Sample records for al carbono aisi

  1. UNA PROPUESTA METODOLÓGICA PARA ANALIZAR PROYECTOS FORESTALES DE CAPTURA DE CARBONO EN CUANTO AL APORTE AL DESARROLLO SOSTENIBLE

    Microsoft Academic Search

    Edgar Moreno Castillo

    2011-01-01

    El presente artículo tuvo como objetivo comparar metodologías de análisis desde los sistemas complejos que involucraran elementos sociales y naturales en interacción entre sí y a diferentes escalas, para ser aplicadas en el estudio de proyectos forestales de captura de carbono. Este tipo de proyectos se denominan mecanismos de mitigación al cambio climático, clasificados dentro del Mecanismo de Desarrollo Limpio

  2. Reciprocating friction and wear behavior of Ti 3AlC 2 and Ti 3AlC 2\\/Al 2O 3 composites against AISI52100 bearing steel

    Microsoft Academic Search

    Ling Wu; Ji-xin Chen; Ming-yue Liu; Yi-wang Bao; Yan-chun Zhou

    2009-01-01

    In this work, the dry sliding friction and wear properties of Ti3AlC2 and Ti3AlC2\\/Al2O3 composites against AISI52100 steel ball were investigated using a reciprocating ball on flat configuration under different normal loads. The results indicated that the friction\\/wear processes of both Ti3AlC2 and the composites against AISI52100 steel experienced two different stages with an abrupt transition between them under all

  3. On the Interface Generated by Hot Isostatic Pressing Compaction Process Between an AISI 304 Container and the Ti6Al4V Powders

    NASA Astrophysics Data System (ADS)

    Scherillo, Fabio; Aprea, Paolo; Astarita, Antonello; Scherillo, Antonella; Testani, Claudio; Squillace, Antonino

    2015-06-01

    In this work, the interface between a Ti6Al4V component made by Hot Isostatic Pressing and the AISI 304 container was studied in detail. The interface is dominated by interdiffusion with evident Kirkendall effect. Different intermetallic phases have been recognized. In particular, on the AISI 304 side of the interface, both ? and ? phases have been identified, whereas on the Ti6Al4V side ? phase (Laves), FeTi, (Fe,Ni)Ti, Ti2Ni, and ?-Ti are present.

  4. Long-term corrosion investigation of AISI 316L, Co-28Cr-6Mo, and Ti-6Al-4V alloys in simulated body solutions

    NASA Astrophysics Data System (ADS)

    Karimi, Shima; Nickchi, Tirdad; Alfantazi, Akram M.

    2012-06-01

    The long-term weight loss, ion release and surface composition of AISI 316L, the Co-28Cr-6Mo and Ti-6Al-4V alloys were investigated in phosphate buffered solutions (PBS) with various bovine serum albumin (BSA) concentrations. All the samples lost weight up to 14 weeks and then started to gain weight. This can be explained by precipitation of dissolved ions on the surface after 14 weeks of immersion. The quantities of the dissolved ions were measured in immersed solution for 8, 14 and 22 weeks by induced coupled plasma-optical emission spectrometer (ICP-OES). The amounts of Fe released from 316L, and Co and Mo released from the Co-28Cr-6Mo alloy decreased after 14 weeks of immersion in PBS and BSA solutions. This observation coincides with the weight change of the samples. The oxide layer composition and concentration of the specimens exposed to solutions for 22 weeks were identified by X-ray photoelectron spectroscopy (XPS) analysis. The XPS results revealed that chromium is the main component of the 316L and Co-28Cr-6Mo alloy. The high Cr concentration of the 316L and Co-Cr-Mo oxide layer corresponds with the slow dissolution rate of Cr compared to other alloying elements of the 316L and Co-28Cr-6Mo alloy.

  5. AISI direct steelmaking program

    SciTech Connect

    Aukrust, E.

    1991-01-09

    AISI with co-funding from DOE has initiated a research and development program aimed at the development of a new process for direct steelmaking, and the program is discussed in this document. The project is expected to cost about $30 million over a three-year period, with the government providing approximately 77 percent of the funds and AISI the balance. In contrast to current steelmaking processes which are largely open and batch, the direct steelmaking process would be closed and continuous. Further, it would use coal directly, thereby avoiding the need for coke ovens. The second year of the Direct Steelmaking Program (November 29, 1989, through November 28, 1990) was a year of significant accomplishment. The various research programs proceeded essentially on schedule and the pilot plant, the centerpiece of the program, was completed about three months behind schedule but began operation in almost a picture-perfect manner. This report presents the last years accomplishments.

  6. Corrosion behavior of AISI 316L stainless steel and ODS FeAl aluminide in eutectic Li{sub 2}CO{sub 3}-K{sub 2}CO{sub 3} molten carbonates under flowing CO{sub 2}-O{sub 2} gas mixtures[Oxide Dispersion Strengthened

    SciTech Connect

    Frangini, S.

    2000-02-01

    A kinetics study on AISI 316L stainless steel and ODS (Oxide-Dispersion-Strengthened) FeAl iron aluminide was conducted concerning its corrosion behavior in molten Li{sub 2}CO{sub 3}-K{sub 2}CO{sub 3} eutectic at 650 C in flowing CO{sub 2}-O{sub 2} gas mixtures. The corrosion resistance of FeAl ODS was demonstrated to be significantly superior to that of austenitic AISI 316L steel under all gas conditions tested in this work. At low CO{sub 2} partial pressure (P{sub CO{sub 2}} = 0.3 atm) the corrosion rate of both alloys decreased with time due to the formation of a protective oxide layer. In dry CO{sub 2} gas, corrosion of AISI steel proceeded at a near-linear rate, indicative of a surface-controlled reaction. FeAl corroded initially following parabolic behavior, but, on further reaction, exhibited some weight loss. A similar behavior was also observed in a 67CO{sub 2}-33O{sub 2} gas mixture. Corrosion of FeAl in high CO{sub 2} gas has been postulated to initiate by acidic fluxing of yttria particles. The attack then develops as pitting and leads to further reaction by general corrosion as a consequence of the formation of active-passive electrochemical cells between the interior of pits and the external surface. The weight loss of AISI 316L in 67CO{sub 2}-33O{sub 2} gas can be ascribed to the high oxidizing power of the gas causing a continuous dissolution of the Cr{sub 2}O{sub 3}layer into a soluble chromate.

  7. Ion release and surface oxide composition of AISI 316L, Co-28Cr-6Mo, and Ti-6Al-4V alloys immersed in human serum albumin solutions.

    PubMed

    Karimi, Shima; Alfantazi, Akram M

    2014-07-01

    The long-term weight loss, ion release, and surface composition of 316L, Co-28Cr-6Mo and Ti-6Al-4V alloys were investigated in a simulated body environment. The samples were immersed in phosphate-buffered saline (PBS) solutions with various human serum albumin (HSA) concentrations for 8, 14, and 22 weeks. The specimens initially lost weight up to 14 weeks and then slightly gained weight. The analysis of the released ions was performed by induced coupled plasma-optical emission spectrometer (ICP-OES). The results revealed that the precipitation of the dissolved Fe and Co could cause the weight gain of the 316L and Co-28Cr-6Mo alloys. The surface chemistry of the specimens was determined by X-ray photoelectron spectroscopy (XPS). The XPS analysis of Co-28Cr-6Mo alloy showed that the interaction of Mo with HSA is different from Mo with bovine serum albumin (BSA). This was also observed for Na adsorption into the oxide layer of Ti-6Al-4V alloy in the presence of HSA and BSA. PMID:24857512

  8. Effect of tip relief on endurance characteristics of super nitralloy and AISI M-50 spur gears

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.; Zaretsky, E. V.

    1974-01-01

    Tests were conducted with two groups of 8.89-centimeter (3.5-in.) pitch diameter spur gears with standard 20 deg involute profile with tip relief made of CVM Super-Nitralloy (5Ni-2Al) and CVM AISI M-50 at a temperature of 350 K (170 F). Super-Nitralloy gears with tip relief had a life 150 percent that of gears without tip relief. An increased scoring phenomenon was noted with the Super-Nitralloy gears with tip relief. Through-hardened AISI M-50 gears with tip relief failed due to tooth fracture. AISI M-50 gears without tip relief had a life approximately 40 times greater than the AISI M-50 gears with tip relief.

  9. Surface fatigue and failure characteristics of hot-forged powder metal AISI 4620, AISI 4640, and machined AISI 4340 steel spur gears

    NASA Technical Reports Server (NTRS)

    Townsend, Dennis P.

    1987-01-01

    Spur gear surface fatigue endurance tests were conducted to investigate hot forged powder metal AISI 4620 and 4640 steel for use as a gear material, to determine endurance characteristics and to compare the results with machined AISI 4340 and 9310 steel gear materials. The as-forged and unground AISI 4620 gear exhibited a 10 percent fatigue life that was approximately one-fourth of that for AISI 9310 and less than one-half that for the AISI 4340 gears. The forged and finish ground AISI 4620 gears exhibited a 10 percent life, approximately 70 percent that of AISI 9310 and slightly better than that of AISI 4340. The AISI 4640 hot forged gears had less fracture toughness and slightly less fatigue life than the AISI 4620 test gears.

  10. Surface fatigue and failure characteristics of hot forged powder metal AISI 4620, AISI 4640, and machined AISI 4340 steel spur gears

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.

    1986-01-01

    Spur gear surface fatigue endurance tests were conducted to investigate hot forged powder metal AISI 4620 and 4640 steel for use as a gear material, to determine endurance characteristics and to compare the results with machined AISI 4340 and 9310 steel gear materials. The as-forged and unground SISI 4620 gear exhibited a 10 percent fatigue life that was approximately one-fourth of that for AISI 9310 and less than one-half that for the AISI 4340 gears. The forged and finish ground AISI 4620 gears exhibited a 10 percent life, approximately 70 percent that of AISI 9310 and slightly better than that of AISI 4340. The AISI 4640 hot forged gears had less fracture toughness and slightly less fatigue life than the AISI 4620 test gears.

  11. Tool Wear and Surface Roughness in Turning AISI 8620 using Coated Ceramic Tool

    Microsoft Academic Search

    S. Thamizhmanii; K. Kamarudin; E. A. Rahim; A. Saparudin; S. Hassan

    2007-01-01

    The purpose of this research paper is to study the tool wear and surface roughness of AISI 8620 material using coated ceramic tool by turning process. Ceramic cutting tools have outstanding material hardness, resistance to high temperatures, wear resistance, chemical stability and hot hardness. Ceramic tool with Al2O3 + TiC (golden) coating was used to investigate the surface roughness and

  12. Comparing the Formability of AISI 304 and AISI 202 Stainless Steels

    NASA Astrophysics Data System (ADS)

    du Toit, M.; Steyn, H. G.

    2012-07-01

    The formability of AISI 202 austenitic stainless steel was compared with that of type AISI 304 stainless steel. Type 202 is a low-nickel austenitic stainless steel alloyed with manganese and nitrogen. In this study, the formability of the two grades was examined using Erichsen cupping tests and room temperature uniaxial tensile tests performed at various angles to the rolling direction. AISI 202 appears to work-harden at a slightly higher rate than AISI 304, even though the austenite in type 202 is more stable than that in 304 with respect to the formation of deformation-induced ?' martensite. Although both grades are predicted to be susceptible to earing during deep drawing, AISI 202 displays a higher work-hardening exponent, higher average normal anisotropy, and a higher limiting drawing ratio than AISI 304. Similar cup heights were measured during Erichsen cupping tests, confirming that the two grades have very similar deep drawing properties. The results of this investigation therefore suggest that AISI 202 is a suitable alternative for AISI 304 in applications requiring good deep drawing properties.

  13. Pulsed Nd:YAG laser welding of AISI 304 to AISI 420 stainless steels

    Microsoft Academic Search

    José Roberto Berretta; Wagner de Rossi; Maurício David Martins das Neves; Ivan Alves de Almeida; Nilson Dias Vieira Junior

    2007-01-01

    The technique to weld AISI 304 stainless steel to AISI 420 stainless steel with a pulsed Nd:YAG laser has been investigated. The main objective of this study was to determine the influence of the laser beam position, with respect to the joint, on weld characteristics. Specimens were welded with the laser beam incident on the joint and moved 0.1 and

  14. Chromizing of plasma nitrided AISI 1045 steel

    Microsoft Academic Search

    F. Hakami; M. Heydarzadeh Sohi; J. Rasizadeh Ghani; M. Ebrahimi

    2011-01-01

    In this study AISI 1045 steel specimens were plasma nitrided at 803K for 5h, in a gas mixture of 75% N2+25% H2. The specimens were then chromized in powder mixtures consisting of ferrochromium, ammonium chloride and alumina at 1273K for 5h. Scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis and Vickers micro-hardness test were used as characterizing techniques. The thickness

  15. Hot hardness characteristics of ausformed AISI M-50, Matrix 2, WD-65, modified AISI 440-C, and Super Nitralloy

    NASA Technical Reports Server (NTRS)

    Chevalier, J. L.; Dietrich, M. W.; Zaretsky, E. V.

    1973-01-01

    Short-term hot hardness studies were performed with ausformed AISI M-50, Matrix 2, WD-65, modified AISI 440-C (14-4-1) and case hardened Super Nitralloy. Hardness levels of each material were measured at elevated temperatures in an electric furnace with a low oxygen environment. Test temperatures ranged from 294 to 877 K. The hot hardness characteristics of the ausformed AISI-M-50, Matrix 2 WD-65, and modified AISI 440-C were the same as those determined for high-speed tool steels. Hot hardness for these steels can be predicted within one point Rockwell C. The hot hardness characteristics of both the case and core of Super Nitralloy were superior to AISI 52100 but inferior to the high-speed tool steels. The short-term Rockwell C hardness at temperature for the Super Nitralloy material between 294 and 769 K can be predicted within one point Rockwell C hardness.

  16. An investigation on borided AISI 1020 steel

    NASA Astrophysics Data System (ADS)

    Altinsoy, I.; Efe, F. G. Celebi; Ipek, M.; Ozbek, I.; Zeytin, S.; Bindal, C.

    2013-12-01

    In this study, we investigated some properties of borided AISI 1020 steel. Boronizing heat treatment was carried out at 800°C, 875°C and 950°C for 2, 4, 6 and 8 h using Ekabor 1 powders. The hardness of borides formed on the steel substrate measured via Vickers indenter was about 1500 HVN. The thickness of boride layers depending on the process temperature and time was ranged from 20.5 to 216 ?m. The presence of Fe2B boride was determined by XRD analysis. SEM microscope studies showed that the borides formed on the AISI 1020 steel have columnar nature. Kinetics studies reveal a parabolic relationship between layer depth and process time, and the activation energy is calculated as 164,356 kJ/mol. Moreover, an attempt was made to investigate the possibility of predicting the iso-thickness of boride layer and to establish an empirical relationship between process parameters of boriding and boride layer for industrial applications.

  17. The preparation, characterization and corrosion behaviour of ion-implanted and ceramic-coated AISI 321 steel samples

    Microsoft Academic Search

    F. Noli; P. Misaelides; H. Baumann; A. Hatzidimitriou

    1996-01-01

    Ion Beam Techniques were used to modify near-surface layers of austenitic stainless steel AISI 321 samples in order to improve their corrosion resistance. Mg-, Y- (implantation energy: 40 keV) and Al-implantation (implantation energy: 40, 60, 80 and 200 keV), as well as Dynamic Ion Mixing (DIM) (SiC deposition and mixing with 160 keV Xe + ions) and Sputtering (Si3N4 deposition

  18. Failure Analysis of AISI304 Stainless Steel Styrene Storage Tank

    Microsoft Academic Search

    Muhammad Sajid Ali Asghar; Fawad Tariq; Ashraf Ali

    2010-01-01

    This paper presents the failure analysis of AISI-304 stainless steel tank that was fabricated by welding and used for the\\u000a storage of styrene monomers. After about 13 years of satisfactory operation, significant cracking was observed adjacent to\\u000a the weld joints and in base plate near tank foundation. Weld repair was by shielded gas arc welding using AISI 308 stainless\\u000a steel filler

  19. JOURNAL DE PHYSIQUE Colloque C2, supplt!ment au no 7, tome 32, Juillet 1971,page C2-112 ANELASTICITY OF AI-Si AND AI-Mg-Si ALLOYS

    E-print Network

    Paris-Sud XI, Université de

    -112 ANELASTICITY OF AI-Si AND AI-Mg-Si ALLOYS by K. M. ENTWISTLE University of Manchester Wires of Al-Siand Al results on the alloys containing magnesium due to rapid volatilisation of this element during solution small in the pseudo-binary A1-Mg, Si alloys. For any composition, the peak height varies during ageing

  20. Laser Surface Hardening of AISI 1045 Steel

    NASA Astrophysics Data System (ADS)

    Li, Ruifeng; Jin, Yajuan; Li, Zhuguo; Qi, Kai

    2014-09-01

    The study investigates laser surface hardening in the AISI 1045 steel using two different types of industrial laser: a high-power diode laser (HPDL) and a CO2 laser, respectively. The effect of process parameters such as beam power, travel speed on structure, case depth, and microhardness was examined. In most cases, a heat-affected zone (HAZ) formed below the surface; a substantial increase in surface hardness was achieved. In addition, big differences were found between the hardened specimens after HPDL surface hardening and CO2 laser surface hardening. For HPDL, depths of the HAZ were almost equal in total HAZ o, without surface melting. For CO2 laser, the depths changed a lot in the HAZ, with surface melting in the center. To better understand the difference of laser hardening results when use these two types of laser, numerical (ANSYS) analysis of the heat conduction involved in the process was also studied. For HPDL method, a rectangular beam spot and uniform energy distribution across the spot were assumed, while for CO2 laser, a circular beam spot and Gaussian energy distribution were assumed. The results showed that the energy distribution variety altered the thermal cycles of the HAZ dramatically. The rectangular HPDL laser beam spot with uniform energy distribution is much more feasible for laser surface hardening.

  1. Effects of low-temperature aging on AISI 444 steel

    NASA Astrophysics Data System (ADS)

    Souza, José A.; Abreu, Hamilton F. G.; Nascimento, Alex M.; de Paiva, José A. C.; de Lima-Neto, Pedro; Tavares, Sérgio S. M.

    2005-06-01

    The consequences of aging at 400 and 475 °C on the mechanical properties, corrosion resistance, and magnetic properties of the ferritic stainless steel (SS) AISI 444 were investigated. Age hardening was measured as a function of aging time at both temperatures and was found to be more intense at 475 °C. The localized corrosion susceptibility increased, while the impact toughness decreased with aging time. These two effects were also more important at 475 °C. Unlike duplex SSs, AISI 444 did not present any variation in coercive force or Curie temperature with aging time. The effects on the Mössbauer spectra were also determined and analyzed.

  2. Dense plasma focus-assisted nitriding of AISI-304

    NASA Astrophysics Data System (ADS)

    Shafiq, M.; Asghar, M.; Ahmad, S.; Sadiq, M.; Qayyum, A.; Zakaullah, M.

    Nitrogen ion implantation into AISI-304 stainless steel is carried out using a dense plasma focus device, operated at a charging voltage of 18 kV (discharge energyD1.45 kJ) with nitrogen filling at optimum pressure of 0.75 mbar. AISI-304 stainless steel samples placed axially above the anode tip are exposed to the ions for 10, 20 and 30 focus shots. X-ray diffraction (XRD), Vickers's micro hardness tester, scanning electron microscopy, and energy dispersive X-ray spectroscopy are used to explore the ion induced changes in the crystallographic structures, surface morphology, elemental composition and surface hardness of the ion irradiated samples. The XRD pattern confirms the formation of an expanded austenite phase, owing to nitrogen incorporated into the existing iron lattice. The results of micro hardness tester show that the hardness is increased about three times at an axial distance of 5 cm for 20 shots.

  3. Elevated temperature fracture toughness of AISI 403 martensitic stainless steel

    NASA Astrophysics Data System (ADS)

    Dubey, J. S.; Wadekar, S. L.; Chakravartty, J. K.

    1998-04-01

    The AISI 403 martensitic stainless steel is used as the end fitting material in pressurised heavy water reactors. The fracture toughness of single quenched and tempered, double quenched and tempered, and Nb-modified variety of this steel has been evaluated at 473 and 573 K. Elevated temperature results are compared with the room temperature values reported in earlier studies. The double quenched and tempered and Nb-modified structures show higher toughness and d J/d a values at elevated temperatures.

  4. Precision radial turning of AISI D2 steel

    Microsoft Academic Search

    J. Paulo Davim; C. Maranhão; P. Faria; A. Abrão; J. C. Rubio; Leonardo R. Silva

    2009-01-01

    This paper compares finite element model (FEM) simulations with experimental and analytical findings concerning precision\\u000a radial turning of AISI D2 steel. FEM machining simulation employs a Lagrangian finite element-based machining model applied\\u000a to predict cutting and thrust forces, cutting temperature and plastic strain distribution. The results show that the difference\\u000a between the experimental and simulated cutting force is near 20%,

  5. Corrosion behavior of ion nitrided AISI 316L stainless steel

    Microsoft Academic Search

    L. Nosei; S. Farina; M. Ávalos; L. Nachez; B. J. Gómez; J. Feugeas

    2008-01-01

    In the present work the corrosion susceptibility of ion nitrided AISI 316L stainless steel was investigated for two different nitriding times and compared with the corrosion susceptibility of the untreated material. Plasma nitriding for short times (30 min) produced the “S” phase or expanded austenite (?N), with a thickness of ?5 ?m and a micro-hardness of 1300–1400 HV0.025 (6.5 times higher than

  6. El precio de la electricidad y la política de cambio climático: ¿qué papel puede jugar un impuesto sobre el carbono en España? \\/The Price of Electricity and Climate Change Policy: What Role May a Carbon Tax Play in Spain?

    Microsoft Academic Search

    MIGUEL BUÑUEL GONZÁLEZ

    2011-01-01

    La política de cambio climático basada en las energías renovables es compatible con la reducción del déficit tarifario del sector eléctrico trasladando a los Presupuestos Generales las primas que subvencionan aquellas energías. Dicha política se potenciaría con un impuesto sobre el carbono, que podría generar una recaudación mayor que las primas al régimen especial eléctrico. La simulación del efecto sobre

  7. Comparison of pitting fatigue life of ausforged and standard forged AISI M-50 and AISI 9310 spur gears

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.; Bamberger, E. N.; Zaretsky, E. V.

    1975-01-01

    Standard forged and ausforged spur gears made of vacuum-induction-melted, consumable-electrode, vacuum-arc-remelted AISI M-50 steel were tested under conditions that produced fatigue pitting. The gears were 8.89 cm (3.5 in.) in pitch diameter and had tip relief. The M-50 standard forged and ausforged test results were compared with each other. They were then compared with results for machined vacuum-arc-remelted AISI 9310 gears tested under identical conditions. Both types of M-50 gears had lives approximately five times that of the 9310 gears. The life at which 10 percent of the M-50 ausforged gears failed was slightly less than that at which the M-50 standard forged gears failed. The ausforged gears had a slightly greater tendency to fail by tooth fracture than did the standard forged gears, most likely because of the better forging and grain flow pattern of standard forged gears.

  8. Effect of Heat Treatment on Microstructure of Modified Cast AISI D3 Cold Work Tool Steel

    Microsoft Academic Search

    Shahram Kheirandish; Hasan Saghafian; Jalal Hedjazi; Mohammad Momeni

    2010-01-01

    The effects of heat treatment on the microstructure of modified cast high chromium high carbon AISI D3 steel were studied. The modified AISI D3 steel was developed by replacing part of chromium with niobium and titanium, in which chromium carbide was partially replaced with MC carbides. The cast samples produced by investment casting were heat treated under different conditions. The

  9. Fatigue crack growth behavior and overload effect of AISI 304 stainless steel in different atmospheres

    Microsoft Academic Search

    Mehmet Halidun Kelestemur

    1998-01-01

    AISI 304 stainless steel shows strain induced martensitic transformation at the crack tip. Such transformation may have effects on crack closure during fatigue crack propagation. Due to importance of AISI 304 in structural applications, the fatigue crack propagation and martensitic transformation in this material have to be investigated thoroughly. Fatigue crack growth behavior, overload retardation and characterization of martensitic transformation

  10. Sociedade de Investigaes Florestais DISTRIBUIO ESPACIAL DE CARBONO EM SOLO SOB FLORESTA

    E-print Network

    Lehmann, Johannes

    83 Sociedade de Investigações Florestais DISTRIBUIÇÃO ESPACIAL DE CARBONO EM SOLO SOB FLORESTA. Este trabalho foi desenvolvido em Juruena (MT), com os seguintes objetivos: estudo da distribuição espacial do teor de carbono e a estimativa do seu estoque na camada de 0- 0,60 m de solo em microbacias sob

  11. Glow Discharge Plasma Nitriding of AISI 304 Stainless Steel

    NASA Astrophysics Data System (ADS)

    Qayyum, A.; Naveed, M. A.; Zeb, S.; Murtaza, G.; Zakaullah, M.

    2007-08-01

    Glow discharge plasma nitriding of AISI 304 austenitic stainless steel has been carried out for different processing time under optimum discharge conditions established by spectroscopic analysis. The treated samples were analysed by X-ray diffraction (XRD) to explore the changes induced in the crystallographic structure. The XRD pattern confirmed the formation of an expanded austenite phase (?N) owing to incorporation of nitrogen as an interstitial solid solution in the iron lattice. A Vickers microhardness tester was used to evaluate the surface hardness as a function of indentation depth (?m). The results showed clear evidence of surface changes with substantial increase in surface hardness.

  12. Crack growth behavior of AISI-4340 steel during environmental exposure

    NASA Technical Reports Server (NTRS)

    Giannuzzi, Lucille A.

    1995-01-01

    AISI-4340 is observed to undergo stress corrosion cracking when subjected to a constant load during exposure to a 3.5% NaCl solution. Crack initiation, nucleation, and growth has been monitored as a function of time. Stepped regions consisting of fast and slow crack growth periods are shown to correspond to microstructural changes observed in the fracture surface of the steel. These regions of fast and slow crack rate variations with time show that the crack growth rates do not increase continuously with an increase in the stress intensity.

  13. Transporte electronico en nanoestructuras de carbono

    NASA Astrophysics Data System (ADS)

    Jodar Ferrandez, Esther

    The aim of this work is the study of the electronic transport properties in several structures made of carbon nanotubes. This dissertation is divided in four chapters: (1) Chapter 1: Carbon Nanotubes. This chapter is a brief review of the foundations of carbon nanotubes (CNT). Main properties of CNT are explained. The subject developed here is important for the understanding of the results obtained in the bulk of this thesis. We carry out, in the first part of this chapter, an historical review of the discovering of CNT, that includes the history of the discovering of fullerenes, the predecessors for carbon nanotubes. Afterwards, a revision of the different methods for synthesizing nanotubes is done. The main part of this chapter treats of the description of the geometry, properties and electronic structure of CNT. Many equations deduced here will be used later. Finally, we discuss some research lines related to carbon nanotubes. (2) Chapter 2: Theoretical and numerical method. In this chapter we describe the numerical method we have developed to obtain the results presented in this work. For this purpose it is necessary to describe previously the theoretical method on which our calculations are based. We extensively explain the Green's function and its properties. A large part of our calculations are based in the obtention the GF of the system under study. This chapter finishes with the application of the equations described in order to obtain electronic properties associated with pure carbon nanotubes as an example of use. Anyway, these previous results will be used later. (3) Chapter 3: Cavities made of nanotubes. We denote as a cavity to the structure formed with a carbon nanotube sandwiched between other two carbon nanotubes (contacts), provided that the central region is wider than these contacts. In this chapter we perform some calculations of the properties associated to the electronic transport in cavities, as the local density of states and the transmission function. We analyze the influence of the width of the cavity and the distance between them (in the case of multiple cavities). Some interesting results are obtained in these calculations which have been published in international journals (Jodar et al. 2006, Jodar y Perez-Garrido 2007). We emphasize the presence of quasi-localized states in the cavities, which affects to the transmission function, the behaviour of some cavities formed with semi-conductor as quantum dots, or the study of the evolution of the system with multiple cavities to the limit of infinite cavities. (4) Chapter 4: Bloch Oscillations. In this chapter we investigate the properties of carbon nanotubes under a constant electric field. This configuration show Bloch oscillations, according to the work of Bloch and Zener. We study here the dynamics of these oscillations for different geometries as a function of the electric field applied. Specially, the behaviour of the occupation probability and the averaged quadratic displacement as a function of time. We have not found bibliography that deals with this phenomenon in Carbon Nanotubes, which is the aim of this chapter. We first study the behaviour of electrons in pure carbon nanotubes in a constant electric field, for different lengths of the CNT and different values of the electric field applied. We show how wavefunctions oscillate with a period that coincides with that given by theoretical expressions of Bloch oscillations for linear chains of atoms. Besides, we show the different kind of behaviour of localized and extended waves. In the final part of this chapter we apply a constant electric field to the structure studied in the chapter 3, i.e., the cavity. We show in this case that, besides Bloch oscillations, electrons can be confined in certain regions only by inserting the nanotube in an electric field.

  14. Formation of titanium aluminum nitride layers on AISI D2 steel by nitro-titanizing treatment

    NASA Astrophysics Data System (ADS)

    Cegil, Ozkan; Sen, Saduman

    2012-09-01

    In this study, titanium aluminum nitride coating was realized on AISI D2 steels by nitro-titanizing treatment. Steel samples were nitrided at 575 °C for 8 h in the first step of the coating process, and then titanized by thermo-reactive diffusion method in the powder mixture consisting of ferro-titanium, aluminum, ammonium chloride and alumina at 1000 °C for 2 h. The effects of the aluminum content to the coating bath were investigated. The thickness of the titanium aluminum nitride layer formed on the steel samples ranged from 6.30±0.5 to 7.89±0.34?m, depending on the aluminum content. The average micro-hardness value of the layer was 1468 ± 96 HV0.005 and 2630± 83 HV0.005. The phases formed on the coating layers are TiN, AlTi3N and Ti3Al2N2 which are characterized by XRD. EDS analysis results showed that coating layer includes titanium, aluminum and nitrogen.

  15. Effect of bacterium Oceanospirillum on the corrosion potential and oxygen reduction of AISI 4340 steel 

    E-print Network

    Popova, Snezana N.

    1992-01-01

    seawater (pH=8). . . . . 10. Effect of velocity on corrosion of AISI 4340 RDE in . . 32 ASTM seawater in the presence and absence of oxygen. . . . 35 I I. E prr of AISI 4340 RDE in ASTM seawater (pH=8), as a function of time . 12. Corrosion current..., by starting from ? 150 mV from E, ~ and moving in the anodic direction to +150 mV above ~~. Potentiodynamic polarization experiments were used as a qualitative technique to characterize the behavior of AISI 4340 steel in ASTM seawater in the presence...

  16. Tribological properties of FeAl intermetallics under dry sliding

    Microsoft Academic Search

    Jun Yang; Peiqing La; Weimin Liu; Qunji Xue

    2004-01-01

    The tribological properties of FeAl intermetallics under dry sliding against AISI52100 steel at ambient conditions were studied on an Optimol SRV oscillating friction and wear tester in a ball-on-disc contact configuration. Effects of load and sliding speed on tribological properties of the FeAl intermetallics were investigated. The worn surfaces of the FeAl intermetallics were examined with a scanning electron microscopy

  17. Pulsed Nd:YAG Laser Microtexturing AISI-O1 Surface for Thermal Spray Coating

    Microsoft Academic Search

    Kelvii Wei Guo; Hon Yuen Tam

    2010-01-01

    Abstract: Pulsed Nd:YAG laser was,used to microtexture AISI-O1 cold work,steel to control the substrate surface characteristics for later thermal spray coating to enhance the wearability. Influence of microtexturing parameters on the 3D surface morphology was studied by Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), and Optical Microscopy (OM). Results show,that when AISI-O1 specimens are irradiated with various parameters, the

  18. Effect of bacterium Oceanospirillum on the corrosion potential and oxygen reduction of AISI 4340 steel

    E-print Network

    Popova, Snezana N.

    1992-01-01

    EFFECT OF BACTERIUM OCEANOSPIRILLUM ON THE CORROSION POTENTIAL AND OXYGEN REDUCI1ON OF AISI 4340 STEEL A Thesis by SNEZANA N. POPOVA Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE December 1992 Major Subject: Chemical Engineering EFFECT OF BACTERIUM OCEANOSPIRILLUM ON THE CORROSION POTENTIAL AND OXYGEN REDUCTION OF AISI 4340 STEEL A Thesis by SNEZANA N. POPOVA Appmved as to style...

  19. The effect of surface nanocrystallization on plasma nitriding behaviour of AISI 4140 steel

    Microsoft Academic Search

    Yang Li; Liang Wang; Dandan Zhang; Lie Shen

    2010-01-01

    A plastic deformation surface layer with nanocrystalline grains was produced on AISI 4140 steel by means of surface mechanical attrition treatment (SMAT). Plasma nitriding of SMAT and un-SMAT AISI 4140 steel was carried out by a low-frequency pulse excited plasma unit. A series of nitriding experiments has been conducted at temperatures ranging from 380 to 500°C for 8h in an

  20. Solid-particle erosion of tungsten carbide/cobalt cermet vs. hardened AISI 440C stainless steel.

    SciTech Connect

    Rateick, R. G., Jr.; Karasek, K. R.; Cunningham, A.; Goretta, K. C.; Routbort, J. L.; Energy Technology; Honeywell

    2006-01-01

    Solid-particle erosion tests were conducted on hardened AISI 440C stainless steel and a cermet that consisted of {approx}90 vol.% submicrometer WC embedded in {approx}10 vol.% Co. Angular Al{sub 2}O{sub 3} abrasives were used as the erodent. Experimental variables were: angle of impact = 20, 50, or 90 degrees; erodent velocity = 60 or 120 m/s; erodent nominal diameter = 63 or 143 {micro}m. For all test conditions, the stainless steel eroded faster than the cermet. Analysis of weight-loss data and examination of eroded surfaces by scanning electron microscopy indicated that the erosion mechanisms were similar for the two hard materials. Both exhibited significant plasticity when impacted, but the stainless steel's response to impact appeared to have been more ductile in nature.

  1. Study on residual stress of AISI304 TIG welding line with laser shock processing by x-ray stress analyzer

    NASA Astrophysics Data System (ADS)

    Zhang, Y. K.; Kong, D. J.; Yin, S. M.; Feng, A. X.; Lu, J. Z.; Ge, T.

    2006-02-01

    The surface of AISI304 TIG welding line was processed by LSP (laser shock processing). The effects on the microstructure, hardness and residual stress of AISI304 welding line by LSP were observed, and its mechanical properties were researched by SEM (scanning electron microscope) and test device of mechanical property. Residual stresses of AISI304 TIG welding line by LSP were measured with Model X-350A X ray analyzer. The test results show that compressive residual stress values of AISI304 TIG welding line by LSP are about 110MPa. Strengthening effects of AISI304 TIG welding line by LSP is very obvious, and fatigue properties of welding line is improved, and tensile residual stresses of welding line are obviously reduced, the distribution of residual stress tends to equality, and service life of AISI304 TIG welding line is improved.

  2. A Life Study of Ausforged, Standard Forged and Standard Machined AISI M-50 Spur Gears

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.; Bamberger, E. N.; Zaretsky, E. V.

    1975-01-01

    Tests were conducted at 350 K (170 F) with three groups of 8.9 cm (3.5 in.) pitch diameter spur gears made of vacuum induction melted (VIM) consumable-electrode vacuum-arc melted (VAR), AISI M-50 steel and one group of vacuum-arc remelted (VAR) AISI 9310 steel. The pitting fatigue life of the standard forged and ausforged gears was approximately five times that of the VAR AISI 9310 gears and ten times that of the bending fatigue life of the standard machined VIM-VAR AISI M-50 gears run under identical conditions. There was a slight decrease in the 10-percent life of the ausforged gears from that for the standard forged gears, but the difference is not statistically significant. The standard machined gears failed primarily by gear tooth fracture while the forged and ausforged VIM-VAR AISI M-50 and the VAR AISI 9310 gears failed primarily by surface pitting fatigue. The ausforged gears had a slightly greater tendency to fail by tooth fracture than the standard forged gears.

  3. Corrosion of annealed AISI 316 stainless steel in sodium environment

    NASA Astrophysics Data System (ADS)

    Ganesan, Vaidehi; Ganesan, Vedaraman

    1998-07-01

    Solution annealed AISI type 316 austenitic stainless steel specimens were exposed in static sodium at 773 and 873 K for durations ranging from 500 to 2000 h. The results, i.e, weight loss data, hardness values, carburisation, depletion rates, sigma phase formation from the ferrite layer, corrosion morphology, roughness values etc. are analysed and discussed in the paper. Corrosion data such as the weight loss/depleted layer thickness and microstructure of fully annealed stainless steel specimens at 773 and 873 K under static sodium conditions (present study) are comparable to those of 20% cold worked stainless steel type 316 specimens at temperatures 973 K and above under dynamic sodium conditions. Annealed specimens leach out at a faster rate than cold worked specimens exposed to sodium.

