WorldWideScience

Sample records for casts surgical

  1. Comparison of the Inclination of Unerupted Mandibular Third Molars on Panoramic Radiography and Casts Made after Surgical Incision

    OpenAIRE

    2009-01-01

    Background and aims Panoramic radiographs are used for surgical planning of unerupted third molars. The major prob-lems associated with panoramic radiography include unequal magnification and geometric distortion of the image. The purpose of this study was the clinical evaluation of the effect of radiographic distortion on the position and classification of unerpted mandibular third molars. Materials and methods Panoramic radiographs of 20 patients with indication for extraction of lower thir...

  2. DENTAL CAST STUDY OF ADULT PATIENTS WITH UNTREATED UNILATERAL CLEFT-LIP OR CLEFT-LIP AND PALATE IN INDONESIA COMPARED WITH SURGICALLY TREATED PATIENTS IN THE NETHERLANDS

    NARCIS (Netherlands)

    SPAUWEN, PHM; HARDJOWASITO, W; BOERSMA, J; LATIEF, BS

    1993-01-01

    To determine differences in maxillary and dentoalveolar relationships between untreated and treated patients having unilateral clefts of the lip and alveolus (UCLA) or lip and palate (UCLP), dental cast assessments were done on 70 untreated adult Indonesian patients (UCLA-I, UCLP-I) and 67 Dutch pat

  3. A comparative study between total contact casting and conventional dressings in the non-surgical management of diabetic plantar foot ulcers.

    Science.gov (United States)

    Ganguly, Suparno; Chakraborty, Koustubh; Mandal, Pankaj Kumar; Ballav, Ambar; Choudhury, Subhankar; Bagchi, Subrata; Mukherjee, Satinath

    2008-04-01

    Of all non-traumatic amputations 50% occur in Diabetics, mostly as a final outcome of foot ulcers. A major biomechanical factor in the causation of foot ulcers in persons with diabetes mellitus is elevated peak plantar pressure. Offloading the ulcer area in the form of equalisation of pressure across the plantar surface can accelerate healing of the ulcer. Total contact casting is one such method of offloading, and this study attempts to investigate the advantages of the above method as compared to conventional dressings in the physiatric management of the depth--ischaemia grades 1A, 1B, 2A, 2B neuropathic plantar ulcers in a diabetic patient. The outcome measure was the time taken for complete resolution of the ulcers. Of the 29 patients in Category A treated with total contact casting involving a total of 39 foot ulcers, 36 healed, which was statistically significant (p ulcers healing in Category B consisting of 26 patients treated by conventional dressings alone. Total contact casting is an effective, rapid, economical, ambulatory and outpatient--based method for the treatment of diabetic foot ulcers.

  4. Caste System

    OpenAIRE

    Hoff, Karla

    2016-01-01

    In standard economics, individuals are rational actors and economic forces undermine institutions that impose large inefficiencies. The persistence of the caste system is evidence of the need for psychologically more realistic models of decision-making in economics. The caste system divides South Asian society into hereditary groups whose lowest ranks are represented as innately polluted. ...

  5. 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

  6. 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.

  7. Nodular cast iron and casting monitoring

    OpenAIRE

    2008-01-01

    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.

  8. Abortion - surgical

    Science.gov (United States)

    Suction curettage; Surgical abortion; Elective abortion - surgical; Therapeutic abortion - surgical ... Surgical abortion involves dilating the opening to the uterus (cervix) and placing a small suction tube into the uterus. ...

  9. Casting materials

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhry, Anil R. (Xenia, OH); Dzugan, Robert (Cincinnati, OH); Harrington, Richard M. (Cincinnati, OH); Neece, Faurice D. (Lyndurst, OH); Singh, Nipendra P. (Pepper Pike, OH)

    2011-06-14

    A foam material comprises a liquid polymer and a liquid isocyanate which is mixed to make a solution that is poured, injected or otherwise deposited into a corresponding mold. A reaction from the mixture of the liquid polymer and liquid isocyanate inside the mold forms a thermally collapsible foam structure having a shape that corresponds to the inside surface configuration of the mold and a skin that is continuous and unbroken. Once the reaction is complete, the foam pattern is removed from the mold and may be used as a pattern in any number of conventional casting processes.

  10. 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.

  11. Surgical Assisting

    Science.gov (United States)

    ... Insert and remove Foley urinary bladder catheter Place pneumatic tourniquet Confirm procedure with surgeon Drape patient within ... Technology and Surgical Assisting (NBSTSA) offers the CertifiedSurgical First Assistant (CSFA) credential, and the National Surgical Assistant ...

  12. 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 ...

  13. Cast irons

    CERN Document Server

    1996-01-01

    Cast iron offers the design engineer a low-cost, high-strength material that can be easily melted and poured into a wide variety of useful, and sometimes complex, shapes. This latest handbook from ASM covers the entire spectrum of one of the most widely used and versatile of all engineered materials. The reader will find the basic, but vital, information on metallurgy, solidification characteristics, and properties. Extensive reviews are presented on the low-alloy gray, ductile, compacted graphite, and malleable irons. New and expanded material has been added covering high-alloy white irons used for abrasion resistance and high-alloy graphitic irons for heat and corrosion resistance. Also discussed are melting furnaces and foundry practices such as melting, inoculation, alloying, pouring, gating and rising, and molding. Heat treating practices including stress relieving, annealing, normalizing, hardening and tempering, autempering (of ductile irons), and surface-hardening treatments are covered, too. ASM Spec...

  14. The ancient Chinese casting techniques

    OpenAIRE

    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...

  15. 21 CFR 888.5980 - Manual cast application and removal instrument.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Manual cast application and removal instrument... SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.5980 Manual cast application and removal instrument. (a) Identification. A manual cast application and removal instrument is...

  16. 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.

  17. LLNL casting technology

    Science.gov (United States)

    Shapiro, A. B.; Comfort, W. J., III

    1994-01-01

    Competition to produce cast parts of higher quality, lower rejection rate, and lower cost is a fundamental factor in the global economy. To gain an edge on foreign competitors, the US casting industry must cut manufacturing costs and reduce the time from design to market. Casting research and development (R&D) are the key to increasing US competiveness in the casting arena. Lawrence Livermore National Laboratory (LLNL) is the home of a wide range of R&D projects that push the boundaries of state-of-the art casting. LLNL casting expertise and technology include: casting modeling research and development, including numerical simulation of fluid flow, heat transfer, reaction/solidification kinetics, and part distortion with residual stresses; special facilities to cast toxic material; extensive experience casting metals and nonmetals; advanced measurement and instrumentation systems. Department of Energy (DOE) funding provides the leverage for LLNL to collaborate with industrial partners to share this advanced casting expertise and technology. At the same time, collaboration with industrial partners provides LLNL technologists with broader insights into casting industry issues, casting process data, and the collective experience of industry experts. Casting R&D is also an excellent example of dual-use technology; it is the cornerstone for increasing US industrial competitiveness and minimizing waste nuclear material in weapon component production. Annual funding for casting projects at LLNL is $10M, which represents 1% of the total LLNL budget. Metal casting accounts for about 80% of the funding. Funding is nearly equally divided between development directed toward US industrial competitiveness and weapon component casting.

  18. Glovebox Advanced Casting System Casting Optimization

    Energy Technology Data Exchange (ETDEWEB)

    Fielding, Randall Sidney [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-03-01

    Casting optimization in the GACS included three broad areas; casting of U-10Zr pins, incorporation of an integral FCCI barrier, and development of a permanent crucible coating. U-10Zr casting was improved over last year’s results by modifying the crucible design to minimize contact with the colder mold. Through these modifications casting of a three pin batch was successful. Incorporation of an integral FCCI barrier also was optimized through furnace chamber pressure changes during the casting cycle to reduce gas pressures in the mold cavities which led to three full length pins being cast which incorporated FCCI barriers of three different thicknesses. Permanent crucible coatings were tested against a base case; 1500°C for 10 minutes in a U-20Pu-10Zr molten alloy. None of the candidate coating materials showed evidence of failure upon initial visual examination. In all areas of work a large amount of characterization will be needed to fully determine the effects of the optimization activities. The characterization activities and future work will occur next year.

  19. High integrity automotive castings

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, D. [Eck Industries Inc., St. Manitowoc, WI (United States)

    2007-07-01

    This paper described the High Integrity Magnesium Automotive Casting (HI-MAC) program, which was developed to ensure the widespread adoption of magnesium in structural castings. The program will encourage the use of low pressure permanent molds, squeeze casting, and electromagnetic pumping of magnesium into dies. The HI-MAC program is currently investigating new heat treatment methods, and is in the process of creating improved fluid flow and solidification modelling to produce high volume automotive components. In order to address key technology barriers, the program has been divided into 8 tasks: (1) squeeze casting process development; (2) low pressure casting technology; (3) thermal treatment; (4) microstructure control; (5) computer modelling and properties; (6) controlled molten metal transfer and filling; (7) emerging casting technologies; and (8) technology transfer throughout the automotive value chain. Technical challenges were outlined for each of the tasks. 1 ref., 3 tabs., 5 figs.

  20. Evolution of halictine castes

    Science.gov (United States)

    Knerer, Gerd

    1980-03-01

    Social halictine bees have female castes that range from species with no size differences to those with a discrete bimodality. Female caste differences are inversely correlated with the number of males produced in the first brood. It is proposed that the sexual dimorphism of solitary forms is being usurped by the female caste system of species in the process of turning social. Thus, caste differences and summer male suppression are greatest in the social species originating from solitary precursors with distinct sexual dimorphism, and are least in species evolving from solitary ancestors with a continuous sexual polymorphism.

  1. Caste in Itself, Caste and Class, or Caste in Class

    OpenAIRE

    Ramkrishna Mukherjee

    2015-01-01

    After the British conquered Bengal and eventually the whole of India,they set out to administer the colony. In this context they encountered two phenomena with which they were not familiar: (1) the relation of people to land for production (and not for revenue receiving, household living, etc.), and (2) the caste system of India, viz. the jati strati?cation of society.

  2. A cast orientation index.

    Science.gov (United States)

    Ivanhoe, J R; Mahanna, G K

    1994-12-01

    This article describes a technique that allows multiple master casts to be precisely oriented to the same path of insertion and withdrawal. This technique is useful in situations where multiple fixed prosthodontic preparations require surveyed restorations and a single master cast is not available.

  3. Higher Education's Caste System

    Science.gov (United States)

    Iannone, Ron

    2004-01-01

    In this article, the author discusses the history of the present caste system in higher education. He shows how the public's perception of this caste system is based on image and not usually on the quality of teaching and curriculum in colleges and universities. Finally, he discusses a model for accessibility to higher education and how higher…

  4. Caste and power

    DEFF Research Database (Denmark)

    Roy, Dayabati

    2011-01-01

    This paper explores the institution of caste and its operation in a micro-level village setting of West Bengal, an Indian state, where state politics at grass roots level is vibrant with functioning local self-government and entrenched political parties. This ethnographic study reveals that caste...

  5. Multi-layers castings

    Directory of Open Access Journals (Sweden)

    J. Szajnar

    2010-01-01

    Full Text Available In paper is presented the possibility of making of multi-layers cast steel castings in result of connection of casting and welding coating technologies. First layer was composite surface layer on the basis of Fe-Cr-C alloy, which was put directly in founding process of cast carbon steel 200–450 with use of preparation of mould cavity method. Second layer were padding welds, which were put with use of TIG – Tungsten Inert Gas surfacing by welding technology with filler on Ni matrix, Ni and Co matrix with wolfram carbides WC and on the basis on Fe-Cr-C alloy, which has the same chemical composition with alloy, which was used for making of composite surface layer. Usability for industrial applications of surface layers of castings were estimated by criterion of hardness and abrasive wear resistance of type metal-mineral.

  6. The ancient Chinese casting techniques

    Directory of Open Access Journals (Sweden)

    Tan Derui

    2011-02-01

    Full Text Available 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 iron, ductile cast iron, brass, cupronickel alloy (Packtong, etc. According to their surface decorative techniques they can be devided into gem inlay, gilding, gold and silver inlay, copper inlay, engraved decoration, surface tin-enrichment, mother-of-pearl inlay, burnished works with gold or silver inlay, surface coloring and cloisonné enamel, etc.

  7. Caste in Itself, Caste and Class, or Caste in Class

    Directory of Open Access Journals (Sweden)

    Ramkrishna Mukherjee

    2015-08-01

    Full Text Available After the British conquered Bengal and eventually the whole of India,they set out to administer the colony. In this context they encountered two phenomena with which they were not familiar: (1 the relation of people to land for production (and not for revenue receiving, household living, etc., and (2 the caste system of India, viz. the jati strati?cation of society.

  8. Clean Metal Casting

    Energy Technology Data Exchange (ETDEWEB)

    Makhlouf M. Makhlouf; Diran Apelian

    2002-02-05

    The objective of this project is to develop a technology for clean metal processing that is capable of consistently providing a metal cleanliness level that is fit for a given application. The program has five tasks: Development of melt cleanliness assessment technology, development of melt contamination avoidance technology, development of high temperature phase separation technology, establishment of a correlation between the level of melt cleanliness and as cast mechanical properties, and transfer of technology to the industrial sector. Within the context of the first task, WPI has developed a standardized Reduced Pressure Test that has been endorsed by AFS as a recommended practice. In addition, within the context of task1, WPI has developed a melt cleanliness sensor based on the principles of electromagnetic separation. An industrial partner is commercializing the sensor. Within the context of the second task, WPI has developed environmentally friendly fluxes that do not contain fluorine. Within the context of the third task, WPI modeled the process of rotary degassing and verified the model predictions with experimental data. This model may be used to optimize the performance of industrial rotary degassers. Within the context of the fourth task, WPI has correlated the level of melt cleanliness at various foundries, including a sand casting foundry, a permanent mold casting foundry, and a die casting foundry, to the casting process and the resultant mechanical properties. This is useful in tailoring the melt cleansing operations at foundries to the particular casting process and the desired properties of cast components.

  9. Symptomatic stent cast.

    LENUS (Irish Health Repository)

    Keohane, John

    2012-02-03

    Biliary stent occlusion is a major complication of endoscopic stent insertion and results in repeat procedures. Various theories as to the etiology have been proposed, the most frequently studied is the attachment of gram negative bacteria within the stent. Several studies have shown prolongation of stent patency with antibiotic prophylaxis. We report the case of stent occlusion from a cast of a previously inserted straight biliary stent; a "stent cast" in an 86-year-old woman with obstructive jaundice. This was retrieved with the lithotrypter and she made an uneventful recovery. This is the first reported case of a biliary stent cast.

  10. Symptomatic stent cast.

    Science.gov (United States)

    Keohane, John; Moore, Michael; O'Mahony, Seamus; Crosbie, Orla

    2008-02-01

    Biliary stent occlusion is a major complication of endoscopic stent insertion and results in repeat procedures. Various theories as to the etiology have been proposed, the most frequently studied is the attachment of gram negative bacteria within the stent. Several studies have shown prolongation of stent patency with antibiotic prophylaxis. We report the case of stent occlusion from a cast of a previously inserted straight biliary stent; a "stent cast" in an 86-year-old woman with obstructive jaundice. This was retrieved with the lithotrypter and she made an uneventful recovery. This is the first reported case of a biliary stent cast.

  11. CENTRIFUGAL CASTING MACHINE

    Science.gov (United States)

    Shuck, A.B.

    1958-04-01

    A device is described that is specifically designed to cast uraniumn fuel rods in a vacuunn, in order to obtain flawless, nonoxidized castings which subsequently require a maximum of machining or wastage of the expensive processed material. A chamber surrounded with heating elements is connected to the molds, and the entire apparatus is housed in an airtight container. A charge of uranium is placed in the chamber, heated, then is allowed to flow into the molds While being rotated. Water circulating through passages in the molds chills the casting to form a fine grained fuel rod in nearly finished form.

  12. The Ankle Injury Management (AIM) trial: a pragmatic, multicentre, equivalence randomised controlled trial and economic evaluation comparing close contact casting with open surgical reduction and internal fixation in the treatment of unstable ankle fractures in patients aged over 60 years.

    Science.gov (United States)

    Keene, David J; Mistry, Dipesh; Nam, Julian; Tutton, Elizabeth; Handley, Robert; Morgan, Lesley; Roberts, Emma; Gray, Bridget; Briggs, Andrew; Lall, Ranjit; Chesser, Tim Js; Pallister, Ian; Lamb, Sarah E; Willett, Keith

    2016-01-01

    BACKGROUND Close contact casting (CCC) may offer an alternative to open reduction and internal fixation (ORIF) surgery for unstable ankle fractures in older adults. OBJECTIVES We aimed to (1) determine if CCC for unstable ankle fractures in adults aged over 60 years resulted in equivalent clinical outcome compared with ORIF, (2) estimate cost-effectiveness to the NHS and society and (3) explore participant experiences. DESIGN A pragmatic, multicentre, equivalence randomised controlled trial incorporating health economic evaluation and qualitative study. SETTING Trauma and orthopaedic departments of 24 NHS hospitals. PARTICIPANTS Adults aged over 60 years with unstable ankle fracture. Those with serious limb or concomitant disease or substantial cognitive impairment were excluded. INTERVENTIONS CCC was conducted under anaesthetic in theatre by surgeons who attended training. ORIF was as per local practice. Participants were randomised in 1 : 1 allocation via remote telephone randomisation. Sequence generation was by random block size, with stratification by centre and fracture pattern. MAIN OUTCOME MEASURES Follow-up was conducted at 6 weeks and, by blinded outcome assessors, at 6 months after randomisation. The primary outcome was the Olerud-Molander Ankle Score (OMAS), a patient-reported assessment of ankle function, at 6 months. Secondary outcomes were quality of life (as measured by the European Quality of Life 5-Dimensions, Short Form questionnaire-12 items), pain, ankle range of motion and mobility (as measured by the timed up and go test), patient satisfaction and radiological measures. In accordance with equivalence trial US Food and Drug Administration guidance, primary analysis was per protocol. RESULTS We recruited 620 participants, 95 from the pilot and 525 from the multicentre phase, between June 2010 and November 2013. The majority of participants, 579 out of 620 (93%), received the allocated treatment; 52 out of 275 (19%) who received CCC later

  13. 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.

  14. 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%.

  15. Casting Characteristics of Aluminum Die Casting Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Makhlouf M. Makhlouf; Diran Apelian

    2002-02-05

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

  16. Colour Metallography of Cast Iron

    Institute of Scientific and Technical Information of China (English)

    Zhou Jiyang; Ph.D Liu Jincheng

    2010-01-01

    @@ Note: This book consists of five sections: Chapter 1 Introduction, Chapter 2 Grey Iron, Chapter 3 Spheroidal Graphite Cast Iron, Chapter 4 Vermicular Cast Iron, and Chapter 5 White Cast Iron. CHINA FOUNDRY publishes this book in several parts serially, starting from the first issue of 2009.

  17. Evaluation of an improved centrifugal casting machine.

    Science.gov (United States)

    Donovan, T E; White, L E

    1985-05-01

    A Type III gold alloy, a silver-palladium alloy, and a base metal alloy were cast in two different centrifugal casting machines. With the number of complete cast mesh squares as an indicator of castability, the Airspin casting machine produced superior castings with all three alloys. The base metal alloy produced the greatest number of complete squares with both casting machines.

  18. The casting of western sculpture during the XIXth century: sand casting versus lost wax casting

    NARCIS (Netherlands)

    Beentjes, T.P.C.

    2014-01-01

    This paper will discuss research into bronze casting techniques as practiced during the XIXth and early XXth century. Both natural sand casting (fonte au sable naturel) and lost wax casting (fonte à la cire perdue) were employed during this period and sometimes rivalled for commissions. Before the X

  19. Colour Metallography of Cast Iron

    Institute of Scientific and Technical Information of China (English)

    Zhou Jiyang; Liu Jincheng

    2010-01-01

    @@ Chapter 3 Spheroidal Graphite Cast Iron(I) Spheroidal Graphite Cast Iron, SG iron in short, refers to the cast iron in which graphite precipitates as spheroidal shape during solidification of liquid iron. The graphite in common commercial cast iron can only be changed from flake to spheroidal shape by spheroidising treatment. Since spheroidal graphite reduces the cutting effect of stress concentration, the metal matrix strength of SG iron can be applied around 70%-90%, thus the mechanical property of SG iron is significantly superior to other cast irons;even the tensile strength of SG iron is higher than that carbon steel.

  20. Cast iron - a predictable material

    Directory of Open Access Journals (Sweden)

    Jorg C. Sturm

    2011-02-01

    Full Text Available 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 simulation has developed from predicting hot spots and solidification to an integral assessment tool for foundries for the entire manufacturing route of castings. The support of the feeding related layout of the casting is still one of the most important duties for casting process simulation. Depending on the alloy poured, different feeding behaviors and self-feeding capabilities need to be considered to provide a defect free casting. Therefore, it is not enough to base the prediction of shrinkage defects solely on hot spots derived from temperature fields. To be able to quantitatively predict these defects, solidification simulation had to be combined with density and mass transport calculations, in order to evaluate the impact of the solidification morphology on the feeding behavior as well as to consider alloy dependent feeding ranges. For cast iron foundries, the use of casting process simulation has become an important instrument to predict the robustness and reliability of their processes, especially since the influence of alloying elements, melting practice and metallurgy need to be considered to quantify the special shrinkage and solidification behavior of cast iron. This allows the prediction of local structures, phases and ultimately the local mechanical properties of cast irons, to asses casting quality in the foundry but also to make use of this quantitative information during design of the casting. Casting quality issues related to thermally driven

  1. Melting and casting of FeAl-based cast alloy

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K. [Oak Ridge National Lab., TN (United States); Wilkening, D. [Columbia Falls Aluminum Co., Columbia Falls, MT (United States); Liebetrau, J.; Mackey, B. [AFFCO, L.L.C., Anaconda, MT (United States)

    1998-11-01

    The FeAl-based intermetallic alloys are of great interest because of their low density, low raw material cost, and excellent resistance to high-temperature oxidation, sulfidation, carburization, and molten salts. The applications based on these unique properties of FeAl require methods to melt and cast these alloys into complex-shaped castings and centrifugal cast tubes. This paper addresses the melting-related issues and the effect of chemistry on the microstructure and hardness of castings. It is concluded that the use of the Exo-Melt{trademark} process for melting and the proper selection of the aluminum melt stock can result in porosity-free castings. The FeAl alloys can be melted and cast from the virgin and revert stock. A large variation in carbon content of the alloys is possible before the precipitation of graphite flakes occurs. Titanium is a very potent addition to refine the grain size of castings. A range of complex sand castings and two different sizes of centrifugal cast tubes of the alloy have already been cast.

  2. Melting and casting of FeAl-based cast alloy

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.; Wilkening, D. [Columbia Falls Aluminum Co., 2000 Aluminum Dr., Columbia Falls, MT 59912 (United States); Liebetrau, J.; Mackey, B. [AFFCO, L.L.C., P.O. Box 1071, Anaconda, MT 59711 (United States)

    1998-12-31

    The FeAl-based intermetallic alloys are of great interest because of their low density, low raw material cost, and excellent resistance to high-temperature oxidation, sulfidation, carburization, and molten salts. The applications based on these unique properties of FeAl require methods to melt and cast these alloys into complex-shaped castings and centrifugal cast tubes. This paper addresses the melting-related issues and the effect of chemistry on the microstructure and hardness of castings. It is concluded that the use of the Exo-Melt{sup TM} process for melting and the proper selection of the aluminum melt stock can result in porosity-free castings. The FeAl alloys can be melted and cast from the virgin and revert stock. A large variation in carbon content of the alloys is possible before the precipitation of graphite flakes occurs. Titanium is a very potent addition to refine the grain size of castings. A range of complex sand castings and two different sizes of centrifugal cast tubes of the alloy have already been cast. (orig.) 18 refs.

  3. [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.

  4. Light metal compound casting

    Institute of Scientific and Technical Information of China (English)

    Konrad J.M.PAPIS; Joerg F.LOEFFLER; Peter J.UGGOWITZER

    2009-01-01

    'Compound casting'simplifies joining processes by directly casting a metallic melt onto a solid metal substrate. A continuously metallurgic transition is very important for industrial applications, such as joint structures of spaceframe constructions in transport industry. In this project, 'compound casting' of light metals is investigated, aiming at weight-saving. The substrate used is a wrought aluminium alloy of type AA5xxx, containing magnesium as main alloying element. The melts are aluminium alloys, containing various alloying elements (Cu, Si, Zn), and magnesium. By replacing the natural oxygen layer with a zinc layer, the inherent wetting difficulties were avoided, and compounds with flawless interfaces were successfully produced (no contraction defects, cracks or oxides). Electron microscopy and EDX investigations as well as optical micrographs of the interfacial areas revealed their continu-ously metallic constitution. Diffusion of alloying elements leads to heat-treatable microstructures in the vicinity of the joining interfaces in Al-Al couples. This permits significant variability of mechanical properties. Without significantly cutting down on wettability, the formation of low-melting intermetallic phases (Al3Mg2 and AI12Mg17 IMPs) at the interface of Al-Mg couples was avoided by applying a protec-tive coating to the substrate.

  5. Bimetallic layered castings alloy steel – carbon cast steel

    Directory of Open Access Journals (Sweden)

    T. Wróbel

    2011-01-01

    Full Text Available In paper is presented technology of bimetallic layered castings based on founding method of layer coating directly in cast processso-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 carbon cast steel, whereas working part (layer is plate of austenitic alloy steel sort X10CrNi 18-8. The ratio of thickness between bearing and working part is 8:1. The quality of the bimetallic layered castings was evaluated on the basis of ultrasonic NDT (non-destructive testing, structure and macro- and microhardness researches.

  6. Casting larger polycrystalline silicon ingots

    Energy Technology Data Exchange (ETDEWEB)

    Wohlgemuth, J.; Tomlinson, T.; Cliber, J.; Shea, S.; Narayanan, M.

    1995-08-01

    Solarex has developed and patented a directional solidification casting process specifically designed for photovoltaics. In this process, silicon feedstock is melted in a ceramic crucible and solidified into a large grained semicrystalline silicon ingot. In-house manufacture of low cost, high purity ceramics is a key to the low cost fabrication of Solarex polycrystalline wafers. The casting process is performed in Solarex designed casting stations. The casting operation is computer controlled. There are no moving parts (except for the loading and unloading) so the growth process proceeds with virtually no operator intervention Today Solarex casting stations are used to produce ingots from which 4 bricks, each 11.4 cm by 11.4 cm in cross section, are cut. The stations themselves are physically capable of holding larger ingots, that would yield either: 4 bricks, 15 cm by 15 an; or 9 bricks, 11.4 cm by 11.4 an in cross-section. One of the tasks in the Solarex Cast Polycrystalline Silicon PVMaT Program is to design and modify one of the castings stations to cast these larger ingots. If successful, this effort will increase the production capacity of Solarex`s casting stations by 73% and reduce the labor content for casting by an equivalent percentage.

  7. 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.

  8. Development of Refractories for Continuous Casting

    Institute of Scientific and Technical Information of China (English)

    TIAN Shouxin; JIN Congjin; YAO Jinfu; LI Zeya

    2004-01-01

    The paper introduces refractories for continuous casting, especially, refractories for continuous casting for clean steel in baosteel. Developing direction of refractories for continuous casting has been pointed out to satisfy the new metallurgical operating practice.

  9. 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.

  10. Biomaterials by freeze casting.

    Science.gov (United States)

    Wegst, Ulrike G K; Schecter, Matthew; Donius, Amalie E; Hunger, Philipp M

    2010-04-28

    The functional requirements for synthetic tissue substitutes appear deceptively simple: they should provide a porous matrix with interconnecting porosity and surface properties that promote rapid tissue ingrowth; at the same time, they should possess sufficient stiffness, strength and toughness to prevent crushing under physiological loads until full integration and healing are reached. Despite extensive efforts and first encouraging results, current biomaterials for tissue regeneration tend to suffer common limitations: insufficient tissue-material interaction and an inherent lack of strength and toughness associated with porosity. The challenge persists to synthesize materials that mimic both structure and mechanical performance of the natural tissue and permit strong tissue-implant interfaces to be formed. In the case of bone substitute materials, for example, the goal is to engineer high-performance composites with effective properties that, similar to natural mineralized tissue, exceed by orders of magnitude the properties of its constituents. It is still difficult with current technology to emulate in synthetic biomaterials multi-level hierarchical composite structures that are thought to be the origin of the observed mechanical property amplification in biological materials. Freeze casting permits to manufacture such complex, hybrid materials through excellent control of structural and mechanical properties. As a processing technique for the manufacture of biomaterials, freeze casting therefore has great promise.

  11. Education and Caste in India

    Science.gov (United States)

    Chauhan, Chandra Pal Singh

    2008-01-01

    This paper analyses the policy of reservation for lower castes in India. This policy is similar to that of affirmative action in the United States. The paper provides a brief overview of the caste system and discusses the types of groups that are eligible for reservation, based on data from government reports. The stance of this paper is that…

  12. Theory of batchwise centrifugal casting

    NARCIS (Netherlands)

    Biesheuvel, P. Maarten; Nijmeijer, Arian; Verweij, Henk

    1998-01-01

    In batchwise centrifugal casting a cylindrical mold is filled with suspension and rotated rapidly around its axis. This results in the movement of the particulate phase toward the cylinder wall and the formation of a tubular cast. Theory is presented for particle transport in the suspension phase an

  13. Lost Foam Casting in China

    Institute of Scientific and Technical Information of China (English)

    YE Sheng-ping; WU Zhi-chao

    2006-01-01

    @@ 1. Lost Foam Casting Committee of Foundry Institution of Chinese Mechanical Engineering Society (FICMES) From the beginning of the 1990s, China entered a research and expansion climax in lost foam casting technology realm after the United States, Germany, and Japan etc.

  14. Colour Metallography of Cast Iron

    Institute of Scientific and Technical Information of China (English)

    Zhou Jiyang; Liu Jincheng

    2009-01-01

    @@ This book consists of five sections:Chapter 1 Introduction,Chapter 2 Grey Iron,Chapter 3 Ductile Iron,Chapter 4Vermicular Cast Iron,and Chapter 5 White Cast Iron. CHINA FOUNDRY publishs this book in several parts serially,starting from the first issue of 2009.

  15. Micro-surgical endodontics.

    Science.gov (United States)

    Eliyas, S; Vere, J; Ali, Z; Harris, I

    2014-02-01

    Non-surgical endodontic retreatment is the treatment of choice for endodontically treated teeth with recurrent or residual disease in the majority of cases. In some cases, surgical endodontic treatment is indicated. Successful micro-surgical endodontic treatment depends on the accuracy of diagnosis, appropriate case selection, the quality of the surgical skills, and the application of the most appropriate haemostatic agents and biomaterials. This article describes the armamentarium and technical procedures involved in performing micro-surgical endodontics to a high standard.

  16. Surgical innovation as sui generis surgical research.

    Science.gov (United States)

    Lotz, Mianna

    2013-12-01

    Successful innovative 'leaps' in surgical technique have the potential to contribute exponentially to surgical advancement, and thereby to improved health outcomes for patients. Such innovative leaps often occur relatively spontaneously, without substantial forethought, planning, or preparation. This feature of surgical innovation raises special challenges for ensuring sufficient evaluation and regulatory oversight of new interventions that have not been the subject of controlled investigatory exploration and review. It is this feature in particular that makes early-stage surgical innovation especially resistant to classification as 'research', with all of the attendant methodological and ethical obligations--of planning, regulation, monitoring, reporting, and publication--associated with such a classification. This paper proposes conceptual and ethical grounds for a restricted definition according to which innovation in surgical technique is classified as a form of sui generis surgical 'research', where the explicit goal of adopting such a definition is to bring about needed improvements in knowledge transfer and thereby benefit current and future patients.

  17. EVOLUTION OF AS—CAST MICROSTRUCTURES OF 356 ALUMINIUM ALLOY CAST BY LIQUIDUS CASTING

    Institute of Scientific and Technical Information of China (English)

    J.Dong; G.M.Lu; 等

    2003-01-01

    A new method (liquidus casting)was used for 356 Al alloy semi-solid slurry mak-ing.The structures of 356 Al alloy cast by a fe mould and semi-continuous casting machine at different temperatures were inves tigated.How the globular grains form was qlso discussed.The results show that either being cast by single Fe mould or semi-continuous machine,the microstructures are not conventional dendrites but fine and net-globular grains.The average grain size is smaller than 30μm and suitable enough for thixoforming,meanwhile it can improve the mechanical properties of fol-lowing products.Under the suitable casting velocity and cooling intensity,most of global grains prolong their global browth and collide with each other before dendritic growth because of the large amount of the nucleation sites.

  18. Freeform fabrication of tissue-simulating phantoms by combining three-dimensional printing and casting

    Science.gov (United States)

    Shen, Shuwei; Zhao, Zuhua; Wang, Haili; Han, Yilin; Dong, Erbao; Liu, Bin; Liu, Wendong; Cromeens, Barrett; Adler, Brent; Besner, Gail; Ray, William; Hoehne, Brad; Xu, Ronald

    2016-03-01

    Appropriate surgical planning is important for improved clinical outcome and minimal complications in many surgical operations, such as a conjoined twin separation surgery. We combine 3D printing with casting and assembling to produce a solid phantom of high fidelity to help surgeons for better preparation of the conjoined twin separation surgery. 3D computer models of individual organs were reconstructed based on CT scanned data of the conjoined twins. The models were sliced, processed, and converted to an appropriate format for Fused Deposition Modeling (FDM). The skeletons of the phantom were printed directly by FDM using Acrylonitrile-Butadiene-Styrene (ABS) material, while internal soft organs were fabricated by casting silicon materials of different compositions in FDM printed molds. The skeleton and the internal organs were then assembled with appropriate fixtures to maintain their relative positional accuracies. The assembly was placed in a FMD printed shell mold of the patient body for further casting. For clear differentiation of different internal organs, CT contrast agents of different compositions were added in the silicon cast materials. The produced phantom was scanned by CT again and compared with that of the original computer models of the conjoined twins in order to verify the structural and positional fidelity. Our preliminary experiments showed that combining 3D printing with casting is an effective way to produce solid phantoms of high fidelity for the improved surgical planning in many clinical applications.

  19. Comparison of marginal accuracy of castings fabricated by conventional casting technique and accelerated casting technique: An in vitro study

    Directory of Open Access Journals (Sweden)

    S Srikanth Reddy

    2013-01-01

    Full Text Available Background: Conventional casting technique is time consuming when compared to accelerated casting technique. In this study, marginal accuracy of castings fabricated using accelerated and conventional casting technique was compared. Materials and Methods: 20 wax patterns were fabricated and the marginal discrepancy between the die and patterns were measured using Optical stereomicroscope. Ten wax patterns were used for Conventional casting and the rest for Accelerated casting. A Nickel-Chromium alloy was used for the casting. The castings were measured for marginal discrepancies and compared. Results: Castings fabricated using Conventional casting technique showed less vertical marginal discrepancy than the castings fabricated by Accelerated casting technique. The values were statistically highly significant. Conclusion: Conventional casting technique produced better marginal accuracy when compared to Accelerated casting. The vertical marginal discrepancy produced by the Accelerated casting technique was well within the maximum clinical tolerance limits. Clinical Implication: Accelerated casting technique can be used to save lab time to fabricate clinical crowns with acceptable vertical marginal discrepancy.

  20. NUMERICAL MODELING OF HARDENING OF UNINTERRUPTEDLY-CASTED BRONZE CASTING

    Directory of Open Access Journals (Sweden)

    E. I. Marukovich

    2009-01-01

    Full Text Available The three-dimensional numerical model for calculation of thermal fields during solidification of continuously casted bronze casting is developed. Coefficients of heat transfer on borders of calculation areas on the basis of the solution of inverse heat transfer conduction problem are determined. The analysis of thermal fields, depending on loop variables of drawing and the sizes of not cooled zone of crystallizer is curried out.

  1. Modelling of flow phenomena during DC casting

    NARCIS (Netherlands)

    Zuidema, J.

    2005-01-01

    Modelling of Flow Phenomena during DC Casting Jan Zuidema The production of aluminium ingots, by semi-continuous casting, is a complex process. DC Casting stands for direct chill casting. During this process liquid aluminium transforms to solid aluminium while cooling down. This is not an instanta

  2. Hernia Surgical Mesh Implants

    Science.gov (United States)

    ... Prosthetics Hernia Surgical Mesh Implants Hernia Surgical Mesh Implants Share Tweet Linkedin Pin it More sharing options ... majority of tissue used to produce these mesh implants are from a pig (porcine) or cow (bovine) ...

  3. Urogynecologic Surgical Mesh Implants

    Science.gov (United States)

    ... Prosthetics Urogynecologic Surgical Mesh Implants Urogynecologic Surgical Mesh Implants Share Tweet Linkedin Pin it More sharing options ... majority of tissue used to produce these mesh implants are from a pig (porcine) or cow (bovine). ...

  4. Abortion - surgical - aftercare

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000658.htm Abortion - surgical - aftercare To use the sharing features on ... please enable JavaScript. You have had a surgical abortion. This is a procedure that ends pregnancy by ...

  5. Casting Using A Polystyrene Pattern

    Science.gov (United States)

    Vasquez, Peter; Guenther, Bengamin; Vranas, Thomas; Veneris, Peter; Joyner, Michael

    1993-01-01

    New technique for making metal aircraft models saves significant amount of time and effort in comparison with conventional lost-wax method. Produces inexpensive, effective wind-tunnel models. Metal wind-tunnel model cast by use of polystyrene pattern.

  6. The CAST Time Projection Chamber

    CERN Document Server

    Autiero, D; Cébrian, S; Carmona, J M; Chesi, Enrico Guido; Davenport, M; Delattre, M; Di Lella, L; Formenti, F; Gomez, H; Hasinoff, M; Irastorza, I G; Lakic, B; Luzón, G; Morales, J; Musa, L; Ortiz, A; Placci, A; Rodríguez, A; Ruz, J; Villar, J A; Zioutas, K

    2007-01-01

    One of the three X-ray detectors of the CAST experiment searching for solar axions is a Time Projection Chamber (TPC) with a multi-wire proportional counter (MWPC) as a readout structure. Its design has been optimized to provide high sensitivity to the detection of the low intensity X-ray signal expected in the CAST experiment. A low hardware threshold of 0.8 keV is safely set during normal data taking periods, and the overall efficiency for the detection of photons coming from conversion of solar axions is 62 %. Shielding has been installed around the detector, lowering the background level to 4.10 x 10^-5 counts/cm^2/s/keV between 1 and 10 keV. During phase I of the CAST experiment the TPC has provided robust and stable operation, thus contributing with a competitive result to the overall CAST limit on axion-photon coupling and mass.

  7. Some Theoretical Considerations on Caste

    Directory of Open Access Journals (Sweden)

    Madhusudan Subedi

    2014-05-01

    Full Text Available Caste as a system of social stratification was an encompassing system in the past. There was reciprocal system of exchange goods and services. With time, occupation and mode of generation of livelihood of various caste groups changed, and the traditional form of jajmani system fizzled out. This paper provides an account of changing perspectives of caste relations in social science writing and political discourse. The discourse of caste has been shifted from ritual hierarchy and social discrimination to an instrument to mobilize people for economic and political gain. DOI: http://dx.doi.org/10.3126/dsaj.v7i0.10437 Dhaulagiri Journal of Sociology and Anthropology Vol. 7, 2013; 51-86

  8. Inoculation of chromium white cast iron

    Directory of Open Access Journals (Sweden)

    D. Kopyciński

    2009-01-01

    Full Text Available It has been proved that an addition of boron carbide introduced as an inoculant to the chromium white cast iron changes the structureof castings. Castings after inoculation revealed a different structure with numerous grains. 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.

  9. Colour Metallography of Cast Iron

    Institute of Scientific and Technical Information of China (English)

    Zhou Jiyang; Liu Jincheng

    2011-01-01

    @@ Vermicular graphite cast iron(VG iron for short in the following sections)is a type of cast iron in which the graphite is intermediate in shape between flake and spheroidal.Compared with the normal flake graphite in grey iron, the graphite in VG iron is shorter and thicker and shows a curved, more rounded shape.Because its outer contour is exactly like a worm, hence it is called vermicular graphite.

  10. Agile Manufacturing Development of Castings

    Science.gov (United States)

    2007-11-02

    responsible for con- verting the available 2D CATIA casting design into a 3D Pro/Engineering geometric model of the casting, for use by Clinkenbeard...changes to the draw- ings. MWM. As the part designer, MWM reviewed and evalu- ated proposed changes to the design. MWM also updated the CATIA ...creation of solid models of the cores and molds, using IGES translations of the CATIA files secured from MWM through GE Transportation Sys- tems. Due

  11. Surgical Anatomy of the Gastrointestinal Tract and Its Vasculature in the Laboratory Rat

    OpenAIRE

    Katarína Vdoviaková; Eva Petrovová; Marcela Maloveská; Lenka Krešáková; Jana Teleky; Mario Zefanias Joao Elias; Darina Petrášová

    2015-01-01

    The aim of this study was to describe and illustrate the morphology of the stomach, liver, intestine, and their vasculature to support the planning of surgical therapeutic methods in abdominal cavity. On adult Wistar rats corrosion casts were prepared from the arterial system and Duracryl Dental and PUR SP were used as a casting medium and was performed macroscopic anatomical dissection of the stomach, liver, and intestine was performed. The rat stomach was a large, semilunar shaped sac with ...

  12. Moldless casting by laser

    Science.gov (United States)

    McLean, Marc A.; Shannon, G. J.; Steen, William M.

    1997-09-01

    The principle of laser cladding involves the use of high power carbon-dioxide lasers and powder deposition technology to provide wear and corrosion resistant surface coatings to engineering components. By injecting metal powder into a laser generated melt pool on a moving substrate a solidified metal track can be produced. Deposition of successive tracks produces a multi-layer build. Laser direct casting (LDC) utilizes a coaxial nozzle enabling consistent omnidirectional deposition to produce 3D components from a selection of metal powders. The influence of the principal process parameters over the process features namely, powder catchment efficiency, beam shape and build rates are presented with several successfully generated 3D components. Nickel, stainless steel and satellite powders were deposited at laser powders of 0.4 to 1.4 kW and speeds of 500 to 1000 mm/min achieving build rates of 3 to 9 mm3/s. Fully dense metallurgical structures have been produced with no cracking or porosity and powder catchment efficiencies up to 85% have been achieved.

