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Sample records for cast gold fixed

  1. Conservative and esthetic cast gold fixed partial dentures-inlay, onlay, and partial veneer retainers, custom composite pontics, and stress-breakers: part I: fundamental design principles.

    Science.gov (United States)

    Stevenson, Richard G; Refela, Jane A

    2009-01-01

    Although in today's dental world implant restorations are considered the standard of care in the replacement of missing teeth, clinical contraindications and patient nonacceptance of implant placement can be encountered. Several scenarios are discussed here in which a single missing tooth can be restored with conservative fixed partial dentures (FPD) that employ cast gold retainers; each with a customized design in order to preserve tooth structure, maintain esthetics, and provide a long-term prognosis. The abutment teeth are prepared for conservative partial coverage restorations by using Brasseler burs (Brasseler USA, Savannah, GA, USA). Impressions are taken of the preparations, along with any retentive features, utilizing either the Vented Pin Channel technique or the Shooshan Plastic Pin technique. The latter technique utilizes Kodex twist drills and corresponding impression pins (Coltene Whaledent Inc., Mahwah, NJ, USA). The conservative FPD with non-rigid connectors is fabricated by using type III gold alloy. The pontic cage portion is chemically prepared utilizing the Panavia F2.0 cement kit (Kuraray America Inc., Houston, TX, USA) or other dual-polymerizing resin cement and restored with any type of direct composite resin material. A palette of opaquers and tints are used for chairside characterization of the esthetic pontic facing. The final polish of the pontic is completed by using FlexiDisc and FlexiBuff discs (Cosmedent Inc., Chicago, IL, USA). CLINICAL SIGNIFICANCE In cases where an implant restoration is contraindicated for replacement of a single tooth, a semi-precision FPD is a conservative, functional, and esthetic alternative.

  2. Galvanic gold plating for fixed dental prosthesis.

    Science.gov (United States)

    Ozcelik, Tuncer Burak; Yilmaz, Burak

    2013-07-01

    Metal ceramic partial fixed dental prostheses have been commonly used for the replacement of missing teeth for many years. Because of an increase in the price of gold, base metal alloys have been the choice of alloy for the fabrication of metal ceramic restorations in many dental clinics. Some major disadvantages of base metals are their corrosion and the dark coloration they may cause at the crown margins. This article describes a galvanic gold-plating technique, which is used to minimize corrosion and improve the esthetics of metal ceramic restorations fabricated with Cr-Co base metal alloys. This technique involves the deposition of a 6 μm to 8 μm 24 K gold layer directly onto the Cr-Co cast prosthesis framework. The technique improves metal surface properties, making them more biocompatible and usable, however, requires additional equipment and experienced laboratory technicians. Clinical studies should be performed to corroborate the long term success of this technique.

  3. GOLD and the fixed ratio

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    Vestbo J

    2012-09-01

    Full Text Available Jørgen VestboUniversity of Manchester, Manchester, UKI read with interest the paper entitled "Diagnosis of airway obstruction in the elderly: contribution of the SARA study" by Sorino et al in a recent issue of this journal.1 Being involved in the Global Initiative for Obstructive Lung Diseases (GOLD, it is nice to see the interest sparked by the GOLD strategy document. However, in the paper by Sorino et al, there are a few misunderstandings around GOLD and the fixed ratio (forced expiratory volume in 1 second/forced volume vital capacity < 0.70 that need clarification.View original paper by Sorino and colleagues.

  4. Conservative and esthetic cast gold fixed partial dentures-inlay, onlay, and partial veneer retainers, custom composite pontics, and stress breakers: part II: utilization of additional retentive features and fabrication of custom pontic facings.

    Science.gov (United States)

    Stevenson, Richard G; Refela, Jane A

    2009-01-01

    Although in today's dental world implant restorations are considered the standard of care in the replacement of missing teeth, clinical contraindications and patient nonacceptance of implant placement can be encountered. Several scenarios are discussed here in which a single missing tooth can be restored with conservative fixed partial dentures (FPD) that employ cast gold retainers; each with a customized design in order to preserve tooth structure, maintain esthetics, and provide a long-term prognosis. The abutment teeth are prepared for conservative partial coverage restorations by using Brasseler burs (Brasseler USA, Savannah, GA, USA). Impressions are taken of the preparations, along with any retentive features, utilizing either the Vented Pin Channel technique or the Shooshan Plastic Pin technique. The latter technique utilizes Kodex twist drills and corresponding impression pins (Coltene Whaledent Inc., Mahwah, NJ, USA). The conservative FPD with non-rigid connectors is fabricated by using type III gold alloy. The pontic cage portion is chemically prepared utilizing the Panavia F2.0 cement kit (Kuraray America Inc., Houston, TX, USA) or other dual-polymerizing resin cement and restored with any type of direct composite resin material. A palette of opaquers and tints are used for chairside characterization of the esthetic pontic facing. The final polish of the pontic is completed by using FlexiDisc and FlexiBuff discs (Cosmedent Inc., Chicago, IL, USA). CLINICAL SIGNIFICANCE In cases where an implant restoration is contraindicated for replacement of a single tooth, a semi-precision FPD is a conservative, functional, and esthetic alternative.

  5. Effects of cast gold surface finishing on plaque retention.

    Science.gov (United States)

    Keenan, M P; Shillingburg, H T; Duncanson, M G; Wade, C K

    1980-02-01

    The relationship between the surface finish on cast gold restorations and the amount of plaque deposited on that surface was examined. Six different finishes were tested. The rough finish was found to accumulate significantly less plaque than the other finishes. Every finish exhibited some plaque accumulation, even after the first 24 hours. Each finish accumulated progressively more plaque at each successive time interval.

  6. Physical, nutrients, biological, meteorological, and other data from bottle casts, CTD casts, and divers, from FIXED PLATFORMS from 06 February 1989 to 12 March 1998 (NODC Accession 9800185)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Physical, chemical, biological, meteorological, and other data were collected from bottle casts, CTD casts, and divers from FIXED PLATFORMS. Data were collected by...

  7. 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.

  8. A comparison of the traditional casting method and the galvanoforming technique in gold alloy prosthetic restorations

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    Sarna-Boś Katarzyna

    2015-09-01

    Full Text Available Gold is a dental material with very good mechanical properties. It is also aesthetic and biocompatible with the tissues of the oral cavity even at 100% purity. Prosthetic restorations made of pure gold or its alloys can be practiced either through a normal casting, as well as through using the galvanoforming technique. The electrolytic method was first introduced into dentistry about 20 years ago and it allows for producing “pure” gold (which means 99.99% Au. The lack of additions of other metals improves the properties of dental prostheses, such as marginal tightness, esthetics, biocompatibility, and it helps in eliminating any allergic reactions. The literature review presented in this paper is a comparison of the traditional casting method with the newer galvanoforming technique.

  9. Fabrication of a maxillary posterior fixed partial denture with a type 4 gold alloy and a dual-polymerizing indirect composite.

    Science.gov (United States)

    Matsumura, Hideo; Mori, Shuichi; Tanoue, Naomi

    2008-03-01

    The aim of the present study was to design and fabricate a maxillary posterior fixed partial denture (FPD) made of a type 4 gold alloy and an indirect composite. Unlike the conventional framework design of a resin veneered restoration, cut-back was extended approximately 1/4 to 1/3 width in the occlusal table of the buccal cusp. Multiple retentive beads 150-200 mum in diameter were placed on the metal surface to be veneered. The gold alloy was cast in a cristobalite mold using a centrifugal casting machine. The cut surface with the retentive beads was air-abraded with alumina, and a priming agent (Alloy Primer) that contained triazine dithione monomer (VTD) was applied. A tooth-colored veneer was then fabricated with a highly loaded light- and heat-cured composite material (Estenia). This design and procedure can be applied as a standardized laboratory technique for fabrication of maxillary posterior restorations and FPDs.

  10. Evaluation of the inclination of maxillary occlusal plane on mounted casts using a fixed value and customized nasion indicator in artex articulator: Facebow system - An in-vivo comparative study.

    Science.gov (United States)

    Ramasamy, Manikandan; Karthigeyan, Suma; Giri, T C; Rajendran, Venkateshwaran; Shetty, Adarsh; Deivanai, Mangala

    2013-06-01

    To evaluate and compare the variations in the inclination of occlusal plane of casts mounted on Artex articulator using a facebow with a fixed value and customized nasion indicator. Twenty two subjects were selected for this investigation. Two maxillary impressions were made, and casts poured. For each of the twenty two subjects, the facebow records were made with, Artex face-bow using a fixed value nasion indicator and customized nasion indicator and mounted. The angle between the occlusal plane of upper cast and the upper articulator arm was measured with a Universal bevel protractor and compared with the gold standard cephalometric value. It shows that, when angle was measured between maxillary occlusal plane and upper member of the articulator, on the mounted cast using a customized nasion indicator and fixed value nasion indicator against the gold standard cephalometric value as a whole, it was found to be not significant. But, if each patient were evaluated individually, there found to be the difference in the angle. Variation in occlusal plane was very minimal and close to the cephalometric value when using customized nasion indicator compared to fixed value nasion indicator on the Artex.

  11. Evaluation of the inclination of maxillary occlusal plane on mounted casts using a fixed value and customized nasion indicator in artex articulator: Facebow system - An in-vivo comparative study

    Directory of Open Access Journals (Sweden)

    Manikandan Ramasamy

    2013-01-01

    Full Text Available Aim: To evaluate and compare the variations in the inclination of occlusal plane of casts mounted on Artex articulator using a facebow with a fixed value and customized nasion indicator. Materials and Methods: Twenty two subjects were selected for this investigation. Two maxillary impressions were made, and casts poured. For each of the twenty two subjects, the facebow records were made with, Artex face-bow using a fixed value nasion indicator and customized nasion indicator and mounted. The angle between the occlusal plane of upper cast and the upper articulator arm was measured with a Universal bevel protractor and compared with the gold standard cephalometric value. Results: It shows that, when angle was measured between maxillary occlusal plane and upper member of the articulator, on the mounted cast using a customized nasion indicator and fixed value nasion indicator against the gold standard cephalometric value as a whole, it was found to be not significant. But, if each patient were evaluated individually, there found to be the difference in the angle. Discussion and Conclusion: Variation in occlusal plane was very minimal and close to the cephalometric value when using customized nasion indicator compared to fixed value nasion indicator on the Artex.

  12. Dimensional accuracy of small gold alloy castings. Part 1. A brief history and the behaviour of inlay waxes.

    Science.gov (United States)

    Morey, E F

    1991-08-01

    Part 1 reviews published studies which relate to materials and techniques contributing to the dimensional accuracy of small dental castings. A brief history of the cire perdue or lost-wax method of casting alloys and the development of modern dental casting materials and techniques are presented. Data on the behaviour of inlay wax, in particular its contraction and distortion, are reviewed as is the extensive literature about the casting shrinkage of gold alloys (Part 2) and the setting and thermal expansion of investments under both laboratory and practical conditions (Part 3). Part 4 discusses the role of the casting ring and its asbestos liner. 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. Comparison of the fit of cast gold crowns fabricated from the digital and the conventional impression techniques

    Science.gov (United States)

    Jeon, Young-Chan; Jeong, Chang-Mo

    2017-01-01

    PURPOSE The purpose of this study was to compare the fit of cast gold crowns fabricated from the conventional and the digital impression technique. MATERIALS AND METHODS Artificial tooth in a master model and abutment teeth in ten patients were restored with cast gold crowns fabricated from the digital and the conventional impression technique. The forty silicone replicas were cut in three sections; each section was evaluated in nine points. The measurement was carried out by using a measuring microscope and I-Soultion. Data from the silicone replica were analyzed and all tests were performed with α-level of 0.05. RESULTS 1. The average gaps of cast gold crowns fabricated from the digital impression technique were larger than those of the conventional impression technique significantly. 2. In marginal and internal axial gap of cast gold crowns, no statistical differences were found between the two impression techniques. 3. The internal occlusal gaps of cast gold crowns fabricated from the digital impression technique were larger than those of the conventional impression technique significantly. CONCLUSION Both prostheses presented clinically acceptable results with comparing the fit. The prostheses fabricated from the digital impression technique showed more gaps, in respect of occlusal surface. PMID:28243386

  14. Comparative Evaluation of Marginal Accuracy of a Cast Fixed Partial Denture Compared to Soldered Fixed Partial Denture Made of Two Different Base Metal Alloys and Casting Techniques: An In vitro Study.

    Science.gov (United States)

    Jei, J Brintha; Mohan, Jayashree

    2014-03-01

    The periodontal health of abutment teeth and the durability of fixed partial denture depends on the marginal adaptation of the prosthesis. Any discrepancy in the marginal area leads to dissolution of luting agent and plaque accumulation. This study was done with the aim of evaluating the accuracy of marginal fit of four unit crown and bridge made up of Ni-Cr and Cr-Co alloys under induction and centrifugal casting. They were compared to cast fixed partial denture (FPD) and soldered FPD. For the purpose of this study a metal model was fabricated. A total of 40 samples (4-unit crown and bridge) were prepared in which 20 Cr-Co samples and 20 Ni-Cr samples were fabricated. Within these 20 samples of each group 10 samples were prepared by induction casting technique and other 10 samples with centrifugal casting technique. The cast FPD samples obtained were seated on the model and the samples were then measured with travelling microscope having precision of 0.001 cm. Sectioning of samples was done between the two pontics and measurements were made, then the soldering was made with torch soldering unit. The marginal discrepancy of soldered samples was measured and all findings were statistically analysed. The results revealed minimal marginal discrepancy with Cr-Co samples when compared to Ni-Cr samples done under induction casting technique. When compared to cast FPD samples, the soldered group showed reduced marginal discrepancy.

  15. Accidental swallowing of a gold cast crown during orthodontic tooth separation.

    Science.gov (United States)

    Kharbanda, O P; Varshney, P; Dutta, U

    1995-01-01

    Accidental swallowing of a gold cast crown that became loose after separation with brass wire for orthodontic band placement, is reported. The intervention to remove the ingested crown subsequent to its location in the GI tract on immediate radiographic examination of chest and abdomen included endoscopic examination. Since the crown had past distal to the duodenum it was decided to keep a watch on its movement by daily radiographic examination. The crown passed with excreta on the 5th day uneventfully. Literature on ingestion of foreign bodies of dental origin is reviewed. Possible emergencies and their management is discussed.

  16. A technique to replicate soft tissues around fixed restoration pontics on working casts.

    Science.gov (United States)

    Chee, W W; Cho, G C; Ikoma, M M; Arcidiacono, A

    1999-03-01

    When missing maxillary incisors are replaced, the patient's primary concern is usually esthetics. Depending on the patient's smile line and the display of the incisors, the esthetic zone may extend to the entire clinical crown and include the surrounding soft tissue. For these patients, the appearance and form of the soft tissue at the base of the pontics is as critical as the esthetics of the incisal edges of the restoration. A technique is presented to precisely transfer the soft tissue morphology of the pontic area to the working cast. This modified master cast allows the laboratory technician to fabricate restorations that will harmonize precisely with the soft tissues of the patient.

  17. Pattern waxes and inaccuracies in fixed and removable partial denture castings.

    Science.gov (United States)

    Diwan, R; Talic, Y; Omar, N; Sadig, W

    1997-05-01

    It is the desire of every dentist and dental technician to produce a restoration that will fit the patient with a minimum of adjustments and certainly one that does not require remaking. Yet many abuse the materials with which they work, either through improper manipulation, lack of familiarity with their properties, or by attempting to reduce laboratory time by taking short cuts. Wax is one of the materials that requires more knowledge and skill to manipulate accurately because it has a considerably higher coefficient of thermal expansion (and contraction) than any other dental material. It often contributes considerably to the inaccuracies of cast dental restorations. This article provides a review of dental waxes used to make prosthodontic castings and points out some of the properties of waxes that must be controlled to make accurate restorations.

  18. Technique to verify the accuracy of a definitive cast before the fabrication of a fixed dental prosthesis.

    Science.gov (United States)

    Farah, Ra'fat I; Alshabi, Abdullah M

    2016-09-01

    This report describes a straightforward technique for verifying the accuracy of a definitive cast by using a maximal intercuspation record fabricated from polyvinyl siloxane occlusal registration material. This precise verification method detects inaccurate casts before the dental prosthesis is fabricated, thus saving chairside and laboratory time while reducing the number of costly prosthesis remakes.

  19. Oceanographic Station Data from bottle casts from fixed stations as part of the International Decade of Ocean Exploration / Controlled Ecosystem Pollution Experiment (IDOE/CEPEX) from 13 September 1973 to 09 October 1973 (NODC Accession 7400382)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Oceanographic Station Data were collected from bottle casts from fixed stations from 13 September 1973 to 09 October 1973. Data were collected by the Skidway...

  20. 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.

  1. The ancient Chinese casting techniques

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    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.

  2. Structural studies on drop-cast film based on functionalized gold nanoparticles network: The effect of thermal treatment

    Energy Technology Data Exchange (ETDEWEB)

    Fontana, Laura [Department of Chemistry, Sapienza University of Rome, P. le A. Moro 5, 00185 Rome (Italy); Fratoddi, Ilaria, E-mail: ilaria.fratoddi@uniroma1.it [Department of Chemistry, Sapienza University of Rome, P. le A. Moro 5, 00185 Rome (Italy); Venditti, Iole [Department of Chemistry, Sapienza University of Rome, P. le A. Moro 5, 00185 Rome (Italy); Ksenzov, Dmitriy [Department of Physics, University of Siegen, Walter-Flex-Straße 3, D-57072 Siegen (Germany); Russo, Maria Vittoria [Department of Chemistry, Sapienza University of Rome, P. le A. Moro 5, 00185 Rome (Italy); Grigorian, Souren [Department of Physics, University of Siegen, Walter-Flex-Straße 3, D-57072 Siegen (Germany)

    2016-04-30

    Graphical abstract: - Highlights: • Gold nanoparticles functionalized by π-conjugated dithiol. • In situ annealing of a gold nanoparticles network. • Structural reorganization of a gold nanoparticles network before and after thermal treatment. - Abstract: In the present work the role of the thermal treatment on the reorganization of gold nanoparticles (AuNPs) functionalized with a π-conjugated dithiol ligand, namely 9,9-didodecyl-2,7-bis-thiofluorene, is studied by grazing incidence X-ray diffraction technique. For a detailed investigation of the structural changes and reorganization occurring in the AuNPs network and of the monitoring of complex interactions between nanoparticles, the line profiles are analyzed in out-of-plane and in-plane directions. The obtained data support the idea of the formation of a uniform network of nanoparticles that after annealing are extended from hexagonal to cubic arrangement.

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

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    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.

  4. 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.

  5. Contents of Fixed-Ammonium (NH4+) in Lamprophyres in the Zhenyuan Gold Orefield, Yunnan Province, China:Implications for Its Characteristics of the Source Region

    Institute of Scientific and Technical Information of China (English)

    吴静; 黄智龙; 罗泰义

    2004-01-01

    This paper determined the fixed-ammonium (NH+4) contents of lamprophyres in the Zhenyuan gold orefield, Yunnan Province, China. The results show that the NH+4 contents of minettes in the orefield range from 120×10 -6 to 469×10 -6 and those of kersantites from 74.3 ×10 -6 to 136×10 -6 . These values are higher than those of other mantle-derived rocks (less than 50×10 -6 ), but lower than those of carbonaceous wall rocks in the orefield (from 1200×10 -6 to 1343×10 -6 ). Combining with the Sr isotopic composition, this paper suggested that lamprophyres in the orefield with high NH+4 contents relative to other mantle-derived rocks would not have resulted from the primary magma contaminated by crustal materials in the process of rising or in the magma chamber, but from mantle metasomatism.

  6. A comparison of the abrasiveness of six ceramic surfaces and gold.

    Science.gov (United States)

    Jacobi, R; Shillingburg, H T; Duncanson, M G

    1991-09-01

    A type III gold alloy and six different ceramic surfaces were secured in an abrasion machine opposing extracted teeth to determine their relative abrasiveness and resistance to wear. The rankings of restorative materials from least abrasive to most abrasive were: gold alloy, polished; cast ceramic, polished; porcelain, polished; cast ceramic, polished and shaded; porcelain, polished and glazed; cast ceramic, cerammed skin shaded; and cast ceramic, cerammed skin unshaded. The ranking of materials from most wear-resistant to least wear-resistant was: gold alloy, cast ceramic cerammed, cast ceramic cerammed and shaded, porcelain polished, porcelain glazed, cast ceramic polished and shaded, and cast ceramic polished.

  7. 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. ...

  8. Similar Marginal Precision of Zirconia- and Metal-Ceramic Fixed Dental Prostheses

    DEFF Research Database (Denmark)

    Nicolaisen, Maj Høygaard; Bahrami, Golnosh; Schropp, Lars

    Similar Marginal Precision of Zirconia- and Metal-Ceramic Posterior Fixed Dental Prostheses Objective: An increased gap between restoration and prepared tooth causes more luting material to be exposed to the oral environment resulting in increased deterioration, leading to bacterial accumulation...... which can cause marginal periodontitis and secondary caries. The purpose of this randomized clinical study was to compare the marginal precision of CAD/CAM Zirconia-ceramic (ZC) and cast gold alloy metal-ceramic (MC) posterior fixed dental prostheses. Methods: As part of an ongoing randomized controlled...... clinical trial, 34 patients were randomized into two groups to receive a 3-unit fixed dental prosthesis (FDP) replacing a second premolar or a first molar. 17 ZC FDPs (BeCe CAD Zirkon, BEGO with Vita VM9, VITA ) and 17 MC FDPs (Bio PontoStar, BEGO with Vita VM13, VITA). All FDPs were made in accordance...

  9. Similar Marginal Precision of Zirconia- and Metal-Ceramic Fixed Dental Prostheses

    DEFF Research Database (Denmark)

    Nicolaisen, Maj Høygaard; Bahrami, Golnosh; Schropp, Lars

    clinical trial, 34 patients were randomized into two groups to receive a 3-unit fixed dental prosthesis (FDP) replacing a second premolar or a first molar. 17 ZC FDPs (BeCe CAD Zirkon, BEGO with Vita VM9, VITA ) and 17 MC FDPs (Bio PontoStar, BEGO with Vita VM13, VITA). All FDPs were made in accordance......Similar Marginal Precision of Zirconia- and Metal-Ceramic Posterior Fixed Dental Prostheses Objective: An increased gap between restoration and prepared tooth causes more luting material to be exposed to the oral environment resulting in increased deterioration, leading to bacterial accumulation...... which can cause marginal periodontitis and secondary caries. The purpose of this randomized clinical study was to compare the marginal precision of CAD/CAM Zirconia-ceramic (ZC) and cast gold alloy metal-ceramic (MC) posterior fixed dental prostheses. Methods: As part of an ongoing randomized controlled...

  10. Hair casts

    Directory of Open Access Journals (Sweden)

    Sweta S Parmar

    2014-01-01

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

  11. 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

  12. Gold Rush!

    Science.gov (United States)

    Brahier, Daniel J.

    1997-01-01

    Describes a mathematical investigation of gold--how it is weighed, stored, used, and valued. For grades 3-4, children estimate the value of treasure chests filled with gold coins and explore the size and weight of gold bars. Children in grades 5-6 explore how gold is mined and used, and how the value of gold changes over time. (PVD)

  13. Cephalometric analysis of casting fixed Twin-block appliance in the treatment of Class ⅡDivision 1 malocclu-sion%铸造成型固定式双垫矫治青春期安氏Ⅱ类1分类错的疗效分析

    Institute of Scientific and Technical Information of China (English)

    易娟; 李慧; 叶翁三杰

    2016-01-01

    Objective To evaluate the casting fixed Twin⁃block appliance on the clinical effects of growing chil⁃dren with skeletal Angle ClassⅡdivision 1 malocclusion. Methods 30 patients with skeletal Angle ClassⅡdivision 1 malocclusion were treated by fixed casting Twin⁃block. Cephalometric data before and after the treatment were mea⁃sured and analyzed. Results Difference of SNA and U6⁃PTM between pretreatment and post⁃treatment was not statisti⁃cally significant (P > 0.05), there was statistically significance of diminution in ANB, OJ or Wits appraisal which de⁃creased after treatment and augment in SNB, Go⁃Gn, Co⁃Gn, L1⁃MP, Sn⁃A⁃UL、Li⁃Si⁃Pg��which changed after treat⁃ment of fixed casting Twin⁃block (P0.05);ANB、OJ、Wits值、Co⁃S等指标治疗后较治疗前减小,差异有统计学意义(P<0.05);SNB、L1⁃MP、Go⁃Gn、Co⁃Go、Co⁃Gn、Sn⁃A⁃UL、Li⁃Si⁃Pg’等指标治疗后较治疗前增加,差异有统计学意义(P<0.05)。结论对于青春期安氏Ⅱ类1分类错患者,应用铸造固定式双垫功能矫治器矫治,具有较好的临床效果。

  14. Gold nephropathy in juvenile rheumatoid arthritis.

    Science.gov (United States)

    Husserl, F E; Shuler, S E

    1979-01-01

    A 2-year-old girl was treated with gold salts for juvenile rheumatoid arthritis. Treatment had to be discontinued when persistent proteinuria was detected. As this case report indicates, close monitoring of the urine is mandatory during treatment with gold salts to detect early signs of toxicity: hematuria followed by casts and then proteinuria as therapy is continued. Histologic examination with electron microscopy will help to differentiate the different forms of gold toxicity. When the findings are consistent with gold-induced renal involvement, therapy should be discontinued. The gold nephropathy usually resolves in time, with no permanent renal damage.

  15. 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.

  16. 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.