  4. Chemical composition of passive films on AISI 304 stainless steel

    SciTech Connect

    Lorang, G.; Da Cunha Belo, M. (Centre E'Etudes de Chimie Metallurgique du CNRS, Vitry-Sur-Seine (France)); Simoes, A.M.P.; Ferreira, M.G.S. (Inst. Superior Tecnico, Lisboa (Portugal). Dept. de Engenharia Quimica)

    1994-12-01

    Chemical characterization of passive films formed on AISI 304 austenitic stainless steel, in a borate/boric acid solution at pH 9.2, under various conditions of potential, temperature, and polarizations time, was made by Auger electron spectroscopy combined with ion sputtering, and x-ray photoelectron spectroscopy (XPS). The depth chemical composition, thickness, and duplex character of the passive layers were determined after processing AES sputter profiles by their quantitative approach based on the sequential layer sputtering model. Moreover, separated contributions of elements in their oxidized and unoxidized state could be disclosed from part to part of the oxide-alloy interface. The XPS study specified the chemical bondings which take placed inside the film, between Fe and oxygen (and water).

  5. CO2 laser welding of AISI 321stainless steel

    NASA Astrophysics Data System (ADS)

    Hussain, A.; Hamdani, A. H.; Akhter, R.

    2014-06-01

    CO2 laser welding of AISI 321austenitic stainless steel has been carried out. Bead on plate welds on 2 mm thick steel were performed with 450W CO2 laser at speeds ranging from 200 to 900 mm/min. It was observed that weld depth and width was decreased with increasing the speed at constant laser power. Butt welds on different sheet thickness of 1, 2 and 2.5 mm were performed with laser power of 450 W and at speed 750, 275 and 175 mm/min, respectively. The microstructures of the welded joints and the heat affected zones (HAZ) were examined by optical microscopy and SEM. The austenite/delta ferrite microstructure was reported in the welded zone. The microhardness and tensile strength of the welded joints were measured and found almost similar to base metal due to austenitic nature of steel.

  6. Fretting of AISI 9310 and selected fretting resistant surface treatments

    NASA Technical Reports Server (NTRS)

    Bill, R. C.

    1977-01-01

    Fretting wear experiments were conducted with uncoated AISI 9310 mating surfaces, and with combinations incorporating a selected coating to one of the mating surfaces. Wear measurements and SEM observations indicated that surface fatigue, as made evident by spallation and surface crack formation, is an important mechanism in promoting fretting wear to uncoated 9310. Increasing humidity resulted in accelerated fretting, and a very noticeable difference in nature of the fretting debris. Of the coatings evaluated, alumimum bronze with a polyester additive was most effective at reducing wear and minimizing fretting damage to the mating uncoated surface, by means of a self-lubricating film that developed on the fretting surfaces. Chromium plate performed as an effective protective coating, itself resisting fretting and not accelerating damage to the uncoated surface.

  7. Fretting of AISI 9310 and selected fretting resistant surface treatments

    NASA Technical Reports Server (NTRS)

    Bill, R. C.

    1977-01-01

    Fretting wear experiments were conducted with uncoated AISI 9310 mating surfaces, and with combinations incorporating a selected coating to one of the mating surfaces. Wear measurements and SEM observations indicated that surface fatigue, as made evident by spallation and surface crack formation, is an important mechanism in promoting fretting wear to uncoated 9310. Increasing humidity resulted in accelerated fretting, and a very noticeable difference in nature of the fretting debris. Of the coatings evaluated, aluminum bronze with a polyester additive was most effective at reducing wear and minimizing fretting damage to the mating uncoated surface, by means of a selflubricating film that developed on the fretting surfaces. Chromium plate performed as an effective protective coating, itself resisting fretting and not accelerating damage to the uncoated surface.

  8. Investment cast AISI H13 tooling for automotive applications

    SciTech Connect

    Maguire, M.C.; Baldwin, M.D. [Sandia National Labs., Albuquerque, NM (United States); Hochanadel, P.W.; Edwards, G.R. [Colorado School of Mines, Golden, OH (United States)

    1995-07-01

    While many techniques exist for production of soft tooling, for die casting there is limited recent experience with cast tooling. The most common US alloy used for manufacture of die casting tooling is wrought AISI H13. If the performance of the cast material is comparable to the wrought counterpart, the use of investment cast HI 3 tooling directly from patterns made via rapid prototyping is of considerable interest. A metallurgical study of investment cast H13 was conducted to evaluate the mechanical behavior in simulated die casting applications. Variable thickness plate investment castings of AISI H13 hot work die steel were produced and characterized in the as-cast and heat-treated conditions. The characterization included light microscopy and mechanical testing. Wrought samples of standard and premium grade H13 were heat-treated and characterized similarly for comparison. Microstructural differences were observed in as-cast samples produced in different section thicknesses. Dendrite cell size and carbide morphology constituted the most prominent microstructural differences observed. After a full heat-treatment, microstructural differences between the wrought material and cast materials were slight regardless of section thickness.The mechanical properties of the cast and heat-treated material proved similar to the properties of the standard heat-treated wrought material. A thermal fatigue testing unit was to con-elate the heat checking susceptibility of H13 steel to its processing and consequent microstructural condition. Surface hardness decreased significantly with thermal cycling, and heat checking was observed in as few as 50 cycles. Thermal softening and thermal fatigue susceptibility were quantified and discussed relative to the microstructural conditions created by processing and heat-treatment. It was found that the premium grade wrought H13 steel provided the best overall resistance to heat checking.

  9. AISI 1020 MALZEMESNDE BORLAMAARTLARININ TABAKA KALINLIINA ETKSNN YAPAY SNR ALARILE ARATIRILMASI INVESTIGATION THE EFFECTS OF BOROIZNG CONDITIONS TO BORIDE LAYER THICKNESS FOR AISI 1020 USING ARTIFICIAL NEURAL NETWORKS

    Microsoft Academic Search

    Hülya DURMU; Filiz TATAN

    In this study, boronizing is a surface hardening method, was applied on AISI 1020 steel. It was carried out using Ekabor 2 powders. The prosess was occured at 820°C, 860°C, 900°C or 940°C in 2, 4, 6 or 8 hour. Microstructures of boronizing samples and boride layer thicknesses were measured. Also the hardness of samples were determined according to depth.

  10. Influence of heat treatments on the intergranular corrosion resistance of the AISI 347 cast and weld metal for high temperature services

    Microsoft Academic Search

    A. Yae Kina; V. M. Souza; S. S. M. Tavares; J. A. Souza; H. F. G. de Abreu

    2008-01-01

    Stabilized austenitic stainless steels such as AISI 347 can be selected to high temperature services due to the high creep resistance of austenite phase. Niobium is added to form fine NbC carbides, which increase the creep resistance and prevents intergranular corrosion. AISI 347 wires and electrodes are frequently used as feed metal to weld AISI 321 and 347 whrought plates.

  11. The surface fatigue life of contour induction hardened AISI 1552 gears

    NASA Astrophysics Data System (ADS)

    Townsend, Dennis P.; Turza, Alan; Chaplin, Mike

    1995-07-01

    Two groups of spur gears manufactured from two different materials and heat treatments were endurance tested for surface fatigue life. One group was manufactured from AISI 1552 and was finished ground to a 0.4 micron (16 micro-in.) rms surface finish and then dual frequency contour induction hardened. The second group was manufactured from CEVM AISI 9310 and was carburized, hardened, and ground to a 0.4 micron (16 micro-in.) rms surface finish. The gear pitch diameter was 8.89 cm (3.5 in.). Test conditions were a maximum Hertz stress of 1.71 GPa (248 ksi), a bulk gear temperature of approximately 350 K (170 F) and a speed of 10,000 rpm. The lubricant used for the tests was a synthetic paraffinic oil with an additive package. The test results showed that the 10 percent surface fatigue (pitting) life of the contour hardened AISI 1552 test gears was 1.7 times that of the carburized and hardened AISI 9310 test gears. Also there were two early failures of the AISI 1552 gears by bending fatigue.

  12. Tribological properties of Fe 3Al–Fe 3AlC 0.5 composites under dry sliding

    Microsoft Academic Search

    Jun Yang; Peiqing La; Weimin Liu; Jiqiang Ma; Qunji Xue

    2005-01-01

    The tribological properties of Fe3Al composites with 40, 60 and 80wt.% Fe3AlC0.5 under dry sliding against AISI52100 steel at ambient conditions were studied. Effects of load and sliding speed on the tribological properties were investigated. Worn surfaces of the composites were analyzed by scanning electron microscopy. It was found that wear rate of the composites were in the magnitude of

  13. The Forming of AISI 409 sheets for fan blade manufacturing

    SciTech Connect

    Foroni, F. D.; Menezes, M. A.; Moreira Filho, L. A. [ITA - Aeronautic Technological Institute, IEM, Praca Mal. Eduardo Gomes, 50 - Vila das Acacias - S. J. Campos, Brasil - CEP 1228-900 (Brazil)

    2007-04-07

    The necessity of adapting the standardized fan models to conditions of higher temperature has emerged due to the growth of concern referring to the consequences of the gas expelling after the Mont Blanc tunnel accident in Italy and France, where even though, with 100 fans in operation, 41 people died. The objective of this work is to present an alternative to the market standard fans considering a new technology in constructing blades. This new technology introduces the use of the stainless steel AISI 409 due to its good to temperatures of gas exhaust from tunnels in fire situation. The innovation is centered in the process of a deep drawing of metallic sheets in order to keep the ideal aerodynamic superficies for the fan ideal performance. Through the impression of circles on the sheet plane it is shown, experimentally, that, during the pressing process, the more deformed regions on the sheet plane of the blade can not reach the deformation limits of the utilized sheet material.

  14. AISI waste oxide recycling program. Final technical report

    SciTech Connect

    Aukrust, E.; Downing, K.B.; Sarma, B.

    1995-08-01

    In March 1995 AISI completed a five-year, $60 million collaborative development program on Direct Steelmaking cost-shared by DOE under the Metals Initiative. This program defined an energy-efficient and environmentally-friendly technology to produce hot metal for steelmaking directly from coal and iron ore pellets without incurring the high capital costs and environmental problems associated with traditional coke oven and blast furnace technology. As it becomes necessary to replace present capacity, this new technology will be favored because of reduced capital costs, higher energy efficiency, and lower operating costs. In April 1994, having failed to move forward with a demonstration plant for direct ironmaking, despite substantial efforts by both Stelco and Geneva Steel, an alternative opportunity was sought to commercialize this new technology without waiting until existing ironmaking capacity needed to be replaced. Recycling and resource recovery of steel plant waste oxides was considered an attractive possibility. This led to approval of a ten-month, $8.3 million joint program with DOE on recycling steel plant waste oxides utilizing this new smelting technology. This highly successful trial program was completed in December 1994. The results of the pilot plant work and a feasibility study for a recycling demonstration plant are presented in this final technical report.

  15. Coupled Multi-Electrode Investigation of Crevice Corrosion of AISI 316 Stainless Steel

    SciTech Connect

    F. Bocher; F. Presuel-Moreno; N.D. Budinasky; J.R. Scully

    2006-06-23

    Close packed coupled multi-electrodes arrays (MEA) simulating a planar electrode were used to measure the current evolution as a function of position during initiation and propagation of crevice corrosion of AISI 316 stainless steel. Scaling laws derived from polarization data enabled the use of rescaled crevices providing spatial resolution. Crevice corrosion of AISI 316 stainless steel in 0.6 M NaCl at 50 C was found to initiate close to the crevice mouth and to spread inwards with time. The local crevice current density increased dramatically over a short period to reach a limiting value.

  16. Electrochemical behavior of Ni-Al-Fe alloys in simulated human body solution

    Microsoft Academic Search

    I. E. Castañeda; J. G. Gonzalez-Rodriguez; J. Colin; M. A. Neri-Flores

    2010-01-01

    An investigation about the corrosion resistance of Ni-Al-Fe intermetallic alloys in simulated human body fluid environments\\u000a has been carried out using electrochemical techniques. Tested alloys included 57 (wt%) Ni-(20 to 30) Al-(12 to 23) Fe using\\u000a the Hank's solution because the high corrosion resistance provided by protective Al2O3 external layer. For comparison, AISI 316L type stainless steel has also been

  17. Failure analysis of an AISI 410 stainless steel airfoil in a steam turbine

    Microsoft Academic Search

    C. A. Poblano-Salas; J. D. O. Barceinas-Sanchez; J. C. Sanchez-Jimenez

    2011-01-01

    A failure analysis was performed to determine the occurrence of cracking in an AISI 410 stainless steel airfoil from a steam turbine. The failure was detected arising from a reinforcing lacing bar located at the upper part of the blade. Failure resulted from nucleation and growth of a crack running transversally to the length of the airfoil. Poor surface preparation

  18. Microstructure development in Nd:YAG laser welding of AISI 304 and Inconel 600

    Microsoft Academic Search

    Maurício David M. das Neves; André Lotto; José Roberto Berretta; Wagner de Rossi; Nilson Dias V. Júnior

    2010-01-01

    In this work, the morphology of solidification of the weld zone (WZ) was studied in a joint formed from dissimilar materials, composed of austenitic AISI 304 stainless steel and Inconel 600 nickel alloy, welded with an Nd:YAG-pulsed laser. The laser beam and optical system parameters were selected with a view to obtain a weld with total penetration and good surface

  19. Fatigue properties of an AISI 1045 steel coated with an electroless NiP deposit

    Microsoft Academic Search

    G. Contreras; C. Fajardo; J. A. Berr??os; A. Pertuz; J. Chitty; H. Hintermann; E. S. Puchi

    1999-01-01

    The fatigue behavior of samples of an AISI 1045 steel plated with electroless Ni-P (EN) deposits, both on an industrial and laboratory scale, has been evaluated under completed reverse bending or rotating bending conditions. The fatigue experiments were conducted in air at a frequency of 50 Hz, in the stress range of 292–346 MPa. On the laboratory scale, the deposition

  20. Carburising of steel AISI 1010 by using a cathode arc plasma process

    Microsoft Academic Search

    Chengming Li; Qi He; Weizhong Tang; Fanxiu Lu

    2004-01-01

    The properties and processes of cathode arc plasma carburizing were studied in this paper. Graphite with high purity and high strength was selected as the cathode arc source to provide carbon atoms. The carbon steel AISI 1010 was used as the substrate. A surface concentration of 1.05 wt.%C and a carburised layer thickness of 780 ?m was obtained at 950

  1. Mechanical properties of duplex layer formed on AISI 403 stainless steel by chromizing and boronizing treatment

    Microsoft Academic Search

    Sang Yul Lee; Gwang Seok Kim; Bum-Suk Kim

    2004-01-01

    In order to improve the high temperature performance of AISI 403 martensitic stainless steel, duplex surface treatment which combines the methods of pack cementation chromizing and boronizing was carried out. Specimens were chromized at 1100 °C for 2 h and were subsequently boronized in a solid medium consisting of EKabor-III powders at 950 °C for 9 h. The characteristics of

  2. A Fuzzy Model for Predicting Surface Roughness in Plasma Arc Cutting of AISI 4140 Steel

    Microsoft Academic Search

    Cebeli Özek; Ula? Çayda?; Engin Ünal

    2012-01-01

    In the present study, fuzzy logic (a tool in artificial intelligence) was used for the prediction of cutting parameters in plasma arc cutting (PAC) process of AISI 4140 steel. The parameters considered in this study were plasma arc current, cutting speed, and thickness of cut material. Fuzzy rule–based modeling was employed for prediction of surface roughness. These models can be

  3. Alberta Initiative for School Improvement: AISI Handbook for Cycle 3, 2006-2009

    ERIC Educational Resources Information Center

    Online Submission, 2006

    2006-01-01

    The purpose of the AISI (Alberta Initiative for School Improvement) Handbook for Cycle 3, 2006-2009 is to provide school authorities with the provincial and local requirements and processes for planning, funding, implementing, managing, evaluating, reporting and sharing school improvement projects. The handbook provides a framework for the…

  4. Computational Modeling of Microstructural-Evolution in AISI 1005 Steel During Gas Metal Arc Butt Welding

    E-print Network

    Grujicic, Mica

    Computational Modeling of Microstructural-Evolution in AISI 1005 Steel During Gas Metal Arc Butt-mechanical finite-element procedure is developed to model conventional gas metal arc welding (GMAW) butt of an externally supplied (shielding) gas/mixture of gases (Ref 1). A schematic of the basic gas metal arc butt

  5. Fatigue life improvement of AISI 304L cruciform welded joints by cryogenic treatment

    Microsoft Academic Search

    P Johan Singh; B Guha; D. R. G Achar

    2003-01-01

    Existing theories and reported practical experience show that cryogenic processing greatly increases abrasion resistance and contact fatigue resistance of some metals and alloys. In the present work, an attempt has been made to investigate the effect of cryogenic treatment on the axial fatigue performance of fillet welded cruciform joints of AISI 304L stainless steel, which failed in the weld metal.

  6. Effect of high-temperature deformation on the mechanical properties of AISI 316 stainless steel

    Microsoft Academic Search

    Mohammed A. Shabara

    1997-01-01

    Accurate and reliable life predictions of mechanical components subjected to stress at elevated temperature may be difficult since the mechanical properties of the material are expected to change. The constitutive equations describing the creep behavior may also change due to softening or hardening processes caused by the applied loading conditions. In this paper the response of AISI Type 316 stainless

  7. Effect of nitrogen on sensitization and stress corrosion cracking of AISI 304 stainless steels

    Microsoft Academic Search

    Mozhi

    1986-01-01

    Sensitization in the heat affected zones of AISI 304 stainless steel (SS) welded piping of boiling water reactors (BWR) has caused intergranular stress corrosion cracking (IGSCC) failures. New grades with reduced carbon levels, to prevent IGSCC, and nitrogen-additions to improve strength, have been proposed as alternative materials, although no systematic study of the effect of nitrogen on SCC of these

  8. HallPetch Behavior in Ultra-Fine-Grained AISI 301LN Stainless Steel

    E-print Network

    Ferreira, Paulo J.

    of ultra-fine-grained austenite has been first demonstrated in special noncommercial metastable Fe-Cr-Ni alloys with negligible C, N, and Mn con- tents.[2­4] More recently, a commercial AISI 304 SS has also been investigated;[5] however, because the austenite phase is rather stable in this alloy

  9. The Effect of PWHT on Electrochemical Behaviour of AISI 316L Weld Metal

    Microsoft Academic Search

    S. Kouh; M. Gojiæ; M. Kraljiæ Rokoviæb

    The subject of investigation was the corrosion behaviour of AISI 316L austenitic stainless steel weld metal as dependent on a protective passive film formed on the steel surface following exposure to w = 3.5 % NaCl. The corrosion properties were examined before PWHT and after it by means of cyclic polarization, electrochemical impedance spectroscopy, and chronoamperometric measurements. Cyclic polarization curves

  10. Residual stress analysis in orthogonal machining of standard and resulfurized AISI 316L steels

    Microsoft Academic Search

    R. M’Saoubi; J. C. Outeiro; B. Changeux; J. L. Lebrun; A. Morão Dias

    1999-01-01

    Residual stresses induced by orthogonal cutting in AISI 316L standard and resulfurized steels have been investigated, with attention given to the role played by the cutting parameters, such as cutting speed, feed rate, tool geometry and tool coating. Depth profiles of residual stress have been determined using the X-ray diffraction technique. The effect of cutting conditions and tool nature on

  11. Dissimilar welding of AISI 310 austenitic stainless steel to nickel-based alloy Inconel 657

    Microsoft Academic Search

    H. Naffakh; M. Shamanian; F. Ashrafizadeh

    2009-01-01

    The current work was carried out to characterize welding of AISI 310 austenitic stainless steel to Inconel 657 nickel–chromium superalloy. The welds were produced using four types of filler materials; the nickel-based corresponding to Inconel 82, Inconel A, Inconel 617 and 310 austenitic stainless steels. This paper describes the selection of welding consumables for the joint. The comparative evaluation was

  12. A Fuzzy Model for Predicting Surface Roughness in Plasma Arc Cutting of AISI 4140 Steel

    Microsoft Academic Search

    Cebeli Özek; Ula? Çayda?; Engin Ünal

    2011-01-01

    In the present study, fuzzy logic (a tool in artificial intelligence) was used for the prediction of cutting parameters in plasma arc cutting process of AISI 4140 steel. The parameters considered in this study were plasma arc current, cutting speed and thickness of cut material. Fuzzy–rule based modeling was employed for prediction of surface roughness. These models can be effectively

  13. A DISCUSSION OF THE SUSCEPTIBILITY OF AISI 410 TO STRESS CORROSION, AND MEANS OF ELIMINATING THE STRESS-CORROSION PROBLEM

    Microsoft Academic Search

    Suss

    1961-01-01

    AISI 410 stainless steel, tempered at 650 deg F for two hours to ; Rockwell hardness (Re) of 36 to 42, is susceptible to stress-corrosibn attack in ; high-temperature, high-purity waters. The time-to-failure is affected ; significantly by the water chemistry. Metallurgical factors contributing to the ; stress-corrosion characteristics are reviewed. AISI 410, tempered at 1125 deg F ; minimum

  14. A comparison of the room-temperature behaviour of AISI 304LN stainless steel and Nimonic 90 under strain cycling

    Microsoft Academic Search

    S. Ganesh Sundara Raman; K. A. Padmanabhan

    1995-01-01

    The influence of room-temperature low-cycle fatigue (LCF) deformation on the microstructure and the consequent modification of the LCF behaviour were examined in the case of AISI 304LN stainless steel and the superalloy Nimonic 90. Secondary hardening due to martensite formation in AISI 304LN enhanced its resistance to plastic flow. On the other hand, in Nimonic 90 shearing of ?? particles

  15. Fatigue behaviour of low temperature carburised AISI 316L austenitic stainless steel

    Microsoft Academic Search

    Lorella Ceschini; Giangiacomo Minak

    2008-01-01

    Low temperature carburising (LTC) was applied to AISI316L austenitic stainless steel and its effect on microstructure and fatigue behaviour was investigated. LTC treatment enhances surface hardness and wear resistance of the steel without reducing its corrosion resistance. Surface hardness up to 1150 Vickers was achieved in the carburised layer, thanks to the formation of the so-called “S-phase”, a carbon-supersaturated austenite phase.

  16. Laves phase precipitation and its transformation kinetics in the ferritic stainless steel type AISI 441

    Microsoft Academic Search

    M. P. Sello; W. E. Stumpf

    2011-01-01

    Electrolytic extraction followed by XRD analysis of precipitates after isothermal annealing of an AISI 441 ferritic stainless steel between 600 and 850°C produced the time–temperature–precipitation (TTP) diagram for the Fe2Nb-Laves phase. The TTP diagram shows two classical C noses, the first one between 750 and 825°C and the second one, estimated to be close to 650–675°C. TEM analyses show two

  17. Tribological properties evaluation of AISI 1095 steel chromized at different temperatures

    Microsoft Academic Search

    Jyh-Wei Lee; Hsi-Chun Wang; Jai-Lin Li; Chao-Chih Lin

    2004-01-01

    Pack chromization process provides a surface modified coating on steel surface with high hardness, corrosion and temperature resistance. AISI 1095 carbon steels were chromized to form chromium–iron nitride and carbides on surface by pack cementation process at 850 and 900 °C for 1–9 h, respectively. Chromized layer with an outer (Cr,Fe)2N1-x and inner (Cr,Fe)23C6 and (Cr,Fe)7C3 phases were observed. The

  18. Formation of chromium nitride layers on AISI 1010 steel by nitro-chromizing treatment

    Microsoft Academic Search

    Ozkan Ozdemir; Saduman Sen; Ugur Sen

    2007-01-01

    In this study, chromium nitride coating was realized on AISI 1010 steels by nitro-chromizing treatment. Steel samples were tufftrided at 575°C for 2h in the first step of the coating process, and then chromized by pack method in the powder mixture consisting of ferro-chromium, ammonium chloride and alumina at 1000°C for 1–4h. Samples were characterized by scanning electron microscopy (SEM),

  19. Duplex surface treatment of AISI 1045 steel via plasma nitriding of chromized layer

    Microsoft Academic Search

    F. Hakami; M. Heydarzadeh Sohi; J. Rasizadeh Ghani

    2011-01-01

    In this work AISI 1045 steel were duplex treated via plasma nitriding of chromized layer. Samples were pack chromized by using a powder mixture consisting of ferrochromium, ammonium chloride and alumina at 1273K for 5h. The samples were then plasma-nitrided for 5h at 803K and 823K, in a gas mixture of 75%N2+25%H2. The treated specimens were characterized by scanning electron

  20. Evaluation on fatigue strength of AISI 4340 steel aluminum coated by electroplating and IVD processes

    Microsoft Academic Search

    Herman Jacobus Cornelis Voorwald; Mauro Pedro Peres; Midori Yoshikawa Pitanga Costa; Maria Odila Hilário Cioffi

    2010-01-01

    In spite of toxicity, hydrogen embrittlement susceptibility, and environmental issues, cadmium electroplating is usually applied\\u000a on high strength AISI 4340 aeronautical steel due to its efficient protection against electrochemical corrosion. Ion vapor\\u000a deposition (IVD) process with pure aluminum also offers good protection against corrosion with the advantages of decreasing\\u000a hydrogen embrittlement susceptibility and improving the fatigue strength of metallic components.

  1. Influence of post irradiation annealing on the mechanical properties and defect structure of AISI 304 steel

    Microsoft Academic Search

    W. Van Renterghem; A. Al Mazouzi; S. Van Dyck

    2011-01-01

    The effect of post irradiation annealing on the mechanical properties and the radiation induced defect structure was investigated on stainless steel, of type AISI 304, that was irradiated up to 24dpa in the decommissioned Chooz A reactor. The material was investigated both in the as-irradiated state as well as after post irradiation annealing. In the as-irradiated specimen the typical radiation

  2. Cavitation erosion behavior of electroless nickel-plating on AISI 1045 steel

    Microsoft Academic Search

    C. J. Lin; J. L. He

    2005-01-01

    Electroless nickel-plating is widely used in anti-corrosion engineering with a bonus of the capability of precipitation hardening due to Ni3P formation after a 1h heat treatment at 400°C. But its application in cavitation erosion protection has been rarely discussed in the literature. In this study, electroless nickel-plating is produced on AISI 1045 steel with and without post-heat treatment and cavitation

  3. Effect of surface nanocrystallization on the corrosion behaviour of AISI 409 stainless steel

    Microsoft Academic Search

    T. Balusamy; Satendra Kumar; T. S. N. Sankara Narayanan

    2010-01-01

    The influence of surface mechanical attrition treatment (SMAT) on the corrosion behaviour of AISI 409 grade stainless steel in 0.6M NaCl was studied. SMAT using 2mm ? 316L stainless steel (SS) balls for 15, 30 and 45min and 5mm ? balls for 15min offers a better corrosion protective ability. In contrast, treatment using 5mm ? balls for 30 and 45min

  4. Fatigue life improvements of the AISI 304 stainless steel ground surfaces by wire brushing

    Microsoft Academic Search

    Nabil Ben Fredj; Mohamed Ben Nasr; Amir Ben Rhouma; Habib Sidhom; Chedly Braham

    2004-01-01

    The surface and subsurface integrity of metallic ground components is usually characterized by an induced tensile residual\\u000a stress, which has a detrimental effect on the fatigue life of these components. In particular, it tends to accelerate the\\u000a initiation and growth of the fatigue cracks. In this investigation, to deliberately generate compressive residual stresses\\u000a into the ground surfaces of the AISI

  5. Effect of high-temperature deformation on the mechanical properties of AISI 316 stainless steel

    NASA Astrophysics Data System (ADS)

    Shabara, Mohammed A. N.

    1997-03-01

    Accurate and reliable life predictions of mechanical components subjected to stress at elevated temperature may be difficult since the mechanical properties of the material are expected to change. The constitutive equations describing the creep behavior may also change due to softening or hardening processes caused by the applied loading conditions. In this paper the response of AISI Type 316 stainless steel at 650 degrees Celsius when subjected to a static tensile stress is examined. A testing technique has been applied to the test material to evaluate the effect of short periods of high temperature deformation on its mechanical properties. Round tensile specimens were subjected to constant tensile stress levels under high temperature of 650 degrees Celsius for periods of time varying from 2 to 8 hours. The specimens were then annealed and tested in tension under room temperature. Test results indicate that the AISI Type-316 exhibited hardening due to short period creep. Yield strength and ultimate tensile strength have increased by 58% and 20%, respectively, after 8 hours creep, over that of the virgin material. Creep was also found to cause a reduction in the ductility of the AISI Type-316 over the temperature and stress levels used in this investigation. Moreover, the changes in these properties were found to increase as creep time increased. From the present work, an empirical equation was obtained for predicting the amount of hardening in the material due to creep. Such an equation may be useful in more involved problems of combined creep and fatigue.

  6. The effect of surface nanocrystallization on plasma nitriding behaviour of AISI 4140 steel

    NASA Astrophysics Data System (ADS)

    Li, Yang; Wang, Liang; Zhang, Dandan; Shen, Lie

    2010-11-01

    A plastic deformation surface layer with nanocrystalline grains was produced on AISI 4140 steel by means of surface mechanical attrition treatment (SMAT). Plasma nitriding of SMAT and un-SMAT AISI 4140 steel was carried out by a low-frequency pulse excited plasma unit. A series of nitriding experiments has been conducted at temperatures ranging from 380 to 500 °C for 8 h in an NH 3 gas. The samples were characterized using X-ray diffraction, scanning electron microscopy, optical microscopy and Vickers microhardness tester. The results showed that a much thicker compound layer with higher hardness was obtained for the SMAT samples when compared with un-SMAT samples after nitriding at the low temperature. In particular, plasma nitriding SMAT AISI 4140 steel at 380 °C for 8 h can produced a compound layer of 2.5 ?m thickness with very high hardness on the surface, which is similar to un-SMAT samples were plasma nitrided at approximately 430 °C within the same time.

  7. Endurance and failure characteristics of modified Vasco X-2, CBS 600 and AISI 9310 spur gears. [aircraft construction materials

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.; Zaretsky, E. V.

    1980-01-01

    Gear endurance tests and rolling-element fatigue tests were conducted to compare the performance of spur gears made from AISI 9310, CBS 600 and modified Vasco X-2 and to compare the pitting fatigue lives of these three materials. Gears manufactured from CBS 600 exhibited lives longer than those manufactured from AISI 9310. However, rolling-element fatigue tests resulted in statistically equivalent lives. Modified Vasco X-2 exhibited statistically equivalent lives to AISI 9310. CBS 600 and modified Vasco X-2 gears exhibited the potential of tooth fracture occurring at a tooth surface fatigue pit. Case carburization of all gear surfaces for the modified Vasco X-2 gears results in fracture at the tips of the gears.

  8. Corrosion-wear monitoring of TiN coated AISI 316 stainless steel by electrochemical noise measurements

    NASA Astrophysics Data System (ADS)

    Quan, Zhenlan; Wu, Pei-Qiang; Tang, Lin; Celis, J.-P.

    2006-11-01

    A modified electrochemical noise (EN) technique has been applied to monitor corrosion-wear of TiN coated AISI 316 stainless steel sliding against corundum in 0.5 M H 2SO 4. Experimental results show that the EN technique can sensitively detect potential and current variations during a corrosion-wear process. Corrosion-wear mechanisms of TiN coatings depend on their substrate properties. When the substrate is passive, such as AISI 316 stainless steel, the potential and current variations reflect the properties of coatings. Depassivation and repassivation alternately take place on the tribo-activated wear area during the steady-state phase.

  9. UTILIDAD DE LA HUELLA ECOLÓGICA Y DEL CARBONO EN EL ÁMBITO DE LA RESPONSABILIDAD SOCIAL CORPORATIVA (RSC) Y EL ECOETIQUETADO DE BIENES Y SERVICIOS

    Microsoft Academic Search

    Adolfo Carballo Penela

    2010-01-01

    El objetivo de este artículo es exponer como aplicar dos indicadores de desarrollo sostenible, la huella ecológica y la huella del carbono en el ámbito de la sostenibilidad empresarial y la responsabilidad social corporativa. Se trata de delimitar claramente el concepto de huella ecológica y huella del carbono corporativa (HEC-HCC), incidiendo en la explicación de su utilidad en el análisis

  10. AISI/DOE Advanced Process Control Program Vol. 6 of 6: Temperature Measurement of Galvanneal Steel

    SciTech Connect

    S.W. Allison; D.L. Beshears; W.W. Manges

    1999-06-30

    This report describes the successful completion of the development of an accurate in-process measurement instrument for galvanneal steel surface temperatures. This achievement results from a joint research effort that is a part of the American Iron and Steel Institute's (AISI) Advanced Process Control Program, a collaboration between the U.S> Department of Energy and fifteen North American Steelmakers. This three-year project entitled ''Temperature Measurement of Galvanneal Steel'' uses phosphor thermography, and outgrowth of Uranium enrichment research at Oak Ridge facilities. Temperature is the controlling factor regarding the distribution of iron and zinc in the galvanneal strip coating, which in turn determines the desired product properties

  11. Wear behavior of AISI 1090 steel modified by pulse plasma technique

    SciTech Connect

    Ayday, Aysun; Durman, Mehmet [Sakarya University, Faculty of Engineering, Department of Metallurgical and Materials Engineering, Adapazar Latin-Small-Letter-Dotless-I , 54187 (Turkey)

    2012-09-06

    AISI 1090 steel was pulse plasma treated (PPT) using a Molybdenum electrode. Two different pulse numbers were chosen to obtain modified layers of 20{+-}5 {mu}m thickness. The dry sliding wear studies performed on this steel with and without PPT against an alumina ball counterpart showed that the PPT improved the wear resistance. The pulse number of the PPT modified layer was found to be highly influential in imparting the wear resistance to this steel, due to enhancement of surface hardness depending on treatment time.

  12. Martensitic stainless steel AISI 420—mechanical properties, creep and fracture toughness

    NASA Astrophysics Data System (ADS)

    Brnic, J.; Turkalj, G.; Canadija, M.; Lanc, D.; Krscanski, S.

    2011-11-01

    In this paper some experimental results and analyses regarding the behavior of AISI 420 martensitic stainless steel under different environmental conditions are presented. That way, mechanical properties like ultimate tensile strength and 0.2 percent offset yield strength at lowered and elevated temperatures as well as short-time creep behavior for selected stress levels at selected elevated temperatures of mentioned material are shown. The temperature effect on mentioned mechanical properties is also presented. Fracture toughness was calculated on the basis of Charpy impact energy. Experimentally obtained results can be of importance for structure designers.

  13. Rolling-contact fatigue lives of steel AISI 52100 balls with eight mineral and synthetic lubricants

    Microsoft Academic Search

    Yinglong Wang; J. E. Fernandez; D. G. Cuervo

    1996-01-01

    This work has evaluated the rolling-contact fatigue lives of AISI 52100 steel balls with several mineral and synthetic oils with and without additive using a four-ball tester. The studied lubricants include S.N.-350 (mineral oil), S.N.-600 (mineral oil), TMP-05 (synthetic polyol ester), TMP-05 + 2%ZnDDP, P.A.G.-9 (synthetic polyalkyl glycol), P.A.G.-12 (synthetic polyalkyl glycol) and Breox-B-135X (synthetic polyalkyl glycol). Weibull plots and

  14. Study of passive films formed on AISI 304 stainless steel by impedance measurements and photoelectrochemistry

    SciTech Connect

    Simoes, A.M.P.; Ferreiro, M.G.S. (Dept. de Engenharia Quimica, Instituto Superior Tecnico, 1096 Lisboa Codex (PT)); Rondot, B.; Belo, M. (Centre National de la Recherche Scientifique, 94 - Vitry-sur-Seine (France). Centre d'Etudes de Chimie Metallurgique)

    1990-01-01

    Moss-Schottky plots and photoelectrochemical measurements were made on films formed at different potentials on AISI 304 stainless steel in a borate/boric acid solution, pH 9.2. The results allowed the determination of the semiconductive properties and band structure of the films, which account for the existence of two kinds of films depending on the formation potential. For potentials below 0 V (SCE), the results point out for a film with an inverse spinel structure constituted by Cr-substituted magnetite with two donor levels. Above 0 V only one donor level is detected, which should be Fe{sup 2 +} on tetrahedral sites.

  15. Investigating early stages of biocorrosion with XPS: AISI 304 stainless steel exposed to Burkholderia species

    NASA Astrophysics Data System (ADS)

    Johansson, Leena-Sisko; Saastamoinen, Tuomas

    1999-04-01

    We have investigated the interactions of an exopolymer-producing bacteria, Burkholderia sp. with polished AISI 304 stainless steel substrates using X-ray photoelectron spectroscopy (XPS). Steel coupons were exposed to the pure bacteria culture in a specially designed flowcell for 6 h during which the experiment was monitored in situ with an optical microscope. XPS results verified the formation of biofilm containing extracellular polymer on all the samples exposed to bacteria. Sputter results indicated that some ions needed for metabolic processes were trapped within the biofilm. Changes in the relative Fe concentration and Fe 2p peak shape indicated that also iron had accumulated into the biofilm.