  13. Light metal compound casting

    Institute of Scientific and Technical Information of China (English)

    Konrad; J.; M.; PAPIS; Joerg; F.; LOEFFLER; Peter; J.; UGGOWITZER

    2009-01-01

    ‘Compound casting’simplifies joining processes by directly casting a metallic melt onto a solid metal substrate. A continuously metallurgic transition is very important for industrial applications, such as joint structures of spaceframe constructions in transport industry. In this project, ‘compound casting’ of light metals is investigated, aiming at weight-saving. The substrate used is a wrought aluminium alloy of type AA5xxx, containing magnesium as main alloying element. The melts are aluminium alloys, containing various alloying elements (Cu, Si, Zn), and magnesium. By replacing the natural oxygen layer with a zinc layer, the inherent wetting difficulties were avoided, and compounds with flawless interfaces were successfully produced (no contraction defects, cracks or oxides). Electron microscopy and EDX investigations as well as optical micrographs of the interfacial areas revealed their continu- ously metallic constitution. Diffusion of alloying elements leads to heat-treatable microstructures in the vicinity of the joining interfaces in Al-Al couples. This permits significant variability of mechanical properties. Without significantly cutting down on wettability, the formation of low-melting intermetallic phases (Al3Mg2 and Al12Mg17 IMPs) at the interface of Al-Mg couples was avoided by applying a protective coating to the substrate.

  14. Precision of Fit of Titanium and Cast Implant Frameworks Using a New Matching Formula

    Directory of Open Access Journals (Sweden)

    Marianella Sierraalta

    2012-01-01

    Full Text Available Statement of the Problem. Fit of prosthodontic frameworks is linked to the lifetime survival of dental implants and maintenance of surrounding bone. Purpose. The purpose of this study was to evaluate and compare the precision of fit of milled one-piece Titanium fixed complete denture frameworks to that of conventional cast frameworks. Material and Methods. Fifteen casts fabricated from a single edentulous CAD/CAM surgical guide were separated in two groups and resin patterns simulating the framework for a fixed complete denture developed. Five casts were sent to dental laboratories to invest, cast in a Palladium-Gold alloy and fit the framework. Ten casts had the resin pattern scanned for fabrication of milled bars in Titanium. Using measuring software, positions of implant replicas in the definitive model were recorded. The three dimensional spatial orientation of each implant replica was matched to the implant replica. Results. Results demonstrated the mean vertical gap of the Cast framework was 0.021 (+0.004 mm and 0.012 (0.002 mm determined by fixed and unfixed best-fit matching coordinate system. For Titanium frameworks they were 0.0037 (+0.0028 mm and 0.0024 (+0.0005 mm, respectively. Conclusions. Milled one-piece Titanium fixed complete denture frameworks provided a more accurate precision of fit then traditional cast frameworks.

  15. EVOLUTION OF AS-CAST MICROSTRUCTURES OF 356 ALUMINIUM ALLOY CAST BY LIQUIDUS CASTING

    Institute of Scientific and Technical Information of China (English)

    J. Dong; G.M. Lu; J.Z. Cui; Z.H. Zhao

    2003-01-01

    A new method (liquidus casting) was used for 356 Al alloy semi-solid slurry mak-ing. The structures of 356 Al alloy cast by a Fe mould and semi-continuous castingmachine at different temperatures were investigated. How the globular grains formwas also discussed. The results show that either being cast by single Fe mould orsemi-continuous machine, the microstructures are not conventional dendrites but fineand net-globular grains. The average grain size is smaller than 30μm and suitableenough for thixoforming, meanwhile it can improve the mechanical properties of fol-lowing products. Under the suitable casting velocity and cooling intensity, most ofglobal grains prolong their global growth and collide with each other before dendriticgrowth because of the large amount of the nucleation sites.

  16. Surgical Lasers In Gynecology

    Science.gov (United States)

    Schellhas, Helmut F.; Barnes, Alfonso E.

    1982-12-01

    Multipurpose surgical CO2 lasers marketed in the USA have been developed to be applicable to a variety of surgical procedures in many surgical fields. They are all suited for endoscopic surgical procedures and can be fitted to all standard surgical microscopes. They all can adjust the focal length of the laser beam to the different standard focal lengths of the surgical microscope which for instance in laryngoscopy is 400 mm and in colposcopy 300 mm. One laser instrument can even change the spot size in a given focal distance which is very advantageous for some microsurgical procedures (Merrimack Laboratories 820). All multipurpose surgical CO2 laser systems provide a multi-articulated surgical arm for free-hand surgery. The surgical arms are cumbersome to use but they are adapted to the surgeons needs with ingenuity. The practicality of the multi-articulated surgical arms depends mostly on the distance of the handpiece from the surgical console which now is also overbridged by the laser tube in most surgical laser system. The spot size of the beam is variable in most handpieces by interchangeable lenses which modify the focal distance of the beam and the power density. Another common feature in all systems is a coaxial He-Ne pilot light which provides a red spot which unfortunately becomes invisible in a bleeding surgical field. Most surgical laser systems have a spacial mode of TEM 00 which is essential for incisional surgery. The continuous mode of beam delivery is used for incisional surgery and also for most endoscopic procedures.

  17. Untouchable castes of Uttar Pradesh

    Directory of Open Access Journals (Sweden)

    Kharinin Artem Igorevich

    2015-04-01

    Full Text Available The Untouchable Castes of Uttar Pradesh are examined in this article. This region is one of the most populated in India. Also it is one of the most social mixed-composed in whole State. That’s why main conclusions which were made on this material can be extrapolated to all social space of country. The authors choose four ethno-caste groups, which represent the majority in untouchables and the three smallest in jaties. Their positions in regional hierarchy and economic specialization are analyzed in detail. There are a lot of information about their number, social structure, literacy rating, endogamy, day-to-day practices, customs and other features. Special accents were pointed on mind orientation of their elites toward integration in modern society or, conversely, toward the conservation of traditional forms of existence. The issues of origin and social evolution of untouchable castes of Uttar Pradesh are examined. There is assessment of castes’ sanskritization or other forms of social selfdevelopment. The quality of “scheduled” castes social environment is analyzed. As a marks of its positiveness the data about discrimination untouchables from other social groups and degree of political representativeness of “scheduled” castes, accessibility of education and labour were chosen. The conclusions were made about development degree of some castes. The factors that play role in positive changes in contemporary conditions were determined. The authors put forward their own hypothesis of future development of untouchable castes in Uttar Pradesh. Empiric base of this article was established on sources that have Indian origin and historical and social research of outstanding western indologies.

  18. Development of vacuum die-casting process

    Institute of Scientific and Technical Information of China (English)

    Masashi Uchida

    2009-01-01

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

  19. As-Cast Acicular Ductile Aluminum Cast Iron

    Institute of Scientific and Technical Information of China (English)

    S M Mostafavi Kashani; S M A Boutorabi

    2009-01-01

    The effects of nickel (2.2%)and molybdenum (0.6%)additions on the kinetics, microstructure, and me-chanical properties of ductile aluminum cast iron were studied under the as-cast and tempered conditions. Test bars machined from cast to size samples were used for mechanical and metallurgical studies. The results showed that adding nickel and molybdenum to the base iron produced an upper bainitic structure, resulting in an increase in strength and hardness. The same trend was shown when the test bars were tempered at 300 ℃ in the range of 300℃ to 400 ℃. The elongation increased with increasing the temperature from 300 ℃ to 400 ℃. The carbon content of the retained austenite also increased with increasing the temperature. The results also showed that the kinetics, mi-crostructure, and mechanical properties of this iron were similar to those of Ni-Mo alloyed silicon ductile iron.

  20. 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.

  1. Biliar y cast syndrome:literature review and a single centre experience in liver transplant recipients

    Institute of Scientific and Technical Information of China (English)

    Narasimhaiah Srinivasaiah; Mettu Srinivas Reddy; Schlok Balupuri; David Talbot; Bryon Jaques; Derek Manas

    2008-01-01

    BACKGROUND: Biliary cast syndrome (BCS) is an unusual complication of orthotopic liver transplantation (OLTx), and its management is dififcult. Limited success using endoscopic retrograde cholangiopancreatography (ERCP) or open exploration to clear casts has been reported, but failure usually results in re-transplantation. We aimed to review our experience with BCS and highlight a novel combined percutaneous and endoscopic approach for duct clearance. A brief review of the literature is given. METHODS: We retrospectively reviewed our experience of managing BCS using case notes review. Details were also gathered from radiology, where interventional procedures were carried out. RESULTS: We had a total of three cases of BCS reported between 2002 and 2005. Multiple attempts were made to remove these casts. All three were treated in a variety of ways. Management is discussed along with highlighting a novel combined percutaneous and endoscopic approach for duct clearance. CONCLUSIONS: BCS is a potential complication of OLTx. Surgical and endoscopic methods of removing casts are used. However, in circumstances where these methods are technically dififcult, a percutaneous endoscopic approach with serial dilatation of the cutaneous port and surgical removal of casts can be done.

  2. Energy Consumption of Die Casting Operations

    Energy Technology Data Exchange (ETDEWEB)

    Jerald Brevick; clark Mount-Campbell; Carroll Mobley

    2004-03-15

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

  3. CAST Physics Proposal to SPSC

    CERN Document Server

    CAST, Collaboration

    2011-01-01

    The CAST experiment has the potential to search for solar axions (dark matter particle candidates) or other particles with similar coupling. E.g., paraphtons (Hidden Sector), chameleons (dark energy), while considering the possibility whether CAST could be transformed to an antenna for relic axions with rest mass up to 0.1 to 1meV. While axion searches suggest detectors with lower background, paraphoton and chameleon searches require detectors with sub-keV threshold energy and the use of transparent windows in front of the Micromegas detectors, which cover 3 out of the 4 CAST magnet exits. Ongoing theoretical estimates and experimental investigations will define the priorities of the suggested 4 physics items of this proposal for the period 2012-2014.

  4. Manual of Surgical Instruments

    Directory of Open Access Journals (Sweden)

    Olga Lidia Sánchez Sarría

    2014-10-01

    Full Text Available Surgical instruments are the group of tools used in surgical procedures. They are very expensive and sophisticated. Consequently, a standardized and meticulous care is essential; they should go through the decontamination, cleaning and sterilization process. These instruments are designed in order to provide surgeons with tools that help them to perform a basic surgical procedure; there are multiple variations and the design depends on their function. This paper aims at showing all surgical instruments that can be used in an operating room during surgery and are not generally included in the medical literature.

  5. WEAR-RESISTANCE OF CHROMIC CAST IRONS OF EUTECTIC COMPOSITION

    Directory of Open Access Journals (Sweden)

    K. E. Baranovskij

    2009-01-01

    Full Text Available Casting of wear-resistant chrome cast irons in combined molds and iron chills is studied. Application of these ways of casting results in blending of carbides and increasing of hardness of castings.

  6. 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.

  7. CAST-IRONS AT HIGH TEMPERATURES

    Directory of Open Access Journals (Sweden)

    A. N. Krutilin

    2008-01-01

    Full Text Available The results of investigations of physical-mechanical characteristics of cast iron slugs, received by semicontinuos way of casting, at temperatures from 850 up to 1100^ С are given. 

  8. Surgical ethics and the challenge of surgical innovation.

    Science.gov (United States)

    Angelos, Peter

    2014-12-01

    Surgical ethics as a specific discipline is relatively new to many. Surgical ethics focuses on the ethical issues that are particularly important to the care of surgical patients. Informed consent for surgical procedures, the level of responsibility that surgeons feel for their patients' outcomes, and the management of surgical innovation are specific issues that are important in surgical ethics and are different from other areas of medicine. The future of surgical progress is dependent on surgical innovation, yet the nature of surgical innovation raises specific concerns that challenge the professionalism of surgeons. These concerns will be considered in the following pages.

  9. CONTINUOUSLY-CYCLIC CASTING OF HOLLOW CYLINDER SLUGS OF HIGH-CHROMIUM CAST IRON

    Directory of Open Access Journals (Sweden)

    E. I. Marukovich

    2009-01-01

    Full Text Available The analysis of castings formation is presented and the package of measures dircted on increase of stability of casting process is developed. Parametres of casting of hollow cylindrical billets by the method of directional solidification out of white high-chromium cast iron are defined.

  10. Developing technological process of obtaining giality casts

    Directory of Open Access Journals (Sweden)

    A. Issagulov

    2014-10-01

    Full Text Available The article considers the process of manufacturing castings using sand-resin forms and alloying furnace. Were the optimal technological parameters of manufacturing shell molds for the manufacture of castings of heating equipment. Using the same upon receipt of castings by casting in shell molds furnace alloying and deoxidation of the metal will provide consumers with quality products and have a positive impact on the economy in general engineering.

  11. Surgical medical record

    DEFF Research Database (Denmark)

    Bulow, S.

    2008-01-01

    A medical record is presented on the basis of selected linguistic pearls collected over the years from surgical case records Udgivelsesdato: 2008/12/15......A medical record is presented on the basis of selected linguistic pearls collected over the years from surgical case records Udgivelsesdato: 2008/12/15...

  12. Recognizing surgical patterns

    NARCIS (Netherlands)

    Bouarfa, L.

    2012-01-01

    In the Netherlands, each year over 1700 patients die from preventable surgical errors. Numerous initiatives to improve surgical practice have had some impact, but problems persist. Despite the introduction of checklists and protocols, patient safety in surgery remains a continuing challenge. This is

  13. When Your Child Needs a Cast

    Science.gov (United States)

    ... 1- to 2-Year-Old When Your Child Needs a Cast KidsHealth > For Parents > When Your Child Needs a Cast Print A A A What's in ... A cast wraps around the broken area and needs to be removed by a doctor when the ...

  14. Prediction of Microporosity in Shrouded Impeller Castings

    Energy Technology Data Exchange (ETDEWEB)

    Viswanathan, S. Nelson, C.D.

    1998-09-01

    The purpose of this Cooperative Research and Development Agreement (CRADA) between the Oak Ridge National Laboratory (ORNL) and Morris Bean and Company was to link computer models of heat and fluid flow with previously developed quality criteria for the prediction of microporosity in a Al-4.5% Cu alloy shrouded impeller casting. The results may be used to analyze the casting process design for the commercial production of 206 o alloy shrouded impeller castings. Test impeller castings were poured in the laboratory for the purpose of obtaining thermal data and porosity distributions. Also, a simulation of the test impeller casting was conducted and the results validated with porosity measurements on the test castings. A comparison of the predicted and measured microporosity distributions indicated an excellent correlation between experiments and prediction. The results of the experimental and modeling studies undertaken in this project indicate that the quality criteria developed for the prediction of microporosity in Al-4.5% Cu alloy castings can accurately predict regions of elevated microporosity even in complex castings such as the shrouded impeller casting. Accordingly, it should be possible to use quality criteria for porosity prediction in conjunction with computer models of heat and fluid flow to optimize the casting process for the production of shrouded impeller castings. Since high levels of microporosity may be expected to result in poor fatigue properties, casting designs that are optimized for low levels of microporosity should exhibit superior fatigue life.

  15. 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.

  16. Squeeze Casting of Steel Weapon Components

    Science.gov (United States)

    1976-09-01

    equipment. The squeeze casting process also differs from rheo- casting.(10-12) Unlike the former, the rheocasting process (8) "Ferrous Die Casting...various phases of rheocasting . At least so far, the process has not been applied to fabrication of complex steel components of the type that are under

  17. Colour Metallography of Cast Iron

    Institute of Scientific and Technical Information of China (English)

    Zhou Jiyang; Liu Jincheng

    2010-01-01

    @@ Spheroidal Graphite Cast Iron(Ⅳ) 3.7 Segregation of SG iron The non-uniform distribution of solute elements during solidification results in the micro segregation of SG iron.As for the redistribution of elements in the phases of the solidification structure,there is no intrinsic difference between SG iron and grey iron[132].

  18. Search for chameleons with CAST

    DEFF Research Database (Denmark)

    Anastassopoulos, V.; Arik, M.; Aune, S.

    2015-01-01

    energy threshold used for axions from 1 keV to 400 eV CAST became sensitive to the converted solar chameleon spectrum which peaks around 600 eV. Even though we have not observed any excess above background, we can provide a 95% C.L. limit for the coupling strength of chameleons to photons of βΥ≤1011...

  19. Inoculation Effects of Cast Iron

    Directory of Open Access Journals (Sweden)

    E. Fraś

    2012-12-01

    Full Text Available The paper presents a solidification sequence of graphite eutectic cells of A and D types, as well as globular and cementite eutectics. The morphology of eutectic cells in cast iron, the equations for their growth and the distances between the graphite precipitations in A and D eutectic types were analyzed. It is observed a critical eutectic growth rate at which one type of eutectic transformed into another. A mathematical formula was derived that combined the maximum degree of undercooling, the cooling rate of cast iron, eutectic cell count and the eutectic growth rate. One type of eutectic structure turned smoothly into the other at a particular transition rate, transformation temperature and transformational eutectic cell count. Inoculation of cast iron increased the number of eutectic cells with flake graphite and the graphite nodule count in ductile iron, while reducing the undercooling. An increase in intensity of inoculation caused a smooth transition from a cementite eutectic structure to a mixture of cementite and D type eutectic structure, then to a mixture of D and A types of eutectics up to the presence of only the A type of eutectic structure. Moreover, the mechanism of inoculation of cast iron was studied.

  20. Colour Metallography of Cast Iron

    Institute of Scientific and Technical Information of China (English)

    Zhou Jiyang; Liu Jincheng

    2010-01-01

    @@ Spheroidal Graphite Cast Iron(Ⅲ) 3.6 Solidification morphology of SG iron Solidification morphology refers to the description of change,distribution and interrelationship of the solidification structures such as graphite spheroids,austenite,eutectic cells,etc.[99

  1. Tape casting of magnesium oxide.

    Energy Technology Data Exchange (ETDEWEB)

    Ayala, Alicia; Corral, Erica L.; Loehman, Ronald E.; Bencoe, Denise Nora; Reiterer, Markus; Shah, Raja A.

    2008-02-01

    A tape casting procedure for fabricating ceramic magnesium oxide tapes has been developed as a method to produce flat sheets of sintered MgO that are thin and porous. Thickness of single layer tapes is in the range of 200-400 {micro}m with corresponding surface roughness values in the range of 10-20 {micro}m as measured by laser profilometry. Development of the tape casting technique required optimization of pretreatment for the starting magnesium oxide (MgO) powder as well as a detailed study of the casting slurry preparation and subsequent heat treatments for sintering and final tape flattening. Milling time of the ceramic powder, plasticizer, and binder mixture was identified as a primary factor affecting surface morphology of the tapes. In general, longer milling times resulted in green tapes with a noticeably smoother surface. This work demonstrates that meticulous control of the entire tape casting operation is necessary to obtain high-quality MgO tapes.

  2. CENTRIFUGAL CASTING OF ANTIFRICTION SILUMIN

    Directory of Open Access Journals (Sweden)

    V. Ju. Stetsenko

    2010-01-01

    Full Text Available It is shown that the way of centrifugal casting into water-cooled mould with vertical rotation axis enables to receive hollow slugs with diameter 100–250 mm, with height under 200 mm with wall thickness under 15 mm of antifriction silumin АК15М3, which will replace expensive antifriction bronze.

  3. Cern Axion Solar Telescope (CAST)

    CERN Multimedia

    2002-01-01

    The CERN Solar Axion Telescope, CAST, aims to shed light on a 30-year-old riddle of particle physics by detecting axions originating from the 15 million degree plasma in the Sun 's core. Axions were proposed as an extension to the Standard Model of particle physics to explain why CP violation is observed in weak but not strong interactions.

  4. The CAST time projection chamber

    Science.gov (United States)

    Autiero, D.; Beltrán, B.; Carmona, J. M.; Cebrián, S.; Chesi, E.; Davenport, M.; Delattre, M.; Di Lella, L.; Formenti, F.; Irastorza, I. G.; Gómez, H.; Hasinoff, M.; Lakic, B.; Luzón, G.; Morales, J.; Musa, L.; Ortiz, A.; Placci, A.; Rodrigurez, A.; Ruz, J.; Villar, J. A.; Zioutas, K.

    2007-06-01

    One of the three x-ray detectors of the CERN Axion Solar Telescope (CAST) experiment searching for solar axions is a time projection chamber (TPC) with a multi-wire proportional counter (MWPC) as a readout structure. Its design has been optimized to provide high sensitivity to the detection of the low intensity x-ray signal expected in the CAST experiment. A low hardware threshold of 0.8 keV is set to a safe level during normal data taking periods, and the overall efficiency for the detection of photons coming from conversion of solar axions is 62%. Shielding has been installed around the detector, lowering the background level to 4.10 × 10-5 counts cm-2 s-1 keV-1 between 1 and 10 keV. During phase I of the CAST experiment the TPC has provided robust and stable operation, thus contributing with a competitive result to the overall CAST limit on axion photon coupling and mass.

  5. Advanced Lost Foam Casting Technology

    Energy Technology Data Exchange (ETDEWEB)

    Charles E. Bates; Harry E. Littleton; Don Askeland; Taras Molibog; Jason Hopper; Ben Vatankhah

    2000-11-30

    This report describes the research done under the six tasks to improve the process and make it more functional in an industrial environment. Task 1: Pattern Pyrolysis Products and Pattern Properties Task 2: Coating Quality Control Task 3: Fill and Solidification Code Task 4: Alternate Pattern Materials Task 5: Casting Distortion Task 6: Technology Transfer

  6. Graphite Formation in Cast Iron

    Science.gov (United States)

    Stefanescu, D. M.

    1985-01-01

    In the first phase of the project it was proven that by changing the ratio between the thermal gradient and the growth rate for commercial cast iron samples solidifying in a Bridgman type furnace, it is possible to produce all types of graphite structures, from flake to spheroidal, and all types of matrices, from ferritic to white at a certain given level of cerium. KC-135 flight experiments have shown that in a low-gravity environment, no flotation occurs even in spheroidal graphite cast irons with carbon equivalent as high as 5%, while extensive graphite flotation occurred in both flake and spheroidal graphite cast irons, in high carbon samples solidified in a high gravity environment. This opens the way for production of iron-carbon composite materials, with high carbon content (e.g., 10%) in a low gravity environment. By using KC-135 flights, the influence of some basic elements on the solidification of cast iron will be studied. The mechanism of flake to spheroidal graphite transition will be studied, by using quenching experiments at both low and one gravity for different G/R ratios.

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

    OpenAIRE

    2016-01-01

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

  8. Continuous squeeze casting process by mass production

    Institute of Scientific and Technical Information of China (English)

    Yun Xia; Rich Jacques

    2006-01-01

    Squeeze casting has become the most competitive casting process in the automotive industry because of its many advantages over high pressure die casting (HPDC). Many squeeze casting R & D and small amount volume making have been implemented around the world, but the mass production control still exists problem. SPX Contech squeeze casting process P2000 successfully achieved the goal of mass production; it includes lower metal turbulence, less gas entrapment, minimum volumetric shrinkage, and thus less porosity. Like other casting processes, however, the quality of squeeze castings is still sensitive to process control and gate and runner design. Casting defects can form in both die-filling and metal solidification phases. The occurrence of casting defects is directly attributed to improper adjustment or lack of control of process parameters including metal filling velocity, temperature, dwell time, cooling pattern, casting design, and etc. This paper presents examples using P2000 techniques to improve part quality in the following areas: runner & gate design, casting & runner layout in the die, squeeze pin application, high thermal conductivityinserts, cooling/heating systems, spray & lubricant techniques,and part stress calculation from shrinkage or displacement prediction after stress relief.

  9. 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.

  10. Process development of thin strip steel casting

    Energy Technology Data Exchange (ETDEWEB)

    Sussman, R.C.; Williams, R.S.

    1990-12-01

    An important new frontier is being opened in steel processing with the emergence of thin strip casting. Casting steel directly to thin strip has enormous benefits in energy savings by potentially eliminating the need for hot reduction in a hot strip mill. This has been the driving force for numerous current research efforts into the direct strip casting of steel. The US Department of Energy initiated a program to evaluate the development of thin strip casting in the steel industry. In earlier phases of this program, planar flow casting on an experimental caster was studied by a team of engineers from Westinghouse Electric corporation and Armco Inc. A subsequent research program was designed as a fundamental and developmental study of both planar and melt overflow casting processes. This study was arranged as several separate and distinct tasks which were often completed by different teams of researchers. An early task was to design and build a water model to study fluid flow through different designs of planar flow casting nozzles. Another important task was mathematically modeling of melt overflow casting process. A mathematical solidification model for the formation of the strip in the melt overflow process was written. A study of the material and conditioning of casting substrates was made on the small wheel caster using the melt overflow casting process. This report discusses work on the development of thin steel casting.

  11. Simulating a high pressure die casting

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-07-01

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

  12. Multiscale Surgical Telerobots

    Energy Technology Data Exchange (ETDEWEB)

    Miles, R R; Seward, K P; Benett, W J; Tendick, F; Bentley, L; Stephan, P L

    2002-01-23

    A project was undertaken to improve robotic surgical tools for telerobotic minimally invasive surgery. The major objectives were to reduce the size of the tools to permit new surgical procedures in confined spaces such as the heart and to improve control of surgical tools by locating positional sensors and actuators at the end effector rather than external to the patient as is currently the state of the technology. A new compact end-effector with wrist-like flexibility was designed. Positional sensors based on MEMS microfabrication techniques were designed.

  13. Inner surface roughness of complete cast crowns made by centrifugal casting machines.

    Science.gov (United States)

    Ogura, H; Raptis, C N; Asgar, K

    1981-05-01

    Six variables that could affect the surface roughness of a casting were investigated. The variables were (1) type of alloy, (2) mold temperature, (3) metal casting temperature, (4) casting machine, (5) sandblasting, and (6) location of each section. It was determined that the training portion of a complete cast crown had rougher surfaces than the leading portion. Higher mold and casting temperatures produced rougher castings, and this effect was more pronounced in the case of the base metal alloy. Sandblasting reduced the roughness, but produced scratched surfaces. Sandblasting had a more pronounced affect on the surface roughness of the base metal alloy cast either at a higher mold temperature or metal casting temperature. The morphology and the roughness profile of the original cast surface differed considerably with the type of alloy used.

  14. Surgical Critical Care Initiative

    Data.gov (United States)

    Federal Laboratory Consortium — The Surgical Critical Care Initiative (SC2i) is a USU research program established in October 2013 to develop, translate, and validate biology-driven critical care....

  15. Guide to Surgical Specialists

    Science.gov (United States)

    ... have expertise in the following areas of responsibility: neonatal surgery (specialized knowledge in the surgical repair of ... and non-operative management of certain types of pain. Common conditions managed by neurologic surgeons include disorders ...

  16. Ambulatory Surgical Measures - National

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Ambulatory Surgical Center Quality Reporting (ASCQR) Program seeks to make care safer and more efficient through quality reporting. ASCs eligible for this...

  17. Ambulatory Surgical Measures - Facility

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Ambulatory Surgical Center Quality Reporting (ASCQR) Program seeks to make care safer and more efficient through quality reporting. ASCs eligible for this...

  18. Pressure rig for repetitive casting

    Science.gov (United States)

    Vasquez, Peter (Inventor); Hutto, William R. (Inventor); Philips, Albert R. (Inventor)

    1989-01-01

    The invention is a pressure rig for repetitive casting of metal. The pressure rig performs like a piston for feeding molten metal into a mold. Pressure is applied to an expandable rubber diaphragm which expands like a balloon to force the metal into the mold. A ceramic cavity which holds molten metal is lined with blanket-type insulating material, necessitating only a relining for subsequent use and eliminating the lengthy cavity preparation inherent in previous rigs. In addition, the expandable rubber diaphragm is protected by the insulating material thereby decreasing its vulnerability to heat damage. As a result of the improved design the life expectancy of the pressure rig contemplated by the present invention is more than doubled. Moreover, the improved heat protection has allowed the casting of brass and other alloys with higher melting temperatures than possible in the conventional pressure rigs.

  19. Search for chameleons with CAST

    Directory of Open Access Journals (Sweden)

    V. Anastassopoulos

    2015-10-01

    Full Text Available In this work we present a search for (solar chameleons with the CERN Axion Solar Telescope (CAST. This novel experimental technique, in the field of dark energy research, exploits both the chameleon coupling to matter (βm and to photons (βγ via the Primakoff effect. By reducing the X-ray detection energy threshold used for axions from 1 keV to 400 eV CAST became sensitive to the converted solar chameleon spectrum which peaks around 600 eV. Even though we have not observed any excess above background, we can provide a 95% C.L. limit for the coupling strength of chameleons to photons of βγ≲1011 for 1<βm<106.

  20. Search for chameleons with CAST

    CERN Document Server

    Anastassopoulos, V; Aune, S; Barth, K; Belov, A; Bräuninger, H; Cantatore, G; Carmona, J M; Cetin, S A; Christensen, F; Collar, J I; Dafni, T; Davenport, M; Desch, K; Dermenev, A; Eleftheriadis, C; Fanourakis, G; Ferrer-Ribas, E; Friedrich, P; Galán, J; García, J A; Gardikiotis, A; Garza, J G; Gazis, E N; Geralis, T; Giomataris, I; Hailey, C; Haug, F; Hasinoff, M D; Hofmann, D H H; Iguaz, F J; Irastorza, I G; Jacoby, J; Jakobsen, A; Jakovčić, K; Kaminski, J; Karuza, M; Kavuk, M; Krčmar, M; Krieger, C; Krüger, A; Lakić, B; Laurent, J M; Liolios, A; Ljubičić, A; Luzón, G; Neff, S; Ortega, I; Papaevangelou, T; Pivovarov, M J; Raffelt, G; Riege, H; Rosu, M; Ruz, J; Savvidis, I; Solanki, S K; Vafeiadis, T; Villar, J A; Vogel, J K; Yildiz, S C; Zioutas, K; Brax, P; Lavrentyev, I; Upadhye, A

    2015-01-01

    In this work we present a search for (solar) chameleons with the CERN Axion Solar Telescope (CAST). This novel experimental technique, in the field of dark energy research, exploits both the chameleon coupling to matter ($\\beta_{\\rm m}$) and to photons ($\\beta_{\\gamma}$) via the Primakoff effect. By reducing the X-ray detection energy threshold used for axions from 1$\\,$keV to 400$\\,$eV CAST became sensitive to the converted solar chameleon spectrum which peaks around 600$\\,$eV. Even though we have not observed any excess above background, we can provide a 95% C.L. limit for the coupling strength of chameleons to photons of $\\beta_{\\gamma}\\!\\lesssim\\!10^{11}$ for $1<\\beta_{\\rm m}<10^6$.

  1. Innovative algorithm for cast detection

    Science.gov (United States)

    Gasparini, Francesca; Schettini, Raimondo; Gallina, Paolo

    2001-12-01

    The paper describes a method for detecting a color cast (i.e. a superimposed dominant color) in a digital image without any a priori knowledge of its semantic content. The color gamut of the image is first mapped in the CIELab color space. The color distribution of the whole image and of the so-called Near Neutral Objects (NNO) is then investigated using statistical tools then, to determine the presence of a cast. The boundaries of the near neutral objects in the color space are set adaptively by the algorithm on the basis of a preliminary analysis of the image color gamut. The method we propose has been tuned and successfully tested on a large data set of images, downloaded from personal web-pages or acquired using various digital and traditional cameras.

  2. Rapid Cycle Casting of Steel

    Science.gov (United States)

    1981-07-01

    such as macrosegregation, hot tears, and blowholes are also difficult to control. Rheocasting l on the other hand, is a recent development which...viscosity. Advantages of the rheocasting process are: * Reduced attack of die or mold because of the reduced tempera- ture (by 1000 C for steel) and...4W W ’ V6W 4 1.2 THE SD PROCESS Many metals, including steel, can be cast at still lower tempera- soliifiction(2) tures than rheocasting by

  3. Computer precision simulation for titanium casting centrifugal mold filling of prescision titanium castings

    Directory of Open Access Journals (Sweden)

    Daming XU

    2004-08-01

    Full Text Available Computer simulation codes were developed based on proposed mathematical model for centrifugal mold filling processes and previous computer software for 3D mold filling and solidification of castings. Sample simulations were implemented for mold filling processes of precision titanium castings under gravity and different centrifugal casting techniques. The computation results show that the alloy melt has a much stronger mold filling ability for thin section castings unde a centrifugal force field than that only under the gravity. A "return back" mold filling manner is showed to be a reasonable technique for centrifugal casting processes, especially for thin section prcision castings.

  4. Transfixation cast technique for arthrodesis of the distal interphalangeal joint of horses.

    Science.gov (United States)

    Easter, J L; Schumacher, J; Watkins, J P

    2011-01-01

    Surgical arthrodesis of the distal interphalangeal (DIP) joint by transfixation casting was used to salvage a three-year-old filly and a yearling filly that were chronically lame because of infection of the DIP joint for breeding. Unlike previously described techniques for arthrodesis of the DIP joint, the technique used did not require insertion of implants across the joint, which may have contributed to the successful outcome.

  5. [The cast structure after vacuum-pressure casting and centrifugal casting].

    Science.gov (United States)

    Finger, W; Jung, T; Quast, U

    1975-02-01

    Evaluation of polished sections revealed the following: 1. Grain size in marginal areas of the crown is, in general, smaller than it is in the occlusal region. 2. Grain size varies depending on the casting method applied. Differences in hardness were found only to a limited extent. They were not always in line with the grain structure. This phenomenon deviating from the rule cannot satisfactorily be explained. The piping distribution was in accordance with observations made so far.

  6. Gating of Permanent Molds for ALuminum Casting

    Energy Technology Data Exchange (ETDEWEB)

    David Schwam; John F. Wallace; Tom Engle; Qingming Chang

    2004-03-30

    This report summarizes a two-year project, DE-FC07-01ID13983 that concerns the gating of aluminum castings in permanent molds. The main goal of the project is to improve the quality of aluminum castings produced in permanent molds. The approach taken was determine how the vertical type gating systems used for permanent mold castings can be designed to fill the mold cavity with a minimum of damage to the quality of the resulting casting. It is evident that somewhat different systems are preferred for different shapes and sizes of aluminum castings. The main problems caused by improper gating are entrained aluminum oxide films and entrapped gas. The project highlights the characteristic features of gating systems used in permanent mold aluminum foundries and recommends gating procedures designed to avoid common defects. The study also provides direct evidence on the filling pattern and heat flow behavior in permanent mold castings.

  7. Clean Cast Steel Technology, Phase IV

    Energy Technology Data Exchange (ETDEWEB)

    Charles E. Bates

    2003-02-24

    The objective of the Clean Cast Steel Technology Program was to improve casting product quality by removing or minimizing oxide defects and to allow the production of higher integrity castings for high speed machining lines. Previous research has concentrated on macro-inclusions that break, chip, or crack machine tool cutters and drills and cause immediate shutdown of the machining lines. The overall goal of the project is to reduce the amount of surface macro-inclusions and improve the machinability of steel castings. Macro-inclusions and improve the machinability of steel castings. Macro-inclusions have been identified by industrial sponsors as a major barrier to improving the quality and marketability of steel castings.

  8. Homogenity of Die Casting and Returning Material

    Directory of Open Access Journals (Sweden)

    J. Malik

    2012-04-01

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

  9. Advanced casting technologies for lightweight automotive applications

    Directory of Open Access Journals (Sweden)

    Alan A. Luo

    2010-11-01

    Full Text Available This paper provides an overview of alloy and process developments in aluminum and magnesium castings for lightweight automotive applications. Wear-resistant aluminum alloys, creep-resistant and high strength/ductility magnesium alloys have been developed for automotive applications. On the process front, vacuum-assisted die casting and high vacuum die casting technologies have been developed for high-integrity body and chassis applications. Thin-wall and hollow casting components are being produced by low-pressure die casting processes for structural applications. Overcasting technology is gaining traction and has enabled mixed material designs for automotive sub-systems such as engine cradles and instrument panel beams. Simulation tools developed to predict the interfacial interactions of the dissimilar components and the structural integrity of the overcast systems are being validated in the casting trials.

  10. Chilling Tendency and Chill of Cast Iron

    Institute of Scientific and Technical Information of China (English)

    E. Fra(s); M. Górny; W. Kapturkiewicz; H. López

    2008-01-01

    An analytical expression is presented for the susceptibility of liquid cast iron to solidify according tothe Fe-C-X metastable system (also known as the chilling tendency of cast iron, CT). The analysis incorpo-rates the nucleation and growth processes associated with the eutectic transformation. The CT is related tothe physicochemical state of the liquid, the eutectic cells in the flake graphite, and the number of nodules innodular cast iron. In particular, the CT can be related to the critical wall thickness, Scr, or the chill width, Wcr,in wedge shaped castings. Finally, this work serves as a guide for understanding the effect of technical fac-tors such as the melt chemistry, the spheroidizing and inoculation practice, and the holding time and tam-perature on the resultant CT and chill of the cast iron. Theoretical calculations of Scr and Wcr compare wellwith experimental data for flake graphite and nodular cast iron.

  11. Method for casting thin metal objects

    Energy Technology Data Exchange (ETDEWEB)

    Pehrson, Brandon P; Moore, Alan F

    2015-04-14

    Provided herein are various embodiments of systems for casting thin metal plates and sheets. Typical embodiments include layers of mold cavities that are oriented vertically for casting the metal plates. In some embodiments, the mold cavities include a beveled edge such that the plates that are cast have a beveled edge. In some embodiments, the mold cavities are filled with a molten metal through an open horizontal edge of the cavity. In some embodiments, the mold cavities are filled through one or more vertical feed orifices. Further disclosed are methods for forming a thin cast metal plate or sheet where the thickness of the cast part is in a range from 0.005 inches to 0.2 inches, and the surface area of the cast part is in a range from 16 square inches to 144 square inches.

  12. 3D Surgical Simulation

    Science.gov (United States)

    Cevidanes, Lucia; Tucker, Scott; Styner, Martin; Kim, Hyungmin; Chapuis, Jonas; Reyes, Mauricio; Proffit, William; Turvey, Timothy; Jaskolka, Michael

    2009-01-01

    This paper discusses the development of methods for computer-aided jaw surgery. Computer-aided jaw surgery allows us to incorporate the high level of precision necessary for transferring virtual plans into the operating room. We also present a complete computer-aided surgery (CAS) system developed in close collaboration with surgeons. Surgery planning and simulation include construction of 3D surface models from Cone-beam CT (CBCT), dynamic cephalometry, semi-automatic mirroring, interactive cutting of bone and bony segment repositioning. A virtual setup can be used to manufacture positioning splints for intra-operative guidance. The system provides further intra-operative assistance with the help of a computer display showing jaw positions and 3D positioning guides updated in real-time during the surgical procedure. The CAS system aids in dealing with complex cases with benefits for the patient, with surgical practice, and for orthodontic finishing. Advanced software tools for diagnosis and treatment planning allow preparation of detailed operative plans, osteotomy repositioning, bone reconstructions, surgical resident training and assessing the difficulties of the surgical procedures prior to the surgery. CAS has the potential to make the elaboration of the surgical plan a more flexible process, increase the level of detail and accuracy of the plan, yield higher operative precision and control, and enhance documentation of cases. Supported by NIDCR DE017727, and DE018962 PMID:20816308

  13. RESEARCH AND APPLICATION OF AS-CAST WEAR RESISTANCE HIGH CHROMIUM CAST IRON

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    The influence of alloy elements, such as boron and silicon, on the microstructure and properties of as-cast high chromium cast iron is studied. The results show that boron and silicon have a great effect on the mechanical properties and the wear resistance. Through proper addition of boron and silicon, the properties of as-cast high chromium cast iron can be improved effectively. Through analyzing the distribution of elements by scanning electron microscope, it has been shown that the addition of boron and silicon lowers the mass fraction of chromium saturated in as-cast austenite, and makes it unstable and liable to be transformed into martensite. The as-cast high chromium cast iron with proper content of boron and silicon is suitable for the manufacture of lining for asphalt concrete mixer and its wear resistance is 14 times that of lining made of low alloy white cast iron.

  14. Influence of Technological Parameters of Furane Mixtures on Shrinkage Creation in Ductile Cast Iron Castings

    Directory of Open Access Journals (Sweden)

    Vasková I.

    2014-10-01

    Full Text Available Ductile cast iron (GS has noticed great development in last decades and its boom has no analogue in history humankind. Ductile iron has broaden the use of castings from cast iron into areas, which where exclusively domains for steel castings. Mainly by castings, which weight is very high, is the propensity to shrinkage creation even higher. Shrinkage creation influences mainly material, construction of casting, gating system and mould. Therefore, the main realized experiment was to ascertain the influence of technological parameters of furane mixture on shrinkage creation in castings from ductile iron. Together was poured 12 testing items in 3 moulds forto determine and compare the impact of various technological parameters forms the propensity for shrinkage in the casting of LGG.

  15. COOLING METHOD OF SILUMINA CASTINGS AK15M3 AT VERTICAL CENTRIFUGAL CASTING

    Directory of Open Access Journals (Sweden)

    V. Yu. Stecenko

    2013-01-01

    Full Text Available The way of cooling of castings from silumin AK15M3 is developed at the vertical centrifugal casting, enabling to receive bimetallic blanks with high-disperse eutectic and hypereutectic microstructures and minimal allowance for machining.

  16. Newly developed vacuum differential pressure casting of thin-walled complicated Al-alloy castings

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The newly designed vacuum differential pressure casting (VDPC) unit was introduced, by which the capability of the VDPC process to produce thin-walled complicated Al-alloy castings, that are free from oxides, gas pore and shrinkage cavity and thus enhance overall part quality, was studied. Experimental results were compared with those of traditional gravity pouring and vacuum suction casting. The first series of experiments were focused on investigating the castability of thin section Al-alloy casting. In the second series of experiments the metallographic evidence, casting strength and soundness were examined. Finally, case studies of very interesting thin walled complicated casting applications were described. The advantages of the described technique have made possible to produce thin walled complicated Al-alloy casting (up to a section thickness of 1 mm), which is not practical for gravity pouring and vacuum suction casting.

  17. Anxiety in veterinary surgical students

    DEFF Research Database (Denmark)

    Langebæk, Rikke; Eika, Berit; Jensen, Asger Lundorff

    2012-01-01

    The surgical educational environment is potentially stressful and this can negatively affect students' learning. The aim of this study was to investigate whether veterinary students' level of anxiety is higher in a surgical course than in a non-surgical course and if pre-surgical training...... in a Surgical Skills Lab (SSL) has an anxiety reducing effect. Investigations were carried out as a comparative study and a parallel group study. Potential participants were fourth-year veterinary students who attended a surgical course (Basic Surgical Skills) and a non-surgical course (Clinical Examination...... and 28 students from 2010). Our results show that anxiety levels in veterinary students are significantly higher in a surgical course than in a non-surgical course (p...

