Science.gov

Sample records for 3al cylinders manufactured

  1. 49 CFR Appendix C to Part 180 - Eddy Current Examination With Visual Inspection for DOT 3AL Cylinders Manufactured of Aluminum...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... for DOT 3AL Cylinders Manufactured of Aluminum Alloy 6351-T6 C Appendix C to Part 180 Transportation... Cylinders Manufactured of Aluminum Alloy 6351-T6 1. Examination Procedure. Each facility performing eddy... ring and probe for each DOT-3AL cylinder manufactured of aluminum alloy 6351-T6 to be inspected must...

  2. 49 CFR Appendix C to Part 180 - Eddy Current Examination With Visual Inspection for DOT 3AL Cylinders Manufactured of Aluminum...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... for DOT 3AL Cylinders Manufactured of Aluminum Alloy 6351-T6 C Appendix C to Part 180 Transportation... Cylinders Manufactured of Aluminum Alloy 6351-T6 1. Examination Procedure. Each facility performing eddy... ring and probe for each DOT-3AL cylinder manufactured of aluminum alloy 6351-T6 to be inspected must...

  3. 49 CFR Appendix C to Part 180 - Eddy Current Examination With Visual Inspection for DOT 3AL Cylinders Manufactured of Aluminum...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... for DOT 3AL Cylinders Manufactured of Aluminum Alloy 6351-T6 C Appendix C to Part 180 Transportation... Cylinders Manufactured of Aluminum Alloy 6351-T6 1. Examination Procedure. Each facility performing eddy... ring and probe for each DOT-3AL cylinder manufactured of aluminum alloy 6351-T6 to be inspected must...

  4. 49 CFR Appendix C to Part 180 - Eddy Current Examination With Visual Inspection for DOT 3AL Cylinders Manufactured of Aluminum...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... for DOT 3AL Cylinders Manufactured of Aluminum Alloy 6351-T6 C Appendix C to Part 180 Transportation... Cylinders Manufactured of Aluminum Alloy 6351-T6 1. Examination Procedure. Each facility performing eddy... ring and probe for each DOT-3AL cylinder manufactured of aluminum alloy 6351-T6 to be inspected must...

  5. 49 CFR Appendix C to Part 180 - Eddy Current Examination With Visual Inspection for DOT 3AL Cylinders Manufactured of Aluminum...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... for DOT 3AL Cylinders Manufactured of Aluminum Alloy 6351-T6 C Appendix C to Part 180 Transportation... Cylinders Manufactured of Aluminum Alloy 6351-T6 1. Examination Procedure. Each facility performing eddy... ring and probe for each DOT-3AL cylinder manufactured of aluminum alloy 6351-T6 to be inspected must...

  6. 49 CFR 178.46 - Specification 3AL seamless aluminum cylinders.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Specification 3AL seamless aluminum cylinders. 178... FOR PACKAGINGS Specifications for Cylinders § 178.46 Specification 3AL seamless aluminum cylinders. (a) Size and service pressure. A DOT 3AL cylinder is a seamless aluminum cylinder with a maximum...

  7. 49 CFR 178.46 - Specification 3AL seamless aluminum cylinders.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Specification 3AL seamless aluminum cylinders. 178... FOR PACKAGINGS Specifications for Cylinders § 178.46 Specification 3AL seamless aluminum cylinders. (a) Size and service pressure. A DOT 3AL cylinder is a seamless aluminum cylinder with a maximum...

  8. 49 CFR 178.46 - Specification 3AL seamless aluminum cylinders.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Specification 3AL seamless aluminum cylinders. 178... FOR PACKAGINGS Specifications for Cylinders § 178.46 Specification 3AL seamless aluminum cylinders. (a) Size and service pressure. A DOT 3AL cylinder is a seamless aluminum cylinder with a maximum...

  9. 49 CFR 178.46 - Specification 3AL seamless aluminum cylinders.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... suitable method that will identify the alloy, the aluminum producer's cast number, the solution heat treat batch number and the lot number. (4) The material must be of uniform quality. Only the following heat... to any test, all cylinders must be subjected to a solution heat treatment and aging...

  10. Manufacturing stresses and strains in filament wound cylinders

    NASA Technical Reports Server (NTRS)

    Calius, E. P.; Kidron, M.; Lee, S. Y.; Springer, G. S.

    1988-01-01

    Tests were performed to verify a previously developed model for simulating the manufacturing process of filament wound cylinders. The axial and hoop strains were measured during cure inside a filament wound Fiberite T300/976 graphite-epoxy cylinder. The measured strains were compared to those computed by the model. Good agreements were found between the data and the model, indicating that the model is a useful representation of the process. For the conditions of the test, the manufacturing stresses inside the cylinder were also calculated using the model.

  11. Manufacture, electromagnetic properties and microstructure of an 18-filament jelly-roll Nb3Al superconducting wire with rapid heating and quenching heat-treatment

    NASA Astrophysics Data System (ADS)

    Pan, X. F.; Feng, Y.; Yan, G.; Cui, L. J.; Chen, C.; Zhang, Y.; Wu, Z. X.; Liu, X. H.; Zhang, P. X.; Bai, Z. M.; Zhao, Y.; Li, L. F.

    2016-01-01

    In this paper, we have reported the manufacture of a novel simple-structured jelly-roll Nb3Al precursor long wire, and its electromagnetic properties and microstructure with different rapid heating and quenching (RHQ) heat-treatments. By comparing three processing methods, it is found that the rolling and drawing (RD) method is more suitable to the fabrication of kilometer-length Nb3Al precursor wire without annealing. Using homemade RHQ equipment, we have successfully carried out RHQ heat-treatment of Nb3Al wire samples with various heating conditions. Based on magnetization and magnetoresistivity measurements, the onset superconducting transition temperature, T c and upper critical field, H c2 (0) of optimal Nb3Al wire reach 17.9 K-18.0 K and 29.7 T, respectively. Through microstructure and composition analysis, the Nb3Al superconductor in the optimal wire displays a typical ‘layer-to-layer’ structure, which comprises alternate crystalline Nb3Al and amorphous Nb layers, and the Nb3Al grains sizes are about 100 nm-300 nm. Furthermore, many small holes are dispersed in the Nb3Al superconductor due to the diffusion reaction from Al to Nb site. The work suggests the simple-structured Nb3Al precursor wire with RHQ heat-treatment is very promising for high-field application.

  12. Manufacturing of Nanocomposite Carbon Fibers and Composite Cylinders

    NASA Technical Reports Server (NTRS)

    Tan, Seng; Zhou, Jian-guo

    2013-01-01

    Pitch-based nanocomposite carbon fibers were prepared with various percentages of carbon nanofibers (CNFs), and the fibers were used for manufacturing composite structures. Experimental results show that these nanocomposite carbon fibers exhibit improved structural and electrical conductivity properties as compared to unreinforced carbon fibers. Composite panels fabricated from these nanocomposite carbon fibers and an epoxy system also show the same properties transformed from the fibers. Single-fiber testing per ASTM C1557 standard indicates that the nanocomposite carbon fiber has a tensile modulus of 110% higher, and a tensile strength 17.7% times higher, than the conventional carbon fiber manufactured from pitch. Also, the electrical resistance of the carbon fiber carbonized at 900 C was reduced from 4.8 to 2.2 ohm/cm. The manufacturing of the nanocomposite carbon fiber was based on an extrusion, non-solvent process. The precursor fibers were then carbonized and graphitized. The resultant fibers are continuous.

  13. Process for manufacturing hollow fused-silica insulator cylinder

    DOEpatents

    Sampayan, Stephen E.; Krogh, Michael L.; Davis, Steven C.; Decker, Derek E.; Rosenblum, Ben Z.; Sanders, David M.; Elizondo-Decanini, Juan M.

    2001-01-01

    A method for building hollow insulator cylinders that can have each end closed off with a high voltage electrode to contain a vacuum. A series of fused-silica round flat plates are fabricated with a large central hole and equal inside and outside diameters. The thickness of each is related to the electron orbit diameter of electrons that escape the material surface, loop, and return back. Electrons in such electron orbits can support avalanche mechanisms that result in surface flashover. For example, the thickness of each of the fused-silica round flat plates is about 0.5 millimeter. In general, the thinner the better. Metal, such as gold, is deposited onto each top and bottom surface of the fused-silica round flat plates using chemical vapor deposition (CVD). Eutectic metals can also be used with one alloy constituent on the top and the other on the bottom. The CVD, or a separate diffusion step, can be used to defuse the deposited metal deep into each fused-silica round flat plate. The conductive layer may also be applied by ion implantation or gas diffusion into the surface. The resulting structure may then be fused together into an insulator stack. The coated plates are aligned and then stacked, head-to-toe. Such stack is heated and pressed together enough to cause the metal interfaces to fuse, e.g., by welding, brazing or eutectic bonding. Such fusing is preferably complete enough to maintain a vacuum within the inner core of the assembled structure. A hollow cylinder structure results that can be used as a core liner in a dielectric wall accelerator and as a vacuum envelope for a vacuum tube device where the voltage gradients exceed 150 kV/cm.

  14. WASTE MINIMIZATION ASSESSMENT FOR ROTOGRAVURE PRINTING CYLINDER MANUFACTURING (EPA/600/S-95/007)

    EPA Science Inventory

    The U.S. Environmental Protection Agency (EPA) has funded a pilot project ot assist small and medium-size manufacturers who want to minimize their generation of waste but who lack the expertise to do so. In an effort to assist these manufacturers Waste Minimization Assessment Cen...

  15. ENVIRONMENTAL RESEARCH BRIEF: WASTE MINIMIZATION ASSESSMENT FOR A MANUFACTURER OF ROTOGRAVURE PRINTING CYLINDERS

    EPA Science Inventory

    The U.S. Environmental Protection Agency (EPA) has funded a pilot project to assist small and medium-size manufacturers who want to minimize their generation of waste but who lack the expertise to do so. aste Minimization Assessment Centers (WMACS) were established at selected un...

  16. ENVIRONMENTAL RESEARCH BRIEF: WASTE MINIMIZATION ASSESSMENT FOR A MANUFACTURER OF NEW AND REWORKED ROTOGRAVURE PRINTING CYLINDERS

    EPA Science Inventory

    The U.S. Environmental Protection Agency (EPA) has funded a pilot project to assist small and medium-size manufacturers who want to minimize their generation of waste but who lack the expertise to do so. aste Minimization Assessment Centers (WMACs) were established at selected un...

  17. WASTE MINIMIZATION ASSESSMENT FOR A MANUFACTURER OF NEW AND REWORKED ROTOGRAVURE PRINTING CYLINDERS (EPA/600/S-95/005)

    EPA Science Inventory

    The U.S. Environmental Protection Agency (EPA) has funded a pilot project to assist small and medium-size manufacturers who want to minimize their generation of waste but who lack the expertise to do so. Waste Minimization Assessment Centers (WMACs) were established at selected u...

  18. RHQT Nb3Al 15-Tesla magnet design study

    SciTech Connect

    Yamada, R.; Ambrosio, G.; Barzi, E.; Kashikin, V.; Kikuchi, A.; Novitski, I.; Takeuchi, T.; Wake, M.; Zlobin, A.; /Fermilab /NIMC, Tsukuba /KEK, Tsukuba

    2005-09-01

    Feasibility study of 15-Tesla dipole magnets wound with a new copper stabilized RHQT Nb{sub 3}Al Rutherford cable is presented. A new practical long copper stabilized RHQT Nb{sub 3}Al strand is presented, which is being developed and manufactured at the National Institute of Material Science (NIMS) in Japan. It has achieved a non-copper J{sub c} of 1000A/mm{sup 2} at 15 Tesla at 4.2K, with a copper over non-copper ratio of 1.04, and a filament size less than 50 microns. For this design study a short Rutherford cable with 28 Nb{sub 3}Al strands of 1 mm diameter will be fabricated late this year. The cosine theta magnet cross section is designed using ROXIE, and the stress and strain in the coil is estimated and studied with the characteristics of the Nb{sub 3}Al strand. The advantages and disadvantages of the Nb{sub 3}Al cable are compared with the prevailing Nb{sub 3}Sn cable from the point of view of stress-strain, J{sub c}, and possible degradation of stabilizer due to cabling. The Nb{sub 3}Al coil of the magnet, which will be made by wind and react method, has to be heat treated at 800 degree C for 10 hours. As preparation for the 15 Tesla magnet, a series of tests on strand and Rutherford cables are considered.

  19. Anaesthesia gas supply: gas cylinders.

    PubMed

    Srivastava, Uma

    2013-09-01

    Invention of oxygen cylinder was one of the most important developments in the field of medical practice. Oxygen and other gases were compressed and stored at high pressure in seamless containers constructed from hand-forged steel in1880. Materials technology has continued to evolve and now medical gas cylinders are generally made of steel alloys or aluminum. The filling pressure as well as capacity has increased considerably while at the same time the weight of cylinders has reduced. Today oxygen cylinder of equivalent size holds a third more oxygen but weighs about 20 kg less. The cylinders are of varying sizes and are color coded. They are tested at regular intervals by the manufacturer using hydraulic, impact, and tensile tests. The top end of the cylinder is fitted with a valve with a variety of number and markings stamped on it. Common valve types include: Pin index valve, bull nose, hand wheel and integral valve. The type of valve varies with cylinder size. Small cylinders have a pin index valve while large have a bull nose type. Safety features in the cylinder are: Color coding, pin index, pressure relief device, Bodok seal, and label attached etc., Safety rules and guidelines must be followed during storage, installation and use of cylinders to ensure safety of patients, hospital personnel and the environment. PMID:24249883

  20. Anaesthesia Gas Supply: Gas Cylinders

    PubMed Central

    Srivastava, Uma

    2013-01-01

    Invention of oxygen cylinder was one of the most important developments in the field of medical practice. Oxygen and other gases were compressed and stored at high pressure in seamless containers constructed from hand-forged steel in1880. Materials technology has continued to evolve and now medical gas cylinders are generally made of steel alloys or aluminum. The filling pressure as well as capacity has increased considerably while at the same time the weight of cylinders has reduced. Today oxygen cylinder of equivalent size holds a third more oxygen but weighs about 20 kg less. The cylinders are of varying sizes and are color coded. They are tested at regular intervals by the manufacturer using hydraulic, impact, and tensile tests. The top end of the cylinder is fitted with a valve with a variety of number and markings stamped on it. Common valve types include: Pin index valve, bull nose, hand wheel and integral valve. The type of valve varies with cylinder size. Small cylinders have a pin index valve while large have a bull nose type. Safety features in the cylinder are: Color coding, pin index, pressure relief device, Bodok seal, and label attached etc., Safety rules and guidelines must be followed during storage, installation and use of cylinders to ensure safety of patients, hospital personnel and the environment. PMID:24249883

  1. Ni{sub 3}Al aluminide alloys

    SciTech Connect

    Liu, C.T.

    1993-10-01

    This paper provides a brief review of the recent progress in research and development of Ni{sub 3}Al and its alloys. Emphasis has been placed on understanding low ductility and brittle fracture of Ni{sub 3}Al alloys at ambient and elevated temperatures. Recent studies have resulted in identifying both intrinsic and extrinsic factors governing the fracture behavior of Ni{sub 3}Al alloys. Parallel efforts on alloy design using physical metallurgy principles have led to properties for structural use. Industrial interest in these alloys is high, and examples of industrial involvement in processing and utilization of these alloys are briefly mentioned.

  2. A new cylinder cooling system using oil

    SciTech Connect

    Harashina, Kenichi; Murata, Katsuhiro; Satoh, Hiroshi; Shimizu, Yasuo; Hamamura, Masahiro

    1995-12-31

    The design of engine cylinders must satisfy two conflicting requirements, good cooling performance and ease of manufacture. A cooling system was designed to permit the circulation of engine lubricating oil as a coolant at high speed through grooves provided on the external periphery of the cylinder liner. Testing in an actual operating engine confirmed that this cooling system design not only provides better heat transfer and higher cooling performance but also simplifies the manufacturing of the cylinder since external cooling fins are not required. In this paper, the authors will discuss the cylinder cooling effect of the new cylinder cooling system, referring mainly to the test results of a single-cylinder motorcycle engine with lubricating oil from the crankcase used as the coolant.

  3. 76 FR 33023 - Safety Advisory; Unauthorized Marking of Compressed Gas Cylinders

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-07

    ...This notice advises the public that PHMSA has recently confirmed an undetermined number of certain (aluminum) cylinders were improperly marked and represented as DOT specification 3AL cylinders. The cylinders were neither marked nor certified by an authorized independent inspection agency (IIA) with its official mark and date, in accordance with the applicable regulatory requirements.......

  4. Ni{sub 3}Al technology transfer

    SciTech Connect

    Sikka, V.K.; Viswanathan, S.; Santella, M.L.

    1997-04-01

    Ductile Ni{sub 3}Al and Ni{sub 3}Al-based alloys have been identified for a range of applications. These applications require the use of material in a variety of product forms such as sheet, plate, bar, wire, tubing, piping, and castings. Although significant progress has been made in the melting, casting, and near-net-shape forming of nickel aluminides, some issues still remain. These include the need for: (1) high-strength castable composition for many applications that have been identified; (2) castability (mold type, fluidity, hot-shortness, porosity, etc.); (3) weld reparability of castings; and (4) workability of cast or powder metallurgy product to sheet, bar, and wire. The four issues listed above can be {open_quotes}show stoppers{close_quotes} for the commercial application of nickel aluminides. This report describes the work completed to address some of these issues during FY 1996.

  5. Ni{sub 3}Al technology transfer

    SciTech Connect

    Sikka, V.K.; Santella, M.L.; Alexander, D.J.

    1995-05-01

    Ductile Ni{sub 3}Al and Ni{sub 3}Al-based alloys have been identified for a range of applications. These applications require the use of material in a variety of product forms such as sheet, plate, bar, tubing, piping, and castings. Although significant progress has been made in the melting, casting, and near-net-shape forming of nickel aluminides, some issues still remain. These include the need for (1)high-strength castable composition for turbochargers, furnace furniture, and hot-die applications; (2) castability (fluidity, hot-shortness, porosity, etc.); (3) weld reparability of castings; and (4) hot fabricability of cast ingots. All of the issues listed above can be {open_quotes}show stoppers{close_quotes} for the commercial application of nickel aluminides. This report describes work completed to address some of these issues during the fourth quarter of FY 1994.

  6. Experimental study on a Nb3Al insert coil under high magnetic field

    NASA Astrophysics Data System (ADS)

    Zhu, Guang; Dai, Yinming; Cheng, Junsheng; Chang, Kun; Liu, Jianhua; Wang, Qiuliang; Pan, Xifeng; Li, Chao

    2016-06-01

    Nb3Al is one of the most promising superconductors to replace Nb3Sn in large scale, high field superconducting magnet. Since the complicated conductor manufacturing process, long and stable Nb3Al conductor is difficult to acquire in a commercial scale. Based on a 70 m length of Nb-Al precursor conductor, we designed and fabricated a Nb3Al coil. The coil winding, low temperature diffusion heat treatment and epoxy impregnation are described in detail. The finished Nb3Al coil is tested as an insert in a background magnet. The test is performed at the background field from 7 T to 15 T. The test results are analyzed and presented in this paper.

  7. Nb3Al Development for HEP Applications

    SciTech Connect

    Sumption, M.D.; Buta, F.; Collings, E.W.; Tomsic, M.; Phillips, J.; McFadden, K.; Wu, X

    2004-06-28

    Recent developments in Nb3Al strand for HEP applications are presented and discussed. The present state of available precursor is detailed. Two routes have been shown to lead to successful construction of MF NbAl composite wires. An extrusion method has so far produced the highest filament counts and smallest filament diameters, but requires more processing steps. A direct restack and draw approach has also been demonstrated which minimizes the number of processing steps while still leading to a high performance conductor. This latter route also allows for a lower cost per billet, potentially allowing the exploration of more process parameters.

  8. 49 CFR 178.39 - Specification 3BN seamless nickel cylinders.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... for hot-drawn cylinders must be marked with the heat number. (d) Manufacture. Cylinders must be... = inside diameter in inches. (g) Heat treatment. The completed cylinders must be uniformly and properly heat-treated prior to tests. (h) Openings in cylinders and connections (valves, fuse plugs, etc.)...

  9. 49 CFR 178.56 - Specification 4AA480 welded steel cylinders.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... cylinders must be marked with the heat number. (d) Manufacture. Cylinders must be manufactured using... less than 0.100 inch. (g) Heat treatment. Each cylinder must be uniformly and properly heat treated prior to tests. Any suitable heat treatment in excess of 1100 °F is authorized except that...

  10. 49 CFR 178.38 - Specification 3B seamless steel cylinders.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... the heat number. (d) Manufacture. Cylinders must be manufactured using equipment and processes... = inside diameter in inches. (g) Heat treatment. The completed cylinders must be uniformly and properly heat-treated prior to tests. (h) Openings in cylinders and connections (valves, fuse plugs, etc.)...

  11. Magnetization anomaly of Nb3Al strands and instability of Nb3Al Rutherford cables

    SciTech Connect

    Yamada, Ryuji; Kikuchi, Akihiro; Wake, Masayoshi; /KEK, Tsukuba

    2006-08-01

    Using a Cu stabilized Nb{sub 3}Al strand with Nb matrix, a 30 meter long Nb{sub 3}Al Rutherford cable was made by a collaboration of Fermilab and NIMS. Recently the strand and cable were tested. In both cases instability was observed at around 1.5 Tesla. The magnetization of this Nb{sub 3}Al strand was measured first using a balanced coil magnetometer at 4.2 K. Strands showed an anomalously large magnetization behavior around at 1.6 T, which is much higher than the usual B{sub c2} {approx} 0.5 Tesla (4.2 K) of Nb matrix. This result is compared with the magnetization data of short strand samples using a SQUID magnetometer, in which a flux-jump signal was observed at 0.5 Tesla, but not at higher field. As a possible explanation for this magnetization anomaly, the interfilament coupling through the thin Nb films in the strands is suggested. The instability problem observed in low field tests of the Nb{sub 3}Al Rutherford cables is attributed to this effect.

  12. Fracture mechanics analysis of NGV fuel cylinders. Part 1: Steel cylinders

    NASA Astrophysics Data System (ADS)

    Connolly, M. P.; Hudak, S. J.; Roy, S.

    1993-02-01

    Compressed natural gas (CNG) cylinders for natural gas vehicles (NGVs) are subject to a combination of pressure cycles, associated with periodic refueling, and a potentially corrosive CNG environment. Under these conditions it has been shown that the life of the cylinder is governed by the corrosion-fatigue crack growth of internal flaws such as voids, pits or folds that may be present after manufacture. For NGV applications, these cylinders are required to operate for at least 15 years and the report, through a detailed fracture mechanics analysis, describes approaches to achieving the desired life. The analysis shows that a 15 year cylinder life can be obtained by using quality control to ensure that no initial defects greater than 0.045 in. X 0.090 in. exist after manufacture. Alternatively, gas drying can be used at the distribution stations to reduce the detrimental effects of the remaining CNG impurities, and thereby, produce long cylinder lives. The analysis also considers the role of in-service inspection/retest and shows that in-service NDE has little advantage, either technically or economically, for ensuring the fitness-for-service of steel NGV cylinders. The analysis also shows that hydrostatic testing of cylinders, either at manufacture or in service, is ineffective for detecting fatigue cracks and therefore should not be implemented as part of a fitness-for-service plan for NGV fuel cylinders. The issue of cylinder geometry was also considered and the analysis shows that improperly designed flat-bottomed CNG cylinders can result in premature fatigue failures originating at the inner wall in the transition region between the cylinder end and sidewall.

  13. 49 CFR 173.304 - Filling of cylinders with liquefied compressed gases.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... has been furnished by an aircraft operator to a passenger in accordance with 14 CFR 121.574, 125.219... specification 3A, 3AA, 3AL, 3E, 3HT, and 39 cylinders, and UN pressure receptacles ISO 9809-1, ISO 9809-2, ISO... rupture disc for DOT 3A, 3AA, 3AL, 3E and 39 cylinders, and UN pressure receptacles ISO 9809-1, ISO...

  14. 49 CFR 173.304 - Filling of cylinders with liquefied compressed gases.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... compressed oxygen that has been furnished by an aircraft operator to a passenger in accordance with 14 CFR... specification 3A, 3AA, 3AL, 3E, 3HT, and 39 cylinders, and UN pressure receptacles ISO 9809-1, ISO 9809-2, ISO... rupture disc for DOT 3A, 3AA, 3AL, 3E and 39 cylinders, and UN pressure receptacles ISO 9809-1, ISO...

  15. 49 CFR 173.304 - Filling of cylinders with liquefied compressed gases.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... compressed oxygen that has been furnished by an aircraft operator to a passenger in accordance with 14 CFR... specification 3A, 3AA, 3AL, 3E, 3HT, and 39 cylinders, and UN pressure receptacles ISO 9809-1, ISO 9809-2, ISO... rupture disc for DOT 3A, 3AA, 3AL, 3E and 39 cylinders, and UN pressure receptacles ISO 9809-1, ISO...

  16. 49 CFR 173.304 - Filling of cylinders with liquefied compressed gases.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... compressed oxygen that has been furnished by an aircraft operator to a passenger in accordance with 14 CFR... specification 3A, 3AA, 3AL, 3E, 3HT, and 39 cylinders, and UN pressure receptacles ISO 9809-1, ISO 9809-2, ISO... rupture disc for DOT 3A, 3AA, 3AL, 3E and 39 cylinders, and UN pressure receptacles ISO 9809-1, ISO...

  17. 49 CFR 173.304 - Filling of cylinders with liquefied compressed gases.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... compressed oxygen that has been furnished by an aircraft operator to a passenger in accordance with 14 CFR... specification 3A, 3AA, 3AL, 3E, 3HT, and 39 cylinders, and UN pressure receptacles ISO 9809-1, ISO 9809-2, ISO... rupture disc for DOT 3A, 3AA, 3AL, 3E and 39 cylinders, and UN pressure receptacles ISO 9809-1, ISO...

  18. 49 CFR 178.46 - Specification 3AL seamless aluminum cylinders.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... suitable method that will identify the alloy, the aluminum producer's cast number, the solution heat treat batch number and the lot number. (4) The material must be of uniform quality. Only the following heat treatable aluminum alloys in table 1 and 2 are permitted as follows: Table 1—Heat or Cast Analysis...

  19. Cylinder valve packing nut studies

    SciTech Connect

    Blue, S.C.

    1991-12-31

    The design, manufacture, and use of cylinder valve packing nuts have been studied to improve their resistance to failure from stress corrosion cracking. Stress frozen photoelastic models have been analyzed to measure the stress concentrations at observed points of failure. The load effects induced by assembly torque and thermal expansion of stem packing were observed by strain gaging nuts. The effects of finishing operations and heat treatment were studied by the strain gage hole boring and X-ray methods. Modifications of manufacturing and operation practices are reducing the frequency of stress corrosion failures.

  20. Commercialization status of Ni{sub 3}Al-based alloys

    SciTech Connect

    Sikka, V.K.

    1997-12-31

    The Ni{sub 3}Al-based alloys have been under development at the Oak Ridge National Laboratory (ORNL) and other research institutions in the United States and around the world for the last ten years. The incremental developments of composition, melting process, casting methods, property data, corrosion data, weldability development, and prototype component testing under production-like operating conditions have pushed the ORNL-developed Ni{sub 3}Al-based alloys closer to commercialization. This paper will present the highlights of incremental technical developments along with the approach and current status of commercialization. It is concluded that cast components are the primary applications of Ni{sub 3}Al-based alloys, and applications range from heat-treating fixtures of forging dies. It is also concluded that the commercialization process is accelerated when technology is licensed to an organization that can produce the alloy, has component manufacturing capability, and is also a user.

  1. Quick release engine cylinder

    DOEpatents

    Sunnarborg, Duane A.

    2000-01-01

    A quick release engine cylinder allows optical access to an essentially unaltered combustion chamber, is suitable for use with actual combustion processes, and is amenable to rapid and repeated disassembly and cleaning. A cylinder member, adapted to constrain a piston to a defined path through the cylinder member, sealingly engages a cylinder head to provide a production-like combustion chamber. A support member mounts with the cylinder member. The support-to-cylinder mounting allows two relationships therebetween. In the first mounting relationship, the support engages the cylinder member and restrains the cylinder against the head. In the second mounting relationship, the cylinder member can pass through the support member, moving away from the head and providing access to the piston-top and head.

  2. The experiments and characteristic analysis of the sealless cylinder

    NASA Astrophysics Data System (ADS)

    Kim, Dong-Soo; Bae, Sang-Kyu

    2005-12-01

    Because the general cylinders use sliding seal, The cause the high friction force and adherence phenomenon when They operates in low speed, and the use of the cylinders is not proper in the clean room and high temperature and high pressure environment. Accordingly, in this study, sealless cylinder attaching conical-type piston without seal is proposed to complement the handicap. This paper shows a performance analysis for conical type sealless cylinders and rod bearings. The pistons without seal have partly cylindrical and conical shapes. The 2dimensional Reynolds equation and FD(finite differential) numerical techniques are utilized for the performance analysis. The relationship among self-centering forces and leakage flows are investigated. Also, the optimal design values for a sealless cylinder are presented. A prototype of sealless cylinder which had rod bearing with four pockets, five pockets, and six pockets was manufactured respectively. The leakage flow tests are conducted to evaluate performance of piston and rod bearing in sealless cylinder.

  3. Feasibility study of Nb3Al Rutherford cable for high field accelerator magnet application

    SciTech Connect

    Yamada, R.; Kikuchi, A.; Ambrosio, G.; Andreev, N.; Barzi, E.; Cooper, C.; Feher, S.; Kashikhin, V.V.; Lamm, M.; Novitski, I.; Takeuchi, T.; Tartaglia, M.; Turrioni, D.; Verweij, A.P.; Wake, M.; Willering, G; Zlobin, A.V.; /Fermilab

    2006-08-01

    Feasibility study of Cu stabilized Nb{sub 3}Al strand and Rutherford cable for the application to high field accelerator magnets are being done at Fermilab in collaboration with NIMS. The Nb{sub 3}Al strand, which was developed and manufactured at NIMS in Japan, has a non-copper Jc of about 844 A/mm{sup 2} at 15 Tesla at 4.2 K, a copper content of 50%, and filament size of about 50 microns. Rutherford cables with 27 Nb{sub 3}Al strands of 1.03 mm diameter were fabricated and tested. Quench tests on a short cable were done to study its stability with only its self field, utilizing a high current transformer. A pair of 2 meter long Nb{sub 3}Al cables was tested extensively at CERN at 4.3 and 1.9 K up to 11 Tesla including its self field with a high transport current of 20.2 kA. In the low field test we observed instability near splices and in the central region. This is related to the flux-jump like behavior, because of excessive amount of Nb in the Nb{sub 3}Al strand. There is possibility that the Nb in Nb{sub 3}Al can cause instability below 2 Tesla field regions. We need further investigation on this problem. Above 8 Tesla, we observed quenches near the critical surface at fast ramp rate from 1000 to 3000 A/sec, with quench velocity over 100 m/sec. A small racetrack magnet was made using a 14 m of Rutherford cable and successfully tested up to 21.8 kA, corresponding to 8.7 T.

  4. Cylinder Test Specification

    SciTech Connect

    Richard Catanach; Larry Hill; Herbert Harry; Ernest Aragon; Don Murk

    1999-10-01

    The purpose of the cylinder testis two-fold: (1) to characterize the metal-pushing ability of an explosive relative to that of other explosives as evaluated by the E{sub 19} cylinder energy and the G{sub 19} Gurney energy and (2) to help establish the explosive product equation-of-state (historically, the Jones-Wilkins-Lee (JWL) equation). This specification details the material requirements and procedures necessary to assemble and fire a typical Los Alamos National Laboratory (LANL) cylinder test. Strict adherence to the cylinder. material properties, machining tolerances, material heat-treatment and etching processes, and high explosive machining tolerances is essential for test-to-test consistency and to maximize radial wall expansions. Assembly and setup of the cylinder test require precise attention to detail, especially when placing intricate pin wires on the cylinder wall. The cylinder test is typically fired outdoors and at ambient temperature.

  5. Cylinder monitoring program

    SciTech Connect

    Alderson, J.H.

    1991-12-31

    Cylinders containing depleted uranium hexafluoride (UF{sub 6}) in storage at the Department of Energy (DOE) gaseous diffusion plants, managed by Martin Marietta Energy Systems, Inc., are being evaluated to determine their expected storage life. Cylinders evaluated recently have been in storage service for 30 to 40 years. In the present environment, the remaining life for these storage cylinders is estimated to be 30 years or greater. The group of cylinders involved in recent tests will continue to be monitored on a periodic basis, and other storage cylinders will be observed as on a statistical sample population. The program has been extended to all types of large capacity UF{sub 6} cylinders.

  6. Delamination of Composite Cylinders

    NASA Astrophysics Data System (ADS)

    Davies, Peter; Carlsson, Leif A.

    The delamination resistance of filament wound glass/epoxy cylinders has been characterized for a range of winding angles and fracture mode ratios using beam fracture specimens. The results reveal that the delamination fracture resistance increases with increasing winding angle and mode II (shear) fraction (GΠ/G). It was also found that interlaced fiber bundles in the filament wound cylinder wall acted as effective crack arresters in mode I loading. To examine the sensitivity of delamina-tion damage on the strength of the cylinders, external pressure tests were performed on filament-wound glass/epoxy composite cylinders with artificial defects and impact damage. The results revealed that the cylinder strength was insensitive to the presence of single delaminations but impact damage caused reductions in failure pressure. The insensitivity of the failure pressure to a single delamination is attributed to the absence of buckling of the delaminated sublaminates before the cylinder wall collapsed. The impacted cylinders contained multiple delaminations, which caused local reduction in the compressive load capability and reduction in failure pressure. The response of glass/epoxy cylinders was compared to impacted carbon reinforced cylinders. Carbon/epoxy is more sensitive to damage but retains higher implosion resistance while carbon/PEEK shows the opposite trend.

  7. The Charpy impact behavior of Fe{sub 3}Al and Fe{sub 3}Al-20 at % Mn alloys

    SciTech Connect

    Liu, J.N.; Yan, W.; Ma, J.L.; Wu, K.H.

    1997-12-31

    A series of experiments were conducted to investigate the impact fracture behavior of Fe{sub 3}Al and Fe{sub 3}Al-20 Mn alloys. The results of this study indicated that: (i) The addition of Mn introduces an ordered L1{sub 2}-type phase in the Fe{sub 3}Al-based alloys. On the other hand, the addition of Mn decreases the order parameter of the DO{sub 3} {alpha} phase. (ii) The total-impact energy of an Fe{sub 3}Al alloy increases with the temperature at the low-temperature range (<600 C), then drops around 700 C, and finally increases again as the temperature further elevates. (iii) The trend of the variation of the impact energy of Fe{sub 3}Al-20 at % Mn alloy with temperature is the same as that of the Fe{sub 3}Al alloy. (iv) And the addition of Mn significantly improves the impact energy of the Fe{sub 3}Al-based alloy, and changes the variation of the crack-growth energy with the testing temperature when the temperature is above 700 C.

  8. Quench tests of Nb3Al small racetrack magnets

    SciTech Connect

    Yamada, R.; Kikuchi, A.; Tartaglia, Michael Albert; Ambrosio, G.; Andreev, N.; Barzi, E.; Carcagno, R.; Feher, S.; Kashikhin, V.V.; Kotelnikov, S.; Lamm, Michael J.; /Fermilab /NIMC, Tsukuba /KEK, Tsukuba

    2007-08-01

    Two Cu stabilized Nb3Al strands, F1 (Nb matrixed) and F3 (Ta matrixed), have been made at NIMS and their Rutherford cables were made at Fermilab in collaboration with NIMS. A Small Race-track magnet using F1 Rutherford cable, the first Nb3Al dipole magnet in the world, was constructed and tested to full current at Fermilab. This magnet was tested extensively to full short sample data and its quench characteristics were studied and reported. The 3-D magnetic field calculation was done with ANSYS to find the peak field. The quench characteristics of the magnet are explained with the characteristics of the Nb3Al strand and Rutherford cable. The other Small Race-track magnet using Ta matrixed F3 strand was constructed and will be tested in the near future. The advantages and disadvantages of these Nb3Al cables are discussed.

  9. Ultrahigh strength of dislocation-free Ni3Al nanocubes.

    PubMed

    Maaß, Robert; Meza, Lucas; Gan, Bin; Tin, Sammy; Greer, Julia R

    2012-06-25

    Individual Ni(3) Al nanocubes under pressure are investigated by comparing the compressive strength of both dislocation-free and irradiated Ni(3) Al nanocubes. The results are dicussed in light of the size-dependent and size-independent strength of face-centered cubic (fcc) nanocrystals in the framework of dislocation nucleation at free surfaces. This study sheds more light on the understanding of fundamental deformation mechanisms and size-affected strength in dislocation-free metallic nanocrystals. PMID:22454244

  10. 49 CFR 173.304a - Additional requirements for shipment of liquefied compressed gases in specification cylinders.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... specification cylinders, as follows: (1) DOT 3, 3A, 3AA, 3AL, 3B, 3BN, 3E, 4B, 4BA, 4B240ET, 4BW, 4E, 39, except...) Liquefied petroleum gas must be shipped in specification cylinders as follows: (i) DOT 3, 3A, 3AA, 3B,...

  11. 49 CFR 173.304a - Additional requirements for shipment of liquefied compressed gases in specification cylinders.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... specification cylinders, as follows: (1) DOT 3, 3A, 3AA, 3AL, 3B, 3BN, 3E, 4B, 4BA, 4B240ET, 4BW, 4E, 39, except...) Liquefied petroleum gas must be shipped in specification cylinders as follows: (i) DOT 3, 3A, 3AA, 3B,...

  12. 49 CFR 173.304a - Additional requirements for shipment of liquefied compressed gases in specification cylinders.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... specification cylinders, as follows: (1) DOT 3, 3A, 3AA, 3AL, 3B, 3BN, 3E, 4B, 4BA, 4B240ET, 4BW, 4E, 39, except...) Liquefied petroleum gas must be shipped in specification cylinders as follows: (i) DOT 3, 3A, 3AA, 3B,...

  13. 49 CFR 173.304a - Additional requirements for shipment of liquefied compressed gases in specification cylinders.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... specification cylinders, as follows: (1) DOT 3, 3A, 3AA, 3AL, 3B, 3BN, 3E, 4B, 4BA, 4B240ET, 4BW, 4E, 39, except...) Liquefied petroleum gas must be shipped in specification cylinders as follows: (i) DOT 3, 3A, 3AA, 3B,...

  14. 49 CFR 173.304a - Additional requirements for shipment of liquefied compressed gases in specification cylinders.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... specification cylinders, as follows: (1) DOT 3, 3A, 3AA, 3AL, 3B, 3BN, 3E, 4B, 4BA, 4B240ET, 4BW, 4E, 39, except...) Liquefied petroleum gas must be shipped in specification cylinders as follows: (i) DOT 3, 3A, 3AA, 3B,...

  15. CNG Cylinder Safety - Education, Outreach, and Next Steps (Presentation)

    SciTech Connect

    Smith, M.; Schroeder, A.

    2014-01-01

    Mr. Schroeder discussed the work that NREL is performing for the U.S. Department of Transportation on compressed natural gas cylinder end-of-life requirements. CNG vehicles are different from most other vehicles in that the CNG fuel storage cylinders have a pre-determined lifetime that may be shorter than the expected life of the vehicle. The end-of-life date for a cylinder is based on construction and test protocols, and is specific to the construction and material of each cylinder. The end-of-life date is important because it provides a safe margin of error against catastrophic cylinder failure or rupture. The end-of-life dates range from 15 to 25 years from the date of manufacture. NREL worked to develop outreach materials to increase awareness of cylinder end-of-life dates, has provided technical support for individual efforts related to cylinder safety and removal, and also worked with CVEF to document best practices for cylinder removal or inspection after an accident. Mr. Smith discussed the engagement of the DOE Clean Fleets Partners, which were surveyed to identify best practices on managing cylinder inventories and approached to provide initial data on cylinder age in a fleet environment. Both DOE and NREL will continue to engage these fleets and other stakeholders to determine how to best address this issue moving forward.

  16. 49 CFR 178.59 - Specification 8 steel cylinders with porous fillings for acetylene.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... the heat number. (d) Manufacture. Cylinders must be manufactured using equipment and processes... cylinders over 18 inches long must be protected by footrings. (f) Heat treatment. Body and heads formed by drawing or pressing must be uniformly and properly heat treated prior to tests. (g) Openings. Openings...

  17. 49 CFR 178.51 - Specification 4BA welded or brazed steel cylinders.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... hotdrawn cylinders must be marked with the heat number. (d) Manufacture. Cylinders must be manufactured... material on one side of seam and applying heat until this material shows uniformly along the seam of the... efficiency factor which must be applied in the girth weld area and heat affected zones which zone must...

  18. Tests of Rotating Cylinders

    NASA Technical Reports Server (NTRS)

    Reid, Elliott G

    1924-01-01

    Tests were made in the no. 1 wind tunnel at Langley Memorial Aeronautical Laboratory to determine the air forces acting on rotating cylinders with axes perpendicular to the direction of motion. One cylinder had a circular cross-section, the other that of a greek cross.

  19. A Sequence of Cylinders

    ERIC Educational Resources Information Center

    Johnson, Erica

    2006-01-01

    Hoping to develop in her students an understanding of mathematics as a way of thinking more than a way of doing, the author of this article describes how her students worked on a spatial reasoning problem stemming from an iteratively constructed sequence of cylinders. She presents an activity of making cylinders out of paper models, and for every…

  20. An overview of the welding of Ni{sub 3}Al and Fe{sub 3}Al alloys

    SciTech Connect

    Santella, M.L.

    1996-12-31

    Weldability (degree to which defect formation is resisted when an alloy is welded) is an issue in fabrication of Ni{sub 3}Al and Fe{sub 3}Al. Work to define and improve welding of Ni{sub 3}Al and Fe{sub 3}Al alloys is reviewed and progress illustrated by examples of current activities. The cast Ni{sub 3}Al alloys currently under development, IC221M and IC396M, have low resistance to solidification cracking and hence difficult to weld. Modifications to the composition of both base alloys and weld deposits,however, increase their resistance to cracking. Crack-free, full-penetration welds were made in centrifugally cast tubes of IC221M. Tensile and stress- rupture properties of the weldments compare favorably with base metal properties. Weldability issues have limited the use of Fe{sub 3}Al alloys to weld overlay applications. Filler metal compositions suitable for weld overlay cladding were developed, and the preheat and postweld heat treatment needed to avoid cracking, were determined experimentally.

  1. Tandem Cylinder Noise Predictions

    NASA Technical Reports Server (NTRS)

    Lockhard, David P.; Khorrami, Mehdi R.; CHoudhari, Meelan M.; Hutcheson, Florence V.; Brooks, Thomas F.; Stead, Daniel J.

    2007-01-01

    In an effort to better understand landing-gear noise sources, we have been examining a simplified configuration that still maintains some of the salient features of landing-gear flow fields. In particular, tandem cylinders have been studied because they model a variety of component level interactions. The present effort is directed at the case of two identical cylinders spatially separated in the streamwise direction by 3.7 diameters. Experimental measurements from the Basic Aerodynamic Research Tunnel (BART) and Quiet Flow Facility (QFF) at NASA Langley Research Center (LaRC) have provided steady surface pressures, detailed off-surface measurements of the flow field using Particle Image Velocimetry (PIV), hot-wire measurements in the wake of the rear cylinder, unsteady surface pressure data, and the radiated noise. The experiments were conducted at a Reynolds number of 166 105 based on the cylinder diameter. A trip was used on the upstream cylinder to insure a fully turbulent shedding process and simulate the effects of a high Reynolds number flow. The parallel computational effort uses the three-dimensional Navier-Stokes solver CFL3D with a hybrid, zonal turbulence model that turns off the turbulence production term everywhere except in a narrow ring surrounding solid surfaces. The current calculations further explore the influence of the grid resolution and spanwise extent on the flow and associated radiated noise. Extensive comparisons with the experimental data are used to assess the ability of the computations to simulate the details of the flow. The results show that the pressure fluctuations on the upstream cylinder, caused by vortex shedding, are smaller than those generated on the downstream cylinder by wake interaction. Consequently, the downstream cylinder dominates the noise radiation, producing an overall directivity pattern that is similar to that of an isolated cylinder. Only calculations based on the full length of the model span were able to

  2. Fiber Tracking Cylinder Nesting

    SciTech Connect

    Stredde, H.; /Fermilab

    1999-03-30

    The fiber tracker consists of 8 concentric carbon fiber cylinders of varying diameters, from 399mm to 1032.2mm and two different lengths. 1.66 and 2.52 meters. Each completed cylinder is covered over the entire o.d. with scintillating fiber ribbons with a connector on each ribbon. These ribbons are axial (parallel to the beam line) at one end and stereo (at 3 deg. to the beam line) at the other. The ribbon connectors have dowel pins which are used to match with the connectors on the wave guide ribbons. These dowel pins are also used during the nesting operation, locating and positioning measurements. The nesting operation is the insertion of one cylinder into another, aligning them with one another and fastening them together into a homogeneous assembly. For ease of assembly. the nesting operation is accomplished working from largest diameter to smallest. Although the completed assembly of all 8 cylinders glued and bolted together is very stiff. individual cylinders are relatively flexible. Therefore. during this operation, No.8 must be supported in a manner which maintains its integrity and yet allows the insertion of No.7. This is accomplished by essentially building a set of dummy end plates which replicate a No.9 cylinder. These end plates are mounted on a wheeled cart that becomes the nesting cart. Provisions for a protective cover fastened to these rings has been made and will be incorporated in finished product. These covers can be easily removed for access to No.8 and/or the connection of No.8 to No.9. Another wheeled cart, transfer cart, is used to push a completed cylinder into the cylinder(s) already mounted in the nesting cart.

  3. An update on corrosion monitoring in cylinder storage yards

    SciTech Connect

    Henson, H.M.; Newman, V.S.; Frazier, J.L.

    1991-12-31

    Depleted uranium, from US uranium isotope enrichment activities, is stored in the form of solid uranium hexafluoride (UF{sub 6}) in A285 and A516 steel cylinders designed and manufactured to ASME Boiler and Pressure Vessel Code criteria. In general, storage facilities are open areas adjacent to the enrichment plants where the cylinders are exposed to weather. This paper describes the Oak Ridge program to determine the general corrosion behavior of UF{sub 6} cylinders, to determine cylinder yard conditions which are likely to affect long term storage of this material, and to assess cylinder storage yards against these criteria. This program is targeted at conditions specific to the Oak Ridge cylinder yards. Based on (a) determination of the current cylinder yard conditions, (b) determination of rusting behavior in regions of the cylinders showing accelerated attack, (c) monitoring of corrosion rates through periodic measurement of test coupons placed within the cylinder yards, and (d) establishment of a computer base to incorporate and retain these data, the technical division is working with the enrichment sites to implement an upgraded system for storage of this material until such time as it is used or converted.

  4. Formation of Nb/sub 3/Al in powder processed Nb-Al superconductors

    SciTech Connect

    Johnson, P.E.

    1987-05-01

    In high magnetic fields, the critical current density is strongly dependent on the upper critical field, which is determined primarily by the stoichiometry of the Nb/sub 3/Al. The critical temperature (T/sub c/), like the upper critical field, is considered to be a measure of the ''intrinsic'' quality of the superconductor, indicating the stoichiometry, order, and strain. If the A15 phase is stoichiometric and well ordered, a high T/sub c/ (and high H/sub C/sub 2//) is expected, regardless of the volume fraction of superconductor. On the other hand, if sigma phase is present with the A15, the resultant composition gradient across the sigma-A15 interface(s) requires that some of the A15 be off-stoichiometric, and therefore that the T/sub c/ (and H/sub C/sub 2//) be low. Thus the extent of the A15 (Nb/sub 3/Al) reaction and the quality of the A15 formed are interdependent. This work focuses on the factors that control the extent of Nb/sub 3/Al formation in Nb/Al powder wires. The morphology and content of the reacted and unreacted wires are studied in optical, SEM, and TEM micrographs. Critical current density data and its dependence on processing are explained in terms of the unreacted microstructure and its effect on the extent of Nb/sub 3/Al formation. As a method of improving the critical current density, a new variation of the conventional powder process for wire manufacturing is developed and tested.

  5. AB INITIO STUDY OF PHONON DISPERSION AND ELASTIC PROPERTIES OF L12 INTERMETALLICS Ti3Al AND Y3Al

    NASA Astrophysics Data System (ADS)

    Arikan, N.; Ersen, M.; Ocak, H. Y.; Iyigör, A.; Candan, A.; UǦUR, Ş.; UǦUR, G.; Khenata, R.; Varshney, D.

    2013-12-01

    In this paper, the structural, elastic and phonon properties of Ti3Al and Y3Al in L12(Cu3Al) phase are studied by performing first-principles calculations within the generalized gradient approximation. The calculated lattice constants, static bulk moduli, first-order pressure derivative of bulk moduli and elastic constants for both compounds are reported. The phonon dispersion curves along several high-symmetry lines at the Brillouin zone, together with the corresponding phonon density of states, are determined using the first-principles linear-response approach of the density functional perturbation theory. Temperature variations of specific heat in the range of 0-500 K are obtained using the quasi-harmonic model.

  6. Relativistic Bessel cylinders

    NASA Astrophysics Data System (ADS)

    Krisch, J. P.; Glass, E. N.

    2014-10-01

    A set of cylindrical solutions to Einstein's field equations for power law densities is described. The solutions have a Bessel function contribution to the metric. For matter cylinders regular on axis, the first two solutions are the constant density Gott-Hiscock string and a cylinder with a metric Airy function. All members of this family have the Vilenkin limit to their mass per length. Some examples of Bessel shells and Bessel motion are given.

  7. 49 CFR 173.302 - Filling of cylinders with nonliquefied (permanent) compressed gases.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... compressed oxygen that has been furnished by an aircraft operator to a passenger in accordance with 14 CFR..., 3E, 3HT, and 39 cylinders, and UN pressure receptacles ISO 9809-1, ISO 9809-2, ISO 9809-3 and ISO... DOT 3A, 3AA, 3AL, 3E, and 39 cylinders, and UN pressure receptacles ISO 9809-1, ISO 9809-2, ISO...

  8. 49 CFR 173.302 - Filling of cylinders with nonliquefied (permanent) compressed gases.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... compressed oxygen that has been furnished by an aircraft operator to a passenger in accordance with 14 CFR..., 3E, 3HT, and 39 cylinders, and UN pressure receptacles ISO 9809-1, ISO 9809-2, ISO 9809-3 and ISO... DOT 3A, 3AA, 3AL, 3E, and 39 cylinders, and UN pressure receptacles ISO 9809-1, ISO 9809-2, ISO...

  9. 49 CFR 173.302 - Filling of cylinders with nonliquefied (permanent) compressed gases.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... operator to a passenger in accordance with 14 CFR §§ 121.574, 125.219, or 135.91 is excepted from the outer..., 3E, 3HT, and 39 cylinders, and UN pressure receptacles ISO 9809-1, ISO 9809-2, ISO 9809-3 and ISO... DOT 3A, 3AA, 3AL, 3E, and 39 cylinders, and UN pressure receptacles ISO 9809-1, ISO 9809-2, ISO...

  10. 49 CFR 173.302 - Filling of cylinders with nonliquefied (permanent) compressed gases.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... compressed oxygen that has been furnished by an aircraft operator to a passenger in accordance with 14 CFR..., 3E, 3HT, and 39 cylinders, and UN pressure receptacles ISO 9809-1, ISO 9809-2, ISO 9809-3 and ISO... DOT 3A, 3AA, 3AL, 3E, and 39 cylinders, and UN pressure receptacles ISO 9809-1, ISO 9809-2, ISO...

  11. 49 CFR 173.302 - Filling of cylinders with nonliquefied (permanent) compressed gases.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... compressed oxygen that has been furnished by an aircraft operator to a passenger in accordance with 14 CFR..., 3E, 3HT, and 39 cylinders, and UN pressure receptacles ISO 9809-1, ISO 9809-2, ISO 9809-3 and ISO... DOT 3A, 3AA, 3AL, 3E, and 39 cylinders, and UN pressure receptacles ISO 9809-1, ISO 9809-2, ISO...

  12. Use of Ni{sub 3}Al-based alloys for walking-beam furnaces

    SciTech Connect

    Sikka, V.K.; Dailey, R.E.

    1996-02-01

    This report summarizes the joint work performed by the Oak Ridge National Laboratory (ORNL) and Rapid Technologies, Inc. (the CRADA partner) to determine the potential of Ni{sub 3}Al-based alloys for use in gas-fired walking-beam furnace components. The report identifies tasks to be performed as part of the CRADA and the organization responsible for each task. The work required under each task was completed and is described. The CRADA accomplished the primary goal of utilizing cast Ni{sub 3}Al-based alloy as rails and other components for walking-beam furnaces manufactured by Rapid Technologies. Rapid Technologies, a small business, is implementing on a commercial basis a highly energy efficient rapid-heating technology for use in the metal manufacturing industry. The rapid heating process allows energy savings of up to 95%. Although goals of all of the tasks of this CRADA were met, there is still a need for a material to work in the rapid heating furnaces at temperatures in the range of 1,350 to 1,400 C. Future effort should be focused in fulfilling this need.

  13. Longitudinal Weld Land Buckling in Compression-Loaded Orthogrid Cylinders

    NASA Technical Reports Server (NTRS)

    Thornburgh, Robert P.; Hilburger, Mark W.

    2010-01-01

    Large stiffened cylinders used in launch vehicles (LV), such as the Space Shuttle External Tank, are manufactured by welding multiple curved panel sections into complete cylinders. The effects of the axial weld lands between the panel sections on the buckling load were studied, along with the interaction between the acreage stiffener arrangement and the weld land geometry. This document contains the results of the studies.

  14. The Effect of Increased Cooling Surface on Performance of Aircraft-Engine Cylinders as Shown by Tests of the NACA Cylinder

    NASA Technical Reports Server (NTRS)

    Schey, Oscar W; Rollin, Verne G; Ellerbrock, Herman H , Jr

    1944-01-01

    A method of constructing fins of nearly optimum proportions has been developed by the NACA to the point where a cylinder has been manufactured and tested. Data were obtained on cylinder temperature for a wide range of inlet-manifold pressures, engine speeds, and cooling-pressure differences.

  15. NGSI: FUNCTION REQUIREMENTS FOR A CYLINDER TRACKING SYSTEM

    SciTech Connect

    Branney, S.

    2012-06-06

    While nuclear suppliers currently track uranium hexafluoride (UF{sub 6}) cylinders in various ways, for their own purposes, industry practices vary significantly. The NNSA Office of Nonproliferation and International Security's Next Generation Safeguards Initiative (NGSI) has begun a 5-year program to investigate the concept of a global monitoring scheme that uniquely identifies and tracks UF{sub 6} cylinders. As part of this effort, NGSI's multi-laboratory team has documented the 'life of a UF{sub 6} cylinder' and reviewed IAEA practices related to UF{sub 6} cylinders. Based on this foundation, this paper examines the functional requirements of a system that would uniquely identify and track UF{sub 6} cylinders. There are many considerations for establishing a potential tracking system. Some of these factors include the environmental conditions a cylinder may be expected to be exposed to, where cylinders may be particularly vulnerable to diversion, how such a system may be integrated into the existing flow of commerce, how proprietary data generated in the process may be protected, what a system may require in terms of the existing standard for UF{sub 6} cylinder manufacture or modifications to it and what the limiting technology factors may be. It is desirable that a tracking system should provide benefit to industry while imposing as few additional constraints as possible and still meeting IAEA safeguards objectives. This paper includes recommendations for this system and the analysis that generated them.

  16. Creep in single crystal Ni{sub 3}Al

    SciTech Connect

    Zhu, W.; Jones, I.P.; Fort, D.; Smallman, R.E.

    1997-12-31

    Single crystals of Ni{sub 3}Al (1 at.%Ta) with a compression axis of [{bar 1}23] were subject to creep at a stress of 550 MPa and a temperature of 520 C. Slip trace and TEM microstructural observations reveal that primary octahedral slip is responsible for the primary creep. In the secondary stage, cube cross slip (010) is operative. There is no obvious sign of inverse creep.

  17. High-performance Ni3Al synthesized from composite powders

    NASA Astrophysics Data System (ADS)

    Chiou, Wen-Chih; Hu, Chen-Ti

    1994-05-01

    Specimens of Ni3Al + B of high density (>99.3 Pct RD) and relatively large dimension have been synthesized from composite powders through processes of replacing plating and electroless Ni-B plating on Al powder, sintering, and thermal-mechanical treatment. The uniformly coated Ni layer over fine Al or Ni core particles constituting these coating/core composite powders has advantages such as better resistance to oxidation relative to pure Al powder, a greater green density as a compacted powder than prealloyed powder, the possibility of atomically added B to the material by careful choice of a suitable plating solution, and avoidance of the expensive powder metallurgy (PM) equipment such as a hot isostatic press (HIP), hot press (HP), etc. The final Ni3Al + B product is made from Ni-B-Al and Ni-B-Ni mixed composite powders by means of traditional PM processes such as compacting, sintering, rolling, and annealing, and therefore, the dimensions of the product are not constrained by the capacity of an HIP or HP. The properties of Ni3Al composite powder metallurgy (CPM) specimens tested at room temperature have been obtained, and comparison with previous reports is conducted. A tensile elongation of about 16 Pct at room temperature was attained.