  16. Sliding wear map for the magnesium alloy Mg9Al0.9 Zn (AZ91)

    Microsoft Academic Search

    H Chen; A. T Alpas

    2000-01-01

    Dry sliding wear tests were performed on a Mg-9.0%, Al-0.9%, Zn (AZ91) alloy using a block on-ring (AISI 52100 steel) configuration. Wear rates were measured within a load range of 1–350N and a sliding velocity range of 0.1–2.0m\\/s Compositions, morphologies and microstructures of worn surfaces and wear debris were characterised by scanning electron microscope (SEM), energy dispersive X-ray spectrometer (EDS)

  17. Dry-sliding tribological behavior of Fe–28Al–5Cr\\/TiC composites

    Microsoft Academic Search

    Xinghua zhang; Jiqiang Ma; Jun Yang; Qinling Bi; Weimin Liu

    2011-01-01

    Dry-sliding tribological performance of the Fe–28Al–5Cr and its composites containing 15, 25, 35, 50wt.% TiC, produced by hot-pressing process, was investigated against an AISI 52100 steel ball in ambient environment at varying applied load and sliding speed. It can be found that the coefficient of friction (COF) is irrespective of TiC content and applied load, but increases from 0.46 to

  18. Surface Treatments for Improved Performance of Spinel-coated AISI 441 Ferritic Stainless Steel

    SciTech Connect

    Stevenson, Jeffry W.; Riel, Eric M.; Stephens, Elizabeth V.; Khaleel, Mohammad A.

    2013-01-01

    Ferritic stainless steels are promising candidates for IT-SOFC interconnect applications due to their low cost and resistance to oxidation at SOFC operating temperatures. However, steel candidates face several challenges; including long term oxidation under interconnect exposure conditions, which can lead to increased electrical resistance, surface instability, and poisoning of cathodes due to volatilization of Cr. To potentially extend interconnect lifetime and improve performance, a variety of surface treatments were performed on AISI 441 ferritic stainless steel coupons prior to application of a protective spinel coating. The coated coupons were then subjected to oxidation testing at 800 and 850°C in air, and electrical testing at 800°C in air. While all of the surface-treatments resulted in improved surface stability (i.e., increased spallation resistance) compared to untreated AISI 441, the greatest degree of improvement (through 20,000 hours of testing at 800°C and 14,000 hours of testing at 850°C) was achieved by surface blasting.

  19. Surface modification of biomedical AISI 316L stainless steel with zirconium carbonitride coatings

    NASA Astrophysics Data System (ADS)

    Wang, L.; Zhao, X.; Ding, M. H.; Zheng, H.; Zhang, H. S.; Zhang, B.; Li, X. Q.; Wu, G. Y.

    2015-06-01

    In the paper, by using radio frequency (rf) magnetron sputtering method, a zirconium carbonitride coating was produced on AISI 316L austenitic stainless steel. The influence of substrate temperature (Ts) on microstructure, mechanical properties, corrosion resistance and hemocompatibility were then investigated. XRD and TEM results revealed that the zirconium carbonitride coatings were almost amorphous when Ts was below 400°C, while nanostructured Zr2CN was formed at Ts of 400 °C. The nanocrystalline formation resulted in a significant increase in the nanohardness of zirconium carbonitride coatings from 17 GPa to over 32 GPa. Electrochemical testing showed that the stable zirconium carbonitride coating had improved the corrosion resistance of AISI 316L stainless steel substrate material. The characterization of platelet adhesion indicated that the zirconium carbonitride coatings presented better hemocompatibility when Ts varied from 25 °C to more than 200 °C, which may be due to the lower surface roughness, interfacial tension and the rate ?sd /?sp , where ?sd and ?sp are the disperse component and polar component of the surface, respectively.

  20. Microstructure, Mechanical and Corrosion Properties of Friction Stir-Processed AISI D2 Tool Steel

    NASA Astrophysics Data System (ADS)

    Yasavol, Noushin; Jafari, Hassan

    2015-05-01

    In this study, AISI D2 tool steel underwent friction stir processing (FSP). The microstructure, mechanical properties, and corrosion resistance of the FSPed materials were then evaluated. A flat WC-Co tool was used; the rotation rate of the tool varied from 400 to 800 rpm, and the travel speed was maintained constant at 385 mm/s during the process. FSP improved mechanical properties and produced ultrafine-grained surface layers in the tool steel. Mechanical properties improvement is attributed to the homogenous distribution of two types of fine (0.2-0.3 ?m) and coarse (1.6 ?m) carbides in duplex ferrite-martensite matrix. In addition to the refinement of the carbides, the homogenous dispersion of the particles was found to be more effective in enhancing mechanical properties at 500 rpm tool rotation rate. The improved corrosion resistance was observed and is attributed to the volume fraction of low-angle grain boundaries produced after friction stir process of the AISI D2 steel.

  1. Improvement in cavitation erosion resistance of AISI 316L stainless steel by friction stir processing

    NASA Astrophysics Data System (ADS)

    Hajian, M.; Abdollah-zadeh, A.; Rezaei-Nejad, S. S.; Assadi, H.; Hadavi, S. M. M.; Chung, K.; Shokouhimehr, M.

    2014-07-01

    Commercial AISI 316L plates with the initial grain size of 14.8 ?m were friction stir processed (FSP) with different processing parameters, resulting in two fine-grained microstructures with the grain sizes of 4.6 and 1.7 ?m. The cavitation erosion behavior, before and after FSP, was evaluated in terms of incubation time, cumulative mass loss and mean depth of erosion. A separate cavitation erosion test was performed on the transverse cross section of a FSP sample to reveal the effect of grain structure. It was observed that FSP samples, depending on their grain size, are at least 3-6 times more resistant than the base material against cavitation erosion. The improvement in cavitation erosion resistance is attributed to smaller grain structure, lower fraction of twin boundaries, and favorable crystallographic orientation of grains in FSP samples. The finer the grain size, the more cavitation erosion resistance was achieved. Moreover, the microstructures of eroded surfaces were studied using a scanning electron microscope equipped with EBSD, and an atomic force microscope. The mechanisms controlling the cavitation erosion damage in friction stir processed AISI 316L are also discussed.

  2. Determination of Proper Austenitization Temperatures for Hot Stamping of AISI 4140 Steel

    NASA Astrophysics Data System (ADS)

    Samadian, Pedram; Parsa, Mohammad Habibi; Shakeri, Amid

    2014-04-01

    High strength steels are desirable materials for use in automobile bodies in order to reduce vehicle weight and increase the safety of car passengers, but steel grades with high strength commonly show poor formability. Recently, steels with controlled microstructures and compositions are used to gain adequate strength after hot stamping while maintaining good formability during processing. In this study, microstructure evolutions and changes in mechanical properties of AISI 4140 steel sheets resulting from the hot stamping process at different austenitization temperatures were investigated. To determine the proper austenitization temperatures, the results were compared with those of the cold-worked and cold-worked plus quench-tempered specimens. Comparisons showed that the austenitization temperatures of 1000 and 1100 °C are proper for hot stamping of 3-mm-thick AISI 4140 steel sheets due to the resultant martensitic microstructure which led to the yield and ultimate tensile strength of 1.3 and 2.1 GPa, respectively. Such conditions resulted in more favorable simultaneous strength and elongation than those of hot-stamped conventional boron steels.

  3. Effects of biofilm formation on the electrochemical behavior of AISI 304 SS in board machine environment

    SciTech Connect

    Carp, L.; Hakkarainen, T. [VTT Manufacturing Technology (Finland); Raaska, L. [VTT Biotechnology and Food Research (Finland)

    1999-11-01

    The electrochemical behavior of and biofilm formation on AISI 304 stainless steel were studied in board machine environment with natural bacteria population. Open circuit potentials, redox-potential as well as different electrochemical measurements were performed. The biofilms formed were analyzed by microbial cultivation and by epifluorescence microscopy. The results of the measurements were compared with those performed both in sterilized white water and in artificial white water. The anodic polarization behavior of just immersed specimens was very similar in biotic (real), artificial and abiotic (sterilized) white water. Pitting initiated at very low potentials and continued to very negative values. The initiation of pitting became more difficult when the immersion time increased to 7 or 8 days in real, artificial or sterilized water. When the immersion time further increased, the pitting nucleated more easily in sterilized white water as well as in artificial white water than in biotic white water. In the laboratory equipment it was possible to maintain the biofilm already formed in the board mill, but the amount of sulfate reducing bacteria decreased and the amount of biofilm did not further increase. The composition and structure of the biofilm formed in laboratory differed from that formed in board mill conditions. The preliminary results indicate that the formation of biofilm in biotic white water rather inhibits than enhances the pitting corrosion of type AISI 304 stainless steel.

  4. Microstructural interpretation of the fluence and temperature dependence of the mechanical properties of irradiated AISI 316

    SciTech Connect

    Johnson, G.D.; Garner, F.A.; Brager, H.R.; Fish, R.L.

    1980-04-17

    The effects of neutron irradiation on the mechanical properties of annealed and 20% cold-worked AISI 316 irradiated in EBR-II were determined for the temperature regime of 370 to 760/sup 0/C for fluences up to 8.4 x 10/sup 22/ n/cm/sup 2/ (E > 0.1 MeV). At irradiation temperatures below about 500/sup 0/C, both annealed and cold-worked material exhibit a substantial increase in the flow stress with increasing fluence. Furthermore, both materials eventually exhibit the same flow stress, which is independent of fluence. At temperatures in the range of 538 to 650/sup 0/C, the cold-worked material exhibits a softening with increasing fluence. Annealed AISI 316 in this temperature regime exhibits hardening and at a fluence of 2 to 3 x 10/sup 22/ n/cm/sup 2/ (E > 0.1 MeV) reaches the same value of flow stress as the cold-worked material.

  5. Pitting and Intergranular Corrosion Resistance of AISI Type 301LN Stainless Steels

    NASA Astrophysics Data System (ADS)

    Ningshen, S.; Kamachi Mudali, U.

    2010-03-01

    The pitting and intergranular corrosion (IGC) resistance of AISI type 301LN stainless steels were evaluated using ASTM methods, anodic polarization, and electrochemical impedance techniques. The IGC results indicated that the microstructure of the samples after sensitization heat treatment at 675 °C for 1 h shows step or dual structure for both imported and indigenous materials indicating insignificant Cr23C6 precipitation. The results of immersion tests in boiling 6% copper sulfate + 16% sulfuric acid + copper solution for 24 h followed by the bend test (ASTM A262 Practice-E method) indicated no crack formation in any of the tested specimens. Pitting corrosion resistance carried out in 6% FeCl3 solution at different temperatures of 22 ± 2 and 50 ± 2 °C (ASTM G 48) up to the period of 72 h revealed pitting corrosion attack in all the investigated alloys. The potentiodynamic anodic polarization results in 0.5 M NaCl revealed variation in passive current density and pitting potential depending on the alloy chemistry and metallurgical condition. The passive film properties studied by electrochemical impedance spectroscopy (EIS) correlated well with the polarization results. The x-ray diffraction (XRD) results revealed the presence of austenite (?) and martensite (?') phases depending on the material condition. The suitability of three indigenously developed AISI type 301LN stainless steels were compared with imported type 301LN stainless steel and the results are highlighted in this article.

  6. Improving the empirical model for plasma nitrided AISI 316L corrosion resistance based on Mössbauer spectroscopy

    NASA Astrophysics Data System (ADS)

    Campos, M.; de Souza, S. D.; de Souza, S.; Olzon-Dionysio, M.

    2011-11-01

    Traditional plasma nitriding treatments using temperatures ranging from approximately 650 to 730 K can improve wear, corrosion resistance and surface hardness on stainless steels. The nitrided layer consists of some iron nitrides: the cubic ? ' phase (Fe4N), the hexagonal phase ? (Fe2 - 3N) and a nitrogen supersatured solid phase ? N . An empirical model is proposed to explain the corrosion resistance of AISI 316L and ASTM F138 nitrided samples based on Mössbauer Spectroscopy results: the larger the ratio between ? and ? ' phase fractions of the sample, the better its resistance corrosion is. In this work, this model is examined using some new results of AISI 316L samples, nitrided under the same previous conditions of gas composition and temperature, but at different pressure, for 3, 4 and 5 h. The sample nitrided for 4 h, whose value for ?/ ? ' is maximum (= 0.73), shows a slightly better response than the other two samples, nitrided for 5 and 3 h ( ?/ ? ' = 0.72 and 0.59, respectively). Moreover, these samples show very similar behavior. Therefore, this set of samples was not suitable to test the empirical model. However, the comparison between the present results of potentiodynamic polarization curves and those obtained previously at 4 and 4.5 torr, could indicated that the corrosion resistance of the sample which only presents the ? N phase was the worst of them. Moreover, the empirical model seems not to be ready to explain the response to corrosion and it should be improved including the ? N phase.

  7. A Computational Study of Plastic Deformation in AISI 304 Induced by Surface Mechanical Attrition Treatment

    NASA Astrophysics Data System (ADS)

    Zhang, X. C.; Lu, J.; Shi, S. Q.

    2010-05-01

    As a technique of grain refinement process by plastic deformation, surface mechanical attrition treatment (SMAT) has been developed to be one of the most effective ways to optimize the mechanical properties of various materials including pure metals and alloys. SMAT can significantly reduce grain size into nanometer regime in the surface layer of bulk materials, providing tremendous opportunities for improving physical, chemical and mechanical properties of the materials. In this work, a computational modeling of the surface mechanical attrition treatment (SMAT) process is presented, in which Johnson-Cook plasticity model and the finite element method were employed to study the high strain rate, elastic-plastic dynamic process of ball impact on a metallic target. AISI 304 steel with low stacking fault energy was chosen as the target material. First, a random impact model was used to analyze the statistic characteristics of ball impact, and then the plastic deformation behavior and residual stress distribution in AISI 304 stainless steel during SMAT were studied. The simulation results show that the compressive residual stress and vertical deformation of the surface structures were directly affected by ball impact frequency, incident impact angle and ball diameter used in SMAT process.

  8. An energy?based damage parameter for the life prediction of AISI 304 stainless steel subjected to mean strain

    Microsoft Academic Search

    2006-01-01

    This study extends the plastic strain energy approach to predict the fatigue life of AISI 304 stainless steel. A modified energy parameter based on the stable plastic strain energy density under tension conditions is proposed to account for the mean strain and stress effects in a low cycle fatigue regime. The fatigue life curve based on the proposed energy parameter

  9. Estimation of plain strain fracture toughness of AISI M2 steel from precracked round-bar specimens

    Microsoft Academic Search

    B. Ule; V. Leskovšek; B. Tuma

    2000-01-01

    The fracture toughness of AISI M2 high speed steel measured in round notched and fatigue precracked tensile specimens is discussed. It was established that the blunting of the fatigue crack tip caused by thermal treatment of specimens had no effect on the fracture toughness. The measured fracture toughness was affected by the eccentricity of the fatigued area and resulted in

  10. Investigating the Tool Life, Cutting Force Components, and Surface Roughness of AISI 302 Stainless Steel Material Under Oblique Machining

    Microsoft Academic Search

    A. M. El-Tamimi; T. M. El-Hossainy

    2008-01-01

    The aim of this work is to investigate the machinability of austenitic AISI 302 stainless steel under oblique cutting. This can be achieved by studying the cutting forces, analysis of tool life, and investigation of the surface roughness at different cutting conditions and nose radius. A factorial experiment and analysis of variance technique are used in which several factors are

  11. Pitting corrosion behavior on crack property in AISI 304L weld metals with varying Cr\\/Ni equivalent ratio

    Microsoft Academic Search

    D. J. Lee; K. H. Jung; J. H. Sung; Y. H. Kim; K. H. Lee; J. U. Park; Y. T. Shin; H. W. Lee

    2009-01-01

    The pitting corrosion behavior on welded joints of AISI 304L austenitic stainless steel was investigated with the flux-cored arc welding (FCAW) process. The dependence of pitting corrosion susceptibility on the microstructure and constituents was compared in weld metals by using three newly designed filler wires. Mechanical examination demonstrated that the tensile and yield strengths were increased with increasing equivalent weight

  12. AISI 304 L stainless steel decontamination by a corrosion process using cerium IV regenerated by ozone Part II: Process optimization

    Microsoft Academic Search

    J. P. Caire; S. Cullie; F. Dalard; J. M. Fulconis; H. Delagrange

    2003-01-01

    Empirical and analytical approaches were used to model a pre-industrial pilot reactor to optimise a new decontamination process for AISI 304 L stainless steel. The alloy corrosion rate was modelled as an analytical function of the total cerium content and the ozone flow injected in the reactor. The empirical model of the corrosion rate, obtained by gravimetry, takes into account

  13. Determination of neutron exposure of AISI 304 stainless steel from a BWR top guide using retrospective dosimetry

    Microsoft Academic Search

    L. R. Greenwood; F. A. Garner; B. M. Oliver; S. M. Bruemmer

    2007-01-01

    Retrospective dosimetry was used to determine the accumulated neutron exposure of AISI 304 stainless steel removed from the top guide of a boiling water reactor located at the Oyster Creek nuclear power station. The material was removed from areas adjacent to cracks that were observed after ?20years of operation. Using the plant operational history and a variety of measurements of

  14. Determination of neutron exposure of AISI 304 stainless steel from a BWR top guide using retrospective dosimetry

    Microsoft Academic Search

    L. R. Greenwood; F. A. Garner; B. M. Oliver; S. M. Bruemmer

    2007-01-01

    Retrospective dosimetry was used to determine the accumulated neutron exposure of AISI 304 stainless steel removed from the top guide of a boiling water reactor located at the Oyster Creek nuclear power station. The material was removed from areas adjacent to cracks that were observed after ˜20 years of operation. Using the plant operational history and a variety of measurements

  15. Effect of fatigue damage on the dynamic tensile behavior of 6061-T6 aluminum alloy and AISI 4140T steel

    Microsoft Academic Search

    U. Sánchez-Santana; C. Rubio-González; G. Mesmacque; A. Amrouche

    2009-01-01

    Usually material properties are determined from damage free materials, but it is not well known how these properties vary with respect to previous fatigue damage. In the present work the dynamic response of fatigue damaged 6061-T6 aluminum alloy and AISI 4140T steel specimens subjected to impact loading was investigated. Samples subjected to previous damage under high cycle fatigue and low

  16. Surface fatigue life and failure characteristics of EX-53, CBS 1000M, and AISI 9310 gear materials

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.

    1985-01-01

    Spur gear endurance tests and rolling-element surface fatigue tests are conducted to investigate EX-53 and CBS 1000M steels for use as advanced application gear materials, to determine their endurance characteristics, and to compare the results with the standard AISI 9310 gear material. The gear pitch diameter is 8.89 cm (3.50 in). Gear test conditions are an oil inlet temperature of 320 K (116 F), an oil outlet temperature of 350 K (170 F), a maximum Hertz stress of 1.71 GPa (248 ksi), and a speed of 10,000 rpm. Bench-type rolling-element fatigue tests are conducted at ambient temperature with a bar specimen speed of 12,500 rpm and a maximum Hertz stress of 4.83 GPa (700 ksi). The EX-53 test gears have a surface fatigue life of twice that of the AISI 9310 spur gears. The CBS 1000M test gears have a surface fatigue life of more than twice that of the AISI 9310 spur gears. However, the CBS 1000M gears experience a 30-percent tooth fracture failure which limits its use as a gear material. The rolling-contact fatigue lines of RC bar specimens of EX-53 and ASISI 9310 are approximately equal. However, the CBS 1000M RC specimens have a surface fatigue life of about 50 percent that of the AISI 9310.

  17. Influence of cutting parameters on drill bit temperature in dry drilling of AISI 1040 steel material using statistical analysis

    Microsoft Academic Search

    Eyup Ba?ci; Babur Ozcelik

    2007-01-01

    Purpose – An investigation of drilling temperature is essential in understanding the drilling mechanism of the material, thus improving the process efficiency. The aim of this study is to experimentally investigate influences of drilling conditions such as the drilling depth, feed rate and spindle speed on the twist drill bit temperature and thrust force in the dry drilling of AISI

  18. Cyclic deformation and near surface microstructures of shot peened or deep rolled austenitic stainless steel AISI 304

    Microsoft Academic Search

    I Altenberger; B Scholtes; U Martin; H Oettel

    1999-01-01

    Cylindrical specimens of the austenitic stainless steel AISI 304 were shot peened or deep rolled with different peening intensities, and rolling pressures, respectively. The resulting near surface properties were characterized by cross sectioning transmission electron microscopy (TEM), residual stress and phase analysis as well as interference line half-width and microhardness measurements. Cyclic deformation curves were obtained by hysteresis measurements under

  19. Void Swelling Of Aisi 321 Analog Stainless Steel Irradiated At Low Dpa Rates In The Bn-350 Reactor

    SciTech Connect

    Maksimkin, O. P.; Tsai, K. V.; Turubarova, L. G.; Doronina, T. A.; Garner, Francis A.

    2006-03-01

    In several recently published studies conducted on a Soviet analog of AISI 321 stainless steel irradiated in either fast reactors or light water reactors, it was shown that the void swelling phenomenon extended to temperatures as low as ~300ºC or less, when produced by neutron irradiation at dpa rates in the range 10-7 to 10-8 dpa/sec. Other studies yielded similar results for AISI 316 and the Russian analog of AISI 316. In the current study a blanket duct assembly from BN-350, constructed from the Soviet analog of AISI 321, also exhibits swelling at dpa rates on the order of 10-8 dpa/sec, with voids seen as low as 281oC and only 0.65 dpa. It appears that low-temperature swelling occurs at low dpa rates in 300 series stainless steels in general, and also occurs during irradiations conducted in either fast or mixed spectrum reactors. Therefore it is expected that a similar behavior will be observed in fusion devices as well.

  20. Taguchi-fuzzy multi output optimization (MOO) in high speed CNC turning of AISI P-20 tool steel

    Microsoft Academic Search

    Anil Gupta; Hari Singh; Aman Aggarwal

    2011-01-01

    This paper presents the application of Taguchi method with logical fuzzy reasoning for multiple output optimization of high speed CNC turning of AISI P-20 tool steel using TiN coated tungsten carbide coatings. The machining parameters (cutting speed, feed rate, depth of cut, nose radius and cutting environment) are optimized with considerations of the multiple performance measures (surface roughness, tool life,

  1. An evaluation of shot peening, residual stress and stress relaxation on the fatigue life of AISI 4340 steel

    Microsoft Academic Search

    M. A. S. Torres; H. J. C. Voorwald

    2002-01-01

    Shot peening is a method widely used to improve the fatigue strength of materials, through the creation of a compressive residual stress field (CRSF) in their surface layers. In the present research the gain in fatigue life of AISI 4340 steel, used in landing gear, is evaluated under four shot peening conditions. Rotating bending fatigue tests were conducted and the

  2. Influência de diferentes condições higrotérmicas na resistência à tração de compósitos de fibra de carbono\\/epóxi modificada

    Microsoft Academic Search

    José Antônio P. Cunha; Michelle L. Costa; Mirabel C. Rezende

    2006-01-01

    Resumo: Este trabalho foi direcionado para a análise dos efeitos higrotérmicos na resistência à tração de compósitos poliméricos termorrígidos. Foram investigados os efeitos da umidade e da temperatura sobre as resistências à tração longitudinal e à tração transversal de compósitos ((0\\/0)s) de fita de carbono unidirecional impregnada com resina epóxi 8552. Os ensaios de resistência à tração longitudinal, realizados à

  3. Hard surfacing of TiAl intermetallic compound by plasma carburization

    Microsoft Academic Search

    T. Noda; M. Okabe; S. Isobe

    1996-01-01

    For an intermetallic compound such as TiAl to be used in various components, the wear resistance is very important. Recently, plasma carburization was performed on the fully lamellar cast alloy with Ti-33.5Al-1Nb-0.5Cr-0.5Si (mass%). The induced surface layer, 3 ?m in thickness, was a carbide, Ti2AlC, with a hardness that was higher than HV836 for a bearing steel AISI52100. The pin-on-disk

  4. Surface nanocrystallization by surface mechanical attrition treatment and its effect on structure and properties of plasma nitrided AISI 321 stainless steel

    Microsoft Academic Search

    Yimin Lin; Jian Lu; Liping Wang; Tao Xu; Qunji Xue

    2006-01-01

    A plastic deformation surface layer with nanocrystalline grains was produced on AISI 321 austenitic stainless steel by means of surface mechanical attrition treatment (SMAT). Low-temperature nitriding of SMAT and un-SMAT AISI 321 stainless steel was carried out in pulsed-DC glow discharge. The effect of SMAT pretreatment on the microstructure and properties of the stainless steel were investigated using X-ray diffraction,

  5. Stress-Corrosion Cracking of AISI 4340 Steel in Aqueous Environments

    NASA Astrophysics Data System (ADS)

    Kalnaus, Sergiy; Zhang, Jixi; Jiang, Yanyao

    2011-02-01

    Stress corrosion cracking of the high-strength martensitic steel AISI 4340 (yield stress = 1503 MPa) in NaCl aqueous solutions of different concentrations was studied experimentally using compact tension specimens in free corroding conditions. The experiments were conducted under the controls of constant load, constant crack opening displacement (COD), constant loading rate, and constant COD rate. Despite the differences in controlling conditions, the experiments yielded similar results for the threshold stress intensity factor and the plateau velocity in the 3.5 wt pct NaCl solution. Dependence of the plateau velocity on the NaCl concentration was observed, whereas the values of the threshold stress intensity factors seem to be independent of the NaCl concentration in distilled water.

  6. Wear Resistance of AISI316L Steel Modified by Pre-FPP Treated DLC Coating

    NASA Astrophysics Data System (ADS)

    Nanbu, Hiroshi; Kikuchi, Shoichi; Kameyama, Yutaka; Komotori, Jun

    In order to improve the adhesion strength of the DLC coating, Fine Particle Peening (FPP) treatment was employed as pretreatment for DLC coatings. FPP treatment was performed using SiC shot particles, and then the AISI316L steel was DLC-coated. The FPP treatment increased the surface roughness of the specimen, and a Si-rich layer was formed on the surface because of the mechanical mixing of SiC shot particles into the steel substrate. Reciprocating sliding wear tests were conducted to measure the friction coefficient. While the non-pretreated (only DLC-coated) specimens showed a sudden increase in friction coefficient resulting from delamination of the DLC coating, the pre-FPP-treated specimens maintained a low friction coefficient during the wear tests. This indicates the strong adhesion of the DLC coating of the pre-FPP-treated specimen caused by the increase in surface roughness and the presence of Si on the surface.

  7. A New Continuous Cooling Transformation Diagram for AISI M4 High-Speed Tool Steel

    NASA Astrophysics Data System (ADS)

    Briki, Jalel; Ben Slima, Souad

    2008-12-01

    The increasing evolution of dilatometric techniques now allows for the identification of structural transformations with very low signal. The use of dilatometric techniques coupled with more common techniques, such as metallographic, hardness testing, and x-ray diffraction allows to plot a new CCT diagram for AISI M4 high-speed tool steel. This diagram is useful for a better selection of alternate solutions, hardening, and tempering heat treatments. More accurate determination of the various fields of transformation of austenite during its cooling was made. The precipitation of carbides highlighted at high temperature is at the origin of the martrensitic transformation into two stages (splitting phenomena). For slow cooling rates, it was possible to highlight the ferritic, pearlitic, and bainitic transformation.

  8. Microstructure evolution and texture development in a friction stir-processed AISI D2 tool steel

    NASA Astrophysics Data System (ADS)

    Yasavol, N.; Abdollah-zadeh, A.; Vieira, M. T.; Jafarian, H. R.

    2014-02-01

    Crystallographic texture developments during friction stir processing (FSP) of AISI D2 tool were studied with respect to grain sizes in different tool rotation rates. Comparison of the grain sizes in various rotation rates confirmed that grain refinement occurred progressively in higher rotation rates by severe plastic deformation. It was found that the predominant mechanism during FSP should be dynamic recovery (DRV) happened concurrently with continuous dynamic recrystallization (CDRX) caused by particle-stimulated nucleation (PSN). The developed shear texture relates to the ideal shear textures of D1 and D2 in bcc metals. The prevalence of highly dense arrangement of close-packed planes of bcc and the lowest Taylor factor showed the lowest compressive residual stress which is responsible for better mechanical properties compared with the grain-precipitate refinement.

  9. Microstructural characterization of the HAZ in AISI 444 ferritic stainless steel welds

    SciTech Connect

    Silva, Cleiton C. [Federal University of Ceara, Department of Materials and Metallurgical Engineering, Welding Engineering Laboratory, Campus do Pici, Building 715, CEP 60455-760, Fortaleza, Ceara (Brazil)], E-mail: cleitonufc@yahoo.com.br; Farias, Jesualdo P.; Miranda, Helio C.; Guimaraes, Rodrigo F. [Federal University of Ceara, Department of Materials and Metallurgical Engineering, Welding Engineering Laboratory, Campus do Pici, Building 715, CEP 60455-760, Fortaleza, Ceara (Brazil); Menezes, John W.A. [Federal University of Ceara, Department of Materials and Metallurgical Engineering, Materials Characterization Laboratory, Campus do Pici, Building 720, CEP 60455-760, Fortaleza, Ceara (Brazil); Neto, Moises A.M. [Federal University of Santa Catarina, Department of Mechanical Engineering, POLO-Laboratorios de Pesquisa em Refrigeracao e Termofisica, Florianopolis, Santa Catarina (Brazil)

    2008-05-15

    Ferritic stainless steel is used as a coating for equipment in the petroleum refining industry. Welding is the main manufacturing and maintenance process used. However, little information on the metallurgical alterations caused by welding of these steels is found in the literature, prompting this study. In this study the authors evaluated the HAZ microstructure of AISI 444 ferritic stainless steel welded plates, by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results indicated that a weld thermal cycle caused microphase precipitation in the HAZ of the ferritic stainless steel. Also needle-like Laves phase precipitation occurred in the HAZ, near the partially-melted zone. Other secondary phases such as chi and sigma were observed, as well as nitride, carbide and carbonitride precipitates.

  10. Comparisons of modified Vasco X-2 and AISI 9310 gear steels

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.; Zaretsky, E. V.

    1980-01-01

    Endurance tests were conducted with four groups of spur gears manufactured from three heats of consumable electrode vacuum melted (CVM) modified Vasco X-2. Endurance tests were also conducted with gears manufactured from CVM AISI 9310. Bench type rolling element fatigue tests were conducted with both materials. Hardness measurements were made to 811 K. There was no statistically significant life difference between the two materials. Life differences between the different heats of modified Vasco X-2 can be attributed to heat treat variation and resultant hardness. Carburization of gear flanks only can eliminate tooth fracture as a primary failure mode for modified Vasco X-2. However, a tooth surface fatigue spall can act as a nucleus of a tooth fracture failure for the modified Vasco X-2.

  11. Microstructural Evolution in Multiway Loading-Forming Process of AISI 5140 Steel Triple Valve Body

    NASA Astrophysics Data System (ADS)

    Sun, Zhichao; Yang, He

    2014-04-01

    The microstructural evolution and distribution rules, such as dynamic recrystallization (DRX) volume fraction, dynamically recrystallized grain size, and average grain size, in multiway loading-forming process of AISI 5140 steel triple valve body have been investigated using numerical simulation, combined with the analytic method by considering the influences of process parameters including loading speed of punch, initial temperature of billet, and friction. The results show that the DRX volume fraction increased, and its distribution became more uniform with the increases of punch loading speed and billet initial temperature, or the decrease of friction factor; the dynamically recrystallized grain size decreased, and its distribution was more uniform, with the increases of punch loading speed and friction factor, or the decrease of billet initial temperature; the average grain size decreased, and its distribution became more uniform with the increases of punch loading speed and billet initial temperature, or decrease of friction factor.

  12. Dynamic fracture toughness and Charpy impact properties of an AISI 403 martensitic stainless steel

    NASA Astrophysics Data System (ADS)

    Sreenivasan, P. R.; Ray, S. K.; Mannan, S. L.; Rodriguez, P.

    1996-04-01

    Dynamic fracture toughness and Charpy impact properties of a normalised and tempered AISI 403 martensitic stainless steel obtained from instrumented impact tests are presented. Procedures for estimating dynamic fracture toughness ( KId) from the load-time traces obtained in instrumented tests of unprecracked Charpy V-notch (CVN) specimens are considered. The estimated KId values show reasonable agreement with those obtained from instrumented drop-weight and precracked Charpy tests. Also, except in the upper transition and uppershelf regions, the ASME KIR curve is generally conservative (i.e. gives lower KId values) when compared to the above KId estimates. The conservatism of the ASME KIR at the upper transition and uppershelf temperatures needs verification/validation. The lowest KId values estimated at the lower shelf temperatures for the above steel, namely, 33-42 MPa?m are in good agreement with the reported values of 35-50 MPa?m for the same steel in the literature.

  13. Characteristics of Laser Beam and Friction Stir Welded AISI 409M Ferritic Stainless Steel Joints

    NASA Astrophysics Data System (ADS)

    Lakshminarayanan, A. K.; Balasubramanian, V.

    2012-04-01

    This article presents the comparative evaluation of microstructural features and mechanical properties of friction stir welded (solid-state) and laser beam welded (high energy density fusion welding) AISI 409M grade ferritic stainless steel joints. Optical microscopy, microhardness testing, transverse tensile, and impact tests were performed. The coarse ferrite grains in the base material were changed to fine grains consisting duplex structure of ferrite and martensite due to the rapid cooling rate and high strain induced by severe plastic deformation caused by frictional stirring. On the other hand, columnar dendritic grain structure was observed in fusion zone of laser beam welded joints. Tensile testing indicates overmatching of the weld metal relative to the base metal irrespective of the welding processes used. The LBW joint exhibited superior impact toughness compared to the FSW joint.

  14. Structural, mechanical and tribological properties of duplex-treated AISI 5140 steel

    SciTech Connect

    Alsaran, Akguen [Department of Mechanical Engineering, Ataturk University, 25240, Erzurum (Turkey)]. E-mail: aalsaran@atauni.edu.tr; Celik, Ayhan [Department of Mechanical Engineering, Ataturk University, 25240, Erzurum (Turkey); Karakan, Mehmet [Department of Mechanical Engineering, Ataturk University, 25240, Erzurum (Turkey)

    2005-01-15

    The structure, hardness, adhesion, surface roughness and tribological properties of duplex-surface-treated (TiN/plasma nitrided), directly TiN-coated and ion-nitrided AISI 5140 steel were investigated using X-ray diffraction, SEM, optical microscopy, a microhardness tester, a scratch tester and a pin-on-disc tribotester. After the plasma nitriding process, the transition treatments were realized to evaluate the effect of the compound layer. It was found that the relative intensity line of TiN (200) and surface roughness increased, but the coating hardness and critical load (Lc) decreased with an increasing amount of {epsilon}-Fe{sub 2-3}N iron nitride in the compound layer. The better tribological properties were obtained with coatings applied on substrates, which included a large amount of {gamma}'-Fe{sub 4}N iron nitride after plasma nitriding.

  15. Effect of five lubricants on life of AISI 9310 spur gears

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.; Zaretsky, E. V.

    1985-01-01

    Spur-gear surface fatigue tests were conducted with five lubricants using a single lot of consumable-electrode vacuum melted (CVM) AISI 9310 spur gears. The lot of gears was divided into five groups, each of which was tested with a different lubricant. The test lubricants are classified as either a synthetic hydrocarbon, mineral oil, or ester-based lubricant. All five lubricants have imilar viscosity and pressure-viscosity coefficients. A pentaerythritol base stock without sufficient antiwear additives produced a surface fatigue life pproximately 22 percent that of the same base stock with chlorine and phosphorus type additives. The presence of sulfur type antiwear additives in the lubricant did not appear to affect the surface fatigue life of the gears tested. No statistical difference in the 10-percent surface fatigue life was produced with four of the five lubricants.

  16. X-ray diffraction study on microstructures of shot/laser-peened AISI316 stainless steel

    NASA Astrophysics Data System (ADS)

    Kumagai, Masayoshi; Akita, Koichi; Itano, Yuta; Imafuku, Muneyuki; Ohya, Shin-ichi

    2013-11-01

    Microstructural features of AISI316 stainless steels processed by shot peening (SP) and laser peening (LP) were studied using X-ray diffraction line profile analyses. Both specimens exhibited similar compressive residual stress profiles. Although the number of dislocations was increased and the crystallites were refined with both processes, the dislocation density in the SP specimen was significantly greater than that in the LP specimen. The crystallite size in the SP specimen was one-third that in the LP specimen. The SP process induced martensite transformation. The variations in the microstructural features differed between samples subjected to the two processes. The SP process resulted in a greater variation in the microstructural features in a sample in which residual stresses similar to that induced by the LP process were induced. Thus, the variations in the microstructural features differed depending on the deformation process.

  17. Dynamic Recrystallization Behavior of AISI 420 Stainless Steel under Hot Compression

    NASA Astrophysics Data System (ADS)

    Cao, Y.; Di, H. S.; Misra, R. D. K.

    2015-04-01

    Hot deformation behavior of AISI 420 stainless steel was studied under hot compression tests in the temperature range of 950 to 1150 °C and strain rates of 0.01 s-1 and 0.1 s-1. The study indicates that higher deformation temperature makes the peak stress pronounced and the occurrence of DRX is detected by inflection point in the work hardening rate vs. flow stress (?-?) plot, irrespective of the shape of flow stress curve. Local misorientation (ML) was calculated to reveal the local change in the crystal orientation. The distribution of ML suggested that the process of DRX reduces the local misorientation during hot deformation. The critical stress for initiation of DRX under different deformation conditions was determined by setting the derivative of the third order polynomial to ?-? plot. A good linear relationship between critical stress (?c) & critical strain (?c) and Zener-Hollomon parameter was established.

