopolybia compressa de Saussure, 1854, in order to relate their caste syndrome with those of other species in the genus. We took eight morphometric measures and females were classified in relation to ovarian development and spermathecal contents. Females of Colony 1 (C1 present a higher distinction between castes than females of Colonies 2 and 3 (C2 and C3, and, in general, queens of the three colonies are larger than workers in some measures but smaller in others. In Pseudopolybia Dalla Torre, 1894, shape rather than size is a more important trait in caste divergence.

  9. The ancient Chinese casting techniques

    OpenAIRE

    Tan Derui; Lian Haiping

    2011-01-01

    In the course of Chinese civilization, which lasted more than 5,000 years, casting production has made a huge contribution. In this paper, some representative metal castings were presented. According to their forming techniques, they can be grouped into stone mould casting, clay mould casting, ablation casting, lost wax casting, stack casting, permanent mould casting, sand casting, etc. According to their materials, they can be categorized into tin bronze, bimetallic bronze, malleable cast ir...

  10. Mechanical properties and microstructure of large IN713LC nickel superalloy castings

    OpenAIRE

    Zýka Jiří; Málek Jaroslav; Hrbáček Karel

    2014-01-01

    When approving large castings for use, mechanical values are measured by room temperature tensile test on test bodies made from the centres of the castings. These test bodies often exhibit lower values than required, in particular ultimate tensile strength and elongation. The presence of fragile niobium carbides in the structure of the alloy was identified as the main cause of this situation, which originated as a result of the slow speed cooling. Because of large grain size compared to gauge...

  11. High temperature corrosion of cast irons and cast steels in dry air

    Energy Technology Data Exchange (ETDEWEB)

    Tholence, F.; Norell, M. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Engineering Metals

    2001-07-01

    The oxidation in dry air of four cast alloys intended for exhaust gas systems has been examined. Particular interest was directed to how the oxide growth was related to the microstructures. The examined alloys were two cast ductile irons, a SiMo alloy (Fe3,86Si0,6Mo3C) and a Ni-Resist alloy (Fe32Ni5,3Si2,1C), and two cast stainless steels, one ferritic (Fe18Cr2,1Mn0,32C) and one austenitic (Fe20Cr9Ni0,47C). Coupons were oxidised for 50 h at temperatures between 650 C and 1050 C. The samples were characterised by using XRD, SEM/EDX and AES. As expected, the overall oxide thickness increased with temperature and partial spallation occurred at the highest temperatures for all alloys. Porous Fe oxide nodules nucleate at the graphite nodules on the ductile irons. These Fe-oxide nodules formed above a continuous layer of Fe-Si-oxide for the SiMo and mixed Fe-Ni-Si oxides for the Ni-Resist. The total oxide thickness is about (60 {mu}m). Thick oxides at the interdendritic regions in the cast steels were attributed to non-Cr-carbides. Segregation of Cr directed the formation of iron oxide nodules to the centre of the dendrites in the austenitic alloy. (orig.)

  12. Virtual Mold Technique in Thermal Stress Analysis during Casting Process

    Institute of Scientific and Technical Information of China (English)

    Si-Young Kwak; Jae-Wook Baek; Jeong-Ho Nam; Jeong-Kil Choi

    2008-01-01

    It is important to analyse the casting product and the mold at the same time considering thermal contraction of the casting and thermal expansion of the mold. The analysis considering contact of the casting and the mold induces the precise prediction of stress distribution and the defect such as hot tearing. But it is difficult to generate FEM mesh for the interface of the casting and the mold. Moreover the mesh for the mold domain spends lots of computational time and memory for the analysis due to a number of meshes. Consequently we proposed the virtual mold technique which only uses mesh of the casting part for thermal stress analysis in casting process. The spring bar element in virtual mold technique is used to consider the contact of the casting and the mold. In general, a volume of the mold is much bigger than that of casting part, so the proposed technique decreases the number of mesh and saves the computational memory and time greatly. In this study, the proposed technique was verified by the comparison with the traditional contact technique on a specimen. And the proposed technique gave satisfactory results.

  13. Network structure and its effects on the strength of Fe-C-Si-Mn alloy castings

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ding-fei; PENG Jian; XU Xing-zhi

    2004-01-01

    Fe-C-Si-Mn alloy castings used as blades in hydroelectric generators are studied and found to contain network structures after some heat treatments. Castings after annealing and normalizing were analyzed by microscope and transmission electron microscopy (TEM). The network formed during annealing was proved by TEM to be pearlite with very fine slices, while that formed during normalizing was proved by TEM and micro-hardness to be martensite or bainite. A theoretical analysis together with experimental studies has proved that the pearlite network is caused by carbon content increase in the interdendritic regions to which carbon atoms transfered from dendritic arms due to lower manganese content there during annealing, while the martensite or bainite network results from the higher hardenability of interdendritic regions where manganese content is higher.Experiments reveal that higher heating temperature or longer heating time enlarges the network size due to manganese homogenization. The network structure has a strengthening function like reinforcing rib, and the smaller the network size, the greater its strengthening capability.

  14. Announcement on the Ranking List of China's Large Casting Enterprises in 2005

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ China is the largest country in casting production worldwide and with many excellent casting producers. Advanced manufacturing technology, scientific management ideas, enormous economic benefit in these enterprises makes them the pioneers of the national casting industry.

  15. Behavior of cermets (Fe powder + Al2O3) obtained 'in situ' in cast iron

    International Nuclear Information System (INIS)

    The introduction of hard ceramic particles in a ferrous matrix modifies its behavior when undergoing stresses associated with wear resistance. So that this occurs, the particles must be properly selected, with reference to their hardness, size, shape and dispersion. These compound materials are called MMC (metal matrix composites) or cermets. This work looks at the methodology for producing cast iron pieces using a traditional sand mold casting process, using MMC tablets, and placing them in some areas of the piece that will undergo wear from abrasion. The following steps are described in the production of MMC tablets and of the casting material in the foundry's pilot plant. The material was studied and the metallurgical quality was evaluated together with its resistance to the abrasive wear

  16. Centerline Depletion in Direct-Chill Cast Aluminum Alloys: The Avalanche Effect and Its Consequence for Turbulent Jet Casting

    Science.gov (United States)

    Wagstaff, Samuel R.; Allanore, Antoine

    2016-07-01

    Avalanche dynamics of sedimenting grains in direct-chill casting of aluminum ingots is investigated as a primary driving force for centerline segregation. An analytical model predicting the importance of avalanche events as a function of casting parameters is proposed and validated with prior art results. New experimental results investigating the transient and steady-state centerline segregation of DC casting with a turbulent jet are reported.

  17. Twin-roll strip casting of magnesium alloys in China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The development status of twin-roll strip casting for magnesium alloys in China was summarized as well as the new progress when several kinds of twin-roll strip casting technologies were developed and used.Horizontal twin-roll casting (HTRC) of magnesium alloys has attracted much attention and has been industrialized in China.Vertical twin roll casting(VTRC) of the magnesium alloys can reach a speed of higher than 30 m/min and its research and development are just beginning and exhibit exciting potential.By comparing the process characteristics of the two technologies,the process stability of HTRC for the magnesium alloys is better,and the casting speed and the cooling rate of VTRC for the magnesium alloys are higher.The quality of the products by the two technologies needs to be improved and further investigated.

  18. Cool Stars in Hot Places

    OpenAIRE

    Megeath, S. T.; Gaidos, E.; Hester, J. J.; Adams, F. C.; Bally, J.; Lee, J. -E.; Wolk, S.

    2007-01-01

    During the last three decades, evidence has mounted that star and planet formation is not an isolated process, but is influenced by current and previous generations of stars. Although cool stars form in a range of environments, from isolated globules to rich embedded clusters, the influences of other stars on cool star and planet formation may be most significant in embedded clusters, where hundreds to thousands of cool stars form in close proximity to OB stars. At the cool stars 14 meeting, ...

  19. Put Yourself in My Place

    Science.gov (United States)

    Schuller, Tom

    2011-01-01

    As the riots in England demonstrated this summer, lack of empathy is a key factor in explaining people's readiness to commit crimes. How one acquires empathy is a major challenge to one's learning. Adult education has historically provided the spaces where people can both reassert and develop their particular collective identity and also learn…

  20. Booking His Place in History

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Late American Pulitzer Prize-winner John Updike is remembered in China The news of the passing of American literary icon John Updike saddened the whole world.In China,the 76-year-old Pulitzer Prize-winning novelist,who

  1. Modal Analysis of Flat Plate Structure in Aluminum Heating Plate Automatic Casting System%铝发热盘自动浇铸系统中平盘结构模态分析

    Institute of Scientific and Technical Information of China (English)

    弓满锋; 隋广洲; 梁炎锋

    2013-01-01

    The inherent frequency and vibration mode of a flat plate structure in the four working-stations aluminum heating plate automatic casting system were studied by modal analysis technology. The former-ten-steps inherent frequency and vibration modes of the structure were calculated by ANSYS 8. 0 finite element software. On the basis of the engineering practical application,the former-three-steps inherent frequency and vibration modes were especially analyzed,and the values were 211. 78,214. 86,225. 12 Hz re-spectively. The conclusion shows that the bending-deflection of rotating flat plate is serious if the quality of casting working-station is heavy,and the maximum deflection appears in the rim of the flat plate. It is harmful to the structure,such as decreasing the safety and lifetime or increasing the difficulties of casting and dismounting products by robot. It is sure that the following measures can be used to increase the flat plate stiffness,such as decreasing the flat plate diameter,retrofitting support device under the rim of flat plate and lightening the casting working-station quality.%  采用模态分析技术研究一种四工位铝发热盘自动浇铸系统中平盘结构的固有频率和振型,应用ANSYS 8.0有限元软件计算出该结构的前10阶固有频率和各阶频率所对应的振型.结合工程实际应用,重点分析了该结构前3阶固有频率,分别是211.78,214.86,225.12 Hz.结果表明:浇铸工位质量较大将导致平盘旋转时弯曲变形较大,且最大变形量出现在平盘轮缘位置.这对结构的安全性、寿命和机器人浇铸、拆装产品操作等都带来不利的影响.要提高平盘刚度,则应适当减小平盘直径、在平盘轮缘下加装支撑装置和减轻浇铸工位的质量.

  2. New Singularities in Unexpected Places

    CERN Document Server

    Barrow, John D

    2015-01-01

    Spacetime singularities have been discovered which are physically much weaker than those predicted by the classical singularity theorems. Geodesics evolve through them and they only display infinities in the derivatives of their curvature invariants. So far, these singularities have appeared to require rather exotic and unphysical matter for their occurrence. Here we show that a large class of singularities of this form can be found in a simple Friedmann cosmology containing only a scalar-field with a power-law self-interaction potential. Their existence challenges several preconceived ideas about the nature of spacetime singularities and impacts upon the end of inflation in the early universe.

  3. Thirsty Plants in Arid Places

    Science.gov (United States)

    Schaffer, Linda; Kingsley, Karla V.

    2009-01-01

    In order to demonstrate how plants remove water from the soil and release it to the atmosphere, students compared open- and closed-growing systems using drought-tolerant and higher water requirement plants. Then, students designed a drought-tolerant garden demonstrating what they had learned. Through this experience, students not only learned…

  4. Everything in its right place

    NARCIS (Netherlands)

    Fluitman, S.B.A.H.A.

    2011-01-01

    This thesis aimed at exploring immunological aspects of mainly obsessive compulsive disorder (OCD) as well as generalized social anxiety disorder (GSAD), major depressive disorder (MDD) and psychosis. First we reviewed nearly 100 clinical studies on immunological disturbancesin anxiety disorders.In

  5. Put waste in its place

    CERN Multimedia

    2009-01-01

    It doesn’t take much of an effort to sort waste, but what a difference it can make - to the environment, of course, but also to CERN’s incineration bill. A variety of containers are provided to allow waste to be sorted before disposal, thereby making recycling easier. Everyone knows that sorting waste reduces pollution. By recycling or recovering waste materials, we can reduce the amount of waste that ends up in an incinerator or land-fill, while giving the used material a second life. That reduces the consumption of raw materials and natural resources—and of budget resources. CERN pays lower bill: disposing of a tonne of waste by incineration costs 230 Swiss francs, while a tonne of paper only costs 10 francs to dispose of. The problem is that much of the waste is not properly sorted. "In 2008, out of more than 1600 tonnes of waste we had to incinerate 600 tonnes, which is an enormous figure!" says Martine Auerbach, wh...

  6. The thermal fatigue resistance of vermicular cast iron coupling with H13 steel units by cast-in process

    International Nuclear Information System (INIS)

    This paper focuses on improving the thermal fatigue resistance on the surface of vermicular cast iron coupling with inserted H13 steel blocks that had different cross sections, by cast-in processing. The microstructure of bionic units was examined by scanning electron microscope. Micro-hardness and thermal fatigue resistance of bionic samples with varied cross sections and spacings were investigated, respectively. Results show that a marked metallurgical bonding zone was produced at interface between the inserted H13 steel block and the parent material - a unique feature of the bionic structure in the vermicular cast iron samples. The micro-hardness of the bionic samples has been significantly improved. Thermal resistance of the samples with the circular cross section was the highest and the bionics sample with spacing of 2 mm spacing had a much longer thermal fatigue life, thus resulting in the improvement for the thermal fatigue life of the bionic samples, due to the efficient preclusion for the generation and propagation of crack at the interface of H13 block and the matrix.

  7. Relationship Between Casting Distortion, Mold Filling, and Interfacial Heat Transfer in Sand Molds

    Energy Technology Data Exchange (ETDEWEB)

    J. K. Parker; K. A. Woodbury; T. S. Piwonka; Y. Owusu

    1999-09-30

    This project sought to determine the relationship between casting dimensions and interfacial heat transfer in aluminum alloy sand castings. The program had four parts; measurement of interfacial heat transfer coefficients in resin bonded and green sand molds, the measurement of gap formation in these molds, the analysis of castings made in varying gatings, orientations and thicknesses, and the measurement of residual stresses in castings in the as-cast and gate removed condition. New values for interfacial heat transfer coefficients were measured, a novel method for gap formation was developed, and the variation of casting dimensions with casting method, gating, and casting orientation in the mold was documented.

  8. Bulk metallic glass tube casting

    International Nuclear Information System (INIS)

    Research highlights: → Tubular specimens of Zr55Cu30Al10Ni5 cast in custom arc-melting furnace. → Tilt casting supplemented by suction casting. → Bulk metallic glass formed only with optimized processing parameters. → Fully amorphous tubes with 1.8 mm wall thickness and 25 mm diameter. - Abstract: Tubular bulk metallic glass specimens were produced, using a custom-built combined arc-melting tilt-casting furnace. Zr55Cu30Al10Ni5 tubes with outer diameter of 25 mm and 0.8-3 mm wall thicknesses were cast, with both tilt and suction casting to ensure mold filling. Tilt casting was found to fill one side of the tube mold first, with the rest of the tube circumference filled subsequently by suction casting. Optimized casting parameters were required to fully fill the mold and ensure glass formation. Too small melt mass and too low arc power filled the mold only partially. However, too large melt mass and higher arc power which lead to the best mold filling also lead to partial crystallization. Variations in processing parameters were explored, until a glassy ring with 1.8 mm thickness was produced. Different sections of the as-cast ring were investigated by X-ray diffraction (XRD), differential scanning calorimetry (DSC), and instrumented indentation to ensure amorphous microstructure. Atomic force microscopy (AFM) was used to compare the surface qualities of the first- and last-filled sections. These measurements confirmed the glassy structure of the cast ring, and that, the tilt cast tube section consistently showed better surface quality than the suction cast section. Optimized casting parameters are required to fully realize the potential of directly manufacturing complex shapes out of high-purity bulk metallic glasses by tilt casting.

  9. Effect of annealing on mechanical properties of ledeburitic cast steel

    Directory of Open Access Journals (Sweden)

    E. Rożniata

    2007-01-01

    Full Text Available Purpose: The paper presents evaluation of influence of grain normalization (refinement as a result of repeatedaustenitizing, and the inclination to precipitate the hypereutectoid cementite in Widmannstätten structure inG200CrMoNi4-6-3 cast steel. Four temperatures of heat refining have been applied.Design/methodology/approach: Basic research of G200CrMoNi4-6-3 cast steel included metallographicanalysis, and hardness and impact strength tests. The heat treatment has been planned on the basis of CCTdiagram prepared for that alloy cast steel.Findings: The test material has been G200CrMoNi4-6-3 hypereutectoid cast steel. The evaluation has beencarried out for four annealing temperatures, i.e. 850°C, 900°C, 950°C and 1050°C. At all annealing temperaturesin the structure of cast steel the precipitation of hypereutectoid cementite along grain boundaries of formeraustenite took place. At the temperature of 850°C one may observe the coagulated hypereutectoid cementiteprecipitates inside of primary grains of austenite. Whereas beginning from the temperature of 900°C thecementite in G200CrMoNi4-6-3 cast steel forms distinct „subgrains” inside of primary grains of austenite.Research limitations/implications: Research financed by the Ministry of Scientific Research and InformationTechnology, grant No. 3 T08B 057 29.Practical implications: G200CrMoNi4-6-3 cast steel of ledeburite class is used mainly for rolls production.Any data related to the structure and mechanical properties of that cast steel are precious for the manufacturersand users of the mill rolls.Originality/value: The new heat treatment of G200CrMoNi4-6-3 cast steel

  10. Section 2--Psychology in Its Place

    Science.gov (United States)

    Radford, John

    2008-01-01

    In 1996, Graham Richards published "Putting Psychology in its Place: An introduction from a critical historical perspective." Here, I seek to consider what is or should be the "place" of Psychology in education, more particularly Higher Education, and not just from a historical perspective. This raises issues about several contexts in which…

  11. Stress/strain Modelling of Casting Processes in the Framework of the Control-Volume Method

    DEFF Research Database (Denmark)

    Hattel, Jesper Henri; Thorborg, Jesper; Andersen, Søren

    1998-01-01

    Realistic computer simulations of casting processes call for the solution of both thermal, fluid-flow and stress/strain related problems. The multitude of the influencing parameters, and their non-linear, transient and temperature dependent nature, make the calculations complex. Therefore the need...... domain, which is highly convenient. The basis of the method is the control volume finite difference approach on structured meshes. The basic assumptions of the method are shortly reviewed and discussed. As for other methods which aim at application oriented analysis of casting deformations and stresses......, the present model is based on the mainly decoupled representation of the thermal, mechanical and microstructural processes. Examples of industrial applications, such as predicting residual deformations in castings and stress levels in die casting dies, are presented...

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

    DEFF Research Database (Denmark)

    Kotas, Petr; Hattel, Jesper Henri; Thorborg, Jesper; Svensson, Ingvar L; Seifeddine, Salem

    2009-01-01

    .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...... in an aluminium alloy is considered including simulation of the entire casting process with emphasis on microstructure formation related to mechanical properties such as elastic modulus, yield stress, ultimate strength and elongation as well as residual stresses. Subsequently, the casting is...

  13. A Place for Everything and Literature in Its Place.

    Science.gov (United States)

    Roser, Nancy L.

    2001-01-01

    Considers how to teach children to become proficient readers and writers in combination with teaching them to appreciate the "art form" of language. Argues that it is unrealistic to expect teachers with pressing responsibilities to regard children's literature as sacred texts--art forms that are too fragile to be transgressed upon by instructional…

  14. Structure of lipid multilayers via drop casting of aqueous liposome dispersions.

    Science.gov (United States)

    Sironi, Beatrice; Snow, Tim; Redeker, Christian; Slastanova, Anna; Bikondoa, Oier; Arnold, Thomas; Klein, Jacob; Briscoe, Wuge H

    2016-05-01

    Understanding the structure of solid supported lipid multilayers is crucial to their application as a platform for novel materials. Conventionally, they are prepared from drop casting or spin coating of lipids dissolved in organic solvents, and lipid multilayers prepared from aqueous media and their structural characterisation have not been reported previously, due to their extremely low lipid solubility (i.e.∼10(-9) M) in water. Herein, using X-ray reflectivity (XRR) facilitated by a "bending mica" method, we have studied the structural characteristics of dioleoylphosphatidylcholine (DOPC) multilayers prepared via drop casting aqueous small unilamellar and multilamellar vesicle or liposome (i.e. SUV and MLV) dispersions on different surfaces, including mica, positively charged polyethylenimine (PEI) coated mica, and stearic trimethylammonium iodide (STAI) coated mica which exposes a monolayer of hydrocarbon tails. We suggest that DOPC liposomes served both as a delivery matrix where an appreciable lipid concentration in water (∼25 mg mL(-1) or 14 mM) was feasible, and as a structural precursor where the lamellar structure was readily retained on the rupture of the vesicles at the solid surface upon solvent evaporation to facilitate rapid multilayer formation. We find that multilayers on mica from MLVs exhibited polymorphism, whereas the SUV multilayers were well ordered and showed stronger stability against water. The influence of substrate chemistry (i.e. polymer coating, charge and hydrophobicity) on the multilayer structure is discussed in terms of lipid-substrate molecular interactions determining the bilayer packing proximal to the solid-liquid interface, which then had a templating effect on the structure of the bilayers distal from the interface, resulting in the overall different multilayer structural characteristics on different substrates. Such a fundamental understanding of the correlation between the physical parameters that characterise liposomes

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

    OpenAIRE

    Konopka, Z.; A. Zyska; M. Łągiewka; Bielecka, A.; S. Nocuń

    2008-01-01

    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 ca...

  16. Special thermite cast irons

    OpenAIRE

    Yu. Zhiguts; I. Kurytnik

    2008-01-01

    The given paper deals with the problems of the synthesis of cast iron by metallothermy synthesis. On the basis of investigated method of calculations structures of charges have been arranged and cast iron has been synthesized further. Peculiarities metallothermic smelting were found, mechanical properties and structure of received cast iron were investigated and different technologies for cast iron receiving were worked out.

  17. Auction game in electric power market place

    International Nuclear Information System (INIS)

    The power industry in the US is presently an evolving changing business environment. While planning to meet future peak demand is still a concern, the efficient utilization of existing generation and transmission resources is fast becoming a primary interest. This interest suggests a move from cost-based market operations to price based market operations. Auction market structure is one of the various ways to perform price based operation. Such a market place would be very new and challenging to all players of the electric power industry. This paper describes an overview of the new business environment. The paper presents a detailed description of the auction game. The trading objectives in the bidding game are defined. The framework of auction process is described by defining the rules to play the game. Finally, strategies for market players are discussed

  18. Safety training: places available in September 2014

    CERN Multimedia

    HSE Unit

    2014-01-01

    There are places available in the forthcoming Safety courses. For updates and registrations, please refer to the Safety Training Catalogue (see here).   Please note that there are 7 places left on the “Territorial Safety Officer (TSO) – Initial” course on September 23-25, 2014 (in French).

  19. Awareness programs and change in taste-based caste prejudice

    DEFF Research Database (Denmark)

    Banerjee, Ritwik; Datta Gupta, Nabanita

    Becker's theory of taste-based discrimination predicts that relative employment of the discriminated social group will improve if there is a decrease in the level of prejudice for the marginally discriminating employer. In this paper we experimentally test this prediction offered by Becker (1971......) in the context of caste in India, with management students (potential employers in the near future) as subjects. First, we measure caste prejudice and show that awareness through a TV social program reduces implicit prejudice against the lower caste and the reduction is sustained over time. Second...

  20. Dynamic control of crystallinity in polymer film casting process

    Directory of Open Access Journals (Sweden)

    Thananchai Leephakpreeda

    2005-05-01

    Full Text Available This paper presents an approach for dynamic control of crystallinity in polymer film casting process. As known, the transients of crystallization dictate the microstructures of semi-crystalline polymer during solidification. In turn, the properties of finished products can be determined by adjustable variables in polymer film casting process such as temperature of chill roll. In this work, an experimental model of the solidification in film casting process is derived by a system identification technique. This model is used to design a digital feedback controller including a state estimator. The simulation results show the effectiveness of the proposed control technique on an extruded film.

  1. The function of +CA suffix in the place names

    Directory of Open Access Journals (Sweden)

    Mehmet Gedizli

    2012-08-01

    Full Text Available The etymological approach generally draws attention to the research on the name of the places in Turkey. Words in Turkish always use the latest addition on narrative and meaning structure. As some additions are used as both meaning and narrative structure, they may refer according to grammar. In this article, by an unorthodox approach, names of the places that +CA suffix name passes are mentioned and the function of this suffix on the names of the places that is effective on finding out the meaning of the name of places is pointed. At the same time, the feature of +CA suffix being derivational affix are showed by the names of the places. The names of the places that are seen in Istanbul, Sakarya, Kocaeli and Düzce provinces form the research material.

  2. Carbides in Nodular Cast Iron with Cr and Mo

    Directory of Open Access Journals (Sweden)

    S. Pietrowski

    2007-07-01

    Full Text Available In these paper results of elements microsegregation in carbidic nodular cast iron have been presented. A cooling rate in the centre of the cross-section and on the surface of casting and change of moulding sand temperature during casting crystallization and its self-cooling have been investigated. TDA curves have been registered. The linear distribution of elements concentration in an eutectic grain, primary and secondary carbides have been made. It was found, that there are two kinds of carbides: Cr and Mo enriched. A probable composition of primary and secondary carbides have been presented.

  3. 59Fe distribution in continuously cast aluminium strip

    International Nuclear Information System (INIS)

    The problems are discussed of the homogeneity of continuously cast aluminium strips by horizontal casting. Theoretically discussed are phenomena present during primary solidification, namely the nonhomogeneous distribution of admixtures and impurities in primary solidified dendritic cells. A survey is given of the distribution of coefficients of basic admixtures and impurities in aluminium. Experimental investigation was carried out within the verification of theoretical research results, of the distribution of iron in continuously cast aluminium strips using radioactive iron 59Fe in form of radioactive foundry alloy containing 1.8% 59Fe. (author). 13 figs., 1 tab

  4. INFLUENCE OF THE METAL MATRIX STRUCTURE OF HIGH-DUTY CAST IRON ON COERCIVELY SENSITIVE MAGNETIC PARAMETER AND SPEED OF SOUND

    OpenAIRE

    S. G. Sandomirsky; V. L. Tsukerman

    2013-01-01

    The analysis of influence of changes in the structure of the metal base of high-duty cast ironcompact castings with a constant form of graphite inclusions on the coercive sensitive magnetic parameters and the speed of sound is held. The efficiency of joint use of the results of magnetic and ultrasonic measurements to control the shape of inclusions in the iron and pearlite content in its metallic matrix is shown.

  5. INFLUENCE OF THE METAL MATRIX STRUCTURE OF HIGH-DUTY CAST IRON ON COERCIVELY SENSITIVE MAGNETIC PARAMETER AND SPEED OF SOUND

    Directory of Open Access Journals (Sweden)

    S. G. Sandomirsky

    2013-01-01

    Full Text Available The analysis of influence of changes in the structure of the metal base of high-duty cast ironcompact castings with a constant form of graphite inclusions on the coercive sensitive magnetic parameters and the speed of sound is held. The efficiency of joint use of the results of magnetic and ultrasonic measurements to control the shape of inclusions in the iron and pearlite content in its metallic matrix is shown.