  18. Strain tolerance in technical Nb3Al superconductors

    NASA Astrophysics Data System (ADS)

    Banno, N.; Takeuchi, T.; Kitaguchi, H.; Tagawa, K.

    2006-10-01

    We observed crack formation in transformation-processed Nb3Al wires at room temperature, the wire being bent with a small clamp fixture with a curvature. The polished cross-section parallel to the longitudinal axis was observed, using a high power optical microscope or a field-emission scanning electron microscope. The bend strain limit for microcrack formation is found, changing the radius of the curvature of the clamp. The bend strain limit was found to be around 0.3% for standard Nb3Al wires. This corresponds to the irreversible tensile strain limit of the Ic characteristics determined with a 0.1 µV cm-1 criterion. Reduction of the barrier thickness should be avoided to keep to the bend strain limit. A new configuration of the Nb3Al wire is demonstrated to improve the bend strain limit. The filament is divided into segments in the transverse cross-section. The wire is fabricated by a double-stacking method. The bend strain limit is enhanced to about 0.85% for the wire surface; the equivalent strain of the outermost filament location is about 0.66%. A simple react and wind test for this wire was performed, where the wire experienced 0.86% bend strain. The degradation of Jc was found to be very small.

  19. Prediction of External Corrosion for Steel Cylinders--2004 Report

    SciTech Connect

    Schmoyer, RLS

    2004-07-07

    Depleted uranium hexafluoride (UF{sub 6}) is stored in over 60,000 steel cylinders at the East Tennessee Technology Park (ETTP) in Oak Ridge, Tennessee, at the Paducah Gaseous Diffusion Plant (PGDP) in Paducah, Kentucky, and at the Portsmouth Gaseous Diffusion Plant (PORTS) in Portsmouth, Ohio. The cylinders range in age from 4 to 53 years. Although when new the cylinders had wall thicknesses specified to within manufacturing tolerances, over the years corrosion has reduced their actual wall thicknesses. The UF{sub 6} Cylinder Project is managed by the United States Department of Energy (DOE) to safely maintain the UF{sub 6} and the cylinders containing it. This report documents activities that address UF{sub 6} Cylinder Project requirements and actions involving forecasting cylinder wall thicknesses. These requirements are delineated in the System Requirements Document (LMES 1997a), and the actions needed to fulfill them are specified in the System Engineering Management Plan (LMES 1997b). The report documents cylinder wall thickness projections based on models fit to ultrasonic thickness (UT) measurement data. UT data is collected at various locations on randomly sampled cylinders. For each cylinder sampled, the minimum UT measurement approximates the actual minimum thickness of the cylinder. Projections of numbers of cylinders expected to fail various thickness criteria are computed from corrosion models relating minimum wall thickness to cylinder age, initial thickness estimates, and cylinder subpopulations defined in terms of plant site, yard, top or bottom storage positions, nominal thickness, etc. In this report, UT data collected during FY03 is combined with UT data collected in earlier years (FY94-FY02), and all of the data is inventoried chronologically and by various subpopulations. The UT data is used to fit models of maximum pit depth and minimum thickness, and the fitted models are used to extrapolate minimum thickness estimates into the future and in

  20. Engine cylinder intake port

    SciTech Connect

    Furlong, C.G.

    1986-08-19

    This patent describes an internal combustion engine, means defining a cylinder closed at one end and having an axis, means defining an inlet passage through the cylinder defining means and communicating with the cylinder through the closed end, and a poppet inlet valve including a stem and head having a valve axis and disposed in the passage for reciprocation on the valve axis to control communication of the inlet passage with the cylinder. The inlet passage is characterized by: a throat of generally circular cross-section opening into the cylinder and adapted to be closed by the inlet valve, an entrance portion spaced from the throat and offset from the valve axis, and means defining a fluid flow path extending from the entrance portion toward and around opposite sides of the valve axis and below the valve head when open to the throat. The fluid flow path defines means having a top wall including first and second ramp portions and a shelf portion spaced from and opposite the throat, the ramp portions sloping downwardly and merging with the shelf portion on generally opposite sides of the valve axis. The ramp portions lie at steep angles to the shelf portion and one of the ramp portions having a substantially steeper angle than the other to slow and direct downwardly fluid flow passing the one of the sides of the valve axis below the one steeper ramp relative to the higher speed and less downward direction of flow passing the other of the sides of the valve axis, whereby preferential entry of swirl developing flow into the shelf area from below the ramp of lower slope is encouraged.

  1. Hf dopants in γ'-Ni3Al alloy

    NASA Astrophysics Data System (ADS)

    Ivanovski, V. N.; Cekić, B.; Umićević, A.; Belošević-Čavor, J.; Schumacher, G.; Koteski, V.; Barudzija, T.

    2013-08-01

    The Time Differential Perturbed Angular (TDPAC) measurements of nuclear quadrupole interactions (NQIs) at 181Ta ion probe in the polycrystalline intermetallic alloy γ'-Ni3Al doped with 0.2 at. % Hf were performed in the temperature range 78-1230 K, in order to determine the lattice location of Hf atoms in the ordered γ'-Ni3Al structure. The two NQIs obtained are discussed within the present L12 cubic structure and a tetragonal distortion of L12 to another two DO22 and L60 type structures. The first low frequency NQI at the site of the 181Ta ion-probe after substitution of aluminum for hafnium in DO22 at ambient temperature, is vQ1(300 K) = 39(1) MHz with η1 = 0. The corresponding high frequency value on the second crystallographic site in L60, is vQ2(300 K) = 204(14) MHz with η2 = 0.47(11). These two NQI's have different temperature behavior. The presence of both DO22 and L60 tetragonal distortions of the parent cubic L12 lattice, detected after adding 0.2 at. % Hf, are with modulations to the lattice constant (a) with a ratio (c/a), 2.04 and 0.87, respectively. Ab initio calculations of electronic and structural properties and hyperfine parameters at the 181Ta ion probe of the γ'-Ni3Al-0.2 at. % Hf alloy were performed using the full potential augmented plane wave plus local-orbital (APW+lo) method as implemented in the WIEN2k code. The accuracy of the calculations and comparison with the experimental results enabled us to identify the observed hyperfine interactions and to infer the EFG sign that cannot be measured in conventional TDPAC measurements.

  2. Torsion of Noncircular Composite Cylinders

    NASA Technical Reports Server (NTRS)

    Rouse, Marshall; Hyer, Michael W.; Haynie, Waddy T.

    2005-01-01

    The paper presents a brief overview of the predicted deformation and failure characteristics of noncircular composite cylinders subjected to torsion. Using a numerical analysis, elliptical cylinders with a minor-to-major diameter ratio of 0.7 are considered. Counterpart circular cylinders with the same circumference as the elliptical cylinders are included for comparison. The cylinders are constructed of a medium-modulus graphite-epoxy material in a quasi-isotropic lay-up. Imperfections generated from the buckling mode shapes are included in the initial cross-sectional geometry of the cylinders. Deformations until first fiber failure, as predicted using the maximum stress failure criterion and a material degradation scheme, are presented. For increasing levels of torsion, the deformations of the elliptical cylinders, in the form of wrinkling of the cylinder wall, occur primarily in the flatter regions of the cross section. By comparison the wrinkling deformations of the circular cylinders are more uniformly distributed around the circumference. Differences in the initial failure and damage progression and the overall torque vs. twist relationship between the elliptical and circular cylinders are presented. Despite differences in the response as the cylinders are being loaded, at first fiber failure the torque and twist for the elliptical and circular cylinders nearly coincide.

  3. On the heat capacity of Ce{sub 3}Al

    SciTech Connect

    Singh, Durgesh Samatham, S. Shanmukharao Venkateshwarlu, D. Gangrade, Mohan Ganesan, V.

    2014-04-24

    Electrical resistivity and heat capacity measurements on Cerium based dense Kondo compound Ce{sub 3}Al have been reported. Clear signatures of first order structural transition at 108K, followed by a Kondo minimum and coherence are clearly seen in resistivity. The structural transition is robust and is not affected by magnetic fields. Heat capacity measurements reveal an anomalous enhancement in the heavy fermion character upon magnetic fields. Vollhardt invariance in specific heat C(T.H) curves have been observed at T=3.7K and at H ≈ 6T.

  4. Recrystallization texture evolution in Ni{sub 3}Al

    SciTech Connect

    Escher, C.; Neves, S.; Gottstein, G.

    1998-01-05

    The recrystallization texture development during annealing of cold rolled Ni{sub 3}Al polycrystals and single crystals was investigated. The recrystallization texture in single crystals, regardless whether boron-free or boron-doped, comprised all eight 35{degree} <111> rotations of the single component deformation texture (close to the brass orientation). No annealing twins were observed in single crystals, in contrast to polycrystals. The recrystallization textures of polycrystals were very weak, but reproducible. Their components can be interpreted as a compromise between {+-} 35{degree} <111> rotations and second order twinning to the deformed matrix.

  5. Development of ODS-Fe{sub 3}Al alloys

    SciTech Connect

    Wright, I.G.; Pint, B.A.; Tortorelli, P.F.; McKamey, C.G.

    1997-12-01

    The overall goal of this program is to develop an oxide dispersion-strengthened (ODS) version of Fe{sub 3}Al that has sufficient creep strength and resistance to oxidation at temperatures in the range 1000 to 1200 C to be suitable for application as heat exchanger tubing in advanced power generation cycles. The main areas being addressed are: (a) alloy processing to achieve the desired alloy grain size and shape, and (b) optimization of the oxidation behavior to provide increased service life compared to semi-commercial ODS-FeCrAl alloys intended for the same applications. The recent studies have focused on mechanically-alloyed powder from a commercial alloy vendor. These starting alloy powders were very clean in terms of oxygen content compared to ORNL-produced powders, but contained similar levels of carbon picked up during the milling process. The specific environment used in milling the powder appears to exert a considerable influence on the post-consolidation recrystallization behavior of the alloy. A milling environment which produced powder particles having a high surface carbon content resulted in a consolidated alloy which readily recrystallized, whereas powder with a low surface carbon level after milling resulted in no recrystallization even at 1380 C. A feature of these alloys was the appearance of voids or porosity after the recrystallization anneal, as had been found with ORNL-produced alloys. Adjustment of the recrystallization parameters did not reveal any range of conditions where recrystallization could be accomplished without the formation of voids. Initial creep tests of specimens of the recrystallized alloys indicated a significant increase in creep strength compared to cast or wrought Fe{sub 3}Al, but the specimens failed prematurely by a mechanism that involved brittle fracture of one of the two grains in the test cross section, followed by ductile fracture of the remaining grain. The reasons for this behavior are not yet understood. The

  6. 49 CFR 178.60 - Specification 8AL steel cylinders with porous fillings for acetylene.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... except that plates and billets for hot-drawn cylinders must be marked with heat number. (d) Manufacture...) Heat treatment is not required after welding or brazing weldable low carbon parts to attachments... brazed to the top or bottom of cylinders and properly heat treated, provided such subsequent welding...

  7. 49 CFR 178.50 - Specification 4B welded or brazed steel cylinders.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... plates and billets for hotdrawn cylinders must be marked with the heat number. (d) Manufacture. Cylinders... material on one side of seam and applying heat until this material shows uniformly along the seam of the... whichever is the greater; D = outside diameter in inches; d = inside diameter in inches. (g) Heat...

  8. 49 CFR 178.36 - Specification 3A and 3AX seamless steel cylinders.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... that plates and billets for hot-drawn cylinders must be marked with the heat number. (d) Manufacture... diameter in inches. (g) Heat treatment. The completed cylinder must be uniformly and properly heat-treated... ensure complete expansion. Any internal pressure applied after heat-treatment and previous to...

  9. Fracture mechanics analysis of NGV fuel cylinders. Part 1. Steel cylinders. Topical report, August 1989-February 1993. [NGV (Natural Gas Vehicles)

    SciTech Connect

    Connolly, M.P.; Hudak, S.J.; Roy, S.

    1993-02-01

    Compressed natural gas (CNG) cylinders for natural gas vehicles (NGVs) are subject to a combination of pressure cycles, associated with periodic refueling, and a potentially corrosive CNG environment. Under these conditions it has been shown that the life of the cylinder is governed by the corrosion-fatigue crack growth of internal flaws such as voids, pits or folds that may be present after manufacture. For NGV applications, these cylinders are required to operate for at least 15 years and the report, through a detailed fracture mechanics analysis, describes approaches to achieving the desired life. The analysis shows that a 15 year cylinder life can be obtained by using quality control to ensure that no initial defects greater than 0.045 in. X 0.090 in. exist after manufacture. Alternatively, gas drying can be used at the distribution stations to reduce the detrimental effects of the remaining CNG impurities, and thereby, produce long cylinder lives. The analysis also considers the role of in-service inspection/retest and shows that in-service NDE has little advantage, either technically or economically, for ensuring the fitness-for-service of steel NGV cylinders. The analysis also shows that hydrostatic testing of cylinders, either at manufacture or in service, is ineffective for detecting fatigue cracks and therefore should not be implemented as part of a fitness-for-service plan for NGV fuel cylinders. The issue of cylinder geometry was also considered and the analysis shows that improperly designed flat-bottomed CNG cylinders can result in premature fatigue failures originating at the inner wall in the transition region between the cylinder end and sidewall.

  10. Weldability of Fe[sub 3]Al-type Aluminide

    SciTech Connect

    David, S.A.; Zacharia, T. )

    1993-05-01

    An investigation was carried out to determine the weldability of a series of Fe[sub 3]Al-type alloys. Autogenous welds were made on thin sheets of iron aluminide alloys using gas tungsten arc (GTA) and electron beam (EB) welding processes at different travel speeds and power levels. The results indicate that although these alloys can be successfully welded using the EB welding process, some compositions may hot crack during GTA welding. Boron and zirconium additions have been found to promote hot cracking in these alloys. Among the alloys investigated, Fe[sub 3]Al modified with chromium, niobium and carbon (FA-129) showed the most promise for good weldability. Hot-cracking severity of this alloy was further investigated using the Sigmajig test. The minimum threshold stress of 25 ksi measured is within the material range of other aluminides and some commercial stainless steels. Also, some of these alloys exhibited a tendency for cold cracking. This is related to severe hydrogen embrittlement associated with this class of alloys.

  11. Na3Al(AsO4)2

    PubMed Central

    Fakhar Bourguiba, Noura; Zid, Mohamed Faouzi; Driss, Ahmed

    2013-01-01

    The structure of the title compound tris­odium aluminium bis­(arsenate), Na3Al(AsO4)2, is built up from AlO4 and AsO4 corner-sharing tetra­hedra, forming an undulating two-dimensional framework parallel to (100). The layers are constituted of large Al6As6O36 rings made up from six AlO4 and AsO4 tetra­hedra in which two sodium cations are situated, the third sodium cation being located in the inter­layer space. The structural relationships between the title compound and Na3Fe(PO4)2, NaAlCo(PO4)2 and Al5Co3(PO4)8 are discussed. PMID:23424394

  12. Antiferromagnetic phase of the gapless semiconductor V3Al

    NASA Astrophysics Data System (ADS)

    Jamer, M. E.; Assaf, B. A.; Sterbinsky, G. E.; Arena, D.; Lewis, L. H.; Saúl, A. A.; Radtke, G.; Heiman, D.

    2015-03-01

    Discovering new antiferromagnetic (AF) compounds is at the forefront of developing future spintronic devices without fringing magnetic fields. The AF gapless semiconducting D 03 phase of V3Al was successfully synthesized via arc-melting and annealing. The AF properties were established through synchrotron measurements of the atom-specific magnetic moments, where the magnetic dichroism reveals large and oppositely oriented moments on individual V atoms. Density functional theory calculations confirmed the stability of a type G antiferromagnetism involving only two-thirds of the V atoms, while the remaining V atoms are nonmagnetic. Magnetization, x-ray diffraction, and transport measurements also support the antiferromagnetism. This archetypal gapless semiconductor may be considered as a cornerstone for future spintronic devices containing AF elements.

  13. Compton Profile Study of Intermetallic Ti{sub 3}Al

    SciTech Connect

    Vyas, V.; Sharma, G.; Mishra, M. C.; Sharma, B. K.; Joshi, K. B.

    2011-10-20

    The Compton scattering measurement on intermetallic alloy Ti{sub 3}Al is reported in this work. The measurement is made using 59.54 keV gamma-rays from Am{sup 241} source. Theoretical calculation of Compton profile is also performed employing CRYSTAL code within the framework of density functional theory to compare with the measurement. The theoretical profile of the alloy is also synthesized following the superposition model taking the published Compton profiles of elemental solids from the APW method. The experimental study of charge transfer in the alloys has also been done by performing the experimental Compton profile measurements on Ti and Al following the superposition model and charge transfer from Al to Ti is clearly seen on the alloy formation.

  14. NMR characteristics in noncentrosymmetric Mo3Al2C

    NASA Astrophysics Data System (ADS)

    Kuo, C. N.; Liu, H. F.; Lue, C. S.

    2012-02-01

    We present an extensive study of the noncentrosymmetric superconductor Mo3Al2C using 27Al nuclear magnetic resonance (NMR) spectroscopy. The NMR line shapes, Knight shifts, as well as spin-lattice relaxation rates in both superconducting and normal states have been identified. In the superconducting phase, the results of the Knight shift and relaxation rate signify the existence of finite density of states, attributed to the strong antisymmetric spin-orbital coupling effect enhanced by intrinsic defects. In the normal state, peculiar changes such as the broadening of the NMR linewidth and the distinct drop of the Knight shift were discerned across a characteristic temperature of T*≃196 K. Moreover, the magnitude of 1/T1T decreases markedly and develops pseudogaplike behavior below T*. We associated these anomalous features with distortions near the Al sites toward a lower symmetric structural environment, leading to the modification of electronic structures around Fermi surfaces.

  15. A characteristic analysis of the fluidic muscle cylinder

    NASA Astrophysics Data System (ADS)

    Kim, Dong-Soo; Bae, Sang-Kyu; Hong, Sung-In

    2005-12-01

    The fluidic muscle cylinder consists of an air bellows tube, flanges and lock nuts. It's features are softness of material and motion, simplicity of structure, low production cost and high power efficiency. Recently, unlikely the pneumatic cylinder, the fluidic muscle cylinder without air leakage, stick slip, friction, and seal was developed as a new concept actuator. It has the characteristics such as light weight, low price, high response, durable design, long life, high power, high contraction, which is innovative product fulfilling RT(Robot Technology) which is one of the nation-leading next generation strategy technologies 6T as well as cleanness technology. The application fields of the fluidic muscle cylinder are so various like fatigue tester, brake, accelerator, high technology testing device such as driving simulator, precise position, velocity, intelligent servo actuator under special environment such as load controlling system, and intelligent robot. In this study, we carried out the finite element modeling and analysis about the main design variables such as contraction ration and force, diameter increment of fluidic muscle cylinder. On the basis of finite element analysis, the prototype of fluidic muscle cylinder was manufactured and tested. Finally, we compared the results between the test and the finite element analysis.

  16. Stresses in and General Instability of Monocoque Cylinders with Cutouts I : Experimental Investigation of Cylinders with a Symmetric Cutout Subjected to Pure Bending

    NASA Technical Reports Server (NTRS)

    Hoff, N J; Boley, Bruno A

    1946-01-01

    Ten 24S-T alclad cylinders of 20-inch diameter, 45- or 58-inch length, and 0.012-inch wall thickness, reinforced with 24S-T aluminum alloy stringers and rings were tested in pure bending. In the middle of the compression side of the cylinders there was a cutout extending over 19 inches in the longitudinal direction, and over an angle of 45 degrees, 90 degrees, or 135 degrees in the circumferential direction. The strain in the stringers and in the sheet covering was measured with metal electric strain gages. The stress distribution in the cylinders deviate considerably from the linear law valid for cylinders without a cutout. The maximum strain measured was about four-thirds of the value calculated from the Mc/I formula when I was taken as the moment of inertia of the cross section of the portion of the cylinder where the cutout was situated. A diagram is presented containing the strain factors defined as the ratios of measured strain to strain calculated with the Mc/I formula. All the 10 cylinders tested failed in general instability. Two symmetric and one antisymmetric pattern of buckling were observed and the buckling load appeared to be independent of the method of manufacture and the length of the cylinder. The buckling load of the cylinders having cutouts extending over 45 degrees, 90 degrees, and 135 degrees was 66, 47, and 31 percent, respectively, of the buckling load of the cylinder without a cutout.

  17. Magnetic properties of single-crystalline UCu3Al2

    NASA Astrophysics Data System (ADS)

    Nakotte, H.; Brueck, E.; Brabers, J. H. V. J.; Prokes, K.; Deboer, F. R.; Sechovsky, V.; Buschow, K. H. J.; Andreev, A. V.; Robinson, R. A.; Puranto, A.

    UCu3Al2 crystallizes in an ordered variant of the hexagonal CaCu5 structure. By neutron powder-diffraction, the U atoms were found to occupy the 1a sites, while the 2c sites are occupied by Cu atoms only and a random occupation of the 3g sites by the remaining Cu and Al is found. The magnetic susceptibility, measured on a single crystal grown by the Czochralski tri-arc technique, is found to be maximal within the hexagonal basal plane with a maximum at about 10 K. For fields applied within the basal plane, the magnetization at 4.2 K exhibits a slight S-shape starting slightly below 15 T. No such anomalies are found for fields applied along the c-axis where the magnetic response is found to be much lower. No additional magnetic peaks, which could be related with long-range antiferromagnetic ordering, were detected in the neutron powder-patterns at low temperatures.

  18. Dynamics of Discrete Breathers in a Pt3Al Crystal

    NASA Astrophysics Data System (ADS)

    Starostenkov, M. D.; Potekaev, A. I.; Dmitriev, S. V.; Zakharov, P. V.; Eremin, A. M.; Kulagina, V. V.

    2016-01-01

    The discrete breathers in a Pt3Al crystal, which exhibit soft (DB1) and hard (DB2) nonlinearity, are shown to possess a number of principal differences. Unlike an immobile and stable DB1, a DB2 breather is mainly localized on four Al atoms and is stretched along one of the close-packed rows of crystals. On the other hand, DB2 can displace hundreds of nanometers along one of the directions of close packing. Having localized a considerable amount of energy, both DB1 and DB2 breathers slowly emit it during their lifetime. A collision of DB1 and DB2 results in part of their energy being released into the Al sublattice, the larger part lost by DB2 that is destroyed faster than DB1. The DB2 breather can effectively transport the energy throughout the crystal, and a collision of DBs results in its considerable localization in the crystal. A capability of transferring the energy can thus give rise to structural transformations far from the focus of excitation of such localized objects.

  19. Analysis of dry cylinder liner behavior during engine operation

    SciTech Connect

    Mizutani, Kazunori; Murata, Katsuhiro; Suzawa, Takashi; Niitsu, Yasuhiko

    1996-09-01

    Engine manufacturers are continuing to develop new engine designs that provide higher power output, lower fuel consumption and lower engine weight. In order to achieve significant engine weight reduction, the light weight cylinder block structure employs dry cylinder liners rather than wet cylinder liners. The cast iron dry liner structure is utilized because of the superior wear and scuff resistance of the cast iron. Thin wall dry cast iron liners are being employed in both gasoline and diesel engines. Dry cylinder liners with wall thickness of 1.5 mm are in production for Japanese automotive diesel engines. In the case of the dry thin wall cast iron liners, 2 design configurations are employed: loose-fit type having a specified clearance between the outer liner surface and the cylinder bore surface; press-in type having an interference fit between the outer surface of liner and the cylinder bore surface. The physical properties of cast iron must be considered during the design phase if successful production designs are to be provided. In addition the operating stress caused by piston slap, combustion pressure variation and resultant effect on operating stress in the liner must be considered during the design. This paper summarizes the results of a series of studies undertaken to determine the effect of piston slap, combustion pressure and initial stress on resultant behavior of thin wall cylinder liners under engine operating conditions. The resultant data may be utilized to improve the overall design of thin wall dry cylinder liners, especially for loose-fit liners.

  20. Electronic structures, elastic properties, and minimum thermal conductivities of cermet M3AlN

    NASA Astrophysics Data System (ADS)

    Wang, Jin; Chen, ZhiQian; Li, ChunMei; Li, Feng; Nie, ChaoYin

    2014-08-01

    The electronic structures and elastic anisotropies of cubic Ti3AlN, Zr3AlN, and Hf3AlN are investigated by pseudopotential plane-wave method based on density functional theory. At the Fermi level, the electronic structures of these compounds are successive with no energy gap between conduct and valence bands, and exhibit metallicity in ground states. In valence band of each partial density of states, the different orbital electrons indicate interaction of corresponding atoms. In addition, the anisotropy of Hf3AlN is found to be significantly different from that of Ti3AlN and Zr3AlN, which involve the differences in the bonding strength. It is notable that Hf3AlN is a desired thermal barrier material with the lowest thermal conductivity at high temperature among the three compounds. Young's moduli of anti-perovskite Ti3AlN, Zr3AlN, and Hf3AlN in full space. Electron density differences on crystal planes (1 0 0), (2 0 0), and (1 1 0) of anti-perovskite Zr3AlN. ="fx1"/>

  1. Carbon-carbon cylinder block

    NASA Technical Reports Server (NTRS)

    Ransone, Philip O. (Inventor)

    1998-01-01

    A lightweight cylinder block composed of carbon-carbon is disclosed. The use of carbon-carbon over conventional materials, such as cast iron or aluminum, reduces the weight of the cylinder block and improves thermal efficiency of the internal combustion reciprocating engine. Due to the negligible coefficient of thermal expansion and unique strength at elevated temperatures of carbon-carbon, the piston-to-cylinder wall clearance can be small, especially when the carbon-carbon cylinder block is used in conjunction with a carbon-carbon piston. Use of the carbon-carbon cylinder block has the effect of reducing the weight of other reciprocating engine components allowing the piston to run at higher speeds and improving specific engine performance.

  2. The distribution alloying elements in alnico 8 and 9 magnets: Site preference of ternary Ti, Fe, Co, and Ni additions in DO3 Fe3Al, Co3Al, and Ni3Al based intermetallic phases

    DOE PAGESBeta

    Samolyuk, G. D.; Újfalussy, B.; Stocks, G. M.

    2014-11-07

    Recently, interest in alnico magnetic alloys has been rekindled due to their potential to substitute for rare-earth based permanent magnets provided modest improvements in their coercivity can be achieved without loss of saturation magnetization. Recent experimental studies have indicated that atomic and magnetic structure of the two phases (one AlNi-based, the other FeCo-based) that comprise these spinodally decomposed alloy is not as simple as previously thought. A key issue that arises is the distribution of Fe, Co and Ti within the AlNi-based matrix phase. In our paper we report the results of first-principles calculations of the site preference of ternarymore » alloying additions in DO3 Fe3Al, Co3Al and Ni3Al alloys, as models for the aluminide phase. For compound compositions that are Al rich, which corresponds to experimental situation, Ti and Fe are found to occupy the sites, while Co and Ni prefer the sites of the DO3 lattice. Finally, an important finding is that the magnetic moments of transition metals in Fe3Al and Co3Al are ordered ferromagnetically, whereas the Ni3Al were found to be nonmagnetic unless the Fe or Co are added as a ternary element.« less

  3. 49 CFR 178.37 - Specification 3AA and 3AAX seamless steel cylinders.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., or electric steel of uniform quality must be used. A heat of steel made under the specifications in... performed on the first and last ingot of each heat of steel. The results of this test must be recorded on... marked with the heat number. (d) Manufacture. Cylinders must be manufactured using equipment...

  4. Manufacturing Success

    ERIC Educational Resources Information Center

    Reese, Susan

    2007-01-01

    According to the National Association of Manufacturers (NAM), "manufacturing is the engine that drives American prosperity". When NAM and its research and education arm, The Manufacturing Institute, released the handbook, "The Facts About Modern Manufacturing," in October 2006, NAM President John Engler noted, that manufacturing output in America…

  5. Prediction of External Corrosion for Steel Cylinders 2003 Report

    SciTech Connect

    Schmoyer, RLS

    2003-09-24

    Depleted uranium hexafluoride (UF{sub 6}) is stored in over 60,000 steel cylinders at the East Tennessee Technology Park (ETTP) in Oak Ridge, Tennessee, at the Paducah Gaseous Diffusion Plant (PGDP) in Paducah, Kentucky, and at the Portsmouth Gaseous Diffusion Plant (PORTS) in Portsmouth, Ohio. The cylinders range in age from six to 52 years. Although when new the cylinders had wall thicknesses specified to within manufacturing tolerances, over the years corrosion has reduced their actual wall thicknesses. The UF{sub 6} Cylinder Project is managed by the United States Department of Energy (DOE) to safely maintain the UF{sub 6} and the cylinders containing it. The requirements of the Project are delineated in the System Requirements Document (LMES 1997a), and the actions needed to fulfill those requirements are specified in the System Engineering Management Plan (LMES 1997b). This report documents activities that address requirements and actions involving forecasting cylinder wall thicknesses. Wall thickness forecasts are based on models fit to ultrasonic thickness (UT) measurement data. First, UT data collected during FY02 is combined with UT data collected in earlier years (FY92-FY01), and all of the data is inventoried chronologically and by various subpopulations. Next, the data is used to model either maximum pit depth or minimum thickness as a function of cylinder age, subpopulation (e.g., PGDP G-yard, bottom-row cylinders), and initial thickness estimates. The fitted models are then used to extrapolate minimum thickness estimates into the future and to compute estimates of numbers of cylinders expected to fail various thickness criteria. A model evaluation is performed comparing UT measurements made in FY02 with model-fitted projections based only on data collected before FY02. The FY02 UT data, entered into the corrosion model database and not available for the previous edition of this report (Schmoyer and Lyon 2002), consists of thickness measurements of 48

  6. Acylinder and freeform optical manufacturing

    NASA Astrophysics Data System (ADS)

    Fess, Edward; Wolfs, Frank; DeFisher, Scott; Ross, James

    2015-10-01

    Aspheric cylinders have the ability to improve optical performance over standard cylindrical surfaces. Over the last several years there has also been development into the application and functionality of utilizing freeform surfaces to improve optical performance. Freeforms have the ability to not only improve image quality over a greater field of view, but can open up the design space of an optical system making it more compact. Freeform geometries, much like aspheric cylinders, may not have an axis of rotation to spin the optic about during manufacturing. This leads to costly fabrication processes and custom metrology set ups, which may inhibit their use. Over the last several years, OptiPro Systems has developed and optimized our eSX grinding, UFF and USF polishing, UltraSurf metrology, and ProSurf software programming technologies to make the processing of these complex geometries much easier and deterministic. In this paper we will discuss the challenges associated with manufacturing complex shapes like aspheric cylinders as well as freeform geometries, and how several technologies working together can overcome them. The technologies focus on metrology feedback to a grinding and polishing machine that is controlled through an iterative computer aided manufacturing software system. We will also present examples of these hard to manufacture shapes with results.

  7. An experimental study of dynamics of towed flexible cylinders

    NASA Astrophysics Data System (ADS)

    Kheiri, M.; Païdoussis, M. P.; Amabili, M.

    2015-07-01

    In this paper, some experiments are described which were designed to illustrate the dynamical behaviour of towed flexible cylinders and to test the theory. A silicone rubber cylinder was manufactured such that it was almost neutrally buoyant when immersed in water. The cylinder was terminated by plexiglas end-pieces and was held in horizontal water flow by a length of nylon thread (towrope). Video capturing along with image processing techniques were used to measure the transverse displacement of the cylinder in the horizontal plane. For the cylinder with relatively streamlined nose and tail end-pieces, non-flexural (rigid-body), as well as flexural instabilities developed as the flow velocity was increased; shortening the towrope was not very effective for stabilizing the system, but a sufficiently blunt tail end-piece had a very significant stabilizing effect. The experimental observations are generally in qualitative agreement with the available nonlinear theory. Quantitative comparison of various quantities, e.g. the instability thresholds, between experiment and theory, based on the estimated values of some of the theoretical nondimensional parameters, is also fairly good.

  8. Amorphization of Zr/sub 3/Al by hydrogenation and subsequent electron irradiation

    SciTech Connect

    Meng, W.J.; Koike, J.; Okamoto, P.R.; Rehn, L.E.

    1988-12-01

    1-MeV electron irradiation of hydrogenated Zr/sub 3/Al (Zr/sub 3/AlH/sub 0.96/) at 10K is studied. A more than 20 fold reduction in the critical dose required for complete amorphization is observed for the hydrogenated specimen as compared to the un-hydrogenated Zr/sub 3/Al under identical irradiation conditions. 11 refs., 4 figs.

  9. Axial cylinder internal combustion engine

    SciTech Connect

    Gonzalez, C.

    1992-03-10

    This patent describes improvement in a barrel type internal combustion engine including an engine block having axial-positioned cylinders with reciprocating pistons arranged in a circular pattern: a drive shaft concentrically positioned within the cylinder block having an offset portion extending outside the cylinder block; a wobble spider rotatably journaled to the offset portion; connecting rods for each cylinder connecting each piston to the wobble spider. The improvement comprising: a first sleeve bearing means supporting the drive shaft in the engine block in a cantilevered manner for radial loads; a second sleeve bearing means rotatably supporting the wobble spider on the offset portion of the drive shaft for radial loads; a first roller bearing means positioned between the offset portion of the drive shaft and the wobble spider carrying thrust loadings only; a second roller bearing means carrying thrust loads only reacting to the first roller bearing located on the opposite end of the driveshaft between the shaft and the engine block.

  10. [Technology of preparing gauges for calibration of medical syringe cylinders].

    PubMed

    Belavin, N F; Vaĭner, E L

    1979-01-01

    Thermal treatment substantially influences the resistance of calibres used in mollification (vacuum calibrating) of glass cylinders for medical syringes, the highest resistance of calibres made of the XH32T alloy and the 12X18H10T steel being achieved through their preliminary annealing in the argon atmosphere. The quality of manufactured syringes is affected also by wrong calibres shape and, formostly, by their out-of-roundness, whose degree in individual cases reaches 2--3 micrometer. PMID:763104

  11. Turbine endwall single cylinder program

    NASA Technical Reports Server (NTRS)

    Langston, L. S.

    1982-01-01

    Detailed measurement of the flow field in front of a large-scale single cylinder, mounted in a wind tunnel is discussed. A better understanding of the three dimensional separation occuring in front of the cylinder on the endwall, and of the vortex system that is formed is sought. A data base with which to check analytical and numerical computer models of three dimensional flows is also anticipated.

  12. (Natural fragmentation of exploding cylinders)

    SciTech Connect

    Grady, D.E.; Hightower, M.M.

    1990-01-01

    The natural fragmentation of a 4140 steel cylinder fully loaded with RX-35-AN insensitive high explosive is investigated through experiment and analysis. Methods of Taylor and Gurney are used to determine the fracture strain and kinematic state of the expanding cylinder. Energy methods based on mechanisms of both tension fracture and adiabatic shear fracture are used to calculate the circumferential fragmentation intensity. 9 refs., 5 figs.

  13. Scalar cylinder-plate and cylinder-cylinder Casimir interaction in higher dimensional spacetime

    NASA Astrophysics Data System (ADS)

    Teo, Lee-Peng

    2015-07-01

    We study the cylinder-plate and the cylinder-cylinder Casimir interaction in the (D +1 )-dimensional Minkowski spacetime due to the vacuum fluctuations of massless scalar fields. Different combinations of Dirichlet (D) and Neumann (N) boundary conditions are imposed on the two interacting objects. For the cylinder-cylinder interaction, we consider the case where one cylinder is inside the other and the case where the two cylinders are outside each other. By computing the transition matrices of the objects and the translation matrices that relate different coordinate systems, the explicit formulas for the Casimir interaction energies are derived. From these formulas, we compute the large separation and small separation asymptotic behaviors of the Casimir interaction. For the cylinder-plate interaction with R ≪L , where R is the radius of the cylinder and L is the distance from the center of the cylinder to the plate, the order of decay of the Casimir interaction only depends on the boundary conditions imposed on the cylinder. The orders are L-D +1/ln (L ) and L-D -1/ln L , respectively, for the Dirichlet and Neumann boundary conditions on the cylinder. For two cylinders with radii R1 and R2 lying parallelly outside each other, the orders of decay of the Casimir interaction energies when R1+R2≪L are L-D +1/(ln L )2, L-D -1/ln L , and L-D -3, respectively, for DD, DN/ND, and NN boundary conditions, where L is the distance between the centers of the cylinders. The more interesting and important characteristic of Casimir interaction appears at small separation. Using the perturbation technique, we compute the small separation asymptotic expansions of the Casimir interaction energies up to the next-to-leading-order terms. The leading terms coincide with the respective results obtained using the proximity force approximation, which is of order d-D +1 /2 , where d is the distance between the two objects. The results on the next-to-leading-order terms are more

  14. Turbulent Flow Past Spinning Cylinders

    NASA Astrophysics Data System (ADS)

    Mehmedagic, Igbal; Carlucci, Donald; Carlucci, Pasquale; Thangam, Siva

    2009-11-01

    Flow past cylinders aligned along their axis where a base freely spins while attached to a non-spinning forebody is considered from a computational and experimental point of view. The time-averaged equations of motion and energy are solved using the modeled form of transport equations for the turbulence kinetic energy and the scalar form of turbulence dissipation with an efficient finite-volume algorithm. An anisotropic two-equation Reynolds-stress model that incorporates the effect of rotation-modified energy spectrum and swirl is used to perform computations for the flow past axially rotating cylinders. Both rigid cylinders as well as that of cylinders with free-spinning base are considered from a computational point of view. A subsonic wind tunnel with a forward-sting mounted spinning cylinder is used for experiments. Experiments are performed for a range of spin rates and free stream flow conditions. The experimental results of Carlucci & Thangam (2001) are used to benchmark flow over spinning cylinders. The data is extended to munitions spinning in the wake of other munitions. Applications involving the design of projectiles are discussed.

  15. Concentration verification of ethanol/nitrogen compressed gas cylinders prior to use for periodic determinations of accuracy in California.

    PubMed

    Matthias, D J; Harvey, D C; DeFraga, D E

    2001-04-01

    A method that uses compressed gas ethanol breath standard (EBS) cylinders to perform periodic determinations of accuracy on evidential breath alcohol instruments in California was developed. To use EBS cylinders, the California State Department of Health Services required verification of the ethanol content of the EBS cylinders using an infrared method. The infrared method developed employs a modified Alcotest 7110 MK III-C manufactured by National Draeger, Inc. that functions at the 9.5-mm wavelength of the infrared spectrum. Criteria and methodology for verifying EBS cylinder ethanol concentrations are described. PMID:11327355

  16. GLOBAL MONITORING OF URANIUM HEXIFLORIDE CYLINDERS NEXT STEPS IN DEVELOPMENT OF AN ACTION PLAN

    SciTech Connect

    Hanks, D.

    2010-06-09

    Over 40 industrial facilities world-wide use standardized uranium hexafluoride (UF{sub 6}) cylinders for transport, storage and in-process receiving in support of uranium conversion, enrichment and fuel fabrication processes. UF{sub 6} is processed and stored in the cylinders, with over 50,000 tU of UF{sub 6} transported each year in these International Organization for Standardization (ISO) qualified containers. Although each cylinder is manufactured to an ISO standard that calls for a nameplate with the manufacturer's identification number (ID) and the owner's serial number engraved on it, these can be quite small and difficult to read. Recognizing that each facility seems to use a different ID, a cylinder can have several different numbers recorded on it by means of metal plates, sticky labels, paint or even marker pen as it travels among facilities around the world. The idea of monitoring movements of UF{sub 6} cylinders throughout the global uranium fuel cycle has become a significant issue among industrial and safeguarding stakeholders. Global monitoring would provide the locations, movements, and uses of cylinders in commercial nuclear transport around the world, improving the efficiency of industrial operations while increasing the assurance that growing nuclear commerce does not result in the loss or misuse of cylinders. It should be noted that a unique ID (UID) attached to a cylinder in a verifiable manner is necessary for safeguarding needs and ensuring positive ID, but not sufficient for an effective global monitoring system. Modern technologies for tracking and inventory control can pair the UID with sensors and secure data storage for content information and complete continuity of knowledge over the cylinder. This paper will describe how the next steps in development of an action plan for employing a global UF{sub 6} cylinder monitoring network could be cultivated using four primary UID functions - identification, tracking, controlling, and accounting.

  17. Substitutional and Interstitial Diffusion in alpha2-Ti3Al(O)

    NASA Technical Reports Server (NTRS)

    Copland, Evan; Young, David J.; Gleeson, Brian; Jacobson, Nathan

    2007-01-01

    The reaction between Al2O3 and alpha2-Ti3Al was studied with a series of Al2O3/alpha2-Ti3Al multiphase diffusion couples annealed at 900, 1000 and 1100 C. The diffusion-paths were found to strongly depend on alpha2- Ti3Al(O) composition. For alloys with low oxygen concentrations the reaction involved the reduction of Al2O3, the formation of a gamma-TiAl reaction-layer and diffusion of Al and O into the alpha2-Ti3Al substrate. Measured concentration profiles across the interaction-zone showed "up-hill" diffusion of O in alpha2-Ti3Al(O) indicating a significant thermodynamic interaction between O and Al, Ti or both. Diffusion coefficients for the interstitial O in alpha2-Ti3Al(O) were determined independently from the interdiffusion of Ti and Al on the substitutional lattice. Diffusion coefficients are reported for alpha2-Ti3Al(O) as well as gamma-TiAl. Interpretation of the results were aided with the subsequent measurement of the activities of Al, Ti and O in alpha 2-Ti3Al(O) by Knudsen effusion-cell mass spectrometry.

  18. Vacancy Ordering In Co3AlCx Alloys: A First Principles Study

    SciTech Connect

    Jiang, Chao

    2008-01-01

    Ordering of structural vacancies in non-stoichiometric Co{sub 3}AlC{sub x} alloys has been studied using a combination of first-principles total energy calculations, a cluster expansion technique, and Monte-Carlo simulations. In the proximity of the experimental1y observed composition of x {approx} 0.59, our exhaustive ground state search yields two stable vacancy-ordered structures: a cubic Co{sub 3}AlC{sub 0.5} phase and a trigonal Co{sub 3}AlC{sub 0.667} phase. By performing finite-temperature Monte-Carlo simulations, the order-disorder transition temperatures of Co{sub 3}AlC{sub 0.5} and CO{sub 3}AlC{sub 0.667} are predicted to be {approx}1925K and {approx}1630K, respectively.

  19. Critical current of a rapid-quenched Nb3Al conductor under transverse compressive and axial tensile stress

    NASA Astrophysics Data System (ADS)

    Seeber, B.; Ferreira, A.; Mondonico, G.; Buta, F.; Senatore, C.; Flükiger, R.; Takeuchi, T.

    2011-03-01

    The electromechanical behavior of a Nb3Al wire manufactured according to the RHQT process (rapid-heating, quenching and transformation) has been investigated at magnetic fields between 15 and 19 T at 4.2 K. Of particular interest was the critical current, Ic, as a function of transverse pressure up to 300 MPa and as a function of axial tensile stress. The studied wires are pieces of a 870 m long copper stabilized Nb3Al wire with a rectangular cross section of 1.81 mm × 0.80 mm. It was observed that the critical current at 300 MPa transverse pressure, applied to the narrow side, is reduced to 93%, 90% and 88% of its stress free value at 15 T, 17 T and 19 T, respectively. After unloading from 300 MPa Ic recovers to 94% and 97% at 19 T and 15 T, respectively. A field dependence of the effect is visible above 200 MPa. For completeness, the critical current was also measured under axial tensile strain. The maximum of Ic is at 0.15% applied strain and irreversibility has been observed above 0.26%. Finally a stress versus strain measurement at 4.2 K has been carried out allowing the conversion from axial strain to stress.

  20. Blower Cooling of Finned Cylinders

    NASA Technical Reports Server (NTRS)

    Schey, Oscar W; Ellerbrock, Herman H , Jr

    1937-01-01

    Several electrically heated finned steel cylinders enclosed in jackets were cooled by air from a blower. The effect of the air conditions and fin dimensions on the average surface heat-transfer coefficient q and the power required to force the air around the cylinders were determined. Tests were conducted at air velocities between the fins from 10 to 130 miles per hour and at specific weights of the air varying from 0.046 to 0.074 pound per cubic foot. The fin dimensions of the cylinders covered a range in pitches from 0.057 to 0.25 inch average fin thicknesses from 0.035 to 0.04 inch, and fin widths from 0.67 to 1.22 inches.

  1. Transient scattering by resistive cylinders

    NASA Astrophysics Data System (ADS)

    Damaskos, N. J.; Brown, R. T.; Jameson, J. R.; Uslenghi, P. L. E.

    1985-01-01

    The two-dimensional scattering of an electromagnetic pulse normally incident on a collection of infinitely long cylinders of arbitrary shape is considered. For E-polarization an electric field integral equation is derived that is applicable to solid cylinders and/or thin sheets, resistive and/or perfectly conducting. The contribution of the self-cell at later times is carefully analyzed. The expression obtained represents a generalization of previously known results. For an incident Gaussian pulse, numerical results are presented for surface currents and far-fields, for perfectly conducting and resistive circular cylinders and strips. A fast Fourier transform (FFT) algorithm is implemented to obtain the backscattering radar cross section, which is in good agreement with results obtained from either exact continuous wave (CW) solutions or the method of moments.

  2. Design fabrication and nondestructive testing of six experimental AGCarb/Intermold 3 cylinder assemblies

    NASA Technical Reports Server (NTRS)

    Thacher, E. F.

    1972-01-01

    Six subscale Intermold cylinder assemblies with a total of twelve different concepts for transition to AGCarb were fabricated. Three of the cylinder assemblies were made by helically winding the hoop fibers and three were of orthogonal configuration. The fabrication process is summarized and details of each manufacturing method are given. The objectives of the test program were to: (1) demonstrate the fabricability of the Intermold 3 subscale flanges, (2) produce an integral transition from Intermold 3 to AGCarb material, (3) define a workable manufacturing process, and (4) identify a best suited inspection method. The objectives were met and the results are described.

  3. Theoretical and positron annihilation study of point defects in intermetallic compound Ni{sub 3}Al

    SciTech Connect

    Jian Sun; Dongliang Lin

    1994-01-01

    The equilibrium equation of point defects in Ll{sub 2} types of intermetallic compounds was established in a new simple method, which is independent of the chemical potentials. The formation energies of the relevant point defects in Ni{sub 3}Al were calculated by EAM potentials and statical relaxations. The concentration of point defects at 1,000 K as a function of bulk composition and the effect of temperature on them were studied for Ni{sub 3}Al alloy. The results show that the Al-antisites are the constitutional defects in hypostoichiometric Ni{sub 3}Al, and the Ni-antisite defects in hyperstoichiometric Ni{sub 3}Al. The two types of vacancies belong to thermal defects. The positron annihilation technique was also conducted to measure the concentration of vacancies in Ni{sub 3}Al alloys with and without boron. Although vacancies interact with the boron dopant, the changes of vacancy concentration Ni{sub 3}Al alloys can not be considered as the main reason in explaining the effect of stoichiometry on the segregation of boron. The effect of stoichiometry on diffusion in Ni{sub 3}Al alloys was discussed additionally.

  4. Design study of 15-Tesla RHQT Nb3Al block type dipole magnet

    SciTech Connect

    Yamada, R.; Ambrosio, G.; Barzi, E.; Kashikin, V.; Kikuchi, A.; Novitski, I.; Takeuchi, T.; Wake, M.; Zlobin, A.; /Fermilab /NIMC, Tsukuba /KEK, Tsukuba

    2005-09-01

    The design study of the block type 15-Tesla RHQT Nb{sub 3}Al dipole magnet, and its merits over Nb{sub 3}Sn magnets are presented. The copper stabilized RHQT Nb{sub 3}Al strand is now becoming commercially available for the application to the accelerator magnets. A 1 mm diameter RHQT Nb{sub 3}Al strand with filament size about 50 {mu}, non-copper Jc about 1000 A/mm{sup 2} at 15 Tesla at 4.2K, copper ratio of 50%, can now be produced over several hundred meters. The stress and strain characteristics of the Nb{sub 3}Al strand are superior to the Nb{sub 3}Sn strand. Another advantage is that it can tolerate a longitudinal strain up to 0.55%. The RHQT Nb{sub 3}Al Rutherford cable will have less chance of contamination of the stabilizer, compared to Nb{sub 3}Sn cable. These characteristics of the RHQT Nb{sub 3}Al will be beneficial for designing and producing 15-Tesla dipole magnets. An example 15-Tesla magnet cross section, utilizing the RHQT Nb{sub 3}Sn strand is presented. A systematic investigation on RHQT Nb{sub 3}Al strands, its Rutherford cables, and building a small racetrack magnet for cable testing are proposed.

  5. Enhancement of polarizabilities of cylinders with cylinder-slab resonances

    PubMed Central

    Xiao, Meng; Huang, Xueqin; Liu, H.; Chan, C. T.

    2015-01-01

    If an object is very small in size compared with the wavelength of light, it does not scatter light efficiently. It is hence difficult to detect a very small object with light. We show using analytic theory as well as full wave numerical calculation that the effective polarizability of a small cylinder can be greatly enhanced by coupling it with a superlens type metamaterial slab. This kind of enhancement is not due to the individual resonance effect of the metamaterial slab, nor due to that of the object, but is caused by a collective resonant mode between the cylinder and the slab. We show that this type of particle-slab resonance which makes a small two-dimensional object much “brighter” is actually closely related to the reverse effect known in the literature as “cloaking by anomalous resonance” which can make a small cylinder undetectable. We also show that the enhancement of polarizability can lead to strongly enhanced electromagnetic forces that can be attractive or repulsive, depending on the material properties of the cylinder. PMID:25641391

  6. Enhancement of polarizabilities of cylinders with cylinder-slab resonances.

    PubMed

    Xiao, Meng; Huang, Xueqin; Liu, H; Chan, C T

    2015-01-01

    If an object is very small in size compared with the wavelength of light, it does not scatter light efficiently. It is hence difficult to detect a very small object with light. We show using analytic theory as well as full wave numerical calculation that the effective polarizability of a small cylinder can be greatly enhanced by coupling it with a superlens type metamaterial slab. This kind of enhancement is not due to the individual resonance effect of the metamaterial slab, nor due to that of the object, but is caused by a collective resonant mode between the cylinder and the slab. We show that this type of particle-slab resonance which makes a small two-dimensional object much "brighter" is actually closely related to the reverse effect known in the literature as "cloaking by anomalous resonance" which can make a small cylinder undetectable. We also show that the enhancement of polarizability can lead to strongly enhanced electromagnetic forces that can be attractive or repulsive, depending on the material properties of the cylinder. PMID:25641391

  7. Cloning of a human ortholog (RPH3AL) of (RNO)Rph3al from a candidate 17p13.3 medulloblastoma tumor suppressor locus.

    PubMed

    Smith, J S; Tachibana, I; Allen, C; Chiappa, S A; Lee, H K; McIver, B; Jenkins, R B; Raffel, C

    1999-07-01

    Allelic loss of 17p13.3 is observed in approximately 40% of medulloblastomas, suggesting the presence of a tumor suppressor gene in this region. Deletion mapping has defined a region of common loss flanking the telomeric marker D17S34, and a recent report delineated a 9-kb homozygous deletion within the D17S34 locus in one such tumor. Using cDNA selection, we have identified a transcript spanning this deletion, designated (HSA)RPH3AL (rabphillin-3A-like), based on its 77% overall amino acid identity with a recently cloned rat gene, (RNO)Rph3al (originally termed Noc2), a gene putatively involved in regulated endocrine exocytosis through its interactions with the cytoskeleton. We determined the exon-intron boundaries of RPH3AL and screened the coding region for mutations by direct sequencing in DNA extracted from 33 tumor samples with allelic loss of 17p13, including 10 medulloblastoma, 14 follicular thyroid cancer (FTC), and 9 ovarian cancer specimens. No mutations were identified. Thus, despite its location in a homozygously deleted 17p13.3 locus, it is unlikely that RPH3AL is a gene involved in the oncogenesis of medulloblastoma, FTC, or ovarian cancer. PMID:10395805

  8. Manufacturing technologies

    NASA Astrophysics Data System (ADS)

    The Manufacturing Technologies Center is at the core of Sandia National Laboratories' advanced manufacturing effort which spans the entire product realization process. The center's capabilities in product and process development are summarized in the following disciplines: (1) mechanical - rapid prototyping, manufacturing engineering, machining and computer-aided manufacturing, measurement and calibration, and mechanical and electronic manufacturing liaison; (2) electronics - advanced packaging for microelectronics, printed circuits, and electronic fabrication; and (3) materials - ceramics, glass, thin films, vacuum technology, brazing, polymers, adhesives, composite materials, and process analysis.

  9. Video Analysis of Rolling Cylinders

    ERIC Educational Resources Information Center

    Phommarach, S.; Wattanakasiwich, P.; Johnston, I.

    2012-01-01

    In this work, we studied the rolling motion of solid and hollow cylinders down an inclined plane at different angles. The motions were captured on video at 300 frames s[superscript -1], and the videos were analyzed frame by frame using video analysis software. Data from the real motion were compared with the theory of rolling down an inclined…

  10. Turbulent Flow Between Rotating Cylinders

    NASA Technical Reports Server (NTRS)

    Shih-I, Pai

    1943-01-01

    The turbulent air flow between rotating cylinders was investigated. The distributions of mean speed and of turbulence were measured in the gap between a rotating inner and a stationary outer cylinder. The measurements led to the conclusion that the turbulent flow in the gap cannot be considered two dimensional, but that a particular type of secondary motion takes place. It is shown that the experimentally found velocity distribution can be fully understood under the assumption that this secondary motion consists of three-dimensional ring-shape vortices. The vortices occur only in pairs, and their number and size depend on the speed of the rotating cylinder; the number was found to decrease with increasing speed. The secondary motion has an essential part in the transmission of the moment of momentum. In regions where the secondary motion is negligible, the momentum transfer follows the laws known for homologous turbulence. Ring-shape vortices are known to occur in the laminar flow between rotating cylinders, but it was hitherto unknown that they exist even at speeds that are several hundred times the critical limit.

  11. Dragging a floating horizontal cylinder

    NASA Astrophysics Data System (ADS)

    Lee, Duck-Gyu; Kim, Ho-Young

    2010-11-01

    A cylinder immersed in a fluid stream experiences a drag, and it is well known that the drag coefficient is a function of the Reynolds number only. Here we study the force exerted on a long horizontal cylinder that is dragged perpendicular to its axis while floating on an air-water interface with a high Reynolds number. In addition to the flow-induced drag, the floating body is subjected to capillary forces along the contact line where the three phases of liquid/solid/gas meet. We first theoretically predict the meniscus profile around the horizontally moving cylinder assuming the potential flow, and show that the profile is in good agreement with that obtained experimentally. Then we compare our theoretical predictions and experimental measurement results for the drag coefficient of a floating horizontal cylinder that is given by a function of the Weber number and the Bond number. This study can help us to understand the horizontal motion of partially submerged objects at air-liquid interface, such as semi-aquatic insects and marine plants.

  12. Rotating Cylinder Treatment System Demonstration

    EPA Science Inventory

    In August 2008, a rotating cylinder treatment system (RCTSTM) demonstration was conducted near Gladstone, CO. The RCTSTM is a novel technology developed to replace the aeration/oxidation and mixing components of a conventional lime precipitation treatment s...