  18. 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.

  19. Improved Foundry Castings Utilizing CAD/CAM

    Science.gov (United States)

    1981-10-01

    designed to simulate the heat transfer behavior during freezing and the subsequent cooling of an arbitrarily shaped 3D casting solidify- ing in a sand...variety of complex 2D and 3D geometries may be simulated by these routines. It is important, however, to be aware of the assumptions made in the design...three-dimensional with a sand mold surrounding a steel casting. The simulation program is desing - ed to simulate any shape. The shape of test casting

  20. Thermal gradient analysis of solidifying casting

    Directory of Open Access Journals (Sweden)

    J. Suchoń

    2008-08-01

    Full Text Available For description of casting solidification and crystallization process the thermal derivative analysis (TDA is commonly used. Besides the process kinetics considered in TDA method to describe the solidification process, the thermal gradient analysis can be also used for this purpose [1, 2]. In conducted studies analysis of thermal gradient distribution inside the solidifying wedge casting was shown which enabled determination of heat flow intensity on casting section.

  1. Theory of uniqueness of Indian Caste System

    OpenAIRE

    Kumar, Ashwin

    2006-01-01

    Classical studies on pre-modern Indian social structure have suggested apparent differences between the Indian caste system and social stratification as one can discern in other parts of the world. However, one needs to question such dogmatic assertions that such vast differences really existed. An endeavor is made in this research paper to reflect on the nature of caste hierarchy in pre-modern India. The caste system forms the significant basis of pre-modern Indian social structure. Early wr...

  2. Caste and wealth inequality in India

    OpenAIRE

    Zacharias, Ajit; Vakulabharanam, Vamsi

    2009-01-01

    In this paper, we conduct the novel exercise of analyzing the relationship between overall wealth inequality and caste divisions in India using nationally representative surveys on household wealth conducted during 1991–92 and 2002–03. According to our findings, the groups in India that are generally considered disadvantaged (known as Scheduled Castes or Scheduled Tribes) have, as one would expect, substantially lower wealth than the "forward" caste groups, while the Other Backward Classes an...

  3. Vacuum-sealed casting process under pressure

    Institute of Scientific and Technical Information of China (English)

    LI Chen-xi; GUO Tai-ming; WU Chun-jing; WANG Hong

    2006-01-01

    A new casting method, the vacuum-sealed mold casting under pressure, has been developed, and thin wall iron castings with high precision and smooth surface have been produced successfully with this casting method. The experimental results show that the liquid iron has a very excellent filling ability because a high negative pressure is formed in the mold cavity during filling process. The vacuum-sealed mold under pressure has very high compressive strength greater than 650 kPa, which is 3-4 times as high as that of the molds produced by high-pressure molding process or vacuum-sealed molding process.

  4. Cast functional accessories for heat treatment furnaces

    Directory of Open Access Journals (Sweden)

    A. Drotlew

    2010-10-01

    Full Text Available The study gives examples of the cast functional accessories operating in furnaces for the heat treatment of metals and alloys. The describeddesign solutions of castings and their respective assemblies are used for charge preparation and handling. They were put in systematicorder depending on furnace design and the technological purpose of heat treatment. Basic grades of austenitic cast steel, used for castings of this type, were enumerated, and examples of general guidelines formulated for their use were stated. The functional accessories described in this study were designed and made by the Foundry Research Laboratory of West Pomeranian University of Technology.

  5. Friction Stir Processing of Cast Superalloys Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR effort examines the feasibility of an innovative fabrication technology incorporating sand casting and friction stir processing (FSP) for producing...

  6. Surgical bleeding in microgravity

    Science.gov (United States)

    Campbell, M. R.; Billica, R. D.; Johnston, S. L. 3rd

    1993-01-01

    A surgical procedure performed during space flight would occur in a unique microgravity environment. Several experiments performed during weightlessness in parabolic flight were reviewed to ascertain the behavior of surgical bleeding in microgravity. Simulations of bleeding using dyed fluid and citrated bovine blood, as well as actual arterial and venous bleeding in rabbits, were examined. The high surface tension property of blood promotes the formation of large fluid domes, which have a tendency to adhere to the wound. The use of sponges and suction will be adequate to prevent cabin atmosphere contamination with all bleeding, with the exception of temporary arterial droplet streams. The control of the bleeding with standard surgical techniques should not be difficult.

  7. Surgical management of presbyopia

    Directory of Open Access Journals (Sweden)

    Torricelli AA

    2012-09-01

    Full Text Available André AM Torricelli, Jackson B Junior, Marcony R Santhiago, Samir J BecharaDivision of Ophthalmology, University of São Paulo Medical School, São Paulo, BrazilAbstract: Presbyopia, the gradual loss of accommodation that becomes clinically significant during the fifth decade of life, is a physiologic inevitability. Different technologies are being pursued to achieve surgical correction of this disability; however, a number of limitations have prevented widespread acceptance of surgical presbyopia correction, such as optical and visual distortion, induced corneal ectasia, haze, anisometropy with monovision, regression of effect, decline in uncorrected distance vision, and the inherent risks with invasive techniques, limiting the development of an ideal solution. The correction of the presbyopia and the restoration of accommodation are considered the final frontier of refractive surgery. The purpose of this paper is to provide an update about current procedures available for presbyopia correction, their advantages, and disadvantages.Keywords: presbyopia, surgical correction, treatment

  8. 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.

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

    OpenAIRE

    2008-01-01

    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.

  10. Spray casting project final report

    Energy Technology Data Exchange (ETDEWEB)

    Churnetski, S.R.; Thompson, J.E.

    1996-08-01

    Lockheed Martin Energy Systems, Inc. (Energy Systems), along with other participating organizations, has been exploring the feasibility of spray casting depleted uranium (DU) to near-net shape as a waste minimization effort. Although this technology would be useful in a variety of applications where DU was the material of choice, this effort was aimed primarily at gamma-shielding components for use in storage and transportation canisters for high-level radioactive waste, particularly in the Multipurpose Canister (MPC) application. In addition to the waste-minimization benefits, spray casting would simplify the manufacturing process by allowing the shielding components for MPC to be produced as a single component, as opposed to multiple components with many fabrication and assembly steps. In earlier experiments, surrogate materials were used to simulate the properties (specifically reactivity and density) of DU. Based on the positive results from those studies, the project participants decided that further evaluation of the issues and concerns that would accompany spraying DU was warranted. That evaluation occupied substantially all of Fiscal Year 1995, yielding conceptual designs for both an intermediate facility and a production facility and their associated engineering estimates. An intermediate facility was included in this study to allow further technology development in spraying DU. Although spraying DU to near-net shape seems to be feasible, a number of technical, engineering, and safety issues would need to be evaluated before proceeding with a production facility. This report is intended to document the results from the spray-casting project and to provide information needed by anyone interested in proceeding to the next step.

  11. Control of Cast Iron Microstructure

    Science.gov (United States)

    Graham, J.; Lillybeck, N.; Franco, N.; Stefanescu, D. M.

    1985-01-01

    The use of microgravity for industrial research in the processing of cast iron was investigated. Solidification experiments were conducted using the KC-135 and F-104 aircraft, and an experiment plan was developed for follow-on experiments using the Shuttle. Three areas of interest are identified: (1) measurement of thermophysical properties in the melt; (2) understanding of the relative roles of homogeneous nucleation, grain multiplication, and innocultants in forming the microstructure; and (3) exploring the possibility of obtaining an aligned graphite structure in hypereutectic Fe, Ni, and Co.

  12. 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.

  13. 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

  14. Clean cast steel technology. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bates, C.E.; Griffin, J.A.

    1998-06-01

    This report documents the results obtained from the Clean Cast Steel Technology Program financially supported by the DOE Metal Casting Competitiveness Research Program and industry. The primary objective of this program is to develop technology for delivering steel free of oxide macroinclusions to mold cavities. The overall objective is to improve the quality of cast steel by developing and demonstrating the technology for substantially reducing surface and sub-surface oxide inclusions. Two approaches are discussed here. A total of 23 castings were produced by submerge pouring along with sixty conventionally poured castings. The submerged poured castings contained, on average, 96% fewer observable surface inclusions (11.9 vs 0.4) compared to the conventionally poured cast parts. The variation in the population of surface inclusions also decreased by 88% from 5.5 to 0.7. The machinability of the casting was also improved by submerged pouring. The submerge poured castings required fewer cutting tool changes and less operator intervention during machining. Subsequent to these trials, the foundry has decided to purchase more shrouds for continued experimentation on other problem castings where submerge pouring is possible. An examination of melting and pouring practices in four foundries has been carried out. Three of the four foundries showed significant improvement in casting quality by manipulating the melting practice. These melting practice variables can be grouped into two separate categories. The first category is the pouring and filling practice. The second category concerns the concentration of oxidizable elements contained in the steel. Silicon, manganese, and aluminum concentrations were important factors in all four foundries. Clean heats can consistently be produced through improved melting practice and reducing exposure of the steel to atmospheric oxygen during pouring and filling.

  15. PERFECTION OF TECHNOLOGY OF CASTINGS PRODUCTION TECHNOLOGY BY CONSUMABLE PATTERNS

    OpenAIRE

    N. I. Urbanovich; O. S. Komarov; V. I. Volosatikov; M. I. Kurbatov; V. G. Pavlovich

    2008-01-01

    The role of closed air gates at casting by gasified models of non-casting polystyrene in the process of castings defects elimination, connected with creation of non-gasified products of polystyrene thermodestruction, is studied.

  16. PERFECTION OF TECHNOLOGY OF CASTINGS PRODUCTION TECHNOLOGY BY CONSUMABLE PATTERNS

    Directory of Open Access Journals (Sweden)

    N. I. Urbanovich

    2008-01-01

    Full Text Available The role of closed air gates at casting by gasified models of non-casting polystyrene in the process of castings defects elimination, connected with creation of non-gasified products of polystyrene thermodestruction, is studied.

  17. 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.

  18. [Optimizing surgical hand disinfection].

    Science.gov (United States)

    Kampf, G; Kramer, A; Rotter, M; Widmer, A

    2006-08-01

    For more than 110 years hands of surgeons have been treated before a surgical procedure in order to reduce the bacterial density. The kind and duration of treatment, however, has changed significantly over time. Recent scientific evidence suggests a few changes with the aim to optimize both the efficacy and the dermal tolerance. Aim of this article is the presentation and discussion of new insights in surgical hand disinfection. A hand wash should be performed before the first disinfection of a day, ideally at least 10 min before the beginning of the disinfection as it has been shown that a 1 min hand wash significantly increases skin hydration for up to 10 min. The application time may be as short as 1.5 min depending on the type of hand rub. Hands and forearms should be kept wet with the hand rub for the recommended application time in any case. A specific rub-in procedure according to EN 12791 has been found to be suitable in order to avoid untreated skin areas. The alcohol-based hand rub should have a proven excellent dermal tolerance in order to ensure appropriate compliance. Considering these elements in clinical practice can have a significant impact to optimize the high quality of surgical hand disinfection for prevention of surgical site infections.

  19. Surgical infections with Mycoplasma

    DEFF Research Database (Denmark)

    Levi-Mazloum, Niels Donald; Prag, Jørgen Brorson; Jensen, J S;

    1997-01-01

    Mycoplasma hominis and Ureaplasma urealyticum are common inhabitants of the human genital tract. Evidence for an aetiological role in pyelonephritis, pelvic inflammatory disease, post-abortion and post-partum fever has been presented. There are sporadic reports of Mycoplasma causing serious extra...... extragenital infection such as septicemia, septic arthritis, neonatal meningitis and encephalitis. We review 38 cases of surgical infections with Mycoplasma....

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

    Directory of Open Access Journals (Sweden)

    Š. Gašpár

    2016-07-01

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

  1. Laboratory grey cast iron continuous casting line with electromagnetic forced convection support

    Directory of Open Access Journals (Sweden)

    J. Szajnar

    2010-07-01

    Full Text Available The article describes the construction of a 20 mm diameter grey cast iron ingots continuous casting laboratory line. This line is made ofthree main units: melting unit (induction furnace, casting unit and the pulling unit. In order to improve the homogeneity of themicrostructure of ingots (by applying forced convection of liquid metal during the crystallization process in this case a crystallizer system generating the forced movement of liquid metal based on a system of electrical power windings of the AC specific frequency. Thissolution allowed to obtain a homogeneous microstructure of the continuous casting of cast iron EN-GJL-200 species.

  2. DEVELOPMENTS IN THE FIELD OF STEEL AND CAST IRON

    Directory of Open Access Journals (Sweden)

    E. B. Ten

    2013-01-01

    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. Casting fine grained, fully dense, strong inorganic materials

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Sam W.; Spencer, Larry S.; Phillips, Michael R.

    2015-11-24

    Methods and apparatuses for casting inorganic materials are provided. The inorganic materials include metals, metal alloys, metal hydrides and other materials. Thermal control zones may be established to control the propagation of a freeze front through the casting. Agitation from a mechanical blade or ultrasonic energy may be used to reduce porosity and shrinkage in the casting. After solidification of the casting, the casting apparatus may be used to anneal the cast part.

  4. [da Vinci surgical system].

    Science.gov (United States)

    Watanabe, Gou; Ishikawa, Norihiro

    2014-07-01

    The da Vinci surgical system was developed by Intuitive Surgical Inc. in the United States as an endoscopic surgical device to assist remote control surgeries. In 1998, the Da Vinci system was first used for cardiothoracic procedures. Currently a combination of robot-assisted internal thoracic artery harvest together with coronary artery bypass grafting (CABG) through a mini-incision (ThoraCAB) or totally endoscopic procedures including anastomoses under robotic assistance (TECAB) are being conducted for the treatment of coronary artery diseases. With the recent advances in catheter interventions, hybrid procedures combining catheter intervention with ThoraCAB or TECAB are anticipated in the future.On the other hand, with the decrease in number of coronary artery bypass surgeries, the share of valvular surgeries is expected to increase in the future. Among them, mitral valvuloplasty for mitral regurgitation is anticipated to be conducted mainly by low-invasive procedures, represented by minimally invasive cardiac surgery( MICS) and robot-assisted surgery. Apart from the intrinsic good surgical view, robotic-assisted systems offer additional advantages of the availability of an amplified view and the easy to observe the mitral valve in the physiological position. Thus, robotic surgical surgeries that make complicated procedures easier are expected to accomplish further developments in the future. Furthermore, while the number of surgeries for atrial septal defects has decreased dramatically following the widespread use of Amplatzer septal occluder, robotic surgery may become a good indication for cases in which the Amplatzer device is not indicated. In Japan, clinical trial of the da Vinci robotic system for heart surgeries has been completed. Statutory approval of the da Vinci system for mitral regurgitation and atrial septal defects is anticipated in the next few years.

  5. Theory of Cast Formation in Electrophoretic Deposition

    NARCIS (Netherlands)

    Biesheuvel, P. Maarten; Verweij, Henk

    1999-01-01

    The rate of cast formation in electrophoretic deposition is described by a combination of the equation of continuity for the suspension phase with expressions for the particle velocity and the movement of the cast-suspension boundary. The assumptions necessary to arrive at the well-known equations o

  6. Model castings with composite surface layer - application

    Directory of Open Access Journals (Sweden)

    J. Szajnar

    2008-10-01

    Full Text Available The paper presents a method of usable properties of surface layers improvement of cast carbon steel 200–450, by put directly in foundingprocess a composite surface layer on the basis of Fe-Cr-C alloy. Technology of composite surface layer guarantee mainly increase inhardness and aberasive wear resistance of cast steel castings on machine elements. This technology can be competition for generallyapplied welding technology (surfacing by welding and thermal spraying. In range of studies was made cast steel test castings withcomposite surface layer, which usability for industrial applications was estimated by criterion of hardness and aberasive wear resistance of type metal-mineral and quality of joint cast steel – (Fe-Cr-C. Based on conducted studies a thesis, that composite surface layer arise from liquid state, was formulated. Moreover, possible is control of composite layer thickness and its hardness by suitable selection of parameters i.e. thickness of insert, pouring temperature and solidification modulus of casting. Possibility of technology application of composite surface layer in manufacture of cast steel slide bush for combined cutter loader is presented.

  7. Geometric aspects of the casting process

    NARCIS (Netherlands)

    Ahn, H.-K.

    2002-01-01

    Manufacturing is the process of converting raw materials into useful products. Among the most important manufacturing processes, casting is a commonly used manufacturing process for plastic and metal objects. The industrial casting process consists of two stages. First, liquid is filled into a cavit

  8. Iron/Phosphorus Alloys for Continuous Casting

    Science.gov (United States)

    Dufresne, E. R.

    1986-01-01

    Continuous casting becomes practicable because of reduced eutectic temperature. Experimental ferrous alloy has melting point about 350 degrees C lower than conventional steels, making possible to cast structural members and eliminating need for hot rolling. Product has normal metal structure and good physical properties. Process used to make rails, beams, slabs, channels, and pipes.

  9. 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.

  10. Numerical modelling of stresses and deformations in casting processes

    DEFF Research Database (Denmark)

    Hattel, Jesper Henri

    1997-01-01

    Keywords: Stresses and deformations, casting, governing equations, thermal strain, control volume method......Keywords: Stresses and deformations, casting, governing equations, thermal strain, control volume method...

  11. Standard digital reference images for titanium castings

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 The digital reference images provided in the adjunct to this standard illustrate various types and degrees of discontinuities occurring in titanium castings. Use of this standard for the specification or grading of castings requires procurement of the adjunct digital reference images, which illustrate the discontinuity types and severity levels. They are intended to provide the following: 1.1.1 A guide enabling recognition of titanium casting discontinuities and their differentiation both as to type and degree through digital radiographic examination. 1.1.2 Example digital radiographic illustrations of discontinuities and a nomenclature for reference in acceptance standards, specifications and drawings. 1.2 The digital reference images consist of seventeen digital files each illustrating eight grades of increasing severity. The files illustrate seven common discontinuity types representing casting sections up to 1-in. (25.4-mm). 1.3 The reference radiographs were developed for casting sections up to 1...

  12. Ferritic-austenitic cast steel - selected problems

    Directory of Open Access Journals (Sweden)

    Z. Stradomski

    2011-07-01

    Full Text Available The author has been involved in the problems occurring in the manufacture of ferritic-austenitic cast steel castings for many years. The author’s remarks and investigation results reported in this article will enable potential manufacturers to determine their own technical capabilities and structural determinants related to the chemical composition of material, which are crucial to the good quality of a casting. Particular emphasis should be laid on the role of enhanced carbon content, the presence of copper, the precipitates of the ζ phase, and the nature of solidification structure in the tendency of duplex-type cast steel to cracking. It seems that in view of the pro-ecological activities undertaken, including flue gas desulphurization in coal-fired power plants, efforts should be made in steel foundries to introduce selected grades of ferritic-austenitic cast steel to production.

  13. INDIAN CASTE SYSTEM: HISTORICAL AND PSYCHOANALYTIC VIEWS.

    Science.gov (United States)

    Vallabhaneni, Madhusudana Rao

    2015-12-01

    This paper elucidates the historical origins and transformations of India's caste system. Surveying the complex developments over many centuries, it points out that three positions have been taken in this regard. One suggests that the caste one is born into can be transcended within one's lifetime by performing good deeds. The other declares caste to be immutable forever. And, the third says that one can be reborn into a higher caste if one lives a virtuous life. Moving on to the sociopolitical realm, the paper notes how these positions have been used and exploited. The paper then attempts to anchor the existence and purpose of the Hindu caste system in Freud's ideas about group psychology and Klein's proposals of splitting and projective identification. The paper also deploys the large group psychology concepts of Volkan and the culturally nuanced psychoanalytic anthropology of Roland and Kakar. It concludes with delineating some ameliorative strategies for this tragic problem in the otherwise robust democratic society of India.

  14. Possible segregation caused by centrifugal titanium casting.

    Science.gov (United States)

    Watanabe, K; Okawa, S; Kanatani, M; Nakano, S; Miyakawa, O; Kobayashi, M

    1996-12-01

    The possibility of the segregation under solidification process using a centrifugal casting machine was investigated using an electron probe microanalyzer with elemental distribution map, line analysis and quantitative analysis. When a very small quantity of platinum was added to local molten titanium during the casting process, macroscopic segregation was observed under conditions of density difference of 0.1 g/cm3 at the most, confirming that the centrifugal force of the casting machine is extremely strong. When a Ti-6Al-4V alloy was cast, however, no macroscopic segregation was observed. The centrifugal force of the casting machine examined in the present study hardly results in the body-force segregation in this titanium alloy.

  15. Application of Integrated Database to the Casting Design

    Institute of Scientific and Technical Information of China (English)

    In-Sung Cho; Seung-Mok Yoo; Chae-Ho Lim; Jeong-Kil Choi

    2008-01-01

    Construction of integrated database including casting shapes with their casting design, technical knowledge, and thermophysical properties of the casting alloys were introduced in the present study. Recognition tech- nique for casting design by industrial computer tomography was used for the construction of shape database. Technical knowledge of the casting processes such as ferrous and non-ferrous alloys and their manufacturing process of the castings were accumulated and the search engine for the knowledge was developed. Database of thermophysical properties of the casting alloys were obtained via the experimental study, and the properties were used for .the in-house computer simulation of casting process. The databases were linked with intelligent casting expert system developed in center for e-design, KITECH. It is expected that the databases can help non casting experts to devise the casting and its process. Various examples of the application by using the databases were shown in the present study.

  16. Spacecraft surgical scrub system

    Science.gov (United States)

    Abbate, M.

    1980-01-01

    Ease of handling and control in zero gravity and minimizing the quantity of water required were prime considerations. The program tasks include the selection of biocidal agent from among the variety used for surgical scrub, formulation of a dispensing system, test, and delivery of flight dispensers. The choice of an iodophore was based on effectiveness on single applications, general familiarity among surgeons, and previous qualification for space use. The delivery system was a choice between the squeeze foamer system and impregnated polyurethane foam pads. The impregnated foam pad was recommended because it is a simpler system since the squeeze foamer requires some applicator to effectively clean the skin surfaces, whereas the form pad is the applicator and agent combined. Testing demonstrated that both systems are effective for use as surgical scrubs.

  17. Vitiligo- A surgical approach

    Directory of Open Access Journals (Sweden)

    Deepti Ghia

    2012-01-01

    Full Text Available Aims and objective- To describe the spectrum of surgical modalities for stable vitiligo patients Methods- Patients having stable vitiligo since past 2 years with no improvement with medical line of treatment were enrolled for surgery after informed consent. Depending upon the size and location of vitiligo patch different modalities were performed. Suction blister, mini-punch grafting, split thickness skin grafting, trypsinised melanocyte-keratinocyte transfer and non-trypsinised melanocyte- keratinocyte transfer (Jodhpur technique and follicular grafting technique have been described photographically which have been performed at a tertiary care hospital. Conclusion- Vitiligo is often difficult to treat, stable patches resistant to medical line of management do respond to surgical treatment; however it is very important to choose the modality of surgery according location of the patch, size of the lesion and available resources.

  18. Hepatic surgical anatomy.

    Science.gov (United States)

    Skandalakis, John E; Skandalakis, Lee J; Skandalakis, Panajiotis N; Mirilas, Petros

    2004-04-01

    The liver, the largest organ in the body, has been misunderstood at nearly all levels of organization, and there is a tendency to ignore details that do not fit the preconception. A complete presentation of the surgical anatomy of the liver includes the study of hepatic surfaces, margins, and fissures; the various classifications of lobes and segments; and the vasculature and lymphatics. A brief overview of the intrahepatic biliary tract is also presented.

  19. Surgical navigation with QR codes

    Directory of Open Access Journals (Sweden)

    Katanacho Manuel

    2016-09-01

    Full Text Available The presented work is an alternative to established measurement systems in surgical navigation. The system is based on camera based tracking of QR code markers. The application uses a single video camera, integrated in a surgical lamp, that captures the QR markers attached to surgical instruments and to the patient.

  20. A prospective randomized study of conservative versus surgical treatment of unstable palmar plate disruption in the proximal interphalangeal finger joint

    DEFF Research Database (Denmark)

    Werlinrud, Jens Christian; Petersen, Kirstin; Lauritsen, Jens;

    2013-01-01

    study in which 83 patients were randomly assigned into 2 groups: (1) conservative treatment with a rigid splint for 2 weeks, (2) surgical reattachment of the palmar plate in local anesthesia followed by 2 weeks of immobilization in a plaster cast. Both groups were thereafter treated by taping...

  1. Guideline implementation: Surgical attire.

    Science.gov (United States)

    Cowperthwaite, Liz; Holm, Rebecca L

    2015-02-01

    Surgical attire helps protect patients from microorganisms that may be shed from the hair and skin of perioperative personnel. The updated AORN "Guideline for surgical attire" provides guidance on scrub attire, shoes, head coverings, and masks worn in the semirestricted and restricted areas of the perioperative setting, as well as how to handle personal items (eg, jewelry, backpacks, cell phones) that may be taken into the perioperative suite. This article focuses on key points of the guideline to help perioperative personnel adhere to facility policies and regulatory requirements for attire. The key points address the potential benefits of wearing scrub attire made of antimicrobial fabric, covering the arms when in the restricted area of the surgical suite, removing or confining jewelry when wearing scrub attire, disinfecting personal items that will be taken into the perioperative suite, and sending reusable attire to a health care-accredited laundry facility after use. Perioperative RNs should review the complete guideline for additional information and for guidance when writing and updating policies and procedures.

  2. Louis Pasteur surgical revolution.

    Science.gov (United States)

    Toledo-Pereyra, Luis H

    2009-01-01

    Louis Pasteur (1822-1895) is considered the most notable medical scientist of his time and perhaps one of the most distinguished of all times in the history of medicine. From Dole in France to Paris, from a student of crystals to "living ferments," and from chemistry to biology and medicine, Pasteur changed the world for the benefit of humanity. The genius of Pasteur dealt with the most pressing issues of his time, basing the germ theory on the effects that microorganisms had on fermentation and putrefaction of organic matter, which gave birth to the science of bacteriology. Many other difficult problems in medicine and biology were tackled by Pasteur, culminating in the spectacular results seen with the treatment of rabies. Surgery was no exception to the scientific conquests of Pasteur. The transformation of the surgical world arose from the antiseptic concepts of Lister that were based on the germ theory of the disease, which had been derived from the germ theory of fermentation and putrefaction discovered by Pasteur. The acceptance of these principles represented the surgical revolution brought on by the science of Pasteur, a revolution that is now accepted in our daily care of surgical patients.

  3. 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.

  4. 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.

  5. The X-ray Telescope of CAST

    OpenAIRE

    Kuster, M.; Bräuninger, H.; Cébrian, S.; Davenport, M.; Elefteriadis, C.; Englhauser, J.; Fischer, H.; Franz, J.; Friedrich, P.; R. Hartmann; Heinsius, F.H.; Hoffmann, D.H.H.; Hoffmeister, G.; Joux, J. N.; Kang, D.

    2007-01-01

    The Cern Axion Solar Telescope (CAST) is in operation and taking data since 2003. The main objective of the CAST experiment is to search for a hypothetical pseudoscalar boson, the axion, which might be produced in the core of the sun. The basic physics process CAST is based on is the time inverted Primakoff effect, by which an axion can be converted into a detectable photon in an external electromagnetic field. The resulting X-ray photons are expected to be thermally distributed between 1 and...

  6. CAST with its micromegas detector installed.

    CERN Multimedia

    Maximilien Brice

    2002-01-01

    The CERN Axion Solar Telescope (CAST) uses a prototype LHC dipole magnet to search for very weakly interacting neutral particles called axions, which should originate in the core of the Sun. The magnet converts the solar axions to photons which are then detected by an X-ray detector based on Micromegas technology. CAST's Micromegas detector has now been installed. Photos 01 02: General view of the CAST experiment with the Micromegas detector in place. Photo 03: Close-up of the micromegas set-up.

  7. Characteristics of cast and welded aluminium nodes

    Energy Technology Data Exchange (ETDEWEB)

    Oedegaard, J.; Polanco, M.; Syvertsen, F.; Sund, H. [SINTEF, Trondheim (Norway). Materials Technology

    2000-07-01

    It has been demonstrated that sand cast aluminium nodes can be produced with properties that gives competitive energy absorption capacity compared with welded aluminium nodes. Sand cast nodes could be mass-produced to a low cost and with properties that should be competitive to the properties of fusion welded nodes. This may open for simpler and more cost-effective joint alternatives when production of aluminium space-frames and subassemblies are in focus. Cast nodes joined to extruded members by adhesive bonding could be one example. (orig.)

  8. PHYSICAL SIMULATION OF CONTINUOUS ROLL CASTING PROCESS

    Institute of Scientific and Technical Information of China (English)

    L.H. Zhan; J. Zhong; X.Q. Li; M.H. Huang

    2005-01-01

    A series of simulating experimental studies on the rheological behavior and its influential factors of aluminum alloy in continuous roll-casting process have been explored in this paper with a Gleeble-1500 Thermal-Mechanical Simulation Tester and a set of special clamp system. Relevant rheological rules in the process of coupling transient solidification and continuous deformation of roll-casting conditions are obtained. Experimental results indicate that four different characteristic stages exist in the whole rheological process, and relative constitutive models suitable for the given conditions of continuous roll casting process have been established through multivariable linear regression analysis of the experimental data.

  9. Optimization of the Chemical Composition of Cast Iron Used for Casting Ball Bearing Grinding Disks

    Institute of Scientific and Technical Information of China (English)

    Aurel Crisan; Sorin Ion; Munteanu; Ioan Ciobanu; Iulian Riposan

    2008-01-01

    The chemical composition of cast iron used for casting ball bearing machining disks was varied to optimize the properties such as castability, hardenability, and durability in ball machining. The cast iron characteristics were most strongly dependent on the Ni content and the carbon saturation degree, So. This paper describes the types of test specimens, the working conditions, and the experimental results. The in-crease of the degree of carbon saturation reduces the tendency to form shrinkholes in the castings. The de-crease in the Ni content negatively affects the final hardening treatment. A way to control solidification de-fects in cast iron, by reducing the Ni content, has been verified on cast disks.

  10. 49 CFR 192.275 - Cast iron pipe.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Cast iron pipe. 192.275 Section 192.275... Cast iron pipe. (a) Each caulked bell and spigot joint in cast iron pipe must be sealed with mechanical leak clamps. (b) Each mechanical joint in cast iron pipe must have a gasket made of a...

  11. Laboratory grey cast iron continuous casting line with electromagnetic forced convection support

    OpenAIRE

    2010-01-01

    The article describes the construction of a 20 mm diameter grey cast iron ingots continuous casting laboratory line. This line is made ofthree main units: melting unit (induction furnace), casting unit and the pulling unit. In order to improve the homogeneity of themicrostructure of ingots (by applying forced convection of liquid metal during the crystallization process) in this case a crystallizer system generating the forced movement of liquid metal based on a system of electrical power win...

  12. Dimensional accuracy of small gold alloy castings. Part 4. The casting ring and ring liners.

    Science.gov (United States)

    Morey, E F

    1992-04-01

    The role of the casting ring and its asbestos liner is discussed. Asbestos as a liner has now largely been replaced by two alternative materials, one based on cellulose and the other on ceramic fibres. The limited literature on the effect of these newer materials on casting accuracy is also reviewed as their introduction may require significant changes in the traditional technology of dental casting.

  13. Spines of Steel: A Case of Surgical Enthusiasm in Cold War America.

    Science.gov (United States)

    Linker, Beth

    2016-01-01

    Just as the prevalence of scoliosis began to decline precipitously after World War II, American orthopedic surgeon Dr. Paul R. Harrington devised a new, invasive surgical system whereby implantable prosthetic metal rods and hooks were used to straighten curved backs. By the 1970s, "Harrington rods" had become the gold standard of surgical scoliosis care in the United States, replacing more conventional methods of exercise, bracing, and casting. This article situates the success of Harrington rods within a much larger and historically longer debate about why, when compared to those in other nations, American surgeons appear to be "more aggressive" and "knife-happy." Using Harrington's papers and correspondence, I argue that patients played a vital role in the rise of spinal surgery. As such, this article examines not only how surgical enthusiasm has been historically measured, defined, and morally evaluated, but also how scoliosis became classified as a debility in need of surgical management.

  14. Diverticulitis: selective surgical management.

    Science.gov (United States)

    Rugtiv, G M

    1975-08-01

    The surgical treatment of complications of diverticulitis remains most challenging. A review of twenty years' experience with one hundred fifteen cases is presented with one proved anastomotic leak and no deaths. Interval primary resection with anastomosis for chronic recurrent disease including colovesical fistula and mesocolic abscess was proved sate with low morbidity. The three-stage procedure for perforated diverticulitis with spreading peritonitis or pericolic abscess was associated with a high rate of complications and morbidity. An aggressive approach with resection without anastomosis in two stages is indicated.

  15. Investigations of Protective Coatings for Castings of High-manganese Cast Steels

    Directory of Open Access Journals (Sweden)

    M. Holtzer

    2013-01-01

    Full Text Available When cast steel castings are made in moulding sands on matrices of high-silica sand, which has a low fire resistance the problem of theso-called chemical penetration is distinctly visible. Whereas this effect appears to a small degree only when moulding sand matrices are of chromite, zircon or olivine sands. Therefore in case of making castings of high-manganese cast steel (e.g. Hadfield steel sands not containing free silica should be applied (e.g. olivine sand or in case of a high-silica matrix protective coatings for moulds and cores should be used. Two protective coatings, magnesite alcoholic (marked as coating 1 and coating 2 originated from different producers and intended for moulds for castings of the Hadfield steel, were selected for investigations. Examinations of the basic properties were performed for these coatings: viscosity, thermal analysis, sedimentation properties, wear resistance. In order to estimate the effectiveness of protective coatings the experimental castings were prepared. When applying coating 1, the surface quality of the casting was worse and traces of interaction between the casting material (cast steel and the coating were seen. When protective coating 2 was used none interactions were seen and the surface quality was better.

  16. Genetic structure of Rajaka caste and affinities with other caste populations of Andhra Pradesh, India.

    Science.gov (United States)

    Parvatheesam, C; Babu, B V; Babu, M C

    1997-01-01

    The present study gives an account of the genetic structure in terms of distribution of a few genetic markers, viz., A1A2B0, Rh(D), G6PD deficiency and haemoglobin among the Rajaka caste population of Andhra Pradesh, India. The genetic relationships of the Rajaka caste with other Andhra caste populations were investigated in terms of genetic distance, i.e., Sq B (mn) of Balakrishnan and Sanghvi. Relatively lesser distance was established between the Rajaka and two Panchama castes. Also, the pattern of genetic distance corroborates the hierarchical order of the Hindu varna system.

  17. Centrifugal Casting of High Speed Steel/Nodular Cast Iron Compound Roll Collar

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The centrifugal casting of compound HSS/nodular cast iron roll collar was studied, and the factors affecting transition zone quality were analyzed. The pouring temperature and interval in pouring are the main factors affecting transition zone quality. By controlling process parameter and flux adding during casting, high quality roll collar was obtained. The cause, why in the casting of HSS part, segregation appears easily, was analyzed and the countermeasure eliminating segregation was put forward, the measure eliminating heat treatment crackling was also put forward.

  18. Alumina Carbon Refractory Products for Continuous Casting

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ 1 Scope This standard specifies the classification.techni-cal requirements,test methods,inspection rules,packing,marking,transportation,storage and quality certificate of alumina carbon refractory products for continuous casting.

  19. ToxCast/ToxRefDB

    Data.gov (United States)

    U.S. Environmental Protection Agency — ToxCast is used as a cost-effective approach for efficiently prioritizing the toxicity testing of thousands of chemicals. It uses data from state-of-the-art high...

  20. Cast Care: Do's and Don'ts

    Science.gov (United States)

    ... has a fiberglass cast that's lined with a water-repellent liner, it's probably OK for him or her ... opportunities Reprint Permissions A single copy of these materials may be reprinted for noncommercial personal use only. " ...

  1. Caste in India, Past and Present

    Science.gov (United States)

    Bishop, Donald H.

    1971-01-01

    Traced is the sociocultural framework for the system in Indian culture which emphasized duty and obligations rather than individual freedom and rights. Also discussed are contemporary changes in the caste system. (DB)

  2. Theory of uniqueness of Indian Caste System

    Directory of Open Access Journals (Sweden)

    Ashwin Kumar

    2006-08-01

    Full Text Available Classical studies on pre-modern Indian social structure have suggested apparent differences between the Indian caste system and social stratification as one can discern in other parts of the world. However, one needs to question such dogmatic assertions that such vast differences really existed. An endeavor is made in this research paper to reflect on the nature of caste hierarchy in pre-modern India. The caste system forms the significant basis of pre-modern Indian social structure. Early writers conceived the caste system of pre-modern India as something unique to India. An attempt is made to question this application of theory of uniqueness in the case of India.

  3. Theory of uniqueness of Indian Caste System

    Directory of Open Access Journals (Sweden)

    Ashwin Kumar

    2005-11-01

    Full Text Available Classical studies on pre-modern Indian social structure have suggested apparent differences between the Indian caste system and social stratification as one can discern in other parts of the world. However, one needs to question such dogmatic assertions that such vast differences really existed. An endeavor is made in this research paper to reflect on the nature of caste hierarchy in pre-modern India. The caste system forms the significant basis of pre-modern Indian social structure. Early writers conceived the caste system of pre-modern India as something unique to India. An attempt is made to question this application of theory of uniqueness in the case of India.

  4. Rare Earth Additions in Continuously Cast Steel

    Science.gov (United States)

    Wilson, William G.; Heaslip, L. J.; Sommerville, I. D.

    1985-09-01

    Rare earth (lanthanide metals) addiiions to continuously cast steel are particularly advantageous because of their ability to refine as-cast structures, reduce segregation and increase hot ductility at temperatures just below that of solidification. The complete shape control of sulfides in steels containing Rare Earth Metals (REM), whether continuously cast or ingot cast, is primarily responsible for improvements in ductility related mechanical properties, weldability, fatigue resistance and resistance to hydrogen damage. Complete sulfide shape control can be obtained with REM additions at sulfur levels as high as.020%. The greatest improvements, however, are obtained with REM additions to low sulfur steels. However, to achieve full operational advantages afforded by REM, nozzle blockage problems must be circumvented. Water model studies indicate a possible solution.

  5. Friction Stir Processing of Cast Superalloys Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase I effort examines the feasibility of an innovative fabrication technology incorporating sand casting and friction stir processing (FSP) for producing...

  6. Advanced lost foam from casting technology

    Energy Technology Data Exchange (ETDEWEB)

    Bates, C. E.; Littleton, H. E.; Askeland, D.; Griffin, J.; Miller, B. A.; Sheldon, D. S.

    1996-05-01

    Previous research made significant advances in understanding the Lost Foam Casting (LFC) Process and clearly identified areas where additional research was needed to improve the process and make it more functional in an industrial environment. The current project focused on five areas listed as follows: Task 1: Precision Pattern Production Task 2: Pattern Coating Consistency Task 3: Sand Fill and Compaction Effects Task 4: Pattern Gating Task 5: Mechanical Properties of Castings. This report summarizes the work done under the current contract in all five areas in the period of October 1, 1994 through December 31, 1995. Twenty-eight (28) companies jointly participate in the project. These companies represent a variety of disciplines, including pattern designers, pattern producers, coating manufacturers, plant design companies, compaction equipment manufacturers, casting producers, and casting buyers.

  7. Anterior distal tibial epiphysiodesis for the treatment of recurrent equinus deformity after surgical treatment of clubfeet

    DEFF Research Database (Denmark)

    Al-Aubaidi, Zaid; Lundgaard, Bjarne; Pedersen, Niels Wisbech

    2011-01-01

    to new posteromedial release, or correction using the Ilizarov fixator. Supramalleolar osteotomy was practiced for the treatment of residual equinus. The aim of this study is to evaluate the effect of anterior epiphysiodesis of the distal tibia on recurrent equinus deformity in patients with clubfeet......ABSTRACT: The treatment of clubfeet has changed constantly. Before the acceptance of the Ponseti serial casting, extensive surgical release was widely used. The treatment of relapse in these surgically treated clubfeet can be very challenging. Many methods have been used ranging from osteotomies...

  8. Fabrication of bulk metallic glasses by centrifugal casting method

    OpenAIRE

    R. Nowosielski; R. Babilas

    2007-01-01

    Purpose: The aim of the present work is characterization of the centrifugal casting method, apparatus andproduced amorphous materials, which are also known as bulk metallic glassesDesign/methodology/approach: The studied centrifugal casting system consists of two main parts: castingapparatus and injection system of molten alloy. The described centrifugal casting method was presented bypreparing a casting apparatus “CentriCast – 5”. The apparatus includes a cylindrical copper mold, which isrot...

  9. Strip Casting of High Performance Structural Alloys

    Institute of Scientific and Technical Information of China (English)

    S S Park; J G Lee; Nack J Kim

    2004-01-01

    There exists a great need for the development of high performance alloys due to increasing demands for energy conservation and environmental protection. Application of strip casting shows a strong potential for the improvement of properties of existing alloys and also for the development of novel alloy systems with superior properties. The present paper reviews our Center's activities in the development of high performance alloys by strip casting. Examples include (1) Al alloys, (2) wrought Mg alloys, and (3) bulk metallic glass (BMG) alloys.