  6. Development of fabrication technology for copper canisters with cast inserts. Status report in August 2001

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Claes-Goeran

    2002-04-01

    This report contains an account of the results of trial fabrication of copper canisters with cast inserts carried out during the period 1998 - 2001. The work of testing of fabrication methods is being focused on a copper thickness of 50 mm. Occasional canisters with 30 mm copper thickness are being fabricated for the purpose of gaining experience and evaluating fabrication and inspection methods for such canisters. For the fabrication of copper tubes, SKB has concentrated its efforts on seamless tubes made by extrusion and pierce and draw processing. Five tubes have been extruded and two have been pierced and drawn during the period. Materials testing has shown that the resultant structure and mechanical properties of these tubes are good. Despite certain problems with dimensional accuracy, it can be concluded that both of these methods can be developed for use in the serial production of SKB' copper tubes. No new trial fabrication with roll forming of copper plate and longitudinal welding has been done. This method is nevertheless regarded as a potential alternative. Copper lids and bottoms are made by forging of continuous-cast bars. The forged blanks are machined to the desired dimensions. Due to the Canister Laboratory's need for lids to develop the technique for sealing welding, a relatively large number of forged blanks have been fabricated. It is noted in the report that the grain size obtained in lids and bottoms is much coarser than in fabricated copper tubes. Development work has been commenced for the purpose of optimizing the forging process. Nine cast inserts have been cast during the three-year period. The results of completed material testing of test pieces taken at different places along the length of the inserts have in several cases shown an unacceptable range of variation in strength properties and structure. In the continued work, insert fabrication will be developed in terms of both casting technique and iron composition. Development

  7. Evolution of microstructure in centrifugal cast Al-Cu alloy

    Directory of Open Access Journals (Sweden)

    Sui Yanwei

    2010-02-01

    Full Text Available In this research, the effects of centrifugal radius and mould rotation speed on microstructure in centrifugal-cast Al-Cu alloy have been investigated. The results show that, with increase of the centrifugal radius or mould rotation speed, the grain size of centrifugal-cast Al-Cu alloy decreases gradually, while the content of white phases containing the Al2Cu precipitated from α-phase, divorced eutectic and regular eutectic microstructure increases, leading to higher Cu macrosegregation. The variation level of microstructure in centrifugal-cast Al-Cu alloy at 600 rpm of mould rotation speed is greater than that at 300 rpm.

  8. Optical storage properties in cast films of an azopolymer

    Directory of Open Access Journals (Sweden)

    Neves Ubaldo Martins das

    2003-01-01

    Full Text Available In this paper we discuss the properties of optically induced birefringence in DR19-MDI cast films that may be used in optical storage applications. The selection of DR19-MDI cast films was based on a comparative study of optical storage properties of Langmuir-Blodgett (LB films from various azopolymers. DR19-MDI possesses a high residual fraction of optical birefringence and good environmental stability, which was corroborated by the data from optical storage experiments. DR19-MDI cast films maintain a reasonable level of birefringence after the initial decay due to chromophore relaxation, thus making them promising candidates for optical storage devices.

  9. Structure and mechanical properties of as-cast Ti–5Sn–xCr alloys

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Hsueh-Chuan; Wu, Shih-Ching; Hsu, Shih-Kuang [Department of Dental Technology and Materials Science, Central Taiwan University of Science and Technology, Taiwan, ROC (China); Institute of Biomedical Engineering and Materials Science, Central Taiwan University of Science and Technology, Taiwan, ROC (China); Chen, Chien-Yu [Advanced Materials and BioMaterials Laboratory, Department of Materials Science and Engineering, Da-Yeh University, 168 University Road, Dacun, Changhua 51591, Taiwan, ROC (China); Ho, Wen-Fu, E-mail: fujii@mail.dyu.edu.tw [Advanced Materials and BioMaterials Laboratory, Department of Materials Science and Engineering, Da-Yeh University, 168 University Road, Dacun, Changhua 51591, Taiwan, ROC (China)

    2014-06-01

    In this study, the effects of chromium (Cr) on the structure and mechanical properties of a Ti–5Sn-based system were examined, with an emphasis on improving the strength/modulus ratio. Commercially pure titanium (c.p. Ti) was used as a control. As-cast Ti–5Sn and a series of Ti–5Sn–xCr (x=1, 3, 5, 7, 9, 11 and 13 wt%) alloys prepared by using a commercial arc-melting vacuum-pressure casting system were investigated. X-ray diffraction (XRD) for phase analysis was conducted using a diffractometer. Three-point bending tests were performed on all specimens to evaluate their mechanical properties. The experimental results indicate that the structure and mechanical properties of these alloys changed with the addition of various amounts of Cr. The as-cast Ti–5Sn has a hexagonal α' phase. When 1 wt% Cr was introduced into the Ti–5Sn alloy, the structure essentially stayed the same. When the Cr content was at 3 wt%, retention of the metastable β phase began. When the Cr content was increased to 5 wt% or greater, the β phase was entirely retained. The ω phase was detected in Ti–5Sn–3Cr and Ti–5Sn–5Cr. Ti–5Sn–5Cr, which had the largest quantity of the ω phase, exhibited the highest microhardness value due to the hardening effect of the ω phase. Among all Ti–5Sn-based alloys, the β-phase Ti–5Sn–7Cr alloy had the lowest elastic modulus. It also exhibited higher bending strength/modulus ratios, which at 26.8 were higher than that of c.p. Ti (8.5) and that of Ti–6Al–4V (17.4). Furthermore, the elastically recoverable angle of this alloy (31.0°) was much greater than that of c.p. Ti (2.7°). In the search for better implant materials, the low modulus, ductile property, excellent elastic recovery capability and high strength/modulus ratio of β-phase Ti–5Sn–7Cr make this alloy a promising candidate.

  10. A dynamic control water distribution model of steel in continuous casting

    International Nuclear Information System (INIS)

    After investigation in many continuous casting shop of steel, a dynamic water distribution model is proposed for flexible control on secondary cooling in continuous casting. In this model, the water cooling intensity is determined by the model casting speed instead of the real casting speed. When the casting speed is steady, the model casting speed is equal to the real casting speed. When the real casting speed is changing, the model casting speed according to calculating algorithm to adjust and approaches to the real one, but there is a time delay between them, so it can avoid the slab surface temperature fluctuated due to casting speed changes. The secondary cooling can be dynamically controlled by monitoring the model casting speed. The compare of the simulation results and the measured results reveals that the temperature field and thickness of slab shell in simulations agree very well with the real production situations.

  11. Crystallization and structure of cast A390.0 alloy with melt overheating temperature

    OpenAIRE

    J. Piątkowski; Gajdzik, B.; T. Matuła

    2012-01-01

    The paper presents the research on the influence of melt overheating temperature on crystallization parameters and primary structure of cast AlSi17Cu5Mg (A390.0) alloy overheated to temperature: 820 °C, 880 °C, 940 °C and 1 000 °C. It was found that the degree of overheating influences the change of microstructure significantly and morphologies of primary silicon of the castings from Al-Si alloys. Research has shown that the overheating of the liquid metal bath is one of the methods of findin...

  12. Residual stresses in a cast iron automotive brake disc rotor

    International Nuclear Information System (INIS)

    Runout, and consequent juddering and pulsation through the brake pedal, is a multi-million dollar per year warranty problem for car manufacturers. There is some suspicion that the runout can be caused by relaxation of residual casting stresses when the disc is overheated during severe-braking episodes. We report here neutron-diffraction measurements of the levels and distribution of residual strains in a used cast iron brake disc rotor. The difficulties of measuring stresses in grey cast iron are outlined and three-dimensional residual-strain distributions are presented and their possible effects discussed

  13. Irradiation response of delta ferrite in as-cast and thermally aged cast stainless steel

    Science.gov (United States)

    Li, Zhangbo; Lo, Wei-Yang; Chen, Yiren; Pakarinen, Janne; Wu, Yaqiao; Allen, Todd; Yang, Yong

    2015-11-01

    To enable the life extension of Light Water Reactors (LWRs) beyond 60 years, it is critical to gain adequate knowledge for making conclusive predictions to assure the integrity of duplex stainless steel reactor components, e.g. primary pressure boundary and reactor vessel internal. Microstructural changes in the ferrite of thermally aged, neutron irradiated only, and neutron irradiated after being thermally aged cast austenitic stainless steels (CASS) were investigated using atom probe tomography. The thermal aging was performed at 400 °C for 10,000 h and the irradiation was conducted in the Halden reactor at ˜315 °C to 0.08 dpa (5.6 × 1019 n/cm2, E > 1 MeV). Low dose neutron irradiation at a dose rate of 5 × 10-9 dpa/s was found to induce spinodal decomposition in the ferrite of as-cast microstructure, and further to enhance the spinodal decomposition in the thermally aged cast alloys. Regarding the G-phase precipitates, the neutron irradiation dramatically increases the precipitate size, and alters the composition of the precipitates with increased, Mn, Ni, Si and Mo and reduced Fe and Cr contents. The results have shown that low dose neutron irradiation can further accelerate the degradation of ferrite in a duplex stainless steel at the LWR relevant condition.

  14. Research based teaching as a model for developing complex pre-cast concrete structures

    DEFF Research Database (Denmark)

    Egholm Pedersen, Ole

    2012-01-01

    This paper describes the potentials of utilising research-based teaching as a method for developing advanced concrete structures in an architectural context. A novel technique for casting concrete elements in PETG plastic is described as a body of research that formed the basis of a case in which...... master students assisted in the development and realisation of an amorphous, catenary grid-shell. Development in many areas simultaneously was essential for the success of the case studies, which made them suitable for a research-based teaching setup, where didactic considerations on a general and......: viewing the teaching studio as an interdisciplinary laboratory. On a specific level, didactic considerations involved a division of responsibility into smaller areas of investigation, allowing the students to conduct relevant experimentation while negotiating other areas of the research. Also, the...

  15. Possibilities of implementing bimetallic hammer castings in crushing industries

    Directory of Open Access Journals (Sweden)

    S. Žic

    2009-01-01

    Full Text Available For decades manganese steel casts have been most used materials for manufacturing elements subjected to impact and high stress abrasion. These materials are used in countless industrial applications that involve crushing of raw material by impact. Some of most important characteristics of manganese cast steels are work-hardening and high strength. Opposite from manganese steels, highly alloyed white cast irons are materials with high amount of hard carbide phases that shows better abrasion resistance but have lower strength and impact energy. Aim of this paper is to investigate possibilities to reduce costs and maintenance periods by implementing bimetallic materials.

  16. Eventful places in the 2011 movements

    DEFF Research Database (Denmark)

    Risager, Bjarke Skærlund

    is dialectical and mutually constitutive: the physical and symbolic characteristics of place influence the formation of the movement and its actions while the latter re-creates the place. This is a corrective to a dominant approach in social movement studies to see movements as a ‘dependent variable......Inspired by the Occupy movement, the Egyptian revolutionaries and other of the 2011 social movements, this paper investigates the relationship between social movement and place. Drawing on first-hand accounts from these movements, I argue that the relationship between movement and place......’ that is to be explained (della Porta 2008) instead of a political subject with the ability to affect itself and society; and a corrective to the growing body of literature on the geographies of social movements that often has a too static and state-centred approach. Using John Agnew’s (1987) conceptualisation of place...

  17. The effect of the gaseous-plasma jet treatment of the powder vanadium cast iron and chromium mixture on the composition, structure powder and the casting properties

    International Nuclear Information System (INIS)

    The peculiarities of interaction in the low-temperature plasma of two powders, essentially differing in the melt temperature, are considered. The particles of the vanadium cast iron and chromium were chosen for the studies. The powders of three compositions with fractions from 50 up to 100 μm were obtained after mixing, combined regrinding and sifting the fractions from 50 up to 100 μm. The powders were transmitted through the plasma in the argon-nitrogen medium and quenched in the water. The conclusion on the oxidation and decarbonization of the particles by melting in the gaseous-plasma jet and cooling in the water may be made by the results of chemical analysis of various powder fractions. It is established, that by combined transfer of the cast iron and chromium particles, differing in the composition and melting temperature, there occurs their redistribution by fractions due to interaction bulk density, spillage density and yield morphology and increase in their internal porosity. Sufficiently high properties of coatings are provided for on the account of the particles statistically uniform distribution in spite of their nonuniformity by composition, structure and properties

  18. In-place HEPA filter penetration test

    Energy Technology Data Exchange (ETDEWEB)

    Bergman, W.; Wilson, K.; Elliott, J. [Lawrence Livermore National Lab., CA (United States)] [and others

    1997-08-01

    We have demonstrated the feasibility of conducting penetration tests on high efficiency particulate air (HEPA) filters as installed in nuclear ventilation systems. The in-place penetration test, which is designed to yield equivalent penetration measurements as the standard DOP efficiency test, is based on measuring the aerosol penetration of the filter installation as a function of particle size using a portable laser particle counter. This in-place penetration test is compared to the current in-place leak test using light scattering photometers for single HEPA filter installations and for HEPA filter plenums using the shroud method. Test results show the in-place penetration test is more sensitive than the in-place leak test, has a similar operating procedure, but takes longer to conduct. Additional tests are required to confirm that the in-place penetration test yields identical results as the standard dioctyl phthalate (DOP) penetration test for HEPA filters with controlled leaks in the filter and gasket and duct by-pass leaks. Further development of the procedure is also required to reduce the test time before the in-place penetration test is practical. 14 refs., 14 figs., 3 tabs.

  19. In-place HEPA filter penetration test

    International Nuclear Information System (INIS)

    We have demonstrated the feasibility of conducting penetration tests on high efficiency particulate air (HEPA) filters as installed in nuclear ventilation systems. The in-place penetration test, which is designed to yield equivalent penetration measurements as the standard DOP efficiency test, is based on measuring the aerosol penetration of the filter installation as a function of particle size using a portable laser particle counter. This in-place penetration test is compared to the current in-place leak test using light scattering photometers for single HEPA filter installations and for HEPA filter plenums using the shroud method. Test results show the in-place penetration test is more sensitive than the in-place leak test, has a similar operating procedure, but takes longer to conduct. Additional tests are required to confirm that the in-place penetration test yields identical results as the standard dioctyl phthalate (DOP) penetration test for HEPA filters with controlled leaks in the filter and gasket and duct by-pass leaks. Further development of the procedure is also required to reduce the test time before the in- place penetration test is practical

  20. The structure of alteration layers on cast glass surfaces

    International Nuclear Information System (INIS)

    Alteration layers developed on SRL-165 simulated waste glasses in dilute sodium silicate/bicarbonate leaching solutions have been examined by Secondary Ionization Mass Spectroscopy (SIMS) using fine-scale, multiple-element depth profiling. Selected samples were examined with an imaging detector system, which demonstrated the horizontal homogeneity of the layer development at all depths within the layer. After 1 day of reaction at 90 degrees C the reaction layer shows depletion of glass elements to a depth of 0.2 μm. The surface of the layer in contact with the solution shows enrichment of Si, Al, and alkali elements even at this short reaction time, suggesting the early stages of development of secondary aluminosilicate phases. With increased reaction time, the layer thickens to about 1.3 μm at 91 days, while the evidence for aluminosilicate development at the surface of the layer becomes more prominent. Penetration of hydrogen into the ''unreacted'' glass proceeds to a depth of about 0.5 μm deeper than the alkali depletion zone. This suggests the mechanism of initial reaction of the glass is by attack of the silicate structure by molecular water or hydroxide ion rather than by alkali-hydrogen ion exchange. The simple structure of the layers developed in the silicate solution is in contrast to the complexity of layer structure found when glasses are reacted in deionized water. Since the conditions for geologic disposal will be closer to those used in the silicate leaching experiments, these results hold promise for the ability to model the system to predict long-term performance after disposal in a repository

  1. Twinning, dynamic recovery and recrystallization in the hot rolling process of twin-roll cast AZ31B alloy

    International Nuclear Information System (INIS)

    Highlights: → Two different types of twinning, {101-bar 2} and {101-bar 1}, occurred in the rolling process, and {101-bar 1} twins tended to be preferred sites for recrystallization. → DRV and discontinuous recrystallization dominated at moderate strain in the rolling process. → Non-basal slip was homogeneously activated at even larger strains and continuous DRX readily took place on the basis of cellular structures. - Abstract: Hot-rolling experiments with a reduction from 10% to 60% in single pass were conducted on AZ31B twin-roll cast sheets. Optical microscope (OM), electron backscattered diffraction (EBSD) tests and transmission electron microscope (TEM) were used to investigate twinning and DRV/DRX behaviors at different stage in the hot-rolling process. Two types of twinning occurred in the initial stage of hot-rolling process. DRV and discontinuous recrystallization dominated at moderate strain while continuous DRX took place homogeneously throughout original grains at the largest strains.

  2. Place in Pacific Islands Climate Education

    Science.gov (United States)

    Barros, C.; Koh, M. W.

    2015-12-01

    Understanding place, including both the environment and its people, is essential to understanding our climate, climate change, and its impacts. For us to develop a sense of our place, we need to engage in multiple ways of learning: observation, experimentation, and opportunities to apply new knowledge (Orr, 1992). This approach allows us to access different sources of knowledge and then create local solutions for local issues. It is especially powerful when we rely on experts and elders in our own community along with information from the global community.The Pacific islands Climate Education Partnership (PCEP) is a collaboration of partners—school systems, nongovernmental organizations, and government agencies—working to support learning and teaching about climate in the Pacific. Since 2009, PCEP partners have been working together to develop and implement classroom resources, curriculum standards, and teacher professional learning opportunities in which learners approach climate change and its impacts first through the lens of their own place. Such an approach to putting place central to teaching and learning about climate requires partnership and opportunities for learners to explore solutions for and with their communities. In this presentation, we will share the work unfolding in the Republic of the Marshall Islands (RMI) as one example of PCEP's approach to place-based climate education. Three weeklong K-12 teacher professional learning workshops took place during June-July 2015 in Majuro, RMI on learning gardens, climate science, and project-based learning. Each workshop was co-taught with local partners and supports educators in teaching climate-related curriculum standards through tasks that can foster sense of place through observation, experimentation, and application of new knowledge. Additionally, we will also share PCEP's next steps in place-based climate education, specifically around emerging conversations about the importance of highlighting

  3. MicroRNAs in Honey Bee Caste Determination.

    Science.gov (United States)

    Ashby, Regan; Forêt, Sylvain; Searle, Iain; Maleszka, Ryszard

    2016-01-01

    The cellular mechanisms employed by some organisms to produce contrasting morphological and reproductive phenotypes from the same genome remains one of the key unresolved issues in biology. Honeybees (Apis mellifera) use differential feeding and a haplodiploid sex determination system to generate three distinct organismal outcomes from the same genome. Here we investigate the honeybee female and male caste-specific microRNA and transcriptomic molecular signatures during a critical time of larval development. Both previously undetected and novel miRNAs have been discovered, expanding the inventory of these genomic regulators in invertebrates. We show significant differences in the microRNA and transcriptional profiles of diploid females relative to haploid drone males as well as between reproductively distinct females (queens and workers). Queens and drones show gene enrichment in physio-metabolic pathways, whereas workers show enrichment in processes associated with neuronal development, cell signalling and caste biased structural differences. Interestingly, predicted miRNA targets are primarily associated with non-physio-metabolic genes, especially neuronal targets, suggesting a mechanistic disjunction from DNA methylation that regulates physio-metabolic processes. Accordingly, miRNA targets are under-represented in methylated genes. Our data show how a common set of genetic elements are differentially harnessed by an organism, which may provide the remarkable level of developmental flexibility required. PMID:26739502

  4. Effect of Slope Plate Variable and Reheating on the Semi-Solid Structure of Ductile Cast Iron

    Institute of Scientific and Technical Information of China (English)

    M. Nili-Ahmadabadi; F. Pahlevani; P. Babaghorbani

    2008-01-01

    Semi-solid metal casting and forming is a promising production method for a wide range of metal alloys. In spite of many applications for semi-solid processed light alloys, few works have reported on the semi-solid processing of iron and steel. In this research, an inclined plate was used to change the dendritic structure of iron to globular. The effects of the length and slope of the plate on the casting structure were examined. The results show that the process effectively changes the dendritic structure to globular. A sloped plate angle of 7.5° and length of 560 mm with a cooling rate of 67 K·s-1 gave the optimum graphite nodu-larity and solid particle globularity. The results also show that the sloped plate more easily prevents inocu-lant fading since the total time processing is rather short. In addition the semi-solid ductile cast iron prepared using the inclined plate method was reheated to examine the effect of reheating conditions on the micro-structure and coarsening kinetics of the alloy. The solid fractions at different reheating temperatures and holding times were used to find the optimum reheating temperature range.

  5. Teaching students in place: the languages of third space learning

    Science.gov (United States)

    Morawski, Cynthia M.

    2016-07-01

    With a perceptive eye cast on geoscience pedagogy for students labeled as disabled, Martinez-Álvarez makes important contributions to the existing conversation on placed-based learning. It is in our local backyards, from the corner basketball court, to the mud bank of a city lake, to the adjacent field where rocky outcrops spill down to a forgotten farmer's field, that we find rich working material for connecting self and community, moving students' out-of-school experiences that feature their cultural and linguistic knowledge, from misconceptions to "alternative conceptions." Informed by her insights regarding the learning of students whose literacy does not match conventional classroom practice, geoscience learning in the place of third space can act as a model of meaning making across the entire curriculum. In the pages that follow, I transact, both aesthetically and efferently, with Martinez-Álvarez's text as she presents her research on special ways of learning in placed-based geoscience explorations with bilingual children experiencing disabilities.

  6. A Thermal Simulation Method for Solidification Process of Steel Slab in Continuous Casting

    Science.gov (United States)

    Zhong, Honggang; Chen, Xiangru; Han, Qingyou; Han, Ke; Zhai, Qijie

    2016-07-01

    Eighty years after the invention of continuous cast of steels, reproducibility from few mm3 samples in the laboratory to m3 product in plants is still a challenge. We have engineered a thermal simulation method to simulate the continuous casting process. The temperature gradient (G L ) and dendritic growth rate (v) of the slab were reproduced by controlling temperature and cooling intensity at hot and chill end, respectively, in our simulation samples. To verify that our samples can simulate the cast slab in continuous casting process, the heat transfer, solidification structure, and macrosegregation of the simulating sample were compared to those of a much larger continuous casting slab. The morphology of solid/liquid interface, solidified shell thickness, and dendritic growth rate were also investigated by in situ quenching the solidifying sample. Shell thickness (δ) determined by our quenching experiment was related to solidification time (τ) by equation: δ = 4.27 × τ 0.38. The results indicated that our method closely simulated the solidification process of continuous casting.

  7. Social interactions affecting caste development through physiological actions in termites

    Directory of Open Access Journals (Sweden)

    DaiWatanabe

    2014-04-01

    Full Text Available A colony of social insects is not only an aggregation of individuals but also a functional unit. To achieve adaptive social behavior in fluctuating environmental conditions, in addition to coordination of physiological status in each individual, the whole colony is coordinated by interactions among colony members. The study on the regulation of social-insect colonies is termed “social physiology”. Termites, a major group of social insects, exhibit many interesting phenomena related to social physiology, such as mechanisms of caste regulation in a colony. In their colonies, there are different types of individuals, i.e., castes, which show distinctive phenotypes specialized in specific colony tasks. Termite castes comprise reproductives, soldiers and workers, and the caste composition can be altered depending on circumstances. For the regulation of caste compositions, interactions among individuals, i.e. social interactions, are thought to be important. In this article, we review previous studies on the adaptive meanings and those on the proximate mechanisms of the caste regulation in termites, and try to understand those comprehensively in terms of social physiology. Firstly, we summarize classical studies on the social interactions. Secondly, previous studies on the pheromone substances that mediate the caste regulatory mechanisms are overviewed. Then, we discuss the roles of a physiological factor, juvenile hormone (JH in the regulation of caste differentiation. Finally, we introduce the achievements of molecular studies on the animal sociality (i.e. sociogenomics in terms of social physiology. By comparing the proximate mechanisms of social physiology in termites with those in hymenopterans, we try to get insights into the general principles of social physiology in social animals.

  8. Chemical Agents: Facts about Sheltering in Place

    Science.gov (United States)

    ... have in your shelter room: First aid kit Flashlight, battery-powered radio, and extra batteries for both ... on the radio and on television emergency broadcast system if you need to shelter in place. What ...

  9. Electronic market places in the energy

    International Nuclear Information System (INIS)

    Electronic market places in the energy domain occurred at the end of the 90's in the US and have started to develop in Europe in the year 2000. About 60 platforms are registered today and this development can be explained by the advantages raised by such an infrastructure: simplification of purchase procedures, reduction of delays in the purchase decision, reduction of administrative costs etc.. However, today none of these electronic market places is profitable and several have closed down. On the other hand, this tool will certainly become necessary in the future and all energy actors are developing projects in this way. This study analyzes the electronic market places phenomenon in the energy domain using 10 market places examples with their key-factors of success. It draws out a complete status of the initiatives developed today and presents some scenarios of evolution. (J.S.)

  10. Geographic Place Names, Published in unknown, SWGRC.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Geographic Place Names dataset as of unknown. Data by this publisher are often provided in Geographic coordinate system; in a Not Sure projection; The extent...

  11. Managament quality of tools in the planned housing casting

    Directory of Open Access Journals (Sweden)

    Jaworski J.

    2007-01-01

    Full Text Available The Kaizen method of housing casting designing was presented in the paper. Algorithm making possibility of identification of tools limiting efficienty of tooling process was formulated. The system of tool management consisting of various was shown.

  12. Phase-oriented surface segregation in an aluminium casting alloy

    International Nuclear Information System (INIS)

    There have been many reports of the surface segregation of minor elements, especially Mg, into surface layers and oxide films on the surface of Al alloys. LM6 casting alloy (Al-12%Si) represents a challenging system to examine such segregation as the alloy features a particularly inhomogeneous phase structure. The very low but mobile Mg content (approximately 0.001 wt.%), and the surface segregation of modifiers such as Na, mean the surface composition responds in a complex manner to thermal treatment conditions. X-ray photoelectron spectroscopy (XPS) has been used to determine the distribution of these elements within the oxide film. Further investigation by dynamic secondary ion mass spectrometry (DSIMS) confirmed a strong alignment of segregated Na and Mg into distinct phases of the structure.

  13. Structural Discrimination – Between a Rock and a Hard Place

    DEFF Research Database (Denmark)

    Skadegaard Thorsen, Mira

    is the tension or discrepancy that arises between acknowledged and unacknowledged experiences of discrimination. These include verbal as well as non-verbal communication, abstract and implicit social codes and behaviors, and embodied experience. The article is primarily theoretical, but takes its......This article examines challenges that arise when discrimination is expressed in communication across perceived differences (inter-cultural communication). More specifically, it looks at how visible minority Danes navigate in regard to structural discrimination (implicit and underlying forms of...... discrimination) imbricated in seemingly neutral everyday communication. It argues that structural discrimination is discursive and constitutive and is expressed in language as well as communicated in the form of naturalizations and embodiments of discrimination. It suggests that structural discrimination is so...

  14. SPRAY CASTING

    OpenAIRE

    SALAMCI, Elmas

    2010-01-01

    ABSTRACT This paper is designed to provide a basic review of spray casting. A brief overview of the historical development of spray  casting and the description of plant and equipment have been given. Following metallurgical characteristics of spray formed alloys, process parameters and solidification mechanism of spray deposition have been discussed in detail. Finally, microstructure and mechanical properties of the selected spray cast Al-Zn-Mg-Cu alloys have been presented and compared...

  15. Identification of temperature changes dynamics in selected castings as a contribution to performance life improvement

    Directory of Open Access Journals (Sweden)

    A. Pytel

    2010-07-01

    Full Text Available Parameters describing boundary conditions and dynamics of temperature changes during casting cooling in foundry moulds and thesuccessive performance, especially as regards the massive cast elements, were discussed. Considering the specific nature of castingoperation, non-standard methods of examination of the isotherms of temperature fields on the casting surface were described to determinelocal overheating resulting from the technological process, chemical composition, properties of the currently applied insulation materials,casting defects and/or design. Identification of these parameters can be interpolated to laboratory conditions and to the validation of virtual models subject to computer simulation. The use in simulation of genetic algorithms combined with the results of measurements under real conditions enables more precise determination of the performance parameters, including critical states of stresses present in a structure. This should allow further optimisation of the massive castings design, considering the specific nature of a manufacturing process (alloy composition included, combined with performance parameters. Measures described here are expected to contribute to the reduced casting weight and longer time of operation.

  16. Consumer views about aging-in-place

    OpenAIRE

    Grimmer K; Kay D; Foot J; Pastakia K

    2015-01-01

    Karen Grimmer, Debra Kay, Jan Foot, Khushnum PastakiaInternational Center for Allied Health Evidence, Sansom Institute, City East Campus, University of South Australia, Adelaide, SA, AustraliaBackground: Supporting older people’s choices to live safely and independently in the community (age-in-place) can maximize their quality of life and minimize unnecessary hospitalizations and residential care placement. Little is known of the views of older people about the aging-in-place process, ...