  13. Analysis on autofrettage of cylinders

    NASA Astrophysics Data System (ADS)

    Zhu, Ruilin; Zhu, Guolin; Tang, Feng

    2012-05-01

    Autofrettage is an effective technique to improve load-bearing capacity and safety for pressure vessels. For autofrettaged cylinder, the depth of plastic zone, or overstrain is a key factor which affects load-bearing capacity and safety. The previous research on overstrain was not done in terms of the point of view of raising load-bearing capacity as far as possible and simultaneously avoiding compressive yield for cylinders experiencing autofrettage handling, and there were no analytic solutions of autofrettage in the above view point presented, the 3rd and 4th strength theories were not applied synthetically in the research to compare the results from these two theories. In this paper, with the aid of the analytic method, based on summing up the authors' previous research, results from autofrettage of a cylinder based on the 3rd and 4th strength theories are studied and compared, and the laws contained in the results are looked into. Then, the essential cause and reason for the obtained laws are analyzed and the inherent and meaning relations between various parameters in autofrettage theory are revealed. It is shown that the maximum radius ratio for equivalent residual stress at inside surface never exceeds the yield strength even for a cylinder experiencing wholly yielded autofrettage, or the critical radius ratio is k c=2.218 457 489 916 7…, irrespective of the 3rd or 4th strength theories. The equation relating the depth of plastic zone with the thickness of a cylinder is identical for the 3rd and 4th strength theories. In form, the optimum load-bearing capacity of an autofrettaged cylinder is two times the initial yield pressure of the unautofrettaged cylinder irrespective of the 3rd or 4th strength theory. The revealed inherent relations between various parameters and varying laws of the parameters as well as the forms of the relations under the 3rd and 4th strength theories not only have theoretical meanings but also have prospects in engineering

  14. Natural convective heat transfer from square cylinder

    NASA Astrophysics Data System (ADS)

    Novomestský, Marcel; Smatanová, Helena; Kapjor, Andrej

    2016-06-01

    This article is concerned with natural convective heat transfer from square cylinder mounted on a plane adiabatic base, the cylinders having an exposed cylinder surface according to different horizontal angle. The cylinder receives heat from a radiating heater which results in a buoyant flow. There are many industrial applications, including refrigeration, ventilation and the cooling of electrical components, for which the present study may be applicable

  15. ADSORPTION AND DISSOCIATION OF O2 ON Ti3Al (0001) STUDIED BY FIRST-PRINCIPLES

    NASA Astrophysics Data System (ADS)

    Wei, Li-Jing; Guo, Jian-Xin; Dai, Xiu-Hong; Wang, Ying-Long; Liu, Bao-Ting

    2015-05-01

    The adsorption and dissociation of oxygen molecule on Ti3Al (0001) surface have been investigated by density functional theory (DFT) with the generalized gradient approximation (GGA). All possible adsorption sites including nine vertical and fifteen parallel sites of O2 are considered on Ti3Al (0001) surface. It is found that all oxygen molecules dissociate except for three vertical adsorption sites after structure optimization. This indicates that oxygen molecules prefer to dissociate on the junction site between Ti and Al atoms. Oxygen atoms coming from dissociation of oxygen molecule tend to occupy the most stable adsorption sites of the Ti3Al (0001) surface. The distance of O-O is related to the surface dissociation distance of Ti3Al (0001) surface. The valence electron localization function (ELF) and projected density of states (DOS) show that the bonds of O-O are breakaway at parallel adsorption end structures.

  16. Entrapment of disorder in drop-tube processed Ni[sub 3]Al

    SciTech Connect

    Sharma, S.C.; Herlach, D.M. ); Sinha, P.P. )

    1993-06-01

    As the highly ordered structure is primarily responsible for the room-temperature brittleness in Ni[sub 3]Al, recent experimental efforts have been addressed to the trapping of disorder during solidification of this intermetallic compound. In their kinetic model for complete disorder trapping, Boettinger and Aziz have predicted the formation of a metastable disordered phase beyond a critical value of the solidification velocity. However, as the order-disorder ([gamma][prime]-[gamma]) transformation temperature, T[sub c], in Ni[sub 3]Al is near the melting temperature, T[sub m] it is very difficult to entrap disorder during solidification of Ni[sub 3]Al. Here the authors report the trapping of partial disorder in the drop-tube processed Ni[sub 3]Al droplets as large as 400 [mu]m.

  17. Integrated two-cylinder liquid piston Stirling engine

    NASA Astrophysics Data System (ADS)

    Yang, Ning; Rickard, Robert; Pluckter, Kevin; Sulchek, Todd

    2014-10-01

    Heat engines utilizing the Stirling cycle may run on low temperature differentials with the capacity to function at high efficiency due to their near-reversible operation. However, current approaches to building Stirling engines are laborious and costly. Typically the components are assembled by hand and additional components require a corresponding increase in manufacturing complexity, akin to electronics before the integrated circuit. We present a simple and integrated approach to fabricating Stirling engines with precisely designed cylinders. We utilize computer aided design and one-step, planar machining to form all components of the engine. The engine utilizes liquid pistons and displacers to harness useful work from heat absorption and rejection. As a proof of principle of the integrated design, a two-cylinder engine is produced and characterized and liquid pumping is demonstrated.

  18. Integrated two-cylinder liquid piston Stirling engine

    SciTech Connect

    Yang, Ning; Rickard, Robert; Pluckter, Kevin; Sulchek, Todd

    2014-10-06

    Heat engines utilizing the Stirling cycle may run on low temperature differentials with the capacity to function at high efficiency due to their near-reversible operation. However, current approaches to building Stirling engines are laborious and costly. Typically the components are assembled by hand and additional components require a corresponding increase in manufacturing complexity, akin to electronics before the integrated circuit. We present a simple and integrated approach to fabricating Stirling engines with precisely designed cylinders. We utilize computer aided design and one-step, planar machining to form all components of the engine. The engine utilizes liquid pistons and displacers to harness useful work from heat absorption and rejection. As a proof of principle of the integrated design, a two-cylinder engine is produced and characterized and liquid pumping is demonstrated.

  19. Some Experimental Results in the Rolling of Ni3Al Alloy

    NASA Technical Reports Server (NTRS)

    Shih, Hui-Ru; Sikka, Vinod K.

    1996-01-01

    This study examines several issues to understand the cold rollability of Ni3Al alloy. It finds that the cold rolling response of Ni3Al alloy (IC50) is very sensitive to the starting thickness. The segregation of elements is worse for the thicker casting as opposed to the thinner section. This is exemplified by the point that cast plus annealed pieces showed cracking at much larger reduction as opposed to the as-cast piece.

  20. Effect of grain size on yield strength of Ni/sub 3/Al and other alloys

    SciTech Connect

    Takeyama, M.; Liu, C.T.

    1988-07-01

    This paper analyzes the effect of grain size on yield stress of ordered Ni/sub 3/Al and Zr/sub 3/Al, and mild steels that show Lueders band propagation after yielding, using the Hall--Petch relation, sigma/sub y/ = sigma/sub 0/+k/sub y/ d/sup -1//sup ///sup 2/, and the new relation proposed by Schulson et al., sigma/sub y/ = sigma/sub 0/+kd/sup -(//sup p//sup +1)/2/ (Schulson et al., Acta Metall. 33, 1587 (1985)). The major emphasis is placed on the analysis of Ni/sub 3/Al data obtained from published and new results, with a careful consideration of the alloy stoichiometry effect. All data, except for binary stoichiometric Ni/sub 3/Al prepared by powder extrusion, fit the Hall--Petch relation, whereas the data from boron-doped Ni/sub 3/Al and mild steels do not follow the Schulson relation. However, no conclusion can be made simply from the curve fitting using either relation. The results are also discussed in terms of Lueders strain and alloy preparation methods. On the basis of the Hall--Petch analysis, the small slope k/sub y/ is obtained only for hypostoichiometric Ni/sub 3/Al with boron, which would be related to a stronger segregation of boron in nickel-rich Ni/sub 3/Al. In addition, the potency for the solid solution strengthening effect of boron is found to be much higher for stoichiometric Ni/sub 3/Al than for hypostoichiometric alloys.

  1. STRESS ANNEALING INDUCED DIFFUSE SCATTERING FROM Ni3(Al,Si) PRECIPITATES

    SciTech Connect

    Barabash, Rozaliya; Ice, Gene E; Karapetrova, Evgenia; Zschack, P.

    2012-01-01

    Diffuse scattering caused by L12 type Ni3 (Al,Si) precipitates after stress annealing of Ni-Al-Si alloys is studied. Experimental reciprocal space maps are compared to the theoretical ones. Oscillations of diffuse scattering due to Ni3 (Al,Sc) precipitates are observed. Peculiarities of diffuse scattering in asymptotic region as compared to Huang scattering region are discussed. Coupling between the stress annealing direction and the precipitate shape is demonstrated.

  2. Degradability Enhancement of Poly(Lactic Acid) by Stearate-Zn3Al LDH Nanolayers

    PubMed Central

    Eili, Mahboobeh; Shameli, Kamyar; Ibrahim, Nor Azowa; Yunus, Wan Md Zin Wan

    2012-01-01

    Recent environmental problems and societal concerns associated with the disposal of petroleum based plastics throughout the world have triggered renewed efforts to develop new biodegradable products compatible with our environment. This article describes the preparation, characterization and biodegradation study of poly(lactic acid)/layered double hydroxide (PLA/LDH) nanocomposites from PLA and stearate-Zn3Al LDH. A solution casting method was used to prepare PLA/stearate-Zn3Al LDH nanocomposites. The anionic clay Zn3Al LDH was firstly prepared by co-precipitation method from a nitrate salt solution at pH 7.0 and then modified by stearate anions through an ion exchange reaction. This modification increased the basal spacing of the synthetic clay from 8.83 Å to 40.10 Å. The morphology and properties of the prepared PLA/stearate-Zn3Al LDH nanocomposites were studied by X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM), thermogravimetric analysis (TGA), tensile tests as well as biodegradation studies. From the XRD analysis and TEM observation, the stearate-Zn3Al LDH lost its ordered stacking-structure and was greatly exfoliated in the PLA matrix. Tensile test results of PLA/stearate-Zn3Al LDH nanocomposites showed that the presence of around 1.0–3.0 wt % of the stearate-Zn3Al LDH in the PLA drastically improved its elongation at break. The biodegradation studies demonstrated a significant biodegradation rate improvement of PLA in the presence of stearate-Zn3Al LDH nanolayers. This effect can be caused by the catalytic role of the stearate groups in the biodegradation mechanism leading to much faster disintegration of nanocomposites than pure PLA. PMID:22942682

  3. Crystal growth of large size Dy3Al5O12 garnet single crystals

    NASA Astrophysics Data System (ADS)

    Kimura, Hideo; Sakamoto, Masaru; Numazawa, Takenori; Sato, Mitsunori; Maeda, Hiroshi

    1990-01-01

    Crystal growth conditions using the Czochralski technique were examined in order to be able to grow large-size disprosium-aluminum-garnet single crystals; these are useful as a working material in a practical magnetic refrigeration system. Using the best conditions, large-size bubble-free Dy3Al5O12 single crystals 50 mm in diameter were grown from a stoichiometric melt composition using a seed of Y3Al5O12 single crystal.

  4. 49 CFR 230.83 - Cylinder cocks.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Steam Locomotives and Tenders Cabs, Warning Signals, Sanders and Lights § 230.83 Cylinder cocks. Each steam locomotive shall be equipped with cylinder cocks which can be operated from the cab of the steam locomotive. All cylinder...

  5. Turbine endwall two-cylinder program

    NASA Technical Reports Server (NTRS)

    Langston, L. S.

    1981-01-01

    A series of experiments to study the three dimensional separation of fluid flow around two isolated cylinders mounted on an endwall are described. Topics covered include: (1) water tunnel testing for both the single and double cylinder cases; (2) wind tunnel flow characteristics; (3) static pressure distribution measured on the cylinders; and (4) design and construction of a pressure reference system.

  6. Surface modification of Ti{sub 3}Al for improved oxidation resistance

    SciTech Connect

    Vaidya, R.U.; Zurek, A.K.; Castro, R.; Sin, Y.W.; Subramanian, K.N.

    1993-08-01

    Ti{sub 3}Al has very attractive properties such as low density and high temperature mechanical strength for elevated temperature structural applications. Its major drawback however, is poor oxidation resistance at temperatures above 600{degrees}C. Potential use of Ti{sub 3}Al in high temperature applications depends on its protection from excessive oxidation. To this effect, Al{sub 2}O{sub 3} and Al{sub 3}Ti were selected as coating materials chemically compatible with Ti{sub 3}Al. Al{sub 2}O{sub 3} acts as a protective layer on the surface of Ti{sub 3}Al and is impervious to oxygen diffusion. Al{sub 3}Ti is resistant to high temperatures and also protects the Ti{sub 3}Al substrate by forming an oxide layer consisting primarily of Al{sub 2}O{sub 3}. In this study, Al{sub 2}O{sub 3} was plasma sprayed onto the surface of Ti{sub 3}Al, while the Al{sub 3}Ti was applied by laser melting. Effectiveness of the coatings were investigated after 10 hours of cyclic oxidation.

  7. Test results of a Nb3Al/Nb3Sn subscale magnet for accelerator application

    DOE PAGESBeta

    Iio, Masami; Xu, Qingjin; Nakamoto, Tatsushi; Sasaki, Ken -ichi; Ogitsu, Toru; Yamamoto, Akira; Kimura, Nobuhiro; Tsuchiya, Kiyosumi; Sugano, Michinaka; Enomoto, Shun; et al

    2015-01-28

    The High Energy Accelerator Research Organization (KEK) has been developing a Nb3Al and Nb3Sn subscale magnet to establish the technology for a high-field accelerator magnet. The development goals are a feasibility demonstration for a Nb3Al cable and the technology acquisition of magnet fabrication with Nb3Al superconductors. KEK developed two double-pancake racetrack coils with Rutherford-type cables composed of 28 Nb3Al wires processed by rapid heating, quenching, and transformation in collaboration with the National Institute for Materials Science and the Fermi National Accelerator Laboratory. The magnet was fabricated to efficiently generate a high magnetic field in a minimum-gap common-coil configuration with twomore » Nb3Al coils sandwiched between two Nb3Sn coils produced by the Lawrence Berkeley National Laboratory. A shell-based structure and a “bladder and key” technique have been used for adjusting coil prestress during both the magnet assembly and the cool down. In the first excitation test of the magnet at 4.5 K performed in June 2014, the highest quench current of the Nb3Sn coil, i.e., 9667 A, was reached at 40 A/s corresponding to 9.0 T in the Nb3Sn coil and 8.2 T in the Nb3Al coil. The quench characteristics of the magnet were studied.« less

  8. PIV measurements of coolant flow field in a diesel engine cylinder head

    NASA Astrophysics Data System (ADS)

    Ma, Hongwei; Zhang, Zhenyang; Xue, Cheng; Huang, Yunlong

    2015-04-01

    This paper presents experimental measurements of coolant flow field in the water jacket of a diesel engine cylinder head. The test was conducted at three different flow rates using a 2-D PIV system. Appropriate tracing particles were selected and delivery device was designed and manufactured before the test. The flow parameters, such as velocity, vorticity and turbulence, were used to analyze the flow field. The effects of vortex which was located between the intake valve and the exhaust valve were discussed. The experimental results showed an asymmetric distribution of velocity in the water jacket. This led to an asymmetric thermal distribution, which would shorten the service life of the cylinder head. The structure optimization to the water jacket of cylinder head was proposed in this paper. The experimental system, especially the 2-D PIV system, is a great help to study the coolant flow structure and analyze cooling mechanism in the diesel engine cylinder head.

  9. Numerical simulation for double-roller rolling process with deep-cylinder ring

    NASA Astrophysics Data System (ADS)

    Dong-sheng, Qian; Jun, Guo; Lin, Hua

    2013-05-01

    Deep-cylinder rings, as the key mechanical parts of heavy energy equipment, have wide application in nuclear reaction pressure vessels, oil hydrogenation reactors and coal liquefaction devices. Double-roller rolling (DRR) is a new rotary plastic forming technology for deep-cylinder ring manufacturing, which has the advantageous of low energy and material consumption, high efficiency, good quality and large processing range, comparing to the conventional processing technology of free forging. In this paper, a numerical simulation investigation on DRR process of deep-cylinder ring is carried out based on ABAQUS FE software. A 3D coupled thermo-mechanical FE model is developed, the forming feasibility and basic deformation laws in the rolling process is analyzed. The results can provide a scientific guidance for the process design and optimization of the DRR with deep-cylinder ring.

  10. Use of the Piv Method for Investigation of Motion Near a Cylinder in Transverse Flow

    NASA Astrophysics Data System (ADS)

    Dobrosel'skii, K. G.

    2016-06-01

    Turbulent flow past a cylinder in a wind tunnel has been investigated experimentally. Averaged velocity fields near the cylinder have been obtained with the optical PIV method and comparative characteristics have been given for noncavitation and cavitation regimes. From the vector patterns of the averaged velocity fields, the author has determined the angles of separation of the boundary layer from the cylinder surface in the considered regimes of flow. It has been shown that cavitation causes the vortex zone behind the cylinder to increase, the separation angles to displace upstream, and the hydraulic resistance to grow. A comparative calculation of the separation angles and the coefficients of hydraulic resistance of cylinders manufactured from different materials has been given. It has been shown that the vortex zone of a Teflon cylinder in flow having a hydrophobic surface differs from the vortex zone of a steel cylinder, particularly for the cavitation regime in which the angles of separation, especially from the upper part, decrease appreciably and the resistance grows.

  11. Use of the Piv Method for Investigation of Motion Near a Cylinder in Transverse Flow

    NASA Astrophysics Data System (ADS)

    Dobrosel'skii, K. G.

    2016-05-01

    Turbulent flow past a cylinder in a wind tunnel has been investigated experimentally. Averaged velocity fields near the cylinder have been obtained with the optical PIV method and comparative characteristics have been given for noncavitation and cavitation regimes. From the vector patterns of the averaged velocity fields, the author has determined the angles of separation of the boundary layer from the cylinder surface in the considered regimes of flow. It has been shown that cavitation causes the vortex zone behind the cylinder to increase, the separation angles to displace upstream, and the hydraulic resistance to grow. A comparative calculation of the separation angles and the coefficients of hydraulic resistance of cylinders manufactured from different materials has been given. It has been shown that the vortex zone of a Teflon cylinder in flow having a hydrophobic surface differs from the vortex zone of a steel cylinder, particularly for the cavitation regime in which the angles of separation, especially from the upper part, decrease appreciably and the resistance grows.

  12. Development of Advanced In-Cylinder Components and Tribological Systems for Low Heat Rejection Diesel Engines

    NASA Technical Reports Server (NTRS)

    Yonushonis, T. M.; Wiczynski, P. D.; Myers, M. R.; Anderson, D. D.; McDonald, A. C.; Weber, H. G.; Richardson, D. E.; Stafford, R. J.; Naylor, M. G.

    1999-01-01

    In-cylinder components and tribological system concepts were designed, fabricated and tested at conditions anticipated for a 55% thermal efficiency heavy duty diesel engine for the year 2000 and beyond. A Cummins L10 single cylinder research engine was used to evaluate a spherical joint piston and connecting rod with 19.3 MPa (2800 psi) peak cylinder pressure capability, a thermal fatigue resistant insulated cylinder head, radial combustion seal cylinder liners, a highly compliant steel top compression ring, a variable geometry turbocharger, and a microwave heated particulate trap. Components successfully demonstrated in the final test included spherical joint connecting rod with a fiber reinforced piston, high conformability steel top rings with wear resistant coatings, ceramic exhaust ports with strategic oil cooling and radial combustion seal cylinder liner with cooling jacket transfer fins. A Cummins 6B diesel was used to develop the analytical methods, materials, manufacturing technology and engine components for lighter weight diesel engines without sacrificing performance or durability. A 6B diesel engine was built and tested to calibrate analytical models for the aluminum cylinder head and aluminum block.

  13. Cable manufacture

    NASA Technical Reports Server (NTRS)

    Gamble, P.

    1972-01-01

    A survey is presented of flat electrical cable manufacturing, with particular reference to patented processes. The economics of manufacture based on an analysis of material and operating costs is considered for the various methods. Attention is given to the competitive advantages of the several processes and their resulting products. The historical area of flat cable manufacture is presented to give a frame of reference for the survey.

  14. Massless rotating fermions inside a cylinder

    SciTech Connect

    Ambruş, Victor E.; Winstanley, Elizabeth

    2015-12-07

    We study rotating thermal states of a massless quantum fermion field inside a cylinder in Minkowski space-time. Two possible boundary conditions for the fermion field on the cylinder are considered: the spectral and MIT bag boundary conditions. If the radius of the cylinder is sufficiently small, rotating thermal expectation values are finite everywhere inside the cylinder. We also study the Casimir divergences on the boundary. The rotating thermal expectation values and the Casimir divergences have different properties depending on the boundary conditions applied at the cylinder. This is due to the local nature of the MIT bag boundary condition, while the spectral boundary condition is nonlocal.

  15. Efficient laser performance of Yb:Y3Al5O12/Cr4+:Y3Al5O12 composite crystals

    NASA Astrophysics Data System (ADS)

    Dong, Jun; Ren, Yingying; Wang, Guangyu; Cheng, Ying

    2013-10-01

    Highly efficient passively Q-switched lasers of Yb:Y3Al5O12/Cr4+:Y3Al5O12 (Yb:YAG/Cr4+:YAG) composite crystals have been demonstrated with an optical-to-optical efficiency of 36%. A slope efficiency of 44% was achieved with respect to the absorbed pump power. An average output power of over 1.75 W was obtained at an absorbed pump power of 4.8 W. Laser pulses with a pulse energy of over 180 μJ, a pulse width of 3 ns and a peak power of 60 kW were achieved. Near-diffraction-limited laser beams with M2 less than 1.3 were obtained. The effects of the absorbed pump power and the transmission of the output coupler on the laser performance of Yb:YAG/Cr4+:YAG composite crystals were addressed.

  16. Conjugate natural convection between horizontal eccentric cylinders

    NASA Astrophysics Data System (ADS)

    Nasiri, Davood; Dehghan, Ali Akbar; Hadian, Mohammad Reza

    2016-06-01

    This study involved the numerical investigation of conjugate natural convection between two horizontal eccentric cylinders. Both cylinders were considered to be isothermal with only the inner cylinder having a finite wall thickness. The momentum and energy equations were discretized using finite volume method and solved by employing SIMPLER algorithm. Numerical results were presented for various solid-fluid conductivity ratios (KR) and various values of eccentricities in different thickness of inner cylinder wall and also for different angular positions of inner cylinder. From the results, it was observed that in an eccentric case, and for KR < 10, an increase in thickness of inner cylinder wall resulted in a decrease in the average equivalent conductivity coefficient (overline{{K_{eq} }} ); however, a KR > 10 value caused an increase in overline{{K_{eq} }} . It was also concluded that in any angular position of inner cylinder, the value of overline{{K_{eq} }} increased with increase in the eccentricity.

  17. Thermoelectric properties and electronic structure of the zintl-phase Sr(3)AlSb(3).

    PubMed

    Zevalkink, Alex; Pomrehn, Gregory; Takagiwa, Yoshiki; Swallow, Jessica; Snyder, G Jeffrey

    2013-12-01

    The Zintl-phase Sr3 AlSb3 , which contains relatively earth-abundant and nontoxic elements, has many of the features that are necessary for good thermoelectric performance. The structure of Sr3 AlSb3 is characterized by isolated anionic units formed from pairs of edge-sharing tetrahedra. Its structure is distinct from previously studied chain-forming structures, Ca3 AlSb3 and Sr3 GaSb3 , both of which are known to be good thermoelectric materials. DFT predicts a relatively large band gap in Sr3 AlSb3 (Eg ≈1 eV) and a heavier band mass than that found in other chain-forming A3 MSb3 phases (A=Sr, Ca; M=Al, Ga). High-temperature transport measurements reveal both high resistivity and high Seebeck coefficients in Sr3 AlSb3 , which is consistent with the large calculated band gap. The thermal conductivity of Sr3 AlSb3 is found to be extremely low (≈ 0.55 W mK(-1) at 1000 K) due to the large, complex unit cell (56 atoms per primitive cell). Although the figure of merit (zT) has not been optimized in the current study, a single parabolic band model suggests that, when successfully doped, zT≈ 0.3 may be obtained at 600 K; this makes Sr3 AlSb3 promising for waste-heat recovery applications. Doping with Zn(2+) on the Al(3+) site has been attempted, but does not lead to the expected increase in carrier concentration. PMID:24115744

  18. Generalized Bistability in Origami Cylinders

    NASA Astrophysics Data System (ADS)

    Reid, Austin; Adda-Bedia, Mokhtar; Lechenault, Frederic

    Origami folded cylinders (origami bellows) have found increasingly sophisticated applications in space flight, medicine, and even experimental nuclear physics. In spite of this interest, a general understanding of the dynamics of an origami folded cylinder has been elusive. By solving the fully constrained behavior of a periodic fundamental origami cell defined by unit vectors, we have found an analytic solution for all possible rigid-face states accessible from a cylindrical Miura-ori pattern. Although an idealized bellows has two rigid-face configurations over a well-defined region, a physical device, limited by nonzero material thickness and forced to balance hinge with plate-bending energy, often cannot stably maintain a stowed configuration. We have identified and measured the parameters which control this emergent bistability, and have demonstrated the ability to fabricate bellows with tunable deployability.

  19. Transposed compression piston and cylinder

    SciTech Connect

    Ross, M.A.

    1992-04-14

    This patent describes an improved V-type two piston Stirling engine wherein the improvement is a transposed compression piston slidably engaged in a mating cylinder. It comprises: a cylindrical body which is pivotally connected to a connecting rod at a pivot axis which is relatively nearer the outer end of the cylindrical body and has a seal relatively nearer the inner end of the cylindrical body.

  20. Manufacturing technologies

    SciTech Connect

    1995-09-01

    The Manufacturing Technologies Center is an integral part of Sandia National Laboratories, a multiprogram engineering and science laboratory, operated for the Department of Energy (DOE) with major facilities at Albuquerque, New Mexico, and Livermore, California. Our Center is at the core of Sandia`s Advanced Manufacturing effort which spans the entire product realization process.

  1. Manufacturing Technology.

    ERIC Educational Resources Information Center

    Barnes, James L.

    This curriculum guide is designed to assist junior high school industrial arts teachers in planning new courses and revising existing courses in manufacturing technology. Addressed in the individual units of the guide are the following topics: introduction to manufacturing, materials processing, personnel management, production management,…

  2. Comparison of hand laid-up tape and filament wound composite cylinders and panels with and without impact damage

    NASA Technical Reports Server (NTRS)

    Jegley, Dawn C.; Lopez, Osvaldo F.

    1991-01-01

    Experimentally determined axial compressive failure loads, strains and failure modes of composite flat panels and cylinders are presented. A comparison of two types of filament wound flat graphite-epoxy panels indicates that the winding pattern can influence structural response. A comparison of hand laid-up tape and filament wound composite cylinders indicates that fabrication method may not significantly influence the failure mode or average failure strain of thick-walled (radius-to-thickness ratio less than 15) graphite-epoxy cylinders. The interaction of manufacturing-induced features (fiber cross-overs) and low-speed impact damage for graphite-epoxy specimens is also presented. Filament would flat panels with many fiber cross-overs exhibited lower failure strains than filament wound panels without fiber cross-overs for all impact speeds examined. Graphite-thermoplastic cylinders exhibited a significantly different failure mode from the graphite-epoxy cylinders.

  3. Analytical Prediction of Temperature Distribution in Cylinder Liner during Various Boring Operations

    NASA Astrophysics Data System (ADS)

    Tang, Yulong; Sasahara, Hiroyuki

    During the boring process of the engine cylinder liner in automotive manufacturing, the heat at the cutting point flows into the cylinder liner and causes it to thermally expand, which is an inescapable machining issue. This affects the machining accuracy of the machined liner. However, the thermal expansion can be minimized under suitable cutting conditions and boring operations. The boring operation of an engine cylinder liner usually has two stages, semi-finishing boring and finishing. Different from the conventional boring operation, a new boring operation which can perform semi-finishing boring and finishing boring in one stage is explored in this paper. By this boring operation, the influence of the thermal expansion of the machined liner can be minimized. This boring operation is called a “simultaneous boring operation” in this paper. To prove the validity of the simultaneous boring operation, a finite element method (FEM) model was developed to predict the thermal behavior in the cylinder liner during the simultaneous boring operation/conventional boring operation. The results show that the machining errors caused by the thermal expansion of the cylinder liner during the simultaneous boring operation are smaller than those of the cylinder liner during the conventional boring operation. To investigate the influence of the cutting conditions on temperature distribution in the cylinder liner during simultaneous boring operation, FEM analysis of the temperature and thermal expansion on the cylinder liner under three levels of cutting speeds (300,600, and 900m/min) combined with two types of cutting fluid (dry, wet) during simultaneous boring was performed. The results showed that the temperature rise of the cylinder liner during a high-speed, wet simultaneous boring operation is small.

  4. A new phase in rapidly solidified Ti[sub 3]Al-based alloys

    SciTech Connect

    Xu Rui; Xu Daming; Li Qingchun . Dept. of Materials Science and Engineering); Li Dong; Cui Yuyou; Hu Zhuangqi . State Key Lab. for RSA)

    1995-01-15

    Rapid solidification processing has been developed to improve the properties of alloys through refining microstructures, disordering and forming metastable phases. The as-melt spun Ti[sub 3]Al-based alloy with Nb additions above 5-at%, which consist of [alpha][sub 2] and [beta][sub 0] phases in a normal condition, exhibited as single [beta][sub 0] structure. Jackson et al have carried out a comparative study of I/M and RS Ti[sub 3]Al-1 Zr(at%) alloy. Their study revealed that considerable refinement of grains and anti-phase domains was achieved in the rapidly solidified material prepared by the pendant drop melt extraction process (PDME). It is suggested that rapid solidification processing can reduce the ordering of the Ti[sub 3]Al-based alloy. In the past years, it was found that the Ti[sub 3]Al-based alloy with alloying additions (mainly Nb) has been studied extensively, and some new phases such as T and O have been observed in the alloys, but less attention has been given to alloys with low Nb additions. The RS Ti[sub 3]Al-base alloys with Nb below 5-at% have been investigated systematically and a new metastable phase, ordering martensite [alpha][double prime][sub 0] (orthogonal), has been observed in these alloys.

  5. Fabrication of Nb3Al superconducting bulks by mechanical alloying method

    NASA Astrophysics Data System (ADS)

    Qi, Ming; Pan, Xi Feng; Zhang, Ping Xiang; Cui, Li Jun; Li, Cheng Shan; Yan, Guo; Chen, Yong Liang; Zhao, Yong

    2014-06-01

    Since it can directly prepare the Nb-Al supersaturated solid solution, mechanical alloying is thought as a promising method to make high-performance Nb3Al superconductors at a low temperature annealing condition, without the complicated rapid heating, quenching and transformation (RHQT) process. In this paper, we investigate the effects of milling time, the content of Al and annealing temperature on phase formation and superconducting properties of mechanical alloying Nb3Al bulks in detail. The study results show that Nb-Al supersaturated solid solution could be obtained by high energy ball milling, as long as the Nb-Al blended powder is ball milled for 1 h, even the amorphous phase appears with the ball milling time prolonging to 10 h, the Nb-Al intermetalics do not come out either. Amorphous phase is hardly beneficial to synthesizing the Nb3Al phase, instead, it will make the products impurity. By optimizing the milling time, elements composition and annealing temperature , pure Nb3Al phase is obtained and the highest onset superconducting transition temperature (Tc-onset) reaches 15.8 K and the critical current density (Jc) 106 A/cm2 at 8 K without outer field. This paper also discusses the main reasons that affect the superconducting properties of mechanical alloying Nb3Al superconductor.

  6. Quench tests and FEM analysis of Nb3Al Rutherford cables and small racetrack magnets

    SciTech Connect

    Yamada, R.; Kikuchi, A.; Chlachidze, G.; Ambrosio, G.; Andreev, N.; Barzi, E.; Carcagno, R.; Kashikin, V.V.; Kotelnikov, S.; Lamm, M.; Novitski, I.; /Fermilab /Tsukuba Magnet Lab. /KEK, Tsukuba

    2008-12-01

    In collaboration between NIMS and Fermilab, we have made copper stabilized Nb{sub 3}Al Rutherford cables, using Nb-matrixed and Ta-matrixed strands. First these cables were investigated at high current in low self field using a flux pump. Using these Rutherford cables, we built and tested small racetrack magnets. The magnet made with the Nb-matrixed strand showed the flux jump instability in low field. The small racetrack magnet wound with the Ta-matrixed Nb{sub 3}Al Rutherford cable was very stable at 4.5 K operation without any instability, as well as at 2.2 K operation. With the successful operation of the small racetrack magnet up to its short sample data, the feasibility of the Nb{sub 3}Al strand and its Rutherford cable for their application to high field magnets is established. The characteristics of Nb{sub 3}Al Rutherford cable is compared with that of the Nb{sub 3}Sn Rutherford cable and the advantages of Nb{sub 3}Al Rutherford cable are discussed.

  7. Relation of strength distribution of Nb 3Al filaments to strength of multifilamentary superconducting composite wire

    NASA Astrophysics Data System (ADS)

    Ochiai, S.; Sawada, T.; Nishino, S.; Hojo, M.; Takahashi, K.; Yamada, Y.

    The distribution of tensile strength of Nb 3Al filaments and its relation to tensile strength of Nb 3Al multifilamentary superconducting composite wire were studied. The main results can be summarized-as follows: (1) The tensile strength of the extracted filaments with an average diameter of 24 μm was estimated based on the two-parameter Weibull distribution function. The shape and scale parameters were 7.0 and 530 MPa (for a standard length of 1 m), respectively. (2) Although the scatter of the strength of the Nb 3Al filaments was large, that of the multifilamentary composite was very small. This means that, when a large number of filaments are embedded in a composite, the stress leading to overall fracture of the composite is not very different from sample to sample, even though the strengths of the embedded filaments are significantly different. This feature was confirmed by means of a computer-aided Monte Carlo simulation. (3) It was shown by experiment and simulation that the strength of the Nb 3Al composite wire has a very slight dependence on length, although the strength of the Nb 3Al filament decreases markedly with increasing length. This result indicates that, even if the length of the composite wire is extended from a short, laboratory scale sample to an industrial scale, the reduction in strength will be very small.

  8. Fire testing of bare uranium hexafluoride cylinders

    SciTech Connect

    Pryor, W.A.

    1991-12-31

    In 1965, the Oak Ridge Gaseous Diffusion Plant (ORGDP), now the K-25 Site, conducted a series of tests in which bare cylinders of uranium hexafluoride (UF{sub 6}) were exposed to engulfing oil fires for the US Atomic Energy Commission (AEC), now the US Department of Energy (DOE). The tests are described and the results, conclusions, and observations are presented. Two each of the following types of cylinders were tested: 3.5-in.-diam {times} 7.5-in.-long cylinders of Monel (Harshaw), 5.0-in.-diam {times} x 30-in.-long cylinders of Monel, and 8-in.-diam {times} 48-in.-long cylinders of nickel. The cylinders were filled approximately to the standard UF{sub 6} fill limits of 5, 55, and 250 lb, respectively, with a U-235 content of 0.22%. The 5-in.- and 8-in.-diam cylinders were tested individually with and without their metal valve covers. For the 3.5-in.-diam Harshaw cylinders and the 5.0-in.-diam cylinder without a valve cover, the valves failed and UF{sub 6} was released. The remaining 6 cylinders ruptured explosively in time intervals ranging from about 8.5 to 11 min.

  9. Fire testing of bare uranium hexafluoride cylinders

    SciTech Connect

    Pryor, W.A.

    1991-12-31

    In 1965, the Oak Ridge Gaseous Diffusion Plant (ORGDP), now the K-25 Site, conducted a series of tests in which bare cylinders of uranium hexafluoride (UF{sub 6}) were exposed to engulfing oil fires for the US Atomic Energy Commission (AEC), now the US Department of Energy (DOE). The tests are described and the results, conclusions, and observations are presented. Two each of the following types of cylinders were tested: 3.5-in.-diam {times} 7.5-in.-long cylinders of Monel (Harshaw), 5.0-in.-diam {times} 30-in.-long cylinders of Monel, and 8-in.-diam {times} 48-in.-long cylinders of nickel. The cylinders were filled approximately to the standard UF{sub 6} fill limits of 5, 55, and 250 lb, respectively, with a U-235 content of 0.22%. The 5-in.- and 8-in.-diam cylinders were tested individually with and without their metal valve covers. For the 3.5-in.-diam Harshaw cylinders and the 5.0-in.-diam cylinder without a valve cover the valves failed and UF{sub 6} was released. The remaining cylinders ruptured explosively in time intervals ranging from about 8.5 to 11 min.

  10. A double species model for study of relaxation of impure Ni 3Al grain boundaries

    NASA Astrophysics Data System (ADS)

    Zheng, Li-Ping; Ma, Yu-Gang; Han, Jia-Guang; Li, D. X.; Zhang, Xiu-Rong

    2004-04-01

    Based on the Monte Carlo simulation conjoined with the embedded atom method (EAM) potentials, the double species model is established to study relaxation of impure Ni 3Al grain boundaries. The present double species model suggests that the impure atoms are not only segregating species but also inducing species. The present model also suggests that study of combination of the positive (the impure atoms induce Ni atoms to substitute into Al sites) and the negative (the impure atoms substitute into Ni sites) bulk effects of impure atoms is available, in order to understand dependence of the cohesion of the impure Ni 3Al grain boundary (or the Ni enrichment at the impure Ni 3Al grain boundary) on the bulk concentration of impure atoms. The double species model is clarified in comparison between the Ni 3AlB and the Ni 3AlMg systems.

  11. Dislocation substructures in shock-loaded Ni{sub 3}Al

    SciTech Connect

    Albert, D.E.; Gray, G.T. III

    1995-07-01

    The deformation substructure and mechanical response of the L1{sub 2} intermetallic, Ni{sub 3}Al, subjected to shock-wave loading was studied. Following shock prestrains to shock pressures of approximately 14.0 GPa, 23.5 GPa, and 47.2 GPa, the reload yield strength of Ni{sub 3}Al was measured to be 750 MPa, 1,250 MPa and 1,500 MPa, respectively. The effective hardening in the shock-loaded Ni{sub 3}Al exceeds that quasistatically obtained when deformed to roughly the same equivalent strains. Coarse planar slip on {l_brace}111{r_brace} type planes, a high density of stacking faults, and deformation twins with a {l_brace}111{r_brace} type twinning plane were observed in the shocked material. An increasing propensity for twinning and stacking fault formation was observed with higher shock peak pressures.

  12. Evolution of ordered {omega} phases in (Zr{sub 3}Al)-Nb alloys

    SciTech Connect

    Tewari, R.; Mukhopadhyay, P.; Banerjee, S.; Bendersky, L.A.

    1999-03-10

    Microstructural investigations on rapidly solidified Zr{sub 3}Al based alloys (binary Zr{sub 3}Al and ternary Zr{sub 3}Al-3Nb and Zr{sub 3}Al-10Nb) have revealed some unusual phase transformation sequences. The Zr{sub 5}Al{sub 3} phase (D8{sub 8} structure) has been found to occur in both the rapidly solidified ternary alloys unlike in the rapidly solidified stoichiometric Zr{sub 3}Al alloy in which the ZrAl phase (B8{sub 2} structure) has been found to be present. The evolution of the D8{sub 8} phase, which could be regarded as one of the ordered derivatives of the {omega} phase, could be described in terms of a superimposition of replacive and displacive ordering waves in the {beta} phase. The orientation relationship between the {beta} and the D8{sub 8} phases has been established. The microstructural changes occurring in the rapidly solidified Zr{sub 3}Al-Nb alloys during aging have been examined. It has been found that on aging the D8{sub 8} phase gets transformed into the B8{sub 2} phase which, on continued aging, transforms to other metastable and equilibrium phases, depending upon the aging temperature. The observed sequence of phase transformations involving different structurally related phases has been along the direction of progressively close packed structures. The symmetry changes associated with the sequence of {omega} related transformations have been summarized in the form of a symmetry tree.

  13. Mechanical alloying as method for introducing carbon in Ni3Al intermetallide

    NASA Astrophysics Data System (ADS)

    Portnoi, V. K.; Leonov, A. V.; Logachev, A. V.; Streletskii, A. N.; Popov, V. A.

    2012-12-01

    The method for the mechanical alloying of Ni-Al-C and Ni3Al-C mixtures was used to obtain nonequilibrium solid Ni(Al,C) solutions in which the carbon content varies from 2.9 to 8.5 at %. The relationship between carbon dissolution and the probability of appearance of deformation-induced stacking faults (SFs) in the formation of mixed (substitutional and interstitial) solid Ni(Al,C) solutions has been found based on an analysis of the diffraction spectra. SFs are assumed to serve as pathways of carbon penetration in nickel-based solid solutions. The effective carbon radius was found to be about 0.0616 nm in the formation of an antiperovskite phase Ni3AlC x . The method of calculating the amount of interstitial carbon was proposed based on the experimental lattice parameters of fcc solid Ni(Al,C) solutions and ordered phases L12 Ni3Al and E21 (Ni3AlC x ). The temperature stability of the nonequilibrium solid Ni(Al,C) solutions was established. It was shown that the decomposition of the solid solutions proceeded according to a spinodal mechanism at a temperature of 400°C with separation into two phases, i.e., an antiperovskite carbide (Ni3AlC x ) and Ni(Al,C). At higher temperatures (600-800°C), carbon precipitates from these phases with the formation of an antiperovskite Ni3AlC0.16, solid Ni(Al) solution, and nanocrystalline graphite.

  14. Manufacturing technology

    SciTech Connect

    Blaedel, K.L.

    1997-02-01

    The specific goals of the Manufacturing Technology thrust area are to develop an understanding of fundamental fabrication processes, to construct general purpose process models that will have wide applicability, to document our findings and models in journals, to transfer technology to LLNL programs, industry, and colleagues, and to develop continuing relationships with industrial and academic communities to advance our collective understanding of fabrication processes. Advances in four projects are described here, namely Design of a Precision Saw for Manufacturing, Deposition of Boron Nitride Films via PVD, Manufacturing and Coating by Kinetic Energy Metallization, and Magnet Design and Application.

  15. Design of nested Halbach cylinder arrays for magnetic refrigeration applications

    NASA Astrophysics Data System (ADS)

    Trevizoli, Paulo V.; Lozano, Jaime A.; Peixer, Guilherme F.; Barbosa, Jader R., Jr.

    2015-12-01

    We present an experimentally validated analytical procedure to design nested Halbach cylinder arrays for magnetic cooling applications. The procedure aims at maximizing the magnetic flux density variation in the core of the array for a given set of design parameters, namely the inner diameter of the internal magnet, the air gap between the magnet cylinders, the number of segments of each magnet and the remanent flux density of the Nd2Fe14B magnet grade. The design procedure was assisted and verified by 3-D numerical modeling using a commercial software package. An important aspect of the optimal design is to maintain an uniform axial distribution of the magnetic flux density in the region of the inner gap occupied by the active magnetocaloric regenerator. An optimal nested Halbach cylinder array was manufactured and experimentally evaluated for the magnetic flux density in the inner gap. The analytically calculated magnetic flux density variation agreed to within 5.6% with the experimental value for the center point of the magnet gap.

  16. Analysis of heat-affected zone cracking in Ni/sub 3/Al alloys

    SciTech Connect

    Santella, M.L.; Maguire, M.C.; David, S.A.

    1986-01-01

    A key issue in the development of Ni/sub 3/Al for engineering applications is their weldability. Detailed welding studies have been done which show that iron-containing nickel aluminides are prone to heat-affected zone (HAZ) cracking. Hot ductility testing of these alloys has suggested that grain boundary cohesive strength controls high temperature ductility and the resistance to HAZ cracking. This analysis cannot, however, be used to explain the behavior of other aluminide alloys. The intention of this work is to more fully characterize the relationship between mechanical behavior and HAZ cracking susceptibility for Ni/sub 3/Al alloys.

  17. Melting and thermodynamic properties of pyrope (Mg3Al2Si3O12)

    USGS Publications Warehouse

    Tequi, C.; Robie, R.A.; Hemingway, B.S.; Neuville, D.R.; Richet, P.

    1991-01-01

    The heat capacity of Mg3Al2Si3O12 glass has been measured from 10 to 1000 K by adiabatic and differential scanning calorimetry. The heat capacity of crystalline pyrope has been determined from drop-calorimetry measurements between 820 and 1300 K. From these and previously published results a consistent set of thermodynamic data is presented for pyrope and Mg3Al2Si3O12 glass and liquid for the interval 0-2000 K. The enthalpy of fusion at 1570 ?? 30 K, the metastable congruent 1-bar melting point, is 241 ?? 12 kJ/mol. ?? 1991.

  18. Experimental and theoretical investigation of the dislocation mechanisms of microcrack nucleation in Ti3Al

    NASA Astrophysics Data System (ADS)

    Yakovenkova, L. I.; Karkina, L. E.; Elkina, O. A.

    2010-04-01

    The dislocation structure and microcracks in Ti3Al samples subjected to deformation with an indenter at room temperature are analyzed by electron microscopy. The reactions of interaction between superdislocations that carry out deformation in the basal, prismatic, and pyramidal planes (of types I and II) are considered. The types of interactions that result in the formation of dislocation barriers, i.e., microcrack nuclei, are found. The Rice-Thompson model is used to study the relation between the fracture sensitivity and the plastic-relaxation ability of the Ti3Al intermetallic compound during microcrack propagation.

  19. Cyclic oxidation of aluminide coatings on Ti3Al+Nb

    NASA Technical Reports Server (NTRS)

    Smialek, James L.; Gedwill, Michael A.; Brindley, Pamela K.

    1990-01-01

    A number of pack aluminide coatings were produced on fiber-reinforced Ti3Al+Nb composites and were compared for their protection effect in cyclic oxidation at 982 C. It was found that pack aluminizing of Ti3Al+Nb can successfully produce an oxidation resistant TiAl3 coating which forms alpha-Al2O3 scales. These coatings offer a substantial improvement over the uncoated matrix material in 982 C cyclic oxidation. Coating cracks were found to contribute to degradation of thick coatings.

  20. Thermomechanical properties of Cr:Tm:Ho:Y sub 3 Al sub 5 O sub 12

    SciTech Connect

    Marion, J.E.

    1990-05-15

    The thermomechanical properties of Cr:Ho:Tm:Y{sub 3}Al{sub 5}O{sub 12} have been measured and compared to similar measurements on Nd:Y{sub 3}Al{sub 5}O{sub 12}. We find that, in general, the properties are similar, with the single exception being thermal diffusivity. Nd:YAG has substantially higher thermal diffusivity than Cr:Tm:Ho:YAG. Consequently, the intrinsic thermal stress resistance figure of merit which governs a materials resistance to fracture in the presence of a steady thermal gradient is lower in Cr:Tm:Ho:YAG than in Nd:YAG. 6 refs., 1 tab.

  1. High-temperature powder synchrotron diffraction studies of synthetic cryolite Na 3AlF 6

    NASA Astrophysics Data System (ADS)

    Zhou, Qingdi; Kennedy, Brendan J.

    2004-03-01

    A high-resolution synchrotron diffraction study of the structures of a synthetic sample of cryolite Na 3AlF 6 from room temperature to 800°C is reported. At room temperature Na 3AlF 6 is monoclinic and the structure is described in space group P2 1/n. Heating the sample to 560°C results in only minor changes to the structure. A first-order transition from this monoclinic structure to a high-temperature cubic structure is observed near 567°C. The cubic Fm 3¯m structure is characterized by disorder of the fluoride atoms.

  2. Direct solid-state precipitation-processed A15 /Nb3Al/ superconducting material

    NASA Astrophysics Data System (ADS)

    Hong, M.; Morris, J. W., Jr.

    1980-12-01

    A 'solid-state precipitation' process was used to prepare superconducting tapes containing Nb3Al in a niobium matrix. Small ingots of Nb-(17-19 at. %)Al were prepared by arc melting, homogenizing, quenching, warm rolling into tape, and aging at 750-900 C to precipitate the A15 phase. Transmission electron microscopy studies revealed Nb3Al precipitation in fine particles which formed a semicontinuous network over subgrain boundaries formed by the recovery of deformation-induced dislocations. Promising high-field critical currents were obtained (current density approximately 10 thousand A/sq cm in a field of 14 T at 4.2 K).

  3. Energy Levels and Intensity Parameters of Ho3(+) Ions in Y3Al5O12 and Lu3Al5O12

    NASA Technical Reports Server (NTRS)

    Walsh, Brian M.; Grew, Gary W.; Barnes, Norman P.

    2006-01-01

    The energy levels of the trivalent lanthanide Ho(sup 3+) in Y3Al5O12 (YAG) and Lu3Al5O12 (LuAG) have been measured. The Stark split levels for the first nine Ho manifolds in these materials have been measured, and the results have been fit to a free ion plus crystal field Hamiltonian to generate a theoretical set of energy levels. Crystal field parameters were varied to determine the best fit between experimental and theoretical energy levels. The energy levels of Ho:LuAG are seen to be very similar to those in Ho:YAG. However, subtle changes resulting from replacing Y(sup 3+) with Lu(sup 3+) in the garnet crystal Y3Al5O12 result in different transition wavelengths in LuAG. This has implications for Ho (sup 5)I7yields (sup 5)I8 lasers operating at approximately 2.1 micrometers. Although the energy levels have been measured previously in Ho:YAG, they have not been measured in Ho:LuAG. A comparison of the energy levels in Ho:YAG measured here show some discrepancies with previous measurements. The consistency of the energy level placement between Ho:LuAG and Ho:YAG indicate that the earlier studies may have some errors in the assignments. Finally, a Judd-Ofelt analysis is performed on Ho:YAG and Ho:LuAG to determine the intensity parameters, and thus, the transition probabilities and branching ratios of the first eight excited manifolds.

  4. On vortex shedding from a hexagonal cylinder

    NASA Astrophysics Data System (ADS)

    Khaledi, Hatef A.; Andersson, Helge I.

    2011-10-01

    The unsteady wake behind a hexagonal cylinder in cross-flow is investigated numerically. The time-dependent three-dimensional Navier-Stokes equations are solved for three different Reynolds numbers Re and for two different cylinder orientations. The topology of the vortex shedding depends on the orientation and the Strouhal frequency is generally higher in the wake of a face-oriented cylinder than behind a corner-oriented cylinder. For both orientations a higher Strouhal number St is observed when Re is increased from 100 to 500 whereas St is unaffected by a further increase up to Re=1000. The distinct variation of St with the orientation of the hexagonal cylinder relative to the oncoming flow is opposite of earlier findings for square cylinder wakes which exhibited a higher St with corner orientation than with face orientation.

  5. Two-stroke multi-cylinder engine

    SciTech Connect

    Okumura, S.; Hakamata, K.

    1988-11-29

    This patent describes an internal combustion engine having a pair of cylinder bores disposed at an angle to each other, pistons reciprocating in the cylinder bores, a crankshaft supported for rotation about an axis relative to the cylinder bores, connecting rods for transferring reciprocation of the pistons into rotation of the crankshaft, the connection between the pistons and the connecting rods being such that a side thrust is exerted on the pistons for causing the pistons to tilt in the cylinder bores during the power strokes of the pistons, and exhaust ports opening into the cylinder bores at one side of a plane passing through the respective cylinder bore axis and parallel to the crankshaft rotational axis, the improvement comprising each of the exhaust ports opening through the same side of the respective plane with respect to the direction of rotation of the crankshaft.

  6. Smart Manufacturing.

    PubMed

    Davis, Jim; Edgar, Thomas; Graybill, Robert; Korambath, Prakashan; Schott, Brian; Swink, Denise; Wang, Jianwu; Wetzel, Jim

    2015-01-01

    Historic manufacturing enterprises based on vertically optimized companies, practices, market share, and competitiveness are giving way to enterprises that are responsive across an entire value chain to demand dynamic markets and customized product value adds; increased expectations for environmental sustainability, reduced energy usage, and zero incidents; and faster technology and product adoption. Agile innovation and manufacturing combined with radically increased productivity become engines for competitiveness and reinvestment, not simply for decreased cost. A focus on agility, productivity, energy, and environmental sustainability produces opportunities that are far beyond reducing market volatility. Agility directly impacts innovation, time-to-market, and faster, broader exploration of the trade space. These changes, the forces driving them, and new network-based information technologies offering unprecedented insights and analysis are motivating the advent of smart manufacturing and new information technology infrastructure for manufacturing. PMID:25898070

  7. Flow in a torsionally oscillating filled cylinder

    NASA Technical Reports Server (NTRS)

    Schafer, C. F.

    1983-01-01

    The flow of a liquid in a completely filled cylinder undergoing torsional oscillations about its longitudinal symmetry axis was studied analytically and experimentally. The objective of the studies was to determine the efficacy of the torsional oscillations in mixing the confined liquid. Flow was found to be confined primarily to toroidal cells at the ends of the cylinder. Cell thickness was about equal to the cylinder radius. The use of baffles at the end walls was shown to enhance the mixing process.

  8. Low-cost, low-weight CNG cylinder development. Final report

    SciTech Connect

    Richards, Mark E.; Melford, K.; Wong, J.; Gambone, L.

    1999-09-01

    This program was established to develop and commercialize new high-strength steel-lined, composite hoop-wrapped compressed natural gas (CNG) cylinders for vehicular applications. As much as 70% of the cost of natural gas vehicles can be related to on-board natural gas storage costs. The cost and weight targets for this program represent significant savings in each characteristic when compared to comparable containers available at the initiation of the program. The program objectives were to optimize specific weight and cost goals, yielding CNG cylinders with dimensions that should, allowing for minor modifications, satisfy several vehicle market segments. The optimization process encompassed material, design, and process improvement. In optimizing the CNG cylinder design, due consideration was given to safety aspects relative to national, international, and vehicle manufacturer cylinder standards and requirements. The report details the design and development effort, encompassing plant modifications, material selection, design issues, tooling development, prototype development, and prototype testing. Extenuating circumstances prevented the immediate commercialization of the cylinder designs, though significant progress was made towards improving the cost and performance of CNG cylinders. A new low-cost fiber was successfully employed while the weight target was met and the cost target was missed by less than seven percent.

  9. Transonic Flow Past Cone Cylinders

    NASA Technical Reports Server (NTRS)

    Solomon, George E

    1955-01-01

    Experimental results are presented for transonic flow post cone-cylinder, axially symmetric bodies. The drag coefficient and surface Mach number are studied as the free-stream Mach number is varied and, wherever possible, the experimental results are compared with theoretical predictions. Interferometric results for several typical flow configurations are shown and an example of shock-free supersonic-to-subsonic compression is experimentally demonstrated. The theoretical problem of transonic flow past finite cones is discussed briefly and an approximate solution of the axially symmetric transonic equations, valid for a semi-infinite cone, is presented.

  10. Fire exposure of empty 30B cylinders

    SciTech Connect

    Ziehlke, K.T.

    1991-12-31

    Cylinders for UF{sub 6} handling, transport, and storage are designed and built as unfired pressure vessels under ASME Boiler and Pressure Vessel Code criteria and standards. They are normally filled and emptied while UF{sub 6} is in its liquid phase. Transport cylinders such as the Model 30B are designed for service at 200 psi and 250{degrees}F, to sustain the process conditions which prevail during filling or emptying operations. While in transport, however, at ambient temperature the UF{sub 6} is solid, and the cylinder interior is well below atmospheric pressure. When the cylinders contain isotopically enriched product (above 1.0 percent U-235), they are transported in protective overpacks which function to guard the cylinders and their contents against thermal or mechanical damage in the event of possible transport accidents. Two bare Model 30B cylinders were accidentally exposed to a storage warehouse fire in which a considerable amount of damage was sustained by stored materials and the building structure, as well as by the cylinder valves and valve protectors. The cylinders were about six years old, and had been cleaned, inspected, hydrotested, and re-certified for service, but were still empty at the time of the fire. The privately-owned cylinders were transferred to DOE for testing and evaluation of the fire damage.

  11. Overseas shipments of 48Y cylinders

    SciTech Connect

    Tanaka, R.T.; Furlan, A.S.

    1991-12-31

    This paper describes experiences with two incidents of overseas shipments of uranium hexafluoride (UF{sub 6}) cylinders. The first incident involved nine empty UF{sub 6} cylinders in enclosed sea containers. Three UF{sub 6} cylinders broke free from their tie-downs and damaged and contaminated several sea containers. This paper describes briefly how decontamination was carried out. The second incident involved a shipment of 14 full UF{sub 6} cylinders. Although the incident did not cause an accident, the potential hazard was significant. The investigation of the cause of the near accident is recounted. Recommendations to alleviate future similar incidents for both cases are presented.

  12. Rotating cylinder design as a lifting generator

    NASA Astrophysics Data System (ADS)

    Asrokin, Azharrudin; Rizal Ramly, Mohammad; Halim Ahmad, Abdul

    2013-12-01

    The airfoil shape of a wing has always been the design to generate lift. But few realized that a simple rotating cylinder can also create lift. However, the explanation and study of how a rotating cylinder creates lift are still complex. In remote area where it is difficult for air vehicle to access, the exploration and discovery of different configuration for design concept is rather important. Due to this reason, there is a need to think of a lift generator that can produce better lift (few fold better than conventional airfoil) at lower speed to take off in a short distance of time. This paper will explain the conditions and the design of such a wing using the rotating cylinder concept that will take off in a short time and requires little takeoff and landing strip. Spokes will be attached to the cylinder to force the surrounding air to rotate along with the cylinder. This will create a vortex that hastens the speed of the air on top of the cylinder and at the same time retarding the speed of air below the cylinder. From the results, the rougher surface cylinder produces more lift when rotating and also, higher speed rotation of the cylinder greatly changes the speed of the surrounding air, thus better lift.

  13. Vortex motion behind a circular cylinder

    NASA Technical Reports Server (NTRS)

    Foeppl, L.

    1983-01-01

    Vortex motion behind a circular cylinder moving through water is discussed. It is shown that a pair of vortices form behind a moving cylinder and that their centers will move along a predictable curve. This curve represents an equilibrium condition which, however, is subject to perturbation. The stability of the vortex pair is investigated. Movement of the vortex pair away from the cylinder is calculated as an explanation of the resistance of the cylinder. Finally, the principles elaborated are applied to the flow around a flat plate.