  17. The Role of Indian Caste Identity and Caste Inconsistent Norms on Status Representation.

    Science.gov (United States)

    Sankaran, Sindhuja; Sekerdej, Maciek; von Hecker, Ulrich

    2017-01-01

    The Indian caste system is a complex social structure wherein social roles like one's profession became 'hereditary,' resulting in restricted social mobility and fixed status hierarchies. Furthermore, we argue that the inherent property of caste heightens group identification with one's caste. Highly identified group members would protect the identity of the group in situations when group norms are violated. In this paper, we were interested in examining the consequence of caste norm violation and how an individual's status is mentally represented. High caste norms are associated with moral values while the lower caste norms are associated with immorality. We predicted a 'black sheep effect,' that is, when high caste individuals' group identity (caste norm violation condition) is threatened their salient high caste identity would increase, thereby resulting in devaluing the status of their fellow in-group member if the latter is perceived as perpetrator. We presented participants with a social conflict situation of a victim and a perpetrator that is 'Caste norm consistent' (Lower caste individual as a perpetrator and higher caste individual as a victim) and vice versa 'Caste norm inconsistent' condition (higher caste individual as perpetrator and lower caste individual as a victim). Then, participants had to choose from nine pictorial depictions representing the protagonists in the story on a vertical line, with varying degrees of status distance. Results showed evidence for the black sheep effect and, furthermore, revealed that no other identity (religious, national, and regional) resulted in devaluing the status of fellow in-group member. These results help us understand the 'black sheep' effect in the context of moral norms and status representation and are discussed in the framework of the Indian society.

  18. 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.

  19. 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.

  20. 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.

  1. Silicon Sheet Growth Development for the Large Area Sheet Task of the Low Cost Solar Array Project. Heat Exchanger Method - Ingot Casting Fixed Abrasive Method - Multi-Wire Slicing

    Science.gov (United States)

    Schmid, F.; Khattak, C. P.

    1978-01-01

    Solar cells fabricated from HEM cast silicon yielded up to 15% conversion efficiencies. This was achieved in spite of using unpurified graphite parts in the HEM furnace and without optimization of material or cell processing parameters. Molybdenum retainers prevented SiC formation and reduced carbon content by 50%. The oxygen content of vacuum cast HEM silicon is lower than typical Czochralski grown silicon. Impregnation of 45 micrometers diamonds into 7.5 micrometers copper sheath showed distortion of the copper layer. However, 12.5 micrometers and 15 micrometers copper sheath can be impregnated with 45 micrometers diamonds to a high concentration. Electroless nickel plating of wires impregnated only in the cutting edge showed nickel concentration around the diamonds. This has the possibility of reducing kerf. The high speed slicer fabricated can achieve higher speed and longer stroke with vibration isolation.

  2. 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.

  3. 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 ...

  4. 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.

  5. 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...

  6. Silicon Ingot Casting - Heat Exchanger Method Multi-wire Slicing - Fixed Abrasive Slicing Technique. Phase 3 Silicon Sheet Growth Development for the Large Area Sheet Task of the Low-cost Solar Array Project

    Science.gov (United States)

    Schmid, F.; Khattak, C. P.

    1979-01-01

    Several 20 cm diameter silicon ingots, up to 6.3 kg. were cast with good crystallinity. The graphite heat zone can be purified by heating it to high temperatures in vacuum. This is important in reducing costs and purification of large parts. Electroplated wires with 45 um synthetic diamonds and 30 um natural diamonds showed good cutting efficiency and lifetime. During slicing of a 10 cm x 10 cm workpiece, jerky motion occurred in the feed and rocking mechanisms. This problem is corrected and modifications were made to reduce the weight of the bladeheat by 50%.

  7. 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...

  8. Fix 40!

    Index Scriptorium Estoniae

    2008-01-01

    Ansambel Fix peab 13. detsembril Tallinnas Saku Suurhallis oma 40. sünnipäeva. Kontserdi erikülaline on ansambel Apelsin, kaastegevad Jassi Zahharov ja HaleBopp Singers. Õhtut juhib Tarmo Leinatamm

  9. Fix 40!

    Index Scriptorium Estoniae

    2008-01-01

    Ansambel Fix peab 13. detsembril Tallinnas Saku Suurhallis oma 40. sünnipäeva. Kontserdi erikülaline on ansambel Apelsin, kaastegevad Jassi Zahharov ja HaleBopp Singers. Õhtut juhib Tarmo Leinatamm

  10. 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.

  11. [Biosynthesis of gold nanoparticles by Azospirillum brasilense].

    Science.gov (United States)

    Kupriashina, M A; Vetchinkina, E P; Burov, A M; Ponomareva, E G; Nikitina, V E

    2014-01-01

    Plant-associated nitrogen-fixing soil bacteria Azospirillum brasilense were shown to reduce the gold of chloroauric acid to elemental gold, resulting in formation of gold nanoparicles. Extracellular phenoloxidizing enzymes (laccases and Mn peroxidases) were shown to participate in reduction of Au+3 (HAuCl4) to Au(0). Transmission electron microscopy revealed accumulation of colloidal gold nanoparticles of diverse shape in the culture liquid of A. brasilense strains Sp245 and Sp7. The size of the electron-dense nanospheres was 5 to 50 nm, and the size of nanoprisms varied from 5 to 300 nm. The tentative mechanism responsible for formation of gold nanoparticles is discussed.

  12. [Covering dental defects with aluminum cast dowel construction and technology of their manufacture].

    Science.gov (United States)

    Khudonogov, G I

    1995-01-01

    Clinical and laboratory studies have revealed benefits of aluminum cast constructions. Its cast dowel inserts are used in the system of fixed metal-free dentures made from ceramics (dental bridges, single crowns, etc.). The high efficiency, availability of casting technology for aluminum reduces patients' treatment periods and ensures accurate attachment of dowel insets to the root canal and stump of a tooth.

  13. Silicon Ingot Casting - Heat Exchanger Method (HEM). Multi-Wire Slicing - Fixed Abrasive Slicing Technique (Fast). Phase 4 Silicon Sheet Growth Development for the Large Area Sheet Task of the Low-Cost Solar Array Project

    Science.gov (United States)

    Schmid, F.

    1981-01-01

    The crystallinity of large HEM silicon ingots as a function of heat flow conditions is investigated. A balanced heat flow at the bottom of the ingot restricts spurious nucleation to the edge of the melted-back seed in contact with the crucible. Homogeneous resistivity distribution over all the ingot has been achieved. The positioning of diamonds electroplated on wirepacks used to slice silicon crystals is considered. The electroplating of diamonds on only the cutting edge is described and the improved slicing performance of these wires evaluated. An economic analysis of value added costs of HEM ingot casting and band saw sectioning indicates the projected add on cost of HEM is well below the 1986 allocation.

  14. Casting technique and restraint choice influence child safety during transport of body casted children subjected to a simulated frontal MVA.

    Science.gov (United States)

    Zielinski, Julie; Oliver, Glen; Sybesma, Justin; Walter, Norman; Atkinson, Patrick

    2009-06-01

    Hip spica casts (or body casts) are commonly applied to young pediatric trauma and hip dysplasia patients. The greatest hip stability in the cast is achieved via fixed hip flexion or abduction and fixed knee flexion. Unfortunately, this fixed position causes difficulties in restraining children for transport because the child cannot typically accommodate their body to the child car seat geometry. The objectives of the current study were to identify a range of reasonable seating options for casted children. These positions were then studied in frontal crash tests to identify the relative injury exposure for the different positions. A revised casting technique was also investigated in an effort to address head-to-cast contact identified during the course of the study. The current study assessed the ability for different child seats and the vehicle seat belts to accommodate casted 1-year-old and 3-year-old crash test dummies. The restrained dummies were then subjected to frontal 30-mph crash tests with uncasted dummies serving as a control. In general, traditional child seats were able to accommodate both children; however, the child's body shifted anteriorly in the cast when the belts were tightened. This shift produced concerns for pulmonary function and the potential for elevated pressure on the superior mesenteric artery. This anterior shift of the chest was reduced when the dummies were restrained by a special hip spica child seat or solely by the vehicle seat belts. When considering all restraint types, the addition of the cast increased the majority of the injury metric magnitudes. For the 3-year-old dummy these increases were determined to be related to the casting technique; an alternative technique significantly reduced the injury metrics. This study demonstrates that there are anticipated variable effects on basic physiologic function for body-casted children based on the method of restraint. Restraint modalities which place the child forward facing with

  15. Pollution reality of gold mining waste on the Witwatersrand

    CSIR Research Space (South Africa)

    Hobbs

    2010-05-01

    Full Text Available system still remain. The pollution reality of gold mining waste is illustrated by a case study in the West Rand area, where decant from gold mines started in 2002. Potential receptors of the pollution in the cast study area include neighbouring property...

  16. 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.

  17. Fixing the Shadows While Moving the Gnomon

    Science.gov (United States)

    Gangui, Alejandro

    2015-01-01

    It is a common practice to fix a vertical gnomon and study the moving shadow cast by it. This shows our local solar time and gives us a hint regarding the season in which we perform the observation. The moving shadow can also tell us our latitude with high precision. In this paper we propose to exchange the roles and while keeping the shadows…

  18. Influence of thermal and mechanical cycling on the flexural strength of ceramics with titanium or gold alloy frameworks

    NARCIS (Netherlands)

    Oyafuso, Denise Kanashiro; Ozcan, Mutlu; Bottino, Marco Antonio; Itinoche, Marcos Koiti

    2008-01-01

    Objectives. The aim of this study was to evaluate the effect of thermal and mechanical cycling alone or in combination, on the flexural strength of ceramic and metallic frameworks cast in gold alloy or titanium. Methods. Metallic frameworks (25 mm x 3 mm x 0.5 mm) (N = 96) cast in gold alloy or comm

  19. Influence of thermal and mechanical cycling on the flexural strength of ceramics with titanium or gold alloy frameworks

    NARCIS (Netherlands)

    Oyafuso, Denise Kanashiro; Ozcan, Mutlu; Bottino, Marco Antonio; Itinoche, Marcos Koiti

    Objectives. The aim of this study was to evaluate the effect of thermal and mechanical cycling alone or in combination, on the flexural strength of ceramic and metallic frameworks cast in gold alloy or titanium. Methods. Metallic frameworks (25 mm x 3 mm x 0.5 mm) (N = 96) cast in gold alloy or

  20. 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.

  1. 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.

  2. 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.

  3. Improving Metal Casting Process

    Science.gov (United States)

    1998-01-01

    Don Sirois, an Auburn University research associate, and Bruce Strom, a mechanical engineering Co-Op Student, are evaluating the dimensional characteristics of an aluminum automobile engine casting. More accurate metal casting processes may reduce the weight of some cast metal products used in automobiles, such as engines. Research in low gravity has taken an important first step toward making metal products used in homes, automobiles, and aircraft less expensive, safer, and more durable. Auburn University and industry are partnering with NASA to develop one of the first accurate computer model predictions of molten metals and molding materials used in a manufacturing process called casting. Ford Motor Company's casting plant in Cleveland, Ohio is using NASA-sponsored computer modeling information to improve the casting process of automobile and light-truck engine blocks.

  4. Performance Steel Castings

    Science.gov (United States)

    2012-09-30

    alloys , foundry, muzzle brake, supply center, tooling, sources Notice Distribution Statement A Format Information Report created in Microsoft Word...Development of Sand Properties 103 Advanced Modeling Dataset.. 105 High Strength Low Alloy (HSLA) Steels 107 Steel Casting and Engineering Support...University, University of Northern Iowa, Non- Ferrous Founders’ Society, QuesTek, buyCASTINGS.com, Spokane Industries, Nova Precision Casting, Waukesha

  5. 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.

  6. 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.

  7. 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…

  8. 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...

  9. 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.

  10. 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.

  11. Hybrid framework with cobalt-chromium alloy and gold cylinder for implant superstructure: Bond strength and corrosion resistance.

    Science.gov (United States)

    Yoshinari, Masao; Uzawa, Shinobu; Komiyama, Yataro

    2016-10-01

    The aim of this in vitro study was to evaluate tensile bond strengths and corrosion resistance of CoCr alloys joined with gold cylinder by a soldering system in comparison with the conventional cast-joining system. CoCr alloys joined with gold cylinder by a soldering system using a high-fusing gold solder (CoCr/Solder/Gold cylinder), gold alloy joined with gold cylinder by a cast joining system (Gold alloy/Gold cylinder) and CoCr castings were fabricated. The tensile bond strength and corrosion resistance in 0.9% NaCl solution (pH 7.4 and pH 2.3) were evaluated. Scanning electron microscopy (SEM) of the fractured surface and electron probe microanalysis (EPMA) of the joined interfaces were also performed. The tensile bond strengths of the CoCr/Solder/Gold cylinder specimens showed similar values as the Gold alloy/Gold cylinder specimens. SEM observation and EPMA analyses suggested firm bonding between the CoCr alloy and gold cylinder. The released elements from the CoCr/Solder/Gold cylinder specimens were similar to ones from CoCr castings. Results showed that superstructures made of CoCr alloys joined with the gold cylinder using a high-fusing gold solder had sufficient bond strength and high corrosion resistance. These hybrid frameworks with cobalt-chromium alloy and gold cylinder are promising prosthesis for implant superstructures with the low cost and favorable mechanical properties instead of conventional high-gold alloys. Copyright © 2016 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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%.

  18. Direct metal laser sintering: a digitised metal casting technology.

    Science.gov (United States)

    Venkatesh, K Vijay; Nandini, V Vidyashree

    2013-12-01

    Dental technology is undergoing advancements at a fast pace and technology is being imported from various other fields. One such imported technology is direct metal laser sintering technology for casting metal crowns. This article will discuss the process of laser sintering for making metal crowns and fixed partial dentures with a understanding of their pros and cons.

  19. Direct Metal Laser Sintering: A Digitised Metal Casting Technology

    OpenAIRE

    Venkatesh, K. Vijay; Nandini, V Vidyashree

    2013-01-01

    Dental technology is undergoing advancements at a fast pace and technology is being imported from various other fields. One such imported technology is direct metal laser sintering technology for casting metal crowns. This article will discuss the process of laser sintering for making metal crowns and fixed partial dentures with a understanding of their pros and cons.

  20. Direct Metal Laser Sintering: A Digitised Metal Casting Technology

    OpenAIRE

    Venkatesh, K. Vijay; Nandini, V Vidyashree

    2013-01-01

    Dental technology is undergoing advancements at a fast pace and technology is being imported from various other fields. One such imported technology is direct metal laser sintering technology for casting metal crowns. This article will discuss the process of laser sintering for making metal crowns and fixed partial dentures with a understanding of their pros and cons.

  1. Adsorption of a linear polyelectrolyte on a gold electrode

    NARCIS (Netherlands)

    Barten, D.; Kleijn, J.M.; Cohen Stuart, M.A.

    2003-01-01

    The adsorption of quaternized poly-2-vinyl pyridine (PVP+), which has a fixed charge per monomer, onto a gold electrode was investigated using reflectometry. The double layer charge and potential of the gold substrate were controlled by means of either the solution pH or by applying an external

  2. Black gold

    CERN Document Server

    Fletcher, MW

    2016-01-01

    Following the Yom Kippur war of October 1973, OPEC raises the price of oil by 70% along with a 5% reduction in oil production. Len Saunders a highly skilled and knowledgeable British engineer for Jaguar motors, is approached by the UK energy commission in the January of 1974 to create a new propulsion system; using a secret document from a German WW2 scientist, that they have come into possession of. Len Saunders sets to work on creating the holy grail of energy. Seven years later 1981, Haidar Farooq the Kuwait oil minister working at OPEC and head of a secret organisation named Black Gold bec

  3. 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.

  4. Going for Gold

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    While the international gold price in February hit the highest point in 25 years at $541.20 per ounce for futures delivery, a new gold rush is sweeping across China. According to the World Gold Council, the London-based gold marketing organization funded by leading global gold mining firms, the purchase of gold products in China grew by 9 percent in the first nine

  5. Melt Cast High Explosives

    Directory of Open Access Journals (Sweden)

    Stanisław Cudziło

    2014-12-01

    Full Text Available [b]Abstract[/b]. This paper reviews the current state and future developments of melt-cast high explosives. First the compositions, properties and methods of preparation of trinitrotoluene based (TNT conventional mixtures with aluminum, hexogen (RDX or octogen (HMX are described. In the newer, less sensitive explosive formulations, TNT is replaced with dinitroanisole (DNANDNANDNAN and nitrotriazolone (NTONTONTO, nitroguanidine (NG or ammonium perchlorate (AP are the replacement for RDRDX and HMX. Plasticized wax or polymer-based binder systems for melt castable explosives are also included. Hydroxyl terminated polybutadiene (HPTB is the binder of choice, but polyethylene glycol, and polycaprolactone with energetic plasticizers are also used. The most advanced melt-cast explosives are compositions containing energetic thermoplastic elastomers and novel highly energetic compounds (including nitrogen rich molecules in whose particles are nanosized and practically defect-less.[b]Keywords[/b]: melt-cast explosives, detonation parameters

  6. 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.

  7. Electrochemical investigation of 18k gold in acidic electrolyte

    Directory of Open Access Journals (Sweden)

    Grekulović Vesna J.

    2009-01-01

    Full Text Available The results of an attempt in using cyclic voltammetry for characterization of gold, silver, copper and 18-k gold alloys by their anodic behavior in 1 mol/dm3 H2SO4 are presented in this paper. Gold alloys containing 75 mass% Au are named as 18-k gold, but it is usually three component alloy containing 75 mass% Au, 12.5 mass% Ag and 12.5 mass% Cu as the main components. Investigated alloys were obtained by melting powders of pure metals mixed in corresponding ratio, casting, cooling in air, rolling and drawing in the wire shape. To achieve the required mechanical properties, the alloys had heat-treated three times. Each alloy exhibits characteristic current peaks on voltammogram that can be used to recognize the kind of present alloying metal in gold. Also, the content of the alloying metal can be roughly estimated from the peak value of current densities.

  8. Gold in Modern Economy

    Directory of Open Access Journals (Sweden)

    Boryshkevych Olena V.

    2014-01-01

    Full Text Available The article studies the role of gold in modern economy. It analyses dynamics and modern state of the gold market. It studies volumes of contracts in exchange and off-exchange markets. In order to reveal changes of key features of the gold market, it focuses on the study of gold demand volumes, studies volumes and geographical changes in the world gold mining, and analyses volumes of monetary gold of central banks and its share in gold and currency reserves. It analyses price fluctuations in the gold market during 1968 – 2013 and identifies main factors that determine the gold price. It identifies interconnection between the state of the gold market and financial markets of countries. The study showed that namely geopolitical and economic instability restricts the spectrum of financial assets for investing and gold is not only a safe investment object but also a profitable one.

  9. 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.

  10. ToxCast Dashboard

    Science.gov (United States)

    The ToxCast Dashboard helps users examine high-throughput assay data to inform chemical safety decisions. To date, it has data on over 9,000 chemicals and information from more than 1,000 high-throughput assay endpoint components.

  11. Control of cast iron and casts manufacturing by Inmold method

    Directory of Open Access Journals (Sweden)

    S. Pietrowski

    2009-07-01

    Full Text Available In this paper the usability of cast iron spheroidizing process in mould control by ATD method as well as by ultrasonic method were presented. Structure of instrumentation needed for control form performance of cast iron spheroidizing by Inmold method was illustrated. Author, pointed out that amount of magnesium master alloy should obtain 0,8 ÷ 1,0% of mass in form at all. Such quantity of preliminary alloy assure of obtain of nodular graphite in cast iron. In consequence of this, is reduce the cast iron liquidus temperature and decrease of recalescence temperature of graphite-eutectic crystallization in compare with initial cast iron. Control of casts can be carried out by ultrasonic method. In plain cast iron, ferritic-pearlitic microstructure is obtaining. Additives of 1,5% Cu ensure pearlitic structure.

  12. 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

  13. 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.

  14. The effect of prefixation on the quality of vascular corrosion casts of rat heart.

    Science.gov (United States)

    Reddy, P A; Douglas, J E; Schulte, M; Hossler, F E

    1995-01-01

    To help define the optimal conditions for the preparation of vascular corrosion casts of rat heart, we examined the effect of prefixation with aldehyde fixatives on the perfusion rates of rat heart and on the quality of vascular casts. For these studies, beating hearts were removed from rats, cannulated via the aortic stump, arrested with KCl, perfused retrograde with buffered saline or fixative, and infused with resin to prepare corrosion casts. Fixatives used were 2.5% glutaraldehyde or 2% paraformaldehyde, and the casting resin consisted of a Mercox-methylmethacrylate mixture (4:1). All perfusion pressures were monitored at 80 to 100 mm Hg using a mercury manometer. The perfusion rate of control hearts was 13 to 14 mL/min. Prefixation with glutaraldehyde and paraformaldehyde reduced perfusion to 8.5 and 8.1 mL/min, respectively. Cast quality was observed grossly and with the scanning electron microscope. Control hearts yielded high quality, complete casts with 2570 capillaries/mm(2+). Casts from prefixed hearts exhibited areas of incomplete vessel filling and resisted complete tissue maceration, leaving tissue remnants adhering to the vessel replicas. Casts from glutaraldehyde-fixed hearts were of very poor quality. Our results indicate that prefixation is an unnecessary step in the preparation of vascular casts of rat heart and is inconsistent with cast quality.

  15. 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

  16. Fixed Target Collisions at STAR

    Science.gov (United States)

    Meehan, Kathryn C.

    2016-12-01

    The RHIC Beam Energy Scan (BES) program was proposed to look for the turn-off of signatures of the quark gluon plasma (QGP), search for a possible QCD critical point, and study the nature of the phase transition between hadronic and partonic matter. Previous results have been used to claim that the onset of deconfinement occurs at a center-of-mass energy of 7 GeV. Data from lower energies are needed to test if this onset occurs. The goal of the STAR Fixed-Target Program is to extend the collision energy range in BES II to energies that are likely below the onset of deconfinement. Currently, STAR has inserted a gold target into the beam pipe and conducted test runs at center-of-mass energies of 3.9 and 4.5 GeV. Tests have been done with both Au and Al beams. First physics results from a Coulomb potential analysis of Au + Au fixed-target collisions are presented and are found to be consistent with results from previous experiments. Furthermore, the Coulomb potential, which is sensitive to the Z of the projectile and degree of baryonic stopping, will be compared to published results from the AGS.

  17. 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.

  18. 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.

  19. [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.

  20. 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.

  1. 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.

  2. 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.

  3. Fixing the shadows while moving the gnomon

    CERN Document Server

    Gangui, Alejandro

    2016-01-01

    It is a common practice to fix a vertical gnomon and study the moving shadow cast by it. This shows our local solar time and gives us a hint regarding the season in which we perform the observation. The moving shadow can also tell us our latitude with high precision. In this paper we propose to exchange the roles and while keeping the shadows fixed on the ground we will move the gnomon. This lets us understand in a simple way the relevance of the tropical lines of latitude and the behavior of shadows in different locations. We then put these ideas into practice using sticks and threads during a solstice on two sites located on opposite sides of the Tropic of Capricorn.

  4. 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.

  5. QCD at Fixed Topology

    CERN Document Server

    Brower, Richard C; Negele, John W; Wiese, U J

    2003-01-01

    Since present Monte Carlo algorithms for lattice QCD may become trapped in a fixed topological charge sector, it is important to understand the effect of calculating at fixed topology. In this work, we show that although the restriction to a fixed topological sector becomes irrelevant in the infinite volume limit, it gives rise to characteristic finite size effects due to contributions from all $\\theta$-vacua. We calculate these effects and show how to extract physical results from numerical data obtained at fixed topology.

  6. Improved Casting Furnace Conceptual Design

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-02-01

    In an attempt to ensure more consistent casting results and remove some schedule variance associated with casting, an improved casting furnace concept has been developed. The improved furnace uses the existing arc melter hardware and glovebox utilities. The furnace concept was designed around physical and operational requirements such as; a charge sized of less than 30 grams, high heating rates and minimal additional footprint. The conceptual model is shown in the report as well as a summary of how the requirements were met.

  7. Casting accuracy of a nickel and beryllium-free cobalt-chromium alloy for crown and bridge prostheses and resin-bonded bridges.

    Science.gov (United States)

    Hansson, O

    1985-01-01

    In the 1970's economic factors dictated the development of alternatives to gold alloys in dentistry in the USA and in Europe. A similar development has not occurred in Sweden because of different laws. Alloys that contain nickel and beryllium present a health hazard and are therefore of little interest to the Swedish market. A review of the literature shows that castings of base-metal alloys are less accurate than castings of conventional gold alloys and of low gold alloys. However, in long-span-bridges and in thin resin-bonded cast restorations, their physical and mechanical properties are superior to those of the gold alloys. In this study the casting accuracy of a nickel- and beryllium-free cobalt-chromium alloy, Neobond II Special, is investigated. Neobond II Special was found to be less accurate than Sjödings C-guld. The marginal discrepancies of the castings were small, however, when the castings were oversized. It also proved to be technique sensitive to conventional dental laboratory procedures. Thus, it seems difficult to get castings with an acceptable retention as well as small marginal discrepancies when using the base-metal alloy.

  8. Physical, wind wave spectra, and other data from meteorological sensors, moored buoy casts, thermistors, and accelerometers in fixed locations in the Gulf of Mexico, South Pacific Ocean, Coastal Waters of Western U.S., Great Lakes, North American Coastline-North, and North American Coastline-South from 01 January 2001 to 31 January 2001 (NODC Accession 0000408)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Physical, wind wave spectra, and other data were collected from fixed platforms in the Gulf of Mexico, South Pacific Ocean, Coastal Waters of Western U.S., Great...

  9. 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.

  10. 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.

  11. 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.

  12. Trapping atmospheric CO2 with gold.

    Science.gov (United States)

    Collado, Alba; Gómez-Suárez, Adrián; Webb, Paul B; Kruger, Hedi; Bühl, Michael; Cordes, David B; Slawin, Alexandra M Z; Nolan, Steven P

    2014-10-07

    The ability of gold-hydroxides to fix CO2 is reported. [Au(IPr)(OH)] and [{Au(IPr)}2(μ-OH)][BF4] react with atmospheric CO2 to form the trigold carbonate complex [{Au(IPr)}3(μ(3)-CO3)][BF4]. Reactivity studies revealed that this complex behaves as two basic and one cationic Au centres, and that it is catalytically active. DFT calculations and kinetic experiments have been carried out.

  13. 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.

  14. 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

  15. 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.

  16. 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…

  17. Plasmonic Gold Decorated MWCNT Nanocomposite for Localized Plasmon Resonance Sensing

    Science.gov (United States)

    Ozhikandathil, J.; Badilescu, S.; Packirisamy, M.