  17. Application of 3D stereoscopic visualization technology in casting aspect

    Institute of Scientific and Technical Information of China (English)

    Kang Jinwu; Zhang Xiaopeng; Zhang Chi; Liu Baicheng

    2014-01-01

    3D stereoscopic visualization technology is coming into more and more common use in the field of entertainment, and this technology is also beginning to cut a striking ifgure in casting industry and scientiifc research. The history, fundamental principle, and devices of 3D stereoscopic visualization technology are reviewed in this paper. The authors’ research achievements on the 3D stereoscopic visualization technology in the modeling and simulation of the casting process are presented. This technology can be used for the observation of complex 3D solid models of castings and the simulated results of solidiifcation processes such as temperature, lfuid lfow, displacement, stress strain and microstructure, as wel as the predicted defects such as shrinkage/porosity, cracks, and deformation. It can also be used for other areas relating to 3D models, such as assembling of dies, cores, etc. Several cases are given to compare the illustration of simulated results by traditional images and red-blue 3D stereoscopic images. The spatial shape is observed better by the new method. The prospect of 3D stereoscopic visualization in the casting aspect is discussed as wel. The need for aided-viewing devices is stil the most prominent problem of 3D stereoscopic visualization technology. However, 3D stereoscopic visualization represents the tendency of visualization technology in the future; and as the problem is solved in the years ahead, great breakthroughs wil certainly be made for its application in casting design and modeling and simulation of the casting processes.

  18. Market Design in Chinese Market Places

    OpenAIRE

    Krug, Barbara; Hendrischke, Hans

    2012-01-01

    textabstractThe market design (MD) approach to institutional analysis provides the analytical tools to evaluate endogenous institution building in local market places irrespective of the institutional setting of the national economy. Implicit in this analysis of endogenous institution building at the market place level is the recognition of institutional diversity, which none of the conventional forms of institutional analysis can provide. We extend the MD approach from its original game theo...

  19. Stereology of carbide phase in modified hypereutectic chromium cast iron

    Directory of Open Access Journals (Sweden)

    J. Suchoń

    2010-04-01

    Full Text Available In paper are presented results of studies of carbide phase stereology modified hypereutectic wear resistance chromium cast iron which contains carbon about 3,5% and chromium about 25%. Three substances were applied to the modification: boron carbide (B4C, ferroniobium (FeNb and mixture of ferroniobium and rare-earth (RE. The measurements of geometrical features of carbides were conducted on microsection taken from castings wich were cooled with various velocities.

  20. Stereology of carbide phase in modified hypereutectic chromium cast iron

    OpenAIRE

    J. Suchoń; A. Studnicki; M. Przybył

    2010-01-01

    In paper are presented results of studies of carbide phase stereology modified hypereutectic wear resistance chromium cast iron which contains carbon about 3,5% and chromium about 25%. Three substances were applied to the modification: boron carbide (B4C), ferroniobium (FeNb) and mixture of ferroniobium and rare-earth (RE). The measurements of geometrical features of carbides were conducted on microsection taken from castings wich were cooled with various velocities.

  1. Worker caste determination in the army ant Eciton burchellii

    OpenAIRE

    Jaffé, Rodolfo; Kronauer, Daniel J. C.; Bernhard Kraus, F; Boomsma, Jacobus J.; Robin F A Moritz

    2007-01-01

    Elaborate division of labour has contributed significantly to the ecological success of social insects. Division of labour is achieved either by behavioural task specialization or by morphological specialization of colony members. In physical caste systems, the diet and rearing environment of developing larvae is known to determine the phenotype of adult individuals, but recent studies have shown that genetic components also contribute to the determination of worker caste. One of the most ext...

  2. Structure and mechanical properties of casting MSR-B magnesium alloy

    Directory of Open Access Journals (Sweden)

    A. Kiełbus

    2006-08-01

    Full Text Available Purpose: MSR-B is a high-strength magnesium alloy characterized by good mechanical properties both at anambient and elevated temperature (up to 200°C. It contains silver and rare earth elements. The aim of this paperis to present the results of research on the microstructure and mechanical properties of the MSR-B magnesiumalloy in an as-cast condition.Design/methodology/approach: For the microstructure observation, a Reichert metallographic microscopeMeF2 and a HITACHI S-3400N scanning electron microscope with a Thermo Noran EDS equipped withSYSTEM SIX were used. A qualitative phase analysis was performed with a JEOL JDX-7S diffractometer.Quantitative examination was conducted using the “MET-ILO” automatic image analysis programme.Findings: Based on the investigation carried out it was found that the MSR-B alloy in an as-cast conditioncharacterized with a solid solution structure α with island of divorced eutectic (α + (Mg,Ag12Nd and probably(Mg,Ag41Nd5 phase. The mean area of the solid solution α grain equals Ā=543 μm2, and the mean surfacefraction of eutectic regions is AA= 5.81%. The yield strength is near 90 MPa in 20°C and near 70 MPa in200°C. Tensile strength is near 180 MPa in both temperatures. The material hardness is 47 HV.Research limitations/implications: Future researches should contain investigations of the influence of alloyadditives on microstructure and mechanical properties of MSR_B alloy in as-cast condition and after heattreatment.Practical implications: MSR-B magnesium alloy is used in the aircraft industry, for wheels, engine casings,gear box casings and rotor heads in helicopters. Results of investigation may be useful for preparing castingtechnology of the Mg-Ag-Nd alloys.Originality/value: The results of the researches make up a basis for the next investigations of magnesium alloyswith addition of Ag and Nd designed to exploitation at temperature to 300°C.

  3. Putting sex education in its place.

    Science.gov (United States)

    Cassell, C

    1981-04-01

    In order to help reduce fears and anxieties regarding the influence of sex education in a public school setting, school and community sexuality educators need to better articulate the difference between formal and structured sex education and non-formal, informal and incidental sex learning. Sex education is only 1 aspect of the sexual learning process. 2 main points have to be clarified for parents and the general public to set the stage for a new way to view the school and community involvement in the sexual learning process: the schools' sexuality education courses constitute only a small portion of the sexual learning process; and sexual learning is not an event for youth only, but a process spanning life. Sex education (the process) connotates an academic setting with a specific curricula taught by a trained instructor, but sexual learning relates to environmental, non-formal incidental learning from a multitude of sources. Studies indicate that teenagers receive about 90% of their contraceptive and sexuality informaation from peers and mass media and that these sources of information are becoming their preferred sources of sex education. What is needed is a way to address and improve the conditions of sexual learning in the community. As home is the ideal environment for primary and positive sexual learning, parents need support in their role as sex educators. Classroom sexuality education curricula in all school settings have a solid place in the process of sexual learning. PMID:6908927

  4. Influences of copper on solidification structure and hardening behavior of high chromium cast irons

    Institute of Scientific and Technical Information of China (English)

    WANG Jun; XIONG Ji; FAN Hong-yuan; SHEN Bao-luo; GAO Sheng-ji

    2008-01-01

    The influences of copper on microstructure and the hardening behavior of high chromium cast irons subjected to sub-critical treatment were investigated.The results show that the mierostructure of the as-cast high chromium cast irons consists of retained austenite,martensite and M7 C3 type eutectic carbide.When copper is added into high chromium cast irons,austenite and carbide contents are increased.The increased addition of copper content from 0%to 1.84%leads to the increase of austenite and carbide from 15.9%and 20.0% to 61.0%and 35.5%,respectively.In the process of sub-critical treatment,the retained austenite in the matrix can be precipitated into secondary carbides and then transforms into martensite in cooling process,which causes the secondary hardening of the alloy under sub-critical treatment.High chromium cast irons containing copper in sub-critical treatment appear the second hardening curve peak due to the precipitation of copper from supersaturated matrix.

  5. Consumer views about aging-in-place

    Directory of Open Access Journals (Sweden)

    Grimmer K

    2015-11-01

    Full Text Available Karen Grimmer, Debra Kay, Jan Foot, Khushnum PastakiaInternational Center for Allied Health Evidence, Sansom Institute, City East Campus, University of South Australia, Adelaide, SA, AustraliaBackground: Supporting older people’s choices to live safely and independently in the community (age-in-place can maximize their quality of life and minimize unnecessary hospitalizations and residential care placement. Little is known of the views of older people about the aging-in-place process, and how they approach and prioritize the support they require to live in the community accommodation of their choice.Purpose: To explore and synthesize the experiences and perspectives of older people planning for and experiencing aging-in-place.Methods: Two purposively sampled groups of community-dwelling people aged 65+ years were recruited for individual interviews or focus groups. The interviews were semistructured, audio-recorded, and transcribed. Themes were identified by three researchers working independently, then in consort, using a qualitative thematic analysis approach.Results: Forty-two participants provided a range of insights about, and strategies for, aging-in-place. Thematic saturation was reached before the final interviews. We identified personal characteristics (resilience, adaptability, and independence and key elements of successful aging-in-place, summarized in the acronym HIPFACTS: health, information, practical assistance, finance, activity (physical and mental, company (family, friends, neighbors, pets, transport, and safety.Discussion: This paper presents rich, and rarely heard, older people’s views about how they and their peers perceive, characterize, and address changes in their capacity to live independently and safely in the community. Participants identified relatively simple, low-cost, and effective supports to enable them to adapt to change, while retaining independence and resilience. The findings highlighted how successful

  6. Optimization of casting defects analysis with supply chain in cast iron foundry process

    Directory of Open Access Journals (Sweden)

    C. Narayanaswamy

    2016-10-01

    Full Text Available Some of the foundries are in need of meeting production targets and due to the urgency they ignore the rejections. The objective of this paper is to analyze the various defects, [1] from molding process in a cast iron foundry. The Failure Mode Effects Analysis (FMEA in quality control [2-6] with suitable supply chain for mold making process considering rejection rates are identified and analyzed in terms of Risk Priority Number (RPN to prioritize the attention for each of the problem. The optimum levels of selected parameters [7] are obtained in this analysis.

  7. FEM Analysis of Physical Field in Level Rolling Process of Inversion Casting by ANSYS Program

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The strain physical field in level rolling process of inversion casting was analyzed by ANSYS program. Plastics train, stress and displacement were gained. The results show that only surfaces train takes place; the maximum stress exists in the geometrical deformation zone ; In the deformation transition zone and the part leaving the rollers, different stress exists. The rolling force estimated with ANSYS program corresponds to those measured.

  8. Nodular cast iron and casting monitoring

    Directory of Open Access Journals (Sweden)

    S. Pietrowski

    2008-10-01

    Full Text Available In this paper quality monitoring of nodular cast iron and casting made of it is presented. A control system of initial liquid cast iron to spheroidization, after spheroidization and inoculation with using of TDA method was shown. An application of an ultrasonic method to assessment of the graphite form and the metal matrix microstructure of castings was investigated.

  9. Study of carbon and silicon loss through oxidation in cast iron base metal using rotary furnace for melting

    Directory of Open Access Journals (Sweden)

    Sylvester Olanrewaju OMOLE

    2015-05-01

    Full Text Available The projection of loss of carbon and silicon through oxidation is uncertain phenomenon depending on the furnace used for melting, which affect the carbon equivalent value (CEV of cast iron produced. CEV enhances the fluidity of molten metal as well as having great effects on the mechanical properties of cast products. Study on the way elemental loss takes place during melting with rotary furnace will give idea of approach to minimize the loss. Therefore, the aim of this work is to study the magnitude of the elemental loss with rotary furnace and means to minimize the loss. 60kg of grey cast iron scrap was charged into rotary furnace of 100kg capacity after preheating the furnace for 40 minutes. Graphite and ferrosilicon was added to the charge in order to obtain a theoretical composition of not less than 4.0% carbon and 2.0% silicon. Charges in the furnace were heated to obtain molten metal which was tapped at 1400°C. Tapping was done for casting at three different times. The castings solidified in sand mould and allowed to cool to room temperature in the mould. Castings were denoted as sample 1, 2 and 3. Final compositions of each casting were analyzed with optical light emission spectrometer. Sample 1 has 2.95% carbon and 1.82% silicon. Sample 2 has 2.88% carbon and 1.70% silicon and sample 3 has 2.75% carbon and 1.63% silicon.

  10. Study on plasma-spraying Ni-Al-WC alloy layer on the surface of chrome cast iron and alloy layer's micro-structure and properties

    International Nuclear Information System (INIS)

    Plasma-spraying Ni-Al-WC alloy layer on the surface of chrome cast iron and alloy layer's micro-structure and properties are studied. The analysis items include chemical composition, phase structure, average microhardness, wear resistance and corrosion resistance. The experimental results indicate that metallurgical combination has been achieved completely between the spraying layer and the surface of chrome cast iron, and that the chemical composition and micro-structure in the surface layer of the sample have been changed basically, and that the microhardness, the wear resistance, the corrosion resistance in the surface layer are increased by a large margin

  11. Sex and Caste-Specific Variation in Compound Eye Morphology of Five Honeybee Species

    OpenAIRE

    Streinzer, Martin; Brockmann, Axel; Nagaraja, Narayanappa; Spaethe, Johannes

    2013-01-01

    Ranging from dwarfs to giants, the species of honeybees show remarkable differences in body size that have placed evolutionary constrains on the size of sensory organs and the brain. Colonies comprise three adult phenotypes, drones and two female castes, the reproductive queen and sterile workers. The phenotypes differ with respect to tasks and thus selection pressures which additionally constrain the shape of sensory systems. In a first step to explore the variability and interaction between...

  12. An Integrated Architecture for Enhanced Structuring of Mobile Market Place

    Directory of Open Access Journals (Sweden)

    Amer Ali Sallam

    2011-01-01

    Full Text Available This paper aims at presenting an integrated architecture for mobile marketplace for efficient transaction and marketing using mobile devices and related infrastructure. This architecture deals with different components of mobile marketplace and it considering a new way of integrating different functionalities of mobile market place. .

  13. An Integrated Architecture for Enhanced Structuring of Mobile Market Place

    Directory of Open Access Journals (Sweden)

    Amer Ali Sallam

    2011-02-01

    Full Text Available This paper aims at presenting an integrated architecture for mobile marketplace for efficient transaction and marketing using mobile devices and related infrastructure. This architecture deals with different components of mobile marketplace and it considering a new way of integrating different functionalities of mobile market place. .

  14. An Experimental Investigation to Facilitate an Improvement in the Design of an Electromagnetic Continuous Casting Mould

    Directory of Open Access Journals (Sweden)

    Lintao Zhang

    2016-04-01

    Full Text Available An electromagnetic continuous casting mould designed is proposed with a non-uniform slit distribution structure. This design has aimed to reduce the number of slits so that the mould’s strength is enhanced, whilst maintaining a similar metallurgy effect. In this paper, the metallurgy effect for the designed mould is investigated through the magnetic field distribution along the casting direction, the uniformity feature in the vicinity of the meniscus region, the temperature variation of the molten alloy pool and the mould wall. The results show that the designed mould achieved a similar effect as compared to the original mould; however, the configuration is simplified. This research highlights the topic of mould structure optimization, which would enable the Electromagnetic continuous casting (EMCC technique to be utilized with greater ease by industry.

  15. The role of graphite morphology and matrix structure on low frequency thermal cycling of cast irons

    Indian Academy of Sciences (India)

    S Y Buni; N Raman; S Seshan

    2004-02-01

    Low frequency thermal cycling tests were carried out on four types of cast iron (viz., austempered ductile iron, pearlitic ductile iron, compacted/vermicular graphite iron and grey cast iron) at predetermined ranges of thermal cycling temperatures. The specimens were unconstrained. Results show that austempered ductile iron has the highest thermal cycling resistance, followed by pearlitic ductile iron and compacted graphite iron, while grey cast iron exhibits the lowest resistance. Microstructural analysis of test specimens subjected to thermal cycling indicates that matrix decomposition and grain growth are responsible for the reduction in hardness while graphite oxidation, de-cohesion and grain boundary separation are responsible for the reduction in the modulus of elasticity upon thermal cycling.

  16. Effect of technological parameters on microstructure in alloy AlCu4Ti using squeeze casting technology

    Science.gov (United States)

    Pastirčák, Richard; Ščury, Ján

    2016-06-01

    The paper deals with the impact of technological parameters on the heat transfer coefficient and microstructure in AlCu4Ti alloy using squeeze casting technology. The casting with crystallization under pressure was used, specifically direct squeeze casting method. The goal was to affect crystallization by pressure with a value 100 MPa. The pressure applied to the melt causes a significant increase of the coefficient of heat transfer between the melt and the mold. By rapid cooling the casting was reflected by changes in the structure. On the basis of the measured values of heat flux and heat transfer coefficient were calculated at the interface between the cast and the mold. The observation of microstructure can conclude, there is no significant influencing of the primary phase. As a result of the pressure was reduced porosity.

  17. Yield improvement and defect reduction in steel casting

    Energy Technology Data Exchange (ETDEWEB)

    Kent Carlson

    2004-03-16

    This research project investigated yield improvement and defect reduction techniques in steel casting. Research and technology development was performed in the following three specific areas: (1) Feeding rules for high alloy steel castings; (2) Unconventional yield improvement and defect reduction techniques--(a) Riser pressurization; and (b) Filling with a tilting mold; and (3) Modeling of reoxidation inclusions during filling of steel castings. During the preparation of the proposal for this project, these areas were identified by the High Alloy Committee and Carbon and Low Alloy Committee of the Steel Founders' Society of America (SFSA) as having the highest research priority to the steel foundry industry. The research in each of the areas involved a combination of foundry experiments, modeling and simulation. Numerous SFSA member steel foundries participated in the project through casting trials and meetings. The technology resulting from this project will result in decreased scrap and rework, casting yield improvement, and higher quality steel castings produced with less iteration. This will result in considerable business benefits to steel foundries, primarily due to reduced energy and labor costs, increased capacity and productivity, reduced lead-time, and wider use and application of steel castings. As estimated using energy data provided by the DOE, the technology produced as a result of this project will result in an energy savings of 2.6 x 10{sup 12} BTU/year. This excludes the savings that were anticipated from the mold tilting research. In addition to the energy savings, and corresponding financial savings this implies, there are substantial environmental benefits as well. The results from each of the research areas listed above are summarized.

  18. As-cast structure refinement of Ti-46Al alloy by hafnium and boron additions

    Institute of Scientific and Technical Information of China (English)

    Zhang Li; Su Yanqing; Yang Huimin; Luo Liangshun; Guo Jingjie

    2009-01-01

    The influence of Hf and B on the solidification structure of cast Ti-46Al alloys was investigated. The results show that the coupling effect of Hf and B changes the solidification structure morphology and strongly refines the grain size. When the Hf+B contents were increased from 0 + 0.0 to 3 + 0.2, 5 + 0.6 and 7 + 1.0 (in at. %), the solidification structure morphology changed from coarse columnar dendrite to fine columnar dendrite,then to equiaxed dendrite, and further to fine near granular grain whilst the average grain size decreased to 20 μm.It is concluded that the columnar dendrite refinement is due to the effect of Hf and B on the decrease of Al diffusion coefficient in the melt. The fine near granular grain formation is attributed to the combined constitutional supercooling formed by AI and B segregation that is strengthened by Hf and B additions at the solid/liquid interface uring solidification, and the TiB2 precipitates acting as heterogeneous nuclei.

  19. Automatic inspection of surface defects in die castings after machining

    Directory of Open Access Journals (Sweden)

    S. J. Świłło

    2011-07-01

    Full Text Available A new camera based machine vision system for the automatic inspection of surface defects in aluminum die casting was developed by the authors. The problem of surface defects in aluminum die casting is widespread throughout the foundry industry and their detection is of paramount importance in maintaining product quality. The casting surfaces are the most highly loaded regions of materials and components. Mechanical and thermal loads as well as corrosion or irradiation attacks are directed primarily at the surface of the castings. Depending on part design and processing techniques, castings may develop surface discontinuities such as cracks or tears, inclusions due to chemical reactions or foreign material in the molten metal, and pores that greatly influence the material ability to withstand these loads. Surface defects may act as a stress concentrator initiating a fracture point. If a pressure is applied in this area, the casting can fracture. The human visual system is well adapted to perform in areas of variety and change; the visual inspection processes, on the other hand, require observing the same type of image repeatedly to detect anomalies. Slow, expensive, erratic inspection usually is the result. Computer based visual inspection provides a viable alternative to human inspectors. Developed by authors machine vision system uses an image processing algorithm based on modified Laplacian of Gaussian edge detection method to detect defects with different sizes and shapes. The defect inspection algorithm consists of three parameters. One is a parameter of defects sensitivity, the second parameter is a threshold level and the third parameter is to identify the detected defects size and shape. The machine vision system has been successfully tested for the different types of defects on the surface of castings.

  20. Surface dosimetry for breast radiotherapy in the presence of immobilization cast material

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, Andrew; Hardcastle, Nicholas; Metcalfe, Peter; Cutajar, Dean; Quinn, Alexandra; Cardoso, Michael; Rosenfeld, Anatoly [Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW (Australia); Foo, Kerwyn [Sydney Medical School, University of Sydney, Sydney, NSW (Australia); Barlin, Sheree, E-mail: anatoly@uow.edu.au [Illawarra Cancer Care Centre, Wollongong Hospital, Wollongong, NSW (Australia)

    2011-02-21

    Curative breast radiotherapy typically leaves patients with varying degrees of cosmetic damage. One problem interfering with cosmetically acceptable breast radiotherapy is the external contour for large pendulous breasts which often results in high doses to skin folds. Thermoplastic casts are often employed to secure the breasts to maintain setup reproducibility and limit the presence of skin folds. This paper aims to determine changes in surface dose that can be attributed to the use of thermoplastic immobilization casts. Skin dose for a clinical hybrid conformal/IMRT breast plan was measured using radiochromic film and MOSFET detectors at a range of water equivalent depths representative of the different skin layers. The radiochromic film was used as an integrating dosimeter, while the MOSFETs were used for real-time dosimetry to isolate the contribution of skin dose from individual IMRT segments. Strips of film were placed at various locations on the breast and the MOSFETs were used to measure skin dose at 16 positions spaced along the film strips for comparison of data. The results showed an increase in skin dose in the presence of the immobilization cast of up to 45.7% and 62.3% of the skin dose without the immobilization cast present as measured with Gafchromic EBT film and MOSFETs, respectively. The increase in skin dose due to the immobilization cast varied with the angle of beam incidence and was greatest when the beam was normally incident on the phantom. The increase in surface dose with the immobilization cast was greater under entrance dose conditions compared to exit dose conditions.

  1. Jamestown and Disneyland: Two Places in Time.

    Science.gov (United States)

    Scrofani, E. Robert; Tideman, Robert

    This unit for high school students uses two dissimilar places in time; (2) Jamestown, Virginia, founded in 1607, one of the earliest settlements in the United States and (2) Disneyland, California, built in 1956, an institution of contemporary culture. The lessons address two fundamental questions in geography: (1) where? and (2) why here rather…

  2. Manufacture of centrifugal Castings

    OpenAIRE

    Minář, Martin

    2015-01-01

    The main goal of this bachelor thesis is to collect basic information related to the production of castings by centrifugal casting. It is focused on horizontal and vertical centrigugal casting, casting of various metals and their alloys, such as zinc, aluminum, iron, steel and silumin. This technology is compared with other casting methods in terms of specific characteristics, amount of usage, production economics, advantages, disadvantages, the resulting quality of castings and other factors.

  3. The UK Casting Industry

    Institute of Scientific and Technical Information of China (English)

    Jincheng Liu

    2006-01-01

    The casting production in the UK in 2004 is presented and analysed. The UK casting industry has played an important role in world casting and manufacturing production. However recent years the rapid development of some developing countries has been shifting the casting production from the western industrialized countries including the UK. The UK casting industry and associated research and technology organizations, universities have been working together very hard to face the serious competition to make the UK casting industry have a sustainable future. The UK casting industry remains strong and plays an important role in world casting and manufacturing production.

  4. Thermal analysis, structure and mechanical properties of the MC MgAl3Zn1 cast alloy

    Directory of Open Access Journals (Sweden)

    L.A. Dobrzański

    2010-06-01

    Full Text Available Purpose: This work presents effect of cooling rate on the mechanical and structural properties and thermal characteristic results of MC MgAl3Zn1 cast alloy.Design/methodology/approach: The experiments were performed using the novel Universal Metallurgical Simulator and Analyzer Platform. Material used in this experiment is experimental magnesium alloy made as-cast.Findings: The research show that the thermal analysis carried out on UMSA Technology Platform is an efficient tool for collect and calculate thermal parameters. The formation temperatures of various thermal parameters, mechanical properties (hardness and ultimate compressive strength and grain size are shifting with an increasing cooling rate.Research limitations/implications: This paper presents results for one alloy - MC MgAl3Zn1 only, cooled with three different solidifications rate i.e. 0.6, 1.2 and 2.4°C/s, for assessment for the liquidus and solidus temperatures and its influence on the mechanical properties and structure.Practical implications: The parameters described can be applied in metal casting industry for selecting magnesium ingot preheating temperature for semi solid processing to achieve requirements properties.Originality/value: The paper contributes to better understanding and recognition an influence of different solidification condition on non-equilibrium thermal parameters of magnesium alloys.

  5. Sex and caste-specific variation in compound eye morphology of five honeybee species.

    Science.gov (United States)

    Streinzer, Martin; Brockmann, Axel; Nagaraja, Narayanappa; Spaethe, Johannes

    2013-01-01

    Ranging from dwarfs to giants, the species of honeybees show remarkable differences in body size that have placed evolutionary constrains on the size of sensory organs and the brain. Colonies comprise three adult phenotypes, drones and two female castes, the reproductive queen and sterile workers. The phenotypes differ with respect to tasks and thus selection pressures which additionally constrain the shape of sensory systems. In a first step to explore the variability and interaction between species size-limitations and sex and caste-specific selection pressures in sensory and neural structures in honeybees, we compared eye size, ommatidia number and distribution of facet lens diameters in drones, queens and workers of five species (Apis andreniformis, A. florea, A. dorsata, A. mellifera, A. cerana). In these species, male and female eyes show a consistent sex-specific organization with respect to eye size and regional specialization of facet diameters. Drones possess distinctly enlarged eyes with large dorsal facets. Aside from these general patterns, we found signs of unique adaptations in eyes of A. florea and A. dorsata drones. In both species, drone eyes are disproportionately enlarged. In A. dorsata the increased eye size results from enlarged facets, a likely adaptation to crepuscular mating flights. In contrast, the relative enlargement of A. florea drone eyes results from an increase in ommatidia number, suggesting strong selection for high spatial resolution. Comparison of eye morphology and published mating flight times indicates a correlation between overall light sensitivity and species-specific mating flight times. The correlation suggests an important role of ambient light intensities in the regulation of species-specific mating flight times and the evolution of the visual system. Our study further deepens insights into visual adaptations within the genus Apis and opens up future perspectives for research to better understand the timing mechanisms

  6. Sex and caste-specific variation in compound eye morphology of five honeybee species.

    Directory of Open Access Journals (Sweden)

    Martin Streinzer

    Full Text Available Ranging from dwarfs to giants, the species of honeybees show remarkable differences in body size that have placed evolutionary constrains on the size of sensory organs and the brain. Colonies comprise three adult phenotypes, drones and two female castes, the reproductive queen and sterile workers. The phenotypes differ with respect to tasks and thus selection pressures which additionally constrain the shape of sensory systems. In a first step to explore the variability and interaction between species size-limitations and sex and caste-specific selection pressures in sensory and neural structures in honeybees, we compared eye size, ommatidia number and distribution of facet lens diameters in drones, queens and workers of five species (Apis andreniformis, A. florea, A. dorsata, A. mellifera, A. cerana. In these species, male and female eyes show a consistent sex-specific organization with respect to eye size and regional specialization of facet diameters. Drones possess distinctly enlarged eyes with large dorsal facets. Aside from these general patterns, we found signs of unique adaptations in eyes of A. florea and A. dorsata drones. In both species, drone eyes are disproportionately enlarged. In A. dorsata the increased eye size results from enlarged facets, a likely adaptation to crepuscular mating flights. In contrast, the relative enlargement of A. florea drone eyes results from an increase in ommatidia number, suggesting strong selection for high spatial resolution. Comparison of eye morphology and published mating flight times indicates a correlation between overall light sensitivity and species-specific mating flight times. The correlation suggests an important role of ambient light intensities in the regulation of species-specific mating flight times and the evolution of the visual system. Our study further deepens insights into visual adaptations within the genus Apis and opens up future perspectives for research to better understand the

  7. Ageing in Place Driving Urban Transformations

    Directory of Open Access Journals (Sweden)

    Marta Kavšek

    2016-03-01

    Full Text Available Abstract Research question: This article provides an answer to the question: What kind of housing do the seniors in Slovenia prefer after a substantial decrease of their functional capacities, i.e. when they already need long-term care services? Purpose: During the study, the seniors participating in the study were still able to live in their current dwelling – in the home where they lived for years together with their family or alone; but because of a substantial decrease of their functional capacities they had become aware that it would be difficult to continue to stay there. We wanted to know where they would like to migrate or move to when needed, and what kind of housing should be provided on the housing market for these cohorts. Method: After our study of the relevant European and American literature we found that the construction of housing for seniors can be developed in different types of structures and that there is a substantial gap between the needs and the availabilities of housing arrangements in Slovenia, which also increases the rigidity of the Slovenian housing market and reduces land rent in comparison with USA and Western Europe. Seniors using long-term care services provided by municipalities in their own homes, living outside the main Slovenian central places, were included in the survey. To identify the preferred structure of the built environment for seniors we organised 3 groups of interviews with assisted living inhabitants from three Slovenian municipalities and evaluated the percentages of each desired type of housing and care. Results: The results show that more than half of Slovenian seniors do not have the possibility to move to retirement villages or other better adapted homes in assisted living housing units, where they could protect their dignity and independence better than in institutional care in nursing homes. Local administration and society: These findings refer to the local administration initiative to

  8. [Which place for physicians in blood supply?].