  14. Internal combustion engine cylinder-to-cylinder balancing with balanced air-fuel ratios

    DOEpatents

    Harris, Ralph E.; Bourn, Gary D.; Smalley, Anthony J.

    2006-01-03

    A method of balancing combustion among cylinders of an internal combustion engine. For each cylinder, a normalized peak firing pressure is calculated as the ratio of its peak firing pressure to its combustion pressure. Each cylinder's normalized peak firing pressure is compared to a target value for normalized peak firing pressure. The fuel flow is adjusted to any cylinder whose normalized peak firing pressure is not substantially equal to the target value.

  15. Recent advances in alloy design of Ni{sub 3}Al alloys for structural use

    SciTech Connect

    Liu, C.T.; George, E.P.

    1996-12-31

    This is a comprehensive review of recent advances in R&D of Ni{sub 3}Al-based alloys for structural use at elevated temperatures in hostile environments. Recent studies indicate that polycrystalline Ni{sub 3}Al is intrinsically quite ductile at ambient temperatures, and its poor tensile ductility and brittle grain-boundary fracture are caused mainly by moisture-induced hydrogen embrittlement when the aluminide is tested in moisture- or hydrogen-containing environments. Tensile ductility is improved by alloying with substitutional and interstitial elements. Among these additives, B is most effective in suppressing environmental embrittlement and enhancing grain-boundary cohesion, resulting in a dramatic increase of tensile ductility at room temperature. Both B-doped and B-free Ni{sub 3}Al alloys exhibit brittle intergranular fracture and low ductility at intermediate temperatures (300-850 C) because of oxygen-induced embrittlement in oxidizing environments. Cr is found to be most effective in alleviating elevated-temperature embrittlement. Parallel efforts on alloy development using physical metallurgy principles have led to development of several Ni{sub 3}Al alloys for industrial use. The unique properties of these alloys are briefly discussed. 56 refs, 15 figs, 3 tabs.

  16. Method For Making Electronic Circuits Having Nial And Ni3al Substrates

    DOEpatents

    Deevi, Seetharama C.; Sikka, Vinod K.

    2001-01-30

    A method for making electronic circuit component having improved mechanical properties and thermal conductivity comprises steps of providing NiAl and/or Ni.sub.3 Al, and forming an alumina layer thereupon prior to applying the conductive elements. Additional layers of copper-aluminum alloy or copper further improve mechanical strength and thermal conductivity.

  17. High-temperature sulfidation of Fe{sub 3}Al thermal spray coatings at 600 C

    SciTech Connect

    Luer, K.R.; DuPont, J.N.; Marder, A.R.

    2000-02-01

    Sulfidation behavior of Fe{sub 3}Al thermal spray coatings was studied in Ar-3.5% H{sub 2}-0.1{degree} hydrogen sulfide (H{sub 2}S) at 600 C for 500 h. Coatings were processed from the same lot of gas atomized Fe{sub 3}Al powder using a high-velocity oxygen fuel (HVOF) process and an air plasma spray (APS) process. In general, the Fe{sub 3}Al-type composition displayed excellent resistance to sulfidation corrosion at 600 C, which correlated with the reported literature on wrought Fe{sub 3}Al alloys. However, the method of processing affected the corrosion response. Particle degradation and porosity were two important factors that affected corrosion resistance. HVOF processing did not degrade significantly the composition of the powder and produced coatings with low porosity, low oxide content, high sulfidation resistance, and high resistance to sulfur penetration. HVOF coatings produced from finer sized powders exhibited slightly more corrosion damage because a greater percentage of the consumable was degraded. In contrast, APS processing caused significant degradation to the consumable and created coatings with a significant quantity of alloy-depleted regions, high oxide content, and high porosity. As a result, sulfur attached alloy-depleted regions within the splats and permeated through the porous splat boundaries to the coating-substrate interface.

  18. Si3AlP: a new promising material for solar cell absorber.

    PubMed

    Yang, Ji-Hui; Zhai, Yingteng; Liu, Hengrui; Xiang, Hongjun; Gong, Xingao; Wei, Su-Huai

    2012-08-01

    First-principles calculations were performed to study the structural and optoelectronic properties of the newly synthesized nonisovalent and lattice-matched (Si(2))(0.6)(AlP)(0.4) alloy (Watkins, T.; et al. J. Am. Chem. Soc.2011, 133, 16212). We found that the most stable structure of Si(3)AlP is a superlattice along the [111] direction with separated AlP and Si layers, which has a similar optical absorption spectrum to silicon. The ordered C1c1-Si(3)AlP is found to be the most stable one among all structures with a basic unit of one P atom surrounded by three Si atoms and one Al atom, in agreement with experimental suggestions. We predict that C1c1-Si(3)AlP has good optical properties, i.e., it has a larger fundamental band gap and a smaller direct band gap than Si; thus, it has much higher absorption in the visible light region. The calculated properties of Si(3)AlP suggest that it is a promising candidate for improving the performance of the existing Si-based solar cells. The understanding on the stability and band structure engineering obtained in this study is general and can be applied for future study of other nonisovalent and lattice-matched semiconductor alloys. PMID:22769022

  19. One step combustion synthesis and thermoluminescence in Y3Al5O12:Ce3+

    NASA Astrophysics Data System (ADS)

    Dhadade, I. H.; Moharil, S. V.; Dhoble, S. J.; Rahangdale, S. R.

    2016-05-01

    In the present paper one step combustion synthesis of compound Y3Al5O12:Ce3+ is reported using a modified procedure and employing mixed (Urea + Glycine) as fuel. Powder X-ray diffraction confirms the formation of said compound. Thermoluminescence study over the wide gamma exposure (1KGy - 13 KGy) Suggests the possible use of the phosphor in dosimetric application.

  20. Ni3Al-based alloys for die and tool application

    DOEpatents

    Liu, Chain T.; Bloom, Everett E.

    2001-01-01

    A novel Ni.sub.3 Al-based alloy exhibits strengths and hardness in excess of the standard base alloy IC-221M at temperatures of up to about 1000.degree. C. The alloy is useful in tool and die applications requiring such temperatures, and for structural elements in engineering systems exposed to such temperatures.

  1. Pressure dependence of the resistivity of Ce/sub 3/Al

    SciTech Connect

    Lawrence, J.M.; Chen, Y.Y.; Thompson, J.D.; Borges, H.A.

    1987-01-01

    Ce/sub 3/Al was prepared from very high purity cerium. The resistivity at various pressures show a structural transition near 100/sup 0/K at zero pressure. This antiferromagnetic heavy fermion behavior evolves smoothly towards nonmagnetic large T/sub K/ (slightly overweight fermion) behavior as the pressure is raised. 3 figs. (DLC)

  2. Electronic circuits having NiAl and Ni.sub.3 Al substrates

    DOEpatents

    Deevi, Seetharama C.; Sikka, Vinod K.

    1999-01-01

    An electronic circuit component having improved mechanical properties and thermal conductivity comprises NiAl and/or Ni.sub.3 Al, upon which an alumina layer is formed prior to applying the conductive elements. Additional layers of copper-aluminum alloy or copper further improve mechanical strength and thermal conductivity.

  3. Electromagnetic-capillary instabilities of a hollow liquid cylinder - Production of spherical shells under microgravity conditions

    NASA Technical Reports Server (NTRS)

    Chow, C.-Y.; Harvanek, M.

    1988-01-01

    An electrical device is proposed for manufacturing spherical shells out of hollow metallic cylinders in a microgravity environment. Such a cylinder is melted by passing a strong axial current through it. The resulting liquid column is unstable to axisymmetric disturbances and breaks up to form hollow spheres after solidification. The stability analysis presented in this paper, which is based on an inviscid magnetohydrodynamic formulation, shows that the size of the spheres may be controlled by varying the strength of the current passed through the column.

  4. Hard sphere packings within cylinders.

    PubMed

    Fu, Lin; Steinhardt, William; Zhao, Hao; Socolar, Joshua E S; Charbonneau, Patrick

    2016-02-23

    Arrangements of identical hard spheres confined to a cylinder with hard walls have been used to model experimental systems, such as fullerenes in nanotubes and colloidal wire assembly. Finding the densest configurations, called close packings, of hard spheres of diameter σ in a cylinder of diameter D is a purely geometric problem that grows increasingly complex as D/σ increases, and little is thus known about the regime for D > 2.873σ. In this work, we extend the identification of close packings up to D = 4.00σ by adapting Torquato-Jiao's adaptive-shrinking-cell formulation and sequential-linear-programming (SLP) technique. We identify 17 new structures, almost all of them chiral. Beyond D ≈ 2.85σ, most of the structures consist of an outer shell and an inner core that compete for being close packed. In some cases, the shell adopts its own maximum density configuration, and the stacking of core spheres within it is quasiperiodic. In other cases, an interplay between the two components is observed, which may result in simple periodic structures. In yet other cases, the very distinction between the core and shell vanishes, resulting in more exotic packing geometries, including some that are three-dimensional extensions of structures obtained from packing hard disks in a circle. PMID:26843132

  5. Optimization of High Temperature Hoop Creep Response in ODS-Fe3Al Tubes

    SciTech Connect

    Kad, B.K.; Heatherington, J.H.; McKamey, C.; Wright, I.; Sikka, V.; Judkins, R.

    2003-04-22

    Oxide dispersion strengthened (ODS) Fe3Al alloys are currently being developed for heat-exchanger tubes for eventual use at operating temperatures of up to 1100 C in the power generation industry. The development challenges include (a) efforts to produce thin walled ODS-Fe3Al tubes, employing powder extrusion methodologies, with (b) adequate increased strength for service at operating temperatures to (c) mitigate creep failures by enhancing the as-processed grain size. A detailed and comprehensive research and development methodology is prescribed to produce ODS-Fe3Al thin walled tubes. Current single step extrusion consolidation methodologies typically yield 8ft. lengths of 1-3/8 inch diameter, 1/8 inch wall thickness ODS-Fe3Al tubes. The process parameters for such consolidation methodologies have been prescribed and evaluated as being routinely reproducible. Recrystallization treatments at 1200 C produce elongated grains (with their long axis parallel to the extrusion axis), typically 200-2000 {micro}m in diameter, and several millimeters long. The dispersion distribution is unaltered on a micro scale by recrystallization, but the high aspect ratio grain shape typically obtained limits grain spacing and consequently the hoop creep response. Improving hoop creep in ODS-alloys requires an understanding and manipulating the factors that control grain alignment and recrystallization behavior. Current efforts are focused on examining the processing dependent longitudinal vs. transverse creep anisotropy, and exploring post-extrusion methods to improve hoop creep response in ODS-Fe3Al alloy tubes. In this report we examine the mechanisms of hoop creep failure and describe our efforts to improve creep performance via variations in thermal-mechanical treatments.

  6. EuAu3Al2: Crystal and Electronic Structures and Spectroscopic, Magnetic, and Magnetocaloric Properties.

    PubMed

    Schmiegel, Jan-Patrick; Block, Theresa; Gerke, Birgit; Fickenscher, Thomas; Touzani, Rachid St; Fokwa, Boniface P T; Janka, Oliver

    2016-09-01

    The intermetallic compound EuAu3Al2 has been prepared by reaction of the elements in tantalum ampules. The structure was refined from single-crystal data, indicating that the title compound crystallizes in the orthorhombic crystal system (a = 1310.36(4), b = 547.87(1), c = 681.26(2) pm) with space group Pnma (wR2 = 0.0266, 1038 F(2) values, 35 parameters) and is isostructural to SrAu3Al2 (LT-SrZn5 type). Full ordering of the gold and aluminum atoms was observed. Theoretical calculations confirm that the title compound can be described as a polar intermetallic phase containing a polyanionic [Au3Al2](δ-) network featuring interconnected strands of edge-sharing [AlAu4] tetrahedra. Magnetic measurements and (151)Eu Mössbauer spectroscopic investigations confirmed the divalent character of the europium atoms. Ferromagnetic ordering below TC = 16.5(1) K was observed. Heat capacity measurements showed a λ-type anomaly at T = 15.7(1) K, in line with the ordering temperature from the susceptibility measurements. The magnetocaloric properties of EuAu3Al2 were determined, and a magnetic entropy of ΔSM = -4.8 J kg(-1) K(-1) for a field change of 0 to 50 kOe was determined. Band structure calculations found that the f-bands of Eu present at the Fermi level of non-spin-polarized calculations are responsible for the ferromagnetic ordering in this phase, whereas COHP chemical bonding coupled with Bader charge analysis confirmed the description of the structure as covalently bonded polyanionic [Au3Al2](δ-) network interacting ionically with Eu(δ+). PMID:27532875

  7. Microgravity Manufacturing

    NASA Technical Reports Server (NTRS)

    Cooper, Ken; Munafo, Paul M. (Technical Monitor)

    2002-01-01

    Manufacturing capability in outer space remains one of the critical milestones to surpass to allow humans to conduct long-duration manned space exploration. The high cost-to-orbit for leaving the Earth's gravitational field continues to be the limiting factor in carrying sufficient hardware to maintain extended life support in microgravity or on other planets. Additive manufacturing techniques, or 'chipless' fabrication, like RP are being considered as the most promising technologies for achieving in situ or remote processing of hardware components, as well as for the repair of existing hardware. At least three RP technologies are currently being explored for use in microgravity and extraterrestrial fabrication.

  8. Balancer structure for three-cylinder engines

    SciTech Connect

    Suzuki, T.

    1987-04-21

    This patent describes a balancer structure for a three-cylinder in-line engine having three cylinders, the latter comprising a first and third cylinder and a second cylinder disposed between the first and third cylinders, a crankshaft having crank arms disposed at angles of 120/sup 0/ with respect to each other and operatively connected to a piston assembly within each of the cylinders, respectively, consisting of: a single crankshaft adjacent and parallel to and rotated at the same speed as the crankshaft but in the opposite direction, means comprising first counterweights securely mounted on the crankshaft only at positions thereof corresponding to the first and third cylinders for balancing of a part of inertia forces of rotating masses and a part of inertia forces of reciprocating masses; means comprising at least one second counterweight securely mounted on the crankshaft substantially opposite to the crank arm corresponding to the second cylinder for balancing of the remainder of the inertia forces of rotating masses; at least two balancers respectively securely mounted on the countershaft at both ends respectively thereof for the balancing of the remainder of the inertia forces of reciprocating masses, and of the couple of inertia of the crankshaft about axes perpendicular to the crankshaft.

  9. A Convenient Storage Rack for Graduated Cylinders

    ERIC Educational Resources Information Center

    Love, Brian

    2004-01-01

    An attempt is made to find a solution to the occasional problem of a need for storing large numbers of graduated cylinders in many teaching and research laboratories. A design, which involves the creation of a series of parallel channels that are used to suspend inverted graduated cylinders by their bases, is proposed.

  10. Vibrations and stresses in layered anisotropic cylinders

    NASA Technical Reports Server (NTRS)

    Mulholland, G. P.; Gupta, B. P.

    1976-01-01

    An equation describing the radial displacement in a k layered anisotropic cylinder was obtained. The cylinders are initially unstressed but are subjected to either a time dependent normal stress or a displacement at the external boundaries of the laminate. The solution is obtained by utilizing the Vodicka orthogonalization technique. Numerical examples are given to illustrate the procedure.

  11. Buckling of laminated composite cylinders - A review

    NASA Technical Reports Server (NTRS)

    Tennyson, R. C.

    1975-01-01

    A brief review of the available static buckling theory for both geometrically 'perfect' and 'imperfect' anisotropic composite circular cylinders is presented for various loading configurations. For comparison purposes, relevant experimental data are discussed, including recent combined loading test results and recommendations are made concerning the design of composite cylinders.

  12. Efficient visual grasping alignment for cylinders

    NASA Technical Reports Server (NTRS)

    Nicewarner, Keith E.; Kelley, Robert B.

    1991-01-01

    Monocular information from a gripper-mounted camera is used to servo the robot gripper to grasp a cylinder. The fundamental concept for rapid pose estimation is to reduce the amount of information that needs to be processed during each vision update interval. The grasping procedure is divided into four phases: learn, recognition, alignment, and approach. In the learn phase, a cylinder is placed in the gripper and the pose estimate is stored and later used as the servo target. This is performed once as a calibration step. The recognition phase verifies the presence of a cylinder in the camera field of view. An initial pose estimate is computed and uncluttered scan regions are selected. The radius of the cylinder is estimated by moving the robot a fixed distance toward the cylinder and observing the change in the image. The alignment phase processes only the scan regions obtained previously. Rapid pose estimates are used to align the robot with the cylinder at a fixed distance from it. The relative motion of the cylinder is used to generate an extrapolated pose-based trajectory for the robot controller. The approach phase guides the robot gripper to a grasping position. The cylinder can be grasped with a minimal reaction force and torque when only rough global pose information is initially available.

  13. Long range order and vacancy properties in Al-rich Fe{sub 3}Al and Fe{sub 3}Al(Cr) alloys

    SciTech Connect

    Kim, S.M.; Morris, D.G.

    1998-05-01

    Neutron powder diffraction measurements have been carried out in situ from room temperature to about 100 C in Fe28Al (28 at.% Al), Fe32.5Al (32.5 at.% Al) and Fe28Al15Cr (28 at.% Al, 5 at.% Cr) alloys. X-ray diffraction and TEM studies provided supporting information. The data were analyzed to obtain information about the temperature dependence of the DO{sub 3} and B2 long range order parameters, the location of the Cr atoms and their effect on the ordering energies, and on the vacancy formation and migration properties in Fe28Al and Fe32.5Al alloys. The location of the ternary alloying addition in DO{sub 3} and B2 ordered Al-rich Fe{sub 3}Al is shown to be consistent with considerations of interatomic bond energies.

  14. Cost-Benefit Analysis for the Advanced Near Net Shape Technology (ANNST) Method for Fabricating Stiffened Cylinders

    NASA Technical Reports Server (NTRS)

    Stoner, Mary Cecilia; Hehir, Austin R.; Ivanco, Marie L.; Domack, Marcia S.

    2016-01-01

    This cost-benefit analysis assesses the benefits of the Advanced Near Net Shape Technology (ANNST) manufacturing process for fabricating integrally stiffened cylinders. These preliminary, rough order-of-magnitude results report a 46 to 58 percent reduction in production costs and a 7-percent reduction in weight over the conventional metallic manufacturing technique used in this study for comparison. Production cost savings of 35 to 58 percent were reported over the composite manufacturing technique used in this study for comparison; however, the ANNST concept was heavier. In this study, the predicted return on investment of equipment required for the ANNST method was ten cryogenic tank barrels when compared with conventional metallic manufacturing. The ANNST method was compared with the conventional multi-piece metallic construction and composite processes for fabricating integrally stiffened cylinders. A case study compared these three alternatives for manufacturing a cylinder of specified geometry, with particular focus placed on production costs and process complexity, with cost analyses performed by the analogy and parametric methods. Furthermore, a scalability study was conducted for three tank diameters to assess the highest potential payoff of the ANNST process for manufacture of large-diameter cryogenic tanks. The analytical hierarchy process (AHP) was subsequently used with a group of selected subject matter experts to assess the value of the various benefits achieved by the ANNST method for potential stakeholders. The AHP study results revealed that decreased final cylinder mass and quality assurance were the most valued benefits of cylinder manufacturing methods, therefore emphasizing the relevance of the benefits achieved with the ANNST process for future projects.

  15. 9. General view of engine between cylinders with high pressure ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. General view of engine between cylinders with high pressure cylinder on left and low pressure cylinder on right. - Carnegie Steel-Ohio Works, Steam Engines, 912 Salt Springs Road, Youngstown, Mahoning County, OH

  16. Motion of vortices outside a cylinder

    NASA Astrophysics Data System (ADS)

    Tulu, Serdar; Yilmaz, Oguz

    2010-12-01

    The problem of motion of the vortices around an oscillating cylinder in the presence of a uniform flow is considered. The Hamiltonian for vortex motion for the case with no uniform flow and stationary cylinder is constructed, reduced, and constant Hamiltonian (energy) curves are plotted when the system is shown to be integrable according to Liouville. By adding uniform flow to the system and by allowing the cylinder to vibrate, we model the natural vibration of the cylinder in the flow field, which has applications in ocean engineering involving tethers or pipelines in a flow field. We conclude that in the chaotic case forces on the cylinder may be considerably larger than those on the integrable case depending on the initial positions of vortices and that complex phenomena such as chaotic capture and escape occur when the initial positions lie in a certain region.

  17. Simulation of the flow around an upstream transversely oscillating cylinder and a stationary cylinder in tandem

    NASA Astrophysics Data System (ADS)

    Bao, Sheng; Chen, Sheng; Liu, Zhaohui; Li, Jing; Wang, Hanfeng; Zheng, Chuguang

    2012-02-01

    The flow around a transversely oscillating cylinder in tandem with a stationary cylinder was studied using the lattice Boltzmann method at Re = 100. The influences of spacing, oscillation frequency, and amplitude on the flow field were investigated in detail. It was found that, when the upstream cylinder oscillates with small amplitude, the flow pattern can be changed significantly from that of its fixed counterpart. First, the stagnation region ceases to exist. Second, the transition from the vortex suppression (VS) regime to the vortex formation (VF) regime appears earlier than when both cylinders are fixed. Moreover, the system has a wider frequency range of lock-in for both tandem cylinders in the VS regime, while the locked frequency range is slightly increased in the VF regime. The locked region of the tandem-paired cylinders is only slightly wider than that of a single oscillating cylinder. When the system is unlocked, different responses occur in the wakes of the two cylinders. Analysis of the power spectral of lift forces, lift phase portraits, and vorticity contours shows that the wake is regular under conditions of small spacing and small oscillating amplitude. However, with larger spacing, higher oscillating frequency or larger amplitude, the oscillation is powerful enough to dominate the flow field, inducing chaotic flow. The drag and lift forces of both oscillating and stationary cylinders are also discussed. The results reveal large differences between the case of one oscillating cylinder and that of two stationary tandem cylinders.

  18. Numerical study of an oscillating smaller cylinder in the wake of an upstream larger cylinder

    NASA Astrophysics Data System (ADS)

    Gao, Yangyang; Yu, Dingyong; Wang, Xikun; Tan, Soon Keat

    2012-06-01

    A numerical study of flow around two tandem cylinders with unequal diameters was carried out. The upstream larger cylinder was fixed and the downstream smaller cylinder was allowed to oscillate in the transverse direction only. Comparisons of the experimental and numerical results were made to investigate the effects of the gap ratio on the maximum vibration amplitude and vortex shedding frequency. The results showed that the vibration response of the smaller cylinder was significantly affected by the presence of the upstream larger cylinder, and resulted in greatly reduced vibration amplitudes. With an increasing gap ratio, the vibration amplitude increased. However, the magnitude was lower than that corresponding to a single cylinder (with the same diameter as that of the downstream smaller cylinder) under the same flow conditions.

  19. Cylinder Expansion in Polypropylene Tubes

    NASA Astrophysics Data System (ADS)

    Pemberton, Steven; Tappan, Bryce; Manner, Virginia

    2015-06-01

    Cylinder Expansion has long been the benchmark test used to establish an equation of state for any detonable energetic material. However, some new explosives have properties that prevent the use of the traditional copper-walled test; two such issues are materials whose detonations proceed more slowly than the acoustic velocity in the copper liner, and materials with failure diameters large enough to render copper testing prohibitively expensive. Results are presented for experiments conducted using a stoichiometric mixture of ammonium perchlorate and dodecane, a slow-detonating explosive. In copper walls inconsistent expansion was observed due to acoustic precursor waves within the wall. Additional testing was performed in polyethylene and polypropylene tubes to determine whether sufficient expansion could be observed, and satisfactory results were achieved with polypropylene. (96TW-2015-0001) Membership Pending.

  20. Processing, properties, and applications of Ni{sub 3}Al-based alloys

    SciTech Connect

    Sikka, V.K.; Santella, M.L.; Liu, C.T.

    1997-06-01

    The Ni{sub 3}Al-based alloys represent a quantum jump in advanced alloys for structural applications at elevated temperatures. These alloys offer benefits of oxidation, carburization, and chlorination resistance, and significantly higher strength than many commercially used alloys. The commercial applications of the Ni{sub 3}Al-based alloys have begun to occur because of their comprehensive development This paper is to provide a review of. (1) alloy development, (2) melting, casting, and processing of alloys, (3) property data, (4) welding process and weldment properties, and (5) case histories of current applications. It is concluded that the cast alloy IC-221M is on its way to commercialization. 22 refs., 8 figs., 2 tabs.

  1. Microstructural observations in rapidly-solidified and heat-treated Ni3Al-Cr alloys

    NASA Technical Reports Server (NTRS)

    Carro, G.; Flanagan, W. F.

    1992-01-01

    The microstructural development following heat treatments of several rapidly-solidified Ni3Al-Cr and Ni3Al-Cr-B alloys is presented. Depending on composition, the as-solidified samples were either 100 percent gamma-prime phase - in the form of fine antiphase domains (APD) - or a mixture of gamma-prime (APDs) and beta phases. Upon annealing, the as-solidified microstructures transform to either APD-free gamma-prime or mixtures of gamma and gamma-prime phases. For those compositions where the quenched microstructures were 100 percent gamma-prime it was observed that APD coarsening followed conventional grain-growth kinetics, but when gamma phase precipitated on the APD boundaries the rate constant changed abruptly while the time exponent remained unaffected. It was also found that alloys containing critical amounts of chromium and boron are susceptible to precipitation of the boride Cr5B3.

  2. Nb/sub 3/Al thin-film synthesis by electron-beam coevaporation

    SciTech Connect

    Kwo, J.; Hammond, R.H.; Geballe, T.H.

    1980-03-01

    Nb/sub 3/Al thin films have been prepared and characterized with varying deposition parameters, including substrate temperature, deposition rate, gas doping, and epitaxial growth. Nb-Al samples made with the optimum substrate temperature have lattice constants following the prediction of Geller radii and a systematic T/sub c/ increment with Al composition, namely, a ..delta..T/sub c//..delta..C of 1.9 K/at% Al. Employment of the self-epitaxial method results in extending the A15 phase boundary by 1 at% Al and an enhancement of T/sub c/ by 2.4 K at a given substrate temperature. By extrapolating from T/sub c/ =16.7 K, the highest transition temperature observed in this work, stoichiometric Nb/sub 3/Al is predicted to have an T/sub c/ onset of 20.7 K.

  3. Dislocation-nucleation-controlled deformation of Ni3Al nanocubes in molecular dynamics simulations

    NASA Astrophysics Data System (ADS)

    Shreiber, Koren; Mordehai, Dan

    2015-12-01

    The strength of Ni3Al nanocubes under compression, as well as the underlying dislocation mechanisms, are analysed in molecular dynamics simulations. For this purpose, the bond-order parameters analysis is extended to multi-atomic systems in order to identify the intrinsic planar defects in Ni3Al. We benchmarked different interatomic potentials and compared the results with experimental ones. The different potentials resulted in different elastic responses under compression but all yielded abruptly at a compressive stress of about 7-8 GPa, followed by a large strain burst. The nanocubes yielded by nucleating Shockley partial dislocations at the vertices on ≤ft\\{1 1 1\\right\\} planes, leaving a structure of faulted planes. The mechanical response was found to be size independent, which we attribute to the cubical shape of the nanoparticle and the lack of stress gradients at its vertices.

  4. Notch-tip deformation of Ni{sub 3}Al single crystals

    SciTech Connect

    Schulson, E.M.; Xu, Y.

    1997-12-31

    In a recent paper on the deformation of notched polycrystals of Ni-rich Ni{sub 3}Al doped with boron, the authors showed that the notch sensitivity of this material is related to the suppression of plastic flow by the triaxial state of tensile stress induced by the notch. Cracks initiate on crystallographic slip planes at the tip of the notch, where the stress and inelastic strain are concentrated, and then propagate once the degree of triaxialty exceeds a critical level. The tensile strength appears to be controlled by crack initiation. To explore further the notch sensitivity of boron-doped Ni{sub 3}Al the authors performed new experiments using notched single crystals. This paper summarizes their observations.

  5. Extended solubility and stability in vapor quenched Ni3Al-X intermetallics

    NASA Technical Reports Server (NTRS)

    Wang, Rong

    1989-01-01

    A series of fine-grain and amorphous Ni3Al-X alloys, where X is a solute of 1 to 45 at. pct hf, C, or Hf+C in continuously graded compositions, was formed simultaneously into a 0.2 mm-thick disk by high-rate sputter codeposition. The as-deposited Ni3Al-X alloys exhibited a disordered L1(2) structure and extended solid solubility limits beyond which amorphous phases were formed. Heat-treatment of the alloys at 900 C resulted in fine grain size of 0.5 micron to 1.5 microns. Ultra fine dispersoids less than 500 A in size were observed, and they seemed resistant to coarsening.

  6. Atomic structure and electronic properties of Ni3Al(111) and (011) surfaces

    NASA Astrophysics Data System (ADS)

    Jurczyszyn, L.; Krupski, A.; Degen, S.; Pieczyrak, B.; Kralj, M.; Becker, C.; Wandelt, K.

    2007-07-01

    We present results of theoretical studies of the structural and electronic properties of (111) and (011) surfaces of paramagnetic Ni3Al alloy. Atomic and electronic structures of these surfaces have been obtained from the density-functional calculations performed with the use of plane wave basis set. Our ab initio calculations show that for all considered surfaces, the topmost Al atoms are located above Ni atoms, and the structural parameters of relaxed surface systems well correspond to experimental data provided by earlier low-energy electron-diffraction measurements. The details of the calculated electronic structure of Ni3Al(111) in the vicinity of the Fermi level were compared with the results of scanning tunneling spectroscopy (STS) measurements which we have performed for this system, and a good agreement has been found between the calculated local-density-of-states distributions and the shape of obtained STS spectra.

  7. Bulk Properties of Ni3Al(gamma') With Cu and Au Additions

    NASA Technical Reports Server (NTRS)

    Bozzolo, Guillermo; Ferrante, John

    1995-01-01

    The BFS method for alloys is applied to the study of 200 alloys obtained from adding Cu and Au impurities to a Ni3Al matrix. We analyze the trends in the bulk properties of these alloys (heat of formation, lattice parameter, and bulk modulus) and detect specific alloy compositions for which these quantities have particular values. A detailed analysis of the atomic interactions that lead to the preferred ordering patterns is presented.

  8. Nanosynthesis routes to new tetrahedral crystalline solids: silicon-like Si3AlP.

    PubMed

    Watkins, Tylan; Chizmeshya, Andrew V G; Jiang, Liying; Smith, David J; Beeler, Richard T; Grzybowski, Gordon; Poweleit, Christian D; Menéndez, José; Kouvetakis, John

    2011-10-12

    We introduce a synthetic strategy to access functional semiconductors with general formula A(3)XY (A = IV, X-Y = III-V) representing a new class within the long-sought family of group IV/III-V hybrid compounds. The method is based on molecular precursors that combine purposely designed polar/nonpolar bonding at the nanoscale, potentially allowing precise engineering of structural and optical properties, including lattice dimensions and band structure. In this Article, we demonstrate the feasibility of the proposed strategy by growing a new monocrystalline AlPSi(3) phase on Si substrates via tailored interactions of P(SiH(3))(3) and Al atoms using gas source (GS) MBE. In this case, the high affinity of Al for the P ligands leads to Si(3)AlP bonding arrangements, which then confer their structure and composition to form the corresponding Si(3)AlP target solid via complete elimination of H(2) at ∼500 °C. First principle simulations at the molecular and solid-state level confirm that the Si(3)AlP building blocks can readily interlink with minimal distortion to produce diamond-like structures in which the P atoms are arranged on a common sublattice as third-nearest neighbors in a manner that excludes the formation of unfavorable Al-Al bonds. High-resolution XRD, XTEM, and RBS indicate that all films grown on Si(100) are tetragonally strained and fully coherent with the substrate and possess near-cubic symmetry. The Raman spectra are consistent with a growth mechanism that proceeds via full incorporation of preformed Si(3)AlP tetrahedra with residual orientational disorder. Collectively, the characterization data show that the structuro-chemical compatibility between the epilayer and substrate leads to flawless integration, as expected for pseudohomoepitaxy of an Si-like material grown on a bulk Si platform. PMID:21877711

  9. Development of ductile Fe{sub 3}Al-based aluminides

    SciTech Connect

    McKamey, C.G.; Sikka, V.K.; Goodwin, G.M.

    1993-07-01

    Iron aluminides based on Fe{sub 3}Al are of interest because of their excellent oxidation and corrosion resistance, especially in sulfur-bearing atmospheres. Work at ORNL has centered on developing Fe{sub 3}Al-based alloys with improved ambient temperature ductilities and increased strengths at temperatures of 600--700C. Ambient temperature brittleness in this system is not ``inherent,`` but is caused by atomic hydrogen which is produced by an environmental reaction between aluminum in the alloy and water vapor in the atmosphere. Great strides have been made in understanding this embrittlement Phenomenon, and the production of alloys with room temperature ductilities of over 10% and tensile yield strengths at 600C of as high as 500 MPa is now possible through modifications in alloy composition and control of thermomechanical processing techniques. Creep rupture lifes of over 200 h at 593C (1100{degrees}F) and 207 MPa (30 ksi) can also be produced through control of alloy composition and microstructure. This paper summarizes our present efforts to improve the tensile and creep rupture properties and gives the status of efforts to commercialize Fe{sub 3}Al-based alloy compositions.

  10. Interface characterization of fiber-reinforced Ni3Al matrix composites

    NASA Astrophysics Data System (ADS)

    Yang, J.-M.; Kao, W. H.; Liu, C. T.

    1989-11-01

    The interfacial reaction characteristics of SCS-6, Sigma, and B4C/B fibers with nickel aluminide (Ni3Al) matrix have been investigated between 780°C to 980°C for times ranging from 1 to 100 hours. The microstructure and elemental compositions across the reaction zone have been analyzed quantitatively using microscopy and electron probe microanalyses, respectively. The results show that Ni3Al reacts extensively with SCS-6, Sigma, and B4C/B fibers to form complex reaction products, and Ni is the dominant diffusing species controlling the extent of reaction. In the SiC/Ni3Al composite, the C-rich layer on the SiC surface can slow down but cannot stop the inward diffusion of Ni into SiC fiber. When the C-rich layer is depleted, a rapid increase in reaction zone thickness occurs. Diffusion barrier coating on the fibers is required to minimize the interfacial reactions.

  11. Practical design of Ni{sub 3}Al with high hot workability

    SciTech Connect

    Wang, Y.; Lin, D.; Zhang, Y.

    1997-12-31

    From the previous work, Ni{sub 3}Al polycrystals with combined addition of magnesium and silicon kept high values of compressive strain at rupture (CSR) when the strain rate rose. In order to further improve hot workability of Ni{sub 3}Al, 7.9 wt.% Cr was added. The compressive tests showed that 30%--40% CSR values of the alloy had been kept in a wide temperature range of 1,173 K--1373 K at strain rates of 10{sup {minus}2}sec{sup {minus}1} and 10{sup {minus}1}sec{sup {minus}1} in contrast with 15%--25% CSR values of the alloy without Cr addition. In practical hot rolling process, at initial deformation temperature of 1,373 K, strain rate of 1.0 sec{sup {minus}1} and by controlling reduction within 10--15% each rolling pass, Ni{sub 3}Al ingots were successfully hot-rolled into polycrystals with different deformations, the maximum of which was 55%. The deformed alloys had manifestly enhanced mechanical properties shown by tensile tests. The dislocation configurations of deformed alloys have been investigated by using transmission electron microscope (TEM).

  12. Mechanical and microstructural response of Ni sub 3 Al at high strain rate and elevated temperatures

    SciTech Connect

    Sizek, H.W.; Gray, G.T. III.

    1990-01-01

    In this paper, the effect of strain rate and temperature on the substructure evolution and mechanical response of Ni{sub 3}Al will be presented. The strain rate response of Ni{sub 3}Al was studied at strain rates from 10{sup {minus}3} s{sup {minus}1} (quasi-static) to 10{sup 4} s{sup {minus}1} using a Split Hopkinson Pressure Bar. The Hopkinson Bar tests were conducted at temperatures ranging from 77K to 1273K. At high strain rates the flow strength increased significantly with increasing temperature, similar to the behavior observed at quasi-static rates. The work hardening rates increased with strain rate and varied with temperatures. The work hardening rates, appeared to be significantly higher than those found for Ni270. The substructure evolution was characterized utilizing TEM. The defect generation and rate sensitivity of Ni{sub 3}Al are also discussed as a function of strain rate and temperature. 15 refs., 4 figs.

  13. Electrical characteristics of SrTiO3/Al2O3 laminated film capacitors

    NASA Astrophysics Data System (ADS)

    Peng, Yong; Yao, Manwen; Chen, Jianwen; Xu, Kaien; Yao, Xi

    2016-07-01

    The electrical characteristics of SrTiO3/Al2O3 (160 nm up/90 nm down) laminated film capacitors using the sol-gel process have been investigated. SrTiO3 is a promising and extensively studied high-K dielectric material, but its leakage current property is poor. SrTiO3/Al2O3 laminated films can effectively suppress the demerits of pure SrTiO3 films under low electric field, but the leakage current value reaches to 0.1 A/cm2 at higher electric field (>160 MV/m). In this study, a new approach was applied to reduce the leakage current and improve the dielectric strength of SrTiO3/Al2O3 laminated films. Compared to laminated films with Au top electrodes, dielectric strength of laminated films with Al top electrodes improves from 205 MV/m to 322 MV/m, simultaneously the leakage current maintains the same order of magnitude (10-4 A/cm2) until the breakdown occurs. The above electrical characteristics are attributed to the anodic oxidation reaction in origin, which can repair the defects of laminated films at higher electric field. The anodic oxidation reactions have been confirmed by the corresponding XPS measurement and the cross sectional HRTEM analysis. This work provides a new approach to fabricate dielectrics with high dielectric strength and low leakage current.

  14. Electronic structure investigation of the cubic inverse perovskite Sc3AlN

    NASA Astrophysics Data System (ADS)

    Magnuson, Martin; Mattesini, Maurizio; Höglund, Carina; Abrikosov, Igor A.; Birch, Jens; Hultman, Lars

    2008-12-01

    The electronic structure and chemical bonding of the recently discovered inverse perovskite Sc3AlN , in comparison to those of ScN and Sc metal, have been investigated by bulk-sensitive soft-x-ray emission spectroscopy. The measured ScL , NK , AlL1 , and AlL2,3 emission spectra are compared with calculated spectra using first-principles density-functional theory including dipole transition-matrix elements. The main Sc3d-N2p and Sc3d-Al3p chemical bond regions are identified at -4 and -1.4eV below the Fermi level, respectively. A strongly modified spectral shape of 3s states in the AlL2,3 emission from Sc3AlN in comparison to that for pure Al metal is found, which reflects the Sc3d-Al3p hybridization observed in the AlL1 emission. The differences between the electronic structures of Sc3AlN , ScN, and Sc metal are discussed in relation to the change in the conductivity and elastic properties.

  15. Electronic structures, elastic properties, and minimum thermal conductivities of cermet M{sub 3}AlN

    SciTech Connect

    Wang, Jin; Chen, ZhiQian; Li, ChunMei; Li, Feng; Nie, ChaoYin

    2014-08-15

    The electronic structures and elastic anisotropies of cubic Ti{sub 3}AlN, Zr{sub 3}AlN, and Hf{sub 3}AlN are investigated by pseudopotential plane-wave method based on density functional theory. At the Fermi level, the electronic structures of these compounds are successive with no energy gap between conduct and valence bands, and exhibit metallicity in ground states. In valence band of each partial density of states, the different orbital electrons indicate interaction of corresponding atoms. In addition, the anisotropy of Hf{sub 3}AlN is found to be significantly different from that of Ti{sub 3}AlN and Zr{sub 3}AlN, which involve the differences in the bonding strength. It is notable that Hf{sub 3}AlN is a desired thermal barrier material with the lowest thermal conductivity at high temperature among the three compounds. - Graphical abstract: 1.Young's moduli of anti-perovskite Ti{sub 3}AlN, Zr{sub 3}AlN, and Hf{sub 3}AlN in full space. 2.Electron density differences on crystal planes (1 0 0), (2 0 0), and (1 1 0) of anti-perovskite Zr{sub 3}AlN. - Highlights: • We calculated three anti-perovskite cermets with first-principles theory. • We illustrated 3D Young modulus and found the anomalous anisotropy. • We explained the anomaly and calculated the minimum thermal conductivities.

  16. Gas cylinder release rate testing and analysis

    NASA Astrophysics Data System (ADS)

    Despres, Joseph; Sweeney, Joseph; Yedave, Sharad; Chambers, Barry

    2012-11-01

    There are varying cylinder technologies employed for the storage of gases, each resulting in a potentially different hazard level to the surroundings in the event of a gas release. Subatmospheric Gas delivery Systems Type I (SAGS I) store and deliver gases subatmospherically, while Subatmospheric Gas delivery Systems Type II (SAGS II) deliver gases subatmospherically, but store them at high pressure. Standard high pressure gas cylinders store and deliver their contents at high pressure. Due to the differences in these cylinder technologies, release rates in the event of a leak or internal component failure, can vary significantly. This paper details the experimental and theoretical results of different Arsine (AsH3) gas cylinder release scenarios. For the SAGS II experimental analysis, Fourier Transform Infrared Spectroscopy (FTIR) was used to determine the spatial concentration profiles when a surrogate gas, CF4, was released via a simulated leak within an ion implanter. Various SAGS I and SAGS II cylinder types and failure modes were tested. Additionally, theoretical analysis was performed to support an understanding of the different potential AsH3 leak rates. The results of this work show that the effects of a leak from the various cylinder types can be quite different, with the concentrations resulting from cylinders containing high pressure gas often being in excess of IDLH levels.

  17. Spanwise plumes in wakes behind heated cylinder

    NASA Astrophysics Data System (ADS)

    Kumar, S. Ajith; Lal, S. Anil; Sameen, A.

    2013-11-01

    3D wake transition in flow past cylinder is interesting theoretically and industrially. A three dimensional Finite volume computation has been performed on an incompressible flow past heated cylinder to understand the wake behavior behind the cylinder, under the Boussinesq assumption. We study the heat transfer characteristics and the coherent structures behind the cylinder at different Prandtl numbers. In forced convection, the 3D transition occurs above Reynolds number, Re = 180-190 (Re is based on the cylinder diameter). However, the present 3D computational analyses show that in mixed convection, the so called ``mode-E'' instability (3D transition of wake behind the cylinder caused by the heating of the cylinder) happens at a much lower Reynolds number. The co-existence of mushroom like coherent structures called the plumes along with the shed vortices is observed for a range of heating conditions. These plumes originates from the core of the upper vortex rows at a definite span wise wavelengths. The dependence of Prandtl number on the span wise wavenumber of these plumes is also analyzed.

  18. Apparel Manufacture

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Marshall Space Flight Center teamed with the University of Alabama in Huntsville (UAH) in 1989 on a program involving development of advanced simulation software. Concurrently, the State of Alabama chartered UAH to conduct a technology advancement program in support of the state's apparel manufacturers. In 1992, under contract to Marshall, UAH developed an apparel-specific software package that allows manufacturers to design and analyze modules without making an actual investment -- it functions on ordinary PC equipment. By 1995, Marshall had responded to requests for the package from more than 400 companies in 36 states; some of which reported savings up to $2 million. The National Garment Company of Missouri, for example, uses the system to design and balance a modular line before committing to expensive hardware; for setting up sewing lines; and for determining the composition of a new team.

  19. Manufacturing technology

    SciTech Connect

    Leonard, J.A.; Floyd, H.L.; Goetsch, B.; Doran, L.

    1993-08-01

    This bulletin depicts current research on manufacturing technology at Sandia laboratories. An automated, adaptive process removes grit overspray from jet engine turbine blades. Advanced electronic ceramics are chemically prepared from solution for use in high- voltage varistors. Selective laser sintering automates wax casting pattern fabrication. Numerical modeling improves performance of photoresist stripper (simulation on Cray supercomputer reveals path to uniform plasma). And mathematical models help make dream of low- cost ceramic composites come true.

  20. Green Manufacturing

    SciTech Connect

    Patten, John

    2013-12-31

    Green Manufacturing Initiative (GMI): The initiative provides a conduit between the university and industry to facilitate cooperative research programs of mutual interest to support green (sustainable) goals and efforts. In addition to the operational savings that greener practices can bring, emerging market demands and governmental regulations are making the move to sustainable manufacturing a necessity for success. The funding supports collaborative activities among universities such as the University of Michigan, Michigan State University and Purdue University and among 40 companies to enhance economic and workforce development and provide the potential of technology transfer. WMU participants in the GMI activities included 20 faculty, over 25 students and many staff from across the College of Engineering and Applied Sciences; the College of Arts and Sciences' departments of Chemistry, Physics, Biology and Geology; the College of Business; the Environmental Research Institute; and the Environmental Studies Program. Many outside organizations also contribute to the GMI's success, including Southwest Michigan First; The Right Place of Grand Rapids, MI; Michigan Department of Environmental Quality; the Michigan Department of Energy, Labor and Economic Growth; and the Michigan Manufacturers Technical Center.

  1. MONOMIALS AND BASIN CYLINDERS FOR NETWORK DYNAMICS

    PubMed Central

    AUSTIN, DANIEL; DINWOODIE, IAN H

    2014-01-01

    We describe methods to identify cylinder sets inside a basin of attraction for Boolean dynamics of biological networks. Such sets are used for designing regulatory interventions that make the system evolve towards a chosen attractor, for example initiating apoptosis in a cancer cell. We describe two algebraic methods for identifying cylinders inside a basin of attraction, one based on the Groebner fan that finds monomials that define cylinders and the other on primary decomposition. Both methods are applied to current examples of gene networks. PMID:25620893

  2. Surface topography characterization of automotive cylinder liner surfaces using fractal methods

    NASA Astrophysics Data System (ADS)

    Lawrence K, Deepak; Ramamoorthy, B.

    2013-09-01

    This paper explores the use of fractal approaches for the possible characterization of automotive cylinder bore surface topography by employing methods such as differential box counting method, power spectral method and structure function method. Three stage plateau honing experiments were conducted to manufacture sixteen cylinder liner surfaces with different surface topographies, for the study. The three fractal methods are applied on the image data obtained using a computer vision system and 3-D profile data obtained using vertical scanning white light interferometer from the cylinder liner surfaces. The computed fractal parameters (fractal dimension and topothesy) are compared and correlated with the measured 3-D Abbott-Firestone curve parameters (Sk, Spk, Svk, Sr1 and Sr2) that are currently used for the surface topography characterization cylinder liner surfaces. The analyses of the results indicated that the fractal dimension (D) computed using the vision data as well as 3-D profile data by employing three different fractal methods consistantly showed a negative correlation with the functional surface topographical parameters that represents roughness at peak (Spk),core (Sk) and valley (Svk) regions and positive correlation with the upper bearing area (Sr1) and lower bearing area (Sr2) of the automotive of cylinder bore surface.

  3. 39. THREECYLINDER HYDRAULIC OIL PUMP (MANUFACTURED BY WORTHINGTON: PUMP AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    39. THREE-CYLINDER HYDRAULIC OIL PUMP (MANUFACTURED BY WORTHINGTON: PUMP AND MACHINERY COMPANY, HOLYOKE MASSACHUSETTS) IN MACHINERY CHAMBER FOR SLUICE GATE WORKS ON GALLERY 1. NOTE OIL TANK ABOVE PUMP MOTOR. VIEW TO NORTHWEST. - Owyhee Dam, Across Owyhee River, Nyssa, Malheur County, OR

  4. Boron-modified Ni3Al intermetallic compound formed by spark plasma sintering of mechanically activated Ni and Al powders

    NASA Astrophysics Data System (ADS)

    Shevtsova, L. I.; Ogneva, T. S.; Mul, D. O.; Esikov, M. A.; Larichkin, A. Yu; Malikov, V. N.

    2016-04-01

    A Ni3Al intermetallic compound was obtained by spark plasma sintering of mechanically activated Ni and Al powders in atomic ratio 3:1 respectively. Samples with boron addition of 0.1 and 0.2% (wt.) and samples without boron were obtained. The maximum value of the relative density (~99 %) has been obtained for the material by sintering of mechanically activated mixture powders modified with 0.1% of boron. No differences have been found between the structure of boron-modified Ni3Al and Ni3Al without boron addition. The maximum level of bending strength (2200 MPa) has been achieved for Ni3Al with 0.1% (wt.) of boron. This value is almost 3 times the bending strength of the sample of Ni3Al sintered without boron addition.

  5. 30 CFR 75.1106-6 - Exemption of small low pressure gas cylinders containing nonflammable or nonexplosive gas mixtures.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... STANDARDS-UNDERGROUND COAL MINES Fire Protection § 75.1106-6 Exemption of small low pressure gas cylinders... from a pressure which does not exceed 250 p.s.i.g., and which is manufactured and sold in conformance... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Exemption of small low pressure gas...

  6. 30 CFR 75.1106-6 - Exemption of small low pressure gas cylinders containing nonflammable or nonexplosive gas mixtures.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... STANDARDS-UNDERGROUND COAL MINES Fire Protection § 75.1106-6 Exemption of small low pressure gas cylinders... from a pressure which does not exceed 250 p.s.i.g., and which is manufactured and sold in conformance... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Exemption of small low pressure gas...

  7. 30 CFR 75.1106-6 - Exemption of small low pressure gas cylinders containing nonflammable or nonexplosive gas mixtures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... STANDARDS-UNDERGROUND COAL MINES Fire Protection § 75.1106-6 Exemption of small low pressure gas cylinders... from a pressure which does not exceed 250 p.s.i.g., and which is manufactured and sold in conformance... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Exemption of small low pressure gas...

  8. 30 CFR 75.1106-6 - Exemption of small low pressure gas cylinders containing nonflammable or nonexplosive gas mixtures.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... STANDARDS-UNDERGROUND COAL MINES Fire Protection § 75.1106-6 Exemption of small low pressure gas cylinders... from a pressure which does not exceed 250 p.s.i.g., and which is manufactured and sold in conformance... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Exemption of small low pressure gas...

  9. 30 CFR 75.1106-6 - Exemption of small low pressure gas cylinders containing nonflammable or nonexplosive gas mixtures.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... STANDARDS-UNDERGROUND COAL MINES Fire Protection § 75.1106-6 Exemption of small low pressure gas cylinders... from a pressure which does not exceed 250 p.s.i.g., and which is manufactured and sold in conformance... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Exemption of small low pressure gas...

  10. Theory of interacting dislocations on cylinders

    NASA Astrophysics Data System (ADS)

    Amir, Ariel; Paulose, Jayson; Nelson, David R.

    2013-04-01

    We study the mechanics and statistical physics of dislocations interacting on cylinders, motivated by the elongation of rod-shaped bacterial cell walls and cylindrical assemblies of colloidal particles subject to external stresses. The interaction energy and forces between dislocations are solved analytically, and analyzed asymptotically. The results of continuum elastic theory agree well with numerical simulations on finite lattices even for relatively small systems. Isolated dislocations on a cylinder act like grain boundaries. With colloidal crystals in mind, we show that saddle points are created by a Peach-Koehler force on the dislocations in the circumferential direction, causing dislocation pairs to unbind. The thermal nucleation rate of dislocation unbinding is calculated, for an arbitrary mobility tensor and external stress, including the case of a twist-induced Peach-Koehler force along the cylinder axis. Surprisingly rich phenomena arise for dislocations on cylinders, despite their vanishing Gaussian curvature.

  11. Multi-cylinder hot gas engine

    DOEpatents

    Corey, John A.

    1985-01-01

    A multi-cylinder hot gas engine having an equal angle, V-shaped engine block in which two banks of parallel, equal length, equally sized cylinders are formed together with annular regenerator/cooler units surrounding each cylinder, and wherein the pistons are connected to a single crankshaft. The hot gas engine further includes an annular heater head disposed around a central circular combustor volume having a new balanced-flow hot-working-fluid manifold assembly that provides optimum balanced flow of the working fluid through the heater head working fluid passageways which are connected between each of the cylinders and their respective associated annular regenerator units. This balanced flow provides even heater head temperatures and, therefore, maximum average working fluid temperature for best operating efficiency with the use of a single crankshaft V-shaped engine block.

  12. Surface modifications of pistons and cylinder liners

    SciTech Connect

    Suzuki, Y. )

    1988-01-01

    With higher brake mean effective pressure (BMEP) of a diesel engine, pistons and cylinder liners suffer from increasing mechanical and thermal loading which causes several problems on these engine parts. The main critical problems are thermally induced cracking on the piston head and scuffing on the cylinder bore. Hard anodizing the piston head is described. It is currently the most effective countermeasure against heat cracking. Another promising method, to reinforce the piston head by means of SiC-whiskers, is also reported. A new process for improving the surface lubrication of the cylinder liner was developed. The bore has numerous finely distributed micropits which act as good oil reservoir. This improves the antiscuffing property of the cylinder liner.

  13. Hydroelastic wave diffraction by a vertical cylinder.

    PubMed

    Brocklehurst, Paul; Korobkin, Alexander; Părău, Emilian I

    2011-07-28

    A linear three-dimensional problem of hydroelastic wave diffraction by a bottom-mounted circular cylinder is analysed. The fluid is of finite depth and is covered by an ice sheet, which is clamped to the cylinder surface. The ice stretches from the cylinder to infinity in all lateral directions. The hydroelastic behaviour of the ice sheet is described by linear elastic plate theory, and the fluid flow by a potential flow model. The two-dimensional incident wave is regular and has small amplitude. An analytical solution of the coupled problem of hydroelasticity is found by using a Weber transform. We determine the ice deflection and the vertical and horizontal forces acting on the cylinder and analyse the strain in the ice sheet caused by the incident wave. PMID:21690136

  14. Experimental Investigations of Flow past Spinning Cylinders

    NASA Astrophysics Data System (ADS)

    Carlucci, Pasquale; Buckley, Liam; Mehmedagic, Igbal; Carlucci, Donald; Thangam, Siva

    2015-11-01

    Experimental investigations of flow past spinning cylinders is presented in the context of their application and relevance to flow past projectiles. A subsonic wind tunnel is used to perform experiments on flow past spinning cylinders that are sting-mounted and oriented such that their axis of rotation is aligned with the mean flow. The experiments cover a Reynolds number range of up to 300000 and rotation numbers of up to 2 (based on cylinder diameter). The experimental validation of the tunnel characteristics and the benchmarking of the flow field in the tunnel are described. The experimental results for spinning cylinders with both rear-mounted and fore-mounted stings are presented along with available computational and experimental findings. This work was funded in part by U. S. Army ARDEC.

  15. Investigations of Flow past Spinning Cylinders

    NASA Astrophysics Data System (ADS)

    Mehmedagic, Igbal; Carlucci, Pasquale; Buckley, Liam; Carlucci, Donald; Aljallis, Elias; Thangam, Siva

    2013-11-01

    A subsonic wind tunnel is used to perform experiments on flow past spinning cylinders. The blunt cylinders are sting-mounted and oriented such that their axis of rotation is aligned with the mean flow. The experiments cover a Reynolds number range of up to 300000 and rotation numbers of up to 1.2 (based on cylinder diameter). The results for spinning cylinders with both rear-mounted and fore-mounted stings are presented. Computations are performed using a two-equation anisotropic turbulence model that is based on proper representation of the energy spectrum to capture rotation and curvature. The model performance is validated with benchmark experimental flows and implemented for analyzing the flow configuration used in the experimental study. Funded in part by U. S. Army, ARDEC.

  16. Manufacturing technology

    SciTech Connect

    Blaedel, K L

    1998-01-01

    The mission of the Manufacturing Technology thrust area at Lawrence Livermore National Laboratory (LLNL) has been to have an adequate base of manufacturing technology, not necessarily resident at LLNL, to conduct their future business. The specific goals were (1) to develop an understanding of fundamental fabrication processes; (2) to construct general purpose process models that have wide applicability; (3) to document their findings and models in journals; (4) to transfer technology to LLNL programs, industry, and colleagues; and (5) to develop continuing relationships with the industrial and academic communities to advance their collective understanding of fabrication processes. In support of this mission, two projects were reported here, each of which explores a way to bring higher precision to the manufacturing challenges that we face over the next few years. The first, ''A Spatial-Frequency-Domain Approach to Designing a Precision Machine Tools,'' is an overall view of how they design machine tools and instruments to make or measure workpieces that are specified in terms of the spatial frequency content of the residual errors of the workpiece surface. This represents an improvement of an ''error budget,'' a design tool that saw significant development in the early 1980's, and has been in active use since then. The second project, ''Micro-Drilling of ICF Capsules,'' is an attempt to define the current state in commercial industry for drilling small holes, particularly laser-drilling. The report concludes that 1-{micro}m diameter holes cannot currently be drilled to high aspect ratios, and then defines the engineering challenges that will have to be overcome to machine holes small enough for NIF capsules.

  17. Design and operation of an aluminium alloy tank using doped Na3AlH6 in kg scale for hydrogen storage

    NASA Astrophysics Data System (ADS)

    Urbanczyk, R.; Peinecke, K.; Meggouh, M.; Minne, P.; Peil, S.; Bathen, D.; Felderhoff, M.