  10. Casting Technology Development for SFR Metallic Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Lee, C.T.; Oh, S.J.; Ryu, H.J.; Kim, K.H.; Lee, Y.S.; Kim, S.K.; Woo, Y.M.; Ko, Y.M.; Lee, C.B. [KAERI, 150 Deokjin-dong, Yuseong, Daejeon, 305-353 (Korea, Republic of)

    2009-06-15

    Fabrication technology of metallic fuel for sodium fast reactor (SFR) is being developed in Korea as a national mid- and long-term nuclear R and D program from 2007. The metallic fuel for SFR should be remotely fabricated under a radiation shielded environment such as a glove box or hot cell, because it contains long-lived minor actinides such as Np, Am and Cm. In order to design a reliable remote fabrication system, various casting techniques have been studied by using U-Zr and U-Zr-RE alloys as surrogate fuel material. Rare earth elements such as Ce or Nd were used as a surrogate for minor actinide elements or solid solution fission products. Macro-scale soundness, microstructures and compositional homogeneity of metallic fuel samples fabricated by vacuum-assisted injection casting, vacuum-assisted gravity casting, centrifugal atomization and continuous casting were compared. Although sound slugs of U-Zr metallic fuel of 4{approx}6 mm in diameter could be fabricated by vacuum-assisted injection casting or vacuum-assisted gravity casting, it was necessary to consider that vaporization of Am and volume of radioactive wastes such as crucibles and molds should be minimized. Effects of casting parameters on the volatile loss, and effects of coatings on the chemical reaction between metallic fuel and molds are discussed. Some methods to reduce the volatile Am loss and waste molds and crucibles will be proposed. Short rods of U-Zr or U-Zr-Ce fuel will be fabricated by the vacuum-assisted gravity casting technique for an irradiation test in the HANARO research reactor from 2010. (authors)

  11. CAST Xi'an Branch Established

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ China Academy of Space Technology (CAST) Xi'an Branch was established on April 8,2008.The new branch consists of the headquarters of the former Xi'an Institute of Space Radio Technology (XISRT) of CAST and five former subsidiaries of the XISRT,i.e.the Institute of Space Electronic Technology,the Institute of Microwave Technology,the Institute of Space Antenna Technology,the Manufacturing Center for Space Electronics and Civilian High-tech Company.

  12. Combination Of Investment And Centrifugal Casting

    Science.gov (United States)

    Creeger, Gordon A.

    1994-01-01

    Modifications, including incorporation of centrifugal casting, made in investment-casting process reducing scrap rate. Used to make first- and second-stage high-pressure-fuel-turbopump nozzles, containing vanes with thin trailing edges and other thin sections. Investment mold spun for short time while being filled, and stopped before solidification occurs. Centrifugal force drives molten metal into thin trailing edges, ensuring they are filled. With improved filling, preheat and pour temperatures reduced and solidification hastened so less hot tearing.

  13. Casting Process Developments for Improving Quality

    Science.gov (United States)

    El-Mahallawy, Nahed A.; Taha, Mohamed A.

    1985-09-01

    This paper presents a short synopsis of the important developments in casting/solidification processes, as well as the important advances in the conventional methods. These developments are discussed related to quality aspects. The position of each process with respect to practice, as well as expected gains in cost, are examined. The paper briefly features the author's work on innovative processes (directional solidification, rheocasting, squeeze-casting and rapid solidification) as well as work of other investigators on developments in conventional methods.

  14. Latest results of cast and future prospects

    CERN Document Server

    Vafeiadis, Theodoros

    2014-01-01

    CERN Axion Solar Telescope (CAST) is currently the most sensitive axion helioscope designed to search for axions and axion-like particles produced in the Sun. CAST completed successfully the second part of CAST phase II where the magnet bores were lled with 3He gas at variable pressure scanning axion masses up to 1.2 eV In the absence of signal it has set the best experimental limit on the axion-photon coupling constant over a broad range of axion masses. In 2013 CAST has improved its sensitivity to solar axions with rest mass below 0.02 eV by upgrading the Micromegas detectors and it will continue in 2014 with the implementation of a second X-ray optic and a new type detector (InGRID). In addition, CAST has extended its sensitivity into the sub-keV energy range using a silicon detector (SDD), to search for solar chameleons. Thus, CAST also became sensitive to dark energy particles. A new generation axion helioscope (IAXO) aims to improve the current axion-photon coupling by 1-1.5 orders of magnitude. This wi...

  15. Microbiological Study of Cast Posts before Cementation

    Directory of Open Access Journals (Sweden)

    Maricela Vallejo-Labrada

    2017-01-01

    Full Text Available This study identifies the most common microorganisms present in type III gold cast posts related to pulpal disease and evaluates the sterilization/disinfection method before cementation in the root canal. Forty-five type III gold cast posts were aseptically collected in sterile sealed plastic bags and taken to the microbiology laboratory to carry out the study: fifteen cast posts had no treatment, fifteen were disinfected (immersion in 70% alcohol during 15 minutes, and fifteen were autoclaved at 121°C for 15 minutes by using saturated steam under 15 psi pressure. By using a two-proportion z-test, the difference was statistically significant (p>0.05 and demonstrates that, in spite of the aseptic pattern used in the cast post collection and laboratory procedures, some cast posts arrive contaminated at the consulting office. The disinfection process worked out in a high percentage and demonstrated that the sterilization by autoclaving eliminated completely the pathogenic microbiota without affecting the cast post shape and integrity that could compromise their final fitting.

  16. Microbiological Study of Cast Posts before Cementation

    Science.gov (United States)

    Ojeda-Garces, Juan Carlos

    2017-01-01

    This study identifies the most common microorganisms present in type III gold cast posts related to pulpal disease and evaluates the sterilization/disinfection method before cementation in the root canal. Forty-five type III gold cast posts were aseptically collected in sterile sealed plastic bags and taken to the microbiology laboratory to carry out the study: fifteen cast posts had no treatment, fifteen were disinfected (immersion in 70% alcohol during 15 minutes), and fifteen were autoclaved at 121°C for 15 minutes by using saturated steam under 15 psi pressure. By using a two-proportion z-test, the difference was statistically significant (p > 0.05) and demonstrates that, in spite of the aseptic pattern used in the cast post collection and laboratory procedures, some cast posts arrive contaminated at the consulting office. The disinfection process worked out in a high percentage and demonstrated that the sterilization by autoclaving eliminated completely the pathogenic microbiota without affecting the cast post shape and integrity that could compromise their final fitting.

  17. 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 ...

  18. Last cast for the LHC

    CERN Multimedia

    2005-01-01

    The first major contract signed for the LHC is drawing to a close. Belgian firm Cockerill Sambre (a member of the Arcelor Group) has just completed production of 50,000 tonnes of steel sheets for the accelerator's superconducting magnet yokes, in what has proved to be an exemplary partnership with CERN. Philippe Lebrun, Head of the AT Department, Lyn Evans, LHC Project Leader, and Lucio Rossi, Head of the AT-MAS Group, in front of the last batch of steel for the LHC at Cockerill Sambre. It was a bright red-letter day at the end of May, when Belgian firm Cockerill Sambre of the Arcelor Group marked the completion of one of the largest contracts for the LHC machine by casting the last batch of steel sheets for the LHC superconducting magnet yokes in the presence of LHC Project Leader Lyn Evans, AT Department Head Philippe Lebrun, Magnets and Superconductors (AT-MAS) Group Leader Lucio Rossi and Head of the AT-MAS Group's components centre Francesco Bertinelli. The yokes constitute approximately 80% of the acc...

  19. Surgical scar revision: An overview

    Directory of Open Access Journals (Sweden)

    Shilpa Garg

    2014-01-01

    Full Text Available Scar formation is an inevitable consequence of wound healing from either a traumatic or a surgical intervention. The aesthetic appearance of a scar is the most important criteria to judge the surgical outcome. An understanding of the anatomy and wound healing along with experience, meticulous planning and technique can reduce complications and improve the surgical outcome. Scar revision does not erase a scar but helps to make it less noticeable and more acceptable. Both surgical and non-surgical techniques, used either alone or in combination can be used for revising a scar. In planning a scar revision surgeon should decide on when to act and the type of technique to use for scar revision to get an aesthetically pleasing outcome. This review article provides overview of methods applied for facial scar revision. This predominantly covers surgical methods.

  20. Methods and apparatuses for manufacturing monocrystalline cast silicon and monocrystalline cast silicon bodies for photovoltaics

    Science.gov (United States)

    Stoddard, Nathan G.

    2011-11-01

    Methods and apparatuses are provided for casting silicon for photovoltaic cells and other applications. With such methods and apparatuses, a cast body of monocrystalline silicon may be formed that is free of, or substantially free of, radially-distributed impurities and defects and having at least two dimensions that are each at least about 35 cm is provided.

  1. Methods and apparatus for manufacturing monocrystalline cast silicon and monocrystalline cast silicon bodies for photovoltaics

    Science.gov (United States)

    Stoddard, Nathan G

    2014-01-14

    Methods and apparatuses are provided for casting silicon for photovoltaic cells and other applications. With such methods and apparatuses, a cast body of monocrystalline silicon may be formed that is free of, or substantially free of, radially-distributed impurities and defects and having at least two dimensions that are each at least about 35 cm is provided.

  2. Mechanical properties of homogenized twin-roll cast and conventionally cast AZ31 magnesium alloys

    Directory of Open Access Journals (Sweden)

    Mariia Zimina

    2015-02-01

    Full Text Available The improvement of mechanical properties of magnesium alloys nowadays is very important, because of the variety of industrial applications. For this goal, the number of casting techniques and further treatments were developed. Among the continuous casting techniques, which allow producing long strips of the alloys, is twin-roll casting. Using this process one can get the magnesium alloy with finest microstructure and higher specific strength. In this paper the comparison of tensile properties of conventionally cast and twin-roll cast AZ31 magnesium alloys was made. Tensile tests were carried out with constant strain rate 10-3 s-1 at temperatures ranging from 100 to 300 °C. Both materials were tested in as-cast state and after homogenization treatment at 450 °C for 10 hours. The investigation showed that there are no significant changes in ductility of AZ31 conventionally cast alloy even after heat treatment, while the ductility of twin-roll cast alloy increases.

  3. FORMATION OF WEAR-RESISTANT CHROMIUM CAST IRON CASTING INTO THE CHILL MOLD

    Directory of Open Access Journals (Sweden)

    E. I. Marukovich

    2013-01-01

    Full Text Available The analysis of thermal processes of formation of castings from wearproof chromic cast irons for replaceable details of centrifugal mills and crushers is carried out. Influence of protective and dividing coverings on intensity of heating of the chill mold is investigated.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-06-01

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

  5. Tophi - surgical treatment.

    Science.gov (United States)

    Słowińska, Iwona; Słowiński, Radosław; Rutkowska-Sak, Lidia

    2016-01-01

    Gout is an inflammatory joint disease associated with deposition of monosodium urate crystals in the bones forming the joints, in periarticular tissues and in other organs. The disease is one of the most frequent causes of disability. This paper presents the case of a 57-year-old male patient treated for generalised gout. A "clinical mask" suggesting another disease was the cause of making the correct diagnosis only six years after the occurrence of the first manifestations. The patient, with high values of inflammatory markers, severe pain and advanced joint destruction, was given an aggressive anti-inflammatory treatment. The unsatisfactory effect of the conservative treatment forced the authors to perform surgical resection of the gouty nodules in the hands. After several operations the function of the hand joints operated on, appearance of the hands and the quality of the patient's life improved significantly.

  6. Tophi – surgical treatment

    Science.gov (United States)

    Słowińska, Iwona; Słowiński, Radosław

    2016-01-01

    Gout is an inflammatory joint disease associated with deposition of monosodium urate crystals in the bones forming the joints, in periarticular tissues and in other organs. The disease is one of the most frequent causes of disability. This paper presents the case of a 57-year-old male patient treated for generalised gout. A “clinical mask” suggesting another disease was the cause of making the correct diagnosis only six years after the occurrence of the first manifestations. The patient, with high values of inflammatory markers, severe pain and advanced joint destruction, was given an aggressive anti-inflammatory treatment. The unsatisfactory effect of the conservative treatment forced the authors to perform surgical resection of the gouty nodules in the hands. After several operations the function of the hand joints operated on, appearance of the hands and the quality of the patient’s life improved significantly. PMID:27994273

  7. Neuronavigation. Principles. Surgical technique.

    Science.gov (United States)

    Ivanov, Marcel; Ciurea, Alexandru Vlad

    2009-01-01

    Neuronavigation and stereotaxy are techniques designed to help neurosurgeons precisely localize different intracerebral pathological processes by using a set of preoperative images (CT, MRI, fMRI, PET, SPECT etc.). The development of computer assisted surgery was possible only after a significant technological progress, especially in the area of informatics and imagistics. The main indications of neuronavigation are represented by the targeting of small and deep intracerebral lesions and choosing the best way to treat them, in order to preserve the neurological function. Stereotaxis also allows lesioning or stimulation of basal ganglia for the treatment of movement disorders. These techniques can bring an important amount of confort both to the patient and to the neurosurgeon. Neuronavigation was introduced in Romania around 2003, in four neurosurgical centers. We present our five-years experience in neuronavigation and describe the main principles and surgical techniques.

  8. Precision Casting via Advanced Simulation and Manufacturing

    Science.gov (United States)

    1997-01-01

    A two-year program was conducted to develop and commercially implement selected casting manufacturing technologies to enable significant reductions in the costs of castings, increase the complexity and dimensional accuracy of castings, and reduce the development times for delivery of high quality castings. The industry-led R&D project was cost shared with NASA's Aerospace Industry Technology Program (AITP). The Rocketdyne Division of Boeing North American, Inc. served as the team lead with participation from Lockheed Martin, Ford Motor Company, Howmet Corporation, PCC Airfoils, General Electric, UES, Inc., University of Alabama, Auburn University, Robinson, Inc., Aracor, and NASA-LeRC. The technical effort was organized into four distinct tasks. The accomplishments reported herein. Task 1.0 developed advanced simulation technology for core molding. Ford headed up this task. On this program, a specialized core machine was designed and built. Task 2.0 focused on intelligent process control for precision core molding. Howmet led this effort. The primary focus of these experimental efforts was to characterize the process parameters that have a strong impact on dimensional control issues of injection molded cores during their fabrication. Task 3.0 developed and applied rapid prototyping to produce near net shape castings. Rocketdyne was responsible for this task. CAD files were generated using reverse engineering, rapid prototype patterns were fabricated using SLS and SLA, and castings produced and evaluated. Task 4.0 was aimed at developing technology transfer. Rocketdyne coordinated this task. Casting related technology, explored and evaluated in the first three tasks of this program, was implemented into manufacturing processes.

  9. Predicting Pattern Tooling and Casting Dimensions for Investment Casting - Phase II

    Energy Technology Data Exchange (ETDEWEB)

    Sabau, Adrian S [ORNL

    2005-09-01

    The investment casting process allows the production of complex-shape parts and close dimensional tolerances. One of the most important phases in the investment casting process is the design of the pattern die. Pattern dies are used to create wax patterns by injecting wax into dies. The wax patterns are used to create a ceramic shell by the application of a series of ceramic coatings, and the alloy is cast into the dewaxed shell mold (Fig. 1.1). However, the complexity of shape and the close dimensional tolerances required in the final casting make it difficult to determine tooling dimensions. The final linear dimension of the casting depends on the cumulative effects of the linear expansions or contractions in each step of the investment casting process (Fig. 1.2). In most cases, the mold geometry or cores restrict the shrinkage of the pattern or the cast part, and the final casting dimensions may be affected by time-dependent processes such as viscoelastic deformation of the wax, and viscoplastic creep and plastic deformations of the shell and alloy. The pattern die is often reworked several times to produce castings whose dimensions are within acceptable tolerances. To date, investment casting technology has been based on hands-on training and experience. Technical literature is limited to experimental, phenomenological studies aimed at obtaining empirical correlations for quick and easy application in industry. The goal of this project was to predict casting dimensions for investment castings in order to meet blueprint nominal during the first casting run. Several interactions have to be considered in a coupled manner to determine the shrinkage factors: these are the die-wax, wax-shell, and shell-alloy interactions (as illustrated in Fig. 1.3). In this work, the deformations of the die-wax and shell-alloy systems were considered in a coupled manner, while the coupled deformation of the wax-shell system was not considered. Future work is needed in order to

  10. Colour Metallography of Cast Iron - Chapter 3: Spheroidal Graphite Cast Iron (Ⅰ

    Directory of Open Access Journals (Sweden)

    Zhou Jiyang

    2010-02-01

    Full Text Available Cast iron, as a traditional metal material, has advantages of low total cost, good castability and machinability, good wear resistance and low notch sensitivity, and is still facing tough challenge in quality, property and variety of types etc. Experts and engineers studying and producing iron castings all around world extremely concern this serious challenge. Over more than 30 years, a great of research work has been carried out on how to further improve its property, expand its application and combine cast iron technology with some hi-techs (for example, computer technology. Nevertheless, cast iron is a multi-element and multi-phase alloy and has complex and variety of structures and still has great development potential in structure and property. For further studying and developing cast iron, theoretical research work is important promise, and the study on solidification process and control mechanism of graphite morphology is fundamental for improving property of cast iron and developing new type of cast iron. Metallography of cast iron normally includes two sections: liquid phase transformation and solid phase transformation. The book, Colour Metallography of Cast Iron, uses colour metallography technique to study solidification structures of cast irons: graphite, carbides, austenite and eutectics; and focuses on solidification processes. With progress of modern solidification theory, the control of material solidification process becomes important measure for improving traditional materials and developing new materials. Solidification structure not only influences mechanical and physical properties of cast iron, but also affects its internal quality. The book uses a large amount of colour photos to describe the formation of solidification structures and their relations. Crystallization phenomena, which cannot be displayed with traditional metallography, are presented and more phase transformation information is obtained from these colour

  11. 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.

  12. Residual forefoot deformity predicts the need for future surgery in clubfeet treated by Ponseti casting.

    Science.gov (United States)

    Hosseinzadeh, Pooya; Peterson, Erik D; Walker, Janet; Muchow, Ryan D; Iwinski, Henry J; Talwalkar, Vishwas R; Milbrandt, Todd A

    2016-03-01

    Tibialis anterior tendon transfer (TATT) is performed for treatment of recurrent clubfeet. We investigated the predictability of residual adductus on the future need for TATT. A retrospective review of 143 patients with clubfoot was performed. The patients were divided into two groups: group 1 with a history of TATT and group 2 with no TATT. Heel-forefoot angle (HFA) was measured. HFA was compared between the groups. HFA was significantly different between groups 1 and 2. Residual adductus deformity in clubfeet treated by Ponseti casting is a risk factor for future need for surgical treatment.

  13. Gating Systems for Sizeable Castings from Al Alloys Cast into Ceramic Moulds

    Directory of Open Access Journals (Sweden)

    I. Stachovec

    2012-04-01

    Full Text Available In contrast to casting to conventional non-reusable “sand” moulds, for which calculating technique for an optimum design of the gating system is comparatively well-developed, a trial-and-error method is applied mostly for casting to ceramic shell moulds made by the investment casting technology. A technologist selects from gating systems of several types (that are standardized by the foundry mostly on the basis of experience. However, this approach is not sustainable with ever growing demands on quality of castings and also the economy of their fabrication as well as with new types of complex sizeable castings introduced to the production gradually (by new customers from the aircraft industry above all any more. The simulation software may be used as a possible tool for making the process of optimising gating systems more effective.

  14. Unique morphology of intratubular light chain casts in multiple myeloma: The amyloid cast nephropathy

    Directory of Open Access Journals (Sweden)

    Alok Sharma

    2014-01-01

    Full Text Available Cast nephropathy is the most frequent pattern of renal involvement in multiple myeloma characterized by presence of tubular casts with characteristic morphology that are composed of monotypic (either kappa or lambda light chains as seen by immunofluorescence microscopy. Rarely these casts may show evidence of amyloidogenesis and assume a unique morphology, which needs to be appreciated for arriving at accurate diagnosis. We present the case of an elderly male presenting with features of acute kidney injury and detected with extensive inspissation of intratubular casts with lambda light chain restriction and a unique morphology with spiculated congophilic periphery. Further investigations confirmed the presence of systemic myeloma. Presence of intratubular amyloid casts is a rare occurrence which needs to be recognized by the pathologist and forms a vital element in timely diagnosis of the systemic disease which often presents with renal involvement.

  15. Mechanism and application of a newly developed pressure casting process: horizontal squeeze casting

    Directory of Open Access Journals (Sweden)

    Li Peijie

    2014-07-01

    Full Text Available Compared to traditional high-pressure die casting (HPDC, horizontal squeeze casting (HSC is a more promising way to fabricate high-integrity castings, owing to a reduced number of gas and shrinkage porosities produced in the casting. In this paper, the differences between HSC and HPDC are assessed, through which it is shown that the cavity filling velocity and the size of the gating system to be the most notable differences. Equipment development and related applications are also reviewed. Furthermore, numerical simulation is used to analyze the three fundamental characteristics of HSC: slow cavity filling, squeeze feeding and slow sleeve filling. From this, a selection principle is given based on the three related critical casting parameters: cavity filling velocity, gate size and sleeve filling velocity. Finally, two specific applications of HSC are introduced, and the future direction of HSC development is discussed.

  16. Applying RP-FDM Technology to Produce Prototype Castings Using the Investment Casting Method

    Directory of Open Access Journals (Sweden)

    M. Macků

    2012-09-01

    Full Text Available The research focused on the production of prototype castings, which is mapped out starting from the drawing documentation up to theproduction of the casting itself. The FDM method was applied for the production of the 3D pattern. Its main objective was to find out whatdimensional changes happened during individual production stages, starting from the 3D pattern printing through a silicon mouldproduction, wax patterns casting, making shells, melting out wax from shells and drying, up to the production of the final casting itself.Five measurements of determined dimensions were made during the production, which were processed and evaluated mathematically.A determination of shrinkage and a proposal of measures to maintain the dimensional stability of the final casting so as to meetrequirements specified by a customer were the results.

  17. 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.

  18. Mechanism and application of a newly developed pressure casting process:horizontal squeeze casting

    Institute of Scientific and Technical Information of China (English)

    Li Peijie; Huang Xiusong; He Liangju; Liu Xiangshang; Wang Benci

    2014-01-01

    Compared to traditional high-pressure die casting (HPDC), horizontal squeeze casting (HSC) is a more promising way to fabricate high-integrity castings, owing to a reduced number of gas and shrinkage porosities produced in the casting. In this paper, the differences between HSC and HPDC are assessed, through which it is shown that the cavity ifling velocity and the size of the gating system to be the most notable differences. Equipment development and related applications are also reviewed. Furthermore, numerical simulation is used to analyze the three fundamental characteristics of HSC: slow cavity ifling, squeeze feeding and slow sleeve ifling. From this, a selection principle is given based on the three related critical casting parameters: cavity filling velocity, gate size and sleeve ifling velocity. Finaly, two speciifc applications of HSC are introduced, and the future direction of HSC development is discussed.

  19. 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.

  20. Effect of casting parameters and deformation on microstructure evolution of twin-roll casting magnesium alloy AZ31

    Institute of Scientific and Technical Information of China (English)

    JU Dong-ying; HU Xiao-dong

    2006-01-01

    Twin roll casting method is a promising route to directly produce magnesium alloy strip. It is a rapid solidification process with high temperature gradient combined with thermal flow and rolling deformation in the casting region. As-cast strip with proper microstructure is requested to serve as next rolling feedstock. However the microstructure of as-cast strip is sensitive for casting conditions during the casting process and the as-cast microstructure greatly affects the mechanical properties. In this work,the effect of casting speed,pouring temperature,deformation as well as anneal process on microstructure and mechanical properties were investigated. The results revels that twin-roll casting process can effectively refine the grain size,improve the morphology and distribution states of Mg17Al12. The homogenization treatment time can be shorted for the fine microstructure and lower the cost dramatically for the next forming process.

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

    Institute of Scientific and Technical Information of China (English)

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

    2005-01-01

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

  2. Computer simulation for centrifugal mold filling of precision titanium castings

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    Computer simulation codes were developed based on a proposed mathematical model for centrifugal mold filling processes and previous computer software for 3D mold filling and solidification of castings (CASM-3D for Windows). Sample simulations were implemented for mold filling processes of precision titanium castings under gravity and different centrifugal casting techniques. The computation results show that the alloy melt has a much stronger mold filling ability for thin section castings under a centrifugal force field than that only under the gravity. A "return back" mold filling manner is showed to be a reasonable technique for centrifugal casting processes, especially for thin section precision castings.

  3. Production of carbide-free thin ductile iron castings

    Institute of Scientific and Technical Information of China (English)

    M. Ashraf Sheikh

    2008-01-01

    The fast cooling rate of thin ductile iron castings requires special consideration to produce carbide-free castings. Extraor-dinary care was taken to select the charge to produce castings of 100-mm long round bars with 16-ram diameter. The castings show the presence of carbides in the bars. Seven melts were made with different temperatures and with different compositions to get rid of carbides. After chemical analyses, it was found that the extra purity of the charge with less than 0.008wt% sulfur in the castings was the cause of carbides. To remove the carbides fi'om the castings, sulfur should be added to the charge.

  4. The X-ray Telescope of CAST

    CERN Document Server

    Kuster, M; Cebrián, S; Davenport, M; Elefteriadis, C; Englhauser, J; Fischer, H; Franz, J; Friedrich, P; Hartmann, R; Heinsius, F H; Hoffmann, Dieter H H; Hoffmeister, G; Joux, J N; Königsmann, K C; Kang, D; Kotthaus, R; Lasseur, C; Lippitsch, A; Lutz, G; Morales, J; Papaevangelou, T; Rodríguez, A; Strüder, L; Vogel, J; Zioutas, K

    2007-01-01

    The Cern Axion Solar Telescope (CAST) is in operation and taking data since 2003. The main objective of the CAST experiment is to search for a hypothetical pseudoscalar boson, the axion, which might be produced in the core of the sun. The basic physics process CAST is based on is the time inverted Primakoff effect, by which an axion can be converted into a detectable photon in an external electromagnetic field. The resulting X-ray photons are expected to be thermally distributed between 1 and 7 keV. The most sensitive detector system of CAST is a pn-CCD detector combined with a Wolter I type X-ray mirror system. With the X-ray telescope of CAST a background reduction of more than 2 orders off magnitude is achieved, such that for the first time the axion photon coupling constant g_agg can be probed beyond the best astrophysical constraints g_agg < 1 x 10^-10 GeV^-1.

  5. The x-ray telescope of CAST

    Science.gov (United States)

    Kuster, M.; Bräuninger, H.; Cebrián, S.; Davenport, M.; Eleftheriadis, C.; Englhauser, J.; Fischer, H.; Franz, J.; Friedrich, P.; Hartmann, R.; Heinsius, F. H.; Hoffmann, D. H. H.; Hoffmeister, G.; Joux, J. N.; Kang, D.; Königsmann, K.; Kotthaus, R.; Papaevangelou, T.; Lasseur, C.; Lippitsch, A.; Lutz, G.; Morales, J.; Rodríguez, A.; Strüder, L.; Vogel, J.; Zioutas

    2007-06-01

    The CERN Axion Solar Telescope (CAST) has been in operation and taking data since 2003. The main objective of the CAST experiment is to search for a hypothetical pseudoscalar boson, the axion, which might be produced in the core of the sun. The basic physics process CAST is based on is the time inverted Primakoff effect, by which an axion can be converted into a detectable photon in an external electromagnetic field. The resulting x-ray photons are expected to be thermally distributed between 1 and 7 keV. The most sensitive detector system of CAST is a pn-CCD detector combined with a Wolter I type x-ray mirror system. With the x-ray telescope of CAST a background reduction of more than 2 orders of magnitude is achieved, such that for the first time the axion photon coupling constant gaγγ can be probed beyond the best astrophysical constraints gaγγ < 1 × 10-10 GeV-1.

  6. CASTing light on dark matter particles

    CERN Multimedia

    2005-01-01

    CERN's CAST collaboration recently released first results from its search for solar axions, a candidate dark matter particle. Though they haven't found any axions yet, they have done much to narrow the hunt. The CAST experiment. Physicists think the universe is permeated with dark matter, particles that don't emit or absorb radiation and so are invisible to traditional telescopes. So far no one has found direct signs of dark matter. A different breed of telescope, however, may be able to see such particles. CERN's Axion Solar Telescope (CAST), currently the world's only working axion helioscope, is a superconducting test magnet from the Large Hadron Collider (LHC) that has been refurbished and outfitted with X-ray detectors, plus a focusing mirror system for X-rays that was recovered from the German space program. CAST stares into the sun in search of particles called axions, one of the leading candidates for dark matter. On 9 November, the CAST collaboration released the results of their first experimen...

  7. Surgical treatment of acquired tracheocele.

    Science.gov (United States)

    Porubsky, Edward A; Gourin, Christine G

    2006-06-01

    Acquired tracheoceles are rare clinical entities that can cause a variety of chronic and recurrent aerodigestive tract symptoms. The management of acquired tracheoceles is primarily conservative, but surgical intervention may be indicated for patients with refractory symptoms. We present a case of acquired tracheocele and describe a method of successful surgical management.

  8. Surgical innovations in canine gonadectomy

    NARCIS (Netherlands)

    Van Goethem, Bart

    2016-01-01

    In this thesis some recent technological developments in human surgery are evaluated for their potential use in veterinary medicine by introducing them as surgical innovations for canine gonadectomy. Barbed sutures achieve wound apposition without surgical knot tying and thus avoid knot-associated n

  9. Acquiring minimally invasive surgical skills

    NARCIS (Netherlands)

    Hiemstra, Ellen

    2012-01-01

    Many topics in surgical skills education have been implemented without a solid scientific basis. For that reason we have tried to find this scientific basis. We have focused on training and evaluation of minimally invasive surgical skills in a training setting and in practice in the operating room.

  10. Land-based turbine casting initiative

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, B.A.; Spicer, R.A. [Howmet Corp., Whitehall, MI (United States)

    1995-10-01

    The Advanced Turbine Systems (ATS) program has set goals which include a large-scale utility turbine efficiency that exceeds 60 percent (LHV) on natural gas and an industrial turbine system heat rate improvement of 15 percent. To meet these goals, technological advances developed for aircraft gas turbine engines need to be applied to land based gas turbines. These technological advances include: directionally solidified and single crystal castings, alloys tailored to exploit these microstructures, complex internal cooling schemes, and coatings. Equiaxed and directionally solidified castings are employed in current land based power generation equipment. These castings do not possess the ability to meet the efficiency targets as outlined above. The production use of premium single crystal components with complex internal cooling schemes in the latest generation of alloys is necessary to meet the ATS goals. However, at present, the use of single crystal components with complex internal cooling schemes is restricted to industrial sized or aeroderivative engines, and prototype utility sized components.

  11. 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.

  12. Cast construction elements for heat treatment furnaces

    Directory of Open Access Journals (Sweden)

    B. Piekarski

    2011-07-01

    Full Text Available The study presents sketches and photos of the cast creep-resistant components used in various types of heat treatment furnaces. The shape of the elements results from the type of the operation carried out in the furnace, while dimensions are adjusted to the size of the furnace working chamber. The castings are mainly made from the high-alloyed, austenitic chromium-nickel or nickel-chromium steel, selecting the grade in accordance with the furnace operating conditions described by the rated temperature, the type and parameters of the applied operating atmosphere, and the charge weight. Typical examples in this family of construction elements are: crucibles, roller tracks, radiant tubes and guides. The majority of castings are produced in sand moulds.

  13. The World's Largest Steel Casting Poured Successfully

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ The world's largest steel casting -- the upper beam (or the top head) for free forging oil hydraulic press with a 18,000-ton force capacity, was poured successfully by CITIC Heavy Machinery Co., Ltd. (CITICHM) on May 22, 2008. This head piece is 11.95 meters long, 3.8 meters wide, 4.59 meters high and about 520 tons in gross weight. Pouring is the most important and critical step during its manufacturing process. The production of this huge casting requires about 830 tons of refined molten steel from 10 smelting furnaces and pouring with six ladles into the mold cavity at one time, which made it currently the world's largest steel casting poured and the most one-time molten steel organized.

  14. Cast Aluminum Alloy for High Temperature Applications

    Science.gov (United States)

    Lee, Jonathan A.

    2003-01-01

    Originally developed by NASA as high performance piston alloys to meet U.S. automotive legislation requiring low exhaust emission, the novel NASA alloys now offer dramatic increase in tensile strength for many other applications at elevated temperatures from 450 F (232 C) to about 750 F (400 C). It is an ideal low cost material for cast automotive components such as pistons, cylinder heads, cylinder liners, connecting rods, turbo chargers, impellers, actuators, brake calipers and rotors. It can be very economically produced from conventional permanent mold, sand casting or investment casting, with silicon content ranging from 6% to 18%. At high silicon levels, the alloy exhibits excellent dimensional stability, surface hardness and wear resistant properties.

  15. A new casting defect healing technology

    Energy Technology Data Exchange (ETDEWEB)

    Hodge, E.S.; Reddoch, T.W. [ForMat Industries, Inc., Knoxville, TN (United States); Viswanathan, S. [Oak Ridge National Lab., TN (United States)

    1997-01-01

    A new technology is presented for healing of defects in 356 aluminium alloys that provides economic upgrading of these cast alloys. It uses pneumatic isostatic forging (PIF) to produce high quality Al alloys products with enhanced mechanical properties uniform throughout the part, allowing higher design allowables and increased usage of Al alloy castings. The fundamental mechanism underlying PIF is a single mode plastic deformation process that uses isostatic application of pressures for 10-30 seconds at temperature. The process can be integrated in-line with other production operations, i.e., using the latent heat from the previous casting step. Results of applying the PIF process indicate lower cost and significant improvement in mechanical properties that rival and often exceed corresponding properties of other technologies like hot isostatic pressing and related processes. This process offers many advantages that are described in this paper in addition to presenting case histories of property enhancement by PIF and the mechanism responsible for property enhancement.

  16. Thin wall ductile and austempered iron castings

    Directory of Open Access Journals (Sweden)

    E. Fraś

    2010-07-01

    Full Text Available It has been shown that it is possible to produce thin wall castings made of ductile iron with wall thickness in the range of 1.2 to 2.9 mm(without chills, cold laps and misruns. Thin wall ductile iron castings can be lighter (380 g than their substitutes made of aluminium alloys (580g. The kinetics of austenitising transformation was studied in unalloyed ductile iron. The advance of transformations during austenitising was monitored by measurement the fraction of martensite and also by dilatometic studies. It has been shown that in thin wall ductile iron castings austenitising at 880 oC for 20 minutes is adequate to obtain the austenite matrix at the end of the first stage of austempering heat treatment cycle.

  17. Diffusion of C and Cr During Creation of Surface Layer on Cast Steel Casting

    Directory of Open Access Journals (Sweden)

    Szajnar J.

    2014-10-01

    Full Text Available In paper a method of improvement in utility properties of unalloyed cast steel casting in result of diffusion of C and Cr in process of creation of surface layer is presented. The aim of paper was determination of diffusion range of basic elements of alloyed surface layer. Moreover a quantitative analysis of carbides phase strengthens alloyed surface layer of casting was carried out. The results of studies shown that important factors of surface layer creation are maximal temperature Tmax on granular insert – cast steel boundary dependent of pouring temperature, granularity Zw of Fe-Cr-C alloy insert and thickness of casting wall gśo. On the basis of obtained results was affirmed that with increase of thickness of casting wall increases range of diffusion in solid state in Fe-Cr-C grains and in liquid state. Moreover the range of Tmax = 13001500oC favours creation of the proper alloyed surface layers on cast steel.

  18. Compound cast product and method for producing a compound cast product

    Science.gov (United States)

    Meyer, Thomas N.; Viswanathan, Srinath

    2002-09-17

    A compound cast product is formed in a casting mold (14) having a mold cavity (16) sized and shaped to form the cast product. A plurality of injectors (24) is supported from a bottom side (26) of the casting mold (14). The injectors (24) are in fluid communication with the mold cavity (16) through the bottom side (26) of the casting mold (14). A molten material holder furnace (12) is located beneath the casting mold (14). The holder furnace (12) defines molten material receiving chambers (36) configured to separately contain supplies of two different molten materials (37, 38). The holder furnace (12) is positioned such that the injectors (24) extend downward into the receiving chamber (36). The receiving chamber (36) is separated into at least two different flow circuits (51, 52). A first molten material (37) is received in a first flow circuit (51), and a second molten material (38) is received into a second flow circuit (52). The first and second molten materials (37, 38) are injected into the mold cavity (16) by the injectors (24) acting against the force of gravity. The injectors (24) are positioned such that the first and second molten materials (37, 38) are injected into different areas of the mold cavity (16). The molten materials (37, 38) are allowed to solidify and the resulting compound cast product is removed from the mold cavity (16).

  19. Mathematical Modeling of Surface Roughness of Castings Produced Using ZCast Direct Metal Casting

    Science.gov (United States)

    Chhabra, M.; Singh, R.

    2015-04-01

    Aim of this investigation is to develop a mathematical model for predicting surface roughness of castings produced using ZCast process by employing Buckingham's π-theorem. A relationship has been proposed between surface roughness of castings and shell wall thickness of the shell moulds fabricated using 3D printer. Based on model, experiments were performed to obtain the surface roughness of aluminium, brass and copper castings produced using ZCast process based on 3D printing technique. Based on experimental data, three best fitted third-degree polynomial equations have been established for predicting the surface roughness of castings. The predicted surface roughness values were then calculated using established best fitted equations. An error analysis was performed to compare the experimental and predicted data. The average prediction errors obtained for aluminium, brass and copper castings are 10.6, 2.43 and 3.12 % respectively. The obtained average surface roughness (experimental and predicted) values of castings produced are acceptable with the sand cast surface roughness values range (6.25-25 µm).

  20. Surgical infection in art.

    Science.gov (United States)

    Meakins, J L

    1996-12-01

    The earliest images of medicine and surgery in Western art are from the late Middle Ages. Although often attractive, at that time they were illustrative and mirrored the text on how to diagnose or treat a specific condition. These drawings in medieval manuscripts represent management of abscesses, perianal infection and fistulas, amputation, and wound dressings. With the Renaissance, art in all its forms flourished, and surgeons were represented at work draining carbuncles, infected bursae, and mastoiditis; managing ulcers, scrofula, and skin infections; and performing amputations. Specific diagnosis can be made, such as streptococcal infection in the discarded leg of the miraculous transplantation performed by Saints Cosmas and Damian and in the works of Rembrandt van Rijn and Frederic Bazille. Evocations of cytokine activity are evident in works by Albrecht Dürer, Edvard Munch, and James Tissot. The iconography of society's view of a surgeon is apparent and often not complimentary. The surgeon's art is a visual art. Astute observation leads to early diagnosis and better results in surgical infection and the septic state. Learning to see what we look at enhances our appreciation of the world around us but, quite specifically, makes us better clinicians.

  1. Quality control of cast brake discs

    Directory of Open Access Journals (Sweden)

    M. Stawarz

    2008-04-01

    Full Text Available The largest industrial application so far have the gray cast irons which are characterized by low tensile and bending strength, while at the same time they have good ultimate comprehensive strength. Additionally, the fatigue strength of gray cast irons is comparatively low and they are only to some extend sensitive for the surface waters effects. Cast iron is the material, which is comparatively easy to be processed, and for this reason – it is not expensive. Brake discs are exploited in particularly hard conditions. They must be resistant both against the thermal fatigue and abrasion wearing (at dry friction as well as against seizing, corrosion and mechanical load [1-3]. The gray cast iron, better than other materials, fulfills all the requirements necessary for making the material for the casts resistant against such tough conditions. This work reflects the researches aiming to define the quality of cast brake discs (ventilated and non-ventilated ones upon a period of their exploitation in real conditions. The following researches were performed: evaluations of the disc surface condition, measurement of disc thickness, examination of run – out flank and metallographic analysis. In order to more detailed recognition of mechanisms and reasons of brake discs wearing in real conditions, one should conduct additional examinations: computer analysis of the microstructure, chemical composition analysis, etc., as well as study of the technology of their production in foundries, where they are manufactured [4]. By obtaining the full set of the mentioned above data one can draw final conclusions and remove causes of possible defects.

  2. Modeling of casting microstructures and defects

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, A.B.; Summers, L.T.; Eckels, D.J.; Sahai, V.

    1997-09-26

    Casting is an ancient art that has been a trial-and-error process for more than 4000 years. To predict the size, shape, and quality of a cast product, casting manufacturers typically cast full-size prototypes. If one part of the process is done incorrectly, the entire process is repeated until an acceptable product is achieved. One way to reduce the time, cost, and waste associated with casting is to use computer modeling to predict not only the quality of a product on the macro- scale, such as distortion and part shape, but also on the micro-scale such as grain defects. Modeling of solidification is becoming increasingly feasible with the advent of parallel computers. There are essentially two approaches to solidification modeling.The first is that of macro-modeling where heat transfer codes model latent heat release during solidification as a constant and based solely on the local temperature. This approach is useful in predicting large scale distortion and final part shape. The second approach, micro-modeling, is more fundamental. The micro-models estimate the latent heat release during solidification using nucleation and grain growth kinetics. Micro-models give insight into cast grain morphology and show promise in the future to predict engineering properties such as tensile strength. The micro-model solidification kinetics can be evaluated using first principles or they can be evaluated using experiments. This work describes an implementation of a micro-model for uranium which uses experimental results to estimate nucleation and growth kinetics.

  3. Fundamentals of Numerical Modelling of Casting Processes

    DEFF Research Database (Denmark)

    Pryds, Nini; Thorborg, Jesper; Lipinski, Marek;

    Fundamentals of Numerical Modelling of Casting Processes comprises a thorough presentation of the basic phenomena that need to be addressed in numerical simulation of casting processes. The main philosophy of the book is to present the topics in view of their physical meaning, whenever possible......, rather than relying strictly on mathematical formalism. The book, aimed both at the researcher and the practicing engineer, as well as the student, is naturally divided into four parts. Part I (Chapters 1-3) introduces the fundamentals of modelling in a 1-dimensional framework. Part II (Chapter 4...

  4. Casting defects analysis by the Pareto method

    Directory of Open Access Journals (Sweden)

    B. Borowiecki

    2011-07-01

    Full Text Available On the basis of receive results formed of diagram Pareto Lorenz. On the basis of receive graph it affirmed, that for 70% general number casting defects answered 3 defects (9 contribution – 100% defects. For 70% general number defects of influence it has three type of causes: sand holes, porosity and slaginclusions. Thedefects show that it is necessary to take up construction gatingsystem. The remaining 8 causes have been concerned only 25%, with general number of casting defects. Analysis of receive results permit to determine of direction of correct actions in order to eliminate or to limit the most defects.

  5. Theoretical Model of Steel Continuous Casting Technology

    Institute of Scientific and Technical Information of China (English)

    C Gheorghies; I Crudu; C Teletin; C Spanu

    2009-01-01

    A theoretical model adapted for studying steel continuous casting technology was proposed.The model based on system theory contained input/output,command,and control parameters.The process was divided into five stages,i.e.,tundish,mold,guiding system,guiding-drawing system,and guiding-drawing-soft reduction system.The model can be used to describe the physicoehemical processes,thermal processes,chemical processes,and characteristics of the cast material according to the above-mentioned stages.It can also be applied to other metallurgical technologies and even to other industries (chemistry,food,etc.).