  18. Acoustic emission studies on welded and thermally treated AISI 304 stainless steel during tensile deformation

    SciTech Connect

    Mukherjee, P.; Barat, P. [Variable Energy Cyclotron Centre, Calcutta (India)] [Variable Energy Cyclotron Centre, Calcutta (India); Jayakumar, T.; Kalyanasundaram, P.; Rajagopalan, C.; Raj, B. [IGCAR, Kalpakkam (India)] [IGCAR, Kalpakkam (India)

    1997-10-15

    The present investigations are planned to study the influence of prior martensites formed due to cold treatment as 77K in AISI 304 SS welded specimens, on strain-induced martensites occurred during tensile deformation using AE technique. AE parameters like count rate and root mean square (r.m.s.) voltage have been used to characterize AE activities generated during tensile deformation process in as-welded and welded-treated samples. Frequency spectrum analysis of AE signals captured from the samples has been done to understand the dynamic behavior of the martensite phase formation. Tensile properties of these samples have also been reported. Volume fraction of the magnetic phase (martensite and delta ferrite) formed in these samples are measured before and after straining. X-ray diffraction (XRD) technique has been used to support the presence of delta ferrite (formed during welding) and martensite in the weld region.

  19. Roughness Reduction in AISI 316L Stainless Steel after Surface Mechanical Attrition Treatment (SMAT)

    NASA Astrophysics Data System (ADS)

    Arifvianto, B.; Suyitno, Suyitno; Mahardika, M.

    2011-12-01

    Surface mechanical attrition treatment (SMAT) enhances the strength of metals by generating nanocrystallites at the surface layer. During the treatment, multiple impacts of milling balls are subjected to the treated surface. Consequently, the structure and roughness of the treated surface are also modified. In this paper, the effect of SMAT on the surface structure and roughness of an initially rough AISI 316L stainless steel is investigated. The SMAT was conducted for 0-20 minutes. The surface morphology, roughness, and volume loss due to the SMAT were studied. The result shows a decreasing roughness by the SMAT. An apparently deformed structure is also observed after 15 minutes of the treatment. However, no significant change in the volume loss is reported due to this treatment. Deformation by the multiple impacts is proposed to be the mechanism of the roughness reduction instead of microcutting by the milling balls during the SMAT.

  20. Corrosion behavior of plasma sprayed hydroxyapatite and hydroxyapatite-silicon oxide coatings on AISI 304 for biomedical application

    NASA Astrophysics Data System (ADS)

    Singh, Gurpreet; Singh, Hazoor; Sidhu, Buta Singh

    2013-11-01

    The objective of this study is to evaluate corrosion resistance of plasma sprayed hydroxyapatite (HA) and HAsbnd silicon oxide (SiO2) coated AISI 304 substrates. In HAsbnd SiO2 coatings, 10 wt% SiO2 and 20 wt% SiO2 was mixed with HA. The feedstock and coatings were characterized by X-ray diffraction and scanning electron microscopy/energy dispersive X-ray spectroscopy. The corrosion resistance was determined for the uncoated and coated samples. The corrosion resistance of the AISI 304 was found more after the deposition of the HAsbnd SiO2 coatings rather than HA coating and uncoated. All the coatings were crack free after 24 h dipping in Ringer's solution for electrochemical corrosion testing.

  1. Control of the wetting properties of an AISI 316L stainless steel surface by femtosecond laser-induced surface modification

    NASA Astrophysics Data System (ADS)

    Kam, D. H.; Bhattacharya, S.; Mazumder, J.

    2012-10-01

    A simple and effective method without vacuum to control the wetting properties of AISI 316L stainless steel using femtosecond laser pulses at high repetition rate has been developed. Both hydrophilic and hydrophobic surfaces were formed by creating micro-conical structures on the surface with femtosecond laser irradiation in air. The scan speed was found to be an effective parameter in controlling micro-cone morphology, size and number densities and contact angles during surface wettability experiments. It was found during surface wettability experiments that the contact angle of water varied from 0° (superhydrophilic) to 113° on laser micro-cone textured surfaces depending on processing conditions. Additionally, a superhydrophobic AISI 316L stainless steel surface was created (contact angle ˜150°) with a functionalized silane coating on already hydrophobic surface geometry.

  2. Evaluation of stress corrosion cracking phenomenon in an AISI type 316LN stainless steel using acoustic emission technique

    Microsoft Academic Search

    H. Shaikh; R. Amirthalingam; T. Anita; N. Sivaibharasi; T. Jaykumar; P. Manohar; H. S. Khatak

    2007-01-01

    This paper deals with the analysis of the acoustic emission (AE) signals to determine the micro-process during stress corrosion cracking (SCC) of AISI type 316LN stainless steel that cause the AE, and thus the mechanism of the SCC process. AE with amplitudes ranging from 27.6 to 46.5dB with different counts, energy and rise times occurred during SCC of type 316LN

  3. Surface roughness and wettability of AISI 316L induced by surface mechanical attrition treatment with different milling ball diameter

    Microsoft Academic Search

    B. Arifvianto; Suyitno

    2009-01-01

    Surface roughness and wettability determines the rate and quality of protein adsorption and cells adhesion on biomaterial. For this case, a rough- and hydrophilic-surface are preferable rather than a smooth- and hydrophobic-one. This paper discusses the effect of milling ball diameter used in surface mechanical attrition treatment (SMAT) on the roughness and wettability of AISI 316L. All samples were treated

  4. Effect of Cr\\/Ni equivalent ratio on ductility-dip cracking in AISI 316L weld metals

    Microsoft Academic Search

    A. Y. Jang; D. J. Lee; S. H. Lee; J. H. Shim; S. W. Kang; H. W. Lee

    2011-01-01

    The ductility-dip cracking (DDC) susceptibility of AISI 316L stainless steel weld metals was examined. Modified flux cored arc welding (FCAW) filler wires were fabricated with various chromium and nickel contents. The solidification mode and delta-ferrite content were determined from the chromium and nickel equivalent ratios (Creq\\/Nieq). Ductility-dip cracking occurred through a grain boundary sliding mechanism in the reheated region of

  5. Comparison of neutron irradiation and nickel ion bombardment in the production of swelling in AISI 316 stainless steel

    Microsoft Academic Search

    T. Lauritzen; W. K. Appleby; W. L. Bell

    1979-01-01

    The high fluence swelling behavior of AISI 316 steel was studied by nickel--ion bombardment of unirradiated and low-fluence reactor preconditioned material and compared with that of high fluence material irradiated in EBR-II. A comparison of swelling rates produced by the two bombarding species shows that the swelling response per dpa produced by nickel ions and neutrons is equivalent at comparable

  6. Microstructure and Mechanical Properties of Laser Clad and Post-cladding Tempered AISI H13 Tool Steel

    NASA Astrophysics Data System (ADS)

    Telasang, Gururaj; Dutta Majumdar, Jyotsna; Wasekar, Nitin; Padmanabham, G.; Manna, Indranil

    2015-05-01

    This study reports a detailed investigation of the microstructure and mechanical properties (wear resistance and tensile strength) of hardened and tempered AISI H13 tool steel substrate following laser cladding with AISI H13 tool steel powder in as-clad and after post-cladding conventional bulk isothermal tempering [at 823 K (550 °C) for 2 hours] heat treatment. Laser cladding was carried out on AISI H13 tool steel substrate using a 6 kW continuous wave diode laser coupled with fiber delivering an energy density of 133 J/mm2 and equipped with a co-axial powder feeding nozzle capable of feeding powder at the rate of 13.3 × 10-3 g/mm2. Laser clad zone comprises martensite, retained austenite, and carbides, and measures an average hardness of 600 to 650 VHN. Subsequent isothermal tempering converted the microstructure into one with tempered martensite and uniform dispersion of carbides with a hardness of 550 to 650 VHN. Interestingly, laser cladding introduced residual compressive stress of 670 ± 15 MPa, which reduces to 580 ± 20 MPa following isothermal tempering. Micro-tensile testing with specimens machined from the clad zone across or transverse to cladding direction showed high strength but failure in brittle mode. On the other hand, similar testing with samples sectioned from the clad zone parallel or longitudinal to the direction of laser cladding prior to and after post-cladding tempering recorded lower strength but ductile failure with 4.7 and 8 pct elongation, respectively. Wear resistance of the laser surface clad and post-cladding tempered samples (evaluated by fretting wear testing) registered superior performance as compared to that of conventional hardened and tempered AISI H13 tool steel.

  7. Comparison of Microstructure and Surface Properties of AISI 1045 Steel After Quenching in Hot Alkaline Salt Bath and Oil

    Microsoft Academic Search

    S. Raygan; J. Rassizadehghani; M. Askari

    2009-01-01

    The effect of quenching in molten alkaline salt bath medium on the microstructure and surface properties of AISI 1045 steel\\u000a in comparison with oil was investigated. Salt bath medium used in this research contained 40% NaOH and 60% KOH with addition\\u000a of 5 wt.% water at 205 °C. Hardening of 1045 steel in this medium resulted in an almost uniform microstructure, which

  8. An investigation on the microstructure and mechanical properties of direct-quenched and tempered AISI 4140 steel

    Microsoft Academic Search

    A. H. Meysami; R. Ghasemzadeh; S. H. Seyedein; M. R. Aboutalebi

    2010-01-01

    Direct quenching (DQ) process is an appropriate method in steels heat treatment field. This method enhances production rate, reduces energy consumption and decreases environment contamination. In this study hot-rolled AISI 4140 steel billets with different diameters (75,80,85,100,105 and 115mm) and 20m length were quenched directly in a water tank. Also some samples with similar size and composition were provided by

  9. The effect of sigma phases formation depending on Cr\\/Ni equivalent ratio in AISI 316L weldments

    Microsoft Academic Search

    Y. H. Kim; D. J. Lee; J. C. Byun; K. H. Jung; J. I. Kim; H. J. Lee; Y. T. Shin; S. H. Kim; H. W. Lee

    2011-01-01

    The crack properties and toughness characteristics in AISI 316L weld metals were investigated in different chemical composition ranges of Cr and Ni contents. Three new filler wires were designed for the flux-cored arc welding (FCAW) process, and the Cr\\/Ni equivalent ratio and solidification mode of each weld metal was controlled. The microstructure revealed ductility-dip cracking (DDC) generated in the specimens

  10. Fatigue life prediction of GTA welded AISI 304L cruciform joints with lack of penetration using local-stress approach

    Microsoft Academic Search

    P Johan Singh; B Guha; D. R. G Achar

    2003-01-01

    The influence of welding procedure on fatigue properties of gas tungsten arc welded (GTAW) AISI 304L load carrying cruciform joints, containing lack of penetration (LOP) has been studied using a crack initiation–propagation (I-P) method. The crack process normally comprises two major phases: (1) the crack initiation life (NI): and (2) the crack propagation life (Np). The local stress-life approach is

  11. Fatigue life prediction of gas tungsten arc welded AISI 304L cruciform joints with different LOP sizes

    Microsoft Academic Search

    P. Johan Singh; D. R. G Achar; B Guha; Hans Nordberg

    2003-01-01

    Fatigue life evaluations have been carried out on gas tungsten arc welded (GTAW) load-carrying cruciform joints of AISI 304L stainless steel with lack of penetration (LOP) using conventional S-N and crack initiation-propagation (I-P) methods. The crack process normally comprises two major phases: (1) the crack initiation life (Ni): and (2) the crack propagation life (Np). The local stress-life approach is

  12. Molecular dynamics simulations of liquids and glasses in the system NaAISi04Si02: Methodology and melt structures

    Microsoft Academic Search

    DANIEL J. STEIN; FRANK J. SPERA

    This is the first of a two-part molecular dynamics (MD) study that examines the effects of temperature, pressure, and composition on the structure and properties of ten compo- sitions in the system NaAISiO.-Si02. Results were obtained for collections of at least 1300 atoms at temperatures between 2500 and 4500 K, pressures of 2-5 GPa, and simulation durations on the order

  13. The effect of Zr-implantation on the thermal oxidation and aqueous corrosion of AISI 321 stainless steel

    Microsoft Academic Search

    F. Noli; P. Misaelides; G. Giorginis; H. Baumann; A. Hatzidimitriou

    1995-01-01

    The effect of Zr-implantation (energy: 40 keV, dose: 1 × 1017 ions\\/cm2) on the oxidation of AISI 321 austenitic stainless steel (Fe\\/Cr18\\/Ni8\\/Ti) has been studied at temperatures of 450, 550 and 650°C, in air. The duration of the oxidation was varied between one and six days. The oxygen distribution on the oxidized samples has been determined using the 16O(d, p)17O

  14. The effect of cold rolling regime on microstructure and mechanical properties of AISI 304L stainless steel

    Microsoft Academic Search

    Ali Hedayati; Abbas Najafizadeh; Ahmad Kermanpur; Farnoosh Forouzan

    2010-01-01

    In this paper, the effect of different thickness reductions by cold rolling on the microstructure and mechanical properties of AISI 304L austenitic stainless steel were investigated. The hot rolled steel strips were subjected to cold rolling at 0°C from 10 to 90% thickness reduction. Microstructures, strain-induced martensitic transformation and mechanical properties of the cold-rolled specimens were characterized by X-ray diffraction,

  15. Empirical models and optimal cutting parameters for cutting forces and surface roughness in hard milling of AISI H13 steel

    Microsoft Academic Search

    Tongchao Ding; Song Zhang; Yuanwei Wang; Xiaoli Zhu

    2010-01-01

    In the present research, an attempt has been made to experimentally investigate the effects of cutting parameters on cutting\\u000a forces and surface roughness in hard milling of AISI H13 steel with coated carbide tools. Based on Taguchi’s method, four-factor\\u000a (cutting speed, feed, radial depth of cut, and axial depth of cut) four-level orthogonal experiments were employed. Three\\u000a cutting force components

  16. Corrosion resistance properties of glow-discharge nitrided AISI 316L austenitic stainless steel in NaCl solutions

    Microsoft Academic Search

    A. Fossati; F. Borgioli; E. Galvanetto; T. Bacci

    2006-01-01

    Glow-discharge nitriding treatments can modify the hardness and the corrosion resistance properties of austenitic stainless steels. The modified layer characteristics mainly depend on the treatment temperature. In the present paper the results relative to glow-discharge nitriding treatments carried out on AISI 316L austenitic stainless steel samples at temperatures ranging from 673 to 773K are reported. Treated and untreated samples were

  17. Synthesis of nanostructured zirconia electrodeposited films on AISI 316L stainless steel and its behaviour in corrosion resistance assessment

    Microsoft Academic Search

    I. Espitia-Cabrera; H. Orozco-Hernández; R. Torres-Sánchez; M. E. Contreras-Garc??a; P. Bartolo-Pérez; L. Mart??nez

    2004-01-01

    This work deals with the study of AISI 316L stainless steel samples coated with nanostructured zirconia thin films, using electrodeposition methods. The chemical composition and compounds formed were determined by X-ray photoelectron spectroscopy (XPS). The morphology of zirconia films was analysed by scanning electron microscopy (SEM) and atomic force microscopy (AFM).Corrosion resistance of the coated steel was tested in a

  18. Behavior of the pulsed ion nitrided AISI 4140 steel\\/CVD TiN coatings as tribological pair

    Microsoft Academic Search

    M. H. Staia; A. Fragiel; S. P. Brühl; J. N. Feugeas; B. J. Gomez

    2000-01-01

    The aim of the present investigation was to determine the effect of pulsed plasma nitriding process on the wear behavior of an AISI 4140 steel. Wear tests were performed using a ball-on-disc configuration with a linear sliding speed of 0.1 m s?1, 5 N load and 700 m sliding distance. The tests were carried out at room temperature in air,

  19. INFLUÊNCIA DOS TRATAMENTOS TÉRMICOS DE ESTABILIZAÇÃO E SOLUBILIZAÇÃO NA RESISTÊNCIA À CORROSÃO INTERGRANULAR DO AÇO INOXIDÁVEL AISI 347 FUNDIDO

    Microsoft Academic Search

    Sérgio Souto Maior Tavares; Vanessa Moura de Souza; José Adaílson de Souza; Aline Yae Kina

    2008-01-01

    Nb-stabilized austenitic stainless steels (e. g., AISI 347) can be selected to high temperature services (500 o C-800 o C), due to the high creep resistance of austenitic structure. Niobium is added to form NbC fine carbides, which has two main functions: prevent intergranular corrosion and increase creep resistance. In the present work it is investigated the importance of the

  20. Surface diffusion modification AISI 304SS stainless steel as bipolar plate material for proton exchange membrane fuel cell

    Microsoft Academic Search

    Jianli Wang; Juncai Sun; Song Li; Zhongsheng Wen; Shijun Ji

    Fe-based stainless steels are the promising candidate materials for bipolar plate of proton exchange membrane fuel cell (PEMFC) due to low cost, ease stamping manufacture, good heat and electric conductivity. A surface modification technology of electroplating Cr followed by heat-diffusion in vacuum furnace is applied for AISI 304SS stainless steel in this paper to improve the Interfacial Contact Resistance (ICR)

  1. The evolution of primary and secondary niobium carbonitrides in AISI 347 stainless steel during manufacturing and long-term ageing

    Microsoft Academic Search

    J. Erneman; M. Schwind; H.-O. Andrén; J.-O. Nilsson; A. Wilson; J. Ågren

    2006-01-01

    Nb(C,N) precipitates were studied in a niobium-stabilised stainless steel (AISI 347) statically aged at 700°C. Scanning electron microscopy and energy filtered transmission electron microscopy were used to determine the volume fraction and precipitate size of primary and secondary Nb(C,N) after ageing times between 0 and 70,000h. The experimental data were correlated with simulations of Nb(C,N) formation based on the assumption

  2. Plasma nitriding process by direct current glow discharge at low temperature increasing the thermal diffusivity of AISI 304 stainless steel

    SciTech Connect

    Prandel, L. V.; Somer, A.; Assmann, A.; Camelotti, F.; Costa, G.; Bonardi, C.; Jurelo, A. R.; Rodrigues, J. B.; Cruz, G. K. [Universidade Estadual de Ponta Grossa, Grupo de Espectroscopia Optica e Fotoacustica de Materiais, Departamento de Fisica, Av. Carlos Cavalcanti, 4748, CEP 84030-900, Ponta Grossa, PR (Brazil)

    2013-02-14

    This work reports for the first time on the use of the open photoacoustic cell technique operating at very low frequencies and at room temperature to experimentally determine the thermal diffusivity parameter of commercial AISI304 stainless steel and AISI304 stainless steel nitrided samples. Complementary measurements of X-ray diffraction and scanning electron microscopy were also performed. The results show that in standard AISI 304 stainless steel samples the thermal diffusivity is (4.0 {+-} 0.3) Multiplication-Sign 10{sup -6} m{sup 2}/s. After the nitriding process, the thermal diffusivity increases to the value (7.1 {+-} 0.5) Multiplication-Sign 10{sup -6} m{sup 2}/s. The results are being associated to the diffusion process of nitrogen into the surface of the sample. Carrying out subsequent thermal treatment at 500 Degree-Sign C, the thermal diffusivity increases up to (12.0 {+-} 2) Multiplication-Sign 10{sup -6} m{sup 2}/s. Now the observed growing in the thermal diffusivity must be related to the change in the phases contained in the nitrided layer.

  3. The effect of equal channel angular extrusion on the microstructure and mechanical properties of AISI 1552, AISI 4340, and A2 tool steels 

    E-print Network

    Shadat, Mohammed Anower

    1998-01-01

    al. " observed good ductility in ausformed steel and did not find any evidence of brittle fracture. Hosoi er al. " reported similar results. On a 410 stainless steel which was subjected to 29% deformation at metastable austenite and a subsequent 16...

  4. Biocompatibility evaluation of surface-treated AISI 316L austenitic stainless steel in human cell cultures.

    PubMed

    Martinesi, M; Bruni, S; Stio, M; Treves, C; Bacci, T; Borgioli, F

    2007-01-01

    The effects of AISI 316L austenitic stainless steel, tested in untreated state or subjected to glow-discharge nitriding (at 10 or 20 hPa) and nitriding + post-oxidizing treatments, on human umbilical vein endothelial cells (HUVEC) and on peripheral blood mononuclear cells (PBMC) were evaluated. All the treated samples showed a better corrosion resistance in PBS and higher surface hardness in comparison with the untreated alloy. In HUVEC put in contact for 72 h with the sample types, proliferation and apoptosis decreased and increased, respectively, in the presence of the nitrided + post-oxidized samples, while only slight differences in cytokine (TNF-alpha, IL-6, and TGF-beta1) release were registered. Intercellular adhesion molecule-1 (ICAM-1) increased in HUVEC incubated with all the treated samples, while vascular cell adhesion molecule-1 (VCAM-1) and E-selectin increased in the presence of all the sample types. PBMC incubated for 48 h with the samples showed a decrease in proliferation and an increase in apoptosis in the presence of the untreated samples and the nitrided + post-oxidized ones. All the sample types induced a remarkable increase in TNF-alpha and IL-6 release in PBMC culture medium, while only the untreated sample and the nitrided at 10 hPa induced an increase in ICAM-1 expression. In HUVEC cocultured with PBMC, previously put in contact with the treated AISI 316L samples, increased levels of ICAM-1 were detected. In HUVEC coincubated with the culture medium of PBMC, previously put in contact with the samples under study, a noteworthy increase in ICAM-1, VCAM-1, and E-selectin levels was always registered, with the exception of VCAM-1, which was not affected by the untreated sample. In conclusion, even if the treated samples do not show a marked increase in biocompatibility in comparison with the untreated alloy, their higher corrosion resistance may suggest a better performance as the contact with physiological environment becomes longer. PMID:16983653

  5. An Electrochemical Processing Strategy for Improving Tribological Performance of Aisi 316 Stainless Steel Under Grease Lubrication

    NASA Astrophysics Data System (ADS)

    Zou, Jiaojuan; Li, Maolin; Lin, Naiming; Zhang, Xiangyu; Qin, Lin; Tang, Bin

    2014-12-01

    In order to improve the tribological performance of AISI 316 stainless steel (316 SS) under grease lubrication, electrochemical processing was conducted on it to obtain a rough (surface texturing-like) surface by making use of the high sensitivity of austenitic stainless steel to pitting corrosion in Cl--rich environment. Numerous corrosion pits or micro-ditches acted as micro-reservoirs on the obtained surface. While the grease could offer consistent lubrication, and then improve the tribological performance of 316 SS. Tribological behaviors of raw 316 SS and the treated sample were measured using a reciprocating type tribometer sliding against GCr15 steel counterpart under dry and grease lubrication conditions. The results showed that the mass losses of the two samples were in the same order of magnitude, and the raw sample exhibited lower friction coefficient in dry sliding. When the tests were conducted under grease lubrication condition, the friction coefficients and mass losses of the treated sample were far lower than those of the raw 316 SS. The tribological performance of 316 SS under grease lubrication was drastically improved after electrochemical processing.

  6. Effect of Hydrogen and Magnetic Field on the Mechanical Behavior of High Strength AISI 4340 Steel

    NASA Astrophysics Data System (ADS)

    Ramanathan, Meenakshisundaram; Saha, Biswadeep; Ren, Chai; Guruswamy, Sivaraman; McCarter, Michael

    2013-04-01

    Presence of hydrogen in materials is known to affect their mechanical properties due to hydrogen embrittlement problem. Steels used in various applications are prone to be exposed to aqueous electrochemical environments, which may introduce hydrogen into the alloy. These alloys are also prone to be simultaneously exposed to magnetic field, which may affect the hydrogen embrittlement susceptibility of these alloys. Therefore, it is important to examine the effect of hydrogen and magnetic field on the mechanical behavior of iron-based alloys. In this work, the effect of hydrogen and magnetic field on the fracture behavior of high strength AISI 4340 steel was examined. Three-point bend test was used to study the fracture behavior. In all the cases, the samples tested with hydrogen charging show a drastic reduction in ductility and fracture stress values. The effect of magnetic field was seen to be negligible. The hydrogen embrittlement was characterized by a change in the fracture surface from a ductile-type fracture to a brittle cleavage-type fracture. Acoustic emission signals collected during the test corresponds to the fracture behavior.

  7. Effect of Fine Particle Peening Treatment prior to Nitriding on Fatigue Properties of AISI 4135 Steel

    NASA Astrophysics Data System (ADS)

    Kikuchi, Shoichi; Komotori, Jun

    In this study, a new hybrid surface modification process, fine particle peening (FPP) treatment prior to nitriding, was proposed. In order to clarify the effects of FPP treatment prior to nitriding on the fatigue strength of notched AISI 4135 steel with a stress concentration factor Kt of 2.36, fatigue tests were conducted at room temperature using a rotational bending fatigue testing machine. Hardness and residual stress distributions were measured in order to characterize the surface-modified layer. As a result, the surface hardness of the FPP-treated specimen before nitriding was higher than that of the nitrided specimen. The surface microstructures of treated specimens were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The crystal structure of the compound layer of the FPP-treated specimen before nitriding was different to that of the nitrided specimen. The compound layer of the FPP-treated specimen was dense. This suggests that FPP treatment prior to nitriding is very effective for improvement of the fatigue strength of steel.

  8. Effect of shot peening on surface fatigue life of carburized and hardened AISI 9310 spur gears

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.; Zaretsky, E. V.

    1982-01-01

    Surface fatigue tests were conducted on two groups of AISI 9310 spur gears. Both groups were manufactured with standard ground tooth surfaces, with the second group subjected to an additional shot peening process on the gear tooth flanks. The gear pitch diameter was 8.89 cm (3.5 in.). Test conditions were a gear temperature of 350 K (170 F), a maximum Hertz stress of 1.71 billion N/sq m (248,000 psi), and a speed of 10,000 rpm. The shot peened gears exhibited pitting fatigue lives 1.6 times the life of standard gears without shot peening. Residual stress measurements and analysis indicate that the longer fatigue life is the result of the higher compressive stress produced by the shot peening. The life for the shot peened gear was calculated to be 1.5 times that for the plain gear by using the measured residual stress difference for the standard and shot peened gears. The measured residual stress for the shot peened gears was much higher than that for the standard gears.

  9. An experimental investigation of pulsed laser-assisted machining of AISI 52100 steel

    NASA Astrophysics Data System (ADS)

    Panjehpour, Afshin; Soleymani Yazdi, Mohammad R.; Shoja-Razavi, Reza

    2014-11-01

    Grinding and hard turning are widely used for machining of hardened bearing steel parts. Laser-assisted machining (LAM) has emerged as an efficient alternative to grinding and hard turning for hardened steel parts. In most cases, continuous-wave lasers were used as a heat source to cause localized heating prior to material removal by a cutting tool. In this study, an experimental investigation of pulsed laser-assisted machining of AISI 52100 bearing steel was conducted. The effects of process parameters (i.e., laser mean power, pulse frequency, pulse energy, cutting speed and feed rate) on state variables (i.e., material removal temperature, specific cutting energy, surface roughness, microstructure, tool wear and chip formation) were investigated. At laser mean power of 425 W with frequency of 120 Hz and cutting speed of 70 m/min, the benefit of LAM was shown by 25% decrease in specific cutting energy and 18% improvement in surface roughness, as compared to those of the conventional machining. It was shown that at constant laser power, the increase of laser pulse energy causes the rapid increase in tool wear rate. Pulsed laser allowed efficient control of surface temperature and heat penetration in material removal region. Examination of the machined subsurface microstructure and microhardness profiles showed no change under LAM and conventional machining. Continuous chips with more uniform plastic deformation were produced in LAM.

  10. Investigation of Low-Cycle Bending Fatigue of AISI 9310 Steel Spur Gears

    NASA Technical Reports Server (NTRS)

    Handschuh, Robert F.; Krantz, Timothy L.; Lerch, Bradley A.; Burke, Christopher S.

    2007-01-01

    An investigation of the low-cycle bending fatigue of spur gears made from AISI 9310 gear steel was completed. Tests were conducted using the single-tooth bending method to achieve crack initiation and propagation. Tests were conducted on spur gears in a fatigue test machine using a dedicated gear test fixture. Test loads were applied at the highest point of single tooth contact. Gear bending stresses for a given testing load were calculated using a linear-elastic finite element model. Test data were accumulated from 1/4 cycle to several thousand cycles depending on the test stress level. The relationship of stress and cycles for crack initiation was found to be semilogarithmic. The relationship of stress and cycles for crack propagation was found to be linear. For the range of loads investigated, the crack propagation phase is related to the level of load being applied. Very high loads have comparable crack initiation and propagation times whereas lower loads can have a much smaller number of cycles for crack propagation cycles as compared to crack initiation.

  11. Inductive plasma source for the ion treatment of AISI-304 SS

    NASA Astrophysics Data System (ADS)

    de la Piedad-Beneitez, A.; Valencia-Alvarado, R.; López-Callejas, R.; Barocio, S. R.; Mercado-Cabrera, A.; Peña-Eguiluz, R.; Muñoz-Castro, A. E.; Granda-Gutiérrez, E. E.; Rodríguez-Méndez, B. G.; Pérez-Martínez, J. A.; Flores-Fuentes, A. A.

    2008-10-01

    The design and construction of a simple inductive plasma source is described as constituted by an evacuated Pyrex glass cylinder reactor with 190 mm inner diameter and 500 mm length. This discharge vessel is coaxially surrounded by a cylindrically wound antenna, 240 mm in diameter, made of 3.2 mm wide copper wire. The antenna is supplied by a 13.56 MHz RF generator whose resulting electric field is able to create the plasma. When nitrogen is admitted to the vessel, the plasma generation takes place within the 0.1-50 Pa work pressure and 300-600 W RF power. The plasma density has been established by double Langmuir probes between 3.2 × 1015 and 2.4 × 1018 m-3. This inductive plasma set up is meant to modify the surface of AISI-304 stainless steel by means of ion deposition, thanks to the sample bias provided by an external - 400 V dc supply, in order to improve the steel hardness without compromising its corrosion resistance. Once accelerated by the negative bias, the plasma ions impinge on the sample nitriding it by diffusion. The treated samples were characterized by x-ray diffraction (XRD) indicating the formation of the expanded gamma phase, by scanning electron microscopy (SEM) providing the atomic percentages of nitrogen, and by microhardness (HV) measurement.

  12. Thermodynamic modeling and kinetics simulation of precipitate phases in AISI 316 stainless steels

    NASA Astrophysics Data System (ADS)

    Yang, Y.; Busby, J. T.

    2014-05-01

    This work aims at utilizing modern computational microstructural modeling tools to accelerate the understanding of phase stability in austenitic steels under extended thermal aging. Using the CALPHAD approach, a thermodynamic database OCTANT (ORNL Computational Thermodynamics for Applied Nuclear Technology), including elements of Fe, C, Cr, Ni, Mn, Mo, Si, and Ti, has been developed with a focus on reliable thermodynamic modeling of precipitate phases in AISI 316 austenitic stainless steels. The thermodynamic database was validated by comparing the calculated results with experimental data from commercial 316 austenitic steels. The developed computational thermodynamics was then coupled with precipitation kinetics simulation to understand the temporal evolution of precipitates in austenitic steels under long-term thermal aging (up to 600,000 h) at a temperature regime from 300 to 900 °C. This study discusses the effect of dislocation density and difusion coefficients on the precipitation kinetics at low temperatures, which shed a light on investigating the phase stability and transformation in austenitic steels used in light water reactors.

  13. Experimental Investigation and Analytical Prediction of ?-Phase Precipitation in AISI 316L Austenitic Stainless Steel

    NASA Astrophysics Data System (ADS)

    Sahlaoui, Habib; Sidhom, Habib

    2013-07-01

    The phase precipitation in industrial AISI 316L stainless steel during aging for up to 80,000 hours between 823 K and 1073 K (550 °C and 800 °C) has been studied using transmission electron microscopy, scanning transmission electron microscopy, and carbon replica energy-dispersive X-ray microanalysis. Three phases were identified: Chromium carbides (M23C6), Laves phase ( ?), and ?-phase (Fe-Cr). M23C6 carbide precipitation occurred firstly and was followed by the ? and ?-phases at grain boundaries when the aging temperature is higher than 873 K (600 °C). Precipitation and growth of M23C6 create chromium depletion zones at the grain boundaries and also retard the ?-phase formation. Thus, the ?-phase is controlled by the kinetic of chromium bulk diffusion and can appear only when the chromium reaches, at grain boundaries and at the M23C6/ ? and M23C6/ ?/ ? interfaces, content higher than a critical value obtained by self-healing. An analytical model, based on equivalent chromium content, has been established in this study and successfully validated to predict the time-temperature-precipitation diagram of the ?-phase. The obtained diagram is in good agreement with the experimental results.

  14. Theoretical and experimental analysis of high power diode laser (HPDL) hardening of AISI 1045 steel

    NASA Astrophysics Data System (ADS)

    Lusquiños, F.; Conde, J. C.; Bonss, S.; Riveiro, A.; Quintero, F.; Comesaña, R.; Pou, J.

    2007-12-01

    Laser surface hardening makes use of the rapid and cooling cycles produced on metals surfaces exposed to a scanning laser beam without affecting the bulk of the sample. Mechanical and chemical properties of the surface can be enhanced through the metallurgical transformations that take place during the mentioned thermal cycles. Steels and cast irons are the usual materials to be hardened by laser and recently the high power diode lasers (HPDL) became the appropriate tool to carry out this process. In this work, some systematic experiments have been carried out to harden AISI 1045 surface samples by a cw (HPDL) working at different power levels (470, 760 W). The main processing parameters (scanning velocity and density power of the laser beam) were tuned from the prediction realized by the numerical (ANSYS) analysis of the heat conduction involved in the process. Such analysis allowed us to put in evidence the variation of the temperature and the cooling rate of the steel sample surface, affecting the uniformity of the demanding mechanical properties of the surface. In this way, a close-loop temperature control of the surface was justified in order to keep the hardness value within the range required. The formation of martensite phase in the laser treated superficial zone confirmed the hardening of the steel.

  15. Effect of two synthetic lubricants on life of AISI 9310 spur gears

    NASA Technical Reports Server (NTRS)

    Townsend, Dennis P.; Shimski, John

    1991-01-01

    Spur-gear fatigue tests were conducted with two lubricants using a single lot of consumable-electrode vacuum-melted (CVM) AISI 9310 spur gears. The gears were case carburized and hardened to Rockwell C60. The gear pitch diameter was 8.89 cm. The lot of gears was divided into two groups, each of which was tested with a different lubricant. The test lubricants can be classified as synthetic polyol-ester-based lubricants. One lubricant was 30 percent more viscous that the other. Both lubricants have similar pressure viscosity coefficients. Test conditions included a bulk gear temperature of 350 K, a maximum Hertz stress of 1.71 GPa at the pitch line, and a speed of 10,000 rpm. The surface fatigue life of gears tested with one lubricant was approximately 2.4 times that for gears tested with the other lubricant. The lubricant with the 30 percent higher viscosity gave a calculated elastohydrodynamic (EHD) film thickness that was 20 percent higher than the other lubricant. This increased EHD film thickness is the most probable reason for the improvement in surface fatigue life of gears tested with this lubricant over gears tested with the less viscous lubricant.

  16. Investigation of mechanically attrited structures induced by repeated impacts on an AISI1045 steel

    NASA Astrophysics Data System (ADS)

    Kermouche, Guillaume; Pacquaut, Guillaume; Langlade, C.; Bergheau, Jean-Michel

    2011-07-01

    Under repeated impact loadings - shot peening process, surface mechanical attrition treatment, erosive wear - metallic surfaces undergo severe plastic deformation which leads sometimes to a local change of their microstructure. These mechanically attrited structures (MAS) exhibit very interesting physical properties: high hardness, better tribological properties, etc. Consequently it is of primary importance to understand the mechanism explaining how these MAS are created and grow under such loadings. In this article, this mechanism is investigated with the help of a coupled experimental and finite element approach. First, the MAS are generated on an AISI1045 steel with a micro-impact tester which allows to know the impact energy and the location of impacts with a very good accuracy. The evolution of the MAS shape as a function of the impact number is presented. Then, the finite element investigation is presented. It is shown that a macroscopic stabilized elastic regime is reached after one hundred impacts. It also appears that a close cycle of plastic strain is observed locally in the zone where material transformation should happen during this regime. The severe plastic deformation achieved after a given number of cycles may thus explain the material transformation. Based on these results, we propose a mechanism based on a plastic strain threshold to explain the growth of the MAS. The resulting MAS size and shape appear to be in very good agreement with the experimental results. Finally, we conclude on the influence of the mechanical parameters that are involved in the proposed mechanism.

  17. DCEMS Study of Thin Stainless Steel Films Deposited by RF Sputtering of AISI316L

    SciTech Connect

    Nomura, K.; Iio, S.; Ujihira, Y.; Terai, T. [School of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)

    2005-04-26

    Thin stainless steel films were prepared on SiO2/Si plate heated at 100 deg. C and 400 deg. C using AISI316L as target, by a RF magnetron Ar sputtering method. RF sputtered-deposited films and the oxidized surface layers by post heating were characterized by depth selective conversion electron Moessbauer spectroscopy (DCEMS) using a He+5%CH4 gas proportional counter. The as-deposited films consisted of magnetic phases, the magnetic orientation of which had a tendency to be perpendicular to the surface of the film. In the case of the deposited films at substrate temperature of 100 deg. C, a small amount of Fe2O3 and ferritic stainless steel formed by post-heating in air. A magnetic subcomponent and a austenite phase were formed in the films deposited at substrate temperature of 400 deg. C. {alpha}-Fe2O3 and magnetite formed easily on the top and middle layers of the films by post-heating in air. The oxide states of the films deposited at different temperatures of substrate were clearly distinguished by post-heating. Thus it was found by DCEMS that the structures of the deposited films were strongly affected by the preparation method and the temperature of the substrate.

