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Sample records for candidate alloys vol

  1. Advanced gas cooled nuclear reactor materials evaluation and development program. Selection of candidate alloys. Vol. 1. Advanced gas cooled reactor systems definition

    International Nuclear Information System (INIS)

    Candidate alloys for a Very High Temperature Reactor (VHTR) Nuclear Process Heal (NPH) and Direct Cycle Helium Turbine (DCHT) applications in terms of the effect of the primary coolant exposure and thermal exposure were evaluated

  2. Advanced gas cooled nuclear reactor materials evaluation and development program. Selection of candidate alloys. Vol. 1. Advanced gas cooled reactor systems definition

    Energy Technology Data Exchange (ETDEWEB)

    Marvin, M.D.

    1978-10-31

    Candidate alloys for a Very High Temperature Reactor (VHTR) Nuclear Process Heal (NPH) and Direct Cycle Helium Turbine (DCHT) applications in terms of the effect of the primary coolant exposure and thermal exposure were evaluated. (FS)

  3. Characterization for Fusion Candidate Vanadium Alloys

    Institute of Scientific and Technical Information of China (English)

    T. Muroga; T. Nagasaka; J. M. Chen; Z. Y. Xu; Q. Y. Huang; y. C. Wu

    2004-01-01

    This paper summarizes recent achievements in the characterization of candidate vanadium alloys obtained for fusion in the framework of the Japan-China Core University Program.National Institute for Fusion Science (NIFS) has a program of fabricating high-purity V-4Cr4Ti alloys. The resulting products (NIFS-HEAT-1,2), were characterized by various research groups in the world including Chinese partners. South Western Institute of Physics (SWIP) fabricated a new V-4Cr-4Ti alloy (SWIP-Heat), and carried out a comparative evaluation of hydrogen embrittlement of NIFS-HEATs and SWIP-Heat. The tensile test of hydrogen-doped alloys showed that the NIFS-HEAT maintained the ductility to relatively high hydrogen levels.The comparison of the data with those of previous studies suggested that the reduced oxygen level in the NIFS-HEATs should be responsible for the increased resistance to hydrogen embrittlement.Based on the chemical analysis data of NIFS-HEATs and SWIP-Heats, neutron-induced activation was analyzed in Institute of Plasma Physics (IPP-CAS) as a function of cooling time after the use in the fusion first wall. The results showed that the low level of Co dominates the activity up to 50 years followed by a domination of Nb or Nb and Al in the respective alloys. It was suggested that reduction of Co and Nb, both of which are thought to have been introduced via cross-contamination into the alloys from the molds used should be crucial for reducing further the activation.

  4. Surface segregation in binary alloy first wall candidate materials

    International Nuclear Information System (INIS)

    We have been studying the conditions necessary to produce a self-sustaining stable lithium monolayer on a metal substrate as a means of creating a low-Z film which sputters primarily as secondary ions. It is expected that because of the toroidal field, secondary ions originating at the first wall will be returned and contribute little to the plasma impurity influx. Aluminum and copper have, because of their high thermal conductivity and low induced radioactivity, been proposed as first wall candidate materials. The mechanical properties of the pure metals are very poorly suited to structural applications and an alloy must be used to obtain adequate hardness and tensile strength. In the case of aluminum, mechanical properties suitable for aircraft manufacture are obtained by the addition of a few at% Li. In order to investigate alloys of a similar nature as candidate structural materials for fusion machines we have prepared samples of Li-doped aluminum using both a pyro-metallurgical and a vapor-diffusion technique. The sputtering properties and surface composition have been studied as a function of sample temperature and heating time, and ion beam mass. The erosion rate and secondary ion yield of both the sputtered Al and Li have been monitored by secondary ion mass spectroscopy and Auger analysis providing information on surface segregation, depth composition profiles, and diffusion rates. The surface composition ahd lithium depth profiles are compared with previously obtained computational results based on a regular solution model of segregation, while the partial sputtering yields of Al and Li are compared with results obtained with a modified version of the TRIM computer program. (orig.)

  5. Pitting, galvanic, and long-term corrosion studies on candidate container alloys for the Tuff Repository

    International Nuclear Information System (INIS)

    Contest Columbus Technologies, Inc. (CC Technologies) investigated the long-term performance of container materials for high-level radioactive waste packages as part of the information needed by the Nuclear Regulatory Commission to assess the Department of Energy's application to construct a geologic repository for the high-level radioactive waste. The scope of work focused on the Tuff Repository and employed short-term techniques, such as electrochemical and mechanical techniques to examine a wide range of possible failure modes. Two classes of alloys were evaluated for use as container materials for the Tuff Repository; Fe-Cr-Ni alloys and copper-base alloys. The candidate Fe-Cr-Ni alloys were Type 304L Stainless Steel (Alloy 304L) and Incoloy Alloy 825 (Alloy 825). The candidate copper-base alloys were CDA 102 Copper (Alloy CDA 102) and CDA 715 Copper-3D Nickel (Alloy CDA 715). The corrosion testing was performed in a simulated J-13 well water and in solutions selected from an experimental matrix from Task 2 of the program. This report summarizes the results of Task 4 (Pitting Studies), Task 6 (Other Failure Modes) and Task 7 (Long-Term Exposures) of the program. Pit-initiation studies, performed in Task 4, focused on anomalous Cyclic Potentiodynamic Polarization (CPP) behavior of the copper-base alloys reported in Task 2 of the program. Pit propagation studies were performed on Alloy CDA 102 in Task A of the program. Two types of galvanic corrosion studies were performed in Task 6 of the program; thermogalvanic couples and borehole linear-container interactions. In the thermogalvanic couples tests, the effect of temperature variation on the surface of the container on acceleration of corrosion was evaluated for two alloys; Alloy CDA 102 and Alloy 304L. Long-term immersion tests were conducted in Task 7 of the program

  6. Spectral emissivity of candidate alloys for very high temperature reactors in high temperature air environment

    International Nuclear Information System (INIS)

    Emissivity measurements for candidate alloys for very high temperature reactors were carried out in a custom-built experimental facility, capable of both efficient and reliable measurements of spectral emissivities of multiple samples at high temperatures. The alloys studied include 304 and 316 austenitic stainless steels, Alloy 617, and SA508 ferritic steel. The oxidation of alloys plays an important role in dictating emissivity values. The higher chromium content of 304 and 316 austenitic stainless steels, and Alloy 617 results in an oxide layer only of sub-micron thickness even at 700 °C and consequently the emissivity of these alloys remains low. In contrast, the low alloy SA508 ferritic steel which contains no chromium develops a thicker oxide layer, and consequently exhibits higher emissivity values

  7. Spectral emissivity of candidate alloys for very high temperature reactors in high temperature air environment

    Energy Technology Data Exchange (ETDEWEB)

    Cao, G., E-mail: gcao@wisc.edu; Weber, S.J.; Martin, S.O.; Sridharan, K.; Anderson, M.H.; Allen, T.R.

    2013-10-15

    Emissivity measurements for candidate alloys for very high temperature reactors were carried out in a custom-built experimental facility, capable of both efficient and reliable measurements of spectral emissivities of multiple samples at high temperatures. The alloys studied include 304 and 316 austenitic stainless steels, Alloy 617, and SA508 ferritic steel. The oxidation of alloys plays an important role in dictating emissivity values. The higher chromium content of 304 and 316 austenitic stainless steels, and Alloy 617 results in an oxide layer only of sub-micron thickness even at 700 °C and consequently the emissivity of these alloys remains low. In contrast, the low alloy SA508 ferritic steel which contains no chromium develops a thicker oxide layer, and consequently exhibits higher emissivity values.

  8. Neutron spectrum effects of the defect production in fusion reactor candidate alloys

    International Nuclear Information System (INIS)

    In the present work, irradiation effects of fission and fusion neutrons on fusion reactor candidate alloys, V-4Cr-4Ti and F82H were studied using the FNS facility and the Kyoto University Reactor (KUR). The comparison of defect structures in two fusion reactor candidate alloys between fusion neutron irradiation and fission neutron irradiation was performed. Even though the irradiation doses were low, the defect formation was detected by positron annihilation spectroscopy. Higher irradiation doses and different irradiation temperatures are required to detect the effects of neutron spectra more precisely. (author)

  9. Dynamic deformation behavior of Al-Zn-Mg-Cu alloy matrix composites reinforced with 20 vol. % SiC

    Energy Technology Data Exchange (ETDEWEB)

    Hong, S.I.; Gray, G.T. III (Los Alamos National Lab., NM (United States)); Lewandowski, J.J. (Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Materials Science and Engineering)

    1993-08-01

    The dynamic mechanical response and substructure evolution of underaged and overaged Al-Zn-Mg-Cu alloys with and without 20 vol.% SiC particles were investigated and compared to those following quasi-static compression. The hardening rates of the overaged composites and control alloys were found to be smaller than those of their underaged counterparts. Overaged composites and the control alloys showed more strain rate sensitive behavior than the underaged composites and alloys. The flow stress of the composites was found to decrease at total strains larger than 0.15 in the high-rate Hopkinson pressure bar test. A more raped decrease in stress in the underaged composites suggests that microstructural damage in the underaged condition is greater than that in the overaged condition tested at high strain rates. Cracks near the SiC/matrix interfaces were observed more frequently in the underaged Hopkinson pressure bar samples. The more frequent interface cracks in the underaged composites are thought to result from much slower relaxation of the stresses and strains built up at the interface due to much more difficult thermally activated deformation.

  10. Effect of oxide films on hydrogen permeability of candidate Stirling heater head tube alloys

    Energy Technology Data Exchange (ETDEWEB)

    Schuon, S R; Misencik, J A

    1981-01-01

    High pressure hydrogen has been selected as the working fluid for the developmental automotive Stirling engine. Containment of the working fluid during operation of the engine at high temperatures and at high hydrogen gas pressures is essential for the acceptance of the Stirling engine as an alternative to the internal combustion engine. Most commercial alloys are extremely permeable to pure hydrogen at high temperatures. A program was undertaken at NASA Lewis Research Center (LeRC) to reduce hydrogen permeability in the Stirling engine heater head tubes by doping the hydrogen working fluid with CO or CO/sub 2/. Small additions of these gases were shown to form an oxide on the inside tube wall and thus reduce hydrogen permeability. A study of the effects of dopant concentration, alloy composition, and effects of surface oxides on hydrogen permeability in candidate heater head tube alloys is summarized. Results showed that hydrogen permeability was similar for iron-base alloys (N-155, A286, IN800, 19-9DL, and Nitronic 40), cobalt-base alloys (HS-188) and nickel-base alloys (IN718). In general, the permeability of the alloys decreased with increasing concentration of CO or CO/sub 2/ dopant, with increasing oxide thickness, and decreasing oxide porosity. At high levels of dopants, highly permeable liquid oxides formed on those alloys with greater than 50% Fe content. Furthermore, highly reactive minor alloying elements (Ti, Al, Nb, and La) had a strong influence on reducing hydrogen permeability.

  11. Au-Ge based Candidate Alloys for High-Temperature Lead-Free Solder Alternatives

    DEFF Research Database (Denmark)

    Chidambaram, Vivek; Hald, John; Hattel, Jesper Henri

    2009-01-01

    and microhardness has been extensively reported. Furthermore, the effects of thermal aging on the microstructure and its corresponding microhardness of these promising candidate alloys have been investigated in this work. After thermal aging at 200°C for different durations ranging from 1 day to 3 weeks...

  12. High temperature behavior of candidate VHTR heat exchanger alloys - HTR2008-58200

    International Nuclear Information System (INIS)

    Several nickel based solid solution alloys are under consideration for application in heat exchangers for very high temperature gas cooled reactors. The principal candidates being considered for this application by the Next Generation Nuclear Plant (NGNP) project are Inconel 617 and Haynes 230. While both of these alloys have an attractive combination of creep strength, fabricability, and oxidation resistance a good deal remains to be determined about their environmental resistance in the expected NGNP helium chemistry and their long term response to thermal aging. A series of experiments has been carried out in a He loop with controlled impurity chemistries within the range expected for the NGNP. The influence of oxygen partial pressure and carbon activity on the microstructure and mechanical properties of Alloys 617 and 230 has been characterized. A relatively simple phenomenological model of the environmental interaction for these alloys has been developed. (authors)

  13. Development of Au-Ge based candidate alloys as an alternative to high-lead content solders

    DEFF Research Database (Denmark)

    Chidambaram, Vivek; Hald, John; Hattel, Jesper Henri

    Au-Ge based candidate alloys have been proposed as an alternative to high-lead content solders that are currently being used for high-temperature applications. The changes in microstructure and microhardness associated with the addition of low melting point metals namely In, Sb and Sn to the Au......-Ge eutectic were investigated in this work. Furthermore, the effects of thermal aging on the microstructure and its corresponding microhardness of these promising candidate alloys have been extensively reported. To investigate the effects of aging temperature, candidate alloys were aged at a lower temperature...... induced by the In atoms were the most effective strengthening mechanism....

  14. Design of lead-free candidate alloys for high-temperature soldering based on the Au–Sn system

    DEFF Research Database (Denmark)

    Chidambaram, Vivek; Hattel, Jesper Henri; Hald, John

    2010-01-01

    Au–Sn based candidate alloys have been proposed as a substitute for high-lead content solders that are currently being used for high-temperature soldering. The changes in microstructure and microhardness associated with the alloying of Ag and Cu to the Au rich side as well to the Sn rich side of...... the Au–Sn binary system were explored in this work. Furthermore, the effects of thermal aging on the microstructure and microhardness of these promising Au–Sn based ternary alloys were investigated. For this purpose, the candidate alloys were aged at a lower temperature, 150°C for up to 1week and...

  15. Ion irradiation testing and characterization of FeCrAl candidate alloys

    Energy Technology Data Exchange (ETDEWEB)

    Anderoglu, Osman [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Aydogan, Eda [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Maloy, Stuart Andrew [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wang, Yongqiang [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-10-29

    The Fuel Cycle Research and Development program’s Advanced Fuels Campaign has initiated a multifold effort aimed at facilitating development of accident tolerant fuels. This effort involves development of fuel cladding materials that will be resistant to oxidizing environments for extended period of time such as loss of coolant accident. Ferritic FeCrAl alloys are among the promising candidates due to formation of a stable Al₂O₃ oxide scale. In addition to being oxidation resistant, these promising alloys need to be radiation tolerant under LWR conditions (maximum dose of 10-15 dpa at 250 – 350°C). Thus, in addition to a number of commercially available alloys, nuclear grade FeCrAl alloys developed at ORNL were tested using high energy proton irradiations and subsequent characterization of irradiation hardening and damage microstructure. This report summarizes ion irradiation testing and characterization of three nuclear grade FeCrAl cladding materials developed at ORNL and four commercially available Kanthal series FeCrAl alloys in FY14 toward satisfying FCRD campaign goals.

  16. Evaluation of candidate Stirling engine heater tube alloys after 3500 hours exposure to high pressure doped hydrogen or helium

    Science.gov (United States)

    Misencik, J. A.; Titran, R. H.

    1984-01-01

    The heater head tubes of current prototype automotive Stirling engines are fabricated from alloy N-155, an alloy which contains 20 percent cobalt. Because the United States imports over 90 percent of the cobalt used in this country and resource supplies could not meet the demand imposed by automotive applications of cobalt in the heater head (tubes plus cylinders and regenerator housings), it is imperative that substitute alloys free of cobalt be identified. The research described herein focused on the heater head tubes. Sixteen alloys (15 potential substitutes plus the 20 percent Co N-155 alloy) were evaluated in the form of thin wall tubing in the NASA Lewis Research Center Stirling simulator materials diesel fuel fired test rigs. Tubes filled with either hydrogen doped with 1 percent CO2 or with helium at a gas pressure of 15 MPa and a temperature of 820 C were cyclic endurance tested for times up to 3500 hr. Results showed that two iron-nickel base superalloys, CG-27 and Pyromet 901 survived the 3500 hr endurance test. The remaining alloys failed by creep-rupture at times less than 3000 hr, however, several other alloys had superior lives to N-155. Results further showed that doping the hydrogen working fluid with 1 vol % CO2 is an effective means of reducing hydrogen permeability through all the alloy tubes investigated.

  17. Potentiodynamic polarization studies on candidate container alloys for the Tuff Repository

    International Nuclear Information System (INIS)

    Cortest Columbus Technologies, Inc. (CC Technologies) is investigating the long-term performance of container materials used for high-level radioactive waste packages. This information is being developed for the Nuclear Regulatory Commission to aid in their assessment of the Department of Energy's application to construct a geologic repository for disposal of high-level radioactive waste. This report summarizes the results of cyclic-potentiodynamic-polarization (CCP) studies performed on candidate container materials for the Tuff Repository. The CPP technique was used to provide an understanding of how specific variables such as environmental composition, temperature, alloy composition, and welding affect both the general- and localized-corrosion behavior of two copper-base and two Fe-Cr-Ni alloys in simulated repository environments. A statistically-designed test solution matrix was formulated, based on an extensive search of the literature, to evaluate the possible range of environmental species that may occur in the repository over the life of the canister. Forty-two CPP curves were performed with each alloy and the results indicated that several different types of corrosion were possible. The copper-base alloys exhibited unusual CCP behavior in that hysteresis was not always associated with pitting. The effects of temperature on the corrosions behavior were evaluated in two types of tests; isothermal tests at temperatures from 50 degrees C to 90 degrees C and heat-transfer tests where the solution was maintained at 50 degrees C and the specimen was internally heated to 90 degrees C. In the isothermal test, CPP curves were obtained with each alloy in simulated environments at 50 degrees C, 75 degrees C, and 90 degrees C. The results of these CCP experiments indicated that no systematic trends were evident for the environments tested. Lastly, the effects of welding on the corrosion behavior of the alloys in simulated environments were examined

  18. Solid particle erosion of steels and nickel based alloys candidates for USC steam turbine blading

    Energy Technology Data Exchange (ETDEWEB)

    Cernuschi, Federico; Guardamagna, Cristina; Lorenzoni, Lorenzo [ERSE SpA, Milan (Italy); Robba, Davide [CESI, Milan (Italy)

    2010-07-01

    The main objective of COST536 Action is to develop highly efficient steam power plant with low emissions, from innovative alloy development to validation of component integrity. In this perspective, to improve the operating efficiency, materials capable of withstanding higher operating temperatures are required. For the manufacturing of components for steam power plants with higher efficiency steels and nickel-based alloys with improved oxidation resistance and creep strength at temperature as high as 650 C - 700 C have to be developed. Candidate alloys for manufacturing high pressure steam turbine diaphragms, buckets, radial seals and control valves should exhibit, among other properties, a good resistance at the erosion phenomena induced by hard solid particles. Ferric oxide (magnetite) scales cause SPE by exfoliating from boiler tubes and steam pipes (mainly super-heaters and re-heaters) and being transported within the steam flow to the turbine. In order to comparatively study the erosion behaviour of different materials in relatively short times, an accelerated experimental simulation of the erosion phenomena must be carried out. Among different techniques to induce erosion on material targets, the use of an air jet tester is well recognised to be one of the most valid and reliable. In this work the results of SPE comparative tests performed at high temperatures (550 C, 600 C and 650 C) at different impaction angles on some steels and nickel based alloys samples are reported. (orig.)

  19. Corrosion and Creep of Candidate Alloys in High Temperature Helium and Steam Environments for the NGNP

    Energy Technology Data Exchange (ETDEWEB)

    Was, Gary; Jones, J. W.

    2013-06-21

    This project aims to understand the processes by which candidate materials degrade in He and supercritical water/steam environments characteristic of the current NGNP design. We will focus on understanding the roles of temperature, and carbon and oxygen potential in the 750-850 degree C range on both uniform oxidation and selective internal oxidation along grain boundaries in alloys 617 and 800H in supercritical water in the temperature range 500-600 degree C; and examining the application of static and cyclic stresses in combination with impure He environments in the temperature rang 750-850 degree C; and examining the application of static and cyclic stresses in combination with impure He environments in the temperature range 750-850 degree C over a range of oxygen and carbon potentials in helium. Combined, these studies wil elucidate the potential high damage rate processes in environments and alloys relevant to the NGNP.

  20. Biologically-Induced Micropitting of Alloy 22, a Candidate Nuclear Waste Packaging Material

    International Nuclear Information System (INIS)

    The effects of potential microbiologically influenced corrosion (MIC) on candidate packaging materials for nuclear waste containment are being assessed. Coupons of Alloy 22, the outer barrier candidate for waste packaging, were exposed to a simulated, saturated repository environment (or microcosm) consisting of crushed rock (tuff) from the Yucca Mountain repository site and a continual flow of simulated groundwater for periods up to five years at room temperature and 30 C. Coupons were incubated with YM tuff under both sterile and non-sterile conditions. Surfacial analysis by scanning electron microscopy of the biotically-incubated coupons show development of both submicron-sized pinholes and pores; these features were not present on either sterile or untreated control coupons. Room temperature, biotically-incubated coupons show a wide distribution of pores covering the coupon surface, while coupons incubated at 30 C show the pores restricted to polishing ridges

  1. New generation super alloy candidates for medical applications: corrosion behavior, cation release and biological evaluation.

    Science.gov (United States)

    Reclaru, L; Ziegenhagen, R; Unger, R E; Eschler, P Y; Constantin, F

    2014-12-01

    Three super alloy candidates (X1 CrNiMoMnW 24-22-6-3-2 N, NiCr21 MoNbFe 8-3-5 AlTi, CoNiCr 35-20 Mo 10 BTi) for a prolonged contact with skin are evaluated in comparison with two reference austenitic stainless steels 316L and 904L. Several electrochemical parameters were measured and determined (E(oc), E(corr), i(corr), b(a), b(c), E(b), R(p), E(crev) and coulometric analysis) in order to compare the corrosion behavior. The cation release evaluation and in vitro biological characterization also were performed. In terms of corrosion, the results reveal that the 904L steels presented the best behavior followed by the super austenitic steel X1 CrNiMoMnW 24-22-6-3-2 N. For the other two super alloys (NiCr and CoNiCr types alloys) tested in different conditions (annealed, work hardened and work hardened+age hardened) it was found that their behavior to corrosion was weak and close to the other reference stainless steel, 316L. Regarding the extraction a mixture of cations in relatively high concentrations was noted and therefore a cocktail effect was not excluded. The results obtained in the biological assays WST-1 and TNF-alpha were in correlation with the corrosion and extraction evaluation. PMID:25491846

  2. Test matrices for irradiation of Path A Prime Candidate and developmental alloys in FFTF

    International Nuclear Information System (INIS)

    These irradiations are generally intended to evaluate the void swelling resistance of the Path A Prime Candidate Alloy (PCA) at high fluence (>100 dpa) relative to 20%-cold-worked type 316 after side-by-side irradiation in the Fast Flux Test Facility (FFTF), as well as to evaluate the improvements achieved by additional minor compositional variations of the PCA. Further, these irradiations also serve as a low helium base line against which to gage more accurately the effects of higher helium generation for similar irradiation of exactly the same alloys in the High Flux Isotope Reactor (HFIR). An initial set of transmission electron microscopy (TEM) disk specimens was assembled for irradiation at approximately 420, 520, and 6000C to fluences of approximately 15, 45, and 75 dpa. Some TEM specimens were discharged at approximately 9.5 to 15.6 dpa at all temperatures, and additional specimens were then reloaded to achieve fluences well beyond 100 dpa. Tensile specimens were also included in the reload for irradiation in an above-core position at approximately 6000C. The general goals of the experiments are outlined and detailed specimen loadings are described. 9 references, 4 tables

  3. Effect of yttrium additions on void swelling in Liquid Metal Fast Breeder Reactor candidate cladding alloys

    International Nuclear Information System (INIS)

    Candidate Liquid Metal Fast Breeder Reactor cladding alloys AL1 (Fe-26% Ni-9% Cr) and AL2 (Fe-35% Ni-12% Cr) without and with the addition of 0.1% yttrium were bombarded by 4 MeV56Fe2+ ions without and with simultaneous bombardment by 0.4 MeV 4He+ ions. These bombardments were conducted at various irradiation temperatures to determine the effect of yttrium on void swelling. The addition of yttrium decreased peak swelling for 4 MeV 56Fe2+ ion bombarded AL1 and AL2 by 28% and 20%, respectively. In all cases where similar sample comparisons were made (i.e., undoped with undoped and doped with doped) and where bombardment conditions were similar (i.e., single with single beam and dual with dual beam), AL1 showed less peak swelling than did AL2. Simultaneously implanting helium during heavy-ion bombardment increased peak swelling in undoped and doped AL1 by factors of 2.3 and 2.6, respectively

  4. Effect of glass-ceramic-processing cycle on the metallurgical properties of candidate alloys for actuator housings

    Energy Technology Data Exchange (ETDEWEB)

    Weirick, L.J.

    1982-01-01

    This report summarizes the results from an investigation on the effect of a glass ceramic processing cycle on the metallurgical properties of metal candidates for actuator housings. The cycle consists of a 980/sup 0/C sealing step, a 650/sup 0/C crystallization step and a 475/sup 0/C annealing step. These temperatue excursions are within the same temperature regime as annealing and heat treating processes normally employed for metals. Therefore, the effect of the processing cycle on metallurgical properties of microstructure, strength, hardness and ductility were examined. It was found that metal candidates which are single phase or solid solution alloys (such as 21-6-9, Hastelloy C-276 and Inconel 625) were not affected whereas multiphase or precipitation hardened alloys (such as Inconel 718 and Titanium ..beta..-C) were changed by the processing cycle for the glass ceramic.

  5. Long-term creep rupture strength of weldment of Fe-Ni based alloy as candidate tube and pipe for advanced USC boilers

    Energy Technology Data Exchange (ETDEWEB)

    Bao, Gang; Sato, Takashi [Babcok-Hitachi K.K., Hiroshima (Japan). Kure Research Laboratory; Marumoto, Yoshihide [Babcok-Hitachi K.K., Hiroshima (Japan). Kure Div.

    2010-07-01

    A lot of works have been going to develop 700C USC power plant in Europe and Japan. High strength Ni based alloys such as Alloy 617, Alloy 740 and Alloy 263 were the candidates for boiler tube and pipe in Europe, and Fe-Ni based alloy HR6W (45Ni-24Fe-23Cr-7W-Ti) is also a candidate for tube and pipe in Japan. One of the Key issues to achieve 700 C boilers is the welding process of these alloys. Authors investigated the weldability and the long-term creep rupture strength of HR6W tube. The weldments were investigated metallurgically to find proper welding procedure and creep rupture tests are ongoing exceed 38,000 hours. The long-term creep rupture strengths of the HST weld joints are similar to those of parent metals and integrity of the weldments was confirmed based on with other mechanical testing results. (orig.)

  6. Stress-corrosion-cracking studies on candidate container alloys for the Tuff Repository

    International Nuclear Information System (INIS)

    Cortest Columbus Technologies, Inc. (CC Technologies) investigated the long-term performance of container materials used for high-level waste package as part of the information needed by the Nuclear Regulatory Commission (NRC) to assess the Department of Energy's application to construct to geologic repository for high-level radioactive waste. At the direction of the NRC, the program focused on the Tuff Repository. This report summarizes the results of Stress-Corrosion-Cracking (SCC) studies performed in Tasks 3, 5, and 7 of the program. Two test techniques were used; U-bend exposures and Slow-Strain-Rate (SSR) tests. The testing was performed on two copper-base alloys (Alloy CDA 102 and Alloy CDA 175) and two Fe-Cr-Ni alloys (Alloy 304L and Alloy 825) in simulated J-13 groundwater and other simulated solutions for the Tuff Repository. These solutions were designed to simulate the effects of concentration and irradiation on the groundwater composition. All SCC testing on the Fe-Cr-Ni Alloys was performed on solution-annealed specimens and thus issues such as the effect of sensitization on SCC were not addressed

  7. Solid-state Diffusion Bonding of Candidate Fe-base and Ni-base Alloys for the Application of S-CO2 Cycle Heat Exchanger

    International Nuclear Information System (INIS)

    To achieve efficient heat transfer, compact type heat exchangers, such as printed circuit or plate fin type heat exchanger, are considered for intermediate heat exchangers (IHXs). Solid-state diffusion bonding (DB) is one of key issues for joining the thin metal sheets with flow passages that are either machined or photo-chemically etched. In this study, diffusion bonding was performed for the candidate Fe-base and Ni-base alloys. Tensile properties of the as-bonded were compared with the as-received and characteristics of the aged in high temperature S-CO2 environment were discussed. Studies on diffusion bonding of candidate alloys for the application of super-critical CO2 cycle were carried out. Strength ratios were close to 1 for Fe-base alloys (F91, SS 316H, and SS 347H), while those of Ni-base alloys (Alloy 600, Alloy 690) and Fe-Ni-Cr alloy (Incoloy 800HT) were somewhat decreased to about 0.8 due to the planar grain boundary and precipitates formed along the bond-line. After exposure in high temperature S-CO2 environment for 1000 h, mechanical properties were not changed substantially and the location of the failure was still in the gauge section away from the bond-line for most alloys. Thus, bond-line which plays a role as grain boundary is thought to have superior corrosion and carburization resistance comparable to that of parent matrix

  8. Fireside corrosion testing of candidate superheater tube alloys, coatings, and claddings - phase II

    Energy Technology Data Exchange (ETDEWEB)

    Blough, J.L.; Stanko, G.J. [Foster Wheeler Development Corp., Livingston, NJ (United States)

    1996-08-01

    In Phase I a variety of developmental and commercial tubing alloys and claddings were exposed to laboratory fireside corrosion testing simulating a superheater or reheater in a coal-fired boiler. Phase II (in situ testing) has exposed samples of 347, RA-8511, HR3C, 253MA, Fe{sub 3}Al + 5Cr, 310 modified, 800HT, NF 709, 690 clad, and 671 clad for over 10,000 hours to the actual operating conditions of a 250-MW coal-fired boiler. The samples were installed on an air-cooled, retractable corrosion probe, installed in the reheater cavity, and controlled to the operating metal temperatures of an existing and advanced-cycle coal-fired boiler. Samples of each alloy will be exposed for 4000, 12,000, and 16,000 hours of operation. The results will be presented for the metallurgical examination of the corrosion probe samples after 4000 hours of exposure.

  9. Development of Barrier Layers for the Protection of Candidate Alloys in the VHTR

    Energy Technology Data Exchange (ETDEWEB)

    Levi, Carlos G. [Battelle Energy Alliance, LLC, Idaho Falls, ID (United States); Jones, J. Wayne [Battelle Energy Alliance, LLC, Idaho Falls, ID (United States); Pollock, Tresa M. [Battelle Energy Alliance, LLC, Idaho Falls, ID (United States); Was, Gary S. [Battelle Energy Alliance, LLC, Idaho Falls, ID (United States)

    2015-01-22

    The objective of this project was to develop concepts for barrier layers that enable leading candi- date Ni alloys to meet the longer term operating temperature and durability requirements of the VHTR. The concepts were based on alpha alumina as a primary surface barrier, underlay by one or more chemically distinct alloy layers that would promote and sustain the formation of the pro- tective scale. The surface layers must possess stable microstructures that provide resistance to oxidation, de-carburization and/or carburization, as well as durability against relevant forms of thermo-mechanical cycling. The system must also have a self-healing ability to allow endurance for long exposure times at temperatures up to 1000°C.

  10. Radiation-Induced Segregation and Phase Stability in Candidate Alloys for the Advanced Burner Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Gary S. Was; Brian D. Wirth

    2011-05-29

    Major accomplishments of this project were the following: 1) Radiation induced depletion of Cr occurs in alloy D9, in agreement with that observed in austenitic alloys. 2) In F-M alloys, Cr enriches at PAG grain boundaries at low dose (<7 dpa) and at intermediate temperature (400°C) and the magnitude of the enrichment decreases with temperature. 3) Cr enrichment decreases with dose, remaining enriched in alloy T91 up to 10 dpa, but changing to depletion above 3 dpa in HT9 and HCM12A. 4) Cr has a higher diffusivity than Fe by a vacancy mechanism and the corresponding atomic flux of Cr is larger than Fe in the opposite direction to the vacancy flux. 5) Cr concentration at grain boundaries decreases as a result of vacancy transport during electron or proton irradiation, consistent with Inverse Kirkendall models. 6) Inclusion of other point defect sinks into the KLMC simulation of vacancy-mediated diffusion only influences the results in the low temperature, recombination dominated regime, but does not change the conclusion that Cr depletes as a result of vacancy transport to the sink. 7) Cr segregation behavior is independent of Frenkel pair versus cascade production, as simulated for electron versus proton irradiation conditions, for the temperatures investigated. 8) The amount of Cr depletion at a simulated planar boundary with vacancy-mediated diffusion reaches an apparent saturation value by about 1 dpa, with the precise saturation concentration dependent on the ratio of Cr to Fe diffusivity. 9) Cr diffuses faster than Fe by an interstitial transport mechanism, and the corresponding atomic flux of Cr is much larger than Fe in the same direction as the interstitial flux. 10) Observed experimental and computational results show that the radiation induced segregation behavior of Cr is consistent with an Inverse Kirkendall mechanism.

  11. Fireside corrosion testing of candidate superheater tube alloys, coatings, and claddings - Phase II

    Energy Technology Data Exchange (ETDEWEB)

    Blough, J.L.; Krawchuk, M.T.; Van Weele, S.F. [Foster Wheeler Development Corp., Livingston, NJ (United States)

    1995-08-01

    A number of developmental and commercial tubing alloys and claddings have previously been exposed in Phase I to laboratory fireside corrosion testing simulating a superheater or reheater in a coal-fired boiler. This program is exposing samples of TP 347, RA-85H, HR-3C, 253MA, Fe{sub 3}Al + 5Cr, 310 modified, NF-709, 690 clad, and 671 clad, which showed good corrosion resistance from Phase 1, to the actual operating conditions of a 250-MW, coal-fired boiler. The samples were installed on air-cooled, retractable corrosion probes, installed in the reheater cavity, and are being controlled to the operating metal temperatures of an existing and advanced-cycle coal-fired boiler. The exposure will continue for 4000, 12,000, and 16,000 hours of operation. After the three exposure times, the samples will be metallurgically examined to determine the wastage rates and mode of attack. The probes were commissioned November 16, 1994. The temperatures are being recorded every 15 minutes, and the weighted average temperature calculated for each sample. Each of the alloys is being exposed to a temperature in each of two temperature bands-1150 to 1260{degrees}F and 1260 to 1325{degrees}F. After 2000 hours of exposure, one of the corrosion probes was cleaned and the wall thicknesses were ultrasonically measured. The alloy performance from the field probes will be discussed.

  12. PHB, crystalline and amorphous magnesium alloys: Promising candidates for bioresorbable osteosynthesis implants?

    International Nuclear Information System (INIS)

    In this study various biodegradable materials were tested for their suitability for use in osteosynthesis implants, in particular as elastically stable intramedullary nails for fracture treatment in paediatric orthopaedics. The materials investigated comprise polyhydroxybutyrate (PHB), which belongs to the polyester family and is produced by microorganisms, with additions of ZrO2 and a bone graft substitute; two crystalline magnesium alloys with significantly different degradation rates ZX50 (MgZnCa, fast) and WZ21 (MgYZnCa, slow); and MgZnCa bulk metallic glasses (BMG). Push-out tests were conducted after various implantation times in rat femur meta-diaphysis to evaluate the shear forces between the implant material and the bone. The most promising materials are WZ21 and BMG, which exhibit high shear forces and push-out energies. The degradation rate of ZX50 is too fast and thus the alloy does not maintain its mechanical stability long enough during the fracture-healing period. PHB exhibits insufficient mechanical properties: it degrades very slowly and the respective low shear forces and push-out energy levels are unsatisfactory. - Highlights: ► In-vivo (rat model) investigation of biodegradable materials suitable for ESIN. ► Materials: polymer PHB, crystalline Mg ZX50 and Mg WZ21, MgZnCa bulk metallic glasses. ► Evaluated interface shear strength, push-out energies, stiffness, histology. ► Mg WZ21 suitable, other materials only after alterations.

  13. Fireside corrosion testing of candidate superheater tube alloys, coatings, and claddings -- Phase 2 field testing

    Energy Technology Data Exchange (ETDEWEB)

    Blough, J.L.; Seitz, W.W.; Girshik, A. [Foster Wheeler Development Corp., Livingston, NJ (United States)

    1998-06-01

    In Phase 1 of this project, laboratory experiments were performed on a variety of developmental and commercial tubing alloys and claddings by exposing them to fireside corrosion tests which simulated a superheater or reheater in a coal-fired boiler. Phase 2 (in situ testing) has exposed samples of 347, RA85H, HR3C, RA253MA, Fe{sub 3}Al + 5Cr, Ta-modified 310, NF 709, 690 clad, 671 clad, and 800HT for up to approximately 16,000 hours to the actual operating conditions of a 250-MW, coal-fired boiler. The samples were installed on air-cooled, retractable corrosion probes, installed in the reheater cavity, and controlled to the operating metal temperatures of an existing and advanced-cycle, coal-fired boiler. Samples of each alloy were exposed for 4,483, 11,348, and 15,883 hours of operation. The present results are for the metallurgical examination of the corrosion probe samples after the full 15,883 hours of exposure. A previous topical report has been issued for the 4,483 hours of exposure.

  14. PHB, crystalline and amorphous magnesium alloys: Promising candidates for bioresorbable osteosynthesis implants?

    Energy Technology Data Exchange (ETDEWEB)

    Celarek, Anna [Institute for Building Construction and Technology E-206-4, Vienna University of Technology, Karlsplatz 13, 1040 Vienna (Austria); Kraus, Tanja [Department of Paediatric Orthopaedics, Medical University of Graz, Auenbruggerplatz 34, 8036 Graz (Austria); Tschegg, Elmar K., E-mail: elmar.tschegg@tuwien.ac.at [Institute for Building Construction and Technology E-206-4, Vienna University of Technology, Karlsplatz 13, 1040 Vienna (Austria); Fischerauer, Stefan F. [Department of Paediatric and Adolescent Surgery, Medical University of Graz, Auenbruggerplatz 34, 8036 Graz (Austria); Stanzl-Tschegg, Stefanie [Department of Material Sciences and Process Engineering, Institute of Physics and Materials Science, University of Natural Resources and Life Sciences, Peter Jordan Str. 82, 1190 Vienna (Austria); Uggowitzer, Peter J. [Department of Materials, Laboratory for Metal Physics and Technology, ETH Zurich, 8093 Zurich (Switzerland); Weinberg, Annelie M. [Department of Paediatric and Adolescent Surgery, Medical University of Graz, Auenbruggerplatz 34, 8036 Graz (Austria)

    2012-08-01

    In this study various biodegradable materials were tested for their suitability for use in osteosynthesis implants, in particular as elastically stable intramedullary nails for fracture treatment in paediatric orthopaedics. The materials investigated comprise polyhydroxybutyrate (PHB), which belongs to the polyester family and is produced by microorganisms, with additions of ZrO{sub 2} and a bone graft substitute; two crystalline magnesium alloys with significantly different degradation rates ZX50 (MgZnCa, fast) and WZ21 (MgYZnCa, slow); and MgZnCa bulk metallic glasses (BMG). Push-out tests were conducted after various implantation times in rat femur meta-diaphysis to evaluate the shear forces between the implant material and the bone. The most promising materials are WZ21 and BMG, which exhibit high shear forces and push-out energies. The degradation rate of ZX50 is too fast and thus the alloy does not maintain its mechanical stability long enough during the fracture-healing period. PHB exhibits insufficient mechanical properties: it degrades very slowly and the respective low shear forces and push-out energy levels are unsatisfactory. - Highlights: Black-Right-Pointing-Pointer In-vivo (rat model) investigation of biodegradable materials suitable for ESIN. Black-Right-Pointing-Pointer Materials: polymer PHB, crystalline Mg ZX50 and Mg WZ21, MgZnCa bulk metallic glasses. Black-Right-Pointing-Pointer Evaluated interface shear strength, push-out energies, stiffness, histology. Black-Right-Pointing-Pointer Mg WZ21 suitable, other materials only after alterations.

  15. Localized corrosion resistance of high nickel alloys as candidate materials for nuclear waste repository. Effect of alloy and weldment aging at 427 C for up to 40,000 h

    International Nuclear Information System (INIS)

    Ni-Cr-Mo alloys (e.g. C-22, C-4 and C-276) are considered candidate materials for nuclear waste containers because they offer excellent resistance to localized attack in conditions that can be encountered at the permanent repository site. Electrochemical and standard immersion tests showed that the most resistant of the studied alloys to localized attack was C-22 alloy and the less resistant was C-4 alloy. It was important to determine if long time exposure to low temperatures (below 500 C) would be detrimental in the resistance of these alloys to localized attack (pitting and crevice corrosion). After aging for 40,000 h at 427 C none of these alloys showed precipitation of a second phase (such as carbides or μ phase) that could promote a higher corrosion susceptibility of the alloys. Moreover, immersion and electrochemical tests showed that, after the same long term aging, the susceptibility to corrosion of both the base material and weldments remained unchanged. The effects of alloying elements on the resistance of the alloys to localized attack is discussed

  16. Fireside corrosion testing of candidate superheater tube alloys, coatings, and claddings -- Phase 2

    Energy Technology Data Exchange (ETDEWEB)

    Blough, J.L.; Seitz, W.W. [Foster Wheeler Development Corp., Livingston, NJ (United States)

    1997-12-01

    In Phase 1 a variety of developmental and commercial tubing alloys and claddings were exposed to laboratory fireside corrosion testing simulating a superheater or reheater in a coal-fired boiler. Phase 2 (in situ testing) has exposed samples of 347 RA-85H, HR3C, 253MA, Fe{sub 3}Al + 5Cr, 310 Ta modified, NF 709, 690 clad, and 671 clad for approximately 4,000, 12,000, and 16,000 hours to the actual operating conditions of a 250-MW coal-fired boiler. The samples were assembled on an air-cooled, retractable corrosion probe, the probe was installed in the reheater activity of the boiler and controlled to the operating metal temperatures of an existing and advanced-cycle coal-fired boiler. The results will be presented for the preliminary metallurgical examination of the corrosion probe samples after 16,000 hours of exposure. Continued metallurgical and interpretive analysis is still on going.

  17. Corrosion inhibition of 6061 Al-15 vol. pct. SiC(p) composite and its base alloy in a mixture of sulphuric acid and hydrochloric acid by 4-(N,N-dimethyl amino) benzaldehyde thiosemicarbazone

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Geetha Mable [Department of Chemistry, National Institute of Technology Karnataka, Surathkal, Srinivasnagar 575 025, Mangalore, Karnataka (India); Nayak, Jagannath [Department of Metallurgical and Materials Engineering, National Institute of Technology Karnataka, Surathkal, Srinivasnagar 575 025, Karnataka (India); Shetty, A. Nityananda, E-mail: nityashreya@gmail.com [Department of Chemistry, National Institute of Technology Karnataka, Surathkal, Srinivasnagar 575 025, Mangalore, Karnataka (India)

    2011-02-15

    Research highlights: {yields} Corrosion inhibition of Al-SiC composite. {yields} DMABT as corrosion inhibitor. {yields} Inhibition through physisorption of DMABT. - Abstract: The corrosion inhibition characteristics of 4-(N,N-dimethylamino) benzaldehyde thiosemicarbazone (DMABT) on the corrosion behavior of 6061 Al-15 vol. pct. SiC(p) composite and its base alloy were studied at different temperatures in acid mixture medium containing varying concentrations of hydrochloric acid and sulphuric acid using Tafel extrapolation technique and ac impedance spectroscopy (EIS). The effect of inhibitor concentration, temperature and concentration of the acid mixture media on the inhibitor action was investigated. It was found that inhibition efficiencies increase with the increase in inhibitor concentration, but decrease with the increase in temperature and with the increase in concentration of the acid media. Thermodynamic parameters for dissolution process were determined. The adsorption of DMABT on both the composite and base alloy was found to be through physisorption obeying Freundlich adsorption isotherm.

  18. Degradation mode survey candidate titanium-base alloys for Yucca Mountain project waste package materials. Revision 1

    International Nuclear Information System (INIS)

    The Yucca Mountain Site Characterization Project (YMP) is evaluating materials from which to fabricate high-level nuclear waste containers (hereafter called waste packages) for the potential repository at Yucca Mountain, Nevada. Because of their very good corrosion resistance in aqueous environments titanium alloys are considered for container materials. Consideration of titanium alloys is understandable since about one-third (in 1978) of all titanium produced is used in applications where corrosion resistance is of primary importance. Consequently, there is a considerable amount of data which demonstrates that titanium alloys, in general, but particularly the commercial purity and dilute α grades, are highly corrosion resistant. This report will discuss the corrosion characteristics of Ti Gr 2, 7, 12, and 16. The more highly alloyed titanium alloys which were developed by adding a small Pd content to higher strength Ti alloys in order to give them better corrosion resistance will not be considered in this report. These alloys are all two phase (α and β) alloys. The palladium addition while making these alloys more corrosion resistant does not give them the corrosion resistance of the single phase α and near-α (Ti Gr 12) alloys

  19. Degradation mode survey candidate titanium-base alloys for Yucca Mountain project waste package materials. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Gdowski, G.E.

    1997-12-01

    The Yucca Mountain Site Characterization Project (YMP) is evaluating materials from which to fabricate high-level nuclear waste containers (hereafter called waste packages) for the potential repository at Yucca Mountain, Nevada. Because of their very good corrosion resistance in aqueous environments titanium alloys are considered for container materials. Consideration of titanium alloys is understandable since about one-third (in 1978) of all titanium produced is used in applications where corrosion resistance is of primary importance. Consequently, there is a considerable amount of data which demonstrates that titanium alloys, in general, but particularly the commercial purity and dilute {alpha} grades, are highly corrosion resistant. This report will discuss the corrosion characteristics of Ti Gr 2, 7, 12, and 16. The more highly alloyed titanium alloys which were developed by adding a small Pd content to higher strength Ti alloys in order to give them better corrosion resistance will not be considered in this report. These alloys are all two phase ({alpha} and {beta}) alloys. The palladium addition while making these alloys more corrosion resistant does not give them the corrosion resistance of the single phase {alpha} and near-{alpha} (Ti Gr 12) alloys.

  20. The influence of long-term low temperature aging on the performance of candidate high-nickel alloys for the nuclear waste repository

    International Nuclear Information System (INIS)

    The phase stability of candidate alloys under repository-relevant conditions is a critical issue that will have an impact on the long-term mechanical and corrosion properties of the metal barrier. For waste packages with the highest thermal outputs, the surface temperature of the containers will rise to a peak temperature of about 250 C. After 100 years the temperature will drop to about 150 C and will continue dropping slowly. This paper discusses the metallurgical phase stability in terms of precipitation and ordering behavior of Ni-Cr-Mo-W alloys after long term aging at temperatures below 550 C. In addition, the effect of low temperature aging on the mechanical and corrosion properties is presented. Charpy impact testing and tensile testing have been used to evaluate the effect of aging on mechanical properties. The corrosion resistance has been assessed using standard ASTM G28A and B test methods

  1. Effect of the temperature, strain rate and microstructure on flow and fracture characteristics of Ti-45Al-2Nb-2Mn+0.8vol.% TiB2 XD alloy

    Science.gov (United States)

    Erice, B.; Pérez-Martín, M. J.; Cendón, D. A.; Gálvez, F.

    2012-05-01

    A series of quasi-static and dynamic tensile tests at varying temperatures were carried out to determine the mechanical behaviour of Ti-45Al-2Nb-2Mn+0.8vol.% TiB2 XD as-HIPed alloy. The temperature for the tests ranged from room temperature to 850 ∘C. The effect of the temperature on the ultimate tensile strength, as expected, was almost negligible within the selected temperature range. Nevertheless, the plastic flow suffered some softening because of the temperature. This alloy presents a relatively low ductility; thus, a low tensile strain to failure. The dynamic tests were performed in a Split Hopkinson Tension Bar, showing an increase of the ultimate tensile strength due to the strain rate hardening effect. Johnson-Cook constitutive relation was used to model the plastic flow. A post-testing microstructural of the specimens revealed an inhomogeneous structure, consisting of lamellar α2 + γ structure and γ phase equiaxed grains in the centre, and a fully lamellar structure on the rest. The assessment of the duplex-fully lamellar area ratio showed a clear relationship between the microstructure and the fracture behaviour.

  2. Evaluation of candidate Stirling engine heater tube alloys after 3500 hours exposure to high pressure doped hydrogen or helium. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Misencik, J.A.; Titran, R.H.

    1984-10-01

    Sixteen commercial tubing alloys were endurance tested at 820/sup 0/ C, 15 MPa in a diesel-fuel fired Stirling engine simulator materials test rig: iron-base N-155, A-286, Incoloy 800, 19-9DL, CG-27, W-545, 12RN72, 253MA, Sanicro 31H and Sanicro 32; nickel-base Inconel 601, Inconel 625, Inconel 718, Inconel 750 and Pyromet 901; and cobalt-base HS-188. The iron-nickel alloys CG-27 and Pyromet 901 exhibited superior oxidation/corrosion resistance to the diesel-fuel combustion products and surpassed the design criterias' 3500 h creep-rupture endurance life. Three other alloys, Inconel 625, W-545, and 12RN72, had creep-rupture failures after 2856, 2777, and 1598 h, respectively. Hydrogen permeability coefficients determined after 250 h of rig exposure show that Pyromet 901 had the lowest Phi value, 0.064x10/sup -6/ cm/sup 2//s MPa/sup 1///sup 2/. The next five hairpin tubes, CG-27, Inconel 601, Inconel 718(wd), Inconel 750, and 12RN72(cw) all had Phi values below 0.2x10/sup -6/ more than a decade lower than the design criteria. Based upon its measured high strength and low hydrogen permeation, CG-27 was selected for 3500 h endurance testing at 21 MPa gas pressure and 820/sup 0/C. Results of the high pressure, 21 MPa, CG-27 endurance test demonstrated that the 1.0 vol % C0/sub 2/ dopant is an effective deterrent to hydrogen permeation. The 21 MPa hydrogen gas pressure apparent permeability coefficient at 820/sup 0/C approached 0.1x10/sup -6/ cm/sup 2/sec MPa/sup 1///sup 2/ after 500 hr, the same as the 15 MPa test. Even at this higher gas pressure and comparable permeation rate, CG-27 passed the 3500 hr endurance test without creep-rupture failures. It is concluded that the CG-27 alloy, in the form of thin wall tubing is suitable for Stirling engine applications at 820/sup 0/C and gas pressures up to 21 MPa.

  3. Performance evaluation of several commercial alloys in a reducing environment

    Science.gov (United States)

    Liu, Y.

    Several commercial alloys including Ebrite, Crofer 22 APU, Haynes 230 and Haynes 242, which are candidates for intermediate-temperature solid oxide fuel cell (SOFC) interconnect materials, were isothermally and cyclically oxidized at 900 °C in the reducing atmosphere of Ar + 5 vol.% H 2 + 3 vol.% H 2O corresponding to the SOFC anode environment. Results indicate that these alloys exhibited good scale spallation resistance with the Ni-base alloys possessing better oxidation resistance over the Fe-base alloys. Both Mn-Cr spinel and Cr 2O 3 were formed in the oxide scales of these alloys. For Crofer 22 APU and Haynes 242, a continuous protective MnO and Mn-Cr spinel layer formed outside on the inner layer of Cr 2O 3. The increase in scale ASR after longer-term thermal exposure in the reducing environment was relatively slower for the Ni-base alloys than for the Fe-base alloys.

  4. Analysis of crystallographic slip and grain boundary sliding in a Ti–45Al–2Nb–2Mn (at%)–0.8 vol%TiB2 alloy by high temperature in situ mechanical testing

    International Nuclear Information System (INIS)

    This work aims to contribute to a further understanding of the fundamentals of crystallographic slip and grain boundary sliding in the γ-TiAl Ti–45Al–2Nb–2Mn (at%)–0.8 vol%TiB2 intermetallic alloy, by means of in situ high-temperature tensile testing combined with electron backscatter diffraction (EBSD). Several microstructures, containing different fractions and sizes of lamellar colonies and equiaxed γ-grains, were fabricated by either centrifugal casting or powder metallurgy, followed by heat treatment at 1300 °C and furnace cooling. in situ tensile and tensile-creep experiments were performed in a scanning electron microscope (SEM) at temperatures ranging from 580 °C to 700 °C. EBSD was carried out in selected regions before and after straining. Our results suggest that, during constant strain rate tests, true twin γ/γ interfaces are the weakest barriers to dislocations and, thus, that the relevant length scale might be influenced by the distance between non-true twin boundaries. Under creep conditions both grain/colony boundary sliding (G/CBS) and crystallographic slip are observed to contribute to deformation. The incidence of boundary sliding is particularly high in γ grains of duplex microstructures. The slip activity during creep deformation in different microstructures was evaluated by trace analysis. Special emphasis was placed in distinguishing the compliance of different slip events with the Schmid law with respect to the applied stress

  5. Analysis of crystallographic slip and grain boundary sliding in a Ti–45Al–2Nb–2Mn (at%)–0.8 vol%TiB{sub 2} alloy by high temperature in situ mechanical testing

    Energy Technology Data Exchange (ETDEWEB)

    Muñoz-Moreno, R. [IMDEA Materials Institute, C/Eric Kandel 2, 28906 Getafe, Madrid (Spain); Department of Materials Science and Engineering, Universidad Carlos III de Madrid, Avda. Universidad 30, 28911 Leganés (Spain); Ruiz-Navas, E.M. [Department of Materials Science and Engineering, Universidad Carlos III de Madrid, Avda. Universidad 30, 28911 Leganés (Spain); Boehlert, C.J. [IMDEA Materials Institute, C/Eric Kandel 2, 28906 Getafe, Madrid (Spain); Department of Chemical Engineering and Materials Science, Michigan State University, 2527 Engineering Building, East Lansing, MI 48824 (United States); Llorca, J. [IMDEA Materials Institute, C/Eric Kandel 2, 28906 Getafe, Madrid (Spain); Department of Materials Science, Polytechnic University of Madrid, 28040 Madrid (Spain); Torralba, J.M. [IMDEA Materials Institute, C/Eric Kandel 2, 28906 Getafe, Madrid (Spain); Department of Materials Science and Engineering, Universidad Carlos III de Madrid, Avda. Universidad 30, 28911 Leganés (Spain); Pérez-Prado, M.T., E-mail: teresa.perez.prado@imdea.org [IMDEA Materials Institute, C/Eric Kandel 2, 28906 Getafe, Madrid (Spain)

    2014-06-01

    This work aims to contribute to a further understanding of the fundamentals of crystallographic slip and grain boundary sliding in the γ-TiAl Ti–45Al–2Nb–2Mn (at%)–0.8 vol%TiB{sub 2} intermetallic alloy, by means of in situ high-temperature tensile testing combined with electron backscatter diffraction (EBSD). Several microstructures, containing different fractions and sizes of lamellar colonies and equiaxed γ-grains, were fabricated by either centrifugal casting or powder metallurgy, followed by heat treatment at 1300 °C and furnace cooling. in situ tensile and tensile-creep experiments were performed in a scanning electron microscope (SEM) at temperatures ranging from 580 °C to 700 °C. EBSD was carried out in selected regions before and after straining. Our results suggest that, during constant strain rate tests, true twin γ/γ interfaces are the weakest barriers to dislocations and, thus, that the relevant length scale might be influenced by the distance between non-true twin boundaries. Under creep conditions both grain/colony boundary sliding (G/CBS) and crystallographic slip are observed to contribute to deformation. The incidence of boundary sliding is particularly high in γ grains of duplex microstructures. The slip activity during creep deformation in different microstructures was evaluated by trace analysis. Special emphasis was placed in distinguishing the compliance of different slip events with the Schmid law with respect to the applied stress.

  6. Considerations on the performance and fabrication of candidate materials for the Yucca Mountain repository waste packages highly corrosion resistant nickel-base and titanium-base alloys

    Energy Technology Data Exchange (ETDEWEB)

    Dalder, E; Goldberg, A

    1995-11-30

    Among the metallurgical factors that affect the performance of a material in a given environment are alloy composition, alloy segregation, depletion of alloying elements, non-uniform microstructures, precipitation leading to an increase in susceptibility to corrosion as well as decreases in ductility, residual plastic deformation, and residual stresses. Precipitation often occurs preferentially at grain boundaries, causing depletion of critical elements in regions adjacent to these boundaries. Continuous grain-boundary precipitates can lead to drops in ductility and toughness. The presence of non-metallic inclusions, if excessive and/or segregated, can also cause embrittlement. Segregation of alloying elements can result in localized galvanic action. Depletion of alloying elements as well as segregation can result in reductions in the concentrations of critical elements below those necessary to resist localized corrosion. Segregation and alloy depletion can also facilitate precipitation that could lead to embrittlement.

  7. Status of uranium-silicon alloy fuel development for the RERTR program

    International Nuclear Information System (INIS)

    As part of the national Reduced Enrichment Research and Test Reactor (RERTR) Program, Argonne National Laboratory (ANL) is engaged in a fuel-alloy development project. The fuel alloys are dispersed in an aluminum matrix and metallurgically roll-bonded within 6061 Al alloy. To date, miniplates with up to 40 vol. % fuel alloy have been successfully fabricated. Thirty-one of these plates have been or are being irradiated in the Oak Ridge Reactor (ORR). Three different fuels have been used in the ANL miniplates: U3Si, U3Si2, or U3SiAl. All three are candidates for permitting higher fuel loadings and thus lower enrichments than would be possible with either UAl/sub x/ or U3O8, the current fuels for plate-type elements. The enrichment level employed at ANL is approx. 19.8%. Continuing effort involves the production of miniplates with up to approx. 60 vol. % fuel, the development of a technology for full-size plate fabrication, and post-irradiation examination of miniplates already removed from the ORR Reactor

  8. Effect of surface treatment on the interfacial contact resistance and corrosion resistance of Fe–Ni–Cr alloy as a bipolar plate for polymer electrolyte membrane fuel cells

    International Nuclear Information System (INIS)

    The bipolar plate is an important component of the PEMFC (polymer electrolyte membrane fuel cell) because it supplies the pathway of electron flow between each unit cell. Fe–Ni–Cr alloy is considered as a good candidate material for bipolar plate, but it is limited to use as a bipolar plate due to its high ICR (interfacial contact resistance) and corrosion problem. In order to explore a cost-effective method on surface modification, various chemical and electrochemical treatments are performed on Fe–Ni–Cr alloy to acquire the effect of the surface modification on the ICR and corrosion behavior. The ICR and corrosion resistance of Fe–Ni–Cr alloy can be effectively controlled by the chemical treatment of immersion in the mixed acid solution with 10 vol% HNO3, 2 vol% HCl and 1 vol% HF for 10 min at 65 °C and then was placed in 30 vol% HNO3 solution for 5 min. The chemical treatment is more effective on reducing ICR and improving corrosion resistance than that of electrochemical methods (be carried out in the 2 mol/L H2SO4 solution with the electrical potential from −0.4 V to 0.6 V) for Fe–Ni–Cr alloy as a bipolar plate for polymer electrolyte membrane fuel cells. - Highlights: • The procedure of the surface treatments on Fe–Ni–Cr alloy as bipolar plate was described in detail. • Effects of various surface treatments on the interfacial contact resistivity and corrosion behavior were discussed. • The mechanism of the surface modification was particularly analyzed

  9. The Candidate

    OpenAIRE

    Osborn, John C

    2013-01-01

    ABSTRACT   The Candidate is an attempt to marry elements of journalism and gaming into a format that both entertains and educates the player. The Google-AP Scholarship, a new scholarship award that is given to several journalists a year to work on projects at the threshold of technology and journalism, funded the project. The objective in this prototype version of the game is to put the player in the shoes of a congressional candidate during an off-year election, specificall...

  10. Comparison of lithium and the eutectic lead-lithium alloy, two candidate liquid metal breeder materials for self-cooled blankets

    International Nuclear Information System (INIS)

    Liquid metals are attractive candidates for both near-term and long-term fusion applications. The subjects of this comparison are the differences between the two candidate liquid metal breeder materials Li and LiPb for use in breeding blankets in the areas of neutronics, magnetohydrodynamics, tritium control, compatibility with structural materials, heat extraction system, safety and required research and development program. Both candidates appear to be promising for use in self-cooled breeding blankets which have inherent simplicity with the liquid metal serving as both breeder and coolant. Each liquid metal breeder has advantages and concerns associated with it, and further development is needed to resolve these concerns. The remaining feasibility question for both breeder materials is the electrical insulation between the liquid metal and the duct walls. Different ceramic coatings are required for the two breeders, and their crucial issues, namely self-healing of insulator cracks and tolerance to radiation-induced electrical degradation, have not yet been demonstrated. (orig.)

  11. Equation of state and phase diagram of Fe-16Si alloy as a candidate component of Earth's core

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Rebecca A.; Campbell, Andrew J.; Caracas, Razvan; Reaman, Daniel M.; Dera, Przymyslaw; Prakapenka, Vitali B. (Ecole); (UC)

    2016-07-29

    The outer core of the Earth contains several weight percent of one or more unknown light elements, which may include silicon. Therefore it is critical to understand the high pressure–temperature properties and behavior of an iron–silicon alloy with a geophysically relevant composition (16 wt% silicon). We experimentally determined the melting curve, subsolidus phase diagram, and equations of state of all phases of Fe–16 wt%Si to 140 GPa, finding a conversion from the D03 crystal structure to a B2+hcp mixture at high pressures. The melting curve implies that 3520 K is a minimum temperature for the Earth's outer core, if it consists solely of Fe–Si alloy, and that the eutectic composition in the Fe–Si system is less than 16 wt% silicon at core–mantle boundary conditions. Comparing our new equation of state to that of iron and the density of the core, we find that for an Fe–Ni–Si outer core, 11.3±1.5 wt% silicon would be required to match the core's observed density at the core–mantle boundary. We have also performed first-principles calculations of the equations of state of Fe3Si with the D03 structure, hcp iron, and FeSi with the B2 structure using density-functional theory.