    2015-08-01

    The synergism of excellent properties of carbon nanotubes and gold nanoparticles is used in this work for bio-sensing of recombinant bovine growth hormones (rbST) by making Multi Wall Carbon Nanotubes (MWCNT) locally optically responsive by augmenting it optical properties through Localized Surface Plasmon Resonance (LSPR). To this purpose, locally gold nano particles decorated gold-MWCNT composite was synthesized from a suspension of MWCNT bundles and hydrogen chloroauric acid in an aqueous solution, activated ultrasonically and, then, drop-casted on a glass substrate. The slow drying of the drop produces a “coffee ring” pattern that is found to contain gold-MWCNT nanocomposites, accumulated mostly along the perimeter of the ring. The reaction is studied also at low-temperature, in the vacuum chamber of the Scanning Electron Microscope and is accounted for by the local melting processes that facilitate the contact between the bundle of tubes and the gold ions. Biosensing applications of the gold-MWCNT nanocomposite using their LSPR properties are demonstrated for the plasmonic detection of traces of bovine growth hormone. The sensitivity of the hybrid platform which is found to be 1 ng/ml is much better than that measuring with gold nanoparticles alone which is only 25 ng/ml.

  18. 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.

  19. Enhanced chemiluminescence-based detection on gold substrate after electrografting of diazonium precursor-coated gold nanoparticles.

    Science.gov (United States)

    Houmed Adabo, Ali; Zeggari, Rabah; Mohamed Saïd, Nasser; Bazzi, Rana; Elie-Caille, Céline; Marquette, Christophe; Martini, Matteo; Tillement, Olivier; Perriat, Pascal; Chaix, Carole; Boireau, Wilfrid; Roux, Stéphane

    2016-04-01

    Since it was demonstrated that nanostructured surfaces are more efficient for the detection based on the specific capture of analytes, there is a real need to develop strategies for grafting nanoparticles onto flat surfaces. Among the different routes for the functionalization of a surface, the reduction of diazonium salts appears very attractive for the covalent immobilization of nanoparticles because this method does not require a pre-treatment of the surface. For achieving this goal, gold nanoparticles coated by precursor of diazonium salts were synthesized by reduction of gold salt in presence of mercaptoaniline. These mercaptoaniline-coated gold nanoparticles (Au@MA) were successfully immobilized onto various conducting substrates (indium tin oxide (ITO), glassy carbon (GC) and gold electrodes with flat terraces) after addition of sodium nitrite at fixed potential. When applied onto the gold electrodes, such a grafting strategy led to an obvious enhancement of the luminescence of luminol used for the biodetection.

  20. Fixed mobile convergence handbook

    CERN Document Server

    Ahson, Syed A

    2010-01-01

    From basic concepts to future directions, this handbook provides technical information on all aspects of fixed-mobile convergence (FMC). The book examines such topics as integrated management architecture, business trends and strategic implications for service providers, personal area networks, mobile controlled handover methods, SIP-based session mobility, and supervisory and notification aggregator service. Case studies are used to illustrate technical and systematic implementation of unified and rationalized internet access by fixed-mobile network convergence. The text examines the technolo

  1. Optically fixed photorefractive correlator

    Institute of Scientific and Technical Information of China (English)

    刘友文; 刘立人; 周常河; 徐良瑛

    2002-01-01

    An optically fixed photorefractive correlator is presented, where two-centre non-volatile holographic recording isemployed to write and fix the matched filter in doubly doped LiNbO3 crystals. This correlator shows good correlationcharacteristics and insensitivity to the writing beam during readout. It can be used in cases requiring stability and notrequiring modification for a long period, and it is refreshed optically when new information needs to be registered.

  2. 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.

  3. 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.

  4. Gold induced apoptsis study

    DEFF Research Database (Denmark)

    Laustsen, Christoffer

    2008-01-01

    Introduction   Cancer cells are highly thermo sensitive. On the basis of an article in Nature the idea arose, for a new non-invasive thermotherapy technique, based on radio frequency inductive heating of nano gold particles in an MR-scanner. Thermotherapy is getting considerably attention...... at the moment, especially in the fields of lasers, they though have some problems concerning the placement of the tumor in the human body. Local heating by MR has tremendous advance in comparison too lasers. The first step is to validate the hypothesis of the inductive heating of the gold nano particles trough...... in silico methods are here proposed for apoptosis studies and for AMG studies.   Methods   MR - heating of high concentration micrometer gold and low concentration nano gold.   CSLM of ethidum bromide stained cell lines, with and witout gold and automated image processing.   AMG gold uptake study...

  5. 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

  6. 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

  7. Diagnostic Value of Manual and Computerized Methods of Dental Casts Analysis

    OpenAIRE

    H. Rahimi; M. Katchooi; Tehranchi, A.; M. Nouri; Massudi, R

    2009-01-01

    Objective: The aim of this study was to evaluate the validity of computerized and manual methods of dental cast analysis.Materials and Methods: Twenty set-ups of upper and lower casts using artificial teeth corresponding to various malocclusions were created for a diagnostic in vitro study. Values of tooth size were calculated from the isolated artificial teeth out of the set-ups, results were considered as a gold standard for the tooth size. Arch width was calculated from the existing set-up...

  8. 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

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. An Application of Microwave Pre-oxidation in Improving Gold Recovery of a Refractory Gold Ore

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Microwave radiation was employed as a pretreating technology to oxidise a refractory gold ore. Heating characteristics showed that, in an identical microwave field, the bulk temperature of the sample increased with microwave power, microwave radiation time and particle size. The rate of sulphur removal increased with microwave radiation time. Particle size also had a significant effect on the oxidation rate. Pyrite and marcasite could be oxidised into Fe2O3 with a high porous structure. When microwave radiation was carried out in a rotary bed, the oxidation was more uniformly developed, in comparison with in a fixed bed. Gold extraction by cyanidation could be remarkably improved after the ore was subjected to microwave radiation. The results showed that gold recovery could be improved from 37% to 69%~81.2%.

  15. 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.

  16. 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.

  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; 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.

  18. Gold in the Books

    Institute of Scientific and Technical Information of China (English)

    江河

    2002-01-01

    In the present Chinese market, more and more businessmen turn to the profit-making trade. Even some counters in the bookstores are selling gold rings, necklaces, bracelets, etc. One day a school teacher asked a store assistant,“Why are you selling gold in your bookstore?”

  19. Gold-Mining

    DEFF Research Database (Denmark)

    Raaballe, J.; Grundy, B.D.

    2002-01-01

    of operating gold mines. Asymmetric information on the reserves in the mine implies that, at a high enough price of gold, the manager of high type finds the extraction value of the company to be higher than the current market value of the non-operating gold mine. Due to this under valuation the maxim of market...... value maximization forces the manager of high type to extract the gold.The implications are three-fold. First, all managers (except the lowest type) extract the gold too soon compared to the first-best policy of leaving the gold in the mine forever. Second, a manager of high type extracts the gold...... sooner than a manager of lower type. Third, a non-operating gold mine is valued as being of the lowest type in the pool and all else equal, high-asymmetri mines are valued lower than low-asymmetri mines. In a qualitative sense these results are robust with respect to different assumptions (re cost...

  20. Enhanced radiative heat transfer between nanostructured gold plates

    CERN Document Server

    Guérout, R; Rosa, F S S; Hugonin, J -P; Dalvit, D A R; Greffet, J -J; Lambrecht, A; Reynaud, S

    2012-01-01

    We compute the radiative heat transfer between nanostructured gold plates in the framework of the scattering theory. We predict an enhancement of the heat transfer as we increase the depth of the corrugations while keeping the distance of closest approach fixed. We interpret this effect in terms of the evolution of plasmonic and guided modes as a function of the grating's geometry.

  1. ADSORPTION OF GOLD ON TBP EXTRACTING RESIN FROM HCl SOLUTION

    Institute of Scientific and Technical Information of China (English)

    GaoHaoqi; CaoZhikai; 等

    1998-01-01

    Adsorption of gold on TBP extracting resin from HCl solution was researched.All the effects of factors,such as solution acidity,TBP content,temperature,etc.,on adsorption equilibrium were discussed and the equilibrium equation was formulated.The breakthough time of adsorption process with fixed bed was studied through experiment.

  2. Fixing Dataset Search

    Science.gov (United States)

    Lynnes, Chris

    2014-01-01

    Three current search engines are queried for ozone data at the GES DISC. The results range from sub-optimal to counter-intuitive. We propose a method to fix dataset search by implementing a robust relevancy ranking scheme. The relevancy ranking scheme is based on several heuristics culled from more than 20 years of helping users select datasets.

  3. 前牙IPS热压铸造全瓷粘接桥修复的3年临床应用研究%All-ceramic resin bonded fixed partial denture made of IPS hot-pressed casting porcelain restore anterior missing teeth: a three years clinical observation

    Institute of Scientific and Technical Information of China (English)

    周团锋; 王新知; 张桂荣

    2011-01-01

    Objective :To clinic observation of IPS Empress2 and IPS e. max all ceramic resin bonded fixed partial dentures used in one anterior teeth lost in upper jaw or less than two anterior tooth lost in lower jaw. Methods : 22 patients, 26 restorations had been made, which included 16 single-retainer all ceramic resin bonded fixed partial dentures and 10 two-retainers all ceramic resin bonded fixed partial dentures. Secondary caries of the abutments, shade in the margin of the retainers and the integrity of the restorations had been observed at 3 months, 6 months, 1 year, 2 years and 3 years after all ceramic resin bonded fixed partial dentures having been bonded. Results : In the 3 years of clinic observation of the anterior all ceramic resin bonded fixed partial dentures, 1 two-retainers restoration lost bond after it had been made for 3 months, a retainer of one two-retainers restoration was broken after 6 months, but they are still used after modified as one-retainer all ceramic resin bonded fixed partial dentures, 1 two-retainers restoration lost bond two year later, It was integrity and re-bonded again that was still stable. No secondary carries and no shade in margin of the retainers had been found. Their color matches with the nature teeth excellently. The success rate was 88.5% . Conclusion: IPS Empress 2 and IPS e. max all ceramic resin bonded fixed partial dentures should be a good selection in one or two teeth lose in anterior jaws.%目的:观察单个上前牙或下颌2个以内前牙缺失采用IPS Empress 2或IPS e.max热压铸造全瓷粘接桥的临床修复效果.方法:22位患者,共制作26件前牙热压铸造全瓷粘接桥,包括16例单翼全瓷粘接桥和10例双翼全瓷粘接桥,修复后3个月、6个月、1年,2年和3年观察修复体的完整性,基牙的继发龋,边缘着色及修复体的颜色匹配.结果:1例双翼全瓷粘接桥修复后3个月脱落;1例双翼全瓷粘接桥6个月后一侧连接体折断,均改为单翼

  4. 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.

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

    Institute of Scientific and Technical Information of China (English)

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

    2016-01-01

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

  6. 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.

  7. A simplified technique for making an interocclusal record in fixed prosthodontics.

    Science.gov (United States)

    Moghadam, Marjan; Moghadam, Bijan

    2005-01-01

    A technique for using flowable composite resin for making interocclusal records in cases involving fixed prosthodontics is described. The precise relation of maxillary and mandibular casts is an essential step in developing accurate occlusion in fixed prosthodontics. This technique consists of direct intraoral fabrication of transfer copings and an interocclusal record using flowable, light-activated composite resin. The technique is simple, does not require advance preparation and can be done during the final impression appointment.

  8. Fillability of Thin-Wall Steel Castings

    Energy Technology Data Exchange (ETDEWEB)

    Robert C. Voigt; Joseph Bertoletti; Andrew Kaley; Sandi Ricotta; Travis Sunday

    2002-07-30

    The use of steel components is being challenged by lighter nonferrous or cast iron components. The development of techniques for enhancing and ensuring the filability of thin-wall mold cavities is most critical for thinner wall cast steel production. The purpose of this research was to develop thin-wall casting techniques that can be used to reliably produce thin-wall castings from traditional gravity poured sand casting processes. The focus of the research was to enhance the filling behavior to prevent misrunds. Experiments were conducted to investigate the influence of various foundry variables on the filling of thin section steel castings. These variables include casting design, heat transfer, gating design, and metal fluidity. Wall thickness and pouring temperature have the greatest effect on casting fill. As wall thickness increases the volume to surface area of the casting increases, which increases the solidification time, allowing the metal to flow further in thicker sect ions. Pouring time is another significant variable affecting casting fill. Increases or decreases of 20% in the pouring time were found to have a significant effect on the filling of thin-wall production castings. Gating variables, including venting, pouring head height, and mold tilting also significantly affected thin-wall casting fill. Filters offer less turbulent, steadier flow, which is appropriate for thicker castings, but they do not enhance thin-wall casting fill.

  9. 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.

  10. Diagnostic Value of Manual and Computerized Methods of Dental Casts Analysis

    Directory of Open Access Journals (Sweden)

    H. Rahimi

    2009-06-01

    Full Text Available Objective: The aim of this study was to evaluate the validity of computerized and manual methods of dental cast analysis.Materials and Methods: Twenty set-ups of upper and lower casts using artificial teeth corresponding to various malocclusions were created for a diagnostic in vitro study. Values of tooth size were calculated from the isolated artificial teeth out of the set-ups, results were considered as a gold standard for the tooth size. Arch width was calculated from the existing set-ups on the dentins.Impressions were taken of the casts with alginate and duplicated with dental stone. Models were measured with digital caliper manually. Then images were taken from the occlusal views of the casts by a digital camera. Measurements were done on digital images with the AutoCAD software.The results of the computerized and manual methods were compared with the gold standard.Intra class correlation coefficient of reliability was used to measure the accuracy ofthe methods and the Friedman technique used to evaluate the significance of differences.Results: Results indicated that all measurements were highly correlated, e.g. gold standard and manual (0.9613-0.9991, gold standard and computerized (0.7118-0.9883, manual and computerized (0.6734-0.9914. Statistically significant differences were present between these methods (P<0.05, but they proved not to be clinically significant.Conclusion: Manual measurement is still the most accurate method when compared to the computerized measurements and the results of measurement by computer should be interpreted with caution.

  11. 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.

  12. 16 CFR Appendix to Part 23 - Exemptions Recognized in the Assay for Quality of Gold Alloy, Gold Filled, Gold Overlay, Rolled...

    Science.gov (United States)

    2010-01-01

    ... Quality of Gold Alloy, Gold Filled, Gold Overlay, Rolled Gold Plate, Silver, and Platinum Industry...—Exemptions Recognized in the Assay for Quality of Gold Alloy, Gold Filled, Gold Overlay, Rolled Gold Plate... be considered in any assay for quality of a gold filled, gold overlay and rolled gold plate industry...

  13. Interconnecting Gold Islands with DNA Origami Nanotubes

    Science.gov (United States)

    Ding, Baoquan; Wu, Hao; Xu, Wei; Zhao, Zhao; Liu, Yan; Yu, Hongbin; Yan, Hao

    2012-01-01

    Scaffolded DNA origami has recently emerged as a versatile, programmable method to fold DNA into arbitrarily shaped nanostructures that are spatially addressable, with sub-10 nm resolution. Toward functional DNA nanotechnology, one of the key challenges is to integrate the bottom up self-assembly of DNA origami with the top-down lithographic methods used to generate surface patterning. In this report we demonstrate that fixed length DNA origami nanotubes, modified with multiple thiol groups near both ends, can be used to connect surface patterned gold islands (tens of nanometers in diameter) fabricated by electron beam lithography (EBL). Atomic force microscopic imaging verified that the DNA origami nanotubes can be efficiently aligned between gold islands with various inter-island distances and relative locations. This development represents progress toward the goal of bridging bottom up and top down assembly approaches. PMID:21070012

  14. Discrepancy measurements of copings prepared by three casting methods and two different alloys, on ITI implants

    Directory of Open Access Journals (Sweden)

    Siadat H.

    2008-04-01

    Full Text Available Background and Aim: An important criterion for success assessment of implant-supported prostheses is marginal fit. Vertical and horizontal discrepancy can result in loosening of the prosthetic screw, crestal bone resorption, peri-implantitis and loss of osseointegration. Despite careful attention to waxing, investing, and casting, marginal discrepancies are inevitable. The aim of this study was to evaluate the marginal gap and overhang in three casting methods with two different alloys in ITI implants.Materials and Methods: In this experimental in vitro study 48 analog abutments were randomly divided into six groups as follows: 1 burn out cap + BegoStar, 2 impression cap + BegoStar, 3 conventional wax up + BegoStar, 4 burn out cap + Verabond2, 5 impression cap + Verabond2, 6 conventional wax up + Verabond2. Waxing was done in 0.7 mm thickness verified by a digital gauge and a putty index was made for all groups. Reamer was used for correction of the finish line after casting in all groups. Castings were seated on analog abutments and embedded in acrylic resin. Specimens were sectioned by isomet instrument and polished and cleaned by ultrasonic cleaner for 10 min. The marginal gap and overextended margins of castings were examined under a  Scanning Electron Microscope (SEM (X200. The mean gap and margin overextension were calculated for each group. Data were analyzed by multivariate analysis and Bonferroni post-hoc test with p<0.05 as the level of significance.Results: No significant difference in gap size was observed among the three casting methods with two alloys (P=0.056. The marginal gap was not different in the studied casting methods (P=0.092. Gold alloy crowns showed lower marginal gaps compared to base metal alloy crowns (P<0.001. No significant difference in overhang size was observed among casting methods with two alloys (P=0.093. Base metal alloy crowns showed less overhang compared to gold alloy crowns (P<0.001. There was a

  15. Fixed textile shutters

    Directory of Open Access Journals (Sweden)

    K.A. Chernova

    2010-06-01

    Full Text Available One of the main socio-economic problems in Russia is the high cost and the poor condition of housing.Such goals as cost reduction, reducing installation time and increasing the service life of structures are accomplishing by creating new technologies of erecting buildings and developing ways ofquickconstruction, using different types of fixed formwork. One of themis textstone.Textstone is an artificial construction stone, containing on the outer surface the reinforcing fine-mesh shell with multifunctional properties, formed by the interwoven threads of a vigorous fixed formwork textile material (basalt, linen, silica and other glass yarns adhered by binding material. The innovative construction technology of production and installation of a new generation of textstone buildings has been registered as a brand TextStone. The fundamental difference between texstone and reinforced concrete and all known building materials is that the whole outer surface of solidified light binders is protected by strong, vigorous and fixed formwork made from inexpensive textile materials. Manufacturing textile shells allows using it as an internal finishing material, reducing or eliminating the cost of finishing work.The use of fixed textile construction shutters during the construction of buildings has obvious technical, economic, operational, sanitary and environmental benefits: short construction time (from 3 to 10 days, compact packaging and light weight of fabric shells, high fire resistance, frost resistance, ease of engineering services installation in the hollow communicating shells; minimal amount of finishing, roofing, heat and noise insulation works. Texstone is a durable solid monolithic construction that provides high viability and earthquakes, hurricanes wind, solar sultriness and frost resistance. Material complies with all sanitary and environmental requirements. Due to such physical, mechanical, operational, sanitary and ecological characteristics

  16. Fixed Sagittal Plane Imbalance

    OpenAIRE

    Savage, Jason W.; Patel, Alpesh A.

    2014-01-01

    Study Design Literature review. Objective To discuss the evaluation and management of fixed sagittal plane imbalance. Methods A comprehensive literature review was performed on the preoperative evaluation of patients with sagittal plane malalignment, as well as the surgical strategies to address sagittal plane deformity. Results Sagittal plane imbalance is often caused by de novo scoliosis or iatrogenic flat back deformity. Understanding the etiology and magnitude of sagittal malalignment is ...

  17. Titanium Aluminide Casting Technology Development

    Science.gov (United States)

    Bünck, Matthias; Stoyanov, Todor; Schievenbusch, Jan; Michels, Heiner; Gußfeld, Alexander

    2017-08-01

    Titanium aluminide alloys have been successfully introduced into civil aircraft engine technology in recent years, and a significant order volume increase is expected in the near future. Due to its beneficial buy-to-fly ratio, investment casting bears the highest potential for cost reduction of all competing production technologies for TiAl-LPTB. However, highest mechanical properties can be achieved by TiAl forging. In view of this, Access e.V. has developed technologies for the production of TiAl investment cast parts and TiAl die cast billets for forging purposes. While these parts meet the highest requirements, establishing series production and further optimizing resource and economic efficiency are present challenges. In order to meet these goals, Access has recently been certified according to aircraft standards, aiming at qualifying parts for production on technology readiness level 6. The present work gives an overview of the phases of development and certification.

  18. 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.

  19. 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.

  20. Fabrication, nanomechanical characterization, and cytocompatibility of gold-reinforced chitosan bio-nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Nimitt G. [Department of Mechanical and Aeronautical Engineering, Clarkson University, Potsdam, NY, 13699 (United States); Materials Science and Engineering PhD Program, Clarkson University, Potsdam, NY, 13699 (United States); Kumar, Ajeet [Center for Advanced Materials Processing, Clarkson University, Potsdam, NY, 13699 (United States); Jayawardana, Veroni N. [Department of Mathematics, Clarkson University, Potsdam, NY, 13699 (United States); Woodworth, Craig D. [Department of Biology, Clarkson University, Potsdam, NY, 13699 (United States); Yuya, Philip A., E-mail: pyuya@clarkson.edu [Department of Mechanical and Aeronautical Engineering, Clarkson University, Potsdam, NY, 13699 (United States)

    2014-11-01

    Chitosan, a naturally derived polymer represents one of the most technologically important classes of active materials with applications in a variety of industrial and biomedical fields. Gold nanoparticles (∼ 32 nm) were synthesized via a citrate reduction method from chloroauric acid and incorporated in Chitosan matrix. Bio-nanocomposite films with varying concentrations of gold nanoparticles were prepared through solution casting process. Uniform distribution of gold nanoparticles was achieved throughout the chitosan matrix and was confirmed with SEM. Synthesis outcomes and prepared nanocomposites were characterized using SEM, TEM, EDX, SAED, UV–vis, XRD, DLS, and Zeta potential for their physical, morphological and structural properties. Nanoscale properties of materials under the influence of temperature were characterized through nanoindentation techniques. From quasi-static nanoindentation, it was observed that hardness and reduced modulus of the nanocomposites were increased significantly in direct proportion to the gold nanoparticle concentration. Gold nanoparticle concentration also showed positive impact on storage modulus and thermal stability of the material. The obtained films were confirmed to be biocompatible by their ability to support growth of human cells in vitro. In summary, the results show enhanced mechanical properties with increasing gold nanoparticle concentration, and provide better understanding of the structure–property relationships of such biocompatible materials for potential biomedical applications. - Highlights: • We fabricated gold reinforced chitosan nanocomposite for biomedical applications. • Gold nanoparticles significantly enhanced nanomechanical properties of chitosan. • Nanocomposite films supported growth of human cells in vitro. • Gold nanoparticles significantly improved cell proliferation on chitosan films.

  1. Computer simulation applied to jewellery casting: challenges, results and future possibilities

    Science.gov (United States)

    Tiberto, Dario; Klotz, Ulrich E.

    2012-07-01

    Computer simulation has been successfully applied in the past to several industrial processes (such as lost foam and die casting) by larger foundries and direct automotive suppliers, while for the jewelry sector it is a procedure which is not widespread, and which has been tested mainly in the context of research projects. On the basis of a recently concluded EU project, the authors here present the simulation of investment casting, using two different softwares: one for the filling step (Flow-3D®), the other one for the solidification (PoligonSoft®). A work on material characterization was conducted to obtain the necessary physical parameters for the investment (used for the mold) and for the gold alloys (through thermal analysis). A series of 18k and 14k gold alloys were cast in standard set-ups to have a series of benchmark trials with embedded thermocouples for temperature measurement, in order to compare and validate the software output in terms of the cooling curves for definite test parts. Results obtained with the simulation included the reduction of micro-porosity through an optimization of the feeding channels for a controlled solidification of the metal: examples of the predicted porosity in the cast parts (with metallographic comparison) will be shown. Considerations on the feasibility of applying the casting simulation in the jewelry sector will be reached, underlining the importance of the software parametrization necessary to obtain reliable results, and the discrepancies found with the experimental comparison. In addition an overview on further possibilities of application for the CFD in jewellery casting, such as the modeling of the centrifugal and tilting processes, will be presented.

  2. 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.

  3. 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.

  4. 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. 

  5. Chitosan-gold-Lithium nanocomposites as solid polymer electrolyte.

    Science.gov (United States)

    Begum, S N Suraiya; Pandian, Ramanathaswamy; Aswal, Vinod K; Ramasamy, Radha Perumal

    2014-08-01

    Lithium micro batteries are emerging field of research. For environmental safety biodegradable films are preferred. Recently biodegradable polymers have gained wide application in the field of solid polymer electrolytes. To make biodegradable polymers films plasticizers are usually used. However, use of plasticizers has disadvantages such as inhomogenities in phases and mechanical instability that will affect the performance of Lithium micro batteries. We have in this research used gold nanoparticles that are environmentally friendly, instead of plasticizers. Gold nanoparticles were directly template upon chitosan membranes by reduction process so as to enhance the interactions of Lithium with the polymer. In this article, for the first time the characteristics of Chitosan-gold-Lithium nanocomposite films are investigated. The films were prepared using simple solution casting technique. We have used various characterization tools such as Small Angle Neutron Scattering (SANS), XRD, FTIR, Raman, FESEM, and AFM, Light scattering, Dielectric and electrical conductivity measurements. Our investigations show that incorporation of gold results in enhancement of conductivity in Lithium containing Chitosan films. Also it affects the dielectric characteristics of the films. We conclude through various characterization tools that the enhancement in the conductivity was due to the retardation of crystal growth of lithium salt in the presence of gold nanoparticles. A model is proposed regarding the formation of the new nanocomposite. The conductivity of these biodegradable films is comparable to those of the current inorganic Lithium micro batteries. This new chitosan-Au-Li nanocomposite has potential applications in the field of Lithium micro batteries.

