National Library of Energy BETA

Sample records for ti ia al

  1. A=17Al (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Al (1993TI07) (Not observed) See (1983ANZQ, 1988WA18, 1992AV03).

  2. A=16Al (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    93TI07) (Not observed) See (1986AN07

  3. A=20Al, etc. (1998TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    98TI06) (Not observed) See (1972AJ02, 1983ANZQ, 1986AN07

  4. TI--CR--AL--O thin film resistors

    DOE Patents [OSTI]

    Jankowski, Alan F.; Schmid, Anthony P.

    2000-01-01

    Thin films of Ti--Cr--Al--O are used as a resistor material. The films are rf sputter deposited from ceramic targets using a reactive working gas mixture of Ar and O.sub.2. Resistivity values from 10.sup.4 to 10.sup.10 Ohm-cm have been measured for Ti--Cr--Al--O film <1 .mu.m thick. The film resistivity can be discretely selected through control of the target composition and the deposition parameters. The application of Ti--Cr--Al--O as a thin film resistor has been found to be thermodynamically stable, unlike other metal-oxide films. The Ti--Cr--Al--O film can be used as a vertical or lateral resistor, for example, as a layer beneath a field emission cathode in a flat panel display; or used to control surface emissivity, for example, as a coating on an insulating material such as vertical wall supports in flat panel displays.

  5. Anisotropic swelling and microcracking of neutron irradiated Ti3AlC2-Ti5Al2C3 materials

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ang, Caen K.; Silva, Chinthaka M.; Shih, Chunghao Phillip; Koyanagi, Takaaki; Katoh, Yutai; Zinkle, Steven J.

    2015-12-17

    Mn + 1AXn (MAX) phase materials based on Ti–Al–C have been irradiated at 400 °C (673 K) with fission neutrons to a fluence of 2 × 1025 n/m2 (E > 0.1 MeV), corresponding to ~ 2 displacements per atom (dpa). We report preliminary results of microcracking in the Al-containing MAX phase, which contained the phases Ti3AlC2 and Ti5Al2C3. Equibiaxial ring-on-ring tests of irradiated coupons showed that samples retained 10% of pre-irradiated strength. Volumetric swelling of up to 4% was observed. Phase analysis and microscopy suggest that anisotropic lattice parameter swelling caused microcracking. Lastly, variants of titanium aluminum carbide may bemore » unsuitable materials for irradiation at light water reactor-relevant temperatures.« less

  6. Effect of neutron irradiation on defect evolution in Ti3SiC2 and Ti2AlC

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Tallman, Darin J.; He, Lingfeng; Garcia-Diaz, Brenda L.; Hoffman, Elizabeth N.; Kohse, Gordon; Sindelar, Robert L.; Barsoum, Michel W.

    2015-10-23

    Here, we report on the characterization of defects formed in polycrystalline Ti3SiC2 and Ti2AlC samples exposed to neutron irradiation – up to 0.1 displacements per atom (dpa) at 350 ± 40 °C or 695 ± 25 °C, and up to 0.4 dpa at 350 ± 40 °C. Black spots are observed in both Ti3SiC2 and Ti2AlC after irradiation to both 0.1 and 0.4 dpa at 350 °C. After irradiation to 0.1 dpa at 695 °C, small basal dislocation loops, with a Burgers vector of b = 1/2 [0001] are observed in both materials. At 9 ± 3 and 10 ±more » 5 nm, the loop diameters in the Ti3SiC2 and Ti2AlC samples, respectively, were comparable. At 1 × 1023 loops/m3, the dislocation loop density in Ti2AlC was ≈1.5 orders of magnitude greater than in Ti3SiC2, at 3 x 1021 loops/m3. After irradiation at 350 °C, extensive microcracking was observed in Ti2AlC, but not in Ti3SiC2. The room temperature electrical resistivities increased as a function of neutron dose for all samples tested, and appear to saturate in the case of Ti3SiC2. The MAX phases are unequivocally more neutron radiation tolerant than the impurity phases TiC and Al2O3. Based on these results, Ti3SiC2 appears to be a more promising MAX phase candidate for high temperature nuclear applications than Ti2AlC.« less

  7. Adhesion evaluation of TiN and (Ti, Al)N coatings on titanium 6Al-4V

    SciTech Connect (OSTI)

    James, R.D.; Gruss, K.A.; Horie, Y.; Davis, R.F.; Paisley, D.L.; Parthasarthi, S.; Tittmann, B.R.

    1996-12-31

    The metallic components of gas turbine engines are continually subjected to hostile atmospheres. Nitride coatings improve the performance of the metallic compressor blades in these engines. To assess the adhesion of nitride coatings on metals, titanium 6% aluminum 4% vanadium substrates were coated with titanium nitride (TiN) using both cathodic arc and electron beam evaporation. Titanium aluminum nitride ((Ti, Al)N) was also deposited using cathodic arc evaporation. The interfaces of the coated samples were loaded in tension using a high speed shock wave which caused spallation either at the interface, in the coating or in the metal. Scanning acoustic microscopy analysis of the spalled samples detected delaminations at the interface in the samples deposited by cathodic arc evaporation. DYNA2D modeling of plate impact spallation experiments revealed the tensile adhesion strength for TiN deposited by both techniques was {approx} 2.0 GPa. The tensile adhesion strength for (Ti, Al)N was less than 1.5 GPa.

  8. Enhanced hardness in epitaxial TiAlScN alloy thin films and rocksalt TiN/(Al,Sc)N superlattices

    SciTech Connect (OSTI)

    Saha, Bivas; Lawrence, Samantha K.; Bahr, David F.; Schroeder, Jeremy L.; Birch, Jens; Sands, Timothy D.

    2014-10-13

    High hardness TiAlN alloys for wear-resistant coatings exhibit limited lifetimes at elevated temperatures due to a cubic-AlN to hexagonal-AlN phase transformation that leads to decreasing hardness. We enhance the hardness (up to 46 GPa) and maximum operating temperature (up to 1050 °C) of TiAlN-based coatings by alloying with scandium nitride to form both an epitaxial TiAlScN alloy film and epitaxial rocksalt TiN/(Al,Sc)N superlattices on MgO substrates. The superlattice hardness increases with decreasing period thickness, which is understood by the Orowan bowing mechanism of the confined layer slip model. These results make them worthy of additional research for industrial coating applications.

  9. Structural, morphological and interfacial characterization of Al-Mg/TiC composites

    SciTech Connect (OSTI)

    Contreras, A. . E-mail: acontrer@imp.mx; Angeles-Chavez, C.; Flores, O.; Perez, R.

    2007-08-15

    Morphological and structural characterization of Al-Mg/TiC composites obtained by infiltration process and wetting by the sessile drop technique were studied. Focusing at the interface, wetting of TiC substrates by molten Al-Mg-alloys at 900 deg. C was investigated. Electron probe microanalysis (EPMA) indicated that aluminum carbide (Al{sub 4}C{sub 3}) is formed at the interface and traces of TiAl{sub 3} in the wetting assemblies were detected. Scanning Electron Microscopy (SEM) observations show that TiC particles do not appear to be uniformly attacked to produce a continuous layer of Al{sub 4}C{sub 3} at the interface. Molten Al-Mg-alloys were infiltrated into TiC preforms with flowing argon at a temperature of 900 deg. C. In the composites no reaction phase was observed by SEM. Quantification of the Al phase in the composite was carried out by X-ray diffraction (XRD) and Rietveld analysis. Chemical mapping analyzed by SEM shows that the Al-Mg alloy surrounds TiC particles. In the composites with 20 wt.% of Mg the Al-Mg-{beta} phase was detected through XRD.

  10. An Experimental and Theoretical Multi-Mbar Study of Ti-6Al-4V

    SciTech Connect (OSTI)

    Tegner, B E; Macleod, S G; CYNN, H; Proctor, J; Evans, W J; McMahon, M I; Ackland, G J

    2011-04-13

    We report results from an experimental and theoretical study of the room temperature (RT) compression of the ternary alloy Ti-6Al-4V. In this work, we have extended knowledge of the equation of state (EOS) from 40 GPa to 221 GPa, and observed a different sequence of phase transitions to that reported previously for pure Ti.

  11. Adhesion strength of sputtered TiAlN-coated WC insert tool

    SciTech Connect (OSTI)

    Budi, Esmar; Razali, M. Mohd.; Nizam, A. R. Md.

    2013-09-09

    The adhesion strength of TiAlN coating that deposited by using DC magnetron sputtering on WC insert tool are studied. TiAlN coating are deposited on Tungsten Carbide (WC) insert tool by varying negatively substrate bias from 79 to 221 volt and nitrogen flow rate from 30 to 72 sccm. The adhesion strength are obtained by using Rockwell indentation test method with a Brale diamond at applied load of 60,100 and 150 kgf. The lateral diameter of indentation is plotted on three different applied loads and the adhesion strength of TiAlN coating was obtained from the curved slopes at 100 and 150 kgf. The lower curve slop indicated better adhesion strength. The results shows that the adhesion strength of sputterred TiAlN coating tend to increase as the negatively substrate bias and nitrogen flow rate are increased.

  12. Recyclability study on Inconel 718 and Ti-6Al-4V powders for...

    Office of Scientific and Technical Information (OSTI)

    Ti-6Al-4V, on the other hand, finds its reuse time governed by the oxygen pick up that occurs during and in between build cycles. The detailed results have been presented. Authors: ...

  13. An experimental study of the (Ti-6Al-4V)-xH phase diagram using...

    Office of Scientific and Technical Information (OSTI)

    An experimental study of the (Ti-6Al-4V)-xH phase diagram using in situ synchrotron XRD and TGADSC techniques This content will become publicly available on February 10, 2017 ...

  14. Flat panel display using Ti-Cr-Al-O thin film

    DOE Patents [OSTI]

    Jankowski, Alan F.; Schmid, Anthony P.

    2002-01-01

    Thin films of Ti--Cr--Al--O are used as a resistor material. The films are rf sputter deposited from ceramic targets using a reactive working gas mixture of Ar and O.sub.2. Resistivity values from 10.sup.4 to 10.sup.10 Ohm-cm have been measured for Ti--Cr--Al--O film <1 .mu.m thick. The film resistivity can be discretely selected through control of the target composition and the deposition parameters. The application of Ti--Cr--Al--O as a thin film resistor has been found to be thermodynamically stable, unlike other metal-oxide films. The Ti--Cr--Al--O film can be used as a vertical or lateral resistor, for example, as a layer beneath a field emission cathode in a flat panel display; or used to control surface emissivity, for example, as a coating on an insulating material such as vertical wall supports in flat panel displays.

  15. Process for producing Ti-Cr-Al-O thin film resistors

    DOE Patents [OSTI]

    Jankowski, Alan F.; Schmid, Anthony P.

    2001-01-01

    Thin films of Ti-Cr-Al-O are used as a resistor material. The films are rf sputter deposited from ceramic targets using a reactive working gas mixture of Ar and O.sub.2. Resistivity values from 10.sup.4 to 10.sup.10 Ohm-cm have been measured for Ti-Cr-Al-O film <1 .mu.m thick. The film resistivity can be discretely selected through control of the target composition and the deposition parameters. The application of Ti-Cr-Al-O as a thin film resistor has been found to be thermodynamically stable, unlike other metal-oxide films. The Ti-Cr-Al-O film can be used as a vertical or lateral resistor, for example, as a layer beneath a field emission cathode in a flat panel display; or used to control surface emissivity, for example, as a coating on an insulating material such as vertical wall supports in flat panel displays.

  16. Laser cladding of Ti-6Al-4V with various carbide powders

    SciTech Connect (OSTI)

    Folkes, J.A.; Shibata, K. )

    1994-06-01

    Laser cladding Ti-6Al-4V can be achieved with various weight percentages of different carbide powders. The microstructure and morphology of the clad layer is determined by the cladding powder composition, for a given set of laser parameters, such that 10 and 20 wt% Cr[sub 3]C[sub 2] results in a [beta] + TiC clad microstructure; 10 and 20 wt% WC results in an [alpha] + TiC clad microstructure (plus some original WC); and Mo[sub 2]C gives an [alpha] + [beta] + TiC or [beta] + TiC structure, depending on the weight percentage of Mo[sub 2]C. The morphology of the TiC in all cases is dendritic or feathery, depending on the carbide content. The microstructure observed in all cases agreed well with that theoretically predicted from the energetics of carbide formation and [beta]-stabilizing properties of each element.

  17. Reactivity enhancement of oxide skins in reversible Ti-doped NaAlH{sub 4}

    SciTech Connect (OSTI)

    Delmelle, Renaud; Borgschulte, Andreas; Gehrig, Jeffrey C.; Züttel, Andreas

    2014-12-15

    The reversibility of hydrogen sorption in complex hydrides has only been shown unambiguously for NaAlH{sub 4} doped with transition metal compounds. Despite a multitude of investigations of the effect of the added catalyst on the hydrogen sorption kinetics of NaAlH{sub 4}, the mechanism of catalysis remains elusive so far. Following the decomposition of TiCl{sub 3}-doped NaAlH{sub 4} by in-situ X-ray photoelectron spectroscopy (XPS), we link the chemical state of the dopant with those of the hydride and decomposition products. Titanium and aluminium change their oxidation states during cycling. The change of the formal oxidation state of Al from III to zero is partly due to the chemical reaction from NaAlH{sub 4} to Al. Furthermore, aluminium oxide is formed (Al{sub 2}O{sub 3}), which coexists with titanium oxide (Ti{sub 2}O{sub 3}). The interplay of metallic and oxidized Ti with the oxide skin might explain the effectiveness of Ti and similar dopants (Ce, Zr…)

  18. Improving the osteointegration of Ti6Al4V by zeolite MFI coating

    SciTech Connect (OSTI)

    Li, Yong; Jiao, Yilai; Li, Xiaokang; Guo, Zheng

    2015-05-01

    Osteointegration is crucial for success in orthopedic implantation. In recent decades, there have been numerous studies aiming to modify titanium alloys, which are the most widely used materials in orthopedics. Zeolites are solid aluminosilicates whose application in the biomedical field has recently been explored. To this end, MFI zeolites have been developed as titanium alloy coatings and tested in vitro. Nevertheless, the effect of the MFI coating of biomaterials in vivo has not yet been addressed. The aim of the present work is to evaluate the effects of MFI-coated Ti6Al4V implants in vitro and in vivo. After surface modification, the surface was investigated using field emission scanning electron microscopy (FE-SEM) and energy dispersive spectroscopy (EDS). No difference was observed regarding the proliferation of MC3T3-E1 cells on the Ti6Al4V (Ti) and MFI-coated Ti6Al4V (M−Ti) (p > 0.05). However, the attachment of MC3T3-E1 cells was found to be better in the M−Ti group. Additionally, ALP staining and activity assays and quantitative real-time RT-PCR indicated that MC3T3-E1 cells grown on the M−Ti displayed high levels of osteogenic differentiation markers. Moreover, Van-Gieson staining of histological sections demonstrated that the MFI coating on Ti6Al4V scaffolds significantly enhanced osteointegration and promoted bone regeneration after implantation in rabbit femoral condylar defects at 4 and 12 weeks. Therefore, this study provides a method for modifying Ti6Al4V to achieve improved osteointegration and osteogenesis. - Highlights: • Osteointegration is a crucial factor for orthopedic implants. • We coated MFI zeolite on Ti6Al4V substrates and investigated the effects in vitro and in vivo. • The MFI coating displayed good biocompatibility and promoted osteogenic differentiation in vitro. • The MFI coating promoted osteointegration and osteogenesis peri-implant in vivo.

  19. Industrial Application of Thin Films (TiAl)N Deposited on Thermo-Wells

    SciTech Connect (OSTI)

    Velez, G.; Jaramillo, S.; Arango, Y. C.; Devia, D.; Quintero, J.; Devia, A.

    2006-12-04

    The thermo-well is formed by two layers, one layer is a ceramic and the other layer is anviloy (comprised tungsten). They are used to coat the thermocouple in the control temperature system during the Aluminum-Silicon alloy melting process. After two weeks of continuous work at 750 deg. C of temperature (the alloy temperature), a high wear in this material is observed, affecting the ceramic. (TiAl)N thin films are deposited directly on the anviloy substrates by the PAPVD (Plasma Assisted Physics Vapor Deposition) in arc pulsed technique, using a TiAl target in a mono-vaporizer system, composed by a reactor and a power controlled system. Two opposite electrodes are placed into the reactor and discharge is produced by a controlled power system. The XRD (X-ray diffraction) patterns show the presence of the (TiAl)N thin film peaks. The morphological characteristics are studied by the scanning probe microscopy (SPM)

  20. Thermo-mechanical processing (TMP) of Ti-48Al-2Nb-2Cr based alloys

    SciTech Connect (OSTI)

    Fuchs, G.E.

    1995-02-01

    The effects of heat treatment and deformation processing on the microstructures and properties of {gamma}-TiAl based alloys produced by ingot metallurgy (I/M) and powder metallurgy (P/M) techniques were examined. The alloy selected for this work is the second generation {gamma}-TiAl based alloy -- Ti-48Al-2Nb-2Cr (at %). Homogenization of I/M samples was performed at a variety of temperatures, followed by hot working by isothermal forging. P/M samples were prepared from gas atomized powders, consolidated by both HIP and extrusion and some of the HIPed material was then hot worked by isothermal forging. The effects of processing, heat treatment and hot working on the microstructures and properties will be discussed.

  1. Initial oxidation of TiAl: An ab-initio investigation

    SciTech Connect (OSTI)

    Bakulin, Alexander V. Kulkova, Svetlana E.; Hu, Qing-Miao; Yang, Rui

    2014-11-14

    We present ab-initio investigation of oxygen adsorption up to two monolayer coverage on the stoichiometric TiAl(100) surface to illustrate the initial oxidation stage. The formation of band gap near the Fermi level demonstrates the transformation from metal to oxide surface with increasing oxygen coverage. The oxidation of Ti rather than Al is observed from our electronic structure calculations. The energy barriers of oxygen diffusion between different sites on surface as well as in subsurface and bulk region are derived. It is shown that the diffusion of oxygen is much easier on the surface than that into the subsurface region.

  2. Isothermal oxidation behavior and microstructure of plasma surface Ta coating on ?-TiAl

    SciTech Connect (OSTI)

    Song, Jian; Zhang, Ping-Ze Wei, Dong-Bo; Wei, Xiang-Fei; Wang, Ya

    2014-12-15

    The oxidation behavior of ?-TiAl with Ta surface coating fabricated by double glow plasma surface alloying technology was investigated by thermogravimetric method. Oxidation experiments were carried out at 750 C and 850 C in air for 100 h. The modification layer was comprised of deposition layer and diffusion layer, which metallurgically adhered to the substrate. Tantalum element decreased with the case depth. The oxidation morphology was studied by a scanning electron microscope and X-ray diffraction. The results highlighted that in the oxidizing process of the oxidation, the phase containing Ta-richer may restrain diffusing outward of the element Al in the matrix. Ti diffused outward, and formed the TiO{sub 2} scales, while the middle layer was rich in Al, and formed the continuous Al{sub 2}O{sub 3} scales after oxidation, which was effective to prevent further infiltration of oxygen atoms, and as a result the oxidation resistance increased immensely. - Highlights: A Ta modified coating was prepared on ?-TiAl using DGP surface alloying technology. The modification layer metallurgically adhered to the substrate. The bonding force is about 60 N, satisfying the demands of practical use. The oxidation resistance increased immensely at 750 C and 850 C.

  3. Direct imaging of LaAlO{sub 3}/SrTiO{sub 3} nanostructures using

    Office of Scientific and Technical Information (OSTI)

    piezoresponse force microscopy (Journal Article) | SciTech Connect Direct imaging of LaAlO{sub 3}/SrTiO{sub 3} nanostructures using piezoresponse force microscopy Citation Details In-Document Search Title: Direct imaging of LaAlO{sub 3}/SrTiO{sub 3} nanostructures using piezoresponse force microscopy The interface between LaAlO{sub 3} and TiO{sub 2}-terminated SrTiO{sub 3} can be switched between metastable conductive and insulating states using a conductive atomic force microscope probe.

  4. Processing, properties, and wear resistance of aluminides. [Fe[sub 3]Al; Al[sub 3]Ti

    SciTech Connect (OSTI)

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

    1993-03-01

    Fully dense alloys based on Fe[sub 3]Al were produced by reaction synthesis from low cost elemental powders using hot pressing, hot isostatic pressing or Ceracon process. The reaction proceeds by outward spreading of a transient liquid phase from the initial aluminum particle site and precipitation of the compound phase from the liquid. Combustion synthesized material has a very fine grain size that is resistant to coarsening at high temperature because of a high density of fine oxides from the prior particle boundaries. The fine grain size results in approximately twice the yield strength in the reaction synthesized material compared to hot extruded pre-alloyed powder. Combustion synthesis has also been successfully applied to joining Fe[sub 3]Al and to forming coatings on carbon steel substrates. Combustion synthesis has been shown to be viable for fabricating trialuminides from elemental powder compacts. Al[sub 3]Ti, Al[sub 73]Ti[sub 24]Cr[sub 3] and Al[sub 67]Ti[sub 25]Cr[sub 8] were examined. Fully dense, homogeneous materials exhibiting an equiaxed grain structure were produced by conducting reaction and homogenization under pressure, or in a furnace at ambient pressure and subsequently densifying the porous preform by hot consolidation. The tetragonal DO[sub 22] structure was the primary reaction product for all compositions. Most of the Cr remained undissolved after reaction and a homogenization heat treatment at 1200C or above was used to put the Cr into solution and form the desired L1[sub 2] phase.

  5. Thermal protection of H13 steel by growth of (TiAl)N films by PAPVD pulsed arc technique

    SciTech Connect (OSTI)

    Jimenez, H.; Devia, D.M.; Benavides, V.; Devia, A. Arango, Y.C.; Arango, P.J.; Velez, J.M.

    2008-08-15

    (TiAl)N Films were grown on H13 steel by a plasma assisted repetitive pulsed arc discharge. To grow the coatings, a TiAl sintered cathode was used, 50% Ti-50% Al. The deposition system consists of a reaction chamber with two electrodes placed face to face. A pulsed power supply, which allows for control of parameters like time active arc, time between arcs, arc energy, and others, is used to generate the discharge. Thermal changes were carried out on H13 steel before and after growing the (TiAl)N films. X-ray diffraction (XRD) was employed to study the coatings, observing the H13 steel and (TiAl)N oxidation temperature. Morphological characteristics were analyzed by means of an Atomic Force Microscopy (AFM). Scanning electron microscopy (SEM) revealed the surface chemical composition of the films and morphological details of the samples.

  6. Influence of the Al distribution on the structure, elastic properties, and phase stability of supersaturated Ti{sub 1-x}Al{sub x}N

    SciTech Connect (OSTI)

    Mayrhofer, P. H.; Music, D.; Schneider, J. M.

    2006-11-01

    Ti{sub 1-x}Al{sub x}N films and/or their alloys are employed in many industrial applications due to their excellent mechanical and thermal properties. Synthesized by plasma-assisted vapor deposition, Ti{sub 1-x}Al{sub x}N is reported to crystallize in the cubic NaCl (c) structure for AlN mole fractions below 0.4-0.91, whereas at larger Al contents the hexagonal ZnS-wurtzite (w) structure is observed. Here we use ab initio calculations to analyze the effect of composition and Al distribution on the metal sublattice on phase stability, structure, and elastic properties of c-Ti{sub 1-x}Al{sub x}N and w-Ti{sub 1-x}Al{sub x}N. We show that the phase stability of supersaturated c-Ti{sub 1-x}Al{sub x}N not only depends on the chemical composition but also on the Al distribution of the metal sublattice. An increase of the metastable solubility limit of AlN in c-Ti{sub 1-x}Al{sub x}N from 0.64 to 0.74 is obtained by decreasing the number of Ti-Al bonds. This can be understood by considering the Al distribution induced changes of the electronic structure, bond energy, and configurational entropy. This may in part explain the large variation of the metastable solubility limit reported in the literature.

  7. Deformation and fracture behavior of composite structured Ti-Nb-Al-Co(-Ni) alloys

    SciTech Connect (OSTI)

    Okulov, I. V. Marr, T.; Schultz, L.; Eckert, J.; Khn, U.; Freudenberger, J.; Oertel, C.-G.; Skrotzki, W.

    2014-02-17

    Tensile ductility of the Ti-based composites, which consist of a ?-Ti phase surrounded by ultrafine structured intermetallics, is tunable through the control of intermetallics. The two Ti-based alloys studied exhibit similar compressive yield strength (about 1000?MPa) and strain (about 35%40%) but show a distinct difference in their tensile plasticity. The alloy Ti{sub 71.8}Nb{sub 14.1}Ni{sub 7.4}Al{sub 6.7} fractures at the yield stress while the alloy Ti{sub 71.8}Nb{sub 14.1}Co{sub 7.4}Al{sub 6.7} exhibits about 4.5% of tensile plastic deformation. To clarify the effect of microstructure on the deformation behavior of these alloys, tensile tests were carried out in the scanning electron microscope. It is shown that the distribution as well as the type of intermetallics affects the tensile ductility of the alloys.

  8. Effect of neutron irradiation on defect evolution in Ti3SiC2 and Ti2AlC

    SciTech Connect (OSTI)

    Tallman, Darin J.; He, Lingfeng; Garcia-Diaz, Brenda L.; Hoffman, Elizabeth N.; Kohse, Gordon; Sindelar, Robert L.; Barsoum, Michel W.

    2015-10-23

    Here, we report on the characterization of defects formed in polycrystalline Ti3SiC2 and Ti2AlC samples exposed to neutron irradiation – up to 0.1 displacements per atom (dpa) at 350 ± 40 °C or 695 ± 25 °C, and up to 0.4 dpa at 350 ± 40 °C. Black spots are observed in both Ti3SiC2 and Ti2AlC after irradiation to both 0.1 and 0.4 dpa at 350 °C. After irradiation to 0.1 dpa at 695 °C, small basal dislocation loops, with a Burgers vector of b = 1/2 [0001] are observed in both materials. At 9 ± 3 and 10 ± 5 nm, the loop diameters in the Ti3SiC2 and Ti2AlC samples, respectively, were comparable. At 1 × 1023 loops/m3, the dislocation loop density in Ti2AlC was ≈1.5 orders of magnitude greater than in Ti3SiC2, at 3 x 1021 loops/m3. After irradiation at 350 °C, extensive microcracking was observed in Ti2AlC, but not in Ti3SiC2. The room temperature electrical resistivities increased as a function of neutron dose for all samples tested, and appear to saturate in the case of Ti3SiC2. The MAX phases are unequivocally more neutron radiation tolerant than the impurity phases TiC and Al2O3. Based on these results, Ti3SiC2 appears to be a more promising MAX phase candidate for high temperature nuclear applications than Ti2AlC.

  9. Environmental effect on room-temperature ductility of isothermally forged TiAl-base alloys

    SciTech Connect (OSTI)

    Nakamura, Morihiko; Hashimoto, Kenki (National Research Inst. for Metals, Tokyo (Japan)); Itoh, Naoyuki (Nippon Steel Corp., Chiba (Japan)); Tsujimoto, Tokuzo (Ibaraki Univ. (Japan). Faculty of Engineering); Suzuki, Toshiyuki (Kougakuin Univ., Tokyo (Japan))

    1994-02-01

    Isothermally forged TiAl-base alloy (Al-rich, Mn-containing, and Cr-containing TiAl) were heat-treated in various conditions, and equiaxed grain structures consisting of [gamma] and [alpha][sub 2] or [beta] phases were obtained. The heat-treated alloys were tensile tested in vacuum and air at room temperature, and the environmental effect on tensile elongation was studied. The ductility of the alloys consisting of equiaxed [gamma] grains and a large amount of [alpha][sub 2] grains was not largely affecting by laboratory air, and a decrease in the amount of [alpha][sub 2] grains resulted in a large reduction of ductility in air. The [beta] phase in the Cr-containing alloy improved the ductility in vacuum, but it resulted in a large reduction of ductility in air.

  10. An Experimental and Theoretical Study of Ti-6Al-4V to Multi-mbar Pressures

    SciTech Connect (OSTI)

    MacLeod, S G; Tegner, B E; Cynn, H; Evans, W J; Proctor, J; McMahon, M I; Ackland, G J

    2012-03-14

    We report results from an experimental and theoretical study of the ternary alloy Ti-6Al-4V to 221 GPa. We observe a phase transition to the hexagonal {omega}-phase at approximately 30 GPa, and then a further transition to the cubic {beta}-phase starting at 94-99 GPa. We do not observe the orthorhombic {gamma} and {delta} phases reported previously in pure Ti. Computational studies show that this sequence is possible only if there is significant local atomic ordering during the compression process, yet insufficient atomic diffusion to reach the phase separated thermodynamic equilibrium state.

  11. Characterization of Mg/Al butt joints welded by gas tungsten arc filling with Zn29.5Al0.5Ti filler metal

    SciTech Connect (OSTI)

    Liu, Fei; Wang, Hongyang; Liu, Liming, E-mail: liulm@dlut.edu.cn

    2014-04-01

    The multivariate alloying design of a welding joint is used in the Mg to Al welding process. A Zn29.5Al0.5Ti alloy is added as filler metal in gas tungsten arc welding of Mg and Al alloy joint based on the analysis of Al and Mg alloy characteristics. The tensile strength, microstructure, and phase constitution of the weld seam are analyzed. The formation of brittle and hard MgAl intermetallic compounds is avoided because of the effects of Zn, Al, and Ti. The average tensile strength of the joint is 148 MPa. Al{sub 3}Ti is first precipitated and functions as the nucleus of heterogeneous nucleation during solidification. Moreover, the precipitated AlMgZn{sub 2} hypoeutectic phase exhibited a feather-like structure, which enhances the property of the MgAl dissimilar joint. - Highlights: Mg alloy AZ31B and Al alloy 6061 are butt welded by fusion welding. The effect of Ti in filler metal is investigated. The formation of MgAl intermetallic compounds is avoided.

  12. Observation of Precipitation Evolution in Fe-Ni-Mn-Ti-Al Maraging Steel using Atom Probe Tomography

    SciTech Connect (OSTI)

    Pereloma, E. V.; Stohr, R A; Miller, Michael K; Ringer, S. P.

    2009-01-01

    We describe the full decomposition sequence in an Fe-Ni-Mn-Ti-Al maraging steel during isothermal annealing at 550 C. Following significant pre-precipitation clustering reactions within the supersaturated martensitic solid solution, (Ni,Fe){sub 3}Ti and (Ni,Fe){sub 3}(Al,Mn) precipitates eventually form after isothermal aging for {approx}60 seconds. The morphology of the (Ni,Fe){sub 3}Ti particles changes gradually during aging from predominantly plate-like to rod-like, and, importantly, Mn and Al were observed to segregate to these precipitate/matrix interfaces. The (Ni,Fe){sub 3}(Al,Mn) precipitates occurred at two main locations: uniformly within the matrix and at the periphery of the (Ni,Fe){sub 3}Ti particles. We relate this latter mode of precipitation to the Mn-Al segregation.

  13. Spin-dependent transport across Co/LaAlO{sub 3}/SrTiO{sub 3} heterojunctions

    SciTech Connect (OSTI)

    Swartz, Adrian G.; Harashima, Satoshi; Xie, Yanwu; Kim, Bongju; Hwang, Harold Y.; Lu, Di; Bell, Christopher; Hikita, Yasuyuki

    2014-07-21

    The conducting interface formed between LaAlO{sub 3} and SrTiO{sub 3} exhibits high electron mobility, tunable carrier densities, and is theoretically predicted to have long spin lifetimes. Thus, the LaAlO{sub 3}/SrTiO{sub 3} heterostructure is a promising system for the transportation of spin information. We have investigated spin-dependent transport across Co/LaAlO{sub 3}/SrTiO{sub 3} heterostructures using an all electrical three terminal geometry and observed Lorentzian magnetoresistance typically associated with Hanle spin dephasing. However, such a picture fails to explain all the experimentally observed behavior. Further, experiments with spin-unpolarized Au/LaAlO{sub 3}/SrTiO{sub 3} heterojunctions support an alternative scenario involving current modulation by spin-dependent transport through defect states in the LaAlO{sub 3} barrier.

  14. Electric field effects in graphene/LaAlO{sub 3}/SrTiO{sub 3}

    Office of Scientific and Technical Information (OSTI)

    heterostructures and nanostructures (Journal Article) | SciTech Connect Electric field effects in graphene/LaAlO{sub 3}/SrTiO{sub 3} heterostructures and nanostructures Citation Details In-Document Search Title: Electric field effects in graphene/LaAlO{sub 3}/SrTiO{sub 3} heterostructures and nanostructures We report the development and characterization of graphene/LaAlO{sub 3}/SrTiO{sub 3} heterostructures. Complex-oxide heterostructures are created by pulsed laser deposition and are

  15. Thermal stability of Ni/Ti/Al ohmic contacts to p-type 4H-SiC

    SciTech Connect (OSTI)

    Yu, Hailong; Shen, Huajun Tang, Yidan; Bai, Yun; Liu, Xinyu; Zhang, Xufang; Wu, Yudong; Liu, Kean

    2015-01-14

    Low resistivity Ni/Ti/Al ohmic contacts on p-type 4H-SiC epilayer were developed, and their thermal stabilities were also experimentally investigated through high temperature storage at 600 °C for 100 h. The contact resistance of the Al/Ti/Ni/SiC contacts degraded in different degrees, and the contact morphology deteriorated with the increases of the average surface roughness and interface voids. X-ray spectra showed that Ni{sub 2}Si and Ti{sub 3}SiC{sub 2}, which were formed during ohmic contact annealing and contributed to low contact resistivity, were stable under high temperature storage. The existence of the TiAl{sub 3} and NiAl{sub 3} intermetallic phases was helpful to prevent Al agglomeration on the interface and make the contacts thermally stable. Auger electron spectroscopy indicated that the incorporation of oxygen at the surface and interface led to the oxidation of Al or Ti resulting in increased contact resistance. Also, the formation of these oxides roughened the surface and interface. The temperature-dependence of the specific contact resistance indicated that a thermionic field emission mechanism dominates the current transport for contacts before and after the thermal treatment. It suggests that the Ni/Ti/Al composite ohmic contacts are promising for SiC devices to be used in high temperature applications.

  16. Role of the Interface on Radiation Damage in the SrTiO3/LaAlO3...

    Office of Scientific and Technical Information (OSTI)

    Role of the Interface on Radiation Damage in the SrTiO3LaAlO3 Heterostructure under Ne2+ ... Country of Publication: United States Language: English Word Cloud More Like This Full ...

  17. Composition, morphology and mechanical properties of sputtered TiAlN coating

    SciTech Connect (OSTI)

    Budi, Esmar; Razali, M. Mohd.; Nizam, A. R. Md.

    2014-03-24

    TiAlN coating was deposited on the tungsten carbide cutting tool by using DC magnetron sputtering system to study the influence of substrate bias and nitrogen flow rate on the composition, morphology and mechanical properties. The negatively substrate bias and nitrogen flow rate was varied from about ?79 to ?221 V and 30 sccm to 72 sccm, respectively. The coating composition and roughness were characterized by using SEM/EDX and Atomic Force Microscopy (AFM), respectively. The dynamic ultra micro hardness tester was used to measure the mechanical properties. The coating hardness increases to about 10-12 GPa with an increase of the negatively substrate bias up to ? 200 V and it tend to decrease with an increase in nitrogen flow rate up to 70 sccm. The increase of hardness follows the increase of Ti and N content and rms coating roughness.

  18. Brazing ZrO{sub 2} ceramic to Ti6Al4V alloy using NiCrSiB amorphous filler foil: Interfacial microstructure and joint properties

    SciTech Connect (OSTI)

    Cao, J., E-mail: cao_jian@hit.edu.cn [Shandong Provincial Key Laboratory of Special Welding Technology, Harbin Institute of Technology at Weihai, Weihai 264209 (China); State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Song, X.G., E-mail: song_xiaoguohit@yahoo.com.cn [Shandong Provincial Key Laboratory of Special Welding Technology, Harbin Institute of Technology at Weihai, Weihai 264209 (China); State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Li, C., E-mail: li_chun1989@yahoo.cn [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Zhao, L.Y., E-mail: Zhao_ly@163.com [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Feng, J.C., E-mail: feng_jicai@163.com [Shandong Provincial Key Laboratory of Special Welding Technology, Harbin Institute of Technology at Weihai, Weihai 264209 (China); State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China)

    2013-07-15

    Reliable brazing of ZrO{sub 2} ceramic and Ti6Al4V alloy was achieved using NiCrSiB amorphous filler foil. The interfacial microstructure of ZrO{sub 2}/Ti6Al4V joints was characterized by scanning electron microscope, energy dispersive spectrometer and micro-focused X-ray diffractometer. The effects of brazing temperature on the interfacial microstructure and joining properties of brazed joints were investigated in detail. Active Ti of Ti6Al4V alloy dissolved into molten filler metal and reacted with ZrO{sub 2} ceramic to form a continuous TiO reaction layer, which played an important role in brazing. Various reaction phases including Ti{sub 2}Ni, Ti{sub 5}Si{sub 3} and ?-Ti were formed in brazed joints. With an increasing of brazing temperature, the TiO layer thickened gradually while the Ti{sub 2}Ni amount reduced. Shear test indicated that brazed joints tend to fracture at the interface between ZrO{sub 2} ceramic and brazing seam or Ti{sub 2}Ni intermetallic layer. The maximum average shear strength reached 284.6 MPa when brazed at 1025 C for 10 min. - Graphical Abstract: Interfacial microstructure of ZrO{sub 2}/TC4 joint brazed using NiCrSiB amorphous filler foil was: ZrO{sub 2}/TiO/Ti{sub 2}Ni + ?-Ti + Ti{sub 5}Si{sub 3}/?-Ti/Widmansttten structure/TC4. - Highlights: Brazing of ZrO{sub 2} ceramic and Ti-6Al-4V alloy was achieved. Interfacial microstructure was TiO/Ti{sub 2}Ni + ? + Ti{sub 5}Si{sub 3}/?/Widmansttten structure. The formation of TiO produced the darkening effect of ZrO{sub 2} ceramic. The highest joining strength of 284.6MPa was obtained.

  19. A transmission electron microscopy study of the deformation behavior underneath nanoindents in nano-scale Al-TiN multilayered composites

    SciTech Connect (OSTI)

    Bhattacharyya, Dhriti; Mara, Nathan A; Dickerson, Patricia O; Misra, Amit; Hoagland, R G

    2009-01-01

    Nano-scale multilayered Al-TiN composites were deposited with DC magnetron sputtering technique in two different layer thickness ratios - Al:TiN = 1:1 and Al:TiN = 9:1. The Al layer thickness varied from 2 nm to 450 nm. The hardness of the samples was tested by nanoindentation using a Berkovich tip. Cross-sectional Transmission Electron Microscopy (TEM) was carried out on samples extracted with Focused Ion Beam (FIB) from below the nanoindents. This paper presents the results of the hardness tests in the Al-TiN multilayers with the two different thickness ratios and the observations from the cross-sectional TEM studies of the regions underneath the indents. These studies showed remarkable strength in the multilayers, as well as some very interesting deformation behavior in the TiN layers at extremely small length scales, where the hard TiN layers undergo co-deformation with the Al layers.

  20. Effect of cryogenic treatment on the plastic property of Ti-6Al-4V titanium alloy

    SciTech Connect (OSTI)

    Gu, K. X.; Wang, J. J.; Yuan, Z.; Zhang, H.; Li, Z. Q.; Zhao, B.

    2014-01-27

    The effect of cryogenic treatment on the plastic property of Ti-6Al-4V plate was studied in the present work. After cryogenic treatment, the low temperature temper at 180 ▭ was conducted in one of the groups and the results were compared with that of the untreated and cryotreated ones. The SLX series program controlled cryogenic equipment was used for the cryogenic treatment. The tensile tests were conducted by universal tensile testing machine and parameters of elongation and area reduction were used to evaluate plastic property. The scanning electron microscope was used to study the morphology of microstructure and fracture surface. The results show that after cryogenic treatment alone the elongation increased 10.6% and the area reduction increased 13.5% while the strength reduced to a small extent. Cryogenic treatment followed with low temperature temper increased the elongation and area reduction just by the extent of 4.7% and 9.5%. It means that the additional low temperature temper after cryogenic is not beneficial to the tensile properties of Ti-6Al-4V alloy. The examination of microstructure by scanning electron microscopy revealed that cryogenic treatment reduced the content of β phase particles which is the main reason for the improvement in plasticity.

  1. Thermodynamic Instability at the Stoichiometric LaAlO3/SrTiO3(001) Interface

    SciTech Connect (OSTI)

    Qiao, Liang; Droubay, Timothy C.; Shutthanandan, V.; Zhu, Zihua; Sushko, P. V.; Chambers, Scott A.

    2010-08-11

    Fully stoichiometric epitaxial LaAlO3 grown on the TiO2-terminated SrTiO3(001) by off-axis pulsed laser deposition is shown to exhibit strong La-Sr cation intermixing. This result is predicted by classical and quantum mechanical calculations of the relative stabilities of abrupt and intermixed states. The extensive cation intermixing has a marked impact on the electronic properties of the interface.

  2. Tribological Characteristics of Single-phase AlMgB14 and Nanocomposite AlMgB14-TiB2 Superhard Coatings

    SciTech Connect (OSTI)

    Qu, Jun; Blau, Peter Julian; Zhu, Dong; Cook, Bruce A; Elmoursi, Alaa A

    2008-01-01

    This study investigated the friction and wear characteristics of AlMgB14 and AlMgB14-TiB2 superhard coatings, produced by pulse laser deposition (PLD) and physical vapor deposition (PVD), respectively. Tests were conducted under unidirectional and reciprocating sliding against AISI 52100 bearing steel in both dry and oil-lubricated conditions. The AlMgB14 coating exhibited an encouraging but short-lived low friction stage (u = 0.2) in dry sliding. The AlMgB14-TiB2 coating reduced the wear rates by one order of magnitude for itself and three orders of magnitude for the counterface compared with the uncoated M2 tool steel in dry sliding. This nanocomposite coating also demonstrated significant extension (>2.5X) of the low friction (non-scuffing) stage in a lubricant starvation sliding.

  3. Effect of Ti-Al cathode composition on plasma generation and plasma transport in direct current vacuum arc

    SciTech Connect (OSTI)

    Zhirkov, I. Petruhins, A.; Dahlqvist, M.; Ingason, A. S.; Rosen, J.; Eriksson, A. O.

    2014-03-28

    DC arc plasma from Ti, Al, and Ti{sub 1-x}Al{sub x} (x?=?0.16, 0.25, 0.50, and 0.70) compound cathodes was characterized with respect to plasma chemistry and charge-state-resolved ion energy. Scanning electron microscopy, X-ray diffraction, and Energy-dispersive X-ray spectroscopy of the deposited films and the cathode surfaces were used for exploring the correlation between cathode-, plasma-, and film composition. Experimental work was performed at a base pressure of 10{sup ?6}?Torr, to exclude plasma-gas interaction. The plasma ion composition showed a reduction of Al of approximately 5 at. % compared to the cathode composition, while deposited films were in accordance with the cathode stoichiometry. This may be explained by presence of neutrals in the plasma/vapour phase. The average ion charge states (Ti?=?2.2, Al?=?1.65) were consistent with reference data for elemental cathodes, and approximately independent on the cathode composition. On the contrary, the width of the ion energy distributions (IEDs) were drastically reduced when comparing the elemental Ti and Al cathodes with Ti{sub 0.5}Al{sub 0.5}, going from??150 and ?175?eV to ?100 and ?75?eV for Ti and Al ions, respectively. This may be explained by a reduction in electron temperature, commonly associated with the high energy tail of the IED. The average Ti and Al ion energies ranged between ?50 and ?61?eV, and ?30 and ?50?eV, respectively, for different cathode compositions. The attained energy trends were explained by the velocity rule for compound cathodes, which states that the most likely velocities of ions of different mass are equal. Hence, compared to elemental cathodes, the faster Al ions will be decelerated, and the slower Ti ions will be accelerated when originating from compound cathodes. The intensity of the macroparticle generation and thickness of the deposited films were also found to be dependent on the cathode composition. The presented results may be of importance for choice of cathodes for thin film depositions involving compound cathodes.

  4. Electric field effects in graphene/LaAlO{sub 3}/SrTiO{sub 3} heterostructures and nanostructures

    SciTech Connect (OSTI)

    Huang, Mengchen; Jnawali, Giriraj; Hsu, Jen-Feng; Dhingra, Shonali; Bi, Feng; Chen, Lu; DUrso, Brian; Irvin, Patrick; Levy, Jeremy; Lee, Hyungwoo; Ryu, Sangwoo; Eom, Chang-Beom; Ghahari, Fereshte; Ravichandran, Jayakanth; Kim, Philip

    2015-06-01

    We report the development and characterization of graphene/LaAlO{sub 3}/SrTiO{sub 3} heterostructures. Complex-oxide heterostructures are created by pulsed laser deposition and are integrated with graphene using both mechanical exfoliation and transfer from chemical-vapor deposition on ultraflat copper substrates. Nanoscale control of the metal-insulator transition at the LaAlO{sub 3}/SrTiO{sub 3} interface, achieved using conductive atomic force microscope lithography, is demonstrated to be possible through the graphene layer. LaAlO{sub 3}/SrTiO{sub 3}-based electric field effects using a graphene top gate are also demonstrated. The ability to create functional field-effect devices provides the potential of graphene-complex-oxide heterostructures for scientific and technological advancement.

  5. Symmetry-dependent interfacial reconstruction to compensate polar discontinuity at perovskite oxide interfaces (LaAlO{sub 3}/SrTiO{sub 3} and LaAlO{sub 3}/CaTiO{sub 3})

    SciTech Connect (OSTI)

    Lee, Joohwi; Moon, Seon Young; Kim, Jin-Sang; Choi, Jung-Hae E-mail: almacore@kist.re.kr; Choi, Jong Kwon; Park, Jaehong; Hwang, Cheol Seong; Baek, Seung-Hyub; Chang, Hye Jung E-mail: almacore@kist.re.kr

    2015-02-16

    We report the crystal symmetry-dependency of the interfacial reconstruction to relieve the polar discontinuity at the complex oxide heterointerfaces. We chose LaAlO{sub 3}/SrTiO{sub 3} and LaAlO{sub 3}/CaTiO{sub 3} interfaces as model systems, where the neutral TiO{sub 2} and the positive LaO{sup +} layers form the polar discontinuity at the interface with TiO{sub 2}-terminated (001) cubic SrTiO{sub 3} and orthorhombic CaTiO{sub 3}. Using scanning transmission electron microscopy, we observed that the interlayer distance abnormally increased at the interface. We performed the first-principles calculations to understand the detailed atomic displacement at the interfaces having no oxygen vacancy and intermixing. Our results show that cations were reconstructed in different ways depending on the crystal symmetry through the octahedral tilts and atomic displacements to compensate the polar discontinuity at the interfaces. Our results imply that the interfacial reconstructions have to be considered along with the ionic compensation (intermixing) and electronic compensation (two dimensional electron gas) to fully understand the interfacial phenomena.

  6. Anomalous Transport in Sketched Nanostructures at the LaAlO3/SrTiO3

    Office of Scientific and Technical Information (OSTI)

    Interface (Journal Article) | SciTech Connect Anomalous Transport in Sketched Nanostructures at the LaAlO3/SrTiO3 Interface Citation Details In-Document Search Title: Anomalous Transport in Sketched Nanostructures at the LaAlO3/SrTiO3 Interface Authors: Cheng, Guanglei ; Veazey, Joshua P. ; Irvin, Patrick ; Cen, Cheng ; Bogorin, Daniela F. ; Bi, Feng ; Huang, Mengchen ; Lu, Shicheng ; Bark, Chung-Wung ; Ryu, Sangwoo ; Cho, Kwang-Hwan ; Eom, Chang-Beom ; Levy, Jeremy Publication Date:

  7. Role of the Interface on Radiation Damage in the SrTiO3/LaAlO3

    Office of Scientific and Technical Information (OSTI)

    Heterostructure under Ne2+ Ion Irradiation (Journal Article) | SciTech Connect Role of the Interface on Radiation Damage in the SrTiO3/LaAlO3 Heterostructure under Ne2+ Ion Irradiation Citation Details In-Document Search Title: Role of the Interface on Radiation Damage in the SrTiO3/LaAlO3 Heterostructure under Ne2+ Ion Irradiation Authors: Bi, Zhenxing [1] ; Uberuaga, Blas [1] ; Vernon, Lj [1] ; Aguiar, Jeffery [1] ; Fu, Engang [1] ; Zheng, Shijan [1] ; Zhang, Shixiong [1] ; Wang, Yongqiang

  8. Microstructure characterization of laser welded Ti-6Al-4V fusion zones

    SciTech Connect (OSTI)

    Xu, Pei-quan; Li, Leijun, E-mail: leijun.li@ualberta.ca; Zhang, Chunbo

    2014-01-15

    The as-welded microstructure of laser-welded Ti-6Al-4V is characterized as a function of CO2 key-hole mode laser welding speed. Martensitic ?? is the predominant phase, with some ? and retained ?. Phase transformation is affected by the cooling rate through laser welding speed. A higher welding speed of 1.6 to 2.0 m/min produced more martensite ?? and less retained ? in the welds. 1.4 m/min welding speed produced small amounts of ?, besides the martensite ??. A trace of ? titanium hydride phase seems to have formed in the weld fusion zone. Moir fringes are a common feature in the TEM microstructure, due to abundance of multi-phase interfaces. Tensile twins and clusters of dislocations indicate that plastic deformation has happened in the as-welded microstructure, indicating the local stress levels to be approaching the yield stress on-cooling during laser welding.