  12. High-temperature deformation of dispersion-strengthened Cu-Zr-Ti-C alloys

    International Nuclear Information System (INIS)

    The hot mechanical behaviour and microstructure of Cu-5 vol.% TiC, Cu-5 vol.% ZrO2 and Cu-2.5 vol.% TiC-2.5 vol.% ZrO2 alloys prepared by reaction milling were studied. After a test of 1 h annealing at 1173 K, the Cu-5 vol.% ZrO2 alloy presented the lower softening resistance to annealing, while the other two ones kept their initial room-temperature hardness (about 2 GPa). Hot-compression tests at 773 and 1123 K, at initial true strain rates of 0.85 x 10-3 and 0.85 x 10-4 s-1 were performed. The Cu-2.5 vol.% TiC-2.5 vol.% ZrO2 and the Cu-5 vol.% ZrO2 alloys were the strongest and softest materials, respectively. Moreover, by electron microscopy, nanometric TiC and micrometric particles were detected in the Cu-5 vol.% TiC and Cu-5 vol.% ZrO2 alloys, respectively. A possible explanation for the observed behaviour of these materials is proposed. In the compression tests, it was also found that strain rate has a low effect on flow stress, as it has been previously observed by various authors in dispersion-strengthened alloys deformed at high temperatures

  13. Vibration Theory, Vol. 1B

    DEFF Research Database (Denmark)

    Asmussen, J. C.; Nielsen, Søren R. K.

    The present collection of MATLAB exercises has been published as a supplement to the textbook, Svingningsteori, Bind 1 and the collection of exercises in Vibration theory, Vol. 1A, Solved Problems. Throughout the exercise references are made to these books. The purpose of the MATLAB exercises is to...... give a better understanding of the physical problems in linear vibration theory and to surpress the mathematical analysis used to solve the problems. For this purpose the MATLAB environment is excellent....

  14. U-Si and U-Si-Al dispersion fuel alloy development for research and test reactors

    International Nuclear Information System (INIS)

    As part of the National Reduced Enrichment Research and Test Reactor Program, Argonne National Laboratory (ANL) is engaged in a fuel alloy development project. Fuel alloy powder prepared with low-enrichment uranium (235U) is dispersed in an aluminum matrix, and metallurgically roll-bonded within a clad of 6061 Al alloy. Miniplates with up to 55 vol.% fuel alloy (up to 7.0 grams total U per cm3) have been successfully fabricated. Fifty-five of these plates have been or are being irradiated in the Oak Ridge Research Reactor. Three fuel alloys have been used in the ANL miniplates: U3Si (U + 4 wt.% Si), U3Si2 (U + 7.5 wt.% Si), and 'U3SiAl' (U + 3.5 wt.% Si + 1.5 wt.% Al). All are candidates for permitting higher fuel loadings and thus lower enrichments of 235U than would be possible with either UAlx or U3O8, the current fuels for plate-type elements. As an adjunct to the development effort, ANL is engaged in the early stages of technology transfer with commercial fabricators of fuel elements for research reactors. Continuing effort also involves the development of a technology for full-size plate fabrication, and the irradiation of miniplates to a burnup of ∼90% 235U depletion. (author)

  15. Lubricated sliding wear behaviour of aluminium alloy composites

    OpenAIRE

    J. C. Walker; Rainforth, W. M.; Jones, H.

    2005-01-01

    Interest in aluminium alloy (Al-alloy) composites as wear resistant materials continues to grow. However, the use of the popular Al-alloy-SiC composite can be limited by the abrasive nature of the SiC, leading to increased counterface wear rates. This study reports new Al-alloy composites that offer high wear resistance, to a level similar to Al-alloy-SiC. Aluminium alloy (2124, 5056) matrix composites reinforced by nominally 15 vol.% of Cr3Si, MoSi2, Ni3Al and SiC particles were prepared by ...

  16. Evaluation of the Machinability of Cast Ti-Si Alloys with Varying Si Content

    Science.gov (United States)

    Hsu, Hsueh-Chuan; Wu, Shih-Ching; Hsu, Shih-Kuang; Hsu, Chih-Cheng; Ho, Wen-Fu

    2016-05-01

    This study evaluated the machinability of a series of binary Ti-Si alloys with a goal of developing a titanium alloy with better machinability than commercially pure titanium (c.p. Ti). The alloys were slotted using a milling machin/span>e and end mills under four cutting conditions. Machinability was evaluated through cutting force. The experimental results indicate that alloying with Si significantly improved the machinability of c.p. Ti in terms of cutting force under the present cutting conditions. As the Si content increases, the cutting force decreases then greatly increases. The cutting forces of c.p. Ti and the Ti-Si alloys increased as the feed rate increased from 30 to 60 m/min under the cutting speed of 55 or 110 m/min. The cutting force of Ti-5Si at cutting speed 55 m/min was approximately 49% lower than that of c.p. Ti; at cutting speed 110 m/min, it was approximately 62% lower than that of c.p. Ti. The cutting force of Ti-10Si was significantly higher than those of the other Ti-Si alloys and c.p. Ti, a result that can be explained by a higher degree of hardness (626 HV) and larger amounts of Ti5Si3 (47.10 vol.%). For Ti-5Si, there was no obvious adhesion of chips observed on the cut surfaces. Furthermore, the specimens had the lowest surface roughness (Ra) values, approximately 0.3-0.4 μm, under the four cutting conditions. When cutting force, chip length, and surface roughness results are considered, the Ti-5Si alloy developed in this study is a viable candidate for machining.

  17. Comportamiento en fluencia de un material compuesto de matriz metálica Al6061-15 vol % SiCw pulvimetalúrgico

    OpenAIRE

    González-Doncel, G.; García-Alonso, E.; R. Fernández

    2005-01-01

    The creep behavior of a powder metallurgy (PM) Al6061-15 vol % SiCw metal matrix composite has been studied. This behavior has been compared to that of 6061Al cast alloy and 6061Al PM alloy. The creep response of the PM unreinforced alloy is better than that of the cast 6061Al alloy. Similarly, the behavior of the composite is better than that of the PM unreinforced alloy. Two microstructural factors have been considered the responsible ones of this improvement. The first one is the dispersio...

  18. An annotated history of container candidate material selection

    International Nuclear Information System (INIS)

    This paper documents events in the Nevada Nuclear Waste Storage Investigations (NNWSI) Project that have influenced the selection of metals and alloys proposed for fabrication of waste package containers for permanent disposal of high-level nuclear waste in a repository at Yucca Mountain, Nevada. The time period from 1981 to 1988 is covered in this annotated history. The history traces the candidate materials that have been considered at different stages of site characterization planning activities. At present, six candidate materials are considered and described in the 1988 Consultation Draft of the NNWSI Site Characterization Plan (SCP). The six materials are grouped into two alloy families, copper-base materials and iron to nickel-base materials with an austenitic structure. The three austenitic candidates resulted from a 1983 survey of a longer list of candidate materials; the other three candidates resulted from a special request from DOE in 1984 to evaluate copper and copper-base alloys. 24 refs., 2 tabs

  19. Main: 1VOL [RPSD[Archive

    Lifescience Database Archive (English)

    Full Text Available 1VOL シロイヌナズナ Arabidopsis Arabidopsis thaliana (L.) Heynh. Transcription Initiation Factor ... ucture Of A Tfiib-Tbp-Tata-Element Ternary Complex Nature ... V. 377 119 1995 Transcription Initiation, Molecula ...

  20. Determination of vanadium in double alloys by complete differential spectrophotometry

    International Nuclear Information System (INIS)

    A differential method to determine vanadium in the binary alloys (V-Cr, V-Al, V-Re) is described. The method is based on the formation of different-ligand vanadium complexes with o-nitrophenylfluorone and diantipyrylmethane. The complex is formed in pH range from 2.0 to 2.5 and extracted by the mixture of 93 vol.% chloroform and 7 vol.% amyl alcohol. Accidental and systematic errors of determination are calculated

  1. Uranium. Suppl. Vol. A3

    International Nuclear Information System (INIS)

    This supplement volume 'Uranium' deals with uranium technology, from winning to the fabrication of nuclear fuels containing uranium and their use in various reactor types. Alternative reprocessing methods for ores are described e.g. winning from phosphate ores and sea water, production of uranium compounds (oxide, carbide, nitride etc., hexafluoride for isotope separation) and of uranium-metals and -alloys as well as the utilization of metallic and other compounds of uranium - single or embedded - as nuclear fuels and their fabrication. The behaviour of the nuclear fuel and the way it modifies during reactor operation are described in an extra volume (supplement volume A4). (RB)

  2. Vanadium-base alloys for fusion reactor applications

    International Nuclear Information System (INIS)

    Vanadium-base alloys offer potentially significant advantages over other candidate alloys as a structural material for fusion reactor first wall/blanket applications. Although the data base is more limited than that for the other leading candidate structural materials, viz., austenitic and ferritic steels, vanadium-base alloys exhibit several properties that make them particularly attractive for the fusion reactor environment. This paper presents a review of the structural material requirements, a summary of the materials data base for selected vanadium-base alloys, and a comparison of projected performance characteristics compared to other candidate alloys. Also, critical research and development (R and D) needs are defined

  3. Dynamics of structures '89. Vol. 3

    International Nuclear Information System (INIS)

    The proceedings, comprising 3 volumes published by the Plzen Centre of the Czechoslovak Society for Science and Technology (Vol. 1 and 2) and by Skoda Works in Plzen (Vol. 3), contain 107 papers, out of which 8 fall within the INIS Subject Scope; these deal with problems related to the earthquake resistance of nuclear power plants. Attention is paid to the evaluation of seismic characteristics of nuclear power plant equipment, to the equipment testing and to calculations of its dynamic characteristics under simulated seismic stress. (Z.M.)

  4. Crisis Communication (Handbooks of Communication Science Vol. 23)

    DEFF Research Database (Denmark)

    Vol. 23 - The Handbook of Communication Science General editors: Peter J. Schultz and Paul Cobley......Vol. 23 - The Handbook of Communication Science General editors: Peter J. Schultz and Paul Cobley...

  5. Oxidation Behavior of GRCop-84 Copper Alloy Assessed

    Science.gov (United States)

    Thomas-Ogbuji, Linus U.

    2002-01-01

    NASA's goal of safe, affordable space transportation calls for increased reliability and lifetimes of launch vehicles, and significant reductions of launch costs. The areas targeted for enhanced performance in the next generation of reusable launch vehicles include combustion chambers and nozzle ramps; therefore, the search is on for suitable liner materials for these components. GRCop-84 (Cu-8Cr-4Nb), an advanced copper alloy developed at the NASA Glenn Research Center in conjunction with Case Western Reserve University, is a candidate. The current liner of the Space Shuttle Main Engine is another copper alloy, NARloy-Z (Cu-3Ag-0.1Zr). It provides a benchmark against which to compare the properties of candidate successors. The thermomechanical properties of GRCop-84 have been shown to be superior, and its physical properties comparable, to those of NARloy-Z. However, environmental durability issues control longevity in this application: because copper oxide scales are not highly protective, most copper alloys are quickly consumed in oxygen environments at elevated temperatures. In consequence, NARloy-Z and most other copper alloys are prone to blanching, a degradation process that occurs through cycles of oxidation-reduction as the oxide is repeatedly formed and removed because of microscale fluctuations in the oxygen-hydrogen fuel systems of rocket engines. The Space Shuttle Main Engine lining typically degraded by blanching-induced hot spots that lead to surface roughening, pore formation, and coolant leakage. Therefore, resistance to oxidation and blanching are key requirements for second-generation reusable launch vehicle liners. The rocket engine ambient includes H2 (fuel) and H2O (combustion product) and is, hence, under reduced oxygen partial pressures. Accordingly, our studies were expanded to include oxygen partial pressures as low as 322 parts per million (ppm) at the temperatures likely to be experienced in service. A comparison of 10-hr weight gains of

  6. Development of Mo base alloys for conductive metal-alumina cermet applications

    International Nuclear Information System (INIS)

    A study of thermal expansion for binary Mo-V and ternary Mo-V-Fe/Mo-V-Co alloys has been conducted, with the aim of finding a composition which matches the CTE of 94% alumina ceramic. The overall goal was to identify an alloy which can be used in conductive 27 vol.% metal/73 vol.% alumina cermets. Besides thermal expansion properties, two additional requirements exist for this alloy: (1) compatibility with a hydrogen sinter fire atmosphere and (2) a single phase BCC microstructure. They have identified a ternary alloy with a nominal composition of Mo-22wt.% V-3Fe for use in cermet fabrication efforts. This paper summarizes thermal expansion properties of the various alloys studied, and compares the results with previous CTE data for Mo-V binary alloys

  7. U-Si and U-Si-Al dispersion fuel alloy development for research and test reactors

    International Nuclear Information System (INIS)

    As part of the National Reduced Enrichment Research and Test Reactor Program, Argonne National Laboratory (ANL) is engaged in a fuel alloy development project. The reduction of the 235U enrichment from above 90% to below 20% for such fuels would lessen the risk of diversion of the fuel for nonpeaceful uses. Fuel alloy powder prepared with low-enrichment uranium (235U) is dispersed in an aluminum matrix, and metallurgically roll bonded within a cladding of 6061 aluminum alloy. Miniplates with up to 55 vol% fuel alloy (up to 7.0 g total U/cm3) have been successfully fabricated. Fifty-five of these plates have been or are being irradiated in the Oak Ridge Research Reactor. Three fuel alloys have been used in the ANL miniplates: U3Si (U + 4 wt% Si), U3Si2 (U + 7.5 wt% Si), and ''U3SiAl'' (U + 3.5 wt% Si + 1.5 wt% Al). All are candidates for permitting higher fuel loadings and thus lower enrichments of 235U than would be possible with either UAl /SUB x/ or U3O8, the current fuels for plate-type elements. A target loading of up to 7.0 g U/cm3 in the fuel zone was selected. To date the fabrication and irradiation results with the silicide fuels have been encouraging, and as an adjunct to the development effort, ANL is engaged in the early stages of technology transfer with commercial fabricators of fuel elements for research reactors. Continuing effort also involves the development of a technology for full-sized plate fabrication and the irradiation of miniplates to a burnup of about 90% 235U depletion

  8. U-Si and U-Si-Al dispersion, fuel alloy development for research and test reactors

    International Nuclear Information System (INIS)

    As part of the National Reduced Enrichment Research and Test Reactor Program, Argonne National Laboratory (ANL) is engaged in a fuel alloy development project. The reduction of the 235U enrichment from above 90% to below 20% for such fuels would lessen the risk of diversion of the fuel for nonpeaceful uses. Fuel alloy powder prepared with low-enrichment uranium (235U) is dispersed in an aluminum matrix, and metallurgically roll bonded within a cladding of 6061 aluminum alloy. Miniplates with up to 55 vol% fuel alloy (up to 7.0 g total U/cm3) have been successfully fabricated. Fifty-five of these plates have been or are being irradiated in the Oak Ridge Research Reactor. Three fuel alloys have been used in the ANL miniplates: U3Si(U + 4 wt% Si), U3Si2(U + 7.5 wt% Si), and ''U3SiAl'' (U + 3.5 wt% Si + 1.5 wt% Al). All are candidates for permitting higher fuel loadings and thus lower enrichments of 235U than would be possible with either UAl/SUB x/ or U3O8, the current fuels for plate-type elements. A target loading of up to 7.0 g U/cm3 in the fuel zone was selected. To date the fabrication and irradiation results with the silicide fuels have been encouraging, and as an adjunct to the development effort, ANL is engaged in the early stages of technology transfer with commercial fabricators of fuel elements for research reactors. Continuing effort also involves the development of a technology for full-sized plate fabrication and the irradiation of miniplates to a burnup of about 90% 235U depletion

  9. Advances in nuclear fuel cycle materials and concepts. Vol. 1

    International Nuclear Information System (INIS)

    This presentation gives an overview of the new trends in the materials used in various steps of the nuclear fuel cycle. This will cover fuels for various types of reactors (PWRs, HTRs, ... etc.) cladding materials, control rod materials, reactor structural materials, as well as materials used in the back end of the fuel cycle. Problems associated with corrosion of fuel cladding materials as well as those in control rod materials (B4 C swelling...etc.), and approaches for combating these influences are reviewed. For the case of reactor pressure vessel materials issues related to the influences of alloy composition, design approaches including the use of more forged parts and minimizing, as for as possible, longitudinal welds especially in the central region, are discussed. Furthermore the application of techniques for recovery of pre-irradiation mechanical properties of PVS components is also covered. New candidate materials for the construction of high level waste containers including modified types of stainless steel (high Ni and high MO), nickel-base alloys and titanium alloys are also detailed. Finally, nuclear fuel cycle concepts involving plutonium and actinides recycling shall be reviewed. 28 figs., 6 tabs

  10. Z physics at LEP 1. Vol. 1

    International Nuclear Information System (INIS)

    The contents of this final report from the Workshop on Z Physics at LEP can be divided into two parts. The first part, comprising Vols. 1 and 2, is a relatively concise but fairly complete handbook on the physics of e+e- annihilation near the Z peak (with normal LEP luminosity and unpolarized beams, appropriate for the first phase of LEP operation). The second part (Vol. 3) is devoted to a review of the existing Monte Carlo event generators for LEP physics. A special effort has been made to co-ordinate the different parts of this report, with the aim of achieving a systematic and balanced review of the subject, rather than having simply a collection of separate contributions. (orig.)

  11. Z Physics at LEP 1. Vol. 3

    International Nuclear Information System (INIS)

    The contents of this final report from the Workshop on Z Physics at LEP can be divided into two parts. The first part, comprising Vols. 1 and 2, is a relatively concise but fairly complete handbook on the physics of e+e- annihilation near the Z peak (with normal LEP luminosity and unpolarized beams, appropriate for the first phase of LEP operation). The second part (Vol. 3) is devoted to a review of the existing Monte Carlo event generators for LEP physics. A special effort has been made to co-ordinate the different parts of this report, with the aim of achieving a systematic and balanced review of the subject, rather than having simply a collection of separate contributions. (orig.)

  12. Z physics at LEP 1. Vol. 2

    International Nuclear Information System (INIS)

    The contents of this final report from the Workshop on Z Physics at LEP can be divided into two parts. The first part, comprising Vols. 1 and 2, is a relatively concise but fairly complete handbook on the physics of e+e- annihilation near the Z peak (with normal LEP luminosity and unpolarized beams, appropriate for the first phase of LEP operation). The second part (Vol. 3) is devoted to a review of the existing Monte Carlo event generators for LEP physics. A special effort has been made to co-ordinate the different parts of this report, with the aim of achieving a systematic and balanced review of the subject, rather than having simply a collection of separate contributions. (orig.)

  13. Fuel powder production from ductile uranium alloys

    International Nuclear Information System (INIS)

    Metallic uranium alloys are candidate materials for use as the fuel phase in very-high-density LEU dispersion fuels. These ductile alloys cannot be converted to powder form by the processes routinely used for oxides or intermetallics. Three methods of powder production from uranium alloys have been investigated within the US-RERTR program. These processes are grinding, cryogenic milling, and hydride-dehydride. In addition, a gas atomization process was investigated using gold as a surrogate for uranium. (author)

  14. Welding of refractory alloys

    International Nuclear Information System (INIS)

    This review primarily summarizes welding evaluations supported by NASA-Lewis Research Center in the 1960s. A literature search run in preparation for this review indicates that more recent work is modest by comparison. Hence, this review restates these accomplishments briefly and addresses opportunities which have evolved in welding technology (such as lasers) in the intervening decade. Emphasis in this review is given to tantalum- and niobium-base alloys. Considerable work was also done to assure that a consistent comparison was made with tungsten. A wide variety of candidate alloys derived primarily from developments directed at aircraft propulsion applications were available. Early efforts by NASA were directed at screening studies to select promising structural alloys for the space power application. This objective required fine tuning of welding procedures, e.g., the demonstration of stringent standards for control of welding atmosphere to assure good corrosion resistance in liquid alkali metals. 16 figures, 6 tables

  15. Large hadron collider workshop. Proceedings. Vol. 3

    International Nuclear Information System (INIS)

    The aim of the LHC workshop at Aachen was to discuss the 'discovery potential' of a high-luminosity hadron collider (the Large Hadron Collider) and to define the requirements of the detectors. Of central interest was whether a Higgs particle with mass below 1 TeV could be seen using detectors potentially available within a few years from now. Other topics included supersymmetry, heavy quarks, excited gauge bosons, and exotica in proton-proton collisions, as well as physics to be observed in electron-proton and heavy-ion collisions. A large part of the workshop was devoted to the discussion of instrumental and detector concepts, including simulation, signal processing, data acquisition, tracking, calorimetry, lepton identification and radiation hardness. The workshop began with parallel sessions of working groups on physics and instrumentaiton and continued, in the second half, with plenary talks giving overviews of the LHC project and the SSC, RHIC, and HERA programmes, summaries of the working groups, presentations from industry, and conclusions. Vol. 1 of these proceedings contains the papers presented at the plenary sessions, Vol. 2 the individual contributions to the physics sessions, and Vol. 3 those to the instrumentation sessions. (orig.)

  16. Large hadron collider workshop. Proceedings. Vol. 1

    International Nuclear Information System (INIS)

    The aim of the LCH workshop at Aachen was to discuss the 'discovery potential' of a high-luminosity hadron collider (the Large Hadron Collider) and to define the requirements of the detectors. Of central interest was whether a Higgs particle with mass below 1 TeV could be seen using detectors potentially available within a few years from now. Other topics included supersymmetry, heavy quarks, excited gauge bosons, and exotica in proton-proton collisions, as well as physics to be observed in electron-proton and heavy-ion collisions. A large part of the workshop was devoted to the discussion of instrumental and detector concepts, including simulation, signal processing, data acquisition, tracking, calorimetry, lepton identification and radiation hardness. The workshop began with parallel sessions of working groups on physics and instrumentation and continued, in the second half, with plenary talks giving overviews of the LHC project and the SSC, RHIC, and HERA programmes, summaries of the working groups, presentations from industry, and conclusions. Vol. 1 of these proceedings contains the papers presented at the plenary sessions, Vol. 2 the individual contributions to the physics sessions, and Vol. 3 those to the instrumentation sessions. (orig.)

  17. Large hadron collider workshop. Proceedings. Vol. 2

    International Nuclear Information System (INIS)

    The aim of the LHC workshop at Aachen was to discuss the 'discovery potential' of a high-luminosity hadron collider (the Large Hadron Collider) and to define the requirements of the detectors. Of central interest was whether a Higgs particle with mass below 1 TeV could be seen using detectors potentially available within a few years from now. Other topics included supersymmetry, heavy quarks, excited gauge bosons, and exotica in proton-proton collisions, as well as physics to be observed in electron-proton and heavy-ion collisions. A large part of the workshop was devoted to the discussion of instrumental and detector concepts, including simulation, signal processing, data acquisition, tracking, calorimetry, lepton identification and radiation hardness. The workshop began with parallel sessions of working groups on physics and instrumentation and continued, in the second half, with plenary talks giving overviews of the LHC project and the SSC, RHIC, and HERA programmes, summaries of the working groups, presentations from industry, and conclusions. Vol.1 of these proceedings contains the papers presented at the plenary sessions, Vol.2 the individual contributions to the physics sessions, and Vol.3 those to the instrumentation sessions. (orig.)

  18. Advanced Gas Cooled Nuclear Reactor Materials Evaluation and Development Program: Topical report I, selection of candidate alloys. Volume 3. Selection of surface coating/substrate systems for screening creep and structural stability studies

    Energy Technology Data Exchange (ETDEWEB)

    1980-06-20

    Considering the high temperature, low O/sub 2/, high C environment of operation in the Very High Temperature Reactor (VHTR) Systems, the utilization of coatings is envisaged to hold potential for extending component lifetimes through the formation of stable and continuous oxide films with enhanced resistance to C diffusion. A survey of the current state of technology for high temperature coatings has been performed. The usefulness of these coatings on the Mo, Ni, and Fe base alloys is discussed. Specifically, no coating substitute was identified for TZM other than the well known W-3 (pack silicide) and Al/sub 2/O/sub 3/ forming coatings were recommended for the Fe and Ni base structural materials. Recommendations as to coating types and processng have been made based on the predicted VHTR component size, shape, base metal and operational environment. Four tests designed to evaluate the effects of selected combinations of coatings and substrate matrices are recommended for consideration.

  19. GP6 - Experimental and theoretical study of thermodynamic properties and phase equilibria in ternary Al-Zn-X alloys

    Czech Academy of Sciences Publication Activity Database

    Brož, P.; Živković, D.; Medved, J.; Talijan, N.; Manasijević, D.; Klančnik, G.; Buršík, Jiří

    Brno : COST office, 2012 - (Kroupa, A.), s. 193-214 ISBN 978-80-905363-3-3. - ( COST MPO602. High-temperature Lead-free Solders. Vol 3) Institutional support: RVO:68081723 Keywords : leads-free solders * phase diagram * aluminuium alloys * zinc alloys * thermal analysis Subject RIV: BJ - Thermodynamics

  20. Corrosion behavior of Alloy 690 and Alloy 693 in simulated nuclear high level waste medium

    Energy Technology Data Exchange (ETDEWEB)

    Samantaroy, Pradeep Kumar; Suresh, Girija; Paul, Ranita [Corrosion Science and Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India); Kamachi Mudali, U., E-mail: kamachi@igcar.gov.in [Corrosion Science and Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India); Raj, Baldev [Corrosion Science and Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India)

    2011-11-15

    Highlights: > Alloy 690 and Alloy 693, both possess good corrosion resistance in simulated HLW. > SEM and EDS confirms the presence of Cr rich precipitates for both the alloys. > Passive film stability of Alloy 690 was found to be higher than Alloy 693. > Both alloys possess few micro pits even at a concentration of 100 ppm Cl{sup -} ion. - Abstract: Nickel based alloys are candidate materials for the storage of high level waste (HLW) generated from reprocessing of spent nuclear fuel. In the present investigation Alloy 690 and Alloy 693 are assessed by potentiodynamic anodic polarization technique for their corrosion behavior in 3 M HNO{sub 3}, 3 M HNO{sub 3} containing simulated HLW and in chloride medium. Both the alloys were found to possess good corrosion resistance in both the media at ambient condition. Microstructural examination was carried out by SEM for both the alloys after electrolytic etching. Compositional analysis of the passive film formed on the alloys in 3 M HNO{sub 3} and 3 M HNO{sub 3} with HLW was carried out by XPS. The surface of Alloy 690 and Alloy 693, both consists of a thin layer of oxide of Ni, Cr, and Fe under passivation in both the media. The results of investigation are presented in the paper.

  1. Corrosion of candidate container materials by Yucca Mountain bacteria

    International Nuclear Information System (INIS)

    Several candidate container materials have been studied in modified Yucca Mountain (YM) ground water in the presence or absence of YM bacteria. YM bacteria increased corrosion rates by 5-6 fold in UNS G10200 carbon steel, and nearly 100-fold in UNS NO4400 Ni-Cu alloy. YM bacteria caused microbiologically influenced corrosion (MIC) through de-alloying or Ni-depletion of Ni-Cu alloy as evidenced by scanning electronic microscopy (SEM) and inductively coupled plasma spectroscopy (ICP) analysis. MIC rates of more corrosion-resistant alloys such as UNS NO6022 Ni-Cr- MO-W alloy, UN's NO6625 Ni-Cr-Mo alloy, and UNS S30400 stainless steel were measured below 0.05 umyr, however YM bacteria affected depletion of Cr and Fe relative to Ni in these materials. The chemical change on the metal surface caused by depletion was characterized in anodic polarization behavior. The anodic polarization behavior of depleted Ni-based alloys was similar to that of pure Ni. Key words: MIC, container materials, YM bacteria, de-alloying, Ni-depletion, Cr-depletion, polarization resistance, anodic polarization,

  2. Filler metal development for hastelloy alloy XR

    International Nuclear Information System (INIS)

    A method of alloy designing has been proposed and validated to develop the filler metal for Hastelloy alloy XR(nuclear reactor grade of Hastelloy alloy X), which is the candidate material for high temperature structure of High-Temperature Engineering Test Reactor (HTTR). In the filler metal development for Hastelloy alloy XR, materials of two heats were melted and fabricated with special emphasis placed on manufacturing process. One is the trial products (alloy termed 'C') designed by using multiple regression analysis in the range of the chemical composition specified as Hastelloy alloy X. The other is filler metal (alloy termed 'D') with optimum boron content in the same chemical composition as Hastelloy alloy XR. The results of the tests on several key items may be summarized as follows: (1) Weldments with alloy'C' showed higher strength and ductility at elevated temperatures than those of alloy'D'. (2) Weldments with alloy'D' had more excellent strength characteristics at elevated temperatures than those of the other conventional filler metals. (3) As for weldability, the crater cracks were slightly observed in the FISCO cracking test, but those were out of the problem in the degree of cracking from the viewpoint of practical application. The results of qualification tests on weldability showed good performance for all welding conditions of the present experiments. On the other hand, the mechanism of hot cracking initiation and the controlling factors in hot cracking susceptibility with relation to boron content have been clarified for Hastelloy alloy XR base metal. (author)

  3. Mechanical Properties of Candidate Materials for Hot Gas Duct of VHTR

    International Nuclear Information System (INIS)

    Hot gas duct of VHTR is operated at 950 .deg.. Ni based superalloys, such as Hastelloy XR, Alloy 617, Haynes 230, for hot gas duct have been candidate material because of good strength and corrosion properties at high temperature. Mechanical properties of these alloys are tested at high temperature to apply to hot gas duct of VHTR

  4. Laser cladding of ZrO2-(Ni alloy) composite coating

    OpenAIRE

    Pei, Y.T.; Ouyang, J.H.; Lei, T.C.

    1996-01-01

    The microstructure of laser-clad 60 vol.% ZrO2 (partially stabilized with 2 mol% Y2O3) plus 40 vol.% Ni alloy composite coating on steel 1045 was investigated by scanning electron microscopy, electron probe microanalysis, X-ray diffraction, energy-dispersive X-ray analysis and microhardness tests. The composite coating consists of a pure ZrO2 clad layer in the outer region and a bonding zone of Ni alloy adjacent to the substrate. The pure ceramic layer exhibits fine equiaxed ZrO2 grains in th...

  5. Physics at LEP2. Vol. 1

    International Nuclear Information System (INIS)

    This is the final report of the Workshop on Physics at LEP2, held at CERN during 1995. The first part of vol. 1 is devoted to aspects of machine physics of particular relevance to experiments, including the energy, luminosity and interaction regions, as well as the measurement of beam energy. The second part of vol. 1 is a relatively concise, but fairly complete, handbook on the physics of e+e- annihilation above the WW threshold and up to √s∼200 GeV. It contains discussions on WW cross-sections and distributions, W mass determination, Standard Model processes, QCD and gamma-gamma physics, as well as aspects of discovery physics, such as Higgs, new particle searches, triple gauge boson couplings and Z'. The second volume contains a review of the existing Monte Carlo generators for LEP2 physics. These include generators for WW physics, QCD and gamma-gamma processes, Bhabha scattering and discovery physics. A special effort was made to co-ordinate the different parts, with a view to achieving a systematic and balanced review of the subject, rather than just publishing a collection of separate contributions. (orig.)

  6. Physics at LEP2. Vol. 2

    International Nuclear Information System (INIS)

    This is final report of the Workshop on Physics at LEP2, held at CERN during 1995. The first part of vol. 1 is devoted to aspects of machine physics of particular relevance to experiments, including the energy, luminosity and interaction regions, as well as the measurement of beam energy. The second part of vol. 1 is a relatively concise, but fairly complete, handbook on the physics of e+e- annihilation above the WW threshold and up to √s∼200 GeV. It contains discussions on WW cross-sections and distributions, W mass determination, Standard Model processes, QCD and gamma-gamma physics, as well as aspects of discovery physics, such as Higgs, new particle searches, triple gauge boson couplings and Z'. The second volume contains a review of the existing Monte Carlo generators for LEP2 physics. These include generators for WW physics, QCD and gamma-gamma processes, Bhabha scattering and discovery physics. A special effort was made to co-ordinate the different parts, with a view to achieving a systematic and balanced review of the subject, rather than just publishing a collection of separate contributions. (orig.)

  7. Cross sections for atomic processes, vol. 2

    International Nuclear Information System (INIS)

    This data collection book contains the data on all processes involving hydrogen and helium isotopes, their ions, electrons and photons, collected systematically and comprehensively, and is compiled subsequently to Vol. 1 as one of the works of the data collection study group in the Institute of Plasma Physics, Nagoya University, Japan. The items of the contents will include energy level, multiplicately excited state, radiation process, electron collision, ionic collision, recombination, collision of neutral atoms, colliding process involving molecules, and other processes. However, the first edition this time contains energy level, radiation process, electron collision and ionic collision, and the data on remaining items are now under collection. Though some criticisms have been heard about Vol. 1, the authors consider that such comprehensive collection based on systematic classification is the foundation of making a generalized data bank expected to become necessary in future. Thus the data collection book includes all relevant processes, and records the experimental data and theoretically calculated results in principle without modification by selecting them systematically. This year, investigation on data evaluation is taken up also as one of the tasks of the study group. (Wakatsuki, Y.)

  8. Corrosion of candidate container materials by Yucca Mountain bacteria

    International Nuclear Information System (INIS)

    Several candidate container materials have been studied in modified Yucca Mountain (YM) ground water in the presence or absence of YM bacteria. YM bacteria increased corrosion rates by 5--6 fold in UNS G10200 carbon steel, and nearly 100-fold in UNS N04400 Ni-Cu alloy. YM bacteria caused microbiologically influenced corrosion (MIC) through de-alloying or Ni-depletion of Ni-Cu alloy as evidenced by scanning electronic microscopy (SEM) and inductively coupled plasma spectroscopy (ICP) analysis. MIC rates of more corrosion-resistant alloys such as UNS N06022 Ni-Cr-Mo- W alloy, UNS N06625 Ni-Cr-Mo alloy, and UNS S30430 stainless steel were measured below 0.05 microm/yr, however YM bacteria affected depletion of Cr and Fe relative to Ni in these materials. The chemical change on the metal surface caused by depletion was characterized in anodic polarization behavior. The anodic polarization behavior of depleted Ni-based alloys was similar to that of pure Ni

  9. A background to risk analysis. Vol. 4

    International Nuclear Information System (INIS)

    This 4-volumes report gives a background of ideas, principles, and examples which might be of use in developing practical methods for risk analysis. Some of the risk analysis techniques described are somewhat experimental. The report is written in an introductory style, but where some point needs further justification or evaluation, this is given in the form of a chapter appendix. In this way, it is hoped that the report can serve two purposes, - as a basis for starting risk analysis work and as a basis for discussing effectiveness of risk analysis procedures. The report should be seen as a preliminary stage, prior to a program of industrial trials of risk analysis methods. Vol. 4 treats human error in plant operation. (BP)

  10. A background to risk analysis. Vol. 2

    International Nuclear Information System (INIS)

    This 4-volumes report gives a background of ideas, principles and examples which might be of use in developing practical methods for risk analysis. Some of the risk analysis techniques described are somewhat experimental. The report is written in an introductory style, but where some point needs further justification or evaluation, this is given in the form of a chapter appendix. In this way, it is hoped that the report can serve two purposes, - as a basis for starting risk analysis work and as a basis for discussing effectiveness of risk analysis procedures. The report should be seen as a preliminary stage, prior to a program of industrial trials of risk analysis methods. Vol. 2 treats generic methods of qualitative failure analysis. (BP)

  11. A background to risk analysis. Vol. 3

    International Nuclear Information System (INIS)

    This 4-volumes report gives a background of ideas, principles, and examples which might be of use in developing practical methods for risk analysis. Some of the risk analysis techniques described are somewhat experimental. The report is written in an introductory style, but where some point needs further justifi- cation or evaluation, this is given in the form of a chapter appenix. In this way, it is hoped that the report can serve two purposes, - as a basis for starting risk analysis work and as a basis for discussing effectiveness of risk analysis procedures. The report should be seen as a preliminary stage, prior to a program of industrial trials of risk analysis methods. Vol. 3 contains chapters on quantification of risk, failure and accident probability, risk analysis and design, and examles of risk analysis for process plant. (BP)

  12. A background risk analysis. Vol. 1

    International Nuclear Information System (INIS)

    This 4-volumes report gives a background of ideas, principles, and examples which might be of use in developing practical methods for risk analysis. Some of the risk analysis techniques, described are somewhat experimental. The report is written in an introductory style, but where some point needs further justification or evaluation, this is given in the form of a chapter appendix. In this way, it is hoped that the report can serve two purposes, - as a basis for starting risk analysis work and as a basis for discussing effectiveness of risk analysis procedures. The report should be seen as a preliminary stage, prior to a program of industrial trials of risk analysis methods. Vol. 1 contains a short history of risk analysis, and chapters on risk, failures, errors and accidents, and general procedures for risk analysis. (BP)

  13. Dark matter candidates

    International Nuclear Information System (INIS)

    One of the simplest, yet most profound, questions we can ask about the Universe is, how much stuff is in it, and further what is that stuff composed of? Needless to say, the answer to this question has very important implications for the evolution of the Universe, determining both the ultimate fate and the course of structure formation. Remarkably, at this late date in the history of the Universe we still do not have a definitive answer to this simplest of questions---although we have some very intriguing clues. It is known with certainty that most of the material in the Universe is dark, and we have the strong suspicion that the dominant component of material in the Cosmos is not baryons, but rather is exotic relic elementary particles left over from the earliest, very hot epoch of the Universe. If true, the Dark Matter question is a most fundamental one facing both particle physics and cosmology. The leading particle dark matter candidates are: the axion, the neutralino, and a light neutrino species. All three candidates are accessible to experimental tests, and experiments are now in progress. In addition, there are several dark horse, long shot, candidates, including the superheavy magnetic monopole and soliton stars. 13 refs

  14. Assessment of potential solder candidates for high temperature applications

    DEFF Research Database (Denmark)

    package with different solders of different melting temperatures. High Pb containing alloys where the lead levels can be above 85% by weight, is one of the solders currently being used in this technology. Responding to market pressure i.e. need for green electronic products there is now an increasing...... pressure to eliminate lead containing materials despite the fact that materials for high Pb containing alloys are currently not affected by any legislations. A tentative assessment was carried out to determine the potential solder candidates for high temperature applications based on the solidification...

  15. Strengthening mechanisms in an Al-Fe-Cr-Ti nano-quasicrystalline alloy and composites

    OpenAIRE

    Pedrazzini, S; Galano, M; Audebert, F.; Collins, DM; Hofmann, F.; Abbey, B.; Korsunsky, A; Lieblich, M.; Garcia Escorial, A.; G. Smith

    2016-01-01

    We report a study of the structure-processing-property relationships in a high strength Al93Fe3Cr2Ti2 nano-quasicrystalline alloy and composites containing 10 and 20 vol.% ductilising pure Al fibres. The superimposed contributions of several different strengthening mechanisms have been modelled analytically using data obtained from systematic characterisation of the monolithic alloy bar. An observed yield strength of 544 MPa has been substantiated from a combination of solid solution strength...

  16. Improvement of high temperature oxidation resistance of γTiAl alloys by slurry coatings

    OpenAIRE

    Musallam, Nicolás Fashho

    2014-01-01

    This research document aims to deepen the understanding of slurry coatings as an effective barrier against the oxidation of promising Titanium-aluminide intermetallic alloys. For that purpose, the research is carried out with a Titanium- Aluminum alloy substrate {(Ti 45Al 2Nb 2Mn + 0.8%vol TiB2){ which was manufactured by means of two different techniques: Hot Isostatic Pressing (HIP) and Centrifugal Casting (CC). Additionally, two different slurry coatings have been applied...

  17. Particle Dark Matter Candidates

    CERN Document Server

    Scopel, Stefano

    2007-01-01

    I give a short overview on some of the favorite particle Cold Dark Matter candidates today, focusing on those having detectable interactions: the axion, the KK-photon in Universal Extra Dimensions, the heavy photon in Little Higgs and the neutralino in Supersymmetry. The neutralino is still the most popular, and today is available in different flavours: SUGRA, nuSUGRA, sub-GUT, Mirage mediation, NMSSM, effective MSSM, scenarios with CP violation. Some of these scenarios are already at the level of present sensitivities for direct DM searches.

  18. Recent progress on gas tungsten arc welding of vanadium alloys

    International Nuclear Information System (INIS)

    This is a progress report on a continuing research project to acquire a fundamental understanding of the metallurgical processes in the welding of vanadium alloys. It also has the goal of developing techniques for welding structural vanadium alloys. The alloy V-4Cr-4Ti is used as a representative alloy of the group; it is also the prime candidate vanadium alloy for the U.S. Fusion Program at the present time. However, other alloys of this class were used in the research as necessary. The present work focuses on recent findings of hydrogen embrittlement found in vanadium alloy welds. It was concluded that the atmosphere in the inert gas glove box was insufficient for welding 6mm thick vanadium alloy plates

  19. Effect of nano-hydroxyapatite reinforcement in mechanically alloyed NiTi composites for biomedical implant.

    Science.gov (United States)

    Akmal, Muhammad; Raza, Ahmad; Khan, Muhammad Mudasser; Khan, M Imran; Hussain, Muhammad Asif

    2016-11-01

    Equi-atomic NiTi alloy composites reinforced with 0, 2, 4 and 6vol.% nano-hydroxyapatite (HA) were successfully synthesized using pressureless sintering. Pure Ni and Ti elements were ball milled for 10h in order to produce a mechanically alloyed equi-atomic NiTi alloy (MA-NiTi). Mechanically alloyed NiTi and HA powders were blended, compacted and then sintered for 3h at 1325K. The sintered density varied inversely with volume percent of HA reinforcement. The X-Ray diffraction spectra and SEM images showed the formation of multiple phases like NiTi, NiTi2, Ni3Ti, and Ni4Ti3. The back scattered-SEM image analysis confirmed the presence of Ni-rich and Ti-rich phases with increasing HA content. The 6vol.% HA reinforced composite showed Ni3Ti as the major phase having the highest hardness value which can be attributed to the presence of relatively harder phases along with higher HA content as a reinforcement. The composite of MA-NiTi with 2vol.% HA manifested the most desirable results in the form of better sintering density mainly due to the minute decomposition of NiTi into other phases. Therefore, the 2vol.% reinforced MA-NiTi composite can be exploited as a novel material for manufacturing biomedical implants. PMID:27523992

  20. Corrosion and electrochemical evaluation of an Al–Si–Cu aluminum alloy in ethanol solutions

    International Nuclear Information System (INIS)

    Highlights: •AC impedance spectroscopy can effectively reveal the corrosion of Al in ethanol. •The addition of 10 vol.% water or acetic acid increases ethanol corrosivity to Al. •Al–Si–Cu–Mg precipitates in the Al alloy are susceptible to the corrosion attack. -- Abstract: The corrosion of aluminum alloy AlSi8Cu3Fe(Zn) in ethanol and ethanol solutions containing 10 vol.% water and 10 vol.% acetic acid, respectively, was investigated by means of electrochemical impedance spectroscopy (EIS), polarization curve, immersion, optical microscopy, scanning electron microscopy and element mapping. The Al alloy in the ethanol and its solutions exhibited a capacitive loop in the measured Nyquist EIS spectra at high frequencies, which can be attributed to the ethanol’s dielectric response. Addition of 10 vol.% acetic acid increased the ethanol corrosivity more significantly than the same amount of water addition. The Al–Si–Cu–Mg precipitated zones in the alloy were susceptible to corrosion attack due to the micro-galvanic effect by the Cu-containing precipitates

  1. Impact toughness improvement of high-strength aluminium alloy by intrinsic and extrinsic fracture mechanisms via hot roll bonding

    International Nuclear Information System (INIS)

    A multilayer aluminium laminate comprising 10 layers of Al-Zn-Mg-Cu alloy (82 vol.%) and nine layers of pure aluminium (18 vol.%) has been processed by hot rolling. The rolled laminate was characterized by electron backscattering diffraction, Charpy impact and shear tests. The multilayer laminate showed an outstanding Charpy impact toughness, which was 18 times higher than that for the as-received Al-Zn-Mg-Cu alloy. The improvement in damage tolerance was due to the high volume fraction of the high-strength aluminium and extrinsic fracture mechanisms.

  2. Degradation mode surveys of high performance candidate container materials

    Energy Technology Data Exchange (ETDEWEB)

    Gdowski, G.E.; McCright, R.D.

    1990-12-01

    Corrosion resistant materials are being considered for the metallic barrier of the Yucca Mountain Project`s high-level radioactive waste disposal containers. Nickel-chromium-molybdenum alloys and titanium alloys have good corrosion resistance properties and are considered good candidates for the metallic barrier. The localized corrosion phenomena, pitting and crevice corrosion, are considered as potentially limiting for the barrier lifetime. An understanding of the mechanisms of localized corrosion and of how various parameters affect it will be necessary for adequate performance assessment of candidate container materials. Examples of some of the concerns involving localized corrosion are discussed. The effects of various parameters, such as temperature and concentration of halide species, on localized corrosion are given. In addition, concerns about aging of the protective oxide layer in the expected service temperature range (50 to 250{degree}C) are presented. Also some mechanistic considerations of localized corrosion are given. 45 refs., 1 tab.

  3. Degradation mode surveys of high performance candidate container materials

    International Nuclear Information System (INIS)

    Corrosion resistant materials are being considered for the metallic barrier of the Yucca Mountain Project's high-level radioactive waste disposal containers. Nickel-chromium-molybdenum alloys and titanium alloys have good corrosion resistance properties and are considered good candidates for the metallic barrier. The localized corrosion phenomena, pitting and crevice corrosion, are considered as potentially limiting for the barrier lifetime. An understanding of the mechanisms of localized corrosion and of how various parameters affect it will be necessary for adequate performance assessment of candidate container materials. Examples of some of the concerns involving localized corrosion are discussed. The effects of various parameters, such as temperature and concentration of halide species, on localized corrosion are given. In addition, concerns about aging of the protective oxide layer in the expected service temperature range (50 to 250 degree C) are presented. Also some mechanistic considerations of localized corrosion are given. 45 refs., 1 tab

  4. Workshop Arboretum Volčji potok

    Directory of Open Access Journals (Sweden)

    Ana Kučan

    2012-01-01

    Full Text Available From its constitution onwards, the Volčji Potok Arboretum has been caught between various conflicting orientations. It is both a scientific, research and educational institution, and a cultural monument with exquisite garden and landscape design features and areas of great natural value and built cultural heritage, as well as commercial venue. At the same time, it functions as a park and an area for mass events, a garden centre and nursery. This variety of functions has helped Arboretum to survive the pressures of time; however, partial and uncoordinated interventions have threatened its original mission and its image and generated a number of conflicting situations. The workshop, organised on the initiative of the Institute for the Protection of Cultural Heritage of Slovenia, which involved students from the Faculty of Architecture and students from the Department of Landscape Architecture of the Biotechnical Faculty in mixed groups, generated eight proposals to solve some of the most urgent problems by introducing optimised development with clearly defined goals and priorities.

  5. Imparting passivity to vapor deposited magnesium alloys

    Science.gov (United States)

    Wolfe, Ryan C.

    Magnesium has the lowest density of all structural metals. Utilization of low density materials is advantageous from a design standpoint, because lower weight translates into improved performance of engineered products (i.e., notebook computers are more portable, vehicles achieve better gas mileage, and aircraft can carry more payload). Despite their low density and high strength to weight ratio, however, the widespread implementation of magnesium alloys is currently hindered by their relatively poor corrosion resistance. The objective of this research dissertation is to develop a scientific basis for the creation of a corrosion resistant magnesium alloy. The corrosion resistance of magnesium alloys is affected by several interrelated factors. Among these are alloying, microstructure, impurities, galvanic corrosion effects, and service conditions, among others. Alloying and modification of the microstructure are primary approaches to controlling corrosion. Furthermore, nonequilibrium alloying of magnesium via physical vapor deposition allows for the formation of single-phase magnesium alloys with supersaturated concentrations of passivity-enhancing elements. The microstructure and surface morphology is also modifiable during physical vapor deposition through the variation of evaporation power, pressure, temperature, ion bombardment, and the source-to-substrate distance. Aluminum, titanium, yttrium, and zirconium were initially chosen as candidates likely to impart passivity on vapor deposited magnesium alloys. Prior to this research, alloys of this type have never before been produced, much less studied. All of these metals were observed to afford some degree of corrosion resistance to magnesium. Due to the especially promising results from nonequilibrium alloying of magnesium with yttrium and titanium, the ternary magnesium-yttrium-titanium system was investigated in depth. While all of the alloys are lustrous, surface morphology is observed under the scanning

  6. Frictional Behavior of Fe-based Cladding Candidates for PWR

    International Nuclear Information System (INIS)

    After the recent nuclear disaster at Fukushima Daiichi reactors, there is a growing consensus on the development of new fuel systems (i.e., accident-tolerant fuel, ATF) that have high safety margins under design-basis accident (DBA) and beyond design-basis accident (BDBA). A common objective of various developing candidates is to archive the outstanding corrosion-resistance under severe accidents such as DBA and DBDA conditions for decreasing hydrogen production and increasing coping time to respond to severe accidents. ATF could be defined as new fuel/cladding system with enhanced accident tolerant to loss of active cooling in the core for a considerably longer time period under severe accidents while maintaining or improving the fuel performance during normal operations. This means that, in normal operating conditions, new fuel systems should be applicable to current operating PWRs for suppressing various degradation mechanisms of current fuel assembly without excessive design changes. When considering that one of the major degradation mechanisms of PWR fuel assemblies is a grid-to-rod fretting (GTRF), it is necessary to examine the tribological behavior of various ATF candidates at initial development stage. In this study, friction and reciprocating wear behavior of two kinds of Fe-based ATF candidates were examined with a reciprocating wear tests at room temperature (RT) air and water. The objective is to examine the compatibilities of these Fe-based alloys against current Zr-based alloy properties, which is used as major structural materials of PWR fuel assemblies. The reciprocating wear behaviors of Fe-based accident-tolerant fuel cladding candidates against current Zr-based alloy has been studied using a reciprocating sliding wear tester in room temperature air and water. Frictional behavior and wear depth were used for evaluating the applicability and compatibilities of Fe-based candidates without significant design changes of PWR fuel assemblies

  7. Frictional Behavior of Fe-based Cladding Candidates for PWR

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Young-Ho; Kim, Hyung-Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Byun, Thak Sang [Oak Ridge National Lab., Oak Ridge (United States)

    2014-10-15

    After the recent nuclear disaster at Fukushima Daiichi reactors, there is a growing consensus on the development of new fuel systems (i.e., accident-tolerant fuel, ATF) that have high safety margins under design-basis accident (DBA) and beyond design-basis accident (BDBA). A common objective of various developing candidates is to archive the outstanding corrosion-resistance under severe accidents such as DBA and DBDA conditions for decreasing hydrogen production and increasing coping time to respond to severe accidents. ATF could be defined as new fuel/cladding system with enhanced accident tolerant to loss of active cooling in the core for a considerably longer time period under severe accidents while maintaining or improving the fuel performance during normal operations. This means that, in normal operating conditions, new fuel systems should be applicable to current operating PWRs for suppressing various degradation mechanisms of current fuel assembly without excessive design changes. When considering that one of the major degradation mechanisms of PWR fuel assemblies is a grid-to-rod fretting (GTRF), it is necessary to examine the tribological behavior of various ATF candidates at initial development stage. In this study, friction and reciprocating wear behavior of two kinds of Fe-based ATF candidates were examined with a reciprocating wear tests at room temperature (RT) air and water. The objective is to examine the compatibilities of these Fe-based alloys against current Zr-based alloy properties, which is used as major structural materials of PWR fuel assemblies. The reciprocating wear behaviors of Fe-based accident-tolerant fuel cladding candidates against current Zr-based alloy has been studied using a reciprocating sliding wear tester in room temperature air and water. Frictional behavior and wear depth were used for evaluating the applicability and compatibilities of Fe-based candidates without significant design changes of PWR fuel assemblies

  8. Aqueous corrosion study on U-Zr alloy

    International Nuclear Information System (INIS)

    In low power or research reactor, U-Zr alloy is a potential candidate for dispersion fuel. Moreover, Zirconium has a low thermal-neutron cross section and uranium alloyed with Zr has excellent corrosion resistance and dimensional stability during thermal cycling. In the present study aqueous corrosion behavior of U-Zr alloy samples was studied in autoclave at 200 deg C temperature. Corrosion rate was determined from weight loss with time. (author)

  9. Candidate Materials Evaluation for Supercritical Water-Cooled Reactor

    International Nuclear Information System (INIS)

    Final technical report on the corrosion, stress corrosion cracking, and radiation response of candidate materials for the supercritical water-cooled reactor concept. The objective of the proposed research was to investigate degradation of materials in the supercritical water environment (SCW). First, representative alloys from the important classes of candidate materials were studied for their corrosion and stress-corrosion cracking (SCC) resistance in supercritical water. These included ferritic/martensitic (F/M) steels, austenitic stainless steels, and Ni-base alloys. Corrosion and SCC tests were conducted at various temperatures and exposure times, as well as in various water chemistries. Second, emerging plasma surface modification and grain boundary engineering technologies were applied to modify the near surface chemistry, microstructure, and stress-state of the alloys prior to corrosion testing. Third, the effect of irradiation on corrosion and SCC of alloys in the as-received and modified/engineered conditions were examined by irradiating samples using high-energy protons and then exposing them to SCW

  10. Electrical Resistance Alloys and Low-Expansion Alloys

    DEFF Research Database (Denmark)

    Kjer, Torben

    1996-01-01

    The article gives an overview of electrical resistance alloys and alloys with low thermal expansion. The electrical resistance alloys comprise resistance alloys, heating alloys and thermostat alloys. The low expansion alloys comprise alloys with very low expansion coefficients, alloys with very low...... thermoelastic coefficients and age hardenable low expansion alloys....

  11. Titanium Alloys and Processing for High Speed Aircraft

    Science.gov (United States)

    Brewer, William D.; Bird, R. Keith; Wallace, Terryl A.

    1996-01-01

    Commercially available titanium alloys as well as emerging titanium alloys with limited or no production experience are being considered for a variety of applications to high speed commercial aircraft structures. A number of government and industry programs are underway to improve the performance of promising alloys by chemistry and/or processing modifications and to identify appropriate alloys and processes for specific aircraft structural applications. This paper discusses some of the results on the effects of heat treatment, service temperatures from - 54 C to +177 C, and selected processing on the mechanical properties of several candidate beta and alpha-beta titanium alloys. Included are beta alloys Timetal 21S, LCB, Beta C, Beta CEZ, and Ti-10-2-3 and alpha-beta alloys Ti-62222, Ti-6242S, Timetal 550, Ti-62S, SP-700, and Corona-X. The emphasis is on properties of rolled sheet product form and on the superplastic properties and processing of the materials.

  12. Carbon Alloys-Multi-functionalization

    Energy Technology Data Exchange (ETDEWEB)

    Yasuda, Eiichi [MSL, Tokyo Institute of Technology, Yokohama 226-8503 (Japan)], E-mail: yasuda.e.aa.@m.titech.ac.jp; Enami, Takashi; Hoteida, Nobuyuki [MSL, Tokyo Institute of Technology, Yokohama 226-8503 (Japan); Lanticse-Diaz, L.J. [University of the Philippines (Philippines); Tanabe, Yasuhiro [Nagoya University (Japan); Akatsu, Takashi [MSL, Tokyo Institute of Technology, Yokohama 226-8503 (Japan)

    2008-02-25

    Last decade after our proposal of the 'Carbon Alloys' concept, many different kinds of Carbon Alloys, such as carbon nanotubes, carbon nanofibers, graphene sheet with magnetism, semi-conducting BCN compounds, graphite intercalation compounds, exfoliated carbon fiber, etc. have been found and developed. To extend the concept further, it is important to make it into intelligent materials by incorporating multiple functions. One example of the multi-functionalization is the development of homo-atomic Carbon Alloys from glassy carbon (GC) that exhibits high electrical conductivity and low gas permeability after treatment at critical conditions. Glassy carbon underwent metamorphosis to graphite spheres at HIP condition, and improved resistance to oxidation after alloying with Ta. The other one is shape utilization of the nano-sized carbon by understanding the effect of its large surfaces or interfaces in nanotechnology treatment. Recently carbon nanofiber was produced by polymer blend technology (PB) which was proposed by Prof. A. Oya during the Carbon Alloy project and progressed into intelligent carbon nanofiber (CNF) materials. CNF is combined into the polymer composites which is a candidate material for the bipolar separator in fuel cell. The superior properties, i.e., high electrical conductivity, high modulus, high strength, etc., of the CNF is being utilized in the preparation of this polymer composite.

  13. Vitamin D Status in Monkey Candidates for Space Flight

    Science.gov (United States)

    Arnaud, S. B.; Wronski, T. J.; Koslovskeya, I.; Dotsenko, R.; Navidi, M.; Wade, Charles E. (Technical Monitor)

    1994-01-01

    In preparation for the Cosmos 2229 Biosatellite space flight experiments in Rhesus monkeys, we evaluated the status of vitamin D in animals of different origins: candidates for space flight raised in Moscow (IMBP) and animals housed at Ames Research Ctr. (ARC) for pilot studies. Diets at IMBP were natural foods found by analysis to contain 1.4% Ca, 2.8% P andng/ml,p<.001) in IMBP than ARC animals. 1,25D (174156 vs. 212+77 pg/ml), Pi and AP were similar. In bone, osteoid and osteoblast surfaces averaged 38114% and 33+15% in all, with %vol. of osteoid higher in IMBP than ARC monkeys of the same BW (p<.05) Indices of bone formation were inversely related to 25D, not 1,25D. Of interest are similar 1,25D levels associated with a wide range of substrate and extensive osteoid in bone of D replete animals.

  14. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J.C.; Van Konynenburg, R.A.; McCright, R.D. (Lawrence Livermore National Lab., CA (USA)); Bullen, D.B. (Science and Engineering Associates, Inc., Pleasanton, CA (USA))

    1988-04-01

    Three iron- to nickel-based austenitic alloys (Types 304L and 316L stainless steels and Alloy 825) are being considered as candidate materials for the fabrication of high-level radioactive-waste containers. Waste will include fuel assemblies from reactors as well as high-level waste in borosilicate glass forms, and will be sent to the prospective repository at Yucca Mountain, Nevada. The decay of radionuclides in the repository will result in the generation of substantial heat and in fluences of gamma radiation. Container materials may undergo any of several modes of degradation in this environment, including atmospheric oxidation; uniform aqueous phase corrosion; pitting; crevice corrosion; sensitization and intergranular stress corrosion cracking (IGSCC); and transgranular stress corrosion cracking (TGSCC). This report is an analysis of data relevant to the pitting, crevice corrosion, and stress corrosion cracking (SCC) of the three austenitic candidate alloys. The candidates are compared in terms of their susceptibilities to these forms of corrosion. Although all three candidates have demonstrated pitting and crevice corrosion in chloride-containing environments, Alloy 825 has the greatest resistance to these types of localized corrosion (LC); such resistance is important because pits can penetrate the metal and serve as crack initiation sites. Both Types 304L and 316L stainless steels are susceptible to SCC in acidic chloride media. In contrast, SCC has not been documented in Alloy 825 under comparable conditions. Gamma radiation has been found to enhance SCC in Types 304 and 304L stainless steels, but it has no detectable effect on the resistance of Alloy 825 to SCC. Furthermore, while the effects of microbiologically induced corrosion have been observed for 300-series stainless steels, nickel-based alloys such as Alloy 825 seem to be immune to such problems. 211 refs., 49 figs., 10 tabs.