  6. Prelude to Gold

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    FEMALE Chinese athletes Fu Mingxia and Wang Junxia recorded outstanding performances at 1996 Atlanta Olympic Games. Fu Mingxia won gold medals in both platform and springboard diving, and in so doing became the first double medal winner in Olympic diving since 1960. Wang Junxia, the holder of several world records in women’s long distance events, struggled against the odds and captured gold in the 5,000-meter event,

  7. Gold nanoprobes for theranostics

    Science.gov (United States)

    Panchapakesan, Balaji; Book-Newell, Brittany; Sethu, Palaniappan; Rao, Madhusudhana; Irudayaraj, Joseph

    2011-01-01

    Gold nanoprobes have become attractive diagnostic and therapeutic agents in medicine and life sciences research owing to their reproducible synthesis with atomic level precision, unique physical and chemical properties, versatility of their morphologies, flexibility in functionalization, ease of targeting, efficiency in drug delivery and opportunities for multimodal therapy. This review highlights some of the recent advances and the potential for gold nanoprobes in theranostics. PMID:22122586

  8. The Gold Standard Programme

    DEFF Research Database (Denmark)

    Neumann, Tim; Rasmussen, Mette; Ghith, Nermin

    2013-01-01

    To evaluate the real-life effect of an evidence-based Gold Standard Programme (GSP) for smoking cessation interventions in disadvantaged patients and to identify modifiable factors that consistently produce the highest abstinence rates.......To evaluate the real-life effect of an evidence-based Gold Standard Programme (GSP) for smoking cessation interventions in disadvantaged patients and to identify modifiable factors that consistently produce the highest abstinence rates....

  9. Joining the Gold Rush

    Institute of Scientific and Technical Information of China (English)

    LIU BO

    2006-01-01

    @@ Flush with advanced technology and large amounts of capital, overseas mining firms are carving a place in the Chinese gold industry Dozens of Western mining companies, particularly those from Canada, are making the journey into the kind of remote corners in China that other overseas investors shy away from. What are they looking for? The answer is one of the most precious substances on the planet: gold.

  10. 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.

  11. 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.

  12. 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

  13. 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.

  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. 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 ...

  16. Fixed-Term Homotopy

    Directory of Open Access Journals (Sweden)

    Hector Vazquez-Leal

    2013-01-01

    Full Text Available A new tool for the solution of nonlinear differential equations is presented. The Fixed-Term Homotopy (FTH delivers a high precision representation of the nonlinear differential equation using only a few linear algebraic terms. In addition to this tool, a procedure based on Laplace-Padé to deal with the truncate power series resulting from the FTH method is also proposed. In order to assess the benefits of this proposal, two nonlinear problems are solved and compared against other semianalytic methods. The obtained results show that FTH is a power tool capable of generating highly accurate solutions compared with other methods of literature.

  17. 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.

  18. 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

  19. 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.

  20. 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

  1. 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.

  2. 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...

  3. 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.

  4. 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].

  5. 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.

  6. 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...

  7. Fixed and Sunk Costs Revisited.

    Science.gov (United States)

    Wang, X. Henry; Yang, Bill Z.

    2001-01-01

    Attempts to clarify the concepts of, and the link between, fixed costs and sunk costs. Argues that the root of confusion is the inconsistency in defining the term fixed costs. Consistently defines fixed and sunk costs, and describes how instructors must teach under these definitions. (RLH)

  8. Fixed sagittal plane imbalance.

    Science.gov (United States)

    Savage, Jason W; Patel, Alpesh A

    2014-12-01

    Study Design Literature review. Objective To discuss the evaluation and management of fixed sagittal plane imbalance. Methods A comprehensive literature review was performed on the preoperative evaluation of patients with sagittal plane malalignment, as well as the surgical strategies to address sagittal plane deformity. Results Sagittal plane imbalance is often caused by de novo scoliosis or iatrogenic flat back deformity. Understanding the etiology and magnitude of sagittal malalignment is crucial in realignment planning. Objective parameters have been developed to guide surgeons in determining how much correction is needed to achieve favorable outcomes. Currently, the goals of surgery are to restore a sagittal vertical axis Sagittal plane malalignment is an increasingly recognized cause of pain and disability. Treatment of sagittal plane imbalance varies according to the etiology, location, and severity of the deformity. Fixed sagittal malalignment often requires complex reconstructive procedures that include osteotomy correction. Reestablishing harmonious spinopelvic alignment is associated with significant improvement in health-related quality-of-life outcome measures and patient satisfaction.

  9. Teleservice for hydraulic excavators operating in open-cast mines; Teleservice bei Tagebau-Hydraulikbaggern

    Energy Technology Data Exchange (ETDEWEB)

    Poettker, A. [Terex Germany GmbH und Co. KG, Dortmund (Germany)

    2005-04-01

    Hydraulic excavators in open-cast mines are cost-intensive capital assets, which must be constantly observed during production in order to ensure availability. Teleservice is one way of reducing the service costs. As open-cast mines are generally developed in areas with a poor infrastructure, the excavators can be reliably reached only via satelite. Several network operators with different data transmission rates are suitable according to the required purpose. Satellite communication is expensive compared to the fixed network. New intelligent network topologies (MANET) are currently undergoing the first field tests. (orig.)

  10. Accuracy of stone casts obtained by different impression materials

    Directory of Open Access Journals (Sweden)

    Adriana Cláudia Lapria Faria

    2008-12-01

    Full Text Available Several impression materials are available in the Brazilian marketplace to be used in oral rehabilitation. The aim of this study was to compare the accuracy of different impression materials used for fixed partial dentures following the manufacturers' instructions. A master model representing a partially edentulous mandibular right hemi-arch segment whose teeth were prepared to receive full crowns was used. Custom trays were prepared with auto-polymerizing acrylic resin and impressions were performed with a dental surveyor, standardizing the path of insertion and removal of the tray. Alginate and elastomeric materials were used and stone casts were obtained after the impressions. For the silicones, impression techniques were also compared. To determine the impression materials' accuracy, digital photographs of the master model and of the stone casts were taken and the discrepancies between them were measured. The data were subjected to analysis of variance and Duncan's complementary test. Polyether and addition silicone following the single-phase technique were statistically different from alginate, condensation silicone and addition silicone following the double-mix technique (p .05 to alginate and addition silicone following the double-mix technique, but different from polysulfide. The results led to the conclusion that different impression materials and techniques influenced the stone casts' accuracy in a way that polyether, polysulfide and addition silicone following the single-phase technique were more accurate than the other materials.

  11. Accuracy of stone casts obtained by different impression materials.

    Science.gov (United States)

    Faria, Adriana Cláudia Lapria; Rodrigues, Renata Cristina Silveira; Macedo, Ana Paula; Mattos, Maria da Gloria Chiarello de; Ribeiro, Ricardo Faria

    2008-01-01

    Several impression materials are available in the Brazilian marketplace to be used in oral rehabilitation. The aim of this study was to compare the accuracy of different impression materials used for fixed partial dentures following the manufacturers' instructions. A master model representing a partially edentulous mandibular right hemi-arch segment whose teeth were prepared to receive full crowns was used. Custom trays were prepared with auto-polymerizing acrylic resin and impressions were performed with a dental surveyor, standardizing the path of insertion and removal of the tray. Alginate and elastomeric materials were used and stone casts were obtained after the impressions. For the silicones, impression techniques were also compared. To determine the impression materials' accuracy, digital photographs of the master model and of the stone casts were taken and the discrepancies between them were measured. The data were subjected to analysis of variance and Duncan's complementary test. Polyether and addition silicone following the single-phase technique were statistically different from alginate, condensation silicone and addition silicone following the double-mix technique (p or = .05) to alginate and addition silicone following the double-mix technique, but different from polysulfide. The results led to the conclusion that different impression materials and techniques influenced the stone casts' accuracy in a way that polyether, polysulfide and addition silicone following the single-phase technique were more accurate than the other materials.

  12. Modelling of horizontal centrifugal casting of work roll

    Science.gov (United States)

    Xu, Zhian; Song, Nannan; Tol, Rob Val; Luan, Yikun; Li, Dianzhong

    2012-07-01

    A numerical model to simulate horizontal centrifugal roll castings is presented in this paper. In order to simulate the flow fluid and solidification of horizontal centrifugal roll casting correctly, the model uses a body fitted mesh technique to represent the geometry. This new method maps a plate layer mesh to a circular mesh. The smooth body fitted mesh method gives more accurate calculation results for cylindrical geometries. A velocity depending on the angular velocity and inner radius of the mould is set up as a velocity boundary condition. The fluid flow coupled with heat transfer and solidification in a rapidly rotating roll is simulated. A gravity free falling method is applied as a pouring condition. A moveable pouring system is also used in the simulations. High speed steel is used to produce the work roll. Two different gating positions and a moveable gating system are simulated in this paper. Results show that the position of pouring system has a significant influence on the temperature distribution. The temperature distribution at a fixed central pouring system is more favourable than the distribution from a side pouring system. A moving gating system method is a better way to obtain a uniform temperature field in centrifugal casting and offers an alternative for existing techniques.

  13. Photoinduced conductivity of a porphyrin-gold composite nanowire

    Energy Technology Data Exchange (ETDEWEB)

    Kilina, Svletana [Los Alamos National Laboratory; Balatsky, Alexander [Los Alamos National Laboratory; Kilin, Dmitri S [UNIV OF FL; Prezhdo, Oleg [UNIV OF WASHINGTON; Tsemekhman, Kiril [NON LANL

    2009-01-01

    Negatively charged phosphine groups on the backbone of DNA are known to attract gold nanoclusters from a colloid, assembling the clusters at fixed intervals. Bridging these intervals with porphyrin-dye linkers forms an infinite conducting chain, a quantum wire whose carrier mobility can be enhanced by photoexcitation. The resulting nanoassembly can be used as a gate: a wire with a controllable conductivity. The electronic structure of the porphyrin-gold wire is studied here by density functional theory, and the conductivity of the system is determined as a function of the photoexcitation energy. Photoexcitations of the dye are found to enhance the wire conductivity by orders of magnitude.

  14. Evaluation of the value of frozen tissue section used as "gold standard" for immunohistochemistry.

    Science.gov (United States)

    Shi, Shan-Rong; Liu, Cheng; Pootrakul, Llana; Tang, Laurie; Young, Andrew; Chen, Ryan; Cote, Richard J; Taylor, Clive R

    2008-03-01

    To examine the use of acetone- or ethanol-fixed frozen tissue sections as the "gold standard" for immunohistochemical analysis, we evaluated frozen sections with various conditions of fixation and antigen retrieval (AR). Fresh human tissues were frozen in OCT. An adjacent tissue block was fixed in 10% neutral buffered formalin (NBF) and paraffin embedded (FFPE). Frozen sections were fixed by 6 protocols: acetone, ethanol, NBF (2 durations), and NBF + calcium chloride (2 durations). AR was used for all NBF-fixed sections. More than half of the antibodies (16/26 [62%]) showed immunohistochemical results indistinguishable between acetone- and NBF-fixed sections; 8 (31%) showed better immunohistochemical signals following NBF and AR; 2 gave better immunohistochemical results for acetone-fixed sections. Most cytoplasmic proteins (10/13) showed comparable immunohistochemical signals between acetone- and NBF-fixed sections. For nuclear proteins, NBF-fixed sections gave better immunohistochemical signals than did acetone-fixed sections. In most cases, NBF yielded stronger signals with less background and better morphology. The data do not support the use of acetone-fixed frozen tissue sections as the gold standard for immunohistochemical analysis. In evaluating new antibodies, a combination of acetone- and NBF-fixed frozen sections should be used, although in practice, FFPE tissue sections may serve as the standard for most antigens for immunohistochemical analysis.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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)

  20. Fixed Access Network Sharing

    Science.gov (United States)

    Cornaglia, Bruno; Young, Gavin; Marchetta, Antonio

    2015-12-01

    Fixed broadband network deployments are moving inexorably to the use of Next Generation Access (NGA) technologies and architectures. These NGA deployments involve building fiber infrastructure increasingly closer to the customer in order to increase the proportion of fiber on the customer's access connection (Fibre-To-The-Home/Building/Door/Cabinet… i.e. FTTx). This increases the speed of services that can be sold and will be increasingly required to meet the demands of new generations of video services as we evolve from HDTV to "Ultra-HD TV" with 4k and 8k lines of video resolution. However, building fiber access networks is a costly endeavor. It requires significant capital in order to cover any significant geographic coverage. Hence many companies are forming partnerships and joint-ventures in order to share the NGA network construction costs. One form of such a partnership involves two companies agreeing to each build to cover a certain geographic area and then "cross-selling" NGA products to each other in order to access customers within their partner's footprint (NGA coverage area). This is tantamount to a bi-lateral wholesale partnership. The concept of Fixed Access Network Sharing (FANS) is to address the possibility of sharing infrastructure with a high degree of flexibility for all network operators involved. By providing greater configuration control over the NGA network infrastructure, the service provider has a greater ability to define the network and hence to define their product capabilities at the active layer. This gives the service provider partners greater product development autonomy plus the ability to differentiate from each other at the active network layer.

  1. 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.

  2. GOLD IS EARNED FROM THE PRODUCTION OF THAI GOLD LEAF

    Directory of Open Access Journals (Sweden)

    Dirk Bax

    2010-06-01

    Full Text Available Thai people like to cover sacred objects or things dear to them with gold leaf.. Statues of Buddha are sometimes covered with so many layers of gold leaf that they become formless figures, that can hardly be recognized. Portraits of beloved ancestors, statues of elephants and grave tombs are often covered with gold leaf. If one considers the number of Thai people and the popularity of the habit, the amount of gold involved could be considerable.

  3. The recasting effects on the high gold dental alloy properties

    Directory of Open Access Journals (Sweden)

    Maksimović V.M.

    2015-01-01

    Full Text Available Noble dental alloys are often reused in dental practice by recasting. The aim of this study was to determine if repeated casting of high gold dental alloys has a detrimental effect on alloy microstructure, type of porosity, structure and microhardness. Results showed that recasting procedure had a strong effect on the change of alloy porosity type. It was also found that alloy microhardness increased with the increase of the number of recasting cycles. At the same time the grain growth and changes of the solid solution phases in the microstructure were observed. [Projekat Ministarstva nauke Republike Srbije, br. III 45012

  4. 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.

  5. 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.

  6. 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.

  7. 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 $1<\\beta_{\\rm m}<10^6$.

  8. 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

  9. Effect of cast steel production metallurgy on the emergence of casting defects

    Directory of Open Access Journals (Sweden)

    L. Čamek

    2016-10-01

    Full Text Available The paper documents metallurgical possibilities of high alloy cast steel production in open induction medium frequency furnaces and an electric arc furnace in a gravity die casting foundry. The observation was focused on the emergence of gas defects in steel castings. The content of gases achieved during the metallurgical processes was evaluated for every unit of the production equipment and the casting ladle before casting into disposable sand moulds. The sand mould area was considered to be constant. The aim was to evaluate the current metallurgical possibilities of affecting the content of gases in high alloy cast steel in the current technical conditions of the foundry.

  10. 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.

  11. Chemistry for oncotheranostic gold nanoparticles.

    Science.gov (United States)

    Trouiller, Anne Juliette; Hebié, Seydou; El Bahhaj, Fatima; Napporn, Teko W; Bertrand, Philippe

    2015-06-24

    This review presents in a comprehensive ways the chemical methods used to functionalize gold nanoparticles with focus on anti-cancer applications. The review covers the parameters required for the synthesis gold nanoparticles with defined shapes and sizes, method for targeted delivery in tumours, and selected examples of anti-cancers compounds delivered with gold nanoparticles. A short survey of bioassays for oncology based on gold nanoparticles is also presented.

  12. Cast titanium overlay denture for a geriatric patient with a reduced vertical dimension.

    Science.gov (United States)

    Guttal, Satyabodh; Patil, Narendra P

    2005-12-01

    An older patient reporting to the dental surgery for his/her dental treatment is becoming a common occurrence. Improved oral hygiene has meant that teeth are retained for a longer time, along with the potential problems of attrition, decreased vertical dimension, temporomandibular joint discomfort/strain, and poor aesthetics. The case in question is that of a 65-year-old male patient who had severe attrition in the lower arch, temporomandibular joint pain and reduced vertical dimension. The maxillary arch had previously been restored with a fixed partial prosthesis. For restoration of the lower teeth, a removable cast titanium overlay denture was fabricated incorporating an increased vertical dimension. Porcelain facings were placed to restore the aesthetics of the anterior teeth. The titanium was cast in a semi-automatic electric arc, pressure type casting machine. A titanium overlay denture with porcelain facing on the anterior teeth may provide a means of restoring a patient's concerns regarding aesthetics and function.

  13. Marginal and internal adaptation of commercially pure titanium and titanium-aluminum-vanadium alloy cast restorations.

    Science.gov (United States)

    Al Wazzan, Khalid A; Al-Nazzawi, Ahmad A

    2007-01-01

    The purpose of this in vitro study was to investigate the marginal accuracy and internal fit of complete cast crowns and three-unit fixed partial dentures (FPDs) cast with commercially pure titanium (CPTi) and Titanium-Aluminum-Vanadium alloy (Ti-6Al-4V). CPTi and Ti-6Al-4V alloy were used to cast twelve single crowns and twelve three-unit FPDs. A traveling microscope was used to measure marginal gap and discrepancies in internal fit. Two and one-way analysis of variance (ANOVA) analyses were used to determine the effects of the marginal and internal fit discrepancies. The Ti-6Al-4V alloy demonstrated a significantly smaller marginal gap than CPTi (Pcast by CPTi or Ti-6Al-4V alloy were within the range of what is clinically acceptable for longevity of restorations.

  14. ['Gold standard', not 'golden standard'

    NARCIS (Netherlands)

    Claassen, J.A.H.R.

    2005-01-01

    In medical literature, both 'gold standard' and 'golden standard' are employed to describe a reference test used for comparison with a novel method. The term 'gold standard' in its current sense in medical research was coined by Rudd in 1979, in reference to the monetary gold standard. In the same w

  15. ['Gold standard', not 'golden standard'

    NARCIS (Netherlands)

    Claassen, J.A.H.R.

    2005-01-01

    In medical literature, both 'gold standard' and 'golden standard' are employed to describe a reference test used for comparison with a novel method. The term 'gold standard' in its current sense in medical research was coined by Rudd in 1979, in reference to the monetary gold standard. In the same

  16. Plasmonic Gold Decorated MWCNT Nanocomposite for Localized Plasmon Resonance Sensing

    Science.gov (United States)

    Ozhikandathil, J.; Badilescu, S.; Packirisamy, M.

    2015-01-01

    The synergism of excellent properties of carbon nanotubes and gold nanoparticles is used in this work for bio-sensing of recombinant bovine growth hormones (rbST) by making Multi Wall Carbon Nanotubes (MWCNT) locally optically responsive by augmenting it optical properties through Localized Surface Plasmon Resonance (LSPR). To this purpose, locally gold nano particles decorated gold–MWCNT composite was synthesized from a suspension of MWCNT bundles and hydrogen chloroauric acid in an aqueous solution, activated ultrasonically and, then, drop-casted on a glass substrate. The slow drying of the drop produces a “coffee ring” pattern that is found to contain gold–MWCNT nanocomposites, accumulated mostly along the perimeter of the ring. The reaction is studied also at low-temperature, in the vacuum chamber of the Scanning Electron Microscope and is accounted for by the local melting processes that facilitate the contact between the bundle of tubes and the gold ions. Biosensing applications of the gold–MWCNT nanocomposite using their LSPR properties are demonstrated for the plasmonic detection of traces of bovine growth hormone. The sensitivity of the hybrid platform which is found to be 1 ng/ml is much better than that measuring with gold nanoparticles alone which is only 25 ng/ml. PMID:26282187

  17. [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.

  18. Digging for Gold

    Science.gov (United States)

    Waters, John K.

    2012-01-01

    In the case of higher education, the hills are more like mountains of data that "we're accumulating at a ferocious rate," according to Gerry McCartney, CIO of Purdue University (Indiana). "Every higher education institution has this data, but it just sits there like gold in the ground," complains McCartney. Big Data and the new tools people are…

  19. GOLD PRESSURE VESSEL SEAL

    Science.gov (United States)

    Smith, A.E.

    1963-11-26

    An improved seal between the piston and die member of a piston-cylinder type pressure vessel is presented. A layer of gold, of sufficient thickness to provide an interference fit between the piston and die member, is plated on the contacting surface of at least one of the members. (AEC)

  20. Gold Nanoparticle Microwave Synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Krantz, Kelsie E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Christian, Jonathan H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Coopersmith, Kaitlin [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Washington, II, Aaron L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Murph, Simona H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-07-27

    At the nanometer scale, numerous compounds display different properties than those found in bulk material that can prove useful in areas such as medicinal chemistry. Gold nanoparticles, for example, display promise in newly developed hyperthermia therapies for cancer treatment. Currently, gold nanoparticle synthesis is performed via the hot injection technique which has large variability in final particle size and a longer reaction time. One underdeveloped area by which these particles could be produced is through microwave synthesis. To initiate heating, microwaves agitate polar molecules creating a vibration that gives off the heat energy needed. Previous studies have used microwaves for gold nanoparticle synthesis; however, polar solvents were used that partially absorbed incident microwaves, leading to partial thermal heating of the sample rather than taking full advantage of the microwave to solely heat the gold nanoparticle precursors in a non-polar solution. Through this project, microwaves were utilized as the sole heat source, and non-polar solvents were used to explore the effects of microwave heating only as pertains to the precursor material. Our findings show that the use of non-polar solvents allows for more rapid heating as compared to polar solvents, and a reduction in reaction time from 10 minutes to 1 minute; this maximizes the efficiency of the reaction, and allows for reproducibility in the size/shape of the fabricated nanoparticles.

  1. Digging for Gold

    Science.gov (United States)

    Waters, John K.

    2012-01-01

    In the case of higher education, the hills are more like mountains of data that "we're accumulating at a ferocious rate," according to Gerry McCartney, CIO of Purdue University (Indiana). "Every higher education institution has this data, but it just sits there like gold in the ground," complains McCartney. Big Data and the new tools people are…

  2. Gold Nanoparticle Microwave Synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Krantz, Kelsie E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Christian, Jonathan H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Coopersmith, Kaitlin [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Washington, II, Aaron L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Murph, Simona H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-07-27

    At the nanometer scale, numerous compounds display different properties than those found in bulk material that can prove useful in areas such as medicinal chemistry. Gold nanoparticles, for example, display promise in newly developed hyperthermia therapies for cancer treatment. Currently, gold nanoparticle synthesis is performed via the hot injection technique which has large variability in final particle size and a longer reaction time. One underdeveloped area by which these particles could be produced is through microwave synthesis. To initiate heating, microwaves agitate polar molecules creating a vibration that gives off the heat energy needed. Previous studies have used microwaves for gold nanoparticle synthesis; however polar solvents were used that partially absorbed incident microwaves, leading to partial thermal heating of the sample rather than taking full advantage of the microwave to solely heat the gold nanoparticle precursors in a non-polar solution. Through this project, microwaves were utilized as the sole heat source, and non-polar solvents were used to explore the effects of microwave heating only as pertains to the precursor material. Our findings show that the use of non-polar solvents allows for more rapid heating as compared to polar solvents, a reduction in reaction time from 10 minutes to 1 minute, maximizes the efficiency of the reaction, and allows for reproducibility in the size/shape of the fabricated nanoparticles.

  3. Aiming for Gold

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Twenty-three years ago he claimed China’s first Olympic gold medal,with a win in the 50-meter pistol shooting competition.Now Xu Haifeng is leading the country’s modern pentathlon team in its bid for success at the Beijing Games

  4. Porous silicon photoluminescence modification by colloidal gold nanoparticles: Plasmonic, surface and porosity roles

    Energy Technology Data Exchange (ETDEWEB)

    Mora, M.B. de la; Bornacelli, J. [Instituto de Física, Universidad Nacional Autónoma de México, México D.F. 04510 (Mexico); Nava, R. [Centro de Investigación en Energía, Universidad Nacional Autónoma de México, Temixco, Morelos 62580 (Mexico); Zanella, R. [Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, México D.F. 04510 (Mexico); Reyes-Esqueda, J.A., E-mail: betarina@gmail.com [Instituto de Física, Universidad Nacional Autónoma de México, México D.F. 04510 (Mexico)

    2014-02-15

    Metal nanoparticles on semiconductors are of interest because of the tunable effect of the surface plasmon resonance on the physical properties of the semiconductor. In this work, colloidal gold nanoparticles obtained by two different methods, with an average size of 6.1±2.0 nm and 5.0±2.0 nm, were added to luminescent porous silicon by drop casting. The gold nanoparticles interact with porous silicon by modifying its optical properties such as photoluminescence. That being said, plasmon effects are not the only to be taken into account; as shown in this work, surface chemical modification and porosity also play a key role in the final performance of photoluminescence of a porous silicon–gold nanoparticle hybrid system. -- Highlights: • A hybrid material consisting of porous silicon and gold nanoparticles was fabricated. • Porous silicon/gold nanoparticle hybrid material was made by drop casting. • Influence of plasmonics, surface chemical modification and porosity on the optical behavior of our material was analyzed. • Porosity is proposed as a parameter control to obtain the best effects on luminescence of the hybrid plasmonic material.

  5. Gold and gold working in Late Bronze Age Northern Greece

    Science.gov (United States)

    Vavelidis, M.; Andreou, S.

    2008-04-01

    Numerous objects of gold displaying an impressive variety of types and manufacturing techniques are known from the Late Bronze Age (LBA) contexts of Mycenaean Greece, but very little is known about the origin and processing of gold during the second millennium b.c. Ancient literature and recent research indicate that northern Greece is probably the richest gold-bearing region in Greece, and yet, very little evidence exists regarding the exploitation of its deposits and the production as well as use of gold in the area during prehistory. The unusual find of a group of small stone crucibles at the prehistoric settlement of Thessaloniki Toumba, one with visible traces of gold melting, proves local production and offers a rare opportunity to examine the process of on-site gold working. Furthermore, the comparison of the chemical composition of prehistoric artefacts from two settlements with those of gold deposits in their immediate areas supports the local extraction of gold and opens up the prospect for some of the Mycenaean gold to have originated in northern Greece. The scarcity of gold items in northern Greek LBA contexts may not represent the actual amount of gold produced and consumed, but could be a result of the local social attitudes towards the circulation and deposition of artefacts from precious metals.

  6. Bulk Copper Electrodeposition on Gold Imaged by In Situ STM

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov; Bech-Nielsen, Gregers; Møller, Per

    1996-01-01

    Electrochemical measurements were carried out simultaneously with acquisition of in situ STM images of copper electrodeposition at low cathodic overpotentials and subsequent dissolution from the underlying polycrystalline gold surfaces. The morphologies of the copper deposits were examined...... for correlation with features of the current-voltage diagram. Copper growth is by nucleation and formation of 3D islands. During the initial stages of bulk copper growth the potentials were fixed at selected values and a balance observed between formation of polycrystalline copper nuclei and of copper crystals....... After the first cycle of copper deposition and dissolution the morphology of the polycrystalline gold surface had apparently changed into a recrystallized phase of a copper-gold alloy. At a given stage of the cycle the potential of the electrode was found to depend linearly on the tip potential...