  9. In-situ single-grain peak profile measurements on Ti-7Al during tensile deformation.

    SciTech Connect (OSTI)

    Lienert, U.; Brandes, M. C.; Bernier, J. V.; Weiss, J.; Shastri, S. D.; Mills, M. J.; Miller, M. P.; US Naval Research Lab.; LLNL; Mechanical Solutions, Inc.; Ohio State Univ.; Cornell Univ.

    2009-10-25

    High-energy three-dimensional X-ray diffraction with medium and high reciprocal space resolution was applied to study in situ tensile deformation of Ti-7Al specimens. Samples with planar and random dislocation microstructures were prepared and characterized by electron microscopy. Stress tensors of individual grains were obtained at several loads up to 2% deformation. The stress tensors were found to rotate, and resolved shear stresses were calculated. High-resolution reciprocal space maps of selected grains were recorded. Azimuthal and radial distributions were visualized and discussed in terms of idealized dislocation structures. Heterogeneous grain rotations were observed for the planar microstructure and found to be consistent with activation of the highest stressed basal slip system. Intra-granular strain gradients were detected in excess of the intrinsic radial dislocation peak broadening. The potential of combining the applied techniques with modeling to obtain multiple length-scale information during deformation of bulk specimens is discussed.

  10. HRTEM Study of Oxide Nanoparticles in 16Cr-4Al-2W-0.3Ti-0.3Y2O3...

    Office of Scientific and Technical Information (OSTI)

    ...6Cr-4Al-2W-0.3Ti-0.3Y2O3 ODS Steel Citation Details In-Document Search Title: HRTEM Study of Oxide Nanoparticles in 16Cr-4Al-2W-0.3Ti-0.3Y2O3 ODS Steel You are accessing a ...

  11. Electronic and atomic structures of Ti{sub 1-x}Al{sub x}N thin films related to their damage behavior

    SciTech Connect (OSTI)

    Tuilier, M.-H.; Pac, M.-J.; Girleanu, M.; Covarel, G.; Arnold, G.; Louis, P.; Rousselot, C.; Flank, A.-M.

    2008-04-15

    Ti and Al K-edge x-ray absorption spectroscopy is used to investigate the electronic structure of Ti{sub 1-x}Al{sub x}N thin films deposited by reactive magnetron sputtering. The experimental near edge spectra of TiN and AlN are interpreted in the light of unoccupied density of state band structure calculations. The comparison of the structural parameters derived from x-ray absorption fine structure and x-ray diffraction reveals segregation between Al-rich and Ti-rich domains within the Ti{sub 1-x}Al{sub x}N films. Whereas x-ray diffraction probes only the crystallized domains, the structural information derived from extended x-ray absorption fine structure analysis turns on both crystalline and grain boundaries. The results are discussed by considering the damage behavior of the films depending on the composition.

  12. The defect-induced changes of the electronic and magnetic properties in the inverse Heusler alloy Ti{sub 2}CoAl

    SciTech Connect (OSTI)

    Chen, Ying; Wu, Bo; Yuan, Hongkuan; Feng, Yu; Chen, Hong

    2015-01-15

    The first-principles calculations are performed to investigate the effect of swap, antisite and vacancy defects of three classes on the electronic and magnetic properties in the inverse Heusler alloy Ti{sub 2}CoAl of half-metallicity. Our calculations reveal that Ti(A/B)–Co and Co–Al swaps, Ti(A/B) and Al vacancy defects as well as Co{sub Ti(A)/Al} and Al{sub Ti(A)/Ti(B)} antisite defects are likely to form in a concentration as high as 12.5%. Among them, Co{sub Ti(A)} antisite is detected to be the most probable defect. It is shown that the spin polarizations of Ti{sub 2}CoAl are considerably reduced by the Ti(A/B)–Co swap and Ti(B)/Al vacancy defects, while a quite high spin polarization around 95% is observed in Co–Al swap as well as Ti(A) vacancy. Remarkably, all the likely antisite defects almost retain the half-metallic character in a concentration of 12.5% even if they have the possibility to form. However, induced by antisites, the Fermi levels shift to the edge of band gap with small peaks arising just above the Fermi level, which may destroy the half-metallicity by spin-flip excitation. - Graphical abstract: The spin polarization and formation energy of various possible defects in inverse Heusler alloy Ti{sub 2}CoAl. The triangle, star and square represent the swap, antisite and vacancy defects, respectively. - Highlights: • The swap, antisite, and vacancy defects are studied in half-metallic Ti{sub 2}CoAl. • The Co{sub Ti(A)} antisite is the most probable among the studied defects. • The antisite defects almost retain the half-metallicity. • Most of swap and vacancy defects have degraded the half-metallicity. • High spin polarizations are detected in Co–Al swap and Ti(A) vacancy defects.

  13. Cation mixing, band offsets and electric fields at LaAlO3/SrTiO3(001) heterojunctions with variable La:Al atom ratio

    SciTech Connect (OSTI)

    Qiao, Liang; Droubay, Timothy C.; Kaspar, Tiffany C.; Sushko, P. V.; Chambers, Scott A.

    2011-08-01

    Interfacial intermixing and electronic structure were investigated at thin (35 unit cells.), epitaxial La1 ? xAl1 + xO3/SrTiO3(001) heterojunctions for x = 0 and 0.05. Angle-resolved X-ray photoelectron spectroscopy reveals rather extensive cation intermixing for all films, independent of composition. The valence band offset for the nominally stoichiometric (x = 0) film is 0.16 0.10 eV, with the valence band maximum of SrTiO3 being deeper in binding energy than that of LaAlO3. Similar values are obtained for x = 0.05. There is no measurable band bending in either the LaAlO3 or the SrTiO3 near the interface. These results are at odds with first principles theoretical predictions based on perfect stoichiometry and an abrupt interface model. However, inclusion of intermixing in the compositional description of the interface results in successful prediction of the valence band offset and absence of band bending.

  14. Photoconductivity and Non-Exponential Relaxation at Insulating LaAlO3/SrTiO3 Interfaces

    SciTech Connect (OSTI)

    Kim, Minu; Bell, C.; Hikita, Y.; Kozuka, Y.; Kim, B.G.; Hwang, H.Y.

    2012-08-17

    LaAlO{sub 3} is grown on SrO terminated (100) SrTiO{sub 3}, and (110) SrTiO{sub 3}, producing insulating heterointerfaces without light. Photocurrent spectroscopy at low temperatures reveals a broad distribution of interface states between 2 eV and 2.7 eV at both interfaces, with a higher density in the (110) case concomitant with relatively shallow traps. The photocurrent relaxation can be well fitted by a stretched exponential form, confirming energetically distributed electron traps. Photo-carrier lifetimes are larger than a few hundred seconds for optical excitation approaching the SrTiO{sub 3} band-gap energy, providing the opportunity to study transient light-induced properties at low temperatures.

  15. High-temperature phase transformation in Cr added TiAl base alloy

    SciTech Connect (OSTI)

    Abe, E.; Niinobe, K.; Nobuki, M.; Nakamura, M.; Tsujimoto, T.

    1999-07-01

    The authors have investigated a microstructure evolution of a Ti-48Al-3.5Cr (in at.%) alloy at high-temperatures ({gt} 1,473K). In the alloy annealed at 1673K for 1.8ks, followed by air-cooling, a characteristic microstructure with a feathery fashion was uniformly formed. From a cooling-rate-controlling study, it was found that formation of the feathery structure is accomplished during continuous cooling from 1673K to 1573K, within the {alpha} + {gamma} two-phase region. Transmission electron microscopy revealed that the feathery structure is composed of lamellar colonies (5--10{micro}m) which are crystallographically tilted slightly (a few degree) with their neighbors. A surprising fact is that lamellae in each colony are mostly the {gamma} phase with few {alpha}{sub 2} phase less than 5% in volume. This suggests that the feathery structure is a metastable product and has not resulted from the {alpha} {r{underscore}arrow} {alpha} + {gamma} transformation above 1,573 K. Instead, the feathery structure formation should be attributed to the non-equilibrium {alpha} {r{underscore}arrow} {gamma} transformation which occurs at high-temperatures with a small degree of supercooling. The authors discuss this interesting phase transformation in terms of the {alpha} {r{underscore}arrow} {gamma} massive transformation, based on the continuous-cooling-transformation (CCT) diagram constructed for the present alloy.

  16. Effect of a ductility layer on the tensile strength of TiAl-based multilayer composite sheets prepared by EB-PVD

    SciTech Connect (OSTI)

    Zhang, Rubing; Zhang, Yaoyao; Liu, Qiang; Chen, Guiqing; Zhang, Deming

    2014-09-15

    TiAl/Nb and TiAl/NiCoCrAl laminate composite sheets with a thickness of 0.4–0.6 mm and dimensions of 150 mm × 100 mm were successfully fabricated by electron beam physical vapor deposition. The microstructures of the sheets were examined, and their mechanical properties were compared with those of TiAl monolithic sheet produced by electron beam physical vapor deposition. Tensile testing was performed at room temperature and 750 °C, and the fracture surfaces were examined by scanning electron microscopy. Among the three microlaminate sheets, the TiAl/NiCoCrAl micro-laminate sheet had the best comprehensive properties at room temperature, and the TiAl/Nb micro-laminate sheet showed the ideal high-temperature strength and plasticity at 750 °C. The result was discussed in terms of metal strengthening mechanism. - Highlights: • TiAl-based multilayer foils was fabricated successfully by using EB-PVD method; • The tensile properties and micro-fracture morphologies of the sheet were investigated; • The deformation behavior of the multilayer foils was discussed.

  17. Equivalence of optical and electrical noise equivalent power of hybrid NbTiN-Al microwave kinetic inductance detectors

    SciTech Connect (OSTI)

    Janssen, R. M. J.; Endo, A.; Visser, P. J. de; Klapwijk, T. M.; Baselmans, J. J. A.

    2014-11-10

    We have measured and compared the response of hybrid NbTiN-Al Microwave Kinetic Inductance Detectors (MKIDs) to changes in bath temperature and illumination by sub-mm radiation. We show that these two stimulants have an equivalent effect on the resonance feature of hybrid MKIDs. We determine an electrical noise equivalent power (NEP) from the measured temperature responsivity, quasiparticle recombination time, superconducting transition temperature, and noise spectrum, all of which can be measured in a dark environment. For the two hybrid NbTiN-Al MKIDs studied in detail, the electrical NEP is within a factor of two of the optical NEP, which is measured directly using a blackbody source.

  18. Recyclability study on Inconel 718 and Ti-6Al-4V powders for use in electron beam melting

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Nandwana, Peeyush; Peter, William H.; Lowe, Larry E.; Dehoff, Ryan R.; Medina, Francisco; Babu, Sudarsanam Suresh; Kirka, Michael M.

    2015-10-20

    In this study, powder bed based additive manufacturing technologies offer a big advantage in terms of reusability of the powders over multiple cycles that result in cost savings. However, currently there are no standards to determine the factors that govern the powder reuse times. This work presents the results from a recyclability study conducted on Inconel 718 and Ti-6Al-4V powders. It has been found that the Inconel 718 powders are chemically stable over a large number of cycles and their reuse time is limited by physical characteristics of powders such as flowability. Ti-6Al-4V, on the other hand, finds its reusemore » time governed by the oxygen pick up that occurs during and in between build cycles. The detailed results have been presented.« less

  19. Recyclability study on Inconel 718 and Ti-6Al-4V powders for use in electron beam melting

    SciTech Connect (OSTI)

    Nandwana, Peeyush; Peter, William H.; Lowe, Larry E.; Dehoff, Ryan R.; Medina, Francisco; Babu, Sudarsanam Suresh; Kirka, Michael M.

    2015-10-20

    In this study, powder bed based additive manufacturing technologies offer a big advantage in terms of reusability of the powders over multiple cycles that result in cost savings. However, currently there are no standards to determine the factors that govern the powder reuse times. This work presents the results from a recyclability study conducted on Inconel 718 and Ti-6Al-4V powders. It has been found that the Inconel 718 powders are chemically stable over a large number of cycles and their reuse time is limited by physical characteristics of powders such as flowability. Ti-6Al-4V, on the other hand, finds its reuse time governed by the oxygen pick up that occurs during and in between build cycles. The detailed results have been presented.

  20. Stoichiometry dependence of potential screening at La ( 1 - δ ) Al ( 1 + δ ) O 3 / SrTiO 3 interfaces

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Weiland, Conan; Sterbinsky, George E.; Rumaiz, Abdul K.; Hellberg, C. Stephen; Woicik, Joseph C.; Zhu, Shaobo; Schlom, Darrell G.

    2015-04-03

    Hard x-ray photoelectron spectroscopy (HAXPES) and variable kinetic energy x-ray photoelectron spectroscopy (VKE-XPS) analyses have been performed on ten-unit-cell-thick La(1-δ)Al(1+δ)O₃ films, with La:Al ratios of 1.1, 1.0, and 0.9, deposited on SrTiO₃. Only Al-rich films are known to have a conductive interface. VKE-XPS, coupled with maximum entropy analysis, shows significant differences in the compositional depth profile among the Al-rich, La-rich, and stoichiometric films: significant La enrichment at the interface is observed in the La-rich and stoichiometric films, while the Al-rich film shows little to no intermixing. Additionally, the La-rich and stoichiometric films show a high concentration of Al at themore » surface, which is not observed in the Al-rich film. HAXPES valence band (VB) analysis shows a broadening of the VB for the Al-rich sample relative to the stoichiometric and La-rich samples. This broadening is consistent with an electric field across the Al-rich film. These results are consistent with a defect-driven electronic reconstruction.« less

  1. An investigation on microstructure evolution and mechanical properties during liquid state diffusion bonding of Al2024 to Ti6Al4V

    SciTech Connect (OSTI)

    Samavatian, Majid; Halvaee, Ayoub; Amadeh, Ahmad Ali; Khodabandeh, Alireza

    2014-12-15

    Joining mechanism of Ti/Al dissimilar alloys was studied during liquid state diffusion bonding process using Cu/Sn/Cu interlayer at 510 C under vacuum of 7.5 10{sup ?5} Torr for various bonding times. The microstructure and compositional changes in the joint zone were analyzed by scanning electron microscopy equipped with energy dispersive spectroscopy and X-ray diffraction. Microhardness and shear strength tests were also applied to study the mechanical properties of the joints. It was found that with an increase in bonding time, the elements of interlayer diffused into the parent metals and formed various intermetallic compounds at the interface. Diffusion process led to the isothermal solidification and the bonding evolution in the joint zone. The results from mechanical tests showed that microhardness and shear strength values have a straight relation with bonding time so that the maximum shear strength of joint was obtained for a bond made with 60 min bonding time. - Highlights: Liquid state diffusion bonding of Al2024 to Ti6Al4V was performed successfully. Diffusion of the elements caused the formation of various intermetallics at the interface. Microhardness and shear strength values have a straight relation with bonding time. The maximum shear strength reached to 36 MPa in 60 min bonding time.

  2. On the preparation of TiAl alloy by direct reduction of the oxide mixtures in calcium chloride melt

    SciTech Connect (OSTI)

    Prabhat K. Tripathy; Derek J. Fray

    2011-11-01

    In recent years, TiAl-based intermetallic alloys are being increasingly considered for application in areas such as (i) automobile/transport sector (passenger cars, trucks and ships) (ii) aerospace industry (jet engines and High Speed Civil Transport propulsion system) and (iii) industrial gas turbines. These materials offer excellent (i) high temperature properties (at higher than 6000C) (ii) mechanical strength and (iii) resistance to corrosion and as a result have raised renewed interest. The combination of these properties make them possible replacement materials for traditional nickel-based super-alloys, which are nearly as twice as dense (than TiAl based alloys). Since the microstructures of these intermetallic alloys affect, to a significant extent, their ultimate performance, further improvements (by way of alteration/modification of these microstructures), have been the subject matter of intense research investigations. It has now been established that the presence of alloy additives, such as niobium, tantalum, manganese, boron, chromium, silicon, nickel and yttrium etc, in specific quantities, impart marked improvement to the properties, viz. fatigue strength, fracture toughness, oxidation resistance and room temperature ductility, of these alloys. From a number of possible alloy compositions, {gamma}-TiAl and Ti-Al-Nb-Cr have, of late, emerged as two promising engineering alloys/materials. . The conventional fabrication process of these alloys include steps such as melting, forging and heat treatment/annealing of the alloy compositions. However, an electrochemical process offers an attractive proposition to prepare these alloys, directly from the mixture of the respective oxides, in just one step. The experimental approach, in this new process, was, therefore, to try to electrochemically reduce the (mixed) oxide pellet to an alloy phase. The removal of oxygen, from the (mixed) oxide pellet, was effected by polarizing the oxide pellet against a graphite electrode in a pool of molten calcium chloride at a temperature of 9000C. The dominant mechanism of the oxygen removal was the ionization of oxygen followed by its subsequent discharge, as CO2/CO, at the anode surface. The removal of oxygen from the oxide mixture helped form the alloy in situ. The presentation shall cover the detailed experimental results pertaining to the preparation, evaluation and characterization of Ti-47Al-2Nb-2Cr (atom%) alloy.

  3. An experimental study of the (Ti-6Al-4V)-xH phase diagram using in situ synchrotron XRD and TGA/DSC techniques.

    SciTech Connect (OSTI)

    Sun, Pei; Fang, Z. Zak; Koopman, Mark; Paramore, James D.; Chandran, K. S. Ravi; Ren, Yang; Lu, Jun

    2015-02-01

    Hydrogen has been investigated for decades as a temporary alloying element to refine the microstructure of Ti-6Al-4V, and is now being used in a novel powder metallurgy method known as "hydrogen sintering and phase transformation". Pseudo-binary phase diagrams of (Ti-6Al-4V)-xH have been studied and developed, but are not well established due to methodological limitations. In this paper, in situ studies of phase transformations during hydrogenation and dehydrogenation of (Ti-6Al-4V)-xH alloys were conducted using high-energy synchrotron X-ray diffraction (XRD), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The eutectoid phase transformation of ? ? ? + ? was observed in the (Ti-6Al-4V)-xH alloy via in situ synchrotron XRD at 211 C with a hydrogen concentration of 37.5 at.% (measured using TGA-DSC). The relationships of hydrogen composition to partial pressure and temperature were investigated in the temperature range 450-900C. Based on these results, a partial pseudo-binary phase diagram of (Ti-6Al-4V)-xH is proposed for hydrogen compositions up to 60 at.% in the temperature range 100-900C. Using the data collected in real time under controlled parameters of temperature, composition and hydrogen partial pressure, this work characterizes relevant phase transformations and microstructural evolution for practical titanium-hydrogen technologies of Ti-6Al-4V.

  4. Role of the interface on radiation damage in the SrTiO{sub 3}/LaAlO{sub 3}

    Office of Scientific and Technical Information (OSTI)

    heterostructure under Ne{sup 2+} ion irradiation (Journal Article) | SciTech Connect Role of the interface on radiation damage in the SrTiO{sub 3}/LaAlO{sub 3} heterostructure under Ne{sup 2+} ion irradiation Citation Details In-Document Search Title: Role of the interface on radiation damage in the SrTiO{sub 3}/LaAlO{sub 3} heterostructure under Ne{sup 2+} ion irradiation We systematically investigated the microstructural evolution of heteroepitaxial SrTiO{sub 3} (STO) thin films grown on a

  5. Capacitance-voltage characteristics of (Al/Ti)/Al{sub 2}O{sub 3}/n-GaN MIS structures

    SciTech Connect (OSTI)

    Ivanov, P. A. Potapov, A. S.; Nikolaev, A. E.; Lundin, V. V.; Sakharov, A. V.; Tsatsulnikov, A. F.; Afanas’ev, A. V.; Romanov, A. A.; Osachev, E. V.

    2015-08-15

    The capacitance-voltage characteristics of (Al/Ti)/Al{sub 2}O{sub 3}/n-GaN metal—insulator-semiconductor (MIS) structures are measured and analyzed. n-Type GaN films are grown on sapphire (0001) substrates by the metal-organic chemical vapor deposition method. An aluminum-oxide layer with a thickness of 60 nm is deposited onto the surface of GaN by the method of atomic-layer deposition from the gas phase. Metallic contacts are deposited by the electron-beam evaporation of titanium and aluminum in vacuum. According to the measurement results, the breakdown-field strength of the oxide, its dielectric constant, and the integrated electron density of states at the oxide-semiconductor interface are 5 × 10{sup 6} V/cm, 7.5, and 3 × 10{sup 12} cm{sup −2}, respectively.

  6. Anisotropic swelling and microcracking of neutron irradiated Ti3AlC2-Ti5Al2C3 materials

    SciTech Connect (OSTI)

    Ang, Caen K.; Silva, Chinthaka M.; Shih, Chunghao Phillip; Koyanagi, Takaaki; Katoh, Yutai; Zinkle, Steven J.

    2015-12-17

    Mn + 1AXn (MAX) phase materials based on Ti–Al–C have been irradiated at 400 °C (673 K) with fission neutrons to a fluence of 2 × 1025 n/m2 (E > 0.1 MeV), corresponding to ~ 2 displacements per atom (dpa). We report preliminary results of microcracking in the Al-containing MAX phase, which contained the phases Ti3AlC2 and Ti5Al2C3. Equibiaxial ring-on-ring tests of irradiated coupons showed that samples retained 10% of pre-irradiated strength. Volumetric swelling of up to 4% was observed. Phase analysis and microscopy suggest that anisotropic lattice parameter swelling caused microcracking. Lastly, variants of titanium aluminum carbide may be unsuitable materials for irradiation at light water reactor-relevant temperatures.

  7. IA Experts Listing 2014 | Department of Energy

    Energy Savers [EERE]

    IA Experts Listing 2014 IA Experts Listing 2014 PDF icon IA Experts Listing January 2014 More Documents & Publications Office of International Affairs Organization Chart PI...

  8. Rolling Hills (IA) | Open Energy Information

    Open Energy Info (EERE)

    Rolling Hills (IA) Jump to: navigation, search Name Rolling Hills (IA) Facility Rolling Hills (IA) Sector Wind energy Facility Type Commercial Scale Wind Facility Status In Service...

  9. Steamboat IA Geothermal Facility | Open Energy Information

    Open Energy Info (EERE)

    IA Geothermal Facility Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Steamboat IA Geothermal Facility General Information Name Steamboat IA Geothermal Facility...

  10. Investigation of the phase equilibrium of alloys of the ternary system Ti-Al-Nb

    SciTech Connect (OSTI)

    Nartova, T.T.; Sopochkin, G.G.

    1987-09-09

    This investigation of the constitution diagram of the ternary system titanium-aluminum-niobium is limited to the specific system Ti-Ti3A1-Nb in order to establish the regions of the alpha and beta solid solutions of titanium, the solid solutions based on aluminide Ti3A1, and the phases conjugated with them. The constitution diagram of the systems Ti-A1 and Ti-Nb obtained from the data were used as the basis for constructing the constitution diagram of the ternary system. The methods of microstructural, thermal and X ray phase analysis were used in the study. The X ray pictures were taken in copper emission from powders that had been preliminarily annealed in a vacuum at 600 for 30 min. Iodic titanium, aluminum brand AV-000 and fillet niobium were used as the source materials. The alloys were remelted five times in an electric-arc furnace with a nonconsumable tungsten electrode in an argon atmosphere, and then by crucibleless melting in the suspended state. The constancy of the chemical composition of the alloys was monitored by their weight after smelting in an electric arc furnace.

  11. Epitaxial growth, structure, and intermixing at the LaAlO{sub 3}/SrTiO{sub 3} interface as the film stoichiometry is varied

    SciTech Connect (OSTI)

    Qiao, L.; Droubay, T. C.; Kaspar, T. C.; Chambers, S. A.; Varga, T.; Bowden, M. E.; Shutthanandan, V.; Zhu, Z.

    2011-02-15

    LaAlO{sub 3} epitaxial films with La:Al cation ratios ranging from 0.9 to 1.2 were grown on TiO{sub 2}-terminated SrTiO{sub 3} (001) substrates by off-axis pulsed laser deposition. Although all films are epitaxial, rocking curve measurements show that the crystallographic quality degrades with increasing La:Al ratio. Films with La:Al ratios of 0.9, 1.0, and 1.1 were coherently strained to the substrate. However, the out-of-plane lattice parameter increases over this range, revealing a decrease in film tetragonality. Although all film surfaces exhibit hydroxylation, the extent of hydroxylation is greater for the La-rich films. Rutherford backscattering spectrometry reveals that La from the film diffuses deeply into the SrTiO{sub 3} substrate and secondary-ion-mass spectroscopy shows unambiguous Sr outdiffusion into the films.

  12. Octahedral rotations in strained LaAlO{sub 3}/SrTiO{sub 3} (001) heterostructures

    SciTech Connect (OSTI)

    Fister, T. T.; Hruszkewycz, S. O.; Proffit, D. L.; Eastman, J. A.; Fuoss, P. H.; Baldo, P. M.; Fong, D. D.; Zhou, H.; Luo, Z.; Seo, S. S. A.; Lee, H. N.

    2014-02-01

    Many complex oxides display an array of structural instabilities often tied to altered electronic behavior. For oxide heterostructures, several different interfacial effects can dramatically change the nature of these instabilities. Here, we investigate LaAlO{sub 3}/SrTiO{sub 3} (001) heterostructures using synchrotron x-ray scattering. We find that when cooling from high temperature, LaAlO{sub 3} transforms from the Pm3{sup }m to the Imma phase due to strain. Furthermore, the first 4 unit cells of the film adjacent to the substrate exhibit a gradient in rotation angle that can couple with polar displacements in films thinner than that necessary for 2D electron gas formation.

  13. Solid-particle erosion of an Al{sub 2}O{sub 3}-SiC-TiC composite

    SciTech Connect (OSTI)

    Jiang, M.; Goretta, K.C.; Singh, D.; Routbort, J.L.; Schuldies, J.J.

    1996-11-01

    An electrodischarge-machinable Al{sub 2}O{sub 3}-SiC-TiC composite developed by Industrial Ceramic Technology, Inc., has a high fracture toughness, 9.6{+-}0.6 MPm{sup 1/2}, as measured by indentation, and a Vickers hardness of 20.3{+-}0.6 GPa. The composite`s resistance to solid-particle erosion was measured for 143-{mu}m dia SiC particles impacting at 20-90{degree} angles and 50-100 m/s velocities. Erosion rate exhibited a maximum for normal incidence, and the erosion resistance was better than that of commercial Al{sub 2}O{sub 3}. SEM indicated that material wastage was by a combination of brittle fracture and microplasticity.

  14. Catalytic Effect of Ti for Hydrogen Cycling in NaAlH4

    Broader source: Energy.gov [DOE]

    A presentation about how hydrogen can be reversibly absorbed and desorbed from NaAlH4 under moderate conditions by the addition of catalysts.

  15. HRTEM Study of Oxide Nanoparticles in 16Cr-4Al-2W-0.3Ti-0.3Y2O3 ODS Steel

    Office of Scientific and Technical Information (OSTI)

    (Conference) | SciTech Connect HRTEM Study of Oxide Nanoparticles in 16Cr-4Al-2W-0.3Ti-0.3Y2O3 ODS Steel Citation Details In-Document Search Title: HRTEM Study of Oxide Nanoparticles in 16Cr-4Al-2W-0.3Ti-0.3Y2O3 ODS Steel Crystal and interfacial structures of oxide nanoparticles in 16Cr-4Al-2W-0.3Ti-0.3Y{sub 2}O{sub 3} ODS ferritic steel have been examined using high-resolution transmission electron microscopy (HRTEM) techniques. Oxide nanoparticles with a complex-oxide core and an amorphous

  16. Tunable bilayer two-dimensional electron gas in LaAlO{sub 3}/SrTiO{sub 3} superlattices

    SciTech Connect (OSTI)

    Ma, H. J. Harsan E-mail: phyarian@nus.edu.sg; Annadi, A.; Zeng, S. W.; Ariando E-mail: phyarian@nus.edu.sg; Huang, Z.; L, W. M.; Wong, L. M.; Wang, S. J.; Venkatesan, T.

    2014-07-07

    We report magnetotransport properties of double heterointerfaces in LaAlO{sub 3}/SrTiO{sub 3}/LaAlO{sub 3}/SrTiO{sub 3}(001) (LAO/STO/LAO/STO). A strong nonlinearity in the Hall resistivity is found when the temperature is below 80?K. This effect is attributed to multichannel conduction of interfacial charges generated in double heterostructures of LAO/STO where two-dimensional electron gas (2DEG) is produced. The multichannel conduction is confirmed by back gating modulation of Hall effect. Our result suggests the possibility to achieve coupled bilayer 2DEG layers in LAO/STO superlattices.

  17. Epitaxial growth, structure and intermixing at the LaAlO3/SrTiO3 interface as the film stoichiometry is varied

    SciTech Connect (OSTI)

    Qiao, Liang; Droubay, Timothy C.; Varga, Tamas; Bowden, Mark E.; Shutthanandan, V.; Zhu, Zihua; Kaspar, Tiffany C.; Chambers, Scott A.

    2011-02-11

    LaAlO3 epitaxial films with La:Al cation ratios ranging from 0.9 to 1.2 were grown on TiO2-terminated SrTiO3 (001) substrates by off-axis pulsed laser deposition. Although all films are epitaxial, rocking curve and Kiessig fringe oscillation measurements show that the crystallographic quality degrades with increasing La:Al ratio. Films with La:Al ratios of 0.9, 1.0, and 1.1 were coherently strained to the substrate. However, the out-of-plane lattice parameter increases over this range, revealing a decrease in film tetragonality. Although all film surfaces exhibit hydroxylation, the extent of hydroxylation is greater for the La-rich films. Rutherford backscattering spectrometry reveals that La from the film diffuses deeply into the SrTiO3 substrate and secondary ion mass spectroscopy shows unambiguous Sr outdiffusion into the films. Intermixing, which is generally not investigated in studies of the LaAlO3/SrTiO3 interface, may have important implications for the mechanism of electrical conductivity.

  18. Built-in and Induced Polarization Across LaAlO3/SrTiO3 Heterojunctions

    SciTech Connect (OSTI)

    Guneeta, Singh-Bhalla

    2011-08-15

    Ionic crystals terminated at oppositely charged polar surfaces are inherently unstable and expected to undergo surface reconstructions to maintain electrostatic stability. Essentially, an electric field that arises between oppositely charged atomic planes gives rise to a built-in potential that diverges with thickness. Here we present evidence of such a built-in potential across polar LaAlO{sub 3} thin films grown on SrTiO{sub 3} substrates, a system well known for the electron gas that forms at the interface. By performing tunneling measurements between the electron gas and metallic electrodes on LaAlO{sub 3} we measure a built-in electric field across LaAlO{sub 3} of 80.1 meV/{angstrom}. Additionally, capacitance measurements reveal the presence of an induced dipole moment across the heterostructure. We forsee use of the ionic built-in potential as an additional tuning parameter in both existing and novel device architectures, especially as atomic control of oxide interfaces gains widespread momentum.

  19. High-cycle fatigue behavior of Ti-5Al-2.5Sn ELI alloy forging at low temperatures

    SciTech Connect (OSTI)

    Ono, Yoshinori; Yuri, Tetsumi; Ogata, Toshio; Demura, Masahiko; Matsuoka, Saburo; Sunakawa, Hideo

    2014-01-27

    High-cycle fatigue properties of Ti-5Al-2.5Sn Extra Low Interstitial (ELI) alloy forging were investigated at low temperatures. The high-cycle fatigue strength at low temperatures of this alloy was relatively low compared with that at ambient temperature. The crystallographic orientation of a facet formed at a fatigue crack initiation site was determined by electron backscatter diffraction (EBSD) method in scanning electron microscope (SEM) to understand the fatigue crack initiation mechanism and discuss on the low fatigue strength at low temperature. Furthermore, in terms of the practical use of this alloy, the effect of the stress ratio (or mean stress) on the high-cycle fatigue properties was evaluated using the modified Goodman diagram.

  20. Understanding the mechanism of conductivity at the LaAlO3/SrTiO3(001) interface

    SciTech Connect (OSTI)

    Chambers, Scott A.

    2011-07-01

    The observation of conductivity at (001)-oriented interfaces of the two band insulators LaAlO3 and SrTiO3 is both fascinating and potentially useful for next-generation electronics. The reigning paradigm to explain the conductivity phenomenon is an electronic reconstruction resulting from the instability created by forming an interface of polar and nonpolar perovskites, leading to the formation of a two-dimensional electron gas. However, the complexities introduced by the strong tendency of the cations to mix across the interface also manifest themselves in the electronic structure, and this mixing gives rise to other ways for the interface to stabilize and become conductive. In this Prospective, arguments for and against these two explanations are explored and strategies for resolving the issue are suggested.

  1. Surface Quality of Ti-6%Al-4%V ELI When Machined Using CVD-Carbide Tools at High Cutting Speed

    SciTech Connect (OSTI)

    Gusri, A. I.; Che Hassan, C. H.; Jaharah, A. G.; Yasir, A.; Zaid, Y.; Yanuar, B.

    2011-01-17

    Machining of Ti-6Al-4V ELI becomes more interested topic due to extremely weight-to-strength ratio and resistance to corrosion at elevated temperature. Quality of machined surface is presented by surface roughness, surface texture and damages of microstructure of titanium alloys. The turning parameters evaluated are cutting speed of 55-95 m/min, feed rate of 0.15-0.35 mm/rev, depth of cut of 0.10-0.20 mm and tool grade of CVD carbide tools. The results show the trend lines of surface roughness value are higher at the initial machining and the surface texture profile has a strong correlation with the feed rate. At the machining condition of cutting speed of 95 m/min, feed rate of 0.35 mm/rev and depth of cut of 0.10 mm produced the with layer with thickness of 2.0 {mu}m.

  2. Investigations on the electronic, structural, magnetic properties related to shape-memory behavior in Ti{sub 2}CoX (X=Al, Ga, In)

    SciTech Connect (OSTI)

    Wei, Xiao-Ping; Chu, Yan-Dong; Sun, Xiao-Wei; E, Yan; Deng, Jian-Bo; Xing, Yong-Zhong

    2015-02-15

    Highlights: • The analysis of phase stability trend is studied for Ti{sub 2}CoX(X = Al, Ga, In). • Ti{sub 2}CoGa is more suitable as shape memory alloy. • Total magnetic moments disappear with a increase of c/a ratio for all systems. • Density of states at the Fermi level are also shown. - Abstract: Using the full-potential local orbital minimum-basis method, we have performed a systematic investigations on the electronic, structural, and magnetic properties related to shape memory applications for Ti{sub 2}CoX (X=Al, Ga, In) alloys. Our results confirm that these alloys are half-metallic ferromagnets with total magnetic moment of 2μ{sub B} per formula unit in austenite phase, and undergo a martensitic transformation at low temperatures. The relative stabilities of the martensitic phases differ considerably between Ti{sub 2}CoX (X=Al, Ga, In). Details of the electronic structures suggest that the differences in hybridizations between the magnetic components are responsible for trends of phase. Quantitative estimates for the energetics and the magnetizations indicate that Ti{sub 2}CoGa is a promising candidate for shape memory applications.

  3. Structural Comparison of n-type and p-type LaAlO3/SrTiO3 Interfaces

    SciTech Connect (OSTI)

    Bell, Christopher

    2011-08-19

    Using a surface x-ray diffraction technique, we investigated the atomic structure of two types of interfaces between LaAlO{sub 3} and SrTiO{sub 3}, that is, p-type (SrO/AlO{sub 2}) and n-type (TiO{sub 2}/LaO) interfaces. Our results demonstrate that the SrTiO{sub 3} in the sample with the n-type interface has a large polarized region, while that with the p-type interface has a limited polarized region. In addition, the atomic intermixing was observed to extend deeper into STO substrate at the n-type interface than at the p-type. These differences result in different degrees of band bending, which likely contributes to the striking difference in electrical conductivity between the two types of interfaces.

  4. Effect of oxygen incorporation on the structure and elasticity of Ti-Al-O-N coatings synthesized by cathodic arc and high power pulsed magnetron sputtering

    SciTech Connect (OSTI)

    Hans, M. Baben, M. to; Music, D.; Ebenhch, J.; Schneider, J. M.; Primetzhofer, D.; Kurapov, D.; Arndt, M.; Rudigier, H.

    2014-09-07

    Ti-Al-O-N coatings were synthesized by cathodic arc and high power pulsed magnetron sputtering. The chemical composition of the coatings was determined by means of elastic recoil detection analysis and energy dispersive X-ray spectroscopy. The effect of oxygen incorporation on the stress-free lattice parameters and Young's moduli of Ti-Al-O-N coatings was investigated by X-ray diffraction and nanoindentation, respectively. As nitrogen is substituted by oxygen, implications for the charge balance may be expected. A reduction in equilibrium volume with increasing O concentration is identified by X-ray diffraction and density functional theory calculations of Ti-Al-O-N supercells reveal the concomitant formation of metal vacancies. Hence, the oxygen incorporation-induced formation of metal vacancies enables charge balancing. Furthermore, nanoindentation experiments reveal a decrease in elastic modulus with increasing O concentration. Based on ab initio data, two causes can be identified for this: First, the metal vacancy-induced reduction in elasticity; and second, the formation of, compared to the corresponding metal nitride bonds, relatively weak Ti-O and Al-O bonds.

  5. Interfacial reactions in epitaxial Al/TiN(111) model diffusion barriers: Formation of an impervious self-limited wurtzite-structure AIN(0001) blocking layer

    SciTech Connect (OSTI)

    Chun, J.-S.; Desjardins, P.; Lavoie, C.; Shin, C.-S.; Cabral, C.; Petrov, I.; Greene, J. E.

    2001-06-15

    Single-crystal TiN(111) layers, 45 nm thick, were grown on MgO(111) by ultrahigh vacuum reactive magnetron sputter deposition in pure N{sub 2} discharges at T{sub s}=700{degree}C. Epitaxial Al(111) overlayers, 160 nm thick, were then deposited at T{sub s}=100{degree}C in Ar without breaking vacuum. Interfacial reactions and changes in bilayer microstructure due to annealing at 620 and 650{degree}C were investigated using x-ray diffraction and transmission electron microscopy (TEM). The interfacial regions of samples annealed at 620{degree}C consist of continuous {approx_equal}7-nm-thick epitaxial wurtzite-structure AlN(0001) layers containing a high density of stacking faults, with {approx_equal}22 nm thick tetragonal Al{sub 3}Ti(112) overlayers. Surprisingly, samples annealed at the higher temperature are more stable against Al{sub 3}Ti formation. TEM analyses of bilayers annealed at 650{degree}C (10{degree}C below the Al melting point!) reveal only the self-limited growth of an {approx_equal}3-nm-thick interfacial layer of perfect smooth epitaxial wurtzite-structure AlN(0001) which serves as an extremely effective deterrent for preventing further interlayer reactions. {copyright} 2001 American Institute of Physics.

  6. Al

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    on the way to the drip line .... 31 Al 28 Mg 32 Si 12 B + 18 O 30 Al* (-pn) 28 Mg 15 C + 18 O 33 Si* (-pn) 31 Al 16 N + 18 O 34 P* (-pn) 32 Si 15 C 10 7 s...

  7. Type Ia Supernova Hubble Residuals and Host-Galaxy Properties (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect Journal Article: Type Ia Supernova Hubble Residuals and Host-Galaxy Properties Citation Details In-Document Search Title: Type Ia Supernova Hubble Residuals and Host-Galaxy Properties Kim et al. (2013) [K13] introduced a new methodology for determining peak- brightness absolute magnitudes of type Ia supernovae from multi-band light curves. We examine the relation between their parameterization of light curves and Hubble residuals, based on photometry synthesized

  8. Microstructural characterization and mechanical properties of high power ultrasonic spot welded aluminum alloy AA6111–TiAl6V4 dissimilar joints

    SciTech Connect (OSTI)

    Zhang, C.Q. Robson, J.D.; Ciuca, O.; Prangnell, P.B.

    2014-11-15

    Aluminum alloy AA6111 and TiAl6V4 dissimilar alloys were successfully welded by high power ultrasonic spot welding. No visible intermetallic reaction layer was detected in as-welded AA6111/TiAl6V4 welds, even when transmission electron microscopy was used. The effects of welding time and natural aging on peak load and fracture energy were investigated. The peak load and fracture energy of welds increased with an increase in welding time and then reached a plateau. The lap shear strength (peak load) can reach the same level as that of similar Al–Al joints. After natural aging, the fracture mode of welds transferred from ductile fracture of the softened aluminum to interfacial failure due to the strength recovery of AA6111. - Highlights: • Dissimilar Al/Ti welds were produced by high power ultrasonic spot welding. • No visible intermetallic reaction layer was detected on weld interface. • The lap shear strength can reach the same level as that of similar Al–Al joints. • The fracture mode becomes interfacial failure after natural aging.

  9. Growth and transport properties of epitaxial lattice matched half Heusler CoTiSb/InAlAs/InP(001) heterostructures

    SciTech Connect (OSTI)

    Kawasaki, Jason K.; Johansson, Linda I. M.; Schultz, Brian D.; Palmstrm, Chris J.

    2014-01-13

    We demonstrate the integration of the lattice matched single crystal epitaxial Half Heusler compound CoTiSb with In{sub 0.52}Al{sub 0.48}As/InP(001) heterostructures using molecular beam epitaxy. CoTiSb belongs to the subset of Half Heusler compounds that is expected to be semiconducting, despite being composed entirely of metallic constituents. The lattice matching and epitaxial alignment of the CoTiSb films were confirmed by reflection high energy electron diffraction and X-ray diffraction. Temperature dependent transport measurements indicate semiconducting-like behavior, with a room temperature Hall mobility of 530 cm{sup 2}/Vs and background Hall carrier density of 9.0??10{sup 17}?cm{sup ?3}, which is comparable to n-Si with similar carrier density. Below 100?K, the films show a large negative magnetoresistance, and possible origins of this negative magnetoresistance are discussed.

  10. Analysis of Wear Mechanisms in Low Friction, Nanocomposite AlMgB14-TiB2 Coatings

    SciTech Connect (OSTI)

    Cook, Bruce A; Harringa, J; Anderegg, A; Russell, A M; Qu, Jun; Blau, Peter Julian; Higdon, Clifton; Elmoursi, Alaa A

    2010-01-01

    Recent developments in coating science and technology offer new opportunities to enhance the energy-efficiency and performance of industrial machinery such as hydraulic fluid pumps and motors. The lubricated friction and wear characteristics of two wear-resistant coatings, diamond-like carbon and a nanocomposite material based on AlMgB{sub 14}-50 vol.% TiB{sub 2}, were compared in pin-on-disk tribotests using Mobil DTE-24{trademark} oil as the lubricant. In each case, the pins were fixed 9.53 mm diameter spheres of AISI 52100 steel, the load was 10 N, and the speed 0.5 m/s in all tests. Average steady-state friction coefficient values of 0.10 and 0.08 were measured for the DLC and nanocomposite, respectively. The coatings and their 52100 steel counterfaces were analyzed after the tests by X-ray photoelectron and Auger spectroscopy for evidence of material transfer or tribo-chemical reactions. The low-friction behavior of the boride nanocomposite coating is due to the formation of lubricative boric acid, B(OH){sub 3}. In contrast, the low-friction behavior of the DLC coating is related to the relatively low dielectric constant of the oil-based lubricant, leading to desorption of surface hydrogen from the coating.

  11. Improved Dark Energy Constraints From ~ 100 New CfA Supernova Type Ia Light

    Office of Scientific and Technical Information (OSTI)

    Curves (Journal Article) | SciTech Connect Improved Dark Energy Constraints From ~ 100 New CfA Supernova Type Ia Light Curves Citation Details In-Document Search Title: Improved Dark Energy Constraints From ~ 100 New CfA Supernova Type Ia Light Curves We combine the CfA3 supernovae Type Ia (SN Ia) sample with samples from the literature to calculate improved constraints on the dark energy equation of state parameter, w. The CfA3 sample is added to the Union set of Kowalski et al. to form the

  12. Wear Mechanism of Chemical Vapor Deposition (CVD) Carbide Insert in Orthogonal Cutting Ti-6Al-4V ELI at High Cutting Speed

    SciTech Connect (OSTI)

    Gusri, A. I.; Che Hassan, C. H.; Jaharah, A. G.

    2011-01-17

    The performance of Chemical Vapor Deposition (CVD) carbide insert with ISO designation of CCMT 12 04 04 LF, when turning titanium alloys was investigated. There were four layers of coating materials for this insert i.e.TiN-Al2O3-TiCN-TiN. The insert performance was evaluated based on the insert's edge resistant towards the machining parameters used at high cutting speed range of machining Ti-6Al-4V ELI. Detailed study on the wear mechanism at the cutting edge of CVD carbide tools was carried out at cutting speed of 55-95 m/min, feed rate of 0.15-0.35 mm/rev and depth of cut of 0.10-0.20 mm. Wear mechanisms such as abrasive and adhesive were observed on the flank face. Crater wear due to diffusion was also observed on the rake race. The abrasive wear occurred more at nose radius and the fracture on tool were found at the feed rate of 0.35 mm/rev and the depth of cut of 0.20 mm. The adhesion wear takes place after the removal of the coating or coating delaminating. Therefore, adhesion or welding of titanium alloy onto the flank and rake faces demonstrates a strong bond at the workpiece-tool interface.

  13. Oxynitrided Surface Layer Produced On Ti6Al4V Titanium Alloy Under Low Temperature Glow Discharge Conditions For Medical Applications

    SciTech Connect (OSTI)

    Wierzchon, T.; Ossowski, M.; Borowski, T.; Morgiel, J.; Czarnowska, E.

    2011-01-17

    In spite that titanium oxides increase biocompatibility of titanium implants but their functional life is limited due to the problems arising from brittles and metalosis. Therefore technology, that allow to produce composite surface layer with controlled microstructure, chemical and phase composition and surface morphology on titanium alloy and eliminates the oxides disadvantages has been existing till now is searched. The requirements of titanium and its alloys implants can be fulfill by the low-temperature glow discharge assisted oxynitriding.The paper describes the surface layer of TiO{sub 2}+TiN+Ti{sub 2}N+{alpha}Ti(N) type produced at temperature 680 deg. C that preserves mechanical properties of titanium alloy Ti6Al4V. Characteristics of produced diffusion multi-phase surface layers in range of phase composition, microstructure (SEM, TEM, XRD) and its properties, such as frictional wear resistance are presented. The biological properties in dependency to the applied sterilization method are also analyzed.Properties of produced surface layers are discussed with reference to titanium alloy. The obtained data show that produced surface layers improves titanium alloy properties both frictional wear and biological. Preliminary in vitro examinations show good biocompatibility and antithrombogenic properties.

  14. Improvement in performance of electrically tunable devices based on nonlinear dielectric SrTiO{sub 3} using a homoepitaxial LaAlO{sub 3} interlayer

    SciTech Connect (OSTI)

    Jia, Q.X.; Findikoglu, A.T.; Reagor, D.; Lu, P.

    1998-08-01

    Improved structural and dielectric properties of nonlinear dielectric SrTiO{sub 3} thin films on LaAlO{sub 3} substrates were accomplished by incorporating a {ital homoepitaxial} LaAlO{sub 3} interlayer between the substrate and the dielectric film. Using this interlayer, the quality factor of SrTiO{sub 3} films with high-temperature superconducting YBa{sub 2}Cu{sub 3}O{sub 7{minus}x} electrodes on LaAlO{sub 3} substrates was improved by more than 50{percent} at 4.2 GHz and 4 K. This improvement, combined with no change in nonlinearity, led to greater than a 50{percent} enhancement of the finesse factor (defined as the product of the quality factor and the fractional shift resonant frequency) for the coplanar waveguide microwave resonators. The reduced planar defect density in the SrTiO{sub 3} films was attributed to this improvement. {copyright} {ital 1998 American Institute of Physics.}

  15. Defining photometric peculiar type Ia supernovae

    SciTech Connect (OSTI)

    Gonzlez-Gaitn, S.; Pignata, G.; Frster, F.; Gutirrez, C. P.; Bufano, F.; Galbany, L.; Hamuy, M.; De Jaeger, T. [Millennium Institute of Astrophysics, Casilla 36-D, Santiago (Chile); Hsiao, E. Y.; Phillips, M. M. [Carnegie Observatories, Las Campanas Observatory, Casilla 601, La Serena (Chile); Folatelli, G. [Kavli Institute for the Physics and Mathematics of the Universe, the University of Tokyo, Kashiwa 277-8583 (Kavli IPMU, WPI) (Japan); Anderson, J. P., E-mail: sgonzale@das.uchile.cl [European Southern Observatory, Alonso de Crdova 3107, Casilla 19, Santiago (Chile)

    2014-11-10

    We present a new photometric identification technique for SN 1991bg-like type Ia supernovae (SNe Ia), i.e., objects with light curve characteristics such as later primary maxima and the absence of a secondary peak in redder filters. This method is capable of selecting this sub-group from the normal type Ia population. Furthermore, we find that recently identified peculiar sub-types such as SNe Iax and super-Chandrasekhar SNe Ia have photometric characteristics similar to 91bg-like SNe Ia, namely, the absence of secondary maxima and shoulders at longer wavelengths, and can also be classified with our technique. The similarity of these different SN Ia sub-groups perhaps suggests common physical conditions. This typing methodology permits the photometric identification of peculiar SNe Ia in large upcoming wide-field surveys either to study them further or to obtain a pure sample of normal SNe Ia for cosmological studies.