    2016-08-01

    In this publication the authors present an aluminium alloy tank for hydrogen storage using 1921 g of Na3AlH6 doped with 4 mol% of TiCl3 and 8 mol% of activated carbon. The tank and the heat exchangers are manufactured by extrusion moulding of Al-Mg-Si based alloys. EN AW 6082 T6 alloy is used for the tank and a specifically developed alloy with a composition similar to EN AW 6060 T6 is used for the heat exchangers. The three heat exchangers have a corrugated profile to enhance the surface area for heat transfer. The doped complex hydride Na3AlH6 is densified to a powder density of 0.62 g cm-3. The hydrogenation experiments are carried out at 2.5 MPa. During one of the dehydrogenation experiments approximately 38 g of hydrogen is released, accounting for gravimetric hydrogen density of 2.0 mass-%. With this tank 15 hydrogenation and 16 dehydrogenation tests are carried out.

  18. Characteristics of Cu stabilized Nb3Al strands with low Cu ratio

    SciTech Connect

    Kikuchi, A.; Yamada, R.; Barzi, E.; Kobayashi, M.; Lamm, M.; Nakagawa, K.; Sasaki, K.; Takeuchi, T.; Turrioni, D.; Zlobin, A.V.; /NIMC, Tsukuba /Fermilab /Hitachi, Tsuchiura Works /KEK, Tsukuba

    2008-12-01

    Characteristics of recently developed F4-Nb{sub 3}Al strand with low Cu ratio are described. The overall J{sub c} of the Nb{sub 3}Al strand could be easily increased by decreasing of the Cu ratio. Although the quench of a pulse-like voltage generation is usually observed in superconducting unstable conductor, the F4 strand with a low Cu ratio of 0.61 exhibited an ordinary critical transition of gradual voltage generation. The F4 strand does not have magnetic instabilities at 4.2 K because of the tantalum interfilament matrix. The overall J{sub c} of the F4 strand achieved was 80-85% of the RRP strand. In the large mechanical stress above 100 MPa, the overall J{sub c} of the F4 strand might be comparable to that of high J{sub c} RRP-Nb{sub 3}Sn strands. The Rutherford cable with a high packing factor of 86.5% has been fabricated using F4 strands. The small racetrack magnet, SR07, was also fabricated by a 14 m F4 cable. The quench current, I{sub q}, of SR07 were obtained 22.4 kA at 4.5 K and 25.2 kA at 2.2 K. The tantalum matrix Nb{sub 3}Al strands are promising for the application of super-cooled high-field magnets as well as 4.2 K operation magnets.

  19. Luminescence of Y3Al5O12:Eu3+ nanophosphors in blood and organic media

    NASA Astrophysics Data System (ADS)

    Kolesnikov, I. E.; Povolotskiy, A. V.; Tolstikova, D. V.; Manshina, A. A.; Mikhailov, M. D.

    2015-02-01

    Lanthanide-doped nanoparticles characterized by their large Stokes’ shifts, narrow emission bands, long lifetimes and high photostability are promising candidates for luminescent labels in biological research. That is why investigation of lanthanide-doped nanoparticles’ fluorescence in complex biological media (like blood and Intralipid) is of great importance from the standpoint of applicability in medicine and biology. Nanopowder of yttrium aluminum garnet doped with Eu3+ was synthesized by the Pechini method. X-ray diffraction data demonstrated formation of cubic crystalline phase without any impurities. The synthesized sample was found to be well-defined 20-50 nm nanoparticles agglomerated to clusters no bigger than 200 nm in diameter. The emission spectrum of nanocrystalline powder consists of characteristic narrow lines attributed to 5D0-7FJ transitions. It was found that the long lifetime of 5D0 level (4.13 ms) allows using time-resolved techniques to eliminate fluorescence of the biological background. The possibility of the luminescence signal detection of Y3Al5O12:Eu3+ nanopowder (0.14 mg per 1 ml) against the background of blood auto-luminescence was demonstrated. Y3Al5O12:Eu3+ phosphors luminescence in blood media showed timing stability whereas fluorescein luminescence dropped down by a factor of 3 after 20 min. It was found that the luminescence signal of Y3Al5O12:Eu3+ phosphors could be detected through 5 mm of biological tissue. The possibility of independent registration of nanopowders doped with different REI-ions (Eu3+ and Nd3+) was investigated.

  20. Multiple Cylinder Free-Piston Stirling Machinery

    NASA Astrophysics Data System (ADS)

    Berchowitz, David M.; Kwon, Yong-Rak

    In order to improve the specific power of piston-cylinder type machinery, there is a point in capacity or power where an advantage accrues with increasing number of piston-cylinder assemblies. In the case of Stirling machinery where primary energy is transferred across the casing wall of the machine, this consideration is even more important. This is due primarily to the difference in scaling of basic power and the required heat transfer. Heat transfer is found to be progressively limited as the size of the machine increases. Multiple cylinder machines tend to preserve the surface area to volume ratio at more favorable levels. In addition, the spring effect of the working gas in the so-called alpha configuration is often sufficient to provide a high frequency resonance point that improves the specific power. There are a number of possible multiple cylinder configurations. The simplest is an opposed pair of piston-displacer machines (beta configuration). A three-cylinder machine requires stepped pistons to obtain proper volume phase relationships. Four to six cylinder configurations are also possible. A small demonstrator inline four cylinder alpha machine has been built to demonstrate both cooling operation and power generation. Data from this machine verifies theoretical expectations and is used to extrapolate the performance of future machines. Vibration levels are discussed and it is argued that some multiple cylinder machines have no linear component to the casing vibration but may have a nutating couple. Example applications are discussed ranging from general purpose coolers, computer cooling, exhaust heat power extraction and some high power engines.

  1. Dynamic Fracture Simulations of Explosively Loaded Cylinders

    SciTech Connect

    Arthur, Carly W.; Goto, D. M.

    2015-11-30

    This report documents the modeling results of high explosive experiments investigating dynamic fracture of steel (AerMet® 100 alloy) cylinders. The experiments were conducted at Lawrence Livermore National Laboratory (LLNL) during 2007 to 2008 [10]. A principal objective of this study was to gain an understanding of dynamic material failure through the analysis of hydrodynamic computer code simulations. Two-dimensional and three-dimensional computational cylinder models were analyzed using the ALE3D multi-physics computer code.

  2. Cylinder Fragmentation Using Gas Gun Techniques

    NASA Astrophysics Data System (ADS)

    Thornhill, T. F.; Reinhart, W. D.; Chhabildas, L. C.; Grady, D. E.; Wilson, L. T.

    2002-07-01

    In this study an experimental technique for study of cylinder fracture fragmentation characteristics has been developed on a two-stage light gas gun. This test method allows the study of cylinder fracture fragmentation in a laboratory environment under well-controlled loading conditions. Application of this technique allows measure of failure strain, strain rates, expansion velocity, and fragmentation toughness. Results of several experiments on Aermet steel are presented.

  3. W-76 PBX 9501 cylinder tests

    SciTech Connect

    Hill, L.G.; Catanach, R.A.

    1998-07-01

    Five 1-inch diameter cylinder tests were fired in support of the W-76 high explosive surveillance program. Three of the tests used baseline material, and two used stockpile return material. The diagnostics were electrical pins to measure detonation velocity and a streak camera to measure wall motion. The data was analyzed for cylinder energy, Gurney energy, and detonation velocity. The results of all three measures were consistent for all five tests, to within the experimental accuracy.

  4. Anomalous temperature dependence of flow stress in a Fe{sub 3}Al alloy

    SciTech Connect

    Song, J.H.; Ha, T.K.; Chang, Y.W.

    2000-01-01

    Iron aluminides have attracted much interest since 1930s when the excellent corrosion resistance was noted in alloys with the composition of more than about 18 at.% Al. These alloys have relatively low material cost, due to the reduced usage of strategic elements like Cr, Mo and Ni, and a lower density than stainless steels. Their tensile strength is also comparable to those of ferritic and austenitic steels. These advantages have led the iron aluminide alloys being considered for many applications in industries needing sulfidation and oxidation resistance (1). However, the poor ductility at ambient temperatures and an abrupt drop in strength above 600 C have limited these alloys for structural applications. In the past years, extensive efforts have been devoted to understanding and improving the metallurgical properties of iron aluminides with the aim of producing more strong, ductile, and corrosion-resistant materials for structural applications. These studies have resulted in significant contributions to the understanding of the fabrication and mechanical properties of iron aluminides. Deformation behavior in iron aluminides is now known to depend on composition, temperature, and the presence or absence of ordered structures. Recent studies have demonstrated that improved engineering ductility of 10--15% can be achieved in wrought Fe{sub 3}Al-based iron aluminide alloys, through the control of composition and microstructure. The effect of strain rate on the deformation behavior of Fe{sub 3}Al alloys, especially on the anomalous temperature dependence of strength is of interest recently and more systematic investigation is now necessitated. Load relaxation test has been generally regarded as a very effective technique to measure the strain rate sensitivity over a wider range of strain rates with very little microstructural changes and has been applied to the plasticity of various rate-sensitive materials. In the present study, the iron aluminide alloys with 27

  5. Incommensurate Magnetic Structure in the Cubic Noncentrosymmetric Ternary Compound Pr5Ru3Al2

    NASA Astrophysics Data System (ADS)

    Makino, Koya; Okuyama, Daisuke; Avdeev, Maxim; Sato, Taku J.

    2016-07-01

    Magnetic susceptibility and neutron powder diffraction experiments have been performed on the noncentrosymmetric ternary compound Pr5Ru3Al2. The previously reported ferromagnetic transition at 24 K was not detected in our improved-quality samples. Instead, magnetic ordering was observed in the DC magnetic susceptibility at T{c} ≃ 3.8 K. The neutron powder diffraction experiment further indicates that an incommensurate magnetic structure is established below Tc with the magnetic modulation vector {{q}} ≃ (0.066,0.066,0.066) (r.l.u.). A candidate for the magnetic structure is proposed using representation analysis.

  6. Ho:Tm:Lu(3)Al(5)O(12) As An Infrared-Laser Material

    NASA Technical Reports Server (NTRS)

    Barnes, Norman P.; Morrison, Clyde A.; Filer, Elizabeth D.

    1995-01-01

    Material selected on basis of quantum-mechanical modeling of lasing properties. Ho:Tm:Lu(3)Al(5)O(12) features relatively low thermal occupation of lower laser level because this level higher than corresponding levels of most other available laser materials. In addition, it has reasonably large effective cross section for stimulated emission because of contribution of several transitions around central strong transition. Yet another desirable property is its calculated rate of upconversion is lower than those of other laser materials. Inasmuch as upconversion detracts from efficiency of laser, this lower rate of upconversion is highly desirable.

  7. An explanation of the small strain-rate sensitivity of Ni{sub 3}Al

    SciTech Connect

    Sun, Y.Q.

    1997-12-31

    Based on the superkink model, an explanation is given in this paper for the small strain-rate sensitivity of the anomalous yield stress of Ni{sub 3}Al. The yield stress is proposed to be the stress needed to destabilize the average superkinks and it varies inversely with superkink height. The yield stress is insensitive to the strain-rate because the superkink height is controlled by the rate at which the superkink widens and is not directly related with the superkink propagation speed.

  8. Dynamic polarizability tensor for circular cylinders

    NASA Astrophysics Data System (ADS)

    Strickland, Diana; Ayón, Arturo; Alù, Andrea

    2015-02-01

    Based on Mie scattering theory, we derive the complete dynamic polarizability tensor for circular, azimuthally symmetric cylinders excited by an arbitrary field distribution, and provide compact expressions for all of its elements. Our results comprise fully dynamic cylinder polarizabilities, improving existing approximate models that use averaged electric or magnetic current lines to describe the scattering response of moderately thin cylinders. We show that the derived polarizability tensor satisfies reciprocity and passivity relations, and analyze its response under different conditions, varying the excitation angle, material properties, and cylinder radius. Interestingly, magnetoelectric effects are shown to arise at oblique incidence, even in the case of centrosymmetric achiral thin cylinders, associated with a weak form of spatial dispersion. This finding is particularly relevant for the proper modeling of individual cylinders and arrays of them, as in the case of metamaterials. We expect this work to find applications in antenna and metamaterial design, and to improve the physical understanding of the wave interaction and spatial dispersion in artificial materials composed of elongated inclusions such as wire media.

  9. Impedance of curved rectangular spiral coils around a conductive cylinder

    NASA Astrophysics Data System (ADS)

    Burke, S. K.; Ditchburn, R. J.; Theodoulidis, T. P.

    2008-07-01

    Eddy-current induction due to a thin conformable coil wrapped around a long conductive cylinder is examined using a second-order vector potential formalism. Compact closed-form expressions are derived for the self- and mutual impedances of curved rectangular spiral coils (i) in free space and (ii) when wrapped around the surface of the cylindrical rod. The validity of these expressions was tested against the results of a systematic series of experiments using a cylindrical Al-alloy rod and conformable coils manufactured using flexible printed-circuit-board technology. The theoretical expressions were in very good agreement with the experimental measurements. The significance of the results for eddy-current nondestructive inspection using flexible coils and flexible coil arrays is discussed.

  10. Ordered omega derivatives in (Zr{sub 3}Al)-Nb alloys

    SciTech Connect

    Tewari, R.; Dey, G.K.; Mukhopadhyay, P.; Banerjee, S.; Bendersky, L.A.

    1998-12-31

    Various kinds of phase transformation, viz., spinodal decomposition, omega transformation, precipitation reactions and martensitic transformation can be induced in ternary (Zr{sub 3}Al)-Nb alloys in conditions far removed from equilibrium. Transformation sequences in alloys containing 3% niobium are described and rationalized in terms of some basic tendencies such as phase separation and chemical ordering in the {beta} (bcc) phase and displacive omega and {beta} to {alpha} (hcp) transformations. Microstructures of rapidly solidified alloy showed a distribution of cuboidal (D8{sub 8} phase) particles in the {beta} matrix. The periodic arrangement of these particles along the <100>{sub {beta}} directions was indicative of a spinodal transformation which preceded their formation. The {beta} {r_arrow} D8{sub 8} transformation could be accomplished by the superimposition of three processes, namely, chemical ordering, lattice collapse akin to {omega} transformation and vacancy ordering. During isothermal aging the D8{sub 8} phase transformed into the B8{sub 2} phase. The observed lattice correspondence and transformation morphology suggested that the D8{sub 8} to B8{sub 2} structural change involved the replacement of structural vacancies in the former by zirconium atoms without any reconstitution of the lattice. The evolution of the equilibrium Zr{sub 3}Al (L1{sub 2} structure) phase during prolonged aging were also studied.

  11. Atomistic process of dislocation cross-slip in Ni{sub 3}Al

    SciTech Connect

    Wen, M.; Lin, D.

    1997-02-01

    In recent years, a great deal of interest has been given to the L1{sub 2} ordered intermetallic compound Ni{sub 3}Al because of its unusual flow behaviors. Based upon the measurements of mechanical properties and the observed dislocation configurations, several models have been proposed to explain the flow stress anomaly, including the anomalous increase of flow stress with temperature, the strain rate sensitivity, the pronounced orientation dependence and the tension/compression asymmetry. The most important common ground of these models is that the flow stress anomaly is the result of cross-slip of <110> superdislocations form {l_brace}111{r_brace} to {l_brace}100{r_brace} planes, forming so-called Kear-Wilsdorf (KW) locks. Computer simulations of superdislocation core structure in Ni{sub 3}Al indicate that the immobility of KW locks is due to the non-planar core structure of 1/2<110> superpartials which always spread their cores onto {l_brace}110{r_brace} planes other than the {l_brace}100{r_brace} antiphase boundary (APB) planes. However, up to now the authors are still unaware of how the cross-slip takes place. The purpose of the present study is to reveal the atomistic process of the cross-slip of 1/2<110> superpartials from {l_brace}111{r_brace} to {l_brace}100{r_brace} planes in L1{sub 2} ordered materials.

  12. Microstructure and tensile properties of Fe3Al produced by combustion synthesis/hot isostatic pressing

    NASA Astrophysics Data System (ADS)

    Rabin, B. H.; Wright, R. N.

    1992-01-01

    Combustion synthesis was carried out in a hot isostatic press (HIP) in order to prepare near-theoretical density Fe3Al and Fe3Al + Cr alloys from elemental powder mixtures. The microstructures and room-temperature tensile properties of these materials were studied in the as-synthesized condition and after heat treatment. As-synthesized materials exhibit a fine, equiaxed grain structure with grain sizes typically less than 10 μm. Yield and ultimate tensile strengths were found to be significantly higher than what has been reported for conventionally processed materials having similar composition. Although lower ductility was generally observed, elongations exceeding 5 pct were obtained in heat-treated Cr-containing alloys. Fracture occurred predominantly by transgranular cleavage. The strengthening of these materials is attributed to the fine grain size resulting from combustion synthesis/HIP processing. Transmission electron microscopy (TEM) revealed the presence of two distinct populations of aluminum oxide particles in the material. Nanometer-sized oxides exist within grains that likely formed at prior iron particle boundaries, and a high density of larger oxides exist along grain boundaries that probably originated from surface oxides on the aluminum powder. The presence of the grain boundary oxides was qualitatively observed to provide resistance to grain growth.

  13. Microstructure and mechanical properties of Ni sub 3 Al-based alloys reinforced with particulates

    SciTech Connect

    McKamey, C.G.; Carmichael, C.A.

    1990-01-01

    Hot-extrusion was used to produce Ni{sub 3}Al-based alloys to which 10 vol % TiN, NbC, HfO{sub 2}, or HfN was added for reinforcement. The TiN, NbC, and HfO{sub 2} particulates produced Ni{sub 3}Al-matrix composites in which no reaction was noted at the particle-matrix interface. However, the addition of HfN resulted in extensive reaction in which the hafnium appeared to diffuse into the matrix. Microstructures of this alloy showed a complex array of phases and voids where the HfN particles are presumed to have been originally. Hot hardness, compression, and compression creep tests were preformed on specimens cut from the extruded bar of each alloy. No significant strengthening was observed for the alloys containing TiN, NbC, or HfO{sub 2}. However the HfN-containing alloy did show significant strengthening in simple compression and compression creep. This presentation will include microstructures and the results of the mechanical properties tests. 26 refs., 5 figs.

  14. Development and commercialization status of Fe{sub 3}Al-based intermetallic alloys

    SciTech Connect

    Sikka, V.K.; Viswanathan, S.; McKamey, C.G.

    1993-06-01

    The Fe{sub 3}Al-based intermetallic alloys offer unique benefits of excellent oxidation and sulfidation resistance, limited by poor room-temperature (RT) ductility and low high-temperature strength. Recent understanding of environmental effects on RT ductility of these alloys has led to progress toward taking commercial advantage of Fe{sub 3}Al-based materials. Cause of low ductility appears to be related to hydrogen formed from reaction with moisture. The environmental effect has been reduced in these intermetallic alloys by two methods. The first deals with producing a more hydrogen-resistant microstructure through thermomechanical processing, and the second dealed with compositional modification. The alloys showing reduced environmental effect have been melted and processed by many different methods. Laboratory and commercial heats have been characterized. Tests have been conducted in both air and controlled environments to quantify environmental effects on these properties. These materials were also tested for aqueous corrosion and resistance to stress corrosion cracking. Oxidation and sulfidation data were generated and effects of minor alloying elements on were also investigated. Several applications have been identified for the newly developed iron aluminides. Commercialization status of these alloys is described.

  15. Fabrication and mechanical properties of Fe sub 3 Al-based iron aluminides

    SciTech Connect

    Sikka, V.K.; McKamey, C.G.; Howell, C.R.; Baldwin, R.H.

    1990-03-01

    Iron aluminides based on Fe{sub 3}Al are ordered intermetallic alloys that offer good oxidation resistance, excellent sulfidation resistance, and lower material cost than many stainless steels. These materials also conserve strategic elements such as chromium and have a lower density than stainless steels. However, limited ductility at ambient temperature and a sharp drop in strength have been major deterrents to their acceptance for structural applications. This report presents results on iron aluminides with room-temperature elongations of 15 to 20%. Ductility values were improved by a combination of thermomechanical processing and heat-treatment control. This method of ductility improvement has been demonstrated for a range of compositions. Melting, casting, and processing of 7-kg (15-lb) heats produced at the Oak Ridge National Laboratory (ORNL) and 70-kg (150-lb) commercial heats are described. Vacuum melting and other refining processes such as electroslag remelting are recommended for commercial heats. The Fe{sub 3}Al-based iron aluminides are hot workable by forging or extruding at temperatures in the range of 850 to 1100{degree}C. rolling at 800{degree}C is recommended with a final 50% reduction at 650{degree}C. Tensile and creep properties of 7- and 70-kg (15- and 150-lb) heats are presented. The presence of impurities such as manganese an silicon played an important role in reducing the ductility of commercially melted heats. 7 refs., 60 figs., 12 tabs.

  16. Turbine Manufacture

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The machinery pictured is a set of Turbodyne steam turbines which power a sugar mill at Bell Glade, Florida. A NASA-developed computer program called NASTRAN aided development of these and other turbines manufactured by Turbodyne Corporation's Steam Turbine Division, Wellsville, New York. An acronym for NASA Structural Analysis Program, NASTRAN is a predictive tool which advises development teams how a structural design will perform under service use conditions. Turbodyne uses NASTRAN to analyze the dynamic behavior of steam turbine components, achieving substantial savings in development costs. One of the most widely used spinoffs, NASTRAN is made available to private industry through NASA's Computer Software Management Information Center (COSMIC) at the University of Georgia.

  17. Anodic Corrosion Behavior of NiFe2O4-Based Cermet in Na3AlF6-K3AlF6-AlF3 for Aluminum Electrolysis

    NASA Astrophysics Data System (ADS)

    Tian, Zhongliang; Lai, Yanqing; Yang, Shu; Li, Jie; Hwang, Jiann-Yang; Liu, Yexiang

    2015-03-01

    A (Cu,Ni)/(10NiO-NiFe2O4) cermet was tested as an inert anode for aluminum electrolysis in Na3AlF6-K3AlF6-AlF3 melt at 1173 K (900 °C), and its corrosion behavior was studied. The results show that the low-temperature Na3AlF6-K3AlF6-AlF3 bath is beneficial, improving the service conditions. With the combined effects of the electrolyte composition and the nascent oxygen during electrolysis, the metal phase (Cu,Ni) at the surface of anode will not be leached preferentially, but be transferred into the aluminates including FeAl2O4, NiAl2O4 and CuAl2O4. This is helpful for the anode to improve its corrosion resistance.

  18. Dynamic Friction Performance of a Pneumatic Cylinder with Al2O3 Film on Cylinder Surface.

    PubMed

    Chang, Ho; Lan, Chou-Wei; Wang, Hao-Xian

    2015-11-01

    A friction force system is proposed for accurately measuring friction force and motion properties produced by reciprocating motion of piston in a pneumatic cylinder. In this study, the proposed system is used to measure the effects of lubricating greases of different viscosities on the friction properties of pneumatic cylinder, and improvement of stick-slip motion for the cylinder bore by anodizing processes. A servo motor-driven ball screw is used to drive the pneumatic cylinder to be tested and to measure the change in friction force of the pneumatic cylinder. Experimental results show, that under similar test conditions, the lubricating grease with viscosity VG100 is best suited for measuring reciprocating motion of the piston of pneumatic cylinder. The wear experiment showed that, in the Al2O3 film obtained at a preset voltage 40 V in the anodic process, the friction coefficient and hardness decreased by 55% and increased by 274% respectively, thus achieving a good tribology and wear resistance. Additionally, the amplitude variation in the friction force of the pneumatic cylinder wall that received the anodizing treatment was substantially reduced. Additionally, the stick-slip motion of the pneumatic cylinder during low-speed motion was substantially improved. PMID:26726680

  19. 49 CFR 173.301 - General requirements for shipment of compressed gases and other hazardous materials in cylinders...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... citations affecting § 173.301, see the List of CFR Sections Affected, which appears in the Finding Aids... authorized. 3A 3AA 3AL 3AX 3A480X 3AAX 3B 3BN 3E 3HT 3T 4AA480 4B 4B240ET 4BA 4BW 4D 4DA 4DS 4E 4L 8 8AL 39...) Specification 2P, 2Q, 3E, 3HT, spherical 4BA, 4D, 4DA, 4DS, and 39 cylinders must be packed in strong...

  20. 49 CFR 173.301 - General requirements for shipment of compressed gases and other hazardous materials in cylinders...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., see the List of CFR Sections Affected, which appears in the Finding Aids section of the printed volume... follows: Packagings 2P 2Q ICC-31 3A 3AA 3AL 3AX 3A480X 3AAX 3B 3BN 3E 3HT 3T 4AA480 4B 4B240ET 4BA 4BW 4D...) Specification 2P, 2Q, 3E, 3HT, spherical 4BA, 4D, 4DA, 4DS, and 39 cylinders must be packed in strong...

  1. 49 CFR 173.301 - General requirements for shipment of compressed gases and other hazardous materials in cylinders...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., see the List of CFR Sections Affected, which appears in the Finding Aids section of the printed volume... ICC-31 3A 3AA 3AL 3AX 3A480X 3AAX 3B 3BN 3E 3HT 3T 4AA480 4B 4B240ET 4BA 4BW 4D 4DA 4DS 4E 4L 8 8AL 39...) Specification 2P, 2Q, 3E, 3HT, spherical 4BA, 4D, 4DA, 4DS, and 39 cylinders must be packed in strong...

  2. 49 CFR 173.301 - General requirements for shipment of compressed gases and other hazardous materials in cylinders...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... citations affecting § 173.301, see the List of CFR Sections Affected, which appears in the Finding Aids... ICC-31 3A 3AA 3AL 3AX 3A480X 3AAX 3B 3BN 3E 3HT 3T 4AA480 4B 4B240ET 4BA 4BW 4D 4DA 4DS 4E 4L 8 8AL 39...) Specification 2P, 2Q, 3E, 3HT, spherical 4BA, 4D, 4DA, 4DS, and 39 cylinders must be packed in strong...

  3. 49 CFR 173.301 - General requirements for shipment of compressed gases and other hazardous materials in cylinders...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., see the List of CFR Sections Affected, which appears in the Finding Aids section of the printed volume... authorized. 3A 3AA 3AL 3AX 3A480X 3AAX 3B 3BN 3E 3HT 3T 4AA480 4B 4B240ET 4BA 4BW 4D 4DA 4DS 4E 4L 8 8AL 39...) Specification 2P, 2Q, 3E, 3HT, spherical 4BA, 4D, 4DA, 4DS, and 39 cylinders must be packed in strong...

  4. Power extraction using flow-induced vibration of a circular cylinder placed near another fixed cylinder

    NASA Astrophysics Data System (ADS)

    Nishi, Yoshiki; Ueno, Yuta; Nishio, Masachika; Quadrante, Luis Antonio Rodrigues; Kokubun, Kentaroh

    2014-05-01

    We conducted an experiment in a towing tank to investigate the performance of an energy extraction system using the flow-induced vibration of a circular cylinder. This experiment tested three different cases involving the following arrangements of cylinder(s) of identical diameter: the upstream fixed-downstream movable arrangement (case F); the upstream movable-downstream fixed arrangement (case R); and a movable isolated cylinder (case I). In cases F and R, the separation distance (ratio of the distance between the centers of the two cylinders to their diameters) is fixed at 1.30. Measurement results show that while cases F and I generate vortex-induced vibration (VIV) resonance responses, case R yields wake-induced vibration (WIV) at reduced velocity over 9.0, which is significantly larger than that of the VIV response, leading to the induction of higher electronic power in a generator. Accordingly, primary energy conversion efficiency is higher in the case involving WIV.

  5. Nondestructive relative permittivity and loss tangent measurements using a split-cylinder resonator

    NASA Astrophysics Data System (ADS)

    Janezic, Michael Daniel

    To keep pace with the expanding wireless and electronics industries, manufacturers are developing innovative materials for improving system performance, and there is a critical need to accurately characterize the electrical properties of these new materials at microwave frequencies. To address this need, this thesis develops a nondestructive method for measuring the relative permittivity and loss tangent of dielectric substrates using a split-cylinder resonator. Three theoretical models for the split-cylinder resonator are derived using mode-matching, least-squares boundary residual, and Hankel-transform methods, from which one can calculate the relative permittivity and loss tangent of a dielectric substrate from measurements of the split-cylinder resonator's TE0np resonant frequency and quality factor. Each of these models has several advantages over previously published models. First, the accuracy of the relative permittivity measurement is increased because each model accurately models the fringing fields that extend beyond the cylindrical-cavity sections. Second, to increase the accuracy of the loss tangent measurement, each model accurately separates the conductive metal losses of the split-cylinder resonator from the dielectric losses of the substrate. Finally, in contrast to previous models for the split-cylinder resonator that use only the TE011 resonant mode, each of the new models include the higher-order TE0np resonant modes, thereby broadening the frequency range over which one can make relative permittivity and loss tangent measurements. In a comparison of the three models, the mode-matching method was found to be superior on the basis of measurement accuracy and computational speed. Relative permittivity and loss tangent measurements for several dielectric materials are performed using a split-cylinder resonator and are in good agreement with measurements made using a circular-cylindrical cavity, split-post resonator, and dielectric post resonator

  6. Determining the Mechanism of In-Service Cylinder Distortion in Aluminum Engine Blocks with Cast-In Gray Iron Liners

    NASA Astrophysics Data System (ADS)

    Lombardi, Anthony; Ravindran, Comondore; Sediako, Dimitry; MacKay, Robert

    2014-12-01

    In recent years, stringent government legislation on vehicle fuel efficiency has pushed the automotive industry to replace steel and cast iron power train components with light weight Al alloys. However, unlike their ferrous-based equivalents, Al-Si alloy engine blocks are prone to permanent dimensional distortion in critical locations such as the cylinder bore regions. Understanding the mechanisms that cause distortion will promote the use of Al alloys over ferrous alloys for power train applications and enable automotive manufacturers to meet emission standards and reduce fuel consumption. In this study, neutron diffraction was used to evaluate residual stress along the Al cylinder bridge and the gray cast iron liners of distorted and undistorted engine blocks. Microstructural analysis was carried out using OM, SEM, and TEM, while mechanical testing was accomplished via ambient and elevated temperature [~453 K (180 °C)] tensile testing. The results suggest that the distorted engine block had high tensile residual stress in the Al cylinder bridge, reaching a maximum of 170 MPa in the hoop direction, which triggered permanent dimensional distortion in the cylinders when exposed to service conditions. In addition, the middle of the cylinder had the highest magnitude of distortion since this region had a combination of high tensile residual stress (hoop stress of 150 MPa) and reduced strength compared with the bottom of the cylinder.

  7. Determining the Mechanism of In-Service Cylinder Distortion in Aluminum Engine Blocks with Cast-In Gray Iron Liners

    NASA Astrophysics Data System (ADS)

    Lombardi, Anthony; Ravindran, Comondore; Sediako, Dimitry; MacKay, Robert

    2014-09-01

    In recent years, stringent government legislation on vehicle fuel efficiency has pushed the automotive industry to replace steel and cast iron power train components with light weight Al alloys. However, unlike their ferrous-based equivalents, Al-Si alloy engine blocks are prone to permanent dimensional distortion in critical locations such as the cylinder bore regions. Understanding the mechanisms that cause distortion will promote the use of Al alloys over ferrous alloys for power train applications and enable automotive manufacturers to meet emission standards and reduce fuel consumption. In this study, neutron diffraction was used to evaluate residual stress along the Al cylinder bridge and the gray cast iron liners of distorted and undistorted engine blocks. Microstructural analysis was carried out using OM, SEM, and TEM, while mechanical testing was accomplished via ambient and elevated temperature [~453 K (180 °C)] tensile testing. The results suggest that the distorted engine block had high tensile residual stress in the Al cylinder bridge, reaching a maximum of 170 MPa in the hoop direction, which triggered permanent dimensional distortion in the cylinders when exposed to service conditions. In addition, the middle of the cylinder had the highest magnitude of distortion since this region had a combination of high tensile residual stress (hoop stress of 150 MPa) and reduced strength compared with the bottom of the cylinder.

  8. Nonlinear spacing and frequency effects of an oscillating cylinder in the wake of a stationary cylinder

    NASA Astrophysics Data System (ADS)

    Yang, Xiaofan; Zheng, Zhongquan Charlie

    2010-04-01

    Nonlinear responses to a transversely oscillating cylinder in the wake of a stationary upstream cylinder are studied theoretically by using an immersed-boundary method at Re=100. Response states are investigated in the three flow regimes for a tandem-cylinder system: the "vortex suppression" regime, the critical spacing regime, and the "vortex formation" regime. When the downstream cylinder is forced to oscillate at a fixed frequency and amplitude, the response state of flow around the two cylinders varies with different spacing between the two cylinders, while in the same flow regime, the response state can change with the oscillating frequency and amplitude of the downstream cylinder. Based on velocity phase portraits, each of the nonlinear response states can be categorized into one of the three states in the order of increasing chaotic levels: lock-in, transitional, or quasiperiodic. These states can also be correlated with velocity spectral behaviors. The discussions are conducted using near-wake velocity phase portraits, spectral analyses, and related vorticity fields. A general trend in the bifurcation diagrams of frequency spacing shows the smaller the spacing, frequency, or amplitude, the less chaotic the response state of the system and more likely the downstream and upstream wakes are in the same response state. The system is not locked-in in any case when the spacing between the cylinders is larger than the critical spacing. The near-wake velocity spectral behaviors correspond to the nonlinear response states, with narrow-banded peaks shown at the oscillation frequency and its harmonics in the lock-in cases. High frequency harmonic peaks, caused by interactions between the upstream wake and the downstream oscillating cylinder, are reduced in the near-wake velocity spectra of the upstream cylinder when the spacing increases.

  9. Directionally solidified Eu doped CaF2/Li3AlF6 eutectic scintillator for neutron detection

    NASA Astrophysics Data System (ADS)

    Kamada, Kei; Hishinuma, Kousuke; Kurosawa, Shunsuke; Shoji, Yasuhiro; Pejchal, Jan; Ohashi, Yuji; Yokota, Yuui; Yoshikawa, Akira

    2015-12-01

    Eu doped CaF2/Li3AlF6 eutectics were grown by μ-PD method. The directionally solidified eutectic with well-aligned 600 nm diameter Eu:CaF2 scintillator fibers surrounded with Li3AlF6 was prepared. The grown eutectics showed an emission peak at 422 nm ascribed to Eu2+ 4f-5d transition from Eu:CaF2 scintillation fiber. Li concentration in the Eu:CaF2-Li3AlF6 eutectic is around 0.038 mol/cm3,which is two times higher than that of LiCaAlF6 single crystal (0.016 mol/cm3). The light yield of Eu:CaF2-Li3AlF6 eutectic was around 7000 ph/neutron. The decay time was about 550 ns (89%) and 1450 ns (11%).

  10. Microstructure and mechanical properties of sputter deposited Ni/Ni3Al multilayer films at elevated temperature

    NASA Astrophysics Data System (ADS)

    Zhang, Chao; Feng, Kai; Li, Zhuguo; Lu, Fenggui; Huang, Jian; Wu, Yixiong

    2016-08-01

    Nano-structured Ni/Ni3Al multilayer was prepared by magnetron sputtering, with individual layer thicknesses h varying from 10 to 160 nm. The microstructure and hardness of Ni/Ni3Al multilayer were investigated by X-ray diffraction, transmission electron microscopy and nanoindentation. The results show that the hardness increases with decreasing h for as-deposited and 500 °C annealed multilayers. When annealed at 700 °C, the hardness approach a peak value at h = 40 nm with followed by softening at smaller h. The influence of individual layer thickness, grain size as well as formation of ordered Ni3Al on strengthening mechanisms of Ni/Ni3Al multilayers at elevated temperature are discussed.

  11. UF{sub 6} cylinder fire test

    SciTech Connect

    Park, S.H.

    1991-12-31

    With the increasing number of nuclear reactors for power generation, there is a comparable increase in the amount of UF{sub 6} being transported. Likewise, the probability of having an accident involving UF{sub 6}-filled cylinders also increases. Accident scenarios which have been difficult to assess are those involving a filled UF{sub 6} cylinder subjected to fire. A study is underway at the Oak Ridge K-25 Site, as part of the US DOE Enrichment Program, to provide empirical data and a computer model that can be used to evaluate various cylinder-in-fire scenarios. It is expected that the results will provide information leading to better handling of possible fire accidents as well as show whether changes should be made to provide different physical protection during shipment. The computer model being developed will be capable of predicting the rupture of various cylinder sizes and designs as well as the amount of UF{sub 6}, its distribution in the cylinder, and the conditions of the fire.

  12. The Cylinder and Semicylinder in Subsonic Flow

    NASA Technical Reports Server (NTRS)

    Bingham, Harry J.; Weimer, David K..; Griffith, Wayland

    1952-01-01

    In studying the diffraction of shock waves around various two-dimensional obstacles we have observed that flow separation and the formation of vortices contributes in an important way to transient loading of the obstacle. The cases of a cylinder and semicylinder are especially interesting because the breakaway point is not clearly defined as it is for objects having sharp corners. Accordingly a number of experiments have been made in the shock tube to observe the influence of Reynolds number and Mach number on the transient flow patterns about a cylinder and about a semicylinder mounted on a smooth plane. Some differences might be anticipated since the plane would impose a symmetry on the flow and produce a viscous boundary layer for which there is no counterpart with the cylinder. In the course of these experiments it was noted that a condition of steady subsonic flow about both the cylinder and semicylinder was approached. Thus a comparison with von Karrnan's theoretical calculation of the drag on a cylinder, from certain characteristics of its wake or "vortex street", was undertaken.

  13. A jumping cylinder on an inclined plane

    NASA Astrophysics Data System (ADS)

    Gómez, R. W.; Hernández-Gómez, J. J.; Marquina, V.

    2012-09-01

    The problem of a cylinder of mass m and radius r, with its centre of mass out of the cylinder’s axis, rolling on an inclined plane that makes an angle α with respect to the horizontal, is analysed. The equation of motion is partially solved to obtain the site where the cylinder loses contact with the inclined plane (jumps). Several simplifications are made: the analysed system consists of an homogeneous disc with a one-dimensional straight line mass parallel to the disc axis at a distance y < r of the centre of the cylinder. To compare our results with experimental data, we use a styrofoam cylinder to which a long brass rod is embedded parallel to the disc axis at a distance y < r from it, so the centre of mass lies at a distance d from the centre of the cylinder. Then the disc rolls without slipping on a long wooden ramp inclined at 15°, 30° and 45° with respect to the horizontal. To determine the jumping site, the movements are recorded with a high-speed video camera (Casio EX ZR100) at 240 and 480 frames per second. The experimental results agree well with the theoretical predictions.

  14. A jumping cylinder in an incline

    NASA Astrophysics Data System (ADS)

    Gomez, Raul W.; Hernandez, Jorge; Marquina, Vivianne

    2012-02-01

    The problem of a cylinder of mass m and radius r, with its center of mass out of the cylinder axis, rolling in an incline that makes an angle α respect to the horizontal is analyzed. The equation of motion is solved to obtain the site where the cylinder loses contact with the incline (jumps). Several simplifications are made: the analyzed system consists of an homogeneous disc with a one dimensional straight line of mass parallel to the disc axis at a distance d < r of the center of the cylinder. To compare our results with experimental data, we use a Styrofoam cylinder of radius r = 10.0 ± 0.05 cm, high h = 5.55 ± 0.05 cm and a mass m1 = 24.45 ± 0.05 g, to which a 9.50 ± 0.01 mm diameter and 5.10 ± 0.001 cm long brass road of mass m2 = 30.75 ± 0.05 g was imbibed parallel to the disc axis at a distance of 5.40 ± 0.05 cm from it. Then the disc rolls on a 3.20 m long wooden ramp inclined at 30 and 45 respect to the horizontal. To determine the jumping site, the movements were recorded with a high-speed video camera (Casio EX ZR100) at 400 frames per second. The experimental results agree well with the theoretical predictions.

  15. Vision-guided gripping of a cylinder

    NASA Technical Reports Server (NTRS)

    Nicewarner, Keith E.; Kelley, Robert B.

    1991-01-01

    The motivation for vision-guided servoing is taken from tasks in automated or telerobotic space assembly and construction. Vision-guided servoing requires the ability to perform rapid pose estimates and provide predictive feature tracking. Monocular information from a gripper-mounted camera is used to servo the gripper to grasp a cylinder. The procedure is divided into recognition and servo phases. The recognition stage verifies the presence of a cylinder in the camera field of view. Then an initial pose estimate is computed and uncluttered scan regions are selected. The servo phase processes only the selected scan regions of the image. Given the knowledge, from the recognition phase, that there is a cylinder in the image and knowing the radius of the cylinder, 4 of the 6 pose parameters can be estimated with minimal computation. The relative motion of the cylinder is obtained by using the current pose and prior pose estimates. The motion information is then used to generate a predictive feature-based trajectory for the path of the gripper.

  16. Balancer structure for three-cylinder engines

    SciTech Connect

    Suzuki, T.

    1986-01-21

    This patent describes a balancer structure for a three-cylinder in-line engine. The in-line engine is indicated in the patent as having a crankshaft having crank arms configured at angles of 120/sup 0/ with respect to each other and operatively connected to a piston assembly within each of the cylinders. This crankshaft and assembly, which serves as a balancer structure as one of its applications, is further characterized in the patent as consisting of a number of component parts. The first component described is a single countershaft adjacent and parallel to the crankshaft. It is specified in the patent that this countershaft must rotate at the same speed as the crankshaft but in an opposite direction in order to fulfill its role in the balancer structure. The patent also details an element of the balancer structure which consists of a means utilizing counterweights mounted on the crankshaft at the first and third cylinder positions. These weights are indicated as partially balancing the inertia forces of reciprocating masses and the entire inertia forces of rotating masses present in the described engine. The required position of these counterweights is indicated as being a location more than 90/sup 0/ from the crank arm for the corresponding cylinder and perpendicular to the second cylinder crank arm. The last component described consists of two balancers mounted on both ends of the countershaft which balance the remainder of the inertia forces of reciprocating masses and the inertia of the crankshaft about axes perpendicular to itself.

  17. Balancer structure for three-cylinder engines

    SciTech Connect

    Suzuki, T.

    1986-02-11

    This patent describes a balancer structure for a three-cylinder in-line engine having aligned three cylinders, a crankshaft having crank arms disposed at angles of 120/sup 0/ with respect to each other and operatively connected to the cylinders, respectively. This structure consists of: 1.) a single countershaft adjacent and parallel to and rotated at the same speed as the crankshaft but in the opposite direction; 2.) a counterweight is securely mounted on the crankshaft only at positions corresponding to the first and third cylinders for balancing a part of inertia force of reciprocating mases and the entire inertia force of rotating masses; 3.) at least one second counterweight securely mounted on the crankshaft substantially opposite to the crank arm corresponding to the second cylinder for balancing another part of the inertia force of the reciprocating masses; 4.) at least two balancers securely mounted on the countershaft at both ends for the balancing of the remainder of the inertia force of the reciprocating masses and a couple of inertia of the crankshaft about an axis perpendicular to the crankshaft.

  18. Circular cylinder wakes and vortex-induced vibrations

    NASA Astrophysics Data System (ADS)

    Bearman, P. W.

    2011-07-01

    This paper presents a selective review of recent research on vortex-induced vibrations of isolated circular cylinders and the flow and vibration of circular cylinders in a tandem arrangement; a common thread being that the topics raised are of particular interest to the author. The influence of Reynolds number on the response of isolated cylinders is presented and recent developments using forced vibration are discussed. The response of a cylinder free to respond in the in-line and transverse directions is contrasted with that of a cylinder responding in only one direction. The interference between two circular cylinders is discussed and prominence given to the case of cylinders in a tandem arrangement. The origin of the time-mean lift force on the downstream cylinder is considered together with the cause of the large amplitude transverse vibration experienced by the cylinder above vortex resonance. This wake-induced vibration is shown to be a form of vortex-induced vibration.

  19. Spectroscopic characteristics of Dy3+ doped Y3Al5O12 transparent ceramics

    NASA Astrophysics Data System (ADS)

    Lupei, A.; Lupei, V.; Gheorghe, C.; Ikesue, A.; Enculescu, M.

    2011-10-01

    The spectroscopic characteristics of Dy3+ in YAG (Y3Al5O12) transparent ceramics prepared by solid state synthesis were investigated, with special attention to the visible (yellow, blue) emissions that could be pumped directly by the new developed blue-violet or near UV laser diodes. The absorption and emission spectra, recorded at different temperatures from 10 to 300 K, were analyzed and relevant new parameters, improved energy level scheme, temperature effects, intensity parameters based on Judd-Ofelt theory and radiative transition rates, branching ratios, etc., were estimated and the data are compared with previous reports on garnet single crystals. The potential of the Dy3+: YAG transparent ceramics for yellow or blue laser emission is discussed.

  20. Scintillation properties of Gd3Al2Ga3O12:Ce3+ single crystal scintillators

    NASA Astrophysics Data System (ADS)

    Sakthong, Ongsa; Chewpraditkul, Weerapong; Wanarak, Chalerm; Kamada, Kei; Yoshikawa, Akira; Prusa, Petr; Nikl, Martin

    2014-07-01

    The scintillation properties of Gd3Al2Ga3O12:Ce3+ (GAGG:Ce) single crystals grown by the Czochralski method with 1 at% cerium in the melt were investigated and results were compared with so far published results in the literature. The light yield (LY) and energy resolution were measured using a XP5200B photomultiplier. Despite about twice higher LY for GAGG:Ce, the energy resolution is only slightly better than that of LuAG:Ce due to its worse intrinsic resolution and non-proportionality of LY. The LY dependences on the sample thickness and amplifier shaping time were measured. The estimated photofraction in pulse height spectra of 320 and 662 keV γ-rays and the total mass attenuation coefficient at 662 keV γ-rays were also determined and compared with the theoretical ones calculated using the WinXCom program.

  1. The quantum free energy barrier for hydrogen vacancy diffusion in Na3AlH6.

    PubMed

    Poma, Adolfo; Monteferrante, Michele; Bonella, Sara; Ciccotti, Giovanni

    2012-11-28

    The path integral single sweep method is used to assess quantum effects on the free energy barrier for hydrogen vacancy diffusion in a defective Na(3)AlH(6) crystal. This process has been investigated via experiments and simulations due to its potential relevance in the H release mechanism in sodium alanates, prototypical materials for solid state hydrogen storage. Previous computational studies, which used density functional methods for the electronic structure, were restricted to a classical treatment of the nuclear degrees of freedom. We show that, although they do not change the qualitative picture of the process, nuclear quantum effects reduce the free energy barrier height by about 18% with respect to the classical calculation improving agreement with available neutron scattering data. PMID:23064527

  2. Nucleation of microcracks during dislocation interactions in a Ti3Al single crystal

    NASA Astrophysics Data System (ADS)

    Kar'kina, L. E.; Yakovenkova, L. I.

    2008-06-01

    Reactions between superdislocations involved in deformation in the basal, prismatic, and type-I and II pyramidal planes in single-crystal Ti3Al are considered. The types of dislocation interactions are established that result in the formation dislocation barriers (microcrack nuclei). The force and energy conditions for microcracks to arise are found. The interaction between a and 2 c + a superdislocations results in microcracks with the plane of opening lying in basal and pyramidal planes; the interaction of 2 c + a superdislocations in different pyramidal planes results in the formation of microcracks in prismatic and pyramidal planes; and the interaction of a superdislocations in basal and/or pyramidal planes does not cause the formation of dislocation barriers. The types of microcracks are classified in terms of the orientation of deformation axes of single crystals, and the regions of the stereographic triangle are determined characterized by a preferential type of crack opening.

  3. Photoluminescence and thermoluminescence properties of Y3(Al,Ga)5O12:Tb3+ phosphor

    NASA Astrophysics Data System (ADS)

    Yousif, A.; Som, S.; Swart, H. C.

    2016-01-01

    A comparative study of the structural, photoluminescence (PL) and thermoluminescence (TL) properties of Y3(Al,Ga)5O12:Tb3+ phosphor powder was performed. The scanning electron microscope images showed that the phosphor particles were agglomerated and irregular in shape. The bigger particles consisted of smaller spherically shaped agglomerated particles ranging in size between 0.5 and 1 μm. The UV-VUV synchrotron radiation was used to study the luminescence properties of the phosphor. The TL study was performed after the sample was irradiated by γ-rays obtained from a 60Co target in the dose range of 10-50 Gy. The effect of heating rate on the TL glow curves and trapping parameters was also calculated. The correlation between PL and TL was explored.

  4. TEM studies of oxidized NiAl and Ni3Al cross sections

    NASA Technical Reports Server (NTRS)

    Doychak, J.; Ruhle, M.

    1989-01-01

    Cross sections of oxide scale/(Ni-Al) intermetallics were prepared by a new method and studied using primarily TEM. The cross sections were prepared by encasing an oxidized metal specimen sandwich in a low-melting-temperature zinc alloy. Observations of oxidized zirconium-doped beta-NiAl cross sections revealed crystallographic voids beneath an adherent Al2O3 scale. The oxide-metal interface was incoherent, but a high dislocation density in the metal near the interface suggested that a large tensile stress was induced by the attached oxide scale. A duplex Al2O3-NiAl2O4 scale formed on zirconium-doped and zirconium/boron-doped gamma-prime-Ni3Al alloys. Additional results are presented involving oxidation mechanisms and oxide-metal interface structures.

  5. Microplasticity and fracture in a Ti-15V-3Cr-3Al-3Sn alloy

    SciTech Connect

    Rabeeh, B.M.; Rokhlin, S.I.; Soboyejo, W.O.

    1996-12-15

    Linear Elasticity is generally considered to occur in most standard textbooks by the strengthening of chemical bonds in the regime below the proportional limit in most materials. In some cases, however, a number of researchers have recognized the possible role of localized microplasticity (microplasticity in this paper refers to localized plasticity on a microstructural level at stresses below the so-called bulk yield stress) in the so-called elastic deformation regime. There is, therefore, a need for careful studies of the micromechanisms of microplasticity in the so-called elastic regime. Micromechanisms of microplasticity will be presented in this paper for a metastable {beta} Ti-15V-3Cr-3Al-3Sn (Ti-15-3) alloy deformed in incremental stages to failure under monotonic loading. Micromechanisms of tensile deformation and fracture will be elucidated for a Ti-15-3 plate with single phase {beta} and Widmanstaetten {alpha}+{beta} microstructures.

  6. Crystallographic study of fatigue cracking in Ni{sub 3}Al(CrB) single crystal

    SciTech Connect

    Zhang, G.P.; Wang, Z.G.; Li, G.Y.; Wu, S.D.

    1997-03-01

    The effect of crystallographic orientation on the fatigue-crack initiation and propagation in Ni{sub 3}Al(CrB) single crystal was studied using a compact-tension specimen. Stage I crystallographic cracking and cleavage fracture were observed. Crystallographic cracking can occur on two or more {l_brace}111{r_brace} slip planes simultaneously. It was shown that the threshold stress intensity for crack initiation from the notch root exhibits a dependence on crystallographic orientation. In addition, an effect of orientation on microcracking behavior was also shown. The number of {l_brace}111{r_brace} planes intersecting with each other determines the different microscopic features on the cleavage fracture surface.

  7. Radial Combustion Dynamics in Fe2O3/Al Thermite: Variability of the Flame Propagation Profiles

    NASA Astrophysics Data System (ADS)

    Durães, L.; Plaksin, I.; Antunes, J.; Campos, J.; Portugal, A.

    2009-12-01

    In this work, the radial combustion in thin circular samples of stoichiometric and over aluminized Fe2O3/Al mixtures is studied. Two confinement materials are tested: stainless steel and PVC. The combustion front profiles are registered by digital video-crono-photography. The radial geometry allows an easy detection of sample heterogeneities, via the circularity distortions of the combustion front profiles. The influence of the Al content in the mixtures and the type of confinement on the combustion propagation dynamics is analyzed. Additionally, an asymmetry parameter of the combustion front profiles is defined and statistically treated via ANOVA. Although the type of confinement contributes more than the mixture composition to the variability of the asymmetry parameter, they both have a weak influence. The main source of variability is the intrinsic variations of the samples, which are due to their heterogeneous character.

  8. Investigation of superplastic behavior of NiAl and Ni{sub 3}Al duplex alloy

    SciTech Connect

    Liu Zhenyun; Lin Dongliang; Gu Yuefeng; Shan Aidang

    1997-12-31

    The superplastic behavior of a NiAl and Ni{sub 3}Al duplex alloy was investigated. It was found that the alloy exhibits superplastic behavior over a narrow temperature range, from 975 C to 1,025 C at the strain rate of 1.52 {times} 10{sup {minus}4}s{sup {minus}1}. A maximum tensile elongation of 149% was obtained at 1,000 C with the strain rate sensitivity up to 0.375. The superplastic deformation of the duplex alloy can be approximately described by an empirical equation of the form: {dot {var_epsilon}} = Ao{sup 2.67} exp({minus}303,000/RT). Optical microstructure and TEM observation show that the superplastic behavior mechanism of the investigated alloy is a process of continuous recovery and recrystallization during deformation.

  9. Microstructure and mechanical properties of P/M (powder metallurgy) Fe sub 3 Al alloys

    SciTech Connect

    Knibloe, J.R.; Wright, R.N. ); Sikka, V.K. )

    1990-01-01

    Alloys based on Fe{sub 3}Al have an equilibrium DO{sub 3} structure at low temperatures and transform to a B2 structure above about 550{degree}C. The influence of different rates of quenching from the B2 region to room temperature on the microstructure and mechanical properties of powder metallurgy (P/M) alloys with two different Cr contents has been examined. By optimizing the processing to maximize the amount of B2 order, room temperature ductility approaching 20% has been achieved although the fracture mode is primarily brittle cleavage. The refined microstructure resulting from P/M processing contributes to enhanced yield strength compared to ingot processed materials with similar ductility. Increasing the Cr content from 2 to 5% has little effect on mechanical properties. 8 refs., 12 figs., 2 tabs.

  10. Titanium self-diffusion and chemical diffusion in Ti{sub 3}Al

    SciTech Connect

    Ruesing, J.; Herzig, C.

    1995-08-15

    Temperature and concentration dependence of the diffusion of Ti and Al has been measured in the ordered {alpha}{sub 2}-phase Ti{sub 3}Al. Ti self-diffusion is almost independent of the Al concentration in the hyperstoichiometric {alpha}{sub 2}-phase. The absolute D*{sub Ti}-values are rather low. Obviously diffusion proceeds by the vacancy mechanism and no constitutional vacancies but Al antisite defects are formed. Chemical diffusion {tilde D} is larger than self-diffusion D*{sub Ti} due to the fact that the thermodynamic factor {Phi} is larger than unity in the {alpha}{sub 2}-phase. Al self-diffusion D*{sub Al} was deduced to be lower than D*{sub Ti} by a factor of two to three in the range of 1,273 K to 1,173 K.

  11. Microstructure and Functional Mechanism of Friction Layer in Ni3Al Matrix Composites with Graphene Nanoplatelets

    NASA Astrophysics Data System (ADS)

    Xue, Bing; Zhu, Qingshuai; Shi, Xiaoliang; Zhai, Wenzheng; Yang, Kang; Huang, Yuchun

    2016-08-01

    Microstructure and functional mechanism of friction layer need to be further researched. In the present work, the friction coefficients and wear rates are analyzed through response surface methodology to obtain an empirical model for the best response. Fitting results show that the tribological performance of Ni3Al matrix composites (NMCs) with graphene nanoplatelets (GNPs) is better than that of NMCs without GNPs, especially at high sliding velocities and high loads. Further research suggests that the formation of integrated friction layer, which consists of a soft microfilm on a hard coating, is the major reason to cause the differences. Of which, the wear debris layer (WDL) with a low shear strength can reduce the shear force. The ultrafine layer (UL), which is much harder and finer, can effectively avoid fracture and improve the load support capacity. Moreover, the GNPs in WDL and UL can be easily sheared and help to withstand the loads, trending to be parallel to the direction of shear force.

  12. Simulation of UAl 4 growth in an UAl 3/Al diffusion couple

    NASA Astrophysics Data System (ADS)

    Kniznik, L.; Alonso, P. R.; Gargano, P. H.; Rubiolo, G. H.

    2011-07-01

    In this work the growth of the UAl 4 phase in an UAl 3/Al diffusion couple is treated as a planar moving boundary problem due to diffusion of Al and U atoms in the direction perpendicular to the interface surface. The diffusion problem was carried out by the DICTRA simulation package which combines data evaluated by Thermo-Calc with a mobility database. A thermodynamic database of the U-Al system, suitable for the Thermo-Calc code, was composed using data from literature. The mobility database was assessed from reported experimental growth of the UAl 4 phase at different temperatures. The Al tracer diffusion coefficient in the UAl 4 phase, DAl∗(UAl) (m/s)=2.7×10-1exp(-209500 (J/mol)/RT), is obtained under the assumption that uranium mobility is negligible.