  6. Thin wall ductile and austempered iron castings

    OpenAIRE

    E. Fraś; M. Górny

    2010-01-01

    It has been shown that it is possible to produce thin wall castings made of ductile iron with wall thickness in the range of 1.2 to 2.9 mm(without chills, cold laps and misruns). Thin wall ductile iron castings can be lighter (380 g) than their substitutes made of aluminium alloys (580g). The kinetics of austenitising transformation was studied in unalloyed ductile iron. The advance of transformations during austenitising was monitored by measurement the fraction of martensite and also by dil...

  7. Combining the casting and punching technology

    Directory of Open Access Journals (Sweden)

    Zh. Ashkeyev

    2016-07-01

    Full Text Available In the article there are presented the results of studying the microstructure of metals obtained by the method of casting and punching in equal-channel step matrixes (ECSM. The analysis of the microstructure of metals obtained on the scanning and transmission microscope showed that owing to realization of intensive shift deformations on the inclined portion of ECSM there emerge shear bands which extend practically in parallel to zones of the matrix channels connection and influence positively closing and sealing all internal defects of cast blanks.

  8. Lymphoplasmacytic lymphoma causing light chain cast nephropathy.

    Science.gov (United States)

    Pérez, Nuria S; Garcia-Herrera, Adriana; Rosiñol, Laura; Palos, Lily; Santiago, Evelyn; Espinosa, Gerard; Solé, Manel; Campistol, Josep M; Quintana, Luis F

    2012-01-01

    Plasma cell dyscrasias are frequently associated with kidney disease through the production of monoclonal immunoglobulin but with a diverse set of pathologic renal patterns. While almost all patients with a renal biopsy showing a cast nephropathy have myeloma, kidney involvement associated with pathological immunoglobulin light chains and lymphoma is rare. To our knowledge, this is the first report of a cast nephropathy associated with lymphoplasmacytic lymphoma. We emphasize the relation between light chain deposition and renal dysfunction in this disease with production of light chains. A therapeutic approach that decreases light chain production appears to be warranted in these patients.

  9. An Integrated Die Casting Design System

    Institute of Scientific and Technical Information of China (English)

    Y; K; Woon; K; S; Lee

    2002-01-01

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

  10. Opportunities and challenges of Chinese die-casting market

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

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

  11. Plans and Measures for Avoiding Casting-Air-Pollution

    Institute of Scientific and Technical Information of China (English)

    ZHOU Jian

    2003-01-01

    This article presents plans of preventing casting-air-pollution in practice, and some avoiding methods in detail. In modern times, environment protection is looked high upon day by day; green-casting thus becomes more and more important.

  12. Prediction of porosity in cast equiaxed alloy 718

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Y.K. [Univ. of Alabama, Tuscaloosa, AL (United States); Sahai, V.; Overfelt, R.A. [Auburn Univ., AL (United States); Berry, J.T. [Mississippi State Univ., MS (United States)

    1995-12-31

    The prediction of porosity distribution in shaped castings is a popular topic at the present time. A number of criteria functions (CFs) have been proposed to assist in such predictions, these functions generally being obtained from computer modeling of solidification. Although considerable attention has been given to the use of CFs with plain carbon steel and aluminum castings, only limited attention has been given to superalloy castings. Using experimental data on porosity distribution in such castings for validation, various criteria functions were compared for effectiveness in predicting the level of porosity in castings of different thicknesses vacuum investment cast in alloy 718. The criteria functions concerned were obtained by interrogating the output of a simulation using commercially available software. The castings were in the form of vertically cast plates attached to a common top gating system. The problems associated with obtaining thermally accurate simulation, as well as appropriate validation are also discussed.

  13. Manufacturing of thin walled near net shape iron castings

    DEFF Research Database (Denmark)

    Larsen, Per Leif

    2003-01-01

    The demand for near net shape thin walled iron castings is growing. This has several reasons, the main one is the need for lowering the fuel consumption of cars; the easiest way to do that is to lower the weight of the cars. The best way to do this was for a period of time believed...... to be substituting iron casings with aluminum castings. Substituting iron castings with aluminum castings is not as easy as first believed, and hence the substitution is very slow. This combined with the lack of fully exploiting the potential in iron castings, makes research in iron castings interesting. The 60.......000.000 cars produced world wide each year consumes enormous amounts of cast parts ! The aim of the project is to develop the green sand molding method on DISAMATIC to be able to deal with the new demands for thin walled near net shape castings in iron....

  14. Microstructure formation and properties of abrasion resistant cast steel

    OpenAIRE

    S. Parzych; Krawczyk, J.

    2010-01-01

    The so-called adamitic cast steels are characterised by a high abrasion resistance. These cast steels are of a pearlitic matrix with uniformly distributed hypereutectoid cementite precipitates. Apart from hypereutectoid cementite very often transformed ledeburite also occurs in the microstructure of these cast steels. Such cast steels contain chromium (app. 1 %) and nickel (app. 0.5 %) as alloy additions and sometimes their silicon content is increased. The presence of molybdenum is also perm...

  15. Optimizing hardenability of high chromium white cast iron

    Institute of Scientific and Technical Information of China (English)

    SU Ying-long; LI Dan; ZHANG Xue-kun

    2006-01-01

    The formulas proposed by J. Dodd and J. L. Parks for calculating the hardenability of high-Cr white cast iron under continuous cooling condition was recommended. For broader application, some supplements were made to the formula. Through tests on the half-cooling time of typical castings, the compositions of ideal alloys were precisely designed using the Dodd's formula. Hardness testing of heat-treated castings showed that the designed compositions were correct. The application of castings demonstrated excellent abrasion resistance.

  16. A silicon sheet casting experiment. [for solar cell water production

    Science.gov (United States)

    Bickler, D. B.; Sanchez, L. E.; Sampson, W. J.

    1980-01-01

    The casting of silicon blanks for solar cells directly without slicing is an exciting concept. An experiment was performed to investigate the feasibility of developing a machine that casts wafers directly. A Czochralski furnace was modified to accept a graphite ingot-simulating fixture. Silicon was melted in the middle of the ingot simulator in a boron nitride mold. Sample castings showed reasonable crystal size. Solar cells were made from the cast blanks. The performance is reported.

  17. Advances on Microstructure Modeling of Solidification Process of Shape Casting

    Institute of Scientific and Technical Information of China (English)

    柳百成; 许庆彦

    2004-01-01

    Simulation technology for shape casting at macro-scale has been successfully put into engineering application in a number of casting plants and as a result the quality of castings is assured, the research and development time is shortened, and the manufacturing cost is greatly saved as well. In this paper, modeling and simulation technologies of solidification process of shape casting at microstructure-scale, especially deterministic, cellular automaton, and phase field models are studied and reviewed.

  18. Is caste destiny? Occupational diversification among Dalits in rural India

    OpenAIRE

    Gang, Ira N.; Sen, Kunal; Yun, Myeong-Su

    2012-01-01

    The caste system - a system of elaborately stratified social hierarchy - distinguishes India from most other societies. Among the most distinctive factors of the caste system is the close link between castes and occupations, especially in rural India, with Dalits or Scheduled Castes (SC) clustered in occupations that were the least well paid and most degrading in terms of manual labour. Along with the Scheduled Tribes (STs), the SCs have the highest incidence of poverty in India, with poverty...

  19. Report on results of current and future metal casting

    Energy Technology Data Exchange (ETDEWEB)

    Unal, Cetin [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Carlson, Neil N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-09-28

    New modeling capabilities needed to simulate the casting of metallic fuels are added to Truchas code. In this report we summarize improvements we made in FY2015 in three areas; (1) Analysis of new casting experiments conducted with BCS and EFL designs, (2) the simulation of INL’s U-Zr casting experiments with Flow3D computer program, (3) the implementation of surface tension model into Truchas for unstructured mesh required to run U-Zr casting.

  20. High speed twin roll casting of 6061 alloy strips

    OpenAIRE

    T. Haga; Sakaguchi, H.; H. Watari; S. Kumai

    2008-01-01

    Purpose: of this paper is to clear the possibility of high speed roll casting of thin strips of two aluminum alloys:6061 and recycled 6061. Mechanical properties of the roll cast 6061 and recycled 6061 strips were investigated inthe frame of this purpose.Design/methodology/approach: Methods used in the present study were high speed twin roll caster and lowtemperature casting. These methods were used to realize rapid solidification and increase the casting speed.Findings: are that 6061 and rec...

  1. THE WEAR RESISTANCE INCREASE OF CHROMIUM CAST IRON

    Directory of Open Access Journals (Sweden)

    V. M. Ilyushenko

    2016-01-01

    Full Text Available The article presents the results of the tests on the wear resistance of chromium cast irons of different compositions obtained in sand forms. It has been shown that increase of the wear resistance and mechanical properties of the cast iron is possible to obtain using the casting in metal molds. A further increase in wear resistance of parts produced in metal molds is possible by changing the technological parameters of casting and alloying by titanium.

  2. Retained surgical sponge: An enigma

    Directory of Open Access Journals (Sweden)

    Gurjit Singh

    2013-01-01

    Full Text Available Retained surgical sponge in the body following a surgery is called "gossypiboma". A 27-year-old female who had undergone lower segment cesarean section 4 months earlier was admitted with complaints of pain abdomen with a palpable mass in left iliac fossa. X-ray, ultrasonography, and CT scan findings were suggestive of retained surgical sponge. Surgical sponge was removed following laparotomy. Surgeons must be aware of the risk factors that lead to gossypiboma, and measures should be taken to prevent it. Besides increasing morbidity and possible mortality, it may result in libel suit for compensation.

  3. Surgical treatment of pediatric rhinosinusitis.

    Science.gov (United States)

    Isaacson, G

    2015-08-01

    Pediatric rhinosinusitis is a common sequela of upper respiratory infections in children. It is usually a self-limited disease, sometimes requiring antibiotic therapy. Surgery may be indicated in children who suffer complication of acute rhinosinusitis, severe recurrent acute rhinosinusitis, rhinosinusitis in cystic fibrosis with or without polyposis, chronic rhinosinusitis refractory to maximal medical management, allergic fungal sinusitis, and paranasal sinus mucoceles. Surgical options include, adenoidectomy, sinus puncture and lavage, open surgical approaches, endoscopic sinus surgery, balloon sinuplasty, and turbinectomy or turbinate reduction. This paper reviews the anatomy and physiology of rhinosinusitis in children and current knowledge of the indications and best methods of surgical treatment.

  4. Towards Safe Robotic Surgical Systems

    DEFF Research Database (Denmark)

    Sloth, Christoffer; Wisniewski, Rafael

    2015-01-01

    A proof of safety is paramount for an autonomous robotic surgical system to ensure that it does not cause trauma to patients. However, a proof of safety is rarely constructed, as surgical systems are too complex to be dealt with by most formal verification methods. In this paper, we design...... a controller for motion compensation in beating-heart surgery, and prove that it is safe, i.e., the surgical tool is kept within an allowable distance and orientation of the heart. We solve the problem by simultaneously finding a control law and a barrier function. The motion compensation system is simulated...

  5. Surgical Skills Beyond Scientific Management

    Science.gov (United States)

    Whitfield, Nicholas

    2015-01-01

    During the Great War, the French surgeon Alexis Carrel, in collaboration with the English chemist Henry Dakin, devised an antiseptic treatment for infected wounds. This paper focuses on Carrel’s attempt to standardise knowledge of infected wounds and their treatment, and looks closely at the vision of surgical skill he espoused and its difference from those associated with the doctrines of scientific management. Examining contemporary claims that the Carrel–Dakin method increased rather than diminished demands on surgical work, this paper further shows how debates about antiseptic wound treatment opened up a critical space for considering the nature of skill as a vital dynamic in surgical innovation and practice. PMID:26090737

  6. Surgical education through video broadcasting.

    Science.gov (United States)

    Nagengast, Eric S; Ramos, Margarita S; Sarma, Hiteswar; Deshpande, Gaurav; Hatcher, Kristin; Magee, William P; Campbell, Alex

    2014-09-01

    Surgical training is facing new obstacles. As advancements in medicine are made, surgeons are expected to know more and to be able to perform more procedures. In the western world, increasing restrictions on residency work hours are adding a new hurdle to surgical training. In low-resource settings, a low attending-to-resident ratio results in limited operative experience for residents. Advances in telemedicine may offer new methods for surgical training. In this article, the authors share their unique experience using live video broadcasting of surgery for educational purposes at a comprehensive cleft care center in Guwahati, India.

  7. Dental arch relationship in children with complete unilateral cleft lip and palate following one-stage and three-stage surgical protocols

    NARCIS (Netherlands)

    Fudalej, P.S.; Katsaros, C.; Bongaarts, C.; Dudkiewicz, Z.; Kuijpers-Jagtman, A.M.

    2011-01-01

    The objective of this study is to compare dental arch relationship following one-stage and three-stage surgical protocols of unilateral cleft lip and palate. Dental casts of 61 children (mean age, 11.2 years; SD, 1.7), consecutively treated in one center with one-stage closure of the complete cleft

  8. Evidence-based surgical wound care on surgical wound infection.

    Science.gov (United States)

    Reilly, Jaqueline

    2002-09-01

    Surgical wound infection is an important outcome indicator in the postoperative period. A 3-year prospective cohort epidemiological study of 2202 surgical patients from seven surgical wards across two hospitals was carried out using gold standard surveillance methodology. This involved following patients up as inpatients and postdischarge surveillance to 30 days by an independent observer. The results led to the development of a mathematical model for risk of clean, elective surgical wound infection. Risk of surgical wound infection was increased by smoking, higher body mass index, presence of malignancy, haematoma formation, increasing numbers of people in theatre, adherent dressing usage, and higher times to suture removal (P<0.05). The results show that this type of surveillance is an effective way of collecting accurate data on wound infection rates. It was noted that patient care practices affected the surgical wound infection rate and the surveillance was used to facilitate the adoption of evidence-based practice, through recommendations for clean surgery, to reduce the risk from extrinsic risk factors for wound infection. As a result of the implementation of this evidence-based practice there was a significant reduction (P<0.05) in the clean wound infection rate.

  9. Clean Cast Steel Technology - Machinability and Technology Transfer

    Energy Technology Data Exchange (ETDEWEB)

    C. E. Bates; J. A. Griffin

    2000-05-01

    There were two main tasks in the Clean Cast Steel Technology - Machinability and Technology Transfer Project. These were (1) determine the processing facts that control the machinability of cast steel and (2) determine the ability of ladle stirring to homogenize ladle temperature, reduce the tap and pouring temperatures, and reduce casting scrap.

  10. PRODUCTION OF CAST DIE INSERTS FOR HOT STRAINING

    Directory of Open Access Journals (Sweden)

    L. R. Dudetskaja

    2009-01-01

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

  11. Caste dominance and economic performance in rural India

    NARCIS (Netherlands)

    Kalwij, Adriaan; Iversen, Vegard; Verschoor, Arjan; Dubey, Amaresh

    2014-01-01

    Using household panel data for rural India covering 1993–94 and 2004–5, we test whether scheduled castes (SCs) and other minority groups perform better or worse in terms of income when resident in villages dominated by (i) upper castes or (ii) their own group. Theoretically, upper-caste dominance co

  12. 46 CFR 153.239 - Use of cast iron.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Use of cast iron. 153.239 Section 153.239 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK... Systems § 153.239 Use of cast iron. (a) Cast iron used in a cargo containment system must meet...

  13. 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.

  14. Retroperitoneal local CastLeman's disease: 4 case reports and literature review%腹膜后局限性CastLeman病4例报告并文献复习

    Institute of Scientific and Technical Information of China (English)

    杨冬园; 周四维

    2013-01-01

    目的:报告偶然发现的4例腹膜后局限性CastLeman病,并结合文献复习,以提高对该疾病的认识及诊疗水平.方法:回顾性分析4例术前未能明确诊断的后腹膜占位性病变病例,经手术切除,术后病理证实为较少见的局限性CastLeman病.结果:4例均经手术完整切除肿瘤,未行辅助治疗,随访7个月~4年2个月,4例患者均无瘤存活,未见肿瘤复发.结论:腹膜后CastLeman病临床症状不典型,术前实验室及影像学检查无特异性,常易误诊.手术探查切除肿瘤为首选治疗方法,疗效较好,最终明确诊断有赖于病理学检查.%Objective: We reported the incidentally found 4 cases of retroperitoneal the local CastLeman's disease and undertook a literature review to improve the diagnosis and treatment of the disease. Method: Retrospectively analyzed 4 cases with retroperitoneal mass which failed to confirm the diagnosis before surgery. After surgical resection, the pathological results were local CastLemans disease. Result: All 4 cases received complete surgical resection of the tumor. No adjuvant therapy was administrated. Follow-up ranged form 4 months to 4 years and 2 months. No recurrence was observed. Conclusion: Retroperitoneal CastLeman's disease has no typical clinical findings. It may pose a diagnose dilemma because of its lack of specific lab test and distinguish radiographic features. Surgical exploration to remove the tumor is the preferred treatment with fair outcome. Eventually confirming diagnosis depends on the pathological examination.

  15. Casting directly from a computer model by using advanced simulation software FLOW-3D Cast ®

    Directory of Open Access Journals (Sweden)

    M. Sirviö

    2009-01-01

    Full Text Available ConiferRob - A patternless casting technique, originally conceived at VTT Technical Research Centre of Finland and furtherdeveloped at its spin-off company, Simtech Systems, offers up to 40% savings in product development costs, and up to two months shorterdevelopment times compared to conventional techniques. Savings of this order can be very valuable on today's highly competitivemarkets. Casting simulation is commonly used for designing of casting systems. However, most of the software are today old fashioned and predicting just shrinkage porosity. Flow Science, VTT and Simtech have developed new software called FLOW-3D Cast ® , whichcan simulate surface defects, air entrainment, filters, core gas problems and even a cavitation.

  16. Study on Compatibility between Converters and Casting Machines for Daily Steelmaking and Continuous Casting Scheduling

    Institute of Scientific and Technical Information of China (English)

    MA Feng-cai; ZHANG Qun

    2009-01-01

    In this paper, daily production scheduling is studied based on the Third Steelmaking Plant of Wuhan Iron and steel corporation (WISCO). To make sure the daily production plan is feasible, method of casting gToup is established, and the compatibility between two converters and three continuous casting devices in the Third Steelmaking Plant of WISCO is analyzed. The process flow chart of daily production scheduling is given in this paper. Then, algorithms and procedures for the simulation of daily production plan is developed. Using the actual data from the Third Steelmaking Plant, the feasible daily steelmaking plan and cast plan are given. The plan contains 7 groups of cast plan, figured out 54 converters, and a- bout 13,500 tons steel.

  17. The effect on cast post dimensions of casting investment and airborne particle abrasion.

    Science.gov (United States)

    Hashem, Danya; German, Matthew J; Wassell, Robert W

    2011-09-01

    Cast posts can sometimes prove difficult to seat fully during fitting. This study compared two different liquid/water dilutions for phosphate bonded investment and the effect of controlled airborne particle abrasion on resulting post diameter. After measuring polymeric post patterns (n = 18), 3 groups were invested using concentrated solution and 3 groups using dilute solution. After casting they were weighed and remeasured then exposed to airborne particle abrasion. Both solutions produced oversized cast posts. Mean diameter reduction during airborne particle abrasion was 8 microm/10s taking an average of 41s to reach precast size. Where a post pattern fits tightly, airborne particle abrasion for 70s should reduce the casting sufficiently to accommodate the cement lute.

  18. 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

  19. Solidification of cast iron - A study on the effect of microalloy elements on cast iron

    DEFF Research Database (Denmark)

    Moumeni, Elham

    The present thesis deals with the heat transfer and solidification of ductile and microalloyed grey cast iron. Heterogeneous nucleation of nodular graphite at inclusions in ductile iron during eutectic solidification has been investigated. A series of ductile iron samples with two different...... of the austenite, in the last region to solidify. The superfine graphite which forms in this type of irons is short (10-20µm) and stubby. The microstructure of this kind of graphite flakes in titanium alloyed cast iron is studied using electron microscopy techniques. The methods to prepare samples of cast iron...... for comprehensive transmission electron microscopy of graphite and the surrounding iron matrix have been developed and explained. Dual beam microscopes are used for sample preparation. A TEM study has been carried out on graphite flakes in grey cast iron using selected area electron diffraction (SAED). Based...

  20. Cast Stainless Steel Ferrite and Grain Structure

    Energy Technology Data Exchange (ETDEWEB)

    Ruud, Clayton O.; Ramuhalli, Pradeep; Meyer, Ryan M.; Mathews, Royce; Diaz, Aaron A.; Anderson, Michael T.

    2012-09-01

    In-service inspection requirements dictate that piping welds in the primary pressure boundary of light-water reactors be subject to a volumetric examination based on the rules contained within the American Society of Mechanical Engineers Boiler and Pressure Vessel Code, Section XI. The purpose of the inspection is the reliable detection and accurate sizing of service-induced degradation and/or material flaws introduced during fabrication. The volumetric inspection is usually carried out using ultrasonic testing (UT) methods. However, the varied metallurgical macrostructures and microstructures of cast austenitic stainless steel piping and fittings, including statically cast stainless steel and centrifugally cast stainless steel (CCSS), introduce significant variations in the propagation and attenuation of ultrasonic energy. These variations complicate interpretation of the UT responses and may compromise the reliability of UT inspection. A review of the literature indicated that a correlation may exist between the microstructure and the delta ferrite content of the casting alloy. This paper discusses the results of a recent study where the goal was to determine if a correlation existed between measured and/or calculated ferrite content and grain structure in CCSS pipe.

  1. 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)

  2. Carburizer Effect on Cast Iron Solidification

    Science.gov (United States)

    Janerka, Krzysztof; Kondracki, Marcin; Jezierski, Jan; Szajnar, Jan; Stawarz, Marcin

    2014-06-01

    This paper presents the effect of carburizing materials on cast iron solidification and crystallization. The studies consisted of cast iron preparation from steel scrap and different carburizers. For a comparison, pig iron was exclusively used in a solid charge. Crystallization analysis revealed the influence of the carburizer material on the crystallization curves as well as differences in the solidification paths of cast iron prepared with the use of different charge materials. The carburizers' influence on undercooling during the eutectic crystallization process was analyzed. The lowest undercooling rate was recorded for the melt with pig iron, then for synthetic graphite, natural graphite, anthracite, and petroleum coke (the highest undercooling rate). So a hypothesis was formulated that eutectic cells are created most effectively with the presence of carbon from pig iron (the highest nucleation potential), and then for the graphite materials (crystallographic similarity with the carbon precipitation in the cast iron). The most difficult eutectic crystallization is for anthracite and petroleum coke (higher undercooling is necessary). This knowledge can be crucial when the foundry plant is going to change the solid charge composition replacing the pig iron by steel scrap and the recarburization process.

  3. CAST reaches milestone but keeps on searching

    CERN Multimedia

    CERN Courier (september 2011 issue)

    2011-01-01

    After eight years of searching for the emission of a dark matter candidate particle, the axion, from the Sun, the CERN Axion Solar Telescope (CAST) has fulfilled its original physics programme.   Members of the CAST collaboration in July, together with dipole-based helioscope. CAST, the world’s most sensitive axion helioscope, points a recycled prototype LHC dipole magnet at the Sun at dawn and dusk, looking for the conversion of axions to X-rays. It incorporates four state-of-the-art X-ray detectors: three Micromegas detectors and a pn-CCD imaging camera attached to a focusing X-ray telescope that was recovered from the German space programme (see CERN Courier April 2010).  Over the years, CAST has operated with the magnet bores - the location of the axion conversion - in different conditions: first in vacuum, covering axion masses up to 20 meV/c2, and then with a buffer gas (4He and later 3He) at various densities, finally reaching the goal of 1.17 eV/c2 on 22 ...

  4. Costs Analysis of Iron Casts Manufacturing

    Directory of Open Access Journals (Sweden)

    S. Kukla

    2012-04-01

    Full Text Available The article presents the issues of costs analysis of iron casts manufacturing using automated foundry lines. Particular attention was paid to departmental costs, conversion costs and costs of in-plant transport. After the Pareto analysis had been carried out, it was possible to set the model area of the process and focus on improving activities related to finishing of a chosen group of casts. In order to eliminate losses, the activities realised in this domain were divided into activities with added value, activities with partially added value and activities without added value. To streamline the production flow, it was proposed to change the location of workstations related to grinding, control and machining of casts. Within the process of constant improvement of manufacturing processes, the aspect of work ergonomics at a workstation was taken into account. As a result of the undertaken actions, some activities without added value were eliminated, efficiency was increased and prime costs of manufacturing casts with regard to finishing treatment were lowered.

  5. The cern axion solar telescope (CAST)

    Energy Technology Data Exchange (ETDEWEB)

    Aalseth, C. E.; Arik, E.; Autiero, D.; Avignone, F. T.; Barth, K.; Bowyer, S. M.; Brauninger, H.; Brodzinski, R. L.; Carmona, J. M.; Cebrian, S.; Celebi, G.; Cetin, S.; Collar, J. I.; Creswick, R.; Delbart, A.; Delattre, M.; DiLella, L.; De Oliveira, R.; Eleftheriadis, Ch.; Erdutan, N.; Fanourakis, G.; Farach, H. A.; Fiorini, C.; Geralis, Th.; Giomataris, I.; Girard, T. A.; Gninenko, S. N.; Golubev, N. A.; Hasinoff, M.; Hoffmann, D.; Irastorza, I. G.; Jacoby, J.; Jeanneau, F.; Knopf, M. A.; Kovzelev, A. V.; Kotthaus, R.; Krčmar, M.; Krečak, Z.; Lakić, B.; Liolios, A.; Ljubičić, A.; Lutz, G.; Longoni, A.; Luzon, G.; Mailov, A.; Matveev, V. A.; Miley, H. S.; Morales, A.; Morales, J.; Mutterer, M.; Nikolaidis, A.; Nussinov, S.; Ortiz, A.; Pitts, W. K.; Placci, A.; Postoev, V. E.; Raffelt, G. G.; Riege, H.; Sampieto, M.; Sarsa, M.; Savvidis, I.; Stipčević, M.; Thomas, C. W.; Thompson, R. C.; Valco, P.; Villar, J. A.; Villierme, B.; Walckiers, L.; Wilcox, W.; Zachariadou, K.; Zioutas, K.

    2002-07-01

    A decommissioned LHC test magnet is being prepared as the CERN Axion Solar Telescope (CAST) experiment. The magnet has a field of 9.6 Tesla and length of 10 meters. It is being mounted on a platform to track the sun over plus or minus 8 to the sixth power vertically and plus or minus 45 to the sixth power, horizontally.

  6. The CAST X-ray telescope

    Energy Technology Data Exchange (ETDEWEB)

    Rosu, Madalin M. [Institut fuer Kernphysik, Technische Universitaet Darmstadt (Germany)

    2010-07-01

    CAST (CERN Axion Solar Telescope) is a project at the European Organization for Nuclear Research CERN in Geneva, which searches for Axions coming from the Sun. The most sensitive detector system used at CAST is the X-ray Wolter type I telescope. Its two constituents, the X-ray mirror optics and the fully depleted EPIC pn-CCD detector, were originally built for ABRIXAS and XMM-Newton space missions. Their combined use provides the X-ray telescope with the highest axion discovery potential of all CAST detectors, excellent imaging capability and almost 100% data tacking reliability in conditions of low background which is suppressed by a factor of 155 by focusing the photons from the aperture of the magnet of 14.5 cm{sup 2} to a spot of roughly 9.3 mm{sup 2} on the CCD chip. For achieving a high sensitivity the CCD chip is operated at -130 C in a vacuum vessel made of aluminum and a passive shield of copper and led to reduce the external {gamma}-ray. All these combined with a extremely thin and homogeneous entrance window of 20 nm located on the back side of the chip result in a quantum efficiency of >95% in the photon energy range of 1 to 7 keV, which is the interesting region for the axion search with the CAST experiment.

  7. Centrifugal Casting of Tubular Perovskite Membranes

    NARCIS (Netherlands)

    Mertins, Frederic H.B.; Kruidhof, Henk; Bouwmeester, Henny J.M.

    2005-01-01

    Dense tubular membranes were produced by centrifugal casting of an aqueous suspension, containing powder particles of the mixed-conducting perovskite La0.5Sr0.5CoO3−δ and a dispersant. The resulting green bodies were dried and sintered to produce tubes with a maximum length of 12 cm, having a relat

  8. New progresses of Chinese art casting

    Institute of Scientific and Technical Information of China (English)

    TAN De-rui

    2007-01-01

    @@ The Chinese art casting with 5 000 years history has been rapidly developed in recent ten years. This benefits from the great development of Chinese economy, the large-scale urban construction and transformation, the increasing demands for the cultural work of art, the loose religious environment and the expanding international market.

  9. Graphite formation in cast iron, phase 2

    Science.gov (United States)

    Stefanescu, D. M.; Fiske, M. R.

    1985-01-01

    Several types of cast irons are directionally solidified aboard the KC-135 aircraft. Also, control samples are run on Earth for comparison. Some of these samples are unusable because of various mechanical problems; the analysis and the interpretation of results on the samples that are run successfully is discussed.

  10. Cast Iron With High Carbon Content

    Science.gov (United States)

    Curreri, P. A.; Hendrix, J. C.; Stefanescu, D. M.

    1986-01-01

    Method proposed for solidifying high-carbon cast iron without carbon particles segregating at upper surface. Solidification carried out in low gravity, for example on airplane flying free-fall parabolic trajectory. Many different microstructures obtained by proposed technique, and percentage by weight of carbon retained in melt much higher than at present.

  11. Development of low-temperature high-strength integral steel castings for offshore construction by casting process engineering

    OpenAIRE

    Lim Sang-Sub; Mun Jae-Chul; Kim Tae-Won; Kang Chung-Gil

    2014-01-01

    In casting steels for offshore construction, manufacturing integral casted structures to prevent fatigue cracks in the stress raisers is superior to using welded structures. Here, mold design and casting analysis were conducted for integral casting steel. The laminar flow of molten metal was analyzed and distributions of hot spots and porosities were studied. A prototype was subsequently produced, and air vents were designed to improve the surface defects caused by the release of gas. A radio...

  12. A new freeze casting technique for ceramics

    Science.gov (United States)

    Araki, Kiyoshi

    A new freeze casting technique for ceramics capable of manufacturing near room temperature with a sublimable vehicle has been developed in order to eliminate expensive processes under extremely cold temperatures in the conventional freeze casting. Fluid concentrated slurries of Al2O 3 powder in molten camphene (C10H16) were successfully prepared at 55°C with a small amount of a dispersant. These slurries were quickly solidified (frozen) at room temperature to yield a rigid solid green body, where the frozen camphene was easily removed by sublimation (freeze-drying) with negligible shrinkage. Sintering was successfully conducted without any special binder burnout process to yield dense sintered bodies (over 98% T.D). An organic alloy with a eutectic composition in the naphthalene (C 10H8)-camphor (C10H16O) binary system with a eutectic temperature of 31°C was also found to be a successful vehicle for the new ceramic freeze casting. The fabrication processes are almost the same as those with camphene. It was found that vehicles with off-eutectic compositions resulted in large voids in the sintered body due to the ceramic particle rejection by pro-eutectic crystals during freezing. At the eutectic composition, fine lamellar microstructure in the solidified vehicle inhibits the particle rejection. The proposed advantages of the new freeze casting technique with a sublimable vehicle include; (1) elimination of extremely cold temperatures used in conventional freeze casting; (2) elimination of troublesome binder burnout process; and (3) fast manufacturing cycle due to quick solidification. Porous ceramic bodies with unique interconnected pore channels were fabricated by the new freeze casting with lower solid content. The unique channels surrounded by fully dense walls have nearly circular cross-sections unlike conventional aqueous freeze casting. The porosity and the channel diameters are controllable by the solid content in the slurry. The unique channels are

  13. Cast Iron And Mineral Cast Applied For Machine Tool Bed - Dynamic Behavior Analysis

    OpenAIRE

    2015-01-01

    Cast iron and mineral cast are the materials most often used in the machine structural elements design (bodies, housings, machine tools beds etc.). The materials significantly differ in physical and mechanical properties. The ability to suppress vibration is one of the most important factors determining the dynamic properties of the machine and has a significant impact on the machining capabilities of a machine tool. Recent research and development trends show that there is a clear tendency t...

  14. The influence of solidification speed during heating on allotropic transformations of chromium cast iron casting

    Directory of Open Access Journals (Sweden)

    M. Przybył

    2008-08-01

    Full Text Available The unique stand to founding dilatometric samples ("on ready” which solidify with different cooling speeds was presented. The dilatometric investigations, X-ray, metallographic they disclosed the occurrence in matrix of chromium cast iron of considerable quantity of austenite in dependence from concentration of chromium (18% and 23% and the speed of solidification. Castings these despite large part of austenite mark with high hardness in raw state.

  15. Essential Tremor (ET): Surgical Options

    Science.gov (United States)

    ... t respond to propranolol, primidone, or other common ET medications and whose tremor has become debilitating, there ... treatments were first introduced. Current surgical options for ET include Deep Brain Stimulation (DBS) , Focused Ultrasound , and ...

  16. Surgical trainees and trauma emergencies.

    Science.gov (United States)

    Wybaillie, E; Broos, P L O

    2010-01-01

    An accident and emergency (A&E) training has been suggested as an essential part of the basic surgical training. The A&E curriculum should be divided into three sections: a critical curriculum, a core curriculum and a comprehensive curriculum. For instance, the critical curriculum contains topics that provide the opportunity to translate the ABCDE principles of trauma management into practice. Furthermore, a post in the A&E department provides the surgical trainee with significant exposure to the management of the polytrauma patient and to the management of other acute general surgical, urological and orthopaedic conditions. By presenting better educational programs and by reducing the non-medical tasks a trainee has to deal with, the education of surgical trainees during A&E attachment can be improved.

  17. Surgical treatment of cranial neuralgias.

    Science.gov (United States)

    Franzini, Angelo; Ferroli, Paolo; Messina, Giuseppe; Broggi, Giovanni

    2010-01-01

    The most common types of cranial neuralgias amenable to surgical therapeutic options are trigeminal neuralgia and glossopharyngeal neuralgia, the former having an approximate incidence of 5/100000 cases per year and the latter of 0.05/100000 cases per year. Surgical therapy of these pathological conditions encompasses several strategies, going from ablative procedures to neurovascular decompression, to radiosurgery. The choice of the most appropriate surgical option (which must be taken into account when all conservative treatments have proven to be unsuccessful) has to take into account many factors, the most important ones being neuroradiological evidence of a neurovascular conflict, severity of symptoms, the age and clinical history of the patient, and the patient's overall medical condition. In this chapter we report our experience with the treatment of trigeminal and glossopharyngeal neuralgia, describing the surgical procedures performed and reviewing the most recent aspects on this subject in the past literature.

  18. Surgical reconstruction of charcot foot neuroarthropathy, a case based review.

    Science.gov (United States)

    Kučera, Tomáš; Šponer, Pavel; Šrot, Jaromír

    2014-01-01

    Our case-based review focuses on limb salvage through operative management of Charcot neuroarthropathy of the diabetic foot. We describe a case, when a below-knee amputation was considered in a patient with chronic Charcot foot with a rocker-bottom deformity and chronic plantar ulceration. Conservative treatment failed. Targeted antibiotic therapy and operative management (Tendo-Achilles lengthening, resectional arthrodesis of Lisfranc and midtarsal joints, fixation with large-diameter axial screws, and plaster cast) were performed. On the basis of this case, we discuss options and drawbacks of surgical management. Our approach led to healing of the ulcer and correction of the deformity. Two years after surgery, we observed a significant improvement in patient's quality of life. Advanced diagnostic and imaging techniques, a better understanding of the biomechanics and biology of Charcot neuroarthropathy, and suitable osteosynthetic material enables diabetic limb salvage.

  19. Intermittent exotropia: Surgical treatment strategies

    Directory of Open Access Journals (Sweden)

    Jai Aditya Kelkar

    2015-01-01

    Full Text Available Surgical management of intermittent exotropias (IXTs is ambiguous, with techniques of management varying widely between institutions. This review aims to examine available literature on the surgical management of IXT. A literature search was performed using PubMed, Web of Knowledge, LILACS, and the University of Liverpool Orthoptic Journals and Conference Transactions Database. All English-language papers published between 1958 and the present day were considered.

  20. Innovation in pediatric surgical education.

    Science.gov (United States)

    Clifton, Matthew S; Wulkan, Mark L

    2015-06-01

    Pediatric surgical training in the United States remained basically unchanged from the model developed by Ladd and Gross in the 1930s until recently. Standardized curriculum and novel evaluation methods are now being implemented. Pediatric Surgical education is currently undergoing a transition to competency-based evaluation and promotion. Unfortunately, there is little data on the efficacy of these changes. This presents an opportunity for further study of how we conduct training, and how we evaluate and promote our trainees.

  1. Aesthetic Surgical Crown Lengthening Procedure

    Science.gov (United States)

    de Oliveira, Pablo Santos; Chiarelli, Fabio; Rodrigues, José A.; Shibli, Jamil A.; Zizzari, Vincenzo Luca; Piattelli, Adriano; Iezzi, Giovanna; Perrotti, Vittoria

    2015-01-01

    The aim of this case report was to describe the surgical sequence of crown lengthening to apically reposition the dentogingival complex, in addition to an esthetic restorative procedure. Many different causes can be responsible for short clinical crown. In these cases, the correct execution of a restorative or prosthetic rehabilitation requires an increasing of the crown length. According to the 2003 American Academy of Periodontology (Practice Profile Survey), crown lengthening is the most habitual surgical periodontal treatment. PMID:26609452

  2. Aesthetic Surgical Crown Lengthening Procedure

    Directory of Open Access Journals (Sweden)

    Pablo Santos de Oliveira

    2015-01-01

    Full Text Available The aim of this case report was to describe the surgical sequence of crown lengthening to apically reposition the dentogingival complex, in addition to an esthetic restorative procedure. Many different causes can be responsible for short clinical crown. In these cases, the correct execution of a restorative or prosthetic rehabilitation requires an increasing of the crown length. According to the 2003 American Academy of Periodontology (Practice Profile Survey, crown lengthening is the most habitual surgical periodontal treatment.

  3. Surgical Treatment of Facial Paralysis

    OpenAIRE

    Mehta, Ritvik P.

    2009-01-01

    The management of facial paralysis is one of the most complex areas of reconstructive surgery. Given the wide variety of functional and cosmetic deficits in the facial paralysis patient, the reconstructive surgeon requires a thorough understanding of the surgical techniques available to treat this condition. This review article will focus on surgical management of facial paralysis and the treatment options available for acute facial paralysis (2 yr). For acute facial paralysis, the main surgi...

  4. Aesthetic Surgical Crown Lengthening Procedure.

    Science.gov (United States)

    de Oliveira, Pablo Santos; Chiarelli, Fabio; Rodrigues, José A; Shibli, Jamil A; Zizzari, Vincenzo Luca; Piattelli, Adriano; Iezzi, Giovanna; Perrotti, Vittoria

    2015-01-01

    The aim of this case report was to describe the surgical sequence of crown lengthening to apically reposition the dentogingival complex, in addition to an esthetic restorative procedure. Many different causes can be responsible for short clinical crown. In these cases, the correct execution of a restorative or prosthetic rehabilitation requires an increasing of the crown length. According to the 2003 American Academy of Periodontology (Practice Profile Survey), crown lengthening is the most habitual surgical periodontal treatment.

  5. The Configurable Aperture Space Telescope (CAST)

    Science.gov (United States)

    Ennico, Kimberly; Bendek, Eduardo A.; Lynch, Dana H.; Vassigh, Kenny K.; Young, Zion

    2016-07-01

    The Configurable Aperture Space Telescope, CAST, is a concept that provides access to a UV/visible-infrared wavelength sub-arcsecond imaging platform from space, something that will be in high demand after the retirement of the astronomy workhorse, the 2.4 meter diameter Hubble Space Telescope. CAST allows building large aperture telescopes based on small, compatible and low-cost segments mounted on autonomous cube-sized satellites. The concept merges existing technology (segmented telescope architecture) with emerging technology (smartly interconnected modular spacecraft, active optics, deployable structures). Requiring identical mirror segments, CAST's optical design is a spherical primary and secondary mirror telescope with modular multi-mirror correctors placed at the system focal plane. The design enables wide fields of view, up to as much as three degrees, while maintaining aperture growth and image performance requirements. We present a point design for the CAST concept based on a 0.6 meter diameter (3 x 3 segments) growing to a 2.6 meter diameter (13 x 13 segments) primary, with a fixed Rp=13,000 and Rs=8,750 mm curvature, f/22.4 and f/5.6, respectively. Its diffraction limited design uses a two arcminute field of view corrector with a 7.4 arcsec/mm platescale, and can support a range of platescales as fine as 0.01 arcsec/mm. Our paper summarizes CAST, presents a strawman optical design and requirements for the underlying modular spacecraft, highlights design flexibilities, and illustrates applications enabled by this new method in building space observatories.

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

    Directory of Open Access Journals (Sweden)

    Iban Vicario

    2016-01-01

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

  7. Characterization of Bimetallic Castings with an Austenitic Working Surface Layer and an Unalloyed Cast Steel Base

    Science.gov (United States)

    Wróbel, Tomasz

    2014-05-01

    The paper presents the technology of bimetallic castings based on the founding method of layer coating directly in the cast process of the so-called method of mold cavity preparation. The prepared castings consist of two fundamental parts, i.e., the base and the working surface layer. The base part of the bimetallic casting is typical foundry material, i.e., unalloyed cast steel, whereas the working layer is a plate of austenitic alloy steel sort X2CrNi 18-9. The quality of the joint between the base part and the working layer was evaluated on the basis of ultrasonic non-destructive testing and structure examinations containing metallographic macro- and microscopic studies with the use of a light microscope (LOM) with microhardness measurements and a scanning electron microscope (SEM) with microanalysis of the chemical composition (energy dispersive spectroscopy—EDS). On the basis of the obtained results it was confirmed that the decisive phenomena needed to create a permanent joint between the two components of the bimetallic casting are carbon and heat transport in the direction from the high-carbon and hot base material which was poured into the mold in the form of liquid metal to the low-carbon and cold material of the working layer which was placed in the mold cavity in the form of a monolithic insert.