  16. Category:Mason, IA | Open Energy Information

    Open Energy Info (EERE)

    Mason, IA Jump to: navigation, search Go Back to PV Economics By Location Media in category "Mason, IA" The following 16 files are in this category, out of 16 total....

  17. Excellent Passivation and Low Reflectivity Al2O3/TiO2 Bilayer Coatings for n-Wafer Silicon Solar Cells: Preprint

    SciTech Connect (OSTI)

    Lee, B. G.; Skarp, J.; Malinen, V.; Li, S.; Choi, S.; Branz, H. M.

    2012-06-01

    A bilayer coating of Al2O3 and TiO2 is used to simultaneously achieve excellent passivation and low reflectivity on p-type silicon. This coating is targeted for achieving high efficiency n-wafer Si solar cells, where both passivation and anti-reflection (AR) are needed at the front-side p-type emitter. It could also be valuable for front-side passivation and AR of rear-emitter and interdigitated back contact p-wafer cells. We achieve high minority carrier lifetimes {approx}1 ms, as well as a nearly 2% decrease in absolute reflectivity, as compared to a standard silicon nitride AR coating.

  18. THE BIRTH RATE OF SNe Ia FROM HYBRID CONe WHITE DWARFS

    SciTech Connect (OSTI)

    Meng, Xiangcun [Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011 (China); Podsiadlowski, Philipp, E-mail: xiangcunmeng@ynao.ac.cn [Department of Astronomy, Oxford University, Oxford OX1 3RH (United Kingdom)

    2014-07-10

    Considering the uncertainties of the C-burning rate (CBR) and the treatment of convective boundaries, Chen et al. found that there is a regime where it is possible to form hybrid CONe white dwarfs (WDs), i.e., ONe WDs with carbon-rich cores. As these hybrid WDs can be as massive as 1.30 M {sub ?}, not much mass needs to be accreted for these objects to reach the Chandrasekhar limit and to explode as Type Ia supernovae (SNe Ia). We have investigated their contribution to the overall SN Ia birth rate and found that such SNe Ia tend to be relatively young with typical time delays between 0.1 and 1 Gyr, where some may be as young as 30 Myr. SNe Ia from hybrid CONe WDs may contribute several percent to all SNe Ia, depending on the common-envelope ejection efficiency and the CBR. We suggest that these SNe Ia may produce part of the 2002cx-like SN Ia class.

  19. Instability, intermixing and electronic structure at the epitaxial LaAlO3/SrTiO3(001) heterojunction

    SciTech Connect (OSTI)

    Chambers, Scott A.; Engelhard, Mark H.; Shutthanandan, V.; Zhu, Zihua; Droubay, Timothy C.; Qiao, Liang; Sushko, P. V.; Feng, Tian; Lee, Hang Don; Gustafsson, Torgny; Garfunkel, Eric; Shah, A.B,; Zuo, J. M.; Ramasse, Q. M.

    2010-10-18

    The question of stability against diffusional mixing at the prototypical LaAlO3/SrTiO3(001) interface is explored using a multi-faceted experimental and theoretical approach. We combine analytical methods with a range of sensitivities to elemental concentrations and spatial separations to investigate interfaces grown using onaxis pulsed laser deposition. We also employ computational modeling based on the density function theory as well as classical force fields to explore the energetic stability of a wide variety of intermixed atomic configurations relative to the idealized, atomically abrupt model. Statistical analysis of the calculated energies for the various configurations is used to elucidate the relative thermodynamic stability of intermixed and abrupt configurations. We find that on both experimental and theoretical fronts, the tendency toward intermixing is very strong. We have also measured and calculated key electronic properties such as potential energy gradients and valence band discontinuity at the interface. We find no measurable electric field in either the LaAlO3 or SrTiO3, and that the valence band offset is near zero, partitioning the band discontinuity almost entirely to the conduction band edge. Significantly, we find it is not possible to account for these electronic properties theoretically without including extensive intermixing in our physical model of the interface. The atomic configurations which give the greatest electrostatic stability are those that eliminate the interface dipole by intermixing, calling into question the conventional explanation for conductivity at this interface electronic reconstruction. Rather, evidence is presented for La indiffusion and doping of the SrTiO3 below the interface as being the cause of the observed conductivity.

  20. Potential-well depth at amorphous-LaAlO{sub 3}/crystalline-SrTiO{sub 3} interfaces measured by optical second harmonic generation

    SciTech Connect (OSTI)

    De Luca, Gabriele; Rubano, Andrea; Gennaro, Emiliano di; Khare, Amit; Granozio, Fabio Miletto; Uccio, Umberto Scotti di; Marrucci, Lorenzo; Paparo, Domenico

    2014-06-30

    By a combination of optical second harmonic generation and transport measurements, we have investigated interfaces formed by either crystalline or amorphous thin films of LaAlO{sub 3} grown on TiO{sub 2}-terminated SrTiO{sub 3}(001) substrates. Our approach aims at disentangling the relative role of intrinsic and extrinsic doping mechanisms in the formation of the two-dimensional electron gas. The different nature of the two mechanisms is revealed when comparing the sample response variation as a function of temperature during annealing in air. However, before the thermal treatment, the two types of interfaces show almost the same intensity of the second harmonic signal, provided the overlayer thickness is the same. As we will show, the second harmonic signal is proportional to the depth of the potential well confining the charges at the interface. Therefore, our result demonstrates that this depth is about the same for the two different material systems. This conclusion supports the idea that the electronic properties of the two-dimensional electron gas are almost independent of the doping mechanism of the quantum well.

  1. Enhancing mid-infrared spectral response at the LaAlO{sub 3}/SrTiO{sub 3} interface by magnetic field

    SciTech Connect (OSTI)

    Feng, Xin; Zhao, Kun Xi, Jian-Feng; Xiang, Wen-Feng; Lu, Zhi-Qing; Sun, Qi; Wu, Shi-Xiang; Ni, Hao

    2014-12-15

    Many unexpected properties have been found in the LaAlO{sub 3}/SrTiO{sub 3} heterostructure, but the interaction of the many ground states at its interface remains unclear. Here, we demonstrate an optical property of this n-type heterostructure where the mid-infrared spectral responsivity at the interface is enhanced by an external magnetic field. The field intensity ranged from 0.8 to 6 kOe at a low temperature (19 K) as measured with our spectral response measurement system. Two spectral peaks related to the spin-orbit coupling effect were also observed at wavelengths 2400 nm and 3700 nm. The intriguing phenomena relate to changes in the crystallographic structure and subband structure at the interface.

  2. Role of oxygen vacancies in magnetic properties of LaAlO{sub 3}/SrTiO{sub 3} interface

    SciTech Connect (OSTI)

    Mohanta, N.; Taraphder, A.

    2014-04-24

    The interface of two band-insulators SrTiO{sub 3} and LaAlO{sub 3} exhibits a highly conducting two-dimensional electron gas which shows low-temperature superconductivity, ferromagnetism and many other novel properties. Several studies reveal that the oxygen vacancies at the interface have strong influence on the electronic and magnetic properties of the interface electrons. Here, we develop an insight into the effects of oxygen vacancies on the magnetic properties of the system; the oxygen vacancies help in establishing ferromagnetism which competes with superconductivity at low temperatures. Simulated Monte-Carlo annealing suggests an ordering of the oxygen vacant sites and sheds light on the experimental observation of the quenching of magnetic moment on annealing. A possible explanation for the coexistence of superconductivity and ferromagnetism is also discussed.

  3. Sweetspot: Near-infrared observations of 13 type Ia supernovae...

    Office of Scientific and Technical Information (OSTI)

    We present 13 Type Ia supernovae (SNe Ia) observed in the rest-frame near-infrared (NIR) ... Our sample includes two SNe Ia at z 0.09, which represent the most distant rest-frame ...

  4. Tunability of conduction at the LaAlO{sub 3}/SrTiO{sub 3} heterointerface: Thickness and compositional studies

    SciTech Connect (OSTI)

    Breckenfeld, E.; Bronn, N.; Mason, N.; Martin, L. W.

    2014-09-22

    The role of chemistry, film thickness, and oxygen pressure in influencing the electrical and thermal transport properties of LaAlO{sub 3}/SrTiO{sub 3} heterointerfaces is explored. Unit-cell precise growth was accomplished for films between 3 and 160 unit cells thick using reflection high-energy electron diffraction-assisted pulsed-laser deposition. Subsequent temperature-dependent studies of electrical resistivity reveal three important observations: (1) by tuning the laser fluence, we can systematically tune the interfacial conductance in a step-wise manner in this system, (2) all films exhibit a critical thickness of 34 unit cells for the onset of conduction, and (3) the nature of the conductance is highly influenced by the stoichiometry of the LaAlO{sub 3} film with La-deficient samples showing dramatic changes with thickness, while stoichiometric and La-excess films show little dependence. Time-domain thermoreflectance studies show a diminished interfacial thermal conductance for the La-deficient films when compared to La-excess and stoichiometric films, suggesting that the interfacial conductance is more influenced by extrinsic factors such as oxygen deficiency.

  5. Band alignment of epitaxial SrTiO3 thin films with (LaAlO3)0.3-(Sr2AlTaO6)0.7 (001)

    SciTech Connect (OSTI)

    Comes, Ryan B.; Xu, Peng; Jalan, Bharat; Chambers, Scott A.

    2015-09-28

    SrTiO3 (STO) epitaxial thin films and heterostructures are of considerable interest due to the wide range of functionalities they exhibit. The alloy perovskite (LaAlO3)0.3-(Sr2AlTaO6)0.7 (LSAT) is commonly used as a substrate for these material structures due to its structural compatibility. However, surprisingly little is known about the electronic properties of the STO/LSAT interface despite its potentially important role in affecting the overall electronic structure of system. We examine the band alignment of STO/LSAT heterostructures using x-ray photoelectron spectroscopy for epitaxial STO films deposited using two different molecular beam epitaxy approaches. We find that the valence band offset ranges from +0.2(1) eV to -0.2(1) eV depending on surface conditions for the film and substrate. From these results we extract a conduction band offset from -2.4(1) eV to -2.8(1) eV, indicating that the conduction band edge is more deeply bound in STO and that LSAT will not act as a sink or trap for electrons in the supported film or multilayer.

  6. Constraining Cosmic Evolution of Type Ia Supernovae (Journal...

    Office of Scientific and Technical Information (OSTI)

    Constraining Cosmic Evolution of Type Ia Supernovae Citation Details In-Document Search Title: Constraining Cosmic Evolution of Type Ia Supernovae We present the first large-scale...

  7. Constraining Cosmic Evolution of Type Ia Supernovae (Journal...

    Office of Scientific and Technical Information (OSTI)

    Constraining Cosmic Evolution of Type Ia Supernovae Citation Details In-Document Search Title: Constraining Cosmic Evolution of Type Ia Supernovae You are accessing a document...

  8. ASTRONOMY AND ASTROPHYSICS Dark Energy, Type Ia supernovae, radiative

    Office of Scientific and Technical Information (OSTI)

    of Oklahoma Univ. of Oklahoma 79 ASTRONOMY AND ASTROPHYSICS Dark Energy, Type Ia supernovae, radiative transfer, Dark Energy, Type Ia supernovae, radiative transfer, The...

  9. Study of the microstructure of plasma sprayed coatings obtained from Al{sub 2}O{sub 3}13TiO{sub 2} nanostructured and conventional powders

    SciTech Connect (OSTI)

    Gral, A.; ?rawski, W.; Lity?ska-Dobrzy?ska, L.

    2014-10-15

    The microstructure of coatings obtained from nanostructured or conventional Al{sub 2}O{sub 3}13TiO{sub 2} powders and deposited by plasma spraying technique on low-carbon steel was examined by transmission electron microscopy techniques. The dominating phase in both coatings was ?-Al{sub 2}O{sub 3} phase. It has been observed that the grains of ?-Al{sub 2}O{sub 3} grew in various shapes and sizes, that are particularly visible in the case of coating sprayed from nanostructured powder. The coatings obtained from the fully melted conventional powders exhibited a typical lamellar microstructure, into which the strips of TiO{sub 2} phase were extended. The microstructure of coatings produced from agglomerates of nanostructured particles also revealed the regions consisting of partially melted ?-Al{sub 2}O{sub 3} powders surrounded by the net-like structure formed from fully melted oxides that improved the coating properties. Along with the observed morphology diversity some changes in the chemical composition on the cross sections of obtained coatings have been also noticed. - Highlights: Plasma sprayed Al{sub 2}O{sub 3}13TiO{sub 2} coatings reveal diversity of microstructure. Microstructure of conventional coating was formed from fully melted crushed powders. Nanostructured coating contains completely and partially melted initial agglomerates.

  10. Structural and magnetic properties of Co{sub 2}Ti{sub 1−x}Fe{sub x}Al (0 ≤ x ≤ 0.5) alloys

    SciTech Connect (OSTI)

    Pal, Lakhan Gupta, Sachin Suresh, K. G.

    2014-04-24

    In this work we studied the effect of partial Fe substitution for Ti on the structural and magnetic properties of the Co{sub 2}TiAl. X-ray diffraction analysis indicates the presence of B2 type disorder for x > 0, (111) reflections are absent for x > 0 which is the characteristic of B2 type disorder. XRD analysis also shows presence of second phase. Magnetization measurements also confirm the presence of dual phase. Curie temperature of the alloys increases with increase in Fe concentration. Saturation magnetic moments agree very well with those calculated by Slater-Pauling rule.

  11. Type Ia Supernovae Project at NERSC

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of star called a white dwarf. The majority of SN Ia explosions occur far away from our galaxy; yet, due to their enormous intrinsic brightness, outshining billions of stars, we can...

  12. IA Blog Archive | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    "always be five years away." For four key clean energy technologies, that clean energy future has already arrived. August 21, 2013 IA Blog Archive ActOnClimate: Secretary...

  13. Effects of the microstructure and porosity on properties of Ti-6Al-4V ELI alloy fabricated by electron beam melting (EBM)

    SciTech Connect (OSTI)

    Galarraga, Haize; Lados, Diana A.; Dehoff, Ryan R.; Kirka, Michael M.; Nandwana, Peeyush

    2016-01-01

    Electron Beam Melting (EBM) is a metal powder bed-based Additive Manufacturing (AM) technology that makes possible the fabrication of three dimensional near-net-shaped parts directly from computer models. EBM technology has been in continuously updating, obtaining optimized properties of the processed alloys. Ti-6Al-4V titanium alloy is the most widely used and studied alloy for this technology and is the focus of this work. Several research works have been completed to study the mechanisms of microstructure formation as well as its influence on mechanical properties. However, the relationship is not completely understood, and more systematic research work is necessary in order to attain a better understanding of these features. In this work, samples fabricated at different locations, orientations, and distances from the build platform have been characterized, studying the relationship of these variables with the resulting material intrinsic characteristics and properties (surface topography, microstructure, porosity, micro-hardness and static mechanical properties). This study has revealed that porosity is the main factor controlling mechanical properties relative to the other studied variables. Therefore, in future process developments, decreasing of the porosity should be considered as the primary goal in order to improve mechanical properties.

  14. Effects of the microstructure and porosity on properties of Ti-6Al-4V alloy fabricated by Electron Beam Melting (EBM)

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Galarraga, Haize; Lados, Diana; Dehoff, Ryan R; Kirka, Michael M; Nandwana, Peeyush

    2016-01-01

    Electron Beam Melting (EBM) is a metal powder bed-based Additive Manufacturing (AM) technology that makes possible the fabrication of three dimensional near-net-shaped parts directly from computer models. EBM technology has been in continuously updating, obtaining optimized properties of the processed alloys. Ti-6Al-4V titanium alloy is the most widely used and studied alloy for this technology and is the focus of this work. Several research works have been completed to study the mechanisms of microstructure formation as well as its influence on mechanical properties. However, the relationship is not completely understood, and more systematic research work is necessary in order tomoreattain a better understanding of these features. In this work, samples fabricated at different locations, orientations, and distances from the build platform have been characterized, studying the relationship of these variables with the resulting material intrinsic characteristics and properties (surface topography, microstructure, porosity, micro-hardness and static mechanical properties). This study has revealed that porosity is the main factor controlling mechanical properties relative to the other studied variables. Therefore, in future process developments, decreasing of the porosity should be considered as the primary goal in order to improve mechanical properties.less

  15. Effects of the microstructure and porosity on properties of Ti-6Al-4V ELI alloy fabricated by electron beam melting (EBM)

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Galarraga, Haize; Lados, Diana A.; Dehoff, Ryan R.; Kirka, Michael M.; Nandwana, Peeyush

    2016-01-01

    Electron Beam Melting (EBM) is a metal powder bed-based Additive Manufacturing (AM) technology that makes possible the fabrication of three dimensional near-net-shaped parts directly from computer models. EBM technology has been in continuously updating, obtaining optimized properties of the processed alloys. Ti-6Al-4V titanium alloy is the most widely used and studied alloy for this technology and is the focus of this work. Several research works have been completed to study the mechanisms of microstructure formation as well as its influence on mechanical properties. However, the relationship is not completely understood, and more systematic research work is necessary in order tomore » attain a better understanding of these features. In this work, samples fabricated at different locations, orientations, and distances from the build platform have been characterized, studying the relationship of these variables with the resulting material intrinsic characteristics and properties (surface topography, microstructure, porosity, micro-hardness and static mechanical properties). This study has revealed that porosity is the main factor controlling mechanical properties relative to the other studied variables. Therefore, in future process developments, decreasing of the porosity should be considered as the primary goal in order to improve mechanical properties.« less

  16. Polar asymmetry of La{sub (1−δ)}Al{sub (1+δ)}O{sub 3}/SrTiO{sub 3} heterostructures probed by optical second harmonic generation

    SciTech Connect (OSTI)

    Rubano, Andrea; De Luca, Gabriele; Marrucci, Lorenzo; Paparo, Domenico; Schubert, Jürgen; Wang, Zhe; Zhu, Shaobo; Schlom, Darrell G.

    2015-09-07

    By combining transport measurements and optical second harmonic generation, we have investigated heterostructures formed between crystalline thin films of LaAlO{sub 3}, with varying stoichiometry and TiO{sub 2}-terminated SrTiO{sub 3}(001) substrates. Optical second harmonic generation directly probes the polarity of these heterostructures, thus complementing the transport data. The stoichiometry and the growth temperature are found to be critical parameters for controlling both the interfacial conductivity and the heterostructure polarity. In agreement with the previous work, all of the samples display an insulator-to-metal transition in the Al-reach region, with the conductivity first increasing and then saturating at the highest Al/La ratios. The second harmonic signal also increases as a function of the Al/La ratio, but, at the highest growth temperature, it does not saturate. This unusual behavior is consistent with the formation of an ordered structure of defect dipoles in the LaAlO{sub 3} film caused by the off-centering of excess Al atoms in agreement with the theory.

  17. On the effect of deep-rolling and laser-peening on the stress-controlled low- and high-cycle fatigue behavior of Ti-6Al-4V at elevated temperatures up to 550?C

    SciTech Connect (OSTI)

    Ritchie, IAltenberger, RKNalla, YSano LWagner, RO

    2012-04-01

    The effect of surface treatment on the stress/life fatigue behavior of a titanium Ti-6Al-4V turbine fan blade alloy is investigated in the regime of 102 to 106 cycles to failure under fully reversed stress-controlled isothermal push-pull loading between 25? and 550?C at a frequency of 5 Hz. Specifically, the fatigue behavior was examined in specimens in the deep-rolled and laser-shock peened surface conditions, and compared to results on samples in the untreated (machined and stress annealed) condition. Although the fatigue resistance of the Ti-6Al-4V alloy declined with increasing test temperature regardless of surface condition, deep-rolling and laser-shock peening surface treatments were found to extend the fatigue lives by factors of more than 30 and 5-10, respectively, in the high-cycle and low-cycle fatigue regimes at temperatures as high as 550?C. At these temperatures, compressive residual stresses are essentially relaxed; however, it is the presence of near-surface work hardened layers, with a nanocystalline structure in the case of deep-rolling and dense dislocation tangles in the case of laser-shock peening, which remain fairly stable even after cycling at 450?-550?C, that provide the basis for the beneficial role of mechanical surface treatments on the fatigue strength of Ti-6Al-4V at elevated temperatures.

  18. DOE - Office of Legacy Management -- Titus Metals - IA 04

    Office of Legacy Management (LM)

    Designated Name: Not Designated Alternate Name: None Location: Waterloo , Iowa IA.04-1 Evaluation Year: 1987 IA.04-2 Site Operations: Extruded uranium billets to produce fuel ...

  19. Optical and ultraviolet observations of the narrow-lined type Ia SN 2012fr in NGC 1365

    SciTech Connect (OSTI)

    Zhang, Ju-Jia; Bai, Jin-Ming; Wang, Bo; Liu, Zheng-Wei [Yunnan Observatories (YNAO), Chinese Academy of Sciences, Kunming 650011 (China); Wang, Xiao-Feng; Zhao, Xu-Lin; Chen, Jun-Cheng [Physics Department and Tsinghua Center for Astrophysics (THCA), Tsinghua University, Beijing 100084 (China); Zhang, Tian-Meng, E-mail: jujia@ynao.ac.cn, E-mail: baijinming@ynao.ac.cn, E-mail: wang_xf@mail.tsinghua.edu.cn [National Astronomical Observatories of China (NAOC), Chinese Academy of Sciences, Beijing 100012 (China)

    2014-07-01

    Extensive optical and ultraviolet (UV) observations of the type Ia supernova (SN Ia) 2012fr are presented in this paper. It has a relatively high luminosity, with an absolute B-band peak magnitude of about 19.5 mag and a smaller post-maximum decline rate than normal SNe Ia (e.g., ?m {sub 15}(B) =0.85 0.05 mag). Based on the UV and optical light curves, we derived that a {sup 56}Ni mass of about 0.88 M {sub ?} was synthesized in the explosion. The earlier spectra are characterized by noticeable high-velocity features of Si II ?6355 and Ca II with velocities in the range of ?22, 000-25, 000 km s{sup 1}. At around the maximum light, these spectral features are dominated by the photospheric components which are noticeably narrower than normal SNe Ia. The post-maximum velocity of the photosphere remains almost constant at ?12,000 km s{sup 1} for about one month, reminiscent of the behavior of some luminous SNe Ia like SN 1991T. We propose that SN 2012fr may represent a subset of the SN 1991T-like SNe Ia viewed in a direction with a clumpy or shell-like structure of ejecta, in terms of a significant level of polarization reported in Maund et al. in 2013.

  20. IA Blog Archive | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Blog Archive IA Blog Archive RSS March 10, 2016 President Obama and Canadian Prime Minister Justin Trudeau at the White House in Washington. | Photo courtesy of the Government of Canada. How the U.S. and Canada are Fighting Climate Change Together Learn how the U.S. and Canada are partnering to build a stronger clean energy future. February 10, 2016 DOE Joins Pakistan's Energy Ministries to Launch $3 Million Program to support Pakistan's Energy Development Department of Energy Assistant

  1. IA News Archive | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    News Archive IA News Archive RSS April 14, 2016 Statement on First Meeting of the United States-Republic of Korea High Level Bilateral Commission Deputy Secretary of Energy Elizabeth Sherwood-Randall and Republic of Korea Vice Foreign Minister Cho Tae-Yul co-chaired the first meeting of the U.S.-ROK High Level Bilateral Commission in Seoul, South Korea. November 23, 2015 Energy Department Announces Six Clean Energy Projects through Partnership with Israel U.S. Department of Energy and Israel's

  2. HUBBLE RESIDUALS OF NEARBY TYPE Ia SUPERNOVAE ARE CORRELATED...

    Office of Scientific and Technical Information (OSTI)

    Host galaxy measurements will yield improved distances to SNe Ia. less Authors: Kelly, Patrick L. ; Burke, David L. 1 ; Hicken, Malcolm ; Mandel, Kaisey S. ; Kirshner, Robert ...

  3. Turbulence-Flame Interactions in Type Ia Supernovae (Journal Article) |

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Journal Article: Turbulence-Flame Interactions in Type Ia Supernovae Citation Details In-Document Search Title: Turbulence-Flame Interactions in Type Ia Supernovae The large range of time and length scales involved in type Ia supernovae (SN Ia) requires the use of flame models. As a prelude to exploring various options for flame models, we consider, in this paper, high-resolution three-dimensional simulations of the small-scale dynamics of nuclear flames in the supernova

  4. Structure and Electrochemistry of LiNi1/3Co1/3-yMyMn1/3O2 (M=Ti, Al, Fe) Positive Electrode Materials

    SciTech Connect (OSTI)

    Wilcox, James; Patoux, Sebastien; Doeff, Marca

    2009-01-14

    A series of materials based on the LiNi1/3Co1/3-yMyMn1/3O2 (M = Ti,Al,Fe) system has been synthesized and examined structurally and electrochemically. It is found that the changes in electrochemical performance depend highly on the nature of the substituting atom and its effect on the crystal structure. Substitution with small amounts of Ti4+ (y = 1/12) leads to the formation of a high-capacity and high-rate positive electrode material. Iron substituted materials suffer from an increased antisite defect concentration and exhibit lower capacities and poor rate capabilities. Single-phase materials are found for LiNi1/3Co1/3-yAlyMn1/3O2 when y<_ 1/4 and all exhibit decreased capacities when cycled to 4.3 V. However, an increase in rate performance and cycle stability upon aluminum substitution is correlated with an improved lamellar structure.

  5. Microstructure and dielectric properties of Ba{sub 1-x}Sr{sub x}TiO{sub 3} films grown on LaAlO{sub 3} substrates

    SciTech Connect (OSTI)

    Gim, Y.; Hudson, T.; Fan, Y.; Kwon, C.; Findikoglu, A. T.; Gibbons, B. J.; Park, B. H.; Jia, Q. X.

    2000-08-21

    We report a systematic study of the microstructure and dielectric properties of barium strontium titanate, Ba{sub 1-x}Sr{sub x}TiO{sub 3}, films grown by laser ablation on LaAlO{sub 3} substrates, where x=0.1-0.9 at an interval of 0.1. X-ray diffraction analysis shows that when x<0.4, the longest unit-cell axis is parallel to the plane of the substrate but perpendicular as x approaches 1. Dielectric constant versus temperature measurements show that the relative dielectric constant has a maximum value and that the peak temperatures corresponding to the maximum relative dielectric constant are about 70 degree sign C higher when x{<=}0.4 but similar when x>0.4, compared with the peak temperatures of the bulk Ba{sub 1-x}Sr{sub x}TiO{sub 3}. At room temperature, the dielectric constant and tunability are relatively high when x{<=}0.4 but start to decrease rapidly as x increases. (c) 2000 American Institute of Physics.

  6. The Distant Type Ia Supernova Rate

    DOE R&D Accomplishments [OSTI]

    Pain, R.; Fabbro, S.; Sullivan, M.; Ellis, R. S.; Aldering, G.; Astier, P.; Deustua, S. E.; Fruchter, A. S.; Goldhaber, G.; Goobar, A.; Groom, D. E.; Hardin, D.; Hook, I. M.; Howell, D. A.; Irwin, M. J.; Kim, A. G.; Kim, M. Y.; Knop, R. A.; Lee, J. C.; Perlmutter, S.; Ruiz-Lapuente, P.; Schahmaneche, K.; Schaefer, B.; Walton, N. A.

    2002-05-28

    We present a measurement of the rate of distant Type Ia supernovae derived using 4 large subsets of data from the Supernova Cosmology Project. Within this fiducial sample, which surveyed about 12 square degrees, thirty-eight supernovae were detected at redshifts 0.25--0.85. In a spatially flat cosmological model consistent with the results obtained by the Supernova Cosmology Project, we derive a rest-frame Type Ia supernova rate at a mean red shift z {approx_equal} 0.55 of 1.53 {sub -0.25}{sub -0.31}{sup 0.28}{sup 0.32} x 10{sup -4} h{sup 3} Mpc{sup -3} yr{sup -1} or 0.58{sub -0.09}{sub -0.09}{sup +0.10}{sup +0.10} h{sup 2} SNu(1 SNu = 1 supernova per century per 10{sup 10} L{sub B}sun), where the first uncertainty is statistical and the second includes systematic effects. The dependence of the rate on the assumed cosmological parameters is studied and the redshift dependence of the rate per unit comoving volume is contrasted with local estimates in the context of possible cosmic star formation histories and progenitor models.

  7. Friction behavior of a multi-interface system and improved performance by AlMgB14–TiB2–C and diamond-like-carbon coatings

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Qu, Jun; Blau, Peter J.; Higdon, Clifton; Cook, Bruce A.

    2016-03-29

    We investigated friction behavior of a bearing system with two interfaces involved: a roller component experiencing rolling–sliding interaction against twin cylinders under point contacts while simultaneously undergoing pure sliding interaction against a socket under a conformal contact. Lubrication modeling predicted a strong correlation between the roller's rolling condition and the system's friction behavior. Experimental observations first validated the analytical predictions using steel and iron components. Diamond-like-carbon (DLC) coating and AlMgB14–TiB2 coating with a carbon topcoat (BAMC) were then applied to the roller and twin cylinders, respectively. In conclusion, testing and analysis results suggest that the coatings effectively decreased the slipmore » ratio for the roller–cylinder contact and the sliding friction at both bearing interfaces and, as a result, significantly reduced the system frictional torque.« less

  8. Search for surviving companions in type Ia supernova remnants

    SciTech Connect (OSTI)

    Pan, Kuo-Chuan; Ricker, Paul M.; Taam, Ronald E. E-mail: pmricker@illinois.edu E-mail: taam@asiaa.sinica.edu.tw

    2014-09-01

    The nature of the progenitor systems of type Ia supernovae (SNe Ia) is still unclear. One way to distinguish between the single-degenerate scenario and double-degenerate scenario for their progenitors is to search for the surviving companions (SCs). Using a technique that couples the results from multi-dimensional hydrodynamics simulations with calculations of the structure and evolution of main-sequence- (MS-) and helium-rich SCs, the color and magnitude of MS- and helium-rich SCs are predicted as functions of time. The SC candidates in Galactic type Ia supernova remnants (Ia SNR) and nearby extragalactic Ia SNRs are discussed. We find that the maximum detectable distance of MS SCs (helium-rich SCs) is 0.6-4 Mpc (0.4-16 Mpc), if the apparent magnitude limit is 27 in the absence of extinction, suggesting that the Large and Small Magellanic Clouds and the Andromeda Galaxy are excellent environments in which to search for SCs. However, only five Ia SNRs have been searched for SCs, showing little support for the standard channels in the singe-degenerate scenario. To better understand the progenitors of SNe Ia, we encourage the search for SCs in other nearby Ia SNRs.

  9. THE ULTRAVIOLET BRIGHTEST TYPE Ia SUPERNOVA 2011de

    SciTech Connect (OSTI)

    Brown, Peter J., E-mail: pbrown@physics.tamu.edu [George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A and M University, Department of Physics and Astronomy, 4242 TAMU, College Station, TX 77843 (United States)

    2014-11-20

    We present and discuss the ultraviolet (UV)/optical photometric light curves and absolute magnitudes of the TypeIa supernova (SN Ia) 2011de from the Swift Ultraviolet/Optical Telescope. We find it to be the UV brightest SN Ia yet observedmore than a factor of 10 brighter than normal SNe Ia in the mid-ultraviolet. We find that the UV/optical brightness and broad light curve evolution can be modeled with additional flux from the shock of the ejecta hitting a relatively large red giant companion separated by 6 10{sup 13} cm. However, the post-maximum behavior of other UV-bright SNe Ia can also be modeled in a similar manner, including objects with UV spectroscopy or pre-maximum photometry which is inconsistent with this model. This suggests that similar UV luminosities can be intrinsic or caused by other forms of shock interaction. The high velocities reported for SN 2011de make it distinct from the UV-bright ''super-Chandrasekhar'' SNe Ia and the NUV-blue group of normal SNe Ia. SN 2011de is an extreme example of the UV variations in SNe Ia.

  10. DIVERSITY OF TYPE Ia SUPERNOVAE IMPRINTED IN CHEMICAL ABUNDANCES

    SciTech Connect (OSTI)

    Tsujimoto, Takuji [National Astronomical Observatory of Japan, Mitaka-shi, Tokyo 181-8588 (Japan); Shigeyama, Toshikazu, E-mail: taku.tsujimoto@nao.ac.jp [Research Center for the Early Universe, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2012-12-01

    A time delay of Type Ia supernova (SN Ia) explosions hinders the imprint of their nucleosynthesis on stellar abundances. However, some occasional cases give birth to stars that avoid enrichment of their chemical compositions by massive stars and thereby exhibit an SN-Ia-like elemental feature including a very low [Mg/Fe] ( Almost-Equal-To - 1). We highlight the elemental feature of Fe-group elements for two low-Mg/Fe objects detected in nearby galaxies, and propose the presence of a class of SNe Ia that yield the low abundance ratios of [Cr, Mn, Ni/Fe]. Our novel models of chemical evolution reveal that our proposed class of SNe Ia (slow SNe Ia) is associated with ones exploding on a long timescale after their stellar birth and give a significant impact on the chemical enrichment in the Large Magellanic Cloud (LMC). In the Galaxy, on the other hand, this effect is unseen due to the overwhelming enrichment by the major class of SNe Ia that explode promptly (prompt SNe Ia) and eject a large amount of Fe-group elements. This nicely explains the different [Cr, Mn, Ni/Fe] features between the two galaxies as well as the puzzling feature seen in the LMC stars exhibiting very low Ca but normal Mg abundances. Furthermore, the corresponding channel of slow SN Ia is exemplified by performing detailed nucleosynthesis calculations in the scheme of SNe Ia resulting from a 0.8 + 0.6 M{sub Sun} white dwarf merger.

  11. LAX XXlCfl jX?iK, Idd+?KYLViG?IA

    Office of Legacy Management (LM)

    f , : I~&l, samtier cipwati8Aa CffUm - . Jiux.lCJ d,# 1754 - - _- - .- t :; . Jesse e. ahizmn*~*ter -2.' -------- - _ &tV' hi@A l f izau Bkteriala ;' . . 1 -7 I _' i' . Fpr&G& r&Q Q,&& fu &fI& L;&& -l&d 2;,i' iI,;/Qi' rIGN CQ&GgJy p;E& p;~p>gyf LAX XXlCfl jX?iK, Idd+?KYLViG?IA i-icfer~~o is &o ta yaw rwarandu3;: l P iimwmbec L?, 1953, reque&in~ a d&q.&ti of khority tA A&sister prog= for th+zz developmrrrl,

  12. Improved Constraints on Type Ia Supernova Host Galaxy Properties using

    Office of Scientific and Technical Information (OSTI)

    Multi-Wavelength Photometry and their Correlations with Supernova Properties (Journal Article) | SciTech Connect Improved Constraints on Type Ia Supernova Host Galaxy Properties using Multi-Wavelength Photometry and their Correlations with Supernova Properties Citation Details In-Document Search Title: Improved Constraints on Type Ia Supernova Host Galaxy Properties using Multi-Wavelength Photometry and their Correlations with Supernova Properties We improve estimates of the stellar mass and

  13. Climate Action Champions: Dubuque, IA | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Dubuque, IA Climate Action Champions: Dubuque, IA The City of Dubuque, Iowa, features a rich history, a diverse arts and cultural scene, and abundant natural beauty, including majestic limestone bluffs along the Mississippi riverfront. Sustainability is among the city’s top priorities for the future. | Photo courtesy of the City of Dubuque. The City of Dubuque, Iowa, features a rich history, a diverse arts and cultural scene, and abundant natural beauty, including majestic limestone bluffs

  14. CEPHEID CALIBRATIONS OF MODERN TYPE Ia SUPERNOVAE: IMPLICATIONS FOR THE

    Office of Scientific and Technical Information (OSTI)

    HUBBLE CONSTANT (Journal Article) | SciTech Connect CEPHEID CALIBRATIONS OF MODERN TYPE Ia SUPERNOVAE: IMPLICATIONS FOR THE HUBBLE CONSTANT Citation Details In-Document Search Title: CEPHEID CALIBRATIONS OF MODERN TYPE Ia SUPERNOVAE: IMPLICATIONS FOR THE HUBBLE CONSTANT This is the first of two papers reporting measurements from a program to determine the Hubble constant to {approx}5% precision from a refurbished distance ladder. We present new observations of 110 Cepheid variables in the

  15. DOE - Office of Legacy Management -- Iowa Army Ammunition Plant - IA 02

    Office of Legacy Management (LM)

    Army Ammunition Plant - IA 02 FUSRAP Considered Sites Iowa Army Ammunition Plant, IA Alternate Name(s): Burlington Ordnance Plant Iowa Ordnance Plant Silas Mason Company IA.02-3 Location: Located in Township 70 North, Range 3 West, Section 32, 5th Principal Meridian, Des Moines County, Burlington, Iowa IA.02-1 IA.02-5 Historical Operations: Assembled nuclear weapons, primarily high explosive components and conducted explosives testing using the high explosive components and depleted uranium. AEC

  16. A SUPER-EDDINGTON WIND SCENARIO FOR THE PROGENITORS OF TYPE Ia SUPERNOVAE

    SciTech Connect (OSTI)

    Ma, Xin; Chen, Xuefei; Chen, Hai-liang; Han, Zhanwen; Denissenkov, Pavel A. E-mail: cxf@ynao.ac.cn

    2013-12-01

    The accretion of hydrogen-rich material on to carbon-oxygen white dwarfs (CO WDs) is crucial for understanding Type Ia supernova (SN Ia) from the single-degenerate model, but this process has not been well understood due to the numerical difficulties in treating H and He flashes during the accretion. For CO WD masses from 0.5 to 1.378 M {sub ?} and accretion rates in the range from 10{sup 8} to 10{sup 5} M {sub ?} yr{sup 1}, we simulated the accretion of solar-composition material on to CO WDs using the state-of-the-art stellar evolution code of MESA. For comparison with steady-state models, we first ignored the contribution from nuclear burning to the luminosity when determining the Eddington accretion rate, and found that the properties of H burning in our accreting CO WD models are similar to those from the steady-state models, except that the critical accretion rates at which the WDs turn into red giants or H-shell flashes occur on their surfaces are slightly higher than those from the steady-state models. However, the super-Eddington wind is triggered at much lower accretion rates than previously thought, when the contribution of nuclear burning to the total luminosity is included. This super-Eddington wind naturally prevents the CO WDs with high accretion rates from becoming red giants, thus presenting an alternative to the optically thick wind proposed by Hachisu etal. Furthermore, the super-Eddington wind works in low-metallicity environments, which may explain SNe Ia observed at high redshifts.

  17. Turbulence-Flame Interactions in Type Ia Supernovae (Journal Article) |

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Journal Article: Turbulence-Flame Interactions in Type Ia Supernovae Citation Details In-Document Search Title: Turbulence-Flame Interactions in Type Ia Supernovae × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and is provided as a public service. Visit OSTI to utilize additional information resources in energy science and technology. A paper copy of

  18. Exploration of R2XM2 (R=Sc, Y, Ti, Zr, Hf, rare earth; X=main group element; M=transition metal, Si, Ge): Structural Motifs, the novel Compound Gd2AlGe2 and Analysis of the U3Si2 and Zr3Al2 Structure Types

    SciTech Connect (OSTI)

    Sean William McWhorter

    2006-05-01

    In the process of exploring and understanding the influence of crystal structure on the system of compounds with the composition Gd{sub 5}(Si{sub x}Ge{sub 1-x}){sub 4} several new compounds were synthesized with different crystal structures, but similar structural features. In Gd{sub 5}(Si{sub x}Ge{sub 1-x}){sub 4}, the main feature of interest is the magnetocaloric effect (MCE), which allows the material to be useful in magnetic refrigeration applications. The MCE is based on the magnetic interactions of the Gd atoms in the crystal structure, which varies with x (the amount of Si in the compound). The crystal structure of Gd{sub 5}(Si{sub x}Ge{sub 1-x}){sub 4} can be thought of as being formed from two 3{sup 2}434 nets of Gd atoms, with additional Gd atoms in the cubic voids and Si/Ge atoms in the trigonal prismatic voids. Attempts were made to substitute nonmagnetic atoms for magnetic Gd using In, Mg and Al. Gd{sub 2}MgGe{sub 2} and Gd{sub 2}InGe{sub 2} both possess the same 3{sup 2}434 nets of Gd atoms as Gd{sub 5}(Si{sub x}Ge{sub 1-x}){sub 4}, but these nets are connected differently, forming the Mo{sub 2}FeB{sub 2} crystal structure. A search of the literature revealed that compounds with the composition R{sub 2}XM{sub 2} (R=Sc, Y, Ti, Zr, Hf, rare earth; X=main group element; M=transition metal, Si, Ge) crystallize in one of four crystal structures: the Mo{sub 2}FeB{sub 2}, Zr{sub 3}Al{sub 2}, Mn{sub 2}AlB{sub 2} and W{sub 2}CoB{sub 2} crystal structures. These crystal structures are described, and the relationships between them are highlighted. Gd{sub 2}AlGe{sub 2} forms an entirely new crystal structure, and the details of its synthesis and characterization are given. Electronic structure calculations are performed to understand the nature of bonding in this compound and how electrons can be accounted for. A series of electronic structure calculations were performed on models with the U{sub 3}Si{sub 2} and Zr{sub 3}Al{sub 2} structures, using Zr and A1 as the building blocks. The starting point for these models was the U{sub 3}Si{sub 2} structure, and models were created to simulate the transition from the idealized U{sub 3}Si{sub 2} structure to the distorted Zr{sub 3}Al{sub 2} structure. Analysis of the band structures of the models has shown that the transition from the U{sub 3}Si{sub 2} structure to the Zr{sub 3}Al{sub 2} structure lifts degeneracies along the {Lambda} {yields} Z direction, indicating a Peierls-type mechanism for the displacement occurring in the positions of the Zr atoms.

  19. Color dispersion and Milky-Way-like reddening among type Ia supernovae...

    Office of Scientific and Technical Information (OSTI)

    Color dispersion and Milky-Way-like reddening among type Ia supernovae Citation Details In-Document Search Title: Color dispersion and Milky-Way-like reddening among type Ia ...

  20. CfA3: 185 TYPE Ia SUPERNOVA LIGHT CURVES FROM THE CfA (Journal...

    Office of Scientific and Technical Information (OSTI)

    We find that 1991bg-like SNe Ia are sufficiently distinct from other SNe Ia in their color ... reddening from intrinsic supernova color, reducing the systematic uncertainty in SN ...

  1. A Chandrasekhar mass progenitor for the Type Ia supernova remnant 3C 397

    Office of Scientific and Technical Information (OSTI)

    from the enhanced abundances of nickel and manganese (Journal Article) | SciTech Connect A Chandrasekhar mass progenitor for the Type Ia supernova remnant 3C 397 from the enhanced abundances of nickel and manganese Citation Details In-Document Search Title: A Chandrasekhar mass progenitor for the Type Ia supernova remnant 3C 397 from the enhanced abundances of nickel and manganese Despite decades of intense efforts, many fundamental aspects of Type Ia supernovae (SNe Ia) remain elusive. One

  2. SN 2006bt: A PERPLEXING, TROUBLESOME, AND POSSIBLY MISLEADING TYPE Ia

    Office of Scientific and Technical Information (OSTI)

    SUPERNOVA (Journal Article) | SciTech Connect SN 2006bt: A PERPLEXING, TROUBLESOME, AND POSSIBLY MISLEADING TYPE Ia SUPERNOVA Citation Details In-Document Search Title: SN 2006bt: A PERPLEXING, TROUBLESOME, AND POSSIBLY MISLEADING TYPE Ia SUPERNOVA SN 2006bt displays characteristics unlike those of any other known Type Ia supernova (SN Ia). We present optical light curves and spectra of SN 2006bt which demonstrate the peculiar nature of this object. SN 2006bt has broad, slowly declining

  3. Type Ia supernovae from merging white dwarfs. II. Post-merger detonations

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Type Ia supernovae from merging white dwarfs. II. Post-merger detonations Citation Details In-Document Search Title: Type Ia supernovae from merging white dwarfs. II. Post-merger detonations Merging carbon-oxygen (CO) white dwarfs are a promising progenitor system for Type Ia supernovae (SNe Ia), but the underlying physics and timing of the detonation are still debated. If an explosion occurs after the secondary star is fully disrupted, the exploding

  4. A STUDY OF CARBON FEATURES IN TYPE Ia SUPERNOVA SPECTRA (Journal Article) |

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect A STUDY OF CARBON FEATURES IN TYPE Ia SUPERNOVA SPECTRA Citation Details In-Document Search Title: A STUDY OF CARBON FEATURES IN TYPE Ia SUPERNOVA SPECTRA One of the major differences between various explosion scenarios of Type Ia supernovae (SNe Ia) is the remaining amount of unburned (C+O) material and its velocity distribution within the expanding ejecta. While oxygen absorption features are not uncommon in the spectra of SNe Ia before maximum light, the presence of strong

  5. Elastic anisotropy, vibrational, and thermodynamic properties of U{sub 2}Ti intermetallic compound with AlB{sub 2}-type structure under high pressure up to 100 GPa

    SciTech Connect (OSTI)

    Yang, Jinwen; Gao, Tao; Liu, Benqiong; Sun, Guangai; Chen, Bo

    2015-03-28

    Structural, elastic anisotropy, dynamical, and thermodynamic properties of U{sub 2}Ti have been studied by employing density functional theory and density functional perturbative theory. The optimized lattice parameters a, c, unit volume V, bulk modulus B, and bond lengths d{sub U-U}, d{sub U-Ti} of U{sub 2}Ti are in favorable agreement with the available experimental data and other theoretical values. The elastic constants under pressure were obtained using “energy-strain” method. The polycrystalline modulus, Poisson's ratio, brittle/ductile characteristics, Debye temperature and the integration of elastic wave velocities over different directions, and hardness under pressure are also evaluated successfully. The anisotropy of the directional bulk modulus and the Young's modulus is systematically predicted for the first time. It turns out that U{sub 2}Ti should be stabilized mechanically up to 100 GPa, this compound just possesses slightly elastic anisotropy at zero pressure; however, the anisotropy becomes more and more significant with the increasing pressure. In particular, the phonon dispersion curves and phonon density of state under pressure are reported for the first time. The Raman and infrared-active phonon modes at Γ point are further assigned. Our results indicate that U{sub 2}Ti is also stable dynamically up to 100 GPa. Additionally, within the calculated phonon density of states, the thermodynamic properties are predicted.

  6. An Analysis of Department of Defense Instruction 8500.2 'Information Assurance (IA) Implementation.'

    SciTech Connect (OSTI)

    Campbell, Philip LaRoche

    2012-01-01

    The Department of Defense (DoD) provides its standard for information assurance in its Instruction 8500.2, dated February 6, 2003. This Instruction lists 157 'IA Controls' for nine 'baseline IA levels.' Aside from distinguishing IA Controls that call for elevated levels of 'robustness' and grouping the IA Controls into eight 'subject areas' 8500.2 does not examine the nature of this set of controls, determining, for example, which controls do not vary in robustness, how this set of controls compares with other such sets, or even which controls are required for all nine baseline IA levels. This report analyzes (1) the IA Controls, (2) the subject areas, and (3) the Baseline IA levels. For example, this report notes that there are only 109 core IA Controls (which this report refers to as 'ICGs'), that 43 of these core IA Controls apply without variation to all nine baseline IA levels and that an additional 31 apply with variations. This report maps the IA Controls of 8500.2 to the controls in NIST 800-53 and ITGI's CoBIT. The result of this analysis and mapping, as shown in this report, serves as a companion to 8500.2. (An electronic spreadsheet accompanies this report.)

  7. Type Ia Supernova Spectral Line Ratios as LuminosityIndicators

    SciTech Connect (OSTI)

    Bongard, Sebastien; Baron, E.; Smadja, G.; Branch, David; Hauschildt, Peter H.