  13. Grain-boundary contamination and ductility loss in boron-doped Ni3Al

    NASA Astrophysics Data System (ADS)

    Takeyama, M.; Liu, C. T.

    1989-10-01

    The effect of heat treatment on ductility loss in a boron-doped Ni3Al was studied by tensile tests of alloy specimens exposed to contaminated environments. Specimens heat-treated extensively in evacuated quartz capsules at 1323 K exhibit only 3.3 pct ductility at 1033 K, whereas a previous study reported a tensile ductility of about 24 pet for specimens heat-treated in a high vacuum system. Aluminum oxide and silicon-contaminated regions were observed at and near external surfaces of capsule-annealed specimens. The reactions occurring during heat treatment are interpreted in terms of thermodynamics. An Auger electron spectroscopy study revealed oxygen penetration along grain boundaries during capsule annealing. Although the surface oxide layer and silicon contamination both contribute to some reductions in ductility, the major cause for embrittlement comes from oxygen penetration along grain boundaries.

  14. Local structure study of Fe dopants in Ni-deficit Ni3Al alloys

    DOE PAGESBeta

    V. N. Ivanovski; Umicevic, A.; Belosevic-Cavor, J.; Lei, Hechang; Li, Lijun; Cekic, B.; Koteski, V.; Petrovic, C.

    2015-08-24

    We found that the local electronic and magnetic structure, hyperfine interactions, and phase composition of polycrystalline Ni–deficient Ni 3-x FexAl (x = 0.18 and 0.36) were investigated by means of 57 Fe Mössbauer spectroscopy. The samples were characterized by X–ray diffraction and magnetization measurements. The ab initio calculations performed with the projector augmented wave method and the calculations of the energies of iron point defects were done to elucidate the electronic structure and site preference of Fe doped Ni 3 Al. Moreover, the value of calculated electric field gradient tensor Vzz=1.6 1021Vm-2 matches well with the results of Mössbauer spectroscopymore » and indicates that the Fe atoms occupy Ni sites.« less

  15. Nucleation of ordered Fe islands on Al 2O 3/Ni 3Al(1 1 1)

    NASA Astrophysics Data System (ADS)

    Lehnert, A.; Krupski, A.; Degen, S.; Franke, K.; Decker, R.; Rusponi, S.; Kralj, M.; Becker, C.; Brune, H.; Wandelt, K.

    2006-05-01

    Scanning tunneling microscopy (STM) has been used to investigate the nucleation and stability of iron clusters on the Al 2O 3/Ni 3Al(1 1 1) surface as a function of coverage and annealing temperature. We show that atomic beam deposition of iron leads to hexagonally ordered cluster arrangements with a distance of 24 Å between the clusters evidencing the template effect of the alumina film. The shape of the iron clusters is two-dimensional (2D) at deposition temperatures from 130 K to 160 K and three-dimensional (3D) at 300 K. However, the 2D iron clusters grown between 130 K and 160 K are stable up to 350 K.

  16. Chromium addition and environmental embrittlement in Fe[sub 3]Al

    SciTech Connect

    McKamey, C.G.; Liu, C.T. . Metals and Ceramics Division)

    1990-01-01

    Iron aluminides based on Fe[sub 3]Al afford excellent oxidation properties at relatively low cost, making them candidates for use as structural material in corrosive environments. Recently, efforts have been devoted to understanding and improving their ductility through control of grain structure, alloy additions and material processing. Studies at this laboratory have shown that the ambient temperature ductility can be increased significantly by additions of up to 6% Cr. This increase in ductility was earlier attributed to increased cleavage strength, easier cross slip due to lower antiphase boundary (APB) energy, and solid softening. Very recent studies of FeAl and Fe[sub 3]Al in various tensile testing environments have indicated that both alloy systems are relatively more ductile at room temperature when tested in vacuum or dry oxygen. Ductilities of 12--18% were attained in both iron aluminide systems in an oxygen pressure of 6.7 [times] 10[sup 4] Pa, while only 2--4% ductility was achieved in normal laboratory air. It seems appropriate to reexamine the mechanism by which chromium produces improved ductility at room temperature in laboratory air and to correlate it with the environmental effects on mechanical properties. In the current investigation, the authors have evaluated room temperature tensile properties of the binary alloy (Fe-28Al, at.%) and ternary alloy containing chromium (Fe-28Al-4Cr) as a function of surface condition and heat treatment. The results indicate that, although chromium may affect cleavage strength and APB energies, its most significant effect on room temperature ductility is to modify the protective surface oxide, resulting in a minimization of environmental embrittlement.

  17. Studies on the Sliding Wear Performance of Plasma Spray Ni-20Cr and Ni3Al Coatings

    NASA Astrophysics Data System (ADS)

    Kaur, Maninder; Singh, Harpreet; Singh, Balraj; Singh, Bhupinder

    2010-01-01

    Two metallic powders namely Ni-20Cr and Ni3Al were coated on AISI 309 SS steel by shrouded plasma spray process. The wear behavior of the bare, Ni-20Cr and Ni3Al-coated AISI 309 SS steel was investigated according to ASTM Standard G99-03 on a Pin-on-Disc Wear Test Rig. The wear tests were carried out at normal loads of 30 and 50 N with a sliding velocity of 1 m/s. Cumulative wear rate and coefficient of friction (μ) were calculated for all the cases. The worn-out surfaces were then examined by scanning electron microscopy analysis. Both the as-sprayed coatings exhibited typical splat morphology. The XRD analysis indicated the formation of Ni phase for the Ni-20Cr coating and Ni3Al phase for the Ni3Al coating. It has been concluded that the plasma-sprayed Ni-20Cr and Ni3Al coatings can be useful to reduce the wear rate of AISI 309 SS steel. The coatings were found to be adherent to the substrate steel during the wear tests. The plasma-sprayed Ni3Al coating has been recommended as a better choice to reduce the wear of AISI 309 SS steel, in comparison with the Ni-20Cr coating.

  18. UF{sub 6} cylinder inspections at PGDP

    SciTech Connect

    Lamb, G.W.; Whinnery, W.N.

    1991-12-31

    Routine inspections of all UF{sub 6} cylinders at the Paducah Gaseous Diffusion Plant have been mandated by the Department of Energy. A specific UF{sub 6} cylinder inspection procedure for what items to inspect and training for the operators prior to inspection duty are described. The layout of the cylinder yards and the forms used in the inspections are shown. The large number of cylinders (>30,000) to inspect and the schedule for completion on the mandated time table are discussed. Results of the inspections and the actions to correct the deficiencies are explained. Future inspections and movement of cylinders for relocation of certain cylinder yards are defined.

  19. Flow past tandem cylinders under forced vibration

    NASA Astrophysics Data System (ADS)

    Yang, Yingchen; Aydin, Tayfun B.; Ekmekci, Alis

    2014-01-01

    Flow past two cylinders in tandem arrangement under forced vibration has been studied experimentally employing the hydrogen bubble visualization technique. The Reynolds number, based on the cylinder diameter, is fixed at Re=250. In stationary state of the two cylinders with P/D=2.0, dual vortex shedding frequencies fL (St=0.14) and fH (St=0.18) are identified. fL is associated with the shear layer reattachment behavior and fH is related to the single bluff body behavior. Under a variety of forced vibrations of the two cylinders at a fixed vibration amplitude A/D=0.25, diverse and highly-repetitive vortex patterns are yielded. They are classified into two typical modes—a low-frequency mode and a high-frequency mode. The two modes are represented by two vortex patterns yielded from in-phase vibration of the two cylinders with P/D=2.0 and at vibration frequencies fe≈fL and fe≈fH. The difference between the two modes is on the number of vortices formed per vibration cycle. For the low-frequency mode, the number is four; for the high-frequency model, it is two. In both modes, the vortex formation is phase-locked to the cylinder motion. For a specified mode with a fixed vortex number per cycle, the way the vortices evolve in the wake can be somewhat different by changing the vibration frequency, pitch ratio, as well as the vibration type. These affecting factors have been examined in this work, and the associated vortex patterns have been characterized and compared.

  20. Pulsatile flow past an oscillating cylinder

    NASA Astrophysics Data System (ADS)

    Qamar, Adnan; Seda, Robinson; Bull, Joseph L.

    2011-04-01

    A fundamental study to characterize the flow around an oscillating cylinder in a pulsatile flow environment is investigated. This work is motivated by a new proposed design of the total artificial lung (TAL), which is envisioned to provide better gas exchange. The Navier-Stokes computations in a moving frame of reference were performed to compute the dynamic flow field surrounding the cylinder. Cylinder oscillations and pulsatile free-stream velocity were represented by two sinusoidal waves with amplitudes A and B and frequencies ωc and ω, respectively. The Keulegan-Carpenter number (Kc=Uo/Dωc) was used to describe the frequency of the oscillating cylinder while the pulsatile free-stream velocity was fixed by imposing ω /Kc=1 for all cases investigated. The parameters of interest and their values were amplitude (0.5Dcylinder values (A=0.5, Kc=0.3, and Re=10 and 20). A lock-in phenomenon (cylinder oscillating frequency matched the vortex shedding frequency) was found when Kc=1 for all cases. This lock-in condition was attributed to be the cause of the rise in drag observed in that operating regime. For optimal performance of the modified TAL design it is recommended to operate the device at higher fiber oscillation amplitudes and lower Kc (avoiding the lock-in regime).

  1. Enhancing fatigue life of cylinder-crown integrated structure by optimizing dimension

    NASA Astrophysics Data System (ADS)

    Zhang, Weiwei; Wang, Xiaosong; Wang, Zhongren; Yuan, Shijian

    2015-03-01

    Cylinder-crown integrated hydraulic press (CCIHP) is a new press structure. The hemispherical hydraulic cylinder also functions as a main portion of crown, which has lower weight and higher section modulus compared with the conventional hydraulic cylinder and press crown. As a result, the material strength capacity is better utilized. During the engineering design of cylinder-crown integrated structure, in order to increase the fatigue life, structural optimization on the basis of the adaptive macro genetic algorithms (AMGA) is first conducted to both reduce weight and decrease peak stress. It is shown that the magnitude of the maximum principal stress is decreased by 28.6%, and simultaneously the total weight is reduced by 4.4%. Subsequently, strain-controlled fatigue test is carried out, and the stress-strain hysteresis loops and cyclic hardening curve are obtained. Based on linear fit, the fatigue properties are calculated and used for the fatigue life prediction. It is shown that the predicted fatigue life is significantly increased from 157000 to 1070000 cycles after structural optimization. Finally, according to the optimization design, a 6300 kN CCIHP has been manufactured, and priority application has been also suggested.

  2. Nonlinear spacing and frequency effects of an oscillating cylinder in the wake of a stationary cylinder

    NASA Astrophysics Data System (ADS)

    Zheng, Z.; Yang, Xiaofan

    2008-11-01

    Nonlinear responses to a transversely oscillating cylinder in the wake of a stationary upstream cylinder are studied theoretically by using an immersed-boundary method. It is found that flow around the two cylinders varies with different spacing between the two cylinders and the oscillation frequency of the downstream cylinder. As known in a stationary tandem-cylinder system, there exist the ``vortex suppression regime'' (VS) and the ``vortex formation regime'' (VF). These two regimes are divided by a critical spacing. When the downstream cylinder is forced to oscillate at a fixed amplitude but different frequency, different flow patterns appear in each of the regime. On the other hand, at the same oscillating frequency but different spacing, the response state (lock-in, transient or non-lock-in) changes. While each state has periodic or quasi-periodic behaviors, nonlinear responses appear. All of the analyses are based on vorticity contours, time histories of the velocities in the near wake regions, spectral analyses, and related phase portraits.

  3. Cylinder wakes in flowing soap films.

    PubMed

    Vorobieff, P; Ecke, R E

    1999-09-01

    We present an experimental characterization of cylinder wakes in flowing soap films. From instantaneous velocity and thickness fields, we find the vortex-shedding frequency, mean-flow velocity, and mean-film thickness. Using the empirical relationship between the Reynolds and Strouhal numbers obtained for cylinder wakes in three dimensions, we estimate the effective soap-film viscosity and its dependence on film thickness. We also compare the decay of vorticity with that in a simple Rankine vortex model with a dissipative term to account for air drag. PMID:11970100

  4. Controllable parabolic-cylinder optical rogue wave

    NASA Astrophysics Data System (ADS)

    Zhong, Wei-Ping; Chen, Lang; Belić, Milivoj; Petrović, Nikola

    2014-10-01

    We demonstrate controllable parabolic-cylinder optical rogue waves in certain inhomogeneous media. An analytical rogue wave solution of the generalized nonlinear Schrödinger equation with spatially modulated coefficients and an external potential in the form of modulated quadratic potential is obtained by the similarity transformation. Numerical simulations are performed for comparison with the analytical solutions and to confirm the stability of the rogue wave solution obtained. These optical rogue waves are built by the products of parabolic-cylinder functions and the basic rogue wave solution of the standard nonlinear Schrödinger equation. Such rogue waves may appear in different forms, as the hump and paw profiles.

  5. A Hybrid Approach To Tandem Cylinder Noise

    NASA Technical Reports Server (NTRS)

    Lockard, David P.

    2004-01-01

    Aeolian tone generation from tandem cylinders is predicted using a hybrid approach. A standard computational fluid dynamics (CFD) code is used to compute the unsteady flow around the cylinders, and the acoustics are calculated using the acoustic analogy. The CFD code is nominally second order in space and time and includes several turbulence models, but the SST k - omega model is used for most of the calculations. Significant variation is observed between laminar and turbulent cases, and with changes in the turbulence model. A two-dimensional implementation of the Ffowcs Williams-Hawkings (FW-H) equation is used to predict the far-field noise.

  6. Development of plasma spray coated cylinder liners

    SciTech Connect

    Tricard, M.; Hagan, J.; Redington, P.; Subramanian, K.; Haselkorn, M.

    1996-09-01

    Improved fuel economy and reduction of emissions can be achieved by insulation of the combustion chamber components to reduce heat rejection. However, such insulation will also increase the operating temperature of the piston ring/cylinder liner interface from approximately 150 C to over 300 C. Since existing ring/liner materials cannot withstand these higher operating temperatures alternatives are needed for this critical tribological interface. This paper describes the development of a cost effective ID grinding technique for machining the bores of plasma sprayed diesel engine cylinder liners.

  7. Cylinder wakes in flowing soap films

    SciTech Connect

    Vorobieff, P.; Ecke, R.E. ); Vorobieff, P. )

    1999-09-01

    We present an experimental characterization of cylinder wakes in flowing soap films. From instantaneous velocity and thickness fields, we find the vortex-shedding frequency, mean-flow velocity, and mean-film thickness. Using the empirical relationship between the Reynolds and Strouhal numbers obtained for cylinder wakes in three dimensions, we estimate the effective soap-film viscosity and its dependence on film thickness. We also compare the decay of vorticity with that in a simple Rankine vortex model with a dissipative term to account for air drag. [copyright] [ital 1999] [ital The American Physical Society

  8. Cloud manufacturing: a new manufacturing paradigm

    NASA Astrophysics Data System (ADS)

    Zhang, Lin; Luo, Yongliang; Tao, Fei; Li, Bo Hu; Ren, Lei; Zhang, Xuesong; Guo, Hua; Cheng, Ying; Hu, Anrui; Liu, Yongkui

    2014-03-01

    Combining with the emerged technologies such as cloud computing, the Internet of things, service-oriented technologies and high performance computing, a new manufacturing paradigm - cloud manufacturing (CMfg) - for solving the bottlenecks in the informatisation development and manufacturing applications is introduced. The concept of CMfg, including its architecture, typical characteristics and the key technologies for implementing a CMfg service platform, is discussed. Three core components for constructing a CMfg system, i.e. CMfg resources, manufacturing cloud service and manufacturing cloud are studied, and the constructing method for manufacturing cloud is investigated. Finally, a prototype of CMfg and the existing related works conducted by the authors' group on CMfg are briefly presented.

  9. The distribution alloying elements in alnico 8 and 9 magnets: Site preference of ternary Ti, Fe, Co, and Ni additions in DO{sub 3} Fe{sub 3}Al, Co{sub 3}Al, and Ni{sub 3}Al based intermetallic phases

    SciTech Connect

    Samolyuk, G. D.; Stocks, G. M.; Újfalussy, B.

    2014-11-07

    Recently, interest in alnico magnetic alloys has been rekindled due to their potential to substitute for rare-earth based permanent magnets provided modest improvements in their coercivity can be achieved without loss of saturation magnetization. Recent experimental studies have indicated that atomic and magnetic structure of the two phases (one AlNi-based, the other FeCo-based) that comprise these spinodally decomposed alloy is not as simple as previously thought. A key issue that arises is the distribution of Fe, Co, and Ti within the AlNi-based matrix phase. In this paper, we report the results of first-principles calculations of the site preference of ternary alloying additions in DO{sub 3} Fe{sub 3}Al, Co{sub 3}Al, and Ni{sub 3}Al alloys, as models for the aluminide phase. For compound compositions that are Al rich, which correspond to experimental situation, Ti and Fe are found to occupy the α sites, while Co and Ni prefer the γ sites of the DO{sub 3} lattice. An important finding is that the magnetic moments of transition metals in Fe{sub 3}Al and Co{sub 3}Al are ordered ferromagnetically, whereas the Ni{sub 3}Al were found to be nonmagnetic unless the Fe or Co is added as a ternary element.

  10. Scattering of a modulated pulse by a circular cylinder with longitudinal slots: Reaction in the cylinder

    NASA Astrophysics Data System (ADS)

    Hosono, Hiroyuki

    1995-11-01

    Transient response from a cylinder with longitudinal slots is more complicated than that from a perfect cylinder because the electromagnetic waves are reflected from various parts of the slotted cylinder: exterior surfaces, interior surfaces, and edges. We gave the numerical analysis for E-polarized and H-polarized cases by combining the modified point matching method (MPMM) with the fast inversion of Laplace transform method (FILT). Numerical results for the inner field are presented and discussed. The physical meaning of the transient waveform is discussed in detail. Also, the precision of the analysis is checked carefully.

  11. Advanced Manufacturing Technologies

    NASA Technical Reports Server (NTRS)

    Fikes, John

    2016-01-01

    Advanced Manufacturing Technologies (AMT) is developing and maturing innovative and advanced manufacturing technologies that will enable more capable and lower-cost spacecraft, launch vehicles and infrastructure to enable exploration missions. The technologies will utilize cutting edge materials and emerging capabilities including metallic processes, additive manufacturing, composites, and digital manufacturing. The AMT project supports the National Manufacturing Initiative involving collaboration with other government agencies.

  12. Oxidation behavior of single-crystal Al2O3-fiber-reinforced Ni3Al-based composites

    NASA Astrophysics Data System (ADS)

    Nourbakhsh, S.; Rhee, W. H.; Sahin, O.; Margolin, H.

    1994-07-01

    A series of single-crystal Al2O3-fiber-reinforced Ni3Al-based intermetallic matrix composites were fabricated by pressure casting. The matrices employed were binary Ni3Al, Ni3Al-0.5 at. pct Cr, and Ni3Al-0.34 at. pct Zr. The development of microstructure upon oxidation in air at either 1100 °C or 1200 °C was investigated by optical, scanning, and transmission electron microscopy. In air-oxidized binary Ni3Al, some of the fibers were fully or partially covered with a layer of oxide. A weak fiber/matrix bond in this system, which led to fiber debonding during composite processing, is believed to be responsible for the ingress of O into the composite and oxidation of the matrix in the debonded regions at the fiber/matrix interface. Addition of Cr to Ni3Al resulted in an almost threefold increase in fiber/matrix bond strength. No oxidation of the interface was observed. A thick layer of oxide was formed around all the fibers when the composite was thermally cycled prior to isothermal annealing. Addition of Zr to Ni3Al resulted in the formation of a layer of ZrO2 on the surface of the fibers during composite processing. The ZrO2 layer provided a fast path for the diffusion of O, which led to the formation of a rootlike oxide structure around the fibers. The rootlike structure consisted of a network of Al2O3-covered ZrO2.

  13. Density functional theory study of oxygen reduction reaction on Pt/Pd3Al(111) alloy electrocatalyst.

    PubMed

    Xiao, B B; Jiang, X B; Jiang, Q

    2016-05-25

    Developing efficient catalysts for the oxygen reduction reaction (ORR) to reduce cathode Pt loading without sacrificing the performance has been under intensive research. Herein, by using density functional theory calculations, the activity and stability of a Pt monolayer supported on Pd3Al(111) as the ORR catalyst have been systematically studied. The simulations demonstrate that due to alloying, the ORR intermediates bind weakly on Pt/Pd3Al(111) with optimal adsorption energy of O and OH. By considering the elemental ORR steps, the ORR mechanism is predicted to be an OOH dissociation mechanism. The rate determining step is OOH dissociation with a reaction barrier of 0.37 eV, lower than the corresponding value on Pt/Pt3Al(111) and Pt(111), indicating the superior activity of Pt/Pd3Al(111). Even considering the unfeasible H adsorption under high potential, the ORR mechanism on Pt/Pd3Al(111) would proceed via O2 hydration, OOH hydration, H2O formation, and H2O desorption, indicating a good ORR electrocatalyst. Furthermore, stability was evaluated by calculating the alloy formation energy and the electrochemical potential shift of surface Pt dissolution. The exceptionally negative alloy formation energy of Pd3Al and the positive dissolution potential shift of the surface Pt atoms show the enhanced durability of Pt/Pd3Al(111). The improved activity, in combination with its enhanced stability, makes the novel ternary alloy electrocatalyst very promising for development of new cathode catalysts for fuel cells. PMID:27167779

  14. Breached cylinder incident at the Portsmouth gaseous diffusion plant

    SciTech Connect

    Boelens, R.A.

    1991-12-31

    On June 16, 1990, during an inspection of valves on partially depleted product storage cylinders, a 14-ton partially depleted product cylinder was discovered breached. The cylinder had been placed in long-term storage in 1977 on the top row of Portsmouth`s (two rows high) storage area. The breach was observed when an inspector noticed a pile of green material along side of the cylinder. The breach was estimated to be approximately 8- inches wide and 16-inches long, and ran under the first stiffening ring of the cylinder. During the continuing inspection of the storage area, a second 14-ton product cylinder was discovered breached. This cylinder was stacked on the bottom row in the storage area in 1986. This breach was also located adjacent to a stiffening ring. This paper will discuss the contributing factors of the breaching of the cylinders, the immediate response, subsequent actions in support of the investigation, and corrective actions.

  15. Rotating Cylinder Treatment System Demonstration (Presentation)

    EPA Science Inventory

    In August 2008, a rotating cylinder treatment system (RCTSTM) demonstration was conducted near Gladstone, CO. The RCTSTM is a novel technology developed to replace the aeration/oxidation and mixing components of a conventional lime precipitation treatment s...

  16. Flow around a helically twisted elliptic cylinder

    NASA Astrophysics Data System (ADS)

    Kim, Woojin; Lee, Jungil; Choi, Haecheon

    2016-05-01

    In the present study, we conduct unsteady three-dimensional simulations of flows around a helically twisted elliptic (HTE) cylinder at the Reynolds numbers of 100 and 3900, based on the free-stream velocity and square root of the product of the lengths of its major and minor axes. A parametric study is conducted for Re = 100 by varying the aspect ratio (AR) of the elliptic cross section and the helical spanwise wavelength (λ). Depending on the values of AR and λ, the flow in the wake contains the characteristic wavelengths of λ, 2λ, 6λ, or even longer than 60λ, showing a wide diversity of flows in the wake due to the shape change. The drag on the optimal (i.e., having lowest drag) HTE cylinder (AR = 1.3 and λ = 3.5d) is lower by 18% than that of the circular cylinder, and its lift fluctuations are zero owing to complete suppression of vortex shedding in the wake. This optimal HTE configuration reduces the drag by 23% for Re = 3900 where the wake is turbulent, showing that the HTE cylinder reduces the mean drag and lift fluctuations for both laminar and turbulent flows.

  17. Diffusion Limited Aggregation on a Cylinder

    NASA Astrophysics Data System (ADS)

    Benjamini, Itai; Yadin, Ariel

    2008-04-01

    We consider the DLA process on a cylinder G × {mathbb{N}} . It is shown that this process “grows arms”, provided that the base graph G has small enough mixing time. Specifically, if the mixing time of G is at most log^{(2-ɛ)}left\\vert G right\\vert , the time it takes the cluster to reach the m th layer of the cylinder is at most of order m \\cdot left\\vert G right\\vert/loglogleft\\vert G right\\vert . In particular we get examples of infinite Cayley graphs of degree 5, for which the DLA cluster on these graphs has arbitrarily small density. In addition, we provide an upper bound on the rate at which the “arms” grow. This bound is valid for a large class of base graphs G, including discrete tori of dimension at least 3. It is also shown that for any base graph G, the density of the DLA process on a G-cylinder is related to the rate at which the arms of the cluster grow. This implies that for any vertex transitive G, the density of DLA on a G-cylinder is bounded by 2/3.

  18. Experimental cylinder comparisons for monitoring seedling emergence

    Technology Transfer Automated Retrieval System (TEKTRAN)

    PVC cylinders are used routinely to examine weed seedbank dynamics. Recent observations in our field experiments led us to examine the impacts of artificial barriers, like PVC, on the soil microclimate conditions within weed emergence trials. Barriers examined in this study were: (a) PVC, where soil...

  19. Desktop Manufacturing Technologies.

    ERIC Educational Resources Information Center

    Snyder, Mark

    1991-01-01

    Desktop manufacturing is the use of data from a computer-assisted design system to construct actual models of an object. Emerging processes are stereolithography, laser sintering, ballistic particle manufacturing, laminated object manufacturing, and photochemical machining. (SK)

  20. Modeling creep deformation of a two-phase TiAl/Ti[sub 3]Al alloy with a lamellar microstructure

    SciTech Connect

    Bartholomeusz, M.F. ); Wert, J.A. . Dept. of Materials Science and Engineering)

    1994-10-01

    A two-phase TiAl/Ti[sub 3]Al alloy with a lamellar microstructure has been previously shown to exhibit a lower minimum creep rate than the minimum creep rates of the constituent TiAl and Ti[sub 3]Al single-phase alloys. Fiducial-line experiments described in the present article demonstrate that the creep rates of the constituent phases within the two-phase TiAl/Ti[sub 3]Al lamellar alloy tested in compression are more than an order of magnitude lower than the creep rates of single-phase TiAl and Ti[sub 3]Al alloys tested in compression at the same stress and temperature. Additionally, the fiducial-line experiments show that no interfacial sliding of the phases in the TiAl/Ti[sub 3]Al lamellar alloy occurs during creep. The lower creep rate of the lamellar alloy is attributed to enhanced hardening of the constituent phases within the lamellar microstructure. A composite-strength model has been formulated to predict the creep rate of the lamellar alloy, taking into account the lower creep rates of the constituent phases within the lamellar microstructure. Application of the model yields a very good correlation between the predicted an experimentally observed minimum creep rates over moderate stress and temperature ranges.

  1. Modeling creep deformation of a two-phase TiAI/Ti3Al alloy with a lamellar microstructure

    NASA Astrophysics Data System (ADS)

    Bartholomeusz, Michael F.; Wert, John A.

    1994-10-01

    A two-phase TiAl/Ti3Al alloy with a lamellar microstructure has been previously shown to exhibit a lower minimum creep rate than the minimum creep rates of the constituent TiAl and Ti3Al single-phase alloys. Fiducial-line experiments described in the present article demonstrate that the creep rates of the constituent phases within the two-phase TiAl/Ti3Al lamellar alloy tested in compression are more than an order of magnitude lower than the creep rates of single-phase TiAl and Ti3Al alloys tested in compression at the same stress and temperature. Additionally, the fiducial-line experiments show that no interfacial sliding of the phases in the TiAl/Ti3Al lamellar alloy occurs during creep. The lower creep rate of the lamellar alloy is attributed to enhanced hardening of the constituent phases within the lamellar microstructure. A composite-strength model has been formulated to predict the creep rate of the lamellar alloy, taking into account the lower creep rates of the constituent phases within the lamellar micro-structure. Application of the model yields a very good correlation between predicted and experimentally observed minimum creep rates over moderate stress and temperature ranges.

  2. Failure of Non-Circular Composite Cylinders

    NASA Technical Reports Server (NTRS)

    Hyer, M. W.

    2004-01-01

    In this study, a progressive failure analysis is used to investigate leakage in internally pressurized non-circular composite cylinders. This type of approach accounts for the localized loss of stiffness when material failure occurs at some location in a structure by degrading the local material elastic properties by a certain factor. The manner in which this degradation of material properties takes place depends on the failure modes, which are determined by the application of a failure criterion. The finite-element code STAGS, which has the capability to perform progressive failure analysis using different degradation schemes and failure criteria, is utilized to analyze laboratory scale, graphite-epoxy, elliptical cylinders with quasi-isotropic, circumferentially-stiff, and axially-stiff material orthotropies. The results are divided into two parts. The first part shows that leakage, which is assumed to develop if there is material failure in every layer at some axial and circumferential location within the cylinder, does not occur without failure of fibers. Moreover before fibers begin to fail, only matrix tensile failures, or matrix cracking, takes place, and at least one layer in all three cylinders studied remain uncracked, preventing the formation of a leakage path. That determination is corroborated by the use of different degradation schemes and various failure criteria. Among the degradation schemes investigated are the degradation of different engineering properties, the use of various degradation factors, the recursive or non-recursive degradation of the engineering properties, and the degradation of material properties using different computational approaches. The failure criteria used in the analysis include the noninteractive maximum stress criterion and the interactive Hashin and Tsai-Wu criteria. The second part of the results shows that leakage occurs due to a combination of matrix tensile and compressive, fiber tensile and compressive, and inplane

  3. Nonlinear bending and collapse analysis of a poked cylinder and other point-loaded cylinders

    SciTech Connect

    Sobel, L.H.

    1983-06-01

    This paper analyzes the geometrically nonlinear bending and collapse behavior of an elastic, simply supported cylindrical shell subjected to an inward-directed point load applied at midlength. The large displacement analysis results for this thin (R/t = 638) poked cylinder were obtained from the STAGSC-1 finite element computer program. STAGSC-1 results are also presented for two other point-loaded shell problems: a pinched cylinder (R/t = 100), and a venetian blind (R/t = 250).

  4. An investigation of the autofrettage of a reciprocating pump fluid cylinder

    SciTech Connect

    Sutton, J.L.

    1984-02-01

    An analytical method is presented for computing the autofrettage pressure to be used to sufficiently prestress a reciprocating pump fluid end. The fluid end configuration consists of a pair of ''tee''-intersecting cylindrical bores in a rectangular block. The analysis is based on a finite element method utilizing an initial stress method and is capable of computing elasto-plastic material stresses in machine components manufactured from strain-hardening materials while they are being subjected to a uniform pressure load. Residual stresses and strains are also computed following the unloading of a component. The method is compared to other theoretical solution techniques and experimental stress analyses completed on a simple ''thick-walled'' cylinder and a fluid end. The finite element analysis was confirmed to be a reasonable method for computing cylinder autofrettage pressures as well as being capable of computing the elastoplastic deformations of geometrically complex machine components.

  5. Interfacial reactions in borsic/Ti-3Al-2-1/2V composite

    NASA Technical Reports Server (NTRS)

    Rao, V. B.; Houska, C. R.; Unnam, J.; Brewer, W. D.; Tenney, D. R.

    1979-01-01

    The paper provides a detailed X-ray characterization of a borsic/Ti-3Al-2-1/2V composite, and to correlate the relative intensities of the reaction products with the mechanical properties. Based on X-ray integrated intensity data two stages of interface reactions were identified: during the first stage there is a simultaneous interdiffusion of Si, C, and Ti atoms at the filament/matrix interface resulting in the formation of Ti5Si3, TiSi and small amounts of TiSi2 and TiC. The second stage is associated with considerable TiSi2 and boride formation. It appears that the alpha-phase of Ti is more reactive in forming silicides and borides than the beta-phase. The silicide intensities and the reaction zone thicknesses are shown to be directly related to the reduction of the ultimate tensile strength by thermal degradation, and the results indicate that silicide reaction products are as detrimental to strength as the borides.

  6. Erosion studies on a Fe sub 3 Al-based iron aluminide and 1100 Al

    SciTech Connect

    Rao, M.; Keiser, J.

    1991-01-01

    Samples of a Fe{sub 3}Al-based iron aluminide alloy were eroded using nominally spherical steel shot. Two distinct erosion mechanisms were observed: (1) extrusion of platelets resulting from spherical particle impacts and (2) cutting of the target by angular particles either present in the initial erodent or formed on impact by fracture of the shot. The overall erosion resistance of the alloy was judged to be relatively good and may be improved by increasing the alloy's ductility. Measurements using a mechanical properties microprobe (MPM) showed that significant work hardening occurred due to erosion, but the hardness dropped off near the surface, apparently due to thermal effects. In contrast no sub-surface softening was observed in samples of 1100 Al which were also eroded by steel shot. In order to model the impact process, single 343 {mu}m WC spheres were shot at the two alloys at velocities between 20 m/s and 900 m/s. Compared to the iron aluminide, the craters on 1100 Al show better developed lips and features indicative of sustained plastic deformation. Both alloys showed thermally induced subsurface softening at high velocities. At lower velocities, only the iron aluminide showed clear thermal effects. Results of the single particle and multiple particle impact tests are reconciled in terms of deformation behavior and thermal effects. 22 refs., 7 figs.

  7. On the small angle twist sub-grain boundaries in Ti3AlC2

    PubMed Central

    Zhang, Hui; Zhang, Chao; Hu, Tao; Zhan, Xun; Wang, Xiaohui; Zhou, Yanchun

    2016-01-01

    Tilt-dominated grain boundaries have been investigated in depth in the deformation of MAX phases. In stark contrast, another important type of grain boundaries, twist grain boundaries, have long been overlooked. Here, we report on the observation of small angle twist sub-grain boundaries in a typical MAX phase Ti3AlC2 compressed at 1200 °C, which comprise hexagonal screw dislocation networks formed by basal dislocation reactions. By first-principles investigations on atomic-scale deformation and general stacking fault energy landscapes, it is unequivocally demonstrated that the twist sub-grain boundaries are most likely located between Al and Ti4f (Ti located at the 4f Wyckoff sites of P63/mmc) layers, with breaking of the weakly bonded Al–Ti4f. The twist angle increases with the increase of deformation and is estimated to be around 0.5° for a deformation of 26%. This work may shed light on sub-grain boundaries of MAX phases, and provide fundamental information for future atomic-scale simulations. PMID:27034075

  8. Magnetic and resistance measurements on boron-doped and undoped Ni(3)Al thin films*

    NASA Astrophysics Data System (ADS)

    Henry, L. L.; Patterson, Edward C.

    2000-03-01

    We report preliminary results of magnetization and I-V measurements of the effects of boron doping on the magnetic and electron transport properties of Ni3Al thin films. Magnetization and resistance measurements in magnetic fields up to 5 T were performed on 500 Ånominal) thick films that were fabricated by ion beam sputtering of compound targets. Both a doped ( ~200 ppm B) and undoped film were investigated. For the boron-doped film, the magnetization is enhanced with a broad transition that occurs in several stages over the temperature range from 27 K to 56 K. Further, as the temperature is increased through the transition range dM/dT fluctuates between negative and positive values, and the magnetization changes from positive to negative near T = 52 K. Results of I-V measurements performed on the samples with the current in the plane of the film, and an applied magnetic field parallel to the plane of the film, are consistent with these results. *Work supported by the LEQSF and the Dept. of Physics, Southern U. and A&M College, Baton Rouge campus.

  9. Three-dimensionally Ordered Macroporous Structure Enabled Nanothermite Membrane of Mn2O3/Al.

    PubMed

    Zheng, Guoqiang; Zhang, Wenchao; Shen, Ruiqi; Ye, Jiahai; Qin, Zhichun; Chao, Yimin

    2016-01-01

    Mn2O3 has been selected to realize nanothermite membrane for the first time in the literature. Mn2O3/Al nanothermite has been synthesized by magnetron sputtering a layer of Al film onto three-dimensionally ordered macroporous (3DOM) Mn2O3 skeleton. The energy release is significantly enhanced owing to the unusual 3DOM structure, which ensures Al and Mn2O3 to integrate compactly in nanoscale and greatly increase effective contact area. The morphology and DSC curve of the nanothermite membrane have been investigated at various aluminizing times. At the optimized aluminizing time of 30 min, energy release reaches a maximum of 2.09 kJ∙g(-1), where the Al layer thickness plays a decisive role in the total energy release. This method possesses advantages of high compatibility with MEMS and can be applied to other nanothermite systems easily, which will make great contribution to little-known nanothermite research. PMID:26935405

  10. Three-dimensionally Ordered Macroporous Structure Enabled Nanothermite Membrane of Mn2O3/Al

    NASA Astrophysics Data System (ADS)

    Zheng, Guoqiang; Zhang, Wenchao; Shen, Ruiqi; Ye, Jiahai; Qin, Zhichun; Chao, Yimin

    2016-03-01

    Mn2O3 has been selected to realize nanothermite membrane for the first time in the literature. Mn2O3/Al nanothermite has been synthesized by magnetron sputtering a layer of Al film onto three-dimensionally ordered macroporous (3DOM) Mn2O3 skeleton. The energy release is significantly enhanced owing to the unusual 3DOM structure, which ensures Al and Mn2O3 to integrate compactly in nanoscale and greatly increase effective contact area. The morphology and DSC curve of the nanothermite membrane have been investigated at various aluminizing times. At the optimized aluminizing time of 30 min, energy release reaches a maximum of 2.09 kJ•g-1, where the Al layer thickness plays a decisive role in the total energy release. This method possesses advantages of high compatibility with MEMS and can be applied to other nanothermite systems easily, which will make great contribution to little-known nanothermite research.

  11. Luminescence and scintillation properties of Lu3Al5O12 nanoceramics sintered by SPS method

    NASA Astrophysics Data System (ADS)

    Pejchal, Jan; Babin, Vladimir; Beitlerova, Alena; Kucerkova, Romana; Panek, Dalibor; Barta, Jan; Cuba, Vaclav; Yamaji, Akihiro; Kurosawa, Shunsuke; Mihokova, Eva; Ito, Akihiko; Goto, Takashi; Nikl, Martin; Yoshikawa, Akira

    2016-03-01

    Ce-doped lutetium aluminum garnet Lu3Al5O12 (LuAG) nanoceramics were fabricated at 1600 °C and 1700 °C by spark-plasma sintering (SPS) method from nano-powders prepared by radiation synthesis. Both undoped and Ce-doped LuAG ceramic samples were also prepared from the nano-powders at 1700 °C with significantly increased pre-heating rate. The backscattered electron images revealed large amount of pores in all the Ce-doped samples causing their significant opacity. On the other hand, very large grains and no pores were revealed in the undoped sample, which was the only transparent one. The radioluminescence measurements revealed superior overall scintillation efficiency of the samples sintered at the temperature 1700 °C, and their defect emission in the UV region was ascribed to oxygen-vacancy-related defects such as F+ centers. The photoluminescence decay of the defect emission was characterized by an extremely fast decay time of a few nanoseconds. Influence of sintering procedure and subsequent annealing on the luminescence and scintillation properties is discussed.

  12. Thermal Behavior of Fe2O3/Al Thermite Mixtures in Air and Vacuum Environments

    SciTech Connect

    Duraes, L.; Santos, R.; Correia, A.; Campos, J.; Portugal, A.

    2006-07-28

    In this work, the thermal behavior of Fe2O3/Al thermite mixtures, in air and vacuum, is studied. The individual reactants and three mixtures - stoichiometric and over aluminized - are tested, by Simultaneous Thermal Analysis (STA) and heating microscopy, with a heating rate of 10 deg. C/min. The STA results show that the presence of O2 from air, or from residual air in vacuum, influenced the reaction scheme. The Al oxidation by this oxygen was extensive, making the thermite reaction with Fe2O3 unviable. There was also evidence of significant conversion of the Fe2O3 into Fe3O4, supporting the previous conclusion. So, the STA curves for the three mixtures were similar and displayed features of the individual reactants' curves. The heating microscopy images confirmed the STA conclusions, with one exception: the thermal explosion of the Al sample close to 550 deg. C. The absence of this phenomenon in STA results was explained by the limited amount of material used in each sample.

  13. Measurement and Evaluation of Crystallographic Texture in Ti-3Al-2.5V Tubing

    NASA Astrophysics Data System (ADS)

    Zhang, H.; Sheng, Z. M.; Zhang, W. F.; Wang, Y. H.; Yan, M. Q.

    2015-06-01

    Although the texture of Ti alloys is currently evaluated by the pole figure, it can only provide incomplete and qualitative information. In this investigation, the textures of Ti-3Al-2.5V tubing were studied to seek for an appropriate method for evaluating Ti tubing texture. The texture measurement was performed by thinning the tubing chemically into foils and flattening them, followed by x-ray diffraction analysis. A Bruker D8 Advance texture goniometer with Cu Kα radiation was employed for measuring the {0002}, {10-10}, {10-12}, {11-20} and {10-13} incomplete pole figures using the Schultz reflection technique. Based on the pole data, the crystallite orientation distribution function (ODF) was synthesized using TexEval V2.5 software, Bruker AXS GmbH. The texture strengths of the three specimens were compared using pole figures and ODF. It is found that it gives rise to a large error in the texture strength using the pole figure to evaluate texture. The orientation densities of the maxima in ODF and the tilt angle of their basal poles from the normal toward the tangential direction can describe the tubing texture accurately, which can evaluate the tubing mechanical properties. Subsequently, ODF can be used to predict the mechanical properties of batches of tubing.

  14. Magnetic ordering of Ce in the heavy-fermion compound Ce3Al

    NASA Astrophysics Data System (ADS)

    Li, W.-H.; Peng, J. C.; Lin, Y.-C.; Lee, K. C.; Lynn, J. W.; Chen, Y. Y.

    1998-06-01

    Neutron diffraction and specific heat measurements have been performed to study the magnetic ordering of the Ce ions in the heavy-fermion compound Ce3Al. Detailed crystal structure analysis, determined using high resolution neutron diffraction patterns and Rietveld method, shows that the Ce ions may be grouped into two types: one in the Ce-Al chain, the other in the Ce-Ce chain. The specific-heat data reveal an anomaly at T≈2.2 K, but the calculated magnetic entropy is much smaller than the expected R ln 2 if all Ce spins ordered. Low temperature neutron diffraction measurements confirm that the transition at 2.2 K is magnetic and is associated with the ordering of the Ce spins. The magnetic unit cell is double the nuclear one along the a and c axes, and contains 48 Ce ions. Only the Ce ions in the Ce-Al chains participate in the ordering at 2.2 K, and they are coupled antiferromagnetically.

  15. Hot Deformation Behavior of Beta Titanium Ti-13V-11Cr-3Al Alloy

    NASA Astrophysics Data System (ADS)

    Abbasi, Seyed Mehdi; Morakkabati, Maryam; Sheikhali, Amir Hossein; Momeni, Amir

    2014-10-01

    Hot compression tests were conducted on Ti-13V-11Cr-3Al beta-Ti alloy in the temperature range of 1203 K to 1353 K (930 °C to 1080 °C) and at strain rates between 0.001 and 1 s-1 The stress-strain curves showed pronounced yield point phenomena at high strain rates and low temperatures. The yield point elongation and flow stresses at the upper and lower yield points were related to the Zener-Hollomon parameter. It was found that dynamic recovery at low strain rates and dynamic recrystallization at high strain rates were the controlling mechanisms of microstructural evolution. The results also showed that strain rate had a stronger influence on the hot deformation behavior than temperature. The microstructural observations and constitutive analysis of flow stress data supported the change in the hot deformation behavior of the studied alloy varies with strain rate. For various applied strain rates, the activation energy for hot deformation was calculated in range of 199.5 to 361.7 kJ/mol. At low strain rates (0.001 and 0.01 s-1), the value of activation energy was very close to the activation energy for the diffusion of V, Cr, and Al in beta titanium. The higher value of activation energy for deformation at high strain rates (0.1 and 1 s-1) was attributed to the accumulation of dislocations and the tendency to initiate dynamic recrystallization.

  16. Postperovskite phase equilibria in the MgSiO3-Al2O3 system.

    PubMed

    Tsuchiya, Jun; Tsuchiya, Taku

    2008-12-01

    We investigate high-P,T phase equilibria of the MgSiO(3)-Al(2)O(3) system by means of the density functional ab initio computation methods with multiconfiguration sampling. Being different from earlier studies based on the static substitution properties with no consideration of Rh(2)O(3)(II) phase, present calculations demonstrate that (i) dissolving Al(2)O(3) tends to decrease the postperovskite transition pressure of MgSiO(3) but the effect is not significant ( approximately -0.2 GPa/mol% Al(2)O(3)); (ii) Al(2)O(3) produces the narrow perovskite+postperovskite coexisting P,T area (approximately 1 GPa) for the pyrolitic concentration (x(Al2O3) approximately 6 mol%), which is sufficiently responsible to the deep-mantle D'' seismic discontinuity; (iii) the transition would be smeared (approximately 4 GPa) for the basaltic Al-rich composition (x(Al2O3) approximately 20 mol%), which is still seismically visible unless iron has significant effects; and last (iv) the perovskite structure spontaneously changes to the Rh(2)O(3)(II) with increasing the Al concentration involving small displacements of the Mg-site cations. PMID:19036928

  17. Computer simulation of superdislocation dissociation in Ni{sub 3}Al

    SciTech Connect

    Wen, M.; Li, S.

    1998-07-24

    The dissociation of a [{bar 1}01] superdislocation in Ni{sub 3}Al is studied by computer simulation techniques using the embedded atom method (EAM). Three types of dissociation are obtained, depending on the initial position of the elastic centers of the superdislocation. One is the stable planar dissociation that the superdislocation dissociates on only one {l_brace}111{r_brace} plane into a pair of 1/2 [{bar 1}01] superpartials separated by an antiphase boundary (APB). Another stable dissociation is that it occurs on two adjacent {l_brace}111{r_brace} planes joined by an intersecting {l_brace}111{r_brace} or (010) plane. The metastable one is that the dissociation occurs in T shape; the superdislocation dissociates on two intersecting {l_brace}111{r_brace} planes into three partials: one 1/2 [{bar 1}01] partial and two widely separated 1/6{l_brace}112{r_brace} Shockley partials with a complex stacking fault (CSF) in between.

  18. The behavior of nanothermite reaction based on Bi2O3/Al

    NASA Astrophysics Data System (ADS)

    Wang, L.; Luss, D.; Martirosyan, K. S.

    2011-10-01

    We studied the impact of aluminum particle size and the thickness of surrounding alumina layer on the dynamic pressure discharge of nanothermite reactions in the Bi2O3/Al system. A pressure discharge from 9 to 13 MPa was generated using as-synthesized Bi2O3 nano-particles produced by combustion synthesis and Al nanoparticles with size from 3 μm to 100 nm. The maximum reaction temperature was measured to be ˜2700 °C. The estimated activation energy of the reaction was 45 kJ/mol. A very large (several orders of magnitude) difference existed between the rate of the pressure pulse release by nanothermite reactions and by thermite reactions with large aluminum particles. The maximum observed pressurization rate was 3200 GPa/s. The time needed to reach the peak pressure was 0.01 ms and 100 ms for aluminum particles with diameter of 100 nm and 70 microns, respectively. The discharge pressure was a monotonic decreasing function of the thickness of the surrounding alumina layer.

  19. Modeling of the dislocation dynamics in Ni{sub 3}Al and the flow stress anomaly

    SciTech Connect

    Devincre, B.; Veyssiere, P.; Kubin, L.; Saada, G.

    1997-12-31

    Ni{sub 3}Al single crystals are known to exhibit a flow stress anomaly between 200 and 800 K. The purpose of this work is to examine such an anomaly by means of a simulation of the dislocation dynamics at a mesoscopic scale. The simulation basic rules are: (i) the dislocation glide in {l_brace}111{r_brace} octahedral planes, (ii) the conditions at which screw lines are locked and unlocked by the formation of Kear-Wilsdorf locks, (iii) the mobility of jogs in the {l_brace}100{r_brace} cube plane. The results suggest that two different temperature regimes occur in the domain of the anomaly. At low temperatures, the plastic flow is governed by kink bow-out, itself a function of the kink length. At high temperatures, the plastic flow is governed by the unlocking of the weakest Kear-Wilsdorf locks in the microstructure. These outcomes of the simulation are discussed in relation with the existing theoretical models of the flow stress anomaly.

  20. Primary creep of Ni{sub 3}(Al, Ta) single crystals at room temperature

    SciTech Connect

    Uchic, M.D.; Nix, W.D.

    1997-12-31

    This study examines the time-dependent deformation of Ni{sub 3}(Al, Ta) at room temperature. Tension creep experiments have been performed on single crystals with one [111]<101> slip system active at the start of the test, where the applied stress ranged from 66.4 MPa (the measured 0.01% flow stress) to 143 MPa (which produced approximately 9% plastic strain). All creep curves displayed primary creep leading to eventual exhaustion, where the measured creep strain declined at a rate faster than predicted for logarithmic creep. However, no correlation between the applied stress and the form of the declining creep rate can be made at this time. Many creep curves can be obtained from one sample, as the creep curves from both virgin samples and samples with prior deformation history (at the same test stress) were indistinguishable. At the beginning of an incremental creep test, where the stress is increased by a small amount to reinitiate plastic flow in an exhausted sample, a significant retardation of the plastic response of the sample occurred when the stress increment was below 4 MPa. Preliminary TEM studies of a sample strained to 6% suggest that room temperature creep tests may not be ideal for examining the flow of Anti-Phase-Boundary (APB) dissociated dislocations.

  1. The stability of irradiation-induced defects in Ni sub 3 Al

    SciTech Connect

    Pedraza, D.F. ); Caro, A. , Villigen ); Farkas, D. )

    1990-01-01

    The L1{sub 2} Ni{sub 3}Al compound is known to be disordered by ion or electron irradiation, while preserving its crystalline structure. In this work, embedded-atom potentials are used to investigate the change of internal energy of the crystal and of the lattice parameter as a function of the degree of long range order. Various vacancy-interstitial configurations are investigated in order to explore the possibility of substantial point defect buildup. It is found that spontaneous recombination is a function of the nature of the interstitial, the vacancy-interstitial distance and the characteristics of the atomic environment of the pair. The vacancy-interstitial interaction is also found to be, in some cases, dependent on the local atomic environment. Local disorder, moreover, can produce in some cases interstitial trapping. The implications of the effects obtained in the present simulations on the possibility of an irradiation-induced amorphous transition are discussed. 15 refs., 2 figs., 3 tabs.

  2. Micromachining of Ti-3Al-2.5V tubes by nanosecond Nd:YAG laser

    NASA Astrophysics Data System (ADS)

    Lin, Yaomin; Gupta, Mool C.

    2013-03-01

    Laser micromachining is one of many laser material processing technologies employed in scientific research and engineering applications. It involves the deposition of photon energy and the material interaction. The intense photothermal energy is transported into the target material causing melting and evaporation. The material is removed layer by layer by melting and flowing away or by direct vaporization / ablation. It is due to the focused small spot size that the laser micromachining can remove material in small quantity at a time, thus precise control of geometrical dimension is possible. In this work, a nanosecond pulsed Nd:Yttrium-Aluminum-Garnet (Nd:YAG) laser was employed to generate relatively long notch of different dimensions (25.4 mm-length × 0.1 mm-width × 0.051/0.102/0.152 mmdepth) on Ti-3Al-2.5V seamless tubes for fatigue life study. Cyclic hydraulic impulse pressure test was conducted to find out the fatigue limits of the titanium tube containing the laser micromachined notch. The results of fatigue lives, crack profile and pattern of crack propagation are presented and discussed in this paper. Scanning electron microscopy was employed to characterize the fatigue crack profile and the laser micronotch. The capability of generating sharper notch root and consistent pre-crack on the surface of materials makes nanosecond pulsed Nd:YAG laser a great choice in preparing for fatigue test samples for crack growth life study.

  3. On the small angle twist sub-grain boundaries in Ti3AlC2

    NASA Astrophysics Data System (ADS)

    Zhang, Hui; Zhang, Chao; Hu, Tao; Zhan, Xun; Wang, Xiaohui; Zhou, Yanchun

    2016-04-01

    Tilt-dominated grain boundaries have been investigated in depth in the deformation of MAX phases. In stark contrast, another important type of grain boundaries, twist grain boundaries, have long been overlooked. Here, we report on the observation of small angle twist sub-grain boundaries in a typical MAX phase Ti3AlC2 compressed at 1200 °C, which comprise hexagonal screw dislocation networks formed by basal dislocation reactions. By first-principles investigations on atomic-scale deformation and general stacking fault energy landscapes, it is unequivocally demonstrated that the twist sub-grain boundaries are most likely located between Al and Ti4f (Ti located at the 4f Wyckoff sites of P63/mmc) layers, with breaking of the weakly bonded Al–Ti4f. The twist angle increases with the increase of deformation and is estimated to be around 0.5° for a deformation of 26%. This work may shed light on sub-grain boundaries of MAX phases, and provide fundamental information for future atomic-scale simulations.

  4. Synthesis and characterization of Sr3Al2O6 nanocomposite as catalyst for biodiesel production.

    PubMed

    Rashtizadeh, Elnaz; Farzaneh, Faezeh; Talebpour, Zahra

    2014-02-01

    Sr-Al mixed oxides nanocomposite as Sr3Al2O6 was prepared by sol-gel method and used as a basic heterogeneous catalyst for transesterification of soybean oil to methyl esters (biodiesel) by methanol. The prepared catalyst was characterized using X-ray diffraction (XRD), Transmission electron microscope (TEM), thermogravimetric analysis (TGA/DTA), temperature-programmed desorption (TPD) and nitrogen adsorption-desorption techniques. The response surface methodology (RSM) based on the Box-Behnken design was employed to investigate the effects of methanol to oil molar ratio, reaction time, catalyst amount and specifically the effect of interaction between process variables on the conversion of oil to biodiesel. Results from this study revealed that individual as well as bilateral variables interactions significantly affect the yield of biodiesel. With this information, it was found that utilization of methanol to oil molar ratio of 25 and 1.3 wt.% of catalyst within reaction time of 61 min and gave the biodiesel yield of 95.7 ± 0.5%. PMID:24384309

  5. High Temperature Mechanical Characterization and Analysis of Al2O3 /Al2O3 Composition

    NASA Technical Reports Server (NTRS)

    Gyekenyesi, John Z.; Jaskowiak, Martha H.

    1999-01-01

    Sixteen ply unidirectional zirconia coated single crystal Al2O3 fiber reinforced polycrystalline Al2O3 was tested in uniaxial tension at temperatures to 1400 C in air. Fiber volume fractions ranged from 26 to 31%. The matrix has primarily open porosity of approximately 40%. Theories for predicting the Young's modulus, first matrix cracking stress, and ultimate strength were applied and evaluated for suitability in predicting the mechanical behavior of Al2O3/Al2O3 composites. The composite exhibited pseudo tough behavior (increased area under the stress/strain curve relative to monolithic alumina) from 22 to 1400 C. The rule-of-mixtures provides a good estimate of the Young's modulus of the composite using the constituent properties from room temperature to approximately 1200 C for short term static tensile tests in air. The ACK theory provides the best approximation of the first matrix cracking stress while accounting for residual stresses at room temperature. Difficulties in determining the fiber/matrix interfacial shear stress at high temperatures prevented the accurate prediction of the first matrix cracking stress above room temperature. The theory of Cao and Thouless, based on Weibull statistics, gave the best prediction for the composite ultimate tensile strength.

  6. Properties of large heats of Fe sub 3 Al-based alloys

    SciTech Connect

    Sikka, V.K.; McKamey, C.G.; Howell, C.R.; Baldwin, R.H.

    1991-03-01

    The scaleup of three Fe{sub 3}Al-based alloys at several commercial vendors is described. The scaleup processes examined the effect of crucible materials (MgO versus Al{sub 2}O{sub 3}), melting practice, vacuum-induction melting, vacuum-arc remelting, electroslag remelting, and processing under commercial conditions. Each alloy is designed for a specific use: sulfidation resistance, room-temperature ductility, and high-temperature strength. One of the alloys was also scaled up through powder production by nitrogen-gas atomization. The scaled-up heats varied in size from 50 to 250 kg (100 to 500 lb). The ingot sizes varied from 38- to 203-mm (1 1/2- to 8-in.) diam. The scaleup processes occurred at Ametek Specialty Metal Products Division; Haynes International, Inc.; Carpenter Technology Corporation; Special Metals Corporation; and Precision Rolled Products, Inc. The processing of 102-mm-diam (4-in.) ingots at the Oak Ridge National Laboratory into plate and sheet is described in detail. Tensile and creep data on a large powder-metallurgy and cast-and-worked alloys are presented. Recommendations are made for future work on the heats scaled up in this study. 2 refs., 25 figs., 6 tabs.