  18. Prediction of Cutting Forces Using ANNs Approach in Hard Turning of AISI 52100 steel

    SciTech Connect

    Makhfi, Souad [Laboratoire des Technologies Industrielles. Universite Ibn Khaldoun de Tiaret, B.P. 78, Tiaret 14000 (Algeria); Laboratoire des Technologies Innovantes E.A. 3899. I.U.T. GMP-Universite de Picardie Jules Verne, avenue des Facultes, Le Bailly, 80025 Amiens Cedex1 (France); Habak, Malek; Velasco, Raphael [Laboratoire des Technologies Innovantes E.A. 3899. I.U.T. GMP-Universite de Picardie Jules Verne, avenue des Facultes, Le Bailly, 80025 Amiens Cedex1 (France); Haddouche, Kamel; Vantomme, Pascal [Laboratoire des Technologies Industrielles. Universite Ibn Khaldoun de Tiaret, B.P. 78, Tiaret 14000 (Algeria)

    2011-05-04

    In this study, artificial neural networks (ANNs) was used to predict cutting forces in the case of machining the hard turning of AISI 52100 bearing steel using cBN cutting tool. Cutting forces evolution is considered as the key factors which affect machining. Predicting cutting forces evolution allows optimizing machining by an adaptation of cutting conditions. In this context, it seems interesting to study the contribution that could have artificial neural networks (ANNs) on the machining forces prediction in both numerical and experiment studies. Feed-forward multi-layer neural networks trained by the error back-propagation (BP) algorithm are used. Levenberg-Marquardt (LM) optimization algorithm was used for finding out weights. The training of the network is carried out with experimental machining data.The input dataset used are cutting speed, feed rate, cutting depth and hardness of the material. The output dataset used are cutting forces (Ft-cutting force, Fa- feed force and Fr- radial force).Results of the neural networks approach, in comparison with experimental data are discussed in last part of this paper.

  19. Effect of lubricant extreme-pressure additives on surface fatigue life of AISI 9310 spur gears

    NASA Technical Reports Server (NTRS)

    Scibbe, H. W.; Townsend, D. P.; Aron, P. R.

    1984-01-01

    Surface fatigue tests were conducted with AISI 9310 spur gears using a formulated synthetic tetraester oil (conforming to MIL-L-23699 specifications) as the lubricant containing either sulfur or phosphorus as the EP additive. Four groups of gears were tested. One group of gears tested without an additive in the lubricant acted as the reference oil. In the other three groups either a 0.1 wt % sulfur or phosphorus additive was added to the tetraester oil to enhance gear surface fatigue life. Test conditions included a gear temperature of 334 K (160 F), a maximum Hertz stress of 1.71 GPa (248 000 psi), and a speed of 10,000 rpm. The gears tested with a 0.1 wt % phosphorus additive showed pitting fatigue life 2.6 times the life of gears tested with the reference tetraester based oil. Although fatigue lives of two groups of gears tested with the sulfur additive in the oil showed improvement over the control group gear life, the results, unlike those obtained with the phosphorus oil, were not considered to be statistically significant.

  20. ALS Association

    MedlinePLUS

    ... ALS New ALS Therapy Target Highlights Role of RNA Processing in the Disease The ALS Association to Present at BIO, World Biotechnology Convention Critical Protein Measurement Means Progress Toward ...

  1. Substrate bias effects on mechanical and tribological properties of substitutional solid solution (Ti, Al)N films prepared by reactive magnetron sputtering

    Microsoft Academic Search

    K. Chu; P. W. Shum; Y. G. Shen

    2006-01-01

    Nitrogen-saturated solid solution titanium–aluminium–nitride (Ti, Al)N thin films were deposited onto Si(100) wafers (for concentration and mechanical analyses) and AISI M42 tool steels (for tribological measurements) at room temperature by reactive close-field unbalanced magnetron sputtering in an Ar–N2 gas mixture. The effects of substrate negative bias voltages (Ub) on the mechanical and tribological properties of these films have been studied.

  2. Sliding friction and wear performance of Ti 6Al 4V in the presence of surface-capped copper nanoclusters lubricant

    Microsoft Academic Search

    Fang Wang; Qin-Ling Bi; Xiao-Bo Wang; Wei-Min Liu

    2008-01-01

    The friction and wear properties of Ti6Al4V sliding against AISI52100 steel ball under different lubricative media of surface-capped copper nanoclusters lubricant—Cu nanoparticles capped with O,O?-di-n-octyldithiophosphate (Cu-DTP), rapeseed oil and rapeseed oil containing 1wt% Cu-DTP was evaluated using an Optimol SRV oscillating friction and wear tester. The wear mechanism was examined using scanning electron microscopy (SEM) and X-ray photoelectron spectrosmeter (XPS).

  3. Comparison of Microstructure and Surface Properties of AISI 1045 Steel After Quenching in Hot Alkaline Salt Bath and Oil

    NASA Astrophysics Data System (ADS)

    Raygan, S.; Rassizadehghani, J.; Askari, M.

    2009-03-01

    The effect of quenching in molten alkaline salt bath medium on the microstructure and surface properties of AISI 1045 steel in comparison with oil was investigated. Salt bath medium used in this research contained 40% NaOH and 60% KOH with addition of 5 wt.% water at 205 °C. Hardening of 1045 steel in this medium resulted in an almost uniform microstructure, which consisted of fine martensite and bainite. In comparison, the microstructure of oil quenched sample was martensite, ferrite, widmanestatten ferrite, and pearlite. Quenching in salt bath lead to improved surface properties, i.e., decrease in surface roughness and a good bearing area curve.

  4. Machining Performance and Surface Integrity of AISI D2 Die Steel Machined Using Electrical Discharge Surface Grinding Process

    NASA Astrophysics Data System (ADS)

    Choudhary, Rajesh; Kumar, Harmesh; Singh, Shankar

    2013-12-01

    The aim of this study is to establish optimum machining conditions for EDSG of AISI D2 die steel through an experimental investigation using Taguchi Methodology. To achieve combined grinding and electrical discharge machining, metal matrix composite electrodes (Cu-SiCp) were processed through powder metallurgy route. A rotary spindle attachment was developed to perform the EDSG experimental runs on EDM machine. Relationships were developed between various input parameters such as peak current, speed, pulse-on time, pulse-off time, abrasive particle size, and abrasive particle concentration, and output characteristics such as material removal rate and surface roughness. The optimized parameters were further validated by conducting confirmation experiments.

  5. Mechanical behavior of AISI 304SS determined by miniature test methods after neutron irradiation to 28 dpa

    SciTech Connect

    Ellen M. Rabenberg; Brian J. Jaques; Bulent H. Sencer; Frank A. Garner; Paula D. Freyer; Taira Okita; Darryl P. Butt

    2014-05-01

    The mechanical properties of AISI 304 stainless steel irradiated for over a decade in the Experimental Breeder Reactor (EBR-II) were measured using miniature mechanical testing methods. The shear punch method was used to evaluate the shear strengths of the neutron-irradiated steel and a correlation factor was empirically determined to predict its tensile strength. The strength of the stainless steel slightly decreased with increasing irradiation temperature, and significantly increased with increasing dose until it saturated above approximately 5 dpa. Ferromagnetic measurements were used to observe and deduce the effects of the stress-induced austenite to martensite transformation as a result of shear punch testing.

  6. Wear resistance of TiAlSiN thin coatings.

    PubMed

    Silva, F J G; Martinho, R P; Alexandre, R J D; Baptista, A P M

    2012-12-01

    In the last decades TiAIN coatings deposited by PVD techniques have been extensively investigated but, nowadays, their potential development for tribological applications is relatively low. However, new coatings are emerging based on them, trying to improve wear behavior. TiAlSiN thin coatings are now investigated, analyzing if Si introduction increases the wear resistance of PVD films. Attending to the application, several wear test configurations has been recently used by some researchers. In this work, TiAISiN thin coatings were produced by PVD Unbalanced Magnetron Sputtering technique and they were conveniently characterized using Scanning Electron Microscopy (SEM) provided with Energy Dispersive Spectroscopy (EDS), Atomic Force Microscopy (AFM), Electron Probe Micro-Analyzer (EPMA), Micro Hardness (MH) and Scratch Test Analysis. Properties as morphology, thickness, roughness, chemical composition and structure, hardness and film adhesion to the substrate were investigated. Concerning to wear characterization, two very different ways were chosen: micro-abrasion with ball-on-flat configuration and industrial non-standardized tests based on samples inserted in a feed channel of a selected plastic injection mould working with 30% (wt.) glass fiber reinforced polypropylene. TiAISiN coatings with a small amount of about 5% (wt.) Si showed a similar wear behavior when compared with TiAIN reported performances, denoting that Si addition does not improve the wear performance of the TiAIN coatings in these wear test conditions. PMID:23447962

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

    SciTech Connect

    Qu, Jun [ORNL; Blau, Peter Julian [ORNL; Zhu, Dong [Eaton Corporation; Cook, Bruce A [Ames Laboratory; Elmoursi, Alaa A [Eaton Corporation

    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.

  8. Effect of SiC particles on the friction and wear behavior of Ti 3Si(Al)C 2-based composites

    Microsoft Academic Search

    D. T. Wan; C. F. Hu; Y. W. Bao; Y. C. Zhou

    2007-01-01

    The non-lubricated, sliding friction and wear behavior of Ti3Si(Al)C2 and SiC-reinforced Ti3Si(Al)C2 composites against AISI 52100 bearing steel ball were investigated using a ball-on-flat, reciprocating tribometer at room temperature. The contact load was varied from 5 to 20N. For monolithic Ti3Si(Al)C2, high friction coefficients between 0.61 and 0.90 and wear rates between 1.79×10?3 and 2.68×10?3mm3(Nm)?1 were measured. With increasing SiC

  9. Effects of electroplated zinc-nickel alloy coatings on the fatigue strength of AISI 4340 high-strength steel

    NASA Astrophysics Data System (ADS)

    Voorwald, H. J. C.; Miguel, I. M.; Peres, M. P.; Cioffi, M. O. H.

    2005-04-01

    Recovered substrates have been extensively used in the aerospace field. Cadmium electroplating has been widely applied to promote protective coatings in aeronautical components, resulting in excellent corrosion protection combined with a good performance in cyclic loading. Ecological considerations allied to the increasing demands for corrosion resistance have resulted in the search for possible alternatives. Zinc-nickel (Zn-Ni) alloys have received considerable interest recently, because these coatings show advantages such as a good resistance to white and red rust, high plating rates, and acceptance in the market. In this study, the effect of electroplated Zn-Ni coatings on AISI 4340 high-strength steel was analyzed for rotating bending fatigue strength, corrosion, and adhesion resistance. The compressive residual stress field was measured by x-ray diffraction prior to fatigue tests. Optical microscopy documented coating thickness, adhesion characteristics, and coverage extent for nearly all substrates. Fractured fatigue specimens were investigated using scanning electron microscopy (SEM). Three different Zn-Ni coating thicknesses were tested, and comparisons with the rotating bending fatigue data from electroplated Cd specimens were performed. Experimental results differentiated the effects of the various coatings on the AISI 4340 steel behavior when submitted to fatigue testing and the influence of coating thickness on the fatigue strength.

  10. Influence of Surface Preparation on the Kinetics of Controlled Gas-Nitrided AISI H13 Steels Used in Extrusion Dies

    NASA Astrophysics Data System (ADS)

    Akhtar, S. S.; Arif, A. F. M.; Yilbas, B. S.; Sheikh, A. K.

    2010-04-01

    In the aluminum extrusion practice, gas nitriding represents an important factor in enhancing the service life of AISI H13 steel dies. It is observed that if the die-bearing surface is not adequately prepared before nitriding, a nonuniform and shallow nitrided layer develops with reduced hardening effect. The focus of this paper is to investigate the influence of different surface conditions in terms of roughness on the kinetics of nitrided layer developed during gas-nitriding process under controlled nitriding potential. Four samples made of AISI H13 steel properly heat treated (quenched and tempered) were considered: without surface preparation, ground, polished, and lapped. All the samples were gas nitrided under the same conditions and examined after being nitrided. The nitrided layers were characterized using different techniques including optical microscopy, scanning electron microscopy, x-ray diffraction analysis, energy dispersive spectrometry mapping, and microhardness analysis. It was found that the surface preparation prior to nitriding significantly enhanced the nitriding kinetics, which in turn resulted in even and deep nitrided case depth. This provided high load-bearing capacity due to increased and deep hardening effect as compared to unprepared sample. A thinner and uniform compound layer with well-resolved phases was achieved in comparison with unprepared sample.

  11. High temperature oxidation behavior of austenitic stainless steel AISI 304 in steam of nanofluids contain nanoparticle ZrO2

    SciTech Connect

    Prajitno, Djoko Hadi, E-mail: djokohp@batan.go.id; Syarif, Dani Gustaman, E-mail: djokohp@batan.go.id [Research Center for Nuclear Materials and Radiometry, Jl. Tamansari 71, Bandung 40132 (Indonesia)

    2014-03-24

    The objective of this study is to evaluate high temperature oxidation behavior of austenitic stainless steel SS 304 in steam of nanofluids contain nanoparticle ZrO{sub 2}. The oxidation was performed at high temperatures ranging from 600 to 800°C. The oxidation time was 60 minutes. After oxidation the surface of the samples was analyzed by different methods including, optical microscope, scanning electron microscope (SEM) and X-ray diffraction (XRD). X-ray diffraction examination show that the oxide scale formed during oxidation of stainless steel AISI 304 alloys is dominated by iron oxide, Fe{sub 2}O{sub 3}. Minor element such as Cr{sub 2}O{sub 3} is also appeared in the diffraction pattern. Characterization by optical microscope showed that cross section microstructure of stainless steel changed after oxidized with the oxide scale on the surface stainless steels. SEM and x-ray diffraction examination show that the oxide of ZrO{sub 2} appeared on the surface of stainless steel. Kinetic rate of oxidation of austenite stainless steel AISI 304 showed that increasing oxidation temperature and time will increase oxidation rate.

  12. The effect of martensite particle size on tensile fracture of surface-carburised AISI 8620 steel with dual phase core microstructure

    Microsoft Academic Search

    Mehmet Erdogan; Suleyman Tekeli

    2002-01-01

    In this study, the production of dual phase microstructure in the core of surface-carburised AISI 8620 cementation steel and the effect of martensite particle size at constant martensite volume fraction on tensile fracture have been investigated. The results showed that specimens with dual phase microstructure in the core exhibited slightly lower tensile and yield strength but superior ductility without sacrificing

  13. Corrosion of nickel—chromium deposit on AISI 316L stainless steel in radioactive water with and without fluoride at pH 4

    Microsoft Academic Search

    G. Bellanger; J. J. Rameau

    1995-01-01

    The electrochemical behavior of samples was studied using potentiodynamic techniques at low scan rates, cyclic voltammetry at high scan rates and electrochemical impedance spectroscopy. The surfaces were examined and analyzed by scanning electron microscopy and X-ray microanalysis, respectively. The results from these different methods are discussed. They show that the deposit is more easily corroded than the AISI 316L stainless

  14. Investigation of the correlation between thermal properties and hardenability of Jominy bars quenched with air–water mixture for AISI 1050 steel

    Microsoft Academic Search

    Mehmet Çakir; Abdullah Özsoy

    2011-01-01

    In this study, the hardenability of AISI 1050 steel has been investigated in different cooling media using Jominy test. The temperature values were recorded using the thermocouples that were placed on sample. The relations between the cooling media and the cooling curves, heat flux, hardenability and heat convection coefficient were shown in graphics. The correlation between thermal properties and hardenability

  15. Effect of magnetic field applied during gas metal arc welding on the resistance to localised corrosion of the heat affected zone in AISI 304 stainless steel

    Microsoft Academic Search

    F. F. Curiel; R. García; V. H. López

    2011-01-01

    Resistance to localised corrosion at the heat affected zone (HAZ) of AISI 304 stainless steel gas metal arc welded (GMAW) in presence of magnetic fields of different intensity was studied. Samples of HAZ, 8mm away from the weld centre, were subjected to electrochemical potentiokinetic reactivation to assess the degree of sensitisation (DOS). The application of magnetic field during welding induced

  16. Role of environmental variables on the stress corrosion cracking of sensitized AISI type 304 stainless steel (SS304) in thiosulfate solutions

    Microsoft Academic Search

    S. Roychowdhury; S. K. Ghosal; P. K. de

    2004-01-01

    The stress corrosion cracking (SCC) behavior of sensitized AISI type 304 stainless steel (SS304) has been studied in dilute thiosulfate solutions as a function of thiosulfate concentrations and applied potentials. The susceptibility to SCC was observed to increase with thiosulfate concentrations and applied potentials. The addition of boric acid produced the reverse effect. A critical potential was found to exist,

  17. Machine Design -2 Consider a machined 60mm diameter shaft made of AISI 1020 HR (Sut = 380 MPa at 20C) quenched

    E-print Network

    Virginia Tech

    Machine Design - 2 Consider a machined 60mm diameter shaft made of AISI 1020 HR (Sut = 380 MPa at 20°C) quenched steel shown below. The shaft is supported by bearings at the ends. Mounted upon the shaft are two collars through which fluctuating loads are applied as shown. A groove is machined

  18. ALS - resources

    MedlinePLUS

    Resources - ALS ... The following organizations are good resources for information on amyotrophic lateral sclerosis : Muscular Dystrophy Association - http://mda.org/disease/amyotrophic-lateral-sclerosis National Amyotrophic Lateral Sclerosis (ALS) ...

  19. INFLUÊNCIA DA PÓS-CURA NA TEMPERATURA DE TRANSIÇÃO VÍTREA EM COMPÓSITOS DE FIBRA DE CARBONO E DE POLIARAMIDA COM MATRIZ DE POLÍMERO TERMOFIXO

    Microsoft Academic Search

    N. M. SILVA; L. F. C. P. LIMA; R. N. FARIA; J. L. ROSSI

    RESUMO Compósitos de matriz polimérica reforçados com fibra de carbono têm sido cada vez mais usados na indústria nuclear, aeronáutica, automobilística e de equipamentos de entretenimento. Isto se deve à sua performance superior em relação aos materiais convencionais sob diversos aspectos, principalmente, no que concerne às relações resistência à ruptura \\/ massa específica e módulo de elasticidade \\/ massa específica

  20. ResistÍncia ao cisalhamento Iosipescu em compÛsitos de fibra de carbono e de vidro com resina epÛxi

    Microsoft Academic Search

    Vanderlei O. GonÁalves; Luiz Cl; Kledermon Garcia; Antonio Carlos; Eduardo Marcelo Bezerra

    2009-01-01

    12 cisalhamento Iosipescu. Os testes foram conduzidos com dois tipos de compÛsitos, fibra de carbono\\/epÛxi e fibra de vidro\\/epÛxi utilizados na indstria aeroespacial e tambÈm uma matriz de resina moldada. Os resultados indicam a efetiva contribuiÁ\\

  1. Near surface chemistry and corrosion behavior of excimer laser surface-melted AISI type 304 stainless steel

    SciTech Connect

    Baer, D.R.; Frydrych, D.J.; Jervis, T.R.

    1988-05-01

    The effects of excimer laser surface melting on the near-surface chemistry, and corrosion behavior of AISI 304 stainless steel have been examined as a function of total energy deposited on the specimen. The surface chemistry resulting from the laser treatments has been examined using Auger electron spectroscopy. Electrochemical methods were used to monitor the corrosion behavior of the specimens in deaerated 0.1 M NaCl. Electron microscopy was used to characterize the extent of local corrosion of the specimens. Laser treatment was observed to increase the chromium concentration of the surface oxide and to reduce the number of pits. Two types of pits were observed on untreated material, but only one type of pit occurred after laser treatment. 7 refs., 5 figs.

  2. Mechanical behavior of AISI 304SS determined by miniature test methods after neutron irradiation to 28 dpa

    NASA Astrophysics Data System (ADS)

    Rabenberg, Ellen M.; Jaques, Brian J.; Sencer, Bulent H.; Garner, Frank A.; Freyer, Paula D.; Okita, Taira; Butt, Darryl P.

    2014-05-01

    The mechanical properties of AISI 304 stainless steel irradiated for over a decade in the Experimental Breeder Reactor (EBR-II) were measured using miniature mechanical testing methods. The shear punch method was used to evaluate the shear strengths of the neutron-irradiated steel and a correlation factor was empirically determined to predict its tensile strength. The strength of the stainless steel slightly decreased with increasing irradiation temperature, and significantly increased with increasing dose until it saturated above approximately 5 dpa. An effective tensile strain hardening exponent was also obtained from the data which shows a relative decrease in ductility of steel with increased irradiation damage. Ferromagnetic measurements were used to observe and deduce the effects of the stress-induced austenite to martensite transformation as a result of shear punch testing.

  3. Influence of superficial coating of CeO[sub 2] on the oxidation behavior of AISI 304 stainless steel

    SciTech Connect

    Mitra, S.K. (Regional Engineering College, Durgapur (India)); Roy, S.K.; Bose, S.K. (Indian Inst. of Technology, Khargapur (India))

    1993-04-01

    The effect of a superficially-applied, cerium-oxide coating on the non-isothermal oxidation behavior of AISI 304 stainless steel in dry air has been investigated. The heating rate employed was 3 K/min up to a final temperature of 1,423 K. The reactive oxide coating not only reduced the reaction rate but also faciliated scale adhesion to the alloy substrate. Post-oxidation analyses of the alloy/scale combination using optical microscopy, SEM, EDAX, and XRD provide evidence for a changeover in the mechanism of oxide growth from the scale/gas interface to the alloy/scale interface for the coated steel. 14 refs., 6 figs.

  4. Application of strainrange partitioning to the prediction of creep-fatigue lives of AISI types 304 and 316 stainless steel

    NASA Technical Reports Server (NTRS)

    Saltsman, J. F.; Halford, G. R.

    1976-01-01

    As a demonstration of the predictive capabilities of the method of Strainrange Partitioning, published high-temperature, low cycle, creep-fatigue test results on AISI Types 304 and 316 stainless steel were analyzed and calculated, cyclic lives compared with observed lives. Predicted lives agreed with observed lives within factors of two for 76 percent, factors of three for 93 percent, and factors of four for 98 percent of the laboratory tests analyzed. Agreement between observed and predicted lives is judged satisfactory considering that the data are associated with a number of variables (two alloys, several heats and heat treatments, a range of temperatures, different testing techniques, etc.) that are not directly accounted for in the calculations.

  5. The significance of passivation treatments on AISI 314 foam pieces to be used as substrates for catalytic applications

    NASA Astrophysics Data System (ADS)

    Bortolozzi, J. P.; Banús, E. D.; Milt, V. G.; Gutierrez, L. B.; Ulla, M. A.

    2010-11-01

    Several properties of metallic foams such as their low density, high mechanical strength and good coefficients of heat and mass transfer make them attractive for applications in catalysis. Important modifications in the composition and morphology of the metallic foam surfaces can take place when they are submitted to treatments at high temperatures. These surface changes are due to the migration of some elements from the metallic core to the pore surface, thus inducing a passivation via an oxide layer formation. This new layer avoids further metallic segregation and generates a surface roughness, both effects having a significant impact on the catalytic coating quality. This work analyzes the effects of calcination temperature and time on the chemistry and morphology of the metallic surface corresponding to the AISI 314 stainless steel foams of 50 and 60 ppi. The chemical and morphological surface changes were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy-Dispersive X-Ray (EDX) analysis and Laser Raman Spectroscopy (LRS). The application of high temperature treatments on AISI 314 foams promotes the formation of a surface layer containing chromium oxide and spinel-type compounds of chromium, iron and manganese. The optimum treatment temperature for this type of structures seems to be 900 °C because both the adhesion and thickness of the layer formed are adequate. For the sample with smaller pores (60 ppi) the optimal treatment time is close to 2 h and for that with larger pores (50 ppi) the recommended time is 20 h. Under these conditions, a compromise is found between adhesion, thickness and surface roughness, suitable for the subsequent deposition of catalytic material.

  6. Comparison of Austenite Decomposition Models During Finite Element Simulation of Water Quenching and Air Cooling of AISI 4140 Steel

    NASA Astrophysics Data System (ADS)

    Babu, K.; Prasanna Kumar, T. S.

    2014-08-01

    An indigenous, non-linear, and coupled finite element (FE) program has been developed to predict the temperature field and phase evolution during heat treatment of steels. The diffusional transformations during continuous cooling of steels were modeled using Johnson-Mehl-Avrami-Komogorov equation, and the non-diffusion transformation was modeled using Koistinen-Marburger equation. Cylindrical quench probes made of AISI 4140 steel of 20-mm diameter and 50-mm long were heated to 1123 K (850 °C), quenched in water, and cooled in air. The temperature history during continuous cooling was recorded at the selected interior locations of the quench probes. The probes were then sectioned at the mid plane and resultant microstructures were observed. The process of water quenching and air cooling of AISI 4140 steel probes was simulated with the heat flux boundary condition in the FE program. The heat flux for air cooling process was calculated through the inverse heat conduction method using the cooling curve measured during air cooling of a stainless steel 304L probe as an input. The heat flux for the water quenching process was calculated from a surface heat flux model proposed for quenching simulations. The isothermal transformation start and finish times of different phases were taken from the published TTT data and were also calculated using Kirkaldy model and Li model and used in the FE program. The simulated cooling curves and phases using the published TTT data had a good agreement with the experimentally measured values. The computation results revealed that the use of published TTT data was more reliable in predicting the phase transformation during heat treatment of low alloy steels than the use of the Kirkaldy or Li model.

  7. AISI 303 OSTEN?T?K PASLANMAZ ÇEL?KLER?N ??LENMES?NDE KESME HIZI VE ?LERLEMEN?N TALA? B?Ç?M?NE ETK?S? THE EFFECT OF CUTTING SPEED AND FEED RATE ON CHIP SHAPE IN AISI 303 AUSTENITIC STAINLESS STEEL MACHINING

    Microsoft Academic Search

    Yakup TURGUT; Hasan Emrah YEYEN

    This study is an experimental analysis into the effect of cutting speed and feed rate on AISI 303 stainless steel machining. Firstly, we maintained a 0,24 mm\\/rev feed rate recommended for the cutter used and conducted experiments at four different cutting speeds. Through these experiments, we determined the cutting speed with the highest quality and conducted experiments at this cutting

  8. The initiation and propagation of stress corrosion cracking in AISI 4340 and 3.5 Ni?Cr?Mo?V rotor steel in constant load tests

    Microsoft Academic Search

    A. Oehlert; A. Atrens

    1996-01-01

    Constant load tests with smooth tensile specimens of AISI 4340 and 3.5 Ni?Cr?Mo?V rotor steel were carried out to investigate the influence of prior creep on the initiation of stress corrosion cracking (SCC). SCC did initiate without any significant pitting corrosion or general corrosion. A period of prior creep in a non-SCC environment resulted in significantly reduced localised corrosion along

  9. Influences of Cr\\/Ni equivalent ratios of filler wires on pitting corrosion and ductility-dip cracking of AISI 316L weld metals

    Microsoft Academic Search

    Y. H. Kim; D. G. Kim; J. H. Sung; I. S. Kim; D. E. Ko; N. H. Kang; H. U. Hong; J. H. Park; H. W. Lee

    2011-01-01

    To study the pitting corrosion of AISI 316L weld metals according to the chromium\\/nickel equivalent ratio (Creq\\/Nieq ratio), three filler wires were newly designed for the flux-cored arc welding process. The weld metal with delta-ferrite\\u000a at less than 3 vol.%, was observed for ductility-dip cracking (DDC) in the reheated region after multi-pass welding. The tensile\\u000a strength and yield strength increased

  10. The dependence of crack properties on the Cr\\/Ni equivalent ratio in AISI 304L austenitic stainless steel weld metals

    Microsoft Academic Search

    D. J. Lee; J. C. Byun; J. H. Sung; H. W. Lee

    2009-01-01

    The crack properties and mechanical characteristics in AISI 304L stainless steel weld metals were evaluated by differentiating solidification mode using three newly designed filler wires with flux-cored arc welding (FCAW) process. Microstructure examination showed that the delta ferrite content in the deposited metals increased with an increasing equivalent ratio of chromium\\/nickel. Solidification cracking was observed in the first layer of

  11. A comparative study of the wear behaviour of sintered and laser surface melted AISI M42 high speed steel diluted with iron

    Microsoft Academic Search

    R. Colaço; E. Gordo; E. M. Ruiz-Navas; M. Otasevic; R. Vilar

    2006-01-01

    Powders of AISI M42 high-speed steel (HSS) were blended with different proportions of water-atomised iron powders. The powders were subsequently submitted to uniaxial pressing and then divided in three lots. The first was submitted to sintering, the second was submitted to sintering plus laser surface melting (LSM) and the third was submitted to sintering plus LSM plus double tempering at

  12. AISI 304 L stainless steel decontamination by a corrosion process using cerium IV regenerated by ozone Part I: Study of the accelerated corrosion process

    Microsoft Academic Search

    J. P. Caire; F. Laurent; S. Cullie; F. Dalard; J. M. Fulconis; H. Delagrange

    2003-01-01

    This paper describes the study of a new decontamination process of AISI 304L stainless steel from dismantled nuclear power plants. A very thin active contaminated surface layer was stripped from the underlying metal by corrosion in a solution of nitric acid with the addition of cerium nitrate. The Ce4+\\/Ce3+ concentration ratio was initially equal to unity and ozone\\/oxygen bubbles were

  13. Role of environmental variables on the stress corrosion cracking of sensitized AISI type 304 stainless steel (SS304) in thiosulfate solutions

    Microsoft Academic Search

    S. Roychowdhury; S. K. Ghosal; P. K. De

    2004-01-01

    The stress corrosion cracking (SCC) behavior of sensitized AISI type 304 stainless steel (SS304) has been studied in dilute\\u000a thiosulfate solutions as a function of thiosulfate concentrations and applied potentials. The susceptibility to SCC was observed\\u000a to increase with thiosulfate concentrations and applied potentials. The addition of boric acid produced the reverse effect.\\u000a A critical potential was found to exist,

  14. Studies on the influence of metallurgical variables on the stress corrosion behavior of aisi 304 stainless steel in sodium chloride solution using the fracture mechanics approach

    Microsoft Academic Search

    H. S. Khatak; J. B. Gnanamoorthy; P. Rodriguez

    1996-01-01

    Stress corrosion data on a nuclear grade AISI type 304 stainless steel in a boiling solution of 5M NaCl+ 0.15M Na2SO4+ 3 mL\\/L HC1 (bp 381 K) for various metallurgical conditions of the steel are presented in this article. The metallurgical\\u000a conditions used are solution annealing, sensitization, 10 pct cold work, 20 pct cold work, solution annealing + sensitization,\\u000a 10

  15. Studies on the influence of metallurgical variables on the stress corrosion behavior of aisi 304 stainless steel in sodium chloride solution using the fracture mechanics approach

    Microsoft Academic Search

    H. S. Khatak; J. B. Gnanamoorthy; P. Rodriguez

    1996-01-01

    Stress corrosion data on a nuclear grade AISI type 304 stainless steel in a boiling solution of 5M NaCl+ 0.15M Na2SO4+ 3 mL\\/L HC1 (bp 381 K) for various metallurgical conditions of the steel are presented in this article. The metallurgical conditions used are solution annealing, sensitization, 10 pct cold work, 20 pct cold work, solution annealing + sensitization, 10

  16. 3-Hydroxybenzoic acid as AISI 316L stainless steel corrosion inhibitorin a H 2 SO 4 –HF–H 2 O 2 pickling solution

    Microsoft Academic Search

    L. Narváez; E. Cano; D. M. Bastidas

    2005-01-01

    3-Hydroxybenzoic acid (3-HBA) was studied for possible use as a AISI 316L stainless steel (SS) corrosion inhibitor in an environmental-friendly aqueous pickling solution of 75 g l-1 sulphuric acid (H2SO4), 25 g l-1 hydrofluoric acid (HF) and 30 g l-1 hydrogen peroxide (H2O2). 3-HBA was tested in concentrations from 5 × 10-5 to 5 × 10-1M at 298 and 313

  17. In vitro response of human peripheral blood mononuclear cells to AISI 316L austenitic stainless steel subjected to nitriding and collagen coating treatments.

    PubMed

    Stio, Maria; Martinesi, Maria; Treves, Cristina; Borgioli, Francesca

    2015-02-01

    Surface modification treatments can be used to improve the biocompatibility of austenitic stainless steels. In the present research two different modifications of AISI 316L stainless steel were considered, low temperature nitriding and collagen-I coating, applied as single treatment or in conjunction. Low temperature nitriding produced modified surface layers consisting mainly of S phase, which enhanced corrosion resistance in PBS solution. Biocompatibility was assessed using human peripheral blood mononuclear cells (PBMC) in culture. Proliferation, lactate dehydrogenase (LDH) levels, release of cytokines (TNF-?, IL-1?, IL-12, IL-10), secretion of metalloproteinase (MMP)-9 and its inhibitor TIMP-1, and the gelatinolytic activity of MMP-9 were determined. While the 48-h incubation of PBMC with all the sample types did not negatively influence cell proliferation, LDH and MMP-9 levels, suggesting therefore a good biocompatibility, the release of the pro-inflammatory cytokines was always remarkable when compared to that of control cells. However, in the presence of the nitrided and collagen coated samples, the release of the pro-inflammatory cytokine IL-1? decreased, while that of the anti-inflammatory cytokine IL-10 increased, in comparison with the untreated AISI 316L samples. Our results suggest that some biological parameters were ameliorated by these surface treatments of AISI 316L. PMID:25655502

  18. Mathematical Modeling of Wear Characteristics of 6061 Al-Alloy-SiCp Composite Using Response Surface Methodology

    NASA Astrophysics Data System (ADS)

    Mandal, Nilrudra; Roy, H.; Mondal, B.; Murmu, N. C.; Mukhopadhyay, S. K.

    2012-01-01

    In the light of attractive wear characteristics as well as high strength to weight ratio, extensive research on Al-based Metal Matrix Composite (MMC) have been carried out globally in the last two decades. However, very limited research has been pursued on tribological behavior of Al-based MMC under combined action of rolling and sliding. This study investigates the wear behavior of 6061 Al-alloy/SiC with 10 vol.% SiCp against hardened and tempered AISI 4340 steel under combined rolling-sliding conditions. 23 factorial design of experiments have been carried out to see the effect of few parameters, i.e., contact stress, speed and duration with respect to wear. The interaction effect has also been studied by 3D graphical contours. A mathematical model is developed using regression analysis technique for prediction of wear behavior of the MMC and adequacy of the model has been validated using analysis of variance (ANOVA) techniques. Finally, the optimization of parameter has also been done using Design Expert software. The results have shown that Response Surface Methodology (RSM) is an effective tool for prediction of wear behavior under combined sliding and rolling action. It is also found that the wear of MMC is much lower than hardened; tempered AISI 4340 steel and rolling speed has the maximum influence in wear of both materials under investigation.

  19. Darlington AL O'Reillys AL

    E-print Network

    Greenslade, Diana

    Ck Tyungun AL Numinbah Valley AL NerangR Natural Bridge Numinbah AL Little Nerang Dam AL Albert R Bromfleet.1 FLOOD WARNING NETWORK Major Roads Railway Digital data supplied Geoscience Australia. All rights

  20. Effect of CO 2 laser cutting process parameters on edge quality and operating cost of AISI316L

    NASA Astrophysics Data System (ADS)

    Eltawahni, H. A.; Hagino, M.; Benyounis, K. Y.; Inoue, T.; Olabi, A. G.

    2012-06-01

    Laser cutting is a popular manufacturing process utilized to cut various types of materials economically. The width of laser cut or kerf, quality of the cut edges and the operating cost are affected by laser power, cutting speed, assist gas pressure, nozzle diameter and focus point position as well as the work-piece material. In this paper CO 2 laser cutting of stainless steel of medical grade AISI316L has been investigated. Design of experiment (DOE) was implemented by applying Box-Behnken design to develop the experiment lay-out. The aim of this work is to relate the cutting edge quality parameters namely: upper kerf, lower kerf, the ratio between them, cut section roughness and operating cost to the process parameters mentioned above. Then, an overall optimization routine was applied to find out the optimal cutting setting that would enhance the quality or minimize the operating cost. Mathematical models were developed to determine the relationship between the process parameters and the edge quality features. Also, process parameters effects on the quality features have been defined. Finally, the optimal laser cutting conditions have been found at which the highest quality or minimum cost can be achieved.

  1. Influence of low energy-high flux nitrogen implantation on the oxidation behavior of AISI 304L austenitic stainless steel

    NASA Astrophysics Data System (ADS)

    Pedraza, F.; Grosseau-Poussard, J. L.; Abrasonis, G.; Rivière, J. P.; Dinhut, J. F.