    Science.gov (United States)

    Danic, B; Pelletier, B

    2013-05-01

    Historically, blood transfusion has been divised, enhanced and organized by physicians. The special status of blood led to ensure that collection of blood and its components were placed under the supervision of a physician. Throughout its history, blood transfusion organization in France has established an exclusive exercise of the collection of blood and its components entrusted to doctors, thus creating the concept of "medicine of donation". This view is changing, and programmed exercise of this activity by nurses led to question about this profession perimeter, its necessary evolution, and finally about the place of physicians in blood supply. PMID:23537956

  9. Non-metallic inclusions in billets casted using horizontal type continuous-casting machine

    International Nuclear Information System (INIS)

    The distribution of non-metallic inclusions in billets of carbon steels, alloyed steels (Kh18N9T) and heat-resistant nickel alloys (EhI437B, EhP109) has been studied. Billets of square and round cross sections have been casted using horisontal continuous-casting machines. Methods of chemical, metallographic, petrographic and X-ray analyses have been applied in investigations. A rise in the content of non-metallic inclusions has been observed in the upper zones of billet cross sections. Inclusions in carbon steels are mainly represented by α-A2O3 in stainless steels - by TiO and TiN, in nickel alloys - by TiN and AlN. Investigations into nitrogen and oxygen distribution have proved the data obtained. Inclusions and gases have been distributed evenly over billet length. Liquid metal blowing with argon and the application of coper-graphite dies have permitted to obtain a metal with an uniform oxide and nitride distribution over billet cross section and lentgh

  10. Making (sense of) places in virtual worlds

    DEFF Research Database (Denmark)

    Gürsimsek, Remzi Ates

    in 3D virtual space to collaborate and co- design the digital content. These co-designers are also the residents of these worlds, as they socialize by building inworld friendships. This article presents a social semiotic analysis of the three-dimensional virtual places and artifacts in the virtual...

  11. Market Design in Chinese Market Places

    NARCIS (Netherlands)

    B. Krug (Barbara); H. Hendrischke (Hans)

    2012-01-01

    textabstractThe Market Design (MD) approach to institutional analysis provides the analytical tools to evaluate endogenous institution building in local market places irrespective of the institutional setting of the national economy. Implicit in this analysis of endogenous institution building at th

  12. Market design in Chinese market places

    NARCIS (Netherlands)

    B. Krug (Barbara); H. Hendrischke (Hans)

    2012-01-01

    textabstractThe market design (MD) approach to institutional analysis provides the analytical tools to evaluate endogenous institution building in local market places irrespective of the institutional setting of the national economy. Implicit in this analysis of endogenous institution building at th

  13. Recrystallization microstructures and textures in AA 5052 continuous cast and direct chill cast aluminum alloy

    International Nuclear Information System (INIS)

    Commercially produced hot bands of AA 5052 continuous cast (CC) and direct chill (DC) cast aluminum alloys were cold rolled to (thickness) reductions of 70%, 80%, and 90% followed by annealing at different conditions. The recrystallization kinetics are found equivalent for both the CC and DC materials. Recrystallization microstructures are different between the CC and DC materials. Evolution of recrystallization texture in the CC and DC materials were investigated by using three-dimensional orientation distribution functions (ODFs) that were determined by X-ray diffraction. The recrystallization texture was correlated with cold rolling reduction (prior to annealing), annealing temperature, and annealing time. Results showed that the R {124} and cube {001} are dominant recrystallization texture components in both CC and DC materials. During annealing, the intensity and volume fraction of the cube component strongly depend on the prior cold rolling history. In contrast, the intensity and volume fraction of the R component remains almost constant regardless of the different cold rolling reductions prior to annealing. After complete recrystallization, the intensity and volume fraction of both R and cube components appear to be independent of the annealing temperature and annealing time

  14. Influence of cooling rate on the structure and mechanical properties of G17CrMoV5 – 10 cast steel

    Directory of Open Access Journals (Sweden)

    G. Golański

    2009-07-01

    Full Text Available The paper presents results of research on the influence of cooling rate on the structure and properties of G17CrMoV5 – 10 (L17HMF cast steel. The material for research was a section taken out from an outer cylinder of a steam turbine body after about 250 000 hours of operation at the temperature of 535°C and pressure 9 MPa. The investigated cast steel was subjected to heat treatment which consisted in cooling at the rates corresponding to the processes, such as: bainitic hardening, normalizing and full annealing. Tempering after the process of cooling from austenitizing temperature was carried out at the temperatures of: 700, 720 and 740°C. Performed research has proved that structures obtained after bainitic hardening and normalizing are characterized by a large strength margin which allows to apply high temperatures of tempering. It has been shown that the cast steel of bainitic structure, with similar mechanical properties as the cast steel of bainitic – ferritic structure, is characterized by almost twice as high impact energy. Full annealing and tempering of the examined cast steel ensures only the required impact strength, with mechanical properties comparable to those after service.

  15. Recurrent cholangitis in the tropics: Worm or cast?

    Directory of Open Access Journals (Sweden)

    Jain P

    2010-01-01

    Full Text Available The development of biliary casts is very rare, especially in non-liver transplant patients. The etiology of these casts is uncertain but several factors have been proposed which lead to bile stasis and/or gallbladder hypo-contractility and promote cast formation. Here, we report a 54-year-old male, with diabetes and ischemic heart disease, who presented with recurrent attacks of cholangitis. Magnetic resonance cholangiopancreatography revealed linear T1 hyperintense and T2 hypointense filling defects in the right and left hepatic ducts extending into the common hepatic duct, and a calculus in the lower common bile duct, raising a suspicion of worm in the biliary tree. In view of failed attempts at extraction on endoscopy, patient underwent surgery. At exploration, biliary casts and stones were extracted from the proximal and the second order bile ducts, with the help of intraoperative choledochoscopy and a bilio-enteric anastomosis was accomplished. Although endoscopic retrieval of the biliary cast can be employed as first-line management, surgery should be considered in case it fails.

  16. Characterization of pores in high pressure die cast aluminum using active thermography and computed tomography

    Science.gov (United States)

    Maierhofer, Christiane; Myrach, Philipp; Röllig, Mathias; Jonietz, Florian; Illerhaus, Bernhard; Meinel, Dietmar; Richter, Uwe; Miksche, Ronald

    2016-02-01

    Larger high pressure die castings (HPDC) and decreasing wall thicknesses are raising the issue of casting defects like pores in aluminum structures. Properties of components are often strongly influenced by inner porosity. As these products are being established more and more in lightweight construction (e.g. automotive and other transport areas), non-destructive testing methods, which can be applied fast and on-site, are required for quality assurance. In this contribution, the application of active thermography for the direct detection of larger pores is demonstrated. The analysis of limits and accuracy of the method are completed by numerical simulation and the method is validated using computed tomography.

  17. Indian Place Names in South Dakota.

    Science.gov (United States)

    Gasque, Thomas J.

    A cursory examination of place names on a map of South Dakota does not reflect the important role that Indians have played in the state and their relation to the land framed by its borders. Only three towns with populations over 1,000 bear names that clearly come from Indian languages: Sioux Falls, Sisseton, and Yankton. The hostile relationship…

  18. Placing Teachers in Global Governance Agendas

    Science.gov (United States)

    Robertson, Susan L.

    2012-01-01

    This article examines the focus on teacher policies and practices by a range of global actors and explores their meaning for the governance of teachers. Through a historical and contemporary reading, I argue that an important shift in the locus of power to govern has taken place. I show how the mechanisms of global governance of teachers are being…

  19. Characterisation and modelling of defect formation in direct-chill cast AZ80 alloy

    Energy Technology Data Exchange (ETDEWEB)

    Mackie, D.; Robson, J.D.; Withers, P.J. [School of Materials, University of Manchester, Manchester M13 9PL (United Kingdom); Turski, M. [Magnesium Elektron UK, Rake Lane, Manchester, M27 8BF (United Kingdom)

    2015-06-15

    Wrought magnesium alloys for demanding structural applications require high quality defect free cast feedstock. The aim of this study was to first identify and characterise typical defects in direct chill cast magnesium–aluminium–zinc (AZ) alloy billet and then use modelling to understand the origins of these defects so they can be prevented. Defects were first located using ultrasonic inspection and were then characterised using X-ray computed tomography (XCT) and serial sectioning, establishing the presence of oxide films and intermetallic particles Al{sub 8}Mn{sub 5} in all defects. A model was developed to predict the flow patterns and growth kinetics of the intermetallic phases during casting, which influence the formation of defects. Simulation of the growth of the intermetallic particles demonstrated that precipitation from the liquid occurs in the mould. The combination of the entrained oxide films and intermetallic particles recirculates in the liquid metal and continues to grow, until large enough to settle, which is predicted to occur at the centre of the mould where the flow is the slowest. Based on these predictions, strategies to reduce the susceptibility to defect formation are suggested. - Highlights: • Casting defects in magnesium direct chill casting have been imaged and characterised in 3-dimensions. • The occurrences of co-located clusters of particles and oxide films have been characterised and explained. • A coupled model has been developed to help interpret the observed trend for defects located towards the centre of billets.

  20. Characterisation and modelling of defect formation in direct-chill cast AZ80 alloy

    International Nuclear Information System (INIS)

    Wrought magnesium alloys for demanding structural applications require high quality defect free cast feedstock. The aim of this study was to first identify and characterise typical defects in direct chill cast magnesium–aluminium–zinc (AZ) alloy billet and then use modelling to understand the origins of these defects so they can be prevented. Defects were first located using ultrasonic inspection and were then characterised using X-ray computed tomography (XCT) and serial sectioning, establishing the presence of oxide films and intermetallic particles Al8Mn5 in all defects. A model was developed to predict the flow patterns and growth kinetics of the intermetallic phases during casting, which influence the formation of defects. Simulation of the growth of the intermetallic particles demonstrated that precipitation from the liquid occurs in the mould. The combination of the entrained oxide films and intermetallic particles recirculates in the liquid metal and continues to grow, until large enough to settle, which is predicted to occur at the centre of the mould where the flow is the slowest. Based on these predictions, strategies to reduce the susceptibility to defect formation are suggested. - Highlights: • Casting defects in magnesium direct chill casting have been imaged and characterised in 3-dimensions. • The occurrences of co-located clusters of particles and oxide films have been characterised and explained. • A coupled model has been developed to help interpret the observed trend for defects located towards the centre of billets

  1. Based on database and asp.net technologies, a web platform of scientific data in the casting forces on the mold-fi lling behavior of titanium melts in vertically rotating molds

    OpenAIRE

    Xu Daming; Fu Hengzhi; Jia Limin

    2008-01-01

    The vertical centrifugal-casting technique is widely used in the manufacture of various irregularlyshaped castings of advanced structural alloys with thin walls, complex shapes and/or large sizes. These castings are used in the increasing applications in aero-space/aviation industries, human teeth/bone repairs with nearnet shaped components, etc. In a vertically rotating casting system, the mold-filling processes of alloy melts, coupled with solidifi cation-heat transfer, may be much more com...

  2. Stages of vermicular cast iron properties modeling in the intelligent design system

    Science.gov (United States)

    Klochkova, K. V.; Petrovich, S. V.; Simonova, L. A.; Yusupov, L. R.

    2015-06-01

    This article presents the structure of intelligent system of the cast iron with vermicular graphite iron (CGI) design under the conditions of current production, the technique of the optimal process TP parameters of the production of CGI parts in the preparatory phase of production based on mental models is designed.

  3. Crystallization and structure of cast A390.0 alloy with melt overheating temperature

    Directory of Open Access Journals (Sweden)

    J. Piątkowski

    2012-07-01

    Full Text Available The paper presents the research on the influence of melt overheating temperature on crystallization parameters and primary structure of cast AlSi17Cu5Mg (A390.0 alloy overheated to temperature: 820 °C, 880 °C, 940 °C and 1 000 °C. It was found that the degree of overheating influences the change of microstructure significantly and morphologies of primary silicon of the castings from Al-Si alloys. Research has shown that the overheating of the liquid metal bath is one of the methods of finding more applications of hypereutectic Al-Si system alloys without the addition of modifiers.

  4. Modelling of fluid flow in tape casting of thin ceramics: Analytical approaches and numerical investigations

    DEFF Research Database (Denmark)

    Jabbaribehnam, Mirmasoud; Hattel, Jesper Henri

    2016-01-01

    Tape casting has been used to produce thin layers of ceramics that can be used as single layers or can be stacked and laminated into multilayered structures. Many startup products such as multilayered inductors, multilayered varistors, piezoelectrics, ceramic fuel cells and lithium ion battery...... the physical parameters crucial to the process. A review of the development of the tape casting process with particular focus on modelling the material flow is presented and in this context the current status is examined and future potential discussed....

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

    Directory of Open Access Journals (Sweden)

    S. Borkowski

    2010-01-01

    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.

  6. A space imaging concept based on a 4m structured spun-cast borosilicate monolithic primary mirror

    Science.gov (United States)

    West, S. C.; Bailey, S. H.; Bauman, S.; Cuerden, B.; Granger, Z.; Olbert, B. H.

    2010-07-01

    Lockheed Martin Corporation (LMC) tasked The University of Arizona Steward Observatory (UASO) to conduct an engineering study to examine the feasibility of creating a 4m space telescope based on mature borosilicate technology developed at the UASO for ground-based telescopes. UASO has completed this study and concluded that existing launch vehicles can deliver a 4m monolithic telescope system to a 500 km circular orbit and provide reliable imagery at NIIRS 7-8. An analysis of such an imager based on a lightweight, high-performance, structured 4m primary mirror cast from borosilicate glass is described. The relatively high CTE of this glass is used to advantage by maintaining mirror shape quality with a thermal figuring method. Placed in a 290 K thermal shroud (similar to the Hubble Space Telescope), the orbit averaged figure surface error is 6nm rms when earth-looking. Space-looking optical performance shows that a similar thermal conditioning scheme combined with a 270 K shroud achieves primary mirror distortion of 10 nm rms surface. Analysis shows that a 3-point bipod mount will provide launch survivability with ample margin. The primary mirror naturally maintains its shape at 1g allowing excellent end-to-end pre-launch testing with e.g. the LOTIS 6.5m Collimator. The telescope includes simple systems to measure and correct mirror shape and alignment errors incorporating technologies already proven on the LOTIS Collimator. We have sketched a notional earth-looking 4m telescope concept combined with a wide field TMA concept into a DELTA IV or ATLAS 552 EELV fairing. We have combined an initial analysis of launch and space performance of a special light-weighted honeycomb borosilicate mirror (areal density 95 kg/m2) with public domain information on the existing launch vehicles.

  7. Skeleton castings dynamic load resistance

    Directory of Open Access Journals (Sweden)

    M. Cholewa

    2013-06-01

    Full Text Available Purpose: The article is to show selected results of research in a field of new type of cast spatial composite reinforcements. This article shows skeleton casting case as a particular approach to continuous, spatial composite reinforcement.Design/methodology/approach: The research is concerning properties of cast spatial microlattice structures called skeleton castings. In this paper results of impact test of skeleton casting with octahedron elementary cell were shown. The selection of internal topology of skeleton casting was based on numerical simulations of stress distribution.Findings: The possibility of manufacturing of geometrically complex skeleton castings without use of advanced techniques was confirmed.Research limitations/implications: With use of computer tomography, analysis of deformation mechanisms was carried out. Different levels of impact energies were usedPractical implications: Spatial skeleton casting with octahedron elementary cell confirmed their usefulness as impact energy absorbers.Originality/value: The overall aim of presented research was to determine the mechanisms of skeleton castings deformation processes. Thanks to CT data next step will be to create accurate numerical model for further simulation and design optimization.

  8. Use of SEM and EDS analysis in the investigation of Al-Si-Cu piston alloy cast porosity

    Directory of Open Access Journals (Sweden)

    D. Kakaš

    2009-07-01

    Full Text Available Porosity formation was detected in the casting thinnest section in the proximity of the as cast surface and near the wall centerline. In order to investigate the cause of the porosity formation light microscopy was used to define as cast structure. After initial findings SEM and EDS analyses were performed. Based on the results it is possible to define cause of the observed porosity. A number of pores originates from the mould filling stage and entrainment of the oxide films, while others appear due to insufficient feeding during solidification.

  9. Inverse thermal analysis method to study solidification in cast iron

    DEFF Research Database (Denmark)

    Dioszegi, Atilla; Hattel, Jesper

    2004-01-01

    solution of a 1-dimensional heat transfer problem connected to solidification of cast alloys. In the analysis, the relation between the thermal state and the fraction solid of the metal is evaluated by a numerical method. This method contains an iteration algorithm controlled by an under relaxation term to......Solidification modelling of cast metals is widely used to predict final properties in cast components. Accurate models necessitate good knowledge of the solidification behaviour. The present study includes a re-examination of the Fourier thermal analysis method. This involves an inverse numerical...... achieve a stable convergence. The heat transfer problem is reduced to 1-dimension to promote the practical application of the method. Thermo-physical properties such as the volumetric heat capacity tabulated in the calculation are introduced as a function of solidifying phases. Experimental equipment was...

  10. Numerical Analysis of Secondary Cooling in Continuous Slab Casting

    Institute of Scientific and Technical Information of China (English)

    Kee-Hyeon Cho; Byung-Moon Kim

    2008-01-01

    In the present study, a numerical optimization program has been developed for predicting the optimal secondary cooling patterns in a continuous slab caster. Optimization strategy using Broydon-Fletcher-Goldfarb-Shanno (BFGS) method is carried out by determining the constant heat transfer coefficients in each spray zone, which could satisfy the casting conditions and metallurgical criteria specified by the engineer. From the present results, it is found that even a slight variation in the pouring temperature, allowable surface temperature, and casting speed could give rise to the changes in the cooling pattern throughout the spray zones.

  11. Virtual X-ray imaging techniques in an immersive casting simulation environment

    International Nuclear Information System (INIS)

    A computer code was developed to simulate radiograph of complex casting products in a CAVETM-like environment. The simulation is based on the deterministic algorithms and ray tracing techniques. The aim of this study is to examine CAD/CAE/CAM models at the design stage, to optimize the design and inspect predicted defective regions with fast speed, good accuracy and small numerical expense. The present work discusses the algorithms for the radiography simulation of CAD/CAM model and proposes algorithmic solutions adapted from ray-box intersection algorithm and octree data structure specifically for radiographic simulation of CAE model. The stereoscopic visualization of full-size of product in the immersive casting simulation environment as well as the virtual X-ray images of castings provides an effective tool for design and evaluation of foundry processes by engineers and metallurgists

  12. Detection and characterization of defects in centrifugally cast stainless steel: Final report

    International Nuclear Information System (INIS)

    Improved ultrasonic inspection techniques would significantly improve the accuracy of assessing the structural integrity of cast stainless steel piping systems in light water reactors. This report addresses the current technology of inspecting cast stainless steel components using ultrasonic imaging methods. A broad range of material samples were ultrasonically characterized, and a systematic justification accommodated all inspection parameters. The data and results were used to develop improved systems, techniques and procedures. Blind tests and actual field results have produced a set of data that objectively defines the state of the art. The overall results indicate success significantly beyond initial expectations. The examination results for certain samples of cast stainless steel show an abnormally high rate of false positive indications. Further refinements are discussed that should reduce the false positive indications reported in these samples. The technology developed has been proven by application to field inspection problems

  13. Effects of Cr - Ni 18/9 Austenitic Cast Steel Modification by Mischmetal

    Directory of Open Access Journals (Sweden)

    M. Gajewski

    2012-12-01

    Full Text Available This paper presents the results of Cr - Ni 18/9 austenitic cast steel modifications by mischmetal. The study was conducted on industrial melts. Cast steel was melted in an electric induction furnace with a capacity of 2000 kg and a basic lining crucible. .The mischmetal was introduced into the ladle during tapping of the cast steel from the furnace. The effectiveness of modification was examined with the carbon content of 0.1% and the presence of δ ferrite in the structure of cast steel stabilized with titanium. The changes in the structure of cast steel and their effect on mechanical properties and intergranular corrosion were studied. It was found that rare earth metals decrease the sulfurcontent in cast steel and above all, they cause a distinct change in morphology of the δ ferrite and non-metallic inclusions. These changes have improved mechanical properties. R02, Rm, and A5 and toughness increased significantly. There was a great increase of the resistance to intergranular corrosion in the Huey test. The study confirmed the high efficiency of cast steel modification by mischmetal in industrial environments. The final effect of modification depends on the form and manner of placing mischmetal into the liquid metal and the melting technology, ie the degree of deoxidation and desulfurization of the metal in the furnace.

  14. Making Place in the Media City

    DEFF Research Database (Denmark)

    Klausen, Maja

    2012-01-01

    The article discusses practices of placemaking through empirical fieldwork undertaken in the subculture of urban exploration in Copenhagen. The making and experience of place is discussed, firstly, in relation to methodology and academic representation and secondly, in relation to urban space and...... media. The article begins by suggesting that the ethnographic research process should be grasped as the making of an ‘ethnographic place’ (Pink 2010), which invites readers/audiences to imagine themselves into the places represented. Based on findings from the fieldwork, the article moves on to the...... the placemaking practices involved are positioned in a wider theoretical framework focusing on social media and urban space. The urban explorers use different social media platforms to share information and pictures, which is said to accelerate ‘a mediatised sense of place’ (Jansson & Falkheimer 2006...

  15. The place of consumption in ecological economics

    DEFF Research Database (Denmark)

    Røpke, Inge; Reisch, Lucia A.

    2004-01-01

    Research concerning consumption in an environmental perspective has become very dynamic in recent years. Throughout the 1990s contributions have emerged from several different disciplines and approaches, and the research now covers a wide variety of topics. As ecological economics is open for...... the following is to give an idea of the disciplinary and methodological breadth and variety of research concerning consumption and environment, and to place ecological economic contributions in perspective....

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

    Institute of Scientific and Technical Information of China (English)

    Yasuhiro Arisuda; Akihito Hasuno; Junji Yoshida; Kazunari Tanii

    2008-01-01

    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.

  17. Modeling fluid-solid thermomechanical interactions in casting processes

    Energy Technology Data Exchange (ETDEWEB)

    Cruchaga, M.A.; Celentano, D.J.; Lewis, R.W.

    2004-02-01

    An integrated formulation for the analysis of casting processes is presented In this work. This model involves the description of the evolution and the coupled interactions of the flow, thermal and mechanical fields occurring during the liquid-solid transformation of the solidifying metal. The corresponding discretized formulation is solved in the context of a fixed-mesh finite element method. Numerical results applying this methodology in two cylindrical casting specimens are first presented to assess the Influence of different phenomena occurring during the process. Moreover, these simulations are compared with available experimental data. (author)

  18. In-place testing summary - 1988

    International Nuclear Information System (INIS)

    This report is another in a series about an on-going in-place testing program of high efficiency filtration and chemical adsorber systems at the Los Alamos National Laboratory. This testing is in support of the Laboratory's airborne waste management programs. Periodic in-place testing, along with Health Physics air sampling will determine whether the air cleaning systems are maintaining acceptable air-cleaning levels. These periodic evaluations help ensure that the plant and surrounding environment are free of any significant radioactive particulates, based on current EPA environmental levels and chemical airborne hazards from processing effluents. The purpose of this report is to provide an overview of system performance and the testing methods and procedures

  19. In-place testing summary (1989)

    International Nuclear Information System (INIS)

    Periodic evaluation of an air-cleaning system is necessary in order to establish a record of its current operating condition. These evaluations along with Health Physics air sampling determine whether air-cleaning integrity is being maintained. The in-place test is conducted in most instances without disrupting plant operations, and only if the systems failed the test would it become necessary to shut down. Testing is conducted on single and multi-stage filter systems and other filtration devices using optical particle counters. The testing procedure requires that the filter system be challenged with a test aerosol having a heterodisperse size distribution in the submicrometer diameter range, 0.1 to 1.0 micrometer. This type of testing is not to be confused with tests performed by the Quality Assurance Testing Stations, whose purpose is directed at filter efficiency. In-place testing of adsorber systems is required for several reasons: (1) chemical poisoning of the adsorbers by organic vapors; (2) settling of the charcoal in the bed due to vibration; and (3) installation defects. There are two methods of in-place testing of adsorber systems. The first method uses a fluorocarbon (Freon 11 gas), the second method uses a radioactive gas (Iodine or Methyl Iodide). At Los Alamos, we use the Freon 11 method. This report presents the results of the 1989 tests, including the methods and procedures used in the testing and calibration of the particle counters and aerosol diluter systems

  20. Placing Ireland in a comparative perspective

    OpenAIRE

    Peillon, Michel

    1994-01-01

    Some recent publications have raised the question of placing Ireland in a comparative perspective. Three such comparative frameworks are investigated in this paper: advanced capitalist countries, (West) European countries, and finally semi-peripheral European societies. Although not an advanced capitalist economy, Ireland displays the central institutional features of such societies. But on closer inspection, it seems that such features can be attributed to a European institutional framewo...

  1. In Search of Place Brand Identity

    DEFF Research Database (Denmark)

    Kvistgaard, Hans-Peter; Blichfeldt, Bodil Stilling; Hird, John

    2015-01-01

    and market. However, a critical question to be addressed is how to define these core values and attributes in a place context and consequently, how to establish the ‘we’ that should be the basis, upon which to develop and market the destination. The purpose of this paper is to discuss the challenges...... voice to in this process, how to practically give these actors voice and how to obtain consensus on core values and attributes across these actors....

  2. Word and Place in Irish Typography

    OpenAIRE

    Dixon, Brian

    2012-01-01

    Toponomic typography, or place-name typography, is not, in any sense a formal discipline. It is, however, common for typographers to find themselves setting the names of locations and settlements within a diverse range of projects. Wayfinding solutions, public transport information material and road signage are but some examples of the instances in which the designer is required to represent and visually interpret those words which mean so much to so many.

  3. Children : Their Place in Organization Studies

    OpenAIRE

    Kavanagh, Donncha

    2013-01-01

    This paper argues that children and childhood constitute a ¿white space¿ in organization studies, which should now be explored, mapped and analysed.Rather than being separate, children and organization are deeply implicated in one another, which provides a rich basis for theoretical inquiry. The paper draws on Spivak's concept of the subaltern and on actor-network theory to articulate how and where organization studies might critically engage with, and find a place for, children and childhood...