  7. Magnetization, Low Field Instability and Quench of RHQT Nb(3)Al Strands

    SciTech Connect

    Yamada, R.; Wake, M.; Kikuchi, A.; Velev, V.; /Fermilab

    2009-01-01

    Since 2005, we made and tested three RHQT Nb{sub 3}Al strands, one with Nb matrix and two with Ta matrix, which are fully stabilized with Cu electroplating. We observed anomalously large magnetization curves extending beyond 1 to 1.5 Tesla with the F1 Nb matrix strand at 4.2 K, when we measured its magnetization with a balanced coil magnetometer. This problem was eliminated with the Ta matrix strands operating at 4.2 K. But with these strands a similar but smaller anomalous magnetization was observed at 1.9 K. We studied these phenomena with FEM. With the F1 Nb matrix strand, it is explained that at low external field, inter-filamentary coupling currents in the outer layers of sub-elements create a shielding effect. It reduces the inside field, keeps the inside Nb matrix superconductive, and stands against a higher outside field beyond the Hc of Nb. At an even higher external field, the superconductivity of the whole Nb matrix collapses and releases a large amount of energy, which may cause a big quench. Depending on the size of the energy in the strand or the cable, a magnet could quench, causing the low field instability. Some attempt to analyze the anomaly with FEM is presented.

  8. Reactive Plasma Spraying of Fine Al2O3/AlN Feedstock Powder

    NASA Astrophysics Data System (ADS)

    Shahien, Mohammed; Yamada, Motohiro; Yasui, Toshiaki; Fukumoto, Masahiro

    2013-12-01

    Reactive plasma spraying (RPS) is a promising technology for in situ formation of aluminum nitride (AlN) coatings. Recently, AlN-based coatings were fabricated by RPS of alumina (Al2O3) powder in N2/H2 thermal plasma. This study investigated the feasibility of RPS of a fine Al2O3/AlN mixture and the influence of the plasma gases (N2, H2) on the nitriding conversion, and coating microstructure and properties. Thick AlN/Al2O3 coatings with high nitride content were successfully fabricated. The coatings consist of h-AlN, c-AlN, Al5O6N, γ-Al2O3, and a small amount of α-Al2O3. Use of fine particles enhanced the nitriding conversion and the melting tendency by increasing the surface area. Furthermore, the AlN additive improved the AlN content in the coatings. Increasing the N2 gas flow rate improved the nitride content and complete crystal growth to the h-AlN phase, and enhanced the coating thickness. On the other hand, though the H2 gas is required for plasma nitriding of the Al2O3 particles, increasing its flow rate decreased the nitride content and the coating thickness. Remarkable influence of the plasma gases on the coating composition, microstructure, and properties was observed during RPS of the fine particles.

  9. Thermoelectric Powers of Cells With NaF-AlF3-Al2O3 Melts

    NASA Astrophysics Data System (ADS)

    Flem, Belinda E.; Xu, Qian; Kjelstrup, Signe; Sterten, Åsmund

    2001-07-01

    A thermodynamic description of the Peltier heat at the aluminum and the oxygen electrode in the system NaF-AlF3-Al2O3 is given. The thermoelectric power in melts with molar ratios n NaF/n AlF3 from 3.0 to 1.0, saturated with alumina are measured. Seebeck coefficients for molten fluoride electrolytes saturated with alumina, electrolytes that are relevant for aluminum electrowinning electrolysis cells, are reported. The results allow determinations of Peltier heats of aluminum, oxygen and carbon electrodes in NaF-AlF3 electrolytes saturated with alumina. For molar ratios of n NaF/n AlF3 between 2.6 and 1.2, there is a Peltier heating of the aluminum cathode. This heating is in the same order of magnitude as the electrolyte Joule heat, when the current density is 0.7 A cm-2. For molar ratio n NaF/n AlF3 equal to 1.0 the Peltier effect at the aluminum electrode approaches zero. From theoretical considerations we expect a drop also for molar ratio 3.0. For the anode we report a Peltier cooling that is larger than the heat produced by the anodic overvoltage, in melts with NaF/AlF3 molar ratio between 2.6 and 1.2 saturated with alumina.

  10. A15 superconductors through direct solid-state precipitation: V3Ga and Nb3Al

    NASA Astrophysics Data System (ADS)

    Hong, M.

    1980-09-01

    The use of a solid-state precipitation process to prepare superconducting tapes containing an A15 phase, V3Ga or Nb3Al in a ductile niobium or vanadium containing BCC matrix is discussed. Ingots were prepared by arc-melting, homogenized, quenched, warm-rolled over 99% into tape and aged at temperatures in the range 600 C - 1000 C to precipitate the superconducting A15 phase. In the V-Ga system, transmission electron microscopy (TEM) studies revealed the A15 precipitates in an elongated form. However, for the Nb-Al samples deformed and aged at 750 C, TEM studies revealed A15 precipitation in fine equi-axed particles which formed as a semicontinuous network over sub-grain boundaries formed by the recovery of deformation-induced dislocations. In the V-Ga system, the maximum critical transition temperature (15 K) was found in materials aged at temperatures of 750 C or below. At these aging temperatures the T sub C initially increased with aging time and passed through a distinct maximum. In the Nb-Al system and T sub C increased with aging time to a plateau and then increased again to a second plateau. The maximum T sub C measured was 17 K. Promising high-field overall critical currents were obtained in the Nb-Al system.

  11. Three-dimensionally Ordered Macroporous Structure Enabled Nanothermite Membrane of Mn2O3/Al

    PubMed Central

    Zheng, Guoqiang; Zhang, Wenchao; Shen, Ruiqi; Ye, Jiahai; Qin, Zhichun; Chao, Yimin

    2016-01-01

    Mn2O3 has been selected to realize nanothermite membrane for the first time in the literature. Mn2O3/Al nanothermite has been synthesized by magnetron sputtering a layer of Al film onto three-dimensionally ordered macroporous (3DOM) Mn2O3 skeleton. The energy release is significantly enhanced owing to the unusual 3DOM structure, which ensures Al and Mn2O3 to integrate compactly in nanoscale and greatly increase effective contact area. The morphology and DSC curve of the nanothermite membrane have been investigated at various aluminizing times. At the optimized aluminizing time of 30 min, energy release reaches a maximum of 2.09 kJ∙g−1, where the Al layer thickness plays a decisive role in the total energy release. This method possesses advantages of high compatibility with MEMS and can be applied to other nanothermite systems easily, which will make great contribution to little-known nanothermite research. PMID:26935405

  12. Investigation of breached depleted UF{sub 6} cylinders

    SciTech Connect

    DeVan, J.H.

    1991-12-31

    In June 1990, during a three-site inspection of cylinders being used for long-term storage of solid depleted UF{sub 6}, two 14-ton cylinders at Portsmouth, Ohio, were discovered with holes in the barrel section of the cylinders. An investigation team was immediately formed to determine the cause of the failures and their impact on future storage procedures and to recommend corrective actions. Subsequent investigation showed that the failures most probably resulted from mechanical damage that occurred at the time that the cylinders had been placed in the storage yard. In both cylinders evidence pointed to the impact of a lifting lug of an adjacent cylinder near the front stiffening ring, where deflection of the cylinder could occur only by tearing the cylinder. The impacts appear to have punctured the cylinders and thereby set up corrosion processes that greatly extended the openings in the wall and obliterated the original crack. Fortunately, the reaction products formed by this process were relatively protective and prevented any large-scale loss of uranium. The main factors that precipitated the failures were inadequate spacing between cylinders and deviations in the orientations of lifting lugs from their intended horizontal position. After reviewing the causes and effects of the failures, the team`s principal recommendation for remedial action concerned improved cylinder handling and inspection procedures. Design modifications and supplementary mechanical tests were also recommended to improve the cylinder containment integrity during the stacking operation.

  13. 58. (Credit JTL) View looking northeast across steam cylinders of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    58. (Credit JTL) View looking northeast across steam cylinders of Allis-Chalmers pumping engine. High-pressure cylinder is in foreground, low-pressure cylinder in background with part of Corliss valve gear visible. - McNeil Street Pumping Station, McNeil Street & Cross Bayou, Shreveport, Caddo Parish, LA

  14. 46 CFR 95.16-20 - Extinguishing agent: Cylinder storage.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... inspection and for weighing in the case of halocarbon system cylinders. (f) The cylinders must be installed... VESSELS FIRE PROTECTION EQUIPMENT Fixed Clean Agent Gas Extinguishing Systems, Details § 95.16-20... in 46 CFR 72.05-10. (b) The cylinders may be stored inside the protected space, if: (1) The...

  15. 46 CFR 95.16-20 - Extinguishing agent: Cylinder storage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... inspection and for weighing in the case of halocarbon system cylinders. (f) The cylinders must be installed... VESSELS FIRE PROTECTION EQUIPMENT Fixed Clean Agent Gas Extinguishing Systems, Details § 95.16-20... in 46 CFR 72.05-10. (b) The cylinders may be stored inside the protected space, if: (1) The...

  16. 46 CFR 95.16-20 - Extinguishing agent: Cylinder storage.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... inspection and for weighing in the case of halocarbon system cylinders. (f) The cylinders must be installed... VESSELS FIRE PROTECTION EQUIPMENT Fixed Clean Agent Gas Extinguishing Systems, Details § 95.16-20... in 46 CFR 72.05-10. (b) The cylinders may be stored inside the protected space, if: (1) The...

  17. Lint Cleaning Performance of a Modified Cylinder Cleaner

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objectives of the experiments were to evaluate the lint cleaning performance of a modified cylinder cleaner with sharp cleaning-edge grid bars and compare the performance of one cylinder cleaner to two cylinder cleaners in series operating at one or two speeds. Overall, in comparison to the base...

  18. Pistons and Cylinders Made of Carbon-Carbon Composite Materials

    NASA Technical Reports Server (NTRS)

    Rivers, H. Kevin (Inventor); Ransone, Philip O. (Inventor); Northam, G. Burton (Inventor); Schwind, Francis A. (Inventor)

    2000-01-01

    An improved reciprocating internal combustion engine has a plurality of engine pistons, which are fabricated from carbon---carbon composite materials, in operative association with an engine cylinder block, or an engine cylinder tube, or an engine cylinder jug, all of which are also fabricated from carbon-carbon composite materials.

  19. Pistons and Cylinders Made of Carbon-Carbon Composite Materials

    NASA Technical Reports Server (NTRS)

    Rivers, H. Kevin (Inventor); Ransone, Philip O. (Inventor); Northam, G. Burton (Inventor); Schwind, Francis A. (Inventor)

    2000-01-01

    An improved reciprocating internal combustion engine has a plurality of engine pistons, which are fabricated from carbon-carbon composite materials, in operative association with an engine cylinder block, or an engine cylinder tube, or an engine cylinder jug, all of which are also fabricated from carbon-carbon composite materials.

  20. 49 CFR 173.316 - Cryogenic liquids in cylinders.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... cylinders. (a) General requirements. (1) A cylinder may not be loaded with a cryogenic liquid colder than... jacket covering the insulation on a cylinder used to transport any flammable cryogenic liquid must be... that may come in contact with oxygen in the cryogenic liquid form may not be installed on any...

  1. 49 CFR 173.316 - Cryogenic liquids in cylinders.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... cylinders. (a) General requirements. (1) A cylinder may not be loaded with a cryogenic liquid colder than... jacket covering the insulation on a cylinder used to transport any flammable cryogenic liquid must be... that may come in contact with oxygen in the cryogenic liquid form may not be installed on any...

  2. 49 CFR 173.316 - Cryogenic liquids in cylinders.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... cylinders. (a) General requirements. (1) A cylinder may not be loaded with a cryogenic liquid colder than... jacket covering the insulation on a cylinder used to transport any flammable cryogenic liquid must be... that may come in contact with oxygen in the cryogenic liquid form may not be installed on any...

  3. 49 CFR 173.316 - Cryogenic liquids in cylinders.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... cylinders. (a) General requirements. (1) A cylinder may not be loaded with a cryogenic liquid colder than... jacket covering the insulation on a cylinder used to transport any flammable cryogenic liquid must be... that may come in contact with oxygen in the cryogenic liquid form may not be installed on any...

  4. 30 CFR 56.16005 - Securing gas cylinders.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Securing gas cylinders. 56.16005 Section 56.16005 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... and Handling § 56.16005 Securing gas cylinders. Compressed and liquid gas cylinders shall be...

  5. 30 CFR 57.16005 - Securing gas cylinders.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Securing gas cylinders. 57.16005 Section 57.16005 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Storage and Handling § 57.16005 Securing gas cylinders. Compressed and liquid gas cylinders shall...

  6. 30 CFR 56.16005 - Securing gas cylinders.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Securing gas cylinders. 56.16005 Section 56.16005 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... and Handling § 56.16005 Securing gas cylinders. Compressed and liquid gas cylinders shall be...

  7. 30 CFR 57.16005 - Securing gas cylinders.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Securing gas cylinders. 57.16005 Section 57.16005 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Storage and Handling § 57.16005 Securing gas cylinders. Compressed and liquid gas cylinders shall...

  8. 49 CFR 176.92 - Cylinders laden in vehicles.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Cylinders laden in vehicles. 176.92 Section 176.92... Requirements for Transport Vehicles Loaded With Hazardous Materials and Transported on Board Ferry Vessels § 176.92 Cylinders laden in vehicles. Any cylinder of Class 2 (compressed gas) material which...

  9. 49 CFR 176.92 - Cylinders laden in vehicles.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Cylinders laden in vehicles. 176.92 Section 176.92... Requirements for Transport Vehicles Loaded With Hazardous Materials and Transported on Board Ferry Vessels § 176.92 Cylinders laden in vehicles. Any cylinder of Class 2 (compressed gas) material which...

  10. 46 CFR 58.30-30 - Fluid power cylinders.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Fluid power cylinders. 58.30-30 Section 58.30-30... MACHINERY AND RELATED SYSTEMS Fluid Power and Control Systems § 58.30-30 Fluid power cylinders. (a) The... all pneumatic power transmission systems. (b) Fluid power cylinders consisting of a container and...

  11. 46 CFR 58.30-30 - Fluid power cylinders.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Fluid power cylinders. 58.30-30 Section 58.30-30... MACHINERY AND RELATED SYSTEMS Fluid Power and Control Systems § 58.30-30 Fluid power cylinders. (a) The... all pneumatic power transmission systems. (b) Fluid power cylinders consisting of a container and...

  12. 46 CFR 58.30-30 - Fluid power cylinders.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Fluid power cylinders. 58.30-30 Section 58.30-30... MACHINERY AND RELATED SYSTEMS Fluid Power and Control Systems § 58.30-30 Fluid power cylinders. (a) The... all pneumatic power transmission systems. (b) Fluid power cylinders consisting of a container and...

  13. 46 CFR 58.30-30 - Fluid power cylinders.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Fluid power cylinders. 58.30-30 Section 58.30-30... MACHINERY AND RELATED SYSTEMS Fluid Power and Control Systems § 58.30-30 Fluid power cylinders. (a) The... all pneumatic power transmission systems. (b) Fluid power cylinders consisting of a container and...

  14. 46 CFR 58.30-30 - Fluid power cylinders.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Fluid power cylinders. 58.30-30 Section 58.30-30... MACHINERY AND RELATED SYSTEMS Fluid Power and Control Systems § 58.30-30 Fluid power cylinders. (a) The... all pneumatic power transmission systems. (b) Fluid power cylinders consisting of a container and...

  15. 30 CFR 57.4601 - Oxygen cylinder storage.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Oxygen cylinder storage. 57.4601 Section 57... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Fire Prevention and Control Welding/cutting/compressed Gases § 57.4601 Oxygen cylinder storage. Oxygen cylinders...

  16. 30 CFR 57.4601 - Oxygen cylinder storage.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Oxygen cylinder storage. 57.4601 Section 57... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Fire Prevention and Control Welding/cutting/compressed Gases § 57.4601 Oxygen cylinder storage. Oxygen cylinders...

  17. 30 CFR 56.4601 - Oxygen cylinder storage.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Oxygen cylinder storage. 56.4601 Section 56... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Fire Prevention and Control Welding/cutting/compressed Gases § 56.4601 Oxygen cylinder storage. Oxygen cylinders shall not...

  18. 30 CFR 57.4601 - Oxygen cylinder storage.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Oxygen cylinder storage. 57.4601 Section 57... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Fire Prevention and Control Welding/cutting/compressed Gases § 57.4601 Oxygen cylinder storage. Oxygen cylinders...

  19. 30 CFR 56.4601 - Oxygen cylinder storage.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Oxygen cylinder storage. 56.4601 Section 56... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Fire Prevention and Control Welding/cutting/compressed Gases § 56.4601 Oxygen cylinder storage. Oxygen cylinders shall not...

  20. 30 CFR 56.4601 - Oxygen cylinder storage.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Oxygen cylinder storage. 56.4601 Section 56... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Fire Prevention and Control Welding/cutting/compressed Gases § 56.4601 Oxygen cylinder storage. Oxygen cylinders shall not...

  1. 30 CFR 57.4601 - Oxygen cylinder storage.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Oxygen cylinder storage. 57.4601 Section 57... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Fire Prevention and Control Welding/cutting/compressed Gases § 57.4601 Oxygen cylinder storage. Oxygen cylinders...

  2. 30 CFR 56.4601 - Oxygen cylinder storage.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Oxygen cylinder storage. 56.4601 Section 56... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Fire Prevention and Control Welding/cutting/compressed Gases § 56.4601 Oxygen cylinder storage. Oxygen cylinders shall not...

  3. 30 CFR 57.4601 - Oxygen cylinder storage.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Oxygen cylinder storage. 57.4601 Section 57... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Fire Prevention and Control Welding/cutting/compressed Gases § 57.4601 Oxygen cylinder storage. Oxygen cylinders...

  4. 30 CFR 56.4601 - Oxygen cylinder storage.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Oxygen cylinder storage. 56.4601 Section 56... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Fire Prevention and Control Welding/cutting/compressed Gases § 56.4601 Oxygen cylinder storage. Oxygen cylinders shall not...

  5. First-principles investigations of interatomic interactions in Ni3Al alloyed by interstitial and substitutional impurities

    NASA Astrophysics Data System (ADS)

    Bogdanov, V. I.; Popov, V. A.; Portnoi, V. K.; Ruban, A. V.

    2013-03-01

    First-principles calculations of the total energy of interstitial and substitutional solid solutions in intermetallic compound Ni3Al were performed based on methods using Vienna ab-initio simulation package (VASP). The results of the calculations for interstitial solutions of carbon in Ni3Al confirmed the priority role of chemical interactions over deformational ones for the nearest neighbors. We attempted to use first-principles methods of calculation of the deformation interaction and continuum approaching in the theory of solutions to calculate coefficients of the concentration changes of the lattice spacing. Comparison of the calculation results with experimental data of substitutional impurities in Ni3Al has shown that the proposed method can aid in the study of the distribution of impurity atoms on the sublattices of the ordered phases, intermetallic compounds. We have proposed a method of calculating the partial molar volume of impurity in interstitial solid solutions.

  6. High-pressure powder x-ray diffraction experiments and ab initio calculation of Ti3AlC2

    NASA Astrophysics Data System (ADS)

    Zhang, Haibin; Wu, Xiang; Nickel, Klaus Georg; Chen, Jixin; Presser, Volker

    2009-07-01

    The structural stability of the layered ternary carbide Ti3AlC2 was studied up to 35 GPa using x-ray diffraction with a Merrill-Basset-type diamond anvil cell and ab initio calculations. The structure (P63/mmc) was stable in the present pressure range without any phase transition. The Birch-Murnaghan equation of state was employed to fit the experimental pressure-volume date, from which the isothermal bulk modulus of Ti3AlC2 was determined as 156±5 GPa, which was also supported by theoretical results. In addition, theoretical calculations described anisotropic pressure dependences of the lattice parameters, electronic structure, and bonding properties of Ti3AlC2.

  7. Lattice Location of 12B in Single-Crystal Ni3Al Studied by -Radiation Detected NMR

    NASA Astrophysics Data System (ADS)

    Fischer, B.; Ittermann, B.; Diehl, E.; Dippel, R.; Ergezinger, K. H.; Frank, H.-P.; Jäger, E.; Seelinger, W.; Sulzer, G.; Ackermann, H.; Stöckmann, H.-J.; Bohn, H. G.

    -radiation detected nuclear magnetic resonance was applied to determine the location of 12B probe nuclei in a Ni3Al single crystal. Combining our results with those of channeling experiments it turned out that more than 90% of the 12B ions occupy the octahedral interstitial site with six Ni ions as nearest neighbours.Translated AbstractGitterplatzbestimmung von 12B im Ni3Al-Einkristall mittels -strahlungsdetektierter NMRDer Einbauplatz des Sondenkerns 12B im Ni3Al-Einkristall wurde durch Kernresonanz mit β-Strahlungsnachweis bestimmt. Aus der Kombination mit Ergebnissen von Gitterführungsexperimenten ergab sich, daß über 90% der 12B-Ionen auf oktaedrischen Zwischengitterplätzen mit sechs Ni-Ionen als nächsten Nachbarn eingebaut werden.

  8. Phase formation and superconducting properties of mechanically alloyed Nb3(Al1‑x Ge x ) system

    NASA Astrophysics Data System (ADS)

    Li, Pingyuan; Chen, Yongliang; Xu, Liyuan; Zhang, Yun; Pan, Xifeng; Yan, Guo; Zhang, Yong; Cheng, C. H.; Feng, Yong; Zhao, Yong

    2016-07-01

    Mechanically alloyed Nb3(Al1‑x Ge x ) compounds with nominal composition x = 0%, 10%, 15%, 20%, 25% and 30% were synthesized using high-energy ball milling. The effects of Ge content and sintering temperature on the formation of the Nb3Al superconducting phase at a relatively low temperature without the extremely high-temperature rapid heating, quenching and transformation process were studied. The results revealed that Ge doping in Nb3Al improved the formation of the A15 phase at low temperatures, enhanced the superconducting transition temperature (T c), and refined the grain structure, thus improving the overall superconducting properties. The pinning behavior was also studied for the optimized sample.

  9. Influence of strontium addition on the mechanical properties of gravity cast Mg-3Al-3Sn alloy

    SciTech Connect

    Germen, Gülşah Şevik, Hüseyin; Kurnaz, S. Can

    2013-12-16

    In this study, the effect of strontium (0.01, 0.1, 0.5, 1 wt%) addition on the microstructure and mechanical properties of the gravity cast Mg-3Al-3Sn alloy were investigated. X-ray diffractometry revealed that the main phases are α−Mg, β−Mg{sub 17}Al{sub 12} and Mg{sub 2}Sn in the Mg-3Al-3Sn alloy. With addition The tensile testing results showed that the yield and ultimate tensile strength and elongation of Mg-3Al-3Sn alloy increased by adding Sr up to 0.1 wt.% and then is gradually decreased with the addition of more alloying element.

  10. High temperature sulfidation of Fe{sub 3}Al and NiCr thermal spray coatings at 600 C

    SciTech Connect

    Luer, K.; DuPont, J.; Marder, A.

    1999-11-01

    Three Fe{sub 3}Al and two Ni45Cr thermal spray coatings were tested in Ar-3.5H{sub 2}-0.1H{sub 2}S for 500h at 600 C and compared to AISI 1008 steel. The three Fe{sub 3}Al-type coatings were processed from the same lot of gas atomized Fe{sub 3}Al powder using a high velocity oxygen fuel (HVOF) thermal spray process and an air plasma spray (APS) process. In general, the Fe{sub 3}Al-type composition displayed excellent resistance to sulfidation corrosion at 600 C which correlated with the reported literature on wrought Fe{sub 3}Al alloys. HVOF processing did not significantly degrade the composition of the consumable and produced coatings with low porosity, low oxide content, high sulfidation resistance, and high resistance to sulfur penetration. In contrast, APS processing caused significant degradation to the particles which reduced the sulfidation resistance of the coating and enabled local sulfidation attack at alloy depleted regions. The APS processed Fe{sub 3}Al coating also contained high porosity which enabled sulfur to fully penetrate the splat boundaries of the coating to the substrate. The two Ni45Cr-type coatings were produced using different processes and different consumables. One of the Ni45Cr coatings was processed using a proprietary wire combustion arc-spray (CAS) process. The second Ni45Cr coating was processed using a HVOF spray process. Both NiCr-type coatings reacted moderately with the sulfidizing gas at 600 C to form a mixed chromium oxide-sulfide scale despite marked differences in coating structure and composition. CAS processing caused significant degradation of the Ni45Cr consumable and produced a coating with low porosity and high oxide content. In contrast, HVOF processing caused negligible degradation of the Ni45Cr consumable and produced a coating with low porosity and moderate oxide content.

  11. Structural changes and self-activated photoluminescence in reductively annealed Sr{sub 3}AlO{sub 4}F

    SciTech Connect

    Green, Robert; Avdeev, Maxim; Vogt, Thomas

    2015-08-15

    White light emission of self-activated photoluminescence (PL) in Sr{sub 3}AlO{sub 4}F under 254 nm light is only observed after annealing in a reducing atmosphere of 5%H{sub 2}/95%Ar. High-resolution neutron powder diffraction reveals that the FSr{sub 6} octahedrons and AlO{sub 4} tetrahedrons in this anti-perovskite structure are closer packed in reduced than in air-annealed samples which show no PL. Careful analysis of temperature-dependent neutron powder diffraction data establishes smaller isotropic displacement parameters for Sr(1) and O in Sr{sub 3}AlO{sub 4}F annealed in a reducing atmosphere indicating that the denser packing of the polyhedral sub-units leads to a slightly deeper potential for the Sr(1) and O atoms. Both the air- and reductively-annealed samples have identical thermal expansion within the temperature range between 3 and 350 K. The Debye temperatures were calculated using the atomic displacement parameters and show no significant differences between the air and reductively annealed samples making the Debye temperature a bad proxy for self-activated PL. - Graphical abstract: Annealing Sr{sub 3}AlO{sub 4}F under reducing conditions results in an intense self-activated photoluminescence which is correlated with a denser packing of FSr{sub 6} and AlO{sub 4} polyhedra. - Highlights: • Sr{sub 3}AlO{sub 4}F made in air does not show self-activated photoluminescence. • Only when annealing Sr{sub 3}AlO{sub 4}F in a reducing gas is photoluminescence observed. • FSr{sub 6} and AlO{sub 4} polyhedra in reduced Sr{sub 3}AlO{sub 4}F structure are packed more efficient. • Smaller displacement parameters are found for under-bonded Sr(1) and O sites.

  12. Oxide Dispersion Strengthened Fe(sub 3)Al-Based Alloy Tubes: Application Specific Development for the Power Generation Industry

    SciTech Connect

    Kad, B.K.

    1999-07-01

    A detailed and comprehensive research and development methodology is being prescribed to produce Oxide Dispersion Strengthened (ODS)-Fe3Al thin walled tubes, using powder extrusion methodologies, for eventual use at operating temperatures of up to 1100C in the power generation industry. A particular 'in service application' anomaly of Fe3Al-based alloys is that the environmental resistance is maintained up to 1200C, well beyond where such alloys retain sufficient mechanical strength. Grain boundary creep processes at such high temperatures are anticipated to be the dominant failure mechanism.

  13. Performance of Air-cooled Engine Cylinders Using Blower Cooling

    NASA Technical Reports Server (NTRS)

    Schey, Oscar W; Ellerbrock, Herman H , Jr

    1936-01-01

    An investigation was made to obtain information on the minimum quantity of air and power required to cool conventional air cooled cylinders at various operating conditions when using a blower. The results of these tests show that the minimum power required for satisfactory cooling with an overall blower efficiency of 100 percent varied from 2 to 6 percent of the engine power depending on the operating conditions. The shape of the jacket had a large effect on the cylinder temperatures. Increasing the air speed over the front of the cylinder by keeping the greater part of the circumference of the cylinder covered by the jacket reduced the temperatures over the entire cylinder.

  14. Neutron Diffraction Study Oxygen Dissolution Alpha(sub 2)-Ti3Al

    NASA Technical Reports Server (NTRS)

    Jones, Camille Y.; Luecke, William E.; Copland, Evan

    2005-01-01

    Rietveld refinements of neutron powder diffraction data on alpha(sub 2)-Ti3Al have been performed to determine the crystal structure as a function of interstitial oxygen (O) concentration for three alloys with a Ti/Al ratio of approximately equal to 2.34 and O concentrations of 0.25%, 3.99% and 7.71%. The structures of the allows are hexagonal in space group P6(sub 3)/mmc where Ti and Al atoms populate unique sites with excess Al at the Ti site and O atoms occupy octahedral interstitial sites surrounded by six Ti sites. The length of the c-axis was found to increase linearly as the O occupancy of the interstitial sites increased; this lattice lengthening effect was much less pronounced along the alpha axis. Correspondingly, the increases in the lengths of Ti-Al and Ti-Ti bonds with a major component of their direction parallel to the c-axis were roughly an order of magnitude greater than the increases in the lengths of Ti-al and Ti-Ti bonds more closely aligned with the alpha-axis. Densities calculated form the lattice parameters and occupancy factors fall in the range (4.118 plus or minus 0.004) grams per cubic centimeter to (4.194 plus or minus 0.004) grams per cubic centimeter, and exhibit a nearly linear increase with oxygen concentration. Measured densities of (4.113 plus or minus 0.001) grams per cubic centimeter, (4.146 plus or minus 0.009) grams per cubic centimeter, and (4.191 plus or minus 0.002) grams per cubic centimeter for these alloys agree with the results of the refinements.

  15. Thermal vacancy formation and positron-vacancy interaction in Ti3Al at high temperatures

    NASA Astrophysics Data System (ADS)

    Würschum, R.; Kümmerle, E. A.; Badura-Gergen, K.; Seeger, A.; Herzig, Ch.; Schaefer, H.-E.

    1996-07-01

    In order to study the formation of thermal vacancies in the Ti-Al alloy system, high-temperature positron lifetime measurements together with a modeling of defect formation in the framework of nearest-neighbor pair bonds were performed for α2Ti3Al and compared to recent results on γTiAl [U. Brossmann, R. Würschum, K. Badura, and H.-E. Schaefer, Phys. Rev. B 49, 6457 (1994)]. Substantial increases of the positron lifetime τ were observed for Ti65.6Al34.4 and Ti77.1Al22.9 in the temperature range T≳1200 K where thermal vacancy concentrations above the detection limit of positron annihilation are expected from the model calculations for the α2 phase. Within the high-temperature increase of the positron lifetime in the α2 and the β phase single-component positron lifetime spectra were observed. This behavior is in contrast to the two-component spectra observed conventionally at intermediate positron trapping rates and is attributed to a fast detrapping and retrapping of positrons at vacancies due to a low positron-vacancy binding energy. For this case, a vacancy formation enthalpy of HFV=(1.55±0.2) eV in α2Ti65.6Al34.4 and HFV=(1.8±0.2) eV in βTi77.1Al22.9 can be derived. These results are discussed in the context of recent 44Ti tracer diffusion studies.

  16. Exploring Manufacturing Technology.

    ERIC Educational Resources Information Center

    Iley, John; And Others

    These teacher's materials for an eight-unit course were developed to help students develop technological literacy, career exploration, and problem-solving skills relative to the manufacturing industries. The eight units include an overview of manufacturing, manufacturing enterprises and systems, manufacturing materials and selection, manufacturing…

  17. Radiation levels on empty cylinders containing heel material

    SciTech Connect

    Shockley, C.W.

    1991-12-31

    Empty UF{sub 6} cylinders containing heel material were found to emit radiation levels in excess of 200 mr/hr, the maximum amount stated in ORO-651. The radiation levels were as high as 335 mr/hr for thick wall (48X and 48Y) cylinders and 1050 mr/hr for thin wall (48G and 48H) cylinders. The high readings were found only on the bottom of the cylinders. These radiation levels exceeded the maximum levels established in DOT 49 CFR, Part 173.441 for shipment of cylinders. Holding periods of four weeks for thick-wall cylinders and ten weeks for thin-wall cylinders were established to allow the radiation levels to decay prior to shipment.

  18. Numerical investigation of local scour at two adjacent cylinders

    NASA Astrophysics Data System (ADS)

    Kim, Hyung Suk; Nabi, Mohamed; Kimura, Ichiro; Shimizu, Yasuyuki

    2014-08-01

    Local scour around cylinders in a side-by-side or tandem arrangement under clear-water conditions is investigated numerically. Large eddy simulations with a Smagorinsky subgrid model are combined with a ghost-cell immersed boundary method, and details of the bed scouring are realized with sophisticated sediment and morphodynamic models. The scour patterns and depths in the two-cylinder cases are shown to be significantly influenced by the cylinder spacing. The features of the scour evolution, depth, and flow fields for a range of cylinder spacings are discussed. The maximum scour depth in the side-by-side cylinder cases increases as the distance between the cylinders decreases, whereas in the tandem cases, it tends to initially increase with increasing distance between the cylinders, after which it gradually decreases beyond the peak point. The maximum scour depths and trends computed using the present model show good agreement with the measured data in the literature.

  19. Numerical simulation for flow around two circular cylinders in tandem

    NASA Astrophysics Data System (ADS)

    Kondo, Norio; Matsukuma, Daisuke

    2005-05-01

    We use a third-order upwind finite element scheme in order to perform numerical stabilization of solutions of the Navier Stokes equations and present numerical results of flow around two circular cylinders in tandem arrangement by two- and three-dimensional computations. The two circular cylinders are arranged with some spacings between the cylinders. It is well known from experimental data that the flow around two circular cylinders denotes very complicated phenomena with the variation of spacing between two cylinders. In addition, the time-averaged drag coefficients of two circular cylinders suddenly change at a certain spacing between the cylinders. We, therefore, make an investigation of such phenomena at the Reynolds number of 1000 by the use of a numerical approach, and the obtained numerical results are also qualitatively compared with experimental data.

  20. Locomotion gaits of a rotating cylinder pair

    NASA Astrophysics Data System (ADS)

    van Rees, Wim M.; Novati, Guido; Koumoutsakos, Petros; Mahadevan, L.

    2015-11-01

    Using 2D numerical simulations of the Navier-Stokes equations, we demonstrate that a simple pair of rotating cylinders can display a range of locomotion patterns of biological and engineering interest. Steadily counter-rotating the cylinders causes the pair to move akin to a vortex dipole for low rotation rates, but as the rotational velocity is increased the direction of motion reverses. Unsteady rotations lead to different locomotion gaits that resemble jellyfish (for in-phase rotations) and undulating swimmers (for out-of-phase rotations). The small number of parameters for this simple system allows us to systematically map the phase space of these gaits, and allows us to understand the underlying physical mechanisms using a minimal model with implications for biological locomotion and engineered analogs.

  1. Log-rolling block copolymers cylinders

    NASA Astrophysics Data System (ADS)

    Kim, So Youn; Kim, Ye Chan; Kim, Dong Hyup; Kwon, Na Kyung; Register, Richard A.

    Shear has been the most effective method to create long range order of micro- or nano- structures in soft materials. When shear is applied, soft particles or polymers tend to align along the shear direction to minimize the viscous dissipation, thus transverse (so-called ``log-rolling'') alignment is unfavored. In this study, for the first time we report the transverse alignment of cylinder-forming block copolymers. Poly(styrene-b-methyl methacrylate), PS-PMMA, can form a metastable hemicylinder structure when confined in a thin film, and this hemicylinder structure can align either along the shear direction, or transverse to the shear direction (``log-rolling''), depending on the shearing temperature. This unusual ``log-rolling'' behavior is explained by the different chain mobility of the two blocks in PS-PMMA; the rigidity of core cylinder is the critical parameter determining the direction of shear alignment.

  2. Cylinder Flow Control Using Plasma Actuators

    NASA Astrophysics Data System (ADS)

    Kozlov, Alexey; Thomas, Flint

    2007-11-01

    In this study the results of flow control experiments utilizing single dielectric barrier discharge plasma actuators to control flow separation and unsteady vortex shedding from a circular cylinder in cross-flow are reported. Two optimized quartz dielectric plasma actuators mounted on the cylinder surface utilizing an improved saw-tooth waveform high-voltage generator allowed flow control at Reynolds number approaching supercritical. Using either steady or unsteady actuation, it is demonstrated that the plasma-induced surface blowing gives rise to a local Coanda effect that promotes the maintenance of flow attachment. PIV based flow fields and wake velocity profiles obtained with hot-wire anemometry show large reductions in vortex shedding, wake width and turbulence intensity.

  3. 2-d Collapsed Polymers on a Cylinder

    NASA Astrophysics Data System (ADS)

    Hsu, Hsiao-Ping; Grassberger, Peter

    2002-08-01

    Partially confined collapsed polymers with attractive interactions are studied in two dimensions. They are described by self-avoiding random walks with nearest-neighbour attractions on the surface of an infinitely long cylinder. We employ the pruned-enriched-Rosenbluth method (PERM) to study this model with different cylinder circumference h, to understand the properties of collapsed polymers affected by confining geometries. The cases of free polymers and of polymers confined to finite volumes were discussed already in [Phys. Rev. E 65, 031807 (2002)] by Grassberger and Hsu. There, we had verified the existence of a surface term in the infinite volume free energy, and a T-dependent bulk chemical potential. Here we present further results on the surface tension and it's T-dependence. We also show that the chemical potential has, in the limit of very long chains, a minimum at a finite value of h.

  4. Boundary Layers of Air Adjacent to Cylinders

    PubMed Central

    Nobel, Park S.

    1974-01-01

    Using existing heat transfer data, a relatively simple expression was developed for estimating the effective thickness of the boundary layer of air surrounding cylinders. For wind velocities from 10 to 1000 cm/second, the calculated boundary-layer thickness agreed with that determined for water vapor diffusion from a moistened cylindrical surface 2 cm in diameter. It correctly predicted the resistance for water vapor movement across the boundary layers adjacent to the (cylindrical) inflorescence stems of Xanthorrhoea australis R. Br. and Scirpus validus Vahl and the leaves of Allium cepa L. The boundary-layer thickness decreased as the turbulence intensity increased. For a turbulence intensity representative of field conditions (0.5) and for νwindd between 200 and 30,000 cm2/second (where νwind is the mean wind velocity and d is the cylinder diameter), the effective boundary-layer thickness in centimeters was equal to [Formula: see text]. PMID:16658855

  5. Anomalous magnetoresistance in magnetized topological insulator cylinders

    SciTech Connect

    Siu, Zhuo Bin; Jalil, Mansoor B. A.

    2015-05-07

    The close coupling between the spin and momentum degrees of freedom in topological insulators (TIs) presents the opportunity for the control of one to manipulate the other. The momentum can, for example, be confined on a curved surface and the spin influenced by applying a magnetic field. In this work, we study the surface states of a cylindrical TI magnetized in the x direction perpendicular to the cylindrical axis lying along the z direction. We show that a large magnetization leads to an upwards bending of the energy bands at small |k{sub z}|. The bending leads to an anomalous magnetoresistance where the transmission between two cylinders magnetized in opposite directions is higher than when the cylinders are magnetized at intermediate angles with respect to each other.

  6. Creep deformation of a two-phase TiAl/Ti[sub 3]Al lamellar alloy and the individual TiAl and Ti[sub 3]Al constituent phases

    SciTech Connect

    Bartholomeusz, M.F.; Wert, J.A. ); Qibin Yang )

    1993-08-01

    Two-phase TiAl/Ti[sub 3]Al alloys in which the constituent phases form a lamellar microstructure are reported to possess good combinations of low-temperature fracture toughness, tensile strength and fatigue resistance. However, information about the high-temperature creep properties of the two-phase TiAl/Ti[sub 3]Al alloys with lamellar microstructures (referred to as lamellar alloys in the remainder of the paper) is limited. Based on a simple rule of mixtures model of strength, it would be expected that the creep rates of the lamellar alloy would be between the creep rates of TiAl and Ti[sub 3]Al. In contrast to composite model predictions of strength, Polvani and coworkers found that the minimum creep rates of two duplex alloys, a [gamma]/[gamma][prime] nickel-base superalloy and NiAl/Ni[sub 2]AlTi, were significantly lower than the minimum creep rates of either of the constituent phases. They also reported that most dislocations in the two-phase NiAl/Ni[sub 2]AlTi alloy were contained within the semi-coherent interfacial dislocation networks between the two phases. Based on this observation they proposed that the creep rate is controlled by the rate at which dislocations moving through both phases are emitted and absorbed by the interphase dislocation networks. The greater strain hardening rate of the lamellar TiAl/Ti[sub 3]Al alloy suggests that it may exhibit lower steady-state creep rates that the individual constituent phases. The objective of the present study is to evaluate the creep properties of a TiAl/ Ti[sub 3]Al lamellar alloy and of the individual constituent phases. In this paper, the results of this investigation will be presented and compared with previously published results for this alloy system.

  7. Free Surface Wave Interaction with a Horizontal Cylinder

    NASA Astrophysics Data System (ADS)

    Oshkai, P.; Rockwell, D.

    1999-10-01

    Classes of vortex formation from a horizontal cylinder adjacent to an undulating free-surface wave are characterized using high-image-density particle image velocimetry. Instantaneous representations of the velocity field, streamline topology and vorticity patterns yield insight into the origin of unsteady loading of the cylinder. For sufficiently deep submergence of the cylinder, the orbital nature of the wave motion results in multiple sites of vortex development, i.e., onset of vorticity concentrations, along the surface of the cylinder, followed by distinctive types of shedding from the cylinder. All of these concentrations of vorticity then exhibit orbital motion about the cylinder. Their contributions to the instantaneous values of the force coefficients are assessed by calculating moments of vorticity. It is shown that large contributions to the moments and their rate of change with time can occur for those vorticity concentrations having relatively small amplitude orbital trajectories. In a limiting case, collision with the surface of the cylinder can occur. Such vortex-cylinder interactions exhibit abrupt changes in the streamline topology during the wave cycle, including abrupt switching of the location of saddle points in the wave. The effect of nominal depth of submergence of the cylinder is characterized in terms of the time history of patterns of vorticity generated from the cylinder and the free surface. Generally speaking, generic types of vorticity concentrations are formed from the cylinder during the cycle of the wave motion for all values of submergence. The proximity of the free surface, however, can exert a remarkable influence on the initial formation, the eventual strength, and the subsequent motion of concentrations of vorticity. For sufficiently shallow submergence, large-scale vortex formation from the upper surface of the cylinder is inhibited and, in contrast, that from the lower surface of the cylinder is intensified. Moreover

  8. LiNbO3 Cylinder Fiber

    NASA Technical Reports Server (NTRS)

    Kornreich, Philip

    2004-01-01

    We have successfully fabricate optical fiber with a thin layer of LiNbO3 at the boundary of the glass core and clear glass cladding. The construction of this fiber is based on our successful Semiconductor Cylinder Fibers (SCF). A schematic representation of a LiN bo, Cylinder Fiber. These fibers can be used as light modulators, sonar detectors and in other applications. The core diameter of the fiber is sufficiently small compared to the light wavelength and the indices of refraction of the core and cladding glasses are sufficiently close in value so that there is sufficient light at the core cladding boundary to interact with the LiNbO3 layer. This fiber functions best when just a single light mode propagates through the fiber. The idea for a LiNbO3 Cylinder Fiber came from Dr. Tracee Jamison of NASA. The optical properties of LiNbO3 can be changed with strain or the application of an electric field. Thus these fibers can be used as acoustic sensors as for example in a sonar. They can also be used as electric field operated light modulators. However, for this application the fibers would be made with a cross section in the form of a "D". The core with its surrounding LiNbO, layer would be close to the flat portion of the "D" shaped fiber. Two metal contacts would be deposited on the flat portion of the fiber on either side of the core. A voltage applied across these contacts will result in an electric field in the core region that can be used for modulating the optical properties of the LiNbO3 layer. To our knowledge this is the first ever LiNbO3 Cylinder Fiber made.

  9. LiNbO3 Cylinder Fiber

    NASA Technical Reports Server (NTRS)

    2004-01-01

    We have successfully fabricate optical fiber with a thin layer of LiNbO3 at the boundary of the glass core and dear glass cladding. The construction of this fiber is based on our successful Semiconductor Cylinder Fibers (SCF). A schematic representation of a LiNbO3 Cylinder Fiber is shown. These fibers can be used as light modulators, sonar detectors and in other applications. The core diameter of the fiber is sufficiently small compared to the light wavelength and the indices of refraction of the core and cladding glasses are sufficiently close in value so that there is sufficient light at the core cladding boundary to interact with the LiNbO3 layer. This fiber functions best when just a single light mode propagates through the fiber. The idea for a LiNbO3 Cylinder Fiber came from Dr. Tracee Jamison of NASA. The optical properties of LiNbO3 can be changed with strain or the application of an electric field. Thus these fibers can be used as acoustic sensors as for example in a sonar. They can also be used as electric field operated light modulators. However, for this application the fibers would be made with a cross section in the form of a 'D'. The core with its surrounding LiNbO, layer would be close to the flat portion of the 'D' shaped fiber. Two metal contacts would be deposited on the flat portion of the fiber on either side of the core. A voltage applied across these contacts will result in an electric field in the core region that can be used for modulating the optical properties of the LiNbO, layer. To our knowledge this is the first ever LiNbO, Cylinder Fiber made.

  10. van der Waals Forces between Cylinders

    PubMed Central

    Mitchell, D. J.; Ninham, B. W.; Richmond, P.

    1973-01-01

    We derive the retarded van der Waals interaction between two long thin parallel dielectric cylinders immersed in a solvent. The result shows that the ultraviolet interactions which may be responsible for the specificity of macromolecular interactions do not operate strongly over distances R ≥ 50 Å. For greater distances the contribution of these frequencies ξ is damped by a factor ∞ e-ξR/c. PMID:4696763

  11. DDES and IDDES of tandem cylinders.

    SciTech Connect

    Balakrishnan, R.; Garbaruk, A.; Shur, M.; Strelets, M.; Spalart, P.; New Technologies and Services - Russia; St.-Peterburg State Polytechnic Univ.; Boeing Commercial Airplanes

    2010-09-09

    The paper presents an overview of the authors contribution to the BANC-I Workshop on the flow past tandem cylinders (Category 2). It includes an outline of the simulation approaches, numerics, and grid used, the major results of the simulations, their comparison with available experimental data, and some preliminary conclusions. The effect of varying the spanwise period in the simulations is strong for some quantities, and not others.

  12. Analysis of mechanical joint in composite cylinder

    NASA Astrophysics Data System (ADS)

    Hong, C. S.; Kim, Y. W.; Park, J. S.

    Joining techniques of composite materials are of great interest in cylindrical structures as the application of composites is widely used for weight-sensitive structures. Little information for the mechanical fastening joint of the laminated shell structure is available in the literature. In this study, a finite element program, which was based on the first order shear deformation theory, was developed for the analysis of the mechanical joint in the laminated composite structure. The failure of the mechanical fastening joint for the laminated graphite/epoxy cylinder subject to internal pressure was analyzed by using the developed program. Modeling of the bolt head in the composite cylinder was studied, and the effect of steel reinforcement outside the composite cylinder on the failure was investigated. The stress component near the bolt head was influenced by the size of the bolt head. The failure load and the failure mode were dependent on the bolt diameter, the number of bolts, and fiber orientation. The failure load was constant when the edge distance exceeds three times the bolt diameter.

  13. High frequency scattering from corrugated stratified cylinders

    NASA Technical Reports Server (NTRS)

    Sarabandi, Kamal; Ulaby, Fawwaz T.

    1991-01-01

    Interest in applying radar remote sensing for the study of forested areas led to the development of a model for scattering from corrugated stratified dielectric cylinders. The model is used to investigate the effect of bark and its roughness on scattering from tree trunks and branches. The outer layer of the cylinder (bark) is assumed to be a low-loss dielectric material and to have a regular (periodic) corrugation pattern. The inner layers are treated as lossy dielectrics with smooth boundaries. A hybrid solution based on the moment method and the physical optics approximation is obtained. In the solution, the corrugations are replaced with polarization currents that are identical to those of the local tangential periodic corrugated surface, and the stratified cylinder is replaced with equivalent surface currents. New expressions for the equivalent physical-optics currents are used which are more convenient than the standard ones. It is shown that the bark layer and its roughness both reduce the radar cross-section. It is also demonstrated that the corrugations can be replaced by an equivalent anisotropic layer.

  14. Cylinder Fragmentation Using Gas Gun Methods

    NASA Astrophysics Data System (ADS)

    Thornhill, Tom; Reinhart, William; Chhabildas, Lalit; Grady, Dennis; Wilson, Leonard

    2001-06-01

    An experimental technique for investigating fracture and fragmentation characteristics of materials has been developed for use on the gas guns. In this method the candidate material is in the cylindrical form. This technique involves the precision alignment of the candidate cylinder, and symmetric impact of a stationary cylinder plug with the moving projectile from the gun. This test method allows the study of cylinder fragmentation in a laboratory environment under well-controlled loading conditions. In this presentation, results of several experiments on Aermet steel will be presented. The fragmentation toughness of the material can be estimated through knowledge of the material strain-rate and mean fragment size derived from the statistical distribution of the fragments. The values for fragmentation toughness will be compared with those obtained from other experimental methods such as explosives loading or ball on plate impact methods. Future developments and directions in test geometry, test methods and diagnostics will also be reported. This work was supported by the U. S. Department of Energy under contract DE-AC04-94AL85000.

  15. Solidification Behavior of gamma'-Ni3Al Containing Alloys in the Ni-Al-O System

    NASA Technical Reports Server (NTRS)

    Copland, Evan

    2007-01-01

    The chemical activities of Al and Ni in gamma(prime)-Ni3Al-containing systems were measured using the multi-cell Knudsen effusion-cell mass spectrometry technique (multi-cell KEMS), over the composition range 8 - 32 at.%Al and temperature range T = 1400 - 1750 K. From these measurements a better understanding of the equilibrium solidification behaviour of gamma(prime)-Ni3Al-containing alloys in the Ni-Al-O system was established. Specifically, these measurements revealed that (1) gamma(prime)-Ni3Al forms via the peritectiod reaction, gamma + Beta (+ A12O3) = gamma (prime) (+ Al2O3), at 1633 +/- 1 K, (2) the {gamma + Beta + Al2O3} phase field is stable over the temperature range 1633 through 1640 K, and (3) equilibrium solidification occurs by the eutectic reaction, L (+ Al2O3) = gamma + Beta (+ Al2O3), at 1640 +/- 1 K and a liquid composition of 24.8 +/- 0.2 at.%Al (at an unknown oxygen content). When projected onto the Ni-Al binary, this behaviour is inconsistent with the current Ni-Al phase diagram and a new diagram is proposed. This new Ni-Al phase diagram explains a number of unusual steady-state solidification structures reported previously and provides a much simpler reaction scheme in the vicinity of the gamma(prime)-Ni3Al phase field.

  16. Synthesis and anisotropic properties of single crystalline Ln2Ru3Al15+x (Ln=Gd, Tb)

    NASA Astrophysics Data System (ADS)

    Morrison, Gregory; Prestigiacomo, Joseph; Haldolaarachchige, Neel; Rai, Binod K.; Young, David P.; Stadler, Shane; Morosan, Emilia; Chan, Julia Y.

    2016-04-01

    Single crystals of Ln2Ru3Al15+x (Ln=Gd, Tb) have been grown using the self-flux method under Ru-poor conditions. The structure of the Gd analog is found to be highly dependent on the synthesis method. Gd2Ru3Al15.08 orders antiferromagnetically at 17.5 K. Tb2Ru3Al15.05 enters an antiferromagnetic state at 16.6 K followed by a likely incommensurate-to-commensurate transition at 14.9 K for crystals oriented with H//ab. For crystals oriented with H//c, a broad maximum is observed in the temperature dependent M/H, indicative of a highly anisotropic magnetic system with the hard axis in the c-direction. The magnetization as a function of field and magnetoresistance along the ab-direction of Tb2Ru3Al15.05 display a stepwise behavior and indicate strong crystalline electric field effects.

  17. Electrical and thermal transport properties of Nb- and Ru-substituted Mo3Al2C superconducting compounds

    NASA Astrophysics Data System (ADS)

    Ramachandran, B.; Jhiang, J. Y.; Kuo, Y. K.; Kuo, C. N.; Lue, C. S.

    2016-03-01

    Partial substitution effects of Nb and Ru on the superconducting and normal-state properties of Mo3Al2C-based compounds, namely Mo3-x Nb x Al2C (x = 0.00-0.25) and Mo3-x Ru x Al2C (x = 0.00-0.15), were investigated by means of electrical, magnetic, and thermoelectric studies. From the resistivity and magnetization data, we noted that the superconducting transition temperature of Mo3Al2C decreases gradually with increasing the dopant content of Nb and Ru, and the superconducting volume fraction also decreases significantly upon the substitution. The electrons dominate the thermoelectric transport in the studied compounds. Moreover, a change of curvature near 50 K in the transport properties of the parent Mo3Al2C compound was observed, prior to the superconducting transition. This is most likely due to the strong electron-phonon interaction which could have originated from the distortions near the Al sites. Finally, it was found that electronic carriers contribute considerably to heat conduction of the Mo3Al2C-based compounds near room temperature, whereas the phonons dominate the low-temperature thermal transport.

  18. Oxidation Resistance of Materials Based on Ti3AlC2 Nanolaminate at 600 °C in Air

    NASA Astrophysics Data System (ADS)

    Ivasyshyn, Andrij; Ostash, Orest; Prikhna, Tatiana; Podhurska, Viktoriya; Basyuk, Tatiana

    2016-08-01

    The oxidation behavior of Ti3AlC2-based materials had been investigated at 600 °C in static air for 1000 h. It was shown that the intense increase of weight gain per unit surface area for sintered material with porosity of 22 % attributed to oxidation of the outer surface of the specimen and surfaces of pores in the bulk material. The oxidation kinetics of the hot-pressed Ti3AlC2-based material with 1 % porosity remarkably increased for the first 15 h and then slowly decreased. The weight gain per unit surface area for this material was 1.0 mg/cm2 after exposition for 1000 h. The intense initial oxidation of Ti3AlC2-based materials can be eliminated by pre-oxidation treatment at 1200 °C in air for 2 h. As a result, the weight gain per unit surface area for the pre-oxidized material did not exceed 0.11 mg/cm2 after 1000 h of exposition at 600 °C in air. It was demonstrated that the oxidation resistance of Ti3AlC2-based materials can be significantly improved by niobium addition.

  19. Comparison Between Nb3Al and Nb3Sn Strands and Cables for High Field Accelerator Magnets

    SciTech Connect

    Yamada, R.; Kikuchi, A.; Barzi, E.; Chlachidze, G.; Rusy, A.; Takeuchi, T.; Tartaglia, M.; Turrioni, D.; Velev, V.; Wake, M.; Zlobin, A.V.; /Fermilab

    2010-01-01

    The Nb{sub 3}Al small racetrack magnet, SR07, has been successfully built and tested to its short sample limit beyond 10 Tesla without any training. Thus the practical application of Nb{sub 3}Al strands for high field accelerator magnets is established. The characteristics of the representative F4 strand and cable, are compared with the typical Nb{sub 3}Sn strand and cable. It is represented by the OST high current RRP Nb{sub 3}Sn strand with 108/127 configuration. The effects of Rutherford cabling to both type strands are explained and the inherent problem of the Nb{sub 3}Sn strand is discussed. Also the test results of two representative small racetrack magnets are compared from the stand point of Ic values, and training. The maximum current density of the Nb{sub 3}Al strands is still smaller than that of the Nb{sub 3}Sn strands, but if we take into account of the stress-strain characteristics, Nb{sub 3}Al strands become somewhat favorable in some applications.

  20. Hydrothermal Synthesis and Luminescent Properties of Eu3+ Doped Sr3Al2O6 Phosphor for White LED.

    PubMed

    Li, Xu; Pan, Heng; Tang, Aiwei; Zhang, Jinping; Guan, Li; Su, Hongxin; Dong, Guoyi; Yang, Zhiping; Wang, Huike; Teng, Feng

    2016-04-01

    Eu3+ ions doped Sr3Al2O6 phosphors were successfully synthesized via a hydrothermal method. The precursor was prepared by low temperature hydrothermal method using ammonia as both alkaline source and precipitator. Then the final product was obtained by high temperature sintering. In addition, the structures, morphologies, and luminescent properties of as-prepared products were thoroughly characterized by X-ray powder diffraction (XRD), Scanning electron microscopy (SEM), Fluorescence spectroscopy (PL). XRD shown a single phase Sr3Al2O6 prepared by a facile hydrothermal method at 250 °C for 10 h. In the PL spectra of as-prepared samples, the optimal value of Eu3+ concentration is 2 mol%. From the fluorescent spectra, the emission peaks of Sr3Al2O6: Eul+ phosphors are centered at around 591 nm, and the excitation peaks are centered at around 233 nm, 323 nm, 394 nm, and 468 nm, respectively, which were assigned to the characteristic transition of Eu3+ ions. The influence of ammonia, and the synthesis temperature on the luminescent properties of Sr3Al206: Eu3+ phosphors were studied in detail. The alkaline earth aluminates luminescent materials activated by rare earth ions have good prospects in the field of new-generation light sources. PMID:27451652

  1. Heat capacity and phase equilibria of almandine, Fe 3Al 2Si 3O 12

    NASA Astrophysics Data System (ADS)

    Anovitz, L. M.; Essene, E. J.; Metz, G. W.; Bohlen, S. R.; Westrum, E. F., Jr.; Hemingway, B. S.