    2003-12-01

    Low energy-high flux (1.2 keV, 1 mA/cm2) nitriding of an austenitic AISI 304L stainless steel has been carried out by implanting a dose of 3.5×1019ions cm-2 at 400 °C for 1 h. An important increase in surface hardness has been found to occur as a result of the formation of the so-called expanded austenite ?N phase. Transmission electron microscopy studies have also shown the existence of hexagonal Cr2N precipitates at the nitrided layer/matrix interfacial region. The oxidation behavior has been then studied in the temperature range between 400 and 550 °C for 24 h under synthetic air. It is shown that nitridation slightly modifies the oxidation kinetics as a result of the progressive transformation of the ?N phase towards CrN precipitation and ?-FeNi matrix formation. More chromium enriched scales are, anyhow, developed on the nitrided steel than in the untreated one. These results are discussed on the basis of the chromium diffusion in the nitrided layer and its preferential chemical bonding with nitrogen atoms.

  2. Observation of an adiabatic shear band in AISI 4340 steel by high-voltage transmission electron microscopy

    NASA Astrophysics Data System (ADS)

    Wittman, C. L.; Meyers, M. A.; Pak, H.-R.

    1990-02-01

    Adiabatic shear bands, formed in a hollow AISI 4340 steel cylinder subjected to dynamic expansion by means of an explosive charge placed in its longitudinal axis, were characterized. The adiabatic shear bands formed in this quenched and tempered steel were of the classical “transformed” type. Scanning electron microscopy (SEM) of etched surfaces revealed that alignment of the lamellae along the direction of shear seems to be the event that precedes shear localization. The transmission electron microscopy of a “white”-etching shear band having undergone a shear strain of approximately 4 revealed that it contained X (Fe5C2) carbides in a martensitic structure. These carbides were observed to form on (112) internal microtwins. Grains could not be resolved inside of the shear band, but they could be observed in the surrounding matrix material. A traverse of the shear band was made, and there existed no definite boundary between the matrix and the shear band. No evidence of a transformation to austenite was observed. Heat transfer calculations were conducted to help explain the features observed inside of the shear band. It is concluded that the “white”-etching bands, commonly referred to in the literature as “transformed” bands, do not exhibit a transformation at values of shear strain of up to 4. The enhanced reflectivity is an etching artifact and is possibly due to microstructural changes, a very small grain size, and carbide redissolution in the bands.

  3. Effect of metallurgical factors on the electrochemical noise measured on AISI Type 430 stainless steels in chloride-containing media

    SciTech Connect

    Gorse, D.; Boulleret, C. [CECM-CNRS, Vitry sur Seine (France); Baroux, B. [Inst. National Polytechnique de Grenoble, Saint Martin d`Heres (France)

    1996-12-31

    Potentiostatic noise measurements are performed on a series of AISI 430 type ferritic stainless steels containing controlled amounts of sulfur (from 8 up to 47 ppm) and titanium (up to 0.37 wt%), in 0.02M sodium chloride (NaCl) aqueous solution (pH 6.6), in a range of potentials below the pitting potential. The authors focus on the evolution of the shape of the current transients, going from a titanium (Ti) free and 41-ppm sulfur-containing alloy to different Ti-bearing alloys with comparable amount of sulfur ({approximately}40 ppm). The results are compared to the case of a Ti-free and low sulfur (8-ppm) containing alloy. The shape of the anodic current transients obeys a power law, t{sup n}. The authors distinguish two different situations, with n either less or larger than 1, which can be associated with the Ti and sulfur content in the steel. The influence of the exposure time under polarization is also discussed. It appears that for the manganese sulfide (MnS)-containing alloys, after prolonged polarization, the shape of the metastable pitting events evolves toward that found for MnS-free alloys (Ti-bearing), or low-sulfur-containing alloys. Attention is drawn to the possible relationship between the shape of the current transients and the metallurgical defects acting as pitting initiation sites.

  4. Influence of sulfate-reducing bacteria on the passive film formed on austenitic stainless steel AISI 304

    SciTech Connect

    Chen, G.; Clayton, C.R.; Sadowski, R.A.; Kearns, J.R. [State Univ. of New York, Stony Brook, NY (United States). Dept. of Materials Science and Engineering; Gillow, J.B.; Francis, A.J. [Brookhaven National Lab., Upton, NY (United States). Dept. of Applied Science

    1995-10-01

    The influence of sulfate-reducing bacteria (SRB) on the passivity of a stainless steel, AISI 304, was investigated with X-ray photoelectron spectroscopy (XPS) and electrochemical techniques. Samples were exposed to SRB in growth media for 5 days. Potentiodynamic polarization tests were then conducted in deaerated 0.1 M HCl to determine if prior exposure to SRB compromised the passivity of the steel. The surface chemistry was analyzed with XPS, immediately after the exposure and following subsequent anodic polarization in 0.1 M HCl. Excess biomass generated by SRB could be rinsed from the steel with deaerated deionized water. Therefore, electrochemical and surface analysis were performed on both rinsed and unrinsed samples. Comparisons were made with control samples which were immersed in uninoculated media. The status of a newly polished sample at each stage of the investigation was given as a basis for comparison. It was found that SRB caused a loss of passivity in the 0.1 M HCl solution, due to the formation of sulfides. The following sulfides were observed: FeS, FeS{sub 2}, NiS, Cr{sub 2}S{sub 3} and possibly Fe{sub 1{minus}x}S{sub x}. The sulfides developed into the sublayer of the substrate during exposure to SRB and remained to hinder repassivation in the test electrolyte.

  5. Determination of neutron exposure of AISI 304 stainless steel from a BWR top guide using retrospective dosimetry

    NASA Astrophysics Data System (ADS)

    Greenwood, L. R.; Garner, F. A.; Oliver, B. M.; Bruemmer, S. M.

    2007-03-01

    Retrospective dosimetry was used to determine the accumulated neutron exposure of AISI 304 stainless steel removed from the top guide of a boiling water reactor located at the Oyster Creek nuclear power station. The material was removed from areas adjacent to cracks that were observed after ˜20 years of operation. Using the plant operational history and a variety of measurements of various radioisotopes or non-radioactive transmutation products produced by irradiation, it was possible to determine the integrated neutron fluence experienced by the cracked region and to specify the accumulated displacement dose. Dose estimates on two separate specimens adjacent to the cracks were found to average 1.5 ± 0.2 dpa, possibly reflecting some uncertainty in measurement but more likely suggesting a small gradient in neutron flux-spectra within the section from which the various analysis specimens were cut. This report demonstrates that it is possible to examine defective components lying outside of the core region and where neutron flux-spectra are not well known, and to use the induced transmutation products to determine the neutron exposure with some confidence by using the examined specimen as its own dosimeter.

  6. Determination of Neutron Exposure of AISI 304 Stainless Steel from a BWR Top Guide using Retrospective Dosimetry

    SciTech Connect

    Greenwood, Lawrence R.; Garner, Francis A.; Oliver, Brian M.; Bruemmer, Stephen M.

    2007-03-31

    Retrospective dosimetry was used to determine the accumulated neutron exposure of AISI 304 stainless steel removed from the top guide of a boiling water reactor located at the Oyster Creek nuclear power station. The material was removed from areas adjacent to cracks that were observed after ~20 years of operation. Using the plant operational history and a variety of measurements of various radioisotopes or non-radioactive transmutation products produced by irradiation, it was possible to determine the integrated flux spectra experienced by the cracked region and to specify the accumulated displacement dose. Dose estimates on two separate specimens adjacent to the cracks were found to average 1.5 ± 0.2 dpa, possibly reflecting some uncertainty in measurement but more likely suggesting a small gradient in neutron flux-spectra within the section from which the various analysis specimens were cut. This report demonstrates that it is possible to examine defective components lying outside of the core region and where neutron flux-spectra are not well known, and to use the induced transmutation products to determine the neutron exposure with some confidence by using the examined specimen as its own dosimeter.

  7. Influences of Processing Time and Discharge Current Density During Pulsed Plasma-Oxidizing process of AISI 316L

    NASA Astrophysics Data System (ADS)

    Díaz-Guillén, J. C.; Vargas-Gutiérrez, G.; Granda-Gutiérrez, E. E.; Aguilar-Martínez, J. A.; González-Albarrán, M. A.; Álvarez-Contreras, L.

    2015-06-01

    The influences of discharge current density and oxidation process duration on surface morphology, crystalline phase composition, and electrochemical corrosion performance of pulsed plasma-oxidized AISI 316L stainless steel were studied. Analysis of results shows that samples treated through DC pulsed plasma oxidation (0.5 mA/cm2, 60 min) exhibit corrosion current values of 2.0 × 10-4 mA/cm2 which represent one eighth of the corrosion current obtained for untreated samples and one half that of chemically passivated samples. Scanning electron microscopy, grazing incidence x-ray diffraction, and Raman analysis show that the improved corrosion performance of oxidized samples could be attributed to morphological changes of the oxidized layer which is composed of hematite and magnetite iron oxides. Corrosion performances of DC plasma-oxidized samples suggest that through this technique, it is possible to obtain comparable or even better corrosion performance than techniques, such as inductively coupled plasma-oxidizing process, but without the inherent higher instrumental requirements of radiofrequency plasma processes.

  8. Surface interactions of a W-DLC-coated biomedical AISI 316L stainless steel in physiological solution.

    PubMed

    Antunes, Renato A; de Lima, Nelson Batista; Rizzutto, Márcia de Almeida; Higa, Olga Zazuco; Saiki, Mitiko; Costa, Isolda

    2013-04-01

    The corrosion stability of a W-DLC coated surgical AISI 316L stainless steel in Hanks' solution has been evaluated. Particle induced X-ray emission (PIXE) measurements were performed to evaluate the incorporation of potentially bioactive elements from the physiological solution. The film structure was analyzed by X-ray diffractometry and micro-Raman spectroscopy. The wear behavior was assessed using the sphere-on-disc geometry. The in vitro biocompatibility of the W-DLC film was evaluated by cytotoxicity tests. The corrosion resistance of the stainless steel substrate decreased in the presence of the PVD layer. EIS measurements suggest that this behavior was closely related to the corrosion attack through the coating pores. PIXE measurements revealed the presence of Ca and P in the W-DLC film after immersion in Hanks' solution. This result shows that the PIXE technique can be applied to identify and evaluate the incorporation of bioactive elements by W-DLC films. The film showed good wear resistance and biocompatibility. PMID:23371768

  9. Influence of Sigma Phase on Pitting Resistance Depending on Solidification Mode in AISI316L Weld Metal

    NASA Astrophysics Data System (ADS)

    Jang, A. Y.; Lee, H. W.

    2012-06-01

    The pitting corrosion resistances were investigated in the AISI 316L stainless steel weld metals with respect to the sigma phase precipitation in a 0.1 M NaCl solution. The modified flux-cored arc welding filler wires were fabricated at various chromium and nickel equivalent ratios using the flux-cored arc welding process. As the Cr/Ni equivalent ratio increased, the precipitated ? phase content increased in the temperature range of 923 K to 1123 K (650 °C to 850 °C), and the specimen that was aged at 1123 K (850 °C) precipitated the ? phase rapidly. The hardness increased with increasing sigma contents. During the potentiodynamic anodic polarization test, the specimens that were aged at 923 K to 1123 K (650 °C to 850 °C) exhibited lower pitting potentials than the as-weld metal. Additionally, the specimens that were aged for longer times exhibited lower pitting potentials. The pits occurred preferentially in the ductility dip cracking in specimen 1, whereas intergranular pits occurred in the sigma phase regions along the vermicular ferrite and acicular ferrite grain boundaries in specimens 2 and 3.

  10. Selection of Wire Electrical Discharge Machining Process Parameters on Stainless Steel AISI Grade-304 using Design of Experiments Approach

    NASA Astrophysics Data System (ADS)

    Lingadurai, K.; Nagasivamuni, B.; Muthu Kamatchi, M.; Palavesam, J.

    2012-06-01

    Wire electrical discharge machining (WEDM) is a specialized thermal machining process capable of accurately machining parts of hard materials with complex shapes. Parts having sharp edges that pose difficulties to be machined by the main stream machining processes can be easily machined by WEDM process. Design of Experiments approach (DOE) has been reported in this work for stainless steel AISI grade-304 which is used in cryogenic vessels, evaporators, hospital surgical equipment, marine equipment, fasteners, nuclear vessels, feed water tubing, valves, refrigeration equipment, etc., is machined by WEDM with brass wire electrode. The DOE method is used to formulate the experimental layout, to analyze the effect of each parameter on the machining characteristics, and to predict the optimal choice for each WEDM parameter such as voltage, pulse ON, pulse OFF and wire feed. It is found that these parameters have a significant influence on machining characteristic such as metal removal rate (MRR), kerf width and surface roughness (SR). The analysis of the DOE reveals that, in general the pulse ON time significantly affects the kerf width and the wire feed rate affects SR, while, the input voltage mainly affects the MRR.

  11. The corrosion protection of AISI(TM) 1010 steel by organic and inorganic zinc-rich primers

    NASA Technical Reports Server (NTRS)

    Danford, M. D.; Mendrek, M. J.

    1995-01-01

    The behavior of zinc-rich primer-coated AISI 1010 steel in 3.5-percent Na-Cl was investigated using electrochemical techniques. The alternating current (ac) method of electrochemical impedance spectroscopy (EIS), in the frequency range of 0.001 to 40,000 Hz, and the direct current (dc) method of polarization resistance (PR), were used to evaluate the characteristics of an organic, epoxy zinc-rich primer and an inorganic, ethyl silicate zinc-rich primer. A dc electromechanical galvanic corrosion test was also used to determine the corrosion current of each zinc-rich primer anode coupled to a 1010 steel cathode. Duration of the EIS/PR and galvanic testing was 21 days and 24 h, respectively. The galvanic test results demonstrated a very high current between the steel cathode and both zinc-rich primer anodes (38.8 and 135.2 microns A/sq cm for the organic and inorganic primers, respectively). The results of corrosion rate determinations demonstrated a much higher corrosion rate of the zinc in the inorganic primer than in the organic primer, due primarily to the higher porosity in the former. EIS equivalent circuit parameters confirmed this conclusion. Based on this investigation, the inorganic zinc-rich primer appears to provide superior galvanic protection and is recommended for additional study for application on solid rocket booster steel hardware.

  12. The effect of prior cold-work on the deformation behaviour of neutron irradiated AISI 304 austenitic stainless steel

    NASA Astrophysics Data System (ADS)

    Karlsen, Wade; Van Dyck, Steven

    2010-11-01

    Cold-work is intentionally employed to increase the yield strength of austenitic stainless steels and also occurs during fabrication processes, but it has also been associated with greater incidence of stress corrosion cracking. This study examined the effect of up to 3.85 dpa neutron irradiation on the deformation behaviour and microstructures of 30% cold-worked AISI 304 material tensile tested at 300 °C. While the deformation behaviour of 0.07 dpa material was similar to non-irradiated material tested at the same temperature, its stress-strain curve was shifted upwards by about 200 MPa. Materials irradiated to over 2 dpa hardened some 400-500 MPa, but showed limited strain hardening capacity, exhibiting precipitous softening with further straining beyond the yield point. The observed behaviour is most likely a consequence of planar deformation products serving as strengtheners to the unirradiated bulk on the one hand, while promoting strain localization on the other, behaviour exacerbated by the subsequent neutron irradiation.

  13. Electrochemical characterization of AISI 316L stainless steel in contact with simulated body fluid under infection conditions.

    PubMed

    López, Danián Alejandro; Durán, Alicia; Ceré, Silvia Marcela

    2008-05-01

    Titanium and cobalt alloys, as well as some stainless steels, are among the most frequently used materials in orthopaedic surgery. In industrialized countries, stainless steel devices are used only for temporary implants due to their lower corrosion resistance in physiologic media when compared to other alloys. However, due to economical reasons, the use of stainless steel alloys for permanent implants is very common in developing countries. The implantation of foreign bodies is sometimes necessary in the modern medical practice. However, the complex interactions between the host and the can implant weaken the local immune system, increasing the risk of infections. Therefore, it is necessary to further study these materials as well as the characteristics of the superficial film formed in physiologic media in infection conditions in order to control their potential toxicity due to the release of metallic ions in the human body. This work presents a study of the superficial composition and the corrosion resistance of AISI 316L stainless steel and the influence of its main alloying elements when they are exposed to an acidic solution that simulates the change of pH that occurs when an infection develops. Aerated simulated body fluid (SBF) was employed as working solution at 37 degrees C. The pH was adjusted to 7.25 and 4 in order to reproduce normal body and disease state respectively. Corrosion resistance was measured by means of electrochemical impedance spectroscopy (EIS) and anodic polarization curves. PMID:17999036

  14. Correlation between surface physicochemical properties and the release of iron from stainless steel AISI 304 in biological media.

    PubMed

    Hedberg, Yolanda; Karlsson, Maria-Elisa; Blomberg, Eva; Odnevall Wallinder, Inger; Hedberg, Jonas

    2014-10-01

    Stainless steel is widely used in biological environments, for example as implant material or in food applications, where adsorption-controlled ligand-induced metal release is of importance from a corrosion, health, and food safety perspective. The objective of this study was to elucidate potential correlations between surface energy and wettability of stainless steel surfaces and the release of iron in complexing biological media. This was accomplished by studying changes in surface energies calculated from contact angle measurements, surface oxide composition (X-ray photoelectron spectroscopy), and released iron (graphite furnace atomic absorption spectroscopy) for stainless steel grade AISI 304 immersed in fluids containing bovine serum albumin or citric acid, and non-complexing fluids such as NaCl, NaOH, and HNO3. It was shown that the surface wettability and polar surface energy components were all influenced by adventitious atmospheric carbon (surface contamination of low molecular weight), rather than differences in surface oxide composition in non-complexing solutions. Adsorption of both BSA and citrate, which resulted in ligand-induced metal release, strongly influenced the wettability and the surface energy, and correlated well with the measured released amount of iron. PMID:25048358

  15. Influence of ultrasonic cavitation on surface residual stresses in AISI 304 stainless steel

    Microsoft Academic Search

    M. R. Sriraman; R. Vasudevan

    1998-01-01

    The effect of ultrasonic cavitation in water on residual stress changes in AlSl 304 stainless steel has been investigated. Studies indicate that high-intensity ultrasonic cavitation introduces a very high compressive residual stress at the surface (due to work-hardening) even for short durations of exposure at ambient temperatures. With increased exposure, the stresses become more compressive; however, they tend to reach

  16. AISI 303 OSTEN?T?K PASLANMAZ ÇEL?KLER?N ??LENMES?NDE KESME HIZI VE ?LERLEMEN?N KESME KUVVETLER? VE YÜZEY PÜRÜZLÜLÜ?Ü ÜZER?NDEK? ETK?LER? THE EFFECTS OF CUTTING SPEED AND FEED RATE ON CUTTING FORCES AND SURFACE ROUGHNESS IN MACHINING OF AISI 303 AUSTENITIC STAINLESS STEEL

    Microsoft Academic Search

    Hasan Emrah YEYEN; Yakup TURGUT

    c,* ?brahim Ç?FTÇ? d Abstract In this study, the effects of cutting speed and feed rate on cutting forces and surface roughness by AISI 303 austenitic stainless steel machining have been investigated. The tests were carried out at four different cutting speeds (120, 150, 180 and 210 m\\/min) and three different feed rates (0.20, 0.24 and 0.30 mm\\/rev) at a

  17. EVALUACIÓN DE LA CORROSIÓN EN CALIENTE POR MÉTODOS ELECTROQUÍMICOS DE UN ACERO AISI 304H EN PRESENCIA DEL ÓXIDO DE NÍQUEL COMO INHIBIDOR. HOT CORROSION EVALUATION BY ELECTROCHEMICAL METHODS OF STAINLESS STEEL AISI 304H IN PRESENCE OF NICKEL OXIDE AS INHIBITOR

    Microsoft Academic Search

    DARIO YESID; HUBER A. ANAYA

    2007-01-01

    In this research, the behaviour of nickel oxide as inhibitor of hot corrosion of stainless steel AISI 304H in presence of a salt compound for 80% V2O5 - 20%Na2SO4 in weight and oxidant atmosphere of 99%O2 - 1%SO2 was studied. Two molars ratios inhibitor \\/ salt 2:1 and 3:1 were used and electrochemical techniques as linear polarization resistance, EIS and

  18. Ionic Liquids as Lubricants of Titanium–Steel Contact. Part 3. Ti6Al4V Lubricated with Imidazolium Ionic Liquids with Different Alkyl Chain Lengths

    Microsoft Academic Search

    A. E. Jiménez; M. D. Bermúdez

    2010-01-01

    The tribological behaviour and surface interactions of Ti6Al4V sliding against AISI 52100 steel have been studied in the presence\\u000a of three commercial methylimidazolium (mim) room-temperature ionic liquids (ILs) containing the same anion, bis(trifluoromethylsulfonyl)amide,\\u000a [(CF3SO2)2N] (Tf2N), and cations with increasing alkyl chain length, 1-ethyl-3-methylimidazolium [C2mim], 1-butyl-3-methylimidazolium [C4mim] and 1-octyl-3-methylimidazolium [C8mim]. Increasing alkyl chain length increases viscosity whilst reducing the onset temperature

  19. Solid-state diffusion welding of wrought AISI 304 stainless steel to Nimonic AP-1 superalloy powder by hot isostatic pressing

    SciTech Connect

    Somani, M.C.; Birla, N.C. [Defence Metallurgical Research Lab., Hyderabad (India); Tekin, A. [Istanbul Technical Univ., Istanbul (Turkey). Dept. of Chemical and Metallurgical Engineering

    1998-02-01

    The diffusion welding characteristics of wrought AISI 304 stainless steel to a superalloy powder Nimonic AP-1 were examined in this study. After encapsulation, evacuation and degassing, the welds were hot isostatically pressed (HIPed) in two different cycles, i.e., 1,200 C (2,192 F)/3h/147 MPa and 1,270 C (2,318 F)/3h/121 MPa. A variation in surface condition of stainless steel was also studied for its influence on properties of the joints. These diffusion-welded joints were characterized for diffusion of alloying elements, microstructural features and tensile properties.

  20. Effects of surface mechanical attrition treatment (SMAT) on a rough surface of AISI 316L stainless steel

    NASA Astrophysics Data System (ADS)

    Arifvianto, B.; Suyitno; Mahardika, M.

    2012-03-01

    Surface mechanical attrition treatment (SMAT) improves mechanical properties of metallic materials through the formation of nanocrystallites at their surface layer. It also modifies the morphology and roughness of the work surface. Surface roughening by the SMAT has been reported previously in a smooth specimen, however in this study the starting point was a rough surface and a smoothening phenomenon is observed. In this paper, the mechanisms involved in the surface smoothening of AISI 316L stainless steel during the SMAT are elucidated. The SMAT was conducted on a specimen with a roughness of Ra = 3.98 ?m for 0-20 min. The size of milling balls used in the SMAT was varied from 3.18 mm to 6.35 mm. The modification of subsurface microhardness, surface morphology, roughness and mass reduction of the specimen due to the SMAT were studied. The result shows the increasing microhardness of the surface and subsurface of the steel due to the SMAT. The impacts of milling balls deform the surface and produce a flat-like structure at this layer. Surface roughness decreases until its saturation is achieved in the SMAT. The mass reduction of the specimens is also detected and may indicate material removal or surface erosion by the SMAT. The size of milling ball is found to be the important feature determining the pattern of roughness evolution and material removal during the SMAT. From this study, two principal mechanisms in the evolution of surface morphology and roughness during the SMAT are proposed, i.e. indentation and surface erosion by the multiple impacts of milling balls. A comparative study with the results of the previous experiment indicates that the initial surface roughness has no influence in the work hardening by the SMAT but it does slightly on the saturated roughness value obtained by this treatment.

  1. A Simple Kinetic Model for the Growth of Fe2B Layers on AISI 1026 Steel During the Powder-pack Boriding

    NASA Astrophysics Data System (ADS)

    Flores-Rentería, M. A.; Ortiz-Domínguez, M.; Keddam, M.; Damián-Mejía, O.; Elias-Espinosa, M.; Flores-González, M. A.; Medina-Moreno, S. A.; Cruz-Avilés, A.; Villanueva-Ibañez, M.

    2015-02-01

    This work focused on the determination of boron diffusion coefficient through the Fe2B layers on AISI 1026 steel using a mathematical model. The suggested model solves the mass balance equation at the (Fe2B/substrate) interface. This thermochemical treatment was carried out in the temperature range of 1123-1273 K for a treatment time ranging from 2 to 8 h. The generated boride layers were characterized by different experimental techniques such as light optical microscopy, scanning electron microscopy, XRD analysis and the Daimler-Benz Rockwell-C indentation technique. As a result, the boron activation energy for AISI 1026 steel was estimated as 178.4 kJ/mol. Furthermore, this kinetic model was validated by comparing the experimental Fe2B layer thickness with the predicted one at a temperature of 1253 K for 5 h of treatment. A contour diagram relating the layer thickness to the boriding parameters was proposed to be used in practical applications.

  2. The effect of microstructure on the thermal fatigue resistance of investment cast and wrought AISI H13 hot work die steel

    SciTech Connect

    Hochanadel, P.W.; Edwards, G.R. [Colorado School of Mines, Golden, CO (United States); Maguire, M.C.; Baldwin, M.D. [Sandia National Labs., Albuquerque, NM (United States)

    1995-07-01

    Variable thickness plate investment castings of AISI H13 hot work die steel were pour and characterized in the as-cast and heat treated conditions. The characterization included light microscopy and mechanical testing. Wrought samples of standard and premium grade H13 steel were heat treated and characterized similarly for comparison. Microstructural differences were observed in as-cast samples poured to different section thicknesses. Dendrite cell size and carbide morphology constituted the most prominent microstructural differences observed. After a full heat treatment, however, Microstructural differences between the wrought material and cast materials were slight regardless of section thickness. The mechanical properties of the cast and heat treated material proved similar to the properties of the standard heat treated wrought material. A thermal fatigue testing unit was designed and built to correlate the heat checking susceptibility of AISI H13 steel to its processing and consequent microstructural condition. Surface hardness decreased significantly with thermal cycling, and heat checking was noticed in as few as 50 cycles. Thermal softening and thermal fatigue susceptibility were quantified and discussed relative to the microstructural conditions created by processing and heat treatment. It was found that the premium grade wrought H13 steel provided the best overall resistance to heat checking; however, the heat-treat cast and as-cast H13 tool steel (made from standard grade wrought H13 tool steel) provided comparable resistance to heat checking in terms Of area fraction of heat checking and maximum crack length.

  3. High temperature oxidation of HFPD thermal-sprayed MCrAlY coatings in simulated gas turbine environments

    NASA Astrophysics Data System (ADS)

    Belzunce, F. J.; Higuera, V.; Poveda, S.; Carriles, A.

    2002-12-01

    NiCrAlY and CoNiCrAlY powders were thermal-sprayed using the high frequency pulse detonation method (HFPD) onto AISI 310 austenitic stainless steel samples to obtain dense, adherent, high temperature oxidation resistant coatings. The oxidation behavior of both types of coatings in a 1000°C simulated gas turbine environment was experimentally determined. The porosity, hardness, coating thickness, and microstructure were not significantly modified by the high temperature oxidation cycles, but the internal oxidation increases significantly after a very low oxidation time. Surface phase composition was evaluated using x-ray diffraction (XRD) and scanning electron microscope (SEM) techniques, revealing the formation of a continuous and highly protective alumina layer. The oxidation kinetics of both coatings can be characterized by parabolic rate constants, which are very close to those for the formation of aluminum oxide on nickel or cobalt based alloys at similar conditions.

  4. Microstructure and corrosion resistance of nanocrystalline TiZrN films on AISI 304 stainless steel substrate

    SciTech Connect

    Lin, Yu-Wei; Huang, Jia-Hong; Yu, Ge-Ping [Instrument Technology Research Center, 20 R and D Road VI, Hsinchu Science-Based Industrial Park, Hsinchu 300, Taiwan, Republic of China and Department of Engineering and System Science, National Tsing Hua University, 101 Kuang Fu Rd., Sec. 2, Hsinchu 300, Taiwan (China); Department of Engineering and System Science, National Tsing Hua University, 101 Kuang Fu Rd., Sec. 2, Hsinchu 300, Taiwan (China); Department of Engineering and System Science, National Tsing Hua University, 101 Kuang Fu Rd., Sec. 2, Hsinchu 300, Taiwan, Republic of China and Institute of Nuclear Engineering and Science, National Tsing Hua University, 101 Kuang Fu Rd., Sec. 2, Hsinchu 300, Taiwan (China)

    2010-07-15

    This study investigated the microstructure and properties of nanocrystalline TiZrN films on AISI 304 stainless steel substrate. TiZrN films were prepared by reactive magnetron sputtering based on the previous optimum coating conditions (substrate temperature, system pressure, nitrogen flow, etc.) for TiN and ZrN thin films. The composition ratio of TiZrN coatings were adjusted by changing the Zr target power, while keeping the Ti target power constant. Experiments were conduced to find the optimum composition with desired properties. The ratio of TiZrN composition was analyzed by x-ray photoelectron spectroscopy and Rutherford backscattering spectrometer. In terms of phase formation, there were two types of coatings that were considered: single-phase solid solutions of TiZrN and interlacing nuclei of TiZr in the matrix of TiZrN. The thickness of all TiZrN films as measured by the secondary ion mass spectroscopy was about 500 nm, and the composition depth profiles indicated that the compositions in the TiZrN films were uniform from the film surface to the 304 stainless steel substrate. The crystal structure of the TiZrN films was determined by x-ray diffraction using a M18XHF-SRA diffractometer with Cu K{sub {alpha}} radiation. A diffraction peak of TiZrN (002) was observed between that of TiN (002) and ZrN (002); similarly, a diffraction peak of TiZrN (111) was observed between that of TiN(111) and ZrN(111), respectively. The corrosion resistance of the TiZrN film deposited on the 304 stainless steel has been investigated by electrochemical measurement. The electrolyte, 0.5M H{sub 2}SO{sub 4} containing 0.05M KSCN, was used for the potentiodynamic polarization. The potentiodynamic scan was conducted from -800 to 800 mV standard calomel electrode (SCE).

  5. Combined bending-torsion fatigue reliability of AISI 4340 steel shafting with K sub t = 2.34. [stress concentration factor

    NASA Technical Reports Server (NTRS)

    Kececioglu, D.; Chester, L. B.; Dodge, T. M.

    1974-01-01

    Results generated by three, unique fatigue reliability research machines which can apply reversed bending loads combined with steady torque are presented. Six-inch long, AISI 4340 steel, grooved specimens with a stress concentration factor of 2.34 and R sub C 35/40 hardness were subjected to various combinations of these loads and cycled to failure. The generated cycles-to-failure and stress-to-failure data are statistically analyzed to develop distributional S-N and Goodman diagrams. Various failure theories are investigated to determine which one represents the data best. The effect of the groove and of the various combined bending-torsion loads on the S-N and Goodman diagrams are determined. Three design applications are presented. The third one illustrates the weight savings that may be achieved by designing for reliability.

  6. Mechanical and tribological properties of AISI 304 stainless steel nitrided by glow discharge compared to ion implantation and plasma immersion ion implantation

    NASA Astrophysics Data System (ADS)

    Foerster, C. E.; Serbena, F. C.; da Silva, S. L. R.; Lepienski, C. M.; Siqueira, C. J. de M.; Ueda, M.

    2007-04-01

    Results about mechanical and tribological behavior of AISI 304 stainless steel nitrided by three different ion beam processes - glow discharge (GD), ion implantation (II) and plasma immersion ion implantation (PI3) are reported. Expanded austenite ?N and nitrides phases (Fe2+xN, ??-Fe4N and Cr-N) were identified as a function of nitriding conditions. Hardness (H) and elastic modulus (E) profiles were obtained by instrumented penetration. The hardness reached values as high as 21 GPa by PI3. Tribological behavior was studied by reciprocating sliding tests with a WC (Co) ball at room temperature (RT) in dry condition. Different wear regimes were identified in the friction coefficient profiles. The profile form and the running-in distance are strongly dependent on the nitriding process. Adhesive and abrasive wear components can be inferred from these friction profiles. Hardness and tribological performance, after the nitriding processes, are discussed in terms of surface microstructure.

  7. Microstructure and property modifications of an AISI H13 (4Cr5MoSiV) steel induced by pulsed electron beam treatment

    SciTech Connect

    Zhang Kemin; Zou Jianxin; Grosdidier, Thierry; Dong Chuang [School of Materials Engineering, Shanghai University of Engineering Science, Shanghai 201620 (China); Shanghai Engineering Research Center of Mg Materials and Applications and School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China) and Laboratoire d'Etude des Textures et Applications aux Materiaux (LETAM, CNRS 3143), Universite Paul Verlaine Metz, Ile du Saulcy, 57045 Metz (France); Laboratoire d'Etude des Textures et Applications aux Materiaux (LETAM, CNRS 3143), Universite Paul Verlaine Metz, Ile du Saulcy, 57045 Metz (France) and Laboratory of Materials Modification by Laser, Electron and Ion Beams, Dalian University of Technology, Dalian 116024 (China); Laboratory of Materials Modification by Laser, Electron and Ion Beams, Dalian University of Technology, Dalian 116024 (China)

    2010-11-15

    In the present work, surface modifications generated by the low energy high current pulsed electron beam (LEHCPEB) treatments have been investigated on an AISI H13 (4Cr5MoSiV) steel. From the observations of scanning electron microscopy, x-ray diffraction, and electron back scattering diffraction determinations, it could be established that the final structure in the melted layer is a mixture of ultrafine {delta} phase, martensite, and residual austenite. The formation of the heterogeneous microstructures on the surface layer is related to the very rapid heating, melting, solidification, and cooling induced by the LEHCPEB irradiation. After the LEHCPEB treatment, the wear resistance of the steel effectively improved. This can be mainly attributed to the higher hardness of the ultrafine structures formed on the top surface and the hardened subsurface layers after the treatment.

  8. Improvement of localised corrosion resistance of AISI 2205 Duplex Stainless Steel joints made by gas metal arc welding under electromagnetic interaction of low intensity

    NASA Astrophysics Data System (ADS)

    García-Rentería, M. A.; López-Morelos, V. H.; García-Hernández, R.; Dzib-Pérez, L.; García-Ochoa, E. M.; González-Sánchez, J.

    2014-12-01

    The resistance to localised corrosion of AISI 2205 duplex stainless steel plates joined by Gas Metal Arc Welding (GMAW) under the effect of electromagnetic interaction of low intensity (EMILI) was evaluated with sensitive electrochemical methods. Welds were made using two shielding gas mixtures: 98% Ar + 2% O2 (M1) and 97% Ar + 3% N2 (M2). Plates were welded under EMILI using the M1 gas with constant welding parameters. The modified microstructural evolution in the high temperature heat affected zone and at the fusion zone induced by application of EMILI during welding is associated with the increase of resistance to localised corrosion of the welded joints. Joints made by GMAW using the shielding gas M2 without the application of magnetic field presented high resistance to general corrosion but high susceptibility to undergo localised attack.

  9. AISI Direct Steelmaking Program

    SciTech Connect

    Aukrust, E.

    1993-01-01

    Pilot plant trials with the horizontal vessel were completed. Design of a third pressurized vessel and an offgas cleaning and tempering system was completed. Installation is now underway. A basic study and a pre-engineering design of a 350,000-metric ton/y demonstration plant were completed, and efforts are underway to develop such a demonstration plant at a host steel company. Foreign filings have been prepared for the two-zone countercurrent smelter (patent applied for). Work with a water model of two-zone smelter was completed. The horizontal smelter program was completed. Trials were conducted to determine how sulfur is partitioned among the hot metal, slag, and offgas. Design of offgas cleaning and tempering loop was completed.

  10. Influence of nickel ion implantation on the inactive braze joining abilities of Al 2O 3 ceramics

    NASA Astrophysics Data System (ADS)

    Zhao, B. R.; Li, G. B.; Gao, P.; Lei, T. Q.; Song, S. C.; Cao, X. J.

    2005-09-01

    Multi-crystalline Al 2O 3 ceramics were implanted with 130 keV Ni + ion beams at 225 °C in a vacuum of 1.33 × 10 -3 Pa. The inactive braze joining abilities of the implanted ceramic to 1Cr18Ni9Ti (AISI 321) stainless steel with Ag 34Cu 16Zn 50 (wt%) brazing material were investigated. The relationships between the joining abilities and the surface compressive stresses produced by the ion implantation were studied for the first time. The results showed that when the fluence was less than 5 × 10 16 ions/cm 2, the surface properties including wetting ability, braze joining ability and produced surface compressive stresses, increased with ion implantation fluence, and reached the maximum value at a point of 5 × 10 16 ions/cm 2. After this point, the properties decreased upon further increasing the ion implantation fluence.

  11. Cyclic response-electrochemical interaction in mono- and polycrystalline AISI 316L stainless steel in H[sub 2]SO[sub 4] solution-I. The influence of mechanical strain on the transient dissolution behavior during corrosion fatigue

    Microsoft Academic Search

    Y. F. Li; G. C. Farrington; C. Laird

    1993-01-01

    Mono-[gamma] and polycrystalline specimens of an AISI stainless steel were cycled in a 1N H[sub 2]SO[sub 4] solution under different potentials. The correspondence between strain wave form and transient current curve has been studied. Transient current, which has been measured with out-of-the-ordinary resolution, has been demonstrated to have two components: the current associated with plastic strain (CAPS) and the current

  12. Microstructural characterisation of a dissimilar weld of alloy D9 and AISI 316M stainless steel produced using a 2.5 kW CW CO 2 laser

    Microsoft Academic Search

    Rakesh Kaul; P. Ganesh; M. O. Ittoop; A. K. Nath; Aniruddha Kumar; R. B. Bhatt; Arun Kumar

    2002-01-01

    The dissimilar weld, a fuel clad tube (D9 alloy) and an end plug made of AISI 316M forms a part of the fuel pin in the 500 MW Indian Prototype Fast Breeder Reactor (PFBR). The present study aimed at the development of a crack resistant microstructure of the dissimilar weld by optimisation of 2.5 kW CO 2 laser welding parameters.