  8. Evolution of surgical skills training

    Institute of Scientific and Technical Information of China (English)

    Kurt E Roberts; Robert L Bell; Andrew J Duffy

    2006-01-01

    Surgical training is changing: one hundred years of tradition is being challenged by legal and ethical concerns for patient safety, work hours restrictions, the cost of operating room time, and complications. Surgical simulation and skills training offers an opportunity to teach and practice advanced skills outside of the operating room environment before attempting them on living patients.Simulation training can be as straight forward as using real instruments and video equipment to manipulate simulated "tissue" in a box trainer. More advanced,virtual reality simulators are now available and ready for widespread use. Early systems have demonstrated their effectiveness and discriminative ability. Newer systems enable the development of comprehensive curricula and full procedural simulations.The Accreditation Council of Graduate Medical Education's (ACGME) has mandated the development of novel methods of training and evaluation. Surgical organizations are calling for methods to ensure the maintenance of skills, advance surgical training, and to credential surgeons as technically competent.Simulators in their current form have been demonstrated to improve the operating room performance of surgical residents. Development of standardized training curricula remains an urgent and important agenda, particularly for minimal invasive surgery.An innovative and progressive approach, borrowing experiences from the field of aviation, can provide the foundation for the next century of surgical training,ensuring the quality of the product. As the technology develops, the way we practice will continue to evolve, to the benefit of physicians and patients.

  9. Bacterial migration through punctured surgical gloves under real surgical conditions

    Directory of Open Access Journals (Sweden)

    Heidecke Claus-Dieter

    2010-07-01

    Full Text Available Abstract Background The aim of this study was to confirm recent results from a previous study focussing on the development of a method to measure the bacterial translocation through puncture holes in surgical gloves under real surgical conditions. Methods An established method was applied to detect bacterial migration from the operating site through the punctured glove. Biogel™ double-gloving surgical gloves were used during visceral surgeries over a 6-month period. A modified Gaschen-bag method was used to retrieve organisms from the inner glove, and thus-obtained bacteria were compared with micro-organisms detected by an intra-operative swab. Results In 20 consecutive procedures, 194 gloves (98 outer gloves, 96 inner gloves were examined. The rate of micro-perforations of the outer surgical glove was 10% with a median wearing time of 100 minutes (range: 20-175 minutes. Perforations occurred in 81% on the non-dominant hand, with the index finger most frequently (25% punctured. In six cases, bacterial migration could be demonstrated microbiologically. In 5% (5/98 of outer gloves and in 1% (1/96 of the inner gloves, bacterial migration through micro-perforations was observed. For gloves with detected micro-perforations (n = 10 outer layers, the calculated migration was 50% (n = 5. The minimum wearing time was 62 minutes, with a calculated median wearing time of 71 minutes. Conclusions This study confirms previous results that bacterial migration through unnoticed micro-perforations in surgical gloves does occur under real practical surgical conditions. Undetected perforation of surgical gloves occurs frequently. Bacterial migration from the patient through micro-perforations on the hand of surgeons was confirmed, limiting the protective barrier function of gloves if worn over longer periods.

  10. Surgical Anatomy of the Gastrointestinal Tract and Its Vasculature in the Laboratory Rat

    Directory of Open Access Journals (Sweden)

    Katarína Vdoviaková

    2016-01-01

    Full Text Available The aim of this study was to describe and illustrate the morphology of the stomach, liver, intestine, and their vasculature to support the planning of surgical therapeutic methods in abdominal cavity. On adult Wistar rats corrosion casts were prepared from the arterial system and Duracryl Dental and PUR SP were used as a casting medium and was performed macroscopic anatomical dissection of the stomach, liver, and intestine was performed. The rat stomach was a large, semilunar shaped sac with composite lining. On the stomach was very marked fundus, which formed a blind sac (saccus cecus. The rat liver was divided into six lobes, but without gall bladder. Intestine of the rat was simple, but cecum had a shape as a stomach. The following variations were observed in the origin of the cranial mesenteric artery. On the corrosion cast specimens we noticed the presence of the anastomosis between middle colic artery (a. colica media and left colic artery (a. colica sinistra. We investigated the second anastomosis between middle colic artery and left colic artery. The results of this study reveal that the functional anatomical relationship between the rat stomach, liver and intestine is important for the development of surgical research in human and veterinary medicine.

  11. Establishment of mathematical moment model in twin casting rolling rolls

    Institute of Scientific and Technical Information of China (English)

    孙斌煜; 苑世剑; 张洪; 杜艳平; 张芳萍

    2002-01-01

    In continuous casting rolling process, the deformed body is different from the hot rolling strip. The metal in casting rolling zone is first assumed to be viscous fluid and the mathematical model of casting rolling force is established, then the calculating formula for casting rolling torque is derived. In addition, considering the effects of deforming cone and appendant torque of rotary junctions sealing ring, the calculating model which accords with casting rolling condition is found out. Theoretical formula is proved by experiment.

  12. 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.

  13. 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.

  14. Surgical versus non-surgical treatment of congenital hyperinsulinism.

    Science.gov (United States)

    Mazor-Aronovitch, Kineret; Landau, Heddy; Gillis, David

    2009-03-01

    Congenital hyperinsulinism is a functional disorder of insulin secretion. In its diffuse severe form, it is traditionally treated with over 95% pancreatectomy. However, even after this procedure normoglycemia is not always achieved. Non-surgical therapy with frequent or continuous feeding, medication and close monitoring is another alternative. In this review we compare the two approaches to this condition focusing on early complications, diabetes, neurological outcome and home management issues. Early complications of pancreatectomy include mechanical, metabolic and infectious complications. Non-surgical interventions can be complicated by unwarranted effects of medications and of invasive procedures. Diabetes occurs with both approaches but much less frequently and years later with non-surgical treatment. Regarding neurodevelopmental outcome, most data come from heterogeneous groups. Nevertheless, it appears that outcome is not adversely affected by avoiding surgery. Home management is far more difficult for the non-surgical form. When the non-surgical approach is successful in achieving normoglycemia and parents are highly motivated, this mode of therapy should be considered.

  15. 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.

  16. Metallic Fuel Casting Development and Parameter Optimization Simulations

    Energy Technology Data Exchange (ETDEWEB)

    R.S. Fielding; J. Crapps; C. Unal; J.R. Kennedy

    2013-03-01

    One of the advantages of metallic fuel is the abilility to cast the fuel slugs to near net shape with little additional processing. However, the high aspect ratio of the fuel is not ideal for casting. EBR-II fuel was cast using counter gravity injection casting (CGIC) but, concerns have been raised concerning the feasibility of this process for americium bearing alloys. The Fuel Cycle Research and Development program has begun developing gravity casting techniques suitable for fuel production. Compared to CGIC gravity casting does not require a large heel that then is recycled, does not require application of a vacuum during melting, and is conducive to re-usable molds. Development has included fabrication of two separate benchscale, approximately 300 grams, systems. To shorten development time computer simulations have been used to ensure mold and crucible designs are feasible and to identify which fluid properties most affect casting behavior and therefore require more characterization.

  17. Formation of microstructures in the spheroidal graphite cast iron

    Science.gov (United States)

    Wang, S.; Daloz, D.; Bruneseaux, F.; Lesoult, G.

    2012-01-01

    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 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.

  18. 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 plates...

  19. 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...

  20. Fatigue life of ablation-cast 6061-T6 components

    Energy Technology Data Exchange (ETDEWEB)

    Tiryakioglu, Murat, E-mail: m.tiryakioglu@unf.edu [School of Engineering. University of North Florida, Jacksonville, FL 32224 (United States); Eason, Paul D. [School of Engineering. University of North Florida, Jacksonville, FL 32224 (United States); Campbell, John [Department of Metallurgy and Materials, University of Birmingham, Edgbaston B15 2TT (United Kingdom)

    2013-01-01

    The fatigue life of 6061-T6 alloy, normally used in its wrought form, was investigated in this study in cast form from parts produced by the new ablation casting process. All specimens were excised from military castings. Unidirectional tensile test results yielded elongation values comparable to forgings and extrusions. A total of 39 fatigue specimens were tested by the rotating cantilever beam technique at five maximum stress levels. Moreover nine specimens excised from a forging were also tested for comparison. Results revealed that the fatigue life of ablation-cast 6061-T6 (i) follows a three-parameter Weibull distribution, and (ii) is comparable to data from the 6061 forging and is superior to conventionally cast Al-7% Si-Mg alloy castings published in the literature. Analysis of the fracture surfaces of ablation-cast 6061-T6 via scanning electron microscopy showed the existence of fracture surface facets and multiple cracks propagating in different directions.

  1. A two-step (altered cast) impression technique in the prosthetic rehabilitation of a patient after a maxillectomy: a clinical report.

    Science.gov (United States)

    Vojvodic, Denis; Kranjcic, Josip

    2013-09-01

    This clinical report describes the prosthetic rehabilitation complicated by trismus (as a consequence of surgery and radiation therapy) of a patient with an acquired maxillary defect, after surgical removal of the right maxillary sinus tumor. The patient was restored with a partial removable dental prosthesis with a hollow bulb obturator to obtain orofacial rehabilitation and defect obturation. Precise obturation requires an accurate impression of the resection defect. A 2-step impression was performed because of trismus. A primary maxillary impression was made with an irreversible hydrocolloid, while a secondary (altered cast) impression was made with a silicone material by using the obturator cast framework as a tray. In that way an altered cast was produced. Subsequently, an obturator prosthesis was processed with a conventional technique.

  2. Genetic evidence on the origins of Indian caste populations.

    Science.gov (United States)

    Bamshad, M; Kivisild, T; Watkins, W S; Dixon, M E; Ricker, C E; Rao, B B; Naidu, J M; Prasad, B V; Reddy, P G; Rasanayagam, A; Papiha, S S; Villems, R; Redd, A J; Hammer, M F; Nguyen, S V; Carroll, M L; Batzer, M A; Jorde, L B

    2001-06-01

    The origins and affinities of the approximately 1 billion people living on the subcontinent of India have long been contested. This is owing, in part, to the many different waves of immigrants that have influenced the genetic structure of India. In the most recent of these waves, Indo-European-speaking people from West Eurasia entered India from the Northwest and diffused throughout the subcontinent. They purportedly admixed with or displaced indigenous Dravidic-speaking populations. Subsequently they may have established the Hindu caste system and placed themselves primarily in castes of higher rank. To explore the impact of West Eurasians on contemporary Indian caste populations, we compared mtDNA (400 bp of hypervariable region 1 and 14 restriction site polymorphisms) and Y-chromosome (20 biallelic polymorphisms and 5 short tandem repeats) variation in approximately 265 males from eight castes of different rank to approximately 750 Africans, Asians, Europeans, and other Indians. For maternally inherited mtDNA, each caste is most similar to Asians. However, 20%-30% of Indian mtDNA haplotypes belong to West Eurasian haplogroups, and the frequency of these haplotypes is proportional to caste rank, the highest frequency of West Eurasian haplotypes being found in the upper castes. In contrast, for paternally inherited Y-chromosome variation each caste is more similar to Europeans than to Asians. Moreover, the affinity to Europeans is proportionate to caste rank, the upper castes being most similar to Europeans, particularly East Europeans. These findings are consistent with greater West Eurasian male admixture with castes of higher rank. Nevertheless, the mitochondrial genome and the Y chromosome each represents only a single haploid locus and is more susceptible to large stochastic variation, bottlenecks, and selective sweeps. Thus, to increase the power of our analysis, we assayed 40 independent, biparentally inherited autosomal loci (1 LINE-1 and 39 Alu elements

  3. 21 CFR 878.4040 - Surgical apparel.

    Science.gov (United States)

    2010-04-01

    ... known as scrub suits, are excluded. (b) Classification. (1) Class II (special controls) for surgical... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Surgical apparel. 878.4040 Section 878.4040 Food... DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4040 Surgical apparel....

  4. 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....

  5. Surgical treatment for male prolactinoma

    Science.gov (United States)

    Song, Yi-Jun; Chen, Mei-Ting; Lian, Wei; Xing, Bing; Yao, Yong; Feng, Ming; Wang, Ren-Zhi

    2017-01-01

    Abstract A total of 184 cases of surgically treated male prolactinoma were analyzed retrospectively to summarize the outcome of this surgical intervention. We analyzed the general characteristics, clinical manifestations, hormone levels, imaging features, preoperative treatments, surgical outcomes, pathology results, and follow-up records for all included patients. The most common clinical manifestations included sexual dysfunction (47.4%), headache (55.9%), and visual disturbance (46.7%). Serum prolactin levels ranged from 150 to 204,952 ng/mL. Tumor size varied from 6 to 70 mm. Pituitary adenomas grew in a parasellar pattern with visual deficits occurring 40.7% of the time. After surgical therapy, 88.6% of patients achieved symptom relief, and 98.4% experienced an immediate postoperative decline in prolactin level. Fifty-seven patients (31.0%) achieved initial remission, and 26 patients (45.6%) experienced recurrence. Hence, our results suggest that in male prolactinoma characterized by a large pituitary diameter and high serum prolactin level, tumor size predicts the degree of gross resection. The prognostic predictors included preoperative tumor growth pattern and Ki-67 index. Citation: Yi-jun S, Mei-ting C, Wei L, Bing X, Yong Y, Ming F, Ren-zhi W. (2016) Surgical treatment for male prolactinoma: a retrospective study of 184 cases PMID:28079813

  6. Can we measure surgical resilience?

    Science.gov (United States)

    Graham, David; Becerril-Martinez, Guillermo; Quinto, Lena; Zhao, Dong Fang

    2016-01-01

    Surgical resilience describes psychological resilience within a surgical setting. Within a surgical setting, psychologically resilient patients have improved recovery and wound-healing. The search for biological correlates in resilient patients has led to the hypothesis that certain endogenous biomarkers (namely neuropeptide Y (NPY), testosterone, and dehydroepiandrosterone (DHEA)) are altered in resilient patients. The concept of surgical resilience raises the question of whether enhanced recovery following surgery can be demonstrated in patients with high titres of resilience biomarkers as compared to patients with low titres of resilience biomarkers. To determine the prognostic value of resilience biomarkers in surgical recovery, a cohort of patients undergoing major surgery should initially be psychometrically tested for their resilience levels before and after surgery so that biomarker levels of NPY, testosterone and DHEA can be compared to a validated psychometric test of resilience. The primary outcome would be length of hospital stay with and without an enhanced recovery program. Secondary outcome measures such as complications, time in rehabilitation and readmission could also be included. If the hypothesis is upheld, resilience biomarkers could be used to support more individualised perioperative management and lead to more efficient and effective allocation of healthcare resources.

  7. Phase Transformation in Cast Superaustenitic Stainless Steels

    Energy Technology Data Exchange (ETDEWEB)

    Lee Phillips, Nathaniel Steven [Iowa State Univ., Ames, IA (United States)

    2006-01-01

    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.

  8. Physics of Spin Casting Dilute Solutions

    CERN Document Server

    Karpitschka, Stefan; Riegler, Hans

    2012-01-01

    We analyze the spin casting of dilute (ideal) binary mixtures of non-volatile solutes in volatile solvents as a prototype for evaporation-controlled processes that are increasingly used to deposit specifically structured (sub)monolayers ("evaporation-induced self-assembly"). The first analytical description of the thinning of a volatile liquid film simultaneously subject to spinning and evaporation is presented. It shows, that the duration of a spin casting process is linked to the process parameters via power laws. A diffusion-advection model leads analytically to the equation governing the spatio-temporal evolution of the internal film composition. Its solution reveals that the solute concentration enrichment, its gradient, and its time evolution are related to the process parameters via power laws. The physics behind the power laws is uncovered and discussed. This reveales universal insights into the interplay between the control parameters and their impact on the spatiotemporal evolution of the film compo...

  9. Palatal Surface Area of Maxillary Plaster Casts

    DEFF Research Database (Denmark)

    Darvann, Tron Andre; Hermann, Nuno V.; Ersbøll, Bjarne Kjær;

    2007-01-01

    -dimensional measurements of selected linear distances, curve lengths, and (surface) areas were carried out on maxillary plaster casts from individuals with unilateral or bilateral cleft lip and palate. The relationship between two-dimensional and three-dimensional measurements was investigated using linear regression....... Results and Conclusions: Error sources in the measurement of three-dimensional palatal segment surface area from a two-dimensional photograph were identified as photographic distortion (2.7%), interobserver error (3.3%), variability in the orientation of the plaster cast (3.2%), and natural shape...... variation (4.6%). The total error of determining the cleft area/palate surface area ratio was 15%. In population studies, the effect of using two-dimensional measurements is a decrease of discriminating power. In well-calibrated setups, a two-dimensional measurement of the cleft area/palate surface area...

  10. Sharatchandra’s Caste and Gender Consciousness

    Directory of Open Access Journals (Sweden)

    Narasingha Sil

    2015-01-01

    Full Text Available Sharatchandra Chattopadhyay’s attitude to the prevalent caste system and social ethos, especially concerning sex, love, and marriage and chastity of married as well as widowed women, shows a marked ambivalence. On one hand, his work demonstrates his progressive and liberal ideas emanating from Western contact and impact on late colonial India, and on Bengal in particular. On the other hand, and by the same token, his attitude to love, marriage, and sex shows marked affinity with the Victorian morality emanating from the society of colonial India’s metropolitan masters. The upshot of this historical and social context is that Sharatchandra was basically a caste conscious Hindu Brahmin and a firm believer in the patriarchal ethos of his contemporary society, his reputation as a compassionate (daradī or maramī writer exposing the ills of his society notwithstanding.

  11. Numerical simulation of semisolid continuous casting process

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A general mathematical model and boundary condition applicable to momentum and heat transfer in the semisolid continuous casting(SCC) process was established. Using the model, the numerical simulation of the momentum and heat transfer of molten metal was carried out in the SCC system. The obtained results fit well with the measured ones. Moreover, using the numerical simulating software, the effect of various factors on breakout and breakage was explored. The obtained results show that heat flow density of copper mold and the withdrawal beginning time are two major influencing factors. The larger the heat flow density of copper mold, or the shorter the withdrawal beginning time, the more stable the semisolid continuous casting process.

  12. Gel cast foam diesel particulate filters

    Energy Technology Data Exchange (ETDEWEB)

    Binner, J.G.P.; Hughes, S. [IPTME, Loughborough Univ., Loughborough (United Kingdom); Sambrook, R.M. [Dytech Corp. Ltd., Dronfield (United Kingdom)

    2004-07-01

    A new manufacturing route for foam ceramics based on gel casting has been developed and is being commercialised. Gel casting employs an organic monomer that is polymerised to cause the in-situ gelation of a foamed aqueous ceramic slurry. The primary advantage is the inherent flexibility of the process; the foams can be near net shape manufactured in a variety of shapes and sizes and after production are simply dried and fired. In addition, the porosity and pore size distribution can be varied to suit the application and a wide range of ceramics can be foamed with densities ranging from 5-40% of theoretical. Applications are diverse and include the potential to be used as diesel particulate filters (DPF). The present work examines this and concludes that filtration efficiencies of {>=}90% are achievable without generating a significant backpressure for the engine. (orig.)

  13. 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.

  14. Mechanical performance of disposable surgical needle holders.

    Science.gov (United States)

    Francis, E H; Towler, M A; Moody, F P; McGregor, W; Himel, H N; Rodeheaver, G T; Edlich, R F

    1992-01-01

    The mechanical performance of disposable Webster surgical needle holders supplied by three different surgical instrument companies was determined by recording the forces (clamping moment) applied by the different needle holder jaws to curved surgical needles. This investigation demonstrated that there was a large variability in the mechanical performance of the disposable needle holders supplied by each surgical instrument company. In addition, the mechanical performance of the disposable needle holder of each surgical instrument company was distinctly different.

  15. Optimum design of cast iron finned radiator

    Institute of Scientific and Technical Information of China (English)

    赵立华; 张泓森; 董重成

    2003-01-01

    The height, thickness and spacing of fins have an impact on the thermal characteristics of a radiator.The calculation of heat output and metal thermal intensity for cast iron finned radiator are given by using heat transfer formula of vertical plate and parallel fins. Each factor having effect on the metal thermal intensity of a radiator is analyzed and the optimum structure parameters of a radiator are given in order to maximize metal thermal intensity.

  16. Superior Weapons Systems Through Castings (SWC)

    Science.gov (United States)

    2012-11-30

    the near elimination of delta ferrite both in the as-cast structure. The morphology of the delta ferrite after HIPing at low temperatures (1950°F...handout for inclusion in NFFS membership/industry mailings Promotion on NFFS website and within NFFS electronic newsletters Coordination with the Foundry... Morphological / Solidification N Deformation Figure 7-1 Possible routes for synthesizing aluminum base nano-composite materials. (A) Self

  17. Prediction of Casting Defects Using Simulation Techniques

    Directory of Open Access Journals (Sweden)

    Tania Rodriguez Moliner

    2010-05-01

    Full Text Available The aim of the present paper is to show the evident advantages of using simulation techniques in foundry technologies. The considerable save of time and economic resources that implies the use of this techniques has spread worldwide. As in Cuba the use is not extended to the foundries, we intend to demonstrate the possibilities of the use of simulation software for the development of casting technologies.

  18. Development and investigation of electroslag continuous casting

    Institute of Scientific and Technical Information of China (English)

    Ximin Zang; Zhouhua Jiang; Tieyi Pan

    2007-01-01

    The principle and technological design of electroslag continuous casting (ESCC), including bifilar mode, T-shaped mould,and metal level detecting system, are detailed. Remelting was carried out for 1Cr18Ni9Ti stainless steel with ESCC. The surface finish, chemical composition, macro- and microstructures, and inclusions of the remelted billets were characterized. ESCC reduces the cost and increases the productivity in comparison to traditional ESR, while achieves comparably excellent products.

  19. Fracture analysis of chilled cast iron camshaft

    OpenAIRE

    Li Ping; Li Fengjun; Cai Anke

    2009-01-01

    The fracture of a camshaft made of chilled cast iron, installed in a home-made Fukang car, happened only after running over a distance of 6,200 km. The fractured camshaft was received to conduct a series of failure analyses using visual inspection, SEM observation of fracture section, microstructure analysis, chemical composition analysis and hardness examination and so on, while those of CKD camshaft made by Citro雗 Company in France was also simultaneously analyzed to compare the difference ...

  20. MALNUTRITION IN THE SURGICAL PATIENTS

    Directory of Open Access Journals (Sweden)

    Andonovska Biljana J.

    2016-12-01

    Full Text Available The term 'malnutrition' is a broad term used to describe any imbalance in the diet. In 2009 it was confirmed that malnutrition is an urgent health problem. The reasons for which malnutrition may develop are different. Loss on cellular, physical and physiological level happens as a consequence of malnutrition. Studies show that in surgical practice there is malnutrition in 50% of patients and that there is an association between inadequate nutritional status and surgical result. It leads to prolonged treatment, increasing of the level of morbidity and mortality, increased hospital costs, etc. Sometimes malnutrition is unrecognised, untreated and worsened in hospitals. For this reason this paper will elaborate: nutrition and a surgical patient, assessment of a nutritional status, assessment of energy requirements, and enteral and parenteral nutrition in order to determine the conditions and procedures that affect the appearance, recognition and treatment of malnutrition.

  1. Surgical Complications of Cochlear Implantation

    Directory of Open Access Journals (Sweden)

    Basir Hashemi

    2010-03-01

    Full Text Available Cochlear implantation is a method used for the treatment ofpatients with profound hearing loss. This procedure may theaccompanied by some major or minor complications. Weevaluated the surgical complications of cochlear implantationin Fars province (south of Iran. A total of 150 patients withcochlear implantation were enrolled in the present study. Mostof the patients were pre-lingual children and most of our deviceswere nucleus prosthesis. We had three device failuresand four major complications, including one misplaced electrode,one case of meningitis, one case of foreign body reactionto suture and one case with extensive hematoma. Thesecomplications were managed successfully by surgical interventionor re-implantation. Facial nerve damage or woundbreakdown was not seen. Minor complications including smallhematoma, edema, stitch infection and dizziness were found in15 cases, which were managed medically. In our center, therate of minor complications was comparable to other centersin the world. But the rate of major surgical complications waslower than other centers.

  2. Nutrition support in surgical oncology.

    Science.gov (United States)

    Huhmann, Maureen B; August, David A

    2009-01-01

    This review article, the second in a series of articles to examine the American Society for Parenteral and Enteral Nutrition (A.S.P.E.N.) Guidelines for the Use of Parenteral and Enteral Nutrition in Adult and Pediatric Patients, evaluates the evidence related to the use of nutrition support in surgical oncology patients. Cancer patients develop complex nutrition issues. Nutrition support may be indicated in malnourished cancer patients undergoing surgery, depending on individual patient characteristics. As with the first article in this series, this article provides background concerning nutrition issues in cancer patients, as well as discusses the role of nutrition support in the care of surgical cancer patients. The goal of this review is to enrich the discussion contained in the clinical guidelines as they relate to recommendations made for surgical patients, cite the primary literature more completely, and suggest updates to the guideline statements in light of subsequently published studies.

  3. Surgical treatment of facial paralysis.

    Science.gov (United States)

    Mehta, Ritvik P

    2009-03-01

    The management of facial paralysis is one of the most complex areas of reconstructive surgery. Given the wide variety of functional and cosmetic deficits in the facial paralysis patient, the reconstructive surgeon requires a thorough understanding of the surgical techniques available to treat this condition. This review article will focus on surgical management of facial paralysis and the treatment options available for acute facial paralysis (facial paralysis (3 weeks to 2 yr) and chronic facial paralysis (>2 yr). For acute facial paralysis, the main surgical therapies are facial nerve decompression and facial nerve repair. For facial paralysis of intermediate duration, nerve transfer procedures are appropriate. For chronic facial paralysis, treatment typically requires regional or free muscle transfer. Static techniques of facial reanimation can be used for acute, intermediate, or chronic facial paralysis as these techniques are often important adjuncts to the overall management strategy.

  4. Die casting process otimization using Taguchi method

    Directory of Open Access Journals (Sweden)

    Denilson Jose Viana

    2013-11-01

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

  5. Fisher Matrix Preloaded -- Fisher4Cast

    CERN Document Server

    Bassett, Bruce A; Hlozek, Renée; Kotze, Jacques

    2009-01-01

    The Fisher Matrix is the backbone of modern cosmological forecasting. We describe the Fisher4Cast software: a general-purpose, easy-to-use, Fisher Matrix framework. It is open source, rigorously designed and tested and includes a Graphical User Interface (GUI) with automated LATEX file creation capability and point-and-click Fisher ellipse generation. Fisher4Cast was designed for ease of extension and, although written in Matlab, is easily portable to open-source alternatives such as Octave and Scilab. Here we use Fisher4Cast to present new 3-D and 4-D visualisations of the forecasting landscape and to investigate the effects of growth and curvature on future cosmological surveys. Early releases have been available at http://www.cosmology.org.za since May 2008 with 750 downloads in the first year. Version 2.0 is made public with this paper and includes a Quick Start guide and the code used to produce the figures in this paper, in the hope that it will be useful to the cosmology and wider scientific communitie...

  6. Die Soldering in Aluminium Die Casting

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-03-15

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

  7. Squeeze Casting of Semiolid A356 Alloy

    Directory of Open Access Journals (Sweden)

    Xiang-Jie Yang

    2014-05-01

    Full Text Available The rheo-squeeze casting (rheo-SQC combining the rheocasting and the SQC was developed, in which semisolid slurry was produced by the low superheat pouring with a shearing field (LSPSF process. The three-dimensional morphology of the primary α-Al phase and the rest spacing of slurry prepared by LSPSF process have been reconstructed and visualized, and the microstructures of squeeze cast A356 alloy have been obtained. Based on the three-dimensional microstructure reconstructed, their three-dimensional characterizations such as solid volume fraction and equivalent diameter of the extracted primary α-Al phase of the slurry were measured and calculated. And the microstructures of cross-section of squeeze cast product were investigated. Compared and analyzed the typical microstructure characteristics of parts in different positions produced by SQC and rheo-SQC, the results show that the primary α-Al phase was in the form of enriched dendrites across the whole section of parts produced by SQC. Nevertheless, in the relative case of the rheo-SQC, the whole formations of dendrites have been inhibited effectively, revealing a conspicuous modification in morphology and refinement of the primary α-Al phase. In addition, the solid fraction decreased from the centre to the verge of products along the slurry flow orientation.

  8. Successful magnet quench test for CAST.

    CERN Multimedia

    Brice Maximilien

    2002-01-01

    The CERN Axion Solar Telescope (CAST) consists of a prototype LHC dipole magnet with photon detectors at each end. It searches for very weakly interacting neutral particles called axions, which should originate in the core of the Sun. The telescope, located at Point 8, can move vertically within its wheeled platform, which travels horizontally along tracks in the floor. In this way, the telescope can view the Sun at sunrise through one end and at sunset through the other end. It has been cooled down to below 1.8 K and reached ~95% of its final magnetic field of 9 tesla before a quench was induced to test the whole cryogenic system under such conditions. The cryogenic system responded as expected to the magnet quench and CAST is now ready to start its three-year search for solar axions. Photos 01 & 02 : Members of the LHC cryogenics team pose in front of the axion telescope on the day of the first quench test, together with some of the CAST collaboration.

  9. Infant Perception of Incongruent Shapes in Cast Shadows

    Directory of Open Access Journals (Sweden)

    Kazuki Sato

    2015-04-01

    Full Text Available A cast shadow occurs when an object blocks the light from an illumination and projects a dark region onto a surface. Previous studies have reported that adults are slower to identify an object when the object has an incongruent cast shadow than when it has a congruent cast shadow (Castiello, 2001. Here, we used the familiarization-novelty preference procedure to examine whether 5- to 8-month-old infants could detect the relationship between object shapes and cast shadows. In Experiment 1, we examined the infants' ability to detect incongruency between objects and cast shadows. Results showed that 7- to 8-month olds could detect incongruence between the object shapes and the cast shadows, whereas 5- to 6-month olds did not. Yet, our control experiment showed that infants could not detect this incongruence from stimuli in which a white outline had been added to the original cast shadow to decrease the possibility of it being perceived as a cast shadow (Experiment 2. The results of these experiments demonstrate that 7- to 8-month olds responded to the congruence of cast shadows and to consistent contrast polarity between the cast shadow and its background.

  10. Physical Simulation of Investment Casting of Complex Shape Parts

    Science.gov (United States)

    Rahimian, Mehdi; Milenkovic, Srdjan; Maestro, Laura; De Azua, Aitor Eguidazu Ruiz; Sabirov, Ilchat

    2015-05-01

    Development of investment casting process has been a challenge for manufacturers of complex shape parts. Numerous experimental casting trials are typically carried out to determine the optimum casting parameters for fabrication of high-quality products. In this work, it is demonstrated that physical simulation of investment casting can successfully predict microstructure and hardness in as-cast complex shape parts. The physical simulation tool consists of a thermal model and melting/solidification experiments in thermo-mechanical simulator. The thermal model is employed to predict local cooling rate during solidification at each point of a casting. Melting/solidification experiments are carried out under controlled cooling rates estimated by the thermal model. Microstructural and mechanical characterization of the solidified specimens is performed; the obtained results predict the local microstructure and mechanical properties of the casting. This concept is applied to investment casting of complex shape nozzle guide vanes from Mar-M247 Ni-based superalloy. Experimental casting trials are performed and the outcomes of physical simulation tool are validated against experimental results. It is shown that phase composition, secondary dendrite arm spacing, grain size, γ/ γ' eutectic size and volume fraction, size and shape of carbide particles, and local microhardness can be predicted at each point of the casting via physical simulation.

  11. Emotions in veterinary surgical students

    DEFF Research Database (Denmark)

    Langebæk, Rikke; Eika, Berit; Pedersen, Lene Tanggaard

    2012-01-01

    A surgical educational environment is potentially stressful and can negatively affect students' learning. The aim of the present study was to investigate the emotions experienced by veterinary students in relation to their first encounter with live-animal surgery and to identify possible sources...... of positive and negative emotions, respectively. During a Basic Surgical Skills course, 155 veterinary fourth-year students completed a survey. Of these, 26 students additionally participated in individual semi-structured interviews. The results of the study show that students often experienced a combination...

  12. Anisotropic shrinkage characteristics of tape cast alumina

    Science.gov (United States)

    Patwardhan, Jaideep Suresh

    Dimensional control during sintering is a major issue in ceramics processing to avoid high post-sintering costs associated with machining of the fired ceramic part to desired tolerances and dimensions. Ceramic forming processes such as tape casting, injection molding, and extrusion involve shear of anisotropic particles resulting in preferential alignment of the particles in the green body. This preferential alignment causes directionality in mechanical, electrical, optical, and magnetic properties and most importantly warpage or distortion during sintering. A large effort has been devoted to synthesizing ceramic green bodies with minimal density gradients and uniform packing and modeling the sintering behavior evolution but little effort has been devoted to characterizing orientation of particles and the effect of preferential alignment on sintering shrinkage anisotropy. A systematic study was initiated to study the effect of processing variables such as shear rate, solids loading, temperature, and binder content on aqueous tape cast alumina. Three different alumina systems: A16-SG, Baikowski RC-UFX DBM and RC-LS DBM were investigated. Aqueous tapes of high solids loading alumina (56 vol. %) were tape cast at various speeds and thicknesses and assuming plane Couette flow a shear rate regime of 21--270 s-1 was investigated. Higher shear rates and high solids loading resulted in higher in-plane anisotropy whereas the anisotropy in the thickness direction was higher for low solids loading systems. The anisotropy was found to be fairly constant above a certain critical shear rate (˜100 s-1) irrespective of the temperature and the solids loading and this correlated with the viscosity-shear rate relationship of the cast slips. The higher shrinkage anisotropy in the thickness direction for the low solids loading systems (35 and 45 vol. %) was attributed to the higher amount of organics in the slip required to sustain the suitable viscosity for tape casting and

  13. Electrochemical characterization of cast titanium alloys.

    Science.gov (United States)

    Cai, Zhuo; Shafer, Ty; Watanabe, Ikuya; Nunn, Martha E; Okabe, Toru

    2003-01-01

    A reaction layer forms on cast titanium alloy surfaces due to the reaction of the molten metal with the investment. This surface layer may affect the corrosion of the alloy in the oral environment. The objective of this study was to characterize the in vitro corrosion behavior of cast titanium alloys. ASTM Grade 2 CP titanium, Ti-6Al-4V, Ti-6Al-7Nb and Ti-13Nb-13Zr alloys were cast into a MgO-based investment. Experiments were performed on castings (N=4) with three surface conditions: (A) as-cast surface after sandblasting, (B) polished surface after removal of the reaction layer, and (C) sandblasted surface after removal of the reaction layer. Open-circuit potential (OCP) measurement, linear polarization, and potentiodynamic cathodic polarization were performed in aerated (air+10% CO(2)) modified Tani-Zucchi synthetic saliva at 37 degrees C. Potentiodynamic anodic polarization was subsequently conducted in the same medium deaerated with N(2)+10% CO(2) gas 2 h before and during the experiment. Polarization resistance (R(P)) and corrosion rate (I(CORR)) were calculated. Numerical results were subjected to nonparametric statistical analysis at alpha=0.05. The OCP stabilized for all the specimens after 6 x 10(4)s. Apparent differences in anodic polarization were observed among the different surfaces for all the metals. A passivation region followed by breakdown and repassivation were seen on specimens with surfaces A and C. An extensive passive region was observed on all the metals with surface B. The Kruskal-Wallis test showed no significant differences in OCP, R(p), I(CORR) or break down potential for each of the three surfaces among all the metals. The Mann-Whitney test showed significantly lower R(P) and higher I(CORR) values for surface C compared to the other surfaces. Results indicate that the surface condition has more effect on corrosion of these alloys than the surface reaction layer. Within the oxidation potential range of the oral cavity, all the metal

  14. Microstructures of electromagnetic casting and direct chill casting LY12 aluminum alloys

    Institute of Scientific and Technical Information of China (English)

    曹志强; 金俊泽; 郝海; 贾非

    2003-01-01

    LY12 aluminum alloys made by electromagnetic casting (EMC) and direct chill casting (DCC), were analyzed by optical microscope, differential scanning calorimetry, transmission electron microscope and X-ray diffraction. It is found that the surface and subsurface quality of the ingot is improved largely due to the absence of an ingot mold, which is impossible to achieve with conventional DCC. It is also found that the intense forced convection can promote the fast superheat evacuation and break the dendrite arms, leading to the grain multiplication and the appearance of a fine equiaxed grains over the whole cross section. As a result, the hardness of EMC specimens increases one time than that from DCC in the as-cast state. Even though after the solid solution treatment and the artificial aging, the DCC ingot still can not get the same hardness as EMC ones.

  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. The impact of breaks during foundry work of the pressure casting machine on casting quality

    Directory of Open Access Journals (Sweden)

    S. Borkowski

    2010-10-01

    Full Text Available The result in the appearance of the technical object damage are its failures, which are considered as the most important causes of productivity loss in the technical objects. The article introduces main types of losses resulting from the downtimes of a casting machine. The time impact analysis of the font mould failure and the remaining time of the machine's failures on the castings quality was conducted. The failure time structure of the font mould and other failures of the machine was presented.

  17. Abrasion Resistance of as-Cast High-Chromium Cast Iron

    Directory of Open Access Journals (Sweden)

    Pokusová Marcela

    2014-12-01

    Full Text Available High chromium cast irons are widely used as abrasion resistant materials. Their properties and wear resistance depend on carbides and on the nature of the matrix supporting these carbides. The paper presents test results of irons which contain (in wt.% 18-22 Cr and 2-5 C, and is alloyed by 1.7 Mo + 5 Ni + 2 Mn to improve the toughness. Tests showed as-cast irons with mostly austenitic matrix achieved hardness 36-53 HRC but their relative abrasion-resistance was higher than the tool steel STN 19436 heat treated on hardness 60 HRC.

  18. Characterization of Casting Defects in Typical Castings of a Directionally Solidified Superalloy

    Science.gov (United States)

    1979-08-01

    used to evaluate grain misorientation effects in D.S. MAR - M247 superalloy (17). Scatter of this nature has been observed previously in equiaxed cast...found associated with the fracture surfaces In the previous study on tje effect of off-axis grain growth on cylindrical cast bars of D.S. MAR - M247 , 1800...significant that no instances of failures associated with emergent grains were observed in the MAR - M247 study. In the present investigation of PWA 1422, no

  19. 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.

  20. SIMULATION OF THE TWIN ROLL STAINLESS STRIP CASTING PROCESS

    Institute of Scientific and Technical Information of China (English)

    Y.C. Miao; X.M. Zhang; G.D. Wang; H.S. Di; X.H. Liu

    2001-01-01

    The position of the solidification completed temperature of twin roll stainless strip casting process is very important to the quality of the casting strip. In order to control this position, the solidification completed temperature should be known at first.The present paper first simulated dendritic microsegregation under conditions of twin roll stainless strip casting, and got the relationship between the temperature and solid fraction of the mush zone. The temperatures such as ZDT (equal to the solidification completed temperature) and LIT (liquid impenetrable temperature), et al., also were obtained. Then by using the turbulent model, the flow and thermal fields of the pool of the twin roll stainless strip casting, and the speed and temperature fields of different casting speeds were given and also explained. The results are coincident with the experimental result. Combined with the results of these two simulations. the appropriated casting speed was found.

  1. Properties shaping and repair of selected types of cast iron

    Directory of Open Access Journals (Sweden)

    J. Szajnar

    2007-04-01

    Full Text Available The paper presents research results of twofold use of TIG - Tungsten Inert Gas also known as GTA - Gas Tungsten Arc. First is surfacing by welding on cold and hot-cold to repair chromium cast iron with chromium content about 15%. Second is remelting with electric arc of selected gray (with pearlitic matrix and ductile (with ferritic-pearlitic matrix cast iron. Repair of cast iron elements was realized in order to cut out a casting defects. Defects decrease a usability of castings for constructional application and increase a manufacturing costs. Application of surface heat treatment guarantees mechanical properties i.e. hardness and wear resistance improvement. The result of investigations show possibility of castings repair by put on defects a good quality padding welds, which have comparable properties with base material. Use of electric arc surface heat treatment resulted in increase of hardness and wear resistance, which was measured on the basis of ASTM G 65 - 00 standard.

  2. Method and mold for casting thin metal objects

    Energy Technology Data Exchange (ETDEWEB)

    Pehrson, Brandon P; Moore, Alan F

    2014-04-29

    Provided herein are various embodiments of systems for casting thin metal plates and sheets. Typical embodiments include layers of mold cavities that are oriented vertically for casting the metal plates. In some embodiments, the mold cavities include a beveled edge such that the plates that are cast have a beveled edge. In some embodiments, the mold cavities are filled with a molten metal through an open horizontal edge of the cavity. In some embodiments, the mold cavities are filled through one or more vertical feed orifices. Further disclosed are methods for forming a thin cast metal plate or sheet where the thickness of the cast part is in a range from 0.005 inches to 0.2 inches, and the surface area of the cast part is in a range from 16 square inches to 144 square inches.

  3. Status quo and development trend of lost foam casting technology

    Directory of Open Access Journals (Sweden)

    Fan Zitian

    2014-07-01

    Full Text Available Lost foam casting (LFC technology has been widely applied to cast iron and cast steel. However, the development of LFC for Al and Mg alloys was relatively slower than that for cast iron and cast steel. The application of LFC to Al and Mg alloys needs more effort, especially in China. In this paper, the development history of LFC is reviewed, and the application situations of LFC to Al and Mg alloys are mainly discussed. Meanwhile, the key problems of LFC for Al and Mg alloys are also pointed out. Finally, the prospects for LFC technology are discussed, and some special new LFC technologies are introduced for casting Al and Mg alloys. In future, the development trends of green LFC technology mainly focus on the special new LFC methods, metal material, coating, heat treatment, new foam materials as well as purification technology of tail gas, etc.

  4. Status quo and development trend of lost foam casting technology

    Institute of Scientific and Technical Information of China (English)

    Fan Zitian; Jiang Wenming; Liu Fuchu; Xiao Botao

    2014-01-01

    Lost foam casting (LFC) technology has been widely applied to cast iron and cast steel. However, the development of LFC for Al and Mg aloys was relatively slower than that for cast iron and cast steel. The application of LFC to Al and Mg aloys needs more effort, especially in China. In this paper, the development history of LFC is reviewed, and the application situations of LFC to Al and Mg aloys are mainly discussed. Meanwhile, the key problems of LFC for Al and Mg aloys are also pointed out. Finaly, the prospects for LFC technology are discussed, and some special new LFC technologies are introduced for casting Al and Mg alloys. In future, the development trends of green LFC technology mainly focus on the special new LFC methods, metal material, coating, heat treatment, new foam materials as wel as puriifcation technology of tail gas, etc.