  15. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    International Nuclear Information System (INIS)

    Three iron- to nickel-based austenitic alloys (Types 304L and 316L stainless steels and Alloy 825) are being considered as candidate materials for the fabrication of high-level radioactive-waste containers. Waste will include fuel assemblies from reactors as well as high-level waste in borosilicate glass forms, and will be sent to the prospective repository at Yucca Mountain, Nevada. The decay of radionuclides in the repository will result in the generation of substantial heat and in fluences of gamma radiation. Container materials may undergo any of several modes of degradation in this environment, including atmospheric oxidation; uniform aqueous phase corrosion; pitting; crevice corrosion; sensitization and intergranular stress corrosion cracking (IGSCC); and transgranular stress corrosion cracking (TGSCC). This report is an analysis of data relevant to the pitting, crevice corrosion, and stress corrosion cracking (SCC) of the three austenitic candidate alloys. The candidates are compared in terms of their susceptibilities to these forms of corrosion. Although all three candidates have demonstrated pitting and crevice corrosion in chloride-containing environments, Alloy 825 has the greatest resistance to these types of localized corrosion (LC); such resistance is important because pits can penetrate the metal and serve as crack initiation sites. Both Types 304L and 316L stainless steels are susceptible to SCC in acidic chloride media. In contrast, SCC has not been documented in Alloy 825 under comparable conditions. Gamma radiation has been found to enhance SCC in Types 304 and 304L stainless steels, but it has no detectable effect on the resistance of Alloy 825 to SCC. Furthermore, while the effects of microbiologically induced corrosion have been observed for 300-series stainless steels, nickel-based alloys such as Alloy 825 seem to be immune to such problems. 211 refs., 49 figs., 10 tabs

  16. Study of the evolution of the microstructure and hardness of Cu-Al and Cu-Al-Ti alloys during their production by reactive milling and extrusion

    International Nuclear Information System (INIS)

    The microstructure and hardness of two alloys produced by reactive milling of elementary powders for 10, 20 and 30 hours and later hot extrusion were studied: a Cu-5 vol.% Al2O3 binary and another Cu-2.5 vol.%TiC-2.5 vol.% Al2O3 ternary. The microstructure of the alloys was characterized with a transmission electron microscope (TEM), X-ray diffraction (XRD) and different methods of chemical analysis. Then their hardness was evaluated before and after annealing at 873 K. The extruded binary alloy showed a micrometric grain structure, with nanometric subgrains (100 nm), together with the formation of nanometric dispersoids of semi-coherent Al203 with the Cu matrix. The ternary alloy showed a microstructure very similar to the binary alloy, except that it also showed the formation of nanometric TiC dispersoids. The nanoparticles acted effectively as anchoring points for the movement of dislocations and grain growth. The microstructure was observed to be stable after annealing treatments for all the alloys. The milled ternary alloy was 32% harder (290 HV) than the hardest binary alloy (milled for 30 hours) (au)

  17. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    International Nuclear Information System (INIS)

    Three iron- to nickel-based austenitic alloys and three copper-based alloys are being considered as candidate materials for the fabrication of high-level radioactive-waste disposal containers. The austenitic alloys are Types 304L and 316L stainless steels and the high-nickel material Alloy 825. The copper-based alloys are CDA 102 (oxygen-free copper), CDA 613 (Cu-7Al), and CDA 715 (Cu-30Ni). Waste in the forms of both spent fuel assemblies from reactors and borosilicate glass will be sent to the prospective repository at Yucca Mountain, Nevada. The decay of radionuclides will result in the generation of substantial heat and gamma radiation. Container materials may undergo any of several modes of degradation in this environment, including undesirable phase transformations due to a lack of phase stability; atmospheric oxidation; general aqueous corrosion; pitting; crevice corrosion; intergranular stress corrosion cracking; and transgranular stress corrosion cracking. Problems specific to welds, such as hot cracking, may also occur. A survey of the literature has been prepared as part of the process of selecting, from among the candidates, a material that is adequate for repository conditions. The modes of degradation are discussed in detail in the survey to determine which apply to the candidate alloys and the extent to which they may actually occur. The eight volumes of the survey are summarized in Sections 1 through 8 of this overview. The conclusions drawn from the survey are also given in this overview

  18. Dynamics of structures '89. Vol. 1 and 2

    International Nuclear Information System (INIS)

    The proceedings, comprising 3 volumes published by the Plzen Centre of the Czechoslovak Society for Science and Technology (Vol. 1 and 2) and by Skoda Works in Plzen (Vol. 3), contain 107 papers, out of which 8 fall within the INIS Subject Scope; these deal with problems related to the earthquake resistance of nuclear power plants. Attention is paid to the evaluation of seismic characteristics of nuclear power plant equipment, to the equipment testing and to calculations of its dynamic characteristics under simulated seismic stress. (Z.M.)

  19. Proceedings of the 1. Arabic conference on chemical applications (Chemia 2). Vol. 2

    International Nuclear Information System (INIS)

    The conference of chemical application was held on 1-5 Nov 1997 in Cairo, This vol.2 contains of chemical application on nuclear materials. Studies on these vol.This second volume covers papers presented on the subjects

  20. Electoral Systems and Candidate Selection

    NARCIS (Netherlands)

    Hazan, Reuven Y.; Voerman, Gerrit

    2006-01-01

    Electoral systems at the national level and candidate selection methods at the party level are connected, maybe not causally but they do influence each other. More precisely, the electoral system constrains and conditions the parties' menu of choices concerning candidate selection. Moreover, in ligh

  1. Changes in crystallographic and microstructural texture during recrystallization of a molybdenum alloy containing a disperse nitride phase

    International Nuclear Information System (INIS)

    Chanqes in crystallographic and microstructural texture during recrystallization annealings in 1200-2000 deg C temperature range were followed using Mo-0.36 vol.% HfN. A consecutive series of microprocesses providing the transition of the alloy from deformed state into recrystallized one was established

  2. Proceedings of the second international conference on environmental impact assessment of all economical activities. Vol. 1

    International Nuclear Information System (INIS)

    Proceedings of the conference consist of 3 volumes: Vol. 1 - 'Environmental Impact Assessment of all Economical Activities including Industry'; Vol. 2 - 'Air Pollution Control and Prevention'; Vol. 3 - Waste Management and Environmental Problems in Construction Industry'. Out of 32 papers contained in Vol. 1, 2 were inputted to INIS. They deal with models of radionuclide transport in food chains and the use of aerial monitoring in the study of environmental contamination. (Z.S.)

  3. Proceedings of the second international conference on environmental impact assessment of all economical activities. Vol. 2

    International Nuclear Information System (INIS)

    Proceedings of the conference consist of 3 volumes: Vol. 1 - 'Environmental Impact Assessment of all Economical Activities including Industry'; Vol. 2 - 'Air Pollution Control and Prevention'; Vol. 3 - Waste Management and Environmental Problems in Construction Industry'. Out of 32 papers contained in Vol. 2, 4 were inputted to INIS. They deal with nuclear fusion as a potential energy source, with environmental aspects of disposal of ashes from power plants in the Czech Republic, and with land reclamation after mining activities. (Z.S.)

  4. Oxygen-Diffused Titanium as a Candidate Brake Rotor Material

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Jun [ORNL; Blau, Peter Julian [ORNL; Jolly, Brian C [ORNL

    2009-01-01

    Titanium alloys are one of several candidate materials for the next generation of truck disk brake rotors. Despite their advantages of lightweight relative to cast iron and good strength and corrosion resistance, titanium alloys are unlikely to be satisfactory brake rotor materials unless their friction and wear behavior can be significantly improved. In this study, a surface engineering process oxygen diffusion was applied to titanium rotors and has shown very encouraging results. The oxygen diffused Ti-6Al-4V (OD-Ti) was tested on a sub-scale brake tester against a flat block of commercial brake lining material and benchmarked against several other Ti-based materials, including untreated Ti-6Al-4V, ceramic particle-reinforced Ti composites (MMCs), and a thermal-spray-coated Ti alloy. With respect to friction, the OD-Ti outperformed all other candidate materials under the imposed test conditions with the friction coefficient remaining within a desirable range of 0.35-0.50, even under the harshest conditions when the disk surface temperature reached nearly 600 C. In addition, the OD-Ti showed significantly improved wear-resistance over the non-treated one and was even better than the Ti-based composite materials.

  5. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    International Nuclear Information System (INIS)

    Six alloys are being considered as possible materials for the fabrication of containers for the disposal of high-level radioactive waste. Three of these candidate materials are copper-based alloys: CDA 102 (oxygen-free copper), CDA 613 (Cu-7Al), and CDA 715 (Cu-30Ni). The other three are iron- to nickel-based austenitic materials: Types 304L and 316L stainless steels and Alloy 825. Radioactive waste will include spent-fuel assemblies from reactors as well as waste in borosilicate glass and will be sent to the prospective site at Yucca Mountain, Nevada, for disposal. The waste-package containers must maintain substantially complete containment for at least 300 yr and perhaps as long as 1000 yr. During the first 50 yr after emplacement, the containers must be retrievable from the disposal site. Shortly after emplacement of the containers in the repository, they will be exposed to high temperatures and high gamma radiation fields from the decay of high-level waste. This radiation will promote the radiolytic decomposition of moist air to hydrogen. This volume surveys the available data on the effects of hydrogen on the six candidate alloys for fabrication of the containers. For copper, the mechanism of hydrogen embrittlement is discussed, and the effects of hydrogen on the mechanical properties of the copper-based alloys are reviewed. The solubilities and diffusivities of hydrogen are documented for these alloys. For the austenitic materials, the degradation of mechanical properties by hydrogen is documented. The diffusivity and solubility of hydrogen in these alloys are also presented. For the copper-based alloys, the ranking according to resistance to detrimental effects of hydrogen is: CDA 715 (best) > CDA 613 > CDA 102 (worst). For the austenitic alloys, the ranking is: Type 316L stainless steel ∼ Alloy 825 > Type 304L stainless steel (worst). 87 refs., 19 figs., 8 tabs

  6. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    Energy Technology Data Exchange (ETDEWEB)

    Gdowski, G.E.; Bullen, D.B. (Science and Engineering Associates, Inc., Pleasanton, CA (USA))

    1988-08-01

    Six alloys are being considered as possible materials for the fabrication of containers for the disposal of high-level radioactive waste. Three of these candidate materials are copper-based alloys: CDA 102 (oxygen-free copper), CDA 613 (Cu-7Al), and CDA 715 (Cu-30Ni). The other three are iron- to nickel-based austenitic materials: Types 304L and 316L stainless steels and Alloy 825. Radioactive waste will include spent-fuel assemblies from reactors as well as waste in borosilicate glass and will be sent to the prospective site at Yucca Mountain, Nevada, for disposal. The waste-package containers must maintain substantially complete containment for at least 300 yr and perhaps as long as 1000 yr. During the first 50 yr after emplacement, the containers must be retrievable from the disposal site. Shortly after emplacement of the containers in the repository, they will be exposed to high temperatures and high gamma radiation fields from the decay of high-level waste. This radiation will promote the radiolytic decomposition of moist air to hydrogen. This volume surveys the available data on the effects of hydrogen on the six candidate alloys for fabrication of the containers. For copper, the mechanism of hydrogen embrittlement is discussed, and the effects of hydrogen on the mechanical properties of the copper-based alloys are reviewed. The solubilities and diffusivities of hydrogen are documented for these alloys. For the austenitic materials, the degradation of mechanical properties by hydrogen is documented. The diffusivity and solubility of hydrogen in these alloys are also presented. For the copper-based alloys, the ranking according to resistance to detrimental effects of hydrogen is: CDA 715 (best) > CDA 613 > CDA 102 (worst). For the austenitic alloys, the ranking is: Type 316L stainless steel {approx} Alloy 825 > Type 304L stainless steel (worst). 87 refs., 19 figs., 8 tabs.

  7. High-entropy alloy: challenges and prospects

    Directory of Open Access Journals (Sweden)

    Y.F. Ye

    2016-07-01

    Full Text Available High-entropy alloys (HEAs are presently of great research interest in materials science and engineering. Unlike conventional alloys, which contain one and rarely two base elements, HEAs comprise multiple principal elements, with the possible number of HEA compositions extending considerably more than conventional alloys. With the advent of HEAs, fundamental issues that challenge the proposed theories, models, and methods for conventional alloys also emerge. Here, we provide a critical review of the recent studies aiming to address the fundamental issues related to phase formation in HEAs. In addition, novel properties of HEAs are also discussed, such as their excellent specific strength, superior mechanical performance at high temperatures, exceptional ductility and fracture toughness at cryogenic temperatures, superparamagnetism, and superconductivity. Due to their considerable structural and functional potential as well as richness of design, HEAs are promising candidates for new applications, which warrants further studies.

  8. Qualification loop tests of cobalt-free hardfacing alloys

    International Nuclear Information System (INIS)

    AECL is conducting endurance tests on valves hard-faced with four cobalt-free alloys. The first phase of the program, in which PWR primary heat transport conditions were simulated in AECL's valve test loop, has reached the 1400 cycle mark. This represents approximately 70% of the target value of 2000 cycles. The candidate alloys are NOREM 01, NOREM 04, EB 5183 and EVERIT 50. One valve with Stellite 6 trim serves as the standard. Prior to loop testing, a baseline inaugural inspection was performed. During testing the loop was shut down at approximately 500 cycle intervals, and the valves were disassembled for examination. The examinations included seat leak tests, profilometry and nondestructive inspection. Corrosion coupons in the loop were used to monitor any material loss due solely to corrosion mechanisms. This interim progress report summarizes the examination results and the relative performance of the candidate alloys. The results to date indicate that, based upon the sliding were damage assessment and seat leakage test results, all the candidate alloys perform better than the Stellite 6 control sample. On the same basis, NOREM 04 and EB 5183 are the best of the candidate alloys; although there are only minor differences in performance among the four alloys at this time. A final assessment can only be made after the cycling tests are complete and the seats and discs have been destructively examined. 3 refs., 31 figs., 9 tabs

  9. Activation analyses for different fusion structural alloys

    International Nuclear Information System (INIS)

    The leading candidate structural materials, viz., the vanadium alloys, the nickel or the manganese stabilized austenitic steels, and the ferritic steels, are analysed in terms of their induced activation in the TPSS fusion power reactor. The TPSS reactor has 1950 MW fusion power and inboard and outboard average neutron wall loading of 3.75 and 5.35 MW/m2 respectively. The results shows that, after one year of continuous operation, the vanadium alloys have the least radioactivity at reactor shutdown. The maximum difference between the induced radioactivity in the vanadium alloys and in the other iron-based alloys occurs at about 10 years after reactor shutdown. At this time, the total reactor radioactivity, using the vanadium alloys, is about two orders of magnitude less than the total reactor radioactivity utilizing any other alloy. The difference is even larger in the first wall, the FW-vanadium activation is 3 orders of magnitude less than other alloys' FW activation. 2 refs., 7 figs

  10. Electrodeposited NiCu Alloy Catalysts for Glucose Oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Jieun; Park, Hansoo; Kim, Sookil [Chung-Ang Univ., Seoul (Korea, Republic of); Ahn, Sang Hyun; Jang, Jong Hyun [Korea Institute of Science and Technology, Seoul (Korea, Republic of)

    2014-07-15

    NiCu alloys have been suggested as potential candidates for catalysts in glucose oxidation. In this study, NiCu alloys with different compositions were prepared on a glassy carbon substrate by changing the electrodeposition potential to examine the effect of Ni/Cu ratios in alloys on catalytic activity toward glucose oxidation. Cyclic voltammetry and chronoamperometry showed that NiCu alloys had higher catalytic activity than pure Ni and Cu catalysts. Especially, Ni{sub 59}Cu{sub 41} had superior catalytic activity, which was about twice that of Ni at a given oxidation potential. X-ray analyses showed that the oxidation state of Ni in NiCu alloys was increased with the content of Cu by lattice expansion. Ni components in alloys with higher oxidation state were more effective in the oxidation of glucose.

  11. Electrodeposited NiCu Alloy Catalysts for Glucose Oxidation

    International Nuclear Information System (INIS)

    NiCu alloys have been suggested as potential candidates for catalysts in glucose oxidation. In this study, NiCu alloys with different compositions were prepared on a glassy carbon substrate by changing the electrodeposition potential to examine the effect of Ni/Cu ratios in alloys on catalytic activity toward glucose oxidation. Cyclic voltammetry and chronoamperometry showed that NiCu alloys had higher catalytic activity than pure Ni and Cu catalysts. Especially, Ni59Cu41 had superior catalytic activity, which was about twice that of Ni at a given oxidation potential. X-ray analyses showed that the oxidation state of Ni in NiCu alloys was increased with the content of Cu by lattice expansion. Ni components in alloys with higher oxidation state were more effective in the oxidation of glucose

  12. Ti-25Ta alloy with the best mechanical compatibility in Ti-Ta alloys for biomedical applications

    International Nuclear Information System (INIS)

    The microstructures, dynamic elastic modulus, and mechanical properties of the Ti-25Ta (mass%) alloy are investigated in this study in order to assess its mechanical compatibility for biomedical applications. The microstructures are examined by X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The dynamic elastic modulus is measured by the resonance vibration method and the mechanical properties are determined from uniaxial tensile tests. The experimental results indicate that the Ti-25Ta alloy exhibits an orthorhombic martensite (α'') twinned structure after solution treatment. The Ti-25Ta alloy has the lowest elastic modulus and the highest ratio of strength to modulus among Ti-Ta alloys. Thus, the Ti-25Ta alloy exhibits the best mechanical compatibility among Ti-Ta alloys and is a promising candidate for novel metallic biomaterials.

  13. The compression strength investigations of AW-AlCu4Mg2Mn alloy based composites reinforced with SiC particles

    Directory of Open Access Journals (Sweden)

    A. Kurzawa

    2011-04-01

    Full Text Available In this paper strength tests of composite materials based on AW-AlCu4Mg2Mn obtained in uniaxial compression test was studied.Materials used for examination were made from AW-AlCu4Mg2Mn alloy and porous preforms of SiC particles (grain size 6÷10μm bypressure infiltration (squeeze casting. The stress-strain curves of the materials with 10% vol., 20% vol., 30% vol. particles of SiC, as well unreinforcement alloy and microstructure of scrap surface samples in a plane parallel to the compressive force were analyzed. The investigated metal matrix composites are characterized by marked reduced the plastic strain values with increasing particle strengthening while the unreinforcement materials throughout the range of deformation show considerable plasticity. In the case of the material containing 10% vol of SiC the plastic strain is a slight strengthening of the material. With increasing of the particle content the plasticity decreases. Materials with 20%vol and 30%vol of SiC particles were brittle cracked at much higher values of stress σ.

  14. Vanadium alloys: development strategy

    International Nuclear Information System (INIS)

    A strategy for the development of vanadium alloys for use in radiation environments is outlined. An attractive reference alloy (V-15Cr-5Ti) has been identified. The critical issues in developing vanadium base alloys are summarized

  15. Effects of surface condition on the corrosion of candidate structural materials in a simulated HTGR-GT environment

    International Nuclear Information System (INIS)

    A simulated high-temperature gas-cooled reactor (HTGR) helium environment was used to study the effects of surface finish conditions on the subsequent elevated-temperature corrosion behavior of key candidate structural materials. The environment contained helium with 500 μatm H2/50 μatm CO/50 μatm CH4/2O at 9000C with total test exposure durations of 3000 hours. Specimens with lapped, grit-blasted, pickled, and preoxidized surface conditions were studied. Materials tested included two cast superalloys, IN 100 and IN 713LC; one centrifugally cast high-temperature alloy, HK 40 one oxice-dispersion-strengthened alloy, Inconel MA 754; and three wrought high-temperature alloys, Hastelloy Alloy X, Inconel Alloy 617, and Alloy 800H

  16. Fracture mechanisms assessment of a multilayer material with high strength and excellent impact toughness based on the aerospace Al 7075 alloy

    International Nuclear Information System (INIS)

    An aluminium multilayer laminate has been processed by hot rolling. It is constituted by 19 alternated layers of high-strength aluminium alloy (Al 7075-T6, 82 % vol) and thinner pure aluminium layers (Al 1050-H24, 18 % vol). The microstructure of the constituent alloys and the composition gradient across the interfaces has been characterized. The multilayer laminate and the as-received aluminium alloys have been tested at room temperature by Vickers microhardness, three-point bend test and impact Charpy test. The outstanding improvement in damage tolerance, which is 18 times higher than that for the as-received Al 7075 alloy, is due to both intrinsic and extrinsic fracture mechanisms operating in the multilayer laminate during mechanical testing. (Author) 19 refs.

  17. luminium alloy - rice husk ash composites production and analysis

    Directory of Open Access Journals (Sweden)

    Abdullahi Mohammed USMAN

    2014-11-01

    Full Text Available This study was carried out to produce and analyse the properties of Aluminium Alloy-Rice Husk Ash composites. Rice husk ash (RHA with high silica content of up to 97.095% was used for the study with the RHA varied from 0vol% – 30vol% at intervals of 5vol% in the aluminium alloy as reinforcement. The density and some mechanical properties of the composites including tensile strength, impact strength, hardness and fatigue strength were investigated. The results showed that the density of the composite decreases with the percentage increase of reinforcement from 2840.242 kgm-3 for the control sample to 2402.899 kgm-3 for 30vol% RHA. The Ultimate Tensile Strength (UTS varies from 164.374 MNm-2 at 0% RHA to 176.837 MNm-2 with maximum value at 10% RHA, impact strength values varies from 84.020kJm-2 at 0% RHA to 155.244 kJm-2 with maximum value at 10% RHA, hardness value varies from 70.467 RHV at 0% RHA to 109.367 RHV with maximum value at 25% RHA and fatigue strength varies from 0.224x106 cycles to 2.582x106 cycles with maximum cycle at 20% RHA. The results of analysis of variance showed that there are significant differences among the means of each property of the composites at different levels of replacement of the ash addition (P<0.05. It was concluded that the produced composites could be used to make engineering components such as automobile body parts, piston and block engine etc.

  18. Investigations of a reduced enrichment dispersion fuel (U-Mo alloy in aluminium matrix) for research reactor fuel pins

    International Nuclear Information System (INIS)

    Russia possesses considerable experience in utilisation of uranium-molybdenum alloys containing in dispersion fuel composition no more than 6 g/cm3 uranium. The feasibility of utilising the U-9 mass.% Mo alloy with reduced enrichment uranium (< 20%) in research reactor dispersion fuel pins has been analysed in the IPPE. Specimens with the 40 vol.% (U-9 mass. % Mo) + 60 vol.% Al fuel have been fabricated by hot pressing. Investigations of thermal physical properties of this fuel as well as tests for compatibility of U-Mo alloy with Al have been carried out in a wide temperature range. Corrosive tests of dispersion fuel have been realised in water. A flow chart of reproducing wastes from fuel pin production has been considered. The results of works carried out enable to hope on successful solution of the problem of utilisation high-density U-Mo fuel in research reactors. (author)

  19. Wear Characteristics of Hybrid Composites Based on Za27 Alloy Reinforced With Silicon Carbide and Graphite Particles

    Directory of Open Access Journals (Sweden)

    S. Mitrović

    2014-06-01

    Full Text Available The paper presents the wear characteristics of a hybrid composite based on zinc-aluminium ZA27 alloy, reinforced with silicon-carbide and graphite particles. The tested sample contains 5 vol.% of SiC and 3 vol.% Gr particles. Compocasting technique has been used to prepare the samples. The experiments were performed on a “block-on-disc” tribometer under conditions of dry sliding. The wear volumes of the alloy and the composite were determined by varying the normal loads and sliding speeds. The paper contains the procedure for preparation of sample composites and microstructure of the composite material and the base ZA27 alloy. The wear surface of the composite material was examined using the scanning electronic microscope (SEM and energy dispersive spectrometry (EDS. Conclusions were obtained based on the observed impact of the sliding speed, normal load and sliding distance on tribological behaviour of the observed composite.

  20. Solidification of Magnesium (AM50A) / vol%. SiCp composite

    Science.gov (United States)

    Zhang, X.; Hu, H.

    2012-01-01

    Magnesium matrix composite is one of the advanced lightweight materials with high potential to be used in automotive and aircraft industries due to its low density and high specific mechanical properties. The magnesium composites can be fabricated by adding the reinforcements of fibers or/and particles. In the previous literature, extensive studies have been performed on the development of matrix grain structure of aluminum-based metal matrix composites. However, there is limited information available on the development of grain structure during the solidification of particulate-reinforced magnesium. In this work, a 5 vol.% SiCp particulate-reinforced magnesium (AM50A) matrix composite (AM50A/SiCp) was prepared by stir casting. The solidification behavior of the cast AM50A/SiCp composite was investigated by computer-based thermal analysis. Optical and scanning electron microscopies (SEM) were employed to examine the occurrence of nucleation and grain refinement involved. The results indicate that the addition of SiCp particulates leads to a finer grain structure in the composite compared with the matrix alloy. The refinement of grain structure should be attributed to both the heterogeneous nucleation and the restricted primary crystal growth.

  1. Soils newsletter. Vol. 26, No. 1

    International Nuclear Information System (INIS)

    Water is a scarce and finite resource, and the FAO Committee on Agriculture (COAG) recently identified the sustainable use of natural resources as a priority area within the agriculture programme. COAG made specific reference to the need for better water management and the improvement of land, soil and water quality. The sub-programme is currently engaged in several projects on water, and will endeavour to expand these activities in the future through both the regular and technical co-operation programmes of the Agency. The final Consultants' Meeting of a 3-year study on 'The comparison of the soil moisture neutron probe with time-domain reflectometry and capacitance methods' was held at IAEA HQ, Vienna, in March 2003. Experts from Australia, Austria, France and the United States of America, and the SSU Seibersdorf, conducted the comparative assessment under various soil and climatic conditions and cropping systems. Two sets of guidelines will be issued from this project. One will be a technical guide to the use of various soil water monitoring instruments and the other will provide guidelines for choosing a soil water measurement sensor. In addition, it is planned to publish a special issue of The Vadose Zone Journal containing scientific articles on the experimental work undertaken in the project. An FAO/IAEA Interregional Training Course on the 'Use of Nuclear and Related Techniques to Increase Water Use Efficiency in Rainfed and Irrigated Agriculture' will be held at the SSU, Seibersdorf, from 1 - 25 July 2003. Fifteen candidates from FAO and IAEA Member States in all regions have been selected to participate. The objective of the course is to transfer knowledge and practical experience to developing countries on the use of nuclear and related techniques to measure and monitor soil water status, including technologies, strategies and approaches to conserve water, reduce wastage and increase water use efficiency in irrigated and rainfed cropping systems

  2. [Reliability of % vol. declarations on labels of wine bottles].

    Science.gov (United States)

    Schütz, Harald; Erdmann, Freidoon; Verhoff, Marcel A; Weiler, Günter

    2005-01-01

    The Council Regulation (EC) no. 1493/1999 of 17 May 1999 on the common organisation of the market in wine (Abl. L 179 dated 14/7/1999) and the GMO Wine 2000 (Annex VII A) stipulates that the labels of wine bottles have to indicate, among others, information on the sales designation of the product, the nominal volume and the alcoholic strength. The latter must not differ by more than 0.5% vol. from the alcoholic strength as established by analysis. Only when quality wines are stored in bottles for more than three years, the accepted tolerance limits are +/- 0.8% vol. The presented investigation results show that deviations have to be taken into account which may be highly relevant for forensic practice. PMID:15887778

  3. Supersymmetric mechanics. Vol. 1. Supersymmetry, noncommutativity and matrix models

    Energy Technology Data Exchange (ETDEWEB)

    Bellucci, S. (ed.) [Istituto Nazionale di Fisica Nucleare, Rome (Italy)

    2006-07-01

    This is the first volume in a series of books on the general theme of Supersymmetric Mechanics; the series is based on lectures and discussions held in 2005 and 2006 at the INFN-Laboratori Nazionali di Frascati. The selected topics include supersymmetry and supergravity, the attractor mechanism, black holes, noncommutative mechanics, super-Hamiltonian formalism and matrix models. All lectures are intended for beginners at the graduate level and nonspecialists from related fields of research and a substantial effort was made to incorporate in the extensive write-ups the results of the animated discussion sessions which followed the individual lectures. A second volume appears as Lecture Notes Physics, Vol. 701 ''Supersymmetric Mechanics - Vol. 2: The Attractor Mechanism'' (2006), ISBN: 3-540-34156-0. (orig.)

  4. The Recovery and Recrystallization of the Cold Rolled V-W-Ti Alloys

    Institute of Scientific and Technical Information of China (English)

    CHENJiming; T.Muroga; T.Nagasaka1; XUYing; XUZengyu

    2002-01-01

    Vanadium alloys, especially that of V4Cr4Ti, are supposed as the promising candidate structural material for fusion applications for their good thermal properties, high temperature strength and the inherent low activation characteristics. However, in recent

  5. Index to Nuclear Safety. A technical progress review by chronology, permuted title, and author. Vol. 11, No. 1 through Vol. 15, No. 6

    International Nuclear Information System (INIS)

    This issue of the Index to Nuclear Safety covers only articles included in Nuclear Safety, Vol. 11, No. 1, through Vol. 15, No. 6. This index is presented in three sections as follows: Chronological List of Articles by Volume; Permuted Title (KWIC) Index; and Author Index. (U.S.)

  6. Direct observation of densification and grain growth in a W--Ni alloy

    Energy Technology Data Exchange (ETDEWEB)

    Riegger, H.; Pask, J.A.; Exner, H.E.

    1979-04-01

    Densification and grain growth in a tungsten--nickel alloy containing 32 vol % of liquid at 1550/sup 0/C were studied by conventional methods aided by hot stage scanning electron microscopy and cinematography. This technique yields important additional qualitative information on the mechanisms. Two stages can be discerned. In stage 1, essentially complete pore elimination, rapid grain growth and adjustment of microstructural geometry take place. In the second stage, microstructure coarsening occurs which is characterized by geometric similarity. Columnar grain growth at the surface is observed due to squeezing out of Ni--W liquid, flooding of surface grains and fast evaporation of the Ni. The driving forces for these processes are discussed showing that a high ratio of grain boundary energy to liquid surface energy is essential. A W--Cu alloy with 32 vol % liquid at 1100/sup 0/C did not show any grain growth due to essentially no solubility of W in Cu at this temperature.

  7. TORSIONAL DEFORMATION AND FATIGUE BEHAVIOUR OF 6061 ALUMINIUM ALLOY

    OpenAIRE

    Marini Marno; Ahmad Badri Ismail

    2012-01-01

    Torsional deformation and fatigue behaviour of both solid and thin-walled tubular specimens were made from as-received and heat treated 6061 aluminium alloy were studied. 6061 aluminium alloy have been widely used as a candidate material in automobile, aerospace, aircraft and structural application because of their superior mechanical properties such as high strength to weight ratio, good ductility and others. The differences in cyclic deformation and fatigue behaviours between round and soli...

  8. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    Energy Technology Data Exchange (ETDEWEB)

    Strum, M.J.; Weiss, H.; Farmer, J.C. (Lawrence Livermore National Lab., CA (USA)); Bullen, D.B. (Science and Engineering Associates, Inc., Pleasanton, CA (USA))

    1988-06-01

    This volume surveys the effects of welding on the degradation modes of three austenitic alloys: Types 304L and 316L stainless steels and Alloy 825. These materials are candidates for the fabrication of containers for the long-term storage of high-level nuclear waste. The metallurgical characteristics of fusion welds are reviewed here and related to potential degradation modes of the containers. Three specific areas are discussed in depth: (1) decreased resistance to corrosion in the forms of preferential corrosion, sensitization, and susceptibility to stress corrosion cracking, (2) hot cracking in the heat-affected zone and the weld zone, and (3) formation of intermetallic phases. The austenitic alloys are ranked as follows in terms of overall weldability: Alloy 825 (best) > Type 316L stainless steel > Type 304L stainless steel (worst). 108 refs., 31 figs., 7 tabs.

  9. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    International Nuclear Information System (INIS)

    This volume surveys the effects of welding on the degradation modes of three austenitic alloys: Types 304L and 316L stainless steels and Alloy 825. These materials are candidates for the fabrication of containers for the long-term storage of high-level nuclear waste. The metallurgical characteristics of fusion welds are reviewed here and related to potential degradation modes of the containers. Three specific areas are discussed in depth: (1) decreased resistance to corrosion in the forms of preferential corrosion, sensitization, and susceptibility to stress corrosion cracking, (2) hot cracking in the heat-affected zone and the weld zone, and (3) formation of intermetallic phases. The austenitic alloys are ranked as follows in terms of overall weldability: Alloy 825 (best) > Type 316L stainless steel > Type 304L stainless steel (worst). 108 refs., 31 figs., 7 tabs

  10. Titanium alloy corrosion in nuclear waste environments

    International Nuclear Information System (INIS)

    A corrosion study has been conducted on the titanium alloys Ti-50A, TiCode 12, and Ti-Pd to evaluate their suitability as a long lifetime (300 to 600 year) canister material for the isolation of nuclear wastes. TiCode 12, selected as the primary candidate material, is shown to be very resistant to environmental attack. Results of electrochemical, general corrosion, and stress corrosion cracking experiments are presented. These data, including those from severe overtests, have shown that TiCode 12 is a viable candidate material for long-term waste isolation. 17 figures

  11. Morphology of MgAl2O4 at interface between Al2O3 and matrix in oxide particles / Al alloy composite materials

    Czech Academy of Sciences Publication Activity Database

    Matsuda, K.; Matsuki, T.; Frank, Luděk; Müllerová, Ilona; Itoh, S.; Akatsu, M.; Uetani, Y.; Ikeno, S.

    Vol. 2. Liege : Belgian Society for Microscopy, 2004, s. 627-628. [EMC 2004 /13./ European Microscopy Congress. Antwerp (BE), 22.08.2004-27.08.2004] R&D Projects: GA ČR GA202/04/0281 Keywords : AJ-Mg-Si alloy * metal matrix composite * SLEEM Subject RIV: JI - Composite Materials

  12. Pressure dependence of magneto-structural properties of Co-doped offstoichiometric Ni.sub.2./sub.MnGa alloys

    Czech Academy of Sciences Publication Activity Database

    Kamarád, Jiří; Fabbrici, S.; Kaštil, Jiří; Albertini, F.; Arnold, Zdeněk; Righi, L.

    Les Ulis Cedex A: E D P SCIENCES, 2013, s. 11002. (EPJ Web of Conferences. vol. 40). ISSN 2100-014X. [Joint European Magnetic Symposia (JEMS) /6./. Parma (IT), 09.09.2012-14.09.2012] Institutional support: RVO:68378271 Keywords : magnetism in metals * alloys and intermetallics Subject RIV: BM - Solid Matter Physics ; Magnetism http://www.epj-conferences.org/

  13. Development of vanadium base alloys for fusion first-wall/blanket applications

    International Nuclear Information System (INIS)

    Vanadium alloys have been identified as a leading candidate material for fusion first-wall/blanket applications. Certain vanadium alloys exhibit favorable safety and environmental characteristics, good fabricability, high temperature and heat load capability, good compatibility with liquid metals and resistance to irradiation damage effects. The current focus is on vanadium alloys with (3-5)% Cr and (3-5)% Ti with a V-4Cr-4Ti alloy as the leading candidate. Preliminary results indicate that the crack-growth rates of certain alloys are not highly sensitive to irradiation. Results from the Dynamic Helium Charging Experiment (DHCE) which simulates fusion relevant helium/dpa ratios are similar to results from neutron irradiated material. This paper presents an overview of the recent results on the development of vanadium alloys for fusion first wall/blanket applications

  14. Processing of Refractory Metal Alloys for JOYO Irradiations

    Energy Technology Data Exchange (ETDEWEB)

    RF Luther; ME Petrichek

    2006-02-21

    This is a summary of the refractory metal processing experienced by candidate Prometheus materiats as they were fabricated into specimens destined for testing within the JOYO test reactor, ex-reactor testing at Oak Ridge National Laboratory (ORNL), or testing within the NRPCT. The processing is described for each alloy from the point of inception to the point where processing was terminated due to the cancellation of Naval Reactor's involvement in the Prometheus Project. The alloys included three tantalum-base alloys (T-111, Ta-10W, and ASTAR-811C), a niobium-base alloy, (FS-85), and two molybdenum-rhenium alloys, one containing 44.5 w/o rhenium, and the other 47.5 w/o rhenium. Each of these alloys was either a primary candidate or back-up candidate for cladding and structural applications within the space reactor. Their production was intended to serve as a forerunner for large scale production ingots that were to be procured from commercial refractory metal vendors such as Wah Chang.

  15. Processing of Refractory Metal Alloys for JOYO Irradiations

    International Nuclear Information System (INIS)

    This is a summary of the refractory metal processing experienced by candidate Prometheus materiats as they were fabricated into specimens destined for testing within the JOYO test reactor, ex-reactor testing at Oak Ridge National Laboratory (ORNL), or testing within the NRPCT. The processing is described for each alloy from the point of inception to the point where processing was terminated due to the cancellation of Naval Reactor's involvement in the Prometheus Project. The alloys included three tantalum-base alloys (T-111, Ta-10W, and ASTAR-811C), a niobium-base alloy, (FS-85), and two molybdenum-rhenium alloys, one containing 44.5 w/o rhenium, and the other 47.5 w/o rhenium. Each of these alloys was either a primary candidate or back-up candidate for cladding and structural applications within the space reactor. Their production was intended to serve as a forerunner for large scale production ingots that were to be procured from commercial refractory metal vendors such as Wah Chang

  16. Rapid Solidification Effects on the Development of an HCP Matrix in a Co-20Cr Alloy

    Science.gov (United States)

    Ramirez-Ledesma, A. L.; Lopez, H. F.; Juarez-Islas, J. A.

    2016-06-01

    In the present work, it is experimentally found that rapid solidification enhances significantly the γ-FCC → ɛ-HCP transformation by generating a high density of ɛ-martensite embryo nucleating defects in a Co-20Cr alloy. Conclusive evidence based on X-ray diffraction determinations combined with SEM and TEM observations indicates that the formation of athermal ɛ-martensite is strongly influenced by rapid solidification conditions ( i.e., up to 89.6 vol pct).

  17. Candidate gene prioritization with Endeavour.

    Science.gov (United States)

    Tranchevent, Léon-Charles; Ardeshirdavani, Amin; ElShal, Sarah; Alcaide, Daniel; Aerts, Jan; Auboeuf, Didier; Moreau, Yves

    2016-07-01

    Genomic studies and high-throughput experiments often produce large lists of candidate genes among which only a small fraction are truly relevant to the disease, phenotype or biological process of interest. Gene prioritization tackles this problem by ranking candidate genes by profiling candidates across multiple genomic data sources and integrating this heterogeneous information into a global ranking. We describe an extended version of our gene prioritization method, Endeavour, now available for six species and integrating 75 data sources. The performance (Area Under the Curve) of Endeavour on cross-validation benchmarks using 'gold standard' gene sets varies from 88% (for human phenotypes) to 95% (for worm gene function). In addition, we have also validated our approach using a time-stamped benchmark derived from the Human Phenotype Ontology, which provides a setting close to prospective validation. With this benchmark, using 3854 novel gene-phenotype associations, we observe a performance of 82%. Altogether, our results indicate that this extended version of Endeavour efficiently prioritizes candidate genes. The Endeavour web server is freely available at https://endeavour.esat.kuleuven.be/. PMID:27131783

  18. Empathy Development in Teacher Candidates

    Science.gov (United States)

    Boyer, Wanda

    2010-01-01

    Using a grounded theory research design, the author examined 180 reflective essays of teacher candidates who participated in a "Learning Process Project," in which they were asked to synthesize and document their discoveries about the learning process over the course of a completely new learning experience as naive learners. This study explored…

  19. Candidate Prediction Models and Methods

    DEFF Research Database (Denmark)

    Nielsen, Henrik Aalborg; Nielsen, Torben Skov; Madsen, Henrik;

    2005-01-01

    This document lists candidate prediction models for Work Package 3 (WP3) of the PSO-project called ``Intelligent wind power prediction systems'' (FU4101). The main focus is on the models transforming numerical weather predictions into predictions of power production. The document also outlines the...

  20. Translating VDM to Alloy

    DEFF Research Database (Denmark)

    Lausdahl, Kenneth

    2013-01-01

    specifications. However, to take advantage of the automated analysis of Alloy, the model-oriented VDM specifications must be translated into a constraint-based Alloy specifications. We describe how a sub- set of VDM can be translated into Alloy and how assertions can be expressed in VDM and checked by the Alloy...

  1. QSAR Study and VolSurf Characterization of Human Intestinal Absorption of Druge

    Institute of Scientific and Technical Information of China (English)

    胡桂香; 商志才; 等

    2003-01-01

    The prediction of human intestinal absorption is a major goal in the design,optimization,and selection of candidates for the develoment of oral drugs.In this study,a computerized method(VolSurf with GRID) was used as a novel tool for predicting human intestinal absorption of test compound,and for determining the critical molecular properties needed for human intestinal absorption.The tested molecules consisted of 20 diverse drug-like compounds.Partial least squares(PLS) discriminant analysis was used to correlate the experimental data with the theoretical molecular properties of human intestinal absorption.A good correlation(r2=0.95,q2=0.86) between the molecular modeling results and the experimental data demonstrated that human intestinal absorption could be predicted from the three-dimensional(3D) molecular structure of a compound .Favorable structureal properties identified for the potent intestinal absorption of drugs included strong imbalance between the center of mass of a molecule and the barycentre of its hydrophilic and hydrophobic regions and a definitive hydrophobic region as well as less hydrogen bonding donors and acceptors in the molecule.

  2. Proceedings of the Seventh Conference of Nuclear Sciences and Applications. Vol.1,2,3

    International Nuclear Information System (INIS)

    The publication has been set up as a textbook for nuclear sciences and applications vol.1: (1) radiochemistry; (2) radiation chemistry; (3) isotope production; (4) waste management; vol.2: (1) nuclear and reactor; (2) physics; (3) plasma physics; (4) instrumentation and devices; (5) trace and ultra trace analysis; (6) environmental; vol.3: (1) radiation protection; (2) radiation health hazards; (3) nuclear safety; (4) biology; (5) agriculture

  3. Microstructural characterization of dispersion-strengthened Cu-Ti-Al alloys obtained by reaction milling

    International Nuclear Information System (INIS)

    The microstructure, electrical conductivity and hot softening resistance of two alloys (G-10 and H-20), projected to attain Cu-2.5 vol.% TiC-2.5 vol.% Al2O3 nominal composition, and prepared by reaction milling and hot extrusion, were studied. The alloys were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and several chemical analysis techniques. The first alloy, G-10, showed the formation of Al2O3 nanodispersoids and the presence of particles from non-reacted raw materials (graphite, Ti and Al). A second alloy, H-20, was prepared employing different fabrication conditions. This alloy exhibited a homogeneous distribution of Al2O3 and Ti-Al-Fe nanoparticles, with the microstructure being stable after annealing and hot compression tests. These nanoparticles acted as effective pinning sites for dislocation slip and grain growth. The room-temperature hardness of the H-20 consolidated material (330 HV) was approximately maintained after annealing for 1 h at 1173 K; the electrical conductivity was 60% IACS (International Annealing Copper Standard)

  4. Compatibility of ITER candidate structural materials with static gallium

    International Nuclear Information System (INIS)

    Tests were conducted on the compatibility of gallium with candidate structural materials for the International Thermonuclear Experimental Reactor, e.g., Type 316 SS, Inconel 625, and Nb-5 Mo-1 Zr alloy, as well as Armco iron, Nickel 270, and pure chromium. Type 316 stainless steel is least resistant to corrosion in static gallium and Nb-5 Mo-1 Zr alloy is most resistant. At 400 degrees C, corrosion rates are ∼4.0, 0.5, and 0.03 mm/yr for type 316 SS, Inconel 625, and Nb-5 Mo- 1 Zr alloy, respectively. The pure metals react rapidly with gallium. In contrast to findings in earlier studies, pure iron shows greater corrosion than nickel. The corrosion rates at 400 degrees C are ≥88 and 18 mm/yr, respectively, for Armco iron and Nickel 270. The results indicate that at temperatures up to 400 degrees C, corrosion occurs primarily by dissolution and is accompanied by formation of metal/gallium intermetallic compounds. The solubility data for pure metals and oxygen in gallium are reviewed. The physical, chemical, and radioactive properties of gallium are also presented. The supply and availability of gallium, as well as price predictions through the year 2020, are summarized

  5. Corrosion Assessment of Candidate Materials for the SHINE Subcritical Assembly Vessel and Components FY15 Report

    Energy Technology Data Exchange (ETDEWEB)

    Pawel, Steven J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-01-01

    In the previous report of this series, a literature review was performed to assess the potential for substantial corrosion issues associated with the proposed SHINE process conditions to produce 99Mo. Following the initial review, substantial laboratory corrosion testing was performed emphasizing immersion and vapor-phase exposure of candidate alloys in a wide variety of solution chemistries and temperatures representative of potential exposure conditions. Stress corrosion cracking was not identified in any of the exposures up to 10 days at 80°C and 10 additional days at 93°C. Mechanical properties and specimen fracture face features resulting from slow-strain rate tests further supported a lack of sensitivity of these alloys to stress corrosion cracking. Fluid velocity was found not to be an important variable (0 to ~3 m/s) in the corrosion of candidate alloys at room temperature and 50°C. Uranium in solution was not found to adversely influence potential erosion-corrosion. Potentially intense radiolysis conditions slightly accelerated the general corrosion of candidate alloys, but no materials were observed to exhibit an annualized rate above 10 μm/y.

  6. Corrosion Assessment of Candidate Materials for the SHINE Subcritical Assembly Vessel and Components FY15 Report

    International Nuclear Information System (INIS)

    In the previous report of this series, a literature review was performed to assess the potential for substantial corrosion issues associated with the proposed SHINE process conditions to produce 99Mo. Following the initial review, substantial laboratory corrosion testing was performed emphasizing immersion and vapor-phase exposure of candidate alloys in a wide variety of solution chemistries and temperatures representative of potential exposure conditions. Stress corrosion cracking was not identified in any of the exposures up to 10 days at 80°C and 10 additional days at 93°C. Mechanical properties and specimen fracture face features resulting from slow-strain rate tests further supported a lack of sensitivity of these alloys to stress corrosion cracking. Fluid velocity was found not to be an important variable (0 to ∼3 m/s) in the corrosion of candidate alloys at room temperature and 50°C. Uranium in solution was not found to adversely influence potential erosion-corrosion. Potentially intense radiolysis conditions slightly accelerated the general corrosion of candidate alloys, but no materials were observed to exhibit an annualized rate above 10 μm/y.

  7. Unexpected magnetic behavior in amorphous Co90Sc10 alloy

    International Nuclear Information System (INIS)

    An amorphous alloy Co90Sc10 has been prepared by rapid quenching from the melt. The results of magnetization measurements show that this alloy has the highest Curie temperature reported for any amorphous transition metal based alloys. Furthermore, for a Co based amorphous alloy, the magnetic moment is remarkably high. Moreover, the alloy exhibits soft magnetic properties. Based on the findings, amorphous Co90Sc10 appears to be an attractive candidate for applications as a soft magnetic material. The temperature dependence of the reduced magnetization can be described by the Bloch power law. The results show that the B coefficient of the amorphous Co90Sc10 alloy, which is a measure of the rigidity of spin waves, exhibits the lowest value observed until now for any amorphous alloy and is comparable to crystalline alloys. It is found that the Sc atoms in the Co90Sc10 alloy lead to an increase of the itinerant spin moment of Co atoms, and, in contrast to this behaviour, to a decrease of the local 3d-electrons of Co

  8. Proceedings of the second international conference on environmental impact assessment of all economical activities. Vol. 3

    International Nuclear Information System (INIS)

    Proceedings of the conference consist of 3 volumes: Vol. 1 - 'Environmental Impact Assessment of all Economical Activities including Industry'; Vol. 2 - 'Air Pollution Control and Prevention'; Vol. 3 - Waste Management and Environmental Problems in Construction Industry'. Out of 39 papers contained in Vol. 3, 3 were inputted to INIS. They deal with the use of portable radioisotope X-ray fluorescence analyzers in the determination of building material contamination by toxic elements, with underground waste repositories and ground water contamination, and the impact of the Temelin nuclear power plant on the hydrosphere and other environmental components. (Z.S.)

  9. A quantitative assessment of microbiological contributions to corrosion of candidate nuclear waste package materials

    International Nuclear Information System (INIS)

    The US Department of Energy is contributing to the design of a potential nuclear waste repository at Yucca Mountain, Nevada. A system to predict the contribution of Yucca Mountain (YM) bacteria to overall corrosion rates of candidate waste package (WP) materials was designed and implemented. DC linear polarization resistance techniques were applied to candidate material coupons that had been inoculated with a mixture of YM-derived bacteria with potentially corrosive activities, or left sterile. Inoculated bacteria caused a 5- to 6-fold increase in corrosion rate of carbon steel C1020 (to approximately 7--8 microm/yr), and an almost 100-fold increase in corrosion rate of Alloy 400 (to approximately 1 microm/yr) was observed due to microbiological activities. Microbiologically Influenced Corrosion (MIC) rates on more resistant materials (CRMs: Alloy 625, Type 304 Stainless Steel, and Alloy C22) were on the order of hundredths of micrometers per year (microm/yr). Bulk chemical and surfacial endpoint analyses of spent media and coupon surfaces showed preferential dissolution of nickel from Alloy 400 coupons and depletion of chromium from CRMs after incubation with YM bacteria. Scanning electron microscopy also showed greater damage to the Alloy 400 surface than that indicated by electrochemical detection methods

  10. IAEA Director General candidates announced

    International Nuclear Information System (INIS)

    Full text: The IAEA today confirms receipt of the nomination of five candidates for Director General of the IAEA. Nominations of the following individuals have been received by the Chairperson of the IAEA Board of Governors, Ms. Taous Feroukhi: Mr. Jean-Pol Poncelet of Belgium; Mr. Yukiya Amano of Japan; Mr. Ernest Petric of Slovenia; Mr. Abdul Samad Minty of South Africa; and Mr. Luis Echavarri of Spain. The five candidates were nominated in line with a process approved by the Board in October 2008. IAEA Director General Mohamed ElBaradei's term of office expires on 30 November 2009. He has served as Director General since 1997 and has stated that he is not available for a fourth term of office. (IAEA)

  11. VALUE ORIENTATIONS OF TEACHER CANDIDATES

    OpenAIRE

    YAPICI, Asım; KUTLU, M.Oğuz; BİLİCAN, F.Işıl

    2012-01-01

    Abstract This cross-sectional, descriptive study examined the change in values in time among teacher candidates. The Schwartz Values Inventory was administered to 708 freshmen and senior students studying at Cukurova University, Education Faculty. The results have shown that the students at the department of Science Education valued power, achievement, stimulation; the department of English Teaching Education valued hedonism; and the department of Education of Religious Culture valued un...

  12. Alloyed steel

    International Nuclear Information System (INIS)

    The composition and properties are listed of alloyed steel for use in the manufacture of steam generators, collectors, spacers, emergency tanks, and other components of nuclear power plants. The steel consists of 0.08 to 0.11% w.w. C, 0.6 to 1.4% w.w. Mn, 0.35 to 0.6% w.w. Mo, 0.02 to 0.07% w.w. Al, 0.17 to 0.37% w.w. Si, 1.7 to 2.7% w.w. Ni, 0.03 to 0.07% w.w. V, 0.005 to 0.012% w.w. N, and the rest is Fe. The said steel showed a sufficiently low transition temperature between brittle and tough structures, a greater depth of hardenability, and better weldability than similar steels. (B.S.)

  13. Soil-structure interaction Vol.3. Influence of ground water

    International Nuclear Information System (INIS)

    This study has been performed for the Nuclear Regulatory Commission (NRC) by the Structural Analysis Division of Brookhaven National Laboratory (BNL). The study was conducted during the fiscal year 1965 on the program entitled 'Benchmarking of Structural Engineering Problems' sponsored by NRC. The program considered three separate but complementary problems, each associated with the soil-structure interaction (551) phase of the seismic response analysis of nuclear plant facilities. The reports, all entitled Soil-Structure Interaction, are presented in three separate volumes, namely: Vol. 1 Influence of Layering by AJ Philippacopoulos, Vol. 2 Influence of Lift-Off by C.A. Miller, Vol. 3 Influence of Ground Water by C.J. Costantino. The two problems presented in Volumes 2 and 3 were conducted at the City University of New York (CUNY) under subcontract to BNL. This report, Volume 3 of the report, presents a summary of the first year's effort on the subject of the influence of foundation ground water on the SSI phenomenon. A finite element computer program was developed for the two-phased formulation of the combined soil-water problem. This formulation is based on the Biot dynamic equations of motion for both the solid and fluid phases of a typical soil. Frequency dependent interaction coefficients were generated for the two-dimensional plane problem of a rigid surface footing moving against a saturated linear soil. The results indicate that interaction coefficients are significantly modified as compared to the comparable values for a dry soil, particularly for the rocking mode of response. Calculations were made to study the impact of the modified interaction coefficients on the response of a typical nuclear reactor building. The amplification factors for a stick model placed atop a dry and saturated soil were computed. It was found that pore water caused the rocking response to decrease and translational response to increase over the frequency range of interest, as

  14. Búsquedas en grandes volúmenes de datos

    OpenAIRE

    Britos, Luis; Di Gennaro, María E.; Gil Costa, Graciela Verónica; Kasián, Fernando; Lobos, Jair; Ludueña, Verónica; Molina, Romina; Printista, Alicia Marcela; Reyes, Nora Susana; Roggero, Patricia; Trabes, Guillermo

    2016-01-01

    En la actualidad los sistemas de información demandan no sólo poder realizar búsquedas eficientes sobre distintos tipos de datos, tales como texto libre, audio, video, secuencias de ADN, etc., sino también poder manejar grandes volúmenes de estos datos. Dada una consulta, el objetivo de un sistema de recuperación de información es obtener lo que podría ser útil o relevante para el usuario, usando una estructura de almacenamiento especialmente diseñada para responderla eficientemente. Nuest...

  15. Creep behaviour of candidate tubular ferritic oxide-dispersion-strengthened heat exchanger components

    Energy Technology Data Exchange (ETDEWEB)

    Rees, M. [Commission of the European Communities, Petten (Netherlands). Joint Research Centre; Hurst, R.C.; Healy, J.C.; Parker, J.D. [University Coll. of Swansea (United Kingdom)

    1996-11-01

    The circumferential creep behaviour of two ferritic oxide dispersion stengthened (Fe-ODS) alloys, MA 956 and ODM 751, was studied by subjecting tubular components to constant internal pressure at 1100 {sup o}C. The grain aspect ratio and grain size governed the creep strength of these materials. The mechanisms of creep failure were investigated by optical microscopy and transmission electron microscopy. In spite of the inferior creep properties in the hoop direction compared to the longitudinal direction, these initial results indicate that, with proper control of the microstructure, tubular Fe-ODS alloys could be considered as candidate materials for heat exchanger components operating at elevated temperatures. (Author)

  16. Selection of candidate container materials for the conceptual waste package design for a potential high level nuclear waste repository at Yucca Mountain

    Energy Technology Data Exchange (ETDEWEB)

    Van Konynenburg, R.A.; Halsey, W.G.; McCright, R.D.; Clarke, W.L. Jr. [Lawrence Livermore National Lab., CA (United States); Gdowski, G.E. [KMI, Inc., Albuquerque, NM (United States)

    1993-02-01

    Preliminary selection criteria have been developed, peer-reviewed, and applied to a field of 41 candidate materials to choose three alloys for further consideration during the advanced conceptual design phase of waste package development for a potential high level nuclear waste repository at Yucca Mountain, Nevada. These three alloys are titanium grade 12, Alloy C-4, and Alloy 825. These selections are specific to the particular conceptual design outlined in the Site Characterization Plan. Other design concepts that may be considered in the advanced conceptual design phase may favor other materials choices.

  17. Selection of candidate container materials for the conceptual waste package design for a potential high level nuclear waste repository at Yucca Mountain

    International Nuclear Information System (INIS)

    Preliminary selection criteria have been developed, peer-reviewed, and applied to a field of 41 candidate materials to choose three alloys for further consideration during the advanced conceptual design phase of waste package development for a potential high level nuclear waste repository at Yucca Mountain, Nevada. These three alloys are titanium grade 12, Alloy C-4, and Alloy 825. These selections are specific to the particular conceptual design outlined in the Site Characterization Plan. Other design concepts that may be considered in the advanced conceptual design phase may favor other materials choices

  18. Effects of the manufacturing process on fracture behaviour of cast TiAl intermetallic alloys

    OpenAIRE

    A. Brotzu; Felli, F.; D. Pilone

    2014-01-01

    The γ -TiAl based intermetallic alloys are interesting candidate materials for high-temperature applications with the efforts being directed toward the replacement of Ni-based superalloys. TiAl-based alloys are characterised by a density (3.5-4 g/cm3) which is less than half of that of Ni-based superalloys, and therefore these alloys have attracted broad attention as potential candidate for high-temperature structural applications. Specific composition/microstructure combinations should be ...

  19. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    International Nuclear Information System (INIS)

    Three copper-based alloys and three iron- to nickel-based austenitic alloys are being considered as possible materials for fabrication of high-level radioactive-waste disposal containers. The waste will include spent fuel assemblies from reactors as well as high-level waste in borosilicate glass and will be sent to the prospective site at Yucca Mountain, Nevada, for disposal. The copper-based alloy materials are CDA 102 (oxygen-free copper), CDA 613 (Cu-7Al), and CDA 715 (Cu-30Ni). The austenitic materials are Types 304L and 316L stainless steels and Alloy 825. The waste-package containers must maintain substantially complete containment for at least 300 yr and perhaps as long as 1000 yr, and they must be retrievable from the disposal site during the first 50 yr after emplacement. The containers will be exposed to high temperatures and high gamma radiation fields from the decay of high-level waste. This volume surveys the available data on the phase stability of both groups of candidate alloys. The austenitic alloys are reviewed in terms of the physical metallurgy of the iron-chromium-nickel system, martensite transformations, carbide formation, and intermetallic-phase precipitation. The copper-based alloys are reviewed in terms of their phase equilibria and the possibility of precipitation of the minor alloying constituents. For the austenitic materials, the ranking based on phase stability is: Alloy 825 (best), Type 316L stainless steel, and then Type 304L stainless steel (worst). For the copper-based materials, the ranking is: CDA 102 (oxygen-free copper) (best), and then both CDA 715 and CDA 613. 75 refs., 24 figs., 6 tabs

  20. Microstructural investigation of uranium rich U–Zr–Nb ternary alloy system

    Energy Technology Data Exchange (ETDEWEB)

    Ghoshal, Kaushik, E-mail: kghoshal@barc.gov.in; Kaity, Santu; Mishra, Sudhir; Kumar, Arun

    2014-03-15

    Uranium rich U–Zr–Nb alloy system is a potential candidate among the family of alloys considered as metallic fuel for fast reactors application. As a part of the program U–7% Zr, U–5% Zr–2% Nb, U–3.5% Zr–3.5% Nb, U–2% Zr–5% Nb and U–7% Nb (composition in wt.%) alloys were prepared. The total amount of Nb and Zr was restricted, because higher addition of non-fissile alloying element not only reduces the fissile content it also decreases the breeding ratio due to parasitic absorption. The alloys were characterized by SEM micrograph. The phase analysis was performed with the help of XRD and the phase transformation temperatures were determined by DTA. The variation in crystal structure with subsequent replacement of Zr with Nb as an alloying element has been highlighted. The as quenched U–7% Nb alloy shows complete γ° phase at ambient temperature.

  1. Microstructure and Mechanical Properties of Solution Heat-Treated Alloy 617 ODS Alloy

    International Nuclear Information System (INIS)

    Alloy 617 is a solution hardened Ni-based Superalloy containing Cr, Co, Mo, and Fe, and is among the best candidate materials for the key components of VHTR (Very High Temperature Reactor) system. As an alternative, Oxide Dispersion Strengthened (ODS) Ni-based superalloys, are known to possess superior high temperature mechanical properties and long-term high temperature microstructural stability due to the nano sized oxide dispersoids, which effectively hinder the dislocation motion at high temperature. This study is focused on the fabrication and characterization of nanosized oxide dispersion strengthened alloy 617. The influences of alloy composition and processing variables such as the content of Y2O3, hot extrusion ratio, and hydrogen reduction on the microstructure and mechanical properties were studied. From the analyses of microstructure of solution heat treated Alloy 617 ODS alloy specimens, a proper solid solution heat treatment temperature to reduce carbides is 1250 .deg. C. The major phases present in the alloy 617 ODS were found to be M23C6 and Al-O

  2. ECONOMICS OF ALEXANDER THE GREAT (15 vols + 4 cdroms) by Gregory Zorzos

    OpenAIRE

    Gregory Zorzos

    2002-01-01

    Research contains many ancient texts (Ancient Greek, Hebrews, Hieroglyphs, Assyrian, Sumerian, Babylonian, Latin, etc.). 1. (MICRO-MACRO ECONOMICS OF ALEXANDER THE GREAT (5 vols + cdrom). Microeconomics and macroeconomics of Alexander the Great. Economic theories, feasibilities, economic plannings, general description of the campaign's business plan etc. 2. BANKS OF ALEXANDER THE GREAT (2 vols + cdrom) Describes banking system, economists, financiers, investors, accountants, bookkeepers, etc,...

  3. Index to Nuclear Safety. A technical progress review by chronology, permuted title, and author. Vol. 11, No. 1--Vol. 17, No. 6

    International Nuclear Information System (INIS)

    This index to Nuclear Safety covers articles in Nuclear Safety Vol. 11, No. 1 (Jan.-Feb. 1970), through Vol. 17, No. 6 (Nov.-Dec. 1976). The index includes a chronological list of articles (including abstract) followed by KWIC and Author Indexes. Nuclear Safety, a bimonthly technical progress review prepared by the Nuclear Safety Information Center, covers all safety aspects of nuclear power reactors and associated facilities. The index lists over 350 technical articles in the last six years of publication

  4. Index to Nuclear Safety. A technical progress review by chronology, permuted title, and author. Vol. 11, No. 1--Vol. 17, No. 6

    Energy Technology Data Exchange (ETDEWEB)

    Cottrell, W.B.; Klein, A.

    1977-02-23

    This index to Nuclear Safety covers articles in Nuclear Safety Vol. 11, No. 1 (Jan.-Feb. 1970), through Vol. 17, No. 6 (Nov.-Dec. 1976). The index includes a chronological list of articles (including abstract) followed by KWIC and Author Indexes. Nuclear Safety, a bimonthly technical progress review prepared by the Nuclear Safety Information Center, covers all safety aspects of nuclear power reactors and associated facilities. The index lists over 350 technical articles in the last six years of publication.