    2005-12-07

    Type Ia supernovae have played a crucial role in thediscovery of the dark energy, via the measurement of their light curvesand the determination of the peak brightness via fitting templates to theobserved lightcurve shape. Two spectroscopic indicators are also known tobe well correlated with peak luminosity. Since the spectroscopicluminosity indicators are obtained directly from observed spectra, theywill have different systematic errors than do measurements usingphotometry. Additionally, these spectroscopic indicators may be usefulfor studies of effects of evolution or age of the SNe~;Ia progenitorpopulation. We present several new variants of such spectroscopicindicators which are easy to automate and which minimize the effects ofnoise. We show that these spectroscopic indicators can be measured byproposed JDEM missions such as snap and JEDI.

  8. Power-law cosmology, SN Ia, and BAO

    SciTech Connect (OSTI)

    Dolgov, Aleksander; Halenka, Vitali; Tkachev, Igor E-mail: vithal@umich.edu

    2014-10-01

    We revise observational constraints on the class of models of modified gravity which at low redshifts lead to a power-law cosmology. To this end we use available public data on Supernova Ia and on baryon acoustic oscillations. We show that the expansion regime a(t)?t{sup ?} with ? close to 3/2 in a spatially flat universe is a good fit to these data.

  9. Microsoft PowerPoint - IEEE IAS PES 102313.pptx

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    DOE's ARRA Smart Grid Program Steve Bossart, Senior Energy Analyst IEEE IAS/PES Pittsburgh Section October 23, 2013 # Topics * OE ARRA Smart Grid Program * OE ARRA Smart Grid Progress * Results and Case Studies * Life After ARRA Smart Grid # DOE OE ARRA Smart Grid Program # American Recovery and Reinvestment Act ($4.5B) * Smart Grid Investment Grants (99 projects) - $3.4 billion Federal; $4.7 billion private sector - > 800 PMUs covering almost 100% of transmission - ~ 8000 distribution

  10. Signatures of a companion star in type Ia supernovae

    SciTech Connect (OSTI)

    Maeda, Keiichi; Kutsuna, Masamichi; Shigeyama, Toshikazu

    2014-10-10

    Although type Ia supernovae (SNe Ia) have been used as precise cosmological distance indicators, their progenitor systems remain unresolved. One of the key questions is whether there is a nondegenerate companion star at the time of a thermonuclear explosion of a white dwarf. In this paper, we investigate whether an interaction between the SN ejecta and the companion star may result in observable footprints around the maximum brightness and thereafter, by performing multidimensional radiation transfer simulations based on hydrodynamic simulations of the interaction. We find that such systems result in variations in various observational characteristics due to different viewing directions, and the predicted behaviors (redder and fainter for the companion direction) are the opposite of what were suggested by the previous study. The variations are generally modest and within observed scatters. However, the model predicts trends between some observables different from those observationally derived, so a large sample of SNe Ia with small calibration errors may be used to constrain the existence of such a companion star. The variations in different colors in optical band passes can be mimicked by external extinctions, so such an effect could be a source of scatter in the peak luminosity and derived distance. After the peak, hydrogen-rich materials expelled from the companion will manifest themselves in hydrogen lines, but Hα is extremely difficult to identify. Alternatively, we find that P{sub β} in postmaximum near-infrared spectra can potentially provide a powerful diagnostic.

  11. Dielectric properties of <001>-oriented Ba{sub 0.6}Sr{sub 0.4}TiO{sub 3} thin films on polycrystalline metal tapes using biaxially oriented MgO/{gamma}-Al{sub 2}O{sub 3} buffer layers

    SciTech Connect (OSTI)

    Choi, W.; Kang, B.S.; Jia, Q.X.; Matias, V.; Findikoglu, A.T.

    2006-02-06

    We report the growth of <001>-oriented Ba{sub 0.6}Sr{sub 0.4}TiO{sub 3} (BST) thin films on polycrystalline Ni-alloy tapes by pulsed laser deposition using biaxially oriented, ion-beam-assisted deposited (IBAD) MgO and {gamma}-Al{sub 2}O{sub 3} buffer layers. Dielectric constant values of our BST films were up to {approx}85% of those in the epitaxial films prepared under similar conditions on single-crystal MgO substrates. No significant dispersion of the dielectric constant was observed for frequencies from 100 Hz to 1 MHz. These results demonstrate the versatility of using IBAD-textured MgO and {gamma}-Al{sub 2}O{sub 3} buffer layers to integrate highly oriented good-quality BST films with nonsingle-crystalline substrates.

  12. ALS Spectrum

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ALS Spectrum Print Begun in 2007, ALS Spectrum is a publication that encapsulates the same type of information contained in the ALS Activity Report but in a short, readable,...

  13. ALS Spectrum

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ALS Spectrum Print Begun in 2007, ALS Spectrum is a publication that encapsulates the same type of information contained in the ALS Activity Report but in a short, readable, ...

  14. ALS Spectrum

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Spectrum Print Begun in 2007, ALS Spectrum is a publication that encapsulates the same type of information contained in the ALS Activity Report but in a short, readable,...

  15. ALS@20

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    tribulations encountered during the construction of the ALS from former Director Jay Marx, current ALS Scientific Director Steve Kevan and Director Roger Falcone talked about...

  16. ALS Spectrum

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Spectrum Print Begun in 2007, ALS Spectrum is a publication that encapsulates the same type of information contained in the ALS Activity Report but in a short, readable, ...

  17. A SEARCH FOR NEW CANDIDATE SUPER-CHANDRASEKHAR-MASS TYPE Ia SUPERNOVAE IN

    Office of Scientific and Technical Information (OSTI)

    THE NEARBY SUPERNOVA FACTORY DATA SET (Journal Article) | SciTech Connect A SEARCH FOR NEW CANDIDATE SUPER-CHANDRASEKHAR-MASS TYPE Ia SUPERNOVAE IN THE NEARBY SUPERNOVA FACTORY DATA SET Citation Details In-Document Search Title: A SEARCH FOR NEW CANDIDATE SUPER-CHANDRASEKHAR-MASS TYPE Ia SUPERNOVAE IN THE NEARBY SUPERNOVA FACTORY DATA SET We present optical photometry and spectroscopy of five Type Ia supernovae discovered by the Nearby Supernova Factory selected to be spectroscopic analogs

  18. Color dispersion and Milky-Way-like reddening among type Ia supernovae

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Color dispersion and Milky-Way-like reddening among type Ia supernovae Citation Details In-Document Search Title: Color dispersion and Milky-Way-like reddening among type Ia supernovae Past analyses of Type Ia supernovae have identified an irreducible scatter of 5%-10% in distance, widely attributed to an intrinsic dispersion in luminosity. Another equally valid source of this scatter is intrinsic dispersion in color. Misidentification of the true source

  19. Type Ia supernovae yielding distances with 3-4% precision (Journal Article)

    Office of Scientific and Technical Information (OSTI)

    | SciTech Connect Type Ia supernovae yielding distances with 3-4% precision Citation Details In-Document Search Title: Type Ia supernovae yielding distances with 3-4% precision The luminosities of Type Ia supernovae (SN), the thermonuclear explosions of white dwarf stars, vary systematically with their intrinsic color and light-curve decline rate. These relationships have been used to calibrate their luminosities to within ~0.14-0.20 mag from broadband optical light curves, yielding

  20. VARIABLE SODIUM ABSORPTION IN A LOW-EXTINCTION TYPE Ia SUPERNOVA (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect VARIABLE SODIUM ABSORPTION IN A LOW-EXTINCTION TYPE Ia SUPERNOVA Citation Details In-Document Search Title: VARIABLE SODIUM ABSORPTION IN A LOW-EXTINCTION TYPE Ia SUPERNOVA Recent observations have revealed that some Type Ia supernovae exhibit narrow, time-variable Na I D absorption features. The origin of the absorbing material is controversial, but it may suggest the presence of circumstellar gas in the progenitor system prior to the explosion, with significant

  1. Industry @ ALS

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Industry @ ALS Industry @ ALS Hewlett Packard Labs Gains Insights with Innovative ALS Research Tools Print Thursday, 05 May 2016 11:21 For the past eight years, Hewlett Packard Labs, the central research organization of Hewlett Packard Enterprise, has been using cutting-edge ALS techniques to advance some of their most promising technological research, including vanadium dioxide phase transitions and atomic movement during memristor operation. Read more... ALS, Molecular Foundry, and aBeam

  2. The Carnegie Supernova Project: Intrinsic colors of type Ia supernovae

    SciTech Connect (OSTI)

    Burns, Christopher R.; Persson, S. E.; Freedman, Wendy L.; Madore, Barry F. [Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Stritzinger, Maximilian; Contreras, Carlos [Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark); Phillips, M. M.; Hsiao, E. Y.; Boldt, Luis; Campillay, Abdo; Castelln, Sergio; Morrell, Nidia; Salgado, Francisco [Carnegie Institution of Washington, Las Campanas Observatory, Colina El Pino, Casilla 601 (Chile); Folatelli, Gaston [Kavli Institute for the Physics and Mathematics of the Universe, Todai Institutes for Advanced Study, the University of Tokyo, 277-8583 Kashiwa (Japan); Suntzeff, Nicholas B. [George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A and M University, Department of Physics and Astronomy, College Station, TX 77843 (United States)

    2014-07-01

    We present an updated analysis of the intrinsic colors of Type Ia supernova (SNe Ia) using the latest data release of the Carnegie Supernova Project. We introduce a new light-curve parameter very similar to stretch that is better suited for fast-declining events, and find that these peculiar types can be seen as extensions to the population of 'normal' SNe Ia. With a larger number of objects, an updated fit to the Lira relation is presented along with evidence for a dependence on the late-time slope of the B V light-curves with stretch and color. Using the full wavelength range from u to H band, we place constraints on the reddening law for the sample as a whole and also for individual events/hosts based solely on the observed colors. The photometric data continue to favor low values of R{sub V} , though with large variations from event to event, indicating an intrinsic distribution. We confirm the findings of other groups that there appears to be a correlation between the derived reddening law, R{sub V} , and the color excess, E(B V), such that larger E(B V) tends to favor lower R{sub V} . The intrinsic u-band colors show a relatively large scatter that cannot be explained by variations in R{sub V} or by the Goobar power-law for circumstellar dust, but rather is correlated with spectroscopic features of the supernova and is therefore likely due to metallicity effects.

  3. HUBBLE RESIDUALS OF NEARBY TYPE Ia SUPERNOVAE ARE CORRELATED WITH HOST

    Office of Scientific and Technical Information (OSTI)

    GALAXY MASSES (Journal Article) | SciTech Connect HUBBLE RESIDUALS OF NEARBY TYPE Ia SUPERNOVAE ARE CORRELATED WITH HOST GALAXY MASSES Citation Details In-Document Search Title: HUBBLE RESIDUALS OF NEARBY TYPE Ia SUPERNOVAE ARE CORRELATED WITH HOST GALAXY MASSES From Sloan Digital Sky Survey u'g'r'i'z' imaging, we estimate the stellar masses of the host galaxies of 70 low-redshift Type Ia supernovae (SNe Ia, 0.015 <z< 0.08) from the hosts' absolute luminosities and mass-to-light

  4. IMPROVED DARK ENERGY CONSTRAINTS FROM {approx}100 NEW CfA SUPERNOVA TYPE Ia

    Office of Scientific and Technical Information (OSTI)

    LIGHT CURVES (Journal Article) | SciTech Connect IMPROVED DARK ENERGY CONSTRAINTS FROM {approx}100 NEW CfA SUPERNOVA TYPE Ia LIGHT CURVES Citation Details In-Document Search Title: IMPROVED DARK ENERGY CONSTRAINTS FROM {approx}100 NEW CfA SUPERNOVA TYPE Ia LIGHT CURVES We combine the CfA3 supernovae Type Ia (SN Ia) sample with samples from the literature to calculate improved constraints on the dark energy equation of state parameter, w. The CfA3 sample is added to the Union set of Kowalski

  5. Improved Distances to Type Ia Supernovae withMulticolor Light Curve Shapes:

    Office of Scientific and Technical Information (OSTI)

    MLCS2k2 (Journal Article) | SciTech Connect Improved Distances to Type Ia Supernovae withMulticolor Light Curve Shapes: MLCS2k2 Citation Details In-Document Search Title: Improved Distances to Type Ia Supernovae withMulticolor Light Curve Shapes: MLCS2k2 We present an updated version of the Multicolor Light Curve Shape method to measure distances to type Ia supernovae (SN Ia), incorporating new procedures for K-correction and extinction corrections. We also develop a simple model to

  6. THE HYBRID CONe WD + He STAR SCENARIO FOR THE PROGENITORS OF TYPE Ia SUPERNOVAE

    SciTech Connect (OSTI)

    Wang, B.; Meng, X.; Liu, D.-D.; Han, Z.; Liu, Z.-W.

    2014-10-20

    Hybrid CONe white dwarfs (WDs) have been suggested to be possible progenitors of type Ia supernovae (SNe Ia). In this Letter, we systematically studied the hybrid CONe WD + He star scenario for the progenitors of SNe Ia, in which a hybrid CONe WD increases its mass to the Chandrasekhar mass limit by accreting He-rich material from a non-degenerate He star. We obtained the SN Ia birthrates and delay times for this scenario using to a series of detailed binary population synthesis simulations. The SN Ia birthrates for this scenario are ∼0.033-0.539 × 10{sup –3} yr{sup –1}, which roughly accounts for 1%-18% of all SNe Ia. The estimated delay times are ∼28 Myr-178 Myr, which makes these the youngest SNe Ia predicted by any progenitor model so far. We suggest that SNe Ia from this scenario may provide an alternative explanation for type Iax SNe. We also presented some properties of the donors at the point when the WDs reach the Chandrasekhar mass. These properties may be a good starting point for investigating the surviving companions of SNe Ia and for constraining the progenitor scenario studied in this work.

  7. Improved Dark Energy Constraints From ~ 100 New CfA Supernova Type Ia Light

    Office of Scientific and Technical Information (OSTI)

    Curves (Journal Article) | SciTech Connect Journal Article: Improved Dark Energy Constraints From ~ 100 New CfA Supernova Type Ia Light Curves Citation Details In-Document Search Title: Improved Dark Energy Constraints From ~ 100 New CfA Supernova Type Ia Light Curves We combine the CfA3 supernovae Type Ia (SN Ia) sample with samples from the literature to calculate improved constraints on the dark energy equation of state parameter, w. The CfA3 sample is added to the Union set of Kowalski

  8. Sweetspot: Near-infrared observations of 13 type Ia supernovae from a new

    Office of Scientific and Technical Information (OSTI)

    NOAO survey probing the nearby smooth Hubble flow (Journal Article) | SciTech Connect Sweetspot: Near-infrared observations of 13 type Ia supernovae from a new NOAO survey probing the nearby smooth Hubble flow Citation Details In-Document Search Title: Sweetspot: Near-infrared observations of 13 type Ia supernovae from a new NOAO survey probing the nearby smooth Hubble flow We present 13 Type Ia supernovae (SNe Ia) observed in the rest-frame near-infrared (NIR) from 0.02 < z < 0.09

  9. THE ABSOLUTE MAGNITUDES OF TYPE Ia SUPERNOVAE IN THE ULTRAVIOLET (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect THE ABSOLUTE MAGNITUDES OF TYPE Ia SUPERNOVAE IN THE ULTRAVIOLET Citation Details In-Document Search Title: THE ABSOLUTE MAGNITUDES OF TYPE Ia SUPERNOVAE IN THE ULTRAVIOLET We examine the absolute magnitudes and light-curve shapes of 14 nearby (redshift z = 0.004-0.027) Type Ia supernovae (SNe Ia) observed in the ultraviolet (UV) with the Swift Ultraviolet/Optical Telescope. Colors and absolute magnitudes are calculated using both a standard Milky Way extinction

  10. Systematic uncertainties associated with the cosmological analysis of the first Pan-STARRS1 type Ia supernova sample

    SciTech Connect (OSTI)

    Scolnic, D.; Riess, A.; Brout, D.; Rodney, S. [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Rest, A. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Huber, M. E.; Tonry, J. L. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Foley, R. J.; Chornock, R.; Berger, E.; Soderberg, A. M.; Stubbs, C. W.; Kirshner, R. P.; Challis, P.; Czekala, I.; Drout, M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Narayan, G. [Department of Physics, Harvard University, 17 Oxford Street, Cambridge, MA 02138 (United States); Smartt, S. J.; Botticella, M. T. [Astrophysics Research Centre, School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN (United Kingdom); Schlafly, E. [Max Planck Institute for Astronomy, Konigstuhl 17, D-69117 Heidelberg (Germany); and others

    2014-11-01

    We probe the systematic uncertainties from the 113 Type Ia supernovae (SN Ia) in the Pan-STARRS1 (PS1) sample along with 197 SN Ia from a combination of low-redshift surveys. The companion paper by Rest et al. describes the photometric measurements and cosmological inferences from the PS1 sample. The largest systematic uncertainty stems from the photometric calibration of the PS1 and low-z samples. We increase the sample of observed Calspec standards from 7 to 10 used to define the PS1 calibration system. The PS1 and SDSS-II calibration systems are compared and discrepancies up to ?0.02 mag are recovered. We find uncertainties in the proper way to treat intrinsic colors and reddening produce differences in the recovered value of w up to 3%. We estimate masses of host galaxies of PS1 supernovae and detect an insignificant difference in distance residuals of the full sample of 0.037 0.031 mag for host galaxies with high and low masses. Assuming flatness and including systematic uncertainties in our analysis of only SNe measurements, we find w =?1.120{sub ?0.206}{sup +0.360}(Stat){sub ?0.291}{sup +0.269}(Sys). With additional constraints from Baryon acoustic oscillation, cosmic microwave background (CMB) (Planck) and H {sub 0} measurements, we find w=?1.166{sub ?0.069}{sup +0.072} and ?{sub m}=0.280{sub ?0.012}{sup +0.013} (statistical and systematic errors added in quadrature). The significance of the inconsistency with w = 1 depends on whether we use Planck or Wilkinson Microwave Anisotropy Probe measurements of the CMB: w{sub BAO+H0+SN+WMAP}=?1.124{sub ?0.065}{sup +0.083}.

  11. Grouping normal type Ia supernovae by UV to optical color differences

    SciTech Connect (OSTI)

    Milne, Peter A.; Brown, Peter J.; Roming, Peter W. A.; Bufano, Filomena; Gehrels, Neil

    2013-12-10

    Observations of many Type Ia supernovae (SNe Ia) for multiple epochs per object with the Swift Ultraviolet Optical Telescope instrument have revealed that there exists order to the differences in the UV-optical colors of optically normal supernovae (SNe). We examine UV-optical color curves for 23 SNe Ia, dividing the SNe into four groups, and find that roughly one-third of 'NUV-blue' SNe Ia have bluer UV-optical colors than the larger 'NUV-red' group. Two minor groups are recognized, 'MUV-blue' and 'irregular' SNe Ia. While we conclude that the latter group is a subset of the NUV-red group, containing the SNe with the broadest optical peaks, we conclude that the 'MUV-blue' group is a distinct group. Separating into the groups and accounting for the time evolution of the UV-optical colors lowers the scatter in two NUV-optical colors (e.g., u v and uvw1 v) to the level of the scatter in b v. This finding is promising for extending the cosmological utilization of SNe Ia into the NUV. We generate spectrophotometry of 33 SNe Ia and determine the correct grouping for each. We argue that there is a fundamental spectral difference in the 2900-3500 wavelength range, a region suggested to be dominated by absorption from iron-peak elements. The NUV-blue SNe Ia feature less absorption than the NUV-red SNe Ia. We show that all NUV-blue SNe Ia in this sample also show evidence of unburned carbon in optical spectra, whereas only one NUV-red SN Ia features that absorption line. Every NUV-blue event also exhibits a low gradient of the Si II ?6355 absorption feature. Many NUV-red events also exhibit a low gradient, perhaps suggestive that NUV-blue events are a subset of the larger low-velocity gradient group.

  12. Melt Processed Single Phase Hollandite Waste Forms For Nuclear Waste Immobilization: Ba{sub 1.0}Cs{sub 0.3}A{sub 2.3}Ti{sub 5.7}O{sub 16}; A = Cr, Fe, Al

    SciTech Connect (OSTI)

    Brinkman, Kyle; Marra, James; Amoroso, Jake; Conradson, Steven D.; Tang, Ming

    2013-09-23

    Cs is one of the more problematic fission product radionuclides to immobilize due to its high volatility at elevated temperatures, ability to form water soluble compounds, and its mobility in many host materials. The hollandite structure is a promising crystalline host for Cs immobilization and has been traditionally fabricated by solid state sintering methods. This study presents the structure and performance of Ba{sub 1.0}Cs{sub 0.3}A{sub 2.3}Ti{sub 5.7}O{sub 16}; A = Cr, Fe, Al hollandite fabricated by melt processing. Melt processing is considered advantageous given that melters are currently in use for High Level Waste (HLW) vitrification in several countries. This work details the impact of Cr additions that were demonstrated to i) promote the formation of a Cs containing hollandite phase and ii) maintain the stability of the hollandite phase in reducing conditions anticipated for multiphase waste form processing.

  13. Domain matched epitaxial growth of (111) Ba{sub 0.5}Sr{sub 0.5}TiO{sub 3} thin films on (0001) Al{sub 2}O{sub 3} with ZnO buffer layer

    SciTech Connect (OSTI)

    Krishnaprasad, P. S. E-mail: mkj@cusat.ac.in; Jayaraj, M. K. E-mail: mkj@cusat.ac.in; Antony, Aldrin; Rojas, Fredy

    2015-03-28

    Epitaxial (111) Ba{sub 0.5}Sr{sub 0.5}TiO{sub 3} (BST) thin films have been grown by pulsed laser deposition on (0001) Al{sub 2}O{sub 3} substrate with ZnO as buffer layer. The x-ray ?-2?, ?-scan and reciprocal space mapping indicate epitaxial nature of BST thin films. The domain matched epitaxial growth of BST thin films over ZnO buffer layer was confirmed using Fourier filtered high resolution transmission electron microscope images of the film-buffer interface. The incorporation of ZnO buffer layer effectively suppressed the lattice mismatch and promoted domain matched epitaxial growth of BST thin films. Coplanar inter digital capacitors fabricated on epitaxial (111) BST thin films show significantly improved tunable performance over polycrystalline thin films.

  14. On silicon group elements ejected by supernovae type IA

    SciTech Connect (OSTI)

    De, Soma; Timmes, F. X. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ (United States); Brown, Edward F. [Joint Institute for Nuclear Astrophysics, University of Notre Dame, IN 46556 (United States); Calder, Alan C. [Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY (United States); Townsley, Dean M. [Department of Physics and Astronomy, The University of Alabama, Tuscaloosa, AL (United States); Athanassiadou, Themis [Swiss National Supercomputing Centre, Via Trevano 131, 6900 Lugano (Switzerland); Chamulak, David A. [Physics Division, Argonne National Laboratory, Argonne, IL (United States); Hawley, Wendy [Laboratoire d'Astrophysique de Marseille, Marseille cedex 13 F-13388 (France); Jack, Dennis, E-mail: somad@asu.edu [Departamento de Astronoma, Universidad de Guanajuato, Apartado Postal 144, 36000 Guanajuato (Mexico)

    2014-06-01

    There is evidence that the peak brightness of a Type Ia supernova is affected by the electron fraction Y {sub e} at the time of the explosion. The electron fraction is set by the aboriginal composition of the white dwarf and the reactions that occur during the pre-explosive convective burning. To date, determining the makeup of the white dwarf progenitor has relied on indirect proxies, such as the average metallicity of the host stellar population. In this paper, we present analytical calculations supporting the idea that the electron fraction of the progenitor systematically influences the nucleosynthesis of silicon group ejecta in Type Ia supernovae. In particular, we suggest the abundances generated in quasi-nuclear statistical equilibrium are preserved during the subsequent freeze-out. This allows potential recovery of Y {sub e} at explosion from the abundances recovered from an observed spectra. We show that measurement of {sup 28}Si, {sup 32}S, {sup 40}Ca, and {sup 54}Fe abundances can be used to construct Y {sub e} in the silicon-rich regions of the supernovae. If these four abundances are determined exactly, they are sufficient to recover Y {sub e} to 6%. This is because these isotopes dominate the composition of silicon-rich material and iron-rich material in quasi-nuclear statistical equilibrium. Analytical analysis shows the {sup 28}Si abundance is insensitive to Y {sub e}, the {sup 32}S abundance has a nearly linear trend with Y {sub e}, and the {sup 40}Ca abundance has a nearly quadratic trend with Y {sub e}. We verify these trends with post-processing of one-dimensional models and show that these trends are reflected in the model's synthetic spectra.

  15. ALS Visitors

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Quick Facts ALS Visitors Print ALS staff members host a variety of scientific, educational, government, and community-related tours each month. April 2014 Congresswoman Jackie Speier, who represents southern San Francisco and northern Peninsula communities, recently spent an afternoon at Berkeley Lab. In addition to an overview of the Lab provided by Lab Director Paul Alivisatos, Speier toured the FLEXLAB and the Advanced Light Source. At the ALS she spoke with Beamline Scientist Ken Goldberg

  16. ALS Spectrum

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    encapsulates the same type of information contained in the ALS Activity Report but in a short, readable, newsletter-like format. Featured scientific and facility developments are...

  17. Phase equilibria, formation, crystal and electronic structure of ternary compounds in Ti-Ni-Sn and Ti-Ni-Sb ternary systems

    SciTech Connect (OSTI)

    Romaka, V.V.; Rogl, P.; Romaka, L.; Stadnyk, Yu.; Melnychenko, N.; Grytsiv, A.; Falmbigl, M.; Skryabina, N.

    2013-01-15

    The phase equilibria of the Ti-Ni-Sn and Ti-Ni-Sb ternary systems have been studied in the whole concentration range by means of X-ray and EPM analyses at 1073 K and 873 K, respectively. Four ternary intermetallic compounds TiNiSn (MgAgAs-type), TiNi{sub 2-x}Sn (MnCu{sub 2}Al-type), Ti{sub 2}Ni{sub 2}Sn (U{sub 2}Pt{sub 2}Sn-type), and Ti{sub 5}NiSn{sub 3} (Hf{sub 5}CuSn{sub 3}-type) are formed in Ti-Ni-Sn system at 1073 K. The TiNi{sub 2}Sn stannide is characterized by homogeneity in the range of 50-47 at% of Ni. The Ti-Ni-Sb ternary system at 873 K is characterized by formation of three ternary intermetallic compounds, Ti{sub 0.8}NiSb (MgAgAs-type), Ti{sub 5}Ni{sub 0.45}Sb{sub 2.55} (W{sub 5}Si{sub 3}-type), and Ti{sub 5}NiSb{sub 3} (Hf{sub 5}CuSn{sub 3}-type). The solubility of Ni in Ti{sub 0.8}NiSb decreases number of vacancies in Ti site up to Ti{sub 0.91}Ni{sub 1.1}Sb composition. - Graphical abstract: Isothermal section of the Ti-Ni-Sn phase diagram and DOS distribution in hypothetical TiNi{sub 1+x}Sn solid solution. Highlights: Black-Right-Pointing-Pointer Ti-Ni-Sn phase diagram was constructed at 1073 K. Black-Right-Pointing-Pointer Four ternary compounds are formed: TiNiSn, TiNi{sub 2-x}Sn, Ti{sub 2}Ni{sub 2}Sn, and Ti{sub 5}NiSn{sub 3}. Black-Right-Pointing-Pointer Three ternary compounds exist in Ti-Ni-Sb system at 873 K. Black-Right-Pointing-Pointer The TiNi{sub 2}Sb compound is absent.

  18. HIGH-VELOCITY LINE FORMING REGIONS IN THE TYPE Ia SUPERNOVA 2009ig (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect VELOCITY LINE FORMING REGIONS IN THE TYPE Ia SUPERNOVA 2009ig Citation Details In-Document Search Title: HIGH-VELOCITY LINE FORMING REGIONS IN THE TYPE Ia SUPERNOVA 2009ig We report measurements and analysis of high-velocity (HVF) (>20,000 km s{sup -1}) and photospheric absorption features in a series of spectra of the Type Ia supernova (SN) 2009ig obtained between -14 days and +13 days with respect to the time of maximum B-band luminosity (B-max). We identify

  19. Hubble Residuals of Nearby SN Ia Are Correlated with Host Galaxy Masses

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Hubble Residuals of Nearby SN Ia Are Correlated with Host Galaxy Masses Citation Details In-Document Search Title: Hubble Residuals of Nearby SN Ia Are Correlated with Host Galaxy Masses From Sloan Digital Sky Survey u{prime} g{prime} r{prime} i{prime} z{prime} imaging, we estimate the stellar masses of the host galaxies of 70 low redshift SN Ia (0.015 < z < 0.08) from the hosts absolute luminosities and mass-to-light ratios. These nearby SN were

  20. ASYMMETRY IN THE OBSERVED METAL-RICH EJECTA OF THE GALACTIC TYPE IA

    Office of Scientific and Technical Information (OSTI)

    SUPERNOVA REMNANT G299.2-2.9 (Journal Article) | SciTech Connect ASYMMETRY IN THE OBSERVED METAL-RICH EJECTA OF THE GALACTIC TYPE IA SUPERNOVA REMNANT G299.2-2.9 Citation Details In-Document Search Title: ASYMMETRY IN THE OBSERVED METAL-RICH EJECTA OF THE GALACTIC TYPE IA SUPERNOVA REMNANT G299.2-2.9 We have performed a deep Chandra observation of the Galactic Type Ia supernova remnant G299.2-2.9. Here we report the initial results from our imaging and spectral analysis. The observed

  1. Type Ia Supernova Hubble Residuals and Host-Galaxy Properties...

    Office of Scientific and Technical Information (OSTI)

    Tao, C.; Thomas, R. C.; Weaver, B. A. 79 ASTRONOMY AND ASTROPHYSICS distance scale, supernovae: general distance scale, supernovae: general Kim et al. (2013) K13 introduced a...

  2. Type Ia Supernova Hubble Residuals and Host-Galaxy Properties...

    Office of Scientific and Technical Information (OSTI)

    Kim et al. (2013) K13 introduced a new methodology for determining peak- brightness ... Resource Relation: Journal Name: Astrophysical Journal Research Org: Ernest Orlando ...

  3. File:USDA-CE-Production-GIFmaps-IA.pdf | Open Energy Information

    Open Energy Info (EERE)

    IA.pdf Jump to: navigation, search File File history File usage Iowa Ethanol Plant Locations Size of this preview: 776 600 pixels. Full resolution (1,650 1,275 pixels,...

  4. "Report Date","U.S.",,,"PADD I",,,"PADD IA",,,"PADD IB",,,"PADD...

    U.S. Energy Information Administration (EIA) Indexed Site

    I",,,"PADD IA",,,"PADD IB",,,"PADD IC",,,"PADD II" ,"Old Reported Value ( per Gallon)","New Revised Value ( per Gallon)","Difference","Old Reported Value ( per Gallon)","New ...

  5. Flames in Type Ia Supernova: Deflagration-Detonation Transition in the

    Office of Scientific and Technical Information (OSTI)

    Oxygen Burning Flame. (Journal Article) | SciTech Connect Journal Article: Flames in Type Ia Supernova: Deflagration-Detonation Transition in the Oxygen Burning Flame. Citation Details In-Document Search Title: Flames in Type Ia Supernova: Deflagration-Detonation Transition in the Oxygen Burning Flame. Abstract not provided. Authors: Kerstein, Alan R. ; Woosley, Stan E. ; Aspden, Andrew J. Publication Date: 2010-10-01 OSTI Identifier: 1121667 Report Number(s): SAND2010-7483J 485788 DOE

  6. New approaches for modeling type Ia supernovae (Conference) | SciTech

    Office of Scientific and Technical Information (OSTI)

    Connect Conference: New approaches for modeling type Ia supernovae Citation Details In-Document Search Title: New approaches for modeling type Ia supernovae × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and is provided as a public service. Visit OSTI to utilize additional information resources in energy science and technology. A paper copy of this document is also

  7. Cosmological parameter uncertainties from SALT-II type Ia supernova light curve models

    SciTech Connect (OSTI)

    Mosher, J.; Sako, M. [Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104 (United States); Guy, J.; Astier, P.; Betoule, M.; El-Hage, P.; Pain, R.; Regnault, N. [LPNHE, CNRS/IN2P3, Universit Pierre et Marie Curie Paris 6, Universi Denis Diderot Paris 7, 4 place Jussieu, F-75252 Paris Cedex 05 (France); Kessler, R.; Frieman, J. A. [Kavli Institute for Cosmological Physics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Marriner, J. [Center for Particle Astrophysics, Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States); Biswas, R.; Kuhlmann, S. [Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL 60439 (United States); Schneider, D. P., E-mail: kessler@kicp.chicago.edu [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States)

    2014-09-20

    We use simulated type Ia supernova (SN Ia) samples, including both photometry and spectra, to perform the first direct validation of cosmology analysis using the SALT-II light curve model. This validation includes residuals from the light curve training process, systematic biases in SN Ia distance measurements, and a bias on the dark energy equation of state parameter w. Using the SN-analysis package SNANA, we simulate and analyze realistic samples corresponding to the data samples used in the SNLS3 analysis: ?120 low-redshift (z < 0.1) SNe Ia, ?255 Sloan Digital Sky Survey SNe Ia (z < 0.4), and ?290 SNLS SNe Ia (z ? 1). To probe systematic uncertainties in detail, we vary the input spectral model, the model of intrinsic scatter, and the smoothing (i.e., regularization) parameters used during the SALT-II model training. Using realistic intrinsic scatter models results in a slight bias in the ultraviolet portion of the trained SALT-II model, and w biases (w {sub input} w {sub recovered}) ranging from 0.005 0.012 to 0.024 0.010. These biases are indistinguishable from each other within the uncertainty; the average bias on w is 0.014 0.007.

  8. THE DETONATION MECHANISM OF THE PULSATIONALLY ASSISTED GRAVITATIONALLY CONFINED DETONATION MODEL OF Type Ia SUPERNOVAE

    SciTech Connect (OSTI)

    Jordan, G. C. IV; Graziani, C.; Weide, K.; Norris, J.; Hudson, R.; Lamb, D. Q.; Fisher, R. T.; Townsley, D. M.; Meakin, C.; Reid, L. B.

    2012-11-01

    We describe the detonation mechanism composing the 'pulsationally assisted' gravitationally confined detonation (GCD) model of Type Ia supernovae. This model is analogous to the previous GCD model reported in Jordan et al.; however, the chosen initial conditions produce a substantively different detonation mechanism, resulting from a larger energy release during the deflagration phase. The resulting final kinetic energy and {sup 56}Ni yields conform better to observational values than is the case for the 'classical' GCD models. In the present class of models, the ignition of a deflagration phase leads to a rising, burning plume of ash. The ash breaks out of the surface of the white dwarf, flows laterally around the star, and converges on the collision region at the antipodal point from where it broke out. The amount of energy released during the deflagration phase is enough to cause the star to rapidly expand, so that when the ash reaches the antipodal point, the surface density is too low to initiate a detonation. Instead, as the ash flows into the collision region (while mixing with surface fuel), the star reaches its maximally expanded state and then contracts. The stellar contraction acts to increase the density of the star, including the density in the collision region. This both raises the temperature and density of the fuel-ash mixture in the collision region and ultimately leads to thermodynamic conditions that are necessary for the Zel'dovich gradient mechanism to produce a detonation. We demonstrate feasibility of this scenario with three three-dimensional (3D), full star simulations of this model using the FLASH code. We characterized the simulations by the energy released during the deflagration phase, which ranged from 38% to 78% of the white dwarf's binding energy. We show that the necessary conditions for detonation are achieved in all three of the models.

  9. ALD Produced B{sub 2}O{sub 3}, Al{sub 2}O{sub 3} and TiO{sub 2} Coatings on Gd{sub 2}O{sub 3} Burnable Poison Nanoparticles and Carbonaceous TRISO Coating Layers

    SciTech Connect (OSTI)

    Weimer, Alan

    2012-11-26

    This project will demonstrate the feasibility of using atomic layer deposition (ALD) to apply ultrathin neutron-absorbing, corrosion-resistant layers consisting of ceramics, metals, or combinations thereof, on particles for enhanced nuclear fuel pellets. Current pellet coating technology utilizes chemical vapor deposition (CVD) in a fluidized bed reactor to deposit thick, porous layers of C (or PyC) and SiC. These graphitic/carbide materials degrade over time owing to fission product bombardment, active oxidation, thermal management issues, and long-term irradiation effects. ALD can be used to deposit potential ceramic barrier materials of interest, including ZrO{sub 2}, Y{sub 2}O{sub 3}:ZrO{sub 2} (YSZ), Al{sub 2}O{sub 3}, and TiO{sub 2}, or neutron-absorbing materials, namely B (in BN or B{sub 2}O{sub 3}) and Gd (in Gd{sub 2}O{sub 3}). This project consists of a two-pronged approach to integrate ALD into the next-generation nuclear plant (NGNP) fuel pellet manufacturing process:

  10. AL2007-03.doc

    Broader source: Energy.gov (indexed) [DOE]

    from GAO and Inspector General (IG) reports of other federal agencies. Introduction The IA relationship involves two Federal agencies that enter into a relationship for the...

  11. Type Ia supernovae from merging white dwarfs. II. Post-merger detonations

    SciTech Connect (OSTI)

    Raskin, Cody; Kasen, Daniel [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Moll, Rainer; Woosley, Stan [Department of Physics and Department of Astronomy, University of California, Santa Cruz, CA (United States); Schwab, Josiah [Department of Physics and Department of Astronomy, University of California, Berkeley, CA (United States)

    2014-06-10

    Merging carbon-oxygen (CO) white dwarfs are a promising progenitor system for Type Ia supernovae (SNe Ia), but the underlying physics and timing of the detonation are still debated. If an explosion occurs after the secondary star is fully disrupted, the exploding primary will expand into a dense CO medium that may still have a disk-like structure. This interaction will decelerate and distort the ejecta. Here we carry out multidimensional simulations of 'tamped' SN Ia models, using both particle and grid-based codes to study the merger and explosion dynamics and a radiative transfer code to calculate synthetic spectra and light curves. We find that post-merger explosions exhibit an hourglass-shaped asymmetry, leading to strong variations in the light curves with viewing angle. The two most important factors affecting the outcome are the scale height of the disk, which depends sensitively on the binary mass ratio, and the total {sup 56}Ni yield, which is governed by the central density of the remnant core. The synthetic broadband light curves rise and decline very slowly, and the spectra generally look peculiar, with weak features from intermediate mass elements but relatively strong carbon absorption. We also consider the effects of the viscous evolution of the remnant and show that a longer time delay between merger and explosion probably leads to larger {sup 56}Ni yields and more symmetrical remnants. We discuss the relevance of this class of aspherical 'tamped' SN Ia for explaining the class of 'super-Chandrasekhar' SN Ia.

  12. Role of the interface on radiation damage in the SrTiO{sub 3...

    Office of Scientific and Technical Information (OSTI)

    under Nesup 2+ ion irradiation We systematically investigated the microstructural evolution of heteroepitaxial SrTiOsub 3 (STO) thin films grown on a single crystal LaAlOsub ...

  13. Ultraviolet observations of Super-Chandrasekhar mass type Ia supernova candidates with swift UVOT

    SciTech Connect (OSTI)

    Brown, Peter J.; Smitka, Michael T.; Krisciunas, Kevin; Wang, Lifan; Kuin, Paul; De Pasquale, Massimiliano; Scalzo, Richard; Holland, Stephen; Milne, Peter

    2014-05-20

    Among Type Ia supernovae (SNe Ia), a class of overluminous objects exist whose ejecta mass is inferred to be larger than the canonical Chandrasekhar mass. We present and discuss the UV/optical photometric light curves, colors, absolute magnitudes, and spectra of three candidate Super-Chandrasekhar mass SNe—2009dc, 2011aa, and 2012dn—observed with the Swift Ultraviolet/Optical Telescope. The light curves are at the broad end for SNe Ia, with the light curves of SN 2011aa being among the broadest ever observed. We find all three to have very blue colors which may provide a means of excluding these overluminous SNe from cosmological analysis, though there is some overlap with the bluest of 'normal' SNe Ia. All three are overluminous in their UV absolute magnitudes compared to normal and broad SNe Ia, but SNe 2011aa and 2012dn are not optically overluminous compared to normal SNe Ia. The integrated luminosity curves of SNe 2011aa and 2012dn in the UVOT range (1600-6000 Å) are only half as bright as SN 2009dc, implying a smaller {sup 56}Ni yield. While it is not enough to strongly affect the bolometric flux, the early time mid-UV flux makes a significant contribution at early times. The strong spectral features in the mid-UV spectra of SNe 2009dc and 2012dn suggest a higher temperature and lower opacity to be the cause of the UV excess rather than a hot, smooth blackbody from shock interaction. Further work is needed to determine the ejecta and {sup 56}Ni masses of SNe 2011aa and 2012dn and to fully explain their high UV luminosities.

  14. Hubble Residuals of Nearby SN Ia Are Correlated with Host Galaxy Masses

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Hubble Residuals of Nearby SN Ia Are Correlated with Host Galaxy Masses Citation Details In-Document Search Title: Hubble Residuals of Nearby SN Ia Are Correlated with Host Galaxy Masses × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and is provided as a public service. Visit OSTI to utilize additional information resources in

  15. Type Ia supernova rate measurements to redshift 2.5 from CANDELS: Searching

    Office of Scientific and Technical Information (OSTI)

    for prompt explosions in the early universe (Journal Article) | SciTech Connect Type Ia supernova rate measurements to redshift 2.5 from CANDELS: Searching for prompt explosions in the early universe Citation Details In-Document Search Title: Type Ia supernova rate measurements to redshift 2.5 from CANDELS: Searching for prompt explosions in the early universe The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) was a multi-cycle treasury program on the Hubble Space

  16. Type Ia supernovae yielding distances with 3-4% precision (Journal Article)

    Office of Scientific and Technical Information (OSTI)

    | SciTech Connect Type Ia supernovae yielding distances with 3-4% precision Citation Details In-Document Search Title: Type Ia supernovae yielding distances with 3-4% precision × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and is provided as a public service. Visit OSTI to utilize additional information resources in energy science and technology. A paper copy of this

  17. A=16Mg (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    93TI07) (Not observed) See (1986AN07

  18. A=16Na (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    93TI07) (Not observed) See (1986AN07

  19. A=16Si (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    93TI07) (Not observed) See (1986AN07

  20. A=19Be (1995TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    95TI07) (Not observed) See (1983ANZQ

  1. A=19He (1995TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    95TI07) (Not observed) See (1983ANZQ

  2. A=19Li (1995TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    95TI07) (Not observed) See (1983ANZQ

  3. Microstructural studies on cast Zr[sub 3]Al-3wt%Nb

    SciTech Connect (OSTI)

    Tewari, R.; Dey, G.K.; Mukhopadhyay, P.; Banerjee, S. . Metallurgy Div.)

    1994-05-01

    In the binary Zr-Al system, Zr[sub 3]Al is the intermetallic phase richest in zirconium. In view of its low absorption cross section for thermal neutrons and its good strength and corrosion resistance, Zr[sub 3]Al may have possible applications as a structural material in thermal reactors. This phase has the ordered cubic L1[sub 2] structure and forms through the peritectoid reaction: [beta]-Zr + Zr[sub 2]Al[minus] > Zr[sub 3]Al, the reaction temperature being 1,292 K. Structurally Zr[sub 3]Al is quite similar to the [alpha][sub 2] or the Ti[sub 3]Al phase (ordered hexagonal DO[sub 19] structure) in the Ti-Al system, the two structures differing only in the stacking sequence of the close packed atomic layers. But for its inherent brittleness, Ti[sub 3]Al is a promising structural material for aerospace applications. It has, however, been demonstrated that niobium additions can reduce the brittleness of this phase. Studies on the Ti[sub 3]Al-Nb system have also shown that niobium stabilizes the high temperature [beta] phase (bcc structure) which, on cooling, can decompose through various phase reactions, generating some interesting microstructures. Similar studies on the Zr[sub 3]Al-Nb system have not been reported yet. The present paper describes some microstructural observations made on a cast Zr[sub 3]Al-3wt%Nb alloy.

  4. Effect of the top electrode materials on the resistive switching characteristics of TiO{sub 2} thin film

    SciTech Connect (OSTI)

    Oh, Sang Chul; Jung, Ho Yong; Lee, Heon

    2011-06-15

    Various metals, such as Pt, stainless steel (SUS), Al, Ni, and Ti, were used as a top electrode (TE) to evaluate the dependency of the resistive switching characteristics on the TE of the metal/TiO{sub 2}/Pt structure. The variation of the chemical composition of TiO{sub 2} in the metal/TiO{sub 2}/Pt structure before and after switching was examined to identify the factors affecting the resistive switching characteristics of the samples with various TE materials. In the case of TE/TiO{sub 2}/Pt structures showing unstable resistive switching behavior, e.g., those with the Al, Ni, and Ti TEs, secondary ion mass spectrometry revealed an increase in the oxygen concentration at the interface area between the TE metal and TiO{sub 2}. This suggests that the oxidation reaction at the interface between the TE metal and TiO{sub 2} might cause the TE/TiO{sub 2}/Pt structure to exhibit unstable resistive switching characteristics. According to these results, the oxidation reaction at the interface between the metal TE and TiO{sub 2} thin film is a primary factor affecting the resistive switching characteristics of TiO{sub 2}-based Resistive Random Access Memory devices.

  5. Strong near-infrared carbon in the Type Ia supernova iPTF13ebh

    SciTech Connect (OSTI)

    Hsiao, E. Y.; Burns, C. R.; Contreras, C.; Höflich, P.; Sand, D.; Marion, G. H.; Phillips, M. M.; Stritzinger, M.; González-Gaitán, S.; Mason, R. E.; Folatelli, G.; Parent, E.; Gall, C.; Amanullah, R.; Anupama, G. C.; Arcavi, I.; Banerjee, D. P. K.; Beletsky, Y.; Blanc, G. A.; Bloom, J. S.; Brown, P. J.; Campillay, A.; Cao, Y.; De Cia, A.; Diamond, T.; Freedman, W. L.; Gonzalez, C.; Goobar, A.; Holmbo, S.; Howell, D. A.; Johansson, J.; Kasliwal, M. M.; Kirshner, R. P.; Krisciunas, K.; Kulkarni, S. R.; Maguire, K.; Milne, P. A.; Morrell, N.; Nugent, P. E.; Ofek, E. O.; Osip, D.; Palunas, P.; Perley, D. A.; Persson, S. E.; Piro, A. L.; Rabus, M.; Roth, M.; Schiefelbein, J. M.; Srivastav, S.; Sullivan, M.; Suntzeff, N. B.; Surace, J.; Woźniak, P. R.; Yaron, O.

    2015-05-22

    We present near-infrared (NIR) time-series spectroscopy, as well as complementary ultraviolet (UV), optical, and NIR data, of the Type Ia supernova (SN Ia) iPTF13ebh, which was discovered within two days from the estimated time of explosion. The first NIR spectrum was taken merely 2.3 days after explosion and may be the earliest NIR spectrum yet obtained of a SN Ia. The most striking features in the spectrum are several NIR C I lines, and the C Iλ1.0693 μm line is the strongest ever observed in a SN Ia. Interestingly, no strong optical C II counterparts were found, even though the optical spectroscopic time series began early and is densely cadenced. Except at the very early epochs, within a few days from the time of explosion, we show that the strong NIR C I compared to the weaker optical C II appears to be general in SNe Ia. iPTF13ebh is a fast decliner with Δm15(B) = 1.79 ± 0.01, and its absolute magnitude obeys the linear part of the width-luminosity relation. It is therefore categorized as a “transitional” event, on the fast-declining end of normal SNe Ia as opposed to subluminous/91bg-like objects. iPTF13ebh shows NIR spectroscopic properties that are distinct from both the normal and subluminous/91bg-like classes, bridging the observed characteristics of the two classes. These NIR observations suggest that composition and density of the inner core are similar to that of 91bg-like events, and that it has a deep-reaching carbon burning layer that is not observed in more slowly declining SNe Ia. Furthermore, there is also a substantial difference between the explosion times inferred from the early-time light curve and the velocity evolution of the Si II λ0.6355 μm line, implying a long dark phase of ~4 days.

  6. Strong near-infrared carbon in the Type Ia supernova iPTF13ebh

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hsiao, E. Y.; Burns, C. R.; Contreras, C.; Höflich, P.; Sand, D.; Marion, G. H.; Phillips, M. M.; Stritzinger, M.; González-Gaitán, S.; Mason, R. E.; et al

    2015-05-22

    We present near-infrared (NIR) time-series spectroscopy, as well as complementary ultraviolet (UV), optical, and NIR data, of the Type Ia supernova (SN Ia) iPTF13ebh, which was discovered within two days from the estimated time of explosion. The first NIR spectrum was taken merely 2.3 days after explosion and may be the earliest NIR spectrum yet obtained of a SN Ia. The most striking features in the spectrum are several NIR C I lines, and the C Iλ1.0693 μm line is the strongest ever observed in a SN Ia. Interestingly, no strong optical C II counterparts were found, even though themore » optical spectroscopic time series began early and is densely cadenced. Except at the very early epochs, within a few days from the time of explosion, we show that the strong NIR C I compared to the weaker optical C II appears to be general in SNe Ia. iPTF13ebh is a fast decliner with Δm15(B) = 1.79 ± 0.01, and its absolute magnitude obeys the linear part of the width-luminosity relation. It is therefore categorized as a “transitional” event, on the fast-declining end of normal SNe Ia as opposed to subluminous/91bg-like objects. iPTF13ebh shows NIR spectroscopic properties that are distinct from both the normal and subluminous/91bg-like classes, bridging the observed characteristics of the two classes. These NIR observations suggest that composition and density of the inner core are similar to that of 91bg-like events, and that it has a deep-reaching carbon burning layer that is not observed in more slowly declining SNe Ia. Furthermore, there is also a substantial difference between the explosion times inferred from the early-time light curve and the velocity evolution of the Si II λ0.6355 μm line, implying a long dark phase of ~4 days.« less

  7. ALS Communications Group

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ALS Communications Group Print From left: Ashley White, Lori Tamura, Keri Troutman, and Carina Braun. The ALS Communications staff maintain the ALS Web site; write and edit all...