  13. Long-term evaluation of solid oxide fuel cell candidate materials in a 3-cell generic stack test fixture, part III: Stability and microstructure of Ce-(Mn,Co)-spinel coating, AISI441 interconnect, alumina coating, cathode and anode

    NASA Astrophysics Data System (ADS)

    Chou, Yeong-Shyung; Stevenson, Jeffry W.; Choi, Jung-Pyung

    2014-07-01

    A generic solid oxide fuel cell stack test fixture was developed to evaluate candidate materials and processing under realistic conditions. Part III of the work investigated the stability of Ce-(Mn,Co) spinel coating, AISI441 metallic interconnect, alumina coating, and cell's degradation. After 6000 h test, the spinel coating showed densification with some diffusion of Cr. At the metal interface, segregation of Si and Ti was observed, however, no continuous layer formed. The alumina coating for perimeter sealing areas appeared more dense and thick at the air side than the fuel side. Both the spinel and alumina coatings remained bonded. EDS analysis of Cr within the metal showed small decrease in concentration near the coating interface and would expect to cause no issue of Cr depletion. Inter-diffusion of Ni, Fe, and Cr between spot-welded Ni wire and AISI441 interconnect was observed and Cr-oxide scale formed along the circumference of the weld. The microstructure of the anode and cathode was discussed relating to degradation of the top and middle cells. Overall, the Ce-(Mn,Co) spinel coating, alumina coating, and AISI441 steel showed the desired long-term stability and the developed generic stack fixture proved to be a useful tool to validate candidate materials for SOFC.

  14. Brazing of hot isostatically pressed-Al2O3 to stainless steel (AlSl 304L) by Mo-Mn route using 72Ag-28Cu braze

    NASA Astrophysics Data System (ADS)

    Mishra, P.; Athavale, S. N.; Pappachan, A. L.; Grover, A. K.; Suri, A. K.; Sengupta, P.; Kale, G. B.; Bhanumurthy, K.; de, P. K.

    2005-06-01

    Joining of stainless steel (AISI 304L) to hot isostatically pressed alumina (HIP-Al2O3) using the brazing alloy 72Ag-28Cu was investigated. The microstructural characterization at various stages of joining, including metallization, annealing of overlaid Ni coating, and brazing, was comprehensively evaluated. The interface structure and the growth of phases were analyzed with optical microscope, scanning electron microscope, and electron probe microanalyzer (EPMA). Additionally, the leak tightness of these joints was assessed using a He-leak detector. Experimental results indicated the development of the manganese aluminate spinel (MnAl2O4) layer at the metallizing stage, which penetrated into HIP-Al2O3. The Ni overlaid coating further resulted in the formation of the Ni(Mo) solid solution layer followed by the Mo-rich phase. During the solid-state reaction and subsequent brazing cycle, the growth of the spinel layer close to HIP-Al2O3 was not adversely affected. The microstructure of the brazed joint was complex. It showed a eutectic structure within the brazed zone and a thin layer of Mo-rich, Ni-rich phases close to HIP-Al2O3. Increasing the brazing time resulted in the excessive growth of the thin layer that seriously affected the leak tightness of the joint.

  15. Finite Element Modelling of the effect of tool rake angle on tool temperature and cutting force during high speed machining of AISI 4340 steel

    NASA Astrophysics Data System (ADS)

    Sulaiman, S.; Roshan, A.; Ariffin, M. K. A.

    2013-12-01

    In this paper, a Finite Element Method (FEM) based on the ABAQUS explicit software which involves Johnson-Cook material model was used to simulate cutting force and tool temperature during high speed machining (HSM) of AISI 4340 steel. In this simulation work, a tool rake angle ranging from 0° to 20° and a range of cutting speeds between 300 to 550 m/min was investigated. The purpose of this simulation analysis was to find optimum tool rake angle where cutting force is smallest as well as tool temperature is lowest during high speed machining. It was found that cutting forces to have a decreasing trend as rake angle increased to positive direction. The optimum rake angle observed between 10° and 18° due to decrease of cutting force as 20% for all simulated cutting speeds. In addition, increasing cutting tool rake angle over its optimum value had negative influence on tool's performance and led to an increase in cutting temperature. The results give a better understanding and recognition of the cutting tool design for high speed machining processes.

  16. Influence of Surface Position along the Working Range of Conoscopic Holography Sensors on Dimensional Verification of AISI 316 Wire EDM Machined Surfaces

    PubMed Central

    Fernández, Pedro; Blanco, David; Rico, Carlos; Valiño, Gonzalo; Mateos, Sabino

    2014-01-01

    Conoscopic holography (CH) is a non-contact interferometric technique used for surface digitization which presents several advantages over other optical techniques such as laser triangulation. Among others, the ability for the reconstruction of high-sloped surfaces stands out, and so does its lower dependence on surface optical properties. Nevertheless, similarly to other optical systems, adjustment of CH sensors requires an adequate selection of configuration parameters for ensuring a high quality surface digitizing. This should be done on a surface located as close as possible to the stand-off distance by tuning frequency (F) and power (P) until the quality indicators Signal-to-Noise Ratio (SNR) and signal envelope (Total) meet proper values. However, not all the points of an actual surface are located at the stand-off distance, but they could be located throughout the whole working range (WR). Thus, the quality of a digitized surface may not be uniform. The present work analyses how the quality of a reconstructed surface is affected by its relative position within the WR under different combinations of the parameters F and P. Experiments have been conducted on AISI 316 wire EDM machined flat surfaces. The number of high-quality points digitized as well as distance measurements between different surfaces throughout the WR allowed for comparing the metrological behaviour of the CH sensor with respect to a touch probe (TP) on a CMM. PMID:24662452

  17. Surface properties of nitrided layer on AISI 316L austenitic stainless steel produced by high temperature plasma nitriding in short time

    NASA Astrophysics Data System (ADS)

    Li, Yang; Wang, Zhuo; Wang, Liang

    2014-04-01

    It has generally been believed that the formation of the S phase or expanded austenite ?N with enough thickness depends on the temperature (lower than 480 °C) and duration of the process. In this work, we attempt to produce nitrogen expanded austenite layer at high temperature in short time. Nitriding of AISI 316L austenitic stainless steel was carried out at high temperatures (>520 °C) for times ranging from 5 to 120 min. The microstructures, chemical composition, the thickness and the morphology of the nitrided layer, as well as its surface hardness, were investigated using X-ray diffraction, X-ray photoelectron spectroscopy, optical microscopy, scanning electron microscopy, and microhardness tester. The corrosion properties of the untreated and nitrided samples were evaluated using anodic polarization tests in 3.5% NaCl solution. The results confirmed that nitrided layer was shown to consist of ?N and a small amount of free-CrN and iron nitrides. High temperature plasma nitriding not only increased the surface hardness but also improved the corrosion resistance of the austenitic stainless steel, and it can critically reduce processing time compared with low temperature nitriding.

  18. Prediction of scuffing failure based on competitive kinetics of oxide formation and removal: Application to lubricated sliding of AISI 52100 steel on steel

    NASA Astrophysics Data System (ADS)

    Cutiongco, Eric C.; Chung, Yip-Wah

    1994-07-01

    A method for predicting scuffing failure based on the competitive kinetics of oxide formation and removal has been developed and applied to the sliding of AISI 52100 steel on steel with poly-alpha-olefin as the lubricant. Oxide formation rates were determining using static oxidation tests on coupons of 52100 steel covered with poly-alpha-olefin at temperatures of 140 C to 250 C. Oxide removal rates were determined at different combinations of initial average nominal contact pressures (950 MPa to 1578 MPa) and sliding velocities (0.4 m/s to 1.8 m/s) using a ball-on-disk vacuum tribotester. The nominal asperity flash temperatures generated during the wear tests were calculated and the temperatures corresponding to the intersection of the the Arrhenius plots of oxide formation and removal rates were determined and taken as the critical failure temperatures. The pressure-velocity failure transition diagram was constructed by plotting the critical failure temperatures along isotherms of average nominal asperity flash temperatures calculated at different combinations of contact stress and sliding speed. The predicted failure transition curve agreed well with experimental scuffing data.

  19. Role of environmental variables on the stress corrosion cracking of sensitized AISI type 304 stainless steel (SS304) in thiosulfate solutions

    NASA Astrophysics Data System (ADS)

    Roychowdhury, S.; Ghosal, S. K.; de, P. K.

    2004-10-01

    The stress corrosion cracking (SCC) behavior of sensitized AISI type 304 stainless steel (SS304) has been studied in dilute thiosulfate solutions as a function of thiosulfate concentrations and applied potentials. The susceptibility to SCC was observed to increase with thiosulfate concentrations and applied potentials. The addition of boric acid produced the reverse effect. A critical potential was found to exist, below which no SCC took place. Potential fluctuations, as recorded in the tests under open circuit conditions, appeared to be correlated with crack initiation and propagation during SCC. Current fluctuations observed in the controlled potential tests also gave indications of crack nucleation; however, at higher applied potentials such fluctuations were absent. The formation and presence of martensite in the specimens seemed to have a minor role in the overall SCC process. The aggressiveness of the thiosulfate concentration was also an important factor in determining the degree of susceptibility to SCC. The results obtained in the slow strain rate tests under open circuit as well as under potential-controlled conditions suggested a film ruptureanodic dissolution type of mechanism operative during SCC of sensitized SS304 in thiosulfate solutions.

  20. The effect of gas mixture of post-oxidation on structure and corrosion behavior of plasma nitrided AISI 316 stainless steel

    NASA Astrophysics Data System (ADS)

    Karimzadeh, N.; Moghaddam, E. G.; Mirjani, M.; Raeissi, K.

    2013-10-01

    In this research, microstructure and corrosion properties of plasma nitriding and post-oxidation treated AISI 316 austenitic stainless steel have been studied. The plasma nitriding treatment was carried out at 450 °C for 5 h in a D.C. plasma setup with a gas mixture of 25% N2-75% H2 followed by post-oxidation in gas mixtures of O2/H2: 1/3, 1/5, 1/9 and 1/12 for 30 min. The treated samples were characterized by SEM, XRD and roughness testing. Potentiodynamic and cyclic polarization tests were also employed to evaluate the corrosion resistance of the samples. The results showed that plasma nitriding treatment decreases corrosion resistance of the steel substrate. However, post-oxidizing treatment improves both uniform and pitting corrosion resistances of the nitrided specimens. This effect was most pronounced by post-oxidizing at lower O2/H2 ratios due to the development of magnetite as a more dense oxide phase over the modified layer.

  1. Corrosion of nickel—chromium deposit on AISI 316L stainless steel in radioactive water with and without fluoride at pH 4

    NASA Astrophysics Data System (ADS)

    Bellanger, G.; Rameau, J. J.

    1995-10-01

    The electrochemical behavior of samples was studied using potentiodynamic techniques at low scan rates, cyclic voltammetry at high scan rates and electrochemical impedance spectroscopy. The surfaces were examined and analyzed by scanning electron microscopy and X-ray microanalysis, respectively. The results from these different methods are discussed. They show that the deposit is more easily corroded than the AISI 316L stainless steel in presence or absence of fluoride. With fluoride and at the prepassive potentials, the Warburg straight line indicates that there is ionic diffusion in the nickel—chromium deposit oxide. The equivalent circuits for the nickel-chromium are proposed and indicate that the deposit can take part in localized corrosion. The use of high scan rates shows the transient kinetics of the oxide formation in presence of fluoride. With fluoride, the pitting currents are higher for nickel-chromium deposits. The SEM photographs and polarization curves show that the Ni?Cr deposit is locally corroded by fluoride, leading to the possibility of crevice formation under this and in 316L stainless steel.

  2. Microstructural Characterization and Wear Behavior of Nano-Boride Dispersed Coating on AISI 304 Stainless Steel by Hybrid High Velocity Oxy-Fuel Spraying Laser Surface Melting

    NASA Astrophysics Data System (ADS)

    Sharma, Prashant; Majumdar, Jyotsna Dutta

    2015-07-01

    The current study concerns the detailed microstructural characterization and investigation of wear behavior of nano-boride dispersed coating developed on AISI 304 stainless steel by high velocity oxy-fuel spray deposition of nickel-based alloy and subsequent laser melting. There is a significant refinement and homogenization of microstructure with improvement in microhardness due to laser surface melting (1200 VHN as compared to 945 VHN of as-sprayed and 250 VHN of as-received substrate). The high temperature phase stability of the as-coated and laser melted surface has been studied by differential scanning calorimeter followed by detailed phase analysis at room and elevated temperature. There is a significant improvement in wear resistance of laser melted surface as compared to as-sprayed and the as-received one due to increased hardness and reduced coefficient of friction. The mechanism of wear has been investigated in details. Corrosion resistance of the coating in a 3.56 wt pct NaCl solution is significantly improved (4.43 E-2 mm/year as compared to 5 E-1 mm/year of as-sprayed and 1.66 mm/year of as-received substrate) due to laser surface melting as compared to as-sprayed surface.

  3. Dissertation; Anerkennung als Diplomarbeit

    Microsoft Academic Search

    Kostal

    2008-01-01

    Keine gleichheitsrechtlichen Bedenken gegen den Ausschluss der Anerkennung einer Dissertation in einer bestimmten Studienrichtung\\u000a als Diplomarbeit einer anderen Studienrichtung durch die Novelle 2006 zum Universitätsgesetz 2002 sowie gegen den Ausschluss\\u000a der Anerkennung einer Dissertation als Dissertation einer anderen Studienrichtung; qualitative Verschiedenheit von Dissertation\\u000a und Diplomarbeit sowie unterschiedliche Qualifikationserfordernisse.

  4. ALS2 mutations

    PubMed Central

    Schneider, Susanne A.; Carr, Lucinda; Deuschl, Guenther; Hopfner, Franziska; Stamelou, Maria; Wood, Nicholas W.; Bhatia, Kailash P.

    2014-01-01

    Objective: To determine the genetic etiology in 2 consanguineous families who presented a novel phenotype of autosomal recessive juvenile amyotrophic lateral sclerosis associated with generalized dystonia. Methods: A combination of homozygosity mapping and whole-exome sequencing in the first family and Sanger sequencing of candidate genes in the second family were used. Results: Both families were found to have homozygous loss-of-function mutations in the amyotrophic lateral sclerosis 2 (juvenile) (ALS2) gene. Conclusions: We report generalized dystonia and cerebellar signs in association with ALS2-related disease. We suggest that the ALS2 gene should be screened for mutations in patients who present with a similar phenotype. PMID:24562058

  5. Who Gets ALS?

    MedlinePLUS

    ... compounds and drugs under investigation. Last revised 4/2015 Site Map | Press Room | FAQ | Privacy Policy | Link ... are owned and copyrighted by The ALS Association. ©2015 Lou Gehrig® used with permission of the Rip ...

  6. Ag-Al-Ca

    NASA Astrophysics Data System (ADS)

    Carow-Watamura, U.; Louzguine, D. V.; Takeuchi, A.

    This document is part of Part 1 http://dx.doi.org/10.1007/97.etType="URL"/> 'Systems from Ag-Al-Ca to Au-Pd-Si' of Subvolume B 'Physical Properties of Ternary Amorphous Alloys' of Volume 37 'Phase Diagrams and Physical Properties of Nonequilibrium Alloys' of Landolt-Börnstein - Group III 'Condensed Matter'. It contains the Chapter 'Ag-Al-Ca' with the content:

  7. Rapidly solidified NiAl and FeAl

    NASA Technical Reports Server (NTRS)

    Gaydosh, D. J.; Crimp, M. A.

    1984-01-01

    Melt spinning was used to produce rapidly solidified ribbons of the B2 intermetallics NiAl and FeAl. Both Fe-40Al and Fe-45Al possessed some bend ductility in the as spun condition. The bend ductility of Fe-40Al, Fe-45Al, and equiatomic NiAl increased with subsequent heat treatment. Heat treatment at approximately 0.85 T (sub m) resulted in significant grain growth in equiatomic FeAl and in all the NiAl compositions. Low bend ductility in both FeAl and NiAl generally coincided with intergranular failure, while increased bend ductility was characterized by increasing amounts of transgranular cleavage fracture.

  8. ALS superbend magnet performance

    SciTech Connect

    Marks, Steve; Zbasnik, John; Byrne, Warren; Calais, Dennis; Chin, Michael; DeMarco, Richard; Fahmie, Michael; Geyer, Alan; Krupnick, Jim; Ottens, Fred; Paterson, James A.; Pipersky, Paul; Robin, David S.; Schlueter, RossD.; Steier, Christoph; Wandesforde, Alan

    2001-12-10

    The Lawrence Berkeley National Laboratory has been engaged in the design, construction and testing of four superconducting dipoles (Superbends) that are installed in three arcs of the Advanced Light Source (ALS), with the fourth magnet as a spare. This represents a major upgrade to the ALS providing an enhanced flux and brightness at photon energies above 10 keV. In preparation for installation, an extensive set of tests and measurements have been conducted to characterize the magnetic and cryogenic performance of the Superbends and to fiducialize them for accurate placement in the ALS storage ring. The magnets are currently installed, and the storage ring is undergoing final commissioning. This paper will present the results of magnetic and cryogenic testing.

  9. DETERMINACIÓN DE LAS RESERVAS DE CARBONO EN LA BIOMASA AÉREA DE SISTEMAS AGROFORESTALES DE Theobroma cacao L. EN EL DEPARTAMENTO DE SAN MARTÌN, PERU DETERMINATION OF CARBON RESERVATIONS IN THE AERIAL BIOMASS OF AGROFORESTRY SYSTEMS OF Theobroma cacao L. IN THE DEPARTMENT OF SAN MARTÌN, PERU

    Microsoft Academic Search

    Juanita Y. Concha; Julio C. Alegre; Vicente Pocomucha

    Resumen En este estudio se evaluó la biomasa aérea en seis diferentes sistemas agroforestales de cacao (Theobroma cacao L.) asociado con especies forestales maderables y frutales; con el propósito de conocer el potencial de captura de carbono por cada sistema. El estudio se realizó en dos diferentes sitios ubicados en la región San Martín (provincias de San Martín y Mariscal

  10. ALS superbend magnet system

    SciTech Connect

    Zbasnik, J.; Wang, S.T.; Chen, J.Y.; DeVries, G.J.; DeMarco, R.; Fahmie, M.; Geyer, A.; Green, M.A.; Harkins, J.; Henderson, T.; Hinkson, J.; Hoyer, E.H.; Krupnick, J.; Marks, S.; Ottens, F.; Paterson, J.A.; Pipersky, P.; Portmann, G.; Robin, D.A.; Schlueter, R.D.; Steier, C.; Taylor, C.E.; Wahrer, R.

    2000-09-15

    The Lawrence Berkeley National Laboratory is preparing to upgrade the Advanced Light Source (ALS) with three superconducting dipoles (Superbends). In this paper we present the final magnet system design which incorporates R&D test results and addresses the ALS operational concerns of alignment, availability, and economy. The design incorporates conduction-cooled Nb-Ti windings and HTS current leads, epoxy-glass suspension straps, and a Gifford-McMahon cryocooler to supply steady state refrigeration. We also present the current status of fabrication and testing.

  11. Al Qaeda Training Manual

    NSDL National Science Digital Library

    2001-01-01

    The first resource is a US Department of Justice release of portions of an English translation of the Al Qaeda training manual located by police in Manchester, England during a search of an Al Qaeda member's home. The manual was found in a computer file described as "the military series" related to the "Declaration of Jihad." The cover and excerpts from the 12 chapters can be viewed as a .pdf file. Content of the text includes religious commentary, organizational tactics, guidelines for member selection, techniques for spying, and security measures. The DOJ does not provide the entire document because it does not want to encourage terrorism.

  12. Initial Symptoms of ALS

    MedlinePLUS

    ... variable from one person to another. Although the mean survival time with ALS is three to five years, many people live five, 10 or more years. Symptoms can begin in the muscles that control speech and swallowing or in the hands, arms, ...

  13. Brambilla, et al. Reply

    E-print Network

    Giovanni Brambilla; Djamel El Masri; Matteo Pierno; Ludovic Berthier; Luca Cipelletti; George Petekidis; Andrew B. Schofield

    2010-08-27

    Brambilla, et al. Reply: van Megen and Williams (vMW) question our recent claim that dense colloidal hard spheres enter at large volume fraction \\phi a dynamical regime not observed in earlier work and not described by the mode-coupling theory (MCT) of the glass transition.

  14. Smith et al Supporting Information

    E-print Network

    Jarvis, Erich D.

    Smith et al 1 Supporting Information for Smith et al. 2006, PLoS Computational Biology 2:e161-hyperpallium apicale; HF-hippocampal formation, and M-mesopallium. #12;Smith et al 2 FigureS2,nolinkswerefoundbetweenelectrodesindifferentbirds,andnolinkswerefoundintothesoundstimulusvariable. CombinedAnalysisofAllBirds'ElectrodesPlusSound #12;Smith et al 3 Analysis of Data from Subsections

  15. Multiaxial fatigue criteria for AISI 304 and 2-1/4 Cr-1 Mo steel at 538/sup 0/C with applications to strain-range partitioning and linear summation of creep and fatigue damage

    SciTech Connect

    Blass, J.J.

    1982-01-01

    An improved multiaxial fatigue failure criterion was developed based on the results of combined axial-torsional strain cycling tests of AISI 304 and 2-1/4 Cr-1 Mo steel conducted at 538/sup 0/C (1000/sup 0/F). The formulation of this criterion involves the shear and normal components of inelastic strain range on the planes of maximum inelastic shear strain range. Optimum values of certain parameters contained in the formulation were obtained for each material by the method of least squares. The ability of this criterion to correlate the test results was compared with that of the usual (Mises) equivalent inelastic strain range criterion. An improved definition of equivalent inelastic strain range resulting from these considerations was used to generalize the theory of Strain Range Partitioning to multiaxial stress-strain conditions and was also applied to the linear summation of creep and fatigue damage.

  16. ALS Project Management Manual

    SciTech Connect

    Krupnick, Jim; Harkins, Joe

    2000-05-01

    This manual has been prepared to help establish a consistent baseline of management practices across all ALS projects. It describes the initial process of planning a project, with a specific focus on the production of a formal project plan. We feel that the primary weakness in ALS project management efforts to date stems from a failure to appreciate the importance of ''up-front'' project planning. In this document, we present a guide (with examples) to preparing the documents necessary to properly plan, monitor, and control a project's activities. While following the manual will certainly not guarantee good project management, failure to address the issues we raise will dramatically reduce the chance of success. Here we define success as meeting the technical goals on schedule and within the prescribed budget.

  17. The AISI direct steelmaking program

    SciTech Connect

    Aukrust, E. (LTV Steel Co., Inc., Cleveland, OH (United States)); Downing, K.B. (Inland Steel Flat Products Co. (United States))

    1991-01-01

    After six months of operation of the pilot plant, the viability of in-bath smelting combined with a high level of post combustion has been demonstrated, and the opportunity exists for an early commercialization of the direct ironmaking part of the process while we continue to research direct steelmaking. The program should be of equal interest to integrated and electric furnace producers. Smelting of ore provides virgin iron units. Additionally, the process has the flexibility of melting scrap and varying the ore-to-scrap ratio over wide ranges. This process does not require coke, thus eliminating the cokemaking operation, a major source of environmental concern.

  18. Reliable Au Wire Bonding to Al\\/Ti\\/Al Pad

    Microsoft Academic Search

    Hiroshi Ueno

    1993-01-01

    In this paper, we describe bond degradation and the bondability of an Au wire to a thin-Al\\/Ti\\/Al pad. It is found that the pad structure of Al(300 nm)\\/Ti(300 nm)\\/Al(1000 nm) is useful for the prevention of bond degradation upon heat treatment at 473 K for 3.6 Ms. Use of the pad necessitated an annealing temperature of at least 723 K,

  19. Optical gain characteristics in Al-rich AlGaN/AlN quantum wells

    SciTech Connect

    Oto, Takao; Banal, Ryan G.; Funato, Mitsuru; Kawakami, Yoichi, E-mail: kawakami@kuee.kyoto-u.ac.jp [Department of Electronic Science and Engineering, Kyoto University, Kyoto 615-8510 (Japan)

    2014-05-05

    The optical gain characteristics of Al-rich AlGaN/AlN quantum wells (QWs) were assessed by the variable stripe length method at room temperature. An Al{sub 0.79}Ga{sub 0.21}N/AlN QW with a well width of 5?nm had a large optical gain of 140?cm{sup ?1}. Increasing the excitation length induced a redshift due to the gain consumption and the consequent saturation of the amplified spontaneous emission. Moreover, a change in the dominant gain polarization with Al composition, which was attributed to switching of the valence band ordering of strained AlGaN/AlN QWs at Al compositions of ?0.8, was experimentally demonstrated.

  20. Al Jazirah, Sudan

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Al Jazirah (also Gezira) is one of the 26 states of Sudan. The state lies between the Blue Nile and the White Nile in the east-central region of the country. It is a well populated area suitable for agriculture. The area was at the southern end of Nubia and little is known about its ancient history and only limited archaeological work has been conducted in this area. The region has benefited from the Gezira Scheme, a program to foster cotton farming begun in 1925. At that time the Sennar Dam and numerous irrigation canals were built. Al Jazirah became the Sudan's major agricultural region with more than 2.5 million acres (10,000 km) under cultivation. The initial development project was semi-private, but the government nationalized it in 1950. Cotton production increased in the 1970s but by the 1990s increased wheat production has supplanted a third of the land formerly seeded with cotton.

    The image was acquired December 25, 2006, covers an area of 56 x 36.4 km, and is located near 14.5 degrees north latitude, 33.1 degrees east longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

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

    SciTech Connect

    Cook, Bruce A [Ames Laboratory; Harringa, J [Ames Laboratory; Anderegg, A [Ames Laboratory; Russell, A M [Iowa State University; Qu, Jun [ORNL; Blau, Peter Julian [ORNL; Higdon, Clifton [Eaton Corporation; Elmoursi, Alaa A [Eaton Corporation

    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.

  2. The thermal stability of AlUSiAl dispersion fuels and AlU alloys

    Microsoft Academic Search

    M. A. Feraday; R. D. Davidson; M. T. Foo; J. E. Winegar

    1982-01-01

    The Al-U alloys showed no dimensional or phase changes after being heated at 400°C for as long as 93 days. These alloys are thermally stable because the fuel phase (UAlâ) is thermodynamically stable with aluminum. Thus the irradiation behavior of the Al-37 wt%U alloy should be as good as that of Al-21 wt%U or Al-28 wt%U alloys at the same

  3. Descenso al Infierno de VenusDescenso al Infierno de VenusDescenso al Infierno de VenusDescenso al Infierno de Venus Manuel Alfonseca

    E-print Network

    Alfonseca, Manuel

    Descenso al Infierno de VenusDescenso al Infierno de VenusDescenso al Infierno de VenusDescenso al Infierno de Venus Manuel Alfonseca #12;Manuel Alfonseca 2 #12;Descenso al infierno de Venus 3 Descenso al infierno de Venus Manuel Alfonseca RESERVADOS TODOS LOS DERECHOS. Salvo usos razonables destinados al

  4. Correlation between Al2O3 particles and interface of Al Al2O3 coatings by cold spray

    Microsoft Academic Search

    Ha Yong Lee; Se Hun Jung; Soo Yong Lee; Young Ho You; Kyung Hyun Ko

    2005-01-01

    Al Al2O3 composite coatings with different Al2O3 particle shapes were prepared on Si and Al substrate by cold spray. The powder compositions of metal (Al) and ceramic (Al2O3) having different sizes and agglomerations were varied into ratios of 10:1 wt% and 1:1 wt%. Al2O3 particles were successfully incorporated into the soft metal matrix of Al. It was found that crater

  5. Correlation between Al 2O 3 particles and interface of Al–Al 2O 3 coatings by cold spray

    Microsoft Academic Search

    Ha Yong Lee; Se Hun Jung; Soo Yong Lee; Young Ho You; Kyung Hyun Ko

    2005-01-01

    Al–Al2O3 composite coatings with different Al2O3 particle shapes were prepared on Si and Al substrate by cold spray. The powder compositions of metal (Al) and ceramic (Al2O3) having different sizes and agglomerations were varied into ratios of 10:1wt% and 1:1wt%. Al2O3 particles were successfully incorporated into the soft metal matrix of Al. It was found that crater formation between the

  6. Frequently Asked Questions about ALS and the ALS Registry

    MedlinePLUS

    ... cancer. However, there are no registries or ongoing tracking efforts for ALS in the United States. The ... primary lateral sclerosis will develop problems with nerve cells for both upper and ... part, locations, and phone numbers for more details. Use the “ALS Clinical ...

  7. Alexandria (Al Iskandariya), Egypt

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This image of Alexandria was taken by astronauts on board the International Space Station in December 2000 using an Electronic Still Camera. A wider-angle view (STS088-739-90) taken from the Space Shuttle in December 1998 is available for context. Alexandria (Al Iskandariya) occupies a T-shaped peninsula and strip of land separating the Mediterranean from Lake Mariout. Originally the town was built upon a mole (stone breakwater) called Heptastadium, which joined the island of Pharos (see referenced website, below) to the mainland. Since then sedimentary deposits have widened the mole. Since 1905, when the 370,000 Alexandrians lived in an area of about 4 sq km between the two harbors, the city (population 4 million; see referenced website, below) has grown beyond its medieval walls and now occupies an area of about 300 sq km. The Mahmudiya Canal, connecting Alexandria with the Nile, runs to the south of the city and, by a series of locks, enters the harbor of the principal port of Egypt (note ships). The reddish and ochre polygons west of Lake Mariout are salt-evaporation, chemical-storage, and water-treatment ponds within the coastal lagoon. Reference Youssef Halim and Fatma Abou Shouk, 2000, Human impacts on Alexandria's marine environment: UNESCO, Coastal Regions and Small Islands Unit (CSI), Coastal Management Sourcebooks 2 (accessed December 20, 2000) Additional photographs taken by astronauts can be viewed at NASA-JSC's Gateway to Astronaut Photography of Earth. Image ISS001-ESC-5025 provided by the Earth Sciences and Image Analysis Laboratory, Johnson Space Center.

  8. 76 FR 38700 - United States, et al.

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-01

    ...DEPARTMENT OF JUSTICE Antitrust Division United States, et al. v. American Express Company, et al.; Public Comments and Response on Proposed...on the proposed Final Judgment in United States, et al. v. American Express Company, et al.,...

  9. Electrical characterization of Al\\/AlO x \\/molecule\\/Ti\\/Al devices

    Microsoft Academic Search

    C. A. Richter; D. R. Stewart; D. A. A. Ohlberg; R. Stanley Williams

    2005-01-01

    We report experimental electrical characterization of Al\\/AlOx\\/molecule\\/Ti\\/Al planar crossbar devices incorporating Langmuir–Blodgett organic monolayers of eicosanoic acid, ‘fast blue’, or chlorophyll-B. Current–voltage and capacitance–voltage measurements on all three molecular device structures exhibited controllable switching hysteresis. Control devices containing no molecules showed no evidence of switching. A model of interface trapped charge mediating electronic transport appears consistent with all of the

  10. ALS - A unique design approach

    Microsoft Academic Search

    Roger A. Chamberlain

    1990-01-01

    An advanced launch system (ALS), which is intended to be flexible and to deliver a wide range of payloads at a reduced cost, is discussed. The ALS concept also features total quality management, modular subsystems, standardized interfaces, standardized missions, and off-line payload encapsulation. The technological improvements include manufacturing of dry structures, use of composite materials, adaptive guidance and control systems,

  11. Al-26 and circumstellar envelopes

    NASA Technical Reports Server (NTRS)

    Glassgold, A. E.

    1995-01-01

    The effects of the radioactive decay of Al-26 on the circumstellar envelopes of asymptotic giant branch stars are analyzed. The gamma-rays emitted by the product nucleus Mg-26 escape most envelopes, but the beta-decay positrons are stopped and can ionize and heat the gas. The ionization may produce observable effects in C-rich circumstellar envelopes, particularly if the photospheric Al-26 abundance is as large as inferred from measurements of live Al-26 in the primitive solar nebula or the observations of interstellar 1.8 MeV gamma-rays. For the nearby carbon star IRC +10216, the measured abundance of the molecular ion HCO(+) provides an upper limit of about 4 x 10(exp -3) for the photospheric Al-26/Al-27 ratio, consistent with presolar SiC grains with about the same C-12/C-13 ratio.

  12. Reliable Au Wire Bonding to Al/Ti/Al Pad

    NASA Astrophysics Data System (ADS)

    Ueno, Hiroshi

    1993-05-01

    In this paper, we describe bond degradation and the bondability of an Au wire to a thin-Al/Ti/Al pad. It is found that the pad structure of Al(300 nm)/Ti(300 nm)/Al(1000 nm) is useful for the prevention of bond degradation upon heat treatment at 473 K for 3.6 Ms. Use of the pad necessitated an annealing temperature of at least 723 K, because of its lower initial bond resistance. With heat treatment after thermosonic ball bonding, the bond resistance is almost invariable and the bond shear strength does not decrease. The life of the bond between the Au wire and the pad is extended with thickening of the Ti layer.

  13. Allegato "B" DOMANDA DI PARTECIPAZIONE AL CONCORSO DI AMMISSIONE AL

    E-print Network

    Sandini, Giulio

    IN ROBOTICA, NEUROSCIENZE, NANOTECNOLOGIE E SCOPERTA FARMACI IN COLLABORAZIONE CON LA FONDAZIONE IIT Si prega'ammissione al Corso di Dottorato di Ricerca in Robotica, Neuroscienze, Nanotecnologie e Scoperta Farmaci

  14. Al-Au-La (010)

    NASA Astrophysics Data System (ADS)

    Carow-Watamura, U.; Louzguine, D. V.; Takeuchi, A.

    This document is part of Part 1 http://dx.doi.org/10.1007/9getType="URL"/> 'Systems from Ag-Al-Ca to Au-Pd-Si' of Subvolume B 'Physical Properties of Ternary Amorphous Alloys' of Volume 37 'Phase Diagrams and Physical Properties of Nonequilibrium Alloys' of Landolt-Börnstein - Group III 'Condensed Matter'. It contains the Chapter 'Al-Au-La (010)' with the content:

  15. Al-La-Nb (068)

    NASA Astrophysics Data System (ADS)

    Carow-Watamura, U.; Louzguine, D. V.; Takeuchi, A.

    This document is part of Part 1 http://dx.doi.org/10.1007/97.etType="URL"/> 'Systems from Ag-Al-Ca to Au-Pd-Si' of Subvolume B 'Physical Properties of Ternary Amorphous Alloys' of Volume 37 'Phase Diagrams and Physical Properties of Nonequilibrium Alloys' of Landolt-Börnstein - Group III 'Condensed Matter'. It contains the Chapter 'Al-La-Nb (068)' with the content:

  16. Al-Ce-V (029)

    NASA Astrophysics Data System (ADS)

    Carow-Watamura, U.; Louzguine, D. V.; Takeuchi, A.

    This document is part of Part 1 http://dx.doi.org/10.1007/97.etType="URL"/> 'Systems from Ag-Al-Ca to Au-Pd-Si' of Subvolume B 'Physical Properties of Ternary Amorphous Alloys' of Volume 37 'Phase Diagrams and Physical Properties of Nonequilibrium Alloys' of Landolt-Börnstein - Group III 'Condensed Matter'. It contains the Chapter 'Al-Ce-V (029)' with the content:

  17. Al-La-Ni (069)

    NASA Astrophysics Data System (ADS)

    Carow-Watamura, U.; Louzguine, D. V.; Takeuchi, A.

    This document is part of Part 1 http://dx.doi.org/10.1007/9getType="URL"/> 'Systems from Ag-Al-Ca to Au-Pd-Si' of Subvolume B 'Physical Properties of Ternary Amorphous Alloys' of Volume 37 'Phase Diagrams and Physical Properties of Nonequilibrium Alloys' of Landolt-Börnstein - Group III 'Condensed Matter'. It contains the Chapter 'Al-La-Ni (069)' with the content:

  18. Al-Cu-Zr (050)

    NASA Astrophysics Data System (ADS)

    Carow-Watamura, U.; Louzguine, D. V.; Takeuchi, A.