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Connector design in a long-span-fixed dental prosthesis: A three-dimensional finite element analysis

    OpenAIRE

    B H Harshitha Gowda; C L Satish Babu

    2013-01-01

    Objectives: The goal of every prosthetic management is to simulate nature and be in harmony with nature within the physiological limits. The occlusal forces on a fixed dental prosthesis are transmitted to the surrounding structures through pontics, connectors and retainers and more stresses are seen at the connector region. To analyze the stress patterns in cast and soldered connectors between the two pontics and between the retainer and pontic of a four unit fixed dental prosthesis on axial ...

  14. 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.

  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. 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.

  17. 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.

  18. 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.

  19. 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...

  20. 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

  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. Maritime Cast Shop Integrated Improvement Plan

    Science.gov (United States)

    2010-08-20

    as well as the risers, sprues and runners that are cut off as scrap from the cast component. The post cast component clean up process should...include several steps  Revert from all sources, risers, sprues, runners and pigged material, must be weighed  The revert must be marked with alloy and...heat all surfaces of the mold to 250F. The higher interior temperature is advantageous in pouring castings with thin sections such as impeller blades

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

    Institute of Scientific and Technical Information of China (English)

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

    2005-01-01

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

  4. A novel approach to mapping load transfer from the plantar surface of the foot to the walls of the total contact cast: a proof of concept study

    Directory of Open Access Journals (Sweden)

    Begg Lindy

    2012-12-01

    Full Text Available Abstract Background Total contact casting is regarded as the gold standard treatment for plantar foot ulcers. Load transfer from the plantar surface of the foot to the walls of the total contact cast has previously been assessed indirectly. The aim of this proof of concept study was to determine the feasibility of a new method to directly measure the load between the cast wall and the lower leg interface using capacitance sensors. Methods Plantar load was measured with pedar® sensor insoles and cast wall load with pliance® sensor strips as participants (n=2 walked along a 9 m walkway at 0.4±0.04 m/sec. The relative force (% on the cast wall was calculated by dividing the mean cast wall force (N per step by the mean plantar force (N per step in the shoe-cast condition. Results The combined average measured load per step upon the walls of the TCC equated to 23-34% of the average plantar load on the opposite foot. The highest areas of load on the lower leg were located at the posterior margin of the lateral malleolus and at the anterior ankle/extensor retinaculum. Conclusions These direct measurements of cast wall load are similar to previous indirect assessment of load transfer (30-36% to the cast walls. This new methodology may provide a more comprehensive understanding of the mechanism of load transfer from the plantar surface of the foot to the cast walls of the total contact cast.

  5. Technological Aspects of Low-Alloyed Cast Steel Massive Casting Manufacturing

    Directory of Open Access Journals (Sweden)

    Szajnara J.

    2013-12-01

    Full Text Available In the paper authors have undertaken the attempt of explaining the causes of cracks net occurrence on a massive 3-ton cast steel casting with complex geometry. Material used for casting manufacturing was the low-alloyed cast steel with increased wear resistance modified with vanadium and titanium. The studies included the primary and secondary crystallization analysis with use of TDA and the qualitative and quantitative analysis of non-metallic inclusions.

  6. 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.

  7. 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.

  8. 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...

  9. Chirality in thiolate-protected gold clusters.

    Science.gov (United States)

    Knoppe, Stefan; Bürgi, Thomas

    2014-04-15

    Over recent years, research on thiolate-protected gold clusters Au(m)(SR)n has gained significant interest. Milestones were the successful determination of a series of crystal structures (Au102(SR)44, Au25(SR)18, Au38(SR)24, Au36(SR)24, and Au28(SR)20). For Au102(SR)44, Au38(SR)24, and Au28(SR)20, intrinsic chirality was found. Strong Cotton effects (circular dichroism, CD) of gold clusters protected by chiral ligands have been reported a long time ago, indicating the transfer of chiral information from the ligand into the cluster core. Our lab has done extensive studies on chiral thiolate-protected gold clusters, including those protected with chiral ligands. We demonstrated that vibrational circular dichroism can serve as a useful tool for the determination of conformation of the ligand on the surface of the cluster. The first reports on crystal structures of Au102(SR)44 and Au38(SR)24 revealed the intrinsic chirality of these clusters. Their chirality mainly arises from the arrangement of the ligands on the surface of the cluster cores. As achiral ligands are used to stabilize the clusters, racemic mixtures are obtained. However, the separation of the enantiomers by HPLC was demonstrated which enabled the measurement of their CD spectra. Thermally induced inversion allows determination of the activation parameters for their racemization. The inversion demonstrates that the gold-thiolate interface is anything but fixed; in contrast, it is rather flexible. This result is of fundamental interest and needs to be considered in future applications. A second line of our research is the selective introduction of chiral, bidentate ligands into the ligand layer of intrinsically chiral gold clusters. The ligand exchange reaction is highly diastereoselective. The bidentate ligand connects two of the protecting units on the cluster surface and thus effectively stabilizes the cluster against thermally induced inversion. A minor (but significant) influence of chiral ligands to

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Design method of electromagnetic field applied to Al-alloy electromagnetic casting

    Institute of Scientific and Technical Information of China (English)

    YANG Jing; DANG Jing-zhi; PENG You-gen; CHENG Jun

    2006-01-01

    The electromagnetic pump imposes the electromagnetic motive force (Lorentz force) on the liquid metal directly and makes it move along the definite direction by using the function of electric current and magnetic field in the conducting fluid.Compared with the traditional die casting, the system of counter-gravity casting can effectively control the speed of fillingto make Al-alloy liquid fill steadily by adjusting controlled-current. So the foundry defects can be decreased or avoided effectively by this system. Based on the theory of electromagnetic pump, the design method of electromagnetic field in electromagnetic pump was investigated emphatically. The rule of magnetic induction intensity B influenced by the divided electromagnet airgap's size was founded. Furthermore, the empirical formula of magnetic induction intensity B in a magnetic airgap for an open magnet in the saturated state was deduced by mathematics regression analysis. Counter-gravity casting applied to the Al-alloy electromagnetic filling was developed with this method. Besides, the electromagnetism filling counter-gravity casting process of the turbo-charge blade wheel was also fixed. The eligibility rate of blade wheel produced by such technique can be increased to 98%. The casts have compact structure and excellent capability.

  15. Influence of casting procedures on the corrosion resistance of clinical dental alloys containing palladium.

    Science.gov (United States)

    Viennot, Stéphane; Lissac, Michèle; Malquarti, Guillaume; Dalard, Francis; Grosgogeat, Brigitte

    2006-05-01

    The aim of this study was to compare the in vitro corrosion resistance in artificial saliva of two palladium-silver alloys (a Pd-Ag (Pors on 4) and an Ag-Pd (Palliag LTG)), with and without casting defects; 1 nickel-chrome alloy and 1 high-gold alloy, cast under recommended conditions, served as controls. For each of the palladium-based alloys, three specimens corresponding to three different casting conditions were used: under recommended conditions, with the use of a graphite-containing investment and crucible, and by reusing the sprues and sprue button. The electrochemical tests were run in Fusayama-Meyer artificial saliva. The open-circuit potential was recorded in mV/SCE at t=24h. Then, potentiodynamic polarization was performed to measure the polarization resistance (R(p)) in kOmega cm(2) and the corrosion current (i(corr)) in microA cm(-2). Data were evaluated with one-way analysis of variance and multiple comparisons test (alpha=0.05). In addition, each specimen was examined by scanning electron microscopy. Compared to the control alloys, the electrochemical experiments in artificial saliva indicated satisfactory corrosion resistance for the Pd-Ag and Ag-Pd alloys; these results are related to their high noble metal content and stable substructure. The Pd-Ag alloy displayed superior electrochemical properties to those of the Ag-Pd alloy regardless of the casting condition. The use of the graphite-containing crucible and investment during the cast process did not dramatically reduce the corrosion resistance values, but the reuse of sprues and the sprue button did. The optimal corrosion resistance values were obtained for the alloys cast according to the recommended conditions.

  16. 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

  17. 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.

  18. Spiky gold nanoshells.

    Science.gov (United States)

    Sanchez-Gaytan, Brenda L; Park, So-Jung

    2010-12-21

    We report a high-yield synthetic method for a new type of metal nanostructure, spiky gold nanoshells, which combine the morphological characteristics of hollow metal nanoshells and nanorods. Our method utilizes block copolymer assemblies and polymer beads as templates for the growth of spiky nanoshells. Various shapes of spiky metal nanoshells were prepared in addition to spherical nanoshells by using block copolymer assemblies such as rod-like micelles, vesicles, and bilayers as templates. Furthermore, spiky gold shells encapsulating magnetic nanoparticles or quantum dots were prepared based on the ability of block copolymers to self-assemble with various types of nanoparticles and molecules. The capability to encapsulate other materials in the core, the shape tunability, and the highly structured surface of spiky nanoshells should benefit a range of imaging, sensing, and medical applications of metal nanostructures.

  19. Gold induced apoptsis study

    DEFF Research Database (Denmark)

    Laustsen, Christoffer

    2008-01-01

    at the moment, especially in the fields of lasers, they though have some problems concerning the placement of the tumor in the human body. Local heating by MR has tremendous advance in comparison too lasers. The first step is to validate the hypothesis of the inductive heating of the gold nano particles trough......Introduction   Cancer cells are highly thermo sensitive. On the basis of an article in Nature the idea arose, for a new non-invasive thermotherapy technique, based on radio frequency inductive heating of nano gold particles in an MR-scanner. Thermotherapy is getting considerably attention...... the low energy radio frequencies. If the method is demonstrated to be feasible, next step is testing in cell line trials.   Confocal microscopy experiments on cells are very hard to do reliable and reproducible statistic on, due to the fact that that it’s user counting which makes the data. Automatic...

  20. The RHIC gold rush

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, T. [Department of Physics, North Carolina State University (United States)

    2003-06-01

    Physicists are colliding gold nuclei to recreate the fireball that existed in the very early universe, and they may have found evidence for quark-gluon plasma. What happens to ordinary matter as you heat it to higher and higher temperatures, or compress it to greater and greater densities? This simple question underpins a major effort to create extreme conditions in the lab, which has recently taken the shape of the Relativistic Heavy Ion Collider (RHIC). This machine has been colliding gold nuclei since 2000, and has produced tantalizing hints that a new state of matter - the quark-gluon plasma - is created in the reactions. But it has also sparked surprises that are sending researchers back to the drawing board. (U.K.)

  1. The RHIC gold rush

    CERN Document Server

    Schäfer, T

    2003-01-01

    Physicists are colliding gold nuclei to recreate the fireball that existed in the very early universe, and they may have found evidence for quark-gluon plasma. What happens to ordinary matter as you heat it to higher and higher temperatures, or compress it to greater and greater densities? This simple question underpins a major effort to create extreme conditions in the lab, which has recently taken the shape of the Relativistic Heavy Ion Collider (RHIC). This machine has been colliding gold nuclei since 2000, and has produced tantalizing hints that a new state of matter - the quark-gluon plasma - is created in the reactions. But it has also sparked surprises that are sending researchers back to the drawing board. (U.K.)

  2. Validation of stress prediction during solidification of cast components

    CSIR Research Space (South Africa)

    Paine, AP

    2007-07-01

    Full Text Available designed box shaped experimental casting was used to validate the commercial finite-element code ProCAST (casting simulation software), with respect to distortions as well as residual stresses....

  3. Accuracy of stereolithography additive casts used in a digital workflow

    DEFF Research Database (Denmark)

    Al-Imam, Hiba; Gram, Mia; Benetti, Ana R

    2017-01-01

    additive (SLA) casts from 2 manufacturers: 9 Dreve SLA casts and 9 Scanbiz SLA casts. All casts were then scanned 9 times with an extraoral scanner to produce the reference data set. Trueness was evaluated by superimposing the data sets obtained by scanning the casts with the reference data set. Precision...... 95.3%, IQR 16.7) and the least RMS (median 25.8 μm, IQR 14.6), followed by Dreve and Scanbiz. Differences in RMS were observed between gypsum and the SLA casts (P... (within 50 μm) and the least RMS, followed by Scanbiz and Dreve. CONCLUSIONS: This study found that gypsum casts had higher accuracy than SLA casts. Within 50 μm, gypsum casts were better than Scanbiz SLA casts, while gypsum casts and Dreve SLA casts had similar trueness. Significant differences were...

  4. 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.

  5. 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.

  6. 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.

  7. Film Ace Takes Gold

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    "Really, I never, never expected to win this," said Chinese director Jia Zhangke on hearing he had taken the top award for his movie Still Life (Sanxia Haoren) at the Venice Film Festival, on September 9. A surprise late entry, Still Life quickly emerged as the favorite and the Gold Lion was again hugged by Chinese. The well-known Chinese director Zhang Yimou won the same award back in 1999, for Not One Less-also a

  8. JUNK: rubbish to gold

    OpenAIRE

    Hanson, Maria

    2015-01-01

    JUNK: rubbish to gold is a playful exploration of community economies (exchange, giving, bartering, gathering, earning, harvesting); putting on display the process of creating the ‘work of art’. Co-created and co-curated by Jivan Astfalck, Laura Bradshaw-Heap and Rachel Darbourne and partnered with charities, who supplied JUNK jewellery. During a public performance 31 jewellers ‘gifted’ their skills, (re)constructing pieces selected from a mountain of JUNK creating reimagined artworks for the...

  9. Rushing for gold

    DEFF Research Database (Denmark)

    Jønsson, Jesper Bosse; Bryceson, Deborah Fahy

    2009-01-01

    African rural dwellers have faced depressed economic prospects for several decades. Now, in a number of mineral-rich countries, multiple discoveries of gold and precious stones have attracted large numbers of prospective small-scale miners. While their 'rush' to, and activities within, mining sit...... affluent than the others, suggesting that movement can be rewarding for those willing to 'try their luck' with the hard work and social networking demands of mining another site....

  10. 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.

  11. 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.

  12. A study to evaluate the effect of oral stereognosis in acceptance of fixed prosthesis

    Directory of Open Access Journals (Sweden)

    Kaushal K Agrawal

    2011-01-01

    Full Text Available Aims: The aim of the study was to evaluate and compare the oral stereognostic ability and satisfaction for fixed prosthesis in human being. Materials and Methods: The present study was carried out on 40 subjects, the purpose being to investigate the relation of oral perception to diagnostic and therapeutic procedures. Two types of cast metal crowns-one had morphology closely resembling original tooth and other one confirmed to ideal contours were constructed on endodontically treated posterior tooth. One cast metal crown was randomly selected from two cast metal crown and fitted on prepared tooth. Oral stereognostic score of subject was determined by correct response to questionnaire based on the recognition ability of subjects. Patient satisfaction level was checked by psychometric parameter Likert scale. Same procedure was repeated with other type of cast metal crown. Results: Data obtained were compared by paired and unpaired two sample t-test. Oral stereognostic score and satisfaction score were found to be higher for cast metal crown with morphology resembling to original tooth due to recognition and discriminatory ability of subjects and recall-memory. Oral stereognostic level was found to be higher in younger than older subjects. The level of satisfaction was found to be higher in older subjects than younger subjects. Conclusion: It was concluded that acceptance of fixed prosthesis is not only based on dentist′s routine procedure of treatment and patient′s judgment about oral health, function, and esthetics, but also depends upon patient′s oral perception and discriminatory skill for external morphology of fixed prosthesis.

  13. 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.

  14. 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.

  15. 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

  16. 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

  17. 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.

  18. Engineering design of centrifugal casting machine

    Science.gov (United States)

    Kusnowo, Roni; Gunara, Sophiadi

    2017-06-01

    Centrifugal casting is a metal casting process in which metal liquid is poured into a rotating mold at a specific temperature. Given round will generate a centrifugal force that will affect the outcome of the casting. Casting method is suitable in the manufacture of the casting cylinder to obtain better results. This research was performed to design a prototype machine by using the concept of centrifugal casting. The design method was a step-by-step systematic approach in the process of thinking to achieve the desired goal of realizing the idea and build bridges between idea and the product. Design process was commenced by the conceptual design phase and followed by the embodiment design stage and detailed design stage. With an engineering design process based on the method developed by G. E. Dieter, draft prototype of centrifugal casting machine with dimension of 550×450×400 mm, ¼ HP motor power, pulley and belt mechanism, diameter of 120-150mm, simultaneously with the characteristics of simple casting product, easy manufacture and maintenance, and relatively inexpensive, was generated.

  19. Detection of Cast Shadows in Surveillance Applications

    DEFF Research Database (Denmark)

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

    2005-01-01

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

  20. 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.

  1. 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.

  2. Gold-gold junction electrodes:the disconnection method.

    Science.gov (United States)

    Dale, Sara E C; Vuorema, Anne; Ashmore, Ellen M Y; Kasprzyk-Horden, Barbara; Sillanpää, Mika; Denuault, Guy; Marken, Frank

    2012-02-01

    The formation of gold-gold junction electrodes for application in electroanalysis is described here based on electro-deposition from a non-cyanide gold plating bath. Converging growth of two hemispherical gold deposits on two adjacent platinum microelectrodes (both 100 µm diameter in glass, ca. 45 µm gap) followed by careful etching in aqueous chloride solution was employed. During growth both gold hemispheres "connect" and during etching "disconnection" is evident in a drop in current. Gold-gold junctions with sub-micron gaps are formed and applied for the electroanalytical detection of sub-micromolar concentrations of hydroquinone in 0.1 M phosphate buffer pH 7 (E(rev) = 0.04 V vs. SCE) and sub-micromolar concentration of dopamine in 0.1 M phosphate buffer pH 7 (E(rev) = 0.14 V vs. SCE). The potential future uses in analysis and limitations of gold-gold junction electrodes are discussed.

  3. 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...

  4. 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...

  5. 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...

  6. 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.

  7. 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.

  8. 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.

  9. Flow field-flow fractionation: a versatile approach for size characterization of alpha-tocopherol-induced enlargement of gold nanoparticles.

    Science.gov (United States)

    Sermsri, Wimut; Jarujamrus, Purim; Shiowatana, Juwadee; Siripinyanond, Atitaya

    2010-04-01

    Flow field-flow fractionation (FlFFF) was used for size characterization of gold nanoparticles. The measured particle sizes obtained from FlFFF for the commercial 10 nm gold nanoparticle standard and the gold nanoparticles synthesized in the laboratory were in good agreement with those measured by transmission electron microscopy (TEM). Further, the capability of alpha-tocopherol to induce enlargement of gold nanoparticles by catalysis of the reduction of AuCl(4)(-) by citrate was observed by monitoring the changes in particle size of gold nanoparticles using FlFFF. The effects of alpha-tocopherol and incubation time on enlargement of the gold nanoparticles were examined. Higher concentrations of alpha-tocopherol resulted in larger nanoparticles. At fixed alpha-tocopherol concentration, larger nanoparticles were formed at longer incubation times.

  10. Management of long span partially edentulous maxilla with fixed removable denture prosthesis

    Directory of Open Access Journals (Sweden)

    Mahilan I Jeyavalan

    2012-01-01

    Full Text Available Restoration of a long span partially edentulous maxilla with tooth supported prosthesis is challenging because of inherent anatomic limitations and unfavourable biomechanics present after the loss of teeth. A tooth supported fixed-removable prosthesis is a treatment option for restoration of such long span partially edentulous maxillary arches. This prosthesis meets the requirements for esthetics, phonetics, comfort, and hygiene, as well as favourable biomechanical stress distribution to the remaining natural tooth abutments. This article presents a procedure for fabrication of a fixed-removable prosthesis that has cement-retained custom cast bar metal substructure and a ball attachment retained removable superstructure prosthesis.

  11. National Radiological Fixed Lab Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — The National Radiological Fixed Laboratory Data Asset includes data produced in support of various clients such as other EPA offices, EPA Regional programs, DOE,...

  12. Elevated Fixed Platform Test Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Elevated Fixed Platform (EFP) is a helicopter recovery test facility located at Lakehurst, NJ. It consists of a 60 by 85 foot steel and concrete deck built atop...

  13. Green Synthesis of Gold Nanoparticles

    Directory of Open Access Journals (Sweden)

    Hamid Reza Ghorbani

    2015-03-01

    Full Text Available There is an increased interest in understanding the toxicity and rational design of gold nanoparticles for biomedical applications in recent years. In this study gold nanoparticles were synthesized using dextrose as a reducing agent. The gold nanoparticles displayed characteristic Surface Plasmon Resonance peak at around 550 nm having a mean particle size of 75±30 nm. In order to identify and analyze nanoparticles, UV–Vis spectroscopy, Scanning electron microscopy (SEM, and dynamic light scattering (DLS were used.

  14. Fixed Exchange Rates and Trade

    OpenAIRE

    Michael W. Klein; Jay C. Shambaugh

    2004-01-01

    A classic argument for a fixed exchange rate is its promotion of trade. Empirical support for this, however, is mixed. While one branch of research consistently shows a small negative effect of exchange rate volatility on trade, another, more recent, branch presents evidence of a large positive impact of currency unions on trade. This paper helps resolve this disconnect. Our results, which use a new data-based classification of fixed exchange rate regimes, show a large, significant effect of ...

  15. The extractive metallurgy of gold

    Science.gov (United States)

    Kongolo, K.; Mwema, M. D.

    1998-12-01

    Mössbauer spectroscopy has been successfully used in investigation of the gold compounds present in ores and the gold species which occur during the process metallurgy of this metal. This paper is a survey of the basic recovery methods and techniques used in extractive metallurgy of gold. Process fundamentals on mineral processing, ore leaching, zinc dust cementation, adsorption on activated carbon, electrowinning and refining are examined. The recovery of gold as a by-product of the copper industry is also described. Alternative processing methods are indicated in order to shed light on new interesting research topics where Mössbauer spectroscopy could be applied.

  16. 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.

  17. Bingham plastic fluid flow model in tape casting of ceramics using two doctor blades – analytical approach

    DEFF Research Database (Denmark)

    Jabbari, Masoud; Hattel, Jesper Henri

    2014-01-01

    , and it is therefore of great interest to be able to control it. One way to control the tape thickness is to use a two doctor blade configuration in the tape casting machine. In this case, it becomes important to fix the height of the slurry in front of both doctor blades according to the desired tape thickness...... and casting speed (belt velocity). In the present work, the flow in both doctor blade regions of a slurry is described with a steady state momentum equation in combination with a Bingham plastic constitutive equation, and this is integrated to a closed form analytical solution for both reservoirs based...

  18. Numerical simulation of casting processes: coupled mould filling and solidification using VOF and enthalpy-porosity method

    Science.gov (United States)

    Richter, Ole; Turnow, Johann; Kornev, Nikolai; Hassel, Egon

    2017-06-01

    Within the scope of industrial casting applications a numerical model for the simultaneous mould filling and solidification process has been formulated, implemented in a finite volume code and successfully validated using analytical and experimental data. In order to account for the developing of free surface flow and the liquid/solid phase change, respectively, the volume-of-fluid and enthalpy-porosity method have been coupled under a volume averaging framework on a fixed Eulerian grid. The coupled method captures the basic physical effects of a combined mould filling and solidification process and provides a trustful method for comprehensive casting simulations.

  19. 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.

  20. Turning lead into gold

    DEFF Research Database (Denmark)

    Jensen, Steffen Moltrup Ernø

    For years the field of entrepreneurship has been blinded by the alchemical promise of turning lead into gold, of finding the ones most likely to become the next Branson, Zuckerberg or Gates. The promise has been created in the midst of political and scientific agendas where certain individuals...... is not to accumulate state or market wealth, but for entrepreneurial skills to become tools towards the liberation of the individual from oppressive systems of control – essentially to add public value rather than economic value. In this presentation I will sketch an anarchist perspective on entrepreneurship, looking...

  1. 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.

  2. Fabrication, nanomechanical characterization, and cytocompatibility of gold-reinforced chitosan bio-nanocomposites

    Science.gov (United States)

    Patel, Nimitt G.; Kumar, Ajeet; Jayawardana, Veroni N.; Woodworth, Craig D.; Yuya, Philip A.

    2017-01-01

    Chitosan, a naturally derived polymer represents one of the most technologically important classes of active materials with applications in a variety of industrial and biomedical fields. Gold nanoparticles (~32 nm) were synthesized via a citrate reduction method from chloroauric acid and incorporated in Chitosan matrix. Bio-nanocomposite films with varying concentrations of gold nanoparticles were prepared through solution casting process. Uniform distribution of gold nanoparticles was achieved throughout the chitosan matrix and was confirmed with SEM. Synthesis outcomes and prepared nanocomposites were characterized using SEM, TEM, EDX, SAED, UV–vis, XRD, DLS, and Zeta potential for their physical, morphological and structural properties. Nanoscale properties of materials under the influence of temperature were characterized through nanoindentation techniques. From quasi-static nanoindentation, it was observed that hardness and reduced modulus of the nanocomposites were increased significantly in direct proportion to the gold nanoparticle concentration. Gold nanoparticle concentration also showed positive impact on storagemodulus and thermal stability of the material. The obtained films were confirmed to be biocompatible by their ability to support growth of human cells in vitro. In summary, the results show enhanced mechanical properties with increasing gold nanoparticle concentration, and provide better understanding of the structure–property relationships of such biocompatiblematerials for potential biomedical applications. PMID:25280713

  3. 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...

  4. 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.)

  5. 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.

  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. A Comparison Simulation of Fixed-fixed Type MEMS Switches

    Science.gov (United States)

    Rezazadeh, G.; Sadeghian, H.; Malekpour, E.

    2006-04-01

    In the present work pull-in voltage of fixed-fixed end type MEMS switches with variative electrostatic area has been calculated using a distributed model and applying a full nonlinear finite difference discretizing method. The governing nonlinear differential equation has been derived using of the variational principle for multi domain electromechanical coupled system. The numerical results of the beam with variative electrostatic area with the results of Coupled-Domain Finite Element method have been compared and very good agreement has been achieved.