  4. In-place testing summary - 1990

    International Nuclear Information System (INIS)

    This is one of several reports concerning an on-going in-place testing program of high efficiency filtration and chemical adsorber systems and portable filtered exhausters at the Los Alamos National Laboratory. This testing is in support of the Laboratory's airborne waste management programs and asbestos abatement programs. Periodic in-place testing, along with health physics air sampling will determine whether the air cleaning systems are maintaining acceptable air-cleaning levels. These periodic evaluations help ensure that the plant and surrounding environment are free of any significant radioactive particulates, based on current EPA environmental levels and chemical airborne hazards from processing effluents. This report will provide an overview of system performance, testing methods and procedures

  5. Casting Ductile Iron in Layer Moulds Made from Ecological Sands

    OpenAIRE

    M. Rączka; K. Gandurski; B. Isendorf

    2012-01-01

    The article contains the results of tests performed under the target project in Hardtop Foundry Charsznica.The objective of the tests and studies was to develop a technology of making high-quality ductile iron castings, combined witheffective means of environmental protection. The studies presented in this article related to castings weighing from 1 to 300 kg made from ductile iron of grades 400-15 and 500-7, using two-layer moulds, where the facing and core sand was the sand with an alkaline...

  6. Correlation between macroscopic porosity location and liquid metal pressure in centrifugal casting technique.

    Science.gov (United States)

    Vaidyanathan, T K; Schulman, A; Nielsen, J P; Shalita, S

    1981-01-01

    Radiographic analysis of uniform cylindrical castings fabricated by the centrifugal casting technique has revealed that the macroscopic porosity is dependent on the location of the sprue attachment to the casting. This is attributed to the significant pressure gradient associated with the centrifugal casting technique. The pressure gradient results in different heat transfer rates at portions of the castings near and away from the free surface of the button. Consequently, the macroscopic porosity is invariably at portions of the casting close to the free surface of the button. In addition, some optimized sprue-reservoir combinations could be predicted and proved, based on this pressure gradient concept. PMID:7002971

  7. The forty years of vermicular graphite cast iron development in China (PartⅠ

    Directory of Open Access Journals (Sweden)

    CHEN Zheng-de

    2007-05-01

    Full Text Available In China, the research and development of vermicular graphite cast iron (VGCI as a new type of engineering material, were started in the same period as in other developed countries; however, its actual industrial application was even earlier. In China, the deep and intensive studies on VGCI began as early as the 1960s. According to the incomplete statistics to date, more than 600 papers on VGCI have been published by Chinese researchers and scholars at national and international conferences, and in technical journals. More than ten types of production methods and more than thirty types of treatment alloy have been studied. Formulae for calculating the critical addition of treatment alloy required to produce VGCI have been put forward, and mechanisms for explaining the formation of dross during treatment were brought forward. The casting properties, metallographic structure, mechanical and physical properties and machining performance of VGCI, as well as the relationships between them, have all been studied in detail. The Chinese Standards for VGCI and VGCI metallographic structure have been issued. In China, the primary crystallization of VGCI has been studied by many researchers and scholars. The properties of VGCI can be improved by heat treatment and addition of alloying elements enabling its applications to be further expanded. Hundreds of kinds of VGCI castings have been produced and used in vehicles, engines, mining equipment, metallurgical products serviced under alternating thermal load, machinery, hydraulic components, textile machine parts and military applications. The heaviest VGCI casting produced is 38 tons and the lightest is only 1 kg. Currently, the annual production of the VGCI in China is about 200 000 tons. The majority of castings are made from cupola iron without pre-treatment, however, they are also produced from electric furnaces and by duplex melting from cupolaelectric furnaces or blast furnace-electric furnace

  8. The forty years of vermicular graphite cast iron development in China (Part 2

    Directory of Open Access Journals (Sweden)

    CHEN Zheng-de

    2007-08-01

    Full Text Available In China, the research and development of vermicular graphite cast iron (VGCI as a new type of engineering material, were started in the same period as in other developed countries; however, its actual industrial application was even earlier. In China, the deep and intensive studies on VGCI began as early as the 1960s. According to the incomplete statistics to date, more than 600 papers on VGCI have been published by Chinese researchers and scholars at national and international conferences, and in technical journals. More than ten types of production methods and more than thirty types of treatment alloy have been studied. Formulae for calculating the critical addition of treatment alloy required to produce VGCI have been put forward, and mechanisms for explaining the formation of dross during treatment were brought forward. The casting properties, metallographic structure, mechanical and physical properties and machining performance of VGCI, as well as the relationships between them, have all been studied in detail. The Chinese Standards for VGCI and VGCI metallographic structure have been issued. In China, the primary crystallization of VGCI has been studied by many researchers and scholars. The properties of VGCI can be improved by heat treatment and addition of alloying elements enabling its applications to be further expanded. Hundreds of kinds of VGCI castings have been produced and used in vehicles, engines, mining equipment, metallurgical products serviced under alternating thermal load, machinery, hydraulic components, textile machine parts and military applications. The heaviest VGCI casting produced is 38 tons and the lightest is only 1 kg. Currently, the annual production of the VGCI in China is about 200 000 tons. The majority of castings are made from cupola iron without pre-treatment, however, they are also produced from electric furnaces and by duplex melting from cupolaelectric furnaces or blast furnace-electric furnace

  9. The forty years of vermicular graphite cast iron development in China (Part Ⅲ

    Directory of Open Access Journals (Sweden)

    QIU han-quan

    2007-11-01

    Full Text Available In China, the research and development of vermicular graphite cast iron (VGCI as a new type of engineering material, were started in the same period as in other developed countries; however, its actual industrial application was even earlier. In China, the deep and intensive studies on VGCI began as early as the 1960s. According to the incomplete statistics to date, more than 600 papers on VGCI have been published by Chinese researchers and scholars at national and international conferences, and in technical journals. More than ten types of production methods and more than thirty types of treatment alloy have been studied. Formulae for calculating the critical addition of treatment alloy required to produce VGCI have been put forward, and mechanisms for explaining the formation of dross during treatment were brought forward. The casting properties, metallographic structure, mechanical and physical properties and machining performance of VGCI, as well as the relationships between them, have all been studied in detail. The Chinese Standards for VGCI and VGCI metallographic structure have been issued. In China, the primary crystallization of VGCI has been studied by many researchers and scholars. The properties of VGCI can be improved by heat treatment and addition of alloying elements enabling its applications to be further expanded. Hundreds of kinds of VGCI castings have been produced and used in vehicles, engines, mining equipment, metallurgical products serviced under alternating thermal load, machinery, hydraulic components, textile machine parts and military applications. The heaviest VGCI casting produced is 38 tons and the lightest is only 1 kg. Currently, the annual production of the VGCI in China is about 200 000 tons. The majority of castings are made from cupola iron without pre-treatment, however, they are also produced from electric furnaces and by duplex melting from cupolaelectric furnaces or blast furnace-electric furnace

  10. The forty years of vermicular graphite cast iron development in China

    Institute of Scientific and Technical Information of China (English)

    QIU han-quan; CHEN Zheng-de

    2007-01-01

    In China, the research and development of vermicular graphite cast iron (VGCI) as a new type of engineering material, were started in the same period as in other developed countries; however, its actual industrial application was even earlier. In China, the deep and intensive studies on VGCI began as early as the 1960s. According to the incomplete statistics to date, more than 600 papers on VGCI have been published by Chinese researchers and scholars at national and international conferences, and in technical journals. More than ten types of production methods and more than thirty types of treatment alloy have been studied. Formulae for calculating the critical addition of treatment alloy required to produce VGCI have been put forward, and mechanisms for explaining the formation of dross during treatment were brought forward. The casting properties, metallographic structure, mechanical and physical properties and machining performance of VGCI, as well as the relationships between them, have all been studied in detail. The Chinese Standards for VGCI and VGCI metallographic structure have been issued. In China, the primary crystallization of VGCI has been studied by many researchers and scholars. The properties of VGCI can be improved by heat treatment and addition of alloying elements enabling its applications to be further expanded. Hundreds of kinds of VGCI castings have been produced and used in vehicles, engines,mining equipment, metallurgical products serviced under alternating thermal load, machinery, hydraulic components, textile machine parts and military applications. The heaviest VGCI casting produced is 38 tons and the lightest is only 1 kg.Currently, the annual production of the VGCI in China is about 200 000 tons. The majority of castings are made from cupola iron without pre-treatment, however, they are also produced from electric furnaces and by duplex melting from cupolaelectric furnaces or blast furnace-electric furnace. Examples of typical

  11. PHASE STRUCTURE AND COMPATIBILITY OF LADDERLIKE POLYPHENYLSILSESQUIOXANE (PPSQ)/POLYCARBONATE (PC) BLENDS PREPARED BY SOLUTION CASTING

    Institute of Scientific and Technical Information of China (English)

    Gui-zhi Li; Liang-he Shi

    1999-01-01

    Blends of PC and PPSQ (A) with high Mw and good ladderlike regularity or PPSQ(B) with low Mw and more defective Si-atoms in its structure have been prepared by solution casting. The dispersed spheres (PPSQ(A)-rich) are unevenly dispersed in the continuous PC-rich phase and there is no phase-inversion as PPSQ(A) content increases when the percentage of PPSQ(A) is not more than70%. PPSQ(B)-rich spheres are evenly dispersed in the continuous phase (PC-rich) and phaseinversion occurs when PPSQ(B) percentage is up to 70%. Tg of PPSQ(A)/PC or PPSQ(B)/PC at some compositions are lower than that of pure PC due to the enlarged free-volume of PC-rich phase because some spheres of rigid PPSQ chains are included in the PC-rich phase. PC and PPSQ(A) or PPSQ(B)are partially compatible. The compatibility of PC and PPSQ(B) is better than that of PC and PPSQ(A)with high Mw and good ladderlike regularity. Heat history has some influence on the TgS and compatibility of PPSQ(A)/PC and PPSQ(B)/PC blends.

  12. Teaching Geoscience in Place for Local Diversity and Sustainability

    Science.gov (United States)

    Semken, S.

    2008-12-01

    within the Greater Southwest. Field studies are included as often as possible. Students review and discuss the geoscientific context and social implications of selected regional issues such as mining and water management. Courses are open to all and promoted to in-service and pre-service K-12 teachers. Front-end, formative, and summative evaluations use mixed methods based in theories of place attachment and experiential learning. Psychometric surveys of the diverse participants reveal variable prior senses of place and limited correlation with expected predictors such as ethnicity, but pre- and post-surveys show significant relative increases in sense of place. From these data and our qualitative findings (coded from participant observations, analysis of student products, and semi-structured exit interviews) we infer that students' knowledge of and attachments to Southwest places were enhanced by the place-based approach to teaching.

  13. Effect of laser treatment on micro-structure and properties of cast magnesium alloys

    Directory of Open Access Journals (Sweden)

    L.A. Dobrzański

    2009-11-01

    Full Text Available Purpose: The goal of this paper is to present the structure and properties of the cast magnesium alloy after laser treatment.Design/methodology/approach: The laser treatment of magnesium alloys with TiC, WC powders was carried out using a high power diode laser (HDPL. The resulting microstructure in the modified surface layer was examined using optical microscopy, scanning electron microscopy and transmission electron microscope. Phase composition was determined by the X-ray diffraction method using the XPert device. The measurements of hardness and wear resistance of the modified surface layer were also studied.Findings: The region after laser treatment has a fine microstructure with hard carbide particles. Hardness of laser surface layer with both TiC and WC particles was improved as compared to alloy without laser treatment.Research limitations/implications: In this research two powders (WC and TiC were used with the particle size over 5 μm. This investigation presents different laser power by one process speed rates.Practical implications: The results obtained in this investigation were promising towards compared other conventional processes. High Power Diode Laser can be used as an economical substitute of Nd:YAG and CO2 to improve the surface magnesium alloy by feeding the carbide particles.Originality/value: The originality of this work is applying of High Power Diode Laser for alloying of magnesium alloy using hard particles like tungsten and titanium carbides.

  14. Bury my Face in Casting Plaster

    Science.gov (United States)

    Judnick, Don

    1976-01-01

    As part of an introductory course in figure drawing, art students spent some time doing portrait studies and profile drawings. When the teacher threw in an ancedote on life masks, it had a double impact. Students learned to better understand underlying bone structure and facial planes and to create a new art product. (Author/RK)

  15. Special thermite cast irons

    Directory of Open Access Journals (Sweden)

    Yu. Zhiguts

    2008-07-01

    Full Text Available The given paper deals with the problems of the synthesis of cast iron by metallothermy synthesis. On the basis of investigated method of calculations structures of charges have been arranged and cast iron has been synthesized further. Peculiarities metallothermic smelting were found, mechanical properties and structure of received cast iron were investigated and different technologies for cast iron receiving were worked out.

  16. Two Concepts Of Place Competition And Specificity Of Targeting In Place Marketing

    OpenAIRE

    Kirill Rozhkov

    2013-01-01

    This paper demonstrates opportunities for the development of the place marketing theory given by pure model of local expenditures (Tiebout 1956) and concepts of the creative class (Florida 2004) and creative city (Bianchini and Landry 1995). Rethinking them in marketing terms, we then analyze their limitations and show why their re-examining can support competition analysis, targeting, and marketing policy of places. In the discussion section, main directions of theoretical research in place ...

  17. Numerical Modeling of Fluid Flow in the Tape Casting Process

    DEFF Research Database (Denmark)

    Jabbari, Masoud; Hattel, Jesper Henri

    2011-01-01

    The flow behavior of the fluid in the tape casting process is analyzed. A simple geometry is assumed for running the numerical calculations in ANSYS Fluent and the main parameters are expressed in non-dimensional form. The effect of different values for substrate velocity and pressure force on the...

  18. The place of the dream in psychotherapy.

    Science.gov (United States)

    Kaplan, D M

    1989-01-01

    The dream assumed an exceptional place in clinical practice beginning with Freud's extraordinary use of dream interpretation in his early presentations of psychoanalytic theory. Early students of analysis misconstrued this emphasis on the dream in theoretical exposition to apply to clinical practice as well. Eventually this difference was clarified, but there is still something exceptional about the dream in clinical practice that survives clarifications of this early misapprehension. The author reviews the historical issues, identifies the exceptional aspects of the dream in psychoanalytic practice, discusses some problems this phenomenon creates for the analyst, and describes several stereotypical attitudes toward the practice of dream interpretation. PMID:2912513

  19. Thin Wall Iron Castings

    Energy Technology Data Exchange (ETDEWEB)

    J.F. Cuttino; D.M. Stefanescu; T.S. Piwonka

    2001-10-31

    Results of an investigation made to develop methods of making iron castings having wall thicknesses as small as 2.5 mm in green sand molds are presented. It was found that thin wall ductile and compacted graphite iron castings can be made and have properties consistent with heavier castings. Green sand molding variables that affect casting dimensions were also identified.

  20. Walking in Place Through Virtual Worlds

    DEFF Research Database (Denmark)

    Nilsson, Niels Chr.; Serafin, Stefania; Nordahl, Rolf

    2016-01-01

    Immersive virtual reality (IVR) is seemingly on the verge of entering the homes of consumers. Enabling users to walk through virtual worlds in a limited physical space presents a challenge. With an outset in a taxonomy of virtual travel techniques, we argue that Walking-in-Place (WIP) techniques...... constitute a promising approach to virtual walking in relation to consumer IVR. Subsequently we review existing approaches to WIP locomotion and highlight the need for a more explicit focus on the perceived naturalness of WIP techniques; i.e., the degree to which WIP locomotion feels like real walking...

  1. Hot tears in niobium stainless steel investment casting

    International Nuclear Information System (INIS)

    Results concerning hot tears in Niobium stainless steel investment castings were analysed. It was observed that solidification mode is the principal parameter in determining the occurrence of this defect: on the other hand, there was no consistent relationship between Creq/Nieq ratio and its occurrence. (author)

  2. Quantitative comparison of caste differences in honeybee hemolymph.

    Science.gov (United States)

    Chan, Queenie W T; Howes, Charles G; Foster, Leonard J

    2006-12-01

    The honeybee, Apis mellifera, is an invaluable partner in agriculture around the world both for its production of honey and, more importantly, for its role in pollination. Honeybees are largely unexplored at the molecular level despite a long and distinguished career as a model organism for understanding social behavior. Like other eusocial insects, honeybees can be divided into several castes: the queen (fertile female), workers (sterile females), and drones (males). Each caste has different energetic and metabolic requirements, and each differs in its susceptibility to pathogens, many of which have evolved to take advantage of the close social network inside a colony. Hemolymph, arthropods' equivalent to blood, distributes nutrients throughout the bee, and the immune components contained within it form one of the primary lines of defense against invading microorganisms. In this study we have applied qualitative and quantitative proteomics to gain a better understanding of honeybee hemolymph and how it varies among the castes and during development. We found large differences in hemolymph protein composition, especially between larval and adult stage bees and between male and female castes but even between adult workers and queens. We also provide experimental evidence for the expression of several unannotated honeybee genes and for the detection of biomarkers of a viral infection. Our data provide an initial molecular picture of honeybee hemolymph, to a greater depth than previous studies in other insects, and will pave the way for future biochemical studies of innate immunity in this animal. PMID:16920818

  3. Effect of flask vibration time on casting integrity, Surface Penetration and Coating Inclusion in lost foam casting of Al-Si Alloy

    International Nuclear Information System (INIS)

    The paper presents the result of an experimental investigation conducted on medium aluminum silicon alloy casting- LM6, using no-vacuum assisted lost foam casting process. The study is directed for establishing the relationship between the flask vibrations times developed for molded sample on the casting integrity, surface penetration and coating inclusion defects of the casting. Four different flask vibration times namely 180, 120, 90 and 60 sec. were investigated. The casting integrity was investigated in terms of fulfilling in all portions and edges. The surface penetration was measured using optical microscope whilst image analyzer was used to quantify the percentage of coating inclusion in the casting. The results show that vibration time has significant influence on the fulfilling as well as the internal integrity of the lost foam casting. It was found that the lower vibration time produced comparatively sound casing.

  4. Urinary casts

    Science.gov (United States)

    ... necrosis , viral disease (such as CMV nephritis ), and kidney transplant rejection . Waxy casts can be found in people with advanced kidney disease and chronic kidney failure . White blood cell ( ...

  5. The Role of Silicon in the Solidification of High-Cr Cast Irons

    Science.gov (United States)

    Bedolla-Jacuinde, A.; Rainforth, M. W.; Mejía, I.

    2013-02-01

    This work analyzes the effect of different additions of silicon (0 to 5.0 pct) on the structure of a high-Chromium white cast iron, with chromium content of 16.8 pct and carbon 2.56 pct. The alloys were analyzed in both as-cast and heat-treated conditions. Casting was undertaken in metallic molds that yielded solidification rates faster than in commercial processes. Nevertheless, there was some degree of segregation of silicon; this segregation resulted in a refinement in the microstructure of the alloy. Silicon also generated a greater influence on the structure by destabilizing the austenitic matrix, and promoted greater precipitation of eutectic carbides. Above 3 pct silicon, pearlite formation occurred in preference to martensite. After the destabilization heat treatment, the matrix structure of the irons up to 3 pct Si consisted of secondary carbides in a martensitic matrix with some retained austenite; higher Si additions produced a ferritic matrix. The different as-cast and heat-treated microstructures were correlated with selected mechanical properties such as hardness, matrix microhardness, and fracture toughness. Silicon additions increased matrix microhardness in the as-cast conditions, but the opposite phenomenon occurred in the heat-treated conditions. Microhardness decreased as silicon content was increased. Bulk hardness showed the same behavior. Fracture toughness was observed to increase up to 2 pct Si, and then decreased for higher silicon contents. These results are discussed in terms of the effect of eutectic carbides' size and the resulting matrix due to the silicon additions.

  6. Thermo-mechanical phenomena in high speed continuous casting processes

    Science.gov (United States)

    Park, Joong Kil

    Thermo-mechanical phenomena during continuous thin slab casting have been studied with the objectives of understanding the mechanism of mold crack formation, and the effect of mold design upon the mechanical behavior of the stand. To achieve these goals, several finite element models have been developed in conjunction with a series of industrial plant trials. First, an investigation of mold crack formation in thin slab casting was undertaken to elucidate the mechanism by which cracks develop and to evaluate possible solutions to the problem. Three-dimensional finite-element thermal-stress models were developed to predict temperature, distortion, and residual stress in thin-slab casting molds, comparing funnel-shaped to parallel molds. Mold wall temperatures were obtained from POSCO in Korea and analyzed to determine the corresponding heat-flux profiles in thin-slab molds. This data was utilized in an elastic-visco-plastic analysis to investigate the deformation of the molds in service for the two different mold shapes. The results of a metallurgical investigation of mold samples containing cracks were used together with the results of the mathematical models, to determine mechanisms and to suggest solutions for the formation of mold cracks. Large cyclic inelastic strains were found in the funnel transition region just below the meniscus, due to the slightly higher temperature at that location. The cracks appear to have propagated by thermal fatigue caused by major level fluctuations. Next, two-dimensional thermo-elastic-visco-plastic analysis was performed for a horizontal slice of the solidifying strand, which moves vertically down the mold during casting. The model calculates the temperature distributions, the stresses and the strains in the solidifying shell, and the air gap between the casting mold and the solidifying strand. Model predictions were verified with an analytical solution and plant trials that were carried out during billet casting at POSCO. The

  7. Mechanisms and mechanics of porosity formation in ductile iron castings

    Directory of Open Access Journals (Sweden)

    M. Perzyk

    2007-12-01

    Full Text Available Shrinkage defects in ductile iron castings can be of two basic types: shrinkage cavities associated with the liquid contraction prior to the expansion period of the iron as well as the porosity, which may appear even if the liquid shrinkage is fully compensated. In the present paper two possible mechanisms of the porosity are presented and analyzed. The first one is the Karsay’s mechanism based on the secondary shrinkage concept. The second one is the mechanism acting during the expansion period of the iron, first suggested by Ohnaka and co-authors and essentially modified by the present authors. The mechanical interactions between casting and mould are determined for the both mechanisms. Their analysis leads to the conclusion, that porosity forms during expansion period of the melt. The direct cause is the negative pressure which appears in the central part of the casting due to the differences in expansion coefficients of the fast cooling surface layer and slow cooling inner region. Observations concerning feeding behavior of ductile iron castings, based on this mechanism, agree well with industrial practice. The secondary shrinkage is not only needless to induce the porosity, but the corresponding mechanism of its occurrence, proposed by Karsay, does not seem to be valid.

  8. INFLUENCE OF FILM STRUCTURE AND LIGHT ON CHARGE TRAPPING AND DISSIPATION DYNAMICS IN SPUN-CAST ORGANIC THIN-FILM TRANSISTORS MEASURED BY SCANNING KELVIN PROBE MICROSCOPY

    Energy Technology Data Exchange (ETDEWEB)

    Teague, L.; Moth, M.; Anthony, J.

    2012-05-03

    Herein, time-dependent scanning Kelvin probe microscopy of solution processed organic thin film transistors (OTFTs) reveals a correlation between film microstructure and OTFT device performance with the location of trapped charge within the device channel. The accumulation of the observed trapped charge is concurrent with the decrease in I{sub SD} during operation (V{sub G}=-40 V, V{sub SD}= -10 V). We discuss the charge trapping and dissipation dynamics as they relate to the film structure and show that application of light quickly dissipates the observed trapped charge.

  9. Casting Ductile Iron in Layer Moulds Made from Ecological Sands

    Directory of Open Access Journals (Sweden)

    M. Rączka

    2012-09-01

    Full Text Available The article contains the results of tests performed under the target project in Hardtop Foundry Charsznica.The objective of the tests and studies was to develop a technology of making high-quality ductile iron castings, combined witheffective means of environmental protection. The studies presented in this article related to castings weighing from 1 to 300 kg made from ductile iron of grades 400-15 and 500-7, using two-layer moulds, where the facing and core sand was the sand with an alkaline organic binder, while backing sand was the sand with an inorganic geopolymer binder.A simplified method of sand reclamation was applied with possible reuse of the reclaim as an addition to the backing sand. The castiron spheroidising treatment and inoculation were selected taking into account the specific conditions of Hardtop Foundry. A pilot batch of castings was made, testing the gating and feeding systems and using exothermic sleeves on risers. The study confirmed the validity of the adopted concept of making ductile iron castings in layer moulds, while maintaining the content of sand with an organic binder at a level of maximum 15%.

  10. 'Desecration' in a Place of Refuge

    Directory of Open Access Journals (Sweden)

    Diana Glazebrook

    2013-08-01

    Full Text Available In this paper I explore two related questions: how does a particular site come to be perceived as sacred, and what is the impact of the destruction of something sacred when it occurs in a place of ‘refuge’? This study is situated on the island of New Guinea, in the experiences of West Papuan people from the Indonesian Province of Papua (formerly Irian Jaya, living as refugees across the international border in Papua New Guinea. The inquiry is grounded in two instances involving a refugee population in a place of refuge. The first instance involves the burning of a church built by a refugee congregation, and the second involves the large-scale occupation by a refugee population of another people’s land. A doubling effect is intended here. Forced migration can simultaneously render refugees vulnerable to the violence of others, and in the process of resettlement, refugees may have no real choice but to engage in actions that violate the land of others.

  11. The abrasive wear behaviour of alloy cast steel in SiC-water slurry

    Directory of Open Access Journals (Sweden)

    R. Zapała

    2009-10-01

    Full Text Available The results of abrasive wear tests carried out in an environment of SiC-water slurry on four grades of cast steel, i.e. carbon cast steel with microadditions of vanadium, low-alloy L70H2GNM cast steel, and high-alloy L120G13 cast steels, without and with microadditions of vanadium, were discussed. Tests were carried out on a Miller machine. A measure of the abrasive wear resistance was the loss of mass in specimens during 16 hour test cycle. It has been proved that the L120G13 cast steel is definitely less resistant to abrasive wear than its L70H2GNM counterpart. On the other hand, no distinct differences in the abrasive wear resistance were noticed between the L120G13 cast steel without vanadium, and the L120G13 cast steel and carbon cast steel, both with microadditions of vanadium.

  12. Effect of Cyclic Heat Treatment on Cast Structure of TiAl Alloy

    Czech Academy of Sciences Publication Activity Database

    Petrenec, Martin; Vraspírová, E.; Němec, K.; Heczko, Milan

    Zurich : Trans Tech Publications, 2014 - (Pešek, L.; Zubko, P.), s. 222-225 ISBN 978-3-03785-876-9. ISSN 1013-9826. - (Key Engineering Materials. 586). [LMP 2012 International Conference on Local Mechanical Properties /9./. Levoča (SK), 07.11.2012-09.11.2012] R&D Projects: GA ČR(CZ) GAP107/11/0704 Institutional support: RVO:68081723 Keywords : TiAl alloy * cyclic heat treatment * refined cast structure * discontinuous coarsening * microhardness Subject RIV: JL - Materials Fatigue, Friction Mechanics

  13. Hair casts

    Directory of Open Access Journals (Sweden)

    Sweta S Parmar

    2014-01-01

    Full Text Available Hair casts or pseudonits are circumferential concretions,which cover the hair shaft in such a way that, it could be easily removed. They are thin, cylindrical, and elongated in length. We present an unusual case of an 8-year-old girl presenting with hair casts. Occurrence of these is unusual, and they may have varied associations. This patient was suffering from developmental delay. It is commonly misdiagnosed as and very important to differentiate from pediculosis capitis.