  8. About the ALS

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and science. You can also view ALS visitors and award recipients. Strategic Plan Roadmap for the renewal of ALS facility and scientific programs. Organization ALS...

  9. TYPE Ia SUPERNOVA COLORS AND EJECTA VELOCITIES: HIERARCHICAL BAYESIAN REGRESSION WITH NON-GAUSSIAN DISTRIBUTIONS

    SciTech Connect (OSTI)

    Mandel, Kaisey S.; Kirshner, Robert P. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Foley, Ryan J., E-mail: kmandel@cfa.harvard.edu [Astronomy Department, University of Illinois at Urbana-Champaign, 1002 West Green Street, Urbana, IL 61801 (United States)

    2014-12-20

    We investigate the statistical dependence of the peak intrinsic colors of Type Ia supernovae (SNe Ia) on their expansion velocities at maximum light, measured from the Si II ?6355 spectral feature. We construct a new hierarchical Bayesian regression model, accounting for the random effects of intrinsic scatter, measurement error, and reddening by host galaxy dust, and implement a Gibbs sampler and deviance information criteria to estimate the correlation. The method is applied to the apparent colors from BVRI light curves and Si II velocity data for 79 nearby SNe Ia. The apparent color distributions of high-velocity (HV) and normal velocity (NV) supernovae exhibit significant discrepancies for B V and B R, but not other colors. Hence, they are likely due to intrinsic color differences originating in the B band, rather than dust reddening. The mean intrinsic B V and B R color differences between HV and NV groups are 0.06 0.02 and 0.09 0.02 mag, respectively. A linear model finds significant slopes of 0.021 0.006 and 0.030 0.009 mag (10{sup 3} km s{sup 1}){sup 1} for intrinsic B V and B R colors versus velocity, respectively. Because the ejecta velocity distribution is skewed toward high velocities, these effects imply non-Gaussian intrinsic color distributions with skewness up to +0.3. Accounting for the intrinsic-color-velocity correlation results in corrections to A{sub V} extinction estimates as large as 0.12 mag for HV SNe Ia and +0.06 mag for NV events. Velocity measurements from SN Ia spectra have the potential to diminish systematic errors from the confounding of intrinsic colors and dust reddening affecting supernova distances.

  10. Effects of Point Defects and Impurities on Kinetics in NaAlH4

    Broader source: Energy.gov [DOE]

    A presentation showing that point defects play an important role in the kinetics of NaAlH4 including vacancies and interstitials consistent with observed effects of Ti.

  11. A=6n (2002TI10)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2002TI10) (Not illustrated) 6n has not been observed. See (1979AJ01, 1988AJ01) and references cited there. More recently (1990AL40) reports a search for 6n in a 14C(7Li, 6n) activation experiment at E(7Li) = 82 MeV. No evidence for 6n was obtained. The method of angular potential functions was used by (1989GO18) in a calculation of the properties of multi-neutron systems which indicated that these systems have no bound states. The ground state energy of a six-neutron drop has been computed with

  12. Access to the ALS

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Access to the ALS Access to the ALS Print User Access The ALS experiment floor (Building 6) is a Controlled Access Area for radiation protection. All ALS users are required to...

  13. Type Ia supernova rate measurements to redshift 2.5 from CANDELS: Searching for prompt explosions in the early universe

    SciTech Connect (OSTI)

    Rodney, Steven A.; Riess, Adam G.; Graur, Or; Jones, David O. [Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, MD 21218 (United States); Strolger, Louis-Gregory; Dahlen, Tomas; Casertano, Stefano; Ferguson, Henry C.; Koekemoer, Anton M. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Dickinson, Mark E. [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Garnavich, Peter [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Hayden, Brian [E.O. Lawrence Berkeley National Lab, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Jha, Saurabh W.; McCully, Curtis; Patel, Brandon [Department of Physics and Astronomy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 (United States); Kirshner, Robert P. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Mobasher, Bahram [Department of Physics and Astronomy, University of California, Riverside, CA 92521 (United States); Weiner, Benjamin J. [Department of Astronomy, University of Arizona, Tucson, AZ 85721 (United States); Cenko, S. Bradley [Astrophysics Science Division, NASA Goddard Space Flight Center, Mail Code 661, Greenbelt, MD 20771 (United States); Clubb, Kelsey I. [Department of Astronomy, University of California, Berkeley, CA 94720 (United States); and others

    2014-07-01

    The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) was a multi-cycle treasury program on the Hubble Space Telescope (HST) that surveyed a total area of ?0.25 deg{sup 2} with ?900 HST orbits spread across five fields over three years. Within these survey images we discovered 65 supernovae (SNe) of all types, out to z ? 2.5. We classify ?24 of these as Type Ia SNe (SNe Ia) based on host galaxy redshifts and SN photometry (supplemented by grism spectroscopy of six SNe). Here we present a measurement of the volumetric SN Ia rate as a function of redshift, reaching for the first time beyond z = 2 and putting new constraints on SN Ia progenitor models. Our highest redshift bin includes detections of SNe that exploded when the universe was only ?3 Gyr old and near the peak of the cosmic star formation history. This gives the CANDELS high redshift sample unique leverage for evaluating the fraction of SNe Ia that explode promptly after formation (<500 Myr). Combining the CANDELS rates with all available SN Ia rate measurements in the literature we find that this prompt SN Ia fraction is f{sub P} = 0.53{sub stat0.10}{sup 0.09}{sub sys0.26}{sup 0.10}, consistent with a delay time distribution that follows a simple t {sup 1} power law for all times t > 40 Myr. However, mild tension is apparent between ground-based low-z surveys and space-based high-z surveys. In both CANDELS and the sister HST program CLASH (Cluster Lensing And Supernova Survey with Hubble), we find a low rate of SNe Ia at z > 1. This could be a hint that prompt progenitors are in fact relatively rare, accounting for only 20% of all SN Ia explosionsthough further analysis and larger samples will be needed to examine that suggestion.

  14. Photoconductive response of a single Au nanorod coupled to LaAlO{sub

    Office of Scientific and Technical Information (OSTI)

    3}/SrTiO{sub 3} nanowires (Journal Article) | SciTech Connect Photoconductive response of a single Au nanorod coupled to LaAlO{sub 3}/SrTiO{sub 3} nanowires Citation Details In-Document Search Title: Photoconductive response of a single Au nanorod coupled to LaAlO{sub 3}/SrTiO{sub 3} nanowires Terahertz (THz) spectroscopy is an important tool that provides resonant access to free carrier motion, molecular rotation, lattice vibrations, excitonic, spin, and other degrees of freedom. Current

  15. SNe Ia tests of quintessence tracker cosmology in an anisotropic background

    SciTech Connect (OSTI)

    Miranda, W.; Carneiro, S.; Pigozzo, C. E-mail: saulo.carneiro@pq.cnpq.br

    2014-07-01

    We investigate the observational effects of a quintessence model in an anisotropic spacetime. The anisotropic metric is a non-rotating particular case of a generalized Gdel's metric and is classified as Bianchi III. This metric is an exact solution of the Einstein-Klein-Gordon field equations with an anisotropic scalar field ?, which is responsible for the anisotropy of the spacetime geometry. We test the model against observations of type Ia supernovae, analyzing the SDSS dataset calibrated with the MLCS2k2 fitter, and the results are compared to standard quintessence models with Ratra-Peebles potentials. We obtain a good agreement with observations, with best values for the matter and curvature density parameters ?{sub M}=0.29 and ?{sub k}=0.01 respectively. We conclude that present SNe Ia observations cannot, alone, distinguish a possible anisotropic axis in the cosmos.

  16. Comparing the host galaxies of type Ia, type II, and type Ibc supernovae

    SciTech Connect (OSTI)

    Shao, X.; Liang, Y. C.; Chen, X. Y.; Zhong, G. H.; Deng, L. C.; Zhang, B.; Shi, W. B.; Zhou, L.; Dennefeld, M.; Hammer, F.; Flores, H. E-mail: ycliang@bao.ac.cn

    2014-08-10

    We compare the host galaxies of 902 supernovae (SNe), including SNe Ia, SNe II, and SNe Ibc, which are selected by cross-matching the Asiago Supernova Catalog with the Sloan Digital Sky Survey (SDSS) Data Release 7. We selected an additional 213 galaxies by requiring the light fraction of spectral observations to be >15%, which could represent well the global properties of the galaxies. Among these 213 galaxies, 135 appear on the Baldwin-Phillips-Terlevich diagram, which allows us to compare the hosts in terms of whether they are star-forming (SF) galaxies, active galactic nuclei (AGNs; including composites, LINERs, and Seyfert 2s) or absorption-line galaxies (Absorps; i.e., their related emission lines are weak or non-existent). The diagrams related to the parameters D{sub n}(4000), H?{sub A}, stellar masses, star formation rates (SFRs), and specific SFRs for the SNe hosts show that almost all SNe II and most of the SNe Ibc occur in SF galaxies, which have a wide range of stellar masses and low D{sub n}(4000). The SNe Ia hosts as SF galaxies following similar trends. A significant fraction of SNe Ia occurs in AGNs and absorption-line galaxies, which are massive and have high D{sub n}(4000). The stellar population analysis from spectral synthesis fitting shows that the hosts of SNe II have a younger stellar population than hosts of SNe Ia. These results are compared with those of the 689 comparison galaxies where the SDSS fiber captures less than 15% of the total light. These comparison galaxies appear biased toward higher 12+log(O/H) (?0.1 dex) at a given stellar mass. Therefore, we believe the aperture effect should be kept in mind when the properties of the hosts for different types of SNe are discussed.

  17. THE EARLIEST NEAR-INFRARED TIME-SERIES SPECTROSCOPY OF A TYPE Ia SUPERNOVA

    SciTech Connect (OSTI)

    Hsiao, E. Y.; Phillips, M. M.; Morrell, N.; Contreras, C.; Roth, M.; Marion, G. H.; Kirshner, R. P.; Burns, C. R.; Freedman, W. L.; Persson, S. E.; Winge, C.; Gerardy, C. L.; Hoeflich, P.; Im, M.; Jeon, Y.; Pignata, G.; Stanishev, V.; and others

    2013-04-01

    We present ten medium-resolution, high signal-to-noise ratio near-infrared (NIR) spectra of SN 2011fe from SpeX on the NASA Infrared Telescope Facility (IRTF) and Gemini Near-Infrared Spectrograph (GNIRS) on Gemini North, obtained as part of the Carnegie Supernova Project. This data set constitutes the earliest time-series NIR spectroscopy of a Type Ia supernova (SN Ia), with the first spectrum obtained at 2.58 days past the explosion and covering -14.6 to +17.3 days relative to B-band maximum. C I {lambda}1.0693 {mu}m is detected in SN 2011fe with increasing strength up to maximum light. The delay in the onset of the NIR C I line demonstrates its potential to be an effective tracer of unprocessed material. For the first time in a SN Ia, the early rapid decline of the Mg II {lambda}1.0927 {mu}m velocity was observed, and the subsequent velocity is remarkably constant. The Mg II velocity during this constant phase locates the inner edge of carbon burning and probes the conditions under which the transition from deflagration to detonation occurs. We show that the Mg II velocity does not correlate with the optical light-curve decline rate {Delta}m{sub 15}(B). The prominent break at {approx}1.5 {mu}m is the main source of concern for NIR k-correction calculations. We demonstrate here that the feature has a uniform time evolution among SNe Ia, with the flux ratio across the break strongly correlated with {Delta}m{sub 15}(B). The predictability of the strength and the onset of this feature suggests that the associated k-correction uncertainties can be minimized with improved spectral templates.

  18. ALS Communications Group

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Communications Group Print From left: Ashley White, Lori Tamura, Keri Troutman, and Carina Braun. The ALS Communications staff maintain the ALS Web site; write and edit all print...

  19. ALS Users' Association Charter

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Awards: David A. Shirley Award for Outstanding Scientific Achievement at the ALS Klaus Halbach Award for Innovative Instrumentation at the ALS Tim Renner User Services Award for...

  20. ALS User Meeting

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    User Meeting ALS User Meeting web banner ALS User Meeting: October 5-7, 2015 Home Agenda Awards Exhibitors Lodging Posters Registration Transportation Workshops Contact Us User...

  1. ALS Users' Association Charter

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Source (ALS) at the Lawrence Berkeley Laboratory (LBL) for their research and the ALS management, as well as to provide a channel for communication with other synchrotron...

  2. ALS User Meeting

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ALS User Meeting Print web banner ALS User Meeting: October 5-7, 2015 Home Agenda Awards Exhibitors Lodging Posters Registration Transportation Workshops Contact Us User Meeting...

  3. ALS User Meeting

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ALS User Meeting October 3-5, 2011 Lawrence Berkeley National Laboratory, California

  4. SPECTROPOLARIMETRY OF THE TYPE Ia SN 2007sr TWO MONTHS AFTER MAXIMUM LIGHT

    SciTech Connect (OSTI)

    Zelaya, P.; Quinn, J. R.; Clocchiatti, A.; Baade, D.; Patat, F.; Hoeflich, P.; Maund, J.; Wang, L.; Wheeler, J. C.

    2013-02-01

    We present late-time spectropolarimetric observations of SN 2007sr, obtained with the Very Large Telescope at the ESO Paranal Observatory when the object was 63 days after maximum light. The late-time spectrum displays strong line polarization in the Ca II absorption features. SN 2007sr adds to the case of some normal Type Ia supernovae that show high line polarization or repolarization at late times, a fact that might be connected with the presence of high-velocity features at early times.

  5. IA REP0 SAND85-2809 Unlimited Release UC-92A

    Office of Scientific and Technical Information (OSTI)

    IA REP0 SAND85-2809 Unlimited Release UC-92A Printed July 1986 High Energy Gas Fracture Experiments in Fluid-Filled Boreholes-Potential Geothermal Application J. F. Cuderman, T. Y. Chu, J. Jung, R. D. Jacobson Prepared by Sandia National Laboratories Albuquerque, New Mexico 87 185 and Livermore, California 94550 for the United States Department of Energy under Contract DE-AC04-76DP00789 DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States

  6. Hard X-ray emission and {sup 44}Ti line features of the Tycho supernova remnant

    SciTech Connect (OSTI)

    Wang, Wei [National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100012 (China); Li, Zhuo, E-mail: wangwei@bao.ac.cn, E-mail: zhuo.li@pku.edu.cn [Department of Astronomy and Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China)

    2014-07-10

    A deep hard X-ray survey of the International Gamma-Ray Astrophysics Laboratory (INTEGRAL) satellite has detected for the first time non-thermal emission up to 90 keV in the Tycho supernova (SN) remnant. Its 3-100 keV spectrum is fitted with a thermal bremsstrahlung of kT ? 0.81 0.45 keV plus a power-law model of ? ? 3.01 0.16. Based on diffusive shock acceleration theory, this non-thermal emission, together with radio measurements, implies that the Tycho remnant may not accelerate protons up to >PeV but to hundreds TeV. Only heavier nuclei may be accelerated to the cosmic ray spectral 'knee'. In addition, using INTEGRAL, we search for soft gamma-ray lines at 67.9 and 78.4 keV that come from the decay of radioactive {sup 44}Ti in the Tycho remnant. A bump feature in the 60-90 keV energy band, potentially associated with the {sup 44}Ti line emission, is found with a marginal significance level of ?2.6?. The corresponding 3? upper limit on the {sup 44}Ti line flux amounts to 1.5 10{sup 5} photon cm{sup 2} s{sup 1}. Implications on the progenitor of the Tycho SN, considered to be a Type Ia SN prototype, are discussed.

  7. A=10F (2004TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2004TI06) (Not illustrated) Not observed: see (1979AJ01). See also (1988AJ01

  8. A=10Ne (2004TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2004TI06) (Not illustrated) Not observed: see (1979AJ01). See also (1988AJ01

  9. A=10O (2004TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2004TI06) (Not illustrated) Not observed: see (1979AJ01). See also (1988AJ01

  10. A=17He (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    93TI07) (Not illustrated) Not observed: see (1986AJ04, 1988POZS

  11. A=17Li (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    93TI07) (Not illustrated) Not observed: see (1986AJ04, 1988POZS

  12. A=17Mg (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Mg (1993TI07) (Not observed) See (1983ANZQ, 1988WA18, 1992AV03).

  13. A=17P (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    93TI07) (Not observed) See (1983ANZQ, 1988WA18, 1992AV03

  14. A=17Si (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Si (1993TI07) (Not observed) See (1983ANZQ, 1988WA18, 1992AV03).

  15. A=18He (1995TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    95TI07) (Not illustrated) Not observed: See (1982AV1A, 1983ANZQ

  16. A=20Be (1998TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    98TI06) (Not observed) See (1977CE05, 1983ANZQ, 1986AN07, 1987SIZX

  17. A=20n (1998TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    98TI06) (Not observed) See (1977CE05, 1983ANZQ, 1986AN07, 1987SIZX

  18. A=7H (2002TI10)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2002TI10) (Not illustrated) 7H has not been observed. Attempts have been made to detect it in the spontaneous fission of 252Cf (1982AL33) and in the 7Li(π-, π+) reaction [see (1984AJ01)]. A study of 9Be(π-, 2p) (1987GO25) found no evidence for 7H. See also the review of (1989OG1B) and the 7Li(π-, π+) investigation reported in (1989GR06). The ground state is calculated to have Jπ = 1/2+ and to be unstable with respect to 1n, 2n, 3n and 4n emission. Excited states are predicted at 4.84, 5.00

  19. Consistent use of type Ia supernovae highly magnified by galaxy clusters to constrain the cosmological parameters

    SciTech Connect (OSTI)

    Zitrin, Adi [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, MS 249-17, Pasadena, CA 91125 (United States); Redlich, Matthias [Universitt Heidelberg, Zentrum fr Astronomie, Institut fr Theoretische Astrophysik, Philosophenweg 12, D-69120 Heidelberg (Germany); Broadhurst, Tom, E-mail: adizitrin@gmail.com [Department of Theoretical Physics, University of Basque Country UPV/EHU, Bilbao (Spain)

    2014-07-01

    We discuss how Type Ia supernovae (SNe) strongly magnified by foreground galaxy clusters should be self-consistently treated when used in samples fitted for the cosmological parameters. While the cluster lens magnification of a SN can be well constrained from sets of multiple images of various background galaxies with measured redshifts, its value is typically dependent on the fiducial set of cosmological parameters used to construct the mass model. In such cases, one should not naively demagnify the observed SN luminosity by the model magnification into the expected Hubble diagram, which would create a bias, but instead take into account the cosmological parameters a priori chosen to construct the mass model. We quantify the effect and find that a systematic error of typically a few percent, up to a few dozen percent per magnified SN may be propagated onto a cosmological parameter fit unless the cosmology assumed for the mass model is taken into account (the bias can be even larger if the SN is lying very near the critical curves). We also simulate how such a bias propagates onto the cosmological parameter fit using the Union2.1 sample supplemented with strongly magnified SNe. The resulting bias on the deduced cosmological parameters is generally at the few percent level, if only few biased SNe are included, and increases with the number of lensed SNe and their redshift. Samples containing magnified Type Ia SNe, e.g., from ongoing cluster surveys, should readily account for this possible bias.

  20. TYCHO SN 1572: A NAKED Ia SUPERNOVA REMNANT WITHOUT AN ASSOCIATED AMBIENT MOLECULAR CLOUD

    SciTech Connect (OSTI)

    Tian, W. W.; Leahy, D. A.

    2011-03-10

    The historical supernova remnant (SNR) Tycho SN 1572 originates from the explosion of a normal Type Ia supernova that is believed to have originated from a carbon-oxygen white dwarf in a binary system. We analyze the 21 cm continuum, H I, and {sup 12}CO-line data from the Canadian Galactic Plane Survey in the direction of SN 1572 and the surrounding region. We construct H I absorption spectra to SN 1572 and three nearby compact sources. We conclude that SN 1572 has no molecular cloud interaction, which argues against previous claims that a molecular cloud is interacting with the SNR. This new result does not support a recent claim that dust, newly detected by AKARI, originates from such an SNR-cloud interaction. We suggest that the SNR has a kinematic distance of 2.5-3.0 kpc based on a nonlinear rotational curve model. Very high energy {gamma}-ray emission from the remnant has been detected by the VERITAS telescope, so our result shows that its origin should not be an SNR-cloud interaction. Both radio and X-ray observations support that SN 1572 is an isolated Type Ia SNR.

  1. Spectroscopic Determination of the Low Redshift Type Ia Supernova Rate from the Sloan Digital Sky Survey

    SciTech Connect (OSTI)

    Krughoff, K. S.; Connolly, Andrew J.; Frieman, Joshua; SubbaRao, Mark; Kilper, Gary; Schneider, Donald P.

    2011-04-10

    Supernova rates are directly coupled to high mass stellar birth and evolution. As such, they are one of the few direct measures of the history of cosmic stellar evolution. In this paper we describe an probabilistic technique for identifying supernovae within spectroscopic samples of galaxies. We present a study of 52 type Ia supernovae ranging in age from -14 days to +40 days extracted from a parent sample of \\simeq 50,000 spectra from the SDSS DR5. We find a Supernova Rate (SNR) of 0.472^{+0.048}_{-0.039}(Systematic)^{+0.081}_{-0.071}(Statistical)SNu at a redshift of = 0.1. This value is higher than other values at low redshift at the 1{\\sigma}, but is consistent at the 3{\\sigma} level. The 52 supernova candidates used in this study comprise the third largest sample of supernovae used in a type Ia rate determination to date. In this paper we demonstrate the potential for the described approach for detecting supernovae in future spectroscopic surveys.

  2. ALS Communications Group

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ALS Communications Group Print From left: Ashley White, Lori Tamura, and Keri Troutman. The ALS Communications staff maintain the ALS Web site; write and edit all print and electronic publications for the ALS, including Science Highlights, Science Briefs, brochures, handouts, and the monthly newsletter ALSNews; and create educational and scientific outreach materials. In addition, members of the group organize bi-monthly Science Cafés, create conference and workshop Web sites and publicity, and

  3. Access to the ALS

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Access to the ALS Print User Access The ALS experiment floor (Building 6) is a Controlled Access Area for radiation protection. All ALS users are required to register with the ALS User Services Office and take safety training (see Complete Safety Training ) before they are issued a Berkeley Lab ID badge and granted access to the facility. Note: Users arriving at the ALS outside registration business hours (Monday-Friday 8:00 a.m.-4:00 p.m.) must notify the User Office in advance and have all

  4. Microstructural evaluation of NiTi-based films deposited by magnetron sputtering

    SciTech Connect (OSTI)

    Crăciunescu, Corneliu M. Mitelea, Ion Budău, Victor; Ercuţa, Aurel

    2014-11-24

    Shape memory alloy films belonging to the NiTi-based systems were deposited on heated and unheated substrates, by magnetron sputtering in a custom made system, and their structure and composition was analyzed using electron microscopy. Several substrates were used for the depositions: glass, Cu-Zn-Al, Cu-Al-Ni and Ti-NiCu shape memory alloy ribbons and kapton. The composition of the Ti-Ni-Cu films showed limited differences, compared to the one of the target and the microstructure for the DC magnetron sputtering revealed crystallized structure with features determined on peel off samples from a Si wafer. Both inter and transcrystalline fractures were observed and related to the interfacial stress developed on cooling from deposition temperature.

  5. Near-infrared line identification in type Ia supernovae during the transitional phase

    SciTech Connect (OSTI)

    Friesen, Brian; Baron, E.; Wisniewski, John P.; Miller, Timothy R.; Parrent, Jerod T.; Thomas, R. C.; Marion, G. H.

    2014-09-10

    We present near-infrared synthetic spectra of a delayed-detonation hydrodynamical model and compare them to observed spectra of four normal Type Ia supernovae ranging from day +56.5 to day +85. This is the epoch during which supernovae are believed to be undergoing the transition from the photospheric phase, where spectra are characterized by line scattering above an optically thick photosphere, to the nebular phase, where spectra consist of optically thin emission from forbidden lines. We find that most spectral features in the near-infrared can be accounted for by permitted lines of Fe II and Co II. In addition, we find that [Ni II] fits the emission feature near 1.98 μm, suggesting that a substantial mass of {sup 58}Ni exists near the center of the ejecta in these objects, arising from nuclear burning at high density.

  6. EARLY OBSERVATIONS AND ANALYSIS OF THE TYPE Ia SN 2014J IN M82

    SciTech Connect (OSTI)

    Marion, G. H.; Vink, J. [University of Texas at Austin, 1 University Station C1400, Austin, TX 78712-0259 (United States); Sand, D. J. [Physics Department, Texas Tech University, Lubbock, TX 79409 (United States); Hsiao, E. Y. [Carnegie Observatories, Las Campanas Observatory, Colina El Pino, Casilla 601 (Chile); Banerjee, D. P. K.; Joshi, V.; Venkataraman, V.; Ashok, N. M. [Astronomy and Astrophysics Division, Physical Research Laboratory, Navrangapura, Ahmedabad - 380009, Gujarat (India); Valenti, S.; Howell, D. A. [Las Cumbres Observatory Global Telescope Network, 6740 Cortona Drive, Suite 102, Santa Barbara, CA 93117 (United States); Stritzinger, M. D. [Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark); Amanullah, R.; Johansson, J. [The Oskar Klein Centre, Physics Department, Stockholm University, Albanova University Center, SE 106 91 Stockholm (Sweden); Binzel, R. P. [Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Bochanski, J. J. [Haverford College, 370 Lancaster Avenue, Haverford, PA 19041 (United States); Bryngelson, G. L. [Department of Physics and Astronomy, Francis Marion University, 4822 East Palmetto Street, Florence, SC 29506 (United States); Burns, C. R. [Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Drozdov, D. [Department of Physics and Astronomy, Clemson University, 8304 University Station, Clemson, SC 29634 (United States); Fieber-Beyer, S. K. [Department of Space Studies, University of North Dakota, University Stop 9008, ND 58202 (United States); Graham, M. L., E-mail: hman@astro.as.utexas.edu [Astronomy Department, University of California at Berkeley, Berkeley, CA 94720 (United States); and others

    2015-01-01

    We present optical and near infrared (NIR) observations of the nearby Type Ia SN 2014J. Seventeen optical and 23 NIR spectra were obtained from 10days before (10d) to 10days after (+10d) the time of maximum B-band brightness. The relative strengths of absorption features and their patterns of development can be compared at one day intervals throughout most of this period. Carbon is not detected in the optical spectra, but we identify C I?1.0693 in the NIR spectra. Mg II lines with high oscillator strengths have higher initial velocities than other Mg II lines. We show that the velocity differences can be explained by differences in optical depths due to oscillator strengths. The spectra of SN 2014J show that it is a normal SN Ia, but many parameters are near the boundaries between normal and high-velocity subclasses. The velocities for O I, Mg II, Si II, S II, Ca II, and Fe II suggest that SN 2014J has a layered structure with little or no mixing. That result is consistent with the delayed detonation explosion models. We also report photometric observations, obtained from 10d to +29d, in the UBVRIJH and K{sub s} bands. The template fitting package SNooPy is used to interpret the light curves and to derive photometric parameters. Using R{sub V} = 1.46, which is consistent with previous studies, SNooPy finds that A{sub V} = 1.80 for E(B V){sub host} = 1.23 0.06 mag. The maximum B-band brightness of 19.19 0.10 mag was reached on February 1.74 UT 0.13days and the supernova has a decline parameter, ?m {sub 15}, of 1.12 0.02 mag.

  7. EVOLUTION OF POST-IMPACT REMNANT HELIUM STARS IN TYPE Ia SUPERNOVA REMNANTS WITHIN THE SINGLE-DEGENERATE SCENARIO

    SciTech Connect (OSTI)

    Pan, Kuo-Chuan; Ricker, Paul M.; Taam, Ronald E. E-mail: pmricker@illinois.edu

    2013-08-10

    The progenitor systems of Type Ia supernovae (SNe Ia) are still under debate. Based on recent hydrodynamics simulations, non-degenerate companions in the single-degenerate scenario (SDS) should survive the supernova (SN) impact. One way to distinguish between the SDS and the double-degenerate scenario is to search for the post-impact remnant stars (PIRSs) in SN Ia remnants. Using a technique that combines multi-dimensional hydrodynamics simulations with one-dimensional stellar evolution simulations, we have examined the post-impact evolution of helium-rich binary companions in the SDS. It is found that these helium-rich PIRSs (He PIRSs) dramatically expand and evolve to a luminous phase (L {approx} 10{sup 4} L{sub Sun }) about 10 yr after an SN explosion. Subsequently, they contract and evolve to become hot blue-subdwarf-like (sdO-like) stars by releasing gravitational energy, persisting as sdO-like stars for several million years before evolving to the helium red-giant phase. We therefore predict that a luminous OB-like star should be detectable within {approx}30 yr after the SN explosion. Thereafter, it will shrink and become an sdO-like star in the central regions of SN Ia remnants within star-forming regions for SN Ia progenitors evolved via the helium-star channel in the SDS. These He PIRSs are predicted to be rapidly rotating (v{sub rot} {approx}> 50 km s{sup -1}) and to have high spatial velocities (v{sub linear} {approx}> 500 km s{sup -1}). Furthermore, if SN remnants have diffused away and are not recognizable at a later stage, He PIRSs could be an additional source of single sdO stars and/or hypervelocity stars.

  8. Measurements of the Rate of Type Ia Supernovae at Redshift z < ~0.3 from the SDSS-II Supernova Survey

    SciTech Connect (OSTI)

    Dilday, Benjamin; Smith, Mathew; Bassett, Bruce; Becker, Andrew; Bender, Ralf; Castander, Francisco; Cinabro, David; Filippenko, Alexei V.; Frieman, Joshua A.; Galbany, Lluis; Garnavich, Peter M.; /Notre Dame U. /Stockholm U., OKC /Stockholm U.

    2010-01-01

    We present a measurement of the volumetric Type Ia supernova (SN Ia) rate based on data from the Sloan Digital Sky Survey II (SDSS-II) Supernova Survey. The adopted sample of supernovae (SNe) includes 516 SNe Ia at redshift z {approx}< 0.3, of which 270 (52%) are spectroscopically identified as SNe Ia. The remaining 246 SNe Ia were identified through their light curves; 113 of these objects have spectroscopic redshifts from spectra of their host galaxy, and 133 have photometric redshifts estimated from the SN light curves. Based on consideration of 87 spectroscopically confirmed non-Ia SNe discovered by the SDSS-II SN Survey, we estimate that 2.04{sub -0.95}{sup +1.61}% of the photometric SNe Ia may be misidentified. The sample of SNe Ia used in this measurement represents an order of magnitude increase in the statistics for SN Ia rate measurements in the redshift range covered by the SDSS-II Supernova Survey. If we assume a SN Ia rate that is constant at low redshift (z < 0.15), then the SN observations can be used to infer a value of the SN rate of r{sub V} = (2.69{sub -0.30-0.01}{sup +0.34+0.21}) x 10{sup -5} SNe yr{sup -1} Mpc{sup -3} (H{sub 0}/(70 km s{sup -1} Mpc{sup -1})){sup 3} at a mean redshift of {approx} 0.12, based on 79 SNe Ia of which 72 are spectroscopically confirmed. However, the large sample of SNe Ia included in this study allows us to place constraints on the redshift dependence of the SN Ia rate based on the SDSS-II Supernova Survey data alone. Fitting a power-law model of the SN rate evolution, r{sub V} (z) = A{sub p} x ((1+z)/(1+z{sub 0})){sup {nu}}, over the redshift range 0.0 < z < 0.3 with z{sub 0} = 0.21, results in A{sub p} = (3.43{sub -0.15}{sup +0.15}) x 10{sup -5} SNe yr{sup -1} Mpc{sup -3} (H{sub 0}/(70 km s{sup -1} Mpc{sup -1})){sup 3} and {nu} = 2.04{sub -0.89}{sup +0.90}.

  9. ALS Activity Reports

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ALS Activity Reports Print These hard-copy annual reports were produced from 1993-2006. They illustrated the depth and breadth of the ALS scientific program with a selection of research results. They also summarized operations and ongoing R&D, highlighted educational outreach efforts and special events, and provided yearly documentation of the beamlines and publications. The Activity Report was replaced in 2007 by ALS Spectrum. The reports for 1996-2006 are available here. Activity Report

  10. ALS Postdoctoral Fellowship Highlights

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Postdoctoral Fellowship Highlights Print Since its inception in 2005, the ALS Postdoctoral Fellowship program has supported young scientists in new and ongoing research projects at the ALS. In many cases, the postdoctoral fellows were also supported by collaborating institutions. These postdoc "highlights" -listed chronologically-feature a description of their projects while at the ALS, resulting publications, and their current positions and research activities. Name Year/Beamline

  11. ALS Users' Association Charter

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Users' Executive Committee ALS Users' Association Charter Print The purpose of the Advanced Light Source Users' Association (ALSUA) is to provide an organized framework for the interaction between those who use the Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory (LBL) for their research and the ALS management, as well as to provide a channel for communication with other synchrotron radiation laboratories and, on suitable occasions, with federal agencies. The ALSUA, representing

  12. ALS Biosciences Crosscutting Review

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Biosciences Crosscutting Review ALS Biosciences Crosscutting Review Print by Steve Kevan and Corie Ralston The ALS organized and recently held a two-day crosscutting review of its bioscience programs. The ALS Scientific Advisory Committee (SAC) sponsors these reviews, which are intended to evaluate the performance of entire research subdisciplines served by the facility and to motivate strategic thinking about capabilities and research directions that are ripe for future development. SAC member

  13. ALS User Meeting Archives

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    proposals submitted to funding agencies and for contributions promoting the ALS in general. 1999 Roland Kawakami, Z.-Q. Qiu (both of the University of California, Berkeley), and...

  14. ALS Chemistry Lab

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the great majority of hazardous chemicals at the ALS are stored in these facilities. Standard chemical safety engineering, administrative and PPE controls are employed in...

  15. ALS Chemistry Lab

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    These spaces are dedicated for chemistry work that involves higher quantities, higher toxicity or reactivity, andor more complex work activity than is allowed on the ALS...

  16. Science DMZ for ALS

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ALS Science Engagement Move your data Programs & Workshops Science Requirements Reviews Case Studies OSCARS Case Studies Science DMZ Case Studies Science DMZ @ UF Science DMZ @ CU ...

  17. 2013 ALS User Meeting

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    3 ALS User Meeting banner Home Agenda Awards Exhibitors Lodging Posters Registration T-Shirt Contest Transportation Workshops Contact Us User Meeting Archives Users' Executive...

  18. 2013 ALS User Meeting

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2013 ALS User Meeting Print banner Home Agenda Awards Exhibitors Lodging Posters Registration T-Shirt Contest Transportation Workshops Contact Us User Meeting Archives Users'...

  19. TYPE Ia SUPERNOVA REMNANT SHELL AT z = 3.5 SEEN IN THE THREE SIGHTLINES TOWARD THE GRAVITATIONALLY LENSED QSO B1422+231

    SciTech Connect (OSTI)

    Hamano, Satoshi; Kobayashi, Naoto [Institute of Astronomy, University of Tokyo, 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan); Kondo, Sohei [Koyama Astronomical Observatory, Kyoto-Sangyo University, Motoyama, Kamigamo, Kita-Ku, Kyoto 603-8555 (Japan); Tsujimoto, Takuji [National Astronomical Observatory of Japan and Department of Astronomical Science, Graduate University for Advanced Studies, 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan); Okoshi, Katsuya [Faculty of Industrial Science and Technology, Tokyo University of Science, 102-1 Tomino, Oshamanbe, Hokkaido 049-3514 (Japan); Shigeyama, Toshikazu, E-mail: hamano@ioa.s.u-tokyo.ac.jp [Research Center for the Early Universe, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033 (Japan)

    2012-08-01

    Using the Subaru 8.2 m Telescope with the IRCS Echelle spectrograph, we obtained high-resolution (R = 10,000) near-infrared (1.01-1.38 {mu}m) spectra of images A and B of the gravitationally lensed QSO B1422+231 (z = 3.628) consisting of four known lensed images. We detected Mg II absorption lines at z = 3.54, which show a large variance of column densities ({approx}0.3 dex) and velocities ({approx}10 km s{sup -1}) between sightlines A and B with a projected separation of only 8.4h{sup -1}{sub 70} pc at that redshift. This is the smallest spatial structure of the high-z gas clouds ever detected after Rauch et al. found a 20 pc scale structure for the same z = 3.54 absorption system using optical spectra of images A and C. The observed systematic variances imply that the system is an expanding shell as originally suggested by Rauch et al. By combining the data for three sightlines, we managed to constrain the radius and expansion velocity of the shell ({approx}50-100 pc, 130 km s{sup -1}), concluding that the shell is truly a supernova remnant (SNR) rather than other types of shell objects, such as a giant H II region. We also detected strong Fe II absorption lines for this system, but with much broader Doppler width than that of {alpha}-element lines. We suggest that this Fe II absorption line originates in a localized Fe II-rich gas cloud that is not completely mixed with plowed ambient interstellar gas clouds showing other {alpha}-element low-ion absorption lines. Along with the Fe richness, we conclude that the SNR is produced by an SN Ia explosion.

  20. A=20He (1998TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    He (1998TI06) (Not observed) See (1977CE05, 1983ANZQ, 1986AN07, 1987SIZX).

  1. A=20Li (1998TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Li (1998TI06) (Not observed) See (1977CE05, 1983ANZQ, 1986AN07, 1987SIZX).

  2. A=5n (2002TI10)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2002TI10) (Not illustrated) See also the A = 5 introductory discussion titled A = 5 resonance parameters.

  3. A Measurement of the Rate of Type Ia Supernovae in Galaxy Clusters from the SDSS-II Supernova Survey

    SciTech Connect (OSTI)

    Dilday, Benjamin; Bassett, Bruce; Becker, Andrew; Bender, Ralf; Castander, Francisco; Cinabro, David; Frieman, Joshua A.; Galbany, Lluis; Garnavich, Peter; Goobar, Ariel; Hopp, Ulrich; /Munich, Tech. U. /Munich U. Observ. /Tokyo U.

    2010-03-01

    We present measurements of the Type Ia supernova (SN) rate in galaxy clusters based on data from the Sloan Digital Sky Survey-II (SDSS-II) Supernova Survey. The cluster SN Ia rate is determined from 9 SN events in a set of 71 C4 clusters at z {le} 0.17 and 27 SN events in 492 maxBCG clusters at 0.1 {le} z {le} 0.3. We find values for the cluster SN Ia rate of (0.37{sub -0.12-0.01}{sup +0.17+0.01}) SNur h{sup 2} and (0.55{sub -0.11-0.01}{sup +0.13+0.02}) SNur h{sup 2} (SNux = 10{sup -12}L{sub x{circle_dot}}{sup -1} yr{sup -1}) in C4 and maxBCG clusters, respectively, where the quoted errors are statistical and systematic, respectively. The SN rate for early-type galaxies is found to be (0.31{sub -0.12-0.01}{sup +0.18+0.01}) SNur h{sup 2} and (0.49{sub -0.11-0.01}{sup +0.15+0.02}) SNur h{sup 2} in C4 and maxBCG clusters, respectively. The SN rate for the brightest cluster galaxies (BCG) is found to be (2.04{sub -1.11-0.04}{sup +1.99+0.07}) SNur h{sup 2} and (0.36{sub -0.30-0.01}{sup +0.84+0.01}) SNur h{sup 2} in C4 and maxBCG clusters, respectively. The ratio of the SN Ia rate in cluster early-type galaxies to that of the SN Ia rate in field early-type galaxies is 1.94{sub -0.91-0.015}{sup +1.31+0.043} and 3.02{sub -1.03-0.048}{sup +1.31+0.062}, for C4 and maxBCG clusters, respectively. The SN rate in galaxy clusters as a function of redshift, which probes the late time SN Ia delay distribution, shows only weak dependence on redshift. Combining our current measurements with previous measurements, we fit the cluster SN Ia rate data to a linear function of redshift, and find r{sub L} = [(0.49{sub -0.14}{sup +0.15}) + (0.91{sub -0.81}{sup +0.85}) x z] SNuB h{sup 2}. A comparison of the radial distribution of SNe in cluster to field early-type galaxies shows possible evidence for an enhancement of the SN rate in the cores of cluster early-type galaxies. With an observation of at most 3 hostless, intra-cluster SNe Ia, we estimate the fraction of cluster SNe that are hostless to be (9.4{sub -5.1}{sup +8.3})%.

  4. TiN coated aluminum electrodes for DC high voltage electron guns

    SciTech Connect (OSTI)

    Mamun, Md Abdullah A.; Elmustafa, Abdelmageed A.; Taus, Rhys; Forman, Eric; Poelker, Matthew

    2015-05-15

    Preparing electrodes made of metals like stainless steel, for use inside DC high voltage electron guns, is a labor-intensive and time-consuming process. In this paper, the authors report the exceptional high voltage performance of aluminum electrodes coated with hard titanium nitride (TiN). The aluminum electrodes were comparatively easy to manufacture and required only hours of mechanical polishing using silicon carbide paper, prior to coating with TiN by a commercial vendor. The high voltage performance of three TiN-coated aluminum electrodes, before and after gas conditioning with helium, was compared to that of bare aluminum electrodes, and electrodes manufactured from titanium alloy (Ti-6Al-4V). Following gas conditioning, each TiN-coated aluminum electrode reached −225 kV bias voltage while generating less than 100 pA of field emission (<10 pA) using a 40 mm cathode/anode gap, corresponding to field strength of 13.7 MV/m. Smaller gaps were studied to evaluate electrode performance at higher field strength with the best performing TiN-coated aluminum electrode reaching ∼22.5 MV/m with field emission less than 100 pA. These results were comparable to those obtained from our best-performing electrodes manufactured from stainless steel, titanium alloy and niobium, as reported in references cited below. The TiN coating provided a very smooth surface and with mechanical properties of the coating (hardness and modulus) superior to those of stainless steel, titanium-alloy, and niobium electrodes. These features likely contributed to the improved high voltage performance of the TiN-coated aluminum electrodes.

  5. FIRST EVIDENCE OF GLOBULAR CLUSTER FORMATION FROM THE EJECTA OF PROMPT TYPE Ia SUPERNOVAE

    SciTech Connect (OSTI)

    Tsujimoto, Takuji [National Astronomical Observatory of Japan, Mitaka-shi, Tokyo 181-8588 (Japan); Bekki, Kenji, E-mail: taku.tsujimoto@nao.ac.jp [ICRAR, M468, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009 (Australia)

    2012-06-01

    Recent spectroscopic observations of globular clusters (GCs) in the Large Magellanic Cloud (LMC) have discovered that one of the intermediate-age GCs, NGC 1718, with [Fe/H] = -0.7 has an extremely low [Mg/Fe] ratio of {approx}-0.9. We propose that NGC 1718 was formed from the ejecta of Type Ia supernovae mixed with very metal-poor ([Fe/H] <-1.3) gas about {approx}2 Gyr ago. The proposed scenario is shown to be consistent with the observed abundances of Fe-group elements such as Cr, Mn, and Ni. In addition, compelling evidence for asymptotic giant branch stars playing a role in chemical enrichment during this GC formation is found. We suggest that the origin of the metal-poor gas is closely associated with efficient gas transfer from the outer gas disk of the Small Magellanic Cloud to the LMC disk. We anticipate that the outer part of the LMC disk contains field stars exhibiting significantly low [Mg/Fe] ratios, formed through the same process as NGC 1718.

  6. PRODUCTION OF THE p-PROCESS NUCLEI IN THE CARBON-DEFLAGRATION MODEL FOR TYPE Ia SUPERNOVAE

    SciTech Connect (OSTI)

    Kusakabe, Motohiko; Iwamoto, Nobuyuki; Nomoto, Ken'ichi E-mail: iwamoto.nobuyuki@jaea.go.jp

    2011-01-01

    We calculate the nucleosynthesis of proton-rich isotopes in the carbon-deflagration model for Type Ia supernovae (SNe Ia). The seed abundances are obtained by calculating the s-process nucleosynthesis that is expected to occur in the repeating helium shell flashes on the carbon-oxygen (CO) white dwarf (WD) during mass accretion from a binary companion. When the deflagration wave passes through the outer layer of the CO WD, p-nuclei are produced by photodisintegration reactions on s-nuclei in a region where the peak temperature ranges from 1.9 to 3.6 x 10{sup 9} K. We confirm the sensitivity of the p-process on the initial distribution of s-nuclei. We show that the initial C/O ratio in the WD does not affect much the yield of p-nuclei. On the other hand, the abundance of {sup 22}Ne left after s-processing has a large influence on the p-process via the {sup 22}Ne({alpha},n) reaction. We find that about 50% of p-nuclides are co-produced when normalized to their solar abundances in all adopted cases of seed distribution. Mo and Ru, which are largely underproduced in Type II supernovae (SNe II), are produced more than in SNe II although they are underproduced with respect to the yield levels of other p-nuclides. The ratios between p-nuclei and iron in the ejecta are larger than the solar ratios by a factor of 1.2. We also compare the yields of oxygen, iron, and p-nuclides in SNe Ia and SNe II and suggest that SNe Ia could make a larger contribution than SNe II to the solar system content of p-nuclei.

  7. ALS Staff Photo

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Print On May 14, 2013, members of ALS staff posed for a group photo in front of the dome. A hi-res version can be downloaded here. The last staff photo was taken in 2006. 2013...

  8. ALS Users' Association Charter

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    facility. Thorough discussion with users of current projects, as well as plans for the future, will place ALS management in a better position to evaluate the needs of users and...

  9. ALS Chemistry Lab

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    To Gain Access to the ALS Chemistry Labs Complete the online course: EHS0348 Chemical Hygiene and Safety. Use the non-LDAP login and enter your badge number (if you have one) as...

  10. ALS in the News

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the ALS is well represented) New Lithium-Ion Battery Discovery Contradicts ... of water-no deeper than a few molecules-to the surface of a barium fluoride crystal. ...

  11. ALS Users' Association Charter

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    users and will enable users to plan more efficiently the utilization of the facility. The role of the ALSUA shall be to advise the ALS Director on matters of concern to users....

  12. ALS Communications Group

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    organize bi-monthly Science Cafs, create conference and workshop Web sites and publicity, and coordinate ALS participation in Lab-wide events such as the Berkeley Lab Open...

  13. Metabolomic profiling of the nectars of Aquilegia pubescens and <i>A. Canadensis

    SciTech Connect (OSTI)

    Noutsos, Christos; Perera, Ann M.; Nikolau, Basil J.; Seaver, Samuel M. D.; Ware, Doreen H.; Motta, Andrea

    2015-05-01

    To date, variation in nectar chemistry of flowering plants has not been studied in detail. Such variation exerts considerable influence on pollinator–plant interactions, as well as on flower traits that play important roles in the selection of a plant for visitation by specific pollinators. Over the past 60 years the Aquilegia genus has been used as a key model for speciation studies. In this study, we defined the metabolomic profiles of flower samples of two Aquilegia species, <i>A. Canadensis and <i>A. pubescens. We identified a total of 75 metabolites that were classified into six main categories: organic acids, fatty acids, amino acids, esters, sugars, and unknowns. The mean abundances of 25 of these metabolites were significantly different between the two species, providing insights into interspecies variation in floral chemistry. Using the PlantSEED biochemistry database, we found that the majority of these metabolites are involved in biosynthetic pathways. Finally, we explored the annotated genome of <i>A. coerulea, using the PlantSEED pipeline and reconstructed the metabolic network of Aquilegia. This network, which contains the metabolic pathways involved in generating the observed chemical variation, is now publicly available from the DOE Systems Biology Knowledge Base (KBase; http://kbase.us).