  5. Oxidation and volatilization of a niobium alloy

    International Nuclear Information System (INIS)

    This report presents the findings from a preliminary investigation into oxidation and volatilization characteristics of a niobium alloy. Niobium is a candidate alloy for use in plasma facing components (PFCS) in experimental fusion reactors like the Intemational Thermonuclear Experimental Reactor (ITER). An experimental alloy was tailored to simulate small changes in chemistry which could result from transmutations from irradiation. The alloy was exposed in air and steam between 800 degree C and 1200 degree C. Volatilized products and hydrogen were collected and measured. Post-test examinations were also performed on the samples to determine the amount of material loss during the exposures. The obtained measurements of volatilization flux (g/m2-s), hydrogen generation rates (liters/m2-s), and recession rates (mm/s) are data which can be used for safety analyses and material performance to predict consequences which may result from an accident involving the ingress of air or steam into the plasma chamber of fusion reactor. In our volatility tests, only molybdenum and niobium were found at release levels above the detection limit. Although molybdenum is present at only 0.12 wt%, the quantities of this element volatilized in air are nearly comparable to the quantities of niobium released. The niobium release in steam is only three to four times higher than that of molybdenum in steam. The hydrogen production of the niobium alloy is compared with other PFC materials that we have tested, specifically, beryllium, graphite, and a tunesten alloy. At high temperatures, the hydrogen production rate of the niobium alloy is among the lowest of these materials, significantly lower than beryllium. To understand what this means in an accident situation, modeling is necessary to predict temperatures, and therefore total hydrogen production. The INEL is currently doing this modeling

  6. Evaluation of the austenitic alloys 304L, 316L, and alloy 825 under Tuff repository conditions

    International Nuclear Information System (INIS)

    Austenitic alloys 304L and 316L and stainless steel 825 were investigated as candidate materials for containers for waste disposal in the relatively benign conditions of the Yucca Mountain site. In this vault there will be very little water, and what there is will contain small amounts of chlorides, nitrates, sulphates and carbonates. The radiation fields will be 104 rad/h initially, but will decay to low levels by the end of the containment period. The initial temperature will be around 250 C, and it will remain above the boiling point of water for the containment period (approximately 300 years). There will be no lithostatic or hydrostatic pressure. Type 304L stainless steel is a base case material used in comparisons with other candidates. Type 316L stainless steel possesses enhanced resistance to sensitization and localized corrosion; alloy 825 is stabilized to have a much better resistance to sensitization and localized corrosion and performs better in chloride environments

  7. Interaction of alumina with liquid Pb83Li17 alloy

    International Nuclear Information System (INIS)

    Highlights: • The role of oxygen in the interaction of alumina with Pb83Li17 alloy was studied. • Li of Pb83Li17 alloy undergoes oxidation even in flowing high pure argon atmosphere. • It was seen that alumina reacts with Pb83Li17 alloy at 550 °C to form LiAlO2 compound. • The reaction is rapid in the presence of oxygen and happens more slowly in the presence of flowing argon. - Abstract: Eutectic lead lithium (Pb83Li17) alloy is being considered a coolant, neutron multiplier and tritium breeder for International Thermonuclear Experimental Reactor (ITER) and Fusion Power Reactors (FPR). In order to reduce the magneto-hydrodynamic drag (MHD) and to prevent corrosion of structural materials due to the flow of lead lithium (Pb83Li17) alloy, alumina (Al2O3) is proposed as a candidate ceramic coating material. Interaction of liquid Pb83Li17 alloy with Al2O3 at the operating temperature of these reactors is therefore an important issue. The present paper deals with the characterization of Pb83Li17 alloy and its interaction with Al2O3 at the reactor operating temperature. The interaction was studied using EPMA, XRD and thermal analysis technique. The result indicates that alumina can interact with Pb83Li17 alloy at 550 °C even in high purity argon atmosphere. The role of oxygen in the interaction process has also been discussed

  8. Alloy Fabrication Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — At NETL’s Alloy Fabrication Facility in Albany, OR, researchers conduct DOE research projects to produce new alloys suited to a variety of applications, from gas...

  9. Charpy impact test results of four low activation ferritic alloys irradiated at 370 degrees C to 15 DPA

    International Nuclear Information System (INIS)

    Miniature CVN specimens of four low activation ferritic alloys have been impact tested following irradiation at 370 degrees C to 15 dpa. Comparison of the results with those of control specimens indicates that degradation in the impact behavior occurs in each of these four alloys. The 9Cr-2W alloy referred to as GA3X and the similar alloy F82H with 7.8Cr-2W appear most promising for further consideration as candidate structural materials in fusion energy system applications. These two alloys exhibit a small DBTT shift to higher temperatures but show increased absorbed energy on the upper shelf

  10. Charpy impact test results of four low activation ferritic alloys irradiated at 370{degrees}C to 15 DPA

    Energy Technology Data Exchange (ETDEWEB)

    Schubert, L.E.; Hamilton, M.L.; Gelles, D.S. [Pacific Northwest National Lab., Richland, WA (United States)

    1996-10-01

    Miniature CVN specimens of four low activation ferritic alloys have been impact tested following irradiation at 370{degrees}C to 15 dpa. Comparison of the results with those of control specimens indicates that degradation in the impact behavior occurs in each of these four alloys. The 9Cr-2W alloy referred to as GA3X and the similar alloy F82H with 7.8Cr-2W appear most promising for further consideration as candidate structural materials in fusion energy system applications. These two alloys exhibit a small DBTT shift to higher temperatures but show increased absorbed energy on the upper shelf.

  11. Promising new cryogenic seal candidate

    International Nuclear Information System (INIS)

    Of the five seal candidates considered for the main propellant system of the Space Shuttle, only one candidate, the fluoroplastic Halar, satisfied all tests including the critical LO2 impact test and the cryogenic compression sealability test. Radiation-cross-linked Halar is a tough, strong thermoplastic that not only endured one hundred 2200 N compression cycles at 83 K while mounted in a standard military O-ring gland without cracking or deforming, but improved in sealability as a result of this cycling. Although these Halar O-rings require much higher sealing forces (approximately 500 N) at room temperature than rubber O-rings, on cooling to cryogenic temperatures the required sealing force only doubles, whereas the sealing force for rubber O-rings increases eightfold. Although these Halar O-rings were inadequately cross-linked, they still exhibited promise as LO2-compatible cryogenic seals. It is expected that their high-temperature properties can be greatly improved by higher degrees of cross-linking (e.g., by 20 mrad of radiation) without compromising their already excellent low-temperature properties. A direct comparison should then be obtained between the best of the cross-linked Halar compounds and the current commercial cryogenic seal materials, filled Teflon and Kel-F

  12. Nickel-Titanium Alloys: Corrosion "Proof" Alloys for Space Bearing, Components and Mechanism Applications

    Science.gov (United States)

    DellaCorte, Christopher

    2010-01-01

    An intermetallic nickel-titanium alloy, 60NiTi (60 wt% Ni, 40 wt% Ti), is shown to be a promising candidate tribological material for space mechanisms. 60NiTi offers a broad combination of physical properties that make it unique among bearing materials. 60NiTi is hard, electrically conductive, highly corrosion resistant, readily machined prior to final heat treatment, and is non-magnetic. Despite its high Ti content, 60NiTi is non-galling even under dry sliding. No other bearing alloy, metallic or ceramic, encompasses all of these attributes. Since 60NiTi contains such a high proportion of Ti and possesses many metallic properties, it was expected to exhibit poor tribological performance typical of Ti alloys, namely galling type behavior and rapid lubricant degradation. In this poster-paper, the oil-lubricated behavior of 60NiTi is presented.

  13. Thermal coatings for titanium-aluminum alloys

    Science.gov (United States)

    Cunnington, George R.; Clark, Ronald K.; Robinson, John C.

    1993-01-01

    Titanium aluminides and titanium alloys are candidate materials for use in hot structure and heat-shield components of hypersonic vehicles because of their good strength-to-weight characteristics at elevated temperature. However, in order to utilize their maximum temperature capability, they must be coated to resist oxidation and to have a high total remittance. Also, surface catalysis for recombination of dissociated species in the aerodynamic boundary layer must be minimized. Very thin chemical vapor deposition (CVD) coatings are attractive candidates for this application because of durability and very light weight. To demonstrate this concept, coatings of boron-silicon and aluminum-boron-silicon compositions were applied to the titanium-aluminides alpha2 (Ti-14Al-21Nb), super-alpha2 (Ti-14Al-23-Nb-2V), and gamma (Ti-33Al-6Nb-1Ta) and to the titanium alloy beta-21S (Ti-15Mo-3Al-3Nb-0.2Si). Coated specimens of each alloy were subjected to a set of simulated hypersonic vehicle environmental tests to determine their properties of oxidation resistance, surface catalysis, radiative emittance, and thermal shock resistance. Surface catalysis results should be viewed as relative performance only of the several coating-alloy combinations tested under the specific environmental conditions of the LaRC Hypersonic Materials Environmental Test System (HYMETS) arc-plasma-heated hypersonic wind tunnel. Tests were also conducted to evaluate the hydrogen transport properties of the coatings and any effects of the coating processing itself on fatigue life of the base alloys. Results are presented for three types of coatings, which are as follows: (1) a single layer boron silicon coating, (2) a single layer aluminum-boron-silicon coating, and (3) a multilayer coating consisting of an aluminum-boron-silicon sublayer with a boron-silicon outer layer.

  14. Investigation on different oxides as candidates for nano-sized ODS particles in reduced-activation ferritic (RAF) steels

    Science.gov (United States)

    Hoffmann, Jan; Rieth, Michael; Lindau, Rainer; Klimenkov, Michael; Möslang, Anton; Sandim, Hugo Ricardo Zschommler

    2013-11-01

    Future generation reactor concepts are based on materials that can stand higher temperatures and higher neutron doses in corrosive environments. Oxide dispersion strengthened steels with chromium contents ranging from 9 to 14 wt.% - produced by mechanical alloying - are typical candidate materials for future structural materials in fission and fusion power plants.

  15. Terbium base alloy

    International Nuclear Information System (INIS)

    Composition of terbium-5-7 % gadolinium alloy with high magnetostriction sensitivity (180x10-8 Oe) is suggested. The alloy is designed for usage under cryogenic temperature within 500-1500 Oe fields. Magnetostriction sensitivity of the suggested alloy is by 2-2.5 times higher, than that of well-known before one. 1 tab

  16. Charpy impact test results for low activation ferritic alloys irradiated to 30 dpa

    Energy Technology Data Exchange (ETDEWEB)

    Schubert, L.E.; Hamilton, M.L.; Gelles, D.S. [Pacific Northwest National Laboratory, Richland, WA (United States)

    1996-04-01

    Miniature specimens of six low activation ferritic alloys have been impact field tested following irradiation at 370{degrees}C to 30 dpa. Comparison of the results with those of control specimens and specimens irradiated to 10 dpa indicates that degradation in the impact behavior appears to have saturated by {approx}10 dpa in at least four of these alloys. The 7.5Cr-2W alloy referred to as GA3X appears most promising for further consideration as a candidate structural material in fusion reactor applications, although the 9Cr-1V alloy may also warrant further investigation.

  17. Comparative study on the corrosion behavior of the cold rolled and hot rolled low-alloy steels containing copper and antimony in flue gas desulfurization environment

    Science.gov (United States)

    Park, S. A.; Kim, J. G.; He, Y. S.; Shin, K. S.; Yoon, J. B.

    2014-12-01

    The correlation between the corrosion and microstructual characteristics of cold rolled and hot rolled low-alloy steels containing copper and antimony was established. The corrosion behavior of the specimens used in flue gas desulfurization systems was examined by electrochemical and weight loss measurements in an aggressive solution of 16.9 vol % H2SO4 + 0.35 vol % HCl at 60°C, pH 0.3. It has been shown that the corrosion rate of hot rolled steel is lower than that of cold rolled steel. The corrosion rate of cold rolled steel was increased by grain refinement, inclusion formation, and preferred grain orientation.

  18. Creep behavior of a dispersion-strengthened Cu-Ti-Al alloy obtained by reaction milling

    International Nuclear Information System (INIS)

    Creep results of a dispersion-strengthened nominal-composition Cu-2.5 vol.%Ti-2.5 vol.%Al alloy, and the adjustment of those results to existing creep models, are presented. The alloy was prepared by reaction milling; its microstructural characterization by transmission electron microscopy had been recently reported elsewhere. Creep tests were here performed at 773, 973 and 1123 K, under loads that produced steady-state creep rates between 9 x 10-7 and 2 x 10-4 s-1. Two deformation models, available in the literature, were considered: dislocation creep, where the strain rate is controlled by the dislocation-particle interaction within the grains, and diffusional creep, controlled by the interaction between grain-boundary dislocations and particles. In all creep experiments the alloy exhibited high values of the apparent stress exponent, as typical for dispersion-strengthened alloys. Through model adjustment, the operating creep mechanisms where determined: at 773 and 1123 K, creep is controlled by dislocation/particle interactions taking place in the matrix and in grain boundaries, respectively, while at the intermediate temperature of 973 K, controlling dislocation-particle interactions would occur both in the matrix and in grain boundaries

  19. Preparation and mechanical properties of in situ TiCx–Ni (Si, Ti) alloy composites

    International Nuclear Information System (INIS)

    Novel in situ TiCx reinforced Ni (Si, Ti) alloy composites with superior mechanical properties were prepared at 1250 °C for 30 min by pressureless sintering Ti3SiC2 (10 and 20 vol%) and Ni as precursors. The Ti3SiC2 particles decomposed into substoichiometric TiCx phase, while the additional Si and partial Ti atoms derived from Ti3SiC2 diffused into Ni matrix to form Ni (Si, Ti) alloy. The in situ formed TiCx phases are mainly dispersed on the grain boundaries of the Ni (Si, Ti) alloying, forming a strong skeleton and refining the microstructures of the metal matrix. The hardness, the yield stress σ0.2% and ultimate compressive strength of 20.6 vol%TiCx–Ni(Si, Ti) composite can reach 2.15±0.04 GPa, 466.8±55.8 MPa and 733.3±78.4 MPa, respectively. The enhanced mechanical properties of TiCx–Ni(Si, Ti) composites are due to the in situ formation of TiCx skeleton, the refined microstructures of Ni (Si, Ti) alloys and solid solution effects as well as good wettability between TiCx and Ni (Si, Ti) matrix

  20. F-Alloy: An Alloy Based Model Transformation Language

    OpenAIRE

    Gammaitoni, Loïc; Kelsen, Pierre

    2015-01-01

    Model transformations are one of the core artifacts of a model-driven engineering approach. The relational logic language Alloy has been used in the past to verify properties of model transformations. In this paper we introduce the concept of functional Alloy modules. In essence a functional Alloy module can be viewed as an Alloy module representing a model transformation. We describe a sublanguage of Alloy called F-Alloy that allows the specification of functional Alloy modules. Module...

  1. Study on corrosion behavior of candidate materials in 650℃ supercritical water

    International Nuclear Information System (INIS)

    The general corrosion behavior of three candidate materials (347, HR3C and In-718) was investigated in 650 ℃/25 MPa deionized water. Morphology and composition of the surface oxide film with different exposure time were observed through FEG-SEM and EDS. The phase constitute was analyzed by GIXRD. For all the test materials, the weight loss follows typical parabolic law and the weight loss of 347 shows more than 40 times higher than that of HR3C and In-718. The oxide film of three alloys mainly consists of Ni(Cr, Fe)2O4. In-718 shows severe pitting and the oxide film of 347 appears significant spalling, while HR3C has compact oxide film. In the high temperature supercritical water, the high Cr content may enhance the general corrosion property of the alloys, while addition of Nb may be detrimental to the pitting resistance of alloys. (authors)

  2. Influence of Particulate Reinforcement and Equal-Channel Angular Pressing on Fatigue Crack Growth of an Aluminum Alloy

    OpenAIRE

    Lisa Köhler; Kristin Hockauf; Thomas Lampke

    2015-01-01

    The fatigue crack growth behavior of unreinforced and particulate reinforced Al 2017 alloy, manufactured by powder metallurgy and additional equal-channel angular pressing (ECAP), is investigated. The reinforcement was done with 5 vol % Al2O3 particles with a size fraction of 0.2–2 µm. Our study presents the characterization of these materials by electron microscopy, tensile testing, and fatigue crack growth measurements. Whereas particulate reinforcement leads to a drastic decrease of the gr...

  3. Effect of Sc2O3 particles on the microstructure and properties of tungsten alloy prepared by spark plasma sintering

    International Nuclear Information System (INIS)

    Highlights: • Effect of Sc2O3 on microstructure and properties of tungsten alloy were studied. • Sc2O3 significantly refined the grain size and increased the density of tungsten alloy. • The tensile strength values of the W–2 vol%Sc2O3 samples were higher than the others. - Abstract: W–Sc2O3 composite powders (W, W–0.5 vol%Sc2O3, and W–2 vol%Sc2O3) doped with highly uniform Sc2O3 particles were successfully synthesized by mechanical alloying followed by hydrogen reduction with Sc2O3 and WO3 powders. The reduced powders were then consolidated by spark plasma sintering at 1700 °C to suppress grain growth during sintering. Field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, and high-resolution transmission electron microscopy analyses, as well as tensile tests and thermal conductivity measurements, were used to characterize the samples. The results showed that the Sc2O3 particles were uniformly distributed in the tungsten grains and grain boundaries. The W–2vol%Sc2O3 composite possess the best relative density and Vickers micro-hardness up to 98.6% and 683.2 Hv, respectively. The Sc2O3 particles significantly refine the grain size and increase the density of tungsten alloy. With increased Sc2O3 content, the thermal conductivity decreased while tensile strength of the samples respectively increased at 700 and 800 °C

  4. Stress corrosion cracking of candidate waste container materials

    International Nuclear Information System (INIS)

    Six alloys have been selected as candidate container materials for the storage of high-level nuclear waste at the proposed Yucca Mountain site in Nevada. These materials are Type 304L stainless steel (SS), Type 316L SS, Incology 825, P-deoxidized Cu, Cu-30%Ni, and Cu-7% Al. The present program has been initiated to determine whether any of these materials can survive for 300 years in the site environment without developing through-wall stress corrosion cracks, and to assess the relative resistance of these materials to stress corrosion cracking (SCC). A series of slow-strain-rate tests (SSRTs) in simulated Well J-13 water which is representative of the groundwater present at the Yucca Mountain site has been completed, and crack-growth-rate (CGR) tests are also being conducted under the same environmental conditions. 13 refs., 60 figs., 22 tabs

  5. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    International Nuclear Information System (INIS)

    Three copper-based alloys, CDA 102 (oxygen-free copper), CDA 613 (Cu-7Al), and CDA 715 (Cu-30Ni), are being considered along with three austenitic candidates as possible materials for fabrication of containers for disposal of high-level radioactive waste. The waste will include spent fuel assemblies from reactors as well as high-level reprocessing wastes in borosilicate glass and will be sent to the prospective repository at Yucca Mountain, Nevada, for disposal. The containers must maintain mechanical integrity for 50 yr after emplacement to allow for retrieval of waste during the preclosure phase of repository operation. Containment is required to be substantially complete for up to 300 to 1000 yr. During the early period, the containers will be exposed to high temperatures and high gamma radiation fields from the decay of high-level waste. The final closure joint will be critical to the integrity of the containers. This volume surveys the available data on the metallurgy of the copper-based candidate alloys and the welding techniques employed to join these materials. The focus of this volume is on the methods applicable to remote-handling procedures in a hot-cell environment with limited possibility of postweld heat treatment. The three copper-based candidates are ranked on the basis of the various closure techniques. On the basis of considerations regarding welding, the following ranking is proposed for the copper-based alloys: CDA 715 (best) > CDA 102 > CDA 613 (worst). 49 refs., 15 figs., 1 tab

  6. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    Energy Technology Data Exchange (ETDEWEB)

    Bullen, D.B.; Gdowski, G.E. (Science and Engineering Associates, Inc., Pleasanton, CA (USA)); Weiss, H. (Lawrence Livermore National Lab., CA (USA))

    1988-06-01

    Three copper-based alloys, CDA 102 (oxygen-free copper), CDA 613 (Cu-7Al), and CDA 715 (Cu-30Ni), are being considered along with three austenitic candidates as possible materials for fabrication of containers for disposal of high-level radioactive waste. The waste will include spent fuel assemblies from reactors as well as high-level reprocessing wastes in borosilicate glass and will be sent to the prospective repository at Yucca Mountain, Nevada, for disposal. The containers must maintain mechanical integrity for 50 yr after emplacement to allow for retrieval of waste during the preclosure phase of repository operation. Containment is required to be substantially complete for up to 300 to 1000 yr. During the early period, the containers will be exposed to high temperatures and high gamma radiation fields from the decay of high-level waste. The final closure joint will be critical to the integrity of the containers. This volume surveys the available data on the metallurgy of the copper-based candidate alloys and the welding techniques employed to join these materials. The focus of this volume is on the methods applicable to remote-handling procedures in a hot-cell environment with limited possibility of postweld heat treatment. The three copper-based candidates are ranked on the basis of the various closure techniques. On the basis of considerations regarding welding, the following ranking is proposed for the copper-based alloys: CDA 715 (best) > CDA 102 > CDA 613 (worst). 49 refs., 15 figs., 1 tab.

  7. Exercises in diagnostic radiology. Vol. 1. 3. ed.

    International Nuclear Information System (INIS)

    The book contains a vast number of exercises to deepen the reader's knowledge in radiology. It should be used towards the end of medical training, e.g. by interns or students just arriving at intern stage, for self-testing and as a supplement to lectures and textbooks. Some knowledge of radiology of the chest is required for the exercises in Vol. 1. The descriptions of cases have been compiled on this basis. Alternatingly easy and difficult exercises are presented, so that the reader may regard errors as an incentive and success as an encouragement. The cases are as varied as an intern may encounter them every night on a night ward. (orig./HP)

  8. volBrain: An Online MRI Brain Volumetry System.

    Science.gov (United States)

    Manjón, José V; Coupé, Pierrick

    2016-01-01

    The amount of medical image data produced in clinical and research settings is rapidly growing resulting in vast amount of data to analyze. Automatic and reliable quantitative analysis tools, including segmentation, allow to analyze brain development and to understand specific patterns of many neurological diseases. This field has recently experienced many advances with successful techniques based on non-linear warping and label fusion. In this work we present a novel and fully automatic pipeline for volumetric brain analysis based on multi-atlas label fusion technology that is able to provide accurate volumetric information at different levels of detail in a short time. This method is available through the volBrain online web interface (http://volbrain.upv.es), which is publically and freely accessible to the scientific community. Our new framework has been compared with current state-of-the-art methods showing very competitive results. PMID:27512372

  9. Componentes volátiles de mamey (mammea americana L.

    Directory of Open Access Journals (Sweden)

    Alicia Lucía Morales

    2010-07-01

    Full Text Available Los componentes volátiles del aroma de mamey (Mammea americana L, fueron extraídos utilizando el método de destilación por arrastre con vapor-extracción simultánea con solvente orgánico. El extracto fue prefraccionado por cromatografía en columna en silica gel con gradiente discontinuo Pentano: Éter etílico para obtener tres fracciones que fueron analizadas por CGAR y CGAR-EM. Se detectaron 34 compuestos, de los cuales fueron identificados 22, siendo los componentes mayoritarios: Furfural (7281 ^ig/kg y E-Famesol (2145 ng/kg

  10. volBrain: An Online MRI Brain Volumetry System

    Science.gov (United States)

    Manjón, José V.; Coupé, Pierrick

    2016-01-01

    The amount of medical image data produced in clinical and research settings is rapidly growing resulting in vast amount of data to analyze. Automatic and reliable quantitative analysis tools, including segmentation, allow to analyze brain development and to understand specific patterns of many neurological diseases. This field has recently experienced many advances with successful techniques based on non-linear warping and label fusion. In this work we present a novel and fully automatic pipeline for volumetric brain analysis based on multi-atlas label fusion technology that is able to provide accurate volumetric information at different levels of detail in a short time. This method is available through the volBrain online web interface (http://volbrain.upv.es), which is publically and freely accessible to the scientific community. Our new framework has been compared with current state-of-the-art methods showing very competitive results.

  11. High strength alloys

    Energy Technology Data Exchange (ETDEWEB)

    Maziasz, Phillip James; Shingledecker, John Paul; Santella, Michael Leonard; Schneibel, Joachim Hugo; Sikka, Vinod Kumar; Vinegar, Harold J.; John, Randy Carl; Kim, Dong Sub

    2012-06-05

    High strength metal alloys are described herein. At least one composition of a metal alloy includes chromium, nickel, copper, manganese, silicon, niobium, tungsten and iron. System, methods, and heaters that include the high strength metal alloys are described herein. At least one heater system may include a canister at least partially made from material containing at least one of the metal alloys. At least one system for heating a subterranean formation may include a tublar that is at least partially made from a material containing at least one of the metal alloys.

  12. High strength alloys

    Energy Technology Data Exchange (ETDEWEB)

    Maziasz, Phillip James [Oak Ridge, TN; Shingledecker, John Paul [Knoxville, TN; Santella, Michael Leonard [Knoxville, TN; Schneibel, Joachim Hugo [Knoxville, TN; Sikka, Vinod Kumar [Oak Ridge, TN; Vinegar, Harold J [Bellaire, TX; John, Randy Carl [Houston, TX; Kim, Dong Sub [Sugar Land, TX

    2010-08-31

    High strength metal alloys are described herein. At least one composition of a metal alloy includes chromium, nickel, copper, manganese, silicon, niobium, tungsten and iron. System, methods, and heaters that include the high strength metal alloys are described herein. At least one heater system may include a canister at least partially made from material containing at least one of the metal alloys. At least one system for heating a subterranean formation may include a tubular that is at least partially made from a material containing at least one of the metal alloys.

  13. Corrosion considerations of high-nickel alloys and titanium alloys for high-level radioactive waste disposal containers

    Energy Technology Data Exchange (ETDEWEB)

    Gdowski, G.E.; McCright, R.D.

    1991-07-01

    Corrosion resistant materials are being considered for the metallic barrier of the Yucca Mountain Project`s high-level radioactive waste disposal containers. High nickel alloys and titanium alloys have good corrosion resistance properties and are considered good candidates for the metallic barrier. The localized corrosion phenomena, pitting and crevice corrosion, are considered as potentially limiting for the barrier lifetime. An understanding of the mechanisms of localized corrosion of how various parameters affect it will be necessary for adequate performance assessments of candidate container materials. Examples of some of the concerns involving candidate container materials. Examples of some of the concerns of involving localized corrosion are discussed. The effects of various parameters, such as temperature and concentration of halide species, on localized corrosion are given. In addition concerns about aging of the protective oxide layer in the expected service temperature range (50 to 250{degrees}C) are presented. Also some mechanistic considerations of localized corrosion are given. 31 refs., 1 tab.

  14. Corrosion considerations of high-nickel alloys and titanium alloys for high-level radioactive waste disposal containers

    International Nuclear Information System (INIS)

    Corrosion resistant materials are being considered for the metallic barrier of the Yucca Mountain Project's high-level radioactive waste disposal containers. High nickel alloys and titanium alloys have good corrosion resistance properties and are considered good candidates for the metallic barrier. The localized corrosion phenomena, pitting and crevice corrosion, are considered as potentially limiting for the barrier lifetime. An understanding of the mechanisms of localized corrosion of how various parameters affect it will be necessary for adequate performance assessments of candidate container materials. Examples of some of the concerns involving candidate container materials. Examples of some of the concerns of involving localized corrosion are discussed. The effects of various parameters, such as temperature and concentration of halide species, on localized corrosion are given. In addition concerns about aging of the protective oxide layer in the expected service temperature range (50 to 250 degrees C) are presented. Also some mechanistic considerations of localized corrosion are given. 31 refs., 1 tab

  15. Biocompatibility of dental alloys

    Energy Technology Data Exchange (ETDEWEB)

    Braemer, W. [Heraeus Kulzer GmbH and Co. KG, Hanau (Germany)

    2001-10-01

    Modern dental alloys have been used for 50 years to produce prosthetic dental restorations. Generally, the crowns and frames of a prosthesis are prepared in dental alloys, and then veneered by feldspar ceramics or composites. In use, the alloys are exposed to the corrosive influence of saliva and bacteria. Metallic dental materials can be classified as precious and non-precious alloys. Precious alloys consist of gold, platinum, and small amounts of non-precious components such as copper, tin, or zinc. The non-precious alloys are based on either nickel or cobalt, alloyed with chrome, molybdenum, manganese, etc. Titanium is used as Grade 2 quality for dental purposes. As well as the dental casting alloys, high purity electroplated gold (99.8 wt.-%) is used in dental technology. This review discusses the corrosion behavior of metallic dental materials with saliva in ''in vitro'' tests and the influence of alloy components on bacteria (Lactobacillus casei and Streptococcus mutans). The test results show that alloys with high gold content, cobalt-based alloys, titanium, and electroplated gold are suitable for use as dental materials. (orig.)

  16. Compatibility of ITER candidate materials with static gallium

    International Nuclear Information System (INIS)

    Corrosion tests have been conducted to determine the compatibility of gallium with candidate structural materials for the International Thermonuclear Experimental Reactor (ITER) first wall/blanket systems, e.g., Type 316 stainless steel (SS), Inconel 625, and Nb-5 Mo-1 Zr. The results indicate that Type 316 SS is least resistant to corrosion in static gallium and Nb-5 Mo-1 Zr alloy is most resistant. At 400 C, corrosion rates for Type 316 SS, Inconel 625, and Nb-5 Mo-1 Zr alloy are ∼ 4.0, 0.5, and 0.03 mm/yr, respectively. Iron, nickel, and chromium react rapidly with gallium. Iron shows greater corrosion than nickel at 400 C (≥ 88 and 18 mm/yr, respectively). The present study indicates that at temperatures up to 400 C, corrosion occurs primarily by dissolution and is accompanied by formation of metal/gallium intermetallic compounds. The growth of intermetallic compounds may control the overall rate of corrosion

  17. Anodic behavior of alloy 22 in bicarbonate containing media: Effect of alloying

    International Nuclear Information System (INIS)

    Alloy 22 is one of the candidates for the manufacture of high level nuclear waste containers. These containers provide services in natural environments characterized by multi-ionic solutions.It is estimated they could suffer three types of deterioration: general corrosion, localized corrosion (specifically crevice corrosion) and stress corrosion cracking (SCC). It has been confirmed that the presence of bicarbonate and chloride ions is necessary to produce cracking, . It has also been determined that the susceptibility to SCC could be related to the occurrence of an anodic peak in the polarization curves in these media at potentials below transpassivity. The aim of this work is to study the effect of alloying elements on the anodic behavior of Alloy 22 in media containing bicarbonate and chloride ions at different concentrations and temperatures. Polarization curves were made on alloy 22 (Ni-22% Cr-13% Mo), Ni-Mo (Ni-28, 5% Mo) and Ni-Cr (Ni-20% Cr) in the following solutions: 1 mol/L NaCl at 90oC, and 1.148 mol/L NaHCO3; 1.148 mol/L NaHCO3 + 1 mol/L NaCl; 1.148 mol/L NaHCO3 + 0.1 mol/L NaCl, at 90oC, 75oC, 60oC and 25oC. It was found that alloy 22 has a anodic current density peak at potentials below transpassivity, only in the presence of bicarbonate ions. Curves performed in 1 mol/L NaCl did not show any anodic peak, in any of the tested alloys. The curves made on alloys Ni-Mo and Ni-Cr in the presence of bicarbonate ions, allowed to determine that Cr, is responsible for the appearance of the anodic peak in alloy 22. The curves of alloy Ni-Mo showed no anodic peak in the studied conditions. The potential at which the anodic peak appears in alloy 22 and Ni-Cr alloy, increases with decreasing temperature. The anodic peak was also affected by solution composition. When chloride ion is added to bicarbonate solutions, the anodic peak is shifted to higher potential and current densities, depending on the concentration of added chloride ions (author)

  18. Development of a new β Ti alloy with low modulus and favorable plasticity for implant material.

    Science.gov (United States)

    Liang, S X; Feng, X J; Yin, L X; Liu, X Y; Ma, M Z; Liu, R P

    2016-04-01

    One of the most important development directions of the Ti and its alloys is the applications in medical field. Development of new Ti alloys with low elastic modulus and/or favorable biocompatibility plays an important role for promoting its application in medical field. In this work, a new β Ti alloy (Ti-31Nb-6Zr-5Mo, wt.%) was designed for implant material using d-electron alloy design method. Microstructure and tensile properties of the designed alloy after hot rolling (HR) and solution followed by aging treatments (SA) were investigated. Results show that the designed alloy is composed of single β phase. However, microstructural analysis shows that the β phase in the designed alloy separates into Nb-rich and Nb-poor phase regions. The Nb-rich regions in HR specimen are typical elongated fiber texture, but are equiaxed particles with several micrometers in SA specimen. Tensile results show that the designed alloy has low Young's modulus of 44 GPa for HR specimen and 48 GPa for SA specimen which are very close to the extreme of Young's modulus of bulk titanium alloys. At the same time, the designed alloy has favorable plasticity in term of elongation of 26.7% for HR specimen and 20.6% for SA specimen, and appropriate tensile strength over 700 MPa. In short, the designed alloy has low elastic modulus close to that of bone and favorable plasticity and strength which can be a potential candidate for hard tissue replacements. PMID:26838858

  19. Vers un contrôle de vol d'un oiseau artificiel

    OpenAIRE

    Lenoir, Yves

    2010-01-01

    Cet article concerne l'étude d'un drone à ailes battantes. Des observations du vol de grands oiseaux, notamment de la cinématique du cycle de leur battement, et la prise en compte de leurs capacités physiologiques ont conduit à un calcul simplifié des forces aérodynamiques engendéres par un oiseau en vol rectiligne stabilisé. Le résultat est utilisé pour trouver les contrôles de gauchissement (vrillage) des ailes assurant le maintien du vol horizontal. La valeur de la puissance moyenne requis...

  20. Compostos Voláteis da Rolha e Sua Incidência no Vinho

    OpenAIRE

    Alice Vilela, Valeria Mazzoleni; Osvaldo Colagrande, Arlete Mendes Faia

    1994-01-01

    Neste trabalho foram avaliados os constituintes voláteis de rolhas de diferente qualidade e proveniência e determinados os compostos que poderão ser cedidos ou absorvidos pela rolha, quando em contacto com o vinho. Verificámos que os compostos voláteis da rolha variam consoante a sua qualidade. Identificámos entre outros o acetato de etilo, o álcool isoamílico, o linalol, o a-terpineol, 1,2-diclorobenzeno, clorobenzeno e clorofórmio. A rolha pode absorver alguns dos constituintes voláte...

  1. The DynAlloy Visualizer

    OpenAIRE

    Bendersky, Pablo; Galeotti, Juan Pablo; Garbervetsky, Diego

    2014-01-01

    We present an extension to the DynAlloy tool to navigate DynAlloy counterexamples: the DynAlloy Visualizer. The user interface mimics the functionality of a programming language debugger. Without this tool, a DynAlloy user is forced to deal with the internals of the Alloy intermediate representation in order to debug a flaw in her model.

  2. Obtention, machining and wear of sintered alloys for automotive applications

    International Nuclear Information System (INIS)

    The aim of this work was the development of materials for automotive applications, in particular, valve seat inserts for gasoline combustion engines. The development involved the following activities: processing by powder metallurgy techniques, heat treatment, mechanical and microstructural characterization, machining and wear of materials. This work was undertaken aiming cost reduction of this component by the use of cheaper and less pollutant elements, eliminating the presence of Co and Pb due to their high cost and toxicological effects, respectively. The accomplishment of a thorough research into patents revealed that the materials studied here present particular compositions and were not yet produced. The results of hardness measurements and the transverse radial strength of the studied materials, after heat treatment, revealed superior properties than the commercial alloys applied at the moment. The machining tests of the material without heat treatment indicated a similar behaviour in comparison to the commercial alloy, suggesting that the new alloy chemistry composition was not deleterious in this sense. After heat treatment, the obtained alloys presented a cutting force increase in relation to the commercial alloy. Wear tests results of heat treated materials presented smaller friction coefficient and mass loss than the commercial alloy, in ali cases. This was especially achieved due to the advantages offered by heat treatment allied to the addition of NbC and Ti/W carbides. The materials obtained here showed to be potential candidates to substitute with advantages, valve seat inserts made of Fe-Co alloys for gasoline combustion engines. (author)

  3. Microstructures and oxidation behavior of some Molybdenum based alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ray, Pratik Kumar [Iowa State Univ., Ames, IA (United States)

    2011-01-01

    The advent of Ni based superalloys revolutionized the high temperature alloy industry. These materials are capable of operating in extremely harsh environments, comprising of temperatures around 1050 C, under oxidative conditions. Demands for increased fuel efficiency, however, has highlighted the need for materials that can be used under oxidative conditions at temperatures in excess of 1200 C. The Ni based superalloys are restricted to lower temperatures due to the presence of a number of low melting phases that melt in the 1250 - 1450 C, resulting in softening of the alloys above 1000 C. Therefore, recent research directions have been skewed towards exploring and developing newer alloy systems. This thesis comprises a part of such an effort. Techniques for rapid thermodynamic assessments were developed and applied to two different systems - Mo-Si alloys with transition metal substitutions (and this forms the first part of the thesis) and Ni-Al alloys with added components for providing high temperature strength and ductility. A hierarchical approach towards alloy design indicated the Mo-Ni-Al system as a prospective candidate for high temperature applications. Investigations on microstructures and oxidation behavior, under both isothermal and cyclic conditions, of these alloys constitute the second part of this thesis. It was seen that refractory metal systems show a marked microstructure dependence of oxidation.

  4. Development of Mg-based Hydrogen Storage Alloy

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Mg-based hydrogen storage alloys are considered as a promising candidate for hydrogen system because of its lightweight, high storage capacity, low price and rich mineral resources. In detail,we reviewed the preparation and properties of Mg-Ni-based hydrogen storage alloys. All kinds of attempts have been done to improve the hydriding and dehydriding behaviors. It is found that the partial substitution of foreign elements can decrease the hydrogen absorption temperature,especially the substitution of a more electronegative element, such as Al and Mn. Mechanical alloying (MA) and mechanical grinding (MG) are the most effective methods to improve the hydriding/dehydriding kinetics and electrochemical capacity, and decrease the desorption temperature, but the corrosion resistance is so poor that the 80% of maximum capacity is lost within ten cycles. Microencapsulation is a useful measurement for improving the corrosion resistance and electrocatalytic activity. In order to improve the properties of the alloys for practical application, the alloys should have a large number of defects, which give activated sites, subsequently,MA, MG and electroless plating should be used to improve the hydriding/dehydriding kinetics and protect the surface of alloys, respectively. The new composite Mg-based alloys give a new way for the hydrogen storage material to practical application. Furthermore we put forward several problems which will be discussed in future.

  5. Development of cast ferrous alloys for Stirling engine application

    International Nuclear Information System (INIS)

    Low cost cast ferrous base alloys that can be used for cylinder and regenerator housing components of the Stirling engine were investigated. The alloys must meet the requirements of high strength and thermal fatigue resistance to approximately 1500 F, compatibility and low permeability with hydrogen, good elevated temperature oxidation/corrosion resistance, and contain a minimum of strategic elements. The phase constituents of over twenty alloy iterations were examined by X-ray diffraction. These alloy candidates were further screened for their tensile and stress rupture strength and surface stability in air at 1450 and 1600 F, respectively. Two alloys, NASAUT 1G (Fe-10Mn-20Cr-1.5C-1.0Si) and NASAUT 4G (Fe-15Mn-12Cr-3Mo-1.5C-1.0Si-1.0Nb), were chosen for more extensive elevated temperature testing. These alloys were found to exhibit nearly equivalent elevated temperature creep strength and oxidation resistance. Silicon present in these alloys at the 1 w/o level permitted the achievement of oxide scale adherence to 1600 F without loss of strength (or ductility) as was noted for equivalent additions of aluminum

  6. BFS Method for Alloys Optimized and Verified for the Study of Ordered Intermetallic Material

    Science.gov (United States)

    1997-01-01

    The aerospace industry has a need for new metallic alloys that are lightweight and have high strength at elevated temperatures. The BFS (Bozzolo, Ferrante, and Smith) method is a new, computationally efficient and physically sound quantum semi-perturbative approach for describing metals and their defects. Based on a simple interpretation of the alloy formation process that identifies strain and chemical contributions to the energy of the alloy, the method provides an atom-by-atom description of an alloy. Its implementation requires little more than algebra and the solution of transcendental equations. At the NASA Lewis Research Center, we have demonstrated that BFS can investigate the properties of a large number of alloys with a minimum computational effort on low-level computers. This screening allows the selection of the best alloy candidates for a particular application and, therefore, promises large cost savings over current approaches.

  7. MODELING OF NI-CR-MO BASED ALLOYS: PART II - KINETICS

    Energy Technology Data Exchange (ETDEWEB)

    Turchi, P A; Kaufman, L; Liu, Z

    2006-07-07

    The CALPHAD approach is applied to kinetic studies of phase transformations and aging of prototypes of Ni-Cr-Mo-based alloys selected for waste disposal canisters in the Yucca Mountain Project (YMP). Based on a previous study on alloy stability for several candidate alloys, the thermodynamic driving forces together with a newly developed mobility database have been used to analyze diffusion-controlled transformations in these Ni-based alloys. Results on precipitation of the Ni{sub 2}Cr-ordered phase in Ni-Cr and Ni-Cr-Mo alloys, and of the complex P- and {delta}-phases in a surrogate of Alloy 22 are presented, and the output from the modeling are compared with experimental data on aging.

  8. Effect of rolling temperature of the magnesium alloy AZ31B formability

    International Nuclear Information System (INIS)

    The magnesium alloy AZ31B presents an interesting set of properties, which makes it potential candidate for applications in automotive and aeronautics. The main limitation of magnesium alloys is the low capacity of plastic forming at room temperature. The main motivation of this project is to understand and control the microstructure and crystallographic texture of magnesium alloys, to improve their formability. The effect of rolling temperature on the formability of the alloy was studied in this stage of the project. The alloy in the form of annealed and recrystallized sheets (2 mm thick) was deformed by rolling at four different temperatures: 25, 100, 200 and 250 deg C. The microstructural characterization was achieved using several complementary techniques of microstructural analysis, such as optical microscopy, scanning electron microscopy, X-ray analysis by energy dispersive, X-ray diffraction and microhardness. Results about the effect of rolling temperature on the alloy formability were presented and discussed. (author)

  9. Evaluation of Nb-base alloys for the divertor structure in fusion reactors

    Energy Technology Data Exchange (ETDEWEB)

    Purdy, I.M. [Argonne National Laboratory, Upton, IL (United States)

    1996-04-01

    Niobium-base alloys are candidate materials for the divertor structure in fusion reactors. For this application, an alloy should resist aqueous corrosion, hydrogen embrittlement, and radiation damage and should have high thermal conductivity and low thermal expansion. Results of corrosion and embrittlement screening tests of several binary and ternary Nb alloys in high-temperature water indicated the Mb-1Zr, Nb-5MO-1Zr, and Nb-5V-1Z4 (wt %) showed sufficient promise for further investigation. These alloys, together with pure Nb and Zircaloy-4 have been exposed to high purity water containing a low concentration of dissolved oxygen (<12 ppb) at 170, 230, and 300{degrees}C for up to {approx}3200 h. Weight-change data, microstructural observations, and qualitative mechanical-property evaluation reveal that Nb-5V-1Zr is the most promising alloy at higher temperatures. Below {approx}200{degrees}C, the alloys exhibit similiar corrosion behavior.

  10. Novel materials. Applications today and tomorrow. Vol. 1 and 2

    International Nuclear Information System (INIS)

    The first and second volume of the report by the Association of German Engineers (VDI Report 670) reflect the main contents of the lectures presented at the conference on 'Materials 88' held in Munich on March 15th and 16th 1988. The main topics of the first volume are: 1.) Cast materials; 2.) Composite materials and metal matrix; 3.) Steel and superalloys; 4.) Coatings technology. The second volume treats the following topics: 5.) Light alloys (e.g., Mg-; Mg/Li-; Al/Li alloys); 6.) Thin coatings (e.g., PVD coatings); 7.) Technical ceramics (e.g., SiSiC, Si3N4, SiC, BN, Al2O3, ZrO2); 8.) Thermal spraying (e.g., plasma spraying, flame spraying); 9.) Hard material coatings. 49 of the total number of 58 lectures were recorded separately for the database. (MM)

  11. Niobium Silicon alloys for Kinetic Inductance Detectors

    CERN Document Server

    Calvo, M; Monfardini, A; Benoit, A; Boudou, N; Bourrion, O; Catalano, A; Dumoulin, L; Goupy, J; Sueur, H Le; Marnieros, S

    2013-01-01

    We are studying the properties of Niobium Silicon amorphous alloys as a candidate material for the fabrication of highly sensitive Kinetic Inductance Detectors (KID), optimized for very low optical loads. As in the case of other composite materials, the NbSi properties can be changed by varying the relative amounts of its components. Using a NbSi film with T_c around 1 K we have been able to obtain the first NbSi resonators, observe an optical response and acquire a spectrum in the band 50 to 300 GHz. The data taken show that this material has very high kinetic inductance and normal state surface resistivity. These properties are ideal for the development of KID. More measurements are planned to further characterize the NbSi alloy and fully investigate its potential.

  12. An Efficient Approach for Candidate Set Generation

    OpenAIRE

    Nawar Malhis; Arden Ruttan; Hazem H. Refai

    2005-01-01

    When Apriori was first introduced as an algorithm for discovering association rules in a database of market basket data, the problem of generating the candidate set of the large set was a bottleneck in Apriori's performance, both in space and computational requirements. At first, many unsuccessful attempts were made to improve the generation of a candidate set. Later, other algorithms that out performed Apriori were developed that generate association rules without using a candidate set. They...

  13. Cardiac evaluation of liver transplant candidates

    OpenAIRE

    Mandell, Mercedes Susan; Lindenfeld, JoAnn; Tsou, Mei-Yung; Zimmerman, Michael

    2008-01-01

    Physicians previously thought that heart disease was rare in patients with end stage liver disease. However, recent evidence shows that the prevalence of ischemic heart disease and cardiomyopathy is increased in transplant candidates compared to most other surgical candidates. Investigators estimate that up to 26% of all liver transplant candidates have at least one critical coronary artery stenosis and that at least half of these patients will die perioperatively of cardiac complications. Ca...

  14. Siim Nestor soovitab : Tallinn Doom Night vol.1. Odessa Pop / Siim Nestor

    Index Scriptorium Estoniae

    Nestor, Siim, 1974-

    2006-01-01

    Soome doom-metal ansambel Reverend Bizarre üritusel "Tallinn Doom Night vol.1" 8. dets. klubis Rockstar's. Indipoppi viljelev Rootsi duo My Darling Yoy! üritusel "Odessa Pop" 9. dets. Tallinnas klubis KuKu

  15. Arvustuse piirid ja auhinnad : mõtteid kirjanduskriitikast vol 2 / Jan Kaus

    Index Scriptorium Estoniae

    Kaus, Jan, 1971-

    2007-01-01

    Tänapäeva eesti kirjanduskriitikast. Vt. ka vol. 1: Kaus, Jan. Eetika, taburetiefekt ja jätkuv objektivisatsioon, Sirp, 15. juuni., lk. 7. Vastukaja: Raudam, Toomas. Arvustuse piiritused //Sirp (2007) 10. aug., lk. 9

  16. Editor's welcome, PORTAL, Vol. 1, No. 2, July 2004

    Directory of Open Access Journals (Sweden)

    Paul Allatson

    2005-03-01

    Full Text Available Since the highly successful inauguration of PORTAL in January 2004, we have received many kind expressions of support from international studies practitioners in a range of fields, and from such places as Canada, Italy, Mexico, Nigeria, New Zealand, Spain, Trinidad, the U.K., and the U.S.A. Particularly gratifying have been the endorsements of the journal and its publishing aims by people involved in their own electronic publishing enterprises. For their generous responses to PORTAL, the Editorial Committee would like to express its collective appreciation to the following people: Professor Jean-Marie Volet, of the University of Western Australia, and the guiding editor of the ground-breaking e-journal Mots Pluriels (www.arts.uwa.edu.au/MotsPluriels; and Francis Leo Collins, member of the Editorial Committee for the Graduate Journal of Asia Pacific Studies (GJAPS, based in Auckland, New Zealand. PORTAL's readers may be interested in the current call for papers from GJAPS (www.arts.auckland.ac.nz/gjaps, for a special issue on "Imagining the Asia-Pacific" (deadline October 31, 2004. This issue of PORTAL contains essays that cover wide terrain: the Chilean diasporic community in Australia; the world of German intellectuals; contemporary Mexican socio-political movements; rural-urban migration in China; and transnational advocacy networks and election monitoring in the Philippines, Chile, Nicaragua and Mexico. In the cultural section of this issue, we are delighted to present a short story from the noted German Studies scholar Anthony Stephens, and the first half of a beautiful, deeply poetic and haunting novel entitled Son, from the London-based writer and art-critic Jennifer Higgie. The novel’s second and final part will appear in PORTAL vol. 2, no. 1, in January 2005. On a different note, we would like to express our support for the inaugural Ubud Writers and Readers Festival, to be held in Ubud, Bali, from October 11 to 17, 2004. The Festival

  17. Synthesis and Characteristics of WC-Co Alloy Fabricated by Mechanical Alloying and Pressure Sintering

    Science.gov (United States)

    Isonishi, Kazuo

    In this paper, the synthesis of WC-Co alloy was investigated. Especially the formation of WC phase during the solid-phase sintering was discussed. The chemical composition of WC-Co was chosen to be WC-20vol%Co. The powder mixture of stoichiometric quantities of elemental powders was mechanical alloyed by using low-energy ball mill under an Ar atmosphere. After 1800ks milling, the X-ray diffraction profile showed only elemental W phase. At DTA runs, W2C and Co6W6C phase formed about 1140K and then transformed to WC and W3Co3C with increasing temperature. Therefore, it is considered that the WC phase synthesized at the sintering process, not milling stage like other investigations. 1800ks milled powder was consolidated by using pulse current sintering method at the temperature of 1373K. The compact consisted mainly of WC with Co and W3Co3C phases. The hardness of the compact was 1648HV and 91.8HRA. The 3-point bending strength was about 2GPa.

  18. Superplasticity in titanium alloys

    OpenAIRE

    J. Sieniawski; Motyka, M.

    2007-01-01

    Purpose: The paper reports characteristic of superplasticity phenomenon in titanium alloys and possibility of its applications.Design/methodology/approach: The main objective of the paper is to show features of superplastic forming of titanium alloys and current research trends aiming at widespread application of this technology.Findings: In the paper characteristic of selected superplastic titanium alloys was presented. The effect of microstructural parameters on superplasticity was consider...

  19. Reseña: Critical Studies on Corporate Responsibility, Governance and Sustainability, Vol. 4 y 6

    Directory of Open Access Journals (Sweden)

    Adrián Zicari

    2014-10-01

    Full Text Available Corporate Social Irresponsibility: A Challenging Concept. Series: Critical Studies on Corporate Responsibility, Governance and Sustainability, Vol. 4. Ralph Tench, William Sun and Brian Jones, 2012, Emerald Group Publishing Limited, 315 pages. Communicating Corporate Social Responsibility Perspectives and Practice. Series: Critical Studies on Corporate Responsibility, Governance and Sustainability, Vol. 6. Ralph Tench, William Sun and Brian Jones, 2014, Emerald Group Publishing Limited, 456 pages

  20. Index to Nuclear Safety: a technical progress review by chronology, permuted title, and author. Vol. 11(1)--Vol. 18(6)

    Energy Technology Data Exchange (ETDEWEB)

    Cottrell, W.B.; Klein, A.

    1978-04-11

    This index to Nuclear Safety covers articles published in Nuclear Safety, Vol. 11, No. 1 (January-February 1970), through Vol. 18, No. 6 (November-December 1977). It is divided into three sections: a chronological list of articles (including abstracts) followed by a permuted-title (KWIC) index and an author index. Nuclear Safety, a bimonthly technical progress review prepared by the Nuclear Safety Information Center (NSIC), covers all safety aspects of nuclear power reactors and associated facilities. Over 450 technical articles published in Nuclear Safety in the last eight years are listed in this index.

  1. Index to Nuclear Safety. A technical progress review by chronology, permuted title, and author. Vol 11, No. 1 through Vol. 16, No. 6

    Energy Technology Data Exchange (ETDEWEB)

    Cottrell, W.B.; Klein, A.

    1976-04-01

    This index to Nuclear Safety covers articles in Nuclear Safety Vol. 11, No. 1 (Jan.-Feb. 1970) through Vol. 16, No. 6 (Nov.-Dec. 1975). Included in the index is a chronological list of articles (including abstract) followed by both a KWIC index and an Author Index. Nuclear Safety is a bimonthly technical progress review prepared by the Nuclear Safety Information Center and covers all safety aspects of nuclear power reactors and associated facilities. The index lists over 300 technical articles in the last six years of publication.

  2. Index to Nuclear Safety. A technical progress review by chronology, permuted title, and author. Vol 11, No. 1 through Vol. 16, No. 6

    International Nuclear Information System (INIS)

    This index to Nuclear Safety covers articles in Nuclear Safety Vol. 11, No. 1 (Jan.-Feb. 1970) through Vol. 16, No. 6 (Nov.-Dec. 1975). Included in the index is a chronological list of articles (including abstract) followed by both a KWIC index and an Author Index. Nuclear Safety is a bimonthly technical progress review prepared by the Nuclear Safety Information Center and covers all safety aspects of nuclear power reactors and associated facilities. The index lists over 300 technical articles in the last six years of publication

  3. Index to Nuclear Safety: a technical progress review by chronology, permuted title, and author. Vol. 11(1)--Vol. 18(6)

    International Nuclear Information System (INIS)

    This index to Nuclear Safety covers articles published in Nuclear Safety, Vol. 11, No. 1 (January-February 1970), through Vol. 18, No. 6 (November-December 1977). It is divided into three sections: a chronological list of articles (including abstracts) followed by a permuted-title (KWIC) index and an author index. Nuclear Safety, a bimonthly technical progress review prepared by the Nuclear Safety Information Center (NSIC), covers all safety aspects of nuclear power reactors and associated facilities. Over 450 technical articles published in Nuclear Safety in the last eight years are listed in this index

  4. Corrosion resistant amorphous alloys

    International Nuclear Information System (INIS)

    A review of publication data on corrosion resistance of amorphous alloys and the methods of amorphization of surface layers of massive materials (laser treatment, iron implantation, detonation-gas spraying, cathode and ion sputtering, electrodeposition) was made. A study was made on corrosion properties of Fe66Cr11B10Si4 alloy in cast state and after laser irradiation, rendering the surface amorphous as well as the samples of Arenco iron and steel 20 with ion-plasma coatings of Fe-Cr-Ni-Ti alloy. It was established that amorphous coatings posses much higher corrosion resistance as compared to crystalline alloys on the same base

  5. Rapid solidification of candidate ferritic steels

    International Nuclear Information System (INIS)

    HT-9 and 9Cr-1Mo steels were rapidly solidified by the liquid dynamic compaction process and 2-1/4Cr-1Mo steel was prepared by the ultrasonic gas atomization process. The consolidation was performed in the ferritic temperature range in order to minimize segregation. These alloys will be tested at ORNL using 1/3 CVN test specimens and the results will be compared with those for conventially processed alloys

  6. Survey of the degradation modes of candidate materials for high-level radioactive waste disposal containers

    International Nuclear Information System (INIS)

    Oxidation and atmospheric corrosion data suggest that addition of Cr provides the greatest improvement in oxidation resistance. Cr-bearing cast irons are resistant to chloride environments and solutions containing strongly oxidizing constituents. Weathering steels, including high content and at least 0.04% Cu, appear to provide adequate resistance to oxidation under temperate conditions. However, data from long-term, high-temperature oxidation studies on weathering steels were not available. From the literature, it appears that the low alloy steels, plain carbon steels, cast steels, and cast irons con-ode at similar rates in an aqueous environment. Alloys containing more than 12% Cr or 36% Ni corrode at a lower rate than plain carbon steels, but pitting may be worse. Short term tests indicate that an alloy of 9Cr-1Mo may result in increased corrosion resistance, however long term data are not available. Austenitic cast irons show the best corrosion resistance. A ranking of total corrosion performance of the materials from most corrosion resistant to least corrosion resistant is: Austenitic Cast Iron; 12% Cr = 36% Ni = 9Cr-1Mo; Carbon Steel = Low Alloy Steels; and Cast Iron. Since the materials to be employed in the Advanced Conceptual Design (ACD) waste package are considered to be corrosion allowance materials, the austenitic cast irons, high Cr steels, high Ni steels and the high Cr-Mo steels should not be considered as candidates for the outer containment barrier. Based upon the oxidation and corrosion data available for carbon steels, low alloy steels, and cast irons, a suitable list of candidate materials for a corrosion allowance outer barrier for an ACD waste package could include, A516, 2.25%Cr -- 1%Mo Steel, and A27

  7. Survey of the degradation modes of candidate materials for high-level radioactive waste disposal containers

    Energy Technology Data Exchange (ETDEWEB)

    Vinson, D.W.; Nutt, W.M.; Bullen, D.B. [Iowa State Univ. of Science and Technology, Ames, IA (United States)

    1995-06-01

    Oxidation and atmospheric corrosion data suggest that addition of Cr provides the greatest improvement in oxidation resistance. Cr-bearing cast irons are resistant to chloride environments and solutions containing strongly oxidizing constituents. Weathering steels, including high content and at least 0.04% Cu, appear to provide adequate resistance to oxidation under temperate conditions. However, data from long-term, high-temperature oxidation studies on weathering steels were not available. From the literature, it appears that the low alloy steels, plain carbon steels, cast steels, and cast irons con-ode at similar rates in an aqueous environment. Alloys containing more than 12% Cr or 36% Ni corrode at a lower rate than plain carbon steels, but pitting may be worse. Short term tests indicate that an alloy of 9Cr-1Mo may result in increased corrosion resistance, however long term data are not available. Austenitic cast irons show the best corrosion resistance. A ranking of total corrosion performance of the materials from most corrosion resistant to least corrosion resistant is: Austenitic Cast Iron; 12% Cr = 36% Ni = 9Cr-1Mo; Carbon Steel = Low Alloy Steels; and Cast Iron. Since the materials to be employed in the Advanced Conceptual Design (ACD) waste package are considered to be corrosion allowance materials, the austenitic cast irons, high Cr steels, high Ni steels and the high Cr-Mo steels should not be considered as candidates for the outer containment barrier. Based upon the oxidation and corrosion data available for carbon steels, low alloy steels, and cast irons, a suitable list of candidate materials for a corrosion allowance outer barrier for an ACD waste package could include, A516, 2.25%Cr -- 1%Mo Steel, and A27.

  8. Marine environment news Vol. 4, no. 1, June 2006

    International Nuclear Information System (INIS)

    The last six months have been a frenetically busy time for us in Monaco. Our Marine Programmes have been positively reviewed by the Standing Advisory Group on Nuclear Applications (SAGNA) and by an External Evaluation of our Programme. Both Groups report to the Director General, Mr Mohammed ElBaradei, and we hope that new investment in personnel and equipment may eventually result from their evaluations and feedback. We were honoured by the visit of His Serene Highness Prince Albert II of Monaco in March 2006 to our facilities. HSH continues to take a personal interest in MEL's isotopic and pollutant analyses of biota and environmental samples from the Arctic environment which we sampled during His Highness' cruise in June 2005 (see Vol. 3. No 2. MEL Newsletter). This issue also shows that MEL has hosted several important workshops and meetings. The US Research Vessel Endeavour visited the port of Monaco in April and MEL hosted an informal reception for the crew. The visit was in connection with ongoing, joint MEL-US studies in ocean carbon sinks in the Mediterranean (the MEDFLUX programme). More recently, MEL has been involved in discussion with Gulf Member States for a Marine Radioactivity Baseline Study. Finally, I am pleased to note that our MEL Newsletter is clearly having a positive outreach with Member States, since we are currently witnessing a doubling in Member States requests through the TC Concept Proposals (2007-2008) for fellowships, courses and capacity building in marine environment

  9. Special Education Teacher Candidate Assessment: A Review

    Science.gov (United States)

    McCall, Zach; McHatton, Patricia Alvarez; Shealey, Monika Williams

    2014-01-01

    Teacher preparation has been under intense scrutiny in recent years. In order for preparation of special education teacher candidates to remain viable, candidate assessment practices must apply practices identified in the extant literature base, while special education teacher education researchers must extend this base with rigorous efforts to…

  10. Do People 'Like' Candidates on Facebook?

    DEFF Research Database (Denmark)

    Nielsen, Rasmus Kleis

    The online popularity of a few exceptional candidates has led many to suggest that social media have given politicians powerful ways of communicating directly with voters. In this paper, we examine whether this is happening on a significant scale and show, based on analysis of 224 candidates invo...