  14. Aging of cast duplex stainless steels in LWR systems

    International Nuclear Information System (INIS)

    A program is being conducted to investigate the significance of in-service embrittlement of cast duplex stainless steels under light-water reactor operating conditions. The existing data are evaluated to determine the expected embrittlement of cast components during the operating lifetime of reactors and to define the objectives and scope of the investigation. This presentation describes the status of the program. Data for the metallurgical characterization of the various cast stainless steels used in the investigation are presented. Charpy impact tests on short-term aged material indicate that CF-3 stainless steels are less susceptible to embrittlement than CF-8 or CF-8M stainless steels. Microstructural characterization of cast stainless steels that were obtained from Georg Fischer Co. and aged for up to 70,000 h at 300, 350, and 4000C reveals the formation of four different types of precipitates that are not α'. Embrittlement of the ferrite phase is primarily due to pinning of the dislocations by two of these precipitates, designated as Type M and Type X. The ferrite phase is embrittled after approx. 8 y at 3000C and shows cleavage fracture. Examination of the fracture surfaces of the impact-test specimens indicates that the toughness of the long-term aged material is determined by the austenite phase. 8 figures, 3 tables

  15. Aging of cast duplex stainless steels in LWR systems

    International Nuclear Information System (INIS)

    A program is being conducted to investigate the significance of in-service embrittlement of cast duplex stainless steels operating conditions. The existing data are evaluated to determine the expected embrittlement of cast components during the operating lifetime of reactors and to define the objectives and scope of the investigation. This presentation describes the status of the program. Data for the metallurgical characterization of the various cast stainless steels used in the investigation are presented. Charpy impact tests on short-term aged material indicate that CF-3 stainless steels are less susceptible to embrittlement than CF-8 or CF-8M stainless steels. Microstructural characterization of cast stainless steels that were obtained from Georg Fischer Co. and aged for up to 70 000 h at 300, 350 and 4000C reveals the formation of four different types of precipitates that are not α'. Embrittlement of the ferrite phase is primarily due to pinning of the dislocations by two of these precipitates, designated as Type M and Type X. The ferrite phase is embrittled after proportional 8 y at 3000C and shows cleavage fracture. Examination of the fracture surfaces of the impact test specimens indicates that the toughness of the long-term aged material is determined by the austenitic phase. (orig./HP)

  16. Caste determination through mating in primitively eusocial societies.

    Science.gov (United States)

    Lucas, Eric R; Field, Jeremy

    2013-10-21

    Eusocial animal societies are typified by the presence of a helper (worker) caste which predominantly cares for young offspring in a social group while investing little in their own direct reproduction. A key question is what determines whether an individual becomes a worker or leaves to initiate her own reproduction. In some insects, caste is determined nutritionally during development. In others, and in vertebrate societies, adults are totipotent and the cues that determine caste are less well known. The mate limitation hypothesis (MLH) states that a female's mating status acts as a cue for caste determination: females that mate become reproductives, while those that fail to mate become workers. The MLH is consistent with empirical observations in sweat bees showing that over the course of the nesting season, there are increases in both the proportion of females that become reproductives and the frequency of males in the mating pool. We modelled a foundress's offspring sex-ratio strategy to investigate whether an increasingly male-biased operational sex-ratio over time is evolutionarily stable under the MLH. Our results indicate that such a pattern could occur if early workers were more valuable than late workers. This pattern was then more likely if male mortality was high, if worker mortality was low, if the value of a worker was high and if the period over which workers can help was short. Our results suggest that the MLH can be evolutionarily stable, but only under restrictive conditions. Manipulative experiments are now required to investigate whether mating determines caste in nature. PMID:23770404

  17. Phosphorus segregation in Cr – Mo – V cast steel after regenerative heat treatment

    Directory of Open Access Journals (Sweden)

    G. Golański

    2009-01-01

    Full Text Available The paper presents results of research on the influence of regenerative heat treatment on segregation of phosphorus in Cr – Mo – V cast steels. The material for investigation was L21HMF and G17CrMoV5 – 10 (L17HMF cast steel after long-term operation at elevated temperatures and after the regenerative heat treatment. Concentration of phosphorus on grain boundaries was revealed by the method of etching metallographic specimens with picric acid. Depth of the grain boundaries’ etch was the measure of phosphorus segregation on grain boundaries. Performed research has proved that the concentration of phosphorus on grain boundaries depends not only on the fraction of this impurity in the cast steel, but also on the fraction of carbon and carbide formers, as well as the type of microstructure obtained through heat treatment. It has been shown that the lowest phosphorus segregation on grain boundaries is characteristic of the cast steels with dominant fraction of bainite in the structure. However, the highest concentration of this impurity has been recognized for the structures which were slowly cooled from the austenitization temperatures.

  18. Effect of Topical Fluoride on Surface of Cast Titanium and Nickel-Chromium: An In Vitro Study

    OpenAIRE

    Gayatri Sheena Suvarna; Ramesh Khandurao Nadiger; Omkar Shetty

    2015-01-01

    Objectives: The aim of this in-vitro study was to evaluate the effect of topical fluoride on surface of cast titanium and nickel-chromium.Materials and Methods: Thirty-nine rectangular specimens of titanium (grade 2) and 39 rectangular specimens of nickel-chromium were cast in equal dimensions and divided into three groups of 13 samples each. Group one specimens of titanium and nickel-chromium were placed in 2% neutral sodium fluoride (NaF) solution for 16 minutes. Group two specimens of tita...

  19. Do scheduled caste and scheduled tribe women legislators mean lower gender-caste gaps in primary schooling in India?

    Science.gov (United States)

    Halim, Nafisa; Yount, Kathryn M; Cunningham, Solveig

    2016-07-01

    Despite India's substantial investments in primary schooling, gaps in schooling persist across gender and caste-with scheduled caste and scheduled tribe (SC/ST) girls being particularly disadvantaged. The representation of SC/ST women in state legislatures may help to mitigate this disadvantage. Specifically, because of her intersecting gender and caste/tribe identities, a SC/ST woman legislator might maintain a strong sense of solidarity especially with SC/ST girls and women, and support legislative policies benefitting SC/ST girls. Consequently, for this reason, we expect that living in a district where SC/ST women represent in state legislatures in a higher proportion may increase SC/ST girls' primary school completion, progression and performance. We tested this hypothesis using district-level data between 2000 and 2004 from the Indian Election Commission, the 2004/5 India Human Development Survey, and the Indian Census of 2001. As expected, the representation of SC/ST women in state legislatures was positively associated with SC/ST girls' grade completion and age-appropriate grade progression but was apparent not SC/ST girls' primary-school performance. SC/ST women's representation in state legislatures may reduce gender-caste gaps in primary-school attainment in India. PMID:27194655

  20. Application of digital radiography in evaluation of crack propagation rate in cast steel specimens

    OpenAIRE

    Sikora, R.; B. Piekarski; K. Świadek; R. Chylińska

    2009-01-01

    A technology that utilizes penetrating X-rays is one of the oldest non-destructive testing methods. Digital radiography combines modern digital image processing algorithms with traditional X-ray testing method. The following paper describes the present use of digital radiograms in flaw detection, and the use of identification and classification algorithms in detection of cracks that occur under the effect of thermal fatigue process in creep-resistant steel castings operating as structural ele...

  1. "Knowing your Place in the World:" How Place and Culture Support and Obstruct Educational Aims

    Science.gov (United States)

    Waite, Sue

    2013-01-01

    There is increasing international interest in learning outside the classroom; place-based education is one manifestation of this. In this article, some conceptualisations of place are considered and attention drawn to alignments with habitus at micro, meso and macro levels. I develop a concept of cultural density as an explanatory tool to theorise…

  2. 'EMOTIONAL INTELLIGENCE OF SCHEDULED CASTE STUDENTS IN RELATION TO SELF CONCEPT'

    OpenAIRE

    Mallikarjun H. Krishnakar; SHIVAKUMAR S.CHENGTI

    2012-01-01

    Historically, general caste students have a head-start over the scheduled caste students in terms of awareness, academic orientation and drive for academic fulfillment. Unequal schooling has limited the educational opportunities disadvantaged scheduled caste children in India. Objective of the Study: 1.To studies the relationship between emotional intelligence and self-concept of schedule caste male, female student of higher secondary and secondary school. Hypotheses: 1.There is significant d...

  3. Mechanical Properties - Structure Correlation for Commercial Specification of Cast Particulate Metal Matrix Composites

    Energy Technology Data Exchange (ETDEWEB)

    Pradeep Rohatgi

    2002-12-31

    In this research, the effects of casting foundry, testing laboratory, surface conditions, and casting processes on the mechanical properties of A359-SiC composites were identified. To observe the effects, A359-SiC composites with 20 and 305 SiC particles were cast at three different foundries and tested at three different laboratories. The composites were cast in sand and permanent molds and tested as-cast and machined conditions. To identify the effect of the volume fraction and distribution of particles on the properties of the composites, particle distribution was determined using Clemex Image analysis systems, and particle volume fraction was determined using wet chemical analysis and Clemex Image analysis systems. The microstructure and fractured surfaces of the samples were analyzed using SEM, and EDX analysis was done to analyze chemical reaction between the particles and the matrix. The results of the tensile strengths exhibited that the tensile strengths depend on the density and porosity of the composites; in general the higher tensile strength is associated with lower porosity and higher density. In some cases, composites with lower density were higher than these with higher density. In the Al-20% SiC samples, the composites with more inclusions exhibited a lower tensile strength than the ones with fewer inclusions. This suggests that macroscopic casting defects such as micro-porosity, shrinkage porosity and inclusions appear to strongly influence the tensile strength more than the microstructure and particle distribution. The fatigue properties of A359/20 vol.% SiC composites were investigated under strain controlled conditions. Hysteresis loops obtained from strain controlled cyclic loading of 20% SiCp reinforced material did not exhibit any measurable softening or hardening. The fatigue life of Al-20% SiC heat treated alloy at a given total strain showed wide variation in fatigue life, which appeared to be related to factors such as inclusions

  4. Biosecurity in a global market place

    International Nuclear Information System (INIS)

    International travel and free trade are modern bywords and the international movement of people, animals and livestock products seen as essential for the global market place to function. Yet is this compatible with a national bio-secure environment? Governments around the world seek to manage the risks posed by infectious disease to livestock, man, the environment and related ecosystems whilst at the same time permitting free trade. Ample examples exist of these competing elements as illustrated by recent outbreaks of avian influenza, bluetongue, severe acute respiratory syndrome (SARS) and most recently in Australia, equine influenza. Whilst the recognition that some 70% of new infectious diseases in man come from animals, even those diseases that affect only animals such as foot and mouth disease, can have devastating effects on trade and economies. The word 'biosecurity' now encompasses most of these elements with processes being developed to identify, mitigate or eliminate these biosecurity risks, and ultimately to prevent adverse events. An added dimension to be considered recently is that of bio-terrorism. So is it time for a new global co-ordinated and collaborative approach to managing biosecurity that recognises the need to encourage not restrict, the global market place? Are there newer approaches that could encourage global trade in livestock and livestock products? One such strategy could be to consider the biosecurity risks of the commodity as opposed to the disease status of the country of origin as a more effective approach for the future. (author)

  5. Ductile iron castings fabricated using metallic moulds

    International Nuclear Information System (INIS)

    The features and suitability of high requirements ductile iron castings production using metallic moulds have been studied in the present work. The structural and mechanical properties of the produced castings have been analysed and compared to the corresponding ones but fabricated using green sand moulds according to a conventional production process. The higher cooling rate in the metallic moulds is the main cause for the appearance of the detected structural changes in castings. The mechanical and microstructural properties obtained directly on castings are remarkable due to the higher nodule count among other factors. Finally, the benefits and inconveniences found in this kind of production methodology using metallic moulds are also discussed. (Author)

  6. Place Marketing Implementation in Different Administrative Subdivisions: Estonian Case Study

    Directory of Open Access Journals (Sweden)

    Andres Agan

    2013-01-01

    Full Text Available The principal scope of this paper is to construct the chain-of-marketing that regards the implementation of a place marketing strategy, in particular regional tourism and development policy. For a few decades place marketing has been mostly a marketing viewpoint for urban areas in the context of tourism in cities or metropols. Smaller rural areas and country-sides have not got so much attention and place marketing is not much used as a strategic tool to improve development in such areas. Place marketing is usually seen as a tourism improvement for tourists, but actually the target audience is much wider. The starting point of the paper was the assumption that the quality of place marketing in these rural areas is not good and strategically elaborated. By comparing three different case studies, Tartu Rural Development Association (Example 1, 4P area in Central-Estonia (Example 2 and Attractions in Municipality of Konguta (Example 3, worst and best practices have been identified, and an answer to the question whether there exists such a thing as ideally sized and structured geographical area that deals with place marketing on the regional level has been sought

  7. High temperature strength of ceramic moulds applied in the investment casting method

    OpenAIRE

    J. Kolczyk; Zych, J.

    2011-01-01

    Ceramic casting moulds strength is an important factor, which influences the quality and properties of castings being produced by the investment casting method. It is especially important during mould pouring with liquid metal. Studies allowing determining the casting mould strength at high temperatures, that means at the ones at which the moulds are poured, are not numerous. None generally accepted (normalized) method for the assessment of such strength exists in practice. The new method of ...

  8. Some problems in the production of ductile irons by investment casting

    OpenAIRE

    Yu Bo; Cai Qizhou; Wei Bokang

    2008-01-01

    Because of the excellent performance of ductile irons and the unique superiority of investment casting, the preparation of complicated and thin-wall ductile iron castings by investment casting shows a good development prospect. In this present work, combined with the actual product experiments, the characteristics of shell making, spheroidization, inoculation and defect prevention are presented, and some suggestions are given for investment casting of ductile iron.

  9. Some problems in the production of ductile irons by investment casting

    Directory of Open Access Journals (Sweden)

    Yu Bo

    2008-02-01

    Full Text Available Because of the excellent performance of ductile irons and the unique superiority of investment casting, the preparation of complicated and thin-wall ductile iron castings by investment casting shows a good development prospect. In this present work, combined with the actual product experiments, the characteristics of shell making, spheroidization, inoculation and defect prevention are presented, and some suggestions are given for investment casting of ductile iron.

  10. New developments in high quality grey cast irons

    Directory of Open Access Journals (Sweden)

    Iulian Riposan

    2014-07-01

    Full Text Available The paper reviews original data obtained by the present authors, revealed in recent separate publications, describing specific procedures for high quality grey irons, and reflecting the forecast needs of the worldwide iron foundry industry. High power, medium frequency coreless induction furnaces are commonly used in electric melting grey iron foundries. This has resulted in low sulphur (1,500 °C, contributing to unfavourable conditions for graphite nucleation. Thin wall castings are increasingly produced by these electric melt shops with a risk of greater eutectic undercooling during solidification. The paper focused on two groups of grey cast irons and their specific problems: carbides and graphite morphology control in lower carbon equivalent high strength irons (CE=3.4%-3.8%, and austenite dendrite promotion in eutectic and slightly hypereutectic irons (CE=4.1%-4.5%, in order to increase their strength characteristics. There are 3 stages and 3 steps involving graphite formation, iron chemistry and iron processing that appear to be important. The concept in the present paper sustains a threestage model for nucleating flake graphite [(Mn,XS type nuclei]. There are three important groups of elements (deoxidizer, Mn/S, and inoculant and three technological stages in electric melting of iron (superheat, pre-conditioning of base iron, final inoculation. Attention is drawn to a control factor (%Mn x (%S ensuring it equals to 0.03 – 0.06, accompanied by 0.005wt.%–0.010wt.% Al and/or Zr content in inoculated irons. It was found that iron powder addition promotes austenite dendrite formation in eutectic and slightly eutectic, acting as reinforcement for the eutectic cells. But, there is an accompanying possible negative influence on the characteristics of the (Mn,XS type graphite nuclei (change the morphology of nuclei from polygonal compact to irregular polygonal, and therefore promote chill tendency in treated irons. A double addition (iron

  11. New developments in high quality grey cast irons

    Institute of Scientific and Technical Information of China (English)

    Iulian Riposan; Mihai Chisamera; Stelian Stan

    2014-01-01

    The paper reviews original data obtained by the present authors, revealed in recent separate publications, describing speciifc procedures for high quality grey irons, and relfecting the forecast needs of the worldwide iron foundry industry. High power, medium frequency coreless induction furnaces are commonly used in electric melting grey iron foundries. This has resulted in low sulphur (1,500 °C), contributing to unfavourable conditions for graphite nucleation. Thin wall castings are increasingly produced by these electric melt shops with a risk of greater eutectic undercooling during solidiifcation. The paper focused on two groups of grey cast irons and their speciifc problems: carbides and graphite morphology control in lower carbon equivalent high strength irons (CE=3.4%-3.8%), and austenite dendrite promotion in eutectic and slightly hypereutectic irons (CE=4.1%-4.5%), in order to increase their strength characteristics. There are 3 stages and 3 steps involving graphite formation, iron chemistry and iron processing that appear to be important. The concept in the present paper sustains a three-stage model for nucleating flake graphite [(Mn,X)S type nuclei]. There are three important groups of elements (deoxidizer,Mn/S, and inoculant) and three technological stages in electric melting of iron (superheat, pre-conditioning of base iron, ifnal inoculation). Attention is drawn to a control factor (%Mn) x (%S) ensuring it equals to 0.03- 0.06, accompanied by 0.005wt.%-0.010wt.% Al and/or Zr content in inoculated irons. It was found that iron powder addition promotes austenite dendrite formation in eutectic and slightly eutectic, acting as reinforcement for the eutectic cells. But, there is an accompanying possible negative influence on the characteristics of the (Mn,X)S type graphite nuclei (change the morphology of nuclei from polygonal compact to irregular polygonal, and therefore promote chill tendency in treated irons). A double addition (iron powder + inoculant

  12. The structure and mechanical properties of pearlitic-ferritic vermicular cast iron

    Directory of Open Access Journals (Sweden)

    E. Guzik

    2012-01-01

    Full Text Available The results of studies on the use of magnesium alloy in modern Tundish + Cored Wire injection method for production of vermicular graphite cast irons were described. The injection of Mg Cored Wire length is a treatment method which can be used to process iron melted in an electric induction furnace. This paper describes the results of using a high-magnesium ferrosilicon alloy in cored wire for the production of vermicular graphite cast irons at the; Tundish + Cored Wire to be injected methods (PE for pearlitic-ferritic matrix GJV with about 25 %ferrite content. The results of calculations and experiments have indicated the length of the Cored Wire to be injected basing on the initial sulfur content and weight of the treated melt. The paper presents a microstructure matrix and vermicular graphite in standard sample and different walled castings. The results of numerous trials have shown that the magnesium Tundish + PE Method process can produce high quality vermicular graphite irons under the specific industrial conditions of the above mentioned foundries.

  13. Effect of Ablation Casting on Microstructure and Casting Properties of A356 Aluminium Casting Alloy

    Institute of Scientific and Technical Information of China (English)

    V.Bohlooli; M.Shabani Mahalli; S.M.A.Boutorabi

    2013-01-01

    Recently the Ablation Casting Technology was invented as a new casting process to improve foundry products quality.In this study,the effects of processing variables on the porosity content,microstructure and feedability of A356 casting alloy were investigated.Secondary dendrite arm spacing (SDAS) and eutectic silicon morphologies were studied to evaluate the influence of Ablation Casting on the microstructure.Casting density was measured in order to identify porosity content and feedability of ablated and non-ablated specimens.In addition,solidification behavior of the samples was investigated by using thermal analysis technique.The cooling curves and the first derivative curves were plotted and compared with each other.Results showed the ablation process could increase solidification rate significantly.In addition,the microstructural evidences revealed that Ablation Casting process results in more fine and homogeneous structure compared to the nonablated casting.The feedability improved,SDAS reduced to 35% and porosity content decreased to 3.84 vol.% by implementing this process.It concluded the Ablation Casting is an effective process to gain higher quality in aluminum foundry.

  14. Cast-to-cast variation in end-plug welds for TRIGA fuel elements

    International Nuclear Information System (INIS)

    In the Institute for Nuclear Research (INR) Pitesti - TRIGA Reactor Department there are under development activities for assembling TRIGA-LEU fuel elements locally manufactured, through autogenous Tungsten-Inert-Gas (TIG) welding. Due to specific problems occurring in welding Ni alloys, namely the dissimilar joint between Inconel 600 and Inconel 800 at the end-plug weld, weldability tests on Inconel 600 under various conditions were performed. The tests had been carried out in two stages: basic tests, on simple turned rods of Inconel 600; confirmation tests, on real (actual) end plug –to – clad welding. The basic tests had been done on simple rods machined (turned) at 13.8 mm (main diameter of the plugs) on which there have been made simple semicircular weldings ( no joint involved). Confirmation tests were done on the plug-clad assembly (dissimilar welding Incoloy-Inconel), with the welding parameters resulted from the preliminary conclusions of the basic tests. After welding, the samples were transversally sectioned, prepared for metallographic examination according to the specific procedure. The samples were examined at the metallographic microscope, and photo records for each sectioned welding bead have been taken . Measurements have been made on the recorded photos resulting the essential characteristics of the penetration: width W, depth d and ratio W/d. From the obtained results the following conclusions can be formulated: the penetration depth of the end-plug weld at the TRIGA fuel element varies substantially depending on the material cast of which the plug is produced; the optimization tests had covered the whole range of parameters in which do not appear systematic defects in welds that are specific to the alloys of Nickel ( porosity, hot cracking); for 2011-2012 casts higher energy (640 As) is required compared to the welding energy used for the 2009 batch, but to be sure that the manufacturing requirements are fulfilled, it is necessary to carry

  15. Lost-Wax Casting in Ancient China: New Discussion on Old Debates

    Science.gov (United States)

    Zhou, Weirong; Huang, Wei

    2015-07-01

    The possible use of lost-wax casting in China has long been a matter of controversy. Based on the study of pertinent ancient texts concerning the technical origins of lost-wax casting in China, direct examination of questioned ancient Chinese bronzes as well as definite lost-wax castings from both overseas and China, and modern production of objects using piece-mold casting, the authors point out their own conceptual ideas about ancient lost-wax casting as follows. First, the lost-wax casting technique does not have its earliest origins in ancient China but rather from the Sumerians in Mesopotamia, where it was predominantly used to cast small human and animal figures (statuettes). Next, some essential characteristics of the lost-wax casting technique can be identified from the point of view of a distortable soft starting model. The locally deformed shape of lost-wax castings is found to be variable. Finally, it is improper to consider the ease of extraction from the mold as the criterion for distinguishing lost-wax casting from piece-mold casting. It is therefore incorrect to conclude that the three-dimensional openwork decorations present on Chinese bronzes from the Spring and Autumn Period, and the Warring States Period, are fabricated using lost-wax castings.

  16. Autonomous Optimization of a Solidification Pattern and Its Effect on Porosity and Segregation in Steel Castings

    DEFF Research Database (Denmark)

    Kotas, Petr; Tutum, Cem Celal; Hattel, Jesper Henri

    2011-01-01

    distribution. This was accomplished by coupling a casting simulation software package with an optimization module. The casting process of the original casting design was simulated using a transient 3D thermal model incorporated in a commercial simulation software package to determine potential flaws...

  17. Solid-particle erosion behavior of cast alloys used in the mining industry

    Institute of Scientific and Technical Information of China (English)

    Hakan Atapek; Sinan Fidan

    2015-01-01

    The erosive-wear response of five commercial ferrous-based cast alloys used for crushing was examined in this study. The micro-structures of the alloys were modified to elucidate the effect of microstructural features on wear. Erosion tests were conducted using alumi-num oxide particles (90–125 µm) at 70 m/s and a normal impact angle (90°). The worn surfaces were characterized by scanning electron mi-croscopy and 3D non-contact laser profilometry. It is found that (i) a pearlitic structure exhibiting a greater plastic deformation than both bainitic and martensitic structures shows the greatest resistance to erosive wear at normal impact and (ii) the fracture characteristics of car-bide and graphite particles plays an important role in determining the erosion wear behavior of the cast alloy matrices.

  18. CA Investment Casting Process of Complex Castings

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    CA (Computer aided) investment casting technique used in superalloy castings of aerospace engine parts was presented. CA investment casting integrated computer application, RP (Rapid Prototyping) process, solidification simulation and investment casting process. It broke the bottle neck of making metal die. Solid model of complex parts were produced by UGII or other software, then translated into STL(Stereolithography) file, after RP process of SLS(Selective Laser Sintering), wax pattern used in investment ...

  19. Improvement of Structure and Properties of Cast Ferrite-Pearlite Steels for Freight Railway Cars

    Directory of Open Access Journals (Sweden)

    A. Rabinovich

    2008-03-01

    Full Text Available As it i s known For increasing of propcnics (YTS 2 380 MPa of cast stcds i t is c f k ~ i v tco incrcasc conlcnt o f alhsti~uiionaal lloyingclcrncnts, (Si, Mn, Cr, Ni. 1 lowevcr it lcads to rising in pricc olstccl ton. lncrcasing of Si and Mn conrcnl only is limitcd hy decreasing o lductility and weld nhility. As a rule silicon contcnt at ~hcsca ccls is not highcr than 0.4-0.67'0 and Si:Mn ratio is not highcr khan 1:2. Nowfor grain rcfincmcnt ~wc sin oculation of stcct by nitrogcn and clcincnrs with high chcmical affinity to nltmgcn. Mostly vanadium i s usd.howcvcr niobium sornctime is uscd. Dissldvantagcs of this arc high cost of alloying clcmcnrs and low thcrrnodynamic stability OFvanadium and niobium nitridcs. Parlicles of V(C,N and Nh(C.N dissolvc during hcating fnr licnt trcatmcnt or during wclding. It [cads lodccrcasing of grain refinement elfcc!.Adaptat ion or this microalloying stratcgy Tor casts producing For rrcight mil way cars let cstirnatc possibility of application thcsc casts in ancw gcnerazion freight railway cars.

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

    Directory of Open Access Journals (Sweden)

    R. Władysiak

    2012-04-01

    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.

  1. Physiology as a caste-defining feature

    OpenAIRE

    Robinson, E. J. H.

    2009-01-01

    Division of labour is a key factor in the ecological success of social insects. Groups of individuals specializing on a particular behaviour are known as castes and are usually distinguished by morphology or age. Physiology plays a key role in both these types of caste, in either the developmental physiology which determines morphology, or the temporal changes in physiology over an insect's life. Physiological correlates of morphological or temporal caste include differences in gland structur...

  2. Health promoting factors in public work places

    Directory of Open Access Journals (Sweden)

    Ylva Fjell

    2008-03-01

    Full Text Available

    Objectives: The main objective of this study was to explore potential health-promoting work factors and their specific associations with self-rated general and mental health, life satisfaction, and low levels of musculoskeletal pain among women and men employed in the public sector.

    Methods: A questionnaire based survey was conducted among 2523 public employees (87% women in 124 work places. The workplaces were distributed between five occupational sectors: the provincial hospital, schools, home care services, domestic/catering, and administrative services. The response rate was 92%. Analyses of variance were used to compare the mean scores of the groups. Spearman’s rank correlation test was used to assess the associations between the work factors and the health measures.

    Results:Many of the potential health promoting work factors were associated with the measures of self-rated health. However the correlations differed according to both gender and occupational sector. The main differences between the sectors were the characteristics of decision latitude-influence and learningdevelopment with the best conditions in the administrative services and schools, and the worst in home care services. Men rated higher in decision latitude-influence than women and had significantly better “opportunities to learn new and to develop in the profession”. Having enough time to complete the work tasks had the highest overall correlation with good health. In addition good relations with and support of supervisors were crucial for well-being among the employees.

    Conclusions: The results highlight the importance of high levels of decision latitude-influence, learningdevelopment, and a fair and impartial attitude among supervisors for the promotion of good health in public work places.

  3. Power plant waste disposals in open-cast mines

    Energy Technology Data Exchange (ETDEWEB)

    Herstus, J.; Stastny, J. [AGE s.r.o. - Aplikovana Geotechnika a Ekologie, Thamova (Czechoslovakia)

    1995-12-01

    High population density in Czech Republic has led, as well as in other countries, to strong NIMBY syndrome influencing the waste disposal location. The largest thermal power plants are situated in neighborhood of extensive open-cast brown coal mines with huge area covered by tipped clayey spoil. Such spoil areas, technically almost useless, are potential space for power giant waste disposal position. There are several limitations, based on specific structural features of tipped clayey spoil, influencing decision to use such area as site for waste disposal. Low shear strength and extremely high compressibility belong to the geotechnical limitations. High permeability of upper ten or more meters of tipped spoil and its changes with applied stress level belongs to transitional features between geotechnical and environmental limitations. The problems of ash and FGD products stabilized interaction with such subgrade represent environmental limitation. The paper reports about the testing procedure developed for thickness and permeability estimation of upper soil layer and gives brief review of laboratory and site investigation results on potential sites from point of view of above mentioned limitations. Also gives an outline how to eliminate the influence of unfavorable conditions.