  5. [Surgical education has its price].

    Science.gov (United States)

    Schröder, W; Krones, C J

    2012-04-01

    The radical economisation of the German health-care system has caused an increasing cost awareness. Following this trend, medical education has been identified as a possible expense factor. The theoretical and practical training of young doctors needs time and costs money. However, a detailed cost analysis is still not available, since the complex daily work schedule of young professionals only allows the calculation of single cost factors. Investigations in the USA estimate the costs of surgical training at US$ 80 000 per year and per resident. At present in Germany, surgical training is indirectly financed by the DRG flat rates of the health insurance companies. Possible alternatives include the implementation of a "training fond" which is financed by a percentage fee of the DRG's as well as an on-top funding by the federal government. This "training fond" would support only those surgical units that offer a structured and certified training to surgical residents. However, a systematic cost analysis of such a structured curriculum is necessary for any further discussion.

  6. Surgical Lasers In Veterinary Medicine

    Science.gov (United States)

    Newman, H. C.

    1987-03-01

    Veterinary medicine is a latecomer in benefiting from the advent of surgical lasers. It is ironic that although most of the basic work in lasers is carried out in animal species with which we are most conversant, veterinary medicine as a profession has not been very extensively involved.

  7. Surgical management of tubal pregnancy

    NARCIS (Netherlands)

    Mol, F.

    2013-01-01

    The work presented in this thesis first addresses the magnitude of the clinical problem of surgically treated tubal pregnancy in The Netherlands. Next, we studied the adherence to recommendations from the Dutch guideline on diagnosis and management of ectopic pregnancy. A systematic review and meta-

  8. Pseudothrombocytopenia in cardiac surgical practice.

    Science.gov (United States)

    Nair, Sukumaran K; Shah, Roma; Petko, Matus; Keogh, Bruce E

    2007-08-01

    Pseudothrombocytopenia is observed occasionally in post-cardiac surgical patients. It is commonly due to EDTA-mediated immunological mechanisms, which lead to agglutination of functionally intact platelets. This condition is harmless and does not warrant platelet transfusion. We describe an instance of pseudothrombocytopenia in our practice and discuss its clinical relevance.

  9. Surgical pearl: the temporary assistant.

    Science.gov (United States)

    Jacobs, Aleda A; Orengo, Ida F

    2008-04-15

    A simple maneuver is presented which simultaneously facilitates both adequate surgical site exposure and sufficient traction. A single suture with high tensile strength can be utilized to this end. This technique is especially helpful when the cutaneous surgeon is operating alone.

  10. Surgical smoke and infection control.

    NARCIS (Netherlands)

    Alp, E.; Bijl, D.; Bleichrodt, R.P.; Hansson, B.M.; Voss, A.

    2006-01-01

    Gaseous byproducts produced during electrocautery, laser surgery or the use of ultrasonic scalpels are usually referred to as 'surgical smoke'. This smoke, produced with or without a heating process, contains bio-aerosols with viable and non-viable cellular material that subsequently poses a risk of

  11. Surgical options after Fontan failure

    DEFF Research Database (Denmark)

    van Melle, Joost P; Wolff, Djoeke; Hörer, Jürgen;

    2016-01-01

    OBJECTIVE: The objective of this European multicenter study was to report surgical outcomes of Fontan takedown, Fontan conversion and heart transplantation (HTX) for failing Fontan patients in terms of all-cause mortality and (re-)HTX. METHODS: A retrospective international study was conducted by...

  12. Surgical Training in the Netherlands

    NARCIS (Netherlands)

    Borel Rinkes, I.H.M.; Gouma, D.J.; Hamming, J.F.

    2008-01-01

    Surgical training in the Netherlands has traditionally been characterized by learning on the job under the classic master-trainee doctrine. Over the past decades, it has become regionally organized with intensive structural training courses, and a peer-based quality control system. Recently, the nat

  13. Surgical treatment of primary hyperparathyroidism

    DEFF Research Database (Denmark)

    Brasso, K; Karstrup, S; Lundby, C M

    1994-01-01

    .9%). Permanent paralysis of the recurrent nerve occurred in three patients (2.9%). Twenty-one patients developed other postoperative complications from which they all recovered without sequelae. No postoperative deaths occurred. Our results show that surgical treatment of primary hyperparathyroidism...

  14. Development,Application and Problem of Ductile Iron Lost Foam Casting Technology in China

    Institute of Scientific and Technical Information of China (English)

    He Wenhao; Ye Shengping; Han Xiaohong; Tang Suoyun

    2010-01-01

    @@ Lost-foam casting is a 21st century green casting technology.Over the past decade,there has been an extraordinary development in lost-foam casting in China;and ductile iron lost-foam casting has developed even more rapidly in foundry equipment,foundry raw materials,and casting engineers.

  15. CHOICE OF MATERIAL AND MANUFACTURING TECHNOLOGY OF CASTING

    Directory of Open Access Journals (Sweden)

    L. I. Kupriyanova

    2016-01-01

    Full Text Available As a result of the carried out work abundant type of steel was chosen for casting production of asterisk of the excavator «Kamatsu». This type of steel is widely used as the wearproof steel working in the conditions of abrasive and shock – abrasive wear. Mathematical modeling of process of filling and hardening of casting was done and it confirmed a choice of the technology to produce casting without faulty parts.

  16. Mandated political representation and crimes against the low castes

    OpenAIRE

    Girard, Victoire

    2016-01-01

    Mandated political representation over the last twenty years has had a different impact on the reporting of crime by the low castes than what is observed for the reporting of crime by women. I exploit the timing of the implementation of mandated political representation of the low castes to examine its effect on crime reports by these people. Mandated political representation of the low castes in India appears to affect the declaration of crime only for two very specific crime categories: ide...

  17. The labor/land ratio and India's caste system

    OpenAIRE

    Duleep, Harriet

    2012-01-01

    This paper proposes that India's caste system and involuntary labor were joint responses by a nonworking landowning class to a low labor/land ratio in which the rules of the caste system supported the institution of involuntary labor. The hypothesis is tested in two ways: longitudinally, with data from ancient religious texts, and cross-sectionally, with twentieth-century statistics on regional population/land ratios linked to anthropological measures of caste-system rigidity. Both the longit...

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

    OpenAIRE

    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 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 proc...

  19. 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.

  20. Gradient porous hydroxyapatite ceramics fabricated by freeze casting method

    Science.gov (United States)

    Zuo, Kai-hui; zhang, Yuan; Jiang, Dongliang; Zeng, Yu-Ping

    2011-04-01

    By controlling the cooling rates and the composition of slurries, the gradient porous hydroxyapatite ceramics are fabricated by the freeze casting method. According to the different cooling rate, the pores of HAP ceramics fabricated by gradient freeze casting are divided into three parts: one is lamellar pores, another is column pore and the last one is fine round pores. The laminated freeze casting is in favour of obtaining the gradient porous ceramics composed of different materials and the ceramics have unclear interfaces.

  1. Dynamic control of crystallinity in polymer film casting process

    OpenAIRE

    Thananchai Leephakpreeda

    2005-01-01

    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 identificatio...

  2. A new approach to develop complicated superalloy castings

    Institute of Scientific and Technical Information of China (English)

    WU Jian-tao; FENG Di; LI Jun-tao; KONG Sheng-guo; PEI Zhong-ye

    2006-01-01

    An integrative computer aided investment casting (CAIC) technology for making complicated superalloy castings was described. Key processes of CAIC were discussed including the choice of SLS (Selectively Laser Sinterihg)materials, sintering parameters, solidification simulation and gating and risering system optimization. Using CAIC process,many large-sized quality superalloy castings with complicated shape and thin wall have been produced successfully and economically in Central Iron & steel Research Institute (CISRI).

  3. A new approach to develop complicated superalloy castings

    Directory of Open Access Journals (Sweden)

    WU Jian-tao

    2006-05-01

    Full Text Available An integrative computer aided investment casting (CAIC technology for making complicated superalloy castings was described. Key processes of CAIC were discussed including the choice of SLS (Selectively Laser Sintering materials, sintering parameters, solidification simulation and gating and risering system optimization. Using CAIC process, many large-sized quality superalloy castings with complicated shape and thin wall have been produced successfully and economically in Central Iron & steel Research Institute (CISRI.

  4. Solidification and microstructure of thin walled ductile cast iron

    DEFF Research Database (Denmark)

    Pedersen, Karl Martin

    2006-01-01

    In the recent years there has been an increasing interest in light constructions in order to save weight in e.g. cars. Ductile cast iron has good mechanical properties but it is necessary to re­duce the wall thicknesses of the castings in order to reduce the weight. Reducing the wall thicknesses...... of the casting will increase the cooling rates and by that change the conditions for nucleation and growth during solidification....

  5. Surgical management of chronic pancreatitis

    Institute of Scientific and Technical Information of China (English)

    Stavros Gourgiotis; Stylianos Germanos; Marco Pericoli Ridolifni

    2007-01-01

    BACKGROUND:Treatment of chronic pancreatitis (CP) is a challenging condition for surgeons. During the last decades, increasing knowledge about pathophysiology of CP, improved results of major pancreatic resections, and integration of sophisticated diagnostic methods in clinical practice have resulted in signiifcant changes in surgery for CP. DATA SOURCES:To detail the indications for CP surgery, the surgical procedures, and outcome, a Pubmed database search was performed. The abstracts of searched articles about surgical management of CP were reviewed. The articles could be identiifed and further scrutinized. Further references were extracted by cross-referencing. RESULTS: Main indications of CP for surgery are intractable pain, suspicion of malignancy, and involvement of adjacent organs. The goal of surgical treatment is to improve the quality of life of patients. The surgical approach to CP should be individualized according to pancreatic anatomy, pain characteristics, baseline exocrine and endocrine function, and medical co-morbidity. The approach usually involves pancreatic duct drainage and resection including longitudinal pancreatojejunostomy, pancreatoduodenectomy (Whipple's procedure), pylorus-preserving pancreatoduodenectomy, distal pancreatectomy, total pancreatectomy, duodenum-preserving pancreatic head resection (Beger's procedure), and local resection of the pancreatic head with longitudinal pancreatojejunostomy (Frey's procedure). Non-pancreatic and endoscopic management of pain has also been advocated. CONCLUSIONS:Surgical procedures provide long-term pain relief, a good postoperative quality of life with preservation of endocrine and exocrine pancreatic function, and are associated with low early and late mortality and morbidity. In addition to available results from randomized controlled trials, new studies are needed to determine which procedure is the most effective for the management of patients with CP.

  6. Surgical travellers: tapestry to Bayeux.

    Science.gov (United States)

    Hedley-Whyte, John; Milamed, Debra R

    2014-09-01

    The planning for surgery in war was revisited in 1937 when Ian Fraser was elected a member of the Surgical Travellers. At their 1938 Surgical Travellers meeting in Vienna, Ian and Eleanor Fraser were evicted from their hotel room by the Nazis. The 1939 meeting in Belfast discussed the organization of surgery and the conduct of Emergency Medical Service Hospitals in the United Kingdom; the vast majority were to be under civilian government and military control. From 1943 lengthy and informative organizational meetings were held at least monthly under the chairmanship of Sir Alexander Hood, KBE, Head of the RAMC. Surgical Consultants, now Major Generals, Brigadiers or Full Colonels in the British and U.S. Armies stationed in the UK, prepared for the invasion of Europe. The allocation of medical, surgical, nursing and auxiliary responsibilities was delineated. Liaison with the RAF and US Army Air Force was close as it was with the proposed leaders, Ulstermen Brooke and Montgomery. Montgomery chose Arthur Porritt as Surgeon in Chief to Supreme Headquarters Allied Expeditionary Force (SHAEF), and Eisenhower, General Albert W. Kenner. Just after D-Day, Porritt met Ian Fraser, who had waded in on Arromanches Beach. The triage and evacuation plans for Allied casualties had been controversial, particularly as regards Landing Ship Tanks (LSTs). The dispute with the Hood-selected surgeons on one side, against medical and surgical deployment of LSTs, and Admiral Ernest King and Winston Churchill on the other, favouring LST use for surgery and evacuation. King and Churchill were correct but total Allied air superiority allowed wide use of many of the Allies' Dakotas; 10,000 DC-3s were eventually in service. Supported by forty Allied combat planes to each Luftwaffe, the dispute about Landing Ship Tank use in about a fortnight became moot. The multifaceted role of the Princess Royal in the Emergency Medical Services of the United Kingdom and her close liaison with the Consultant

  7. Reengineering of Permanent Mould Casting with Lean Manufacturing Methods

    Directory of Open Access Journals (Sweden)

    R. Władysiak

    2007-07-01

    Full Text Available At the work were introduced main areas of production system project of casts produced in permanent moulds, that constitutes reengineering of conventional production system according to Lean Manufacturing (LM methods. New resolution of cooling of dies with water mist was shown to casting of car wheels made from aluminium alloys in low pressure casting process. It was implemented as a part of goal-oriented project in R.H. Alurad Sp.z o.o. in Gorzyce. Its using intensifies solidification and self-cooling of casts shortening the time of casting cycle by the 30%. It was described reorganizing casting stations into multi-machines cells production and the process of their fast tool’s exchange with applying the SMED method. A project of the system was described controlling the production of the foundry with the computer aided light Kanban system. A visualization of the process was shown the production of casts with use the value stream mapping method. They proved that applying casting new method in the technology and LM methods allowed to eliminate down-times, to reduce the level of stocks, to increase the productivity and the flow of the castings production.

  8. An heuristic based practical tool for casting process design

    Energy Technology Data Exchange (ETDEWEB)

    Nanda, N.K.; Smith, K.A.; Voller, V.R.; Haberle, K.F. [Univ. of Minnesota, Minneapolis, MN (United States). Dept. of Civil Engineering

    1995-12-31

    The work in this paper reports on an heuristic based computer tool directed at casting process design; in particular key design parameters, such as part orientation, location of sprues, feeding rates, etc. The underlying principal used is that a given casting can be represented on identifying and classifying its critical features. The input to the system consists of the attributes of the features and the graphical output provides semi-quantitative information on key design parameters. Results on real castings match those of the expert casting designers and in some cases potential design improvements have been suggested by the system.

  9. Investment casting or powder metallurgy – the ecological aspect

    Directory of Open Access Journals (Sweden)

    J. Tomasik

    2009-04-01

    Full Text Available The paper presents an analysis of manufacturing methods of material-saving products in relation to investment castings and sinteredpowder technology. Surface microgeometry, shape accuracy, performance parameters, manufacturing costs and energy consumption weretaken into account to make the optimal choice. The analysis was conducted by comparing test results for sintered powder products basedon Distaloy AB alloy that consists of 0.55% C, 1.5% Cu, 1.75% Ni and 0.5% Mo and investment castings made of high alloy cast steel andnodular cast iron. The analysis made it possible to choose the best technology, considering also the ecological aspect.

  10. 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.

  11. Digital management technology and its application to investment casting enterprises

    Directory of Open Access Journals (Sweden)

    Xiao-yuan Ji

    2016-09-01

    Full Text Available With the advent of Industry 4.0, more and more investment casting enterprises are implementing production manufacturing systems, especially in the last two years. This paper summarizes three new common requirements of the digital management aspect in precision casting enterprises, and puts forward three corresponding techniques. They are: the production process tracking card technology based on the main-sub card mode; the workshop site production process processing technology based on the barcode; and the equipment data integration technology. Then, this paper discusses in detail the principle, application and effect of these technologies; to provide the reference for enterprises to move towards digital casting and intelligent casting.

  12. Advanced precision expendable pattern casting technology. 1994 Summary report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-05-01

    Casting technology is described. The following areas are reported on: precision pattern production; pattern coating; sand fill and compaction; pattern gating; mechanical properties; and technology transfer efforts.

  13. Caste ratios affect the reproductive output of social trematode colonies.

    Science.gov (United States)

    Kamiya, T; Poulin, R

    2013-03-01

    Intraspecific phenotypic diversification in social organisms often leads to formation of physical castes which are morphologically specialized for particular tasks within the colony. The optimal caste allocation theory argues that specialized morphological castes are efficient at specific tasks, and hence different caste ratios should affect the ergonomic efficiency, hence reproductive output of the colony. However, the reproductive output of different caste ratios has been documented in few species of insects with equivocal support for the theory. This study investigated whether the ratios of nonreproductive and reproductive morphs affect the reproductive output of a recently discovered social trematode, Philophthalmus sp., in which the nonreproductive members are hypothesized to be defensive specialists. A census of natural infections and a manipulative in vitro experiment demonstrated a positive association between the reproductive output of trematode colonies and the ratio of nonreproductive to reproductive morphs in the presence of an intra-host trematode competitor, Maritrema novaezealandensis. On the contrary, without the competitor, reproductive output was negatively associated with the proportion of nonreproductive castes in colonies. Our findings demonstrate for the first time a clear fitness benefit associated with the nonreproductive castes in the presence of a competitor while illustrating the cost of maintaining such morphs in noncompetitive situations. Although the proximate mechanisms controlling caste ratio remain unclear in this trematode system, this study supports the prediction that the fitness of colonies is influenced by the composition of specialized functional morphs in social organisms, suggesting a potential for adaptive shifts of caste ratios over evolutionary time.

  14. SYSTEMATIC AND DYNAMIC PROPER-TIES OF CASTING HOT SPOT

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The variation of casting hot spot with proceeding of solidification and components of casting-mold system is studied by the technique of numerical simulation of solidification.The result shows that the thickest part of casting is not exactly the last part of solidification in the casting, while the last part of solidification is not exactly casting hot spot at the early stage of solidification.The location, size, shape and number of casting hot spot change with geomitric, physical and technological factors of the casting-mold system such as thickness of the casting secondary wall and with the passage of time in the course of the solidification.The former is known as the systematic property of hot spot and the latter, dynamic property.Only when the properties of hot spot are grasped completely and accurately, can it be fed more effectively.By doing so, not only sound castings can be obtained, but also riser efficiency can be improved.

  15. PRINCIPALLY NEW EFFECTIVE CASTING PROCESS OF THE HOLLOW CYLINDRICAL SLUGS OF CAST IRON BY METHOD OF DIRECTIONAL SOLIDIFICATION

    Directory of Open Access Journals (Sweden)

    E. I. Marukovich

    2010-01-01

    Full Text Available The advantages of the new method of the hollow ingots production of cast iron are presented. The thermal state of crystallizer at cyclic temperature influences on its inside face, the ingot hardening and cast iron structure formation in conditions of intensive one-sided heat sink is examined. The comparative data on properties and exploitation characteristics of the parts, produced by different ways of casting is given.

  16. Influence of melt feeding scheme and casting parameters during direct-chill casting on microstructure of an AA7050 billet

    OpenAIRE

    Zhang, L; T. Subroto; Katgerman, L.; Eskin, DG; Miroux, A

    2012-01-01

    © The Minerals, Metals & Materials Society and ASM International 2012 Direct-chill (DC) casting billets of an AA7050 alloy produced with different melt feeding schemes and casting speeds were examined in order to reveal the effect of these factors on the evolution of microstructure. Experimental results show that grain size is strongly influenced by the casting speed. In addition, the distribution of grain sizes across the billet diameter is mostly determined by melt feeding scheme. Grains...

  17. Shrinkages in heavy-sized cast components of nodular cast iron – NDT and fatigue

    Directory of Open Access Journals (Sweden)

    Bleicher Christoph

    2014-06-01

    Full Text Available Material defects like shrinkages, dross, pores and chunky graphite are likely to occur in thick-walled castings and are a challenge for the foundries and their customers. These defects are mostly detected with handheld ultrasonic testing (UT or X-ray analysis. Within a research project done at the Fraunhofer Institute for Structural Durability and System Reliability LBF, the fatigue of Dross, shrinkages and chunky graphite in thick-walled cast material GGG-40 was estimated based on X-ray and fatigue tests on bending specimens. High fatigue reductions were received for the different material imperfections. Based on these impressions a further research project was executed at the Fraunhofer LBF to get an estimation of the informational value of UT in relation to fatigue of shrinkages in thick-walled castings of the material EN-GJS-400-18U-LT, EN-GJS-450-18 and EN-GJS-700-2. With the help of X-ray analysis and the UT technique Sampling Phased Array (SPA information about geometry and density were derived for a numerical analysis of shrinkages in thick-walled castings concerning fatigue. The following text summarizes the fatigue results achieved in the two research projects with the help of the X-ray and UT analysis.

  18. Evaluation of the Inertness of Investment Casting Molds Using Both Sessile Drop and Centrifugal Casting Methods

    Science.gov (United States)

    Cheng, Xu; Yuan, Chen; Green, Nick; Withey, Paul

    2013-02-01

    The investment casting process is an economic production method for engineering components in TiAl-based alloys and offers the benefits of a near net-shaped component with a good surface finish. An investigation was undertaken to develop three new face coat systems based on yttria, but with better sintering properties. These face coat systems were mainly based on an yttria-alumina-zirconia system (Y2O3-0.5 wt pct Al2O3-0.5 wt pct ZrO2), an yttria-fluoride system (Y2O3-0.15 wt pct YF3), and an yttria-boride system (Y2O3-0.15 wt pct B2O3). After sintering, the chemical inertness of the face coat was first tested and analyzed using a sessile drop test through the metal wetting behavioral change for each face coat surface. Then, the interactions between the shell and metal were studied by centrifugal investment casting TiAl bars. Although the sintering aids in yttria can decrease the chemical inertness of the face coat, the thickness of the interaction layer in the casting was less than 10 μm; therefore, these face coats still can be possible face coat materials for investment casting TiAl alloys.

  19. Caste and Punishment : The Legacy of Caste Culture in Norm Enforcement

    OpenAIRE

    Hoff, Karla Ruth; Kshetramade, Mayuresh; Fehr, Ernst

    2009-01-01

    Well-functioning groups enforce social norms that restrain opportunism, but the social structure of a society may encourage or inhibit norm enforcement. This paper studies how the exogenous assignment to different positions in an extreme social hierarchy - the caste system - affects individuals' willingness to punish violations of a cooperation norm. Although the analysis controls for indi...

  20. Continuation of Crosscutting Technology Development at Cast

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Roe-Hoan

    2012-03-31

    This Final Technical Report describes progress made on the sub-projects awarded in the Cooperative Agreement DE-FC26-05NT42457: Continuation of Crosscutting Technology Development at Center for Advanced Separation Technologies (CAST). The final reports for each sub-project are attached in the appendix. Much of the research to be conducted with Cooperative Agreement funds will be longer-term, high-risk, basic research and will be carried out in five broad areas: a) Solid-solid separation b) Solid-liquid separation c) Chemical/Biological Extraction d) Modeling and Control, and e) Environmental Control.

  1. Internal adaptation of cast titanium crowns

    Directory of Open Access Journals (Sweden)

    Sicknan Soares da Rocha

    2007-08-01

    Full Text Available As the adaptation of titanium crowns obtained by Rematitan Plus investment, specific for titanium, is not recognized to be suitable, this study evaluated the effect of the concentration of the specific liquid and the temperature of the mold of investments on the internal misfit of crowns cast on commercially pure titanium. Individual dies of epoxy resin were obtained, representing teeth prepared for full-crown restoration with a 6-degree axial surface convergence angle and shoulder (1.0 mm. For the waxing of each crown, a ring-shaped stainless steel matrix (8.0mm internal diameter; 7.5 mm height was adapted above the individual dies of epoxy resin. The Rematian Plus investment was mixed according to the manufacturer's instructions using two different concentrations of the specific liquid: 100%, 75%. Casting was performed in a Discovery Plasma Ar-arc vacuum-pressure casting machine with molds at temperatures of 430ºC, 515ºC and 600ºC. The crowns were cleaned individually in a solution (1% HF + 13% HNO3 for 10 min using a ultrasonic cleaner, with no internal adaptations, and luted with zinc phosphate cement under a 5 kg static load. The crown and die assemblies were embedded in resin and sectioned longitudinally. The area occupied by cement was observed using stereoscopic lens (10X and measured by the Leica Qwin image analysis system (mm². The data for each experimental condition (n=8 were analyzed by Kruskal-Wallis non-parametric test (á=0.05. The results showed that liquid dilution and the increase in mold temperature did not significantly influence the levels of internal fit of the cast titanium crowns. The lowest means (±SD of internal misfit were obtained for the 430ºC/100%: (7.25 mm² ±1.59 and 600ºC/100% (8.8 mm² ±2.25 groups, which presented statistically similar levels of internal misfit.

  2. CAST begins its search for solar axions.

    CERN Multimedia

    Maximilien Brice

    2002-01-01

    The CERN Axion Solar Telescope (CAST) consists of a prototype LHC dipole magnet with photon detectors at each end. It has started searching for very weakly interacting neutral particles called axions, which should originate in the core of the Sun. Photos 01 02: The telescope, located at Point 8, can move vertically within its wheeled yellow platform, which travels horizontally along tracks in the floor. In this way, the telescope can view the Sun at sunrise through one end (left) and at sunset through the other. Photos 03 04: Sunrise photon detectors at one end of the telescope.

  3. 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

  4. Materials on dies for pressure die casting

    Directory of Open Access Journals (Sweden)

    E. Ragan

    2012-01-01

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

  5. Web life: Planet SciCast

    Science.gov (United States)

    2009-08-01

    So what is the site about? Planet SciCast is an online repository for short films about science - a bit like a science-specific, moderated version of YouTube. As of July 2009, the site hosts over 150 films on topics ranging from CERN's Large Hadron Collider to fun things to do with treacle. New content appears on the site every few weeks, and some films include links to information about related experiments, demos and activities. The site also runs an annual competition aimed at getting more people involved in making science films, with prizes in categories like "best original score" and "best presenter".

  6. Phase Transformations in Cast Duplex Stainless Steels

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yoon-Jun [Iowa State Univ., Ames, IA (United States)

    2004-01-01

    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 σ and χ 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 (σ + χ) 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, σ was stabilized with increasing Cr addition and χ by increasing Mo addition. However, a delicate balance among Ni and other minor elements such as N and Si also exists. Phase equilibria in DSS can be affected by

  7. Sharing casting technological data on web site

    Institute of Scientific and Technical Information of China (English)

    Sun Xun; Li Hailan; Wang Junqing; Piao Dongxue; Hou Gang; Guan Yang; Wang Penghua; Zhu Qiang; Xle Huasheng

    2008-01-01

    Based on database and asp.net technologies, a web platform of scientific data in the casting technology field has been developed. This paper presents the relevant data system structure, the approaches to the data collection, the applying methods and policy in data sharing, and depicts the collected and shared data recently finished. Statistics showed that there are about 20,000 visitors in China every day visiting the related data through the web, proving that many engineers or other relevant persons are interested in the data.

  8. Optimization of squeeze casting parameters for non symmetrical AC2A aluminium alloy castings through Taguchi method

    Energy Technology Data Exchange (ETDEWEB)

    Senthil, P. [Coimbatore Institute of Engineering and Technology, Coimbatore (India); Amirthagadeswaran, K. S. [Government College of Technology, Coimbatore (India)

    2012-04-15

    This paper reports a research in which an attempt was made to prepare AC2A aluminium alloy castings of a non symmetrical component through squeeze casting process. The primary objective was to investigate the influence of process parameters on mechanical properties of the castings. Experiments were conducted based on orthogonal array suggested in Taguchi's offline quality control concept. The experimental results showed that squeeze pressure, die preheating temperature and compression holding time were the parameters making significant improvement in mechanical properties. The optimal squeeze casting condition was found and mathematical models were also developed for the process.

  9. Effect of casting speed and delay time on the residual stresses in centrifugal casting of aluminium rods

    Directory of Open Access Journals (Sweden)

    Adesoji A. OYEDEJI

    2016-07-01

    Full Text Available Longitudinal slitting technique has been employed to determine the residual stresses in centrifugal cast aluminium rods. Residual stresses were found to decrease with increase in casting speed in the centrifugal casting. The residual stresses of the aluminium rods cast at speeds of 100, 200, 300, 400 and 500rpm and at zero (0 second delay time have lower residual stresses as compared to those cast at the same varying casting speeds at ten (10 seconds delay time. At the different casting speeds, residual stress ratio (g was found to decrease with increase in the casting speeds with values of 40.91%, 31.82%, 22.73%, 13.64% and 9.09% at zero second delay time, while at ten seconds delay time the residual stress ratios were 68.18%, 59.09%, 54.55%, 50.00% and 36.36% respectively. Reduction in residual stress with increase in speed and delay time is attributed to the greater centrifugal forces created by the increasing casting speeds on the solidification of the molten aluminium.

  10. Simulation study on three casting processes for a marine propeller hub body

    Directory of Open Access Journals (Sweden)

    Wang Tongmin

    2013-11-01

    Full Text Available The mold filling and solidification process of a marine propeller hub were simulated using ProCAST? Three casting processes ?gravity casting, centrifugal casting and low pressure casting ?were compared in order to get the best process. The heat transfer coefficient of the casting/mold interface was determined using a reverse method. The simulated results of velocity, temperature and shrinkage porosity distribution were discussed in detail for the three casting processes. A smooth filling was found in all three casting processes, especially the low pressure casting exhibiting a better filling performance than the other two, but the solidification processes were different. The casting did not experience the sequential solidification, and the feeding paths were blocked, leading to shrinkage porosity defects in the riser and the bottom of the casting in gravity casting and in the upper zone of the casting in low pressure casting. While, the sequential solidification was well controlled in the solidification process of centrifugal casting, and majority of the shrinkage porosity defects can only be observed in the riser. It could be concluded that the centrifugal casting process is the most suitable casting process for the production of propeller hub body. The casting experiments verified the simulation results, and a defect-free propeller hub was obtained by centrifugal casting with a rotational speed of 150 r.in-1.

  11. Surgical intervention in patients with necrotizing pancreatitis

    NARCIS (Netherlands)

    Besselink, MG; de Bruijn, MT; Rutten, JP; Boermeester, MA; Hofker, HS; Gooszen, HG

    2006-01-01

    Background: This study evaluated the various surgical strategies for treatment of (suspected) infected necrotizing pancreatitis (INP) and patient referrals for this condition in the Netherlands. Methods: This retrospective study included all 106 consecutive patients who had surgical treatment for IN

  12. Caste biology and behaviour of Bulbitermes sarawakensis (Isoptera, Nasutitermitinae) in Malaysia

    NARCIS (Netherlands)

    Lommen, S.T.E.; Huis, van A.; Sajap, A.S.

    2004-01-01

    Morphometrics, caste composition and behaviour were studied in Bulbitermes sarawakensis (Isoptera; Nasutitermitinae) in Malaysia. Morphometric studies displayed two larval stages, a presoldier and a soldier caste, two worker castes and different nymphal stages. Four different nymphs with long wings

  13. 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.

  14. China’s Aluminum Alloy Die Castings Industry has Promising Prospects

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>Engine aluminum alloy engine block die casting experienced rapid development in recent years. Domestic enterprises introduced large die casting machine automatic production lines, and developed large aluminum alloy die cast-

  15. 77 FR 17119 - Pipeline Safety: Cast Iron Pipe (Supplementary Advisory Bulletin)

    Science.gov (United States)

    2012-03-23

    ... Pipeline and Hazardous Materials Safety Administration Pipeline Safety: Cast Iron Pipe (Supplementary... operators of natural gas cast iron distribution pipelines and state pipeline safety representatives. Recent deadly explosions in Philadelphia and Allentown, Pennsylvania involving cast iron pipelines installed...

  16. A New Surgical Technique for Ingrown Toenail

    OpenAIRE

    Seyed Reza Mousavi; Jaledin Khoshnevice

    2012-01-01

    Background. Ingrowing toenails are a common condition which, when recurrent and painful, are often treated surgically. The aim of this study is to present a new simple surgical technique for ingrown toenails with good results. Method and Patients. The selected 250 patients with affected toes were surgically treated by our technique and observed from 1998 to 2004. Marginal nail elevation combined with surgical excision of the granulation tissue was more successful. For fixing the nail margin o...

  17. Sushruta: Foundation for Surgical Practice

    Directory of Open Access Journals (Sweden)

    Siddharth P. Dubhashi

    2016-04-01

    Full Text Available Sushruta was an ancient Indian surgeon (600 B.C. who resided in Varanasi.The teachings and work of Sushruta is compiled in a treatise called Sushruta Samhita (Sushruta's compendium, which is believed to be a part of Atharvaveda. It contains 184 chapters, descriptions of 1,120 illnesses, 300 surgical procedures, classification of human surgery in 8 categories, over 120 surgical instruments and around 700 drugs of animal, plant and mineral origin. Sushruta was one of the earliest exponents of surgery as an art and science. Sushruta's principles and teachings took surgery in ancient India to a noteworthy pedestal, making it the Golden Age of Surgery. He is truly the “Father of Surgery” and “Father of Plastic Surgery”. It is extremely essential that we put his principles into practice, and preserve the dignity of our noble profession. That would be the ideal tribute to this legendary figure.

  18. Surgical training in the Netherlands.

    Science.gov (United States)

    Borel-Rinkes, Inne H M; Gouma, Dirk J; Hamming, Jaap F

    2008-10-01

    Surgical training in the Netherlands has traditionally been characterized by learning on the job under the classic master-trainee doctrine. Over the past decades, it has become regionally organized with intensive structural training courses, and a peer-based quality control system. Recently, the nationwide programme has been modernized further and now involves a systematic, competency-based education with structural training courses, formalized assessment and room for reflection by residents under the supervision of surgical teaching groups. To this end, a uniform web-based digital portfolio is being introduced to facilitate monitoring of the individual resident's progress. Though requiring inspirational leadership, commitment, and determination, this modernization has sparked enthusiasm among trainees and teachers.

  19. Surgical skin-marking techniques.

    Science.gov (United States)

    Granick, M S; Heckler, F R; Jones, E W

    1987-04-01

    Surgical skin-marking inks and dyes are in everyday use for designing and planning incisions in plastic and reconstructive surgery. We have traced the historical development of surgical skin-marking techniques from ancient times to the present. The biochemical characteristics of the commonly used marking agents are discussed. A three-part experiment utilizing a pig model was carried out to test the tissue inflammatory response to the various dyes and inks when used intradermally as tattoos, the persistence of such tattoos, and the ease of skin erasure for each of eight stains. Methylene blue and gentian violet are recommended as the best all-purpose marking agents. The use of proprietary inks is discouraged.

  20. Surgical considerations about amyloid goiter.

    Science.gov (United States)

    García Villanueva, Augusto; García Villanueva, María Jesús; García Villanueva, Mercedes; Rojo Blanco, Roberto; Collado Guirao, María Vicenta; Cabañas Montero, Jacobo; Beni Pérez, Rafael; Moreno Montes, Irene

    2013-05-01

    Amyloidosis is an uncommon syndrome consisting of a number of disorders having in common an extracellular deposit of fibrillary proteins. This results in functional and structural changes in the affected organs, depending on deposit location and severity. Amyloid infiltration of the thyroid gland may occur in 50% and up to 80% of patients with primary and secondary amyloidosis respectively. Amyloid goiter (AG) is a true rarity, usually found associated to secondary amyloidosis. AG may require surgical excision, usually because of compressive symptoms. We report the case of a patient with a big AG occurring in the course of a secondary amyloidosis associated to polyarticular onset juvenile idiopathic arthritis who underwent total thyroidectomy. Current literature is reviewed, an attempt is made to provide action guidelines, and some surgical considerations on this rare condition are given.

  1. Surgical tools and medical devices

    CERN Document Server

    Jackson, Mark

    2016-01-01

    This new edition presents information and knowledge on the field of biomedical devices and surgical tools. The authors look at the interactions between nanotechnology, nanomaterials, design, modeling, and tools for surgical and dental applications, as well as how nanostructured surfaces can be created for the purposes of improving cell adhesion between medical devices and the human body. Each original chapter is revised in this second edition and describes developments in coatings for heart valves, stents, hip and knee joints, cardiovascular devices, orthodontic applications, and regenerative materials such as bone substitutes. There are also 8 new chapters that address: Microvascular anastomoses Inhaler devices used for pulmonary delivery of medical aerosols Surface modification of interference screws Biomechanics of the mandible (a detailed case study) Safety and medical devices The synthesis of nanostructured material Delivery of anticancer molecules using carbon nanotubes Nano and micro coatings for medic...

  2. Aesthetic Surgical Crown Lengthening Procedure

    OpenAIRE

    2015-01-01

    The aim of this case report was to describe the surgical sequence of crown lengthening to apically reposition the dentogingival complex, in addition to an esthetic restorative procedure. Many different causes can be responsible for short clinical crown. In these cases, the correct execution of a restorative or prosthetic rehabilitation requires an increasing of the crown length. According to the 2003 American Academy of Periodontology (Practice Profile Survey), crown lengthening is the most h...

  3. [Surgical anatomy of the nose].

    Science.gov (United States)

    Nguyen, P S; Bardot, J; Duron, J B; Jallut, Y; Aiach, G

    2014-12-01

    Thorough knowledge of the anatomy of the nose is an essential prerequisite for preoperative analysis and the understanding of surgical techniques. Like a tent supported by its frame, the nose is an osteo-chondral structure covered by a peri-chondroperiosteal envelope, muscle and cutaneous covering tissues. For didactic reasons, we have chosen to treat this chapter in the form of comments from eight key configurations that the surgeon should acquire before performing rhinoplasty.

  4. Surgical checklists: the human factor.

    LENUS (Irish Health Repository)

    O Connor, Paul

    2013-05-14

    BACKGROUND: Surgical checklists has been shown to improve patient safety and teamwork in the operating theatre. However, despite the known benefits of the use of checklists in surgery, in some cases the practical implementation has been found to be less than universal. A questionnaire methodology was used to quantitatively evaluate the attitudes of theatre staff towards a modified version of the World Health Organisation (WHO) surgical checklist with relation to: beliefs about levels of compliance and support, impact on patient safety and teamwork, and barriers to the use of the checklist. METHODS: Using the theory of planned behaviour as a framework, 14 semi-structured interviews were conducted with theatre personnel regarding their attitudes towards, and levels of compliance with, a checklist. Based upon the interviews, a 27-item questionnaire was developed and distribute to all theatre personnel in an Irish hospital. RESULTS: Responses were obtained from 107 theatre staff (42.6% response rate). Particularly for nurses, the overall attitudes towards the effect of the checklist on safety and teamworking were positive. However, there was a lack of rigour with which the checklist was being applied. Nurses were significantly more sensitive to the barriers to the use of the checklist than anaesthetists or surgeons. Moreover, anaesthetists were not as positively disposed to the surgical checklist as surgeons and nurse. This finding was attributed to the tendency for the checklist to be completed during a period of high workload for the anaesthetists, resulting in a lack of engagement with the process. CONCLUSION: In order to improve the rigour with which the surgical checklist is applied, there is a need for: the involvement of all members of the theatre team in the checklist process, demonstrated support for the checklist from senior personnel, on-going education and training, and barriers to the implementation of the checklist to be addressed.

  5. Crown lengthening: a surgical flap approach.

    Science.gov (United States)

    Lundergan, W; Hughes, W R

    1996-09-01

    In many instances it is not possible to place a restoration margin without encroaching on the periodontal attachment apparatus. A surgical crown-lengthening procedure can provide a good solution to this common clinical problem. This article discusses indication and contraindication for surgical crown-lengthening procedures and presents an appropriate surgical technique.

  6. Fighting surgical site infections in small animals

    DEFF Research Database (Denmark)

    Verwilghen, Denis; Singh, Ameet

    2015-01-01

    A diverse array of pathogen-related, patient-related, and caretaker-related issues influence risk and prevention of surgical site infections (SSIs). The entire surgical team involved in health care settings in which surgical procedures are performed play a pivotal role in the prevention of SSIs...

  7. Surgical Treatment for Hepatocellular Carcinoma

    Directory of Open Access Journals (Sweden)

    Ahmad A Madkhali

    2015-01-01

    Full Text Available Hepatocellular carcinoma (HCC is an epithelial tumor derived from hepatocytes; it accounts for 80% of all primary liver cancers and ranks globally as the fourth leading cause of cancer-related deaths. HCC treatment is a multidisciplinary and a multimodal task, with surgery in the form of liver resection and liver transplantation (LT representing the only potentially curative modality. However, there are variable opinions and discussions about applying these surgical options and using other supporting treatments. This article is a narrative review that includes articles published from 1984 to 2013 located by searching scientific databases such as PubMed, SCOPUS, and Elsevier, with the main keyword of hepatocellular carcinoma in addition to other keywords such as liver transplantation, liver resection, transarterial chemoembolization, portal vein embolization, bridging therapy, and downstaging. In this review, we focus mainly on the surgical treatment options offered for HCC, in order to illustrate the current relevant data available in the literature to help in applying these surgical options and to use other supporting treatment modalities when appropriate.

  8. Surgical Treatment of Skin Tumors

    Directory of Open Access Journals (Sweden)

    Gonca

    2015-06-01

    Full Text Available When we mention about surgical treatment of any tumor residing on the skin independent of its benign or malignant nature, the first method we recall is excision. Elliptical excision is the mainstay of the dermatologic surgery. Each excision ends with a defect for which we are responsible to repair functionally and cosmetically. The diameter of the tumor we excised and the safety margin used for excision determine the diameter of the final defect. After achieving tumor free lateral and deep margins with the appropriate surgical method, we decide between the repair options of second intention healing, primary repair, flaps, full or split thickness grafts, considering the diameter and the anatomic localization of the defect, for the best functional and cosmetic result for that specific defect. This review overviews not only the most common dermatologic surgical methods, but also Mohs surgery which is a method rarely used in our country, although it is the treatment of choice for the treatment of high risk basal cell carcinoma (BCC and squamous cell carcinoma (SCC.

  9. Simulation-based surgical education.

    Science.gov (United States)

    Evgeniou, Evgenios; Loizou, Peter

    2013-09-01

    The reduction in time for training at the workplace has created a challenge for the traditional apprenticeship model of training. Simulation offers the opportunity for repeated practice in a safe and controlled environment, focusing on trainees and tailored to their needs. Recent technological advances have led to the development of various simulators, which have already been introduced in surgical training. The complexity and fidelity of the available simulators vary, therefore depending on our recourses we should select the appropriate simulator for the task or skill we want to teach. Educational theory informs us about the importance of context in professional learning. Simulation should therefore recreate the clinical environment and its complexity. Contemporary approaches to simulation have introduced novel ideas for teaching teamwork, communication skills and professionalism. In order for simulation-based training to be successful, simulators have to be validated appropriately and integrated in a training curriculum. Within a surgical curriculum, trainees should have protected time for simulation-based training, under appropriate supervision. Simulation-based surgical education should allow the appropriate practice of technical skills without ignoring the clinical context and must strike an adequate balance between the simulation environment and simulators.