    1993-09-01

    The heat capacity of a synthetic almandine, Fe 3Al 2Si 3O 12, was measured from 6 to 350 K using equilibrium, intermittent-heating quasi-adiabatic calorimetry and from 420 to 1000 K using differential scanning calorimetry. These measurements yield Cp298 = 342.80 ± 1.4 J/mol · K and S298o = 342.60 J/mol · K. Mössbauer characterizations show the almandine to contain less than 2 ± 1% of the total iron as Fe 3+. X-ray diffraction studies of this synthetic almandine yield a = 11.521 ± 0.001 Å and V298o = 115.11 +- 0.01 cm 3/mol, somewhat smaller than previously reported. The low-temperature Cp data indicate a lambda transition at 8.7 K related to an antiferromagnetic-paramagnetic transition with TN = 7.5 K. Modeling of the lattice contribution to the total entropy suggests the presence of entropy in excess of that attributable to the effects of lattice vibrations and the magnetic transition. This probably arises from a low-temperature electronic transition (Schottky contribution). Combination of the Cp data with existing thermodynamic and phase equilibrium data on almandine yields ΔGf,298 o = -4938.3 kJ/mol and ΔHf,298 o= - 5261.3 kJ/mol for almandine when calculated from the elements. The equilibrium almandine = hercynite + fayalite + quartz limits the upper T/P for almandine and is metastably located at ca. 570°C at P = 1 bar, with a dP/dT of +17 bars/°C. This agrees well with reversed experiments on almandine stability when they are corrected for magnetite and hercynite solid-solutions. In ‖ O2- T space, almandine oxidizes near QFM by the reactions almandine + O2 = magnetite + sillimanite + quartzandalmandine + 02 = hercynite + magnetite + quartz. With suitable correction for reduced activities of solid phases, these equilibria provide useful oxygen barometers for medium- to high-grade metamorphic rocks.

  2. Heat capacity and phase equilibria of almandine, Fe3Al2Si3O12

    USGS Publications Warehouse

    Anovitz, Lawrence M.; Essene, E.J.; Metz, G.W.; Bohlen, S.R.; Westrum, E.F., Jr.; Hemingway, B.S.

    1993-01-01

    The heat capacity of a synthetic almandine, Fe3Al2Si3O12, was measured from 6 to 350 K using equilibrium, intermittent-heating quasi-adiabatic calorimetry and from 420 to 1000 K using differential scanning calorimetry. These measurements yield Cp298 = 342.80 ?? 1.4 J/mol ?? K and S298o = 342.60 J/mol ?? K. Mo??ssbauer characterizations show the almandine to contain less than 2 ?? 1% of the total iron as Fe3+. X-ray diffraction studies of this synthetic almandine yield a = 11.521 ?? 0.001 A?? and V298o = 115.11 +- 0.01 cm3/mol, somewhat smaller than previously reported. The low-temperature Cp data indicate a lambda transition at 8.7 K related to an antiferromagnetic-paramagnetic transition with TN = 7.5 K. Modeling of the lattice contribution to the total entropy suggests the presence of entropy in excess of that attributable to the effects of lattice vibrations and the magnetic transition. This probably arises from a low-temperature electronic transition (Schottky contribution). Combination of the Cp data with existing thermodynamic and phase equilibrium data on almandine yields ??Gf,298o = -4938.3 kJ/mol and ??Hf,298o= -5261.3 kJ/mol for almandine when calculated from the elements. The equilibrium almandine = hercynite + fayalite + quartz limits the upper T P for almandine and is metastably located at ca. 570??C at P = 1 bar, with a dP dT of +17 bars/??C. This agrees well with reversed experiments on almandine stability when they are corrected for magnetite and hercynite solid-solutions. In {norm of matrix}O2-T space, almandine oxidizes near QFM by the reactions almandine + O2 = magnetite + sillimanite + quartz and almandine + 02 = hercynite + magnetite + quartz. With suitable correction for reduced activities of solid phases, these equilibria provide useful oxygen barometers for medium- to high-grade metamorphic rocks. ?? 1993.

  3. A review of the Model 5A uranium hexafluoride cylinder

    SciTech Connect

    Dorning, R.E. II

    1989-05-23

    Both the Model 5A (Monel 400) and 5A (Monel 400) Modified five-inch cylinders have been used at the Portsmouth GDP to withdraw, store, and ship highly enriched uranium hexafluoride. As a result of a generic cracking problem with Monel 400 valve-boss material, a cylinder modification was implemented in the mid 1970s. This modification resulted in the violation of the ASME ''Code'' stamp status of the Model 5A Modified cylinder. Hydrostatic testing-to- rupture data indicated that the Model 5A Modified cylinders had ruptured strengths equivalent to that of the original Model 5A cylinders. An independent consultant reviewed the available information and confirmed that the Model 5A Modified cylinders ''will with proper maintenance continue to perform satisfactorily for many additional years of service.'' Based on the test data and consultant's review, DOE approved continued use of the 5A Modified cylinder and also requested procurement of replacement 5B cylinders be expedited. Currently, the 5A modified cylinders are in the production, storage, shipment cycle, and a sufficient number of 5B cylinders has been ordered to accommodate the projected product shipping requirements for the Navy flow. 3 tabs.

  4. Measurements of the Flowfield Interaction Between Tandem Cylinders

    NASA Technical Reports Server (NTRS)

    Neuhart, Dan H.; Jenkins, Luther N.; Choudhari, Meelan M.; Khorrami, Mehdi R.

    2009-01-01

    This paper presents the most recent measurements from an ongoing investigation of the unsteady wake interference between a pair of circular cylinders in tandem. The purpose of this investigation is to help build an in-depth experimental database for this canonical flow configuration that embodies the effects of component interaction in landing gear noise. This new set of measurements augments the previous database at the primary Reynolds number (based on tunnel speed and cylinder diameter) of 1.66 105 in four important respects. First, better circumferential resolution of surface pressure fluctuations is obtained via cylinder "clocking". Second, higher resolution particle image velocimetry measurements of the shear layer separating from the cylinders are achieved. Third, the effects of simultaneous boundary layer trips along both the front and rear cylinders, versus front cylinder alone in the previous measurements, are studied. Lastly, on-surface and off-surface characteristics of unsteady flow near the "critical" cylinder spacing, wherein the flow switches intermittently between two states that are characteristic of lower and higher spacings, are examined. This critical spacing occurs in the middle of a relatively sudden change in the drag of either cylinder and is characterized by a loud intermittent noise and a flow behavior that randomly transitions between shear layer attachment to the rear cylinder and constant shedding and rollup in front of it. Analysis of this bistable flow state reveals much larger spanwise correlation lengths of surface pressure fluctuations than those at larger and smaller values of the cylinder spacing.

  5. Synthesis of Y3Al5O12 : Ce3+ phosphors by a modified impinging stream method: a crystal growth and luminescent properties study

    NASA Astrophysics Data System (ADS)

    Zhou, Zhi; Liu, Suqin; Wang, Fengchao; Liu, Younian

    2012-05-01

    A Y3Al5O12 : Ce3+ (YAG : Ce3+) phosphor was successfully prepared by a modified impinging stream (IS) method at a temperature of 1200 °C. The as-obtained sample has perfect crystallinity, uniform morphology and good dispersion due to the added size classification (SC) process and low-temperature calcination. The mechanism of YAG : Ce3+ crystal growth was proposed based on the results of scanning electron microscopy and x-ray diffractometry, which agreed with the Ostwald ripening process. The excitation and emission spectra revealed that the excitation band distributes between 310 nm and 520 nm and peaks at 342 nm and 460 nm, and the emission band covers from 470 nm to 650 nm and centres at 532.5 nm, respectively. White light can be obtained from the fabricated light-emitting diodes using the prepared phosphor, and the CIE coordinate, correlated colour temperature and luminescence efficiency are (0.312, 0.321), 7560 K and 80.7 lm W-1, respectively. All the results indicated that the modified IS method is a promising way to prepare the YAG : Ce3+ phosphor, and SC process is effective in producing the phosphor with uniform morphology, ideal size and size distribution. This method has a broad industrial prospect in phosphor manufacture.

  6. Blade Manufacturing Improvement: Remote Blade Manufacturing Demonstration

    SciTech Connect

    ASHWILL, THOMAS D.

    2003-05-01

    The objective of this program was to investigate manufacturing improvements for wind turbine blades. The program included a series of test activities to evaluate the strength, deflection, performance, and loading characteristics of the prototype blades. The original contract was extended in order to continue development of several key blade technologies identified in the project. The objective of the remote build task was to demonstrate the concept of manufacturing wind turbine blades at a temporary manufacturing facility in a rural environment. TPI Composites successfully completed a remote manufacturing demonstration in which four blades were fabricated. The remote demonstration used a manufacturing approach which relied upon material ''kits'' that were organized in the factory and shipped to the site. Manufacturing blades at the wind plant site presents serious logistics difficulties and does not appear to be the best approach. A better method appears to be regional manufacturing facilities, which will eliminate most of the transportation cost, without incurring the logistical problems associated with fabrication directly onsite. With this approach the remote facilities would use commonly available industrial infrastructure such as enclosed workbays, overhead cranes, and paved staging areas. Additional fatigue testing of the M20 root stud design was completed with good results. This design provides adhesive bond strength under fatigue loading that exceeds that of the fastener. A new thru-stud bonding concept was developed for the M30 stud design. This approach offers several manufacturing advantages; however, the test results were inconclusive.

  7. Differences in scour around a single surface-piercing cylinder and a submerged cylinder

    NASA Astrophysics Data System (ADS)

    Beninati, M. L.; Volpe, M. A.; Riley, D. R.; Krane, M.

    2011-12-01

    The equilibrium state of scour for a single surface piercing cylinder and a submerged cylinder of specific aspect ratio are presented. The equilibrium state is defined by a scour depth and associated time interval for a given set of flow conditions. Control variables such as sediment coarseness (or grain size) and cylinder size are held constant, while the flow intensity is varied. Sediment bed form topology is characterized with a series of two-dimensional slices across the bed for both the surface-piercing and submerged cylinder cases. Test results will help identify the geometry and pattern of the scour around the cylinders to aid in the optimal design of marine hydrokinetic (MHK) support structures in an effort to help minimize the deleterious impact of these devices on the local substrate. This study is performed in the small-scale testing platform in the hydraulic flume facility (32 ft long, 4 ft wide and 1.25 ft deep) in the Environmental Fluid Mechanics and Hydraulics Laboratory (EFM&H) at Bucknell University. The cylinders, of the same material and diameter, are placed centrally in the sediment filled test section (2.5 ft long, 2 ft wide and 0.75 ft deep) of the platform. Flow field measurements are taken with a 16-MHz Micro Acoustic Doppler Velocimeter while water depth is acquired using an ultrasonic distance sensor. These devices are attached to a gantry system that can be accurately positioned anywhere in the test section. Clear-water conditions (in the absence of live-bed scour) are maintained to study the effect of the horseshoe and wake vortices on the displacement of sediment around the cylinder as well as downstream of the device. Bed form topology is measured using an HR Wallingford 2D Sediment Bed Profiler with a low-powered laser distance sensor to accurately characterize changes in bed form around the cylinders. Additionally, specifications for testing such as operational procedures for start-up and shut-down of the facility are given.

  8. Detection of cylinder unbalance from Bayesian inference combining cylinder pressure and vibration block measurement in a Diesel engine

    NASA Astrophysics Data System (ADS)

    Nguyen, Emmanuel; Antoni, Jerome; Grondin, Olivier

    2009-12-01

    In the automotive industry, the necessary reduction of pollutant emission for new Diesel engines requires the control of combustion events. This control is efficient provided combustion parameters such as combustion occurrence and combustion energy are relevant. Combustion parameters are traditionally measured from cylinder pressure sensors. However this kind of sensor is expensive and has a limited lifetime. Thus this paper proposes to use only one cylinder pressure on a multi-cylinder engine and to extract combustion parameters from the other cylinders with low cost knock sensors. Knock sensors measure the vibration circulating on the engine block, hence they do not all contain the information on the combustion processes, but they are also contaminated by other mechanical noises that disorder the signal. The question is how to combine the information coming from one cylinder pressure and knock sensors to obtain the most relevant combustion parameters in all engine cylinders. In this paper, the issue is addressed trough the Bayesian inference formalism. In that cylinder where a cylinder pressure sensor is mounted, combustion parameters will be measured directly. In the other cylinders, they will be measured indirectly from Bayesian inference. Experimental results obtained on a four cylinder Diesel engine demonstrate the effectiveness of the proposed algorithm toward that purpose.

  9. Separation of Creeping Flow past Two Circular Cylinders

    NASA Astrophysics Data System (ADS)

    Miyazaki, Takeshi; Hasimoto, Hidenori

    1980-10-01

    The steady two-dimensional Stokes flow past two circular cylinders of equal radii is considered, where the direction of the flow is parallel to the line joining the centers. Separation of the flow from the cylinders occurs if the parameter t{=}(distance between two cylinders)/(diameter of the cylinders) is less than 1.57. If t is less than 1.07 the twin eddies attached to both cylinders coalesce to form two separation lines joining two cylinders. As t decreases, the number of the separation lines increases, and Moffatt vortices are formed at t{=}0 (i.e. in contact). These results are in accordance with the experiments given by Taneda.

  10. Steady flows around two cylinders at low Reynolds numbers

    NASA Astrophysics Data System (ADS)

    Tatsuno, Masakazu

    1989-06-01

    Steady flow patterns around two circular cylinders are experimentally studied at Reynolds numbers lower than unity. The cylinders are towed at a uniform speed in a tank filled with glycerin, and the dependence of the streamline patterns on the ratio of the radii of the two cylinders, their mutual spacing, and the angle between the line joining the centers and the direction of the flow are studied. When the two cylinders are in tandem arrangements, the process of changes of the first twin eddies in the gap is in accordance with the theoretical results of Miyazaki and Hasimoto. When the two cylinders are in staggered arrangement, the flow separation occurs both at small values of gaps and at large ratio of the radii of the two cylinders.

  11. Acoustics and Surface Pressure Measurements from Tandem Cylinder Configurations

    NASA Technical Reports Server (NTRS)

    Hutcheson, Florence V.; Brooks, Thomas F.; Lockard, David P.; Choudhari, Meelan M.; Stead, Daniel J.

    2014-01-01

    Acoustic and unsteady surface pressure measurements from two cylinders in tandem configurations were acquired to study the effect of spacing, surface trip and freestream velocity on the radiated noise. The Reynolds number ranged from 1.15x10(exp 5) to 2.17x10(exp 5), and the cylinder spacing varied between 1.435 and 3.7 cylinder diameters. The acoustic and surface pressure spectral characteristics associated with the different flow regimes produced by the cylinders' wake interference were identified. The dependence of the Strouhal number, peak Sound Pressure Level and spanwise coherence on cylinder spacing and flow velocity was examined. Directivity measurements were performed to determine how well the dipole assumption for the radiation of vortex shedding noise holds for the largest and smallest cylinder spacing tested.

  12. Comparative study on interface and bulk charges in AlGaN/GaN metal-insulator-semiconductor heterostructures with Al2O3, AlN, and Al2O3/AlN laminated dielectrics

    NASA Astrophysics Data System (ADS)

    Zhu, Jie-Jie; Ma, Xiao-Hua; Chen, Wei-Wei; Hou, Bin; Xie, Yong; Hao, Yue

    2016-05-01

    In this paper, the interface and bulk charges in AlGaN/GaN metal-insulator-semiconductor (MIS) heterostructures with AlN, Al2O3, and Al2O3/AlN laminated dielectrics were studied. In situ plasma pretreatment resulted negligible interface trap states and voltage hysteresis. The fixed charge density at Al2O3/AlN (or Al2O3/barrier) interface was estimated to be 1.66 × 1013 cm-2 by using flat-band voltage shift, and the oxide bulk charge concentration was 2.86 × 1017 cm-3. The interface charge density at other interfaces were at the order of 1011 cm-2. Simulation results using the above charge density/concentration indicated that Al2O3/AlN interface fixed charges dominated the dielectric-related voltage shift in AlGaN/GaN MIS heterostructures, which caused a large voltage shift of -3 V with 10 nm Al2O3 thickness, while the flat-band voltage variety resulting from other types of charges was within 0.1 V.

  13. Energy Use in Manufacturing

    EIA Publications

    2006-01-01

    This report addresses both manufacturing energy consumption and characteristics of the manufacturing economy related to energy consumption. In addition, special sections on fuel switching capacity and energy-management activities between 1998 and 2002 are also featured in this report.

  14. Feed Formulation and Manufacture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter provides information on feed formulation and manufacture. To formulate and manufacture high quality fish feeds, including tilapia feeds, one should have knowledge of nutrient requirements, nutrient composition, digestibility, and availability of feed ingredients; impacts of manufacturin...

  15. [Asthma and diving with a cylinder].

    PubMed

    Boutet, S; Salvia, P; Potiron, M

    1999-09-01

    Undersea diving is an activity that is practised more and more in holiday clubs. There is no precise legislation on the causes of unfitness of the amateur, in contrast to the professional diver, where the medical criteria are strict and controlled. When diving with a cylinder, on descent, the ventilatory load increases with increase of the ambient pressure and dynamic resistance in the airways increases. "As with an insufficient respiration on the surface, a healthy subject when diving has a ventilatory ability that is drastically reduced". Moreover with cylinder ventilation, the diver has available a reserve of gas under pressure from which he inspires with the aid of a breathing apparatus (regulator): he breathes dry gas that is dried before compression in the reservoirs, chilled by the relief valve on leaving the reservoir. This inhalation of cold, dry air associated with a hyperventilation during the descent produces ideal conditions to trigger exercise induced asthma. All subjects who present a bronchial hyperreactivity have the risk when diving with a cylinder of triggering a bronchospasm that is identical with that of a sporting asthmatic. During surfacing: the re-surfacing diver runs the risk of an accident of pulmonary suppression if he does not expire sufficiently during his return to the surface: the mass of intrapulmonary air of the resurfacer dilates and the excess of volume is exhaled by the diver: a volume of air of 5 l at 10 m depth corresponds to a volume of 10 l on the surface. Therefore the airways must remain free: an obstruction of the peripheral airways associated with an urgent re-surfacing produces a very rapid thoracic dilation which is responsible for pulmonary barotrauma (pulmonary barotrauma is frequently lethal with 30% of accidental deaths). PMID:10524270

  16. Adaptronic tools for superfinishing of cylinder bores

    NASA Astrophysics Data System (ADS)

    Roscher, Hans-Jürgen; Hochmuth, Carsten; Hoffmann, Michael; Praedicow, Michael

    2012-04-01

    Today in the production of internal combustion engines it is possible to make pistons as well as cylinders, for all practical purposes, perfectly round. The negative consequences of the subsequent assembly processes and operation of the engine is that the cylinders and pistons are deformed, resulting in a loss of power and an increase in fuel consumption. This problem can be solved by using an adaptronic tool, which can machine the cylinder to a predetermined nonround geometry, which will deform to the required geometry during assembly and operation of the engine. The article describes the actuatory effect of the tool in conjunction with its measuring and controlling algorithms. The adaptronic tool consists out the basic tool body and three axially-staggered floating cutter groups, these cutter groups consist out of guides, actuators and honing stones. The selective expansion of the tool is realised by 3 piezoelectric multilayer-actuators deployed in a series - parallel arrangement. It is also possible to superimpose actuator expansion on the conventional expansion. A process matrix is created during the processing of the required and actual contour data in a technology module. This is then transferred over an interface to the machine controller where it is finally processed and the setting values for the piezoelectric actuators are derived, after which an amplifier generates the appropriate actuator voltages. A slip ring system on the driveshaft is used to transfer the electricity to the actuators in the machining head. The functioning of the adaptronic form-honing tool and process were demonstrated with numerous experiments. The tool provides the required degrees of freedom to generate a contour that correspond to the inverse compound contour of assembled and operational engines.

  17. Cylinder yard inspections and corrective actions

    SciTech Connect

    Barlow, C.R.; Ziehlke, K.T.; Pryor, W.A.

    1990-07-31

    Inspection of valves on stored uranium hexafluoride (UF{sub 6}) cylinders was initiated at the three diffusion plant sites in Oak Ridge, Tennessee, Paducah, Kentucky, and Portsmouth, Ohio as the result of the discovery of valve defects and evidence of valve leaks at the Oak Ridge K-25 plant. The coordinated inspection culminated in the identification of additional factors related to long-term safe storage of UF{sub 6}, and plans for correction of such deficiencies are presently being developed and implemented. These corrective actions supplement existing programs aimed at assurance of safe storage as summarized in the report.

  18. Coalescence of two viscous cylinders by capillarity

    SciTech Connect

    Hopper, R.W. )

    1993-12-01

    The creeping plane flow of two viscous cylinders coalescing under the influence of surface tension is described theoretically in a series of three articles. Part I is a theoretical overview. The physical assumptions affecting applicability of the theory are discussed. The shape as a function of time and of the initial diameter ratio D [>=] 1 is given in parametric form. For D = 1 and D = [infinity], the shape sequences are known exactly; for finite D > 1, a first-order differential equation is solved numerically. The time requires a quadrature. This is accurate, and easier than solving the fluid-dynamical field equations. The theory encompasses time-dependent liquid properties.

  19. Topograph for Inspection of Engine Cylinder Walls

    NASA Astrophysics Data System (ADS)

    Franz, Stefan; Leonhardt, Klaus; Windecker, Robert; Tiziani, Hans J.

    1999-12-01

    The microstructural inspection of engine cylinder walls is an important task for quality management in the automotive industry. Until recently, mainly tactile methods were used for this purpose. We present an optical instrument based on microscopic fringe projection that permits fast, reliable, and nondestructive measurements of microstructure. The field of view is 0.8 mm 1.2 mm, with a spatial sampling of 1100 700 pixels. In contrast to conventional tactile sensors, the optical method provides fast in situ three-dimensional surface characterizations that provide more information about the surface than do line profiles. Measurements are presented, and advantages of this instrument for characterization of a surface are discussed.

  20. Cylinder light concentrator and absorber: theoretical description.

    PubMed

    Kildishev, Alexander V; Prokopeva, Ludmila J; Narimanov, Evgenii E

    2010-08-01

    We present a detailed theoretical description of a broadband omnidirectional light concentrator and absorber with cylinder geometry. The proposed optical "trap" captures nearly all the incident light within its geometric cross-section, leading to a broad range of possible applications--from solar energy harvesting to thermal light emitters and optoelectronic components. We have demonstrated that an approximate lamellar black-hole with a moderate number of homogeneous layers, while giving the desired ray-optical performance, can provide absorption efficiencies comparable to those of ideal devices with a smooth gradient in index. PMID:20721056

  1. Recording Rapidly Changing Cylinder-wall Temperatures

    NASA Technical Reports Server (NTRS)

    Meier, Adolph

    1942-01-01

    The present report deals with the design and testing of a measuring plug suggested by H. Pfriem for recording quasi-stationary cylinder wall temperatures. The new device is a resistance thermometer, the temperature-susceptible part of which consists of a gold coating applied by evaporation under high vacuum and electrolytically strengthened. After overcoming initial difficulties, calibration of plugs up to and beyond 400 degrees C was possible. The measurements were made on high-speed internal combustion engines. The increasing effect of carbon deposit at the wall surface with increasing operating period is indicated by means of charts.

  2. Influence of Nd and Y on texture of as-extruded Mg-5Li-3Al-2Zn alloy

    NASA Astrophysics Data System (ADS)

    Wu, Liqun; Zhang, Tianlong; Cui, Chongliang; Wu, Ruizhi; Zhang, Milin; Hou, Legan

    2016-07-01

    Mg-5Li-3Al-2Zn alloys with the additions of Y and Nd were prepared using induction melting furnace under the atmosphere of pure argon; then they were extruded. The textures of the as-extruded alloys were analyzed by pole figures and electron backscatter diffraction. Results show that the addition of a small amount of Nd can weaken the basal texture. The further increase of Nd content has no corresponding further influence on texture. When a small amount of Y is used to replace Nd, the basal texture can be further weakened and the prismatic slip system can be further activated. In the alloy of Mg-5Li-3Al-2Zn-1.2Y-0.8Nd, the basal textures almost vanish.

  3. Development of Ta-matrix Nb3Al Strand and Cable for High-Field Accelerator Magnet

    SciTech Connect

    Tsuchiya, K.; Ghosh, A.; Kikuchi, A.; Takeuchi, T.; Banno, N.; Iijima, Y.; Nimori, S.; Takigawa, H.; Terashima, A.; Nakamoto, T.; Kuroda, Y.; Maruyama, M.; Takao, T.; Tanaka, K.; Nakagawa, K.; Barzi, E.; Yamada, R.; Zlobin, A.

    2011-08-03

    Research and development of Nb{sub 3}Al strands and cables for a high field accelerator magnet is ongoing under the framework of the CERN-KEK collaboration. In this program, new Ta-matrix Nb{sub 3}Al strands were developed and their mechanical properties and superconducting properties were studied. The non-Cu J{sub c} values of these strands were 750 {approx} 800 A/mm{sup 2} at 15 T and 4.2 K. Using these strands, test fabrication of 27-strand Rutherford cable was carried out in collaboration with NIMS and Fermilab. The properties of the strands extracted from the cable were examined and it was found that there was no degradation of the superconducting properties of the strands. In this paper, we report the fabrication of the strands and the cable in brief and present some of the results obtained by studying their properties.

  4. Surface Properties of the IN SITU Formed Ceramics Reinforced Composite Coatings on TI-3AL-2V Alloys

    NASA Astrophysics Data System (ADS)

    Liu, Peng; Guo, Wei; Hu, Dakui; Luo, Hui; Zhang, Yuanbin

    2012-04-01

    The synthesis of hard composite coating on titanium alloy by laser cladding of Al/Fe/Ni+C/Si3N4 pre-placed powders has been investigated in detail. SEM result indicated that a composite coating with metallurgical joint to the substrate was formed. XRD result indicated that the composite coating mainly consisted of γ-(Fe, Ni), FeAl, Ti3Al, TiC, TiNi, TiC0.3N0.7, Ti2N, SiC, Ti5Si3 and TiNi. Compared with Ti-3Al-2V substrate, an improvement of the micro-hardness and the wear resistance was observed for this composite coating.

  5. The unusual chemical bonding and thermoelectric properties of a new type Zintl phase compounds Ba3Al2As4

    NASA Astrophysics Data System (ADS)

    Yang, Gui; Zhang, Guangbiao; Wang, Chao; Wang, Yuanxu

    2016-07-01

    Ba3Al2As4 exhibits an unusual anisotropic electrical conductivity, that is, the electrical conductivity along the chain is smaller than those along other two directions. The results is conflict with previous conclusion for Ca5M2Pn6. Earlier studies on Ca5M2Pn6 showed that a higher electrical conductivity could be obtained along the chain. The band decomposed charge density is used to explain such unusual behavior. Our calculations indicate the existence of a conductive pathway near the Fermi level is responsible for the electrons transport. Further, the Ba-As bonding of Ba3Al2As4 has some degree covalency which is novel for the Zintl compounds.

  6. Site preference and lattice relaxation around 4d and 5d refractory elements in Ni3Al.

    PubMed

    Umićević, Ana; Mahnke, Heinz-Eberhard; Belošević-Čavor, Jelena; Cekić, Božidar; Schumacher, Gerhard; Madjarevic, Ivan; Koteski, Vasil

    2016-01-01

    X-ray absorption spectroscopy is employed to investigate site preference and lattice relaxation around Mo, Ru, Hf, W and Re dopants in Ni3Al. The site occupation preference and the measured distances between the refractory elements as dopants and the nearest host atoms are compared with the results of ab initio calculations within the density functional theory. Combined experimental and theoretical results indicate that Mo, Hf, W and Re atoms reside on the Al sublattice in Ni3Al, while Ru atoms occupy the Ni sublattice. A more pronounced lattice relaxation was detected in the case of Hf and Ru doping, with a strong outward relaxation of the nearest Ni and Al atoms. PMID:26698076

  7. Stability of Trace Gases in High-Pressure Cylinders

    NASA Astrophysics Data System (ADS)

    Hall, B. D.; Montzka, S. A.; Novelli, P. C.; Dutton, G. S.; Elkins, J. W.

    2001-12-01

    Long-term observations of atmospheric trace gases require calibration methods that are consistent and reproducible over the duration of the observations. Small trends in calibration can be difficult to detect, and can mask or alter the apparent atmospheric trends. Trace gas standards in high-pressure cylinders are often used for the calibration of gas chromatographic instruments employed for long-term monitoring, as well as for the collection of archive air samples. We have studied the stability of part-per-million-, part-per-billion-, and part-per-trillion-level gas mixtures (in air) in aluminum and stainless steel cylinders. The stability of a particular compound depends on the type and size of the cylinder, the passivation method employed, and the pressure of the gas in the cylinder. We will report on stability studies involving mixtures of methyl halides, chlorinated solvents, nitrous oxide (N2O), sulfur hexafluoride (SF6), carbon monoxide (CO), and carbonyl sulfide (COS). Methyl halides (CH3Cl and CH3Br) appear to be more stable in stainless steel than in aluminum cylinders. N2O and SF6 show good stability in both types of cylinders. CO tends to increase with time in aluminum cylinders. The stability of CO may improve with higher volume to surface area ratio, but further testing is required. Some chlorinated solvents, such as CH3CCl3, decrease rapidly in non-passivated aluminum cylinders, but can be stable in passivated aluminum and stainless steel cylinders.

  8. Flow past two tandem square cylinders vibrating transversely in phase

    NASA Astrophysics Data System (ADS)

    Mithun, M. G.; Tiwari, Shaligram

    2014-10-01

    Numerical investigations have been carried out to study the wake characteristics of flow past two tandem square cylinders vibrating in phase. Both the cylinders vibrate in a transverse direction, i.e., perpendicular to the incoming flow with the same frequency and amplitude. The frequency of vibration of the cylinders and the inter-cylinder spacing are varied for fixed values of the Reynolds number (Re = 100) and the amplitude ratio (A/D = 0.4). The synchronous or lock-in regime for the oscillatory wake of the vibrating cylinders has been identified by varying the frequency of the vibration from {{f}_{e}} = 0.4 {{f}_{0}} to 1.6 {{f}_{0}} ({{f}_{0}} being the frequency of vortex shedding behind a stationary square cylinder). The characteristics of lift and drag and the mechanism of vortex shedding are studied by varying the excitation frequency within the lock-in range for each value of inter-cylinder spacing. The complex interaction of flow between the cylinders gives rise to a variety of characteristically different shedding patterns in their wake. For values of inter-cylinder spacing equal to 2D and 3D, periodic, as well as quasi-periodic, lock-in behaviors are observed in the synchronous range.

  9. LES of the flow around two cylinders in tandem

    NASA Astrophysics Data System (ADS)

    Palau-Salvador, G.; Stoesser, T.; Rodi, W.

    2008-11-01

    The flow around an arrangement of two cylinders in tandem exhibits a remarkably complex behaviour that is of interest for many engineering problems, such as environmental flows or structural design. In the present paper, a Large Eddy Simulation using a staggered Cartesian grid has been performed for the flow around two cylinders in tandem of diameter D=20mm and height H=50mm submerged in an open channel with height h=60mm. The two axes have a streamwise spacing of 2D. The Reynolds number is 1500, based on the cylinder diameter and the free-stream velocity u. The results obtained show that no vortex shedding occurs in the gap between the two cylinders where the separated shear layers produced by the upstream cylinder reattach on the surface of the downstream one. The flow separates on the top of the first cylinder with the presence of two spiral nodes known as owl-face configuration. On top of the downstream cylinder, the flow is attached. A complex mean flow develops in the gap and also behind the second cylinder. Comparisons with PIV measurements reveal good general agreement, but there are differences concerning some details of the flow in the gap between the cylinders.

  10. Enrichment Assay Methods Development for the Integrated Cylinder Verification System

    SciTech Connect

    Smith, Leon E.; Misner, Alex C.; Hatchell, Brian K.; Curtis, Michael M.

    2009-10-22

    International Atomic Energy Agency (IAEA) inspectors currently perform periodic inspections at uranium enrichment plants to verify UF6 cylinder enrichment declarations. Measurements are typically performed with handheld high-resolution sensors on a sampling of cylinders taken to be representative of the facility's entire product-cylinder inventory. Pacific Northwest National Laboratory (PNNL) is developing a concept to automate the verification of enrichment plant cylinders to enable 100 percent product-cylinder verification and potentially, mass-balance calculations on the facility as a whole (by also measuring feed and tails cylinders). The Integrated Cylinder Verification System (ICVS) could be located at key measurement points to positively identify each cylinder, measure its mass and enrichment, store the collected data in a secure database, and maintain continuity of knowledge on measured cylinders until IAEA inspector arrival. The three main objectives of this FY09 project are summarized here and described in more detail in the report: (1) Develop a preliminary design for a prototype NDA system, (2) Refine PNNL's MCNP models of the NDA system, and (3) Procure and test key pulse-processing components. Progress against these tasks to date, and next steps, are discussed.

  11. Stability of Flow around a Cylinder in Plane Poiseuille Flow

    NASA Astrophysics Data System (ADS)

    Dou, Hua-Shu; Ben, An-Qing; Fluid Mechanics Research Team

    2013-11-01

    Simulation of Navier-Stokes equations is carried out to study the stability of flow around a cylinder in plane Poiseuille flow. The energy gradient method is employed to analyze the mechanism of instability of cylinder wake. The ratio of the channel width to the cylinder diameter is 30, and the Reynolds number based on the cylinder diameter and incoming centerline velocity is 26 and 100, respectively. The incoming flow is given as being laminar. It is found that the instability of the cylinder wake, starting near the front stagnation point upstream. The recirculation zone behind the cylinder has no effect on the stability of the wake. In the wake behind the recirculation zone, the flow stability is controlled by the energy gradient in the shear layer along the two sides of the wake. At high Re, the energy gradient of averaged flow in the channel interacts with the wake vortex, strengthening the wake vortex structure. Due to the large ratio of the channel width to the cylinder diameter, the disturbance caused by the cylinder mainly occurs in the vicinity of the centerline and has little effect on the flow near the wall. The velocity profile on the two sides of the cylinder wake in the downstream channel remains laminar (parabolic profile). Professor in Fluid Mechanics; AIAA Associate Fellow.

  12. Coupled Thermo-Mechanical Analyses of Dynamically Loaded Rubber Cylinders

    NASA Technical Reports Server (NTRS)

    Johnson, Arthur R.; Chen, Tzi-Kang

    2000-01-01

    A procedure that models coupled thermo-mechanical deformations of viscoelastic rubber cylinders by employing the ABAQUS finite element code is described. Computational simulations of hysteretic heating are presented for several tall and short rubber cylinders both with and without a steel disk at their centers. The cylinders are compressed axially and are then cyclically loaded about the compressed state. The non-uniform hysteretic heating of the rubber cylinders containing a steel disk is presented. The analyses performed suggest that the coupling procedure should be considered for further development as a design tool for rubber degradation studies.

  13. Workforce Development for Manufacturing

    ERIC Educational Resources Information Center

    Bernard, Rosalie

    2007-01-01

    In a recent skills gap report, the National Association of Manufacturers (NAM) noted some disturbing trends in the gap between the demand for highly skilled manufacturing workers and the potential supply. The NAM report notes that smaller manufacturers rank finding qualified workers ahead of energy costs, taxes and government regulations on the…

  14. Prediction of External Corrosion for Steel Cylinders--2007 Report

    SciTech Connect

    Schmoyer, Richard L

    2008-01-01

    Depleted uranium hexafluoride (DUF{sub 6}) is stored in over 62,000 containment cylinders at the Paducah Gaseous Diffusion Plant (PGDP) in Paducah, Kentucky, and at the Portsmouth Gaseous Diffusion Plant (PORTS) in Portsmouth, Ohio. Over 4,800 of the cylinders at Portsmouth were recently moved there from the East Tennessee Technology Park (ETTP) in Oak Ridge, Tennessee. The cylinders range in age up to 56 years and come in various models, but most are 48-inch diameter 'thin-wall'(312.5 mil) and 'thick-wall' (625 mil) cylinders and 30-inch diameter '30A' (including '30B') cylinders with 1/2-inch (500 mil) walls. Most of the cylinders are carbon steel, and they are subject to corrosion. The United States Department of Energy (DOE) manages the cylinders to maintain them and the DUF{sub 6} they contain. Cylinder management requirements are specified in the System Requirements Document (LMES 1997a), and the activities to fulfill them are specified in the System Engineering Management Plan (LMES 1997b). This report documents activities that address DUF{sub 6} cylinder management requirements involving measuring and forecasting cylinder wall thicknesses. As part of these activities, ultrasonic thickness (UT) measurements are made on samples of cylinders. For each sampled cylinder, multiple measurements are made in an attempt to find, approximately, the minimum wall thickness. Some cylinders have a skirt, which is an extension of the cylinder wall to protect the head (end) and valve. The head/skirt interface crevice is thought to be particularly vulnerable to corrosion, and for some skirted cylinders, in addition to the main body UT measurements, a separate suite of measurements is also made at the head/skirt interface. The main-body and head/skirt minimum thickness data are used to fit models relating minimum thickness to cylinder age, nominal thicknesses, and cylinder functional groups defined in terms of plant site, storage yard, top or bottom row storage positions, etc

  15. Role of Tricoordinate Al Sites in CH3ReO3/Al2O3 Olefin Metathesis Catalysts.

    PubMed

    Valla, Maxence; Wischert, Raphael; Comas-Vives, Aleix; Conley, Matthew P; Verel, René; Copéret, Christophe; Sautet, Philippe

    2016-06-01

    Re2O7 supported on γ-alumina is an alkene metathesis catalyst active at room temperature, compatible with functional groups, but the exact structures of the active sites are unknown. Using CH3ReO3/Al2O3 as a model for Re2O7/Al2O3, we show through a combination of reactivity studies, in situ solid-state NMR, and an extensive series of DFT calculations, that μ-methylene structures (Al-CH2-ReO3-Al) containing a Re═O bound to a tricoordinated Al (AlIII) and CH2 bound to a four-coordinated Al (AlIVb) are the precursors of the most active sites for olefin metathesis. The resting state of CH3ReO3/Al2O3 is a distribution of μ-methylene species formed by the activation of the C-H bond of CH3ReO3 on different surface Al-O sites. In situ reaction with ethylene results in the formation of Re metallacycle intermediates, which were studied in detail through a combination of solid-state NMR experiments, using labeled ethylene, and DFT calculations. In particular, we were able to distinguish between metallacycles in TBP (trigonal-bipyramidal) and SP (square-pyramidal) geometry, the latter being inactive and detrimental to catalytic activity. The SP sites are more likely to be formed on other Al sites (AlIVa/AlIVa). Experimentally, the activity of CH3ReO3/Al2O3 depends on the activation temperature of alumina; catalysts activated at or above 500 °C contain more active sites than those activated at 300 °C. We show that the dependence of catalytic activity on the Al2O3 activation temperature is related to the quantity of available AlIII-defect sites and adsorbed H2O. PMID:27140286

  16. Stress response by the strain-rate change in binary, stoichiometric Ni{sub 3}Al single crystal

    SciTech Connect

    Demura, M.; Hirano, T.

    1997-12-31

    The strain-rate dependence of flow stress in single crystals of binary, stoichiometric Ni{sub 3}Al was studied in the temperature region of the yield stress anomaly. Below 400 K, the steady-state flow stress was found to be independent of strain rate, though it changed temporarily when the strain rate was changed. The strain-rate insensitivity can be explained by assuming that the flow stress is controlled by the multiplication/immobilization of mobile dislocations.

  17. Stress corrosion cracking of a superplastic and nonsuperplastic Zn-22.3Al alloy in 3% NaCl solution

    SciTech Connect

    Yeh, M.S.; Chang, J.C.; Chuang, T.H.

    1999-04-01

    Through appropriate heat treatments, a Zn-22.3wt%Al (Zn-22.3Al) alloy can be prepared in both superplastic and nonsuperplastic specimens. It has been found that the superplastic Zn-22.3Al alloy possesses a very fine microduplex structure, while the nonsuperplastic alloy has a lamellar duplex structure with locally coarsened second phases. The very different microstructures of both specimens result in different corrosion and stress corrosion cracking (SCC) behaviors in 3% NaCl solution. In addition, the fractographs of both the superplastic and nonsuperplastic Zn-22.3Al specimens after SCC tests under various anodic applied potentials have been compared. Through the observations, a mechanism for the SCC in this case was proposed to show that the cracks proceeded with successive processes of oxide film rupture and Zn-Al matrix tearing. Such a mechanism is more evident for the fractography of nonsuperplastic specimens, on which a series of parallel strips inserted with dimple-bands can be obviously found.

  18. Corrosion behavior of an HVOF-sprayed Fe3Al coating in a high-temperature oxidizing/sulfidizing environment

    SciTech Connect

    Covino, Bernard S., Jr.; Bullard, Sophie J.; Cramer, Stephen D.; Holcomb, Gordon R.; Ziomek-Moroz, Margaret; Shrestha, S.; Harvey, D.

    2005-01-01

    An iron aluminide (Fe3Al) intermetallic coating was deposited onto a F22 (2.25Cr-1Mo) steel substrate using a JP-5000 high velocity oxy-fuel (HVOF) thermal spray system. The as-sprayed coating was examined by electron microscopy and X-ray diffraction and was characterized in terms of oxidation and adhesion. Fe3Al-coated steel specimens were exposed to a mixed oxidizing/sulfidizing environment at 500, 600, 700, and 800DGC for approximately seven days. The gaseous environment consisted of N2-10%CO-5%CO2-2%H2O-0.12%H2S (by volume). All specimens gained mass after exposure to the environment and the mass gains were found to be inversely proportional to temperature increases. Representative specimens exposed at each temperature were cross-sectioned and subjected to examination under a scanning electron microscope (SEM) and X-ray mapping. Results are presented in terms of corrosion weight gain and corrosion product formation. The purpose of the research presented here was to evaluate the effectiveness of an HVOF-sprayed Fe3Al coating in protecting a steel substrate exposed to a fossil energy environment.

  19. Analysis of the microstructure of Cr-Ni surface layers deposited on Fe{sub 3}Al by TIG

    SciTech Connect

    Ma Haijun . E-mail: hjma123@mail.sdu.edu.cn; Li Yajiang; Wang Juan

    2006-12-15

    A series of Cr-Ni alloys were overlaid on a Fe{sub 3}Al surface by tungsten inert gas arc welding (TIG) technology. The microstructure of the Cr-Ni surface layers were analysed by means of optical metallography, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results indicated that when the appropriate TIG parameters were used and Cr25-Ni13 and Cr25-Ni20 alloys were used for the overlaid materials, the Cr-Ni surface layers were crack-free. The matrix of the surface layer was austenite (A), pro-eutectoid ferrite (PF), acicular ferrite (AF), carbide-free bainite (CFB) and lath martensite (LM), distributed on the austenitic grain boundaries as well as inside the grains. The phase constituents of the Cr25-Ni13 surface layer were {gamma}-Fe, Fe{sub 3}Al, FeAl, NiAl, an Fe-C compound and an Fe-C-Cr compound. The microhardness of the fusion zone was lower than that of the Fe{sub 3}Al base metal and Cr25-Ni13 surface layer.

  20. Fatigue-damage evolution and damage-induced reduction of critical current of a Nb3Al superconducting composite

    NASA Astrophysics Data System (ADS)

    Ochiai, S.; Sekino, F.; Sawada, T.; Ohno, H.; Hojo, M.; Tanaka, M.; Okuda, H.; Koganeya, M.; Hayashi, K.; Yamada, Y.; Ayai, N.; Watanabe, K.

    2003-09-01

    We have studied the fatigue-damage mechanism of a Nb3Al superconducting composite at room temperature, and the influences of the fatigue damages introduced at room temperature on the critical current at 4.2 K and the residual strength at room temperature. The main (largest) fatigue crack arose first in the clad copper and then extended into the inner core with an increasing number of stress cycles. The cracking of the Nb3Al filaments in the core region occurred at a late stage (around 60-90% of the fatigue life). Once the fracture of the core occurred, it extended very quickly, resulting in a quick reduction in critical current and the residual strength with increasing stress cycles. Such a behaviour was accounted for by the crack growth calculated from the S-N curves (the relation of the maximum stress to the number of stress cycles at failure) combined with the Paris law. The size and distribution of the subcracks along the specimen length, and therefore the reduction in critical current of the region apart from the main crack, were dependent on the maximum stress level. The large subcracks causing fracture of the Nb3Al filaments were formed when the maximum stress was around 300-460 MPa, resulting in large reduction in critical current, but not when the maximum stress was outside such a stress range.

  1. Characterization and Wear Behavior of Heat-treated Ni3Al Coatings Deposited by Air Plasma Spraying

    NASA Astrophysics Data System (ADS)

    Mehmood, K.; Rafiq, M. A.; Nusair Khan, A.; Ahmed, F.; Mudassar Rauf, M.

    2016-07-01

    Air plasma spraying was utilized to deposit Ni3Al coatings on AISI-321 steel substrate. The deposited coatings were isothermally heat-treated at various temperatures from 500 to 800 °C for 10, 30, 60, and 100 h. The x-ray diffraction analysis revealed NiO formation in Ni3Al at 500 °C after 100 h, and the percentage of NiO increased with increasing exposure time and temperature. The hardness of the coating increased with the formation of NiO. The DSC test showed the formation of minor phases, Al3Ni and Al3Ni2, within the coating along with the major phase Ni3Al. TGA revealed a slowing down of the oxidation rate upon surface oxide formation. The pin-on-disk wear test on the as-sprayed and heat-treated coatings showed that wear rate and coefficient of friction decreased with an increase in the NiO phase content.

  2. Evaluation of the Transient Liquid Phase (TLP) Bonding Process for Ti3Al-Based Honeycomb Core Sandwich Structure

    NASA Technical Reports Server (NTRS)

    Bird, R. Keith; Hoffman, Eric K.

    1998-01-01

    The suitability of using transient liquid phase (TLP) bonding to fabricate honeycomb core sandwich panels with Ti-14Al-21Nb (wt%) titanium aluminide (T3Al) face sheets for high-temperature hypersonic vehicle applications was evaluated. Three titanium alloy honeycomb cores and one Ti3Al alloy honeycomb core were investigated. Edgewise compression (EWC) and flatwise tension (FWT) tests on honeycomb core sandwich specimens and tensile tests of the face sheet material were conducted at temperatures ranging from room temperature to 1500 F. EWC tests indicated that the honeycomb cores and diffusion bonded joints were able to stabilize the face sheets up to and beyond the face sheet compressive yield strength for all temperatures investigated. The specimens with the T3Al honeycomb core produced the highest FWT strengths at temperatures above 1000 F. Tensile tests indicated that TLP processing conditions resulted in decreases in ductility of the Ti-14Al-21Nb face sheets. Microstructural examination showed that the side of the face sheets to which the filler metals had been applied was transformed from equiaxed alpha2 grains to coarse plates of alpha2 with intergranular Beta. Fractographic examination of the tensile specimens showed that this transformed region was dominated by brittle fracture.

  3. Characterization and Wear Behavior of Heat-treated Ni3Al Coatings Deposited by Air Plasma Spraying

    NASA Astrophysics Data System (ADS)

    Mehmood, K.; Rafiq, M. A.; Nusair Khan, A.; Ahmed, F.; Mudassar Rauf, M.

    2016-05-01

    Air plasma spraying was utilized to deposit Ni3Al coatings on AISI-321 steel substrate. The deposited coatings were isothermally heat-treated at various temperatures from 500 to 800 °C for 10, 30, 60, and 100 h. The x-ray diffraction analysis revealed NiO formation in Ni3Al at 500 °C after 100 h, and the percentage of NiO increased with increasing exposure time and temperature. The hardness of the coating increased with the formation of NiO. The DSC test showed the formation of minor phases, Al3Ni and Al3Ni2, within the coating along with the major phase Ni3Al. TGA revealed a slowing down of the oxidation rate upon surface oxide formation. The pin-on-disk wear test on the as-sprayed and heat-treated coatings showed that wear rate and coefficient of friction decreased with an increase in the NiO phase content.

  4. An In-Cylinder Study of Soot and NO in a DI Diesel Engine. Final report

    SciTech Connect

    Litzinger, T.A.

    1995-10-18

    Clearly the reduction of NOx and particulate emissions remains a major challenge to Diesel engine manufacturers due to increasingly stringent emission standards in the US and other countries. The well documented NOx/particulate trade-off observed in Diesel engines makes the simultaneous reduction of both emissions particularly difficult for manufacturers to achieve. In an effort to provide an improved understanding of the fundamental processes which result in this trade-off, a program was carried out at Penn State to develop the appropriate engine facilities and laser diagnostics to permit in-cylinder studies of Diesel combustion and emissions production with the support of the Department of Energy Advanced Industrial Technology Division . This work has also been supported by the Cummins Engine Company, Lubrizol Corporation and the National Science Foundation. An optically accessible, direct injection, Diesel engine was constructed for these studies. The major objective of the, design of the engine was to maximize optical access under conditions representative of Diesel engine combustion in small bore, commercial engines. Intake air is preheated and boosted in pressure to make the in-cylinder conditions of heat release and pressure as realistic as possible. Another important objective of the design was flexibility in combustion chamber geometry to permit a variety of head and bowl geometries to be studied. In all the results reported in this report a square bowl was used to simplify the introduction of laser light sheets into the engine.

  5. CORSSTOL: Cylinder Optimization of Rings, Skin, and Stringers with Tolerance sensitivity

    NASA Technical Reports Server (NTRS)

    Finckenor, J.; Bevill, M.

    1995-01-01

    Cylinder Optimization of Rings, Skin, and Stringers with Tolerance (CORSSTOL) sensitivity is a design optimization program incorporating a method to examine the effects of user-provided manufacturing tolerances on weight and failure. CORSSTOL gives designers a tool to determine tolerances based on need. This is a decisive way to choose the best design among several manufacturing methods with differing capabilities and costs. CORSSTOL initially optimizes a stringer-stiffened cylinder for weight without tolerances. The skin and stringer geometry are varied, subject to stress and buckling constraints. Then the same analysis and optimization routines are used to minimize the maximum material condition weight subject to the least favorable combination of tolerances. The adjusted optimum dimensions are provided with the weight and constraint sensitivities of each design variable. The designer can immediately identify critical tolerances. The safety of parts made out of tolerance can also be determined. During design and development of weight-critical systems, design/analysis tools that provide product-oriented results are of vital significance. The development of this program and methodology provides designers with an effective cost- and weight-saving design tool. The tolerance sensitivity method can be applied to any system defined by a set of deterministic equations.

  6. Some Investigations of the General Instability of Stiffened Metal Cylinders VIII : Stiffened Metal Cylinders Subjected to Pure Torsion

    NASA Technical Reports Server (NTRS)

    Dunn, Louis G

    1947-01-01

    An experimental investigation of the general instability of reinforced thin-walled metal cylinders was carried out at the California Institute of Technology. The basic parameters involved were the spacing and sectional properties of the stiffening elements, the wall thickness, and the diameter of the cylinder. An analysis of the experimental data led to a suitable parameter for estimating the general instability stress of reinforced metal cylinders when subjected to pure torsion loading.

  7. Near-wake flow structure of elliptic cylinders close to a free surface: effect of cylinder aspect ratio

    NASA Astrophysics Data System (ADS)

    Daichin, K. V.; Lee, Sang Joon

    The flow fields behind elliptic cylinders adjacent to a free surface were investigated experimentally in a circulating water channel. A range of cylinder aspect ratios (AR=2, 3, 4) were considered, while the cross-sectional area of the elliptical cylinder was kept constant. The main objective of this study was to investigate the effect of cylinder aspect ratio and a free surface on the flow structure in the near-wake behind elliptic cylinders. For each elliptic cylinder, the flow structure was analyzed for various values of the submergence depth of the cylinder beneath the free surface. The flow fields were measured using a single-frame double-exposure PIV (Particle Image Velocimetry) system. For each experimental condition, 350 instantaneous velocity fields were obtained and ensemble-averaged to obtain the mean velocity field and spatial distribution of the mean vorticity statistics. The results show that near-wake can be classified into three typical flow patterns: formation of a Coanda flow, generation of substantial jet-like flow, and attachment of this jet flow to the free surface. The general flow structure observed behind the elliptic cylinders resembles the structure previously reported for a circular cylinder submerged near a free surface. However, the wake width and the angle of downward deflection of the shear layer developed from the lower surface of the elliptic cylinder differ from those observed for a circular cylinder. These trends are enhanced as cylinder aspect ratio is increased. In addition, the free surface distortion is also discussed in the paper.

  8. 49 CFR 178.36 - Specification 3A and 3AX seamless steel cylinders.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Specification 3A and 3AX seamless steel cylinders... FOR PACKAGINGS Specifications for Cylinders § 178.36 Specification 3A and 3AX seamless steel cylinders... conform to the following: (1) A DOT-3A cylinder is a seamless steel cylinder with a water...

  9. 49 CFR 178.45 - Specification 3T seamless steel cylinder.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Specification 3T seamless steel cylinder. 178.45... PACKAGINGS Specifications for Cylinders § 178.45 Specification 3T seamless steel cylinder. (a) Type, size, and service pressure. A DOT 3T cylinder is a seamless steel cylinder with a minimum water capacity...

  10. 49 CFR 178.56 - Specification 4AA480 welded steel cylinders.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Specification 4AA480 welded steel cylinders. 178... FOR PACKAGINGS Specifications for Cylinders § 178.56 Specification 4AA480 welded steel cylinders. (a) Type, size, and service pressure. A DOT 4AA480 cylinder is a welded steel cylinder having a...

  11. 49 CFR 178.36 - Specification 3A and 3AX seamless steel cylinders.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Specification 3A and 3AX seamless steel cylinders... FOR PACKAGINGS Specifications for Cylinders § 178.36 Specification 3A and 3AX seamless steel cylinders... conform to the following: (1) A DOT-3A cylinder is a seamless steel cylinder with a water...

  12. 49 CFR 178.60 - Specification 8AL steel cylinders with porous fillings for acetylene.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Specification 8AL steel cylinders with porous...) SPECIFICATIONS FOR PACKAGINGS Specifications for Cylinders § 178.60 Specification 8AL steel cylinders with porous fillings for acetylene. (a) Type and service pressure. A DOT 8AL cylinder is a seamless steel cylinder...

  13. 49 CFR 178.56 - Specification 4AA480 welded steel cylinders.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Specification 4AA480 welded steel cylinders. 178... FOR PACKAGINGS Specifications for Cylinders § 178.56 Specification 4AA480 welded steel cylinders. (a) Type, size, and service pressure. A DOT 4AA480 cylinder is a welded steel cylinder having a...

  14. 49 CFR 178.36 - Specification 3A and 3AX seamless steel cylinders.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Specification 3A and 3AX seamless steel cylinders... FOR PACKAGINGS Specifications for Cylinders § 178.36 Specification 3A and 3AX seamless steel cylinders... conform to the following: (1) A DOT-3A cylinder is a seamless steel cylinder with a water...

  15. 49 CFR 178.38 - Specification 3B seamless steel cylinders.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Specification 3B seamless steel cylinders. 178.38... PACKAGINGS Specifications for Cylinders § 178.38 Specification 3B seamless steel cylinders. (a) Type, size, and service pressure. A DOT 3B cylinder is seamless steel cylinder with a water capacity (nominal)...

  16. 49 CFR 178.56 - Specification 4AA480 welded steel cylinders.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Specification 4AA480 welded steel cylinders. 178... FOR PACKAGINGS Specifications for Cylinders § 178.56 Specification 4AA480 welded steel cylinders. (a) Type, size, and service pressure. A DOT 4AA480 cylinder is a welded steel cylinder having a...

  17. 49 CFR 178.60 - Specification 8AL steel cylinders with porous fillings for acetylene.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Specification 8AL steel cylinders with porous...) SPECIFICATIONS FOR PACKAGINGS Specifications for Cylinders § 178.60 Specification 8AL steel cylinders with porous fillings for acetylene. (a) Type and service pressure. A DOT 8AL cylinder is a seamless steel cylinder...

  18. 49 CFR 178.38 - Specification 3B seamless steel cylinders.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Specification 3B seamless steel cylinders. 178.38... PACKAGINGS Specifications for Cylinders § 178.38 Specification 3B seamless steel cylinders. (a) Type, size, and service pressure. A DOT 3B cylinder is seamless steel cylinder with a water capacity (nominal)...

  19. 49 CFR 178.45 - Specification 3T seamless steel cylinder.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Specification 3T seamless steel cylinder. 178.45... PACKAGINGS Specifications for Cylinders § 178.45 Specification 3T seamless steel cylinder. (a) Type, size, and service pressure. A DOT 3T cylinder is a seamless steel cylinder with a minimum water capacity...

  20. 49 CFR 178.36 - Specification 3A and 3AX seamless steel cylinders.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Specification 3A and 3AX seamless steel cylinders... FOR PACKAGINGS Specifications for Cylinders § 178.36 Specification 3A and 3AX seamless steel cylinders... conform to the following: (1) A DOT-3A cylinder is a seamless steel cylinder with a water...