  4. Temperature-induced anomalous structural changes of Al-12wt.%Sn-4wt.%Si melt and its influence on as-cast structure

    Directory of Open Access Journals (Sweden)

    Wang Zhiming

    2010-05-01

    Full Text Available The temperature dependence of the viscosity of liquid Al-12wt.%Sn-4wt.%Si was studied with a high-temperature viscosity apparatus. Anomalous changes of viscosity of the melt were found at 1,103 K and 968 K in the cooling process, which indicates anomalous structural changes of the melt. It is calculated that the anomalous structural change is associated with an abrupt decrease of atomic clusters’ size and activation energy in the melt. According to the temperature of the anomalous structural changes, melt heat treatment process (quenching from superheat to pouring temperature was performed on Al-12wt.%Sn-4wt.%Si melt prior to pouring, aimed to keep the small atomic clusters from higher temperature to lower pouring temperature. The results suggest that relatively small atomic clusters at the pouring temperature in the melt could generate a deep under-cooling of nucleation in the subsequent solidification process, and refine the as-cast structure. After being quenched from superheating to pouring temperature, the relatively small atomic clusters, especially the Si-Si clusters in the melt will grow to equilibrium state (relatively big atomic clusters with holding time, resulting in the prominent coarsening of the Si morphology in the as-cast structure.

  5. Replication of specifically microstructured surfaces in A356-alloy via lost wax investment casting

    International Nuclear Information System (INIS)

    A common way of realizing microstructural features on metallic surfaces is to generate the designated pattern on each single part by means of microstructuring technologies such as e.g. laser ablation, electric discharge machining or micromilling. The disadvantage of these process chains is the limited productivity due to the additional processing of each part. The approach of this work is to replicate microstructured surfaces from a master pattern via lost wax investment casting in order to reach a higher productivity. We show that microholes of different sizes ( 15–22 µm at depths of 6–14 µm) can be replicated in AlSi7Mg-alloy from a laser-structured master pattern via investment casting. However, some loss of molding accuracy during the multi-stage molding process occurs. Approximately 50% of the original microfeature's heights are lost during the wax injection step. In the following process step of manufacturing a gypsum-bonded mold, a further loss in the surface quality of the microfeatures can be observed. In the final process step of casting the aluminum melt, the microfeatures are filled without any loss of molding accuracy and replicate the surface quality of the gypsum mold. The contact angle measurements of ultrapure water on the cast surfaces show a decrease in wettability on the microstructured regions (75°) compared to the unstructured region (60°)

  6. Social marketing: its place in public health.

    Science.gov (United States)

    Ling, J C; Franklin, B A; Lindsteadt, J F; Gearon, S A

    1992-01-01

    This review of the public health role of social marketing begins by tracing the history of social marketing and noting that social marketing adopts the traditional marketing framework of product, price, place, and promotion and embraces several methods of commercial marketing as well as consumer research. However, no universally acknowledged definition exists. A review of the literature is divided into three time periods representing early theoretical development, the evaluation of experiences, and increasing acceptance. Concerns about social marketing are discussed in terms of ethics, disempowerment, and the commercialization of health information. Examples of social marketing are then provided from developing countries and are analyzed in groupings defined as tangible products, sustained health practices, and service utilization. Practitioners' views and concerns are also reviewed. The strengths of social marketing include knowledge of the audience, systematic use of qualitative methods, use of incentives, closer monitoring, strategic use of the mass media, realistic expectations, aspiring to high standards, and recognition of price. Weaknesses of social marketing include its time, money, and human requirements; the fact that marketing elements are missing (public health lacks the flexibility to adjust products and services to clients' interests and preferences); and the potential serious impact on the future of Public Service Announcements, which may die out because social marketers pay for air time. After placing social marketing in context with other practices designed to achieve social change, the review ends with the prediction that the public health role of social marketing is likely to increase. The World Health Organization's recent call for health promotion and the UN Children's Fund's social mobilization actions are provided as examples of this increased role. It is noted, however, that social marketing alone cannot solve public health problems. PMID

  7. MAGMAsoft simulation applied in verification of technology to produce new range of alloy steel castings

    Directory of Open Access Journals (Sweden)

    A. Gwiżdż

    2010-07-01

    Full Text Available The article presents the results of MAGMAsoft application in simulation of the pouring and solidfication of castings made fromGS20Mn5 steel, basing on some principles adopted in the starting technology. The results of simulation were disclosed in the form of 3Ddrawings, showing the technology of pouring, selected stages of solidification, and porosity in castings made by the examined technology. Using simulation results, some modifications were introduced to the pouring technology, the simulation was repeated, and the results obtained for the technology before and after the modification were compared. Based on the guidelines provided in new technology, the pattern tooling was made. The process of mould preparation was described, along with the process of steel melting and pouring. Castings made by the new technology were X-rayed and subjected to heat treatment according to the newly developed cycle. Together with the main casting, test wedges were poured. Mechanical tests and structure examinations were performed. The results of the tests and investigations were evaluated.

  8. Safety Training: places available in October 2014

    CERN Multimedia

    2014-01-01

    There are places available in the forthcoming Safety courses. For updates and registrations, please refer to the Safety Training Catalogue. Safety Training, HSE Unit safety-training@cern.ch Title of the course EN Title of the course FR Date Hours Language Chemical Safety ATEX Habilitation - Level 2 Habilitation ATEX - Niveau 2 16-Oct-14 to 17-Oct-14 9:00 - 17:30 French Cryogenic Safety Cryogenic Safety - Fundamentals Sécurité Cryogénie - Fondamentaux 23-Oct-14 10:00 - 12:00 English Cryogenic Safety - Helium Transfer Sécurité Cryogénie - Transfert d'hélium 30-Oct-14 9:30 - 12:00 English Electrical Safety Habilitation Electrique - Electrician Low Voltage - Initial Habilitation électrique - Électricien basse tension - Initial 02-Oct-14 to 06-Oct-14 9:00 - 17:30 English 20-Oct-14 to 22-Oct-14 9:00 -...

  9. Materials for Advanced Ultrasupercritical Steam Turbines Task 4: Cast Superalloy Development

    Energy Technology Data Exchange (ETDEWEB)

    Thangirala, Mani

    2015-09-30

    The Steam Turbine critical stationary structural components are high integrity Large Shell and Valve Casing heavy section Castings, containing high temperature steam under high pressures. Hence to support the development of advanced materials technology for use in an AUSC steam turbine capable of operating with steam conditions of 760°C (1400°F) and 35 Mpa (5000 psia), Casting alloy selection and evaluation of mechanical, metallurgical properties and castability with robust manufacturing methods are mandated. Alloy down select from Phase 1 based on producability criteria and creep rupture properties tested by NETL-Albany and ORNL directed the consortium to investigate cast properties of Haynes 282 and Haynes 263. The goals of Task 4 in Phase 2 are to understand a broader range of mechanical properties, the impact of manufacturing variables on those properties. Scale up the size of heats to production levels to facilitate the understanding of the impact of heat and component weight, on metallurgical and mechanical behavior. GE Power & Water Materials and Processes Engineering for the Phase 2, Task 4.0 Castings work, systematically designed and executed casting material property evaluation, multiple test programs. Starting from 15 lbs. cylinder castings to world’s first 17,000 lbs. poured weight, heavy section large steam turbine partial valve Haynes 282 super alloy casting. This has demonstrated scalability of the material for steam Turbine applications. Activities under Task 4.0, Investigated and characterized various mechanical properties of Cast Haynes 282 and Cast Nimonic 263. The development stages involved were: 1) Small Cast Evaluation: 4 inch diam. Haynes 282 and Nimonic 263 Cylinders. This provided effects of liquidus super heat range and first baseline mechanical data on cast versions of conventional vacuum re-melted and forged Ni based super alloys. 2) Step block castings of 300 lbs. and 600 lbs. Haynes 282 from 2 foundry heats were evaluated which

  10. Effect of combined electromagnetic fields on surface quality and structure of a HDC casting 5182 Al alloy ingot

    Institute of Scientific and Technical Information of China (English)

    Qingfeng ZHU; Zhihao ZHAO; Yubo ZUO; Xiangjie WANG; Jianzhong CUI

    2012-01-01

    5182 Al alloy ingots with the diameters of 100 mm are produced by conventional and combined electromagnetic fields (CEMF) horizontal direction chill (HDC) casting process.The effect of CEMF on the ingot surface quality and floating grains is investigated.The results show that the CEMF is effective in reducing the segregation layer in both top and bottom sub-surfaces.Big floating grains with coarse dendrite arms mainly distribute in the crescent-shaped area near the bottom in the conventional HDC casting ingot.With the application of the CEMF,they disappear in the whole cross section of the HDC casting ingot and the equiaxed grains are significantly refined.

  11. Centrifugally cast for top performance

    International Nuclear Information System (INIS)

    Centrifugally cast nickel-chromium alloy components, supplied by Fahralloy-Wisconsin Ltd. are being used for the lattice tubes in CANDU reactors. Horizontal centrifugal casting facilities enable tubular shapes to be made with outside diameters of 3 to 23 in.; lengths of up to 162 in. A unique feature of horizontal casting is that the mechanical properties are the same in all directions. The structure is also completely homogeneous and combines characteristically high resistance to heat and corrosion with enhanced physical and mechanical properties. (R.A.)

  12. Safety Training: places available in May 2013

    CERN Document Server

    Isabelle CUSATO, HSE Unit

    2013-01-01

    There are places available in the forthcoming Safety courses. For updates and registrations, please refer to the Safety Training Catalogue.   May 2013 (alphabetical order) Conduite de chariots élévateurs (driving of forklifts) 06-MAY-13 to 07-MAY-13, 8.30 – 17.30, in French with handouts in English Self Rescue Mask Training 02-MAY-13, 8.30 – 10.00, in English 02-MAY-13, 10.30 – 12.00, in English 07-MAY-13, 8.30 – 10.00, in French 07-MAY-13, 10.30 – 12.00, in English 14-MAY-13, 8.30 – 10.00, in French 14-MAY-13, 10.30 – 12.00, in French 16-MAY-13, 8.30 – 10.00, in English 16-MAY-13, 10.30 – 12.00, in English 21-MAY-13, 8.30 – 10.00, in French 21-MAY-13, 10.30 – 12.00, in French 23-MAY-13, 8.30 – 10.00, in English 23-MAY-13, 10.30 – 12.00, in English 28-MAY-13, 8.30 – 10.00, in French 28-MAY-13, 10.30 – 12.00, in French 30-MAY-1...

  13. Improved material properties of solution-cast starch films: effect of varying amylopectin structure and amylose content of starch from genetically modified potatoes

    OpenAIRE

    Menzel, Carolin; Andersson, Mariette; Andersson, Roger; Vázquez Gutiérrez, José Luis; Daniel, Geoffrey; Langton, Maud; Gällstedt, Mikael; Koch, Kristine

    2015-01-01

    High-amylose potato starches were produced through genetic modification resulting in changed granule morphology and composition, with higher amylose content and increased chain length of amylopectin. The increased amylose content and structural changes in amylopectin enhanced film-forming behavior and improved barrier and tensile properties in starch films. The molecular structure in these starches was related to film-forming properties. Solution-cast films of high-amylose starch revealed a h...

  14. Safety Training: places available in February

    CERN Multimedia

    DGS Unit

    2012-01-01

    There are places available in the forthcoming Safety courses. For updates and registrations, please refer to the Safety Training Catalogue. FEBRUARY 2012 (alphabetical order) Conduite de Plates-Formes Elevatrices Mobiles de Personnel (PEMP) / Cherry-picker driving : 09-FEB-12 au 10-FEB-12, 08.00 – 17.30, in French (with possibility to have handouts in English) Magnetic Fields : 03-FEB-12, 9.30 – 12.00, in French Self-rescue mask : 02-FEB-12, 8.30 – 10.00, in French 02-FEB-12, 10.30 – 12.00, in English 07-FEB-12, 8.30 – 10.00, in French 07-FEB-12, 10.30 – 12.00, in English 14-FEB-12, 8.30 – 10.00, in French 14-FEB-12, 10.30 – 12.00, in English 16-FEB-12, 8.30 – 10.00, in French 16-FEB-12, 10.30 – 12.00, in English 21-FEB-12, 8.30 – 10.00, in French 21-FEB-12, 10.30 – 12.00, in English 28-FEB-12, 8.30 – 10.00, in French 28-FEB-12, 10.30 – 12.00, in English Radiologic...

  15. Detection by ultrasonic waves of discontinuities in cast steels and weldings of austenitic stainless steels

    International Nuclear Information System (INIS)

    The study of discontinuities in cast iron and austenitic weldings by means of ultrasound is extremely difficult when materials present rough structures. By virtue of the necessity existing in nuclear power plants and others, of verify to the integrity of cast pieces an austenitic weldings, such a verification is being studying at global level. Materials with a rough grain structure, frequently present in industry, are: bombs to moving fluids, pipe fittings, elbows and austenitic weldings. This problem, traditionally, has been studied varying the frequency in gropers. A new approach will be presented here, based in the use of the high sensibility of the equipment and piezoelectric tablet, as well as the maximum withdrawal of perturbation zone in X-ray tube (Author)

  16. Safety Training: places available in March

    CERN Multimedia

    HSE Unit

    2012-01-01

    There are places available in the forthcoming Safety courses. For updates and registrations, please refer to the Safety Training Catalogue. MARCH 2012 (alphabetical order, titles of courses in the original language) Echafaudages, réception et conformité (Scaffolding, reception and conformity): From 29-FEB-12 to 02-MAR-12, 09.00 – 17.30, in French (in Domarin, dept. 38) Laser Users : 09-MAR-12, 09.00 – 12.30, in English Self-Rescue Mask training : 08-MAR-12, 08.30 – 10.00, in French 08-MAR-12, 10.30 – 12.00, in English 13-MAR-12, 08.30 – 10.00, in French 13-MAR-12, 10.30 – 12.00, in English 20-MAR-12, 08.30 – 10.00, in French 20-MAR-12, 10.30 – 12.00, in English 22-MAR-12, 08.30 – 10.00, in French 22-MAR-12, 10.30 – 12.00, , in English 27-MAR-12, 08.30 – 10.00, in French 27-MAR-12, 10.30 – 12.00, in English Habilitation électrique pour Electriciens en b...

  17. Influence of selected parameters of AlSi/CrFeC composite castings manufacturing on the resulted structure

    Directory of Open Access Journals (Sweden)

    A. Dulęba

    2012-05-01

    Full Text Available Purpose: The main aim of studies was to determine influence: size of reinforcing particles, frequency and the current intensity on the morphology of reinforcing phase precipitates in AlSi11/CrFe30C8 composites castings produced of rotating electromagnetic field.Design/methodology/approach: In this paper the technology of AlSi11/CrxCy composites produced with Cr30Fe8C ex situ particles is described. Technological conception of investigations was based on assumption that Cr-Fe matrix of particles dissolved in Al-Si composite matrix and carbide phases became actual reinforcement of the composite.Findings: The results of investigations and their analysis shown, that contribution of these variables parameters essentially influence on the morphology of reinforcing phase. On the basis of analysis results determined the most effective technological parameters to produced composite casting.Research limitations/implications: In the further research, authors of this paper are going to extend the scope of research about the another shape of the trial composite casting. Presented the technological process of composites producing created the possibility selection of different reinforcing particles depending on the technological and commercial properties.Practical implications: Determined possibility to control of volume fraction and distribution of reinforcing phase with used of the electromagnetic field, it can be used for example in the control of utility properties wear-resistant materials with a high coefficient of friction such as brake discs.Originality/value: The work presents the use of the electromagnetic field to shaping the structure and distribution of reinforcing phase in composite matrix. Within the range of this investigation created the new experimental stand to production of composites under electromagnetic field.

  18. Safety Training: places available in January 2013

    CERN Document Server

    Isabelle CUSATO, HSE Unit

    2012-01-01

    There are places available in the forthcoming Safety courses. For updates and registrations, please refer to the Safety Training Catalogue.   January 2013 (alphabetical order) Ergonomics - Applying ergonomic principles in the workplace 24-JAN-13 to 24-JAN-13, 9:00 – 12:00, in English Etre TSO au CERN 23-JAN-13 to 25-JAN-13, 9:00 – 17:30, in French Self-Rescue Mask training 08-JAN-13 to 08-JAN-13, 8:30 – 10:00, in French 08-JAN-13 to 08-JAN-13, 10:30 – 12:00, in French 10-JAN-13 to 10-JAN-13, 8:30 – 10:00, in English 10-JAN-13 to 10-JAN-13, 10:30 – 12:00, in English 15-JAN-13 to 15-JAN-13, 8:30 – 10:00, in French 15-JAN-13 to 15-JAN-13, 10:30 – 12:00, in French 17-JAN-13 to 17-JAN-13, 8:30 – 10:00, in English 17-JAN-13 to 17-JAN-13, 10:30 – 12:00, in English 22-JAN-13 to 22-JAN-13, 8:30 – 10:00, in French 22-JAN-13 to 22-JAN-13, 10:30 – 12:00, in French 24-JAN-13 to 24-JAN-13,...

  19. Safety Training: places available in April 2014

    CERN Multimedia

    Safety Training team, HSE Unit

    2014-01-01

    There are places available in the forthcoming Safety courses. For updates and registrations, please refer to the Safety Training Catalogue (see here).   April 2014 (alphabetical order) ATEX Habilitation - Level 2 03-APR-14 to 04-APR-14, 9.00 – 17.30, in French Cryogenic Safety - Level 1 10-APR-14, 10.00 – 12.00, in English Electrical Palett Truck – Driving 15-APR-14, 8.30 – 12.30, in French (hand-outs in English for non-French-speaking participants) Fire Extinguisher 09-APR-14, 10.30 – 12.00, in French 16-APR-14, 10.30 – 12.00, in English 23-APR-14, 10.30 – 12.00, in English First Aider - Level 1 – Initial 03-APR-14, 8.30 – 17.30, in French 10-APR-14, 8.30 – 17.30, in English 16-APR-14, 8.30 – 17.30, in English 24-APR-14, 8.30 – 17.30, in English First Aider - Level 1 – Refresher 17-APR-14, 8.30 – 12.30, in English 17-APR-14, 13.30 – 17.30, in...

  20. Safety Training: places available in October 2013

    CERN Document Server

    Isabelle CUSATO, HSE Unit

    2013-01-01

    There are places available in the forthcoming Safety courses. For updates and registrations, please refer to the Safety Training Catalogue.   October 2013 (alphabetical order) Habilitation ATEX niveau 1 (ATEX habilitation level 1) 08-OCT-13, 9.00 – 17.30, in French Conduite de plates-formes élévatrices mobiles de personnel (PEMP) (Driving cherry-pickers) 21-OCT-13 to 22-OCT-13, 08.30 – 17.30, in French with handouts in English Ergonomics - Applying ergonomic principles in the workplace 03-OCT-13, 9.00 – 12.00, in English Être TSO au CERN (Being a TSO at CERN) 29-OCT-13 to 31-OCT-13, 9.00 – 17.30, in French Self-Rescue Mask Training 01-OCT-13, 10.30 – 12.30, in French 03-OCT-13, 10.30 – 12.30, in English 04-OCT-13, 8.30 – 10.30, in English 08-OCT-13, 10.30 – 12.30, in French 09-OCT-13, 10.30 – 12.30, in English 15-OCT-13, 10.30 – 12.30, in French 17-OCT-13, 10.30...

  1. In the Beginning, This Was an Empty Place... Place-Related Narratives in Timofeyevka, Siberia

    Directory of Open Access Journals (Sweden)

    Sandis Laime

    2014-08-01

    Full Text Available The current article focuses on the place-related narratives collected in Timofeyevka village (Novosibirsk Oblast, Russian Federation, which was established in 1895 by emigrants from eastern Latvia (Latgale. The aim of the article is to discuss the reasons for the creation and functions of these narratives, at the same time attempting to grasp the significance of referring to the specific place. The material has been subdivided and characterised in detail in four groups according to its genre affiliation: personal and collective experience stories, memorates and legends. The article is based on material collected in Timofeyevka during the fieldwork of 2004 and 2006.

  2. Safety Training: places available in January 2014

    CERN Multimedia

    Safety Training Team, HSE Unit

    2014-01-01

    There are places available in the forthcoming Safety courses. For updates and registrations, please refer to the Safety Training Catalogue (see here).   January 2014 (alphabetical order) Confined space 28-JAN-14, 9.00 – 17.30, in French Ergonomics – Office 30-JAN-14, 9.00 – 12.00, in French Fire Extinguisher 08-JAN-14, 10.30 – 12.00, in French 24-JAN-14, 10.30 – 12.00, in English 31-JAN-14, 10.30 – 12.00, in French First Aider - Level 1 – Initial 16-JAN-14, 8.30 – 17.30, in French 30-JAN-14, 8.30 – 17.30, in French First Aider – Refresher 09-JAN-14, 8.30 – 12.30, in French 09-JAN-14, 13.30 – 17.30, in French Habilitation électrique - Electrician Low Voltage - Initial 22-JAN-14 au 24-JAN-14, 9.00 – 17.30, in English Habilitation électrique - Electrician Low and High Voltage - Initial 28-JAN-14 au 31-JAN-14, 9.00 – 17.30, in French ...

  3. Safety Training: places available in January 2014

    CERN Multimedia

    Safety Training Team, HSE Unit

    2013-01-01

    There are places available in the forthcoming Safety courses. For updates and registrations, please refer to the Safety Training Catalogue (see here).   January 2014 (alphabetical order) Confined space 28-JAN-14, 9.00 – 17.30, in French Ergonomics – Office 30-JAN-14, 9.00 – 12.00, in French Fire Extinguisher 08-JAN-14, 10.30 – 12.00, in French 24-JAN-14, 10.30 – 12.00, in English 31-JAN-14, 10.30 – 12.00, in French First Aider - Level 1 – Initial 16-JAN-14, 8.30 – 17.30, in French 30-JAN-14, 8.30 – 17.30, in French First Aider – Refresher 09-JAN-14, 8.30 – 12.30, in French 09-JAN-14, 13.30 – 17.30, in French Habilitation électrique - Electrician Low Voltage - Initial 22-JAN-14 au 24-JAN-14, 9.00 – 17.30, in English Habilitation électrique - Electrician Low and High Voltage - Initial 28-JAN-14 au 31-JAN-14, 9.00 – 17.30, in French ...

  4. Safety Training: places available in February 2014

    CERN Multimedia

    The Safety Training Team, HSE Unit

    2014-01-01

    There are places available in the forthcoming Safety courses. For updates and registrations, please refer to the Safety Training Catalogue (see here).   February 2014 (alphabetical order) ATEX Habilitation - Level 1 04-FEB-14, 9.00 – 17.30, in French Electrical Work - Lock-out 05-FEB-14, 13.30 – 17.30, in French Ergonomics – Office 06-FEB-14, 9.00 – 12.00, in English Fire Extinguisher 26-FEB-14, 10.30 – 12.00, in French 05-FEB-14, 10.30 – 12.00, in English First Aider - Level 1 – Initial 20-FEB-14, 8.30 – 17.30, in French First Aider - Refresher 06-FEB-14, 8.30 – 12.30, in French 06-FEB-14, 13.30 – 17.30, in French 13-FEB-14, 8.30 – 12.30, in English 13-FEB-14, 13.30 – 17.30, in English Habilitation électrique - Electrician Low Voltage – Initial 10-FEB-14 to 12-FEB-14, 9.00 – 17.30, in French Habilitation électrique - Electrician ...

  5. Safety Training: places available in March 2014

    CERN Multimedia

    Safety Training team, HSE Unit

    2014-01-01

    There are places available in the forthcoming Safety courses. For updates and registrations, please refer to the Safety Training Catalogue (see here).   March 2014 (alphabetical order) Ergonomics - Worksite and Workshop 24-MAR-14, 9.00 – 17.30, in French Fire Extinguisher 05-MAR-14, 10.30 – 12.00, in French 12-MAR-14, 8.30 – 10.00, in English 12-MAR-14, 10.30 – 12.00, in English First Aider - Level 1 – Initial 27-MAR-14, 8.30 – 17.30, in English First Aider – Refresher 20-MAR-14, 8.30 – 12.30, in French 20-MAR-14, 13.30 – 17.30, in French Habilitation électrique - Electrician Low Voltage – Initial 17-MAR-14 to 19-MAR-14, 9.00 – 17.30, in French 24-MAR-14 to 26-MAR-14, 9.00 – 17.30, in English Habilitation électrique - Electrician Low and High Voltage – Initial 18-MAR-14 to 21-MAR-14, 9.00 – 17.30, in English Habilitation &eacut...

  6. Thickness control and interface quality as functions of slurry formulation and casting speed in side-by-side tape casting

    DEFF Research Database (Denmark)

    Bulatova, Regina; Jabbari, Mirmasoud; Kaiser, Andreas; Della Negra, Michela; Andersen, Kjeld Bøhm; Gurauskis, Jonas; Bahl, Christian R.H.

    2014-01-01

    -controlled. A well-defined steep interface was obtained by co-casting slurries with similar viscosities above 4000mPas at a speed of 40cm/min. The elastic properties of green tapes were proven to be defined by the binder concentration in the recipe formulation. The interfaces in graded tapes were shown to...

  7. Safety Training: places available in April 2013

    CERN Multimedia

    Isabelle CUSATO, HSE Unit

    2013-01-01

    There are places available in the forthcoming Safety courses. For updates and registrations, please refer to the Safety Training Catalogue.   April 2013 (alphabetical order) Conduite de plates-formes élévatrices mobiles de personnel (PEMP) (cherry-picker driving) 15-APR-13 to 16-APR-13, 8.30 – 17.30, in French, with handouts in English Être TSO au CERN 09-APR-13 to 11-APR-13, 9.00 – 17.30, in French First-Aiders – Basic Course 18-APR-13, 8.15 – 17.30, in French First-Aiders – Refresher Course 04-APR-13, 8.15 – 12.30, in French 04-APR-13, 13.15 – 17.30, in French Habilitation ATEX niveau 2 (ATEX habilitation level 2) 11-APR-13 to 12-APR-13, 9.00 – 17.30, in French Habilitation électrique personnel électricien basse tension (electricial habilitation for electricians in low voltage) 08-APR-13 to 10-APR-13, 9.00 – 17.30, in French Habilitation &eac...

  8. Safety Training: places available in June

    CERN Multimedia

    GS Department

    2012-01-01

    There are places available in the forthcoming Safety courses. For updates and registrations, please refer to the Safety Training Catalogue. June 2012 (alphabetical order) Champs magnétiques 08-JUN-12, 09h30 – 12h00, en anglais Conduite de plates-formes élévatrices mobiles de personnel (PEMP) (Cherry-picker training) 11-JUN-12 to 12-JUN-12, 08.00 – 17.00, in French (with possibility to have the handouts in English) Ergonomics - Applying ergonomic principles in the workplace 14-JUN-12, 09.00 – 12.00, in French First Aiders - Basic Course 06-JUN-12 to 07-JUN-12, 08.00 – 17.00, in French (total : 1.5 days) First Aiders - Refresher Course 07-JUN-12, 13.00 – 17.00, in French 12-JUN-12, 08.00 – 12.00, in English 12-JUN-12, 13.00 – 17.00, in English Habilitation ATEX niveau 2 (ATEX certification –  level 2) 07-JUN-12 to 08-JUN-12, 9.00 – 17.30, in French Habilitation &eacut...