  14. Constraints on the progenitor system of the type Ia supernova 2014J from pre-explosion Hubble space telescope imaging

    SciTech Connect (OSTI)

    Kelly, Patrick L.; Fox, Ori D.; Filippenko, Alexei V.; Shen, Ken J.; Zheng, WeiKang; Graham, Melissa L.; Tucker, Brad E.; Cenko, S. Bradley; Schaefer, Gail

    2014-07-20

    We constrain the properties of the progenitor system of the highly reddened Type Ia supernova (SN Ia) 2014J in Messier 82 (M82; d ? 3.5 Mpc). We determine the supernova (SN) location using Keck-II K-band adaptive optics images, and we find no evidence for flux from a progenitor system in pre-explosion near-ultraviolet through near-infrared Hubble Space Telescope (HST) images. Our upper limits exclude systems having a bright red giant companion, including symbiotic novae with luminosities comparable to that of RS Ophiuchi. While the flux constraints are also inconsistent with predictions for comparatively cool He-donor systems (T ? 35,000 K), we cannot preclude a system similar to V445 Puppis. The progenitor constraints are robust across a wide range of R{sub V} and A{sub V} values, but significantly greater values than those inferred from the SN light curve and spectrum would yield proportionally brighter luminosity limits. The comparatively faint flux expected from a binary progenitor system consisting of white dwarf stars would not have been detected in the pre-explosion HST imaging. Infrared HST exposures yield more stringent constraints on the luminosities of very cool (T < 3000 K) companion stars than was possible in the case of SN Ia 2011fe.

  15. Spectroscopic Properties of Star-Forming Host Galaxies and Type Ia Supernova Hubble Residuals in a Nearly Unbiased Sample

    SciTech Connect (OSTI)

    D'Andrea, Chris B.; et al.

    2011-12-20

    We examine the correlation between supernova host galaxy properties and their residuals on the Hubble diagram. We use supernovae discovered during the Sloan Digital Sky Survey II - Supernova Survey, and focus on objects at a redshift of z < 0.15, where the selection effects of the survey are known to yield a complete Type Ia supernova sample. To minimize the bias in our analysis with respect to measured host-galaxy properties, spectra were obtained for nearly all hosts, spanning a range in magnitude of -23 < M_r < -17. In contrast to previous works that use photometric estimates of host mass as a proxy for global metallicity, we analyze host-galaxy spectra to obtain gas-phase metallicities and star-formation rates from host galaxies with active star formation. From a final sample of ~ 40 emission-line galaxies, we find that light-curve corrected Type Ia supernovae are ~ 0.1 magnitudes brighter in high-metallicity hosts than in low-metallicity hosts. We also find a significant (> 3{\\sigma}) correlation between the Hubble residuals of Type Ia supernovae and the specific star-formation rate of the host galaxy. We comment on the importance of supernova/host-galaxy correlations as a source of systematic bias in future deep supernova surveys.

  16. A POSSIBLE EVOLUTIONARY SCENARIO OF HIGHLY MAGNETIZED SUPER-CHANDRASEKHAR WHITE DWARFS: PROGENITORS OF PECULIAR TYPE Ia SUPERNOVAE

    SciTech Connect (OSTI)

    Das, Upasana; Mukhopadhyay, Banibrata; Rao, A. R. E-mail: bm@physics.iisc.ernet.in

    2013-04-10

    Several recently discovered peculiar Type Ia supernovae seem to demand an altogether new formation theory that might help explain the puzzling dissimilarities between them and the standard Type Ia supernovae. The most striking aspect of the observational analysis is the necessity of invoking super-Chandrasekhar white dwarfs having masses {approx}2.1-2.8 M{sub Sun }, M{sub Sun} being the mass of Sun, as their most probable progenitors. Strongly magnetized white dwarfs having super-Chandrasekhar masses have already been established as potential candidates for the progenitors of peculiar Type Ia supernovae. Owing to the Landau quantization of the underlying electron degenerate gas, theoretical results yielded the observationally inferred mass range. Here, we sketch a possible evolutionary scenario by which super-Chandrasekhar white dwarfs could be formed by accretion on to a commonly observed magnetized white dwarf, invoking the phenomenon of flux freezing. This opens multiple possible evolution scenarios ending in supernova explosions of super-Chandrasekhar white dwarfs having masses within the range stated above. We point out that our proposal has observational support, such as the recent discovery of a large number of magnetized white dwarfs by the Sloan Digital Sky Survey.

  17. ALS Activity Reports

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Activity Reports Print These hard-copy annual reports were produced from 1993-2006. They illustrated the depth and breadth of the ALS scientific program with a selection of research results. They also summarized operations and ongoing R&D, highlighted educational outreach efforts and special events, and provided yearly documentation of the beamlines and publications. The Activity Report was replaced in 2007 by ALS Spectrum. The reports for 1996-2006 are available here. Activity Report 2006

  18. ALS Beamlines Directory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ALS Beamlines Directory Print Beamlines, Parameters, Contact Information, and Schedules Click on the image to download a high-resolution version of the ALS beamclock. Beamline Parameters Beamline and endstation technical information is available through the links below. Unless otherwise noted, all beamlines are currently operational. Individual beamline schedules are posted when available. Please contact the responsible beamline scientist for additional schedule information. When calling from

  19. ALS Beamlines Directory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ALS Beamlines Directory Print Beamlines, Parameters, Contact Information, and Schedules Click on the image to download a high-resolution version of the ALS beamclock. Beamline Parameters Beamline and endstation technical information is available through the links below. Unless otherwise noted, all beamlines are currently operational. Individual beamline schedules are posted when available. Please contact the responsible beamline scientist for additional schedule information. When calling from

  20. ALS Beamlines Directory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ALS Beamlines Directory Print Beamlines, Parameters, Contact Information, and Schedules Click on the image to download a high-resolution version of the ALS beamclock. Beamline Parameters Beamline and endstation technical information is available through the links below. Unless otherwise noted, all beamlines are currently operational. Individual beamline schedules are posted when available. Please contact the responsible beamline scientist for additional schedule information. When calling from

  1. ALS Activity Reports

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Activity Reports Print These hard-copy annual reports were produced from 1993-2006. They illustrated the depth and breadth of the ALS scientific program with a selection of research results. They also summarized operations and ongoing R&D, highlighted educational outreach efforts and special events, and provided yearly documentation of the beamlines and publications. The Activity Report was replaced in 2007 by ALS Spectrum. The reports for 1996-2006 are available here. Activity Report 2006

  2. ALS Activity Reports

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Activity Reports Print These hard-copy annual reports were produced from 1993-2006. They illustrated the depth and breadth of the ALS scientific program with a selection of research results. They also summarized operations and ongoing R&D, highlighted educational outreach efforts and special events, and provided yearly documentation of the beamlines and publications. The Activity Report was replaced in 2007 by ALS Spectrum. The reports for 1996-2006 are available here. Activity Report 2006

  3. ALS Users' Association Charter

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Users' Association Charter Print The purpose of the Advanced Light Source Users' Association (ALSUA) is to provide an organized framework for the interaction between those who use the Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory (LBL) for their research and the ALS management, as well as to provide a channel for communication with other synchrotron radiation laboratories and, on suitable occasions, with federal agencies. The ALSUA, representing the research workers, will be in

  4. Emission mechanisms in Al-rich AlGaN/AlN quantum wells assessed by excitation power dependent photoluminescence spectroscopy

    SciTech Connect (OSTI)

    Iwata, Yoshiya; Banal, Ryan G.; Ichikawa, Shuhei; Funato, Mitsuru; Kawakami, Yoichi

    2015-02-21

    The optical properties of Al-rich AlGaN/AlN quantum wells are assessed by excitation-power-dependent time-integrated (TI) and time-resolved (TR) photoluminescence (PL) measurements. Two excitation sources, an optical parametric oscillator and the 4th harmonics of a Ti:sapphire laser, realize a wide range of excited carrier densities between 10{sup 12} and 10{sup 21 }cm{sup −3}. The emission mechanisms change from an exciton to an electron-hole plasma as the excitation power increases. Accordingly, the PL decay time is drastically reduced, and the integrated PL intensities increase in the following order: linearly, super-linearly, linearly again, and sub-linearly. The observed results are well accounted for by rate equations that consider the saturation effect of non-radiative recombination processes. Using both TIPL and TRPL measurements allows the density of non-radiative recombination centers, the internal quantum efficiency, and the radiative recombination coefficient to be reliably extracted.

  5. Radiogenic p-isotopes from type Ia supernova, nuclear physics uncertainties, and galactic chemical evolution compared with values in primitive meteorites

    SciTech Connect (OSTI)

    Travaglio, C.; Gallino, R.; Rauscher, T.; Dauphas, N.; Rpke, F. K.; Hillebrandt, W. E-mail: claudia.travaglio@b2fh.org

    2014-11-10

    The nucleosynthesis of proton-rich isotopes is calculated for multi-dimensional Chandrasekhar-mass models of Type Ia supernovae (SNe Ia) with different metallicities. The predicted abundances of the short-lived radioactive isotopes {sup 92}Nb, {sup 97,} {sup 98}Tc, and {sup 146}Sm are given in this framework. The abundance seeds are obtained by calculating s-process nucleosynthesis in the material accreted onto a carbon-oxygen white dwarf from a binary companion. A fine grid of s-seeds at different metallicities and {sup 13}C-pocket efficiencies is considered. A galactic chemical evolution model is used to predict the contribution of SN Ia to the solar system p-nuclei composition measured in meteorites. Nuclear physics uncertainties are critical to determine the role of SNe Ia in the production of {sup 92}Nb and {sup 146}Sm. We find that, if standard Chandrasekhar-mass SNe Ia are at least 50% of all SN Ia, they are strong candidates for reproducing the radiogenic p-process signature observed in meteorites.

  6. Persistent C II absorption in the normal type Ia supernova 2002fk

    SciTech Connect (OSTI)

    Cartier, Rgis; Zelaya, Paula [Millennium Institute of Astrophysics, Casilla 36-D, Santiago (Chile); Hamuy, Mario; Maza, Jos; Gonzlez, Luis; Huerta, Leonor [Departamento de Astronoma, Universidad de Chile, Casilla 36-D, Santiago (Chile); Pignata, Giuliano [Departamento Ciencias Fisicas, Universidad Andres Bello, Av. Repblica 252, Santiago (Chile); Frster, Francisco [Center for Mathematical Modelling, Universidad de Chile, Avenida Blanco Encalada 2120, Piso 7, Santiago (Chile); Folatelli, Gaston [Institute for the Physics and Mathematics of the Universe (IPMU), University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan); Phillips, Mark M.; Morrell, Nidia; Contreras, Carlos; Roth, Miguel; Gonzlez, Sergio [Carnegie Institution of Washington, Las Campanas Observatory, Colina el Pino s/n, Casilla 601 (Chile); Krisciunas, Kevin; Suntzeff, Nicholas B. [Department of Physics and Astronomy, Texas A and M University, 4242 TAMU, College Station, TX 77843 (United States); Clocchiatti, Alejandro [Departamento de Astronoma y Astrofsica, Pontificia Universidad Catlica de Chile, Casilla 306, Santiago (Chile); Coppi, Paolo [Department of Astronomy, Yale University, New Haven, CT 06520-8101 (United States); Koviak, Kathleen, E-mail: rcartier@das.uchile.cl [Carnegie Institution of Washington, 813 Santa Barbara Street, Pasadena, CA 911901 (United States)

    2014-07-01

    We present well-sampled UBVRIJHK photometry of SN 2002fk starting 12 days before maximum light through 122 days after peak brightness, along with a series of 15 optical spectra from 4 to +95 days since maximum. Our observations show the presence of C II lines in the early-time spectra of SN 2002fk, expanding at 11,000 km s{sup 1} and persisting until 8 days past maximum light with a velocity of ?9000 km s{sup 1}. SN 2002fk is characterized by a small velocity gradient of v-dot {sub Si} {sub II}=26 km s{sup 1} day{sup 1}, possibly caused by an off-center explosion with the ignition region oriented toward the observer. The connection between the viewing angle of an off-center explosion and the presence of C II in the early-time spectrum suggests that the observation of C II could be also due to a viewing angle effect. Adopting the Cepheid distance to NGC 1309 we provide the first H {sub 0} value based on near-infrared (near-IR) measurements of a Type Ia supernova (SN) between 63.0 0.8 (3.4 systematic) and 66.7 1.0 (3.5 systematic) km s{sup 1} Mpc{sup 1}, depending on the absolute magnitude/decline rate relationship adopted. It appears that the near-IR yields somewhat lower (6%-9%) H {sub 0} values than the optical. It is essential to further examine this issue by (1) expanding the sample of high-quality near-IR light curves of SNe in the Hubble flow, and (2) increasing the number of nearby SNe with near-IR SN light curves and precise Cepheid distances, which affords the promise to deliver a more precise determination of H {sub 0}.

  7. AL PRO | Open Energy Information

    Open Energy Info (EERE)

    search Name: AL-PRO Place: Grossheide, Lower Saxony, Germany Zip: 26532 Sector: Wind energy Product: AL-PRO is an inndependent expert office for wind forecasts, wind...

  8. AL2007-08.doc

    Broader source: Energy.gov (indexed) [DOE]

    Assessment Tool, IEEE Standard 1680-2006 for Environmental Assessment of Personal Computer Products. When is this Acquisition Letter (AL) Effective? This AL is effective...

  9. Data Management at the ALS

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Data Management at the ALS Print Users of the ALS are responsible for meeting their data management obligations to their home institutions and granting agencies. Except as noted ...

  10. 2012 ALS User Meeting Awards

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2012 ALS User Meeting Awards Print Recipients of the 2012 Users' Executive Committee awards and Student Poster Competition were announced Tuesday, October 9, at the ALS User...

  11. 2012 ALS User Meeting Awards

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2 ALS User Meeting Awards Recipients of the 2012 Users' Executive Committee awards and Student Poster Competition were announced Tuesday, October 9, at the ALS User Meeting. David...

  12. A=16Li (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Li (1993TI07) (Not illustrated) This nucleus has not been observed. Shell model studies (1988POZS) are used to predict J and the magnetic dipole moment....

  13. A=16He (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    93TI07) (Not illustrated) This nucleus has not been observed. See (1982AV1A, 1983ANZQ, 1986AJ04

  14. A=19Mg (1995TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Mg (1995TI07) (Not observed) See (1987AJ02) and (1987GU1K, 1987PO01, 1993HI08

  15. ALS Staff Photo

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Staff Photo Print On May 14, 2013, members of ALS staff posed for a group photo in front of the dome. A hi-res version can be downloaded here. The last staff photo was taken in 2006. 2013 staff photo

  16. Femtosecond laser-induced periodic surface structure on the Ti-based nanolayered thin films

    SciTech Connect (OSTI)

    Petrovi?, Suzana M.; Gakovi?, B.; Peruko, D.; Stratakis, E.; Department of Materials Science and Technology, University of Crete, 710 03 Heraklion, Crete ; Bogdanovi?-Radovi?, I.; ?ekada, M.; Fotakis, C.; Department of Physics, University of Crete, 714 09 Heraklion, Crete ; Jelenkovi?, B.

    2013-12-21

    Laser-induced periodic surface structures (LIPSSs) and chemical composition changes of Ti-based nanolayered thin films (Al/Ti, Ni/Ti) after femtosecond (fs) laser pulses action were studied. Irradiation is performed using linearly polarized Ti:Sapphire fs laser pulses of 40 fs pulse duration and 800 nm wavelength. The low spatial frequency LIPSS (LSFL), oriented perpendicular to the laser polarization with periods slightly lower than the irradiation wavelength, was typically formed at elevated laser fluences. On the contrary, high spatial frequency LIPSS (HSFL) with uniform period of 155 nm, parallel to the laser light polarization, appeared at low laser fluences, as well as in the wings of the Gaussian laser beam distribution for higher used fluence. LSFL formation was associated with the material ablation process and accompanied by the intense formation of nanoparticles, especially in the Ni/Ti system. The composition changes at the surface of both multilayer systems in the LSFL area indicated the intermixing between layers and the substrate. Concentration and distribution of all constitutive elements in the irradiated area with formed HSFLs were almost unchanged.

  17. Recovery of Li from alloys of Al- Li and Li- Al using engineered scavenger compounds

    DOE Patents [OSTI]

    Riley, W. D.; Jong, B. W.; Collins, W. K.; Gerdemann, S. J.

    1994-01-01

    A method of producing lithium of high purity from lithium aluminum alloys using an engineered scavenger compound, comprising: I) preparing an engineered scavenger compound by: a) mixing and heating compounds of TiO2 and Li2CO3 at a temperature sufficient to dry the compounds and convert Li.sub.2 CO.sub.3 to Li.sub.2 O; and b) mixing and heating the compounds at a temperature sufficient to produce a scavenger Li.sub.2 O.3TiO.sub.2 compound; II) loading the scavenger into one of two electrode baskets in a three electrode cell reactor and placing an Al-Li alloy in a second electrode basket of the three electrode cell reactor; III) heating the cell to a temperature sufficient to enable a mixture of KCl-LiCl contained in a crucible in the cell to reach its melting point and become a molten bath; IV) immersing the baskets in the bath until an electrical connection is made between the baskets to charge the scavenger compound with Li until there is an initial current and voltage followed by a fall off ending current and voltage; and V) making a connection between the basket electrode containing engineered scavenger compound and a steel rod electrode disposed between the basket electrodes and applying a current to cause Li to leave the scavenger compound and become electrodeposited on the steel rod electrode.

  18. MID-IR SPECTRA OF TYPE Ia SN 2014J IN M82 SPANNING THE FIRST 4 MONTHS

    SciTech Connect (OSTI)

    Telesco, Charles M.; Li, Dan; Barnes, Peter J.; Mariñas, Naibí; Zhang, Han; Höflich, Peter; Álvarez, Carlos; Fernández, Sergio; Rebolo, Rafael; Hough, James H.; Levenson, N. A.; Pantin, Eric; Roche, Patrick E-mail: phoeflich77@gmail.com

    2015-01-10

    We present a time series of 8-13 μm spectra and photometry for SN 2014J obtained 57, 81, 108, and 137 days after the explosion using CanariCam on the Gran Telescopio Canarias. This is the first mid-IR time series ever obtained for a Type Ia supernova (SN Ia). These observations can be understood within the framework of the delayed detonation model and the production of ∼0.6 M {sub ☉} of {sup 56}Ni, consistent with the observed brightness, the brightness decline relation, and the γ-ray fluxes. The [Co III] line at 11.888 μm is particularly useful for evaluating the time evolution of the photosphere and measuring the amount of {sup 56}Ni and thus the mass of the ejecta. Late-time line profiles of SN 2014J are rather symmetric and not shifted in the rest frame. We see argon emission, which provides a unique probe of mixing in the transition layer between incomplete burning and nuclear statistical equilibrium. We may see [Fe III] and [Ni IV] emission, both of which are observed to be substantially stronger than indicated by our models. If the latter identification is correct, then we are likely observing stable Ni, which might imply central mixing. In addition, electron capture, also required for stable Ni, requires densities larger than ∼1 × 10{sup 9} g cm{sup –3}, which are expected to be present only in white dwarfs close to the Chandrasekhar limit. This study demonstrates that mid-IR studies of SNe Ia are feasible from the ground and provide unique information, but it also indicates the need for better atomic data.

  19. Nearby Supernova Factory Observations of SN 2005gj: Another TypeIa Supernova in a Massive Circumstellar Envelope

    SciTech Connect (OSTI)

    Aldering, G.; Antilogus, P.; Bailey, S.; Baltay, C.; Bauer, A.; Blanc, N.; Bongard, S.; Copin, Y.; Gangler, E.; Gilles, S.; Kessler, R.; Kocevski, D.; Lee, B.C.; Loken, S.; Nugent, P.; Pain, R.; Pecontal, E.; Pereira, R.; Perlmutter, S.; Rabinowitz, D.; Rigaudier, G.; Scalzo, R.; Smadja, G.; Thomas, R.C.; Wang, L.; Weaver, B.A.; Rabinowitz, D.; Bauer, A.

    2006-06-01

    We report the independent discovery and follow-up observations of supernova 2005gj by the Nearby Supernova Factory. This is the second confirmed case of a ''hybrid'' Type Ia/IIn supernova, which like the prototype SN 2002ic, we interpret as the explosion of a white dwarf interacting with a circumstellar medium. Our early-phase photometry of SN 2005gj shows that the strength of the interaction between the supernova ejecta and circumstellar material is much stronger than for SN 2002ic. Our .rst spectrum shows a hot continuum with broad and narrow H{alpha} emission. Later spectra, spanning over 4 months from outburst, show clear Type Ia features combined with broad and narrow H{gamma}, H{beta},H{alpha} and He I {lambda}{lambda}5876,7065 in emission. At higher resolution, P Cygni profiles are apparent. Surprisingly, we also observe an inverted P Cygni profile for [O III] {lambda}5007. We find that the lightcurve and measured velocity of the unshocked circumstellar material imply mass loss as recently as 8 years ago. This is in contrast to SN 2002ic, for which an inner cavity in the circumstellar material was inferred. Within the context of the thin-shell approximation, the early lightcurve is well-described by a flat radial density profile for the circumstellar material. However, our decomposition of the spectra into Type Ia and shock emission components allows for little obscuration of the supernova, suggesting an aspherical or clumpy distribution for the circumstellar material. We suggest that the emission line velocity profiles arise from electron scattering rather than the kinematics of the shock. This is supported by the inferred high densities, and the lack of evidence for evolution in the line widths. Ground- and space-based photometry, and Keck spectroscopy, of the host galaxy are used to ascertain that the host galaxy has low metallicity (Z/Z{sub {circle_dot}} < 0.3; 95% confidence) and that this galaxy is undergoing a significant star formation event that began roughly 200 {+-} 70 Myr ago. We discuss the implications of these observations for progenitor models and cosmology using Type Ia supernovae.

  20. DISPLAYING THE HETEROGENEITY OF THE SN 2002cx-LIKE SUBCLASS OF TYPE Ia SUPERNOVAE WITH OBSERVATIONS OF THE Pan-STARRS-1 DISCOVERED SN 2009ku

    SciTech Connect (OSTI)

    Narayan, G.; Foley, R. J.; Berger, E.; Chornock, R.; Rest, A.; Soderberg, A. M.; Kirshner, R. P.; Botticella, M. T.; Smartt, S.; Valenti, S.; Huber, M. E.; Scolnic, D.; Grav, T.; Burgett, W. S.; Chambers, K. C.; Flewelling, H. A.; Gates, G.; Kaiser, N.; Magnier, E. A.; Morgan, J. S. E-mail: rfoley@cfa.harvard.edu

    2011-04-10

    SN 2009ku, discovered by Pan-STARRS-1, is a Type Ia supernova (SN Ia), and a member of the distinct SN 2002cx-like class of SNe Ia. Its light curves are similar to the prototypical SN 2002cx, but are slightly broader and have a later rise to maximum in g. SN 2009ku is brighter ({approx}0.6 mag) than other SN 2002cx-like objects, peaking at M{sub V} = -18.4 mag, which is still significantly fainter than typical SNe Ia. SN 2009ku, which had an ejecta velocity of {approx}2000 km s{sup -1} at 18 days after maximum brightness, is spectroscopically most similar to SN 2008ha, which also had extremely low-velocity ejecta. However, SN 2008ha had an exceedingly low luminosity, peaking at M{sub V} = -14.2 mag, {approx}4 mag fainter than SN 2009ku. The contrast of high luminosity and low ejecta velocity for SN 2009ku is contrary to an emerging trend seen for the SN 2002cx class. SN 2009ku is a counterexample of a previously held belief that the class was more homogeneous than typical SNe Ia, indicating that the class has a diverse progenitor population and/or complicated explosion physics. As the first example of a member of this class of objects from the new generation of transient surveys, SN 2009ku is an indication of the potential for these surveys to find rare and interesting objects.

  1. A complete strain temperature phase diagram for BiFeO3 films on SrTiO3 and

    Office of Scientific and Technical Information (OSTI)

    LaAlO3 (0 0 1) (Journal Article) | SciTech Connect A complete strain temperature phase diagram for BiFeO3 films on SrTiO3 and LaAlO3 (0 0 1) Citation Details In-Document Search Title: A complete strain temperature phase diagram for BiFeO3 films on SrTiO3 and LaAlO3 (0 0 1) Authors: Siemons, Wolter [1] ; Beekman, Christianne [1] ; MacDougall, Gregory J [1] ; Zarestky, Jerel L [1] ; Nagler, Stephen E [1] ; Christen, Hans M [1] + Show Author Affiliations ORNL [ORNL Publication Date: 2014-01-01

  2. Microstructure and tribological performance of nanocomposite Ti-Si-C-N coatings deposited using hexamethyldisilazane precursor

    SciTech Connect (OSTI)

    Wei Ronghua; Rincon, Christopher; Langa, Edward; Yang Qi

    2010-09-15

    Thick nanocomposite Ti-Si-C-N coatings (20-30 {mu}m) were deposited on Ti-6Al-4V substrate by magnetron sputtering of Ti in a gas mixture of Ar, N{sub 2}, and hexamethyldisilazane (HMDSN) under various deposition conditions. Microstructure and composition of the coatings were studied using scanning electron microscopy, x-ray diffraction, and energy dispersive x-ray spectroscopy, while the mechanical and tribological properties of these coatings were studied using Rc indentation, and micro- and nanoindentations, solid particle erosion testing, and ball-on-disk wear testing. It has been observed that the Si concentration of these coatings is varied from 0% (TiN) to 15% (Ti-Si-C-N), while the structure of these coatings is similar to the nanocomposite Ti-Si-N coatings and consists of nanocrystalline B1 structured Ti(C,N) in an amorphous matrix of SiC{sub x}N{sub y} with the grain size of 5->100 nm, depending on the coating preparation process. These coatings exhibit excellent adhesion when subjected to Rc indentation tests. The microhardness of these coatings varies from 1200 to 3400 HV25, while the nanohardness varies from 10 to 26 GPa. Both the microhardness and nanohardness are slightly lower than those of similar coatings prepared using trimethylsilane. However, the erosion test using a microsand erosion tester at both 30 deg. and 90 deg. incident angles shows that these coatings have very high erosion resistance and up to a few hundred times of improvement has been observed. These coatings also exhibit very high resistance to sliding wear with a low coefficient of friction of about 0.2 in dry sliding. There are a few advantages of using the HMDSN precursor to prepare the Ti-Si-C-N coatings over conventional magnetron sputtered deposition of Ti-Si-N coatings including composition uniformity, precursor handling safety, and high deposition rate. The coatings can be applied to protect gas turbine compressor blades from solid particle erosion and steam turbine blades from liquid droplet erosion, as well as other mechanical components that experience severe abrasion. These coatings may also be used in areas where both high wear resistance and low friction are required.

  3. The permeation behavior of deuterium through 1Cr18Ni9Ti stainless steel with TiN+TiC-TiN multiple films

    SciTech Connect (OSTI)

    Xiong, Y.; Song, J.; Luo, D.; Lei, Q.; Chen, C.

    2015-03-15

    The prevention of tritium losses via permeation through structure components is an important issue in fusion technology. The production of thin layers on materials with low diffusivity and/or low surface recombination constants (so-called permeation barriers) seems to be the most practical method to reduce or hinder the permeation of tritium through materials. TiN+TiC+TiN multiple films are deposited on the surface of 1Cr18Ni9Ti stainless steel by ion-beam assisted deposition technology. The characteristics of films are tested by XPS ASEM and XRD, which shows that the film are compact and uniform with a thickness of about 15 μm, and have a good adherence with the substrate below 773 K. The diffraction peaks in the XRD patterns for TiC and TiN are broadened, implying that the multiple films are deposited on the surface of 1Cr18Ni9Ti stainless steel. Meanwhile, the C-H bonded CH{sub 4}-appears in the infrared spectra of multiple films, suggesting that the CH{sub 4}- is in a static state, so hydrogen atom cannot migrate from the site bonded with carbon to a neighboring site. The measured deuterium permeability in 1Cr18Ni9Ti stainless steel coated with multiple films is 2-3 orders of magnitude lower than that of pure 1Cr18Ni9Ti stainless steel substrate from 473 K to 773 K. However, this barrier is partly destroyed above 773 K.

  4. Recovery of Li from alloys of Al-Li and Li-Al using engineered scavenger compounds

    SciTech Connect (OSTI)

    Riley, W.D.; Jong, B.W.; Collins, W.K.; Gerdemann, S.J.

    1992-01-01

    The invention relates to a process for obtaining Li metal selectively recovered from Li-Al or Al-Li alloy scrap by: (1) removing Li from aluminum-lithium alloys at temperatures between about 400 C-750 C in a molten salt bath of KC1-LiCl using lithium titanate (Li2O.3TiO2) as an engineered scavenger compound (ESC); and (2) electrodepositing of Li from the loaded ESC to a stainless steel electrode. By use of the second step, the ESC is prepared for reuse. A molten salt bath is required in the invention because of the inability of molten aluminum alloys to wet the ESC.

  5. Ti Leggett | Argonne Leadership Computing Facility

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Ti Leggett Deputy Project Directcor & Deputy Director of Operations Argonne National Laboratory 9700 S. Cass Avenue Building 240 - Room 3132 Argonne, IL 60439 630-252-1937 tleggett

  6. A=18Li (1995TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Li (1995TI07) (Not illustrated) 18Li has not been observed. Shell model calculations described in (1988POZS) predict the ground-state magentic dipole moment and charge and matter...

  7. A=8Be (2004TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2004TI06) (See Energy Level Diagrams for 8Be) GENERAL: References to articles on general properties of 8Be published since the previous review (1988AJ01) are grouped into...

  8. A=10B (2004TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2004TI06) (See Energy Level Diagrams for 10B) GENERAL: References to articles on general properties of 10B published since the previous review (1988AJ01) are grouped into...

  9. A=7Be (2002TI10)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2002TI10) (See Energy Level Diagrams for 7Be) GENERAL: References to articles on general properties of 7Be published since the previous review (1988AJ01) are grouped into...

  10. A=8He (2004TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2004TI06) (See Energy Level Diagrams for 8He) GENERAL: References to articles on general properties of 8He published since the previous review (1988AJ01) are grouped into...

  11. A=9C (2004TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2004TI06) (See Energy Level Diagrams for 9C) GENERAL: References to articles on general properties of 9C published since the previous review (1988AJ01) are grouped into categories...

  12. A=7He (2002TI10)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2002TI10) (See Energy Level Diagrams for 7He) GENERAL: References to articles on general properties of 7He published since the previous review (1988AJ01) are grouped into...

  13. A=9Be (2004TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2004TI06) (See Energy Level Diagrams for 9Be) GENERAL: References to articles on general properties of 9Be published since the previous review (1988AJ01) are grouped into...

  14. A=10C (2004TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2004TI06) (See Energy Level Diagrams for 10C) GENERAL: References to articles on general properties of 10C published since the previous review (1988AJ01) are grouped into...

  15. A=8B (2004TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2004TI06) (See Energy Level Diagrams for 8B) GENERAL: References to articles on general properties of 8B published since the previous review (1988AJ01) are grouped into categories...

  16. A=10N (2004TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2004TI06) (Not illustrated) GENERAL: References to articles on general properties of 10N published since the previous review (1988AJ01) are grouped into categories and listed,...

  17. A=10Li (2004TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2004TI06) (See Energy Level Diagrams for 10Li) GENERAL: References to articles on general properties of 10Li published since the previous review (1988AJ01) are grouped into...

  18. A=6Be (2002TI10)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2002TI10) (See Energy Level Diagrams for 6Be) GENERAL: References to articles on general properties of 6Be published since the previous review (1988AJ01) are grouped into...

  19. A=9He (2004TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2004TI06) (See the Isobar Diagram for 9He) GENERAL: References to articles on general properties of 9He published since the previous review (1988AJ01) are grouped into categories...

  20. A=5Li (2002TI10)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2002TI10) (See Energy Level Diagrams for 5Li) GENERAL: References to articles on general properties of 5Li published since the previous review (1988AJ01) are grouped into...

  1. A=9Li (2004TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2004TI06) (See Energy Level Diagrams for 9Li) GENERAL: References to articles on general properties of 9Li published since the previous review (1988AJ01) are grouped into...

  2. A=9B (2004TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2004TI06) (See Energy Level Diagrams for 9B) GENERAL: References to articles on general properties of 9B published since the previous review (1988AJ01) are grouped into categories...

  3. A=10He (2004TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2004TI06) (See Energy Level Diagrams for 10He) GENERAL: References to articles on general properties of 10He published since the previous review (1988AJ01) are grouped into...

  4. A=18Mg, etc. (1995TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    95TI07) (Not observed) See (1986AN07) and (1983ANZQ). See also the results of calculations of β+/electron capture half lives for neutron deficient nuclei in (1993HI08

  5. A=6B (2002TI10)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2002TI10) (Not illustrated) Not observed: see ( 1984AJ01, 1989GR06 [6Li(π+, π-) at Eπ+ = 180, 240 MeV], 1993PO11 [properties of exotic light nuclei]) (1998SU18

  6. A=6C (2002TI10)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2002TI10) (Not illustrated) Not observed: see (1979AJ01, 1984AJ01, 1989GR06 [6Li(π+, π-) at Eπ+ = 180, 240 MeV], 1993PO11 [properties of exotic light nuclei]) (1998SU18

  7. A=9N (2004TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2004TI06) (Not illustrated) Not observed: see (1988AJ01). Mass excesses of 46.56 and 46.40 MeV have been estimated from two different mass formulae (2000PO32). 9N would then be...

  8. Crystal Structure and Thermodynamic Stability of Ba/Ti-Substituted Pollucites for Radioactive Cs/Ba Immobilization

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Xu, Hongwu; Chavez, Manuel E.; Mitchell, Jeremy N.; Garino, Terry J.; Schwarz, Haiqing L.; Rodriguez, Mark A.; Rademacher, David X.; Nenoff, Tina Maria

    2015-04-23

    An analogue of the mineral pollucite (CsAlSi2O6), CsTiSi2O6.5 has a potential host phase for radioactive Cs. However, as 137Cs and 135Cs transmute to 137Ba and 135Ba, respectively, through the beta decay, it is essential to study the structure and stability of this phase upon Cs → Ba substitution. In this work, two series of Ba/Ti-substituted samples, CsxBa(1-x)/2TiSi2O6.5 and CsxBa1-xTiSi2O7-0.5x, (x = 0.9 and 0.7), were synthesized by high-temperature crystallization from their respective precursors. Synchrotron X-ray diffraction and Rietveld analysis reveal that while CsxBa(1-x)/2TiSi2O6.5 samples are phase-pure, CsxBa1-xTiSi2O7-0.5x samples contain Cs3x/(2+x)Ba(1-x)/(2+x)TiSi2O6.5 pollucites (i.e., also two-Cs-to-one-Ba substitution) and a secondary phase, fresnoitemore » (Ba2TiSi2O8). Thus, the CsxBa1-xTiSi2O7-0.5x series is energetically less favorable than CsxBa(1-x)/2TiSi2O6.5. To study the stability systematics of CsxBa(1-x)/2TiSi2O6.5 pollucites, high-temperature calorimetric experiments were performed at 973 K with or without the lead borate solvent. Enthalpies of formation from the constituent oxides (and elements) have thus been derived. Our results show that with increasing Ba/(Cs + Ba) ratio, the thermodynamic stability of these phases decreases with respect to their component oxides. Hence, from the energetic viewpoint, continued Cs → Ba transmutation tends to destabilize the parent silicotitanate pollucite structure. However, the Ba-substituted pollucite co-forms with fresnoite (which incorporates the excess Ba), thereby providing viable ceramic waste forms for all the Ba decay products.« less

  9. TiBor Skin - Energy Innovation Portal

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Advanced Materials Advanced Materials Find More Like This Return to Search TiBor Skin Y-12 National Security Complex Contact Y12 About This Technology Publications: PDF Document Publication Fact Sheet (336 KB) PDF Document Publication Presentation (400 KB) PDF Document Publication Patent Application Publication (2,825 KB) Technology Marketing Summary Y-12 invites interested companies to license its patent-pending method known as TiBor Skin. This two-part technology enables creation and

  10. A Chandrasekhar mass progenitor for the Type Ia supernova remnant 3C 397 from the enhanced abundances of nickel and manganese

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yamaguchi, Hiroya; Badenes, Carles; Foster, Adam R.; Bravo, Eduardo; Williams, Brian J.; Maeda, Keiichi; Nobukawa, Masayoshi; Eriksen, Kristoffer A.; Brickhouse, Nancy S.; Petre, Robert; et al

    2015-03-12

    Despite decades of intense efforts, many fundamental aspects of Type Ia supernovae (SNe Ia) remain elusive. One of the major open questions is whether the mass of an exploding white dwarf (WD) is close to the Chandrasekhar limit. Here, we report the detection of strong K-shell emission from stable Fe-peak elements in the Suzaku X-ray spectrum of the Type Ia supernova remnant (SNR) 3C 397. The high Ni/Fe and Mn/Fe mass ratios (0.11–0.24 and 0.018–0.033, respectively) in the hot plasma component that dominates the K-shell emission lines indicate a degree of neutronization in the supernova ejecta that can only bemore » achieved by electron capture in the dense cores of exploding WDs with a near-Chandrasekhar mass. This suggests a single-degenerate origin for 3C 397, since Chandrasekhar mass progenitors are expected naturally if the WD accretes mass slowly from a companion. Altogether with other results supporting the double-degenerate scenario, our work adds to the mounting evidence that both progenitor channels make a significant contribution to the SN Ia rate in star-forming galaxies.« less

  11. Instability of Hydrogenated TiO2

    SciTech Connect (OSTI)

    Nandasiri, Manjula I.; Shutthanandan, V.; Manandhar, Sandeep; Schwarz, Ashleigh M.; Oxenford, Lucas S.; Kennedy, John V.; Thevuthasan, Suntharampillai; Henderson, Michael A.

    2015-11-06

    Hydrogenated TiO2 (H-TiO2) is toted as a viable visible light photocatalyst. We report a systematic study on the thermal stability of H-implanted TiO2 using X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), Rutherford backscattering spectrometry (RBS) and nuclear reaction analysis (NRA). Protons (40 keV) implanted at a ~2 atom % level within a ~120 nm wide profile of rutile TiO2(110) were situated ~300 nm below the surface. NRA revealed that this H-profile broadened preferentially toward the surface after annealing at 373 K, dissipated out of the crystal into vacuum at 473 K, and was absent within the beam sampling depth (~800 nm) at 523 K. Photoemission showed that the surface was reduced in concert with these changes. Similar anneals had no effect on pristine TiO2(110). The facile bulk diffusivity of H in rutile, as well as its activity toward interfacial reduction, significantly limits the utilization of H-TiO2 as a photocatalyst. This work was supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. Pacific Northwest National Laboratory (PNNL) is a multiprogram national laboratory operated for DOE by Battelle. The research was performed using the Environmental Molecular Sciences Laboratory (EMSL), a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory.

  12. Aluminum Stabilized NbTi Conductor Test Coil Design, Fabrication, and Test Results

    SciTech Connect (OSTI)

    Andreev, N.; Chlachidze, G.; Evbota, D.; Kashikhin, V.S.; Lamm, M.; Makarov, A.; Tartaglia, M.; Nakamoto, T.; Ogitsu, T.; Tanaka, K.; Yamamoto, A.; /KEK, Tsukuba

    2011-09-01

    A new generation of precision muon conversion experiments is planned at both Fermilab and KEK. These experiments will depend upon a complex set of solenoid magnets for the production, momentum selection and transport of a muon beam to a stopping target, and for tracking detector momentum analysis of candidate conversion electrons from the target. Baseline designs for the production and detector solenoids use NbTi cable that is heavily stabilized by an extruded high RRR aluminum jacket. A U.S.-Japan research collaboration has begun whose goal is to advance the development of optimized Al-NbTi conductors, gain experience with the technology of winding coils from this material, and test the conductor performance as modest length samples become available. For this purpose, a 'conductor test' solenoid with three coils was designed and built at Fermilab. A sample of the RIKEN Al-NbTi conductor from KEK was wound into a 'test' coil; this was sandwiched between two 'field' coils wound from doubled SSC cable, to increase the peak field on the RIKEN test coil. All three solenoid coils were epoxy impregnated, and utilized aluminum outer bandage rings to apply preload to the coils when cold. The design and fabrication details, and results of the magnet quench performance tests are presented and discussed.

  13. 2012 ALS User Meeting Awards

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2 ALS User Meeting Awards Recipients of the 2012 Users' Executive Committee awards and Student Poster Competition were announced Tuesday, October 9, at the ALS User Meeting. David A. Shirley Award for Outstanding Scientific Achievement at the ALS shirley award The David A. Shirley Award for Scientific Achievement went to, from left, Carl Percival (University of Manchester), Dudley Shallcross [(University of Bristol) not pictured], and Craig Taatjes and David Osborn (Sandia), for making the first

  14. ALS Scientific Advisory Committee Charter

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Scientific Advisory Committee Charter Print This document was revised and approved December 18, 2008. I. FUNCTION AND REPORTING The ALS Scientific Advisory Committee (SAC) is advisory to the Berkeley Lab Director through the ALS Director. The SAC serves two primary functions: It acts as a "board of directors" to advise the Laboratory on current and future ALS operations, allocation of facility resources, strategic planning, budget development, and other major issues; and It reviews

  15. ALS Scientific Advisory Committee Charter

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Scientific Advisory Committee Charter Print This document was revised and approved December 18, 2008. I. FUNCTION AND REPORTING The ALS Scientific Advisory Committee (SAC) is advisory to the Berkeley Lab Director through the ALS Director. The SAC serves two primary functions: It acts as a "board of directors" to advise the Laboratory on current and future ALS operations, allocation of facility resources, strategic planning, budget development, and other major issues; and It reviews

  16. ALS Scientific Advisory Committee Charter

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the Laboratory on current and future ALS operations, allocation of facility resources, strategic planning, budget development, and other major issues; and It reviews major...

  17. ALS Evidence Confirms Combustion Theory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ALS Evidence Confirms Combustion Theory Print Researchers recently uncovered the first step in the process that transforms gas-phase molecules into solid particles like soot and...

  18. ALS Collaborative Postdoctoral Fellowship Program

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the National Center of Electron Microscopy, and the National Energy Research Scientific Computing Center. ALS Collaborative Postdoctoral Fellowships normally provide only partial...

  19. ALS Collaborative Postdoctoral Fellowship Program

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    scientists) to discuss possible projects and to identify external sources of matching funds. Applicants must then submit a completed ALS Collaborative Postdoctoral...

  20. ALS Scientific Advisory Committee Charter

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    It acts as a "board of directors" to advise the Laboratory on current and future ALS operations, allocation of facility resources, strategic planning, budget development, and...

  1. ALS Collaborative Postdoctoral Fellowship Program

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    who will collaborate closely with ALS staff and users in new and emerging scientific and engineering research fields. The program will provide advanced training for careers paths...

  2. AL2007-05.doc

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AL 2007-05 Acquisition Regulation Date 03292007 ACQUISITION LETTER This Acquisition ... LETTERS REMAINING IN EFFECT NUMBER DATE SUBJECT 93-4 040793 Displaced Workers ...

  3. Effect of reinforcing particle type on morphology and age-hardening behavior of Al4.5 wt.% Cu based nanocomposites synthesized through mechanical milling

    SciTech Connect (OSTI)

    Mostaed, A.; Saghafian, H.; Mostaed, E.; Shokuhfar, A.; Rezaie, H.R.

    2013-02-15

    The effects of reinforcing particle type (SiC and TiC) on morphology and precipitation hardening behavior of Al4.5%Cu based nanocomposites synthesized via mechanical milling were investigated in the current work. In order to study the microstructure and morphology of mechanically milled powder, X-ray diffraction technique, scanning electron microscopy and high resolution transmission electron microscopy were utilized. Results revealed that at the early stages of mechanical milling, when reinforcing particles are polycrystal, the alloying process is enhanced more in the case of using the TiC particles as reinforcement. But, at the final stages of mechanical milling, when reinforcing particles are single crystal, the alloying process is enhanced more in the case of using the SiC ones. Transmission electron microscopy results demonstrated that Al4.5 wt.%Cu based nanocomposite powders were synthesized and confirmed that the mutual diffusion of aluminum and copper occurs through the interfacial plane of (200). The hardness results showed that not only does introducing 4 vol.% of reinforcing particles (SiC or TiC) considerably decrease the porosity of the bulk composite samples, but also it approximately doubles the hardness of Al4.5 wt.%Cu alloy (53.4 HB). Finally, apart from TEM and scanning electron microscopy observation which are localized, a decline in hardness in the TiC and SiC contained samples, respectively, after 1.5 and 2 h aging time at 473 K proves the fact that the size of SiC particles is smaller than the size of the TiC ones. - Highlights: ? HRTEM results show mutual diffusion of Al and Cu occurs through the (200) planes. ? TiC particles enhance alloying process more than the SiC ones at the early stages of MM. ? SiC particles enhance alloying process more than the TiC ones at the final stages of MM.

  4. Materials Data on TiAlFe2 (SG:225) by Materials Project

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  5. Materials Data on Ti3AlC (SG:221) by Materials Project

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  6. ALS Collaborative Postdoctoral Fellowship Program

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Collaborative Postdoctoral Fellowship Program Print The Advanced Light Source (ALS) Collaborative Postdoctoral Fellowship program provides challenging opportunities to conduct research and instrument development in areas supporting the scientific programs of the Department of Energy (DOE), Lawrence Berkeley National Laboratory (LBNL), and the ALS that include physical, chemical, material, energy, environmental, geological, and biological sciences. Fellows pursue individual research projects as

  7. Cosmological constraints from measurements of type Ia supernovae discovered during the first 1.5 yr of the Pan-STARRS1 survey

    SciTech Connect (OSTI)

    Rest, A. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Scolnic, D.; Riess, A.; Rodney, S.; Brout, D. [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Foley, R. J.; Chornock, R.; Berger, E.; Soderberg, A. M.; Stubbs, C. W.; Kirshner, R. P.; Challis, P.; Czekala, I.; Drout, M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Huber, M. E.; Tonry, J. L. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Narayan, G. [Department of Physics, Harvard University, 17 Oxford Street, Cambridge, MA 02138 (United States); Smartt, S. J. [Astrophysics Research Centre, School of Mathematics and Physics, Queens University Belfast, Belfast BT71NN (United Kingdom); Schlafly, E. [Max Planck Institute for Astronomy, Knigstuhl 17, D-69117 Heidelberg (Germany); Botticella, M. T. [INAF-Osservatorio Astronomico di Capodimonte, Salita Moiariello 16, I-80131 Napoli (Italy); and others

    2014-11-01

    We present griz {sub P1} light curves of 146 spectroscopically confirmed Type Ia supernovae (SNe Ia; 0.03 < z < 0.65) discovered during the first 1.5 yr of the Pan-STARRS1 Medium Deep Survey. The Pan-STARRS1 natural photometric system is determined by a combination of on-site measurements of the instrument response function and observations of spectrophotometric standard stars. We find that the systematic uncertainties in the photometric system are currently 1.2% without accounting for the uncertainty in the Hubble Space Telescope Calspec definition of the AB system. A Hubble diagram is constructed with a subset of 113 out of 146 SNe Ia that pass our light curve quality cuts. The cosmological fit to 310 SNe Ia (113 PS1 SNe Ia + 222 light curves from 197 low-z SNe Ia), using only supernovae (SNe) and assuming a constant dark energy equation of state and flatness, yields w=?1.120{sub ?0.206}{sup +0.360}(Stat){sub ?0.291}{sup +0.269}(Sys). When combined with BAO+CMB(Planck)+H {sub 0}, the analysis yields ?{sub M}=0.280{sub ?0.012}{sup +0.013} and w=?1.166{sub ?0.069}{sup +0.072} including all identified systematics. The value of w is inconsistent with the cosmological constant value of 1 at the 2.3? level. Tension endures after removing either the baryon acoustic oscillation (BAO) or the H {sub 0} constraint, though it is strongest when including the H {sub 0} constraint. If we include WMAP9 cosmic microwave background (CMB) constraints instead of those from Planck, we find w=?1.124{sub ?0.065}{sup +0.083}, which diminishes the discord to <2?. We cannot conclude whether the tension with flat ?CDM is a feature of dark energy, new physics, or a combination of chance and systematic errors. The full Pan-STARRS1 SN sample with ?three times as many SNe should provide more conclusive results.

  8. Morphology, deformation, and defect structures of TiCr{sub 2} in Ti-Cr alloys

    SciTech Connect (OSTI)

    Chen, K.C.; Allen, S.M.; Livingston, J.D.

    1992-12-31

    The morphologies and defect structures of TiCr{sub 2} in several Ti-Cr alloys have been examined by optical metallography, x-ray diffraction, and transmission electron microscopy (TEM), in order to explore the room-temperature deformability of the Laves phase TiCr{sub 2}. The morphology of the Laves phase was found to be dependent upon alloy composition and annealing temperature. Samples deformed by compression have also been studied using TEM. Comparisons of microstructures before and after deformation suggest an increase in twin, stacking fault, and dislocation density within the Laves phase, indicating some but not extensive room-temperature deformability.