  11. Replacement of Co-base alloy for radiation exposure reduction in the primary system of PWR

    International Nuclear Information System (INIS)

    Of numerous Co-free alloys developed to replace Co-base stellite used in valve hardfacing material, two iron-base alloys of Armacor M and Tristelle 5183 and one nickel-base alloy of Nucalloy 488 were selected as candidate Co-free alloys, and Stellite 6 was also selected as a standard hardfacing material. These four alloys were welded on 316SS substrate using TIG welding method. The first corrosion test loop of KAERI simulating the water chemistry and operation condition of the primary system of PWR was designed and fabricated. Corrosion behaviors of the above four kinds of alloys were evaluated using this test loop under the condition of 300 deg C, 1500 psi. Microstructures of weldment of these alloys were observed to identify both matrix and secondary phase in each weldment. Hardnesses of weld deposit layer including HAZ and substrate were measured using micro-Vickers hardness tester. The status on the technology of Co-base alloy replacement in valve components was reviewed with respect to the classification of valves to be replaced, the development of Co-free alloys, the application of Co-free alloys and its experiences in foreign NPPs, and the Co reduction program in domestic NPPs and industries. 18 tabs., 20 figs., 22 refs. (Author)

  12. Amorphous Alloy Membranes for High Temperature Hydrogen Separation

    Energy Technology Data Exchange (ETDEWEB)

    Coulter, K

    2013-09-30

    At the beginning of this project, thin film amorphous alloy membranes were considered a nascent but promising new technology for industrial-scale hydrogen gas separations from coal- derived syngas. This project used a combination of theoretical modeling, advanced physical vapor deposition fabricating, and laboratory and gasifier testing to develop amorphous alloy membranes that had the potential to meet Department of Energy (DOE) targets in the testing strategies outlined in the NETL Membrane Test Protocol. The project is complete with Southwest Research Institute® (SwRI®), Georgia Institute of Technology (GT), and Western Research Institute (WRI) having all operated independently and concurrently. GT studied the hydrogen transport properties of several amorphous alloys and found that ZrCu and ZrCuTi were the most promising candidates. GT also evaluated the hydrogen transport properties of V, Nb and Ta membranes coated with different transition-metal carbides (TMCs) (TM = Ti, Hf, Zr) catalytic layers by employing first-principles calculations together with statistical mechanics methods and determined that TiC was the most promising material to provide catalytic hydrogen dissociation. SwRI developed magnetron coating techniques to deposit a range of amorphous alloys onto both porous discs and tubular substrates. Unfortunately none of the amorphous alloys could be deposited without pinhole defects that undermined the selectivity of the membranes. WRI tested the thermal properties of the ZrCu and ZrNi alloys and found that under reducing environments the upper temperature limit of operation without recrystallization is ~250 °C. There were four publications generated from this project with two additional manuscripts in progress and six presentations were made at national and international technical conferences. The combination of the pinhole defects and the lack of high temperature stability make the theoretically identified most promising candidate amorphous alloys

  13. Rare-earth magnets and their applications. Vol. 2. Proceedings

    International Nuclear Information System (INIS)

    The following topics were dealt with: permanent magnets, rare- earth magnets, manufacturing, markets, powder metallurgy, sintering, mechanical alloying, nanocrystalline magnets, Curie temperature, domain structure, exchange coupling, stoichiometry effects, coercive force, remanence, magnetisation distribution, demagnetisation, mechanical properties, deformation behaviour, microstructure, grain size effects, texture, magnetic anisotropy, hydrogen assisted processing, nitriding, hydrogen embrittlement, permanent magnet motors, permanent magnet generators, brushless machines, linear motors, DC motors, AC motors, servomotors, magnetic levitation, magnetic field calculations, magnetic damping, magnet system design, system optimisation, corrosion protection, magnetometers, hard magnetic films, magnetostriction, magnetic multilayers, spin glass behaviour

  14. Experimental characterization of the mechanical behavior of two solder alloys for high temperature power electronics applications

    OpenAIRE

    Msolli, Sabeur; Alexis, Joël; Dalverny, Olivier; Karama, Moussa

    2015-01-01

    An experimental investigation of two potential candidate materials for the diamond die attachment is presented in this framework. These efforts are motivated by the need of developing a power electronic packaging for the diamond chip. The performance of the designed packaging relies particularly on the specific choice of the solder alloys for the die/substrate junction. To implement a high temperature junction, AuGe and AlSi eutectic alloys were chosen as die attachment and characterized expe...

  15. Arc welding of high strength aluminium alloys for armour systems applications

    OpenAIRE

    Pickin, Craig Graeme

    2011-01-01

    The ternary Al-Cu-Mg system 2xxx series aluminium alloys were examined as construction materials for armour system applications based upon comparable ballistic properties to the currently employed Al-7xxx series alloys. Utilising MIG welding solidification cracking was evident when welding constrained Al-2024 candidate base material using Al-2319 filler, the only available consumable wire for this series. A previously developed thermodynamic model suggested that an incompatible...

  16. Electrochemical characterization of oxidized nanostructured superelastic Ti-Nb-Zr alloy for medical implants

    OpenAIRE

    Zhukova Yulia; Pustov Yury; Sheremetyev Vadim; Konopatsky Anton; Filonov Mikhail; Brailovski Vladimir

    2015-01-01

    Metastable Ti-Nb-based shape memory and superelastic alloys are known to be strong candidates for bone implant applications. The issues of the materials’ biochemical and biomechanical compatibility and its characterization are reviewed. Thermomechanical treatment is conventionally applied to these alloys in order to obtain supreme functional properties; the processing scheme comprises cold rolling and post-deformation air annealing. The structure and electrochemical characteristics of anneali...

  17. Thermofluency in zirconium alloys

    International Nuclear Information System (INIS)

    A summary is presented about the theoretical and experimental results obtained at present in thermofluency under radiation in zirconium alloys. The phenomenon of thermofluency is presented in a general form, underlining the thermofluency at high temperature because this phenomenon is similar to the thermofluency under radiation, which ocurrs in zirconium alloys into the operating reactor. (author)

  18. High temperature niobium alloys

    International Nuclear Information System (INIS)

    Niobium alloys are currently being used in various high temperature applications such as rocket propulsion, turbine engines and lighting systems. This paper presents an overview of the various commercial niobium alloys, including basic manufacturing processes, properties and applications. Current activities for new applications include powder metallurgy, coating development and fabrication of advanced porous structures for lithium cooled heat pipes

  19. Ultrahigh temperature intermetallic alloys

    Energy Technology Data Exchange (ETDEWEB)

    Brady, M.P.; Zhu, J.H.; Liu, C.T.; Tortorelli, P.F.; Wright, J.L.; Carmichael, C.A.; Walker, L.R. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.

    1997-12-01

    A new family of Cr-Cr{sub 2}X based alloys with fabricability, mechanical properties, and oxidation resistance superior to previously developed Cr-Cr{sub 2}Nb and Cr-Cr{sub 2}Zr based alloys has been identified. The new alloys can be arc-melted/cast without cracking, and exhibit excellent room temperature and high-temperature tensile strengths. Preliminary evaluation of oxidation behavior at 1100 C in air indicates that the new Cr-Cr{sub 2}X based alloys form an adherent chromia-based scale. Under similar conditions, Cr-Cr{sub 2}Nb and Cr-Cr{sub 2}Zr based alloys suffer from extensive scale spallation.

  20. Alloys in energy development

    International Nuclear Information System (INIS)

    The development of new and advanced energy systems often requires the tailoring of new alloys or alloy combinations to meet the novel and often stringent requirements of those systems. Longer life at higher temperatures and stresses in aggressive environments is the most common goal. Alloy theory helps in achieving this goal by suggesting uses of multiphase systems and intermediate phases, where solid solutions were traditionally used. However, the use of materials under non-equilibrium conditions is now quite common - as with rapidly solidified metals - and the application of alloy theory must be modified accordingly. Under certain conditions, as in a reactor core, the rate of approach to equilibrium will be modified; sometimes a quasi-equilibrium is established. Thus an alloy may exhibit enhanced general diffusion at the same time as precipitate particles are being dispersed and solute atoms are being carried to vacancy sinks. We are approaching an understanding of these processes and can begin to model these complex systems

  1. Electronic structure and phase equilibria in ternary substitutional alloys

    International Nuclear Information System (INIS)

    A reliable, consistent scheme to study phase equilibria in ternary substitutional alloys based on the tight-binding approximation is presented. With electronic parameters from linear muffin-tin orbital calculations, the computed density of states and band structures compare well with those from more accurate abinitio calculations. Disordered alloys are studied within the tight-binding coherent-potential approximation extended to alloys; energetics of ordered systems are obtained through effective pair interactions computed with the general perturbation method; and partially ordered alloys are studied with a novel simplification of the molecular coherent-potential approximation combined with the general perturbation method. The formalism is applied to bcc-based Zr-Ru-Pd alloys which are promising candidates for medical implant devices. Using energetics obtained from the above scheme, we apply the cluster- variation method to study phase equilibria for particular pseudo- binary alloys and show that results are consistent with observed behavior of electronic specific heat coefficient with composition for Zr0.5(Ru, Pd)0.5

  2. Brazing with plated alloys

    International Nuclear Information System (INIS)

    The use of braze alloy preforms on complex geometry components is at times a very difficult task requiring extensive handling of the parts or even tack welding of the preform to ensure that it is held in place. One method of overcoming these difficulties is the use of plated braze alloys (i.e., filler metals) applied directly to the braze region. Plating helps to avoid the potential for contamination resulting from handling and also ensures that the braze alloy is located properly. Examples are discussed in which an electroplated silver-copper alloy is used as an alternative to the BAg8 preforms and electroless nickel is used as a replacement for an amorphous Ni-P braze alloy foil. A toroidal cooling plate with helical flow channels was fabricated from oxygen-free high conductivity (OFHC) and brazed using the electroplated silver-copper alloy. The silver-copper braze alloy was applied to the copper substrate in a laminated fashion of alternating layers of silver and copper, which in combination approximated the eutectic composition (72% Ag-28% Cu by weight). Examination of the brazed assemblies indicated that in both cases the advantages of using plated braze alloys are numerous. These advantages include decreased labor, improved cleanliness and exactness of braze alloy placement. The primary disadvantage was an increased tendency for solidification defects presumably resulting from contaminants in the plating baths. This last observation is presently being examined in greater detail. The end results is that the assemblies brazed with the plated alloys were acceptable for the intended application and that the use of plating facilitated the successful assembly of these components

  3. Editor's welcome, PORTAL, Vol. 3, No. 1, January 2006

    Directory of Open Access Journals (Sweden)

    Paul Allatson

    2006-02-01

    Full Text Available Welcome to the first appearance of PORTAL for 2006 (vol. 3, no. 1, a special issue entitled ‘Other Worlds’ guest edited by James Goodman and Christina Ho from the Faculty of Humanities and Social Sciences, University of Technology Sydney (UTS. The papers collected in this special issue focus on what the guest editors call “the transformative power of social movements” that respond to the processes and discourses of globalization and globalism by generating alternative sites and spaces of agency, or ‘other worlds.’ The contributors to the issue originally presented papers at a conference held in April 2005 in Sydney, with the title ‘Other Worlds: Social Movements and the Making of Alternatives.’ That conference was organized by the Research Initiative on International Activism at UTS, and supported by the Research Committee on Social Movements and Collective Action of the International Sociological Association. The Editorial Committee of PORTAL would like to thank both institutions for their support of the event that led to this special issue. I would also like to thank Wayne Peake, Kate Barclay, and Murray Pratt for their editorial efforts in seeing this issue through to publication. The Editorial Committee is pleased to showcase in the Cultural Works Section a short meditative piece by local writer Joel Scott, who is currently undertaking studies in Pamplona, Spain. When considered in the context of the special issue’s discussions of ‘other worlds’ that precede it, Scott’s ‘God, We’re Not Immigrants! A Reflection on Moving and Staying,’ provides an evocative insight into the sociocultural and imaginative limits that may preclude the construction of alternative ‘worlds.’

  4. Effect of Sc{sub 2}O{sub 3} particles on the microstructure and properties of tungsten alloy prepared by spark plasma sintering

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hong-Yu [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Luo, Lai-Ma, E-mail: luolaima@126.com [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); National–Local Joint Engineering Research Centre of Nonferrous Metals and Processing Technology, Hefei 230009 (China); Chen, Jing-Bo [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Li, Ping [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); National–Local Joint Engineering Research Centre of Nonferrous Metals and Processing Technology, Hefei 230009 (China); Luo, Guang-Nan [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Cheng, Ji-Gui [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); National–Local Joint Engineering Research Centre of Nonferrous Metals and Processing Technology, Hefei 230009 (China); Wu, Yu-Cheng, E-mail: ycwu@hfut.edu.cn [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); National–Local Joint Engineering Research Centre of Nonferrous Metals and Processing Technology, Hefei 230009 (China)

    2015-07-15

    Highlights: • Effect of Sc{sub 2}O{sub 3} on microstructure and properties of tungsten alloy were studied. • Sc{sub 2}O{sub 3} significantly refined the grain size and increased the density of tungsten alloy. • The tensile strength values of the W–2 vol%Sc{sub 2}O{sub 3} samples were higher than the others. - Abstract: W–Sc{sub 2}O{sub 3} composite powders (W, W–0.5 vol%Sc{sub 2}O{sub 3}, and W–2 vol%Sc{sub 2}O{sub 3}) doped with highly uniform Sc{sub 2}O{sub 3} particles were successfully synthesized by mechanical alloying followed by hydrogen reduction with Sc{sub 2}O{sub 3} and WO{sub 3} powders. The reduced powders were then consolidated by spark plasma sintering at 1700 °C to suppress grain growth during sintering. Field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, and high-resolution transmission electron microscopy analyses, as well as tensile tests and thermal conductivity measurements, were used to characterize the samples. The results showed that the Sc{sub 2}O{sub 3} particles were uniformly distributed in the tungsten grains and grain boundaries. The W–2vol%Sc{sub 2}O{sub 3} composite possess the best relative density and Vickers micro-hardness up to 98.6% and 683.2 Hv, respectively. The Sc{sub 2}O{sub 3} particles significantly refine the grain size and increase the density of tungsten alloy. With increased Sc{sub 2}O{sub 3} content, the thermal conductivity decreased while tensile strength of the samples respectively increased at 700 and 800 °C.

  5. Impact of neutron irradiation on ITER candidate Hall sensors

    Czech Academy of Sciences Publication Activity Database

    Sentkerestiová, Jana; Ďuran, Ivan; Viererbl, L.; Bolshakova, I.

    Vol. 31F. Varšava: European Physical Society, 2007 - (Gasior, P.; Wolowski, J.), s. 2.152-2.152. (Europhysics Conference Abstracts. ECA Vol. 31F (2007)). ISBN 978-83-926290-0-9. [EPS Conference on Plasma Physics/34rd./. Varšava (PL), 02.07.2007-06.07.2007] Institutional research plan: CEZ:AV0Z20430508 Keywords : Hall sensors * neutron irradiation Subject RIV: BL - Plasma and Gas Discharge Physics

  6. Possibility to use high-chromium nickel base alloys in accordance with criteria of operational capability of materials for ITEP first wall

    International Nuclear Information System (INIS)

    Experimental data on corrosion resistance, strength and plastic properties are presented for alloy KhNM-1 and steel 00Kh16N15M3B. It is shown that alloy KhNM substantially surpasses austenitic stainless steel in processing (weldability) and operational (tendency to corrosion cracking) properties as a candidate material for ITER first wall and blanket

  7. Cattle Candidate Genes for Milk Production Traits

    OpenAIRE

    Kadlec,Tomáš

    2012-01-01

    The aim of this thesis is to make an overview of important candidate genes affecting milk yield and milk quality parameters, with an emphasis on genes associated with the quantity and quality of milk proteins and milk fat.

  8. Evaluating historical candidate genes for schizophrenia

    DEFF Research Database (Denmark)

    Farrell, M S; Werge, T; Sklar, P;

    2015-01-01

    Prior to the genome-wide association era, candidate gene studies were a major approach in schizophrenia genetics. In this invited review, we consider the current status of 25 historical candidate genes for schizophrenia (for example, COMT, DISC1, DTNBP1 and NRG1). The initial study for 24 of these...... genes explicitly evaluated common variant hypotheses about schizophrenia. Our evaluation included a meta-analysis of the candidate gene literature, incorporation of the results of the largest genomic study yet published for schizophrenia, ratings from informed researchers who have published on these...... genes, and ratings from 24 schizophrenia geneticists. On the basis of current empirical evidence and mostly consensual assessments of informed opinion, it appears that the historical candidate gene literature did not yield clear insights into the genetic basis of schizophrenia. A likely reason why...

  9. Scattering Properties of Candidate Planetary Regolith Materials

    Science.gov (United States)

    Nelson, R. M.; Smythe, W. D.; Hapke, B. W.; Hale, A. S.; Piatek, J. A.

    2001-01-01

    The laboratory investigation of the scattering properties of candidate planetary regolith materials is an important technique for understanding the physical properties of a planetary regolith. Additional information is contained in the original extended abstract.

  10. Characterization of nanoparticles as candidate reference materials

    International Nuclear Information System (INIS)

    We report the characterization of three different nanoparticles (silica, silver and multi-walled carbon nanotubes) as candidate reference material. We focus our analysis on the size distribution of those particles as measured by different microscopy techniques. (author)

  11. Characterization of nanoparticles as candidate reference materials

    Energy Technology Data Exchange (ETDEWEB)

    Martins Ferreira, E.H.; Robertis, E. de; Landi, S.M.; Gouvea, C.P.; Archanjo, B.S.; Almeida, C.A.; Araujo, J.R. de; Kuznetsov, O.; Achete, C.A., E-mail: smlandi@inmetro.gov.br [Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMETRO), Rio de Janeiro, RJ (Brazil)

    2013-07-01

    We report the characterization of three different nanoparticles (silica, silver and multi-walled carbon nanotubes) as candidate reference material. We focus our analysis on the size distribution of those particles as measured by different microscopy techniques. (author)

  12. 76 FR 4896 - Call for Candidates

    Science.gov (United States)

    2011-01-27

    ... accepted accounting principles for federal government entities. Generally, non-federal Board members are... From the Federal Register Online via the Government Publishing Office FEDERAL ACCOUNTING STANDARDS ADVISORY BOARD Call for Candidates AGENCY: Federal Accounting Standards Advisory Board. ACTION:...

  13. 76 FR 36130 - Call for Candidates

    Science.gov (United States)

    2011-06-21

    ... establish generally accepted accounting principles for federal government entities. Generally, non- federal... From the Federal Register Online via the Government Publishing Office FEDERAL ACCOUNTING STANDARDS ADVISORY BOARD Call for Candidates AGENCY: Federal Accounting Standards Advisory Board. ACTION: Request...

  14. Mechanisms Governing the Creep Behavior of High Temperature Alloys for Generation IV Nuclear Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Vasudevan, Vijay [Univ. of Cincinnati, OH (United States); Carroll, Laura [Idaho National Lab. (INL), Idaho Falls, ID (United States); Sham, Sam [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-04-06

    This research project, which includes collaborators from INL and ORNL, focuses on the study of alloy 617 and alloy 800H that are candidates for applications as intermediate heat exchangers in GEN IV nuclear reactors, with an emphasis on the effects of grain size, grain boundaries and second phases on the creep properties; the mechanisms of dislocation creep, diffusional creep and cavitation; the onset of tertiary creep; and theoretical modeling for long-term predictions of materials behavior and for high temperature alloy design.

  15. Relationship between irradiation swelling behaviour of alloys and their valence electron structure

    International Nuclear Information System (INIS)

    The relationship between valence electron structure of alloys and their irradiation swelling behaviour has been investigated on basis of results of valence electron structure calculated by means of the empirical electron theory. The difference of the irradiation swelling behaviour among three prior candidate alloys has been explained by their different valence electron structure, and the intrinsic relation between nickel content of iron-nickel-based alloys and their irradiation swelling behaviour has been clarified. From the viewpoint of valence electron structure, intermetallic compounds are potential structural materials with excellent resistance to irradiation swelling. (4 tabs.)

  16. Defect interactions in Sn1−xGex random alloys

    KAUST Repository

    Chroneos, Alexander

    2009-06-23

    Sn1−xGex alloys are candidates for buffer layers to match the lattices of III-V or II-VI compounds with Si or Ge for microelectronic or optoelectronic applications. In the present work electronic structure calculations are used to study relative energies of clusters formed between Sn atoms and lattice vacancies in Ge that relate to alloys of low Sn content. We also establish that the special quasirandom structure approach correctly describes the random alloy nature of Sn1−xGex with higher Sn content. In particular, the calculated deviations of the lattice parameters from Vegard’s Law are consistent with experimental results.

  17. Technical evaluation of major candidate blanket systems for fusion power reactor

    International Nuclear Information System (INIS)

    The key functions required for tritium breeding blankets for a fusion power reactor are: (1) self-sufficient tritium breeding, (2) in-situ tritium recovery and low tritium inventory, (3) high temperature cooling giving a high efficiency of electricity generation and (4) thermo-mechanical reliability and simplified remote maintenance to obtain high plant availability. Blanket performance is substantially governed by materials selection. Major options of structure/breeder/coolant/neutron multiplier materials considered for the present design study are PCA/Li2O/H2O/Be, Mo-alloy/Li2O/He/Be, Mo-alloy/LiAlO2/He/Be, V-alloy/Li/Li/none, and Mo-alloy/Li/He/none. In addition, remote maintenance of blankets, tritium recovery system, heat transport and energy conversion have been investigated. In this report, technological problems and critical R and D issues for power reactor blanket development are identified and a comparison of major candidate blanket concepts is discussed in terms of the present materials data base, economic performance, prospects for future improvements, and engineering feasibility and difficulties based on the results obtained from individual design studies. (author)

  18. Accelerated artificial ageing regimes of commercial aluminium alloys. II. Al-Cu, Al-Zn-Mg-(Cu), Al-Mg-Si-(Cu)

    Energy Technology Data Exchange (ETDEWEB)

    Ber, L.B. [All-Union Inst. of Light Alloys, Moscow (Russian Federation)

    2000-03-15

    For pt.I see ibid., vol.280, p.83-90, 2000. For Al-Cu, Al-Zn-Mg-(Cu), Al-Mg-Si-(Cu) commercial aluminium alloys effects of temperature and exposure on the phase composition and morphology of hardener precipitates, strength and plasticity were carried out. These results are submitted as TTT (time-temperature-transformation) and TTP (time-temperature-properties) diagrams for ageing. For acceleration of ageing the two-stage ageing regimes with high-temperature stages are used, the characteristics hardener precipitates remaining close to optimum. The examples of the accelerated ageing regimes in industrial conditions for sheets from 1201 alloy (type of 2219), sheets from V95 alloy (type of 7075), forgings from AK6 alloy (system Al-Mg-Si-Cu) are presented. The comparison of the mechanical properties, damage tolerance, corrosion resistance of the semi-products processed by standard and accelerated regimes is given. (orig.)

  19. Vaccine candidates for malaria: what's new?

    Science.gov (United States)

    Takashima, Eizo; Morita, Masayuki; Tsuboi, Takafumi

    2016-01-01

    Although it is more than a decade since the parasite genome information was obtained, standardized novel genome-wide selection/prioritization strategies for candidacy of malaria vaccine antigens are still sought. In the quest to systematically identify candidates, it is impossible to overemphasize the usefulness of wheat germ cell-free technology in expressing quality proteins for the post-genome vaccine candidate discovery. PMID:26559316

  20. Reference vanadium alloy V-4Cr-4Ti for fusion application

    International Nuclear Information System (INIS)

    Vanadium alloys exhibit important advantages as a candidate structural material for fusion first-wall/blanket applications. These advantages include high temperature and high wall load capability, favorable safety and environmental features, resistance to irradiation damage, and alloys of interest are readily fabricable. A substantial data base has been developed on laboratory-scale heats of V-Ti, V-Cr-Ti and V-Ti-Si alloys before and after irradiation. Investigations in recent years have focused primarily on compositions of V-(0--15)Cr-(0--20)Ti (0--1)Si. Results from these investigations have provided a basis for identifying a V-4Cr-4Ti alloy as the US reference vanadium alloy for further development. Major results obtained on one production-scale heat and three laboratory heats with compositions of V-(4--5)Cr-(4--5)Ti are presented in this paper. Properties measured were input properties, tensile properties, creep, and radiation effects

  1. Effect of Fluoride Ions on the Anodic Behavior of Mill Annealed and Aged Alloy 22

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, M A; Carranza-, R M; Rebak, R B

    2003-10-07

    Alloy 22 (N06022) is the current candidate alloy to fabricate the external wall of the high level nuclear waste containers for the Yucca Mountain repository. It was of interest to study and compare the general and localized corrosion susceptibility of Alloy 22 in saturated NaF solutions ({approx} 1 M NaF) at 90 C. Standard electrochemical tests such as cyclic potentiodynamic polarization, amperometry, potentiometry, and electrochemical impedance spectroscopy were used. Studied variables included the solution pH and the alloy microstructure (thermal aging). Results show that Alloy 22 is highly resistant to general and localized corrosion in pure fluoride solutions. Thermal aging is not detrimental and even seems to be slightly beneficial for general corrosion in alkaline solutions.

  2. Blood triggered corrosion of magnesium alloys

    International Nuclear Information System (INIS)

    Intravascular stents manufactured out of bioabsorbable magnesium (Mg) or Mg-alloys are considered as auspicious candidates for the next stent generation. However, before clinical application numerous physical and biological tests, especially to predict the clinically highly important degradation kinetics in vivo, have to be performed. In a Chandler-Loop model, the initial degradation of eight different magnesium alloys during 6 h in contact with human whole blood was investigated. The magnesium release varied between 0.91 ± 0.33 mg/cm2 (MgAl9Zn1) and 2.57 ± 0.38 mg/cm2 (MgZn1). No correlation could be found with Mg release data obtained after immersion in simulated body fluid (SBF). This pilot study showed that Mg corrosion is highly influenced by the biological test environment (SBF or blood, etc.) and that a modified Chandler-Loop model with human whole blood may be superior to predict corrosion of Mg alloys under clinical conditions than the SBF models presently used.

  3. Microstructure stability of candidate stainless steels for Gen-IV SCWR fuel cladding application

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jian, E-mail: jili@nrcan.gc.ca [CanmetMATERIALS, Natural Resources Canada, 183 Longwood Rd. S., Hamilton, ON (Canada); Zheng, W. [CanmetMATERIALS, Natural Resources Canada, 183 Longwood Rd. S., Hamilton, ON (Canada); Penttilä, S. [VTT Technical Research Center of Finland, Materials for Power Engineering, P.O. Box 1000, FI-02044 VTT (Finland); Liu, P. [CanmetMATERIALS, Natural Resources Canada, 183 Longwood Rd. S., Hamilton, ON (Canada); Woo, O.T.; Guzonas, D. [AECL Chalk River Laboratory, Chalk River, Ontario (Canada)

    2014-11-15

    In the past few years, significant progress has been made in materials selection for Gen-IV SCWR fuel cladding applications. Current studies indicate that austenite stainless steels such as 310H are promising candidates for in-core applications. Alloys in this group are promising for their corrosion resistance, SCC resistance, high temperature mechanical properties and creep resistance at temperatures up to 700 °C. However, one under-studied area of this alloy is the long-term microstructure stability under the proposed reactor operating condition. Unstable microstructure not only results in embrittlement but also has the potential to reduce their resistance to corrosion or stress-corrosion cracking. In this study, stainless steels 310H and 304H were tested for their SCWR corrosion resistance and microstructure stability.

  4. Cardiac evaluation of liver transplant candidates

    Institute of Scientific and Technical Information of China (English)

    Mercedes Susan Mandell; JoAnn Lindenfeld; Mei-Yung Tsou; Michael Zimmerman

    2008-01-01

    Physicians previously thought that heart disease was rare in patients with end stage liver disease. However, recent evidence shows that the prevalence of ischemic heart disease and cardiomyopathy is increased in transplant candidates compared to most other surgical candidates. Investigators estimate that up to 26% of all liver transplant candidates have at least one critical coronary artery stenosis and that at least half of these patients will die perioperatively of cardiac complications. Cardiomyopathy also occurs in greater frequency. While all patients with advanced cardiac disease have defects in cardiac performance, a larger than expected number of patients have classical findings of dilated, restrictive and hypertropic cardiomyopathy. This may explain why up to 56% of patients suffer from hypoxemia due to pulmonary edema following transplant surgery. There is considerable controversy on how to screen transplant candidates for the presence of heart disease. Questions focus upon, which patients should be screened and what tests should be used. This review examines screening strategies for transplant candidates and details the prognostic value of common tests used to identify ischemic heart disease. We also review the physiological consequences of cardiomyopathy in transplant candidates and explore the specific syndrome of "cirrhotic cardiomyopathy".

  5. Nuclear power newsletter, Vol. 6, no. 1, March 2009

    International Nuclear Information System (INIS)

    The main topics in the current issue are: Natural Circulation Phenomena, Modelling, and Reliability of Passive Systems that Utilize Natural Circulation; Training and Development for Nuclear Power Plant Managers; Review Mission on the Ageing Management Programme Held at Paks Nuclear Power Plant; Detection, Research, Management and Monitoring of Ageing Factors in Nuclear Power Plants; Good Practices to Manage Stress Corrosion Cracking of Austenitic Alloys in Light Water Reactors; Management Systems; Strengthening Nuclear Power Infrastructure; PRADA and a systematic approach of Acquisition/Diversion Pathway Analysis; Natural Circulation Phenomena, Modeling, and Reliability of Passive Systems that Utilize Natural Circulation; Small Reactors without On-site Refueling; Developing Methodologies to Assess Passive Safety System Performance in Advanced Reactors; IAEA Fast Reactor Knowledge Preservation Initiative (FRKP)

  6. Mechanical Properties of Ni-base ODS Alloy Influenced by Process Variables

    International Nuclear Information System (INIS)

    According to a recent investigation, no proven industrial technology could be directly used for such applications. For example, extensive work on Alloy 617 which is the candidate material for the intermediate heat exchanger (IHX) in very high temperature reactors (VHTR) shows that Alloy 617 exhibit quite good creep properties, the maximum service temperature of Alloy 617 is much less than that required for the VHTR-IHX applications. In this regard, oxide dispersion strengthened (ODS) materials have received a great attention owing to their excellent mechanical properties at higher temperatures, e.g., creep resistance. As part of an alloy development program for nickel base ODS alloy, we have produced an ODS Alloy 617 via mechanical alloying and hot extrusion, and characterized its microstructural evolution during the process and evaluated mechanical properties at elevated temperatures. The current work reports the effects of process variables and yttria contents on the microstructure and mechanical properties of ODS Alloy 617. From the experimental work on the influences of yttria content, and process variables such as hot-extrusion ratio and hydrogen reduction on the mechanical properties of ODS Alloy 617, it is concluded that reduction of yttria contents from 0.6 wt.% to 0.45 wt.% and increasing hot extrusion ratio from 6.25:1 to 9:1 improve the ductility at elevated temperatures without the sacrifice of strength

  7. Unexpected magnetic behavior in amorphous Co{sub 90}Sc{sub 10} alloy

    Energy Technology Data Exchange (ETDEWEB)

    Ghafari, M., E-mail: mohammad.ghafari@kit.edu, E-mail: skamali@utsi.edu; Gleiter, H. [Herbert Gleiter Institute of Nanoscience, Nanjing University of Science and Technology, Nanjing 210094 (China); Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen (Germany); Sakurai, Y.; Itou, M. [Japan Synchrotron Radiation Research Institute (JASRI), SPring-8, 1-1-1 Kouto, Sayo, Sayo, Hyogo (Japan); Peng, G.; Fang, Y. N.; Feng, T. [Herbert Gleiter Institute of Nanoscience, Nanjing University of Science and Technology, Nanjing 210094 (China); Hahn, H. [Herbert Gleiter Institute of Nanoscience, Nanjing University of Science and Technology, Nanjing 210094 (China); Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen (Germany); KIT-TUD Joint Research Laboratory Nanomaterials, Institute of Materials Science, Technische Universität Darmstadt (TUD), Jovanka-Bontschits-Str. 2, 64287 Darmstadt (Germany); Kamali, S., E-mail: mohammad.ghafari@kit.edu, E-mail: skamali@utsi.edu [Department of Mechanical, Aerospace and Biomedical Engineering, University of Tennessee Space Institute, Tullahoma, Tennessee 37388 (United States)

    2015-09-28

    An amorphous alloy Co{sub 90}Sc{sub 10} has been prepared by rapid quenching from the melt. The results of magnetization measurements show that this alloy has the highest Curie temperature reported for any amorphous transition metal based alloys. Furthermore, for a Co based amorphous alloy, the magnetic moment is remarkably high. Moreover, the alloy exhibits soft magnetic properties. Based on the findings, amorphous Co{sub 90}Sc{sub 10} appears to be an attractive candidate for applications as a soft magnetic material. The temperature dependence of the reduced magnetization can be described by the Bloch power law. The results show that the B coefficient of the amorphous Co{sub 90}Sc{sub 10} alloy, which is a measure of the rigidity of spin waves, exhibits the lowest value observed until now for any amorphous alloy and is comparable to crystalline alloys. It is found that the Sc atoms in the Co{sub 90}Sc{sub 10} alloy lead to an increase of the itinerant spin moment of Co atoms, and, in contrast to this behaviour, to a decrease of the local 3d-electrons of Co.

  8. Chromium Activity Measurements in Nickel Based Alloys for Very High Temperature Reactors: Inconel 617, Haynes 230, and Model Alloys

    International Nuclear Information System (INIS)

    The alloys Haynes 230 and Inconel 617 are potential candidates for the intermediate heat exchangers (IHXs) of (very) high temperature reactors ((V)-HTRs). The behavior under corrosion of these alloys by the (V)-HTR coolant (impure helium) is an important selection criterion because it defines the service life of these components. At high temperature, the Haynes 230 is likely to develop a chromium oxide on the surface. This layer protects from the exchanges with the surrounding medium and thus confers certain passivity on metal. At very high temperature, the initial microstructure made up of austenitic grains and coarse intra- and intergranular M6C carbide grains rich in W will evolve. The M6C carbides remain and some M23C6 richer in Cr appear. Then, carbon can reduce the protective oxide layer. The alloy loses its protective coating and can corrode quickly. Experimental investigations were performed on these nickel based alloys under an impure helium flow (Rouillard, F., 2007, 'Mecanismes de formation et de destruction de la couche d'oxyde sur un alliage chrominoformeur en milieu HTR, Ph.D. thesis, Ecole des Mines de Saint-Etienne, France). To predict the surface reactivity of chromium under impure helium, it is necessary to determine its chemical activity in a temperature range close to the operating conditions of the heat exchangers (T approximate to 1273 K). For that, high temperature mass spectrometry measurements coupled to multiple effusion Knudsen cells are carried out on several samples: Haynes 230, Inconel 617, and model alloys 1178, 1181, and 1201. This coupling makes it possible for the thermodynamic equilibrium to be obtained between the vapor phase and the condensed phase of the sample. The measurement of the chromium ionic intensity (I) of the molecular beam resulting from a cell containing an alloy provides the values of partial pressure according to the temperature. This value is compared with that of the pure substance (Cr) at the same temperature

  9. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    International Nuclear Information System (INIS)

    Three copper-based alloys, CDA 102 (oxygen-free, high-purity copper), CDA 613 (aluminum bronze), and CDA 715 (Cu-30Ni), are candidates for the fabrication of high-level radioactive-waste disposal containers. Waste will include spent fuel assemblies from reactors as well as borosilicate glass, and will be sent to the prospective repository site at Yucca Mountain in Nye County, Nevada. The decay of radionuclides will result in the generation of substantial heat and in fluxes of gamma radiation outside the containers. In this environment, container materials might degrade by atmospheric oxidation, general aqueous phase corrosion, localized corrosion (LC), and stress corrosion cracking (SCC). This volume is a critical survey of available data on pitting and crevice corrosion of the copper-based candidates. Pitting and crevice corrosion are two of the most common forms of LC of these materials. Data on the SCC of these alloys is surveyed in Volume 4. Pitting usually occurs in water that contains low concentrations of bicarbonate and chloride anions, such as water from Well J-13 at the Nevada Test Site. Consequently, this mode of degradation might occur in the repository environment. Though few quantitative data on LC were found, a tentative ranking based on pitting corrosion, local dealloying, crevice corrosion, and biofouling is presented. CDA 102 performs well in the categories of pitting corrosion, local dealloying, and biofouling, but susceptibility to crevice corrosion diminishes its attractiveness as a candidate. The cupronickel alloy, CDA 715, probably has the best overall resistance to such localized forms of attack. 123 refs., 11 figs., 3 tabs

  10. High Performance Cluster Computing: Architectures and Systems, Vol. 1 - High Performance Cluster Computing: Programming and Applications, Vol. 2 : Rajkumar Buyya, Ed. Prentice Hall PTR, Upper Saddle River, NJ, 1999

    OpenAIRE

    Tinetti, Fernando Gustavo

    2002-01-01

    The two volumes attempt to render a self-contained idea of the state of the art of cluster computing by the year 1999. In the whole, thirty-six articles are presented in Vol. 1 and twenty-nine articles in Vol.2. In each volume, the articles are grouped according to the topics dealt with.

  11. The potential for using disused coastal mineshafts to exploit wave energy : Vol. 1: Main report; Vol. 2: Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Scholes, H.; Millar, D.L.; Eyre, J.M.; Dibley, R.; Davey, G.; Haywood, M.

    2004-07-01

    This report summarises the findings of a project investigating the potential use of abandoned mine shafts in Cornwall as oscillating water column wave power generation devices, and assesses the Waveshaft concept in phase 1 prior to further examination of selected sites in phase 2. Details are given of the criteria for the mine shafts, identification of candidate shafts, remediation/enhancement requirements, and wave climate along with power conversion issues, overall estimated waveshaft resource in Cornwall, environmental impacts and legal protection, and an economic appraisal. Inspection and safety protocols, mine location maps, and wave power data are presented in appendices.

  12. Corrosion tests of candidate fuel cladding and reactor internal structural materials

    International Nuclear Information System (INIS)

    Corrosion screening tests were conducted on candidate materials for nuclear fuel cladding and reactor internals of supercritical water reactor (SCWR) in static and flowing supercritical water (SCW) autoclave at the temperatures of 550, 600 and 650°C, pressure of about 25MPa, deaerated or saturated dissolved hydrogen (STP). Samples are nickel base alloy type Hastelloy C276, austenitic stainless steels type 304NG and AL-6XN, ferritic/martensitic (F/M) steel type P92, and oxide dispersion strengthened steel MA 956. This paper focuses on the formation and breakdown of corrosion oxide scales, and proposes the future trend for the development of SCWR fuel cladding materials. (author)

  13. Corrosion tests of candidate fuel cladding and reactor internal structural materials

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, L.; Zhu, F.; Bao, Y. [Shanghai Jiao Tong Univ., School of Nuclear Science and Engineering, Shanghai (China); Tang, R. [Nuclear Power Inst. of China, National Key Lab. for Nuclear Fuel and Materials, Chengdu, Sichuan (China)

    2010-07-01

    Corrosion screening tests were conducted on candidate materials for nuclear fuel cladding and reactor internals of supercritical water reactor (SCWR) in static and flowing supercritical water (SCW) autoclave at the temperatures of 550, 600 and 650°C, pressure of about 25MPa, deaerated or saturated dissolved hydrogen (STP). Samples are nickel base alloy type Hastelloy C276, austenitic stainless steels type 304NG and AL-6XN, ferritic/martensitic (F/M) steel type P92, and oxide dispersion strengthened steel MA 956. This paper focuses on the formation and breakdown of corrosion oxide scales, and proposes the future trend for the development of SCWR fuel cladding materials. (author)

  14. Are new TiNbZr alloys potential substitutes of the Ti6Al4V alloy for dental applications? An electrochemical corrosion study

    International Nuclear Information System (INIS)

    The main aim of this work was to assess the electrochemical behavior of new Ti35Nb5Zr and Ti35Nb10Zr alloys in artificial saliva at 37 °C to verify if they are indicated to be used as biomaterials in dentistry as alternatives to Ti6Al4V alloys in terms of corrosion protection efficiency of the material. Electrochemical impedance spectroscopy (EIS) experiments were carried out for different periods of time (0.5–216 h) in a three-electrode cell, where the working electrode (Ti alloys) was exposed to artificial saliva at 37 °C. The near-surface region of the alloys was investigated using x-ray photoelectron spectroscopy (XPS). All alloys exhibited an increase in corrosion potential with the immersion time, indicating the growth and stabilization of the passive film. Ti35Nb5Zr and Ti6Al4V alloys had their EIS results interpreted by a double-layer circuit, while the Ti35Nb10Zr alloy was modeled by a one-layer circuit. In general, the new TiNbZr alloys showed similar behavior to that observed for the Ti6Al4V. XPS results suggest, in the case of the TiNbZr alloys, the presence of a thicker passive layer containing a lower fraction of TiO2 phase than that of Ti6Al4V. After long-term immersion, all alloys develop a calcium phosphate phase on the surface. The new TiNbZr alloys appear as potential candidates to be used as a substitute to Ti6Al4V in the manufacturing of dental implant-abutment sets. (paper)

  15. Are new TiNbZr alloys potential substitutes of the Ti6Al4V alloy for dental applications? An electrochemical corrosion study.

    Science.gov (United States)

    Ribeiro, Ana Lúcia Roselino; Hammer, Peter; Vaz, Luís Geraldo; Rocha, Luís Augusto

    2013-12-01

    The main aim of this work was to assess the electrochemical behavior of new Ti35Nb5Zr and Ti35Nb10Zr alloys in artificial saliva at 37 °C to verify if they are indicated to be used as biomaterials in dentistry as alternatives to Ti6Al4V alloys in terms of corrosion protection efficiency of the material. Electrochemical impedance spectroscopy (EIS) experiments were carried out for different periods of time (0.5-216 h) in a three-electrode cell, where the working electrode (Ti alloys) was exposed to artificial saliva at 37 °C. The near-surface region of the alloys was investigated using x-ray photoelectron spectroscopy (XPS). All alloys exhibited an increase in corrosion potential with the immersion time, indicating the growth and stabilization of the passive film. Ti35Nb5Zr and Ti6Al4V alloys had their EIS results interpreted by a double-layer circuit, while the Ti35Nb10Zr alloy was modeled by a one-layer circuit. In general, the new TiNbZr alloys showed similar behavior to that observed for the Ti6Al4V. XPS results suggest, in the case of the TiNbZr alloys, the presence of a thicker passive layer containing a lower fraction of TiO2 phase than that of Ti6Al4V. After long-term immersion, all alloys develop a calcium phosphate phase on the surface. The new TiNbZr alloys appear as potential candidates to be used as a substitute to Ti6Al4V in the manufacturing of dental implant-abutment sets. PMID:24280708

  16. Machining of titanium alloys

    CERN Document Server

    2014-01-01

    This book presents a collection of examples illustrating the resent research advances in the machining of titanium alloys. These materials have excellent strength and fracture toughness as well as low density and good corrosion resistance; however, machinability is still poor due to their low thermal conductivity and high chemical reactivity with cutting tool materials. This book presents solutions to enhance machinability in titanium-based alloys and serves as a useful reference to professionals and researchers in aerospace, automotive and biomedical fields.

  17. Refractory alloy component fabrication

    International Nuclear Information System (INIS)

    Purpose of this report is to describe joining procedures, primarily welding techniques, which were developed to construct reliable refractory alloy components and systems for advanced space power systems. Two systems, the Nb-1Zr Brayton Cycle Heat Receiver and the T-111 Alloy Potassium Boiler Development Program, are used to illustrate typical systems and components. Particular emphasis is given to specific problems which were eliminated during the development efforts. Finally, some thoughts on application of more recent joining technology are presented. 78 figures

  18. Pareto-optimal alloys

    DEFF Research Database (Denmark)

    Bligaard, Thomas; Johannesson, Gisli Holmar; Ruban, Andrei; Skriver, Hans Lomholt; Jacobsen, Karsten Wedel; Nørskov, Jens Kehlet

    2003-01-01

    cost. In this letter we present a database consisting of the lattice parameters, bulk moduli, and heats of formation for over 64 000 ordered metallic alloys, which has been established by direct first-principles density-functional-theory calculations. Furthermore, we use a concept from economic theory......, the Pareto-optimal set, to determine optimal alloy solutions for the compromise between low compressibility, high stability, and cost....

  19. MANHATTAN DISTRICT HISTORY PROJECT Y THE LOS ALAMOS PROJECT VOL. I INCEPTION UNTIL AUGUST 1945

    Energy Technology Data Exchange (ETDEWEB)

    Hawkins, D.

    1961-12-01

    THESE TWO VOLUMES CONSTITUTE A RECORD OF THE TECHNICAL, ADMINISTRATIVE , AND POLICY-MAKING ACTIVITIES OF THE LOS ALAMOS PROJECT (PROJECT Y) FROM ITS INCEPTION UNDER THE MANHATTAN DISTRICT THROUGH THE DEVELOPMENT OF THE ATOMIC BOMB (VOL. I), AND DURING THE PERIOD FOLLOWING THE END OF WORLD WAR II UNTIL THE MANHATTAN DISTRICT RELINQUISHED CONTROL TO THE ATOMIC ENERGY COMMISSION AS OF JANUARY 1947 (VOL. II). ALTHOUGH SECURITY REGULATIONS HAVE REQUIRED SOME DELETIONS IN THE ORIGINAL TEXT OF THE TWO VOLUMES, EVERY EFFORT HAS BEEN MADE TO RETAIN THE ORIGINAL LANGUAGE AND EXPRESSIONS OF THE AUTHORS.

  20. MANHATTAN DISTRICT HISTORY PROJECT Y THE LOS ALAMOS PROJECT VOL. II AUGUST 1945 THROUGH DECEMBER 1946

    Energy Technology Data Exchange (ETDEWEB)

    Truslow, E. C.; Smith, R. C.

    1961-12-01

    THESE TWO VOLUMES CONSTITUTE A RECORD OF THE TECHNICAL, ADMINISTRATIVE , AND POLICY-MAKING ACTIVITIES OF THE LOS ALAMOS PROJECT (PROJECT Y) FROM ITS INCEPTION UNDER THE MANHATTAN DISTRICT THROUGH THE DEVELOPMENT OF THE ATOMIC BOMB (VOL. I), AND DURING THE PERIOD FOLLOWING THE END OF WORLD WAR II UNTIL THE MANHATTAN DISTRICT RELINQUISHED CONTROL TO THE ATOMIC ENERGY COMMISSION AS OF JANUARY 1947 (VOL. II). ALTHOUGH SEC URITY REGULATIONS HAVE REQUIRED SOME DELETIONS IN THE ORIGINAL TEXT OF THE TWO VOLUMES, EVERY EFFORT HAS BEEN MADE TO RETAIN THE ORIGINAL LANGUGAGE AND EXPERSSIONS OF THE AUTHORS.

  1. Production and characterization of Al-Mg matrix composite by mechanical alloying

    International Nuclear Information System (INIS)

    Mechanical alloying technique has been used to produce aluminium-based metal matrix composite powders. Powders of AI, Mg (5 wt %) and SiC (10-40 vol %) were used for the composite development. These powders were mechanically mixed in planetary ball mill (Retsch PM 200). The parameters used were 10:1 ball to powder weight ratio, 800 rpm speed of vial rotation and WC as grinding media. These milled powders were characterized by XRD. Mechanical alloying for the production of composite was achieved in only one step. There was decrease in density with the increase of contents of SiC. Compacted samples were sintered at 580 Co for 80 minutes. Maximum density achieved was 98.7% for composite containing 40 % SiC. Vickers hardness of consolidated samples was found to increase with the increase of SiC contents. (author)

  2. Production of chromium base alloys by ball milling in hydrogen iodide

    Science.gov (United States)

    Arias, A.

    1975-01-01

    The effects of processing variables on the tensile properties and ductile-to-brittle transition temperature (DBTT) of Cr + 4 vol% ThO2 alloys and of pure Cr produced by ball milling in hydrogen iodide were investigated. Hot rolled Cr + ThO2 was stronger than either hot pressed Cr + ThO2 or pure Cr at temperatures up to 1540 C. Hot pressed Cr + ThO2 had a DBTT of 500 C as compared with -8 to 24 C for the hot rolled Cr + ThO2 and with 140 C for pure Cr. It is postulated that the dispersoid in the hot rolled alloys lowers the DBTT by inhibiting recovery and recrystallization of the strained structure.

  3. Microstructure and mechanical properties of aluminum alloy matrix composite reinforced with nano-particle MgO

    Energy Technology Data Exchange (ETDEWEB)

    Yar, A. Ansary, E-mail: arash_ansaryyar@yahoo.co [Department of Materials, Islamic Azad University, South Tehran Branch, P.O. Box 11365-4435, Tehran (Iran, Islamic Republic of); Montazerian, M.; Abdizadeh, H. [School of Metallurgy and Materials Engineering, University of Tehran, P.O. Box 11365-4563, Tehran (Iran, Islamic Republic of); Baharvandi, H.R. [Malek Ashtar University of Technology, P.O. Box 16765-3454, Tehran (Iran, Islamic Republic of)

    2009-09-18

    In this research, aluminum alloy (A356.1) matrix composites reinforced with 1.5, 2.5 and 5 vol% nano-particle MgO were fabricated via stir casting method. Fabrication was performed at various casting temperatures, viz. 800, 850 and 950 deg. C. Optimum amount of reinforcement and casting temperature were determined by evaluating the density, microstructure and mechanical properties of composites. The composites were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Hardness and compression tests were carried out in order to identify mechanical properties. The results reveal that the composites containing 1.5 vol% reinforcement particle fabricated at 850 deg. C have homogenous microstructure as well as improved mechanical properties.

  4. Screening on binary Zr-1X (X = Ti, Nb, Mo, Cu, Au, Pd, Ag, Ru, Hf and Bi) alloys with good in vitro cytocompatibility and magnetic resonance imaging compatibility.

    Science.gov (United States)

    Zhou, F Y; Qiu, K J; Li, H F; Huang, T; Wang, B L; Li, L; Zheng, Y F

    2013-12-01

    In this study, the microstructures, mechanical properties, corrosion behaviors, in vitro cytocompatibility and magnetic susceptibility of Zr-1X alloys with various alloying elements, including Ti, Nb, Mo, Cu, Au, Pd, Ag, Ru, Hf and Bi, were systematically investigated to explore their potential use in biomedical applications. The experimental results indicated that annealed Zr-1X alloys consisted entirely or primarily of α phase. The alloying elements significantly increased the strength and hardness of pure Zr and had a relatively slight influence on elastic modulus. Ru was the most effective enhancing element and Zr-1Ru alloy had the largest elongation. The results of electrochemical corrosion indicated that adding various elements to Zr improved its corrosion resistance, as indicated by the reduced corrosion current density. The extracts of the studied Zr-1X alloys produced no significant deleterious effects on osteoblast-like cells (MG 63), indicating good in vitro cytocompatibility. All except for Zr-1Ag alloy showed decreased magnetic susceptibility compared to pure Zr, and Zr-1Ru alloy had the lowest magnetic susceptibility value, being comparable to that of α' phase Zr-Mo alloy and Zr-Nb alloy and far lower than that of Co-Cr alloy and Ti-6Al-4V alloy. Among the experimental Zr-1X alloys, Zr-1Ru alloy possessing high strength coupled with good ductility, good in vitro cytocompatibility and low magnetic susceptibility may be a good candidate alloy for medical devices within a magnetic resonance imaging environment. PMID:23928334

  5. Evaluating historical candidate genes for schizophrenia.

    Science.gov (United States)

    Farrell, M S; Werge, T; Sklar, P; Owen, M J; Ophoff, R A; O'Donovan, M C; Corvin, A; Cichon, S; Sullivan, P F

    2015-05-01

    Prior to the genome-wide association era, candidate gene studies were a major approach in schizophrenia genetics. In this invited review, we consider the current status of 25 historical candidate genes for schizophrenia (for example, COMT, DISC1, DTNBP1 and NRG1). The initial study for 24 of these genes explicitly evaluated common variant hypotheses about schizophrenia. Our evaluation included a meta-analysis of the candidate gene literature, incorporation of the results of the largest genomic study yet published for schizophrenia, ratings from informed researchers who have published on these genes, and ratings from 24 schizophrenia geneticists. On the basis of current empirical evidence and mostly consensual assessments of informed opinion, it appears that the historical candidate gene literature did not yield clear insights into the genetic basis of schizophrenia. A likely reason why historical candidate gene studies did not achieve their primary aims is inadequate statistical power. However, the considerable efforts embodied in these early studies unquestionably set the stage for current successes in genomic approaches to schizophrenia. PMID:25754081

  6. Texture in low-alloyed uranium alloys

    International Nuclear Information System (INIS)

    The dependence of the preferred orientation of cast and heat-treated polycrystalline adjusted uranium and uranium -0.1 w/o chromium alloys on the production process was studied. The importance of obtaining material free of preferred orientation is explained, and a survey of the regular methods to determine preferred orientation is given. Dilatometry, tensile testing and x-ray diffraction were used to determine the extent of the directionality of these alloys. Data processing showed that these methods are insufficient in a case of a material without any plastic forming, because of unreproducibility of results. Two parameters are defined from the results of Schlz's method diffraction test. These parameters are shown theoretically and experimentally (by extreme-case samples) to give the deviation from isotropy. Application of these parameters to the examined samples showes that cast material has preferred orientation, though it is not systematic. This preferred orientation was reduced by adequate heat treatments

  7. Deformation behaviour and microstructural development in 6061 aluminium alloy containing large Al2O3 particles at elevated temperature

    International Nuclear Information System (INIS)

    Hot deformation behaviour of 6061 aluminium alloy containing 15 vol.% of Al2O3 particles (average size 25 μm) was studied in a temperature range of 200 to 500 deg C at constant strain rates 0.001-1s1. True stress-true strain curves of the composite shows that dynamic recovery is occurring during deformation at high temperature. Effect of temperature and strain rate on the deformation behaviour of the reinforced material was studied by evaluating stress exponent, n' and activation energy, Q. It was found that the reinforced material exhibited slightly higher n' and Q values than the unreinforced alloy. The composite displayed much higher strength compared to the monolithic alloy at low temperature and as temperature increased, the strength of the composite decreased rapidly, and the difference in the flow stresses for the two materials became smaller. Finer substructure was present in the reinforced alloy compared to the monolithic alloy under similar deformation conditions. Subgrain size was found to be inversely related to InZ (Z is temperature compensated strain rate) and flow stress, σ, for both reinforced and unreinforced alloys. 23 refs., 1 tab., 10 figs

  8. Closing the door on dark matter candidates

    International Nuclear Information System (INIS)

    Cold dark matter candidates - if they exist - will be present in, and perhaps dominate the mass density of, the halo of our Galaxy. As they pass the vicinity of the Sun, such halo particles will be focussed gravitationally, pass through the Sun and - occasionally - be captured and accumulate in the solar core. When the density in the core of the Sun of dark matter candidates has increased sufficiently, they will annihilate and among the annihilation products will be energetic (≥ GeV) ''ordinary'' neutrinos (νe, νμ, ντ) which are detectable in deep underground experiments. The event rates in such detectors from the capture and annihilation of various dark matter candidates (Dirac and Majorana neutrinos, Sneutrinos and Photinos) are presented and it is shown how comparison with data may lead to constraints on (or, the exclusion of) the masses of these particles. 6 refs

  9. WC-3015 alloy (high-temperature alloy)

    International Nuclear Information System (INIS)

    WC-3015 Nb alloy containing 28 to 30 Hf, 1 to 2 Zr, 13 to 16 W, 0 to 4 Ta, 0 to 5 Ti, 0.07 to 0.33 C, less than or equal to 0.02 N, less than or equal to 0.03 O, less than or equal to 0.001 H was developed for use at high temperature in oxidizing environments. Its composition can be tailored to meet specific requirements. When WC-3015 is exposed to O at elevated temperature, Hf and Nb oxidized preferentially and HfO2 dissolves in Nb2O5 to form 6HfO-Nb2O5. This complex oxide has a tight cubic lattice which resists the diffusion of O into the substrate. During 24-h exposure to air at 24000F, the alloy oxidizes to a depth of approximately 0.035 in. with a surface recession of 0 to 0.004 in. Oxidation resistance of WC-3015 welds and base material can be further enhanced greatly by applying silicide coatings. WC-3015 alloy can be machined by conventional and electrical-discharge methods. It can be hot worked readily by extrusion, forging or rolling. Cold working can be used at room or elevated temperature. It can be welded by the electron-beam or Tig processes. Physical constants, typical mechanical properties at 75 to 24000F, and effects of composition and heat treatment on tensile and stress-rupture properties of the alloy are tabulated

  10. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    Energy Technology Data Exchange (ETDEWEB)

    Gdowski, G.E.; Bullen, D.B. (Science and Engineering Associates, Inc., Pleasanton, CA (USA))

    1988-08-01

    Three copper-based alloys and three iron- to nickel-based austenitic alloys are being considered as possible materials for fabrication of containers for disposal of high-level radioactive waste. This waste will include spent fuel assemblies from reactors as well as high-level waste in borosilicate glass and will be sent to the prospective site at Yucca Mountain, Nevada, for disposal. The containers must maintain substantially complete containment for at least 300 yr and perhaps as long as 1000 yr. During the first 50 yr after emplacement, they must be retrievable from the disposal site. Shortly after the containers are emplaced in the repository, they will be exposed to high temperatures and high gamma radiation fields from the decay of the high-level waste. This volume surveys the available data on oxidation and corrosion of the iron- to nickel-based austenitic materials (Types 304L and 316L stainless steels and Alloy 825) and the copper-based alloy materials (CDA 102 (oxygen-free copper), CDA 613 (Cu-7Al), and CDA 715 (Cu-30Ni)), which are the present candidates for fabrication of the containers. Studies that provided a large amount of data are highlighted, and those areas in which little data exists are identified. Examples of successful applications of these materials are given. On the basis of resistance to oxidation and general corrosion, the austenitic materials are ranked as follows: Alloy 825 (best), Type 316L stainless steel, and then Type 304L stainless steel (worst). For the copper-based materials, the ranking is as follows: CDA 715 and CDA 613 (both best), and CDA 102 (worst). 110 refs., 30 figs., 13 tabs.

  11. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    International Nuclear Information System (INIS)

    Three copper-based alloys and three iron- to nickel-based austenitic alloys are being considered as possible materials for fabrication of containers for disposal of high-level radioactive waste. This waste will include spent fuel assemblies from reactors as well as high-level waste in borosilicate glass and will be sent to the prospective site at Yucca Mountain, Nevada, for disposal. The containers must maintain substantially complete containment for at least 300 yr and perhaps as long as 1000 yr. During the first 50 yr after emplacement, they must be retrievable from the disposal site. Shortly after the containers are emplaced in the repository, they will be exposed to high temperatures and high gamma radiation fields from the decay of the high-level waste. This volume surveys the available data on oxidation and corrosion of the iron- to nickel-based austenitic materials (Types 304L and 316L stainless steels and Alloy 825) and the copper-based alloy materials [CDA 102 (oxygen-free copper), CDA 613 (Cu-7Al), and CDA 715 (Cu-30Ni)], which are the present candidates for fabrication of the containers. Studies that provided a large amount of data are highlighted, and those areas in which little data exists are identified. Examples of successful applications of these materials are given. On the basis of resistance to oxidation and general corrosion, the austenitic materials are ranked as follows: Alloy 825 (best), Type 316L stainless steel, and then Type 304L stainless steel (worst). For the copper-based materials, the ranking is as follows: CDA 715 and CDA 613 (both best), and CDA 102 (worst). 110 refs., 30 figs., 13 tabs

  12. Biocompatibility of new Ti-Nb-Ta base alloys.

    Science.gov (United States)

    Hussein, Abdelrahman H; Gepreel, Mohamed A-H; Gouda, Mohamed K; Hefnawy, Ahmad M; Kandil, Sherif H

    2016-04-01

    β-type titanium alloys are promising materials in the field of medical implants. The effect of β-phase stability on the mechanical properties, corrosion resistance and cytotoxicity of a newly designed β-type (Ti77Nb17Ta6) biocompatible alloys are studied. The β-phase stability was controlled by the addition of small quantities of Fe and O. X-ray diffraction and microstructural analysis showed that the addition of O and Fe stabilized the β-phase in the treated solution condition. The strength and hardness have increased with the increase in β-phase stability while ductility and Young's modulus have decreased. The potentio-dynamic polarization tests showed that the corrosion resistance of the new alloys is better than Ti-6Al-4V alloy by at least ten times. Neutral red uptake assay cytotoxicity test showed cell viability of at least 95%. The new alloys are promising candidates for biomedical applications due to their high mechanical properties, corrosion resistance, and reduced cytotoxicity. PMID:26838885

  13. Technology status of tantalum alloys for space nuclear power applications

    International Nuclear Information System (INIS)

    Tantalum alloys have a variety of properties which make them attractive candidates for application in nuclear power systems required to operate in space at elevated temperatures (1200 to 16000K) for extended time periods. Most of the technology development on this class of alloys which is pertinent to space system application occurred during the 1960 to 1972 time period under NASA sponsorship. The most extensive data bases resulting from this earlier work were obtained on the alloys T-111 (Ta-8W-2Hf) and ASTAR 811C (Ta-8W-1Re-0.7Hf-0.025C). Emphasis in this paper is directed at the following technical factors: producibility, creep strength, weldability and compatibility. These factors are considered to be the most important elements in the selection of alloys for this application. Review of the available information indicates that alloys of this type are appropriate for application in many systems, particularly those utilizing alkali metals as the working fluid. 43 refs

  14. Corrosion behavior of β titanium alloys for biomedical applications

    International Nuclear Information System (INIS)

    The corrosion behavior of biocompatible β titanium alloys Ti-13Mo-7Zr-3Fe (TMZF) and Ti-35Nb-7Zr-5Ta (TiOsteum) was investigated in 0.9% NaCl and 5 M HCl solutions. Extra-low-interstitial Ti-6Al-4V, which is also a candidate material for biomedical applications, was studied for comparison. The as-received TiOsteum and TMZF alloys exhibited single-phase β and α + β microstructures, respectively, so the latter was also investigated in the solutionized and quenched condition. In 0.9% NaCl solution, all three alloys exhibited spontaneous passivity and very low corrosion rates. Ti-6Al-4V and the as-received TMZF exhibited active-passive transitions in 5 M HCl whereas TiOsteum and TMZF in the metastable β condition showed spontaneous passivity. Potentiodynamic polarization tests, weight loss and immersion tests revealed that TiOsteum exhibited the best corrosion resistance in 5 M HCl. Analysis of surfaces of the corroded specimens indicated that the α/β phase boundaries were preferential sites for corrosion in Ti-6Al-4V while the β phase was preferentially attacked in the two-phase TMZF. The performance of the alloys in corrosive environment was discussed in terms of the volume fraction of the constituent phases and partitioning of alloying elements between these phases.