  8. Diclofenac Induced Fixed Drug Eruption

    Directory of Open Access Journals (Sweden)

    Dr. Umeshchandra C Honnaddi

    2016-02-01

    Full Text Available Background: Diclofenac is the most commonly used non-steroidal anti-inflammatory drug (NSAID for treating various inflammatory and painful conditions. It is generally well tolerated; gastric upset is the most common adverse effect. However very few cases of fixed drug eruptions were reported. Here we present a case of Diclofenac Induced Fixed Drug Eruption. A 62 year old male patient developed fixed drug eruptions with plaques on left thigh two days after receiving diclofenac for osteoarthritic pain. Other etiologies including insect bite, infections were ruled out. One week later after stopping the drug, the lesions were subsided. Diclofenac was strongly suspected as the casual drug. CD8+ effector T-cells have shown to play an important role. However it seems to be a reversible and drug related event. Although it is not life-threatening, fixed drug eruption can have significant effect on the quality of life of patients.Conclusion: Diclofenac is one of the most commonly prescribed NSAIDs by the Physicians. It is usually well tolerated, gastric upset is the most common adverse effect noted with this drug. This case is being reported to highlight a drug as safe as Diclofenac may also be associated with Fixed Drug Eruptions.

  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. The structure of abrasion-resisting castings made of chromium cast iron

    Directory of Open Access Journals (Sweden)

    D. Kopyciński

    2011-01-01

    Full Text Available In this study presents the analyse of chrome iron cast structure (as-cast condition which are used in rugged conditions abrasion-percussive and high temperature. While producing the casts of chrome iron major influence has been preserve the structure of technologi cal process parameters. The addition to Fe-C-Cr alloy Ni, Mo or Cu and then proper heat treatment leads to the improvement of functional and mechanical cast qualities. Then it is possible to develop high mechanical properties which are recommended by PN-EN12513. As can it be seen from the above research silicon is an adverse chemical element in this kind of alloy cast iron. However, the reason of cracksappearing in chrome iron casts are phosphorus eutectic microareas. When the compound of Si and P reach the critical point, described inPN-88/H-83144 outdated standard, the microareas might appear.

  11. Exothermic properties of plaster-synthetic composite casts.

    Science.gov (United States)

    Burghardt, Rolf D; Anderson, John G; Reed, Rob A; Herzenberg, John E

    2014-03-01

    Plaster casts can cause burns. Synthetic casts do not. Composite plaster-synthetic casts have not been thoroughly evaluated. This study analyzed the temperature from plaster casts compared with composite casts in a variety of in vitro conditions that would simulate clinical practice. A Pyrex cylinder filled with constant body temperature circulating water simulated a human extremity. Circumferential casts, of either plaster or composite construction (plaster inner layer with outer synthetic layer), were applied to the model. Peak temperatures generated by the exothermic reactions were studied relative to the following variables: dip water temperature (24 °C versus 40 °C), cast thickness (16, 30, and 34 ply), and delayed (5-min) versus immediate application of the synthetic outer layers. Peak temperatures from the all-plaster casts were compared with the composite casts of the same thickness. Finally, the relative cast strength was determined. Potentially dangerous high temperatures were measured only when 40 °C dip water was used or when thick (30- or 34-ply) casts were made. Cast strength increased with increasing cast thickness. However, the presence of synthetics in the composite casts layers did not increase cast strength in every case. When applying composite casts, the outer synthetic layers should be applied several minutes after the plaster to minimize temperature rise. Composite casts do not routinely generate peak temperatures higher than plaster casts of similar thickness. Because the skin of children and the elderly is more temperature-sensitive than average adult skin, extra care should be taken to limit the exothermic reaction when casting children and the elderly: clean, room temperature dip water, minimal required cast thickness, avoidance of insulating pillows/blankets while the cast is drying.

  12. 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...

  13. Gold electrodes from recordable CDs

    Science.gov (United States)

    Angnes; Richter; Augelli; Kume

    2000-11-01

    Gold electrodes are widely used in electrochemistry and electroanalytical chemistry. The notable performance when used in stripping analysis of many ionic species and the extraordinary affinity of thio compounds for its surface make these electrodes very suitable for many applications. This paper reports a simple and novel way to construct gold electrodes (CDtrodes) using recordable CDs as the gold source. The nanometer thickness of the gold layer of recordable disks (50-100 nm) favors the construction of band nanoelectrodes with areas as small as 10(-6) cm2. The plane surface can be easily used for the construction of conventional-sized gold electrodes for batch or flow injection analysis or even to obtain electrodes as large as 100 cm2. The low price of commercial recordable CDs allows a "one way use". The evaluation and applicability of these electrodes in the form of nanoelectrodes, in batch and associated with flow cells, are illustrated in this paper.

  14. 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...

  15. Evidence of the Big Fix

    CERN Document Server

    Hamada, Yuta; Kawana, Kiyoharu

    2014-01-01

    We give an evidence of the Big Fix. The theory of wormholes and multiverse suggests that the parameters of the Standard Model are fixed in such a way that the total entropy at the late stage of the universe is maximized, which we call the maximum entropy principle. In this paper, we discuss how it can be confirmed by the experimental data, and we show that it is indeed true for the Higgs vacuum expectation value $v_{h}$. We assume that the baryon number is produced by the sphaleron process, and that the current quark masses, the gauge couplings and the Higgs self coupling are fixed when we vary $v_{h}$. It turns out that the existence of the atomic nuclei plays a crucial role to maximize the entropy. This is reminiscent of the anthropic principle, however it is required by the fundamental low in our case.

  16. Evidence of the big fix

    Science.gov (United States)

    Hamada, Yuta; Kawai, Hikaru; Kawana, Kiyoharu

    2014-06-01

    We give an evidence of the Big Fix. The theory of wormholes and multiverse suggests that the parameters of the Standard Model are fixed in such a way that the total entropy at the late stage of the universe is maximized, which we call the maximum entropy principle. In this paper, we discuss how it can be confirmed by the experimental data, and we show that it is indeed true for the Higgs vacuum expectation value vh. We assume that the baryon number is produced by the sphaleron process, and that the current quark masses, the gauge couplings and the Higgs self-coupling are fixed when we vary vh. It turns out that the existence of the atomic nuclei plays a crucial role to maximize the entropy. This is reminiscent of the anthropic principle, however it is required by the fundamental law in our case.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Ambiguous chairs cast in fabric formed concrete

    DEFF Research Database (Denmark)

    Manelius, Anne-Mette

    2009-01-01

    On the basis of a specific experiment with a new casting technique for concrete structures, this paper discusses explorations of materiality as a way of generating discussion of the use of new technologies....

  2. 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.

  3. 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...

  4. 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.

  5. 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)

  6. 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.

  7. 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.

  8. 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. " ...

  9. 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...

  10. Fixed-point signal processing

    CERN Document Server

    Padgett, Wayne T

    2009-01-01

    This book is intended to fill the gap between the ""ideal precision"" digital signal processing (DSP) that is widely taught, and the limited precision implementation skills that are commonly required in fixed-point processors and field programmable gate arrays (FPGAs). These skills are often neglected at the university level, particularly for undergraduates. We have attempted to create a resource both for a DSP elective course and for the practicing engineer with a need to understand fixed-point implementation. Although we assume a background in DSP, Chapter 2 contains a review of basic theory

  11. Perfect and Imperfect Gauge Fixing

    CERN Document Server

    Shirzad, A

    2006-01-01

    Gauge fixing may be done in different ways. We show that using the chain structure to describe a constrained system, enables us to use either a perfect gauge, in which all gauged degrees of freedom are determined; or an imperfect gauge, in which some first class constraints remain as subsidiary conditions to be imposed on the solutions of the equations of motion. We also show that the number of constants of motion depends on the level in a constraint chain in which the gauge fixing condition is imposed. The relativistic point particle, electromagnetism and the Polyakov string are discussed as examples and perfect or imperfect gauges are distinguished.

  12. Fixed effects analysis of variance

    CERN Document Server

    Fisher, Lloyd; Birnbaum, Z W; Lukacs, E

    1978-01-01

    Fixed Effects Analysis of Variance covers the mathematical theory of the fixed effects analysis of variance. The book discusses the theoretical ideas and some applications of the analysis of variance. The text then describes topics such as the t-test; two-sample t-test; the k-sample comparison of means (one-way analysis of variance); the balanced two-way factorial design without interaction; estimation and factorial designs; and the Latin square. Confidence sets, simultaneous confidence intervals, and multiple comparisons; orthogonal and nonorthologonal designs; and multiple regression analysi

  13. Cationic gold staining of glomerular anionic sites in archived tissue, reprocessed from paraffin wax into LR gold resin.

    Science.gov (United States)

    Goode, N P; Shires, M; Aparicio, S R; Davison, A M

    1993-05-01

    Glomerular capillary wall anionic sites have been demonstrated by cationic gold staining of archived renal biopsy tissue (up to 10 years old), obtained from six patients, originally embedded in paraffin wax, and subsequently reprocessed into LR gold resin. The staining patterns at pH 2.5 and pH 7.0, demonstrating different glomerular basement membrane (GBM) anionic constituents, were compared in three patients from whom tissue directly processed into LR gold and reprocessed tissue was available. Ultrastructural preservation was poorer and shrinkage artefact greater in paraformaldehyde-lysine periodate (PLP) as opposed to formol saline-fixed reprocessed tissue. However, GBM anionic site expression was well preserved, or even enhanced (lamina rara externa, pH 7.0) in reprocessed tissue, using either fixative. Although it may not be possible to compare subtle changes in anionic site distribution in variously fixed and processed tissues, due to these artefacts, the technique enables retrospective study of charge status in archived material from disease groups in which there are distinct anionic site aberrations.

  14. 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)

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Wear of double crown systems: electroplated vs. casted female part

    Directory of Open Access Journals (Sweden)

    Stefan Bayer

    2012-06-01

    Full Text Available OBJECTIVES: The wear of telescopic crowns is a common problem often reducing the patient's satisfaction with the denture and resulting in a renewal of the denture. The study aims to compare the wear behavior of conical crowns using electroplated copings (group E with standard telescopic crowns with cast female parts (group C. MATERIAL AND METHODS: 10 conical crowns were milled for each group of a cast gold alloy. The specimen of group E had a conicity of 2º. The cast secondary crowns of group C had a 0º design. The electroplated coping was established by direct electroforming. An apparatus accomplishing 10,000 wear cycles performed the wear test. The retentive forces and the correlating distance during insertion and separation were measured. The wear test was separated in a start phase, an initial wear phase and the long term wear period. The retention force value and the force-distance integral of the first 0.33 mm of each cycle were calculated. RESULTS: The retentive forces were significantly higher for group E and the integrals were significantly lower for this group except the integral at cycle 10,000. The changes of retention force and integral did not differ significantly between both groups in all phases. The change of the integrals as well as the integral at the particular cycles showed higher interquartile distances for group C. CONCLUSIONS: Within the limitations of this study the tested conical crowns showed clinically acceptable retentive properties. The values reached a range comparable to retentive elements tested in recent literature. The values of group C showed higher ranges. The force measured for group E was significantly higher than for group C but the integrals showed an opposite tendency. The results indicate that an exclusive analysis of the force is not sufficient as the integral is not equivalent to the force although it describes the retentive property of the system in a better way than the force over a distance is

  20. 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...

  1. A hybrid metaheuristic method to optimize the order of the sequences in continuous-casting

    Directory of Open Access Journals (Sweden)

    Achraf Touil

    2016-06-01

    Full Text Available In this paper, we propose a hybrid metaheuristic algorithm to maximize the production and to minimize the processing time in the steel-making and continuous casting (SCC by optimizing the order of the sequences where a sequence is a group of jobs with the same chemical characteristics. Based on the work Bellabdaoui and Teghem (2006 [Bellabdaoui, A., & Teghem, J. (2006. A mixed-integer linear programming model for the continuous casting planning. International Journal of Production Economics, 104(2, 260-270.], a mixed integer linear programming for scheduling steelmaking continuous casting production is presented to minimize the makespan. The order of the sequences in continuous casting is assumed to be fixed. The main contribution is to analyze an additional way to determine the optimal order of sequences. A hybrid method based on simulated annealing and genetic algorithm restricted by a tabu list (SA-GA-TL is addressed to obtain the optimal order. After parameter tuning of the proposed algorithm, it is tested on different instances using a.NET application and the commercial software solver Cplex v12.5. These results are compared with those obtained by SA-TL (simulated annealing restricted by tabu list.

  2. 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...

  3. 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 ...

  4. 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...

  5. GOLD AND LAND PRICES WITH CAPITAL ACCUMULATION IN AN ECONOMY WITH INDUSTRIAL AND AGRICULTURAL SECTORS

    Directory of Open Access Journals (Sweden)

    ZHANG WEI-BIN

    2016-04-01

    Full Text Available The purpose of this study is to examine dynamic interactions among gold value, land price and economic structure in a growth model with capital accumulation. The paper proposes a two-sector general equilibrium model with land and gold prices as endogenous variables. The economy consists of industrial and agricultural sectors with fixed land and gold. Land is used for residential use and agricultural production and gold is used for saving and decorations. The portfolio equilibrium growth model is based on the neoclassical growth theory and Ricardian theory. We simulate the model to demonstrate that the economic system has a unique stable steady state. We show how exogenous changes in preference and technology affect the transitory processes and long-term equilibrium.

  6. Flat coalgebraic fixed point logics

    CERN Document Server

    Schröder, Lutz

    2010-01-01

    Fixed point logics have a wide range of applications in computer science, in particular in artificial intelligence and concurrency. The most expressive logics of this type are the mu-calculus and its relatives. However, popular fixed point logics tend to trade expressivity for simplicity and readability, and in fact often live within the single variable fragment of the mu-calculus. The family of such flat fixed point logics includes, e.g., CTL, the *-nesting-free fragment of PDL, and the logic of common knowledge. Here, we extend this notion to the generic semantic framework of coalgebraic logic, thus covering a wide range of logics beyond the standard mu-calculus including, e.g., flat fragments of the graded mu-calculus and the alternating-time mu-calculus (such as ATL), as well as probabilistic and monotone fixed point logics. Our main results are completeness of the Kozen-Park axiomatization and a timed-out tableaux method that matches EXPTIME upper bounds inherited from the coalgebraic mu-calculus but avo...

  7. Landau Gauge Fixing on GPUs

    CERN Document Server

    Cardoso, Nuno; Bicudo, Pedro; Oliveira, Orlando

    2012-01-01

    In this paper we present and explore the performance of Landau gauge fixing in GPUs using CUDA. We consider the steepest descent algorithm with Fourier acceleration, and compare the GPU performance with a parallel CPU implementation. Using $32^4$ lattice volumes, we find that the computational power of a single Tesla C2070 GPU is equivalent to approximately 256 CPU cores.

  8. Fixed drug eruption to tartrazine.

    Science.gov (United States)

    Orchard, D C; Varigos, G A

    1997-11-01

    An 11-year-old girl with a recurrent fixed drug eruption to tartrazine on the dorsum of the left hand is presented. Oral provocation tests to both the suspected food, an artificially coloured cheese crisp, and to tartrazine were positive. This case highlights fire need to consider artificial flavours, colours and preservatives as potential culprits in classic drug eruptions.

  9. Fixed maxillary and mandibular zirconia implant frameworks milled with anatomically contoured molars: a clinical report.

    Science.gov (United States)

    Al-Mazedi, Mohammad; Razzoog, Michael E; Yaman, Peter

    2014-11-01

    Retrospective studies on restoring the patients with complete edentulism have reported a variety of complications, including the excessive wear and fracture of the acrylic resin teeth. Approaches to slow the process of wear include the use of porcelain teeth or altering the occlusal surface of acrylic resin teeth with amalgam or gold. Two 1-piece fixed zirconia implant frameworks masked with gingival porcelain and stained anatomically contoured first and second molars and individual ceramic crowns were used to restore both arches to optimum function and esthetics. This clinical report describes the steps for one method of providing the fixed prosthetic needs of the patients who is edentulous.

  10. Adhesives for fixed orthodontic bands.

    Science.gov (United States)

    Millett, Declan T; Glenny, Anne-Marie; Mattick, Rye Cr; Hickman, Joy; Mandall, Nicky A

    2016-10-25

    Orthodontic treatment involves using fixed or removable appliances (dental braces) to correct the positions of teeth. It has been shown that the quality of treatment result obtained with fixed appliances is much better than with removable appliances. Fixed appliances are, therefore, favoured by most orthodontists for treatment. The success of a fixed orthodontic appliance depends on the metal attachments (brackets and bands) being attached securely to the teeth so that they do not become loose during treatment. Brackets are usually attached to the front and side teeth, whereas bands (metal rings that go round the teeth) are more commonly used on the back teeth (molars). A number of adhesives are available to attach bands to teeth and it is important to understand which group of adhesives bond most reliably, as well as reducing or preventing dental decay during the treatment period. To evaluate the effectiveness of the adhesives used to attach bands to teeth during fixed appliance treatment, in terms of:(1) how often the bands come off during treatment; and(2) whether they protect the banded teeth against decay during fixed appliance treatment. The following electronic databases were searched: Cochrane Oral Health's Trials Register (searched 2 June 2016), Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 5) in the Cochrane Library (searched 2 June 2016), MEDLINE Ovid (1946 to 2 June 2016) and EMBASE Ovid (1980 to 2 June 2016). We searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. Randomised and controlled clinical trials (RCTs and CCTs) (including split-mouth studies) of adhesives used to attach orthodontic bands to molar teeth were selected. Patients with full arch fixed orthodontic appliance(s) who had bands attached to molars were included. All review authors

  11. Event Display for the Fixed Target Experiment BM@N

    Directory of Open Access Journals (Sweden)

    Gertsenberger Konstantin

    2016-01-01

    Full Text Available One of the main problems to be solved in modern high energy physics experiments on particle collisions with a fixed target is the visual representation of the events during the experiment run. The article briefly describes the structure of the BM@N facility at the Nuclotron being under construction at the Joint Institute for Nuclear Research with the aim to study properties of the baryonic matter in collisions of ions with fixed target at energies up to 4 GeV/nucleon (for Au79+. Aspects concerning the visualization of data and detector details at the modern experiments and possibilities of practical applications are discussed. We present event display system intended to visualize the detector geometries and events of particle collisions with the fixed target, its options and features as well as integration with BMNRoot software. The examples of graphical representation of simulated and reconstructed points and particle tracks with BM@N geometry are given for central collisions of Au79+ ions with gold target and deuterons with carbon target.

  12. Event Display for the Fixed Target Experiment BM@N

    Science.gov (United States)

    Gertsenberger, Konstantin

    2016-02-01

    One of the main problems to be solved in modern high energy physics experiments on particle collisions with a fixed target is the visual representation of the events during the experiment run. The article briefly describes the structure of the BM@N facility at the Nuclotron being under construction at the Joint Institute for Nuclear Research with the aim to study properties of the baryonic matter in collisions of ions with fixed target at energies up to 4 GeV/nucleon (for Au79+). Aspects concerning the visualization of data and detector details at the modern experiments and possibilities of practical applications are discussed. We present event display system intended to visualize the detector geometries and events of particle collisions with the fixed target, its options and features as well as integration with BMNRoot software. The examples of graphical representation of simulated and reconstructed points and particle tracks with BM@N geometry are given for central collisions of Au79+ ions with gold target and deuterons with carbon target.

  13. Discoloration of gingiva in the presence of fixed dental restorations

    Directory of Open Access Journals (Sweden)

    Ristić Ljubiša

    2005-01-01

    Full Text Available Aim. To investigate the frequency of discoloration of gingiva in the presence of fixed dental restorations, regarding the type of alloy of which restorations were made, and to show histopathological changes of discolored gingiva. Methods. One hundred and eighty four patients of both sexes were examined. The average age of the examinees was 52. They were divided into four groups according to the alloys from which their restorations were made. Standardized history questionnaires and clinical examination procedures were developed for this study. In ten examinees, whose teeth were indicated for extraction and who had a discoloration of gingiva, the samples of tissue were taken from the discolored gingiva for histopathological examination. Results. Our results showed the presence of discolored gingiva in all four groups. It was most frequent in the examinees with fixed restorations made of Ni-Cr alloy (43,5% and less frequent in those with fixed dental restorations made of gold alloy (26,5%. Histopathological examination showed the presence of tissue foreign body granulomas with giant cells in which the metal particles were found, partially as small and partially as large particles. Conclusion. Results suggested that grayish discoloration of gingiva was present in all four groups of examinees. The highest number of examinees with discolored gingiva was in the group with restorations made of Ni-Cr alloy. Grayish discoloration of gingiva was a consequence of incorporation of metal particles into gingival tissue.

  14. Can mushrooms fix atmospheric nitrogen?

    Indian Academy of Sciences (India)

    H S Jayasinghearachchi; Gamini Seneviratne

    2004-09-01

    It is generally reported that fungi like Pleurotus spp. can fix nitrogen (N2). The way they do it is still not clear. The present study hypothesized that only associations of fungi and diazotrophs can fix N2. This was tested in vitro. Pleurotus ostreatus was inoculated with a bradyrhizobial strain nodulating soybean and P. ostreatus with no inoculation was maintained as a control. At maximum mycelial colonization by the bradyrhizobial strain and biofilm formation, the cultures were subjected to acetylene reduction assay (ARA). Another set of the cultures was evaluated for growth and nitrogen accumulation. Nitrogenase activity was present in the biofilm, but not when the fungus or the bradyrhizobial strain was alone. A significant reduction in mycelial dry weight and a significant increase in nitrogen concentration were observed in the inoculated cultures compared to the controls. The mycelial weight reduction could be attributed to C transfer from the fungus to the bradyrhizobial strain, because of high C cost of biological N2 fixation. This needs further investigations using 14C isotopic tracers. It is clear from the present study that mushrooms alone cannot fix atmospheric N2. But when they are in association with diazotrophs, nitrogenase activity is detected because of the diazotrophic N2 fixation. It is not the fungus that fixes N2 as reported earlier. Effective N2 fixing systems, such as the present one, may be used to increase protein content of mushrooms. Our study has implications for future identification of as yet unidentified N2 systems occurring in the environment.

  15. Directed Assembly of Gold Nanoparticles

    DEFF Research Database (Denmark)

    Westerlund, Axel Rune Fredrik; Bjørnholm, Thomas

    2009-01-01

    As a complement to common "top-down" lithography techniques, "bottom-up" assembly techniques are emerging as promising tools to build nanoscale structures in a predictable way. Gold nanoparticles that are stable and relatively easy to synthesize are important building blocks in many such structures...... due to their useful optical and electronic properties. Programmed assembly of gold nanoparticles in one, two, and three dimensions is therefore of large interest. This review focuses on the progress from the last three years in the field of directed gold nanoparticle and nanorod assembly using...

  16. 41 CFR 101-45.002 - Gold.

    Science.gov (United States)

    2010-07-01

    ... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Gold. 101-45.002 Section... PERSONAL PROPERTY § 101-45.002 Gold. (a) Gold will be sold in accordance with this section and part 102-38 of the Federal Management Regulation. (b) Sales of gold shall be processed to— (1) Use the sealed bid...

  17. 20th-Century Gold Rush.

    Science.gov (United States)

    Wargo, Joseph G.

    1992-01-01

    Presents Nevada's gold rush activities spurred by technological advancements in search methods. Describes the events that led to the twentieth-century gold rush, the techniques for finding deposits and the geological formation process of disseminated gold deposits. Vignettes present the gold extraction process, cross-section, and profile of a…

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Casting of MOD inlay using rings with holes on both sides: 12∼18 wt%Au-20∼26Pd-14.48∼26.48Cu-40Ag-1.5Zn-0.02Ir alloys.

    Science.gov (United States)

    Ohkuma, Kazuo; Kazama, Miku; Ogura, Hideo

    2012-01-01

    Using a casting ring with openings on both sides and a water-absorbent polymer, heterogeneity is maintained in a single casting and a precise MOD inlay can be produced. We produced 9 different kinds of gold-silver-palladium (Au-Ag-Pd) alloys by changing the ratio of palladium, gold, and copper and investing them, and changing parameters such as the angulation of the casting ring openings and the water:powder ratios to produce MOD inlay castings. We measured the expansion and shrinkage percentage of the castings in both the buccolingual and mesiodistal directions. From this experiment, we learned that precise MOD inlay castings can be produced using rings with 240° openings when invested in a thick mix having a standard water:powder ratio or using rings with 200° openings when invested in a thick mix having a water:powder ratio for a 12 wt%Au-20∼26Pd-20.48∼26.48Cu-40Ag-1.5Zn-0.02Ir alloyes.

  4. Protein-mediated autoreduction of gold salts to gold nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Basu, Nivedita; Bhattacharya, Resham; Mukherjee, Priyabrata [Department of Biochemistry and Molecular Biology, College of Medicine, Mayo Clinic, Rochester, MN 55905 (United States)], E-mail: Mukherjee.Priyabrata@mayo.edu

    2008-09-01

    Here we report for the first time that proteins can function as unique reducing agents to produce gold nanoparticles from gold salts. We demonstrate that three different proteins, namely, bovine serum albumin (BSA), Rituximab (RIT-an anti-CD20 antibody) and Cetuximab (C225-anti-EGFR antibody), reduce gold salts to gold nanoparticles (GNP). Interestingly, among all the three proteins tested, only BSA can reduce gold salts to gold nanotriangles (GNT). BSA-induced formation of GNT can be controlled by carefully selecting the reaction condition. Heating or using excess of ascorbic acid (AA) as additional reducing agent shifts the reaction towards the formation of GNP with flower-like morphology, whereas slowing down the reaction either by cooling or by adding small amount of AA directs the synthesis towards GNT formation. GNT is formed only at pH 3; higher pHs (pH 7 and pH 10) did not produce any nanoparticles, suggesting the involvement of specific protein conformation in GNT formation. The nanomaterials formed by this method were characterized using UV-visible (UV-vis) spectroscopy and transmission electron microscopy (TEM). This is an important finding that will have uses in various nanotechnological applications, particularly in the green synthesis of novel nanomaterials based on protein structure.