  9. Carrier-Controlled Ferromagnetism in SrTiO3

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Moetakef, Pouya; Williams, James R.; Ouellette, Daniel G.; Kajdos, Adam P.; Goldhaber-Gordon, David; Allen, S. James; Stemmer, Susanne

    2012-06-27

    Magnetotransport and superconducting properties are investigated for uniformly La-doped SrTiO3 films and GdTiO3/SrTiO3 heterostructures, respectively. GdTiO3/SrTiO3 interfaces exhibit a high-density 2D electron gas on the SrTiO3 side of the interface, while, for the SrTiO3 films, carriers are provided by the dopant atoms. Both types of samples exhibit ferromagnetism at low temperatures, as evidenced by a hysteresis in the magnetoresistance. For the uniformly doped SrTiO3 films, the Curie temperature is found to increase with doping and to coexist with superconductivity for carrier concentrations on the high-density side of the superconducting dome. The Curie temperature of the GdTiO3/SrTiO3 heterostructures scales with themore » thickness of the SrTiO3 quantum well. The results are used to construct a stability diagram for the ferromagnetic and superconducting phases of SrTiO3.« less

  10. Structure and physical properties of single crystal PrCr{sub 2}Al{sub 20} and CeM{sub 2}Al{sub 20} (M=V, Cr): A comparison of compounds adopting the CeCr{sub 2}Al{sub 20} structure type

    SciTech Connect (OSTI)

    Kangas, Michael J.; Schmitt, Devin C.; Sakai, Akito; Nakatsuji, Satoru; Institute of Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581 ; Chan, Julia Y.

    2012-12-15

    Crystal growth and full structure determination of compounds adopting the CeCr{sub 2}Al{sub 20} structure type, LnTi{sub 2}Al{sub 20} (Ln=La-Pr, Sm, and Yb), LnV{sub 2}Al{sub 20} (Ln=La-Pr, and Sm), and LnCr{sub 2}Al{sub 20} (Ln=La-Pr, Sm, and Yb), are reported. Resistivity, magnetic susceptibility, and heat capacity of flux grown single crystals of the nonmagnetic CeM{sub 2}Al{sub 20} (Ln=Ce, Yb; M=Ti, V) compounds are compared to PrCr{sub 2}Al{sub 20}. Of particular interest is PrCr{sub 2}Al{sub 20} which does not show any phase transition down to the lowest temperature of the measurement (400 mK in resistivity measurement and 1.8 K for magnetic susceptibility measurements) and exhibits Kondo behavior at low temperatures. - Graphical abstract: Crystal structure of SmV{sub 2}Al{sub 20} showing the interpenetrating diamond-like samarium network and pyrochlore-like vanadium network. Highlights: Black-Right-Pointing-Pointer Single crystals of LnM{sub 2}Al{sub 20} were grown from a molten aluminum flux. Black-Right-Pointing-Pointer Magnetic, electrical, and specific heat of single crystal LnM{sub 2}Al{sub 20} are presented. Black-Right-Pointing-Pointer PrCr{sub 2}Al{sub 20} exhibits evidence of Kondo effect.

  11. No X-rays from the very nearby type Ia SN 2014J: Constraints on its environment

    SciTech Connect (OSTI)

    Margutti, R.; Parrent, J.; Kamble, A.; Soderberg, A. M.; Milisavljevic, D.; Drout, M. R.; Kirshner, R. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Foley, R. J. [Astronomy Department, University of Illinois at Urbana-Champaign, 1002 W. Green Street, Urbana, IL 61801 (United States)

    2014-07-20

    Deep X-ray observations of the post-explosion environment around the very nearby Type Ia SN 2014J (d{sub L} = 3.5 Mpc) reveal no X-ray emission down to a luminosity L{sub x} < 7 10{sup 36} erg s{sup 1} (0.3-10 keV) at ?t ? 20 days after the explosion. We interpret this limit in the context of inverse Compton emission from upscattered optical photons by the supernova shock and constrain the pre-explosion mass-loss rate of the stellar progenitor system to be M-dot <10{sup ?9} M{sub ?} yr{sup ?1} (for wind velocity v{sub w} = 100 km s{sup 1}). Alternatively, the SN shock might be expanding into a uniform medium with density n{sub CSM} < 3 cm{sup 3}. These results rule out single-degenerate (SD) systems with steady mass loss until the terminal explosion and constrain the fraction of transferred material lost at the outer Lagrangian point to be ?1%. The allowed progenitors are (1) white dwarf-white dwarf progenitors, (2) SD systems with unstable hydrogen burning experiencing recurrent nova eruptions with recurrence time t < 300 yr, and (3) stars where the mass loss ceases before the explosion.

  12. Development of ODS FeCrAl alloys for accident-tolerant fuel cladding

    SciTech Connect (OSTI)

    Dryepondt, Sebastien N.; Hoelzer, David T.; Pint, Bruce A.; Unocic, Kinga A.

    2015-09-18

    FeCrAl alloys are prime candidates for accident-tolerant fuel cladding due to their excellent oxidation resistance up to 1400 C and good mechanical properties at intermediate temperature. Former commercial oxide dispersion strengthened (ODS) FeCrAl alloys such as PM2000 exhibit significantly better tensile strength than wrought FeCrAl alloys, which would alloy for the fabrication of a very thin (~250 m) ODS FeCrAl cladding and limit the neutronic penalty from the replacement of Zr-based alloys by Fe-based alloys. Several Fe-12-Cr-5Al ODS alloys where therefore fabricated by ball milling FeCrAl powders with Y2O3 and additional oxides such as TiO2 or ZrO2. The new Fe-12Cr-5Al ODS alloys showed excellent tensile strength up to 800 C but limited ductility. Good oxidation resistance in steam at 1200 and 1400 C was observed except for one ODS FeCrAl alloy containing Ti. Rolling trials were conducted at 300, 600 C and 800 C to simulate the fabrication of thin tube cladding and a plate thickness of ~0.6mm was reached before the formation of multiple edge cracks. Hardness measurements at different stages of the rolling process, before and after annealing for 1h at 1000 C, showed that a thinner plate thickness could likely be achieved by using a multi-step approach combining warm rolling and high temperature annealing. Finally, new Fe-10-12Cr-5.5-6Al-Z gas atomized powders have been purchased to fabricate the second generation of low-Cr ODS FeCrAl alloys. The main goals are to assess the effect of O, C, N and Zr contents on the ODS FeCrAl microstructure and mechanical properties, and to optimize the fabrication process to improve the ductility of the 2nd gen ODS FeCrAl while maintaining good mechanical strength and oxidation resistance.

  13. Giant persistent photoconductivity in BaTiO{sub 3}/TiO{sub 2} heterostructures

    SciTech Connect (OSTI)

    Plodinec, Milivoj; anti?, Ana; Gajovi?, Andreja; Zavanik, Janez; ?eh, Miran

    2014-10-13

    The persistent photoconductivity (PPC) effect in nanotube arrays of barium titanate and TiO{sub 2} (BTO/TiO{sub 2}NT) was studied at room temperature under daylight illumination. The BTO/TiO{sub 2}NT heterostructures exhibited a giant PPC effect that was six orders of magnitude higher than the dark conductivity, followed by a slow relaxation for 3 h. The PPC in this material was explained by the existence of defects at the surfaces and the interfaces of the investigated heterostructures. The sample was prepared using a two-step synthesis: the anodization of a Ti-foil and a subsequent hydrothermal synthesis. The structural and electrical characteristics were studied by micro-Raman spectroscopy, field-emission-gun scanning electron microscopy, and impedance spectroscopy.

  14. ASYMMETRY IN THE OBSERVED METAL-RICH EJECTA OF THE GALACTIC TYPE IA SUPERNOVA REMNANT G299.22.9

    SciTech Connect (OSTI)

    Post, Seth; Park, Sangwook [Department of Physics, University of Texas at Arlington, Arlington, Box 19059, TX 76019 (United States); Badenes, Carles [Department of Physics and Astronomy and Pittsburgh Particle Physics, Astrophysics, and Cosmology Center (PITT-PACC), University of Pittsburgh, 3941 OHara Street, Pittsburgh, PA 15260 (United States); Burrows, David N. [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States); Hughes, John P. [Department of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ 08854-8019 (United States); Lee, Jae-Joon [Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of); Mori, Koji [Department of Applied Physics, University of Miyazaki, 1-1 Gakuen Kibana-dai Nishi, Miyazaki 889-2192 (Japan); Slane, Patrick O., E-mail: seth.post@mavs.uta.edu, E-mail: badenes@pitt.edu, E-mail: burrows@astro.psu.edu, E-mail: jph@physics.rutgers.edu, E-mail: mori@astro.miyazaki-u.ac.jp, E-mail: slane@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2014-09-01

    We have performed a deep Chandra observation of the Galactic TypeIa supernova remnant G299.22.9. Here we report the initial results from our imaging and spectral analysis. The observed abundance ratios of the central ejecta are in good agreement with those predicted by delayed-detonation TypeIa supernovae models. We reveal inhomogeneous spatial and spectral structures of metal-rich ejecta in G299.22.9. The Fe/Si abundance ratio in the northern part of the central ejecta region is higher than that in the southern part. A significant continuous elongation of ejecta material extends out to the western outermost boundary of the remnant. In this western elongation, both the Si and Fe are enriched with a similar abundance ratio to that in the southern part of the central ejecta region. These structured distributions of metal-rich ejecta material suggest that this TypeIa supernova might have undergone a significantly asymmetric explosion and/or has been expanding into a structured medium.

  15. ALS 20th Anniversary Celebration

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    20th Anniversary Celebration Print The 20th anniversary of the ALS was celebrated on Friday, October 4, with style, good humor, lots of stories, and a very large cake. More...

  16. ALS 20th Anniversary Celebration

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The 20th anniversary of the ALS was celebrated on Friday, October 4, with style, good humor, lots of stories, and a very large cake. More important, however, was the large number...

  17. ALS Doctoral Fellowship in Residence

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and technological research. As the world's first third-generation synchrotron radiation source, the ALS offers outstanding performance in the VUV-soft x-ray energy range and...

  18. Scott Taylor, ALS Safety Manager

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    for safety inspections. There weren't division safety coordinators back in those days, Taylor explains. Joining the ALS reminds Taylor of his early days at the Lab, when he felt...

  19. ALS Doctoral Fellowship in Residence

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Doctoral Fellowship in Residence Print The Advanced Light Source (ALS), a division of Lawrence Berkeley National Laboratory, is a national user facility that generates intense x-ray radiation for scientific and technological research. As the world's first third-generation synchrotron radiation source, the ALS offers outstanding performance in the VUV-soft x-ray energy range and excellent performance into the hard x-ray region. The facility welcomes researchers from universities, industries, and

  20. ALS Doctoral Fellowship in Residence

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Doctoral Fellowship in Residence Print The Advanced Light Source (ALS), a division of Lawrence Berkeley National Laboratory, is a national user facility that generates intense x-ray radiation for scientific and technological research. As the world's first third-generation synchrotron radiation source, the ALS offers outstanding performance in the VUV-soft x-ray energy range and excellent performance into the hard x-ray region. The facility welcomes researchers from universities, industries, and

  1. ALS Doctoral Fellowship in Residence

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Doctoral Fellowship in Residence Print The Advanced Light Source (ALS), a division of Lawrence Berkeley National Laboratory, is a national user facility that generates intense x-ray radiation for scientific and technological research. As the world's first third-generation synchrotron radiation source, the ALS offers outstanding performance in the VUV-soft x-ray energy range and excellent performance into the hard x-ray region. The facility welcomes researchers from universities, industries, and

  2. ALS Evidence Confirms Combustion Theory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ALS Evidence Confirms Combustion Theory ALS Evidence Confirms Combustion Theory Print Wednesday, 22 October 2014 11:43 Researchers recently uncovered the first step in the process that transforms gas-phase molecules into solid particles like soot and other carbon-based compounds. It's a discovery that could help combustion chemists make more efficient, less polluting fuels and help materials scientists fine-tune their carbon nanotubes and graphene sheets for faster, smaller electronics. In

  3. A=20B (1998TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of 20B is predicted to be 69.08 MeV (1974TH01). 20B is then unstable with respect to breakup into 19B + n by 0.9 MeV: see 19B in (1995TI07) and (1978AJ03, 1983ANZQ) and see the...

  4. A=18C (1995TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of the 48Ca(18O, 18C)48Ti reaction. 18C is then bound by 4.188 MeV with respect to breakup into 17C + n. See also (1982FI10, 1987AJ02, 1992WA22). 1. 18C(-)18N Qm 11.807 The...

  5. A=18Na (1995TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    95TI07) (Not observed) 18Na has not been observed; its atomic mass excess has been estimated to be 25.32 MeV (1993AU05); it is then unbound with respect to proton emission by 1.6 MeV: see (1978AJ03). See also (1986AN07) and (1983ANZQ

  6. A=5Be (2002TI10)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2002TI10) (See the Isobar Diagram for 5Be) See also the A = 5 introductory discussion titled A = 5 resonance parameters. The absence of any group structure in the neutron spectrum in the reaction 3He(3He, n)5Be at E(3He) = 18.0 to 26.0 MeV indicates that 5Beg.s

  7. The corrosivity and passivity of sputtered Mg-Ti alloys

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Song, Guang -Ling; Unocic, Kinga A.; Meyer, III, Harry M.; Cakmak, Ercan; Brady, Michael P.; Gannon, Paul E.; Himmer, Phil; Andrews, Quinn

    2015-11-30

    Our study explored the possibility of forming a “stainless” Mg–Ti alloy. The electrochemical behavior of magnetron-sputtered Mg–Ti alloys was measured in a NaCl solution, and the surface films on the alloys were examined by XPS, SEM and TEM. Increased corrosion resistance was observed with increased Ti content in the sputtered Mg–Ti alloys, but passive-like behavior was not reached until the Ti level (atomic %) was higher than the Mg level. Moreover, the surface film that formed on sputtered Mg–Ti based alloys in NaCl solution was thick, discontinuous and non-protective, whereas a thin, continuous and protective Mg and Ti oxide filmmore » was formed on a sputtered Ti–Mg based alloy.« less

  8. The corrosivity and passivity of sputtered Mg-Ti alloys

    SciTech Connect (OSTI)

    Song, Guang -Ling; Unocic, Kinga A.; Meyer, III, Harry M.; Cakmak, Ercan; Brady, Michael P.; Gannon, Paul E.; Himmer, Phil; Andrews, Quinn

    2015-11-30

    Our study explored the possibility of forming a “stainless” Mg–Ti alloy. The electrochemical behavior of magnetron-sputtered Mg–Ti alloys was measured in a NaCl solution, and the surface films on the alloys were examined by XPS, SEM and TEM. Increased corrosion resistance was observed with increased Ti content in the sputtered Mg–Ti alloys, but passive-like behavior was not reached until the Ti level (atomic %) was higher than the Mg level. Moreover, the surface film that formed on sputtered Mg–Ti based alloys in NaCl solution was thick, discontinuous and non-protective, whereas a thin, continuous and protective Mg and Ti oxide film was formed on a sputtered Ti–Mg based alloy.

  9. Epitaxial growth of NiTiO3 with a distorted ilmenite structure

    SciTech Connect (OSTI)

    Varga, Tamas; Droubay, Timothy C.; Bowden, Mark E.; Nachimuthu, Ponnusamy; Shutthanandan, V.; Bolin, Trudy B.; Shelton, William A.; Chambers, Scott A.

    2012-06-30

    MTiO3 (M = Fe, Mn, Ni) compounds have received recent attention as possible candidates for new multiferroic materials capable of magnetization switching by application of an electric field. Epitaxial Ni1-xTi1-yO3 films of different thickness and composition were deposited on Al2O3(0001) by pulsed laser deposition, and characterized using several techniques. Structural parameters for the metastable LiNbO3-type NiTiO3 structure with the space group R3c were predicted using density functional theory calculations, and compared with the experimental results. Our structural data from x-ray diffraction and x-ray absorption spectroscopy indicate that epitaxial ilmenite-type NiTiO3 films were successfully grown. Furthermore, lattice strain exerted by the sapphire substrate results in a distorted ilmenite structure similar to the LiNbO3-type one. Our results demonstrate the potential of oxide heteroepitaxy to stabilize metastable multiferroic phases that may be difficult to prepare or are inaccessible in the bulk.

  10. Influence of fatigue on the nanohardness of NiTiCr-wires

    SciTech Connect (OSTI)

    Frotscher, M.; Young, M. L.; Bei, Hongbin; George, Easo P; Neuking, K.; Eggeler, G.

    2009-01-01

    Testing parameters, such as rotational speed and bending radius, have a strong influence on the fatigue life of pseudoelastic NiTi shape-memory alloys during bending rotation fatigue (BRF) experiments [M. F. X. Wagner, Int. J. Mat. Res. 97 (2006), p. 1687-1696. and M. Frotscher, et al., Thermomechanical processing, microstructure and bending rotation fatigue of ultra-fine grained NiTiCr-wires, Proceedings of the International Conference for Shape Memory and Superelastic Technologies (SMST 2007), Tsukuba, Japan, ASM International, (2008), p. 149-158.]. Previous studies showed a decrease in the fatigue life for smaller bending radius (i.e. higher equivalent strain) and larger rotational speed. This observation is associated with an increase of dislocation density, the stabilization of stressinduced martensite during cycling, and an increase of the plateau stresses due to self-heating. In the present study, we examine the influence of these fatigue parameters on the nanohardness and shape recovery of pseudoelastic NiTiCr shape-memory alloy wires by nanoindentation. We show that nanoindentation is a suitable method for the characterization of fatigue-related microstructural changes, which affect the mechanical properties.

  11. Structural characterization of the FeTiO{sub 3}-MnTiO{sub 3} solid solution

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Structural characterization of the FeTiO{sub 3}-MnTiO{sub 3} solid solution Citation Details In-Document Search Title: Structural characterization of the FeTiO{sub 3}-MnTiO{sub 3} solid solution We have synthesized the (Mn{sub 1-x}Fe{sub x})TiO{sub 3} (0.0{<=}x{<=}1.0) solid solution compounds by high-temperature sintered methods, and characterized their crystal structures by combining X-ray diffraction, Moessbauer spectroscopy and Raman

  12. Experimental investigations of material models for Ti-6A1-4V and 2024-T3

    SciTech Connect (OSTI)

    Leseur, D

    1999-05-03

    This report describes studies of the deformation and failure behavior of Ti-6Al-4V and 2024-T3 aluminum. Data was obtained at high strain rates and large strains using the split Hopkinson pressure bar technique. This information, plus additional data from the literature, was used to critically evaluate the ability of the Johnson Cook material model to represent the deformation and failure response of Ti-6AMV and 2024-T3 under conditions relevant to simulations of engine containment and the influence of uncontained engine debris on aircraft structures. This model is being used in the DYNA3D finite element code, which is being developed/validated for evaluating aircraft/engine designs relative to the federal airworthiness standards and for improving mitigation/containment technology. The results of the experimental work reported here were used to define a new set of material constants for the strength component of the Johnson Cook model for Ti-6Al-4V and 2024-T3. The capabilities and limitations of the model are reviewed. The model can accurately represent the stress-strain response of the materials. The major concern with the Johnson Cook material model is its ability to accurately represent the stress - strain rate response at strain rates greater than 10{sup 3}-10{sup 4} s{sup {minus}1}. Additional work is also needed to adequately account for failure via shear localization, which was the dominant failure mode at high strain rates in both materials. Failure modeling in both Ti-6Al-N and 2024-T3 will be considered further in future reports.

  13. Role of Y-Al oxides during extended recovery process of a ferritic ODS alloy

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Capdevila, C.; Pimentel, G.; Aranda, M. M.; Rementeria, R.; Dawson, K.; Urones-Garrote, E.; Tatlock, G. J.; Miller, Michael K.

    2015-08-04

    The microstructural stability of Y-Al oxides during the recrystallization of Fe-Cr-Al oxide dispersion strengthened alloy is studied in this work. The goal is to determine the specific distribution pattern of oxides depending where they are located: in the matrix or at the grain boundaries. It was concluded that those located at the grain boundaries yielded a faster coarsening than the ones in the matrix, although no significant differences in composition and/or crystal structure were observed. However, the recrystallization heat treatment leads to the dissolution of the Y2O3 and its combination with Al to form the YAlO3 perovskite oxide particles process,more » mainly located at the grain boundaries. Lastly, atom probe tomography analysis revealed a significant Ti build-up at the grain boundaries that might affect subsequent migration during recrystallization.« less

  14. Role of Y-Al oxides during extended recovery process of a ferritic ODS alloy

    SciTech Connect (OSTI)

    Capdevila, C.; Pimentel, G.; Aranda, M. M.; Rementeria, R.; Dawson, K.; Urones-Garrote, E.; Tatlock, G. J.; Miller, Michael K.

    2015-08-04

    The microstructural stability of Y-Al oxides during the recrystallization of Fe-Cr-Al oxide dispersion strengthened alloy is studied in this work. The goal is to determine the specific distribution pattern of oxides depending where they are located: in the matrix or at the grain boundaries. It was concluded that those located at the grain boundaries yielded a faster coarsening than the ones in the matrix, although no significant differences in composition and/or crystal structure were observed. However, the recrystallization heat treatment leads to the dissolution of the Y2O3 and its combination with Al to form the YAlO3 perovskite oxide particles process, mainly located at the grain boundaries. Lastly, atom probe tomography analysis revealed a significant Ti build-up at the grain boundaries that might affect subsequent migration during recrystallization.

  15. Microsoft Word - AL2006-11.doc

    Broader source: Energy.gov (indexed) [DOE]

    Guide Chapter 7.1, Acquisition Planning Acquisition Guide Chapter 42.5, Contract Management Planning When is this Acquisition Letter (AL) Effective? This AL is effective...

  16. ALS@20 Kick-Off Celebration

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    tribulations encountered during the construction of the ALS from former Director Jay Marx, current ALS Scientific Director Steve Kevan and Director Roger Falcone talked about...

  17. ALS Ceramics Materials Research Advances Engine Performance

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ALS Ceramics Materials Research Advances Engine Performance ALS Ceramics Materials Research Advances Engine Performance Print Thursday, 27 September 2012 00:00 ritchie ceramics...

  18. Structural and Morphological Difference Between Ti/TiN/TiCN Coatings Grown in Multilayer and Graded Form

    SciTech Connect (OSTI)

    Restrepo, E.; Baena, A.; Agudelo, C.; Castillo, H.; Devia, A.; Marino, A.

    2006-12-04

    Thin films can be grown in super-lattice, multilayers and graded form, having each one advantages and disadvantages. The difference between multilayer and graded coatings is the interface. In multilayers the interface is abrupt and in graded coatings it is diffuse. The interface influences many chemical and physical properties of the materials, and its choice depends on the application. Graded coatings have the advantage of having gradual properties such as thermal expansion coefficient and lattice parameter, avoiding adherence problems due to good match between their component materials. In this work the comparison between some properties of coatings grown as multilayer and graded is performed. The materials are produced using the sputtering DC technique because of its facility to control the deposition parameters and generate a slow growth. The target is a disc of titanium and the samples are made of stainless steel 304. The working gases are argon, nitrogen and methane, which are mixed according to the material to be produced, i.e. Ti layer is grown with argon, the TiN film is produced with a mixture of argon and nitrogen, and the TiCN material is obtained mixing argon, nitrogen and methane. These materials are characterized with AFM in order to determine grain size and with XPS studying the chemical composition and performing depth profiles.

  19. Bioactive glass coatings with hydroxyapatite and Bioglass (registered) particles on Ti-based implants. 1. Processing

    SciTech Connect (OSTI)

    Gomez-Vega, J.M.; Saiz, E.; Tomsia, A.P.; Marshall, G.W.; Marshall, S.J.

    1999-06-01

    Silicate-based glasses with thermal expansion coefficients that match those of Ti6Al4V were prepared and used to coat Ti6Al4V by a simple enameling technique. Bioglass (BG) (registered) or hydroxyapatite (HA) particles were embedded on the coatings in order to enhance their bioactivity. HA particles were partially embedded during heating and remained firmly embedded on the coating after cooling. There was no apparent reaction at the glass/HA interface at the temperatures used in this work (800-840 degrees C). In contrast, BG particles softened and some infiltration into the glass coating took place during heat treatment. In this case, particles with sizes over 45 (mu)m were required, otherwise the particles became hollow due to the infiltration and crystallization of the glass surface. The concentration of the particles on the coating was limited to 20% of surface coverage. Concentrations above this value resulted in cracked coatings due to excessive induced stress. Cracks did not prop agate along the interfaces when coatings were subjected to Vickers indentation tests, indicating that the particle/glass and glass/metal interfaces exhibited strong bonds. Enameling, producing excellent glass/metal adhesion with well-attached bioactive particles on the surface, is a promising method of forming reliable and lasting implants which can endure substantial chemical and mechanical stresses.

  20. Influence of Ni on Martensitic Phase Transformations in NiTi Shape Memory Alloys

    SciTech Connect (OSTI)

    Frenzel, J.; George, Easo P; Dlouhy, A.; Somsen, Ch.; Wagner, M. F.-X; Eggeler, G.

    2010-01-01

    High-precision data on phase transformation temperatures in NiTi, including numerical expressions for the effect of Ni on M{sub S}, M{sub F}, A{sub S}, A{sub F} and T{sub 0}, are obtained, and the reasons for the large experimental scatter observed in previous studies are discussed. Clear experimental evidence is provided confirming the predictions of Tang et al. 1999 regarding deviations from a linear relation between the thermodynamic equilibrium temperature and Ni concentration. In addition to affecting the phase transition temperatures, increasing Ni contents are found to decrease the width of thermal hysteresis and the heat of transformation. These findings are rationalized on the basis of the crystallographic data of Prokoshkin et al. 2004 and the theory of Ball and James. The results show that it is important to document carefully the details of the arc-melting procedure used to make shape memory alloys and that, if the effects of processing are properly accounted for, precise values for the Ni concentration of the NiTi matrix can be obtained.

  1. A Review Corrosion of TI Grade 7 and Other TI Alloys in Nuclear Waste Repository Environments

    SciTech Connect (OSTI)

    F. Hua; K. Mon; P. Pasupathi; G. Gordon

    2004-05-11

    Titanium alloy degradation modes are reviewed in relation to their performance in repository environments. General corrosion, localized corrosion, stress corrosion cracking, hydrogen induced cracking, microbially influenced corrosion, and radiation-assisted corrosion of Ti alloys are considered. With respect to the Ti Grade 7 drip shields selected for emplacement in the repository at Yucca Mountain, general corrosion, hydrogen induced cracking, and radiation-assisted corrosion will not lead to failure within the 10,000 year regulatory period; stress corrosion cracking (in the absence of disruptive events) is of no consequence to barrier performance; and localized corrosion and microbially influenced corrosion are not expected to occur. To facilitate the discussion, Ti Grades 2, 5, 7, 9, 11, 12, 16, 17, 18, and 24 are included in this review.

  2. Nature of Transactions (TI) Code | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    Nature of Transactions (TI) Code U.S. Department of Energy / U.S. Nuclear Regulatory Commission Nuclear Materials Management & Safeguards System Nature of Transactions (TI) Code* Nature of Transactions (TI) Code* Code: Description: A Initiates lease and financial responsibility of DOE-owned material B Transfer of lease and financial responsiblity of DOE-owned material C Transfer of DOE-owned material with no change in lease or financial responsibility D Return to DOE for credit under DOE

  3. Expectations for the hard x-ray continuum and gamma-ray line fluxes from the typE IA supernova SN 2014J in M82

    SciTech Connect (OSTI)

    The, Lih-Sin [Department of Physics and Astronomy, Clemson University, SC 29634 (United States); Burrows, Adam, E-mail: tlihsin@clemson.edu, E-mail: burrows@astro.princeton.edu [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)

    2014-05-10

    The hard X-ray continuum and gamma-ray lines from a Type Ia supernova dominate its integrated photon emissions and can provide unique diagnostics of the mass of the ejecta, the {sup 56}Ni yield and spatial distribution, its kinetic energy and expansion speed, and the mechanism of explosion. Such signatures and their time behavior 'X-ray' the bulk debris field in direct fashion, and do not depend on the ofttimes problematic and elaborate UV, optical, and near-infrared spectroscopy and radiative transfer that have informed the study of these events for decades. However, to date no hard photons have ever been detected from a Type Ia supernova in explosion. With the advent of the supernova SN 2014J in M82, at a distance of ?3.5 Mpc, this situation may soon change. Both NuSTAR and INTEGRAL have the potential to detect SN 2014J, and, if spectra and light curves can be measured, would usefully constrain the various explosion models published during the last ?30 yr. In support of these observational campaigns, we provide predictions for the hard X-ray continuum and gamma-line emissions for 15 Type Ia explosion models gleaned from the literature. The model set, containing as it does deflagration, delayed detonation, merger detonation, pulsational delayed detonation, and sub-Chandrasekhar helium detonation models, collectively spans a wide range of properties, and hence signatures. We provide a brief discussion of various diagnostics (with examples), but importantly make the spectral and line results available electronically to aid in the interpretation of the anticipated data.

  4. Type Ia Supernovae

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    that the universe is undergoing an accelerated expansion - a result which fits the General Relativity if a yet unknown form of "dark" energy is assumed to dominate the...

  5. IA News Archive

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Dilma Rousseff of Brazil and he announced the creation of a Strategic Energy Dialogue (SED) to support the two countries' common goals of developing safe, secure and affordable...

  6. IA Blog Archive

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    2014 21:03:00 +0000 921386 at http:energy.gov Ministers Meet in Addis Ababa for U.S.-Africa Energy Ministerial http:energy.goviaarticlesministers-meet-addis-ababa-us-africa-...

  7. Gorchakova-IA

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Google Rules of Behavior Form Google Rules of Behavior Form Google Rules of Behavior Form File Google Drive for Work Rules of Behavior Form More Documents & Publications Audit Report: DOE-OIG-16-12 Remote Access Options April 2014 Cybersecurity Awareness Campaign - Malware

    Atl anta, Georgia, March 19-23, 2001 1 Estimate of Horizontal Cloud Inhomogeneity Effect on Solar Radiative Fluxes for Conditions of Winter Zvenigorod Experiment I. A. Gorchakova, G. S. Golitsyn, and I. I. Mokhov

  8. THE EFFECT OF THE PRE-DETONATION STELLAR INTERNAL VELOCITY PROFILE ON THE NUCLEOSYNTHETIC YIELDS IN TYPE Ia SUPERNOVA

    SciTech Connect (OSTI)

    Kim, Yeunjin; Jordan, G. C. IV; Graziani, Carlo; Lamb, D. Q.; Truran, J. W.; Meyer, B. S.

    2013-07-01

    A common model of the explosion mechanism of Type Ia supernovae is based on a delayed detonation of a white dwarf. A variety of models differ primarily in the method by which the deflagration leads to a detonation. A common feature of the models, however, is that all of them involve the propagation of the detonation through a white dwarf that is either expanding or contracting, where the stellar internal velocity profile depends on both time and space. In this work, we investigate the effects of the pre-detonation stellar internal velocity profile and the post-detonation velocity of expansion on the production of {alpha}-particle nuclei, including {sup 56}Ni, which are the primary nuclei produced by the detonation wave. We perform one-dimensional hydrodynamic simulations of the explosion phase of the white dwarf for center and off-center detonations with five different stellar velocity profiles at the onset of the detonation. In order to follow the complex flows and to calculate the nucleosynthetic yields, approximately 10,000 tracer particles were added to every simulation. We observe two distinct post-detonation expansion phases: rarefaction and bulk expansion. Almost all the burning to {sup 56}Ni occurs only in the rarefaction phase, and its expansion timescale is influenced by pre-existing flow structure in the star, in particular by the pre-detonation stellar velocity profile. We find that the mass fractions of the {alpha}-particle nuclei, including {sup 56}Ni, are tight functions of the empirical physical parameter {rho}{sub up}/v{sub down}, where {rho}{sub up} is the mass density immediately upstream of the detonation wave front and v{sub down} is the velocity of the flow immediately downstream of the detonation wave front. We also find that v{sub down} depends on the pre-detonation flow velocity. We conclude that the properties of the pre-existing flow, in particular the internal stellar velocity profile, influence the final isotopic composition of burned matter produced by the detonation.

  9. Thermoelastic Analysis of a Vibrating TiB/Ti Cantilever Beam Using Differential Thermography

    SciTech Connect (OSTI)

    Byrd, Larry; Wyen, Travis; Byrd, Alex

    2008-02-15

    Differential thermography has been used to detect the fluctuating temperatures due the thermoelastic effect for a number of years. This paper examines functionally graded TiB/Ti cantilever beams excited on an electromechanical shaker in fully reversed bending. Finite difference analysis of specimens was used to look at the effect of heat conduction, convection and the fundamental frequency on the surface temperature distribution and compared to experimental data. The thermoelastic effect was also used to detect cracking and the stress field at the tip of the fixture during fatigue.

  10. Ab initio Study of He Stability in hcp-Ti

    SciTech Connect (OSTI)

    Dai, Yunya; Yang, Li; Peng, SM; Long, XG; Gao, Fei; Zu, Xiaotao T.

    2010-12-20

    The stability of He in hcp-Ti was studied using ab initio method based on density functional theory. The results indicate that a single He atom prefers to occupy the tetrahedral site rather than the octahedral site. The interaction of He defects with Ti atoms has been used to explain the relative stabilities of He point defects in hcp-Ti. The relative stability of He defects in hcp-Ti is useful for He clustering and bubble nucleation in metal tritides, which provides the basis for development of improved atomistic models.

  11. Cathodic cage plasma deposition of TiN and TiO{sub 2} thin films on silicon substrates

    SciTech Connect (OSTI)

    Sousa, Romulo R. M. de; Sato, Patricia S.; Nascente, Pedro A. P.; Viana, Bartolomeu C.; Alves, Clodomiro; Nishimoto, Akio

    2015-07-15

    Cathodic cage plasma deposition (CCPD) was used for growing titanium nitride (TiN) and titanium dioxide (TiO{sub 2}) thin films on silicon substrates. The main advantages of the CCPD technique are the uniformity, tridimensionality, and high rate of the film deposition that occurs at higher pressures, lower temperatures, and lower treatment times than those used in conventional nitriding treatments. In this work, the influence of the temperature and gas atmosphere upon the characteristics of the deposited films was investigated. The TiN and TiO{sub 2} thin films were characterized by x-ray diffraction, scanning electron microscopy, and Raman spectroscopy to analyze their chemical, structural, and morphological characteristics, and the combination of these results indicates that the low-cost CCPD technique can be used to produce even and highly crystalline TiN and TiO{sub 2} films.

  12. On the possibility of neutron generation in an imploding TiD{sub 2} puff Z pinch

    SciTech Connect (OSTI)

    Baksht, Rina B.; Tel-Aviv University, Tel Aviv ; Oreshkin, Vladimir I.; Tomsk Polytechnic University, Tomsk ; Rousskikh, Alexander G.

    2013-08-15

    Simulation of implosion of a TiD{sub 2} puff Z pinch is reported. The Z pinch is supposed to be produced by the plasma flow generated by a vacuum arc, as described by Rousskikh et al.[Phys. Plasmas 18, 092707 (2011)]. To simulate the implosion, a one-dimensional two-temperature radiative magnetohydrodynamics code was used. The simulation has shown that neutrons are generated during the implosion of a TiD{sub 2} puff Z pinch due to thermalization of the pinch plasma stagnated on axis. It has been shown that the necessary condition for neutron generation is that the ion temperature must be substantially higher than the electron temperature. For a pinch current of 1 MA, the predicted yield of 'thermal' neutrons is 2.5 10{sup 9} neutrons/shot.

  13. Strain-dependence Of The Structure And Ferroic Properties Of Epitaxial Ni-1 (-) Ti-x(1) (-) O-y(3) Thin Films Grown On Sapphire Substrates

    SciTech Connect (OSTI)

    Varga, Tamas; Droubay, Timothy C.; Bowden, Mark E.; Stephens, Sean A.; Manandhar, Sandeep; Shutthanandan, V.; Colby, Robert J.; Hu, Dehong; Shelton, William A.; Chambers, Scott A.

    2015-03-01

    Polarization-induced weak ferromagnetism has been predicted a few years back in perovskite MTiO3 (M = Fe, Mn, Ni) [Fennie, Phys. Rev. Lett. 100, 167203 (2008)]. We set out to stabilize this metastable perovskite structure by growing NiTiO3 epitaxially on sapphire Al2O3 (001) substrate, and to control the polar and magnetic properties via strain. Epitaxial Ni1-xTi1-yO3 films of different Ni/Ti ratios and thicknesses were deposited on Al2O3 substrates by pulsed laser deposition at different temperatures, and characterized using several techniques. The effect of film thickness, deposition temperature, and film stoichiometry on lattice strain, film structure, and physical properties was investigated. Our structural data from x-ray diffraction, electron microscopy, and x-ray absorption spectroscopy shows that substrate-induced strain has a marked effect on the structure and crystalline quality of the films. Physical property measurements reveal a dependence of the Nel transition and lattice polarization on strain, and highlight our ability to control the ferroic properties in NiTiO3 thin films by film stoichiometry and thickness.

  14. Microsoft Word - AL2008-05.doc

    Energy Savers [EERE]

    Department of Energy No. AL 2008-05 Acquisition Regulation Date 04/03/2008 ACQUISITION LETTER This Acquisition Letter is issued under the authority of the DOE and NNSA Procurement Executives. Subject: Environmental, Energy, and Transportation Management References: Executive Order 13423, dated January 24, 2007 Implementing Instructions, dated March 28, 2007 When is this Acquisition Letter (AL) effective? This AL is effective upon issuance. When does this AL Expire? This AL remains in effect

  15. ALS Evidence Confirms Combustion Theory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ALS Evidence Confirms Combustion Theory Print Researchers recently uncovered the first step in the process that transforms gas-phase molecules into solid particles like soot and other carbon-based compounds. It's a discovery that could help combustion chemists make more efficient, less polluting fuels and help materials scientists fine-tune their carbon nanotubes and graphene sheets for faster, smaller electronics. In addition, the results could have implications for the burgeoning field of

  16. ALS Evidence Confirms Combustion Theory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ALS Evidence Confirms Combustion Theory Print Researchers recently uncovered the first step in the process that transforms gas-phase molecules into solid particles like soot and other carbon-based compounds. It's a discovery that could help combustion chemists make more efficient, less polluting fuels and help materials scientists fine-tune their carbon nanotubes and graphene sheets for faster, smaller electronics. In addition, the results could have implications for the burgeoning field of

  17. ALS Evidence Confirms Combustion Theory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ALS Evidence Confirms Combustion Theory Print Researchers recently uncovered the first step in the process that transforms gas-phase molecules into solid particles like soot and other carbon-based compounds. It's a discovery that could help combustion chemists make more efficient, less polluting fuels and help materials scientists fine-tune their carbon nanotubes and graphene sheets for faster, smaller electronics. In addition, the results could have implications for the burgeoning field of

  18. ALS Evidence Confirms Combustion Theory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ALS Evidence Confirms Combustion Theory Print Researchers recently uncovered the first step in the process that transforms gas-phase molecules into solid particles like soot and other carbon-based compounds. It's a discovery that could help combustion chemists make more efficient, less polluting fuels and help materials scientists fine-tune their carbon nanotubes and graphene sheets for faster, smaller electronics. In addition, the results could have implications for the burgeoning field of

  19. Magnetic Hardening of CeFe11Ti and the Effect of TiC Addition (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect Magnetic Hardening of CeFe11Ti and the Effect of TiC Addition Citation Details In-Document Search Title: Magnetic Hardening of CeFe11Ti and the Effect of TiC Addition Authors: Zhou, Chen ; Haddad, Daad ; Kukreja, Ratandeep S. ; Pinkerton, Frederick E. ; Sun, Kewei ; Kramer, M. J. Publication Date: 2015-04-01 OSTI Identifier: 1221660 Report Number(s): IS-J 8423 Journal ID: ISSN 0018-9464 DOE Contract Number: AC02-07CH11358; 0472-1526 Resource Type: Journal Article

  20. Role of double Ti O 2 layers at the interface of FeSe/ SrTi O 3

    Office of Scientific and Technical Information (OSTI)

    superconductors (Journal Article) | SciTech Connect SciTech Connect Search Results Journal Article: Role of double Ti O 2 layers at the interface of FeSe/ SrTi O 3 superconductors Citation Details In-Document Search This content will become publicly available on May 16, 2017 Title: Role of double Ti O 2 layers at the interface of FeSe/ SrTi O 3 superconductors Authors: Zou, Ke ; Mandal, Subhasish ; Albright, Stephen D. ; Peng, Rui ; Pu, Yujia ; Kumah, Divine ; Lau, Claudia ; Simon, Georg H.

  1. Role of double Ti O 2 layers at the interface of FeSe/ SrTi O 3

    Office of Scientific and Technical Information (OSTI)

    superconductors (Journal Article) | DOE PAGES Publisher's Accepted Manuscript: Role of double Ti O 2 layers at the interface of FeSe/ SrTi O 3 superconductors This content will become publicly available on May 16, 2017 « Prev Next » Title: Role of double Ti O 2 layers at the interface of FeSe/ SrTi O 3 superconductors Authors: Zou, Ke ; Mandal, Subhasish ; Albright, Stephen D. ; Peng, Rui ; Pu, Yujia ; Kumah, Divine ; Lau, Claudia ; Simon, Georg H. ; Dagdeviren, Omur E. ; He, Xi ;

  2. Structure-Curie temperature relationships in BaTiO 3 -based ferroelect...

    Office of Scientific and Technical Information (OSTI)

    ferroelectric perovskites: Anomalous behavior of ( Ba , Cd ) TiO 3 from DFT, ... ferroelectric perovskites: Anomalous behavior of ( Ba , Cd ) TiO 3 from DFT, ...

  3. Equation of State Model Quality Study for Ti and Ti64.

    SciTech Connect (OSTI)

    Wills, Ann Elisabet; Sanchez, Jason James

    2015-02-01

    Titanium and the titanium alloy Ti64 (6% aluminum, 4% vanadium and the balance ti- tanium) are materials used in many technologically important applications. To be able to computationally investigate and design these applications, accurate Equations of State (EOS) are needed and in many cases also additional constitutive relations. This report describes what data is available for constructing EOS for these two materials, and also describes some references giving data for stress-strain constitutive models. We also give some suggestions for projects to achieve improved EOS and constitutive models. In an appendix, we present a study of the 'cloud formation' issue observed in the ALEGRA code. This issue was one of the motivating factors for this literature search of available data for constructing improved EOS for Ti and Ti64. However, the study shows that the cloud formation issue is only marginally connected to the quality of the EOS, and, in fact, is a physical behavior of the system in question. We give some suggestions for settings in, and improvements of, the ALEGRA code to address this computational di culty.

  4. Synthesis of AlN/Al Polycrystals along with Al Nanoparticles Using Thermal Plasma Route

    SciTech Connect (OSTI)

    Kanhe, Nilesh S.; Nawale, A. B.; Kulkarni, N. V.; Bhoraskar, S. V.; Mathe, V. L.; Das, A. K.

    2011-07-15

    This paper for the first time reports the (200) oriented growth of hexagonal Aluminum nitride crystals during synthesis of aluminum nanoparticles in dc transferred arc thermal plasma reactor by gas phase condensation in nitrogen plasma. The structural and morphological study of as synthesized AlN crystal and aluminium nanoparticles was done by using the x-ray diffraction method, scanning electron microscopy and transmission electron microscopy.

  5. A=19B (1995TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    95TI07) (Not illustrated) 19B has been observed in the bombardment of Be by 12 MeV/A 56Fe ions (1984MU27) and in the fragmentation of 44 MeV/A 40Ar (1988GU1A) and 55 MeV/A 48Ca (1991MU19). See also (1989DE52). The mass excess adopted by (1993AU05) is 59.360 ± 0.400 MeV. Shell model predictions for low-lying levels are discussed in (1992WA22). See also (1989PO1K, 1990LO11

  6. A=20N (1998TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    98TI06) (Not illustrated) 20N is particle stable. Its atomic mass excess is 21.770 ± 0.050 MeV (1995AU04). It has been observed in heavy-ion transfer (1989OR03) and projectile fragmentation reactions (1987GI05, 1988DUZT, 1988MU08, 1990MU06, 1991OR01) and in target fragmentation reactions (1988WO09, 1991RE02, 1993WOZZ). See also the review (1988VI1D). Mass measurements were reported in (1987GI05, 1988WO09, 1989OR03, 1991OR01, 1993WOZZ). Nuclear matter rms radii have been derived from

  7. A=3Li (1987TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    1987TI07) GENERAL: The previous compilation (1975FI08) listed a small number of references reporting on the four reactions discussed below. Only one of the experiments cited contained any evidence for a 3p resonance, and the discussion suggested that the observed enhancement in 3He(p, n) was more likely a final state interaction. In the work reported since (1975FI08) and listed below, only (1974POZN) contains any mention of the tri-proton, and no evidence for its existence was observed. 1. 2H(p,

  8. A Study of Selected Properties and Applications of AlMgB14 and Related Composites: Ultra-Hard Materials

    SciTech Connect (OSTI)

    Theron L. Lewis

    2002-05-28

    This research presents a study of the hardness, electrical, and thermal properties AlMgB{sub 14} containing Al{sub 2}MgO{sub 4} spinel. This research also investigated how much Al{sub 2}MgO{sub 4} spinel consistently forms with AlMgB{sub 14}, if AlMgB{sub 14} materials can be produced by hot isostatic pressing (HIP), what effects TiC and TiB{sub 2} have on this composite material, and the importance of mechanical alloying. Included also is a study of the variation in hardness measurements and how they relate to SI units. Heretofore, all ultra-hard materials (hardness > 40 GPA) have been found to be cubic in structure, electrical insulators, and expensive; the behavior of AlMgB{sub 14}, which in certain specimens and compositions can have hardness values greater than 40 GPa, is therefore quite unusual since it is non-cubic, conductive, and moderate in cost. This offers an opportunity to investigate the relationship between hardness, thermal, and electrical properties from a new perspective. The main purpose of this project was to characterize the different properties of the AlMgB{sub 14} materials and to demonstrate that this material can be made in bulk. The technologies used for this study include microhardness measurement techniques, scanning electron microscopy, energy dispersive spectroscopy, x-ray diffraction spectroscopy, x-ray diffraction spectroscopy at different temperatures, optical microscopy, thermomechanical analysis, differential thermal analysis, 4-point probe resistivity, density techniques, Seebeck Effect, and Hall Effect. This research may lead to use of this material for applications where high abrasion resistance along with electrical conduction is needed. Also this research gave more information about a material that could have a great impact on industrial applications.

  9. Fabrication of TiO{sub 2} Thick Film for Photocatalyst from Commercial TiO{sub 2} Powder

    SciTech Connect (OSTI)

    Asteti, S. Fuji; Syarif, D. Gustaman

    2008-03-17

    Photocatalytic activity of TiO{sub 2} thick film ceramics made of commercial TiO{sub 2} powder has been studied. The TiO{sub 2} powder was nano sized one that was derived from dried TiO{sub 2} suspension. The TiO{sub 2} suspension was made by pouring some blended commercial TiO{sub 2} powder into some amount of water. The paste of TiO{sub 2} was made by mixing the nano sized TiO{sub 2} powder with organic vehicle and glass frit. The paste was spread on a glass substrate. The paste was dried at 100 deg. C and heated at different temperatures (400 deg. C and 500 deg. C) for 60 minutes to produce thick film ceramics. The photocatalytic activity of these films was evaluated by measuring the concentration of a solution of methylene blue where the thick films were inside after being illuminated by UV light at various periods of times. The initial concentration of the methylene blue solution was 5 ppm. Structural analyses were carried out by X-ray diffraction (XRD). The XRD analyses showed that the produced thick film ceramic had mainly crystal structure of anatase. According to the photocatalytical data, it was known that the produced thick film ceramics were photocatalyst which were capable of decomposing an organic compound such as the methylene blue.

  10. Al Corn Clean Fuel | Open Energy Information

    Open Energy Info (EERE)

    Corn Clean Fuel Jump to: navigation, search Name: Al-Corn Clean Fuel Place: Claremont, North Dakota Product: Al-Corn is an ethanol plant located in Claremont, North Dakota, which...

  11. ALS Operating Schedule on Google Calendar

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ALS Operating Schedule on Google Calendar Print ALS Operating Schedule Your browser does not appear to support JavaScript, but this page needs to use JavaScript to display...

  12. Category:Montgomery, AL | Open Energy Information

    Open Energy Info (EERE)

    Montgomery, AL Jump to: navigation, search Go Back to PV Economics By Location Media in category "Montgomery, AL" The following 16 files are in this category, out of 16 total....

  13. Electrostatic carrier doping of GdTiO{sub 3}/SrTiO{sub 3} interfaces

    SciTech Connect (OSTI)

    Moetakef, Pouya; Cain, Tyler A.; Zhang, Jack Y.; Janotti, Anderson; Van de Walle, Chris G.; Stemmer, Susanne; Ouellette, Daniel G.; Allen, S. James; Klenov, Dmitri O.; Rajan, Siddharth

    2011-12-05

    Heterostructures and superlattices consisting of a prototype Mott insulator, GdTiO{sub 3}, and the band insulator SrTiO{sub 3} are grown by molecular beam epitaxy and show intrinsic electronic reconstruction, approximately 1/2 electron per surface unit cell at each GdTiO{sub 3}/SrTiO{sub 3} interface. The sheet carrier densities in all structures containing more than one unit cell of SrTiO{sub 3} are independent of layer thicknesses and growth sequences, indicating that the mobile carriers are in a high concentration, two-dimensional electron gas bound to the interface. These carrier densities closely meet the electrostatic requirements for compensating the fixed charge at these polar interfaces. Based on the experimental results, insights into interfacial band alignments, charge distribution, and the influence of different electrostatic boundary conditions are obtained.