  9. Safety Training: places available in February 2013

    CERN Multimedia

    Isabelle CUSATO, HSE Unit

    2013-01-01

    There are places available in the forthcoming Safety courses. For updates and registrations, please refer to the Safety Training Catalogue.   February 2013 (alphabetical order) Noise - Understanding the risks 01-FEB-13, 10.00 – 12.30, in French Magnetic Fields 08-FEB-13, 9.00 – 11.30, in French Conduite de plates-formes élévatrices mobiles de personnel (PEMP) – Cherry-picker driving 18-FEB-13 to 19-FEB-13, 8.30 – 17.30, in French Self-Rescue Mask Training 05-FEB-13, 8.30 – 10.00, in French 05-FEB-13, 10.30 – 12.00, in French 12-FEB-13, 8.30 – 10.00, in French 12-FEB-13, 10.30 – 12.00, in French 14-FEB-13, 8.30 – 10.00, en anglais 14-FEB-13, 10.30 – 12.00, en anglais 19-FEB-13, 8.30 – 10.00, in French 19-FEB-13, 10.30 – 12.00, in French 21-FEB-13, 8.30 – 10.00, en anglais 21-FEB-13, 10.30 – 12.00, en anglais 26-FEB-13, 8.30 &ndash...

  10. Safety Training: places available in September 2013

    CERN Multimedia

    Isabelle Cusato, HSE Unit

    2013-01-01

    There are places available in the forthcoming Safety courses. For updates and registrations, please refer to the Safety Training Catalogue. September 2013 (alphabetical order) Conduite de plates-formes élévatrices mobiles de personnel (PEMP) (Cherry-picker driving) 12-SEP-13 au 13-SEP-13, 8.30 – 17.30, in French with handouts in English Ergonomics - Applying ergonomic principles in the workplace 19-SEP-13, 9.00 – 12.00, in French Être TSO au CERN (Being TSO at CERN) 10-SEP-13 to 12-SEP-13, 8.30 – 17.30, in French Habilitation ATEX - niveau 2 (ATEX habilitation - level 2) 19-SEP-13 to 20-SEP-13, 9.00 – 17.30, in French Habilitation électrique personnel électricien basse tension (electrical habilitation for electricians in low voltage) 11-SEP-13 to 13-SEP-13, 9.00 – 17.30, in English 23-SEP-13 to 25-SEP-13, 9.00 – 17.30, in French Habilitation électrique personnel non &eacut...

  11. Contested Spaces. Meaningful Places. Contemporary Performances of Place and Belonging in Spain and Brazil

    Directory of Open Access Journals (Sweden)

    Maria J. C. Krom

    2009-12-01

    Full Text Available This essay aims to contribute to current anthropological debate on space and place, analysing in two instances of festival performance how, on the one hand the politics of appropriation of space contributes to the configuration of power relations, and how on the other hand, participants in these festivals engage individually and collectively with physical space(s to create places which they experience as meaningful in terms of identity and belonging.

  12. Strong composite films with layered structures prepared by casting silk fibroin-graphene oxide hydrogels.

    Science.gov (United States)

    Huang, Liang; Li, Chun; Yuan, Wenjing; Shi, Gaoquan

    2013-05-01

    Composite films of graphene oxide (GO) sheets and silk fibroin (SF) with layered structures have been prepared by facile solution casting of SF-GO hydrogels. The as-prepared composite film containing 15% (by weight, wt%) of SF shows a high tensile strength of 221 ± 16 MPa and a failure strain of 1.8 ± 0.4%, which partially surpass those of natural nacre. Particularly, this composite film also has a high modulus of 17.2 ± 1.9 GPa. The high mechanical properties of this composite film can be attributed to its high content of GO (85 wt%), compact layered structure and the strong hydrogen bonding interaction between SF chains and GO sheets. PMID:23538717

  13. Safety Training - places available in October

    CERN Multimedia

    Isabelle CUSATO, HSE Unit

    2012-01-01

    There are places available in the forthcoming Safety courses. For updates and registrations, please refer to the Safety Training Catalogue. October 2012 (alphabetical order) Conduite de plates-formes élévatrices mobiles de personnel (PEMP) – Cherry-picker driving 08-OCT-12 to 09-OCT-12, 9.00 – 17.30, in French 11-OCT-12 to 12-OCT-12, 9.00 – 17.30, in French 17-OCT-12 to 18-OCT-12, 9.00 – 17.30, in French 29-OCT-12 to 30-OCT-12, 9.00 – 17.30, in French With the possibility to have the handouts in English Echafaudages - Réception, conformité (Scaffolding - reception, conformity) 24-OCT-12 to 26-OCT-12, 8.30 – 17.30, in French (location: Domarin, French department 38) First Aiders - Basic Course 04-OCT-12, 8.30 – 17.30, in English Habilitation électrique personnel non électricien (non electricians) 03-OCT-12 to 04-OCT-12, 9.00 – 17.30 (total 1.5 day), in English...

  14. Safety Training: places available in March 2013

    CERN Multimedia

    Isabelle Cusato, HSE Unit

    2013-01-01

    There are places available in the forthcoming Safety courses. For updates and registration, please refer to the Safety Training Catalogue.   March 2013 (alphabetical order) Conduite de plates-formes élévatrices mobiles de personnel (PEMP) (cherry-picker driving) 18-MAR-13 to 19-MAR-13, 8.30 – 17.30, in French with handouts in English First-Aiders – Basic course 14-MAR-13, 8.15 – 17.30, in French 21-MAR-13, 8.15 – 17.30, in English 28-MAR-13, 8.15 – 17.30, in French Habilitation électrique personnel électricien basse et haute tension (habilitation électrique for electricians in low and high voltage) 11-MAR-13 to 22-MAR-13 (total hours : 32), 9.00 – 17.30, in English Habilitation électrique personnel non électricien (electrical habilitation for non electricians) 27-MAR-13 to 28-MAR-13, 9.00 – 17.30, in French Habilitation électrique perso...

  15. Safety Training: places available in June 2013

    CERN Multimedia

    Isabelle CUSATO, HSE Unit

    2013-01-01

    There are places available in the forthcoming Safety courses. For updates and registrations, please refer to the Safety Training Catalogue.   June 2013 (alphabetical order) First Aiders - Basic Course 13-JUN-13, 8.15 – 17.30, in English First Aiders - Refresher Course 06-JUN-13, 8.15 – 12.30, in French 06-JUN-13, 13.15 – 17.30, in French Habilitation ATEX niveau 1 (Habilitation ATEX level 1) 28-JUN-13, 9.00 – 17.30, in French Habilitation électrique personnel électricien basse et haute tensions (habilitation électrique for electricians in low and high voltage) 10-JUN-13 to 13-JUN-13, 9.00 – 17.30, in English Habilitation électrique personnel non électricien (habilitation électrique for non electricians) 03-JUN-13 (afternoon) to 04-JUN-13 (full day), 9.00 – 17.30, in English Laser Experts 03-JUN-13 to 04-JUN-13, 9.00 – 17.30, in English Laser Users 28-JUN-...

  16. Influence of Refiner in ZA-12 Alloys During Centrifugal Casting Process

    Science.gov (United States)

    Jyothi, P. N.; Shailesh, Rao A.; Jagath, M. C.; Channakeshavalu, K.

    2014-05-01

    The behavior of the molten melt plays a predominant role in determining the quality cast product. In continuous casting, addition of refiner 1% (Al+Ti+B2) onto the molten metal increases its mechanical properties as a result of the nucleation within the process. In this article, the effect of refiners in the centrifugal casting process was studied. Eutectic ZA-12 alloys were taken for our experiment and cast at various rotational speeds (400 rpm, 600 rpm, and 800 rpm) with and without the addition of refiners. Rather than increase in the solidification rate as in continuous casting, these refiners diminish the solidification rate, which in turn forms an irregular-shaped cast tube. The microstructure and hardness for the entire cast specimen were discussed finally.

  17. The structure and mechanical properties of as-cast Zr-Ti alloys

    International Nuclear Information System (INIS)

    This study has investigated the structure and mechanical properties of pure Zr and a series of binary Zr-Ti alloys in order to determine their potential application as dental implant materials. The titanium contents of these alloys range from 10 to 40 wt.% and were prepared by arc melting in inert gas. This study evaluated the phase and structure of these Zr-Ti alloys using an X-ray diffraction (XRD) for phase analysis, and an optical microscope for microstructure analysis of the etched alloys. Three-point bending tests were performed to evaluate the mechanical properties of all specimens. The experimental results indicated that the pure Zr and Zr-10Ti comprised entirely of an acicular hexagonal structure of α' phase. When the Ti content increased to 20 wt.%, a significant amount of β phase was retained. However, when the Ti content increased to 40 wt.%, only the equi-axed, retained β phase was observed in the cast alloy. Moreover, the hardness values and bending strengths of the Zr-Ti alloys decreased with an increasing Ti content. Among pure Zr and Zr-Ti alloys, the α'-phase Zr-10Ti alloy has the greatest hardness and bending strength. The pure Zr and Zr-Ti alloys exhibit a similar elastic modulus ranging from 68 GPa (Zr-30Ti) to 78 GPa (Zr-40Ti). Based on the results of elastic moduli, pure Zr and Zr-Ti alloys are found to be suitable for implant materials due to lower modulus. Like bending strength, the elastically recoverable angle of Zr-Ti alloys decreased as the concentration of Ti increased. In the current search for a better implant material, the Zr-10Ti alloy exhibited the highest bending strength/modulus ratios as large as 25.3, which are higher than that of pure Zr (14.9) by 70%, and commercially pure Ti (8.7) by 191%. Thus, Zr-Ti alloy's low modulus, ductile property, excellent elastic recovery capability and impressive strength confirm that it is a promising candidate for dental implant materials.

  18. Simulation of Hardening and Cooling Processes for Moving Melts in Special Casting Technologies

    Directory of Open Access Journals (Sweden)

    R. I. Esman

    2008-01-01

    Full Text Available A mathematical model and an algorithm for numerical solution of conjugate problem concerning hydrodynamics and heat transfer of hardening and cooling processes with liquid metal flow is given in the paper.Quantitative relationships between heating and hydrodynamic parameters of moving melts in the channels of metallic molds of special casting technologies have been determined in the paper. The analysis of temperature pattern and velocity field makes it possible to reveal an influence of boundary conditions on melt flow structure.

  19. Role of yttrium in heavy section spheroidal graphite cast iron

    International Nuclear Information System (INIS)

    Magnesium ferrosilicon alloys (Mg = 5-7%) are widely used abroad, while rare earth-magnesium ferrosilicon alloys (Mg = 8-10%, Ce RE = 5-9%) are used predominantly in China. Recently, due to the exploitation of natural resources of yttrium rare earth at home, a new type of alloy--yttrium based-rare earth ferrosilicon (YRE=25-40%, Si=40%) has been developed and put into trail as a substitute for conventional rare earth magnesium ferrosilicon alloy in some of the foundries for manufacturing heavy section spheroidal graphite cast iron. In this paper the effect of yttrium on mechanical properties and microstructures of heavy section spheroidal graphite cast iron are studied. Some simulating experiments were carried out in laboratory

  20. Safety Training: places available in April

    CERN Multimedia

    2012-01-01

    There are places available in the forthcoming Safety courses. For updates and registrations, please refer to the Safety Training Catalogue. April 2012 (alphabetical order) Noise - Understanding the risks 18-APR-12, 10.00 – 12.30, in French Conduite de chariots élévateurs / Driving of forklifts 23-APR-12 to 24-APR-12, 09.00 – 17.30, in French (with possibility to have the handouts in English) First-aiders – Basic course 23-APR-12 to 24-APR-12, 08.30 – 17.30 and 08.30 – 12.30 (total: one day and a half), in French First Aiders - Refresher Course 24-APR-12, 13.30 – 17.30, in French Habilitation électrique personnel non électricien / Habilitation électrique for non electricians 02-APR-12 to 03-APR-12, 09.00 – 17.30 and 09.00 – 12.30 (total: one day and a half), in French Manipulation d’extincteurs : exercices sur feux réels / Use of fire extinguisher ...

  1. In-situ surface hardening of cast iron by surface layer metallurgy

    International Nuclear Information System (INIS)

    Abrasive wear is a serious problem in many cast iron castings used in industry. To minimize failure and repair of these components, different strategies exist to improve their surface microhardness thus enhancing their wear resistance. However, most of these methods lead to very brittle and/or expensive castings. In the current work a new method for surface hardening is presented which utilizes surface layer metallurgy to generate in-situ a boron-enriched white cast iron surface layer with a high microhardness on a gray cast iron casting. To do this, sand molds are coated with a ferroboron suspension and cast with a cast iron melt. After solidification, a 100–900 µm thick layer of boron-enriched ledeburite is formed on the surface of the casting which produces an increase in the average microhardness from 284 HV0.1±52 HV0.1 to 505 HV0.1±87 HV0.1. Analyses of the samples' core reveal a typical cast iron microstructure which leads to the conclusion that the coating mainly affects the castings' surface. By varying the grain size of the ferroboron powder in the coatings, it is shown that a powder size ≤100 µm is most suitable to create a boron-enriched ledeburite surface layer possessing high hardness values

  2. Fluid Flow in Continuous Casting Mold with a Configured Nozzle

    Institute of Scientific and Technical Information of China (English)

    王镭; 沈厚发; 柳百成

    2004-01-01

    The influence of a configured nozzle on the turbulent fluid flow in a continuous casting mold was investigated using the simulation program Visual Cast, which used the finite difference method and the SIMPLER algorithm. CAD software was used to construct the complicated nozzle in the calculational region. The simulation accuracy was validated by comparison with the classic driven cavity flow problem. The simulation results agree well with water modeling experiments. The simulations show that the velocity distribution at the nozzle port is uneven and the jet faces downward more than the nozzle outlet. Simulations with a configured nozzle and the inlet velocity at the nozzle entrance give precise results and overcome the traditional difficulty in determining the nozzle outlet velocity.

  3. Castability of ductile iron in thin walled castings (TWDI

    Directory of Open Access Journals (Sweden)

    M. Górny

    2008-10-01

    Full Text Available In work it has been presented results of influence of pouring temperature (Tp and carbon equivalent (CE on castability of ductile iron in thin walled castings with wall thickness of 1, 2 and 3 mm, respectively. Analysis was done on ductile iron with carbon equivalent ranging from 4.30 to 5.00 and pouring temperature varied from 1400 to 1500 oC. It has been shown that a statistical liner relationship exists between wall thickness and castability. Influence of CE and Tp on castability of cast iron flowing through channel with wall thickness of 2 and 3 mm can be presented by means of correlation equations (L = f(CE, Tp. Statistical analysis shows that pouring temperature has much higher influence on castability in comparison with influence of carbon equivalent.

  4. Cold cracking in DC-cast high strength aluminum alloy ingots: An intrinsic problem intensified by casting process parameters

    NARCIS (Netherlands)

    Lalpoor, M.; Eskin, D.G.; Ruvalcaba, D.; Fjaer, H.G.; Ten Cate, A.; Ontijt, N.; Katgerman, L.

    2011-01-01

    For almost half a century the catastrophic failure of direct chill (DC) cast high strength aluminum alloys has been challenging the production of sound ingots. To overcome this problem, a criterion is required that can assist the researchers in predicting the critical conditions which facilitate the

  5. Preparation of Plaster Moulage (Cast in Plastic Surgery patients

    Directory of Open Access Journals (Sweden)

    Rana R

    2003-01-01

    Full Text Available The purpose of this paper is to describe the technique of making casts using alginate compound for negative and dental stone plaster for positive impressions. With certain modifications a cast could be made of any part of the body and one can make a museum of interesting cases. Casts serve as useful teaching material especially in cleft lip and palate patients to study the effect of surgery on growth and development of the cleft lip-palate-nose complex in relation to the remaining face. It also helps in planning reconstruction in cases of facial defects, recording serial changes in multistage surgery, pre-operative and post-operative comparison as in rhinoplasty, ear reconstruction, hand etc; for comparing results before and after treatment in keloid and hypertrophic scars, fabrication of implants and preparation of prosthesis. In spite of newer modalities like 3-D imaging and stereolithography, the usefulness of this old technique in certain interesting cases can not be denied.

  6. Early Functional Treatment and Modern Cast Making for Indications in Hand Surgery.

    Science.gov (United States)

    Bohr, S; Pallua, N

    2016-01-01

    Cast treatment can serve both as a nonsurgical treatment option and as a means for providing postoperative protection. However, with the duration of immobilization intervals, the benefits of cast treatment, especially in hand surgery, are at risk of being outweighed by undesired drawbacks such as joint stiffening and contracture formation. In order to minimize potential complications commonly associated with cast treatment, efforts to further improve cast making must attempt to reconcile two conflicting objectives: (1) to achieve stability and rigidity at the site of injury (e.g., fracture retention) and (2) to allow free range of joint movement as early as possible. In addition, in order to assure patient compliance, modern cast treatments should aim to improve wearing-comfort of the cast. This paper describes modern cast designs for four common types hand injuries, with sample cases highlighting the clinical outcome of each treatment. PMID:27190653

  7. Early Functional Treatment and Modern Cast Making for Indications in Hand Surgery

    Directory of Open Access Journals (Sweden)

    S. Bohr

    2016-01-01

    Full Text Available Cast treatment can serve both as a nonsurgical treatment option and as a means for providing postoperative protection. However, with the duration of immobilization intervals, the benefits of cast treatment, especially in hand surgery, are at risk of being outweighed by undesired drawbacks such as joint stiffening and contracture formation. In order to minimize potential complications commonly associated with cast treatment, efforts to further improve cast making must attempt to reconcile two conflicting objectives: (1 to achieve stability and rigidity at the site of injury (e.g., fracture retention and (2 to allow free range of joint movement as early as possible. In addition, in order to assure patient compliance, modern cast treatments should aim to improve wearing-comfort of the cast. This paper describes modern cast designs for four common types hand injuries, with sample cases highlighting the clinical outcome of each treatment.

  8. Early Functional Treatment and Modern Cast Making for Indications in Hand Surgery

    Science.gov (United States)

    Bohr, S.; Pallua, N.

    2016-01-01

    Cast treatment can serve both as a nonsurgical treatment option and as a means for providing postoperative protection. However, with the duration of immobilization intervals, the benefits of cast treatment, especially in hand surgery, are at risk of being outweighed by undesired drawbacks such as joint stiffening and contracture formation. In order to minimize potential complications commonly associated with cast treatment, efforts to further improve cast making must attempt to reconcile two conflicting objectives: (1) to achieve stability and rigidity at the site of injury (e.g., fracture retention) and (2) to allow free range of joint movement as early as possible. In addition, in order to assure patient compliance, modern cast treatments should aim to improve wearing-comfort of the cast. This paper describes modern cast designs for four common types hand injuries, with sample cases highlighting the clinical outcome of each treatment.

  9. Energy and resource efficiency in aluminium die casting

    CERN Document Server

    Heinemann, Tim

    2016-01-01

    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.

  10. Control of Wear-Resistance Properties in Ti-added Hypereutectic High Chromium Cast Iron

    OpenAIRE

    Liu, Qiang

    2012-01-01

    High chromium cast iron (HCCI) is considered as one of the most useful wear resistance materials and their usage are widely spread in industry. The wear resistance and mechanical properties of HCCI mainly depend on type, size, number, morphology of hard carbides and the matrix structure (γ or α). The Hypereutectic HCCI with large volume fractions of hard carbides is preferred to apply in wear applications. However, the coarser and larger primary M7C3 carbides will be precipitated during the s...

  11. Putting in place the LHC computing organization

    CERN Multimedia

    Akesson, T

    2001-01-01

    Following the CERN review of computing, the ball is in the able hands of the CERN directorate to translate the review recommendations into the implementation of a LHC computing organization. From the ATLAS point of view it is rather clear what is needed: A credible set-up that can get into place the total computing infrastructure to match ATLAS global computing requirements, and not just at CERN. The next six months will demonstrate if CERN is on a good track to get operational an organization that can tackle this global challenge. CERN put forward to the 15th of June Council a paper that invites comments on a LHC Computing Grid Project as part of the CERN base program. In particular, it asked for new resources, of 25+25 MCHF, for CERN to build the CERN-part of a prototype that should be matched to the need of the experiments for the forthcoming data challenges. The intention of CERN now is to discuss with member-states in July to establish a sufficient resource-base to get approval at the September Commit...

  12. Transport Properties and Transport Phenomena in Casting Nickel Superalloys

    Science.gov (United States)

    Felicelli, S. D.; Sung, P. K.; Poirier, D. R.; Heinrich, J. C.

    1998-11-01

    Nickel superalloys that are used in the high-temperature regions of gas-turbine engines are cast by directional solidification (DS). In the DS processes, the castings are cooled from below, and three zones exist during solidification: (1) an all-solid zone at the bottom, (2) a "mushy zone" that is comprised of solid and liquid material, and (3) an overlying all-liquid zone. Computer simulations can be useful in predicting the complex transport phenomena that occur during solidification, but realistic simulations require accurate values of the transport properties. In addition to transport properties, the thermodynamic equilibria between the solid and liquid during solidification must also be known with reasonable accuracy. The importance of using reasonably accurate estimations of the transport properties is illustrated by two-dimensional simulations of the convection during solidification and the coincidental macrosegregation in the DS castings of multicomponent Ni-base alloys. In these simulations, we examine the sensitivity of the calculated results to measured partition ratios, thermal expansion coefficients, and viscosities that are estimated by regression analyses and correlations of existing property data.

  13. Phase characterization in two centrifugally cast HK stainless steel tubes

    International Nuclear Information System (INIS)

    The petrochemical industry has been using 25% Cr - 20% Ni centrifugally cast stainless steel since the early 1960s in reformer and pyrolysis furnaces. This class of material has replaced the traditional superalloys showing similar creep behavior, with substantial reduction in costs. The use of the centrifugal casting technique for tube production has also contributed to better quality in these components. During the past two decades, several studies have been conducted concerning the improvement in the performance of this material at high temperatures. Some of them were related to failure analysis and life prediction, while others were related to the chemical composition balance and to new alloying procedures. As a consequence, a new generation of centrifugally cast steels has been developed in the form of niobium-modified HK and HP steels. The creep resistance of these alloys appears to be dependent on the composition, morphology, and distribution of carbides that form within them. The purpose of the study reported herein is to characterize the precipitation effects occurring during long- term service in two HK-type steels, one being of basic HK composition and the other a niobium-modified alloy

  14. An optimization of injecting system in die casting

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    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.

  15. Volume Visual Attention Maps (VVAM) in ray-casting rendering.

    Science.gov (United States)

    Beristain, Andoni; Congote, John; Ruiz, Oscar

    2012-01-01

    This paper presents an extension visual attention maps for volume data visualization, where eye fixation points become rays in the 3D space, and the visual attention map becomes a volume. This Volume Visual Attention Map (VVAM) is used to interactively enhance a ray-casting based direct volume rendering (DVR) visualization. The practical application of this idea into the biomedical image visualization field is explored for interactive visualization. PMID:22356956

  16. Blue space geographies: Enabling health in place.

    Science.gov (United States)

    Foley, Ronan; Kistemann, Thomas

    2015-09-01

    Drawing from research on therapeutic landscapes and relationships between environment, health and wellbeing, we propose the idea of 'healthy blue space' as an important new development Complementing research on healthy green space, blue space is defined as; 'health-enabling places and spaces, where water is at the centre of a range of environments with identifiable potential for the promotion of human wellbeing'. Using theoretical ideas from emotional and relational geographies and critical understandings of salutogenesis, the value of blue space to health and wellbeing is recognised and evaluated. Six individual papers from five different countries consider how health can be enabled in mixed blue space settings. Four sub-themes; embodiment, inter-subjectivity, activity and meaning, document multiple experiences within a range of healthy blue spaces. Finally, we suggest a considerable research agenda - theoretical, methodological and applied - for future work within different forms of blue space. All are suggested as having public health policy relevance in social and public space. PMID:26238330

  17. PLACES AVAILABLES IN THE FUTURE COURSES

    CERN Document Server

    Enseignement Technique; Monique Duval; Tel. 74924

    2000-01-01

    Places are available in the following courses : Premiers pas avec votre PC12 - 15.9.00(4 demi-journées) LabView hands-on13.11.00(4 hours)LabView Basics 114 - 16.11.00(3 days)WORD20, 21 et 26, 27.9.00(4 jours) JAVA programming level 125 - 26.9.00(2 days)Gaz inflammables 1 26.9.00(1 journée)Hands-on Object-Oriented Analysis, Design & Programming with C++2 - 6.10.00(5 days)Advanced aspects of PERL 56.10.00(1 day)Initiation au WWW10 - 12.10.00(3 demi-journées)Nouveautés de WORD19 et 20.10.00(2 jours)FileMaker17, 18 et 24, 25.10.00(4 jours)UNIX pour non-programmeurs30.10 - 1.11.00 (3 jours)ACCESS 1er niveau30 - 31.10.00(2 jours)Introduction à PowerPoint6.11.00(1 journée)Excel13, 14 et 20, 21.11.00(4 jours)MS-Project 1er niveau14-17.11.00(4 demi-journées)If you wish to participate in one of these courses, please discuss with your supervisor and apply electronically directly from the course description pages that can be found on the...

  18. Structural Features and High-Temperature Strength of the Metal of Centrifugally Cast Tubes from Steel 15Kh1M1F

    International Nuclear Information System (INIS)

    Special features of the structure and properties of the metal of centrifugally cast large-diameter tubes from steel 15Kh1M1F used in hot reheat steam conduits of high-power generating units are discussed. The metal of the tubes in the initial state is shown to possess structural heterogeneity primarily represented by segregation bands. The segregation bands are responsible for scattering of the mechanical properties and a 5 - 10% decrease in the long-term strength in the initial condition. The decline of the long-term strength intensifies with the propagation of the segregation over the cross section of the tubes. The segregation lowers the stability of the structure and properties of the tubes in operation at a high level of long-term plasticity. By reducing the degree of segregation in centrifugally cast tubes the time of their operation in steam conduits can be increased to 200,000 h

  19. A finite element model for thermomechanical analysis in casting processes

    International Nuclear Information System (INIS)

    This paper summarizes the recent work of the authors in the numerical simulation of casting processes. In particular, a coupled thermomechanical model to simulate the solidification problem in casting has been developed. The model, based on a general isotropic thermoelasto-plasticity theory and formulated in a macroscopical point of view, includes generalized phase-change effects and considers the different thermomechanical behaviour of the solidifying material during its evolution from liquid to solid. For this purpose, a phase-change variable, plastic evolution equations and a temperature-dependent material constitutive law have been defined. Some relevant aspects of this model are presented here. Full thermomechanical coupling terms have been considered as well as variable thermal and mechanical boundary conditions: the first are due to air gap formation, while the second involve a contact formulation. Particular details concerning the numerical implementation of this model are also mentioned. An enhanced staggered scheme, used to solve the highly non-linear fully coupled finite element equations, is proposed. Furthermore, a proper convergence criterion to stop the iteration process is adopted and, although the quadratic convergence of Newton-Rapshon's method is not achieved, several numerical experiments demonstrate reasonable convergence rates. Finally, an experimental cylindrical casting test problem, including phase-change phenomena, temperature-dependent constitutive properties and contact effects, is analyzed. Numerical results are compared with some laboratory measurements. (orig.)

  20. Observation of Nanometric Silicon Oxide Bifilms in a Water-Atomized Hypereutectic Cast Iron Powder

    Science.gov (United States)

    Boisvert, Mathieu; Christopherson, Denis; L'Espérance, Gilles

    2016-06-01

    This study investigated the reasons for the irregular structure of primary graphite nodules that were formed in a hypereutectic cast iron powder during water atomization. The graphite nodules contain a significant amount of micron-sized pores and multiple nanometric voids that formed from silicon oxide bifilms. The bifilms theory is often used to explain the mechanisms responsible for the presence of pores in castings. However, even if many results presented in the literature tend to corroborate the existence of bifilms, to this date, only indirect evidences of their existence were presented. The observations presented in this paper are the first to show the double-sided nature of these defects. These observations support the bifilms theory and give an explanation for the presence of porosities in castings. The bifilms were used as substrate for graphite growth during solidification. The irregular structure of the graphite nodules is a consequence of the rather random structure of the bifilms that were introduced in the melt as a result of turbulences on the surface of the melt during pouring. The confirmation of the existence of bifilms can contribute to the understanding of the mechanical properties of various metallic parts.