  15. Mechanical Properties and Corrosion Characteristics of Thermally Aged Alloy 22

    Energy Technology Data Exchange (ETDEWEB)

    Rebak, R B; Crook, P

    2002-05-30

    Alloy 22 (UNS N06022) is a candidate material for the external wall of the high level nuclear waste containers for the potential repository site at Yucca Mountain. In the mill-annealed (MA) condition, Alloy 22 is a single face centered cubic phase. When exposed to temperatures on the order of 600 C and above for times higher than 1 h, this alloy may develop secondary phases that reduce its mechanical toughness and corrosion resistance. The objective of this work was to age Alloy 22 at temperatures between 482 C and 760 C for times between 0.25 h and 6,000 h and to study the mechanical and corrosion performance of the resulting material. Aging was carried out using wrought specimens as well as gas tungsten arc welded (GTAW) specimens. Mechanical and corrosion testing was carried out using ASTM standards. Results show-that the higher the aging temperature and the longer the aging time, the lower the impact toughness of the aged material and the lower its corrosion resistance. However, extrapolating both mechanical and corrosion laboratory data predicts that Alloy 22 will remain corrosion resistant and mechanically robust for the projected lifetime of the waste container.

  16. Corrosion behavior of {beta} titanium alloys for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Atapour, M. [Department of Materials Science and Engineering, Ohio State University, Columbus, OH 43210 (United States); Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Pilchak, A.L. [Department of Materials Science and Engineering, Ohio State University, Columbus, OH 43210 (United States); Air Force Research Laboratory, Materials and Manufacturing Directorate/RXLM, Wright Patterson Air Force Base, OH 45433 (United States); Universal Technology Corporation, Dayton OH 45432 (United States); Frankel, G.S., E-mail: frankel.10@osu.edu [Department of Materials Science and Engineering, Ohio State University, Columbus, OH 43210 (United States); Williams, J.C. [Department of Materials Science and Engineering, Ohio State University, Columbus, OH 43210 (United States)

    2011-07-20

    The corrosion behavior of biocompatible {beta} titanium alloys Ti-13Mo-7Zr-3Fe (TMZF) and Ti-35Nb-7Zr-5Ta (TiOsteum) was investigated in 0.9% NaCl and 5 M HCl solutions. Extra-low-interstitial Ti-6Al-4V, which is also a candidate material for biomedical applications, was studied for comparison. The as-received TiOsteum and TMZF alloys exhibited single-phase {beta} and {alpha} + {beta} microstructures, respectively, so the latter was also investigated in the solutionized and quenched condition. In 0.9% NaCl solution, all three alloys exhibited spontaneous passivity and very low corrosion rates. Ti-6Al-4V and the as-received TMZF exhibited active-passive transitions in 5 M HCl whereas TiOsteum and TMZF in the metastable {beta} condition showed spontaneous passivity. Potentiodynamic polarization tests, weight loss and immersion tests revealed that TiOsteum exhibited the best corrosion resistance in 5 M HCl. Analysis of surfaces of the corroded specimens indicated that the {alpha}/{beta} phase boundaries were preferential sites for corrosion in Ti-6Al-4V while the {beta} phase was preferentially attacked in the two-phase TMZF. The performance of the alloys in corrosive environment was discussed in terms of the volume fraction of the constituent phases and partitioning of alloying elements between these phases.

  17. Characterization of the microstructure in Mg based alloy

    KAUST Repository

    Kutbee, Arwa T

    2013-06-01

    The cast products Mg–Sn based alloys are promising candidates for automobile industries, since they provide a cheap yet thermally stable alternative to existing alloys. One drawback of the Mg–Sn based alloys is their insufficient hardness. The hardenability can be improved by engineering the microstructure through additions of Zn to the base alloy and selective aging conditions. Therefore, detailed knowledge about the microstructural characteristics and the role of Zn to promote precipitation hardening is essential for age hardenable Mg-based alloys. In this work, microstructural investigation of the Mg–1.4Sn–1.3Zn–0.1Mn (at.%) precipitation system was performed using TEM. The chemical composition of the precipitates was analyzed using EDS. APT was employed to obtain precise chemical information on the distribution of Zn in the microstructure. It was found from microstructural studies that different precipitates with varying sizes and phases were present; lath-shaped precipitates of the Mg2Sn phase have an incoherent interface with the matrix, unlike the lath-shaped MgZn2 precipitates. Furthermore, nano-sized precipitates dispersed in the microstructure with short-lath morphology can either be enriched with Sn or Zn. On the other hand, APT analysis revealed the strong repulsion between Sn and Zn atoms in a portion of the analysis volume. However, larger reconstruction volume required to identify the role of Zn is still limited to the optimization of specimen preparation.

  18. Cattle Candidate Genes for Meat Production Traits

    OpenAIRE

    Bláhová, Alice

    2013-01-01

    The objective of this study was to compile a summary of the most important candidate genes for meat production. The studied genes were: GH, GHR, MSTN, MyoD family, leptin, IGF, TG5, SCD, DGAT and STAT5A. Growth hormone (GH) is involved in physiological processes of growth and metabolism. Growth hormone receptor (GHR) has been proposed as a candidate gene for meat production in cattle. Myostatin is a significant marker. It affects the amount of muscle, reduces marbling and elevate meat tendern...

  19. Mechanisms of oxygen reduction reactions for carbon alloy catalysts via first principles molecular dynamics

    International Nuclear Information System (INIS)

    Carbon alloy catalysts (CACs) are one of promising candidates for platinum-substitute cathode catalysts for polymer electrolyte fuel cells. We have investigated possible mechanisms of oxygen reduction reactions (ORRs) for CACs via first-principles-based molecular dynamics simulations. In this contribution, we review possible ORRs at likely catalytic sites of CACs suggested from our simulations. (author)

  20. Suitability of Tophet C-Alloy 52/Kovar components to hydrogen environments

    International Nuclear Information System (INIS)

    The suitability of Tophet C-Alloy 52/Kovar weldments to hydrogen embrittlement were investigated because of their potential as candidate materials in fabrication of minaturized initiators for pyrotechnics. Cathodic charged samples were statically loaded for extended periods of time resulting in no load failures and in ductile fracture surfaces indicating resistance to hydrogen embrittlement. 20 figures

  1. Titanium alloys. Advances in alloys, processes, products and applications

    OpenAIRE

    Blenkinsop, P.

    1993-01-01

    The last few years have been a period of consolidation of existing alloys and processes. While the aerospace industry remains the principal driving force for alloy development, the paper illustrates examples of new markets being established in "older" alloys, by a combination of product/process development and a re-examination of engineering design parameters. Considerable attention is still being directed towards the titanium aluminide systems, but other more conventional alloy developments ...

  2. Correlation between diffusion barriers and alloying energy in binary alloys

    DEFF Research Database (Denmark)

    Vej-Hansen, Ulrik Grønbjerg; Rossmeisl, Jan; Stephens, Ifan; Schiøtz, Jakob

    2016-01-01

    In this paper, we explore the notion that a negative alloying energy may act as a descriptor for long term stability of Pt-alloys as cathode catalysts in low temperature fuel cells.......In this paper, we explore the notion that a negative alloying energy may act as a descriptor for long term stability of Pt-alloys as cathode catalysts in low temperature fuel cells....

  3. Low modulus Ti–Nb–Hf alloy for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    González, M., E-mail: Marta.Gonzalez.Colominas@upc.edu [Department of Materials Science and Metallurgy, Universitat Politècnica de Catalunya (UPC), Avda. Diagonal 647, 08028 Barcelona (Spain); Materials Science, Elisava Escola Superior de Disseny i Enginyeria de Barcelona, La Rambla 30-32, 08002 Barcelona (Spain); Peña, J. [Department of Materials Science and Metallurgy, Universitat Politècnica de Catalunya (UPC), Avda. Diagonal 647, 08028 Barcelona (Spain); Materials Science, Elisava Escola Superior de Disseny i Enginyeria de Barcelona, La Rambla 30-32, 08002 Barcelona (Spain); Gil, F.J.; Manero, J.M. [Department of Materials Science and Metallurgy, Universitat Politècnica de Catalunya (UPC), Avda. Diagonal 647, 08028 Barcelona (Spain); Ciber-BBN (Spain)

    2014-09-01

    β-Type titanium alloys with a low elastic modulus are a potential strategy to reduce stress shielding effect and to enhance bone remodeling in implants used to substitute failed hard tissue. For biomaterial application, investigation on the mechanical behavior, the corrosion resistance and the cell response is required. The new Ti25Nb16Hf alloy was studied before and after 95% cold rolling (95% C.R.). The mechanical properties were determined by tensile testing and its corrosion behavior was analyzed by potentiostatic equipment in Hank's solution at 37 °C. The cell response was studied by means of cytotoxicity evaluation, cell adhesion and proliferation measurements. The stress–strain curves showed the lowest elastic modulus (42 GPa) in the cold worked alloy and high tensile strength, similar to that of Ti6Al4V. The new alloy exhibited better corrosion resistance in terms of open circuit potential (E{sub OCP}), but was similar in terms of corrosion current density (i{sub CORR}) compared to Ti grade II. Cytotoxicity studies revealed that the chemical composition of the alloy does not induce cytotoxic activity. Cell studies in the new alloy showed a lower adhesion and a higher proliferation compared to Ti grade II presenting, therefore, mechanical features similar to those of human cortical bone and, simultaneously, a good cell response. - Highlights: • Presents low elastic modulus and high strength and elastic deformability. • Exhibits good biocompatibility in terms of cytotoxicity and cell response. • Corrosion resistance of this alloy is good, similar to that of Ti grade II. • Potential candidate for implants used to substitute failed hard tissue.

  4. Development of Oxidation Protection Coatings for Gamma Titanium Aluminide Alloys

    Science.gov (United States)

    Wallace, T. A.; Bird, R. K.; Sankaran, S. N.

    2003-01-01

    Metallic material systems play a key role in meeting the stringent weight and durability requirements for reusable launch vehicle (RLV) airframe hot structures. Gamma titanium aluminides (gamma-TiAl) have been identified as high-payoff materials for high-temperature applications. The low density and good elevated temperature mechanical properties of gamma-TiAl alloys make them attractive candidates for durable lightweight hot structure and thermal protection systems at temperatures as high as 871 C. However, oxidation significantly degrades gamma-TiAl alloys under the high-temperature service conditions associated with the RLV operating environment. This paper discusses ongoing efforts at NASA Langley Research Center to develop durable ultrathin coatings for protecting gamma-TiAl alloys from high-temperature oxidation environments. In addition to offering oxidation protection, these multifunctional coatings are being engineered to provide thermal control features to help minimize heat input into the hot structures. This paper describes the coating development effort and discusses the effects of long-term high-temperature exposures on the microstructure of coated and uncoated gamma-TiAl alloys. The alloy of primary consideration was the Plansee alloy gamma-Met, but limited studies of the newer alloy gamma-Met-PX were also included. The oxidation behavior of the uncoated materials was evaluated over the temperature range of 704 C to 871 C. Sol-gel-based coatings were applied to the gamma-TiAl samples by dipping and spraying, and the performance evaluated at 871 C. Results showed that the coatings improve the oxidation resistance, but that further development is necessary.

  5. Low modulus Ti–Nb–Hf alloy for biomedical applications

    International Nuclear Information System (INIS)

    β-Type titanium alloys with a low elastic modulus are a potential strategy to reduce stress shielding effect and to enhance bone remodeling in implants used to substitute failed hard tissue. For biomaterial application, investigation on the mechanical behavior, the corrosion resistance and the cell response is required. The new Ti25Nb16Hf alloy was studied before and after 95% cold rolling (95% C.R.). The mechanical properties were determined by tensile testing and its corrosion behavior was analyzed by potentiostatic equipment in Hank's solution at 37 °C. The cell response was studied by means of cytotoxicity evaluation, cell adhesion and proliferation measurements. The stress–strain curves showed the lowest elastic modulus (42 GPa) in the cold worked alloy and high tensile strength, similar to that of Ti6Al4V. The new alloy exhibited better corrosion resistance in terms of open circuit potential (EOCP), but was similar in terms of corrosion current density (iCORR) compared to Ti grade II. Cytotoxicity studies revealed that the chemical composition of the alloy does not induce cytotoxic activity. Cell studies in the new alloy showed a lower adhesion and a higher proliferation compared to Ti grade II presenting, therefore, mechanical features similar to those of human cortical bone and, simultaneously, a good cell response. - Highlights: • Presents low elastic modulus and high strength and elastic deformability. • Exhibits good biocompatibility in terms of cytotoxicity and cell response. • Corrosion resistance of this alloy is good, similar to that of Ti grade II. • Potential candidate for implants used to substitute failed hard tissue

  6. Mechanical properties and microstructure of copper alloys and copper alloy-stainless steel laminates for fusion reactor high heat flux applications

    Science.gov (United States)

    Leedy, Kevin Daniel

    A select group of copper alloys and bonded copper alloy-stainless steel panels are under consideration for heat sink applications in first wall and divertor structures of a planned thermonuclear fusion reactor. Because these materials must retain high strengths and withstand high heat fluxes, their material properties and microstructures must be well understood. Candidate copper alloys include precipitate strengthened CuNiBe and CuCrZr and dispersion strengthened Cu-Alsb2Osb3 (CuAl25). In this study, uniaxial mechanical fatigue tests were conducted on bulk copper alloy materials at temperatures up to 500sp°C in air and vacuum environments. Based on standardized mechanical properties measurement techniques, a series of tests were also implemented to characterize copper alloy-316L stainless steel joints produced by hot isostatic pressing or by explosive bonding. The correlation between mechanical properties and the microstructure of fatigued copper alloys and the interface of copper alloy-stainless steel laminates was examined. Commercial grades of these alloys were used to maintain a degree of standardization in the materials testing. The commercial alloys used were OMG Americas Glidcop CuAl25 and CuAl15; Brush Wellman Hycon 3HP and Trefimetaux CuNiBe; and Kabelmetal Elbrodur and Trefimetaux CuCrZr. CuAl25 and CuNiBe alloys possessed the best combination of fatigue resistance and microstructural stability. The CuAl25 alloy showed only minimal microstructural changes following fatigue while the CuNiBe alloy consistently exhibited the highest fatigue strength. Transmission electron microscopy observations revealed that small matrix grain sizes and high densities of submicron strengthening phases promoted homogeneous slip deformation in the copper alloys. Thus, highly organized fatigue dislocation structure formation, as commonly found in oxygen-free high conductivity Cu, was inhibited. A solid plate of CuAl25 alloy hot isostatically pressed to a 316L stainless steel

  7. Palladium-rare-earth metal alloys-advanced materials for hydrogen power engineering

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Hydrogen of no less than 99. 999 % (vol. fraction) purity is a principal power media of hydrogen power engineering. A single method for the preparation of high purity hydrogen consists in its separation from vapour-gas mixtures via the selective diffusion of hydrogen through a palladium membrane. The rate of hydrogen diffusion and the strength and stability during the operation in aggressive gases are important characteristics of palladium membranes. The increase in the strength, plasticity, and hydrogen-permeability of membrane alloys can be reached by alloying palladium with the formation of solid solutions.The formation of wide ranges of palladium-rare-earth metal (REM) solid solutions is an interesting feature of palladium. Earlier, we have shown that the alloying of Pd with REM substantially increases the rate of hydrogen diffusion and markedly increases the strength of palladium on retention of the adequate plasticity.In this work, we have studied alloys of the Pd-Y and Pd-Y-Me systems. It was shown that the following conditions should be satisfied to prepare high-quality alloys exhibiting high service properties: (1)the use of high-purity components (whose purity is no less than 99.95%, mass fraction), in particular,high-purity Y prepared by vacuum distillation, and (2) holding the reached purity for the final product.For this purpose, we suggested a cycle of manufacturing operations including the preparation of a vacuumtight foil of 50 (m thick as the final stage.The hydrogen-permeability of the alloys was measured at different temperatures and hydrogen pressures. The instability of operation of binary Pd-Y alloys w alloying the composition with a Ⅷ Group metal. For example, the alloy of the optimum composition Pd-8Y-Me in the annealed state exhibits the following mechanical properties: HV= 75 kg/mm2 , σu = 58 kg/mm2 , and δ= 20%. Its hydrogen-permeability (QH2) measured as a function of the temperature exceeds that of the Pd-23Ag alloy (that is widely

  8. Effect of antimony on the corrosion behavior of low-alloy steel for flue gas desulfurization system

    International Nuclear Information System (INIS)

    The alloying effect of Sb in a new low-alloy steel for the purpose of FGD materials was investigated by potentiodynamic polarization, linear polarization resistance measurement, electrochemical impedance spectroscopy (EIS) and weight loss measurements in an aggressive solution of 16.9 vol.% H2SO4 + 0.35 vol.% HCl (modified green death solution) at 60 deg. C, pH -0.3. All measurements confirmed the marked improvement in the corrosion behavior of the low-alloy steel via the addition of a small amount of Sb, particularly for the 0.10Sb steel. Pitting corrosion was detected by scanning electron microscopy (SEM) on the surface of blank steel and 0.05Sb steel, but not 0.10Sb steel, after weight loss measurements. X-ray photoelectron spectroscopy (XPS) analysis of the corroded surfaces after EIS and linear polarization measurements showed that the decrease in corrosion rates was due to the formation of a protective Sb2O5 oxide film on the surface of the Sb-containing steels. Moreover, the addition of 0.10% Sb stimulated the development of high corrosion inhibiting, Cu-containing compounds which further inhibited the anodic and cathodic reactions

  9. 49. Meeting of the Chemical Societies: Proceedings of the contributions. Vol. 2

    International Nuclear Information System (INIS)

    The publication has been set up as a abstracts of the meeting dealing with chemical problems. The book (Vol. 2) consists of the sections: (C) Physical chemistry; (D) History of the chemistry; (E) Food chemistry and technology; (D) Environmental chemistry; (E) Nuclear chemistry and radioecology; (H) Synthetic polymers

  10. Book review: Vetter, H. 2005. Terralog. Turtles of the World. Vol. 3. Central and South America

    Directory of Open Access Journals (Sweden)

    2006-12-01

    Full Text Available Book review: Vetter, H. 2005. Terralog. Turtles of the World. Vol. 3. Central and South America/Schildkröten der Welt Band 3. Mittel- und Südamerika: 1-128, color pictures 606 + 9. Edition Chimaira, Frankfurt, Germany.ISBN 3-930612-82-8; 29.7 x 20.8 cm

  11. A new look at biomedical Ti-based shape memory alloys.

    Science.gov (United States)

    Biesiekierski, Arne; Wang, James; Gepreel, Mohamed Abdel-Hady; Wen, Cuie

    2012-05-01

    Shape memory alloys (SMAs) are materials that exhibit a distinct thermomechanical coupling, one that gives rise to a wide variety of applications across a broad range of fields. One of the most successful roles is in the construction of novel medical implants. Unfortunately, concerns have been raised about the biocompatibility of the most popular SMA, nitinol (NiTi), due to the known toxic, allergenic and carcinogenic properties of nickel. Given the unique capabilities of SMAs, it is apparent that there is a need for a new class of alloys - alloys that exhibit the full range of shape memory abilities yet are also free of any undesirable side effects. This article reviews the literature surrounding SMAs and identifies the metals Ti, Au, Sn, Ta, Nb, Ru and Zr as candidates for the production of thoroughly biocompatible SMAs. Hf and Re are also promising, though more research is necessary before a definitive statement can be made. Further, the Ti-(Ta,Nb)-(Zr,Hf) alloy system is particularly suited for orthopaedic implants due to a reduced Young's modulus. However, concerns over this system's shape memory properties exist, and should be taken into consideration. Alternate alloy systems that demonstrate higher bulk moduli may still be considered, however, if they are formed into a porous structure. Due to the nature of the alloying components, blended elemental powder metallurgy is recommended for the manufacture of these alloys, particularly due to the ease with which it may be adapted to the formation of porous alloys. PMID:22326786

  12. A study of surface tension driven segregation in monotectic alloy systems

    Science.gov (United States)

    Andrews, J. Barry; Andrews, Rosalia N.; Gowens, Terrell F.

    1988-01-01

    The compatibilities of various monotectic alloy systems with several different crucible materials were evaluated. The study was carried out using small candidate alloy samples of compositions that produced fifty volume percent of each liquid phase at the monotectic temperature. Compatibility was based on the evaluation of the wetting tendency of the two immiscible phases with the crucible material in a one-g solidified sample. Three types of wetting phenomena were observed during the evaluation. Type 1 indicates an alloy-crucible combination where the L2 phase preferentially wets the crucible material. Since L2 is usually the minority phase in desirable alloys, this material combination would be difficult to process and is therefore considered incompatible. Type 2 behavior indicates an alloy-crucible combination where the L1 phase preferentially wets the crucible material. This type of combination is considered compatible since surface tension effects should aid in processing the alloy to a useful form. Type 3 indicates any combination that leads to major reactions between the alloy and crucible material, gas entrapment, or separation of the metal from the crucible wall. Additional compatibility evaluations would have to be carried out on combinations of this category. The five alloy systems studied included aluminum-bismuth, copper-lead, aluminum-indium, aluminum-lead and cadmium-gallium. The systems were combined with crucibles of alumina, boron nitride, mullite, quartz, silicon carbide and zirconia.

  13. Study crevice corrosion alloys C-22 and 625 by electrochemical noise

    International Nuclear Information System (INIS)

    C-22 and 625 alloys are two of the Ni –Cr-Mo alloys considered as candidate materials to form the corrosion resistance engineered barriers for nuclear waste repositories. The corrosion resistance of these alloys is remarkable in a wide variety of environments. Despite of their resistance these alloys are susceptible to crevice corrosion in a certain aggressive environments. This work presents the use of electrochemical noise technique to study crevice corrosion susceptibility of alloys C-22 and 625 in 1M NaCl acidic solutions at 60ºC and 90ºC. Asymmetrical electrodes and a complementary platinum electrode were used to assess the influence of cathodic reaction in crevice process. The obtained records were analyzed directly and through statistical parameters. The potential drop and the simultaneous increment of the current records indicated the occurrence of crevice corrosion. The alternative use of a platinum electrode resulted in higher currents and higher potentials and reduced the induction time to crevice formation. The reason for this behavior is that platinum surface allows faster cathodic reactions than C-22 and 625 alloys. The standard deviation of the current records was responsive to the crevice corrosion intensity. C-22 alloy had better crevice corrosion performance than 625 alloy. (author)

  14. Phase equilibria, microstructure, and high temperature oxidation resistance of novel refractory high-entropy alloys

    Energy Technology Data Exchange (ETDEWEB)

    Gorr, B., E-mail: gorr@ifwt.mb.uni-siegen.de [Institut für Werkstofftechnik, Universität Siegen, Paul-Bonatz-Str. 9-11, 57068 Siegen (Germany); Azim, M.; Christ, H.-J. [Institut für Werkstofftechnik, Universität Siegen, Paul-Bonatz-Str. 9-11, 57068 Siegen (Germany); Mueller, T. [Institut für Bau- und Werkstoffchemie, Universität Siegen, Paul-Bonatz-Str. 9-11, 57068 Siegen (Germany); Schliephake, D.; Heilmaier, M. [Institut für Angewandte Materialien – Werkstoffkunde (IAM-WK), Karlsruhe Institute of Technology (KIT), Engelbert-Arnold-Str. 4, D-76131 Karlsruhe (Germany)

    2015-03-05

    Highlights: • A new candidate for applications at high temperature is proposed. • The calculated melting point of the alloy is 1700 °C. • The alloy possesses a simple microstructure. • The alloy exhibits perspectives in terms of mechanical properties and oxidation resistance. - Abstract: A new refractory high-entropy alloy system Mo–W–Al–Cr–x is proposed as a family of candidate materials for structural applications at high temperatures. Thermodynamic assessment was used to set the chemical composition of the first alloy as 20Mo–20W–20Al–20Cr–20Ti (at.%) with a calculated melting temperature of about 1700 °C. A single disordered BCC phase should be stable at high temperatures between 1077 °C and 1700 °C. Microstructural examination and XRD results clearly show that the alloy in the as-cast condition exhibits a non-homogeneous microstructure with pronounced dendritic and interdendritic regions. Heat treatment processes, however, reveal a strong tendency of the alloy 20Mo–20W–20Al–20Cr–20Ti to homogenize. While possessing a high hardness of around 800HV, the crack-free indents allow the assumption that the alloy studied may be intrinsically ductile at room temperature. Despite the fact that the alloy possesses 40 at.% of refractory elements, high temperature oxidation tests show a surprisingly good oxidation resistance. Strategies to enhance the long-term stability of the disordered BCC phase aiming at achieving the required mechanical properties as well as optimizing the alloy’s chemical composition in terms of high temperature oxidation resistance are discussed.

  15. INVESTIGATION OF MAGNESIUM ALLOYS MACHINABILITY

    Directory of Open Access Journals (Sweden)

    Berat Barıs BULDUM

    2013-01-01

    Full Text Available Magnesium is the lightest structural metal. Magnesium alloys have a hexagonal lattice structure, which affects the fundamental properties of these alloys. Plastic deformation of the hexagonal lattice is more complicated than in cubic latticed metals like aluminum, copper and steel. Magnesium alloy developments have traditionally been driven by industry requirements for lightweight materials to operate under increasingly demanding conditions. Magnesium alloys have always been attractive to designers due to their low density, only two thirds that of aluminium and its alloys [1]. The element and its alloys take a big part of modern industry needs. Especially nowadays magnesium alloys are used in automotive and mechanical (trains and wagons manufacture, because of its lightness and other features. Magnesium and magnesium alloys are the easiest of all metals to machine, allowing machining operations at extremely high speed. All standard machining operations such as turning, drilling, milling, are commonly performed on magnesium parts.

  16. Structural thermodynamics of alloys

    CERN Document Server

    Manenc, Jack

    1973-01-01

    Technical progress has for a very long time been directly dependent on progress in metallurgy, which is itself connected with improvements in the technology of alloys. Metals are most frequently used in the form of alloys for several reasons: the quantity of pure metal in its native state in the earth's crust is very limited; pure metals must be extracted from ores which are themselves impure. Finally, the methods of treatment used lead more easily to alloys than to pure metals. The most typical case is that of iron, where a pure ore may be found, but which is the starting point for cast iron or steel, alloys of iron and carbon. In addition, the properties of alloys are in general superior to those of pure metals and modem metallurgy consists of controlling these properties so as to make them conform to the requirements of the design office. Whilst the engineer was formerly compelled to adapt his designs and constructions to the materials available, such as wood, stone, bronze, iron, cast iron and ordinary st...

  17. Narrow gap HST welding process and its application to candidate pipe material for 700 C USC boiler component

    Energy Technology Data Exchange (ETDEWEB)

    Bao, Gang; Sato, Takashi; Fukuda, Yuji [Babcock-Hitachi K.K., Hiroshima (Japan). Kure Research Lab.; Mitsuhata, Koichi [Babcock-Hitachi K.K., Hiroshima (Japan). Kure Div.

    2008-07-01

    Increasing steam temperature and pressure conditions of 700 C USC (Ultra Super Critical) power plants under consideration require the adoption of Ni-based alloys. One of the most crucial issues for the application of 700 C USC power plants is the establishment of welding technology for the thick-walled components. This paper reports the research results on the practicability of candidate material for the thickwalled components. The weld test was conducted on Ni-based Alloy617 (52Ni-22Cr- 13Co-9Mo-Ti-Al) by using the narrow gap HST (Hot wire Switching TIG) welding process developed by Babcock-Hitachi K.K with the matching filler wire of Alloy617. The weldability and strength properties of weld joint were examined. The sound weld joint was achieved. The advantages of narrow gap HST welding process for the thick-walled components of Ni-based alloy were discussed from the viewpoints of weld metal chemical composition and creep rupture strength. Due to the good shielding effect, the melting loss of alloy elements in the weld consumable during the narrow gap HST welding procedure was suppressed successfully. The narrow gap HST weld joint showed comparable strength with the parent metal. (orig.)

  18. Promoting Team Leadership Skills in Doctoral Candidates

    Science.gov (United States)

    Suleiman, Mahmoud; Whetton, Danny

    2014-01-01

    Doctoral programs can serve as an optimal opportunity for candidates to engage in tasks and activities to transform them and their schools. The paradigm shifts in such preparation involve moving from sitting and getting to making and taking. Most importantly, it requires building leadership skills and styles necessary to bring about desired change…

  19. Secondary Teacher Candidates' Lesson Planning Learning

    Science.gov (United States)

    Santoyo, Christina; Zhang, Shaoan

    2016-01-01

    Teacher candidates (TCs) use clinical experiences to enact concepts taught in their university courses; therefore field experiences may be the most important component of teacher preparation (Hammerness et al., 2005). TCs require support and guidance as they learn to adapt curriculum materials for effective use in the classroom (Davis, 2006). They…

  20. The Responsibility Education of Teacher Candidates

    Science.gov (United States)

    Toremen, Fatih

    2011-01-01

    In this study, it was aimed to take the views and suggestions of academicians working at the faculty of education on what can be done about teacher candidates' responsibility education. This study was designed on the basis of qualitative research approach and purposive sampling method was used. Data were collected by unstructured interview method…

  1. Microlensing Binaries with Candidate Brown Dwarf Companions

    DEFF Research Database (Denmark)

    Shin, I.-G; Han, C.; Gould, A.;

    2012-01-01

    Brown dwarfs are important objects because they may provide a missing link between stars and planets, two populations that have dramatically different formation histories. In this paper, we present the candidate binaries with brown dwarf companions that are found by analyzing binary microlensing ...

  2. FAME's Search for Extrasolar Planet Candidates

    Science.gov (United States)

    Johnston, K.

    FAME is a five year survey mission to observe the positions, proper motions, and parallaxes of 40,000,000 stars down to 15th magnitude with accuracies of 50 microarcseconds at 9th magnitude. In addition to producing an astrometric and photometric catalog unparalleled for its accuracy and size, the survey will provide significant astrophysics results and search for extrasolar planet candidates.

  3. Query by image example: The CANDID approach

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, P.M.; Cannon, M. [Los Alamos National Lab., NM (United States). Computer Research and Applications Group; Hush, D.R. [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Electrical and Computer Engineering

    1995-02-01

    CANDID (Comparison Algorithm for Navigating Digital Image Databases) was developed to enable content-based retrieval of digital imagery from large databases using a query-by-example methodology. A user provides an example image to the system, and images in the database that are similar to that example are retrieved. The development of CANDID was inspired by the N-gram approach to document fingerprinting, where a ``global signature`` is computed for every document in a database and these signatures are compared to one another to determine the similarity between any two documents. CANDID computes a global signature for every image in a database, where the signature is derived from various image features such as localized texture, shape, or color information. A distance between probability density functions of feature vectors is then used to compare signatures. In this paper, the authors present CANDID and highlight two results from their current research: subtracting a ``background`` signature from every signature in a database in an attempt to improve system performance when using inner-product similarity measures, and visualizing the contribution of individual pixels in the matching process. These ideas are applicable to any histogram-based comparison technique.

  4. Candidal Leukoplakia on Patient with Removable Denture

    Directory of Open Access Journals (Sweden)

    Shiril Paskalis

    2013-07-01

    Full Text Available Candida infection is a common problem in patients using removable dentures, with the most frequent type is denture stomatitis. But other type of candidal infection could also happen in these patients, such as candidal leukoplakia. We reported a 61 years old female patient who complained a painful lesion under her lower removable denture. Oral examination revealed white plaque that could not be rubbed over an ulcer on the lingual part of alveolar processes under the lower removable denture plate, and also an erythematous area on palatum durum above the upper full denture. The patient was suspected to have candidal leukoplakia on the lingual part of the mandible and denture stomatitis on the palate area. The treatment consisted of nystatin oral suspension, chlorhexidine solution, multivitamins, along with denture replacement and oral health education. The entire lesion resolved within 2 months therapy. Candidal infection treatment on denture patient needs not only medication or denture replacement, but also patient compliance to achieve maximal result.

  5. Social Justice Perceptions of Teacher Candidates

    Science.gov (United States)

    Turhan, Muhammed

    2010-01-01

    This study aims to determine the social justice perceptions of teacher candidates being trained in an education faculty. For this purpose, national and international literature was reviewed by the researcher and a 32-item questionnaire was developed and implemented on 237 senior year education faculty students. Data from the questionnaires were…

  6. Gallium-67 imaging in candidal esophagitis

    Energy Technology Data Exchange (ETDEWEB)

    Rundback, J.H.; Goldfarb, C.R.; Ongseng, F. (Beth Israel Medical Center, New York, NY (USA))

    1990-01-01

    Ga-67 scanning has been used to evaluate esophageal carcinoma. It has demonstrated candidal infection in other body sites and, in one previous case, in the esophagus. The authors present a case of diffuse esophageal uptake of Ga-67 in esophageal candidiasis.

  7. Gallium-67 imaging in candidal esophagitis

    International Nuclear Information System (INIS)

    Ga-67 scanning has been used to evaluate esophageal carcinoma. It has demonstrated candidal infection in other body sites and, in one previous case, in the esophagus. The authors present a case of diffuse esophageal uptake of Ga-67 in esophageal candidiasis

  8. INVESTIGATION OF MAGNESIUM ALLOYS MACHINABILITY

    OpenAIRE

    Berat Barıs BULDUM; Aydın SIK; Iskender OZKUL

    2013-01-01

    Magnesium is the lightest structural metal. Magnesium alloys have a hexagonal lattice structure, which affects the fundamental properties of these alloys. Plastic deformation of the hexagonal lattice is more complicated than in cubic latticed metals like aluminum, copper and steel. Magnesium alloy developments have traditionally been driven by industry requirements for lightweight materials to operate under increasingly demanding conditions. Magnesium alloys have always been attra...

  9. Productive Machining of Titanium Alloys

    OpenAIRE

    Čejka, Libor

    2013-01-01

    This diploma thesis is focused on a productive machining of titanium alloys. At the beginning it deals about titanium and its alloys. It describes chip generation mechanism, tool blunting and surface quality. Further it contains modern strategies of efficient titanium alloys machining. Then it analyzes contemporary manufacturing technology of hinge made of titanium alloy Ti-6Al-4V in Frentech Aerospace s.r.o. company, and at the end finds possibility of savings by inovation of roughing process.

  10. Relationship between carburization and zero-applied-stress creep dilation in Alloy 800H and Hastelloy X

    International Nuclear Information System (INIS)

    Typical HTGR candidate alloys can carburize when exposed to simulated service environments. The carbon concentration gradients so formed give rise to internal stresses which could cause dilation. Studies performed with Hastelloy X and Alloy 800H showed that dilations of up to almost 1% can occur at 10000C when carbon pickup is high. Dilation was normally observed only when the carbon increase was >1000 μg/cm2 and ceased when diffusing carbon reached the center of the specimen. (Auth.)

  11. Engineering design on optimum volume for a reactor of vol-oxidizer

    International Nuclear Information System (INIS)

    A high-capacity vol-oxidizer which can handle a several ten kgs of HM/batch is being developed to supply U3O8 powders to an electrolytic reduction reactor. It is a device for a decladding and vol-oxidation of rod-cuts (hulls + pellets) that can convert UO2 pellets to U3O8 powder. In this paper we deal with the engineering design on optimum volume for a reactor of vol-oxidizer. In order to design an optimum reactor, we evaluated various mechanical (slitting, ball mill, roller straightening) and chemical methods (muffle furnace, rotary kiln), and produced a theoretical equation which can calculate the volume with various weights and lengths of the rod-cuts. Also, with the acryl reactors with a scale of centimeters and hulls, a theoretical equation was confirmed for the safety design. In order to verify the optimum volume of vol-oxidizer reactor, the reactor and measurement system were manufactured and hull separation tests were conducted using the measurement system and hulls with 50kgHM/batch for the optimum volume of reactor. The conditions of the hull separation tests are as follows; the rotation speed of the reactor is 3-10 rpm, the variation of the spent fuel weight is from 10 kg HM/batch to 50 kg HM/batch(10, 20, 30, 40, 50 kg HM/batch), hull length is 5 cm and vibration didn't run. Finally, we have analyzed the vol-oxidizer reactor for remote operability and maintainability, also, the remote assembling and disassembling possibility of a modular reactor was tested for optimization (S/F 50 kg HM/batch). (author)

  12. De-alloyed platinum nanoparticles

    Science.gov (United States)

    Strasser, Peter; Koh, Shirlaine; Mani, Prasanna; Ratndeep, Srivastava

    2011-08-09

    A method of producing de-alloyed nanoparticles. In an embodiment, the method comprises admixing metal precursors, freeze-drying, annealing, and de-alloying the nanoparticles in situ. Further, in an embodiment de-alloyed nanoparticle formed by the method, wherein the nanoparticle further comprises a core-shell arrangement. The nanoparticle is suitable for electrocatalytic processes and devices.

  13. Low cycle fatigue life of two nickel-base casting alloys in a hydrogen environment. [for high-pressure oxidizer turbopump turbine nozzles

    Science.gov (United States)

    Cooper, R. A.

    1976-01-01

    Samples of two nickel-base casting alloys, Mar-M-246 (a Martin Company alloy) and 713LC (a low-carbon modification of the alloy 713C developed by International Nickel Company) were tested as candidate materials for the high-pressure fuel and high-pressure oxidizer turbopump turbine nozzles. The samples were subjected to tensile tests and to low cycle fatigue tests in high-pressure hydrogen to study the influence of the hydrogen environment. The Mar-M-246 material was found to have a three times higher cyclic life in hydrogen than the 713LC alloy, and was selected as the nozzle material.

  14. Bonding tungsten, W–Cu-alloy and copper with amorphous Fe–W alloy transition

    International Nuclear Information System (INIS)

    W/Cu graded materials are the leading candidate materials used as the plasma facing components in a fusion reactor. However, tungsten and copper can hardly be jointed together due to their great differences in physical properties such as coefficient of thermal expansion and melting point, and the lack of solid solubility between them. To overcome those difficulties, a new amorphous Fe–W alloy transitional coating and vacuum hot pressing (VHP) method were proposed and introduced in this paper. The morphology, composition and structure of the amorphous Fe–W alloy coating and the sintering interface of the specimens were analyzed by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) and X-ray diffraction (XRD). The thermal shock resistance of the bonded composite was also tested. The results demonstrated that amorphous structure underwent change from amorphous to nano grains during joining process, and the joined W/Cu composite can endued plasma thermal shock resistance with energy density more than 5.33 MW/m2. It provides a new feasible technical to join refractory tungsten to immiscible copper with amorphous Fe–W alloy coating

  15. Mechanical and Physical Properties of In-Zn-Ga Lead-Free Solder Alloy for Low Energy Consumption

    Science.gov (United States)

    Ervina Efzan, M. N.; Nur Faziera, M. N.; Bakri Abdullah, Mohd Mustafa Al

    2016-06-01

    Due to the demand in the use of electronics devices in industry, the usage of solder connections has increased. Concerning with the toxicity of lead in Sn-37Pb solder alloy, developing lead free solder alloy with low melting temperature is one of the most important issues in electronic industry. Previously, researchers found out that the most promising candidate of lead free solder alloy is Sn-3.0Ag-0.5Cu (SAC). However, the melting temperature of this solder alloy is 217°C, 34°C higher than Sn-37Pb. This can lead to high energy consumption in electronic industry. In this paper, In-Zn-Ga solder alloy was investigated as a potential candidate replacing SAC. This study covers on the physical and mechanical properties of the solder alloy. Differential Scanning Calorimetry (DSC) testing shows that this solder alloy gave low melting temperature as low as 141.31°C. The addition of Ga in In-Zn solder alloy lowered the melting temperature compared to SAC and Sn-37Pb. From coefficient of thermal expansion (CTE) analysis, the In-Zn-Ga solder alloy gives good expansion properties and able to avoid the mismatch between the solder and copper substrates. The density of In-Zn-Ga solder alloy is 6.801g/cm3, lower than SAC and Sn-37Pb. For the strength, single lap shear testing was conducted on the In-Zn-Ga solder alloy and the results is near to the strength of SAC.

  16. Finite Element Method (FEM) Calculations of Stress-Strain Behavior of Alpha-Beta Ti-Mn Alloys: Part I. Stress-Strain Relations

    Science.gov (United States)

    Ankem, Sreeramamurthy; Margolin, Harold

    1982-04-01

    By use of a NASTRAN18 Computer Program, the Finite Element Method (FEM) has been employed to calculate the effect of particle size, matrix, and volume fraction on the stress-strain relations of α -β titanium alloys. It was found that for a given volume fraction, the calculated stress-strain curve was higher for a finer particle size than for a coarse particle size within the range of the strains considered, and this behavior was seen for all the different volume fraction alloys considered. For a 50:50 vol pct α -β alloy, the stress-strain curve with β, the stronger phase, as the matrix was higher than that with α, the softer phase, as the matrix. The calculated stress-strain curves for four different vol pct α alloys were compared with their corresponding experimental curves, and in general, good agreement was found. Whenever there were discrepancies, they were discussed by comparing the morphology of the mesh used in the calculations with the morphology of the actual materials.

  17. Hydrogen in titanium alloys

    International Nuclear Information System (INIS)

    The titanium alloys that offer properties worthy of consideration for fusion reactors are Ti-6Al-4V, Ti-6Al-2Sn-4Zr-2Mo-Si (Ti-6242S) and Ti-5Al-6Sn-2Zr-1Mo-Si (Ti-5621S). The Ti-6242S and Ti-5621S are being considered because of their high creep resistance at elevated temperatures of 5000C. Also, irradiation tests on these alloys have shown irradiation creep properties comparable to 20% cold worked 316 stainless steel. These alloys would be susceptible to slow strain rate embrittlement if sufficient hydrogen concentrations are obtained. Concentrations greater than 250 to 500 wppm hydrogen and temperatures lower than 100 to 1500C are approximate threshold conditions for detrimental effects on tensile properties. Indications are that at the elevated temperature - low hydrogen pressure conditions of the reactors, there would be negligible hydrogen embrittlement

  18. Shape Memory Alloys

    Directory of Open Access Journals (Sweden)

    Deexith Reddy

    2016-07-01

    Full Text Available Shape memory alloys (SMAs are metals that "remember" their original shapes. SMAs are useful for such things as actuators which are materials that "change shape, stiffness, position, natural frequency, and other mechanical characteristics in response to temperature or electromagnetic fields" The potential uses for SMAs especially as actuators have broadened the spectrum of many scientific fields. The study of the history and development of SMAs can provide an insight into a material involved in cutting-edge technology. The diverse applications for these metals have made them increasingly important and visible to the world. This paper presents the working of shape memory alloys , the phenomenon of super-elasticity and applications of these alloys.

  19. 22 CFR 11.8 - Travel expenses of candidates.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Travel expenses of candidates. 11.8 Section 11... Travel expenses of candidates. The travel and other personal expenses of candidates incurred in... Department may issue round-trip invitational travel orders to bring candidates to Washington at...

  20. Double Glow Plasma Surface Alloyed Burn-resistant Titanium Alloy

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ping-ze; XU Zhong; HE Zhi-yong; ZHANG Gao-hui

    2004-01-01

    Conventional titanium alloy may be ignited and burnt under high temperature, high pressure and high gas flow velocity condition. In order to avoid this problem, we have developed a new kind of burn-resistant titanium alloy-double glow plasma surface alloying burn-resistant titanium alloy. Alloying element Cr, Mo, Cu are induced into the Ti-6Al-4V and Ti-6.5Al-0.3Mo-l.5Zr-0.25Si substrates according to double glow discharge phenomenon, Ti-Cr ,Ti-Mo, Ti-Cu binary burn-resistant alloy layers are formed on the surface of Ti-6Al-4V and Ti-6.5Al-0.3Mo-l.5Zr-0.25Si alloys. The depth of the surface burn-resistant alloy layer can reach to above 200 microns and alloying element concentration can reach 90%.Burn-resistant property experiments reveal that if Cr concentration reach to 14%, Cu concentration reach to 12%, Mo concentration reach to 10% in the alloying layers, ignition and burn of titanium alloy can be effectively avoided.

  1. Double Glow Plasma Surface Alloyed Burn-resistant Titanium Alloy

    Institute of Scientific and Technical Information of China (English)

    ZHANGPing-ze; XUZhong; HEZhi-yong; ZHANGGao-hui

    2004-01-01

    Conventional titanium alloy may be ignited and burnt under high temperature, high pressure and high gas flow velocity condition. In order to avoid this problem, we have developed a new kind of burn-resistant titanium alloy-double glow plasma surface alloying burn-resistant titanium alloy. Alloying element Cr, Mo, Cu are induced into the Ti-6A1-4V and Ti-6.5Al-0.3Mo-1.5Zr-0.25Si substrates according to double glow discharge phenomenon, Ti-Cr ,Ti-Mo, Ti-Cu binary burn-resistant alloy layers are formed on the surface of Ti-6A1-4V and Ti-6.5Al-0.3Mo-1.5Zr-0.25Si alloys. The depth of the surface burn-resistant alloy layer can reach to above 200 microns and alloying element concentration can reach 90%. Burn-resistant property experiments reveal that if Cr concentration reach to 14%, Cu concentration reach to 12%, Mo concentration reach to 10% in the alloying layers, ignition and burn of titanium alloy can be effectively avoided.

  2. Candidate marketing takes the guessing game out of choosing employers.

    Science.gov (United States)

    Russell, Judith; Havel, Stacey

    2010-01-01

    Candidate marketing builds a foundation for relationships between employers and potential employees. Additionally, candidate marketing differentiates organizations in the marketplace. Organizations using candidate marketing to communicate the employer brand can expect a higher quality of candidates, and new employees are better prepared for the work environment and culture. Today, organizations can use a variety of integrated tools and techniques to communicate and build relationships with candidates. Candidate marketing demonstrates an organization's willingness towards transparency, and ability to invite open conversations between candidates and members of the organizations. PMID:20672542

  3. Machining of Titanium Alloys

    OpenAIRE

    Karásek, Jan

    2008-01-01

    The main goal of this work is the analysis of manufacturing costs for the component of wheel´s blower. Followed by setting up the size of specific cutting force for milling operation of the titanium alloy Ti-Al6-Mo2-Cr2-Fe-Si, the used tool was a milling cutter which is made out of sintered carbide with conical and spherical face. The final values which are at intervals of 1500 to 1800 MPa were compared with the values of the Sandvik Coromant firm kc = 1690 MPa, for titanium alloy with the st...

  4. Shape memory effect alloys

    International Nuclear Information System (INIS)

    Although the pseudo- or super-elasticity phenomena and the shape memory effect were known since the 1940's, the enormous curiosity and the great interest to their practical applications emerged with the development of the NITINOL alloy (Nickel-Titanium Naval Ordance Laboratory) by the NASA during the 1960's. This fact marked the appearance of a new class of materials, popularly known as shape memory effect alloys (SMEA). The objective of this work is to present a state-of-the-art of the development and applications for the SMEA. (E.O.)

  5. Soldering of aluminium alloys

    International Nuclear Information System (INIS)

    A literature survey about soldering in general and aluminium alloys soldering in particular is presented. The existing methods of soldering aluminium alloys are described. These include soldering with flux, soldering after preliminary plating, vacuum brazipressure and temperature (NTP), sample age calculation based on 14C half life of 5570 and 5730 years, age correction for NTP, dendrochronological corrections and the relative radiocarbon concentration. All results are given with one standard deviation. Input data test (Chauvenet's criterion), gas purity test, standard deviation test and test of the data processor are also included in the program. (author)

  6. Localized corrosion of a candidate container material for high-level nuclear waste disposal

    International Nuclear Information System (INIS)

    Localized corrosion is one of the important considerations in the design of metallic containers used for the geologic disposal of high-level nuclear waste. This paper addresses the effect of environmental factors on the localized corrosion behavior of alloy 825, one of the candidate alloys for containers in the Yucca Mountain repository site. A two-level, full factorial experimental design was used to examine the main effects and interactions of chloride, sulfate, nitrate, fluoride, and temperature. This was augmented by additional experiments involving chloride and temperature at several levels. Cyclic, potentiodynamic polarization tests were used to determine the relative susceptibility of the alloy to localized corrosion. Crevice corrosion was detected at chloride levels as low as 20 ppm, and both pitting and crevice corrosion were observed at higher chloride levels. Among the environmental factors, chloride and sulfate were found to be promoters of localized corrosion, while nitrate and fluoride were inhibitors of localized corrosion. The experiments indicated that the electrochemical parameters (e.g., pitting potential, repassivation potential, or the difference between them) were not sufficient indicators of localized corrosion. Instead, the visual observation and electrochemical parameters were combined into an index, termed localized corrosion index (LCI), to quantify the extent of localized corrosion

  7. Isothermal grain growth of reactive spray formed 7075 alloys in semi-solid state

    Institute of Scientific and Technical Information of China (English)

    Huimin Liu; Hua Cui; Bin Yang; Jishan Zhang

    2004-01-01

    The grain growth behavior in reactive spray formed 7075+2.91vol%TiC Al alloy was studied and compared with that of spray formed 7075 Al alloy at semi-solid state. The effects of in-situ TiC particles on the microstructure of spray formed 7075 Al alloy were also investigated. The specimens were heat-treated isothermally at various temperatures between the solidus and liquidus of 7075 Al alloy for times in the range of 10-60 min, then quenched in water. The microstructure of reheated specimens was characterized using scanning electron microscopy and optical microscopy. The grain size was measured using a mean linear intercept method.Results show that the in-situ TiC particles can effectively retard grain growth and refine the grain at a limited size. The grain growth exponent in Arrhenius equation increases from 2 to 3, which indicates that the in-situ TiC particles have the significant pinning effect on grain coarsening in the semi-solid state.

  8. Microstructure of Fe-Cr-C hardfacing alloys with additions of Nb, Ti and, B

    International Nuclear Information System (INIS)

    The abrasive wear of machine parts and tools used in the mining, earth moving, and transporting of mineral materials can be lowered by filler wire welding of hardfacing alloys. In this paper, the microstructures of Fe-Cr-C and Fe-Cr-C-Nb/Ti hardfacing alloys and deposits and those of newly developed Fe-Cr-C-B and Fe-Ti-Cr-C-B ones are described. They show up to 85 vol.% of primarily solidified coarse hard phases; i.e., Carbides of MC-, M/sub 7/C/sub 3/-, M/sub 3/C-type and Borides of MB/sub 2/-, M/sub 3/B/sub 2/-, M/sub 2/B-, M/sub 3/B-, M/sub 23/B/sub 6/-type, which are embedded in a hard eutectic. This itself consists of eutectic hard phases and a martensitic or austenitic metal matrix. The newly developed Fe-Cr-C-B alloys reach hardness values of up to 1200 HV and are harder than all purchased ones. The primary solidification of the MB/sub 2/-type phase of titanium requires such high amounts of titanium and boron that these alloys are not practical for manufacture as commercial filler wires

  9. Electrochemical oxidation of zirconium alloys in pre-transition and post-transition kinetic regimes at corrosion in electrolyte solutions

    International Nuclear Information System (INIS)

    With the aim of investigation on oxidation of zirconium alloys (Zr+2.5% Nb) the critical thickness of beginning of spalling of froming oxide films in HCl and NHO3 aqueous solutions was evaluated by coulometry with accelerated procedure. Some variants of predeposition of modificated oxide coatings are proposed increase pre-transition regime time and to decrease corrosion during post-transition regime. Increase in agressivity of solutions (addition of 1 vol.% HF) and UV irradiation are found to increase 3-4 times pre-transition period

  10. Pemilihan Bahan Alloy Untuk Konstruksi Gigitiruan

    OpenAIRE

    Medila Dahlan

    2008-01-01

    Pada kedokteran gigi bahan alloy sangat banyak digunakan dalam segala bidang. Dalam pembuatan konstruksi gigitiman biasanya digunakan alloy emas, alloy kobalt kromium, alloy nikei kromium dan alloy stainless steel sebagai komponen gigitiman kerangka logam serta pembuatan mahkota dan jembatan. Pemilihan bahan alloy dapat dilakukan berdasarkan sifat yang dimiiiki oleh masing-masing bahan alloy sehingga akan didapat hasil konstmksi gigitiruan yang memuaskan. Pada pemakaiannya didaiam mulut...

  11. Hydrogen embrittlement of vanadium alloys

    International Nuclear Information System (INIS)

    The mechanical properties of several vanadium alloys were measured with the hydrogen concentration high up to 113 mg/kg. The results showed that the alloys with low mechanical strength had better properties against hydrogen embrittlement. Oxygen in the alloy, especially that in the alloys with high strength, could enhance the hydrogen embrittlement. Mechanism analysis was given to show that the brittle fracture was mainly caused by intergranular failure. The effects of oxygen concentration and the strength of the alloy were both resulted from their contributions to the grain strength and the grain boundary strength

  12. Galvanic corrosion in odontological alloys

    International Nuclear Information System (INIS)

    Galvanic corrosion can occur when different alloys are placed in direct contact within the oral cavity or within tissues. Concern has been expressed associated with the coupling of selected restorative materials as well as implant material with various alloys used for restorative procedures. This could be critical if the crown or bridge had subgingival finish line with a metallic zone in contact with the tissue, and the implant was made in titanium alloy. The present work shows the results of galvanic coupling studies done on implants of titanium alloy connected to nickel-chromium and cobalt-chromium alloys. (Author)

  13. Almanac of the contributions of the 49. meeting of the chemical societies. Selected papers from Vol. 1,2,3

    International Nuclear Information System (INIS)

    The publication has been set up as a abstracts of the meeting dealing with chemical problems. The book (Vol. 1) consists of the sections: (A) Analytical chemistry; (B) Inorganic chemistry. The book (Vol. 2) consists of the sections: (C) Physical chemistry; (D) History of the chemistry; (E) Food chemistry and technology; (D) Environmental chemistry; (E) Nuclear chemistry and radioecology; (H) Synthetic polymers. The book (Vol. 3) consists of the sections: (I) Fibres, Textile and foil materials; (J) Wood, pulp, paper; (K) Organic Chemistry; (L) Bio-organic chemistry; (M) Didactic of the chemistry

  14. Candidate Species Selection: Cultural and Photosynthetic Aspects

    Science.gov (United States)

    Mitchell, C. A.

    1982-01-01

    Cultural information is provided for a data base that will be used to select candidate crop species for a controlled ecological life support system (CELSS). Lists of food crops which will satisfy most nutritional requirements of humans and also fit within the scope of cultural restrictions that logically would apply to a closed, regenerating system were generated. Cultural and environmental conditions that will allow the most rapid production of edible biomass from candidate species in the shortest possible time are identified. Cultivars which are most productive in terms of edible biomass production by (CE) conditions, and which respond to the ever-closed approach to optimization realized by each shortened production cycle are selected. The experimental approach with lettuce was to grow the crop hydroponically in a growth chamber and to manipulate such variables as light level and duration, day/night temperature, and nutrient form and level in the solution culture.

  15. New drug candidates in tuberculosis treatment

    Directory of Open Access Journals (Sweden)

    Begüm Evranos Aksöz

    2014-12-01

    makes them quit the treatment. From these problems emerges the need for development of effective new drugs, with smaller duration of therapy, less side effects and without the problem of resistance. After a long period such as 40 years, a new drug molecule bedaquiline was approved in December 2012 by FDA while the drug was in phase II research. Bedaquiline will be used in multidrug resistant tuberculosis therapy. When the chemical structures of bedaquilline and other candidate drugs were examined, the structures such as diarylquinoline, oxazolidinone, nitroimidazole, ethylenediamine drew attention. These common structures will be directive in designing new molecules. In this review, bedaquiline and other candidate drug molecules such as sutezolide, linezolide, PA-824, delamanide, rifapentine, gatifloxacin, moxifloxacin, BTZ-043, TBA-354, CPZEN-45, DC-159a, Q201, SQ-609, SQ-641 were mentioned.

  16. Optical Nova Candidate in M 31

    Science.gov (United States)

    Henze, M.; Burwitz, V.; Pietsch, W.; Updike, A.; Milne, P.; Williams, G.; Hartmann, D. H.

    2008-06-01

    We report the discovery of an optical nova candidate in M 31 on two 11x60s stacked R filter CCD images obtained with the robotic 60cm telescope with an E2V CCD (2kx2k) of the Livermore Optical Transient Imaging System (Super-LOTIS, located at Steward Observatory, Kitt Peak, Arizona, USA). The object was first detected on 2008 June 14.46 and 16.46 UT with respective magnitudes of 18.0 and 17.7. The position for the nova candidate is RA = 00h42m37.72s, Dec = +41d12'30.0"(J2000, accuracy of 0.3"), which is 1'14" west and 3'39" south of the core of M 31. All magnitudes given are obtained from a photometric solution using R magnitudes of the Local Group Survey M 31 catalogue (Massey et al.

  17. Spectroscopic follow up of Kepler planet candidates

    DEFF Research Database (Denmark)

    Latham..[], D. W.; Cochran, W. D.; Marcy, G.W.;

    2010-01-01

    Spectroscopic follow-up observations play a crucial role in the confirmation and characterization of transiting planet candidates identified by Kepler. The most challenging part of this work is the determination of radial velocities with a precision approaching 1 m/s in order to derive masses from...... spectroscopic orbits. The most precious resource for this work is HIRES on Keck I, to be joined by HARPS-North on the William Herschel Telescope when that new spectrometer comes on line in two years. Because a large fraction of the planet candidates are in fact stellar systems involving eclipsing stars and not...... planets, our strategy is to start with reconnaissance spectroscopy using smaller telescopes, to sort out and reject as many of the false positives as possible before going to Keck. During the first Kepler observing season in 2009, more than 100 nights of telescope time were allocated for this work, using...

  18. A Low-Cost Hierarchical Nanostructured Beta-Titanium Alloy with High Strength

    Energy Technology Data Exchange (ETDEWEB)

    Devaraj, Arun; Joshi, Vineet V.; Srivastava, Ankit; Manandhar, Sandeep; Moxson, Vladimir S.; Duz, Volodymr; Lavender, Curt A.

    2016-04-09

    Lightweighting of automobiles by use of novel low-cost, high strength-to-weight ratio structural materials can reduce the consumption of fossil fuels and in turn CO2 emission. Working towards this goal we achieved high strength in a low cost β-titanium alloy, Ti-1Al-8V-5Fe (Ti185), by hierarchical nanostructure consisting of homogenous distribution of micron-scale and nanoscale α-phase precipitates within the β-phase matrix. The sequence of phase transformation leading to this hierarchical nanostructure is explored using electron microscopy and atom probe tomography. Our results suggest that the high number density of nanoscale α-phase precipitates in the β-phase matrix is due to ω assisted nucleation of α resulting in high tensile strength, greater than any current commercial titanium alloy. Thus hierarchical nanostructured Ti185 serves as an excellent candidate for replacing costlier titanium alloys and other structural alloys for cost-effective lightweighting applications.

  19. A low-cost hierarchical nanostructured beta-titanium alloy with high strength

    Science.gov (United States)

    Devaraj, Arun; Joshi, Vineet V.; Srivastava, Ankit; Manandhar, Sandeep; Moxson, Vladimir; Duz, Volodymyr A.; Lavender, Curt

    2016-04-01

    Lightweighting of automobiles by use of novel low-cost, high strength-to-weight ratio structural materials can reduce the consumption of fossil fuels and in turn CO2 emission. Working towards this goal we achieved high strength in a low cost β-titanium alloy, Ti-1Al-8V-5Fe (Ti185), by hierarchical nanostructure consisting of homogenous distribution of micron-scale and nanoscale α-phase precipitates within the β-phase matrix. The sequence of phase transformation leading to this hierarchical nanostructure is explored using electron microscopy and atom probe tomography. Our results suggest that the high number density of nanoscale α-phase precipitates in the β-phase matrix is due to ω assisted nucleation of α resulting in high tensile strength, greater than any current commercial titanium alloy. Thus hierarchical nanostructured Ti185 serves as an excellent candidate for replacing costlier titanium alloys and other structural alloys for cost-effective lightweighting applications.