  14. Microsoft Word - al2007-11.doc | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    al2007-11.doc Microsoft Word - al2007-11.doc PDF icon Microsoft Word - al2007-11.doc More Documents & Publications Acquisition Letter: AL2005-08 Microsoft Word - al2004-03.doc OPAM...

  15. AL2002-01.pdf | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    2-01.pdf AL2002-01.pdf PDF icon AL2002-01.pdf More Documents & Publications AL2002-04.pdf AL2002-08.pdf AL2002-06...

  16. AL2002-04.pdf | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    4.pdf AL2002-04.pdf PDF icon AL2002-04.pdf More Documents & Publications AL2004-01r2.pdf AL2002-01.pdf AL2002-08...

  17. Aluminium distribution in ZSM-5 revisited: The role of Al-Al interactions

    SciTech Connect (OSTI)

    Ruiz-Salvador, A. Rabdel; Grau-Crespo, Ricardo; Gray, Aileen E.; Lewis, Dewi W.

    2013-02-15

    We present a theoretical study of the distribution of Al atoms in zeolite ZSM-5 with Si/Al=47, where we focus on the role of Al-Al interactions rather than on the energetics of Al/Si substitutions at individual sites. Using interatomic potential methods, we evaluate the energies of the full set of symmetrically independent configurations of Al siting in a Si{sub 94}Al{sub 2}O{sub 192} cell. The equilibrium Al distribution is determined by the interplay of two factors: the energetics of the Al/Si substitution at an individual site, which tends to populate particular T sites (e.g., the T14 site), and the Al-Al interaction, which at this Si/Al maximises Al-Al distances in general agreement with Dempsey's rule. However, it is found that the interaction energy changes approximately as the inverse of the square of the distance between the two Al atoms, rather than the inverse of the distance expected if this were merely charge repulsion. Moreover, we find that the anisotropic nature of the framework density plays an important role in determining the magnitude of the interactions, which are not simply dependent on Al-Al distances. - Graphical abstract: Role of Al-Al interactions in high silica ZSM-5 is shown to be anisotropic in nature and not dependent solely on Coulombic interactions. Highlights: Black-Right-Pointing-Pointer Si-Al distribution in ZSM-5 is revisited, stressing the role of the Al-Al interaction. Black-Right-Pointing-Pointer Coulomb interactions are not the key factors controlling the Al siting. Black-Right-Pointing-Pointer Anisotropy of the framework is identified as a source of departure from Dempsey's rule.

  18. Development of Ti/Ti{sub 3}Sn functionally gradient material produced by eutectic bonding method

    SciTech Connect (OSTI)

    Kirihara, S.; Takeda, M.; Tsujimoto, T. [Ibaraki Univ., Hitachi (Japan). Faculty of Engineering] [Ibaraki Univ., Hitachi (Japan). Faculty of Engineering

    1996-07-15

    Although many materials which have a single function have been developed, future needs are anticipated to include materials which have various functions. A functionally gradient material (FGM) which has characteristics of two different materials is a promising candidate for multi-functional material. The present methods for production of FGM, however, are very complicated and costly. In this study the authors answer the serious problem of high production cost by fabricating the FGM by a eutectic bonding method. This fabrication method includes structural control of FGM by changing the cooling process. They describe Ti/Ti{sub 3}Sn FGM obtained by the eutectic bonding method, and tell how the structure of its composition gradient part is changed by controlling the cooling process.

  19. Band alignment in visible-light photo-active CoO/SrTiO{sub 3} (001) heterostructures

    SciTech Connect (OSTI)

    Seo, Hosung; Demkov, Alexander A.

    2014-12-28

    Epitaxial oxide heterostructures are of fundamental interest in a number of problems ranging from oxide electronics to model catalysts. The epitaxial CoO/SrTiO{sub 3} (001) heterostructure on Si(001) has been recently studied as a model oxide catalyst for water splitting under visible light irradiation (Ngo et al., J. Appl. Phys. 114, 084901 (2013)). We use density functional theory to investigate the valence band offset at the CoO/SrTiO{sub 3} (001) interface. We examine the mechanism of charge transfer and dielectric screening at the interface and demonstrate that charge transfer is mediated by the metal-induced gap states in SrTiO{sub 3}, while the dielectric screening at the interface is largely governed by the ionic polarization of under-coordinated oxygen. Based on this finding, we argue that strain relaxation in CoO plays a critical role in determining the band offset. We find that the offsets of 1.361.10?eV, calculated in the Schottky-limit are in excellent agreement with the experimental value of 1.20?eV. In addition, we investigate the effect of the Hubbard correction, applied on the Co 3d states, on the dipole layer and potential shift at the interface.

  20. Nondestructive evaluation of Ni-Ti shape memory alloy

    SciTech Connect (OSTI)

    Meir, S.; Gordon, S.; Karsh, M.; Ayers, R.; Olson, D. L.; Wiezman, A.

    2011-06-23

    The nondestructive evaluation of nickel titanium (Ni-Ti) alloys for applications such as heat treatment for biomaterials applications (dental) and welding was investigated. Ni-Ti alloys and its ternary alloys are valued for mechanical properties in addition to the shape memory effect. Two analytical approaches were perused in this work. Assessment of the microstructure of the alloy that determines the martensitic start temperature (Ms) of Ni-Ti alloy as a function of heat treatment, and secondly, an attempt to evaluate a Friction Stir Welding, which involves thermo-mechanical processing of the alloy.

  1. A=16B (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    93TI07) (Not illustrated) This nucleus has not been observed in the 4.8 GeV proton bombardment of a uranium target. It is particle unstable. Its mass excess is predicted to be 37.97 MeV; it would then be unstable with respect to decay into 15B + n by 0.93 MeV. See (1985WA02, 1986AJ04). The ground state is predicted to have Jπ = 0- and the first three excited states are predicted to lie at 0.95, 1.10, and 1.55 MeV [Jπ = 2-, 3-, 4-] in a (0 + 1)ℏω space shell model calculation. See (1983ANZQ,

  2. A=16C (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    93TI07) (See Energy Level Diagrams for 16C) GENERAL: See Table Prev. Table 16.1 preview 16.1 [General Table] (in PDF or PS) and Table Prev. Table 16.2 preview 16.2 [Table of Energy Levels] (in PDF or PS) here. 1. 16C(β-)16N Qm = 8.012 The half life of 16C is 0.747 ± 0.008 sec. It decays to 16N*(0.12, 3.35, 4.32) [Jπ = 0-, 1+, 1+]: see Table Prev. Table 16.3 preview 16.3 (in PDF or PS) and (1993CH06). See also (1986AJ04) and see (1986KI05, 1988WA1E, 1992WA1L) for theoretical discussions of

  3. A=16F (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    93TI07) (See Energy Level Diagrams for 16F) GENERAL: See Table Prev. Table 16.29 preview 16.29 [General Table] (in PDF or PS) here. See also Table Prev. Table 16.30 preview 16.30 [Table of Energy Levels] (in PDF or PS) here. 1. (a) 14N(3He, n)16F Qm = -0.957 (b) 14N(3He, np)15O Qm = -0.421 Obserevd neutron groups from reaction (a) and results from reaction (b) are displayed in Table Prev. Table 16.31 preview 16.31 (in PDF or PS). A recent measurement of n-p angular correlations from 14N(3He,

  4. A=16Ne (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    93TI07) (See the Isobar Diagram for 16Ne) GENERAL: See Table Prev. Table 16.29 preview 16.29 [General Table] (in PDF or PS) and Table Prev. Table 16.32 preview 16.32 [Table of Energy Levels] (in PDF or PS). Mass of 16Ne: The Q-values of the 20Ne(α, 8He) and 16O(π+, π-) reactions lead to atomic mass excesses of 23.93 ± 0.08 MeV (1978KE06), 23.978 ± 0.024 MeV (1983WO01) and 24.048 ± 0.045 MeV (1980BU15) [recalculated using the (1985WA02) masses for 8He, 16O and 20Ne]. The weighted mean is

  5. A=16O (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    93TI07) (See Energy Level Diagrams for 16O) GENERAL: See Table Prev. Table 16.12 preview 16.12 [General Table] (in PDF or PS) and Table Prev. Table 16.13 preview 16.13 [Table of Energy Levels] (in PDF or PS). < r2 > 1/2 = 2.710 ± 0.015 fm (1978KI01) Abundance = (99.762 ± 0.015)% (1984DE53) |g| = 0.556 ± 0.004 (1984AS03) 1. 9Be(9Be, 2n)16O Qm = 11.289 Total reaction cross sections and characteristic γ-ray cross sections for 9Be + 9Be were measured for Ec.m. = 1.4 - 3.4 MeV (1988LA25).

  6. A=17C (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    93TI07) (See the Isobar Diagram for 17C) The atomic mass excess given by (1988WA18) for 17C is 21035 ± 17 keV. See also (1986AN07). 17C is then stable with respect to 16C + n by 0.73 MeV. Eβ- (max) to 17Ng.s. = 13.16 MeV. See also (1986BI1A). The half-life of 17C has been measured to be 202 ± 17 msec (1986CU01), 220 ± 80 msec (1986DU07), 180 ± 31 msec (1988SA04), and 174 ± 31 msec (1991RE02). Relative intensities of β-delayed gammas were measured by (1986DU07, 1986HU1A, 1986JEZY) [see

  7. A=17Ne (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    93TI07) (See the Isobar Diagram for 17Ne) GENERAL: See Table Prev. Table 17.26 preview 17.26 [Table of Energy Levels] (in PDF or PS). 1. (a) 17Ne(β+)17F* → 16O + p Qm = 13.928 (b) 17Ne(β+)17F → 13N + α Qm = 8.711 (c) 17Ne(β+)17F Qm = 14.529 The half-life of 17Ne has been reported as 109.0 ± 1.0 msec (1971HA05) and 109.3 ± 0.6 msec (1988BO39): the weighted mean is 109.2 ± 0.6 and we adopt it. The decay is primarily to the proton unstable states of 17F at 4.65, 5.49, 6.04 and 8.08 MeV

  8. A=18B (1995TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    95TI07) (Not illustrated) 18B has not been observed in the bombardment of Ta by 44 MeV/A Ar ions (1985DE60, 1985LA03, 1986PO13) or in the bombardment of Be by 12 MeV/A 56Fe ions (1984MU27). 18B has been predicted to have a mass excess of 52.3 MeV (1993AU05). It would then be unstable with respect to 17B + n by 0.5 MeV: see (1978AJ03, 1985WA02). 18B is calculated to have Jπ = 4- and to have excited states at 0.62, 0.86 and 1.59 MeV with Jπ = 1-, 2- and 2- (1985PO10).The shell model calculations

  9. A=19N (1995TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    95TI07) (See the Isobar Diagram for 19N) 19N has been produced in a number of different multinucleon transfer reactions (1983AJ01, 1987AJ02), and these results lead to an adopted value (1993AU05) of 15.860 ± 0.016 MeV for the mass excess. 19N is then stable with respect to decay into 18N + n by 5.33 MeV. The half-life has been measured to be 0.32 ± 0.10 s (1986DU07), 0.21+0.2-0.1 s (1988MU08), 0.235 ± 0.032 s (1988SA04), 0.300 ± 0.080 s (1988DUZT), 0.329 ± 0.019 s (1991RE02). The neutron

  10. Electronic transport through Al/InN nanowire/Al junctions (Journal Article)

    Office of Scientific and Technical Information (OSTI)

    | SciTech Connect Electronic transport through Al/InN nanowire/Al junctions Citation Details In-Document Search This content will become publicly available on February 1, 2017 Title: Electronic transport through Al/InN nanowire/Al junctions We report non-linear electronic transport measurement of Al/Si-doped n-type InN nanowire/Al junctions performed at T = 0.3 K, below the superconducting transition temperature of the Al electrodes. The proximity effect is observed in these devices through

  11. Modeling and experimental studies of oxide covered metal surfaces: TiO{sub 2}/Ti a model system. Progress report

    SciTech Connect (OSTI)

    Smyrl, W.H.

    1991-12-31

    Prior work in our laboratories at the Corrosion Research Center has shown that thin, anodic TiO{sub 2} films formed by the Slow Growth Mode (SGM) on polycrystalline titanium and microcrystalline with a texture that varies from one metal grain to another. Furthermore, the underlying metal grains are mapped by the photoelectrochemical response of the oxide. The same characteristics have also been demonstrated in our laboratory for ZnO grown on Zn. The TiO{sub 2}/Ti system has been chosen for study both because of its importance in energy systems, and because it can serve as a model system for other metal-metal oxide couples. The investigations of anodic TiO{sub 2} films on Ti have shown that the properties of thin films are consistent with the rutile form of the oxide. Both experimental data and theoretical calculations show the close resemblance to results on single crystal TiO{sub 2}. Furthermore, the modeling studies reveal that the optical transitions near the bandedge arise from the bulk band structure. The photoelectrochemical properties of anodic TiO{sub 2} films have now been shown to obey the simple Gaertner-Butler model for the semiconductor-electrolyte interface, with a few modifications. The most important deviation has now been shown to be a result of multiple internal reflections in the oxide film.

  12. Modeling and experimental studies of oxide covered metal surfaces: TiO sub 2 /Ti a model system

    SciTech Connect (OSTI)

    Smyrl, W.H.

    1991-01-01

    Prior work in our laboratories at the Corrosion Research Center has shown that thin, anodic TiO{sub 2} films formed by the Slow Growth Mode (SGM) on polycrystalline titanium and microcrystalline with a texture that varies from one metal grain to another. Furthermore, the underlying metal grains are mapped by the photoelectrochemical response of the oxide. The same characteristics have also been demonstrated in our laboratory for ZnO grown on Zn. The TiO{sub 2}/Ti system has been chosen for study both because of its importance in energy systems, and because it can serve as a model system for other metal-metal oxide couples. The investigations of anodic TiO{sub 2} films on Ti have shown that the properties of thin films are consistent with the rutile form of the oxide. Both experimental data and theoretical calculations show the close resemblance to results on single crystal TiO{sub 2}. Furthermore, the modeling studies reveal that the optical transitions near the bandedge arise from the bulk band structure. The photoelectrochemical properties of anodic TiO{sub 2} films have now been shown to obey the simple Gaertner-Butler model for the semiconductor-electrolyte interface, with a few modifications. The most important deviation has now been shown to be a result of multiple internal reflections in the oxide film.

  13. Controlling Atomic Layer Deposition of TiO2 in Aerogels through Surface Functionalization

    SciTech Connect (OSTI)

    Ghosal, S; Baumann, T F; King, J S; Kucheyev, S; Wang, Y; Worsley, M A; Biener, J; Bent, S F; Hamza, A V

    2009-03-09

    This report demonstrates a chemical functionalization method for controlling atomic layer deposition (ALD) of TiO{sub 2} in low-density nanoporous materials. Functionalization of silica aerogel with trimethylsilane is shown to strongly suppress TiO{sub 2} growth via ALD. Subsequent modification of the functionalization through selective removal of the hydrocarbon groups reactivates the aerogel towards TiO{sub 2} deposition. These results demonstrate the potential use of ALD as a selective tool for creating novel nanoporous materials. Nanoporous materials present significant technological advantage for a wide range of applications, including catalysis, energy storage and conversion, nanoelectronics to name just a few (1-4). Hence, there is considerable interest in developing synthetic pathways for the fabrication of nanoporous materials with tailored properties. Aerogels (AGs) are unique low-density, open-cell porous materials consisting of submicrometer pores and ligaments that can be used as a robust material platform for designing novel nanoporous materials. In recent years, a synthetic approach based on ALD on AG templates has emerged as a promising method for the directed growth of nanoporous materials (5-11, 18). This approach has been used successfully to prepare millimeter-sized high aspect ratio aerogels coated uniformly with zinc oxide (ZnO), tungsten (W) and alumina (Al{sub 2}O{sub 3}) (10, 11). The ALD process utilizes two sequential, self-limiting surface reactions resulting in a layer-by-layer growth mode. The self limiting nature of the surface reactions makes ALD a particularly suitable technique for uniform deposition onto high aspect ratio porous substrates. Additionally, chemical specificity of the surface reactions in ALD enables one to control the deposition process through selective functionalization of the substrate surface. In fact the functionalization of planar substrates such as silicon wafers with organosilane groups (R{sub n}SiX{sub 4-n} (n = 1-3)) has been shown to deactivate the substrate towards ZrO{sub 2}, HfO{sub 2}, ZnO, and TiO{sub 2} ALD processes (12-16). A possible mechanism for the deactivation effect is the blocking of surface functional groups, such as hydroxyl (OH) moieties, which serve as chemisorption sites for the ALD precursors and hence are essential for nucleating the deposition process. Henceforth, we shall refer to these surface functional groups as nucleation sites for the ALD process.

  14. A=6H (2002TI10)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    88 MeV (1986BE35) () 16 nbsr at 8. 6H is unstable with respect to breakup into 3H + 3n by 2.7 0.4 MeV, 1.8 0.5 MeV (1984AL08), 2.6 0.5 MeV, ...

  15. Photoinduced electron transfer in perylene-TiO2 nanoassemblies

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ABSTRACT: The photosensitization effect of three perylene dye derivatives on titanium dioxide nanoparticles (TiO2 NPs) has been investigated. The dyes used, 1,7-dibromoperylene-3,4...

  16. Strain-dependence Of The Structure And Ferroic Properties Of Epitaxial NiTiO3 Thin Films Grown On Different Substrates

    SciTech Connect (OSTI)

    Varga, Tamas; Droubay, Timothy C.; Bowden, Mark E.; Kovarik, Libor; Hu, Dehong; Chambers, Scott A.

    2015-08-14

    Polarization-induced weak ferromagnetism has been predicted a few years back in perovskite MTiO3 (M = Fe, Mn, Ni) [Fennie, Phys. Rev. Lett. 100, 167203 (2008)]. We set out to stabilize this metastable perovskite structure by growing NiTiO3 epitaxially on different substrates, and to investigate the dependence of polar and magnetic properties on strain. Epitaxial NiTiO3 films were deposited on Al2O3, Fe2O3, and LiNbO3 substrates by pulsed laser deposition, and characterized using several techniques. The effect of substrate choice on lattice strain, film structure, and physical properties was investigated. Our structural data from x-ray diffraction and electron microscopy shows that substrate-induced strain has a marked effect on the structure and crystalline quality of the films. Physical property measurements reveal a dependence of the weak ferromagnetism and lattice polarization on strain, and highlight our ability to control the ferroic properties in NiTiO3 thin films by the choice of substrate. Our results are also consistent with the theoretical prediction that the ferromagnetism in acentric NiTiO3 is polarization-induced. From the substrates studied here, the perovskite substrate LiNbO3 proved to be the most promising one for strong multiferroism.

  17. Strain-Dependence of the Structure and Ferroic Properties of Epitaxial NiTiO3Thin Films Grown on Different Substrates

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Varga, Tamas; Droubay, Timothy C.; Bowden, Mark E.; Kovarik, Libor; Hu, Dehong; Chambers, Scott A.

    2015-01-01

    Polarization-induced weak ferromagnetism has been predicted a few years back in perovskite MTiO3(M = Fe, Mn, and Ni). We set out to stabilize this metastable perovskite structure by growing NiTiO3epitaxially on different substrates and to investigate the dependence of polar and magnetic properties on strain. Epitaxial NiTiO3films were deposited on Al2O3, Fe2O3, and LiNbO3substrates by pulsed laser deposition and characterized using several techniques. The effect of substrate choice on lattice strain, film structure, and physical properties was investigated. Our structural data from X-ray diffraction and electron microscopy shows that substrate-induced strain has a marked effect on the structure and crystallinemorequality of the films. Physical property measurements reveal a dependence of the weak ferromagnetism and lattice polarization on strain and highlight our ability to control the ferroic properties in NiTiO3thin films by the choice of substrate. Our results are also consistent with the theoretical prediction that the ferromagnetism in acentric NiTiO3is polarization induced. From the substrates studied here, the perovskite substrate LiNbO3proved to be the most promising one for strong multiferroism.less

  18. Strain-Dependence of the Structure and Ferroic Properties of Epitaxial NiTiO 3 Thin Films Grown on Different Substrates

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Varga, Tamas; Droubay, Timothy C.; Bowden, Mark E.; Kovarik, Libor; Hu, Dehong; Chambers, Scott A.

    2015-01-01

    Polarization-induced weak ferromagnetism has been predicted a few years back in perovskite MTiO 3 (M = Fe, Mn, and Ni). We set out to stabilize this metastable perovskite structure by growing NiTiO 3 epitaxially on different substrates and to investigate the dependence of polar and magnetic properties on strain. Epitaxial NiTiO 3 films were deposited on Al 2 O 3 , Fe 2 O 3 , and LiNbO 3 substrates by pulsed laser deposition and characterized using several techniques. The effect of substrate choice on lattice strain, film structure, and physical properties was investigated. Our structural data from X-raymore » diffraction and electron microscopy shows that substrate-induced strain has a marked effect on the structure and crystalline quality of the films. Physical property measurements reveal a dependence of the weak ferromagnetism and lattice polarization on strain and highlight our ability to control the ferroic properties in NiTiO 3 thin films by the choice of substrate. Our results are also consistent with the theoretical prediction that the ferromagnetism in acentric NiTiO 3 is polarization induced. From the substrates studied here, the perovskite substrate LiNbO 3 proved to be the most promising one for strong multiferroism.« less

  19. Martensite transformation of epitaxial Ni-Ti films

    SciTech Connect (OSTI)

    Buschbeck, J.; Kozhanov, A.; Kawasaki, J. K.; James, R. D.; Palmstroem, C. J.

    2011-05-09

    The structure and phase transformations of thin Ni-Ti shape memory alloy films grown by molecular beam epitaxy are investigated for compositions from 43 to 56 at. % Ti. Despite the substrate constraint, temperature dependent x-ray diffraction and resistivity measurements reveal reversible, martensitic phase transformations. The results suggest that these occur by an in-plane shear which does not disturb the lattice coherence at interfaces.

  20. Microstructure of V-based ohmic contacts to AlGaN/GaN heterostructures at a reduced annealing temperature

    SciTech Connect (OSTI)

    Schmid, A. Schroeter, Ch.; Otto, R.; Heitmann, J.; Schuster, M.; Klemm, V.; Rafaja, D.

    2015-02-02

    Ohmic contacts with V/Al/Ni/Au and V/Ni/Au metalization schemes were deposited on AlGaN/GaN heterostructures. The dependence of the specific contact resistance on the annealing conditions and the V:Al thickness ratio was shown. For an optimized electrode stack, a low specific contact resistance of 8.9??10{sup ?6} ? cm{sup 2} was achieved at an annealing temperature of 650?C. Compared to the conventional Ti/Al/Ni/Au contact, this is a reduction of 150?K. The microstructure and contact formation at the AlGaN/metal interface were investigated by transmission electron microscopy including high-resolution micrographs and energy dispersive X-ray analysis. It was shown that for low-resistive contacts, the resistivity of the metalization has to be taken into account. The V:Al thickness ratio has an impact on the formation of different intermetallic phases and thus is crucial for establishing ohmic contacts at reduced annealing temperatures.

  1. ALS Ceramics Materials Research Advances Engine Performance

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ALS Ceramics Materials Research Advances Engine Performance ALS Ceramics Materials Research Advances Engine Performance Print Thursday, 27 September 2012 00:00 ritchie ceramics This 3D image of a ceramic composite specimen imaged under load at 1750C shows the detailed fracture patterns that researchers are able to view using ALS Beamline 8.3.2. The vertical white lines are the individual silicon carbide fibers in this sample about 500 microns in diameter. LBNL senior materials scientist and U.C.

  2. IBM Probes Material Capabilities at the ALS

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    IBM Probes Material Capabilities at the ALS IBM Probes Material Capabilities at the ALS Print Wednesday, 12 February 2014 11:05 Vanadium dioxide, one of the few known materials that acts like an insulator at low temperatures but like a metal at warmer temperatures, is a somewhat futuristic material that could yield faster and much more energy-efficient electronic devices. Researchers from IBM's forward-thinking Spintronic Science and Applications Center (SpinAps) recently used the ALS to gain

  3. ALS Ceramics Materials Research Advances Engine Performance

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ALS Ceramics Materials Research Advances Engine Performance ALS Ceramics Materials Research Advances Engine Performance Print Thursday, 27 September 2012 00:00 ritchie ceramics This 3D image of a ceramic composite specimen imaged under load at 1750C shows the detailed fracture patterns that researchers are able to view using ALS Beamline 8.3.2. The vertical white lines are the individual silicon carbide fibers in this sample about 500 microns in diameter. LBNL senior materials scientist and U.C.

  4. Analysis of natural gases, AL, AR, FL, GA, IL, IN, IA, KY, LA, MD, MI, MS, MO, NJ, NY, NC, OH, PA, TN, VA, and WV; 1951-1991 (for microcomputers). Data file

    SciTech Connect (OSTI)

    Not Available

    1991-01-01

    The U.S. Bureau of Mines diskette contains analysis and related source data for 2,357 natural gas samples collected from miscellaneous states, which include the following states: Alabama, Arkansas (except Arkoma Basin), Florida, Georgia, Illinois, Indiana, Iowa, Kentucky, Louisiana, Maryland, Michigan, Mississippi, Missouri, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia, and West Virginia. All samples were obtained and analyzed as part of the Bureau's investigations of occurrences of helium in natural gases of countries with free market economies. The survey has been conducted since 1917. The analysis contained on the diskette contain the full range of component analysis data. Five files are on the diskette: READ.ME, MISC.TXT, MISC.DBF, USHEANAL.DBF, and BASINCDE.TXT.

  5. Al Furat Petroleum Company | Open Energy Information

    Open Energy Info (EERE)

    Furat Petroleum Company Name: Al Furat Petroleum Company Place: Damascus, Syria Product: oil and hydrocarbon gas Year Founded: 1985 Phone Number: 00963-11- (6183333) Website:...

  6. Microsoft Word - Final MR AL.doc

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Department of Energy No. AL 2009-01 Acquisition Regulation Date: 10062008 ACQUISITION ... Subject: Management Reserve and Contingency References: FAR Subpart 15.4 Contract Pricing ...

  7. Crystallographic Consulting Brings Research to the ALS

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of the participating research team (PRT) members at the Berkeley Center for Structural Biology (BCSB), which operates five ALS beamlines. As PRT members, companies are...

  8. Ringleader: Cobber Lam, ALS Systems Administrator

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Cobber Lam, ALS Systems Administrator Print Cobber Lam started working at Berkeley Lab 10 years ago as a student assistant, while attending college at Cal State East Bay. Within two months, he was assigned to the ALS and has stayed put ever since. He used to be matrixed via IT, but last year he became a direct ALS employee. ALS IT support is divided between Lam and Tim Kellogg, with Lam being more forward-facing, dealing with users and staff, and Kellogg working on the back-end mostly with

  9. Al Turi Biomass Facility | Open Energy Information

    Open Energy Info (EERE)

    NEEDS 2006 Database Retrieved from "http:en.openei.orgwindex.php?titleAlTuriBiomassFacility&oldid397128" Feedback Contact needs updating Image needs updating...

  10. Al Tayyar Energy | Open Energy Information

    Open Energy Info (EERE)

    Jump to: navigation, search Name: Al Tayyar Energy Place: Abu Dhabi, United Arab Emirates Sector: Renewable Energy Product: Provides development capital and equity investments...

  11. April 27, 2015-Special ALS Colloquium

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Years Janos Kirz, ALS Abstract Rntgen's great discovery became an instant public sensation. Fascination with the "new kind of rays" that could reveal the structure of opaque...

  12. ALS Reveals New State of Matter

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ALS Reveals New State of Matter ALS Reveals New State of Matter Print Wednesday, 13 October 2010 00:00 ALS user groups from Princeton and Stanford have been making waves this past year with several high-profile papers and extensive news coverage of their work on a new state of matter embodied by "topological insulators," materials that conduct electricity only on their surfaces. First identified at the ALS in 2007 by a Princeton team led by M. Zahid Hasan, topological insulators have

  13. Microsoft Word - al2006-12.doc

    Broader source: Energy.gov (indexed) [DOE]

    AL-2006-12 (092906) 7 III. What Procedures Ensure Effective Audit Management? Some strategies for managing required audit activity include: 1. Contracting officers should...

  14. IBM Probes Material Capabilities at the ALS

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Researchers from IBM's forward-thinking Spintronic Science and Applications Center (SpinAps) recently used the ALS to gain greater insight into vanadium dioxide's unusual phase ...

  15. A comparative study of precipitation effects in Ti only and Ti-V Ultra Low Carbon (ULC) strip steels

    SciTech Connect (OSTI)

    Ooi, S.W.; Fourlaris, G. . E-mail: g.fourlaris@swansea.ac.uk

    2006-04-15

    Two ULC steel grades were investigated, one based on combined vanadium and titanium additions and the other based on titanium only additions. It has been established that TiC formation during interphase precipitation retards grain growth of the {l_brace}111{r_brace} texture grains during continuous annealing and hence positively affects the r value of the Ti only steel. The formation of newly formed TiC precipitates on dislocations during continuous annealing has been found to result in an increase of the yield strength in both steel grades, as the annealing temperature is increased. It is also confirmed that VC particles formed during the coiling process dissolve during the continuous annealing cycles. Suitable continuous annealing cycles can be adopted to produce high formable steels with a bake hardening potential using the beneficial effects of combined Ti-V additions.

  16. Native SrTiO3 (001) surface layer from resonant Ti L2,3 reflectance spectroscopy

    SciTech Connect (OSTI)

    Valvidares, Manuel; Huijben, Mark; Yu, Pu; Ramesh, Ramamoorthy; Kortright, Jeffrey

    2010-11-03

    We quantitatively model resonant Ti L2,3 reflectivity Rs,p(q, hn) from several SrTiO3 (001) single crystals having different initial surface preparations and stored in ambient conditions before and between measurements. All samples exhibit unexpected 300 K Rs(hn) - Rp(hn) anisotropy corresponding to weak linear dichroism and tetragonal distortion of the TiO6 octahedra indicating a surface layer with properties different from cubic SrTiO3. Oscillations in Rs(q) confirm a ubiquitous surface layer 2-3 nm thick that evolves over a range of time scales. Resonant optical constant spectra derived from Rs,p(hn) assuming a uniform sample are refined using a single surface layer to fit measured Rs(q). Differences in surface layer and bulk optical properties indicate that the surface is significantly depleted in Sr and enriched in Ti and O. While consistent with the tendency of SrTiO3 surfaces toward non-stoichiometry, this layer does not conform simply to existing models for the near surface region and apparently forms via room temperature surface reactions with the ambient. This new quantitative spectral modeling approach is generally applicable and has potential to study near-surface properties of a variety of systems with unique chemical and electronic sensitivities.

  17. AL 2014-06 ACQUISITION LETTERS REMAINING IN EFFECT | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AL 2014-06 ACQUISITION LETTERS REMAINING IN EFFECT AL 2014-06 ACQUISITION LETTERS REMAINING IN EFFECT AL 2014-06 ACQUISITION LETTERS REMAINING IN EFFECT Acquisition Letters (AL)...

  18. AL2010-01.pdf | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    1.pdf AL2010-01.pdf PDF icon AL2010-01.pdf More Documents & Publications G Microsoft Word - AL-Omnibus FY 2009 Apr 22 2009 all sections.doc Microsoft Word - AL-Consolidated Approps...

  19. AL2007-09.pdf | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    7-09.pdf AL2007-09.pdf PDF icon AL2007-09.pdf More Documents & Publications AL2007-04.pdf RL-2007OMCPIA.pdf AL2007-06.pdf...

  20. AL2007-04.pdf | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    4.pdf AL2007-04.pdf PDF icon AL2007-04.pdf More Documents & Publications Preliminary Notice of Violation, BWXT Y-12 LLC - EA-2007-04 AL2007-05.doc&0; AL2007-09...

  1. AL2007-06.pdf | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    6.pdf AL2007-06.pdf PDF icon AL2007-06.pdf More Documents & Publications AL2007-04.pdf AL2007-09.pdf RL-2007OMCPIA...

  2. Microsoft Word - AL2003-04.doc | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Microsoft Word - AL2003-04.doc PDF icon Microsoft Word - AL2003-04.doc More Documents & Publications Microsoft Word - AL2006-08.doc AL2004-01r2.pdf City of Tulare Renewable Biogas ...

  3. Microsoft Word - al2004-03.doc | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    al2004-03.doc Microsoft Word - al2004-03.doc PDF icon Microsoft Word - al2004-03.doc More Documents & Publications Acquisition Letter: AL2005-08 OPAM Policy Acquisition Guides ...

  4. Microsoft Word - al2005-06.doc | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    - al2005-06.doc PDF icon Microsoft Word - al2005-06.doc More Documents & Publications Microsoft Word - AL2006-01.doc OPAM Policy Acquisition Guides Acquisition Letter: AL2005-08...

  5. Microsoft Word - AL2008-05.doc | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Microsoft Word - AL2008-05.doc Microsoft Word - AL2008-05.doc Microsoft Word - AL2008-05.doc More Documents & Publications Microsoft Word - AL 2010-07 Acquistion Letters Remaining...

  6. Microsoft Word - al2005-04.doc | Department of Energy

    Energy Savers [EERE]

    al2005-04.doc Microsoft Word - al2005-04.doc PDF icon Microsoft Word - al2005-04.doc More Documents & Publications AL2005-04ClassDeviation.pdf Microsoft Word - Matrixpart2.doc...

  7. Microsoft Word - AL2004-02.doc | Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    Microsoft Word - AL2004-02.doc More Documents & Publications Microsoft Word - AL2005-02.doc Microsoft Word - al2005-04.doc Microsoft Word - AL-Omnibus FY 2009 Apr 22 2009 all...

  8. Electronic structure of cation-codoped TiO{sub 2} for visible-light photocatalyst applications from hybrid density functional theory calculations

    SciTech Connect (OSTI)

    Long, Run; English, Niall J.

    2011-04-04

    The electronic structures of Mg/Ca- and/or Mo/W- (mono- and co-) doped anatase TiO{sub 2} have been investigated via generalized Kohn-Sham theory with the Heyd-Scuseria-Ernzerhof hybrid functional for exchange-correlation (J. Heyd et al., [J. Chem. Phys. 118, 8207 (2003)], J. Heyd et al., [J. Chem. Phys. 124, 219906 (2006)], and J. Paier et al., [J. Chem. Phys. 125, 249901 (2006)]), in the context of density functional theory. Gap narrowing is small for monodoping, which also creates impuritiy bands in the ''forbidden gap,'' either as acceptor or donor states, limiting possible utility as visible-light photocatalysts. However, codoping of Mg/Ca and Mo/W not only induces appreciable gap narrowing, but also serves to passivate the impurity bands, which can harvest visible-light to a greater extent. Considering ionic radii, Mg and Mo should constitute the best cation-pair.

  9. Magneto-transport in LaTi{sub 1−x}Mn{sub x}O{sub 3}/SrTiO{sub 3} oxide heterostructures

    SciTech Connect (OSTI)

    Kumar, Pramod Dogra, Anjana Budhani, R. C.

    2014-04-24

    We report the growth of ultrathin film of Mn doped LaTiO{sub 3} on TiO{sub 2} terminated SrTiO{sub 3} (001) substrate by pulsed laser deposition (PLD) and their electrical transport characteristics including magnetoresistance (MR). Though the replacement of Mn in LaTiO{sub 3} at the Ti site in dilute limit does not affect the metallic behaviour of films but variation in resistance is observed. Normalised resistance behaviour is explained on the basis of variation in charge carriers and increased interaction between Mn atoms in the system under investigation.

  10. Microsoft Word - Maeder et al.doc

    Office of Scientific and Technical Information (OSTI)

    60247 Preprint Title: The Methanosarcina barkeri genome: comparative analysis with Methanosarcina acetivorans and Methanosarcina mazei reveals extensive rearrangement within methanosarcinal genomes Author(s): Dennis L. Maeder, Iain Anderson, et al Division: Genomics November 2006 Journal of Bacteriology Maeder et al. May 18, 2006 1 1 The Methanosarcina barkeri genome: comparative analysis 2 with Methanosarcina acetivorans and Methanosarcina mazei 3 reveals extensive rearrangement within

  11. Ferroelectric Self-assembled PbTiO3 Perovskite Nanostructures onto

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    (100)SrTiO3 Substrates from a Novel Microemulsion-aided Sol-Gel Preparation Ferroelectric Self-assembled PbTiO3 Perovskite Nanostructures onto (100)SrTiO3 Substrates from a Novel Microemulsion-aided Sol-Gel Preparation Figure 1. PbTiO3 nanostructures onto (100) SrTiO3 substrates. Topography image obtained by Scanning Force Microscopy (SFM), showing nanosized and uniform PbTiO3 particles with a short range one dimensional periodicity detected by the Fast Fourier Transform of the topography

  12. Materials Data on Ca3Ti2AlSi3O14F (SG:2) by Materials Project

    SciTech Connect (OSTI)

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  13. Materials Data on Ca3TiAl2Si3O13F2 (SG:2) by Materials Project

    SciTech Connect (OSTI)

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  14. Materials Data on SrLa4TiAl4O15 (SG:51) by Materials Project

    SciTech Connect (OSTI)

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  15. Direct imaging of LaAlO{sub 3}/SrTiO{sub 3} nanostructures using...

    Office of Scientific and Technical Information (OSTI)

    Authors: Huang, Mengchen ; Bi, Feng ; Irvin, Patrick ; Levy, Jeremy, E-mail: jlevy@pitt.edu 1 ; Ryu, Sangwoo ; Eom, Chang-Beom 2 + Show Author Affiliations Department of ...

  16. Electric field effects in graphene/LaAlO{sub 3}/SrTiO{sub 3}...

    Office of Scientific and Technical Information (OSTI)

    ; Levy, Jeremy, E-mail: jlevy@pitt.edu 1 ; Lee, Hyungwoo ; Ryu, Sangwoo ; Eom, Chang-Beom 2 ; Ghahari, Fereshte ; Ravichandran, Jayakanth ; Kim, Philip 3 + Show Author ...

  17. Incorporation of chromium into TiO{sub 2} nanopowders

    SciTech Connect (OSTI)

    Kollbek, Kamila; Sikora, Marcin; Kapusta, Czesław; Szlachetko, Jakub; Radecka, Marta; Lyson-Sypien, Barbara; Zakrzewska, Katarzyna

    2015-04-15

    Highlights: • Nanopowders of TiO{sub 2}:Cr with different amount of Cr dopant were obtained by flame spray synthesis, FSS. • Increase in the optical absorption and a shift of the absorption edge were observed upon Cr doping. • HERFD-XANES measurements indicated that the average valence state of titanium ions was preserved. • Increasing magnetic susceptibility of a paramagnetic character was observed upon Cr doping. - Abstract: The paper reports on the results of a study of optical, electronic and magnetic properties of TiO{sub 2} nanopowders doped with Cr ions. Diffused reflectance spectra reveal an increase in the optical absorption and a shift of the absorption edge towards lower energies upon Cr doping. Direct information on the Ti electronic state and the symmetry of its nearest environment is obtained from XANES Ti K-edge spectra. Magnetic behaviour is probed by means of the temperature dependence of DC magnetic susceptibility. Increasing magnetic susceptibility of a paramagnetic character is observed upon increasing chromium doping. The Curie constant of TiO{sub 2}:10 at.% Cr sample (0.12 emu K/mol Oe) is lower than that expected for Cr{sup 3+} (0.1875 emu K/mol Oe) possibly due to the appearance of Cr{sup 4+} or the presence of the orbital contribution to the magnetic moment.

  18. ALS Reveals New State of Matter

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ALS Reveals New State of Matter Print ALS user groups from Princeton and Stanford have been making waves this past year with several high-profile papers and extensive news coverage of their work on a new state of matter embodied by "topological insulators," materials that conduct electricity only on their surfaces. First identified at the ALS in 2007 by a Princeton team led by M. Zahid Hasan, topological insulators have been the subject of intense interest, based on unusual quantum

  19. ALS Reveals New State of Matter

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ALS Reveals New State of Matter Print ALS user groups from Princeton and Stanford have been making waves this past year with several high-profile papers and extensive news coverage of their work on a new state of matter embodied by "topological insulators," materials that conduct electricity only on their surfaces. First identified at the ALS in 2007 by a Princeton team led by M. Zahid Hasan, topological insulators have been the subject of intense interest, based on unusual quantum

  20. April 27, 2015-Special ALS Colloquium

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    April 27, 2015-Special ALS Colloquium April 27, 2015-Special ALS Colloquium Print Wednesday, 22 April 2015 13:19 Special Event on Monday, April 27 @ 12 noon, USB 15-253 X-Ray Microscopy: The First 120 Years Janos Kirz, ALS Abstract Röntgen's great discovery became an instant public sensation. Fascination with the "new kind of rays" that could reveal the structure of opaque objects swept the world in 1896. Fifty years later it was widely recognized that the short wavelength of the

  1. ALS Reveals New State of Matter

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ALS Reveals New State of Matter Print ALS user groups from Princeton and Stanford have been making waves this past year with several high-profile papers and extensive news coverage of their work on a new state of matter embodied by "topological insulators," materials that conduct electricity only on their surfaces. First identified at the ALS in 2007 by a Princeton team led by M. Zahid Hasan, topological insulators have been the subject of intense interest, based on unusual quantum

  2. OPTICAL AND NEAR-INFRARED POLARIMETRY OF HIGHLY REDDENED Type Ia SUPERNOVA 2014J: PECULIAR PROPERTIES OF DUST IN M82

    SciTech Connect (OSTI)

    Kawabata, K. S.; Akitaya, H.; Itoh, R.; Moritani, Y. [Hiroshima Astrophysical Science Center, Hiroshima University, Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Yamanaka, M. [Department of Physics, Faculty of Science and Engineering, Konan University, Okamoto, Kobe, Hyogo 658-8501 (Japan); Maeda, K.; Nogami, D. [Department of Astronomy, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan); Ui, T.; Kawabata, M.; Mori, K.; Takaki, K.; Ueno, I.; Chiyonobu, S.; Harao, T.; Matsui, R.; Miyamoto, H.; Nagae, O. [Department of Physical Science, Hiroshima University, Kagamiyama, Higashi-Hiroshima 739-8526 (Japan); Nomoto, K.; Suzuki, N. [Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo, Kashiwa, Chiba 277-8583 (Japan); Tanaka, M., E-mail: kawabtkj@hiroshima-u.ac.jp [National Astronomical Observatory of Japan, Osawa, Mitaka, Tokyo 181-8588 (Japan); and others

    2014-11-01

    We present optical and near-infrared multi-band linear polarimetry of the highly reddened Type Ia supernova (SN) 2014J that appeared in M82. SN 2014J exhibits large polarization at shorter wavelengths, e.g., 4.8% in the B band, which decreases rapidly at longer wavelengths, while the position angle of the polarization remains at approximately 40 over the observed wavelength range. These polarimetric properties suggest that the observed polarization is likely predominantly caused by the interstellar dust within M82. Further analysis shows that the polarization peaks at a wavelengths much shorter than those obtained for the Galactic dust. The wavelength dependence of the polarization can be better described by an inverse power law rather than by the Serkowski law for Galactic interstellar polarization. These points suggest that the nature of the dust in M82 may be different from that in our Galaxy, with polarizing dust grains having a mean radius of <0.1 ?m.

  3. The Morphology of TiO[subscript 2] (B) Nanoparticles (Journal...

    Office of Scientific and Technical Information (OSTI)

    The Morphology of TiOsubscript 2 (B) Nanoparticles Citation Details In-Document Search Title: The Morphology of TiOsubscript 2 (B) Nanoparticles Authors: Hua, Xiao ; Liu, Zheng ...

  4. FIRST-PRINCIPLES PHASE STABILITY IN THE TI-V ALLOY SYSTEM (Journal...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: FIRST-PRINCIPLES PHASE STABILITY IN THE TI-V ALLOY SYSTEM Citation Details In-Document Search Title: FIRST-PRINCIPLES PHASE STABILITY IN THE TI-V ALLOY SYSTEM ...

  5. Electric control of magnetism at the Fe/BaTiO3 interface (Journal...

    Office of Scientific and Technical Information (OSTI)

    Electric control of magnetism at the FeBaTiO3 interface Citation Details In-Document Search Title: Electric control of magnetism at the FeBaTiO3 interface Interfacial ...

  6. Local Metal and Deuterium Ordering in the Deuterated ZrTiNi C14...

    Office of Scientific and Technical Information (OSTI)

    Local Metal and Deuterium Ordering in the Deuterated ZrTiNi C14 Laves Phase Citation Details In-Document Search Title: Local Metal and Deuterium Ordering in the Deuterated ZrTiNi ...

  7. Electric control of magnetism at the Fe/BaTiO3 interface (Journal...

    Office of Scientific and Technical Information (OSTI)

    Electric control of magnetism at the FeBaTiO3 interface Citation Details In-Document Search Title: Electric control of magnetism at the FeBaTiO3 interface You are accessing a ...

  8. High-Ti-concentration aerogels for bright x-ray sources (Technical...

    Office of Scientific and Technical Information (OSTI)

    Ti-concentration aerogels for bright x-ray sources Citation Details In-Document Search Title: High-Ti-concentration aerogels for bright x-ray sources Authors: Perez, F ; Patterson,...

  9. High-Ti-concentration aerogels for bright x-ray sources (Technical...

    Office of Scientific and Technical Information (OSTI)

    Ti-concentration aerogels for bright x-ray sources Citation Details In-Document Search Title: High-Ti-concentration aerogels for bright x-ray sources You are accessing a...

  10. Deformation behavior of Nb nanowires in TiNiCu shape memory alloy...

    Office of Scientific and Technical Information (OSTI)

    in TiNiCu shape memory alloy matrix This content will become publicly available on August 18, 2016 Title: Deformation behavior of Nb nanowires in TiNiCu shape memory alloy matrix ...

  11. Conversion of 1,3-Propylene Glycol on Rutile TiO2(110) (Journal...

    Office of Scientific and Technical Information (OSTI)

    Conversion of 1,3-Propylene Glycol on Rutile TiO2(110) Citation Details In-Document Search Title: Conversion of 1,3-Propylene Glycol on Rutile TiO2(110) The adsorption of...

  12. The crystal and magnetic structure of Ti-substituted LaCrO{sub...

    Office of Scientific and Technical Information (OSTI)

    On account of a miscibility gap, a higher degree of Ti-substitution at the Cr site cannot be achieved; as a consequence the solid state solubility of Ti in LaCrOsub 3 at 1573 K ...

  13. Structure-Curie temperature relationships in BaTiO 3 -based ferroelectric

    Office of Scientific and Technical Information (OSTI)

    perovskites: Anomalous behavior of ( Ba , Cd ) TiO 3 from DFT, statistical inference, and experiments (Journal Article) | SciTech Connect Structure-Curie temperature relationships in BaTiO 3 -based ferroelectric perovskites: Anomalous behavior of ( Ba , Cd ) TiO 3 from DFT, statistical inference, and experiments Citation Details In-Document Search This content will become publicly available on April 11, 2017 Title: Structure-Curie temperature relationships in BaTiO 3 -based ferroelectric

  14. Microsoft Word - AL2005-11.doc

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    appropriate reviews; and (5) ensure they pay only for what they negotiated. AL 2005-11 (071505) - 2 - Background DEAR 970.3102-3-70 DOE Policy is based on the assumption...

  15. ALS History: The First 20 Years

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    History: The First 20 Years Print Below is an interactive timeline covering highlights of the first 20 years of ALS history. By no means exhaustive, it is meant to provide a broad ...

  16. Al Husseini Amelio JV | Open Energy Information

    Open Energy Info (EERE)

    Solar Product: JV company to develop a 1GW solar plant in Jordan and an integrated 200MW thin-film module factory. References: Al-Husseini & Amelio JV1 This article is a stub....

  17. Footprinting Technique Gives ALS Users New Insights

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    formation. The ALS XFP experts at Beamline 5.3.1. From left: Research Scientist Sayan Gupta, Beamline 5.3.1 Scientist Rich Celestre, and BCSB Head Corie Ralston. XFP, a powerful...

  18. Summary Slides of ALS Industry Highlights

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Print No. Slide Beamline Full Web Highlight ALSNews Volume 17 Takeda Advances Diabetes Research at ALS 5.0.2, 5.0.3 06.02.2015 Vol. 364 16 Metrology for Next-Generation...

  19. ALS Reveals New State of Matter

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    New State of Matter Print ALS user groups from Princeton and Stanford have been making waves this past year with several high-profile papers and extensive news coverage of...

  20. Western Baldwin County, AL Grid Interconnection Project

    SciTech Connect (OSTI)

    Thomas DeBell

    2011-09-30

    The Objective of this Project was to provide an additional supply of electricity to the affected portions of Baldwin County, AL through the purchase, installation, and operation of certain substation equipment.