  5. Metallic gold beads in hyaluronic acid

    DEFF Research Database (Denmark)

    Pedersen, Dan Sonne; Tran, Thao Phuong; Smidt, Kamille;

    2013-01-01

    by exploiting macrophage-induced liberation of gold ions (dissolucytosis) from gold surfaces. Injecting gold beads in hyaluronic acid (HA) as a vehicle into the cavities of the brain can delay clinical signs of disease progression in the MS model, experimental autoimmune encephalitis (EAE). This study....... In conclusion, our findings support that bio-liberation of gold from metallic gold surfaces have anti-inflammatory properties similar to classic gold compounds, warranting further studies into the pharmacological potential of this novel gold-treatment and the possible synergistic effects of hyaluronic acid....

  6. Gold-Catalyzed Synthesis of Heterocycles

    Science.gov (United States)

    Arcadi, Antonio

    2014-04-01

    The following sections are included: * Introduction * Synthesis of Heterocycles via Gold-Catalyzed Heteroatom Addition to Unsaturated C-C Bonds * Synthesis of Heterocyclic Derivatives through Gold-Catalyzed Cyclization of Polyunsaturated Compounds * Synthesis of Heterocyclic Compounds via α-Oxo Gold Carbenoid * Synthesis of Heterocyclic Derivatives through Gold-Catalyzed Cycloaddition Reactions * Synthesis of Heterocyclic Derivatives through Gold-Catalyzed Activation of Carbonyl Groups and Alcohols * Synthesis of Heterocyclic Compounds through Gold-Mediated C-H Bond Functionalization * Gold-Catalyzed Domino Cyclization/Oxidative Coupling Reactions * Conclusions * References

  7. 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.

  8. 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

  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. 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.

  11. 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.

  12. 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.

  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. 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.

  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. 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.

  17. Charged Hadron Distributions In 19.6-gev Gold+gold Collisions

    CERN Document Server

    Picha, R

    2005-01-01

    Experimental results from a low-energy heavy ion run in year 2001 at the Relativistic Heavy Ion Collider (RHIC) using the Solenoidal Tracker at RHIC (STAR) detector are presented. From the collisions of gold ions at sNN = 19.6 GeV, six species of particles (π±, K±, p, and p¯) are identified via energy loss mechanism and their transverse mass spectra are analyzed at midrapidity (|y| < 0.5) and m T − m0 < 1.0 GeV/c 2. Rapidity distributions, particle ratios, and hadronic freeze-out conditions are discussed. This study provides a low energy measurement at RHIC which is very close to that at the SPS for cross comparison between collider experiments and fixed target experiments. The analysis provides a good reference to study excitation functions of strangeness production, net baryon, and collective flow inside heavy ion collisions.

  18. Gold island fiber optic sensor

    Science.gov (United States)

    Meriaudeau, Fabrice; Wig, A. G.; Passian, A.; Downey, Todd R.; Buncick, Milan; Ferrell, Trinidad L.

    1999-12-01

    A fiber optic chemical sensor based on gold-island surface plasmon excitation is presented. The sensing part of the fiber is the end of the fiber onto which a thin layer of gold has been deposited to form a particulate surface. Annealing the gold reshapes the particles and produces an optical absorbance near 535 nm with the fiber in air. The optical absorption resonance of the gold particles is shifted if the fiber is immersed in a medium other than air. These resonance shifts are examined by transmission spectroscopy through the fiber. Experimental results for the sensitivity and dynamic range in the measurement of liquid solutions are in agreement with a basic theoretical model which characterizes the surface plasmon using nonretarded electrodynamics.

  19. Biomass processing over gold catalysts

    CERN Document Server

    Simakova, Olga A; Murzin, Dmitry Yu

    2014-01-01

    The book describes the valorization of biomass-derived compounds over gold catalysts. Since biomass is a rich renewable feedstock for diverse platform molecules, including those currently derived from petroleum, the interest in various transformation routes has become intense. Catalytic conversion of biomass is one of the main approaches to improving the economic viability of biorefineries.  In addition, Gold catalysts were found to have outstanding activity and selectivity in many key reactions. This book collects information about transformations of the most promising and important compounds derived from cellulose, hemicelluloses, and woody biomass extractives. Since gold catalysts possess high stability under oxidative conditions, selective oxidation reactions were discussed more thoroughly than other critical reactions such as partial hydrogenation, acetalization, and isomerization. The influence of reaction conditions, the role of the catalyst, and the advantages and disadvantages of using gold are pre...

  20. Gold, currencies and market efficiency

    Science.gov (United States)

    Kristoufek, Ladislav; Vosvrda, Miloslav

    2016-05-01

    Gold and currency markets form a unique pair with specific interactions and dynamics. We focus on the efficiency ranking of gold markets with respect to the currency of purchase. By utilizing the Efficiency Index (EI) based on fractal dimension, approximate entropy and long-term memory on a wide portfolio of 142 gold price series for different currencies, we construct the efficiency ranking based on the extended EI methodology we provide. Rather unexpected results are uncovered as the gold prices in major currencies lay among the least efficient ones whereas very minor currencies are among the most efficient ones. We argue that such counterintuitive results can be partly attributed to a unique period of examination (2011-2014) characteristic by quantitative easing and rather unorthodox monetary policies together with the investigated illegal collusion of major foreign exchange market participants, as well as some other factors discussed in some detail.

  1. Gold, coal and oil.

    Science.gov (United States)

    Dani, Sergio U

    2010-03-01

    Jared Diamond has hypothesized that guns, germs and steel account for the fate of human societies. Here I propose an extension of Diamond's hypothesis and put it in other terms and dimensions: gold, coal and oil account not only for the fate of human societies but also for the fate of mankind through the bodily accumulation of anthropogenic arsenic, an invisible weapon of mass extinction and evolutionary change. The background is clear; arsenic species fulfill seven criteria for a weapon of mass extinction and evolutionary change: (i) bioavailability to all living organisms; (ii) imperceptibility; (iii) acute toxicity; (iv) bioaccumulation and chronic toxicity; (v) adverse impact on reproductive fitness and reproductive outcomes and early-age development and growth in a wide range of microbial, plant and animal species including man; (vi) widespread geographical distribution, mobility and ecological persistence on a centennial to millennial basis and (vii) availability in necessary and sufficient amounts to exert evolutionarily meaningful effects. The proof is becoming increasingly feasible as human exploitation of gold, coal and oil deposits cause sustainable rises of arsenic concentrations in the biosphere. Paradoxically, humans are among the least arsenic-resistant organisms because humans are long-lived, encephalized and complex social metazoans. An arsenic accumulation model is presented here to describe how arsenic accumulates in the human body with increasing age and at different provisionally safe exposure levels. Arsenic accumulates in the human body even at daily exposure levels which are within the lowest possible WHO provisional tolerance limits, yielding bodily arsenic concentrations which are above WHO provisional limits. Ongoing consequences of global scale arsenic poisoning of mankind include age-specific rises in morbidity and mortality followed by adaptive changes. The potential rise of successful forms of inborn resistance to arsenic in humans

  2. Gold-catalyzed domino reactions.

    Science.gov (United States)

    Michelet, Véronique

    2015-01-01

    Gold-catalyzed reactions have appeared to be highly attractive tools for chemists to promote novel transformations to prepare elaborated structures from simple starting materials. This chapter presents selected and original examples of domino processes in the presence of gold catalysts, highlighting reports implying hydration, hydroxylation, and hydroamination as key starting point for cascade transformations. Domino processes implying 1,n-enynes, asymmetric domino transformations, and applications of all the presented processes in total synthesis are presented.

  3. On Fixing number of Functigraphs

    OpenAIRE

    Fazil, Muhammad; Javaid, Imran; Murtaza, Muhammad

    2016-01-01

    The fixing number of a graph $G$ is the order of the smallest subset $S$ of its vertex set $V(G)$ such that stabilizer of $S$ in $G$, $\\Gamma_{S}(G)$ is trivial. Let $G_{1}$ and $G_{2}$ be disjoint copies of a graph $G$, and let $g:V(G_{1})\\rightarrow V(G_{2})$ be a function. A functigraph $F_{G}$ consists of the vertex set $V(G_{1})\\cup V(G_{2})$ and the edge set $E(G_{1})\\cup E(G_{2})\\cup \\{uv:v=g(u)\\}$. In this paper, we study the behavior of the fixing number in passing from $G$ to $F_{G}...

  4. Oral rehabilitation with fixed prosthesis

    OpenAIRE

    Watanabe Velásquez, Romel; Dpto. Académico Estomatología Rehabilitadora. Facultad Odontología. UNMSM. Lima, Perú.; Salcedo Moncada, Doris; Dpto. Académico Estomatología Rehabilitadora. Facultad Odontología. UNMSM. Lima, Perú.; Ochoa Tataje, Julio; Dpto. Académico Estomatología Rehabilitadora. Facultad Odontología. UNMSM. Lima, Perú; Horna Palomino, Hernán; Dpto. Académico Estomatología Rehabilitadora. Facultad Odontología. UNMSM. Lima, Perú.; Herrera Cisneros, Marco; Dpto. Académico Estomatología Rehabilitadora. Facultad Odontología. UNMSM. Lima, Perú.; Paz Fernández, Juan José; Dpto. Académico Estomatología Rehabilitadora. Facultad Odontología. UNMSM. Lima, Perú.

    2014-01-01

    This treatment was carried out in a 58 years old male patient, who has had the antecedent of a car crash accident two years before; he loosed several teeth and fractured others. Pulp necrosis and alteration of occlusal plane occurred. Because of the pathologies presented, it was installed a multidisciplinary treatment phase having periodontal, endodontic, surgical and orthodontic procedures, tehe installation of posts, crowns and fixed bridges. Treatment was carried out for five months. El...

  5. Casting a look at pediatric plastic bronchitis.

    Science.gov (United States)

    Jasinovic, Tin; Kozak, Frederick K; Moxham, J Paul; Chilvers, Mark; Wensley, David; Seear, Michael; Campbell, Andrew; Ludemann, Jeffrey P

    2015-10-01

    To review clinical presentations and management strategies for children with plastic bronchitis. Retrospective chart review. Seven patients required rigid bronchoscopy to remove bronchial casts over a 17-year study period. Mean age at presentation was 60 months. Mean follow-up was 53 months. Co-morbidities included: congenital heart disease (n=3), chronic pulmonary disorders (n=2) and sickle cell disease (n=1). 4 patients required multiple bronchoscopies for recurrent casts. Adjunctive topical therapies were administered in all 7 patients, without complication. Rigid bronchoscopy for cast removal was performed in 2 patients who were on extra-corporal membrane oxygenation (ECMO), using special precautions to safeguard the ECMO catheters. Bronchial casts in children may present acutely or sub-acutely. Recurrent casts are unusual; however, in combination with severe cardiac disease may lead to mortality. Adjunctive topical therapies are still under investigation. Special safeguards for ECMO catheters are imperative. This case series complements and adds to the International Plastic Bronchitis Registry. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  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. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Zirconia in fixed implant prosthodontics.

    Science.gov (United States)

    Guess, Petra Christine; Att, Wael; Strub, Joerg Rudolf

    2012-10-01

    CAD/CAM technology in combination with zirconia ceramic has increasingly gained popularity in implant dentistry. This narrative review presents the current knowledge on zirconia utilized as framework material for implant-borne restorations and implant abutments, laboratory tests and developments, clinical performance, and possible future trends for implant dentistry are addressed. A review of available literature from 1990 through 2010 was conducted with search terms zirconia,"implants,"abutment,"crown," and "fixed dental prosthesis" using electronic databases (PubMed) and manual searching. Latest applications of zirconia in implant dentistry include implant abutments, multiple unit and full-arch frameworks as well as custom-made bars to support fixed and removable prostheses. High biocompatibility, low bacterial surface adhesion as well as favorable chemical properties of zirconia ceramics are reported. Zirconia stabilized with yttrium oxide exhibits high flexural strength and fracture toughness due to a transformation toughening mechanism. Preliminary clinical data confirmed the high stability of zirconia for abutments and as a framework material for implant borne crowns and fixed dental prostheses. Zirconia abutment or framework damage has rarely been encountered. However, veneering porcelain fractures are the most common technical complication in implant-supported zirconia restorations. These porcelain veneer failures have led to concerns regarding differences in coefficient of thermal expansions between core and veneering porcelain and their respective processing techniques. As presently evidence of clinical long-term data is missing, caution with regard to especially extensive implant-borne zirconia frameworks is recommended. © 2010 Wiley Periodicals, Inc.

  12. A fixed-point farrago

    CERN Document Server

    Shapiro, Joel H

    2016-01-01

    This text provides an introduction to some of the best-known fixed-point theorems, with an emphasis on their interactions with topics in analysis. The level of exposition increases gradually throughout the book, building from a basic requirement of undergraduate proficiency to graduate-level sophistication. Appendices provide an introduction to (or refresher on) some of the prerequisite material and exercises are integrated into the text, contributing to the volume’s ability to be used as a self-contained text. Readers will find the presentation especially useful for independent study or as a supplement to a graduate course in fixed-point theory. The material is split into four parts: the first introduces the Banach Contraction-Mapping Principle and the Brouwer Fixed-Point Theorem, along with a selection of interesting applications; the second focuses on Brouwer’s theorem and its application to John Nash’s work; the third applies Brouwer’s theorem to spaces of infinite dimension; and the fourth rests ...

  13. 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.

  14. Properties improvement of the al 7075 alloy castings

    Directory of Open Access Journals (Sweden)

    Gulišija Zvonko P.

    2014-01-01

    Full Text Available The microstructure and the mechanical properties of the samples obtained by conventional vertical continuous casting and electromagnetic casting of 7075 aluminum as-cast alloy were investigated. The better surface quality, more homogeneous alloying elements distribution and hence the microstructure and better mechanical properties were obtained in samples casted with electromagnetic field (EMF compared with samples casted without EMF. The microstructure was analyzed by optical microscope and the variation of alloying elements, Zn and Mg, through the sample cross section was examined by chemical analysis. The mechanical properties of samples casted with and without electromagnetic field were determined using computerized materials testing machine Zwick/Roel Z 100.

  15. 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.

  16. Effects of resistance form on attachment strength of resin-retained castings.

    Science.gov (United States)

    Wilkes, P W; Shillingburg, H T; Johnson, D L

    2000-01-01

    This study evaluated the effects of tooth preparation design on resistance to dislodgment of a resin-bonded fixed partial denture (RBFPD). The variations of tooth preparation tested included axial coverage, retentive grooves, and an occlusal rest. Patterns of the tooth preparation designs were prepared and cast in a base metal alloy. Retainer patterns were waxed to refractory casts of metal dies, cast, finished and then bonded to the dies. The complete assemblies were loaded to failure on an Instron mechanical testing machine, and analysis indicated that retainers with occlusal rests were the most resistant. Grooves provided no statistically significant increase in resistance to failure of the cement. Increased axial coverage did not increase resistance to dislodgment. Successful fixed partial dentures (FPDs) depend on cast retainers to resist displacement of the restoration during function. Introduction of resin-bonded restorations opened the possibility of FPDs with minimal reduction of abutments. Specific questions concerning long term success and tooth preparation designs were prominent concerns. The influence of resistance form on overall stability of a restoration was also of particular interest. Buonocore established the foundation for retention of composite resins to acid-pitted enamel. Rochette used this technology to bond perforated cast metal splints to periodontally compromised teeth. A mechanical interlock was created as composite resin engaged these perforations and sustained the cast splint to acid-etched enamel. Howe adapted this design for replacement of anterior teeth by adding porcelain to a metal ceramic framework and then bonding the framework to abutments without tooth preparations. The advantages of these procedures were their conservative nature, esthetics, and ease of rebonding after dislodgment. Livaditis and Thompson adapted the procedure proposed by Tanaka of corrosion-pitting the bonding surface of a base metal alloy. They increased the

  17. A quadrant tray and bite registration as an alternative to dual-arch impressions for fixed prosthetics: a clinical and dental laboratory technique.

    Science.gov (United States)

    Hammond, Barry D; Myers, Michael L; Haywood, Van B

    2011-01-01

    To perform fixed prosthodontic procedures, dentists take a full-arch or quadrant impression and articulate the casts. The dual-arch impression technique is a popular quadrant technique for crown fabrication. The technique described in this article, which uses a quadrant impression and separate interocclusal record, offers several advantages over the traditional dual-arch method.

  18. Gold mining areas in Suriname: reservoirs of malaria resistance?

    Directory of Open Access Journals (Sweden)

    Adhin MR

    2014-05-01

    Full Text Available Malti R Adhin,1 Mergiory Labadie-Bracho,2 Stephen Vreden31Faculty of Medical Sciences, Department of Biochemistry, Anton de Kom Universiteit van Suriname, 2Prof Dr Paul C Flu Institute for Biomedical Sciences, 3Academic Hospital Paramaribo, Paramaribo, SurinameBackground: At present, malaria cases in Suriname occur predominantly in migrants and people living and/or working in areas with gold mining operations. A molecular survey was performed in Plasmodium falciparum isolates originating from persons from gold mining areas to assess the extent and role of mining areas as reservoirs of malaria resistance in Suriname.Methods: The status of 14 putative resistance-associated single nucleotide polymorphisms in the pfdhfr, pfcrt, pfmdr1, and pfATP6 genes was assessed for 28 samples from gold miners diagnosed with P. falciparum malaria using polymerase chain reaction amplification and restriction fragment length polymorphism analysis, and the results were compared with earlier data from nonmining villagers.Results: Isolates from miners showed a high degree of homogeneity, with a fixed pfdhfr Ile51/Asn108, pfmdr1 Phe184/Asp1042/Tyr1246, and pfcrt Thr76 mutant genotype, while an exclusively wild-type genotype was observed for pfmdr1 Asn86 and pfdhfr Ala16, Cys59, and Ile164, and for the pfATP6 positions Leu263/Ala623/Ser769. Small variations were observed for pfmdr1 S1034C. No statistically significant difference could be detected in allele frequencies between mining and nonmining villagers.Conclusion: Despite the increased risk of malaria infection in individuals working/living in gold mining areas, we did not detect an increase in mutation frequency at the 14 analyzed single nucleotide polymorphisms. Therefore, mining areas in Suriname cannot yet be considered as reservoirs for malaria resistance.Keywords: Plasmodium falciparum, gold mining, mutation frequency, Suriname

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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).

  7. 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.

  8. 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).

  9. Simulation of the aluminum alloy A356 solidification cast in cylindrical permanent molds

    OpenAIRE

    2008-01-01

    A mathematical model based on the control volume method with fixed mesh was selected in order to simulate the solidification of cylindrical castings poured in permanent steel mold. The latent heat was incorporated using the effective specific heat. The application of the model allowed us to obtain the solidification front and the temperature fields at any time from the pouring. The mold was made of the SAE 1010 steel. Two mold temperatures were evaluated: 25°C and 300°C. The mathematical mode...

  10. 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.

  11. 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.

  12. Gold nanoparticle (AuNPs) and gold nanopore (AuNPore) catalysts in organic synthesis.

    Science.gov (United States)

    Takale, Balaram S; Bao, Ming; Yamamoto, Yoshinori

    2014-04-07

    Organic synthesis using gold has gained tremendous attention in last few years, especially heterogeneous gold catalysis based on gold nanoparticles has made its place in almost all organic reactions, because of the robust and green nature of gold catalysts. In this context, gold nanopore (AuNPore) with a 3D metal framework is giving a new dimension to heterogeneous gold catalysts. Interestingly, AuNPore chemistry is proving better than gold nanoparticles based chemistry. In this review, along with recent advances, major discoveries in heterogeneous gold catalysis are discussed.

  13. Modeling of gold production in Malaysia

    Science.gov (United States)

    Muda, Nora; Ainuddeen, Nasihah Rasyiqah; Ismail, Hamizun; Umor, Mohd Rozi

    2013-04-01

    This study was conducted to identify the main factors that contribute to the gold production and hence determine the factors that affect to the development of the mining industry in Malaysia. An econometric approach was used by performing the cointegration analysis among the factors to determine the existence of long term relationship between the gold prices, the number of gold mines, the number of workers in gold mines and the gold production. The study continued with the Granger analysis to determine the relationship between factors and gold production. Results have found that there are long term relationship between price, gold production and number of employees. Granger causality analysis shows that there is only one way relationship between the number of employees with gold production in Malaysia and the number of gold mines in Malaysia.

  14. 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.

  15. 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...

  16. 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.

  17. 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...

  18. 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...

  19. 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.

  20. 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.).

  1. Optimization of the investment casting process

    Directory of Open Access Journals (Sweden)

    M. Martinez-Hernandez

    2012-04-01

    Full Text Available Rapid prototyping is an important technique for manufacturing. This work refers to the manufacture of hollow patterns made of polymeric materials by rapid prototyping technologies for its use in the preparation of ceramic molds in the investment casting process. This work is focused on the development of a process for manufacturing patterns different from those that currently exist due to its hollow interior design, allowing its direct use in the fabrication of ceramic molds; avoiding cracking and fracture during the investment casting process, which is an important process for the foundry industry.

  2. Repair welding of cast iron coated electrodes

    Science.gov (United States)

    Żuk, M.; Górka, J.; Dojka, R.; Czupryński, A.

    2017-08-01

    Welding cast iron is a complex production procedure. Repair welding was used to repair damaged or poorly made castings. This is due to a tendency to cracking of the material during welding as well as after it. Welding cast iron can be carried out on hot or on cold. Hot welding requires high heat material and the use of welding material in the form of cast iron. In the case of cold welding, it is possible to use different materials. Mostly used filler metals are nickel and copper based. The work shows the course of research concerning repairmen of ductile iron with arc welding method. For the reparation process four types of ESAB company coated electrodes dedicated for cast iron were used with diameter 3.2 and 4 mm: ES 18-8-6B (4mm), EB 150 (4mm), OK NiCl, EŻM. In the cast iron examined during the testing grooves were made using plasma methods, in order to simulate the removed casting flaws. Then the welding process with coated electrodes was executed. The process utilized low welding current row of 100A, so there would only be a small amount of heat delivered to the heat affected zone (HAZ). Short stitches were made, after welding it was hammered, in order to remove stresses. After the repair welding the part of studies commenced which purpose was finding surface defects using visual testing (VT) and penetration testing (PT). In the second part, a series of macro and microscopic studies were executed witch the purpose of disclosuring the structure. Then the hardness tests for welds cross sections were performed. An important aspect of welding cast iron is the colour of the padding weld after welding, more precisely the difference between the base material and padding weld, the use of different materials extra gives the extra ability to select the best variant. The research of four types of coated electrode was executed, based on the demands the best option in terms of aesthetic, strength and hardness.

  3. An alternative approach in fabrication of fixed complete dentures using a duplicate denture.

    Science.gov (United States)

    Afshari, Fatemeh S; Hallas, Matthew B; Knoernschild, Kent L

    2012-10-01

    The traditional prosthetic steps in the fabrication of a fixed complete denture after implant osseointegration include final impression, verification of implant positioning in the working cast, mounting of the working cast, and mock denture wax trial insertion prior to the laboratory fabrication of the metal substructure; however, in patient scenarios of immediate loading of implants, the interim conversion prosthesis can be used to advance from the final impression to the milling of the underlying framework in one appointment. Consistency in the initial wax trial insertion, radiographic guide, and intraoral positioning of the conversion prosthesis can result in a well-designed definitive prosthesis in less time with the use of the existing duplicate complete denture. © 2012 by the American College of Prosthodontists.

  4. Non-Gold Base Dental Casting Alloys. Volume 2. Porcelain-Fused-to-Metal Alloys.

    Science.gov (United States)

    1986-08-01

    kaolin , and/or alumina. a. Quartz Quartz has a high fusion temperature , and acts as the frimeworK around which the other ingredients can flow.7 Quartz...until it has cooled to room temperature . The metal and the - porcelain retain heat differently , and thus will cool at different rates. Rushing the case at...dental porcelain to a recommended temperature for a specific period of time. SINTERING - Another term to describe the "firing" of dental porcelain

  5. Polarization-corrosion behavior of commercial gold- and silver-base casting alloys in Fusayama solution.

    Science.gov (United States)

    Johnson, D L; Rinne, V W; Bleich, L L

    1983-12-01

    Based on polarization measurements, high Au alloys are highly corrosion-resistant and exhibit the lowest corrosion rates; intermediate Au, Ag, and Pd alloys with Cu are passive but exhibit higher corrosion rates. Twenty weight percent (w/o) In-Ag alloys exhibit active corrosion behavior at potentials only 100 mV noble to the corrosion potential.

  6. Monoclonal antibody "gold rush".

    Science.gov (United States)

    Maggon, Krishan

    2007-01-01

    The market, sales and regulatory approval of new human medicines, during the past few years, indicates increasing number and share of new biologics and emergence of new multibillion dollar molecules. The global sale of monoclonal antibodies in 2006 were $20.6 billion. Remicade had annual sales gain of $1 billion during the past 3 years and five brands had similar increase in 2006. Rituxan with 2006 sales of $4.7 billion was the best selling monoclonal antibody and biological product and the 6th among the top selling medicinal brand. It may be the first biologic and monoclonal antibody to reach $10 billion annual sales in the near future. The strong demand from cancer and arthritis patients has surpassed almost all commercial market research reports and sales forecast. Seven monoclonal antibody brands in 2006 had sales exceeding $1 billion. Humanized or fully human monoclonal antibodies with low immunogenicity, enhanced antigen binding and reduced cellular toxicity provide better clinical efficacy. The higher technical and clinical success rate, overcoming of technical hurdles in large scale manufacturing, low cost of market entry and IND filing, use of fully human and humanized monoclonal antibodies has attracted funds and resources towards R&D. Review of industry research pipeline and sales data during the past 3 years indicate a real paradigm shift in industrial R&D from pharmaceutical to biologics and monoclonal antibodies. The antibody bandwagon has been joined by 200 companies with hundreds of new projects and targets and has attracted billions of dollars in R&D investment, acquisitions and licensing deals leading to the current Monoclonal Antibody Gold Rush.

  7. Room temperature Coulomb blockade mediated field emission via self-assembled gold nanoparticles

    Science.gov (United States)

    Wang, Fei; Fang, Jingyue; Chang, Shengli; Qin, Shiqiao; Zhang, Xueao; Xu, Hui

    2017-02-01

    Coulomb blockade mediated field-emission current was observed in single-electron tunneling devices based on self-assembled gold nanoparticles at 300 K. According to Raichev's theoretical model, by fixing a proper geometric distribution of source, island and drain, the transfer characteristics can be well explained through a combination of Coulomb blockade and field emission. Coulomb blockade and field emission alternately happen in our self-assembled devices. The Coulomb island size derived from the experimental data is in good agreement with the average size of the gold nanoparticles used in the device. The integrated tunneling can be adjusted via a gate electrode.