  20. Preparation of porous U-10%Mo alloy by powder metallurgy and its microstructure characterization

    International Nuclear Information System (INIS)

    U-Mo alloy is one of candidates of metallic fuel for advanced nuclear reactor due to its good irradiation behavior. Reasonably analysis suggests that the irradiation swell of U-Mo alloy can be decreased by introducing homogeneously distributed voids, because they can accommodate gaseous fission products. The process of preparing low density U-Mo alloy by powder metallurgy was described, including preparing low density bulk materials by pressing and vacuum sintering. A serial of U-10%Mo alloys with different densities were obtained and the microstructure was analyzed by optical microscopy (OM) and scanning electron microscopy (SEM). It is proved that the density of sample increases with sinister time under 1100℃. The void ratio can be controlled by adjusting sinister process conveniently. (authors)

  1. Precipitation kinetics and phase stability in Nb-Ti-Al base alloys

    International Nuclear Information System (INIS)

    Niobium alloys are candidates for the next generation of high temperature materials needed for hotter, more efficient aircraft engines. Model ternary Nb-Ti-Al and quaternary Nb-Ti-Al-Cr alloys were studied to determine low temperature phase stability and precipitation kinetics. Optical microscopy, transmission electron microscopy, and electron diffraction were used for microstructural analysis. The results obtained from low temperature aging of the ternary alloys show evidence of a transformation of the ordered bcc (B2) phase to a fine lath structure consisting of variants of orthorhombic Ti2AlNb in a Nb-Ti bcc matrix. Compositions of these alloys are near the B2 phase field, with a nominal Ti/Nb atom ratio of 1.25. In this paper additional results concerning phase equilibria and precipitation kinetics are discussed

  2. Reducing stigma and discrimination: Candidate interventions

    OpenAIRE

    Kassam Aliya; Brohan Elaine; Thornicroft Graham; Lewis-Holmes Elanor

    2008-01-01

    Abstract This paper proposes that stigma in relation to people with mental illness can be understood as a combination of problems of knowledge (ignorance), attitudes (prejudice) and behaviour (discrimination). From a literature review, a series of candidate interventions are identified which may be effective in reducing stigmatisation and discrimination at the following levels: individuals with mental illness and their family members; the workplace; and local, national and international. The ...

  3. Tantalum oxide coatings as candidate environmental barriers

    OpenAIRE

    Moldovan, Monica; Weyant, C. M.; Johnson, D. Lynn; Faber, K. T.

    2004-01-01

    Tantalum (Ta) oxide, due to its high-temperature capabilities and thermal expansion coefficient similar to silicon nitride, is a promising candidate for environmental barriers for silicon (Si) nitride-based ceramics. This paper focuses on the development of plasma-sprayed Ta oxide as an environmental barrier coating for silicon nitride. Using a D-optimal design of experiments, plasma-spray processing variables were optimized to maximize coating density. The effect of processing variables on c...

  4. Sensitive Radio Survey of Obscured Quasar Candidates

    CERN Document Server

    Alexandroff, Rachael M; van Velzen, Sjoert; Greene, Jenny E; Strauss, Michael A

    2016-01-01

    We study the radio properties of moderately obscured quasars over a range of redshifts to understand the role of radio activity in accretion using the Jansky Very Large Array (JVLA) at 6.0GHz and 1.4GHz. Our z~2.5 sample consists of optically-selected obscured quasar candidates, all of which are radio-quiet, with typical radio luminosities of $\

  5. Nonclinical Development of BCG Replacement Vaccine Candidates

    OpenAIRE

    Bernd Eisele; Martin Gengenbacher; Reginald Kidd; David McCown; Sheldon Morris; Steven Derrick; David Hokey; Dominick Laddy; Rosemary Chang; Megan Fitzpatrick; Leander Grode; Kamalakannan Velmurugan; Stefan H. E. Kaufmann; John Fulkerson; Brennan, Michael J.

    2013-01-01

    The failure of current Mycobacterium bovis bacille Calmette–Guérin (BCG) vaccines, given to neonates to protect against adult tuberculosis and the risk of using these live vaccines in HIV-infected infants, has emphasized the need for generating new, more efficacious and safer replacement vaccines. With the availability of genetic techniques for constructing recombinant BCG (rBCG) strains containing well-defined gene deletions or insertions, new vaccine candidates are under evaluation at both ...

  6. Optical durability testing of candidate solar mirrors

    Energy Technology Data Exchange (ETDEWEB)

    Jorgensen, G.; Kennedy, C.; King, D.; Terwilliger, K.

    2000-03-24

    Durability testing of a variety of candidate solar reflector materials at outdoor test sites and in laboratory accelerated weathering chambers is the main activity within the Advanced Materials task of the Concentrated Solar Power (CSP) Program. Outdoor exposure testing (OET) at up to eight outdoor, worldwide exposure sites has been underway for several years. This includes collaboration under the auspices of the International Energy Agency (IEA) Solar Power and Chemical Energy Systems (SolarPACES) agreement. Outdoor sites are fully instrumented in terms of monitoring meteorological conditions and solar irradiance. Candidate materials are optically characterized prior to being subjected to exposure in real and simulated weathering environments. Optical durability is quantified by periodically re-measuring hemispherical and specular reflectance as a function of exposure time. By closely monitoring the site- and time-dependent environmental stress conditions experienced by the material samples, site-dependent loss of performance may be quantified. In addition, accelerated exposure testing (AET) of these materials in parallel under laboratory-controlled conditions may permit correlating the outdoor results with AET, and subsequently predicting service lifetimes. Test results to date for a large number of candidate solar reflector materials are presented in this report. Acronyms are defined. Based upon OET and AET results to date, conclusions can be drawn about the optical durability of the candidate reflector materials. The optical durability of thin glass, thick glass, and two metallized polymers can be characterized as excellent. The all-polymeric construction, several of the aluminized reflectors, and a metallized polymer can be characterized as having intermediate durability and require further improvement, testing and evaluation, or both.

  7. Comparing Candidate Selection : A Feminist Institutionalist Approach

    OpenAIRE

    Bjarnegard, Elin; Kenny, Meryl

    2016-01-01

    This contribution evaluates the theoretical and methodological challenges ofresearching the gendered dynamics of candidate selection in comparativeperspective. It argues that comparative studies should take into account not only thegendered nature of political parties and their wider institutional context, but mustalso investigate the informal aspects of the selection process and their genderedconsequences. The article explores these dynamics by revisiting original in-depthresearch on the can...

  8. Various Approaches for Targeting Quasar Candidates

    Science.gov (United States)

    Zhang, Y.; Zhao, Y.

    2015-09-01

    With the establishment and development of space-based and ground-based observational facilities, the improvement of scientific output of high-cost facilities is still a hot issue for astronomers. The discovery of new and rare quasars attracts much attention. Different methods to select quasar candidates are in bloom. Among them, some are based on color cuts, some are from multiwavelength data, some rely on variability of quasars, some are based on data mining, and some depend on ensemble methods.

  9. MANAGEMENT OF ALLOSENSITIZED CARDIAC TRANSPLANT CANDIDATES

    OpenAIRE

    Velez, Mauricio; Johnson, Maryl R.

    2009-01-01

    Cardiac transplantation remains the best treatment in advanced heart failure patients with a high risk of death. However, an inadequate supply of donor hearts decreases the likelihood of transplantation for many patients. Ventricular assist devices (VAD) are being increasingly used as a bridge to transplant in patients who may not survive long enough to receive a heart. This expansion in VAD use has been associated with increasing rates of allosensitization in cardiac transplant candidates. A...

  10. Critical Thinking Tendencies of Music Teacher Candidates

    OpenAIRE

    Duygu PİJİ KÜÇÜK; Yusuf Barış UZUN

    2013-01-01

    In this study, determining critical thinking and education levels, which are in sub-dimensions, of music teacher candidates, determining critical thinking tendency and the relations between sub dimensions and detecting if or if not critical thinking tendency creates a difference in terms of gender, class and what type of school they graduated from are aimed. Work group composes of 274 students being educated in the Departments of Music Education GSEB of Education Faculty of Bolu Abant İzzet B...

  11. Preoperative Anxiety in Candidates for Heart Surgery

    OpenAIRE

    Fathi, Mehdi; Alavi, Seyed Mostafa; Joudi, Marjan; Joudi, Mitra; Mahdikhani, Helia; Ferasatkish, Rasool; Bakhshandeh, Houman; Jabbari Nooghabi, Mehdi

    2014-01-01

    Objective: The goal of this study was to evaluate preoperative anxiety and its predisposing factors in a group of adult patients who were candidate for any kind of heart surgery. Methods: We evaluated preoperative anxiety in 300 patients undergoing heart surgery whose ages ranged between 18-65 years. Relationship of probable demographic factors like gender, educational level, marital status, number of children, family support, opium addiction, occupational status, and left ventricular ejectio...

  12. Alcoholism and Alternative Splicing of Candidate Genes

    OpenAIRE

    Toshikazu Sasabe; Shoichi Ishiura

    2010-01-01

    Gene expression studies have shown that expression patterns of several genes have changed during the development of alcoholism. Gene expression is regulated not only at the level of transcription but also through alternative splicing of pre-mRNA. In this review, we discuss some of the evidence suggesting that alternative splicing of candidate genes such as DRD2 (encoding dopamine D2 receptor) may form the basis of the mechanisms underlying the pathophysiology of alcoholism. These reports sugg...

  13. Phase stability and elastic modulus of Ti alloys containing Nb, Zr, and/or Sn from first-principles calculations

    International Nuclear Information System (INIS)

    The alloying effects of Nb, Zr, and/or Sn on the phase stability and elastic properties of Ti are investigated by using a first-principles method. Our calculation results indicate that a carefully designed Ti-Nb-Zr-Sn system can be a good candidate for low modulus biomedical materials. We find that the well-known correlation between the e/a ratio and both elastic and phase stabilities for Ti alloyed with transition metal elements breaks down for the Ti-Sn alloy

  14. Nuclear safety in EU candidate countries

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-10-01

    Nuclear safety in the candidate countries to the European Union is a major issue that needs to be addressed in the framework of the enlargement process. Therefore WENRA members considered it was their duty to offer their technical assistance to their Governments and the European Union Institutions. They decided to express their collective opinion on nuclear safety in those candidate countries having at least one nuclear power plant: Bulgaria, the Czech Republic, Hungary, Lithuania, Romania, Slovakia and Slovenia. The report is structured as follows: A foreword including background information, structure of the report and the methodology used, General conclusions of WENRA members reflecting their collective opinion, For each candidate country, an executive summary, a chapter on the status of the regulatory regime and regulatory body, and a chapter on the nuclear power plant safety status. Two annexes are added to address the generic safety characteristics and safety issues for RBMK and VVER plants. The report does not cover radiation protection and decommissioning issues, while safety aspects of spent fuel and radioactive waste management are only covered as regards on-site provisions. In order to produce this report, WENRA used different means: For the chapters on the regulatory regimes and regulatory bodies, experts from WENRA did the work. For the chapters on nuclear power plant safety status, experts from WENRA and from French and German technical support organisations did the work. Taking into account the contents of these chapters, WENRA has formulated its general conclusions in this report.

  15. Nuclear safety in EU candidate countries

    International Nuclear Information System (INIS)

    Nuclear safety in the candidate countries to the European Union is a major issue that needs to be addressed in the framework of the enlargement process. Therefore WENRA members considered it was their duty to offer their technical assistance to their Governments and the European Union Institutions. They decided to express their collective opinion on nuclear safety in those candidate countries having at least one nuclear power plant: Bulgaria, the Czech Republic, Hungary, Lithuania, Romania, Slovakia and Slovenia. The report is structured as follows: A foreword including background information, structure of the report and the methodology used, General conclusions of WENRA members reflecting their collective opinion, For each candidate country, an executive summary, a chapter on the status of the regulatory regime and regulatory body, and a chapter on the nuclear power plant safety status. Two annexes are added to address the generic safety characteristics and safety issues for RBMK and VVER plants. The report does not cover radiation protection and decommissioning issues, while safety aspects of spent fuel and radioactive waste management are only covered as regards on-site provisions. In order to produce this report, WENRA used different means: For the chapters on the regulatory regimes and regulatory bodies, experts from WENRA did the work. For the chapters on nuclear power plant safety status, experts from WENRA and from French and German technical support organisations did the work. Taking into account the contents of these chapters, WENRA has formulated its general conclusions in this report

  16. Ferromagnetic bulk glassy alloys

    International Nuclear Information System (INIS)

    This paper deals with the review on the formation, thermal stability and magnetic properties of the Fe-based bulk glassy alloys in as-cast bulk and melt-spun ribbon forms. A large supercooled liquid region over 50 K before crystallization was obtained in Fe-(Al, Ga)-(P, C, B, Si), Fe-(Cr, Mo, Nb)-(Al, Ga)-(P, C, B) and (Fe, Co, Ni)-Zr-M-B (M=Ti, Hf, V, Nb, Ta, Cr, Mo and W) systems and bulk glassy alloys were produced in a thickness range below 2 mm for the Fe-(Al, Ga)-(P, C, B, Si) system and 6 mm for the Fe-Co-(Zr, Nb, Ta)-(Mo, W)-B system by copper-mold casting. The ring-shaped glassy Fe-(Al, Ga)-(P, C, B, Si) alloys exhibit much better soft magnetic properties as compared with the ring-shaped alloy made from the melt-spun ribbon because of the formation of the unique domain structure. The good combination of high glass-forming ability and good soft magnetic properties indicates the possibility of future development as a new bulk glassy magnetic material

  17. Shape Memory Alloy Actuator

    Science.gov (United States)

    Baumbick, Robert J. (Inventor)

    2002-01-01

    The present invention discloses and teaches a unique, remote optically controlled micro actuator particularly suitable for aerospace vehicle applications wherein hot gas, or in the alternative optical energy, is employed as the medium by which shape memory alloy elements are activated. In gas turbine powered aircraft the source of the hot gas may be the turbine engine compressor or turbine sections.

  18. Alloy catalyst material

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention relates to a novel alloy catalyst material for use in the synthesis of hydrogen peroxide from oxygen and hydrogen, or from oxygen and water. The present invention also relates to a cathode and an electrochemical cell comprising the novel catalyst material, and the process use...

  19. High strength ferritic alloy

    International Nuclear Information System (INIS)

    A high strength ferritic steel is specified in which the major alloying elements are chromium and molybdenum, with smaller quantities of niobium, vanadium, silicon, manganese and carbon. The maximum swelling is specified for various irradiation conditions. Rupture strength is also specified. (U.K.)

  20. Cladding Alloys for Fluoride Salt Compatibility

    Energy Technology Data Exchange (ETDEWEB)

    Muralidharan, Govindarajan [ORNL; Wilson, Dane F [ORNL; Walker, Larry R [ORNL; Santella, Michael L [ORNL; Holcomb, David Eugene [ORNL

    2011-06-01

    This report provides an overview of several candidate technologies for cladding nickel-based corrosion protection layers onto high-temperature structural alloys. The report also provides a brief overview of the welding and weld performance issues associated with joining nickel-clad nickel-based alloys. From the available techniques, two cladding technologies were selected for initial evaluation. The first technique is a line-of-sight method that would be useful for cladding large structures such as vessel interiors or large piping. The line-of-sight method is a laser-based surface cladding technique in which a high-purity nickel powder mixed into a polymer binder is first sprayed onto the surface, baked, and then rapidly melted using a high-power laser. The second technique is a vapor phase technique based on the nickel-carbonyl process that is suitable for cladding inaccessible surfaces such as the interior surfaces of heat exchangers. An initial evaluation for performed on the quality of nickel claddings processed using the two selected cladding techniques.

  1. U.S. Contribution 1994 Summary Report Task T12: Compatibility and irradiation testing of vanadium alloys

    International Nuclear Information System (INIS)

    Vanadium alloys exhibit important advantages as a candidate structural material for fusion first wall/blanket applications. These advantages include fabricability, favorable safety and environmental features, high temperature and high wall load capability, and long lifetime under irradiation. Vanadium alloys with (3-5)% chromium and (3-5)% titanium appear to offer the best combination of properties for first wall/blanket applications. A V-4Cr-4Ti alloy is recommended as the reference composition for the ITER application. This report provides a summary of the R ampersand D conducted during 1994 in support of the ITER Engineering Design Activity. Progress is reported for Vanadium Alloy Production, Welding, Physical Properties, Baseline Mechanical Properties, Corrosion/Compatibility, Neutron Irradiation Effects, Helium Transmutation Effects on Irradiated Alloys, and the Status of Irradiation Experiments. Separate abstracts have been prepared for individual reports from this publication

  2. Tensile and compressive creep behaviour of Al{sub 2}O{sub 3} (Saffil[reg]) short fiber reinforced magnesium alloy AE42

    Energy Technology Data Exchange (ETDEWEB)

    Dieringa, Hajo [GKSS Forschungszentrum Geesthacht GmbH, Institute for Materials Research, D-21502 Geesthacht (Germany)]. E-mail: hajo.dieringa@gkss.de; Huang, Yuanding [GKSS Forschungszentrum Geesthacht GmbH, Institute for Materials Research, D-21502 Geesthacht (Germany); Maier, Petra [GKSS Forschungszentrum Geesthacht GmbH, Institute for Materials Research, D-21502 Geesthacht (Germany); Hort, Norbert [GKSS Forschungszentrum Geesthacht GmbH, Institute for Materials Research, D-21502 Geesthacht (Germany); Kainer, Karl Ulrich [GKSS Forschungszentrum Geesthacht GmbH, Institute for Materials Research, D-21502 Geesthacht (Germany)

    2005-11-25

    The development of metal matrix composites (MMCs) is one possibility to overcome the disadvantage of poor high temperature creep properties of present magnesium alloys. Short fiber reinforcement improves the high temperature creep resistance of magnesium alloys. Tensile and compressive creep properties of magnesium alloy AE42 (4 wt.% aluminium and 2 wt.% rare earths) reinforced with 20 vol.% alumina (Saffil[reg]) fibers were investigated in the temperature range of 175-300 deg. C and stress range of 40-140 MPa, respectively. The MMC was manufactured by direct squeeze casting. The materials investigated show different behaviour depending on type of loading. Stress exponents were calculated from the stress dependence of the minimum creep rate in order to find indications for the possible mechanisms of deformation. The need of correcting the stress dependence of the minimum creep rate by a threshold stress was found. Electron microscopy was performed to investigate the fracture surface of a tensile creep specimen.

  3. The Analysis of the General Performance and Mechanical Behavior of Unirradiated FeCrAl Alloys Before and After Welding

    Energy Technology Data Exchange (ETDEWEB)

    Gussev, Maxim N. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Field, Kevin G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Yamamoto, Yukinori [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-06-03

    The present report summarizes and discusses the preliminary results for the in-depth characterization of the modern, nuclear-grade FeCrAl alloys currently under development. The alloys were designed for enhanced radiation tolerance and weldability, and the research is currently being pursued by the Department of Energy (DOE) Nuclear Energy Enabling Technologies (NEET) program. Last year, seven candidate FeCrAl alloys with well-controlled chemistry and microstructures were designed and produced; welding was performed under well-controlled conditions. The structure and general performance of unirradiated alloys were assessed using standardized and advanced microstructural characterization techniques and mechanical testing. The primary objective is to identify the best candidate alloy, or at a minimum to identify the contributing factors that increase the weldability and radiation tolerance of FeCrAl alloys, therefore enabling future generations of FeCrAl alloys to deliver better performance parameters. This report is structured so as to describe these critical assessments of the weldability; radiation tolerance will be reported on in later reports from this program.

  4. Estimation of U and Zr in U-Zr alloys

    International Nuclear Information System (INIS)

    Metallic fuel (U-Pu-Zr) is considered as a candidate for future Fast Breeder Reactors (FBRs) due to its inherent safety, high atom density, high thermal conductivity and higher breeding ratio compared to ceramic fuels. In order to understand the ternary alloy system, U-Pu-Zr several studies are being carried out at our centre. Compositional assay of these alloys forms a vital part of the fast reactor programme. As a part of this, chemical assay of U-Zr are being initiated. In this paper, U-Zr alloys (XZr = 0.1, 0.4, 0.95) were prepared by arc melting the stoichiometric amounts of U and Zr in a tri-arc furnace. These alloys were remelted thrice for homogenization and then dissolved in HNO3: HF mixture. The chemical assay of these alloys was carried out by complexometry, ultraviolet (UV) visible spectrophotometry and by X-ray fluorescence spectrometry (XRF). The amount of Zr present in these solutions were determined by back titration method using Bi(NO3)3 as titrant and EDTA as complexing agent with xylenol orange as the indicator. UV-Visible spectrophotometry was also carried out to measure the quantity of Zr in the above solutions for comparison. The absorbance was measured at λmax around 540 nm with xylenol orange as the complexing agent. U present in these solutions were determined by Davis Gray method using visual end point titration. XRF measurements also were carried out for determining U in these alloy solutions. In all the above measurements interference from U was not observed for measuring the Zr content

  5. Corrosion Behavior of Alloys in Molten Fluoride Salts

    Science.gov (United States)

    Zheng, Guiqiu

    The molten fluoride salt-cooled high-temperature nuclear reactor (FHR) has been proposed as a candidate Generation IV nuclear reactor. This reactor combines the latest nuclear technology with the use of molten fluoride salt as coolant to significantly enhance safety and efficiency. However, an important challenge in FHR development is the corrosion of structural materials in high-temperature molten fluoride salt. The structural alloys' degradation, particularly in terms of chromium depletion, and the molten salt chemistry are key factors that impact the lifetime of nuclear reactors and the development of future FHR designs. In support of materials development for the FHR, the nickel base alloy of Hastelloy N and iron-chromium base alloy 316 stainless steel are being actively considered as critical structural alloys. Enriched 27LiF-BeF2 (named as FLiBe) is a promising coolant for the FHR because of its neutronic properties and heat transfer characteristics while operating at atmospheric pressure. In this study, the corrosion behavior of Ni-5Cr and Ni-20Cr binary model alloys, and Hastelloy N and 316 stainless steel in molten FLiBe with and without graphite were investigated through various microstructural analyses. Based on the understanding of the corrosion behavior and data of above four alloys in molten FLiBe, a long-term corrosion prediction model has been developed that is applicable specifically for these four materials in FLiBe at 700ºC. The model uses Cr concentration profile C(x, t) as a function of corrosion distance in the materials and duration fundamentally derived from the Fick's diffusion laws. This model was validated with reasonable accuracy for the four alloys by fitting the calculated profiles with experimental data and can be applied to evaluate corrosion attack depth over the long-term. The critical constant of the overall diffusion coefficient (Deff) in this model can be quickly calculated from the experimental measurement of alloys' weight

  6. Anodic behavior of nickel alloys in media containing bicarbonate ions

    International Nuclear Information System (INIS)

    Alloy 22 has been designed to resist corrosion in oxidizing and reducing conditions. Thanks to these properties it is considered a possible candidate for the fabrication of containers of high-level radioactive waste. Since the containers provide services in natural environments characterized by multi-ionic solutions, it is estimated they could suffer three types of deterioration: general corrosion, localized corrosion (specifically crevice corrosion) and stress corrosion cracking (SCC). It has been confirmed that the presence of bicarbonate and chloride ions is required in order to produce cracking. It has also been determined that the susceptibility to SCC could be related to the occurrence of an anodic peak in the polarization curves in these media potentials below trans-passivity. The aim of this work is to study the anodic behavior of Alloy 22 in different media containing bicarbonate and chloride ions in various concentrations and temperatures and compare the results with other alloys containing nickel, and relate them to the susceptibility to stress corrosion cracking in a future job. Polarization curves were made on alloy 22 (Ni-Cr-Mo), 600 (Ni- Cr-Fe), 800h (Ni-Fe- Cr) and 201 (Ni commercially pure) in the following environments: 1.148 mol/L NaHCO3, 1.148 mol/L NaHCO3 + 1 mol/L NaCl, 1.148 mol/L NaHCO3 + 0.1 mol/L NaCl. The tests were performed at the following temperatures: 90°C, 75°C, 60°C and 25°C. It was found that alloy 22 has a current peak in the anodic domain at potentials below trans-passivity between 200 and 300 m VECS, when the test temperature was 90°C. The potential, at which this peak occurred, increased with decreasing temperature. Also there was a variation of the peak with the composition of the solution. When bicarbonate ions were added to a solution containing chloride ions, the peak potential shifted to higher current densities, depending on the concentration of added chloride ions. It was found that diminishing the content of

  7. Formation of barrier-type anodic films on ZE41 magnesium alloy in a fluoride/glycerol electrolyte

    International Nuclear Information System (INIS)

    Highlights: • Barrier anodic films formed on ZE41 Mg alloy in glycerol/fluoride electrolyte. • Films contain oxygen and fluorine species; formation ratio ∼1.3 nm V−1. • Nanocrystalline film structure, with MgO and MgF2. • Zinc enrichment in alloy beneath anodic film. • Modified film formed above Mg-Zn-RE second phase. - Abstract: Barrier-type, nanocrystalline anodic films have been formed on a ZE41 magnesium alloy under a constant current density of 5 mA cm−2 in a glycerol/fluoride electrolyte, containing 5 vol.% of added water, at 293 K. The films contain magnesium, fluorine and oxygen as the major species, and lower amounts of alloying element species. The films grow at an efficiency of ∼0.8 to 0.9, with a formation ratio in the range of ∼1.2 to 1.4 nm V−1 at the matrix regions and with a ratio of ∼1.8 nm V−1 at Mg-Zn-RE second phase. At the former regions, rare earth species are enriched at the film surface and zinc is enriched in the alloy. A carbon- and oxygen-rich band within the film suggests that the films grow at the metal/film and film/electrolyte interfaces

  8. The in-situ Ti alloying of aluminum alloys and its application in A356 alloys

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    This research has investigated the in-situ Ti alloying of aluminum alloys and its application to A356 alloys and wheels through the evaluation of microstructure and mechanical properties, The results showed that stable titanium content can be obtained by adding a small quantity of TiO2 into electrolyte of pure aluminum. Under this approach, a greater than 95% absorptivity of titanium was achieved, and the microstructure of the specimens was changed to fine equiaxed grains from coarse columnar grains in the pure aluminum. In comparison with the tradition A356 alloys and wheels, the corresponding microstructure in the testing A356 alloys and wheels was finer. Although the tensile strength was similar between the testing and the tradition A356 alloys and wheels, the ductility of the former (testing) is superior to that of the later (tradition), leading to an excellent combination of strength and ductility from the testing alloys and wheels.

  9. Phase stability effects on the corrosion behavior of the metal barrier candidate materials for the nuclear waste management program

    International Nuclear Information System (INIS)

    Six candidate materials are currently under consideration by the Nuclear Waste Management Program (NWMP) at Lawrence Livermore National Laboratory as potential metal barrier materials for high-level nuclear waste storage. The waste package, which must meet the Nuclear Regulatory Commission licensing requirements for the Nevada Nuclear Waste Storage Investigations Project (NNWSI), will contain spent fuel from civilian nuclear power plants PWR and BWR fuel assemblies, commercial high level waste (CHLW) in the form of borosilicate glass containing commercial spent fuel reprocessing wastes and defense high level waste (DHLW) contained in borosilicate glass. The waste package is being designed for emplacement in the unsaturated zone above the water table at the Yucca Mountain site in Nevada. This location should result in a slightly oxidizing repository environment. The Metal Barrier Selection and Testing Task is responsible for the selection of the materials to be employed in the waste package container. The candidate materials include three iron to nickel-based austenitic materials and three copper-based alloy materials. The austenitic materials are AISI 304L stainless steel, AISI 316L stainless steel and alloy 825. The copper-based alloy materials are CDA 102 (OFHC copper), CDA 613 (Cu-7Al) and CDA 715 (Cu-30Ni). The selection of the final metal barrier material is dependent upon the expected behavior of these materials in the repository environment

  10. Investigation on different oxides as candidates for nano-sized ODS particles in reduced-activation ferritic (RAF) steels

    International Nuclear Information System (INIS)

    Future generation reactor concepts are based on materials that can stand higher temperatures and higher neutron doses in corrosive environments. Oxide dispersion strengthened steels with chromium contents ranging from 9 to 14 wt.% – produced by mechanical alloying – are typical candidate materials for future structural materials in fission and fusion power plants. Y2O3 has proven to be a good candidate for addition to ferritic steels during mechanical alloying to form nano-sized dispersion oxide particles during compacting of the material. These oxide particles have many positive effects on the material such as improved high-temperature properties and higher corrosion resistance. However, there is potential for improvements by choosing different oxides. In this present work, four different oxides (MgO, La2O3, Ce2O3 and ZrO2) are selected by looking at their thermal stabilities and Gibbs free enthalpies of various chemical compositions. These oxides are mixed and mechanically alloyed with ferritic steel powder (Fe13Cr1W0.3Ti) and compared to a reference material produced with Y2O3 (Fe13Cr1W0.3Ti + Y2O3). The materials were characterized in terms of their mechanical properties and detailed microstructural investigations by transmission electron microscopy and electron backscatter diffraction. All further results of the mechanical testing and microstructural characterizations are analyzed, compared, and discussed in this paper

  11. In vivo corrosion behaviour of magnesium alloy in association with surrounding tissue response in rats.

    Science.gov (United States)

    Miura, Chieko; Shimizu, Yoshinaka; Imai, Yoshimichi; Mukai, Toshiji; Yamamoto, Akiko; Sano, Yuya; Ikeo, Naoko; Isozaki, Shuji; Takahashi, Toru; Oikawa, Miho; Kumamoto, Hiroyuki; Tachi, Masahiro

    2016-04-01

    Biodegradable magnesium (Mg) alloys are the most promising candidates for osteosynthesis devices. However, their in vivo corrosion behaviour has not been fully elucidated. The aim of this study was to clarify the influence of the physiological environment surrounding Mg alloys on their corrosion behaviour. A Mg-1.0Al alloy with a fine-grained structure was formed into plates using titanium (Ti) as a control. These plates were implanted into the subperiosteum in the head, subcutaneous tissue of the back, and in the muscle of the femur of rats for 1, 2 and 4 weeks. The volumes of the remaining Mg alloy and of the insoluble salt deposition and gas cavities around the Mg alloy were determined by microtomography, and the volume losses were calculated. Then, the tissue response around the plates in each implantation site was examined histopathologically, and its relation to the respective volume loss was analyzed. These analyses determined that the Mg alloy was corroded fastest in the head, at an intermediate level in the back, and slowest in the femur. The insoluble salt deposition at the Mg alloy surface had no influence on the volume loss. Gas cavities formed around the Mg alloy at all implantation sites and decreased after 4 weeks. Histopathological examination revealed that the Mg alloy exhibited good biocompatibility, as was seen with Ti. In addition, vascularized fibrous capsules formed around the plates and became mature with time. Notably, the volume loss in the different anatomical locations correlated with capsule thickness. Together, our results suggest that, to facilitate the successful clinical application of Mg alloys, it will be necessary to further comprehend their interactions with specific in vivo environments. PMID:26947358

  12. 51. Meeting of the Chemical Societies: Almanac of Contributions, Vol. Program, 1, 2, 3, 4 Molecular Models (Workshop)

    International Nuclear Information System (INIS)

    The publication has been set up as a abstracts of the meeting dealing with different chemical problems. The book (Vol. 1) consists of the sections: All-plenary lectures (9 papers); (D) History of the chemistry (14); (K) Didactics of chemistry (32); The book (Vol. 2) consists of the sections: (A) Analytical chemistry (48); (B) Inorganic chemistry (75); (C) Physical chemistry (27); (F) Nuclear chemistry and radioecology (12); (L) Environmental chemistry and toxicology (33); (M) Agricultural chemistry (20). The book (Vol. 3) consists of the sections: (E) Wood, pulp, paper (15); (G) Macromolecular chemistry (42); (H) Organic chemistry, bio-organic chemistry and pharmaceutical chemistry (96); (I) Food chemistry and biochemistry (34); (J) Textile, fibres and foil materials (9). The book (Vol. 4) consists of the workshop Molecular models (3 papers)

  13. High-Temperature Phase Change Materials (PCM) Candidates for Thermal Energy Storage (TES) Applications

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, J. C.

    2011-09-01

    It is clearly understood that lower overall costs are a key factor to make renewable energy technologies competitive with traditional energy sources. Energy storage technology is one path to increase the value and reduce the cost of all renewable energy supplies. Concentrating solar power (CSP) technologies have the ability to dispatch electrical output to match peak demand periods by employing thermal energy storage (TES). Energy storage technologies require efficient materials with high energy density. Latent heat TES systems using phase change material (PCM) are useful because of their ability to charge and discharge a large amount of heat from a small mass at constant temperature during a phase transformation like melting-solidification. PCM technology relies on the energy absorption/liberation of the latent heat during a physical transformation. The main objective of this report is to provide an assessment of molten salts and metallic alloys proposed as candidate PCMs for TES applications, particularly in solar parabolic trough electrical power plants at a temperature range from 300..deg..C to 500..deg.. C. The physical properties most relevant for PCMs service were reviewed from the candidate selection list. Some of the PCM candidates were characterized for: chemical stability with some container materials; phase change transformation temperatures; and latent heats.

  14. Powder metallurgical processing of self-passivating tungsten alloys for fusion first wall application

    International Nuclear Information System (INIS)

    Self-passivating tungsten based alloys are expected to provide a major safety advantage compared to pure tungsten, presently the main candidate material for first wall armour of future fusion reactors. In case of a loss of coolant accident with simultaneous air ingress, a protective oxide scale will be formed on the surface of W avoiding the formation of volatile and radioactive WO3. Bulk WCr12Ti2.5 alloys were manufactured by mechanical alloying (MA) and hot isostatic pressing (HIP), and their properties compared to bulk WCr10Si10 alloys from previous work. The MA parameters were adjusted to obtain the best balance between lowest possible amount of contaminants and effective alloying of the elemental powders. After HIP, a density >99% is achieved for the WCr12Ti2.5 alloy and a very fine and homogeneous microstructure with grains in the submicron range is obtained. Unlike the WCr10Si10 material, no intergranular ODS phase inhibiting grain growth was detected. The thermal and mechanical properties of the WCr10Si10 material are dominated by the silicide (W,Cr)5Si3; it shows a sharp ductile-to brittle transition in the range 1273–1323 K. The thermal conductivity of the WCr12Ti2.5 alloy is close to 50 W/mK in the temperature range of operation; it exhibits significantly higher strength and lower DBTT – around 1170 K – than the WCr10Si10 material

  15. An assessment of Fe-Cr-Mn austenitic alloys for fusion service using fast reactor irradiation

    International Nuclear Information System (INIS)

    A series of model Fe-Cr-Mn alloys and various solute-modified high manganese alloys have been irradiated in the Fast Flux Test Facility in order to provide an early assessment of the consequences of substituting manganese for nickel in austenitic stainless steel. The purpose of this substitution is to reduce the level of long term radioactivation of this alloy, a candidate structural material for use in fusion energy devices. Simple Fe-Mn and Fe-Cr-Mn alloys were found to exhibit much of the same behavior observed in Fe-Ni and Fe-Ni-Cr alloys. In particular, they tend to swell at /approximately/1%/dpa after an incubation period that is dependent on irradiation temperature, alloy composition and cold working. The phase stability, both in and out of reactor, is altered substantially by the substitution of manganese, however. It nonetheless appears that appropriate levels of solute modification can be used to improve both the swelling resistance and phase stability. An alloy with a base composition of Fe-20Mn-15Cr appears to offer the best promise for further research. 24 refs., 9 figs., 4 tabs

  16. Hydrogen transport and embrittlement for palladium coated vanadium-chromium-titanium alloys

    International Nuclear Information System (INIS)

    Vanadium based alloys have been identified as a leading candidate material for fusion first-wall blanket structure application because they exhibit favorable safety and environmental characteristics, good fabricability, potential for high performance and long-time operation lifetime in a fusion environment. As part of a study of the thermodynamics, kinetics and embrittlement properties of hydrogen in vanadium based alloys, experiments were conducted to determine the rate of hydrogen transport through the vanadium reference alloys, V-7.5Cr-15Ti and V-4Cr-4Ti, and to determine these alloys' hydrogen embrittlement, they were exposed to hydrogen pressures of 3 and 300 kPa (0.03--3 atm) at temperatures between 380 and 475 C. To facilitate hydrogen entry and egress, tubes of these alloys were coated with palladium on the inside and outside faces. Observed permeabilities were 0.015 to 0.065 micromoles/(m2sPa0.5) for the V-7.5Cr-15Ti alloy and 0.02 to 0.05 micromoles/m2sPa0.5 for the V-4Cr-4Ti alloy depending on the quality of the coat and the operating temperature. At 1.7 atm hydrogen, V-7.5Cr-15Ti embrittled at temperatures below 380 C while V-4Cr-4Ti embrittled around 330 C

  17. Effect of Microalloying on Wettability, Oxidation and Solidification Morphology of Sn-9Zn Alloy

    Institute of Scientific and Technical Information of China (English)

    Wei Xiuqin; Huang Huizhen; Zhou Lang; Zhang Meng

    2005-01-01

    Eutectic alloy Sn-9Zn is an attractive candidate for lead-free solders. However, its wettability to copper is poor thus,its development was limited. Effects of less than 1% (mass fraction) additions of mischmetal consisting mainly of La and Ce, heavy rare earth Y, pure P, Al, Mg and Ti elements on the wetting/adhesion behavior of Sn-9Zn alloy to copper, as well as the associated oxidation and solidification morphology of this alloy were examined. The results show that harmful effect on the wettability can be found when adding Al and Ti elements, while the wettability can be improved slightly by adding Mg and Y elements. The adhesion of the alloy to copper can be decreased by Mg element. The RE and P are found to significantly improve the wettability. In addition, oxidation of the alloy can be increased by adding RE, while little effect on the oxidation behavior can be found by adding P element. As-solidified Sn-9Zn alloy has a rough surface with protrusions and cavities shaped by coarse needle-like crystallites, while the Sn-37Pb sample has a rather smooth surface, which indicates the different solidification behavior of Sn-9Zn alloy and the Sn-37Pb one. The additions of the different elements investigated in this study do not alter Sn-9Zn's as-solidified morphology.

  18. Hot Workability of CuZr-Based Shape Memory Alloys for Potential High-Temperature Applications

    Science.gov (United States)

    Biffi, Carlo Alberto; Tuissi, Ausonio

    2014-07-01

    The research on high-temperature shape memory alloys has been growing because of the interest of several potential industrial fields, such as automotive, aerospace, mechanical, and control systems. One suitable candidate is given by the CuZr system, because of its relative low price in comparison with others, like the NiTi-based one. In this context, the goal of this work is the study of hot workability of some CuZr-based shape memory alloys. In particular, this study addresses on the effect of hot rolling process on the metallurgical and calorimetric properties of the CuZr system. The addition of some alloying elements (Cr, Co, Ni, and Ti) is taken into account and their effect is also put in comparison with each other. The alloys were produced by means of an arc melting furnace in inert atmosphere under the shape of cigars. Due to the high reactivity of these alloys at high temperature, the cigars were sealed in a stainless steel can before the processing and two different procedures of hot rolling were tested. The characterization of the rolled alloys is performed using discrete scanning calorimetry in terms of evolution of the martensitic transformation and scanning electron microscopy for the microstructural investigations. Additionally, preliminary tests of laser interaction has been also proposed on the alloy more interesting for potential applications, characterized by high transformation temperatures and its good thermal stability.

  19. Abnormal grain growth of Zr-1wt.%Nb alloy and the effect of Mo addition

    International Nuclear Information System (INIS)

    Increasingly harsh operation conditions of water reactors, such as high burn-up fuel cycles, demand improved Zr-based alloys for the reactor core applications. Enhanced corrosion resistance, better than that of Zircaloy-4, was realized in the newly developed Zr-based alloys containing Nb and Sn. Zr-Nb alloy was developed for pressure tubes of heavy water reactors while Zr-Nb-Si alloys such as ZIRLO and E635 alloys are currently under evaluation as candidate materials for advanced fuel claddings. In the Zr-based alloys containing Nb, generally a fine grain structure is maintained due to the presence of a small amount of retained β. There is a good possibility, therefore, of abnormal grain growth provided that the role of β phase is consistent. Addition of Mo in Zr-Nb alloy, in this respect, is expected to bring about a crucial effect on stabilizing the microstructure. The present work addresses the problem of abnormal grain growth in Zr-Nb system and presents a possible way of curing it by addition of Mo

  20. Mechanical properties and deformation behavior of as-cast Ti-Sn alloys

    International Nuclear Information System (INIS)

    In this study, the mechanical properties of as-cast Ti-Sn alloys with Sn content ranging from 1 to 30 wt.% prepared using a dental cast machine were investigated and compared with commercially pure titanium (c.p. Ti), which was used as a control. Experimental results indicated that the diffraction peaks of all the Ti-Sn alloys matched those for α Ti, and no β phase peaks or any intermediate phases were found. All the Ti-Sn alloys had higher bending strengths, bending moduli and elastic recovery angles than those of c.p. Ti. For example, the bending strength of the Ti-1Sn alloy was higher than that of c.p. Ti by 68%, its bending modulus was higher than that of c.p. Ti by 43% and its elastically recoverable angle was higher than that of c.p. Ti by as much as 240%. Additionally, the Ti-1Sn, Ti-5Sn and Ti-10Sn alloys exhibited ductile properties. When the Sn content was 20 wt.% or greater, the alloys showed brittle properties. Our research suggested that Ti-1Sn alloy had the most favorable mechanical properties of all the metals in this study, making it the best candidate for prosthetic dental applications.

  1. In vitro corrosion and biocompatibility study of phytic acid modified WE43 magnesium alloy

    Science.gov (United States)

    Ye, C. H.; Zheng, Y. F.; Wang, S. Q.; Xi, T. F.; Li, Y. D.

    2012-02-01

    Phytic acid (PA) conversion coating on WE43 magnesium alloy was prepared by the method of immersion. The influences of phytic acid solution with different pH on the microstructure, properties of the conversion coating and the corrosion resistance were investigated by SEM, FTIR and potentiodynamic polarization method. Furthermore, the biocompatibility of different pH phytic acid solution modified WE43 magnesium alloys was evaluated by MTT and hemolysis test. The results show that PA can enhance the corrosion resistance of WE43 magnesium especially when the pH value of modified solution is 5 and the cytotoxicity of the PA coated WE43 magnesium alloy is much better than that of the bare WE43 magnesium alloy. Moreover, all the hemolysis rates of the PA coated WE43 Mg alloy were lower than 5%, indicating that the modified Mg alloy met the hemolysis standard of biomaterials. Therefore, PA coating is a good candidate to improve the biocompatibility of WE43 magnesium alloy.

  2. International congress on forest decline research: State of knowledge and perspectives. Vol. 2. Proceedings

    International Nuclear Information System (INIS)

    In the two lecture volumes of the Proceedings of the International Congress on Forest Decline Research the papers are presented according to the topics of the plenary and poster sessions. The sessions had been devoted to the damage symptoms in forest decline, to the main stressors (atmosphere, climate, soil, biota), to the effects of the stressors (on rhizosphere, on decomposers, and on plants) (see vol. 1), to case studies (in Germany and abroad), to regional comparisons, to critical loads, and to silvicultural measures (see vol. 2). Additionally personal impressions about the forest decline phenomen in Germany and its causes and opinions about the perspective in regard to research needs, to silvicultural practices and to emission control are given. (orig./vhe)

  3. International congress on forest decline research: State of knowledge and perspectives. Vol. 1. Proceedings

    International Nuclear Information System (INIS)

    In the two lecture volumes of the Proceedings of the International Congress on Forest Decline Research the papers are presented according to the topics of the plenary and poster sessions. The sessions had been devoted to the damage symptoms in forest decline, to the main stressors (atmosphere, climate, soil, biota), to the effects of the stressors (on rhizosphere, on decomposers, and on plants) (see vol. 1), to case studies (in Germany and abroad), to regional comparisons, to critical loads, and to silvicultural measures (see vol. 2). Additionally personal impressions about the forest decline phenomen in Germany and its causes and opinions about the perspective in regard to research needs, to silvicultural practices and to emission control are given. (orig./vhe)

  4. Advanced ordered intermetallic alloy deployment

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C.T.; Maziasz, P.J.; Easton, D.S. [Oak Ridge National Lab., TN (United States)

    1997-04-01

    The need for high-strength, high-temperature, and light-weight materials for structural applications has generated a great deal of interest in ordered intermetallic alloys, particularly in {gamma}-based titanium aluminides {gamma}-based TiAl alloys offer an attractive mix of low density ({approximately}4g/cm{sup 3}), good creep resistance, and high-temperature strength and oxidation resistance. For rotating or high-speed components. TiAl also has a high damping coefficient which minimizes vibrations and noise. These alloys generally contain two phases. {alpha}{sub 2} (DO{sub 19} structure) and {gamma} (L 1{sub 0}), at temperatures below 1120{degrees}C, the euticoid temperature. The mechanical properties of TiAl-based alloys are sensitive to both alloy compositions and microstructure. Depending on heat-treatment and thermomechanical processing, microstructures with near equiaxed {gamma}, a duplex structure (a mix of the {gamma} and {alpha}{sub 2} phases) can be developed in TiAl alloys containing 45 to 50 at. % Al. The major concern for structural use of TiAl alloys is their low ductility and poor fracture resistance at ambient temperatures. The purpose of this project is to improve the fracture toughness of TiAl-based alloys by controlling alloy composition, microstructure and thermomechanical treatment. This work is expected to lead to the development of TiAl alloys with significantly improved fracture toughness and tensile ductility for structural use.

  5. Aging of Alloy 617 at 650 and 750 Degrees C

    Energy Technology Data Exchange (ETDEWEB)

    Julian Benz; Thomas Lillo; Richard Wright

    2013-01-01

    Alloy 617 has been selected as the primary candidate for heat exchanger applications in advanced reactors. For the VHTR this application could require extended service up to a reactor outlet temperature of 950°C. A key hurdle to using this alloy in the VHTR heat exchanger application is qualifying the alloy for Section III of the ASME Boiler and Pressure Vessel Code. In order to Code qualify the material it is necessary to characterize the influence of long term aging on the mechanical behavior. Alloy 617 has been aged at 650 and 750°C for times up to 5300 hours. The microstructure after aging has been characterized using optical and transmission electron microscopies. It has been determined that in addition to carbides, a significant volume fraction of ?’ phase (Ni3Al) is formed at these temperatures. The ?’ does not contribute significantly to changing the tensile or impact properties of the aged material. It does, however, appear to increase creep resistance and impede creep crack growth.

  6. Microstructure of electroplated Cu(Ag) alloy thin films

    International Nuclear Information System (INIS)

    Electroplated Cu(Ag) alloy thin films are potential candidates for future electronic devices in terms of lifetime and reliability compared to copper as the state of the art interconnect material. In the present paper we focus on the microstructure of Cu(Ag) alloy films considering the grain evolution as well as silver incorporation and segregation. We show that Ag alloying addition prevents room temperature recrystallization. Thermally induced grain growth occurs mainly between 180 oC and 330 oC. Silver can be incorporated as solid solution into the Cu matrix by up to 0.8 at.% after annealing and even in higher concentrations in the as-deposited state, which is significantly above the equilibrium solubility limit. Precipitations are formed by the continuous mode and can be mainly found at the film surface but also inside the Cu(Ag) grains as ball-shaped particles. Based on our results a reliability improvement is expected by mechanical strengthening due to alloying effects while maintaining a low electrical resistivity and a {111} fiber texture.

  7. Single crystal studies of platinum alloys for oxygen reduction electrodes

    DEFF Research Database (Denmark)

    Ulrikkeholm, Elisabeth Therese

    In this thesis the discovery, characterization and testing of new catalysts for the oxygen reduction reaction (ORR) is investigated. Experiments on sputter cleaned, polycrystalline Pt5Y and Pt5Gd crystals have shown that these alloys are excelent candidates for catalysts for the ORR. To mimic the...... behavior of bulk single crystals, deposition of yttrium and gadolinium on a clean, annealed Pt(111) crystal were investigated in UHV. PtxY and PtxGd alloys terminated with a single atomic layer of platinum were formed after annealing to 500 °C in UHV. These alloys will be referred to as Y/Pt(111) and Gd.......89×1.89 structure, and the Gd/Pt(111) sample has formed a 1.90×1.90 structure compared to pure platinum. From the XPS measurements, it is most likely that alloys with the Pt5Y and Pt5Gd stoichiometry have been formed. The reactivity of the surfaces were probed using TPD. These measurements showed sharp desorption...

  8. Effect of rolling temperature of the magnesium alloy AZ31B formability; Efeito da temperatura de laminacao na deformabilidade da liga de magnesio AZ31B

    Energy Technology Data Exchange (ETDEWEB)

    Catorceno, L.L.C.; Zimmermann, A.J.O.; Padilha, A.F., E-mail: litzy.catorceno@poli.usp.b [Universidade de Sao Paulo (DEMM/EP/USP), SP (Brazil). Escola Politecnica. Dept. de Engenharia Metalurgica e de Materiais

    2010-07-01

    The magnesium alloy AZ31B presents an interesting set of properties, which makes it potential candidate for applications in automotive and aeronautics. The main limitation of magnesium alloys is the low capacity of plastic forming at room temperature. The main motivation of this project is to understand and control the microstructure and crystallographic texture of magnesium alloys, to improve their formability. The effect of rolling temperature on the formability of the alloy was studied in this stage of the project. The alloy in the form of annealed and recrystallized sheets (2 mm thick) was deformed by rolling at four different temperatures: 25, 100, 200 and 250 deg C. The microstructural characterization was achieved using several complementary techniques of microstructural analysis, such as optical microscopy, scanning electron microscopy, X-ray analysis by energy dispersive, X-ray diffraction and microhardness. Results about the effect of rolling temperature on the alloy formability were presented and discussed. (author)

  9. Characterization of the Ti-10Nb-10Zr-5Ta Alloy for Biomedical Applications. Part 1: Microstructure, Mechanical Properties, and Corrosion Resistance

    Science.gov (United States)

    Vladescu, A.; Braic, V.; Balaceanu, M.; Braic, M.; Parau, A. C.; Ivanescu, S.; Fanara, C.

    2013-08-01

    Ti-10Nb-10Zr-5Ta alloy was investigated as possible material candidate for replacing Ti6Al4V in medical applications. The alloy was prepared in a levitation melting furnace and characterized in terms of elemental and phase composition, microstructure, mechanical properties, and corrosion resistance in simulated body fluid and Fusayama Meyer artificial saliva solutions. The characteristics of the new alloy were compared to those of the Ti6Al4V alloy. The Ti-10Nb-10Zr-5Ta system was found to posses of a polyhedral structure consisting in α' and β phases. X-ray structural analysis revealed a mixture of hexagonal α' martensite (main phase, with grain size of about 21 nm) and β bcc phase. The Ti-10Nb-10Zr-5Ta alloy exhibited some better mechanical properties (Young modulus, tensile properties) and corrosion resistance (polarization resistance, corrosion current density, and corrosion rate), as compared to Ti6Al4V alloy.

  10. Interphase thermodynamic bond in heterogeneous alloys: effects on alloy properties

    International Nuclear Information System (INIS)

    Inconsistency between a conventional thermodynamic description of alloys as a mechanical mixture of phases and a real alloys state as a common thermodynamic system in which there is a complicated physical-chemical phases interaction has been considered. It is supposed that in heterogeneous alloys (eutectic ones, for instance), so called interphase thermodynamic bond can become apparent due to a partial electron levels splitting under phase interaction. Thermodynamic description of phase equilibrium in alloys is proposed taking into account a thermodynamic bond for the system with phase diagram of eutectic type, and methods of the value of this bond estimation are presented. Experimental evidence (Al-Cu-Si, Al-Si-Mg-Cu, U-Mo + Al) of the effect of interphase thermodynamic bond on temperature and enthalpy of melting of alloys are produced as well as possibility of its effects on alloys electrical conduction, strength, heat and corrosion resistance is substantiated theoretically

  11. Proceedings of the third arab conference on the peaceful uses of atomic energy, vol.a,b

    International Nuclear Information System (INIS)

    The publication has been set up as a textbook for peaceful uses of atomic energy vol.A: (1) reactor,materials,energy; (2) nuclear raw materials; (3) radiocesium-waste; (4) nuclear safety; (5) nuclear physics; (6) radiochemistry; (7) radiobiology; vol.B: (1) nuclear medicine; (2) agriculture and soil science; (3) isotope hydrology; (4) food preservation; (5) insect eradication; (6 )industrial application; (7) nuclear activation analysis; (8) health physics and environmental studies

  12. Electron beam-assisted healing of nanopores in magnesium alloys

    Science.gov (United States)

    Zheng, He; Liu, Yu; Cao, Fan; Wu, Shujing; Jia, Shuangfeng; Cao, Ajing; Zhao, Dongshan; Wang, Jianbo

    2013-01-01

    Nanopore-based sensing has emerged as a promising candidate for affordable and powerful DNA sequencing technologies. Herein, we demonstrate that nanopores can be successfully fabricated in Mg alloys via focused electron beam (e-beam) technology. Employing in situ high-resolution transmission electron microscopy techniques, we obtained unambiguous evidence that layer-by-layer growth of atomic planes at the nanopore periphery occurs when the e-beam is spread out, leading to the shrinkage and eventual disappearance of nanopores. The proposed healing process was attributed to the e-beam-induced anisotropic diffusion of Mg atoms in the vicinity of nanopore edges. A plausible diffusion mechanism that describes the observed phenomena is discussed. Our results constitute the first experimental investigation of nanopores in Mg alloys. Direct evidence of the healing process has advanced our fundamental understanding of surface science, which is of great practical importance for many technological applications, including thin film deposition and surface nanopatterning. PMID:23719630

  13. Properties of Alloy 617 for Heat Exchanger Design

    Energy Technology Data Exchange (ETDEWEB)

    Wright, Richard Neil [Idaho National Laboratory; Carroll, Laura Jill [Idaho National Laboratory; Benz, Julian Karl [Idaho National Laboratory; Wright, Julie Knibloe [Idaho National Laboratory; Lillo, Thomas Martin [Idaho National Laboratory; Lybeck, Nancy Jean [Idaho National Laboratory

    2014-10-01

    Abstract – Alloy 617 is among the primary candidates for very high temperature reactor heat exchangers anticipated for use up to 950ºC. Elevated temperature properties of this alloy and the mechanisms responsible for the observed tensile, creep and creep-fatigue behavior have been characterized over a wide range of test temperatures up to 1000ºC. Properties from the current experimental program have been combined with archival information from previous VHTR research to provide large data sets for many heats of material, product forms, and weldments. The combined data have been analyzed to determine conservative values of yield and tensile strength, strain rate sensitivity, creep-rupture behavior, fatigue and creep- fatigue properties that can be used for engineering design of reactor components. Phenomenological models have been developed to bound the regions over which the engineering properties are well known or can be confidently extrapolated for use in design.

  14. Creep properties of refractory alloys for space nuclear power applications

    International Nuclear Information System (INIS)

    To satisfy power, mass, and volume requirements, space nuclear power systems are designed with refractory alloys for fuel cladding and reactor structures. This paper presents analysis of existing and new creep data for the refractory alloys that are candidates for fuel cladding or reactor structural applications for space power reactors. Analysis includes use of empirical parameters such as Larson-Miller, Dorn, Orr-Sherby-Dorn, and Manson-Haferd to predict long-term creep properties with data from relatively short-term tests. References curves for stress to produce 1% creep strain in 7 years versus these parameters are presented for Nb-1% Zr, PWC-11, Mo-11 and 14% Re, T-111, ASTAR-811C, CVD-W, W-5% Re, and W-25% Re

  15. TORSIONAL DEFORMATION AND FATIGUE BEHAVIOUR OF 6061 ALUMINIUM ALLOY

    Directory of Open Access Journals (Sweden)

    marini marno

    2012-02-01

    Full Text Available Torsional deformation and fatigue behaviour of both solid and thin-walled tubular specimens were made from as-received and heat treated 6061 aluminium alloy were studied. 6061 aluminium alloy have been widely used as a candidate material in automobile, aerospace, aircraft and structural application because of their superior mechanical properties such as high strength to weight ratio, good ductility and others. The differences in cyclic deformation and fatigue behaviours between round and solid specimens where a stress gradient exist, and thin-walled tubular specimens where a uniform stress state is commonly assumed, are also discussed. Von Mises and Tresca criteria has been used to predict the monotonic and cyclic deformation curve and compared to the torsional data obtained from the experiment. The S-N curve was used to present and evaluate the fatigue life of the specimens. Through fractographic analysis, failure criteria of fracture surfaces were observed and discussed. 

  16. Optical Nova Candidates in M 31

    Science.gov (United States)

    Henze, M.; Burwitz, V.; Pietsch, W.; Updike, A.; Milne, P.; Williams, G.; Hartmann, D. H.

    2008-06-01

    We report the discovery of an optical nova candidate in M 31 on two 11x60s stacked R filter CCD images obtained with the robotic 60cm telescope with an E2V CCD (2kx2k) of the Livermore Optical Transient Imaging System (Super-LOTIS, located at Steward Observatory, Kitt Peak, Arizona, USA). The object was first detected on 2008 June 06.47 and 07.47 UT with respective magnitudes of 18.0 and 17.9.

  17. Blend Analysis of HATNet Transit Candidates

    Directory of Open Access Journals (Sweden)

    Bakos G.Á.

    2011-02-01

    Full Text Available Candidate transiting planet systems discovered by wide-field groundbased surveys must go through an intensive follow-up procedure to distinguish the true transiting planets from the much more common false positives. Especially pernicious are configurations of three or more stars which produce radial velocity and light curves that are similar to those of single stars transited by a planet. In this contribution we describe the methods used by the HATNet team to reject these blends, giving a few illustrative examples.

  18. Dark Matter and its Particle Candidates

    CERN Document Server

    Bottino, A

    1999-01-01

    In these lectures we first briefly review the main observational facts which imply that most part of matter in the Universe is not visible and some recent intriguing experimental data which would point to a significant contribution to Omega due to a cosmological constant. We subsequently discuss some particle candidates for dark matter, with particular emphasis for the neutralino. We present the main properties of this particle, also in the light of the most recent experimental results in direct search for relic particles; furthermore, we discuss the perspectives for their indirect searches.

  19. Assessment of candidate accident management strategies

    International Nuclear Information System (INIS)

    A set of candidate accident management strategies, whose purpose is to prevent or mitigate in-vessel core damage, were identified from various Nuclear Regulatory Commission (NRC) and industry reports. These strategies have been grouped in this report by the challenges they are intended to meet, and assessed to provide information which may be useful to individual licensees for consideration when they perform their Individual Plant Examinations. Each assessment focused on describing and explaining the strategy, considering its relationship to existing requirements and practices as well as identifying possible associated adverse effects. 10 refs

  20. Reducing stigma and discrimination: Candidate interventions

    Directory of Open Access Journals (Sweden)

    Kassam Aliya

    2008-04-01

    Full Text Available Abstract This paper proposes that stigma in relation to people with mental illness can be understood as a combination of problems of knowledge (ignorance, attitudes (prejudice and behaviour (discrimination. From a literature review, a series of candidate interventions are identified which may be effective in reducing stigmatisation and discrimination at the following levels: individuals with mental illness and their family members; the workplace; and local, national and international. The strongest evidence for effective interventions at present is for (i direct social contact with people with mental illness at the individual level, and (ii social marketing at the population level.

  1. Candidate gene effects on beef quality

    OpenAIRE

    Ekerljung, Marie

    2012-01-01

    The contribution of five candidate genes to the variation in meat tenderness, pH, colour, marbling and water holding capacity (WHC) was analysed in muscle samples from 243 young bulls of Angus, Charolais, Hereford, Limousin, or Simmental breed, raised in Swedish commercial herds. The animals were genotyped for single nucleotide polymorphisms (SNPs) in the genes encoding calpain 1 (CAPN1:c.947G>C), calpastatin, (CAST:c.155C>T), diacylglycerol O-acyltransferase 1 (DGAT1), leptin (UASMS2C>T) a...

  2. Oxidation Behavior of Mo-Si-B Alloys in Wet Air; TOPICAL

    International Nuclear Information System (INIS)

    Multiphase composite alloys based on the Mo-Si-B system are candidate materials for ultra-high temperature applications. In non load-bearing uses such as thermal barrier coatings or heat exchangers in fossil fuel burners, these materials may be ideally suited. The present work investigated the effect of water vapor on the oxidation behavior of Mo-Si-B phase assemblages. Three alloys were studied: Alloy 1= Mo(sub 5)Si(sub 3)B(sub x) (T1)- MoSi(sub 2)- MoB, Alloy 2= T1- Mo(sub 5)SiB(sub 2) (T2)- Mo(sub 3)Si, and Alloy 3= Mo- T2- Mo(sub 3)Si. Tests were conducted at 1000 and 1100C in controlled atmospheres of dry air and wet air nominally containing 18, 55, and 150 Torr H(sub 2)O. The initial mass loss of each alloy was approximately independent of the test temperature and moisture content of the atmosphere. The magnitude of these initial losses varied according to the Mo content of the alloys. All alloys formed a continuous, external silica scale that protected against further mass change after volatilization of the initially formed MoO(sub 3). All alloys experienced a small steady state mass change, but the calculated rates cannot be quantitatively compared due to statistical uncertainty in the individual mass measurements. Of particular interest is that Alloy 3, which contains a significant volume fraction of Mo metal, formed a protective scale. All alloys formed varying amounts of subscale Mo and MoO(sub 2). This implies that oxygen transport through the external silica scale has been significantly reduced. For all alloys, water vapor accelerated the growth of a multiphase interlayer at the silica scale/unoxidized alloy interface. This interlayer is likely composed of fine Mo and MoO(sub 2) that is dispersed within a thin silica matrix. Alloy 3 was particularly sensitive to water accelerated growth of this interlayer. At 1100 C, the scale thickness after 300 hours increased from about 20 mm in dry air to nearly 100 mm in wet air

  3. Intermetallic Nickel-Titanium Alloys for Oil-Lubricated Bearing Applications

    Science.gov (United States)

    DellaCorte, C.; Pepper, S. V.; Noebe, R.; Hull, D. R.; Glennon, G.