  10. Surgical smoke and ultrafine particles

    Directory of Open Access Journals (Sweden)

    Nowak Dennis

    2008-12-01

    Full Text Available Abstract Background Electrocautery, laser tissue ablation, and ultrasonic scalpel tissue dissection all generate a 'surgical smoke' containing ultrafine ( Methods To measure the amount of generated particulates in 'surgical smoke' during different surgical procedures and to quantify the particle number concentration for operation room personnel a condensation particle counter (CPC, model 3007, TSI Inc. was applied. Results Electro-cauterization and argon plasma tissue coagulation induced the production of very high number concentration (> 100000 cm-3 of particles in the diameter range of 10 nm to 1 μm. The peak concentration was confined to the immediate local surrounding of the production side. In the presence of a very efficient air conditioning system the increment and decrement of ultrafine particle occurrence was a matter of seconds, with accumulation of lower particle number concentrations in the operation room for only a few minutes. Conclusion Our investigation showed a short term very high exposure to ultrafine particles for surgeons and close assisting operating personnel – alternating with longer periods of low exposure.

  11. Uncommon surgical emergencies in neonatology.

    Science.gov (United States)

    Angotti, R; Bulotta, A L; Ferrara, F; Molinaro, F; Cerchia, E; Meucci, D; Messina, M

    2014-12-30

    Objective. Over the past decade, multiple factors have changed the pattern of neonatal surgical emergencies. An increase in prenatal screenings and the development of neonatal tertiary care centres have changed the clinical approach to these kids. Materials and methods. Between 1995 to 2011 were retrospectively reviewed 34 patients with diagnosis of uncommon rare neonatal surgical emergencies at our institute. We analyzed: sex, gestational age, weight at birth, primary pathology, prenatal diagnosis, associated anomalies, age and weight at surgery, clinical presentation, start of oral feeding and hospitalization. The follow-up was performed at 6,12, 24 and 36 months. Results. There were 21 male and 13 female. The gestational age ranged between 28 and 36 weeks. The weight at birth ranged between 700 and 1400 grams. Oral feeding was started between 4th and 10th postoperative day. The average hospitalization was about 70.47 days. To date, all patients have finished the followup. They are healthy. Conclusion. The outcome of the patients with uncommon surgical emergencies is different based on the etiology. Overall survival is generally good but is influenced by the associated anomalies.

  12. Ethical issues in surgical innovation.

    Science.gov (United States)

    Miller, Megan E; Siegler, Mark; Angelos, Peter

    2014-07-01

    Innovation is responsible for most advances in the field of surgery. Innovative approaches to solving clinical problems have significantly decreased morbidity and mortality for many surgical procedures, and have led to improved patient outcomes. While innovation is motivated by the surgeon's expectation that the new approach will be beneficial to patients, not all innovations are successful or result in improved patient care. The ethical dilemma of surgical innovation lies in the uncertainty of whether a particular innovation will prove to be a "good thing." This uncertainty creates challenges for surgeons, patients, and the healthcare system. By its very nature, innovation introduces a potential risk to patient safety, a risk that may not be fully known, and it simultaneously fosters an optimism bias. These factors increase the complexity of informed consent and shared decision making for the surgeon and the patient. Innovative procedures and their associated technology raise issues of cost and resource distribution in the contemporary, financially conscious, healthcare environment. Surgeons and institutions must identify and address conflicts of interest created by the development and application of an innovation, always preserving the best interest of the patient above the academic or financial rewards of success. Potential strategies to address the challenges inherent in surgical innovation include collecting and reporting objective outcomes data, enhancing the informed consent process, and adhering to the principles of disclosure and professionalism. As surgeons, we must encourage creativity and innovation while maintaining our ethical awareness and responsibility to patients.

  13. Decision making in surgical oncology.

    Science.gov (United States)

    Lamb, B; Green, J S A; Vincent, C; Sevdalis, N

    2011-09-01

    Decisions in surgical oncology are increasingly being made by multi-disciplinary teams (MDTs). Although MDTs have been widely accepted as the preferred model for cancer service delivery, the process of decision making has not been well described and there is little evidence pointing to the ideal structure of an MDT. Performance in surgery has been shown to depend on non-technical skills, such as decision making, as well as patient factors and the technical skills of the healthcare team. Application of this systems approach to MDT working allows the identification of factors that affect the quality of decision making for cancer patients. In this article we review the literature on decision making in surgical oncology and by drawing from the systems approach to surgical performance we provide a framework for understanding the process of decision making in MDTs. Technical factors that affect decision making include the information about patients, robust ICT and video-conferencing equipment, a minimum dataset with expert review of radiological and pathological information, implementation and recording of the MDTs decision. Non-technical factors with an impact on decision making include attendance of team members at meetings, leadership, teamwork, open discussion, consensus on decisions and communication with patients and primary care. Optimising these factors will strengthen the decision making process and raise the quality of care for cancer patients.

  14. Shallow water model for horizontal centrifugal casting

    Science.gov (United States)

    Boháček, J.; Kharicha, A.; Ludwig, A.; Wu, M.

    2012-07-01

    A numerical model was proposed to simulate the solidification process of an outer shell of work roll made by the horizontal centrifugal casting technique. Shallow water model was adopted to solve the 2D average flow dynamics of melt spreading and the average temperature distribution inside the centrifugal casting mould by considering the centrifugal force, Coriolis force, viscous force due to zero velocity on the mould wall, gravity, and energy transport by the flow. Additionally, a 1D sub-model was implemented to consider the heat transfer in the radial direction from the solidifying shell to the mould. The solidification front was tracked by fulfilling the Stefan condition. Radiative and convective heat losses were included from both, the free liquid surface and the outer wall of the mould. Several cases were simulated with the following assumed initial conditions: constant height of the liquid metal (10, 20, and 30 mm), uniform temperature of the free liquid surface (1755 K). The simulation results have shown that while the solidification front remained rather flat, the free surface was disturbed by waves. The amplitude of waves increased with the liquid height. Free surface waves diminished as the solidification proceeded.

  15. Prediction of Microstructure in ADI Castings

    Directory of Open Access Journals (Sweden)

    Guzik E.

    2016-12-01

    Full Text Available Tests were carried out on samples of low-alloy ductile iron with additions of Ni, Cu and Mo, subjected to austempering heat treatment. The samples were austenitized at 850, 900 and 950 °C, and then austempered at T = 210, 240, 270, 300 and 330 °C. The ausferritizing treatment was carried out in a salt bath for the time τ = 2 - 8 hours. Additionally, tests and studies covered samples subjected to the ausferritizing treatment at 270 °C with the time of holding castings in a bath from 2 to 24 hours. Evaluation covered the results of the ADI microstructure examinations and hardness measurements. The ADI matrix morphology was identified counting the average number of ausferrite plates and measuring their width and spacing. The regression equations HB = f (τ, T and τ = f (HB, T were derived to establish the, so-called, “process window”, allowing obtaining a priori the required microstructure of ADI and, consequently, the required mechanical properties, mainly hardness, shaping the functional properties of castings, abrasion wear resistance – in particular.

  16. Horizontal electromagnetic casting of thin metal sheets

    Energy Technology Data Exchange (ETDEWEB)

    Hull, John R. (Hinsdale, IL); Lari, Robert J. (Aurora, IL); Praeg, Walter F. (Palos Park, IL); Turner, Larry R. (Naperville, IL)

    1988-01-01

    Thin metal sheets are cast by magnetically suspending molten metal deposited within a ferromagnetic yoke and between AC conducting coils and linearly displacing the magnetically levitated liquid metal while it is being cooled to form a solid metal sheet. Magnetic flux increases as the molten metal sheet moves downward and decreases as the molten metal sheet moves upward to stabilize the sheet and maintain it in equilibrium as it is linearly displaced and solidified by cooling gases. A conducting shield is electrically coupled to the molten metal sheet by means of either metal sheet engaging rollers or brushes on the solidified metal, and by means of an electrode in the vessel containing the molten metal thereby providing a return path for the eddy currents induced in the metal sheet by the AC coil generated magnetic flux. Variation in the geometry of the conducting shield allows the magnetic flux between the metal sheet and the conducting shield to be varied and the thickness in surface quality of the metal sheet to be controlled. Side guards provide lateral containment for the molten metal sheet and stabilize and shape the magnetic field while a leader sheet having electromagnetic characteristics similar to those of the metal sheet is used to start the casting process and precedes the molten metal sheet through the magnet and forms a continuous sheet therewith. The magnet may be either U-shaped with a single racetrack coil or may be rectangular with a pair of facing bedstead coils.

  17. Horizontal electromagnetic casting of thin metal sheets

    Energy Technology Data Exchange (ETDEWEB)

    Hull, John R. (Hinsdale, IL); Lari, Robert J. (Aurora, IL); Praeg, Walter F. (Palos Park, IL); Turner, Larry R. (Naperville, IL)

    1987-01-01

    Thin metal sheets are cast by magnetically suspending molten metal deposited within a ferromagnetic yoke and between AC conducting coils and linearly displacing the magnetically levitated liquid metal while it is being cooled to form a solid metal sheet. Magnetic flux increases as the molten metal sheet moves downward and decreases as the molten metal sheet moves upward to stabilize the sheet and maintain it in equilibrium as it is linearly displaced and solidified by cooling gases. A conducting shield is electrically coupled to the molten metal sheet by means of either metal sheet engaging rollers or brushes on the solidified metal, and by means of an electrode in the vessel containing the molten metal thereby providing a return path for the eddy currents induced in the metal sheet by the AC coil generated magnetic flux. Variation in the geometry of the conducting shield allows the magnetic flux between the metal sheet and the conducting shield to be varied and the thickness in surface quality of the metal sheet to be controlled. Side guards provide lateral containment for the molten metal sheet and stabilize and shape the magnetic field while a leader sheet having electromagnetic characteristics similar to those of the metal sheet is used to start the casting process and precedes the molten metal sheet through the magnet and forms a continuous sheet therewith. The magnet may be either U-shaped with a single racetrack coil or may be rectangular with a pair of facing bedstead coils.

  18. Fracture analysis of chilled cast iron camshaft

    Directory of Open Access Journals (Sweden)

    Li Ping

    2009-05-01

    Full Text Available The fracture of a camshaft made of chilled cast iron, installed in a home-made Fukang car, happened only after running over a distance of 6,200 km. The fractured camshaft was received to conduct a series of failure analyses using visual inspection, SEM observation of fracture section, microstructure analysis, chemical composition analysis and hardness examination and so on, while those of CKD camshaft made by Citro雗 Company in France was also simultaneously analyzed to compare the difference between them. The results showed that the fracture of the camshaft mainly results from white section in macrostructure and Ledeburite in microstructure; the crack in the fractured camshaft should be recognized to initiate at the boundary of coarser needle-like carbide and matrix, and then propagate through the transverse section. At the same time, the casting defects such as dendritic shrinkage, accumulated inclusion and initiated crack and abnormal external force might stimulate the fracture of camshaft as well. Based on failure analysis, some measures have been employed, and as a result, the fracture of home-made camshafts has been effectively prevented.

  19. Fracture analysis of chilled cast iron camshaft

    Institute of Scientific and Technical Information of China (English)

    Li Ping; Li Fengjun; Cai Anke; Wei Bokang

    2009-01-01

    The fracture of a camshaft made of chilled cast iron, installed in a home-made Fukang car, happened only after running over a distance of 6,200 km. The fractured camshaft was received to conduct a series of failure analyses using visual inspection, SEM observation of fracture section, microstructure analysis, chemical composition analysis and hardness examination and so on, while those of CKD camshaft made by Citroen Company in France was also simultaneously analyzed to compare the difference between them. The results showed that the fracture of the camshaft mainly results from white section in macrostructure and Ledeburite in microstructure; the crack in the fractured camshaft should be recognized to initiate at the boundary of coarser needle-like carbide and matrix, and then propagate through the transverse section. At the same time, the casting defects such as dendritic shrinkage, accumulated inclusion and initiated crack and abnormal external force might stimulate the fracture of camshaft as well. Based on failure analysis, some measures have been employed, and as a result, the fracture of home-made camshafts has been effectively prevented.

  20. Solidification microstructure of M2 high speed steel by different casting technologies

    OpenAIRE

    Zhou Xuefeng; Fang Feng; Jiang Jianjing

    2011-01-01

    The present work investigated the solidification microstructure of AISI M2 high speed steel manufactured by different casting technologies, namely iron mould casting and continuous casting. The results revealed that the as-cast structure of the steel was composed of the iron matrix and the M2C eutectic carbide networks, which were greatly refined in the ingot made by continuous casting process, compared with that by the iron mould casting process. M2C eutectic carbides presented variation in ...

  1. 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.

  2. Casting Porosity-Free Grain Refined Magnesium Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Schwam, David [Case Western Reserve University

    2013-08-12

    The objective of this project was to identify the root causes for micro-porosity in magnesium alloy castings and recommend remedies that can be implemented in production. The findings confirm the key role played by utilizing optimal gating and risering practices in minimizing porosity in magnesium castings. 

  3. 25 CFR 217.6 - Method of casting votes.

    Science.gov (United States)

    2010-04-01

    ... the status quo. At the time they notify the superintendent of the votes cast on an issue, each joint... 25 Indians 1 2010-04-01 2010-04-01 false Method of casting votes. 217.6 Section 217.6 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS MANAGEMENT OF TRIBAL ASSETS...

  4. Refining cast implant-retained restorations by electrical discharge machining.

    Science.gov (United States)

    Schmitt, S M; Chance, D A; Cronin, R J

    1995-03-01

    The UCLA abutment was developed to create implant-retained restorations with ideal contours, excellent esthetics, and minimal vertical space requirements for restorative materials. A major drawback of this abutment is that casting inaccuracies in the lost-wax process are difficult to control. This article describes a method of refining cast implant-retained restorations by use of electrical discharge machining.

  5. Laser surface treatment of grey cast iron for automotive applications

    NARCIS (Netherlands)

    Ocelik, V.; Tang, P.N.; de Boer, M.C.; de Oliveira, U.; de Hosson, J.T.M.; DeHosson, JTM; Brebbia, CA; Nishida, SI

    2005-01-01

    The surface of pearlitic grey cast iron was treated using a 2 kW Nd:YAG laser beam with the final aim to improve its surface properties, mainly for automotive applications. Two kinds of laser surface treatments were experimentally applied. In the laser surface hardening approach the surface of cast

  6. Independent origins of Indian caste and tribal paternal lineages.

    Science.gov (United States)

    Cordaux, Richard; Aunger, Robert; Bentley, Gillian; Nasidze, Ivane; Sirajuddin, S M; Stoneking, Mark

    2004-02-03

    The origins of the nearly one billion people inhabiting the Indian subcontinent and following the customs of the Hindu caste system are controversial: are they largely derived from Indian local populations (i.e. tribal groups) or from recent immigrants to India? Archaeological and linguistic evidence support the latter hypothesis, whereas recent genetic data seem to favor the former hypothesis. Here, we analyze the most extensive dataset of Indian caste and tribal Y chromosomes to date. We find that caste and tribal groups differ significantly in their haplogroup frequency distributions; caste groups are homogeneous for Y chromosome variation and more closely related to each other and to central Asian groups than to Indian tribal or any other Eurasian groups. We conclude that paternal lineages of Indian caste groups are primarily descended from Indo-European speakers who migrated from central Asia approximately 3,500 years ago. Conversely, paternal lineages of tribal groups are predominantly derived from the original Indian gene pool. We also provide evidence for bidirectional male gene flow between caste and tribal groups. In comparison, caste and tribal groups are homogeneous with respect to mitochondrial DNA variation, which may reflect the sociocultural characteristics of the Indian caste society.

  7. The surface layer of austempered ductile iron investment castings properties

    OpenAIRE

    D. Myszka; M. Kłębczyk; Zych, A.; L. Kwiatkowski

    2009-01-01

    The article presents a unique process of carbonnitriding and nitriding the precision casting surfaces of austempered ductile iron. The results of the research are pointing that adequate process parameters allow to obtain multiple increase of wear resistance and a significant increase of corrosion resistance. Also, changes of cast microstructure and hardness are presented.

  8. Worker caste determination in the army ant Eciton burchellii.

    Science.gov (United States)

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

    2007-10-22

    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 extreme cases of worker caste differentiation occurs in the army ant genus Eciton, where queens mate with many males and colonies are therefore composed of numerous full-sister subfamilies. This high intracolonial genetic diversity, in combination with the extreme caste polymorphism, provides an excellent test system for studying the extent to which caste determination is genetically controlled. Here we show that genetic effects contribute significantly to worker caste fate in Eciton burchellii. We conclude that the combination of polyandry and genetic variation for caste determination may have facilitated the evolution of worker caste diversity in some lineages of social insects.

  9. Gears castings from ductile iron of improved abrasion wear resistance

    Directory of Open Access Journals (Sweden)

    D. Kopyciński

    2011-10-01

    Full Text Available The aim of this study was to develop an industrial technological process for the manufacturing of castings from alloyed ductile iron characterized by improved resistance to abrasion wear. The outcome of the study was the implementation of developed technology under the industrial conditions of ASPAMET Foundry Plant and start up of production of a wide range of cast gears.

  10. The surface layer of austempered ductile iron investment castings properties

    Directory of Open Access Journals (Sweden)

    D. Myszka

    2009-01-01

    Full Text Available The article presents a unique process of carbonnitriding and nitriding the precision casting surfaces of austempered ductile iron. The results of the research are pointing that adequate process parameters allow to obtain multiple increase of wear resistance and a significant increase of corrosion resistance. Also, changes of cast microstructure and hardness are presented.

  11. 49 CFR 192.755 - Protecting cast-iron pipelines.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Protecting cast-iron pipelines. 192.755 Section... NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Maintenance § 192.755 Protecting cast-iron pipelines. When an operator has knowledge that the support for a segment of a buried...

  12. 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.

  13. Development of Continuous Electrical Steel and Casting Technology of New Products

    Institute of Scientific and Technical Information of China (English)

    WANG Li-tao; DENG Chen-hong; DONG Mei; SHI Li-fa; ZHANG Jian-ping

    2012-01-01

    The development of continuous casting technology of electrical steel was analyzed. The technologies and products characteristics of conventional continuous casting, thin slab continuous casting and rolling, middle thin slab continuous casting and rolling and twin-roll thin strip were compared. Conventional continuous casting technology was widely adopted in producing electrical steel, thin slab continuous casting and rolling and middle thin slab contin- uous casting and roiling technology industrialized electrical steel~ and study of twin-roll thin strip casting technology was focused on fundamental experiments.

  14. 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.

  15. 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.

  16. Waterproof casts for immobilization of children's fractures and sprains.

    Science.gov (United States)

    Shannon, Elizabeth G; DiFazio, Rachel; Kasser, James; Karlin, Lawrence; Gerbino, Peter

    2005-01-01

    This study was designed to determine the efficacy of waterproof cast-lining materials in children with short-arm, long-arm, and short-leg casts. Eligible patients had healing fractures 2 weeks after reduction, stable fractures requiring no reduction, or sprains. A total of 165 waterproof-lined casts were applied and 124 children and parents completed a survey (76.9%) upon cast removal. Results revealed 79% very satisfied, 21% satisfied, and 0% dissatisfied. There were 16 (12.9%) minor skin integrity issues. Waterproof casts in stable fractures and sprains allow acceptable immobilization with no significant associated unusual risk and allow children to resume their usual recreational water activities and hygiene regimen without risk of adverse results.

  17. DESIGN AND FABRICATION OF A CENTRIFUGAL CASTING MACHINE

    Directory of Open Access Journals (Sweden)

    Adedipe Oyewole

    2011-12-01

    Full Text Available The design and fabrication of a centrifugal casting machine was successfully carried out. The operation of the machine was based on the principle of centrifugal force. Suitable design theory, analysis and calculation were adopted carried out in the course of the work. The mold is bolted to the base plate which can rotate at moderatespeeds thereby forcing the molten metal against the inner walls of the mold. This machine could be used to cast small engineering components. The centrifugal force on the machine was determined to be 3207.3N, while the required power on the machine was 854.7W. A test was carried out on the fabricated centrifugal casting machine with aluminum alloy and the machine was able to cast 6kg of aluminum alloy and the casting was successful.

  18. Tundish Technology for Casting Clean Steel: A Review

    Science.gov (United States)

    Sahai, Yogeshwar

    2016-08-01

    With increasing demand of high-quality clean steel, cleanliness is of paramount importance in steel production and casting. Tundish plays an important role in controlling the continuously cast steel quality as it links a batch vessel, ladle, to a continuous casting mold. Tundish is also the last vessel in which metal flows before solidifying in mold. For controlling the quality of steel, flow and temperature control of the melt are critical, and these are presented in this paper. Use of proper flux, design of flow control devices, and gas injection in tundish become important factors in casting clean steel. Recycling of hot tundish, centrifugal flow tundish, H-shaped tundish, etc. are some of the developments which were implemented to cast clean steel and these are discussed.

  19. Modeling of Mold Filling and Solidification in Lost Foam Casting

    Institute of Scientific and Technical Information of China (English)

    Fengjun LI; Houfa SHEN; Baicheng LIU

    2003-01-01

    Based on the characteristics of the lost foam casting (LFC) and the artificial neural network technique, a mathematicalmodel for the simulation of the melt-pattern interface movement during the mold filling of LFC has been proposed andexperimentally verified. The simulation results are consistent with the experiments in both the shapes of melt frontand filling sequences. According to the calculated interface locations, the fluid flow and the temperature distributionsduring the mold filling and solidification processes were calculated, and the shrinkage defect of a lost foam ductileiron casting was predicted by considering the mold wall movement in LFC. The simulation method was applied tooptimize the casting design of lost foam ductile iron castings. It is shown that the model can be used for the defectsprediction and for casting design optimization in the practical LFC production.

  20. Structure and properties of stir-cast zinc alloys

    Energy Technology Data Exchange (ETDEWEB)

    LeHuy, H.; Blain J.; Masounave, J.; Bata, G.L. (Industrial Materials Research Institute, Boucherville, P.Q. (Canada))

    Stir casting (or rheocasting) of ZA-27 zinc alloys was investigated experimentally. By vigorously agitating the alloys during cooling, the dendrites that were forming were fragmented giving a unique structure composed of spherical and rosette shaped particles suspended in the remaining liquid. Under high shear rates ({center dot}{gamma} = 300s{sup {minus}1} or more) the slurries with primary particle concentrations as high as 60% displayed viscosities as low as 20 poises and could easily be casted. The effects of processing variables such as shearing and cooling rates and casting temperatures were studied. Their relative importance on the rheological and microstructural behavior of the stir cast alloys are discussed. Results from viscosity measurements on slurries show that non-dendritical ZA-27 alloys obey a power law fluid model. Finally, results from mechanical and compressive studies carried out on solidified slurries are discussed and compared to conventional casted and wrought alloy properties.

  1. Integration of CAD/CAE System for Casting Process Design

    Institute of Scientific and Technical Information of China (English)

    周舰; 荆涛

    2003-01-01

    Concurrent engineering is needed to modernize the foundry industry and to reduce the scrap from castings and thus increase the economic profit. This paper presents an integrated 3-D CAD/CAE system for a foundry using concurrent engineering which considers casting structure, casting type, and manufacturing properties in the CAD module to design the pouring system, the riser, the chill core and so on. A visualized solid model is developed for the casting component with the model design enhanced by CAE analysis. Heat transfer and fluid flow simulation are used to analyze the initial design. The whole product development process is analyzed using concurrent engineering methods. The application shows that the integrated system can improve the efficiency of the design and manufacturing process of die casting.

  2. Surgical correction of cleft lip and palate.

    Science.gov (United States)

    Jayaram, Rahul; Huppa, Christoph

    2012-01-01

    Surgical cleft repair aims to restore function of the oro-nasal sphincter and oro-nasal soft tissues and re-establish the complex relationship between perioral and perinasal muscle rings without compromising subsequent mid-facial growth and development. Here we review the surgical anatomy of this region, optimal timing for surgical repair and current thinking on the use of surgical adjuncts. In addition, an overview of current surgical techniques available for the repair of cleft lip, cleft palate and velopharyngeal insufficiency is presented. Finally, we briefly discuss nasal revision surgery and the use of osteotomy, including distraction osteogenesis in the cleft patient.

  3. The Influence of Casting Conditions on the Microstructure of As-Cast U-10Mo Alloys: Characterization of the Casting Process Baseline

    Energy Technology Data Exchange (ETDEWEB)

    Nyberg, Eric A.; Joshi, Vineet V.; Lavender, Curt A.; Paxton, Dean M.; Burkes, Douglas

    2013-12-13

    Sections of eight plate castings of uranium alloyed with 10 wt% molybdenum (U-10Mo) were sent from Y-12 to the Pacific Northwest National Laboratory (PNNL) for microstructural characterization. This report summarizes the results from this study.

  4. Gating of Permanent Molds for Aluminum Casting

    Energy Technology Data Exchange (ETDEWEB)

    David Schwam; John F. Wallace; Tom Engle; Qingming Chang

    2004-01-01

    This report summarizes a two-year project, DE-FC07-011D13983 that concerns the gating of aluminum castings in permanent molds. The main goal of the project is to improve the quality of aluminum castings produced in permanent molds. The approach taken was to determine how the vertical type gating systems used for permanent mold castings can be designed to fill the mold cavity with a minimum of damage to the quality of the resulting casting. It is evident that somewhat different systems are preferred for different shapes and sizes of aluminum castings. The main problems caused by improper gating are entrained aluminum oxide films and entrapped gas. The project highlights the characteristic features of gating systems used in permanent mold aluminum foundries and recommends gating procedures designed to avoid common defects. The study also provides direct evidence on the filling pattern and heat flow behavior in permanent mold castings. Equipment and procedure for real time X-Ray radiography of molten aluminum flow into permanent molds have been developed. Other studies have been conducted using water flow and behavior of liquid aluminum in sand mold using real time photography. This investigation utilizes graphite molds transparent to X-Rays making it possible to observe the flow pattern through a number of vertically oriented grating systems. These have included systems that are choked at the base of a rounded vertical sprue and vertical gating systems with a variety of different ingates into the bottom of a mold cavity. These systems have also been changed to include gating systems with vertical and horizontal gate configurations. Several conclusions can be derived from this study. A sprue-well, as designed in these experiments, does not eliminate the vena contracta. Because of the swirling at the sprue-base, the circulating metal begins to push the entering metal stream toward the open runner mitigating the intended effect of the sprue-well. Improved designs of

  5. Cast Stone Formulation At Higher Sodium Concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K. M.; Edwards, T. A.; Roberts, K. B.

    2013-10-02

    A low temperature waste form known as Cast Stone is being considered to provide supplemental Low Activity Waste (LAW) immobilization capacity for the Hanford site. Formulation of Cast Stone at high sodium concentrations is of interest since a significant reduction in the necessary volume of Cast Stone and subsequent disposal costs could be achieved if an acceptable waste form can be produced with a high sodium molarity salt solution combined with a high water to premix (or dry blend) ratio. The objectives of this study were to evaluate the factors involved with increasing the sodium concentration in Cast Stone, including production and performance properties and the retention and release of specific components of interest. Three factors were identified for the experimental matrix: the concentration of sodium in the simulated salt solution, the water to premix ratio, and the blast furnace slag portion of the premix. The salt solution simulants used in this study were formulated to represent the overall average waste composition. The cement, blast furnace slag, and fly ash were sourced from a supplier in the Hanford area in order to be representative. The test mixes were prepared in the laboratory and fresh properties were measured. Fresh density increased with increasing sodium molarity and with decreasing water to premix ratio, as expected given the individual densities of these components. Rheology measurements showed that all of the test mixes produced very fluid slurries. The fresh density and rheology data are of potential value in designing a future Cast Stone production facility. Standing water and density gradient testing showed that settling is not of particular concern for the high sodium compositions studied. Heat of hydration measurements may provide some insight into the reactions that occur within the test mixes, which may in turn be related to the properties and performance of the waste form. These measurements showed that increased sodium

  6. Cast Stone Formulation At Higher Sodium Concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K. M.; Roberts, K. A.; Edwards, T. B.

    2013-09-17

    A low temperature waste form known as Cast Stone is being considered to provide supplemental Low Activity Waste (LAW) immobilization capacity for the Hanford site. Formulation of Cast Stone at high sodium concentrations is of interest since a significant reduction in the necessary volume of Cast Stone and subsequent disposal costs could be achieved if an acceptable waste form can be produced with a high sodium molarity salt solution combined with a high water to premix (or dry blend) ratio. The objectives of this study were to evaluate the factors involved with increasing the sodium concentration in Cast Stone, including production and performance properties and the retention and release of specific components of interest. Three factors were identified for the experimental matrix: the concentration of sodium in the simulated salt solution, the water to premix ratio, and the blast furnace slag portion of the premix. The salt solution simulants used in this study were formulated to represent the overall average waste composition. The cement, blast furnace slag, and fly ash were sourced from a supplier in the Hanford area in order to be representative. The test mixes were prepared in the laboratory and fresh properties were measured. Fresh density increased with increasing sodium molarity and with decreasing water to premix ratio, as expected given the individual densities of these components. Rheology measurements showed that all of the test mixes produced very fluid slurries. The fresh density and rheology data are of potential value in designing a future Cast Stone production facility. Standing water and density gradient testing showed that settling is not of particular concern for the high sodium compositions studied. Heat of hydration measurements may provide some insight into the reactions that occur within the test mixes, which may in turn be related to the properties and performance of the waste form. These measurements showed that increased sodium

  7. Cast Stone Formulation At Higher Sodium Concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K. M.; Roberts, K. A.; Edwards, T. B.

    2014-02-28

    A low temperature waste form known as Cast Stone is being considered to provide supplemental Low Activity Waste (LAW) immobilization capacity for the Hanford site. Formulation of Cast Stone at high sodium concentrations is of interest since a significant reduction in the necessary volume of Cast Stone and subsequent disposal costs could be achieved if an acceptable waste form can be produced with a high sodium molarity salt solution combined with a high water to premix (or dry blend) ratio. The objectives of this study were to evaluate the factors involved with increasing the sodium concentration in Cast Stone, including production and performance properties and the retention and release of specific components of interest. Three factors were identified for the experimental matrix: the concentration of sodium in the simulated salt solution, the water to premix ratio, and the blast furnace slag portion of the premix. The salt solution simulants used in this study were formulated to represent the overall average waste composition. The cement, blast furnace slag, and fly ash were sourced from a supplier in the Hanford area in order to be representative. The test mixes were prepared in the laboratory and fresh properties were measured. Fresh density increased with increasing sodium molarity and with decreasing water to premix ratio, as expected given the individual densities of these components. Rheology measurements showed that all of the test mixes produced very fluid slurries. The fresh density and rheology data are of potential value in designing a future Cast Stone production facility. Standing water and density gradient testing showed that settling is not of particular concern for the high sodium compositions studied. Heat of hydration measurements may provide some insight into the reactions that occur within the test mixes, which may in turn be related to the properties and performance of the waste form. These measurements showed that increased sodium

  8. Methods and apparatuses for manufacturing geometric multicrystalline cast silicon and geometric multicrystalline cast silicon bodies for photovoltaics

    Science.gov (United States)

    Stoddard, Nathan G

    2015-02-10

    Methods and apparatuses are provided for casting silicon for photovoltaic cells and other applications. With such methods and apparatuses, a cast body of geometrically ordered multi-crystalline silicon may be formed that is free or substantially free of radially-distributed impurities and defects and having at least two dimensions that are each at least about 10 cm is provided.

  9. Recent Development of Lost Foam Casting Technology Comment on the 7th Chinese Lost Foam Casting Symposium

    Institute of Scientific and Technical Information of China (English)

    LIU Zi-li

    2006-01-01

    @@ The 7th Chinese Lost Foam Casting (LFC) Symposium & the 1st LFC Technology Exposition were held on May 21-23 at Nanjing University of Aeronautics and Astronautics (NUAA), and the conference theme . was "Recent development of lost foam casting technology".

  10. Effects of casting speed on microstructure and segregation of electromagnetically stirred Aluminum alloy in continuous casting process

    Institute of Scientific and Technical Information of China (English)

    LEE Dock-Young; KANG Suk-Won; CHO Duck-Ho; KIM Ki-Bae

    2006-01-01

    Recently, a semi-solid metal processing has been acknowledged as a cost-effective technique to be able to manufacture high quality product for the transportation industry.In this study a hypo-eutectic Al alloy was fabricated by means of an electromagnetic stirrer in continuous casting process and the microstructural change during solidification due to a fluid flow by electromagnetic stirring was examined.Due to the forced fluid flow during solidification a dendritic phase of primary α phase of Al alloy was turned into a globular phase, which can make the Al alloy get a thixotropic behavior in the semi-solid region.In order to establish the quantitative relationship between microstructure and the process parameters, the morphology shape, a silicon distribution and a size of primary α phase were observed according to casting speed in continuous casting machine.The primary α phase was turned into the degenerate dendrites approaching a spherical configuration with increasing casting speed.The fine-grained and equiaxed microstructure appeared at higher casting speed.A segregation behavior of Si element was declined with increasing casting speed and a very uniform distribution of Si element was observed on the billet at a casting speed of 600 mm·min-1.A thickness of the solidifying shell of the billet was shortened with increasing the casting speed.

  11. Using dummies for surgical skills training

    DEFF Research Database (Denmark)

    Langebæk, Rikke

    2011-01-01

    teaching methods for veterinary surgical training. At the Department of Small Animal Clinical Sciences, Faculty of Life Sciences, a number of low fidelity, stuffed toy animal dummies was developed for the Surgical Skills Lab in order to teach 4th year students the basic surgical skills. In the Surgical......Effective acquisition of a skill requires practise. Therefore it is of great importance to provide veterinary students with opportunities to practice their surgical skills before carrying out surgical procedures on live patients. Some veterinary schools let students perform entire surgical...... procedures on research animals, in order to learn the basic skills along the way. From an ethical point of view it is questionable however to use live research animals for the sole purpose of practising surgery, and also, research animals are very costly. It is therefore necessary to identify alternative...

  12. Casting defects of Ti-6Al-4V alloy in vertical centrifugal casting processes with graphite molds

    Science.gov (United States)

    Jia, Limin; Xu, Daming; Li, Min; Guo, Jingjie; Fu, Hengzhi

    2012-02-01

    Numerical simulation and experimental investigation are utilized to analyze the casting defects of Ti-6Al-4V alloy formed under different vertical centrifugal casting conditions in graphite molds. Mold rotating rates of 0, 110 and 210 rpm are considered in experimental process. Results show that centrifugal forces have significant effects on the quantity of both macropores and microdefects (micropores, microcracks and inclusions). The relative amount of all macro- and micro-scopic casting defects decreases from 62.4 % to 24.8 % with the increasing of the centrifugal force, and the macropore quantity in stepped casting decreases exponentially with the increase of the gravitation coefficient. The relative proportions of both micropores and microcracks decrease with the mold-rotating rate increase, but the relative proportion of inclusions increases significantly. Besides this, the mold-filling sequence is proved to be an important factor in casting quality control.

  13. Microstructure and Property of Hypereutectic High Chromium Cast Iron Prepared by Slope Cooling Body-Centrifugal Casting Method

    Institute of Scientific and Technical Information of China (English)

    Zhifu HUANG; Jiandong XING; Anfeng ZHANG

    2006-01-01

    In this paper, the ring-type ingot of hypereutectic high Cr cast iron was obtained by slope cooling bodycentrifugal casting method (SC-CCM), and its microstructure and impact toughness were investigated, respectively. The results indicated that, first, the primary carbides in the microstructure are prominently finer than those in the hypereutectic high Cr cast iron prepared by conventional casting method. Second, in the ring-type ingot, the primary carbides near radial outer field are finer than those near radial inner field; furthermore, there is dividing field in the microstructure. Finally, the impact toughness values of the specimens impacted on the radial outer face and on the radial inner face are improved respectively about 36% and 138%more than that of the hypereutectic high Cr one prepared by conventional casting method.

  14. Development of low-temperature high-strength integral steel castings for offshore construction by casting process engineering

    Directory of Open Access Journals (Sweden)

    Lim Sang-Sub

    2014-12-01

    Full Text Available In casting steels for offshore construction, manufacturing integral casted structures to prevent fatigue cracks in the stress raisers is superior to using welded structures. Here, mold design and casting analysis were conducted for integral casting steel. The laminar flow of molten metal was analyzed and distributions of hot spots and porosities were studied. A prototype was subsequently produced, and air vents were designed to improve the surface defects caused by the release of gas. A radiographic test revealed no internal defects inside the casted steel. Evaluating the chemical and mechanical properties of specimens sampled from the product revealed that target values were quantitatively satisfied. To assess weldability in consideration of repair welding, the product was machined with grooves and welded, after which the mechanical properties of hardness as well as tensile, impact, and bending strengths were evaluated. No substantive differences were found in the mechanical properties before and after welding.

  15. Development of low-temperature high-strength integral steel castings for offshore construction by casting process engineering

    Science.gov (United States)

    Lim, Sang-Sub; Mun, Jae-Chul; Kim, Tae-Won; Kang, Chung-Gil

    2014-12-01

    In casting steels for offshore construction, manufacturing integral casted structures to prevent fatigue cracks in the stress raisers is superior to using welded structures. Here, mold design and casting analysis were conducted for integral casting steel. The laminar flow of molten metal was analyzed and distributions of hot spots and porosities were studied. A prototype was subsequently produced, and air vents were designed to improve the surface defects caused by the release of gas. A radiographic test revealed no internal defects inside the casted steel. Evaluating the chemical and mechanical properties of specimens sampled from the product revealed that target values were quantitatively satisfied. To assess weldability in consideration of repair welding, the product was machined with grooves and welded, after which the mechanical properties of hardness as well as tensile, impact, and bending strengths were evaluated. No substantive differences were found in the mechanical properties before and after welding.

  16. 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;

    2014-01-01

    A novel method of co-casting called side-by-side tape casting was developed aiming to form thin functionally graded films with varying properties within a single plane. The standard organic-based recipe was optimized to co-cast slurries into thick graded tapes. Performed numerical simulations...... identified the stable flow beneath the blade with a shear rate profile independent of slurry viscosity as long as the slurry load in the casting tank was low. Thickness and interface shape could be well predicted if the rheological behaviour of slurries is known and the processing parameters are well......-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 withstand...

  17. 电机机座铸件的消失模铸造%Lost Foam Casting for Motor Block Castings

    Institute of Scientific and Technical Information of China (English)

    吴志超; 叶升平; 胡国良; 常湫生

    2001-01-01

    针对出口电机机座铸件,简要介绍了其消失模模具设计、成型发泡及铸件的浇注试验情况,确定了合适的铸造工艺参数,生产出了合格的铸件,证实了消失模铸造工艺生产电机机座铸件的可行性。%The design of lost foam die, pattern molding process, and pouring experiment of exported motor block casting were studied. The pertient casting technological parameters were determined. Qualified casting was made successfully, which testified the feasibility using lost foam casting to manufacture motor block casting.

  18. Low speed centrifugal casting of Functionally Graded solid cast ingot by anomalous particle distribution

    Science.gov (United States)

    Mer, K. K. S.; Ray, S.

    2011-12-01

    Functionally graded cylindrical ingot of Al-Al2O3 composite synthesized by centrifugal casting shows particle distribution and hardness decreasing radially from the outer radius to inner radius. The progressive decrease in alumina content and hardness from the outer radius towards the center may be attributed to higher centrifugal force acting on relatively denser alumina particles during rotation, as compared to that acting on lighter alloy melt. It is also observed, as one moves down from the top to the bottom of cast ingot the alumina content decreases. This is surprising in view of higher density of alumina particles relative to the melt. The particle settling should have resulted at more particles towards the bottom, but distribution observed is in contradiction.

  19. Micro precision casting based on investment casting for micro structures with high aspect ratio

    Institute of Scientific and Technical Information of China (English)

    YANG Chuang; LI Bang-sheng; REN Ming-xing; FU Heng-zhi

    2009-01-01

    Microcasting is one of the significant technologies for the production of metallic micro parts with high aspect ratio (ratio of flow length to diameter). A micro precision casting technology based on investment casting using centrifugal method was investigated. The micro parts of Zn-4%Al alloy with an aspect ratio up to 200 was produced at the centrifugal speed of 1 500 r/min and the mold temperature of 270 ℃. The investigations on the relationship between flow length and rotational speed were carried out. For microcasting, the flow length is not only dependent on the centrifugal speed under the constant centrifugal radius, but also on the preheating temperature of mold. The flow length increases as the rotational speed and the mold temperature increase, and is much higher at a mold temperature of 270 ℃ than at other mold temperatures.

  20. Disc degeneration: current surgical options

    Directory of Open Access Journals (Sweden)

    C Schizas

    2010-10-01

    Full Text Available Chronic low back pain attributed to lumbar disc degeneration poses a serious challenge to physicians. Surgery may be indicated in selected cases following failure of appropriate conservative treatment. For decades, the only surgical option has been spinal fusion, but its results have been inconsistent. Some prospective trials show superiority over usual conservative measures while others fail to demonstrate its advantages. In an effort to improve results of fusion and to decrease the incidence of adjacent segment degeneration, total disc replacement techniques have been introduced and studied extensively. Short-term results have shown superiority over some fusion techniques. Mid-term results however tend to show that this approach yields results equivalent to those of spinal fusion. Nucleus replacement has gained some popularity initially, but evidence on its efficacy is scarce. Dynamic stabilisation, a technique involving less rigid implants than in spinal fusion and performed without the need for bone grafting, represents another surgical option. Evidence again is lacking on its superiority over other surgical strategies and conservative measures. Insertion of interspinous devices posteriorly, aiming at redistributing loads and relieving pain, has been used as an adjunct to disc removal surgery for disc herniation. To date however, there is no clear evidence on their efficacy. Minimally invasive intradiscal thermocoagulation techniques have also been tried, but evidence of their effectiveness is questioned. Surgery using novel biological solutions may be the future of discogenic pain treatment. Collaboration between clinicians and basic scientists in this multidisciplinary field will undoubtedly shape the future of treating symptomatic disc degeneration.