  8. 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.

  9. 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.

  10. 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.

  11. 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....

  12. Photocatalytic properties of thin films of ruthenium metallopolymers/gold nanoparticle: Polyoxometalate composites using visible excitation

    Institute of Scientific and Technical Information of China (English)

    朱杰

    2013-01-01

    Thin layers of an electrostatically associated adduct RuPVP-AuNP:POM formed between the polyoxomolybdate, [S2 Mo18 O62 ]4, the polycationic metallopolymer [Ru(bpy)2(PVP)10 ](ClO4)2 and DMAP-protected gold nanoparticle have been deposited onto electrodes using two separate methods, alternate immersion layer-by-layer assembly and pre-assembled drop-casting; PVP is poly(4-vinylpyridine), BPY is 2,2’-bipyridyl, and DMAP is 4-dimethylaminopyridine. Significantly, the efficiency of the photocatalysis depends markedly on the structure of the [RuPVP-AuNP:POM] even when photonic properties are very similar. Strikingly, despite their similar photonic properties, an additional optical transition is observed in UV-vis and the Raman spectra of pre-assembled drop cast [RuPVP-AuNP:POM], which was not seen in dip coated [RuPVP-AuNP:POM]. Importantly, this electronic communication enhances the photocatalytic oxidation of benzaldehyde by a factor of more than four. While there is clear evidence for photosensitisation in the drop cast not present for the dip coated systems, the magnitude of the photocurrent, i.e.,(82.2 6.6) nA·cm 2for pre-assembled drop cast [RuPVP-AuNP:POM] at a ruthenium to Au nanoparticle mole ratio of 48:1, is twice as large as that those found in [Ru-PVP:POM] film.

  13. Enhancements in Magnesium Die Casting Impact Properties

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-06-30

    The need to produce lighter components in transportation equipment is the main driver in the increasing demand for magnesium castings. In many automotive applications, components can be made of magnesium or aluminum. While being lighter, often times the magnesium parts have lower impact and fatigue properties than the aluminum. The main objective of this study was to identify potential improvements in the impact resistance of magnesium alloys. The most common magnesium alloys in automotive applications are AZ91D, AM50 and AM60. Accordingly, these alloys were selected as the main candidates for the study. Experimental quantities of these alloys were melted in an electrical furnace under a protective atmosphere comprising sulfur hexafluoride, carbon dioxide and dry air. The alloys were cast both in a permanent mold and in a UBE 315 Ton squeeze caster. Extensive evaluation of tensile, impact and fatigue properties was conducted at CWRU on permanent mold and squeeze cast test bars of AZ91, AM60 and AM50. Ultimate tensile strength values between 20ksi and 30ksi were obtained. The respective elongations varied between 25 and 115. the Charpy V-notch impact strength varied between 1.6 ft-lb and 5 ft-lb depending on the alloy and processing conditions. Preliminary bending fatigue evaluation indicates a fatigue limit of 11-12 ksi for AM50 and AM60. This is about 0.4 of the UTS, typical for these alloys. The microstructures of the cast specimens were investigated with optical and scanning electron microscopy. Concomitantly, a study of the fracture toughness in AM60 was conducted at ORNL as part of the study. The results are in line with values published in the literature and are representative of current state of the art in casting magnesium alloys. The experimental results confirm the strong relationship between aluminum content of the alloys and the mechanical properties, in particular the impact strength and the elongation. As the aluminum content increases from about 5

  14. Connector design in a long-span-fixed dental prosthesis: A three-dimensional finite element analysis

    Directory of Open Access Journals (Sweden)

    B H Harshitha Gowda

    2013-01-01

    Full Text Available Objectives: The goal of every prosthetic management is to simulate nature and be in harmony with nature within the physiological limits. The occlusal forces on a fixed dental prosthesis are transmitted to the surrounding structures through pontics, connectors and retainers and more stresses are seen at the connector region. To analyze the stress patterns in cast and soldered connectors between the two pontics and between the retainer and pontic of a four unit fixed dental prosthesis on axial and non axial loading and also to observe and ascertain the need to modify the design of the rigid connectors. Materials and Methods: Subsequently four models each of cast and soldered connectors with cylindrical and triangular design, of dimension 3 × 4 mm and thickness 0.5 mm was designed for the study. The first premolar and second molar were considered as the abutments and 2 nd premolar and 1 st molar as the pontics. The analysis was done using ANSYS version 8.0 software and by placing axial and non-axial load of 40 Newtons each. Results: Von Misses stresses were observed at the connector region between the two pontics, especially in the cervical region. Conclusion: The cylindrical cast connectors showed less stress in comparison to triangular design and the difference in the stress distribution of cast and soldered connectors were marginal. Clinical Significance: The occlusal forces on a fixed dental prosthesis are transmitted to the surrounding structures through pontics, connectors and retainers with maximum stresses concentrated at the connectors. Hence this three-dimensional finite element analysis study investigated stress distribution in a four unit posterior fixed dental prosthesis, having cylindrical and triangular connector designs.

  15. Gold process mineralogy: Objectives, techniques, and applications

    Science.gov (United States)

    Zhou, Joe Y.; Cabri, Louis J.

    2004-07-01

    The extractive metallurgy of gold is largely driven by mineralogical factors such as gold particle size; association with other minerals; coatings; presence of cyanicides, oxygen consumers, and preg-robbers; presence of refractory gold minerals; and locking of submicroscopic gold in sulfide and sulfarsenide mineral structures. Gold process mineralogy addresses all issues related to gold ore processing by the detailed study of an ore or a mill product. The methodology is widely used as a predictive tool in feasibility studies and during the process development stage, and as a trouble-shooting tool for mineral processing and hydrometallurgical operations.

  16. Serum gold concentrations during treatment with auranofin.

    Science.gov (United States)

    Van Riel, P L; Gribnau, F W; Van de Putte, L B; Arts, C W; Van Aernsbergen, A

    1987-03-01

    Serum gold concentrations were measured in rheumatoid arthritis patients during chronic treatment with the orally adsorbable gold compound auranofin. In agreement with data in the literature, the highest serum gold concentration was reached after 16 weeks of treatment with 6 mg auranofin daily. A striking finding in this study was that thereafter the serum gold concentrations did not appear to plateau but declined gradually. Statistically this resulted in a significantly lower concentration after one year as compared with week 16 (p less than 0.05, paired t-test). It is suggested that a shift from protein bound gold to cell-bound gold might be the explanation.

  17. 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...

  18. 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.

  19. Understanding sexual violence as a form of caste violence

    OpenAIRE

    Prachi Patil

    2016-01-01

    The paper attempts to understand narratives of sexual violence anchored within the dynamics of social location of caste and gender. Apparent caste-patriarchy and gender hierarchies which are at play in cases of sexual violence against lower-caste and dalit women speak about differential experiences of rape and sexual abuse that women have in India. The paper endeavours to establish that sexual violence is also a form of caste violence by rereading the unfortunate cases of Bhanwari Devi, Khair...

  20. 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.

  1. 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...

  2. 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.

  3. 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.

  4. 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...

  5. 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.

  6. Phage based green chemistry for gold ion reduction and gold retrieval.

    Science.gov (United States)

    Setyawati, Magdiel I; Xie, Jianping; Leong, David T

    2014-01-22

    The gold mining industry has taken its toll on the environment, triggering the development of more environmentally benign processes to alleviate the waste load release. Here, we demonstrate the use of bacteriophages (phages) for biosorption and bioreduction of gold ions from aqueous solution, which potentially can be applied to remediate gold ions from gold mining waste effluent. Phage has shown a remarkably efficient sorption of gold ions with a maximum gold adsorption capacity of 571 mg gold/g dry weight phage. The product of this phage mediated process is gold nanocrystals with the size of 30-630 nm. Biosorption and bioreduction processes are mediated by the ionic and covalent interaction between gold ions and the reducing groups on the phage protein coat. The strategy offers a simple, ecofriendly and feasible option to recover of gold ions to form readily recoverable products of gold nanoparticles within 24 h.

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

    DEFF Research Database (Denmark)

    Banerjee, Ritwik; Datta Gupta, Nabanita

    ) in the context of caste in India, with management students (potential employers in the near future) as subjects. First, we measure caste prejudice and show that awareness through a TV social program reduces implicit prejudice against the lower caste and the reduction is sustained over time. Second, we find...

  8. 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...

  9. 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

  10. 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.

  11. 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.

  12. Non-rigid Reconstruction of Casting Process with Temperature Feature

    Science.gov (United States)

    Lin, Jinhua; Wang, Yanjie; Li, Xin; Wang, Ying; Wang, Lu

    2017-09-01

    Off-line reconstruction of rigid scene has made a great progress in the past decade. However, the on-line reconstruction of non-rigid scene is still a very challenging task. The casting process is a non-rigid reconstruction problem, it is a high-dynamic molding process lacking of geometric features. In order to reconstruct the casting process robustly, an on-line fusion strategy is proposed for dynamic reconstruction of casting process. Firstly, the geometric and flowing feature of casting are parameterized in manner of TSDF (truncated signed distance field) which is a volumetric block, parameterized casting guarantees real-time tracking and optimal deformation of casting process. Secondly, data structure of the volume grid is extended to have temperature value, the temperature interpolation function is build to generate the temperature of each voxel. This data structure allows for dynamic tracking of temperature of casting during deformation stages. Then, the sparse RGB features is extracted from casting scene to search correspondence between geometric representation and depth constraint. The extracted color data guarantees robust tracking of flowing motion of casting. Finally, the optimal deformation of the target space is transformed into a nonlinear regular variational optimization problem. This optimization step achieves smooth and optimal deformation of casting process. The experimental results show that the proposed method can reconstruct the casting process robustly and reduce drift in the process of non-rigid reconstruction of casting.

  13. 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

  14. 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.

  15. Homotopies and the Universal Fixed Point Property

    DEFF Research Database (Denmark)

    Szymik, Markus

    2015-01-01

    A topological space has the fixed point property if every continuous self-map of that space has at least one fixed point. We demonstrate that there are serious restraints imposed by the requirement that there be a choice of fixed points that is continuous whenever the self-map varies continuously...

  16. Variable-Frequency Ultrasonic Treatment on Microstructure and Mechanical Properties of ZK60 Alloy during Large Diameter Semi-Continuous Casting

    Directory of Open Access Journals (Sweden)

    Xingrui Chen

    2017-05-01

    Full Text Available Traditional fixed-frequency ultrasonic technology and a variable-frequency ultrasonic technology were applied to refine the as-cast microstructure and improve the mechanical properties of a ZK60 (Mg–Zn–Zr alloy during large diameter semi-continuous casting. The acoustic field propagation was obtained by numerical simulation. The microstructure of the as-cast samples was characterized by optical and scanning electron microscopy. The variable-frequency ultrasonic technology shows its outstanding ability in grain refinement compared with traditional fixed-ultrasonic technology. The variable-frequency acoustic field promoted the formation of small α-Mg globular grains and changed the distribution and morphology of β-phases throughout the castings. Ultimate tensile strength and elongation are increased to 280 MPa and 8.9%, respectively, which are 19.1% and 45.9% higher than the values obtained from billets without ultrasonic treatment and are 11.6% and 18.7% higher than fixed-frequency ultrasound treated billets. Different refinement efficiencies appear in different districts of billets attributed to the sound attenuation in melt. The variable-frequency acoustic field improves the refinement effect by enhancing cavitation-enhanced heterogeneous nucleation and dendrite fragmentation effects.

  17. Utilization of nitrogen fixing trees

    Energy Technology Data Exchange (ETDEWEB)

    Brewbaker, J.L.; Beldt, R. van den; MacDicken, K.; Budowski, G.; Kass, D.C.L.; Russo, R.O.; Escalante, G.; Herrera, R.; Aranguren, J.; Arkcoll, D.B.; Doebereinger, J. (cord.)

    1983-01-01

    Six papers from the symposium are noted. Brewbaker, J.L., Beldt, R. van den, MacDicken, K. Fuelwood uses and properties of nitrogen-fixing trees, pp 193-204, (Refs. 15). Includes a list of 35 nitrogen-fixing trees of high fuelwood value. Budowski, G.; Kass, D.C.L.; Russo, R.O. Leguminous trees for shade, pp 205-222, (Refs. 68). Escalante, G., Herrera, R., Aranguren, J.; Nitrogen fixation in shade trees (Erythrina poeppigiana) in cocoa plantations in northern Venezuela, pp 223-230, (Refs. 13). Arkcoll, D.B.; Some leguminous trees providing useful fruits in the North of Brazil, pp 235-239, (Refs. 13). This paper deals with Parkia platycephala, Pentaclethra macroloba, Swartzia sp., Cassia leiandra, Hymenaea courbaril, dipteryz odorata, Inga edulis, I. macrophylla, and I. cinnamonea. Baggio, A.J.; Possibilities of the use of Gliricidia sepium in agroforestry systems in Brazil, pp 241-243; (Refs. 15). Seiffert, N.F.; Biological nitrogen and protein production of Leucaena cultivars grown to supplement the nutrition of ruminants, pp 245-249, (Refs. 14). Leucaena leucocephala cv. Peru, L. campina grande (L. leucocephala), and L. cunningham (L. leucocephalae) were promising for use as browse by beef cattle in central Brazil.

  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. 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.

  20. 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.

  1. 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.

  2. 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...

  3. 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.

  4. 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.

  5. 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 ...

  6. 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)

  7. Palatal Surface Area of Maxillary Plaster Casts

    DEFF Research Database (Denmark)

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

    2007-01-01

    Objective: To investigate the relationship between corresponding two-dimensional and three-dimensional measurements on maxillary plaster casts taken from photographs and three-dimensional surface scans, respectively. Materials and Methods: Corresponding two-dimensional and three-dimensional measu......Objective: To investigate the relationship between corresponding two-dimensional and three-dimensional measurements on maxillary plaster casts taken from photographs and three-dimensional surface scans, respectively. Materials and Methods: Corresponding two-dimensional and three......-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...

  8. 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

  9. 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.

  10. [Pain after cementation of cast restorations

    NARCIS (Netherlands)

    Gerritsen, A.E.

    2004-01-01

    Some patients experience pain after cementation of a cast restoration on a vital tooth. Limited data are available on the prevalence of this pain. In many cases the pain disappears within two weeks. The major cause of the pain might be attributed to more permeability of the dentine after

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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...

  18. 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...

  19. 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.

  20. 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.

  1. 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.

  2. New Trends in Gold Catalysts

    Directory of Open Access Journals (Sweden)

    Leonarda F. Liotta

    2014-07-01

    Full Text Available Gold is an element that has fascinated mankind for millennia. The catalytic properties of gold have been a source of debate, due to its complete chemical inertness when in a bulk form, while it can oxidize CO at temperatures as low as ~200 K when in a nanocrystalline state, as discovered by Haruta in the late 1980s [1]. Since then, extensive activity in both applied and fundamental research on gold has been initiated. The importance of the catalysis by gold represents one of the fasted growing fields in science and is proven by the promising applications in several fields, such as green chemistry and environmental catalysis, in the synthesis of single-walled carbon nanotubes, as modifiers of Ni catalysts for methane steam and dry reforming reactions and in biological and electrochemistry applications. The range of reactions catalyzed by gold, as well as the suitability of different supports and the influence of the preparation conditions have been widely explored and optimized in applied research [2]. Gold catalysts appeared to be very different from the other noble metal-based catalysts, due to their marked dependence on the preparation method, which is crucial for the genesis of the catalytic activity. Several methods, including deposition-precipitation, chemical vapor deposition and cation adsorption, have been applied for the preparation of gold catalysts over reducible oxides, like TiO2. Among these methods, deposition-precipitation has been the most frequently employed method for Au loading, and it involves the use of tetrachloroauric (III acid as a precursor. On the other hand, the number of articles dealing with Au-loaded acidic supports is smaller than that on basic supports, possibly because the deposition of [AuCl4]− or [AuOHxCl4−x]− species on acidic supports is difficult, due to their very low point of zero charge. Despite this challenge, several groups have reported the use of acidic zeolites as supports for gold. Zeolites

  3. Nanobubble trouble on gold surfaces

    DEFF Research Database (Denmark)

    Holmberg, Maria; Kuhle, A.; Garnaes, J.

    2003-01-01

    When analyzing surfaces related to biosensors with in situ atomic force microscopy (AFM), the existence of nanobubbles called for our attention. The bubbles seem to form spontaneously when gold surfaces are immersed in clean water and are probably a general phenomenon at water-solid interfaces....... Besides from giving rise to undesired effects in, for example, biosensors, nanobubbles can also cause artifacts in AFM imaging. We have observed nanobubbles on unmodified gold surfaces, immersed in clean water, using standard silicon AFM probes. Nanobubbles can be made to disappear from contact mode AFM...

  4. Economic geology: Gold buried by oxygen

    OpenAIRE

    Gaillard, Fabrice; Copard, Y.

    2015-01-01

    International audience; he Witwatersrand Basin in South Africa contains extraordinary amounts of gold. Thermodynamic calculations suggest that the gold may have accumulated there in response to a perfect storm of conditions available only during the Archaean.

  5. Economic geology: Gold buried by oxygen

    OpenAIRE

    Gaillard, Fabrice; Copard, Y.

    2015-01-01

    International audience; he Witwatersrand Basin in South Africa contains extraordinary amounts of gold. Thermodynamic calculations suggest that the gold may have accumulated there in response to a perfect storm of conditions available only during the Archaean.

  6. Photo-Thermal Effects in 1D Gratings of Gold Nanoparticles

    Directory of Open Access Journals (Sweden)

    Giovanna Palermo

    2017-01-01

    Full Text Available This work investigates the heat delivered by a mono-layer 1D grating of gold nanoparticles (GNPs created by photo-reduction through two-photon direct laser writing (2P-DLW in a poly-vinyl alcohol (PVA matrix doped with HAuCl4, under resonant laser radiation. We drop cast a film of a PVA + HAuCl4 mixture onto a glass substrate, in which we create gratings of 1 mm2 made by stripes of GNPs characterized by high polydispersivity. We demonstrate that, by controlling the pitch of the GNP stripes, we obtain different values of the photo-induced temperature variations. In the framework of thermo-plasmonics, the experimental investigation of the heat generation from a monolayer of gold nanoparticles represents a key element as a starting point to design thermo-smart platforms for sensing, solar energy harvesting and thermo-catalysis.

  7. New Design for Rapid Prototyping of Digital Master Casts for Multiple Dental Implant Restorations

    Science.gov (United States)

    Romero, Luis; Jiménez, Mariano; Espinosa, María del Mar; Domínguez, Manuel

    2015-01-01

    Aim This study proposes the replacement of all the physical devices used in the manufacturing of conventional prostheses through the use of digital tools, such as 3D scanners, CAD design software, 3D implants files, rapid prototyping machines or reverse engineering software, in order to develop laboratory work models from which to finish coatings for dental prostheses. Different types of dental prosthetic structures are used, which were adjusted by a non-rotatory threaded fixing system. Method From a digital process, the relative positions of dental implants, soft tissue and adjacent teeth of edentulous or partially edentulous patients has been captured, and a maser working model which accurately replicates data relating to the patients oral cavity has been through treatment of three-dimensional digital data. Results Compared with the conventional master cast, the results show a significant cost savings in attachments, as well as an increase in the quality of reproduction and accuracy of the master cast, with the consequent reduction in the number of patient consultation visits. The combination of software and hardware three-dimensional tools allows the optimization of the planning of dental implant-supported rehabilitations protocol, improving the predictability of clinical treatments and the production cost savings of master casts for restorations upon implants. PMID:26696528

  8. Fixed-Orderl1-Control for Systems with Time-Delay

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In this paper, fixed-orderl1-control for systems with time-delay is studied, and sufficient conditions for solvability of state-feedback l1-control and dynamic output-feedback l1-control are obtained. This paper also gives the forms of solution tol1-controller. In the paper, the problem is not cast into infinite dimensional constrained convex optimal problem, but an upper bound of l1-norm is optimized. Although thel1-control is sub-optimal, the analysis and design are simple. The result of the paper improves and develops thel1-control method.

  9. 31 CFR 100.4 - Gold coin and gold certificates in general.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Gold coin and gold certificates in general. 100.4 Section 100.4 Money and Finance: Treasury Regulations Relating to Money and Finance EXCHANGE OF PAPER CURRENCY AND COIN In General § 100.4 Gold coin and gold certificates in general....

  10. Complex issues in accounting for fixed assets

    Directory of Open Access Journals (Sweden)

    Mykhaylo Luchko

    2013-11-01

    Full Text Available This paper considers the mentioned complex issues of business fixed assets accounting. The main emphasis in this case refers to the change in value of fixed assets over time. Author studied problems of the regulatory revaluation of fixed assets in accordance with the applicable accounting standards (regulations. Particular attention is paid to the revaluation and impairment of the business fixed assets objects and their recording on accounts. Author analyzed the complex issues in establishing the fair value of fixed assets. Attention is focused on the harmonization of accounting information with tax calculations and reporting provided by the Ukrainian Tax Code. In considering the matter referred to the tax differences (temporary and permanent. Established tax differences in depreciation of fixed assets, impairment amounts and revaluation of fixed assets and accounting entries to them.

  11. Understanding sexual violence as a form of caste violence

    Directory of Open Access Journals (Sweden)

    Prachi Patil

    2016-07-01

    Full Text Available The paper attempts to understand narratives of sexual violence anchored within the dynamics of social location of caste and gender. Apparent caste-patriarchy and gender hierarchies which are at play in cases of sexual violence against lower-caste and dalit women speak about differential experiences of rape and sexual abuse that women have in India. The paper endeavours to establish that sexual violence is also a form of caste violence by rereading the unfortunate cases of Bhanwari Devi, Khairlanji, Lalasa Devi and Delta Meghwal Keywords: caste-patriarchy, Dalit women, POA Act, rape, sexual violence

  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. 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.

  15. Simple fixed functional space maintainer.

    Science.gov (United States)

    Goenka, Puneet; Sarawgi, Aditi; Marwah, Nikhil; Gumber, Parvind; Dutta, Samir

    2014-01-01

    Premature loss of a primary tooth is one of the most common etiology for malocclusion. Space maintainers are employed to prevent this complication. In anterior region, esthetics is an important concern along with function and space management. Fiber-reinforced composite (FRC) retained space maintainer solves all these purposes ef ficiently and ef fectively. In addition, the technique is simple and the appliance is very comfortable inside the oral cavity. Here is a case of premature loss of anterior primary tooth which was replaced by FRC retained esthetic functional space maintainer. The appliance was found to be functioning satisfactorily inside the oral cavity till the last visit (1 Year). How to cite this article: Goenka P, Sarawgi A, Marwah N, Gumber P, Dutta S. Simple Fixed Functional Space Maintainer. Int J Clin Pediatr Dent 2014;7(3):225-228.

  16. Fixed Point and Aperiodic Tilings

    CERN Document Server

    Durand, Bruno; Shen, Alexander

    2008-01-01

    An aperiodic tile set was first constructed by R.Berger while proving the undecidability of the domino problem. It turned out that aperiodic tile sets appear in many topics ranging from logic (the Entscheidungsproblem) to physics (quasicrystals) We present a new construction of an aperiodic tile set that is based on Kleene's fixed-point construction instead of geometric arguments. This construction is similar to J. von Neumann self-reproducing automata; similar ideas were also used by P. Gacs in the context of error-correcting computations. The flexibility of this construction allows us to construct a ``robust'' aperiodic tile set that does not have periodic (or close to periodic) tilings even if we allow some (sparse enough) tiling errors. This property was not known for any of the existing aperiodic tile sets.

  17. Single-crystalline gold nanoplates from a commercial gold plating solution.

    Science.gov (United States)

    Li, Zhonghao; Lapeyre, Véronique; Ravaine, Valérie; Ravaine, Serge; Kuhn, Alexander

    2009-03-01

    A novel route was proposed to synthesize gold nanoplates using a commercial gold plating solution as the reactant. Single-crystalline gold nanoplates can be successfully synthesized by reacting gold plating solution with HCl. The as-prepared nanoplates are from several micrometers to tens of micrometers in size. The effects of reactant concentration and temperature on the morphology of the gold products were investigated. The size of the gold nanoplate increases with the decrease of the amount of gold plating solution, while irregular gold nanoparticles are formed as the HCl concentration becomes low. When the reaction temperature is as low as room temperature, nanoplates with a concavity form. Specifically, it is found that the Cl- plays an important role for the formation of these gold nanoplates. The formation mechanism of the gold nanoplates is studied in detail.

  18. Gold and Silver Extraction from Leach Solutions

    OpenAIRE

    Bagdaulet K. Kenzhaliyev; Renata R. Iskhakova; Zamzagul D. Dosymbaeva; Esen N. Sulejmenov

    2014-01-01

    There has been carried out an investigation on the extraction of gold and silver from thiosulfate solutions: standard test and technological solutions of chemical and electrochemical leaching. The influence of related metals on the process of extracting gold from solution was studied. There has been conducted a comparative study of the IR spectra of solutions after the sorption of gold, silver and related metals.

  19. Highly active thermally stable nanoporous gold catalyst

    Science.gov (United States)

    Biener, Juergen; Wittstock, Arne; Biener, Monika M.; Bagge-Hansen, Michael; Baeumer, Marcus; Wichmann, Andre; Neuman, Bjoern

    2016-12-20

    In one embodiment, a system includes a nanoporous gold structure and a plurality of oxide particles deposited on the nanoporous gold structure; the oxide particles are characterized by a crystalline phase. In another embodiment, a method includes depositing oxide nanoparticles on a nanoporous gold support to form an active structure and functionalizing the deposited oxide nanoparticles.

  20. CO oxidation on gold nanoparticles: Theoretical studies

    DEFF Research Database (Denmark)

    Remediakis, Ioannis; Lopez, Nuria; Nørskov, Jens Kehlet

    2005-01-01

    We present a summary of our theoretical results regarding CO oxidation on both oxide-supported and isolated gold nanoparticles. Using Density Functional Theory we have studied the adsorption of molecules and the oxidation reaction of CO on gold clusters. Low-coordinated sites on the gold...