    2009-01-01

    An intermetallic nickel-titanium alloy, NITINOL 60 (60NiTi), containing 60 wt% nickel and 40 wt% titanium, is shown to be a promising candidate material for oil-lubricated rolling and sliding contact applications such as bearings and gears. NiTi alloys are well known and normally exploited for their shape memory behavior. When properly processed, however, NITINOL 60 exhibits excellent dimensional stability and useful structural properties. Processed via high temperature, high-pressure powder metallurgy techniques or other means, NITINOL 60 offers a broad combination of physical properties that make it unique among bearing materials. NITINOL 60 is hard, electrically conductive, highly corrosion resistant, less dense than steel, readily machined prior to final heat treatment, nongalling and nonmagnetic. No other bearing alloy, metallic or ceramic encompasses all of these attributes. Further, NITINOL 60 has shown remarkable tribological performance when compared to other aerospace bearing alloys under oil-lubricated conditions. Spiral orbit tribometer (SOT) tests were conducted in vacuum using NITINOL 60 balls loaded between rotating 440C stainless steel disks, lubricated with synthetic hydrocarbon oil. Under conditions considered representative of precision bearings, the performance (life and friction) equaled or exceeded that observed with silicon nitride or titanium carbide coated 440C bearing balls. Based upon this preliminary data, it appears that NITINOL 60, despite its high titanium content, is a promising candidate alloy for advanced mechanical systems requiring superior and intrinsic corrosion resistance, electrical conductivity and nonmagnetic behavior under lubricated contacting conditions.

  4. Effects of the manufacturing process on fracture behaviour of cast TiAl intermetallic alloys

    Directory of Open Access Journals (Sweden)

    A. Brotzu

    2014-01-01

    Full Text Available The γ -TiAl based intermetallic alloys are interesting candidate materials for high-temperature applications with the efforts being directed toward the replacement of Ni-based superalloys. TiAl-based alloys are characterised by a density (3.5-4 g/cm3 which is less than half of that of Ni-based superalloys, and therefore these alloys have attracted broad attention as potential candidate for high-temperature structural applications. Specific composition/microstructure combinations should be attained with the aim of obtaining good mechanical properties while maintaining satisfactory oxidation resistance, creep resistance and high temperature strength for targeted applications. Different casting methods have been used for producing TiAl based alloys. In our experimental work, specimens were produced by means of centrifugal casting. Tests carried out on several samples characterised by different alloy compositions highlighted that solidification shrinkage and solid metal contraction during cooling produce the development of relevant residual stresses that are sufficient to fracture the castings during cooling or to produce a delayed fracture. In this work, crack initiation and growth have been analysed in order to identify the factors causing the very high residual stresses that often produce explosive crack propagation throughout the casting.

  5. High-temperature Titanium Alloys

    Directory of Open Access Journals (Sweden)

    A.K. Gogia

    2005-04-01

    Full Text Available The development of high-temperature titanium alloys has contributed significantly to the spectacular progress in thrust-to-weight ratio of the aero gas turbines. This paper presents anoverview on the development of high-temperature titanium alloys used in aero engines and potential futuristic materials based on titanium aluminides and composites. The role of alloychemistry, processing, and microstructure, in determining the mechanical properties of titanium alloys is discussed. While phase equilibria and microstructural stability consideration haverestricted the use of conventional titanium alloys up to about 600 "C, alloys based on TiPl (or,, E,AINb (0, TiAl (y, and titaniumltitanium aluminides-based composites offer a possibility ofquantum jump in the temperature capability of titanium alloys.

  6. Beitraege zur Astronomiegeschichte, Band 5 (Acta Historica Astronomiae Vol. 18)

    Science.gov (United States)

    Duerbeck, H. W.; Dick, W. R.; Hamel, J.

    2003-01-01

    spectra in 1836. The authors quote details from the observing book and present some sketches (whose reproduction is somewhat poor, and the reader is referred to Häfner's history of Munich Observatory, discussed elsewhere in this volume of JAD, to see a better colour reproduction of a spectral sketch of Lamont). The impact of these studies (or rather the lack of it) is also briefly reviewed. Manfred Strumpf (Gotha) describes the difficulties in finding suitable directors for the Gotha Observatory - when the funds became smaller and the post thus became less and less attractive. Only the wealthy Nikolaus von Konkoly, a serious amateur and pioneer of astrophysics, applied even twice, but the administration was reluctant to seriously consider his offer. The result was that the chosen candidates were mainstream astronomers who used Gotha only as a step to foster their career and to find a better position as soon as possible. Finally, Peter Brosche (Daun) and Endre Zsoldos (Budapest) trace the life of a hitherto elusive craftsman-scientist, Friedrich Schwab. He was chosen to be the mechanic of one of the Venus transit expeditions of the German Empire (1882 to Punta Arenas), became university mechanic in Klausenburg, and later teacher at the technical school in Ilmenau. He was an active observer of variable stars and also a specialist in endomological studies. The authors have located a grand-son and have put to light some valuable notes and photographs. As can be seen from the summaries given above, this collection of essays deals mainly with historical events that occurred in Germany and neighboring countries, and focuses mainly on events in the 17th to 19th centuries. All contributions are written in German. The editors have taken care that generally a high standard was kept, although topic and realization make some articles more pleasant to read than others.

  7. AEREX 350 alloy: A 220 ksi minimum tensile strength fastener alloy for service up to 1350 degree F

    International Nuclear Information System (INIS)

    AEREX trademark 350 Alloy is a new high strength, high temperature, corrosion resistant fastener material which has been developed to service the more demanding requirements typical of newer gas turbine engines. It exhibits the highest creep- and stress-rupture resistance known for any fastener material between 620 and 760 C (1,150 and 1,400 F). Furthermore, its coefficient of thermal expansion is equivalent to conventional nickel base superalloys, such as Waspaloy and Udimet 720. These characteristics combined with its excellent tensile and impact strengths, thermal stability and resistance to stress relaxation suggest that AEREX 350 Alloy is an excellent candidate for high temperature fastener applications, such as those existing in aircraft and land-based gas turbine engines

  8. Rare earth ferrosilicon alloy

    International Nuclear Information System (INIS)

    In order to obtain RE ferrosilicon alloy with good quality and competitive price, it is essential that proper choice of raw materials, processing technology and equipments should be made based on the characteristics of Bai-Yun-Ebo mineral deposits. Experimental work and actual production practice indicate that pyrometallurgical method is suitable for the extraction and isolation of the rare earths and comprehensive utilization of the metal values contained in the feed material is capable of reducing cost of production of RE ferrosilicon alloy. In the Bai-Yun-Ebo deposit, the fluorite type medium lean ore (with respect to iron content) makes a reserve of considerable size. The average content of the chief constituents are given

  9. Effects of a range of machined and ground surface finishes on the simulated reactor helium corrosion of several candidate structural materials

    International Nuclear Information System (INIS)

    This report discusses the corrosion behavior of several candidate reactor structural alloys in a simulated advanced high-temperature gas-cooled reactor (HTGR) environment over a range of lathe-machined and centerless-ground surface finishes. The helium environment contained 50 Pa H2/5 Pa CO/5 Pa CH4/2O (500 μatm H2/50 μatm CO/50 μatm CH4/2O) at 9000C for a total exposure of 3000 h. The test alloys included two vacuum-cast superalloys (IN 100 and IN 713LC); a centrifugally cast austenitic alloy (HK 40); three wrought high-temperature alloys (Alloy 800H, Hastelloy X, and Inconel 617); and a nickel-base oxide-dispersion-strengthened alloy (Inconel MA 754). Surface finish variations did not affect the simulated advanced-HTGR corrosion behavior of these materials. Under these conditions, the availability of reactant gaseous impurities controls the kinetics of the observed gas-metal interactions. Variations in the near-surface activities and mobilities of reactive solute elements, such as chromium, which might be expected to be affected by changes in surface finish, do not seem to greatly influence corrosion in this simulated advanced HTGR environment. 18 figures, 4 tables

  10. Corrosion Assessment of Candidate Materials for the SHINE Subcritical Assembly Vessel and Components FY14 Report

    Energy Technology Data Exchange (ETDEWEB)

    Pawel, Steven J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-10-01

    Laboratory corrosion testing of candidate alloys—including Zr-4 and Zr-2.5Nb representing the target solution vessel, and 316L, 2304, 304L, and 17-4 PH stainless steels representing process piping and balance-of-plant components—was performed in support of the proposed SHINE process to produce 99Mo from low-enriched uranium. The test solutions used depleted uranyl sulfate in various concentrations and incorporated a range of temperatures, excess sulfuric acid concentrations, nitric acid additions (to simulate radiolysis product generation), and iodine additions. Testing involved static immersion of coupons in solution and in the vapor above the solution, and was extended to include planned-interval tests to examine details associated with stainless steel corrosion in environments containing iodine species. A large number of galvanic tests featuring couples between a stainless steel and a zirconium-based alloy were performed, and limited vibratory horn testing was incorporated to explore potential erosion/corrosion features of compatibility. In all cases, corrosion of the zirconium alloys was observed to be minimal, with corrosion rates based on weight loss calculated to be less than 0.1 mil/year with no change in surface roughness. The resulting passive film appeared to be ZrO2 with variations in thickness that influence apparent coloration (toward light brown for thicker films). Galvanic coupling with various stainless steels in selected exposures had no discernable effect on appearance, surface roughness, or corrosion rate. Erosion/corrosion behavior was the same for zirconium alloys in uranyl sulfate solutions and in sodium sulfate solutions adjusted to a similar pH, suggesting there was no negative effect of uranium resulting from fluid dynamic conditions aggressive to the passive film. Corrosion of the candidate stainless steels was similarly modest across the entire range of exposures. However, some sensitivity to corrosion of the stainless steels was

  11. Survey of the degradation modes of candidate materials for high-level radioactive waste disposal containers. Final report

    International Nuclear Information System (INIS)

    One of the most significant factors impacting the performance of waste package container materials under repository relevant conditions is the thermal environment. This environment will be affected by the areal power density of the repository, which is dictated by facility design, and the dominant heat transfer mechanism at the site. The near-field environment will evolve as radioactive decay decreases the thermal output of each waste package. Recent calculations (Buscheck and Nitao, 1994) have addressed the importance of thermal loading conditions on waste package performance at the Yucca Mountain site. If a relatively low repository thermal loading design is employed, the temperature and relative humidity near the waste package may significantly affect the degradation of corrosion allowance barriers due to moist air oxidation and radiolytically enhanced corrosion. The purpose this report is to present a literature review of the potential degradation modes for moderately corrosion resistant nickel copper and nickel based candidate materials that may be applicable as alternate barriers for the ACD systems in the Yucca Mountain environment. This report presents a review of the corrosion of nickel-copper alloys, summaries of experimental evaluations of oxidation and atmospheric corrosion in nickel-copper alloys, views of experimental studies of aqueous corrosion in nickel copper alloys, a brief review of galvanic corrosion effects and a summary of stress corrosion cracking in these alloys

  12. Impact of phase stability on the corrosion behavior of the austenitic candidate materials for NNWSI [Nevada Nuclear Waste Storage Investigations

    International Nuclear Information System (INIS)

    The Nuclear Waste Management Program at Lawrence Livermore National Laboratory is responsible for the development of the waste package design to meet the Nuclear Regulatory Commission licensing requirements for the Nevada Nuclear Waste Storage Investigations (NNWSI) Project. The metallic container component of the waste package is required to assist in providing substantially complete containment of the waste for a period of up to 1000 years. Long term phase stability of the austenitic candidate materials (304L and 316L stainless steels and alloy 825) over this time period at moderate temperatures (100-2500C) can impact the mechanical and corrosion behavior of the metal barrier. A review of the technical literature with respect to phase stability of 304L, 316L and 825 is presented. The impact of martensitic transformations, carbide precipitation and intermediate (σ, chi, and eta) phase formation on the mechanical properties and corrosion behavior of these alloys at repository relevant conditions is discussed. The effect of sensitization on intergranular stress corrosion cracking (IGSCC) of each alloy is also addressed. A summary of the impact of phase stability on the degradation of each alloy in the proposed repository environment is included. 32 refs., 6 figs

  13. Thermodynamic Database for Zirconium Alloys

    OpenAIRE

    Jerlerud Pérez, Rosa

    2006-01-01

    For many decades zirconium alloys have been commonly used in the nuclear power industry as fuel cladding material. Besides their good corrosion resistance and acceptable mechanical properties the main reason for using these alloys is the low neutron absorption. Zirconium alloys are exposed to a very severe environment during the nuclear fission process and there is a demand for better design of this material. To meet this requirement a thermodynamic database is useful to support material desi...

  14. High-temperature Titanium Alloys

    OpenAIRE

    A.K. Gogia

    2005-01-01

    The development of high-temperature titanium alloys has contributed significantly to the spectacular progress in thrust-to-weight ratio of the aero gas turbines. This paper presents anoverview on the development of high-temperature titanium alloys used in aero engines and potential futuristic materials based on titanium aluminides and composites. The role of alloychemistry, processing, and microstructure, in determining the mechanical properties of titanium alloys is discussed. While phase eq...

  15. Structure of ordered alloys

    International Nuclear Information System (INIS)

    Recent progress in studying ordered alloys by lattice fringe imaging is reviewed. Firstly the optimum experimental conditions for producing images suitable for interpretation are outlined. Secondly lattice and conventional imaging are compared and the advantages of the former for obtaining atomic level detail and compositional estimates are described. Finally some important results from this program are discussed, particularly the evidence for a microdomain model of short-range order and the fine structure of various ordered lattice defects

  16. Atomic-level Electron Microscopy of Metal and Alloy Electrocatalysts

    DEFF Research Database (Denmark)

    Deiana, Davide

    flat surfaces and exposed to different sintering conditions. Ex situ STEM imaging has been used to monitor the variation of the particle dimensions through the analysis of particle area distributions. Clusters with a monomodal size distribution exhibited intrinsic sintering resistance on different...... and its dissolution into the electrolyte. The formed Pt-rich shell prevents further dissolution of the rare earth metal protecting the alloyed core. Pt−Hg and Pd−Hg have been identified by Density Functional Theory (DFT) calculations as promising candidates for the electrochemical production of hydrogen...

  17. Uncovering the nucleus candidate for NGC 253

    CERN Document Server

    Günthardt, G I; Camperi, J A; Díaz, R J; Gomez, P L; Bosch, G; Schirmer, M

    2015-01-01

    NGC253 is the nearest spiral galaxy with a nuclear starburst which becomes the best candidate to study the relationship between starburst and AGN activity. However, this central region is veiled by large amounts of dust, and it has been so far unclear which is the true dynamical nucleus. The near infrared spectroscopy could be advantageous in order to shed light on the true nucleus identity. Using Flamingos-2 at Gemini South we have taken deep K-band spectra along the major axis and through the brightest infrared source. We present evidence showing that the brightest near infrared and mid infrared source in the central region, already known as radio source TH7 and so far considered just a stellar supercluster, in fact, presents various symptoms of a genuine galactic nucleus. Therefore, it should be considered a valid nucleus candidate. It is the most massive compact infrared object in the central region, located at 2.0" of the symmetry center of the galactic bar. Moreover, our data indicate that this object i...

  18. Tracking quintessence and cold dark matter candidates

    International Nuclear Information System (INIS)

    We study the generation of a kination-dominated phase in the context of a quintessential model with an inverse-power-law potential and a Hubble-induced mass term for the quintessence field. The presence of kination is associated with an oscillating evolution of the quintessence field and the barotropic index. We find that, in sizeable regions of the parameter space, a tracker scaling solution can be reached sufficiently early to alleviate the coincidence problem. Other observational constraints originating from nucleosynthesis, the inflationary scale, the present acceleration of the universe and the dark-energy-density parameter can be also met. The impact of this modified kination-dominated phase on the thermal abundance of cold dark matter candidates is also investigated. We find that: 1. the enhancement of the relic abundance of the WIMPs with respect to the standard paradigm, crucially depends on the hierarchy between the freeze-out temperature and the temperature at which the extrema in the evolution of the quintessence field are encountered, and; 2. the relic abundance of e-WIMPs takes its present value close to the temperature at which the earliest extremum of the evolution of the quintessence field occurs and, as a consequence, both gravitinos and axinos arise as natural cold dark matter candidates. In the case of unstable gravitinos, the gravitino constraint can be satisfied for values of the initial temperature well above those required in the standard cosmology

  19. Pulsar Candidates Toward Fermi Unassociated Sources

    CERN Document Server

    Frail, D A; Jagannathan, P; Intema, H T

    2016-01-01

    We report on a search for steep spectrum radio sources within the 95% confidence error ellipses of the Fermi unassociated sources from the Large Array Telescope (LAT). Using existing catalogs and the newly released GMRT all-sky survey at 150 MHz we identify compact radio sources that are bright at MHz frequencies but faint or absent at GHz frequencies. Such steep spectrum radio sources are rare and constitute a sample of pulsar candidates, selected independently of period, dispersion measure, interstellar scattering and orbital parameters. We find point-like, steep spectrum candidates toward 11 Fermi sources. Based on the gamma-ray/radio positional coincidence, the rarity of such radio sources, and the properties of the 3FGL sources themselves, we argue that many of these sources could be pulsars. They may have been missed by previous radio periodicity searches due to interstellar propagation effects or because they lie in an unusually tight binary. If this hypothesis is correct, then renewed gamma-ray and ra...

  20. Nonclinical Development of BCG Replacement Vaccine Candidates.

    Science.gov (United States)

    Velmurugan, Kamalakannan; Grode, Leander; Chang, Rosemary; Fitzpatrick, Megan; Laddy, Dominick; Hokey, David; Derrick, Steven; Morris, Sheldon; McCown, David; Kidd, Reginald; Gengenbacher, Martin; Eisele, Bernd; Kaufmann, Stefan H E; Fulkerson, John; Brennan, Michael J

    2013-01-01

    The failure of current Mycobacterium bovis bacille Calmette-Guérin (BCG) vaccines, given to neonates to protect against adult tuberculosis and the risk of using these live vaccines in HIV-infected infants, has emphasized the need for generating new, more efficacious and safer replacement vaccines. With the availability of genetic techniques for constructing recombinant BCG (rBCG) strains containing well-defined gene deletions or insertions, new vaccine candidates are under evaluation at both the preclinical and clinical stages of development. Since most BCG vaccines in use today were evaluated in clinical trials decades ago and are produced by outdated processes, the development of new BCG vaccines offers a number of advantages that include a modern well-defined manufacturing process along with state-of-the-art evaluation of safety and efficacy in target populations. We provide a description of the preclinical development of two novel rBCGs, VPM1002 that was constructed by adding a modified hly gene coding for the protein listeriolysin O (LLO) from Listeria monocytogenes and AERAS-422, which carries a modified pfoA gene coding for the protein perfringolysin O (PFO) from Clostridium perfringens, and three genes from Mycobacterium tuberculosis. Novel approaches like these should be helpful in generating stable and effective rBCG vaccine candidates that can be better characterized than traditional BCG vaccines. PMID:26343962

  1. Nonclinical Development of BCG Replacement Vaccine Candidates

    Directory of Open Access Journals (Sweden)

    Bernd Eisele

    2013-04-01

    Full Text Available The failure of current Mycobacterium bovis bacille Calmette–Guérin (BCG vaccines, given to neonates to protect against adult tuberculosis and the risk of using these live vaccines in HIV-infected infants, has emphasized the need for generating new, more efficacious and safer replacement vaccines. With the availability of genetic techniques for constructing recombinant BCG (rBCG strains containing well-defined gene deletions or insertions, new vaccine candidates are under evaluation at both the preclinical and clinical stages of development. Since most BCG vaccines in use today were evaluated in clinical trials decades ago and are produced by outdated processes, the development of new BCG vaccines offers a number of advantages that include a modern well-defined manufacturing process along with state-of-the-art evaluation of safety and efficacy in target populations. We provide a description of the preclinical development of two novel rBCGs, VPM1002 that was constructed by adding a modified hly gene coding for the protein listeriolysin O (LLO from Listeria monocytogenes and AERAS-422, which carries a modified pfoA gene coding for the protein perfringolysin O (PFO from Clostridium perfringens, and three genes from Mycobacterium tuberculosis. Novel approaches like these should be helpful in generating stable and effective rBCG vaccine candidates that can be better characterized than traditional BCG vaccines.

  2. Advanced Vaccine Candidates for Lassa Fever

    Directory of Open Access Journals (Sweden)

    Igor S. Lukashevich

    2012-10-01

    Full Text Available Lassa virus (LASV is the most prominent human pathogen of the Arenaviridae. The virus is transmitted to humans by a rodent reservoir, Mastomys natalensis, and is capable of causing lethal Lassa Fever (LF. LASV has the highest human impact of any of the viral hemorrhagic fevers (with the exception of Dengue Fever with an estimated several hundred thousand infections annually, resulting in thousands of deaths in Western Africa. The sizeable disease burden, numerous imported cases of LF in non-endemic countries, and the possibility that LASV can be used as an agent of biological warfare make a strong case for vaccine development. Presently there is no licensed vaccine against LF or approved treatment. Recently, several promising vaccine candidates have been developed which can potentially target different groups at risk. The purpose of this manuscript is to review the LASV pathogenesis and immune mechanisms involved in protection. The current status of pre-clinical development of the advanced vaccine candidates that have been tested in non-human primates will be discussed. Major scientific, manufacturing, and regulatory challenges will also be considered.

  3. Advanced vaccine candidates for Lassa fever.

    Science.gov (United States)

    Lukashevich, Igor S

    2012-11-01

    Lassa virus (LASV) is the most prominent human pathogen of the Arenaviridae. The virus is transmitted to humans by a rodent reservoir, Mastomys natalensis, and is capable of causing lethal Lassa Fever (LF). LASV has the highest human impact of any of the viral hemorrhagic fevers (with the exception of Dengue Fever) with an estimated several hundred thousand infections annually, resulting in thousands of deaths in Western Africa. The sizeable disease burden, numerous imported cases of LF in non-endemic countries, and the possibility that LASV can be used as an agent of biological warfare make a strong case for vaccine development. Presently there is no licensed vaccine against LF or approved treatment. Recently, several promising vaccine candidates have been developed which can potentially target different groups at risk. The purpose of this manuscript is to review the LASV pathogenesis and immune mechanisms involved in protection. The current status of pre-clinical development of the advanced vaccine candidates that have been tested in non-human primates will be discussed. Major scientific, manufacturing, and regulatory challenges will also be considered. PMID:23202493

  4. Advanced Vaccine Candidates for Lassa Fever

    Science.gov (United States)

    Lukashevich, Igor S.

    2012-01-01

    Lassa virus (LASV) is the most prominent human pathogen of the Arenaviridae. The virus is transmitted to humans by a rodent reservoir, Mastomys natalensis, and is capable of causing lethal Lassa Fever (LF). LASV has the highest human impact of any of the viral hemorrhagic fevers (with the exception of Dengue Fever) with an estimated several hundred thousand infections annually, resulting in thousands of deaths in Western Africa. The sizeable disease burden, numerous imported cases of LF in non-endemic countries, and the possibility that LASV can be used as an agent of biological warfare make a strong case for vaccine development. Presently there is no licensed vaccine against LF or approved treatment. Recently, several promising vaccine candidates have been developed which can potentially target different groups at risk. The purpose of this manuscript is to review the LASV pathogenesis and immune mechanisms involved in protection. The current status of pre-clinical development of the advanced vaccine candidates that have been tested in non-human primates will be discussed. Major scientific, manufacturing, and regulatory challenges will also be considered. PMID:23202493

  5. Oligocrystalline shape memory alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ueland, Stian M.; Chen, Ying; Schuh, Christopher A. [Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States)

    2012-05-23

    Copper-based shape memory alloys (SMAs) exhibit excellent shape memory properties in single crystalline form. However, when they are polycrystalline, their shape memory properties are severely compromised by brittle fracture arising from transformation strain incompatibility at grain boundaries and triple junctions. Oligocrystalline shape memory alloys (oSMAs) are microstructurally designed SMA structures in which the total surface area exceeds the total grain boundary area, and triple junctions can even be completely absent. Here it is shown how an oligocrystalline structure provides a means of achieving single crystal-like SMA properties without being limited by constraints of single crystal processing. Additionally, the formation of oSMAs typically involves the reduction of the size scale of specimens, and sample size effects begin to emerge. Recent findings on a size effect on the martensitic transformation in oSMAs are compared and a new regime of heat transfer associated with the transformation heat evolution in these alloys is discussed. New results on unassisted two-way shape memory and the effect of loading rate in oSMAs are also reported. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Aluminum alloy impact sparkling

    Directory of Open Access Journals (Sweden)

    M. Dudyk

    2008-08-01

    Full Text Available The cast machine parts are widely used in many branches of industry. A very important issue is gaining the appropriate knowledge relating to the application of castings in places of explosion risks including but not limited to mining, chemical industry and rescue works. A possibility of explosion risks occurrence following the impact sparkling of the cast metal parts is still not solved problem in scientific research. In relation to this issue, in this article, the results of the study are presented, and relating to the tendency to impact sparkling of the aluminium alloys used in machine building. On the grounds of the results obtained, it was demonstrated that the registered impact sparkles bunches of feathers from the analyzed alloys: AlSi7Mg, (AK7; AlSi9Mg, (AK9; AlSi6Cu4, (AK64 and AlSi11, (AK11 show significant differences between each other. The quantitative analysis of the temperature distribution and nuclei surface area performed on the example of the alloy AK9 (subjected to defined period of corrosion allows for the statement that they are dangerous in conditions of explosion risk. Following this fact, designers and users of machine parts made from these materials should not use them in conditions where the explosive mixtures occur.

  7. CASE via MS: Ranking Structure Candidates by Mass Spectra

    OpenAIRE

    Kerber, Adalbert; Meringer, Markus; Rücker, Christoph

    2006-01-01

    Two important tasks in computer-aided structure elucidation (CASE) are the generation of candidate structures from a given molecular formula, and the ranking of structure candidates according to compatibility with an experimental spectrum. Candidate ranking with respect to electron impact mass spectra is based on virtual fragmentation of a candidate structure and comparison of the fragments’ isotope distributions against the spectrum of the unknown compound, whence a structure–spectrum compat...

  8. Amorphous yttrium-iron alloys

    International Nuclear Information System (INIS)

    The magnetic properties of amorphous yttrium-iron alloys Ysub(1-x)Fesub(x) have been studied over a wide concentration range 0.32 2Fe17 alloys, lead in the amorphous state to spin-glass behaviour and asperomagnetic order. The dominant positive interactions produce short-range ferromagnetic correlations which persist up to room temperature. However magnetic saturation cannot be achieved for any of the alloys in applied fields of up to 180 kOe, indicating that strong negative interactions are also present. Exchange interactions become increasingly positive with increasing x, and the magnetic properties of iron-rich alloys approach those of a normal ferromagnet. (author)

  9. Titanium and titanium alloy forgings

    International Nuclear Information System (INIS)

    The specification covers nine grades of annealed titanium and titanium alloy forgings as follows: Grade F-1, F-2, F-3, and F-4 unalloyed titanium; Grade F-5 titanium alloy (6% aluminum, 4% vanadium); Grade F-6 titanium alloy (5% aluminum, 2.5% tin); Grade F-7 and F-11 unalloyed titanium plus palladium; Grade F-12 titanium alloy (0.3% molybdenum, 0.8% nickel). The specification includes ordering information, manufacture, chemical requirements, mechanical requirements, nondestructive tests, dimensions and permissible variations, finish, certification, packaging, and marking

  10. CREEP AND CREEP-FATIGUE OF ALLOY 617 WELDMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Wright, Jill; Carroll, Laura; Wright, Richard

    2014-08-01

    The Very High Temperature Reactor (VHTR) Intermediate Heat Exchanger (IHX) may be joined to piping or other components by welding. Creep-fatigue deformation is expected to be a predominant failure mechanism of the IHX1 and thus weldments used in its fabrication will experience varying cyclic stresses interrupted by periods of elevated temperature deformation. These periods of elevated temperature deformation are greatly influenced by a materials’ creep behavior. The nickel-base solid solution strengthened alloy, Alloy 617, is the primary material candidate for a VHTR-type IHX, and it is expected that Alloy 617 filler metal will be used for welds. Alloy 617 is not yet been integrated into Section III of the Boiler and Pressure Vessel Code, however, nuclear component design with Alloy 617 requires ASME (American Society of Mechanical Engineers) Code qualification. The Code will dictate design for welded construction through significant performance reductions. Despite the similar compositions of the weldment and base material, significantly different microstructures and mechanical properties are inevitable. Experience of nickel alloy welds in structural applications suggests that most high temperature failures occur at the weldments or in the heat-affected zone. Reliably guarding against this type of failure is particularly challenging at high temperatures due to the variations in the inelastic response of the constituent parts of the weldment (i.e., weld metal, heat-affected zone, and base metal) [ref]. This work focuses on the creep-fatigue behavior of nickel-based weldments, a need noted during the development of the draft Alloy 617 ASME Code Case. An understanding of Alloy 617 weldments when subjected to this important deformation mode will enable determination of the appropriate design parameters associated with their use. Specifically, the three main areas emphasized are the performance reduction due to a weld discontinuity in terms of the reduced number of

  11. Identity Functions and Empathetic Tendencies of Teacher Candidates

    Science.gov (United States)

    Ay, Alpaslan; Kadi, Aysegul

    2016-01-01

    Objective of this research is to investigate identity functions and empathetic tendencies of teacher candidates. Sample consists of 232 teacher candidates in social studies teacher education. Survey model is preferred to investigate the difference between identity functions and empathetic tendencies of teacher candidates. And also correlational…

  12. Opinions of the Geography Teacher Candidates toward Mind Maps

    Science.gov (United States)

    Seyihoglu, Aysegul

    2013-01-01

    The purpose of this study is to reveal the opinions of the teacher candidates about mind mapping technique used in Geography education of undergraduate program. In this study, the qualitative research techniques were used. The study group consists of 55 teacher candidates. The teacher candidates have been asked for their opinions about the process…

  13. Perceptions of Candidate Teachers about Concept of the Project

    Science.gov (United States)

    Tortop, Hasan Said

    2014-01-01

    The aim of study is to investigate candidate teachers' metaphors about project concept in Turkey. Study group of research is 171 candidate teachers enrolled 2011-2012 educational terms one of the faculty of education in Turkey. Data was obtained from the candidate teachers' completion of the sentence "Project is like ..., because ...".…

  14. Fabrication of a Textured Non-Magnetic Ni-12at.%V Alloy Substrate for Coated Conductors

    DEFF Research Database (Denmark)

    Gao, M. M.; Grivel, Jean-Claude; Suo, H. L.;

    2011-01-01

    Ni-12at.%V alloy is a promising candidate for non-magnetic cube textured metallic substrates used for high temperature coated conductors. In this work, a textured Ni-12at.%V substrate has been fabricated by powder metallurgy route. After cold rolling and recrystallization annealing, a cube texture...

  15. Computer Simulation and Experimental Validation on the Oxidation and Sulfate Corrosion Resistance of Novel Chromium Based High Temperature Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Shizhong

    2013-02-28

    This report summarizes our recent works of ab initio molecular dynamics inter-atomic potentials development on dilute rare earth element yttrium (Y) etc. doped chromium (Cr) alloy systems, its applications in oxidation and corrosion resistance simulation, and experiment validation on the candidate systems. The simulation methods, experimental validation techniques, achievements already reached, students training, and future improvement are briefly introduced.

  16. Effect of manganese and chromium on microstructure and toughness of Fe-Cr-Mn alloys resulting from solid-solution treatment

    International Nuclear Information System (INIS)

    This study is aimed at making clear the effect of Mn and Cr on the microstructure and toughness of an Fe-Cr-Mn alloy which is considered as one of the candidate alloys for reduced activation materials for the first wall application of the fusion reactor. The microstructures of Fe-12% Cr-(5∼30)% Mn(mass%) alloys after solution treatment at 1373 K for 3.6 ks are markedly varied with Mn contents; α'(martensite) + δ(ferrite) in 5% Mn alloy, α' + δ + ε(martensite) + γ(austenite) in the 10% Mn alloy, α' + ε + γ in 15% Mn alloy, ε + γ in the 20% Mn alloy, and ε + γ +δ in the 25% Mn alloy, and γ + δ in the 30% Mn alloy. It is to be noted that the δ phase increases with increasing Mn content when the Fe-12% Cr alloy contains more than 25% Mn, which suggests that Mn plays the role of a ferrite former. In Fe-15% Mn-Cr alloy, the δ phase is not observed in the range of Cr contents up to 12%, whereas it is markedly increased with the addition of 16% Cr. C, N and Ni are very helpful in forming the γ phase in these alloys as generally known in Fe-Cr-Ni alloys. The toughness evaluated by the Charpy impact test at 273 K and room temperature is very low in the 5% Mn alloy which consists of the α' and δ phases. It is, however, significantly improved by a small amount of the γ phase and increases with increase of γ phase stability. (author)

  17. Compatibility studies of AISI type 316 stainless steel with lead-lithium eutectic alloy

    International Nuclear Information System (INIS)

    Spent fuel subassemblies from the Fast Breeder Test Reactor (FBTR) are to be stored in leak tight cotainers until they are required to be sent for reprocessing. Use of advanced fuels like uranium carbides and plutonium carbides, which are known to be highly chemically active with oxygen and moisture demands adequate leak tightness during long term storage to avoid undesirable chemical reactions. Use of low melting alloys which acts as liquid/solid sealants in the storage containers in which fuel subassemblies are to be kept is being considered for this purpose. Lead-lithium (0.7 wt % lithium) eutectic alloy was chosen as one of the candidate alloys for the purpose on the basis of theoretical assessments. The candidate sealing alloy should have good compatibility with the structural materials of fuel subassemblies as well as the fuel and fission products. AISI type 316 stainless steel in solution annealed, ten and twenty percent cold worked condition is the clad and wrapper material used for the fabrication of fuel pins and subassemblies. Compatibility studies between eutectic Pb-Li alloy and AISI type 316 stainless steel material in the above conditions were undertaken at different temperatures and time durations. The studies indicate that the tensile properties of AISI type 316 stainless steel are not subject to any serious jeopardisation through contact with this molten Pb-Li eutectic alloy for periods extending even upto 7000 hours at 873 K. Thus use of Pb-Li eutectic alloy would be suitable for the storage of irradiated fuel. (author). 16 refs., 38 figs., 3 tabs

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

    Science.gov (United States)

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

    2015-10-01

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

  19. Metallurgical Bonding Development of V-4Cr-4Ti Alloy for the DIII-D Radiative Divertor Program

    International Nuclear Information System (INIS)

    General Atomics (GA), in conjunction with the Department of Energy's (DOE) DIII-D Program, is carrying out a plan to utilize a vanadium alloy in the DIII-D tokamak as part of the DIII-D Radiative Divertor (RD) upgrade. The V-4Cr-4Ti alloy has been selected in the U.S. as the leading candidate vanadium alloy for fusion applications. This alloy will be used for the divertor fabrication. Manufacturing development with the V-4Cr-4Ti alloy is a focus of the DIII-D RD Program. The RD structure, part of which will be fabricated from V-4Cr-4Ti alloy, will require many product forms and types of metal/metal bonded joints. Metallurgical bonding methods development on this vanadium alloy is therefore a key area of study by GA. Several solid state (non-fusion weld) and fusion weld joining methods are being investigated. To date, GA has been successful in producing ductile, high strength, vacuum leak tight joints by all of the methods under investigation. The solid state joining was accomplished in air, i.e., without the need for a vacuum or inert gas environment to prevent interstitial impurity contamination of the V-4Cr-4Ti alloy

  20. A direct molecular link between the autism candidate gene RORa and the schizophrenia candidate MIR137

    Science.gov (United States)

    Devanna, Paolo; Vernes, Sonja C.

    2014-02-01

    Retinoic acid-related orphan receptor alpha gene (RORa) and the microRNA MIR137 have both recently been identified as novel candidate genes for neuropsychiatric disorders. RORa encodes a ligand-dependent orphan nuclear receptor that acts as a transcriptional regulator and miR-137 is a brain enriched small non-coding RNA that interacts with gene transcripts to control protein levels. Given the mounting evidence for RORa in autism spectrum disorders (ASD) and MIR137 in schizophrenia and ASD, we investigated if there was a functional biological relationship between these two genes. Herein, we demonstrate that miR-137 targets the 3'UTR of RORa in a site specific manner. We also provide further support for MIR137 as an autism candidate by showing that a large number of previously implicated autism genes are also putatively targeted by miR-137. This work supports the role of MIR137 as an ASD candidate and demonstrates a direct biological link between these previously unrelated autism candidate genes.

  1. Fuel behavior in severe accidents and Mo-alloy based cladding designs to improve accident tolerance

    International Nuclear Information System (INIS)

    The severe accidents at TMI-2 and Fukushima-Daiichi led to core meltdown and hydrogen explosions. The main source of energy causing core melting is the decay heat from β-, β+, and γ decays of short-lived isotopes following a power scram. The exothermic reaction of Zr-alloy cladding can further increase the cladding temperature leading to rapid cladding corrosion and hydrogen production. The most effective mitigation to minimize core damage in a severe accident is to extend the duration of heat removal capacity via battery-supported passive cooling for as long as practically possible. Replacing the Zr-alloy cladding with a higher heat resistant cladding with lower enthalpy release rate may also provide additional coping time for accident management. Such a heat resistant cladding may also overcome the current licensing concerns about Zr-alloy hydriding and post quench ductility issues in a design base loss of coolant accident (LOCA). Zr-alloy cladding, while has been optimized for normal operation in high pressure water and steam of light water reactors, will rapidly lose its corrosion resistance and tensile and creep strength in high pressure steam. Evaluation of alternate cladding materials and designs have been performed to search for a new fuel cladding design which will substantially improve the safety margins at elevated temperatures during a severe accident, while maintaining the excellent fuel performance attributes of the current Zr-alloy cladding. The screening criteria for the evaluation include neutronic properties, material availability, adaptability and operability in current LWRs, resistance to melting. The new designs also need to be fabricable, maintain sufficient strength and resist to attack by high pressure steam. Engineering metals, alloys and ceramics which can meet some or most of these requirements are limited. Following review of the properties of potential candidates, it is concluded that molybdenum alloys may potentially achieve the

  2. Ferritic Alloys as Accident Tolerant Fuel Cladding Material for Light Water Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Rebak, Raul B. [General Electric Global Research, Schnectady, NY (United States)

    2014-12-30

    The objective of the GE project is to demonstrate that advanced steels such as iron-chromium-aluminum (FeCrAl) alloys could be used as accident tolerant fuel cladding material in commercial light water reactors. The GE project does not include fuel development. Current findings support the concept that a FeCrAl alloy could be used for the cladding of commercial nuclear fuel. The use of this alloy will benefit the public since it is going to make the power generating light water reactors safer. In the Phase 1A of this cost shared project, GE (GRC + GNF) teamed with the University of Michigan, Los Alamos National Laboratory, Brookhaven National Laboratory, Idaho National Laboratory, and Oak Ridge National Laboratory to study the environmental and mechanical behavior of more than eight candidate cladding materials both under normal operation conditions of commercial nuclear reactors and under accident conditions in superheated steam (loss of coolant condition). The main findings are as follows: (1) Under normal operation conditions the candidate alloys (e.g. APMT, Alloy 33) showed excellent resistance to general corrosion, shadow corrosion and to environmentally assisted cracking. APMT also showed resistance to proton irradiation up to 5 dpa. (2) Under accident conditions the selected candidate materials showed several orders of magnitude improvement in the reaction with superheated steam as compared with the current zirconium based alloys. (3) Tube fabrication feasibility studies of FeCrAl alloys are underway. The aim is to obtain a wall thickness that is below 400 µm. (4) A strategy is outlined for the regulatory path approval and for the insertion of a lead fuel assembly in a commercial reactor by 2022. (5) The GE team worked closely with INL to have four rodlets tested in the ATR. GE provided the raw stock for the alloys, the fuel for the rodlets and the cost for fabrication/welding of the rodlets. INL fabricated the rodlets and the caps and welded them to

  3. A review of candidate ceramic materials for use as heat shield tiles in a supercritical-water-cooled-reactor

    International Nuclear Information System (INIS)

    The proposed Canadian supercritical-water-cooled reactor (SCWR) utilizes a reactor shell made of a zirconium alloy insulated with a ceramic tile heat shield. The main consideration in the selection of a tile material will be resistance to corrosion in supercritical water and long term microstructure stability, in addition to thermal conductivity. This paper provides a review of the literature on corrosion behaviours of ceramic materials in supercritical water and ranks candidate ceramic materials accordingly. Materials reviewed include alumina, zirconia, silica glasses, silicon carbide, silicon nitride, sialon, mullite, and aluminum nitride. (author)

  4. ELECTIONS PENSION FUND 3rd candidate

    CERN Multimedia

    2001-01-01

    ORGANISATION EUROPEENNE POUR LA RECHERCHE NUCLEAIRE CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH CAISSE DE PENSIONS / PENSION FUND Caisse de Pensions - ELECTIONS - Pension Fund This candidature has been duly registered and is hereby presented in accordance with paragraph 6.h of the Regulations for Elections to the Governing Board of the Pension Fund. Candidate : Name : Hauviller First Name : Claude Dear colleague of CERN and ESO, For the first time, I am standing and requesting your support to become a member of the Governing Board of our Pension Fund. CERN staff member since 1974, I have already carried elective mandates: I have been Delegate to the Staff Council and Member of the Senior Staff Consultative Committee (the Nine). For the majority of us, our Pension Fund is our only social provident scheme and source of retirement income; I believe I can usefully contribute to its successful management and help ensure its balance. Our Fund reaches its majority: soon, there will be more beneficiaries tha...

  5. ELECTIONS PENSION FUND CANDIDATE NR 3

    CERN Multimedia

    2001-01-01

    ORGANISATION EUROPEENNE POUR LA RECHERCHE NUCLEAIRE CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH CAISSE DE PENSIONS / PENSION FUND Caisse de Pensions - ELECTIONS - Pension Fund This candidature has been duly registered and is hereby presented in accordance with paragraph 6.h of the Regulations for Elections to the Governing Board of the Pension Fund. Candidate : Name : HAUVILLER First Name : Claude Dear colleague of CERN and ESO, For the first time, I am standing and requesting your support to become a member of the Governing Board of our Pension Fund. CERN staff member since 1974, I have already carried elective mandates: I have been Delegate to the Staff Council and Member of the Senior Staff Consultative Committee (the Nine). For the majority of us, our Pension Fund is our only social provident scheme and source of retirement income; I believe I can usefully contribute to its successful management and help ensure its balance. Our Fund reaches its majority: soon, there will be more beneficiaries tha...

  6. Pituitary stem cells: candidates and implications.

    Science.gov (United States)

    Nassiri, Farshad; Cusimano, Michael; Zuccato, Jeff A; Mohammed, Safraz; Rotondo, Fabio; Horvath, Eva; Syro, Luis V; Kovacs, Kalman; Lloyd, Ricardo V

    2013-09-01

    The pituitary is the master endocrine gland of the body. It undergoes many changes after birth, and these changes may be mediated by the differentiation of pituitary stem cells. Stem cells in any tissue source must display (1) pluripotent capacity, (2) capacity for indefinite self-renewal, and (3) a lack of specialization. Unlike neural stem cells identified in the hippocampus and subventricular zone, pituitary stem cells are not associated with one specific cell type. There are many major candidates that are thought to be potential pituitary stem cell sources. This article reviews the evidence for each of the major cell types and discuss the implications of identifying a definitive pituitary stem cell type. PMID:23423660

  7. ELECTIONS PENSION FUND 4th candidate

    CERN Document Server

    2001-01-01

    ORGANISATION EUROPEENNE POUR LA RECHERCHE NUCLEAIRE CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH CAISSE DE PENSIONS / PENSION FUND Caisse de Pensions - ELECTIONS - Pension Fund This candidature has been duly registered and is hereby presented in accordance with paragraph 6.h of the Regulations for Elections to the Governing Board of the Pension Fund. Candidate : Name : MYERS First Name : Stephen I have been at CERN since 1972, and was elected member of the Governing Board for the first time in 1998. The Governing Board then nominated me to the Investments Committee where I have been a member since the beginning of 1999. Since then I have actively participated in redefining and transforming the investment portfolio in order to improve the overall return and where possible reduce the risk. The portfolio has recently been greatly improved and now allows much simpler more transparent monitoring of our investment. I have also actively participated and hopefully made useful contributions in discussions conc...

  8. ELECTIONS PENSION FUND CANDIDATE NR 4

    CERN Document Server

    2001-01-01

    ORGANISATION EUROPEENNE POUR LA RECHERCHE NUCLEAIRE CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH CAISSE DE PENSIONS / PENSION FUND Caisse de Pensions - ELECTIONS - Pension Fund This candidature has been duly registered and is hereby presented in accordance with paragraph 6.h of the Regulations for Elections to the Governing Board of the Pension Fund. Candidate : Name : MYERS First Name : Stephen I have been at CERN since 1972, and was elected member of the Governing Board for the first time in 1998. The Governing Board then nominated me to the Investments Committee where I have been a member since the beginning of 1999. Since then I have actively participated in redefining and transforming the investment portfolio in order to improve the overall return and where possible reduce the risk. The portfolio has recently been greatly improved and now allows much simpler more transparent monitoring of our investment. I have also actively participated and hopefully made useful contributions in discussions conc...

  9. Radion Candidate for the LHC Diphoton Resonance

    CERN Document Server

    Bardhan, Debjyoti; Chakraborty, Amit; Maitra, Ushoshi; Raychaudhuri, Sreerup; Samui, Tousik

    2015-01-01

    The recent observation of a modest excess in diphoton final states at the LHC, by both the ATLAS and CMS Collaborations, has sparked off the expected race among theorists to find the right explanation for this proto-resonance, assuming that the signal will survive and not prove to be yet another statistical fluctuation. We carry out a general analysis of this `signal' in the case of a scalar which couples only to pairs of gluons (for production) and photons (for diphoton decay modes), and establish that an explanation of the observed resonance, taken together with the null results of new physics searches in all the other channels, requires a scalar with rather exotic behaviour. We then demonstrate that a fairly simple-minded extension of the minimal Randall-Sundrum model can yield a radion candidate which might reproduce this exotic behaviour.

  10. New potential AChE inhibitor candidates.

    Science.gov (United States)

    de Paula, A A N; Martins, J B L; dos Santos, M L; Nascente, L de C; Romeiro, L A S; Areas, T F M A; Vieira, K S T; Gambôa, N F; Castro, N G; Gargano, R

    2009-09-01

    We have theoretically studied new potential candidates of acetylcholinesterase (AChE) inhibitors designed from cardanol, a non-isoprenoid phenolic lipid of cashew Anacardium occidentale nut-shell liquid. The electronic structure calculations of fifteen molecule derivatives from cardanol were performed using B3LYP level with 6-31G, 6-31G(d), and 6-311+G(2d,p) basis functions. For this study we used the following groups: methyl, acetyl, N,N-dimethylcarbamoyl, N,N-dimethylamine, N,N-diethylamine, piperidine, pyrrolidine, and N,N-methylbenzylamine. Among the proposed compounds we identified that the structures with substitution by N,N-dimethycarbamoyl, N,N-dimethylamine, and pyrrolidine groups were better correlated to rivastigmine, and represent possible AChE inhibitors against Alzheimer disease. PMID:19446931

  11. Halopentacenes: Promising Candidates for Organic Semiconductors

    Institute of Scientific and Technical Information of China (English)

    DU Gong-He; REN Zhao-Yu; GUO Ping; ZHENG Ji-Ming

    2009-01-01

    We introduce polar substituents such as F, Cl, Br into pentacene to enhance the dissolubility in common organic solvents while retaining the high charge-carrier mobilities of pentacene. Geometric structures, dipole moments,frontier molecule orbits, ionization potentials and electron affinities, as well as reorganization energies of those molecules, and of pentacene for comparison, are successively calculated by density functional theory. The results indicate that halopentacenes have rather small reorganization energies (< 0.2 eV), and when the substituents are in position 2 or positions 2 and 9, they are polarity molecules. Thus we conjecture that they can easily be dissolved in common organic solvents, and are promising candidates for organic semiconductors.

  12. UCD Candidates in the Hydra Cluster

    CERN Document Server

    Wehner, Elizabeth

    2007-01-01

    NGC 3311, the giant cD galaxy in the Hydra cluster (A1060), has one of the largest globular cluster systems known. We describe new Gemini GMOS (g',i') photometry of the NGC 3311 field which reveals that the red, metal-rich side of its globular cluster population extends smoothly upward into the mass range associated with the new class of Ultra-Compact Dwarfs (UCDs). We identify 29 UCD candidates with estimated masses > 6x10^6 solar masses and discuss their characteristics. This UCD-like sequence is the most well defined one yet seen, and reinforces current ideas that the high-mass end of the globular cluster sequence merges continuously into the UCD sequence, which connects in turn to the E galaxy structural sequence.

  13. Impact of irradiation on the tensile and fatigue properties of two titanium alloys

    International Nuclear Information System (INIS)

    The attachment of the first wall modules of the ITER FEAT fusion reactor is designed using flexible connectors made from titanium alloys.. An assessment of the tensile and fatigue performance of two candidate alloys, a classical two phase Ti6Al4V alloy and a monophase α alloy Ti5Al2.5Sn, has been carried out using 590 MeV protons for the simulation of the fusion neutrons. The dose deposited was up to 0.3 dpa and the irradiation temperature was between 40 deg. C and 350 deg. C. The unirradiated tensile performances of both alloys are roughly identical. The radiation hardening is much stronger in the α+β alloy compared with the α alloy, and the ductility is correspondingly strongly reduced. A very fine precipitation observed by TEM in the primary and secondary α grains of the dual phase alloy seems to be the cause of the intense radiation hardening observed. Two different regimes have been observed in the behaviour of the cyclic stresses. At a high imposed strain, the softening is small in the Ti6Al4V and larger in the Ti5Al2.5Sn. At a low imposed strain, and for both alloys, cyclic softening occurs up to about 800 cycles, but then a transition occurs, after which a regime of cyclic hardening appears. This cyclic hardening disappears after irradiation. In both materials, and for all test conditions, the compressive stress of the hysteresis loop was found to be larger than the tensile stress. The stress asymmetry seems to be triggered by the plastic deformation. The fatigue resistance of the Ti5Al2.5Sn alloy is slightly better than that of the Ti6Al4V alloy. The irradiation did not significantly affect the fatigue performance of both alloys, except for high imposed strains, where a life reduction was observed in the case of the Ti6Al4V alloy. SEM micrographs showed that the fractures were transgranular and pseudo-brittle

  14. The structure and mechanical properties of as-cast Zr-Ti alloys

    International Nuclear Information System (INIS)

    This study has investigated the structure and mechanical properties of pure Zr and a series of binary Zr-Ti alloys in order to determine their potential application as dental implant materials. The titanium contents of these alloys range from 10 to 40 wt.% and were prepared by arc melting in inert gas. This study evaluated the phase and structure of these Zr-Ti alloys using an X-ray diffraction (XRD) for phase analysis, and an optical microscope for microstructure analysis of the etched alloys. Three-point bending tests were performed to evaluate the mechanical properties of all specimens. The experimental results indicated that the pure Zr and Zr-10Ti comprised entirely of an acicular hexagonal structure of α' phase. When the Ti content increased to 20 wt.%, a significant amount of β phase was retained. However, when the Ti content increased to 40 wt.%, only the equi-axed, retained β phase was observed in the cast alloy. Moreover, the hardness values and bending strengths of the Zr-Ti alloys decreased with an increasing Ti content. Among pure Zr and Zr-Ti alloys, the α'-phase Zr-10Ti alloy has the greatest hardness and bending strength. The pure Zr and Zr-Ti alloys exhibit a similar elastic modulus ranging from 68 GPa (Zr-30Ti) to 78 GPa (Zr-40Ti). Based on the results of elastic moduli, pure Zr and Zr-Ti alloys are found to be suitable for implant materials due to lower modulus. Like bending strength, the elastically recoverable angle of Zr-Ti alloys decreased as the concentration of Ti increased. In the current search for a better implant material, the Zr-10Ti alloy exhibited the highest bending strength/modulus ratios as large as 25.3, which are higher than that of pure Zr (14.9) by 70%, and commercially pure Ti (8.7) by 191%. Thus, Zr-Ti alloy's low modulus, ductile property, excellent elastic recovery capability and impressive strength confirm that it is a promising candidate for dental implant materials.

  15. Processing and characterization of oxide dispersion strengthened 14YWT ferritic alloys

    Science.gov (United States)

    West, Michael Keith

    Oxide dispersion strengthened (ODS) ferritic steels are currently being investigated as candidate materials for nuclear applications due to their increased high temperature strength and low activation characteristics. Recent studies have shown that ODS ferritic steels containing Ti exhibit enhanced high temperature properties due to the formation of a very fine dispersion of nanometer-sized oxide clusters based on Ti, Y, and O. Studies are currently underway to examine so called 14YWT alloys with nominal compositions of Fe-14Cr-3W-0.4Ti (wt. %) mechanically alloyed with 0.25 (wt.%) Y2O3. The focus of this study was to investigate how the early stages of processing of 14YWT alloys during mechanical milling, heat treatment, and consolidation affect the structure and properties of the alloys. The 14YWT alloys were milled at different times up to 80 hours, along with alloy powder compositions of Fe-14Cr + 0.25 wt.% Y2O 3 (14Y) and Fe-14Cr without Y2O3 (Fe-14Cr). The evolution of the microstructure and mechanical properties during milling was examined with a combination of optical metallography, x-ray diffraction, electron microscopy, atom probe tomography, and nanoindentation. Alloy powders were also heat treated and studied using high temperature x-ray diffraction and differential scanning calorimetry methods. Special attention was paid to milling parameters and temperature ranges which lead to the formation of nanosized oxide clusters in the alloys. Finally, the microstructure of consolidated alloys was examined and related to milling and heat treatment methods. Mechanical properties and microstructure during milling were similar in the three alloy powders examined regardless of dispersoid or alloy addition. Mechanical mixing of the alloy powders was inefficient after 40 hours of milling. Milling did not produce bulk amorphous phases but quickly reduced the crystallite size to ˜10-20 nm. Milling also resulted in relatively uniform dissolution of Y2O3. Thermal

  16. Creep rupture behavior of candidate materials for nuclear process heat applications

    International Nuclear Information System (INIS)

    Creep and stress rupture properties are determined for the candidate materials to be used in hightemperature gas-cooled reactor (HTGR) components. The materials and test methods are briefly described based on experimental results of test durations of about20000 h. The medium creep strengths of the alloys Inconel-617, Hastelloy-X, Nimonic-86, Hastelloy-S, Manaurite-36X, IN-519, and Incoloy-800H are compared showing that Inconel-617 has the best creep rupture properties in the temperature range above 8000C. The rupture time of welded joints is in the lower range of the scatterband of the parent metal. The properties determined in different simulated HTGR atmospheres are within the scatterband of the properties obtained in air. Extrapolation methods are discussed and a modified minimum commitment method is favored

  17. CRISPLD2: a novel NSCLP candidate gene.

    Science.gov (United States)

    Chiquet, Brett T; Lidral, Andrew C; Stal, Samuel; Mulliken, John B; Moreno, Lina M; Arcos-Burgos, Mauricio; Arco-Burgos, Mauricio; Valencia-Ramirez, Consuelo; Blanton, Susan H; Hecht, Jacqueline T

    2007-09-15

    Non-syndromic cleft lip with or without cleft palate (NSCLP) results from the complex interaction between genes and environmental factors. Candidate gene analysis and genome scans have been employed to identify the genes contributing to NSCLP. In this study, we evaluated the 16q24.1 chromosomal region, which has been identified by multiple genome scans as an NSCLP region of interest. Two candidate genes were found in the region: interferon regulatory factor 8 (IRF8) and cysteine-rich secretory protein LCCL domain containing 2 (CRISPLD2). Initially, Caucasian and Hispanic NSCLP multiplex families and simplex parent-child trios were genotyped for single nucleotide polymorphisms (SNPs) in both IRF8 and CRISPLD2. CRISPLD2 was subsequently genotyped in a data set comprised of NSCLP families from Colombia, South America. Linkage disequilibrium analysis identified a significant association between CRISPLD2 and NSCLP in both our Caucasian and Hispanic NSCLP cohorts. SNP rs1546124 and haplotypes between rs1546124 and either rs4783099 or rs16974880 were significant in the Caucasian multiplex population (P=0.01, P=0.002 and P=0.001, respectively). An altered transmission of CRISPLD2 SNPs rs8061351 (P=0.02) and rs2326398 (P=0.06) was detected in the Hispanic population. No association was found between CRISPLD2 and our Colombian population or IRF8 and NSCLP. In situ hybridization showed that CRISPLD2 is expressed in the mandible, palate and nasopharynx regions during craniofacial development at E13.5-E17.5, respectively. Altogether, these data suggest that genetic variation in CRISPLD2 has a role in the etiology of NSCLP. PMID:17616516

  18. Lattice thermal conductivity of disordered NiPd and NiPt alloys

    Energy Technology Data Exchange (ETDEWEB)

    Alam, Aftab; Mookerjee, Abhijit [S N Bose National Centre for Basic Sciences, JD Block, Sector III, Salt Lake City, Kolkata 700098 (India)

    2006-05-17

    Numerical calculations of lattice thermal conductivity are reported for the binary alloys NiPd and NiPt. The present work is a continuation of an earlier paper by us (Alam and Mookerjee 2005 Phys. Rev. B 72 214207), which developed a theoretical framework for the calculation of configuration-averaged lattice thermal conductivity and thermal diffusivity in disordered alloys. The formulation was based on the augmented space theorem (Mookerjee 1973 J. Phys. C: Solid State Phys. 6 L205) combined with a scattering diagram technique. In this paper we shall show the dependence of the lattice thermal conductivity on a series of variables like phonon frequency, temperature and alloy composition. The temperature dependence of {kappa}(T) and its relation to the measured thermal conductivity is discussed. The concentration dependence of {kappa} appears to justify the notion of a minimum thermal conductivity as discussed by Kittel, Slack and others (Kittel 1948 Phys. Rev. 75 972, Brich and Clark 1940 Am. J. Sci. 238 613; Slack 1979 Solid State Physics vol 34, ed H Ehrenreich, F Seitz and D Turnbull (New York: Academic) p 1). We also study the frequency and composition dependence of the thermal diffusivity averaged over modes. A numerical estimate of this quantity gives an idea about the location of the mobility edge and the fraction of states in the frequency spectrum which is delocalized.

  19. Hot rolling effect on mechanical properties of copper alloys strengthened by dispersion and uniaxially hot pressed

    International Nuclear Information System (INIS)

    Copper powder of 140 μm mean size was mechanical alloyed with several compounds, 2% B, C, 2% ZrC, 1% CrB, 2% Cr3C2, 1 and 2 vol % ZrB2 in a RETSCH PM high energy balls mill. The alloying process was carried out in stainless steel containers during 6 or 8 h of milling, under argon atmosphere, and the ball to powder charge ratio was 5:1. Instead of HIP processing, the alloyed powders were consolidated by uniaxial hot pressing at 650 degree centigrades for 2 h at a pressure of 90 MOa in argon atmosphere. Afterward the compact samples of 30x10x10 mm were hot rolled at 850 degree centigrades with area reduction from 10 to 40%. If an homogeneous hot pressing process is obtained, the subsequent hot rolling can be avoided as only an annealing effect is produced,characterized by a small decrease in hardness and tensile strength with a small increase in ductility. (Author) 18 refs

  20. Lattice thermal conductivity of disordered NiPd and NiPt alloys

    International Nuclear Information System (INIS)

    Numerical calculations of lattice thermal conductivity are reported for the binary alloys NiPd and NiPt. The present work is a continuation of an earlier paper by us (Alam and Mookerjee 2005 Phys. Rev. B 72 214207), which developed a theoretical framework for the calculation of configuration-averaged lattice thermal conductivity and thermal diffusivity in disordered alloys. The formulation was based on the augmented space theorem (Mookerjee 1973 J. Phys. C: Solid State Phys. 6 L205) combined with a scattering diagram technique. In this paper we shall show the dependence of the lattice thermal conductivity on a series of variables like phonon frequency, temperature and alloy composition. The temperature dependence of κ(T) and its relation to the measured thermal conductivity is discussed. The concentration dependence of κ appears to justify the notion of a minimum thermal conductivity as discussed by Kittel, Slack and others (Kittel 1948 Phys. Rev. 75 972, Brich and Clark 1940 Am. J. Sci. 238 613; Slack 1979 Solid State Physics vol 34, ed H Ehrenreich, F Seitz and D Turnbull (New York: Academic) p 1). We also study the frequency and composition dependence of the thermal diffusivity averaged over modes. A numerical estimate of this quantity gives an idea about the location of the mobility edge and the fraction of states in the frequency spectrum which is delocalized