    This document is part of Part 1 http://dx.doi.org/10.1007/9getType="URL"/> 'Systems from Ag-Al-Ca to Au-Pd-Si' of Subvolume B 'Physical Properties of Ternary Amorphous Alloys' of Volume 37 'Phase Diagrams and Physical Properties of Nonequilibrium Alloys' of Landolt-Börnstein - Group III 'Condensed Matter'. It contains the Chapter 'Al-Cu-Zr (050)' with the content:

  19. Effect of microscale texture on cutting performance of WC/Co-based TiAlN coated tools under different lubrication conditions

    NASA Astrophysics Data System (ADS)

    Zhang, Kedong; Deng, Jianxin; Xing, Youqiang; Li, Shipeng; Gao, Huanhuan

    2015-01-01

    Commonly known the severe friction between the tool and chip affects the tool life and the quality of the machined surfaces. Introducing a lubricant into the tool-chip interface can be used to alleviate the friction, the effectiveness of which may be improved by surface texturing of the tools. Thus, surface textures were fabricated using laser on the rake of the cemented carbide (WC/Co) inserts, then TiAlN films were coated on the textured tools. The effect of the textures on the cutting performance was investigated using the textured coated tools and conventional coated tools in cutting AISI 1045 hardened steel tests. Two batches of cutting tests were carried out, in regimes of full and starved lubrication. The machining performance was assessed in terms of the cutting forces, friction coefficient at the tool-chip interface, surface roughness of machined workpiece and tool wear on the rake face. Results show that the cutting performance of textured tools was enhanced, especially under the full lubrication condition.

  20. Deutsch als Zweitsprache in der Lehrerausbildung

    E-print Network

    Prediger, Susanne

    Deutsch als Zweitsprache in der Lehrerausbildung Bedarf ­ Umsetzung ­ Perspektiven Dokumentation. Jörg Roche, Ludwig-Maximilians-Universität München Deutsch als Zweitsprache in der Lehrerausbildung Deutsch als Fremdsprache, Ludwig- Maximilians-Universität München Wie wird die Qualität der Da

  1. [Current treatment of AL amyloidosis].

    PubMed

    Desport, Estelle; Moumas, Eric; Abraham, Julie; Delbès, Sébastien; Lacotte-Thierry, Laurence; Touchard, Guy; Fermand, Jean-Paul; Bridoux, Frank; Jaccard, Arnaud

    2011-11-01

    Systemic AL amyloidosis is a rare complication of monoclonal gammopathies. Renal manifestations are frequent, mostly characterized by heavy proteinuria, with nephrotic syndrome and renal failure in more than half of the patients at diagnosis. Without treatment, median survival does not exceed 12 months. Amyloid heart disease and diffusion of amyloid deposits are associated with reduced survival. Treatment of systemic AL amyloidosis has been profoundly modified with the introduction of international criteria for the definition of organ involvement and hematologic response, and with the use of sensitive tests for the measurement of serum-free light chain levels. Melphalan plus dexamethasone is now established as the gold standard for first line treatment of systemic AL, with similar efficacy and reduced treatment-related mortality compared to high-dose therapy. Modern chemotherapy regimens, based on the use of novel agents such as bortezomib and lenalidomide, might further improve patient survival. PMID:21497573

  2. AlN/Fe/AlN nanostructures for magnetooptic magnetometry

    SciTech Connect

    Lišková-Jakubisová, E., E-mail: liskova@karlov.mff.cuni.cz; Viš?ovský, Š. [Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 5, 12116 Prague 2 (Czech Republic); Široký, P.; Hrabovský, D.; Pištora, J. [Nanotechnology Center, Technical University of Ostrava, 17. listopadu 15/2172, 70833 Ostrava Poruba (Czech Republic); Harward, I.; Celinski, Z. [Center for Magnetism and Magnetic Nanostructures, University of Colorado at Colorado Springs, 1420 Austin Bluffs Pkwy., Colorado Springs, Colorado 80918 (United States)

    2014-05-07

    AlN/Fe/AlN/Cu nanostructures with ultrathin Fe grown by sputtering on Si substrates are evaluated as probes for magnetooptical (MO) mapping of weak currents. They are considered for a laser wavelength of ??=?410?nm (3.02?eV) and operate at oblique light incidence angles, ?{sup (0)}, to enable detection of both in-plane and out-of-plane magnetization. Their performance is evaluated in terms of MO reflected wave electric field amplitudes. The maximal MO amplitudes in AlN/Fe/AlN/Cu are achieved by a proper choice of layer thicknesses. The nanostructures were characterized by MO polar Kerr effect at ?{sup (0)}???5° and longitudinal Kerr effect spectra (?{sup (0)}?=?45°) at photon energies between 1 and 5?eV. The nominal profiles were refined using a model-based analysis of the spectra. Closed form analytical expressions are provided, which are useful in the search for maximal MO amplitudes.

  3. A nuclear magnetic resonance probe of Fe-Al and Al20V2Eu intermetallics 

    E-print Network

    Chi, Ji

    2009-05-15

    Al-rich Fe-Al systems (FeAl2, Fe2 Al5 and Fe4Al13) and Al20V2Eu have complicated structures with quasicrystal-like features making these materials potentially of interest for magnetic behavior. However, there is not much work on these materials...

  4. Sobrevivir al cáncer: comer bien

    Cancer.gov

    Sobrevivir al cáncer: comer bien Por el Instituto Nacional del Cáncer Bethesda, MD. - Más de 13 millones de personas que viven en Estados Unidos han recibido un diagnóstico de cáncer. Muchas de las personas que han tenido cáncer quieren seguir una

  5. Hasler et al. SUPPLEMENTAL MATERIAL

    E-print Network

    Knutson, Brian

    could win or avoid losing #12;Hasler et al. 2 money by pressing the button during target presentation's disappearance with a variable delay of 1450-1850 ms notified participants whether they had won or lost money; denoted by outline of triangles). Reward cues signaled the possibility of winning either $0.20 (32 trials

  6. Dry sliding wear behaviour of Al–12Si and Al–12Si–3Cu cast alloys

    Microsoft Academic Search

    K. G. Basavakumar; P. G. Mukunda; M. Chakraborty

    2009-01-01

    This paper attempts to investigate the influence of the microstructural changes on the dry sliding wear behaviour of Al–12Si and Al–12Si–3Cu cast alloys by grain refinement (Al–1Ti–3B), modification (Al–10Sr) and combined action of both (Al–1Ti–3B+Al–10Sr). Results indicate that combined grain refined and modified Al–12Si–3Cu cast alloys have microstructures consisting of uniformly distributed ?-Al grains, eutectic Al–silicon and fine CuAl2 particles

  7. Sliding wear behavior of plasma sprayed Fe 3Al–Al 2O 3 graded coatings

    Microsoft Academic Search

    Jingde Zhang; Kangning Sun; Jiangting Wang; Baoyan Tian; Hongsheng Wang; Yansheng Yin

    2008-01-01

    Fe3Al–Al2O3 double-layer coatings (DC), Fe3Al–Fe3Al\\/50%Al2O3–Al2O3 triple-layer coatings (TC) and Fe3Al–Al2O3 graded coatings (GC) were produced from a series of Fe3Al\\/Al2O3 composite powders with different compositions on low carbon steel substrate using PLAXAIR plasma spraying equipment. Friction behaviors and wear resistance of the three kinds of coatings have been investigated under different loads. Tests were carried out using an MRH-3 standard

  8. (12) United States Patent Vertes et al.

    E-print Network

    Vertes, Akos

    (12) United States Patent Vertes et al. (54) LASER DESORPTION IONIZATION AND PEPTIDE SEQUENCING Suizdak et al. 6,589,485 B2 7/2003 Koster 6,794,196 B2 912004 Fonash et al. 6,846,681 B2 112005 Buriak et al. 6,881,950 B2 4/2005 Schlaf et aI. 111111

  9. AlSb/InAs/AlSb quantum wells

    NASA Technical Reports Server (NTRS)

    Kroemer, Herbert

    1990-01-01

    Researchers studied the InAs/AlSb system recently, obtaining 12nm wide quantum wells with room temperature mobilities up to 28,000 cm(exp 2)/V center dot S and low-temperature mobilities up to 325,000 cm(exp 2)/V center dot S, both at high electron sheet concentrations in the 10(exp 12)/cm(exp 2) range (corresponding to volume concentrations in the 10(exp 18)/cm(exp 2) range). These wells were not intentionally doped; the combination of high carrier concentrations and high mobilities suggest that the electrons are due to not-intentional modulation doping by an unknown donor in the AlSb barriers, presumably a stoichiometric defect, like an antisite donor. Inasmuch as not intentionally doped bulk AlSb is semi-insulating, the donor must be a deep one, being ionized only by draining into the even deeper InAs quantum well. The excellent transport properties are confirmed by other observations, like excellent quantum Hall effect data, and the successful use of the quantum wells as superconductive weak links between Nb electrodes, with unprecendentedly high critical current densities. The system is promising for future field effect transistors (FETs), but many processing problems must first be solved. Although the researchers have achieved FETs, the results so far have not been competitive with GaAs FETs.

  10. Tunneling through Al/AlOx/Al junction: Analytical models and first-principles simulations

    NASA Astrophysics Data System (ADS)

    Zemanová Diešková, M.; Ferretti, A.; Bokes, P.

    2013-05-01

    Ultrathin AlOx layers are nowadays widely employed to make tunneling junctions and, as a common practice, experimental transport data are often rationalized in terms of analytical models invoking effective electronic and geometric properties of the oxide layer. In this paper we examine the reliability of such models by performing first-principles simulations of the transport properties of Al/AlOx/Al junctions. The band gap, effective mass, and interface width obtained from ground state density-functional calculations are used within a potential barrier model, known also as the Simmons model, and its predictions of the conductance are compared with first-principles results. We also propose an analytical expression for the conductance based on a tight-binding model of the interface oxide. We show that the success of the potential barrier model in fitting experimental transport measurements rests on its formal similarity with the tight binding model which, in contrast to the former, is directly related to the realistic electronic structure of the interface.

  11. Proximity effect in Nb/Al, AlOxide, Al/Nb Josephson tunnel junctions

    NASA Astrophysics Data System (ADS)

    Houwman, E. P.; Gijsbertsen, J. G.; Flokstra, J.; Rogalla, H.; Le Grand, J. B.; de Korte, P. A. J.; Golubov, A. A.

    1993-03-01

    Regions with reduced energy gap induced by the proximity effect give rise to quasi-particle loss in Josephson-junction X-ray detectors, but may also be used advantageously for quasi-particle collection. The influence of the thickness of the Al proximity layers in Nb/Al1,AlO(x),Al2/Nb Josephson tunnel junctions on the electrical characteristics has been investigated theoretically and experimentally. Theoretically it is found that the strength of the proximity effect is mainly determined by the proximity parameters gammaM1 (gammaM2) of the electrodes. Good fits of the measured I-V curves with theory were obtained for junctions with thicknesses dA11 ranging from 4 to 25 nm and dA12 = 3 nm, with gammaM2 about 0.12 and gammaM1/gammaM2 = dA11/dA12. For all junctions the proximity knee remains more pronounced than predicted.

  12. Dissimilar metal joining of aluminum alloy to galvanized steel with Al–Si, Al–Cu, Al–Si–Cu and Zn–Al filler wires

    Microsoft Academic Search

    Honggang Dong; Wenjin Hu; Yuping Duan; Xudong Wang; Chuang Dong

    Aluminum alloy sheets were lap joined to galvanized steel sheets by gas tungsten arc welding (GTAW) with Al–5% Si, Al–12% Si, Al–6% Cu, Al–10% Si–4% Cu and Zn–15% Al filler wires. Different amounts of Si, Cu and Zn were introduced into the weld through different filler wires. The effects of alloying elements on the microstructure in the weld and tensile

  13. AlN nanowires for Al-based composites with high strength and low thermal expansion

    Microsoft Academic Search

    Y. B. Tang; Y. Q. Liu; C. H. Sun; H. T. Conga

    2007-01-01

    Based on the synthesis of a sufficient amount of AlN nanowires (AlN-NWs), AlN-NWs\\/Al composites with homogenously distributed AlN-NWs were fabricated. Microstructural observations reveal that the interface between AlN-NWs and Al matrix is clean and bonded well, and no interfacial reaction product was formed at the nanowire-matrix boundary. Mechanical properties including yield and tensile strength of the composites were improved with

  14. Nucleants of Eutectic Silicon in Al-Si Hypoeutectic Alloys: ?-(Al, Fe, Si) or AlP Phase

    NASA Astrophysics Data System (ADS)

    Liang, Song-Mao; Schmid-Fetzer, Rainer

    2014-11-01

    A thermodynamic description of the Al-Si-P-Fe quaternary system focused on Al-(Si)-rich alloys is developed. The solidification sequence in typical Al-7Si cast alloys is derived using thermodynamic calculations of the phase diagrams and solidification simulation under Scheil and constrained Scheil conditions. The previously claimed nucleation of eutectic silicon by ?-(Al,Fe,Si) particles is not possible because under all conditions, ?-(Al,Fe,Si) precipitates after (Si) in pertinent alloys. Variation of P in the ppm range is crucial because it changes the solidification sequence of AlP and (Si).

  15. Laser-driven performance of the Al/Al2O3/Al multi-layer flyer

    NASA Astrophysics Data System (ADS)

    Chen, Shaojie; Wu, Lizhi; Shen, Ruiqi; Ye, Yinghua; Hua, Tianli

    2013-12-01

    To assess the effect of the Al2O3 layer on the performance of a laser-driven flyer, the photonic Doppler velocimetry (PDV) and the polyvinylidene fluoride (PVDF) piezoelectric film were used. The experiment results show that because of the addition of Al2O3 insulation layer the velocity of the Al/Al2O3/Al multi-layer flyer decreased 4.8% in comparison with the Al single-layer flyer, but the impact stress increased 61.4%, up to 870 MPa at 248 mJ laser energy. Moreover, the planarity and the integrity of the flyer plate were improved.

  16. ASSIGNACI DE DEPARTAMENTS DE REFERNCIA AL PDI ADSCRIT ORGNICAMENT ALS CENTRES DOCENTS

    E-print Network

    Politècnica de Catalunya, Universitat

    ASSIGNACIÓ DE DEPARTAMENTS DE REFERÈNCIA AL PDI ADSCRIT ORGÀNICAMENT ALS CENTRES DOCENTS Acord núm.115/2011 del Consell de Govern pel qual s'aprova l'assignació de departaments de referència al PDI;Assignació de departaments de referència al PDI adscrit orgànicament als centres docents Antecedents La UPC

  17. The Collections - Dar al-Athar al-Islamiyyah

    NSDL National Science Digital Library

    Regarded by experts as one of a handful of the most comprehensive collections of Islamic art in the world, the al-Sabah holdings in Kuwait feature 20,000 objects from geographically and chronologically diverse locations. Nine categories - Metals, Ceramics, Glass, Ivory & Wood, Jewelry & Hardstone, Numismatics, Rugs & Textiles, Manuscripts & Calligraphy, and Stone & Stucco - can be accessed from the collections page with the click of a mouse. Within each category, short essays contextualize the beautiful photographs of ancient, medieval, and modern Islamic art in a wide variety of mediums and styles.

  18. Mg isotopic heterogeneity, Al-Mg isochrons, and canonical 26Al/27Al in the early solar system

    NASA Astrophysics Data System (ADS)

    Wasserburg, G. J.; Wimpenny, Josh; Yin, Qing-Zhu

    2012-12-01

    Abstract-There is variability in the Mg isotopic composition that is a reflection of the widespread heterogeneity in the isotopic composition of the elements in the solar system at approximately 100 ppm. Measurements on a single calcium-aluminum-rich inclusion (CAI) gave a good correlation of 26Mg/24Mg with 27<span class="hlt">Al</span>/24Mg, yielding an isochron corresponding to an initial (26<span class="hlt">Al</span>/27<span class="hlt">Al</span>)o = (5.27 ± 0.18) × 10-5 and an initial (26Mg/24Mg)o = -0.127 ± 0.032‰ relative to the standard. This isochron is parallel to that obtained by <link href="#b41 #b42">Jacobsen et <span class="hlt">al</span>. (2008), but is distinctively offset. This demonstrates that there are different initial Mg isotopic compositions in different samples with the same 26<span class="hlt">Al</span>/27<span class="hlt">Al</span>. No inference about uniformity/heterogeneity of 26<span class="hlt">Al</span>/27<span class="hlt">Al</span> on a macro scale can be based on the initial (26Mg/24Mg)o values. Different values of 26<span class="hlt">Al</span>/27<span class="hlt">Al</span> for samples representing the same point in time would prove heterogeneity of 26<span class="hlt">Al</span>/27<span class="hlt">Al</span>. The important issue is whether the bulk solar inventory of 26<span class="hlt">Al</span>/27<span class="hlt">Al</span> was approximately 5 × 10-5 at some point in the early solar system. We discuss ultra refractory phases of solar type oxygen isotope composition with 26<span class="hlt">Al</span>/27<span class="hlt">Al</span> from approximately 5 × 10-5 to below 0.2 × 10-5. We argue that the real issues are: intrinsic heterogeneity in the parent cloud; mechanism and timing for the later production of 16O-poor material; and the relationship to earlier formed 16O-rich material in the disk. 26<span class="hlt">Al</span>-free refractories can be produced at a later time by late infall, if there is an adequate heat source, or from original heterogeneities in the placental molecular cloud from which the solar system formed.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASA-TRS&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19940032245&hterms=Nanometer+copper&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DNanometer%2Bcopper"><span id="translatedtitle">Ni<span class="hlt">Al</span>-base composite containing high volume fraction of <span class="hlt">Al</span>N for advanced engines</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hebsur, Mohan (inventor); Whittenbeger, John D. (inventor); Lowell, Carl F. (inventor)</p> <p>1994-01-01</p> <p>A particulate reinforced Ni<span class="hlt">Al-Al</span>N composite alloy has a Ni<span class="hlt">Al</span> matrix and greater than about 13 volume percent fine particles of <span class="hlt">Al</span>N within the matrix. The particles preferably have a diameter from about 15 nanometers to about 50 nanometers. The particulate reinforced Ni<span class="hlt">Al-Al</span>N composite alloy may be prepared by cryomilling prealloyed Ni<span class="hlt">Al</span> in liquid nitrogen using grinding media having a diameter of from about 2 to 6 mm at an impeller speed of from about 450 RPM to about 800 RPM. The cryomilling may be done for a duration of from about 4 hours to about 20 hours to obtain a cryomilled powder. The cryomilled powder may be consolidated to form the particulate reinforced Ni<span class="hlt">Al-Al</span>N composite alloy. The particulate reinforced alloy can further include a toughening alloy. The toughening alloy may include NiCr<span class="hlt">Al</span>Y, FeCr<span class="hlt">Al</span>Y, and Fe<span class="hlt">Al</span>.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2012MMTA...43.3249E"><span id="translatedtitle">Investigation of Wear Anisotropy in a Severely Deformed <span class="hlt">Al-Al</span>3Ti Composite</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>El-Hadad, Shimaa; Sato, Hisashi; Watanabe, Yoshimi</p> <p>2012-09-01</p> <p>In the current investigation, <span class="hlt">Al-Al</span>3Ti composite was processed by equal channel angular pressing (ECAP). ECAP was carried out using routes A and BC up to eight passes of deformation. It was observed that increasing the number of ECAP passes causes fragmentation of <span class="hlt">Al</span>3Ti platelet particles and decreases their sizes compared to their original sizes in the undeformed <span class="hlt">Al-Al</span>3Ti specimens. Moreover, the microstructure of route A-ECAPed <span class="hlt">Al-Al</span>3Ti composite samples showed a strong alignment of the fragmented <span class="hlt">Al</span>3Ti particles parallel to the pressing axis. On the other hand, ECAPed <span class="hlt">Al-Al</span>3Ti alloy specimens by route BC have a relatively homogeneous distribution of <span class="hlt">Al</span>3Ti particles. Because of the platelet <span class="hlt">Al</span>3Ti particle fragmentation by ECAP, all the ECAPed specimens showed small anisotropy in their wear property in spite of this observed anisotropic microstructure induced by route A-ECAP.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2012MMTA..tmp..147E"><span id="translatedtitle">Investigation of Wear Anisotropy in a Severely Deformed <span class="hlt">Al-Al</span>3Ti Composite</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>El-Hadad, Shimaa; Sato, Hisashi; Watanabe, Yoshimi</p> <p>2012-05-01</p> <p>In the current investigation, <span class="hlt">Al-Al</span>3Ti composite was processed by equal channel angular pressing (ECAP). ECAP was carried out using routes A and BC up to eight passes of deformation. It was observed that increasing the number of ECAP passes causes fragmentation of <span class="hlt">Al</span>3Ti platelet particles and decreases their sizes compared to their original sizes in the undeformed <span class="hlt">Al-Al</span>3Ti specimens. Moreover, the microstructure of route A-ECAPed <span class="hlt">Al-Al</span>3Ti composite samples showed a strong alignment of the fragmented <span class="hlt">Al</span>3Ti particles parallel to the pressing axis. On the other hand, ECAPed <span class="hlt">Al-Al</span>3Ti alloy specimens by route BC have a relatively homogeneous distribution of <span class="hlt">Al</span>3Ti particles. Because of the platelet <span class="hlt">Al</span>3Ti particle fragmentation by ECAP, all the ECAPed specimens showed small anisotropy in their wear property in spite of this observed anisotropic microstructure induced by route A-ECAP.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/servlets/purl/7368756"><span id="translatedtitle">The <span class="hlt">ALS</span> Gun Electronics system</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lo, C.C.</p> <p>1993-05-01</p> <p>The <span class="hlt">ALS</span> Gun Electronics system has been designed to accommodate gun with a custom made socket and high speed electronics circuit which is capable of producing single and multiple electron bunches with time jitters measured at better than 50 PS. The system generates the gated RF signal at ground level before sending it up to the 120 KV-biased gun deck via a fiber optic cable. The current pulse width as a function of grid bias, using an Eimac 8847A planar triode simulating an electron gun, was measured to show the relationship between the two parameters.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=FEDREG&redirectUrl=http://www.gpo.gov:80/fdsys/pkg/FR-2011-04-05/pdf/2011-7938.pdf"><span id="translatedtitle">76 FR 18783 - United States et <span class="hlt">al</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2011-04-05</p> <p>...DEPARTMENT OF JUSTICE Antitrust Division United States et <span class="hlt">al</span>. v. Dean Foods Company; Proposed Final Judgment, Stipulation...the Eastern District of Wisconsin in United States of America, et <span class="hlt">al</span>. v. Dean Foods Company, Civil Action No....</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NIH-MEDLINEPLUS&redirectUrl=http://www.nlm.nih.gov/medlineplus/news/fullstory_152840.html"><span id="translatedtitle">Could Type 2 Diabetes Shield Against <span class="hlt">ALS</span>?</span></a></p> <p><a target="_blank" href="http://medlineplus.gov/">MedlinePLUS</a></p> <p></p> <p></p> <p>... 2015) Monday, June 1, 2015 MONDAY, June 1, 2015 (HealthDay News) -- Type 2 diabetes may reduce the risk of developing the neurodegenerative disease amyotrophic lateral sclerosis (<span class="hlt">ALS</span>), a new study suggests. <span class="hlt">ALS</span>, ...</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/1051452"><span id="translatedtitle">Effects of the <span class="hlt">Al</span> content on pore structures of porous Tie<span class="hlt">Al</span> alloys</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Jaing, Y [State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China; He, Y H [State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China; Xu, N P [Membrane Science and Technology Research Center, Nanjing University of Technology, Nanjing 210009, C; Zou, J [School of Engineering and Centre for Microscopy and Microanalysis, The University of Queensland, QLD; Huang, B [State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China; Lui, C T [Oak Ridge National Laboratory (ORNL)</p> <p>2008-01-01</p> <p>Porous Tie<span class="hlt">Al</span> alloys with different nominal compositions were fabricated through a reactive synthesis of Ti and <span class="hlt">Al</span> elemental powders. It has been found that the pore parameters vary with the <span class="hlt">Al</span> contents, indicating that the nature of the pores can be manipulated through changing the <span class="hlt">Al</span> contents. In addition, detailed structural characterizations showed that the fabricated porous Tie<span class="hlt">Al</span> alloys can have three crystalline phases (i.e., a2-Ti3<span class="hlt">Al</span>, g-Ti<span class="hlt">Al</span>, and Ti<span class="hlt">Al</span>3) when using different compositions. The fundamental reasons behind these phenomena have been explored.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2010OPhy....8.1015I"><span id="translatedtitle">Fabrication of <span class="hlt">Al</span>2O3/<span class="hlt">Al</span> structure by nitric acid oxidation at room temperature</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Iwata, Takashi; Matsumoto, Taketoshi; Terakawa, Sumio; Kobayashi, Hikaru</p> <p>2010-12-01</p> <p>A thick <span class="hlt">Al</span>2O3/aluminum (<span class="hlt">Al</span>) structure has been fabricated by oxidation of <span class="hlt">Al</span> with 68wt% and 98wt% nitric acid (HNO3) aqueous solutions at room temperature. Measurements of the <span class="hlt">Al</span>2O3 thickness vs. the oxidation time show that reaction and diffusion are the rate-determining steps for oxidation with 68wt% and 98wt% HNO3 solutions, respectively. Observation of transmission electron micrographs shows that the <span class="hlt">Al</span>2O3 layer formed with 68wt% HNO3 has a structure with cylindrically shaped pores vertically aligned from the <span class="hlt">Al</span>2O3 surface to the <span class="hlt">Al</span>2O3/<span class="hlt">Al</span> interface. Due to the porous structure, diffusion of HNO3 proceeds easily, resulting in the reaction-limited oxidation mechanism. In this case, the <span class="hlt">Al</span>2O3/<span class="hlt">Al</span> structure is considerably rough. The <span class="hlt">Al</span>2O3 layer formed with 98wt% HNO3 solutions, on the other hand, possesses a denser structure without pores, and the <span class="hlt">Al</span>2O3/<span class="hlt">Al</span> interface is much smoother, but the thickness of the <span class="hlt">Al</span>2O3 layer formed on crystalline <span class="hlt">Al</span> regions is much smaller than that on amorphous <span class="hlt">Al</span> regions. Due to the relatively uniform <span class="hlt">Al</span>2O3 thickness, the leakage current density flowing through the <span class="hlt">Al</span>2O3 layer formed with 68wt% HNO3 is lower than that formed with 98wt% HNO3.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2712389"><span id="translatedtitle">Phosphorus Enhances <span class="hlt">Al</span> Resistance in <span class="hlt">Al</span>-resistant Lespedeza bicolor but not in <span class="hlt">Al</span>-sensitive L. cuneata Under Relatively High <span class="hlt">Al</span> Stress</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Sun, Qing Bin; Shen, Ren Fang; Zhao, Xue Qiang; Chen, Rong Fu; Dong, Xiao Ying</p> <p>2008-01-01</p> <p>Background and Aims Aluminium (<span class="hlt">Al</span>) toxicity and phosphorus (P) deficiency often co-exist in acidic soils and limit crop production worldwide. Lespedeza bicolor is a leguminous forage species that grows very well in infertile, acidic soils. The objective of this study was to investigate the effects of <span class="hlt">Al</span> and P interactions on growth of Lespedeza and the distributions of <span class="hlt">Al</span> and P in two different <span class="hlt">Al</span>-resistant species, and to explore whether P can ameliorate the toxic effect of <span class="hlt">Al</span> in the two species. Methods Two species, Lespedeza bicolor and L. cuneata, were grown for 30 d with alternate <span class="hlt">Al</span> and P treatments in a hydroponics system. Harvested roots were examined using a root-system scanner, and the contents of <span class="hlt">Al</span>, P and other nutrient elements in the plants were determined using inductively coupled plasma-atomic emission spectroscopy (ICP-AES). Haematoxylin staining was used to observe the distribution of <span class="hlt">Al</span> in the roots of seedlings. After pre-culture with or without P application, organic acids in the exudates of roots exposed to <span class="hlt">Al</span> were held in an anion-exchange resin, eluted with 2 m HCl and then analysed using high-performance liquid chromatography (HPLC). Key Results Lespedeza bicolor exhibited a stronger <span class="hlt">Al</span> resistance than did L. cuneata; <span class="hlt">Al</span> exclusion mechanisms may mainly be responsible for resistance. P application alleviated the toxic effect of <span class="hlt">Al</span> on root growth in L. bicolor, while no obvious effects were observed in L. cuneata. Much less <span class="hlt">Al</span> was accumulated in roots of L. bicolor than in L. cuneata after P application, and the P contents in both roots and shoots increased much more for L. bicolor than for L. cuneata. Lespedeza bicolor showed a higher P/<span class="hlt">Al</span> ratio in roots and shoots than did L. cuneata. P application decreased the <span class="hlt">Al</span> accumulation in root tips of L. bicolor but not in L. cuneata. The amount of <span class="hlt">Al</span>-induced organic acid (citrate and malate) exudation from roots pre-cultured with P was much less than from roots without P application; no malate and citrate exudation was detected in L. cuneata. Conclusions P enhanced <span class="hlt">Al</span> resistance in the <span class="hlt">Al</span>-resistant L. bicolor species but not in the <span class="hlt">Al</span>-sensitive L. cuneata under relatively high <span class="hlt">Al</span> stress, although P in L. cuneata might also possess an alleviative potential. Enhancement of <span class="hlt">Al</span> resistance by P in the resistant species might be associated with its more efficient P accumulation and translocation to shoots and greater <span class="hlt">Al</span> exclusion from root tips after P application, but not with an increased exudation of organic acids from roots. PMID:18757448</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/8858049"><span id="translatedtitle">Cell death mechanisms in <span class="hlt">ALS</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bredesen, D E; Wiedau-Pazos, M; Goto, J J; Rabizadeh, S; Roe, J A; Gralla, E B; Ellerby, L M; Valentine, J S</p> <p>1996-10-01</p> <p>Mutations in copper-zinc superoxide dismutase (CuZnSOD) that are associated with familial <span class="hlt">ALS</span> (FALS) are dominant, gain-of-function mutations, but the nature of the function gained has not been identified. In addition to catalyzing the dismutation of superoxide, copper-zinc superoxide dismutase also displays peroxidase activity. Whereas mutants A4V and G93A retained superoxide dismutase activity, they demonstrated a markedly enhanced copper-dependent peroxidase activity in comparison with that of the wild type enzyme as detected by the spin trap 5,5'-dimethyl-1-pyrroline N-oxide (DMPO) in electron paramagnetic resonance measurements. Two copper chelators, diethyldithiocarbamate and penicillamine, inhibited the mutants' peroxidase activity, but not that of the wild type enzyme, at stoichiometric concentrations; furthermore, these copper chelators enhanced neural survival in a cell-culture model of <span class="hlt">ALS</span> but did not alter survival of cells expressing only wild type copper-zinc superoxide dismutase. These observations suggest that oxidative reactions catalyzed by mutant copper-zinc superoxide dismutases may initiate the neuropathologic changes of FALS. PMID:8858049</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/40129832"><span id="translatedtitle">Wrench structural deformation in Ras <span class="hlt">Al</span> Hilal-<span class="hlt">Al</span> Athrun area, NE Libya: a new contribution in Northern <span class="hlt">Al</span> Jabal <span class="hlt">Al</span> Akhdar Belt</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Maher A. El Amawy; Ahmed M. Muftah; Mohamed Abd El-Wahed; Aymn Nassar</p> <p></p> <p><span class="hlt">Al</span> Jabal <span class="hlt">Al</span> Akhdar is a NE\\/SW- to ENE\\/WSW-trending mobile part in Northern Cyrenaica province and is considered a large sedimentary\\u000a belt in northeast Libya. Ras <span class="hlt">Al</span> Hilal-<span class="hlt">Al</span> Athrun area is situated in the northern part of this belt and is covered by Upper\\u000a Cretaceous–Tertiary sedimentary successions with small outcrops of Quaternary deposits. Unmappable and very restricted thin\\u000a layers of</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://fuse.pha.jhu.edu/papers/technical/spie4013/4013-57p2.pdf"><span id="translatedtitle"><span class="hlt">Al</span>+LiF Coated Focal Plane</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p></p> <p></p> <p><span class="hlt">Al</span>+LiF Coated Mirror #2 Focal Plane Assemblies (4) Detectors (2) <span class="hlt">Al</span>+LiF Coated Mirror #1 SiC Coated Mirror #2 SiC Coated Mirror #1 Rowland Circles <span class="hlt">Al</span>+LiF Coated Grating #2 <span class="hlt">Al</span>+LiF Coated Grating #1 SiC of the channels are coated with silicon carbide (SiC), which provides an approximately constant reflectivity</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://tuprints.ulb.tu-darmstadt.de/3788/7/Dissertation,%20Clemens%20Wall,%20TU%20Darmstadt.pdf"><span id="translatedtitle">Mangan-Nickel-und Cobaltverbindungen <span class="hlt">als</span> Konversionselektrodenmaterialien</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Hoffmann, Rolf</p> <p></p> <p>Mangan- Nickel- und Cobaltverbindungen <span class="hlt">als</span> Konversionselektrodenmaterialien für Lithium ____________________________________________________63 5.1 SYNTHESE UND CHARAKTERISIERUNG VON NANOSKALIGEM LIF ______________________________63 5</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/22150036"><span id="translatedtitle">Aluminium distribution in ZSM-5 revisited: The role of <span class="hlt">Al-Al</span> interactions</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ruiz-Salvador, A. Rabdel, E-mail: rabdel@imre.oc.uh.cu [Group of Materials Developed by Design, Division of Chemistry and Technology of Materials, Institute of Materials Science and Engineering (IMRE), University of Havana, Havana 10400 (Cuba); Grau-Crespo, Ricardo; Gray, Aileen E.; Lewis, Dewi W. [Department of Chemistry, University College London, 20 Gordon Street, London, WC1H OAJ (United Kingdom)] [Department of Chemistry, University College London, 20 Gordon Street, London, WC1H OAJ (United Kingdom)</p> <p>2013-02-15</p> <p>We present a theoretical study of the distribution of <span class="hlt">Al</span> atoms in zeolite ZSM-5 with Si/<span class="hlt">Al</span>=47, where we focus on the role of <span class="hlt">Al-Al</span> interactions rather than on the energetics of <span class="hlt">Al</span>/Si substitutions at individual sites. Using interatomic potential methods, we evaluate the energies of the full set of symmetrically independent configurations of <span class="hlt">Al</span> siting in a Si{sub 94}<span class="hlt">Al</span>{sub 2}O{sub 192} cell. The equilibrium <span class="hlt">Al</span> distribution is determined by the interplay of two factors: the energetics of the <span class="hlt">Al</span>/Si substitution at an individual site, which tends to populate particular T sites (e.g., the T14 site), and the <span class="hlt">Al-Al</span> interaction, which at this Si/<span class="hlt">Al</span> maximises <span class="hlt">Al-Al</span> 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 <span class="hlt">Al</span> 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 <span class="hlt">Al-Al</span> distances. - Graphical abstract: Role of <span class="hlt">Al-Al</span> 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-<span class="hlt">Al</span> distribution in ZSM-5 is revisited, stressing the role of the <span class="hlt">Al-Al</span> interaction. Black-Right-Pointing-Pointer Coulomb interactions are not the key factors controlling the <span class="hlt">Al</span> siting. Black-Right-Pointing-Pointer Anisotropy of the framework is identified as a source of departure from Dempsey's rule.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://www.ecologia.edu.mx/publicaciones/resumeness/7.1/pdf/ordonez%20y%20masera%202001.pdf"><span id="translatedtitle">Captura de <span class="hlt">carbono</span> ante el cambio climático</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>José Antonio; Benjamín Ordóñez; Omar Masera</p> <p>2001-01-01</p> <p>Human activities have been generating high greenhouse gas emissions (GHG) from two principal sources: fossil fuel used to produce energy and vegetation removal during land use changes and forestry practices. The main GHG are carbon dioxide (CO2), carbon monoxide (CO), clorofluorocarbons (CFCs), nitrogen oxide (NOx) and methane (CH4). CO 2 is the most important GHG, since it has the highest</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://hal.inria.fr/docs/00/14/36/39/PDF/Lazennec.pdf"><span id="translatedtitle">Freund et <span class="hlt">al</span>. Mechanisms underlying differential expression</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Boyer, Edmond</p> <p></p> <p>), colon (Brew et <span class="hlt">al</span>., 1996), lung (Masuya et <span class="hlt">al</span>., 2001), ovary (Xu & Fidler, 2000) and melanoma cancers as a growth and differentiation factor in human cancers, by modulating metastasis and angiogenesis (Xie, 2001Freund et <span class="hlt">al</span>. - 1 - Mechanisms underlying differential expression of interleukin-8 in breast cancer</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://soils.ifas.ufl.edu/academics/Syllabus/Fall%202013/ALS_5155_Global_Agroecosystems_Syllabus_Fall_2013.pdf"><span id="translatedtitle"><span class="hlt">ALS</span> Global Agroecosystems -Draft 1 Global Agroecosystems</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Ma, Lena</p> <p></p> <p><span class="hlt">ALS</span> Global Agroecosystems - Draft 1 Global Agroecosystems <span class="hlt">ALS</span> 5XXX (This course is also taught at the undergraduate level as <span class="hlt">ALS</span> 4XXX) INSTRUCTORS: Dr. Diane Rowland, Associate Professor, University of Florida and timely global issue in agroecology and effectively communicate in video format. CLASS FORMAT Three 50</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2002cosp...34E2076L"><span id="translatedtitle"><span class="hlt">Al-Al</span>3Ni eutectic alloy and <span class="hlt">Al</span>/WC(Ni) composite directionally solidified under microgravity and normal gravity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Luo, X.; Huang, Q.; Liu, B.; Zhang, X.; Li, Y.</p> <p></p> <p>Directional solidification of <span class="hlt">Al-Al</span>3 Ni eutectic alloy and <span class="hlt">Al</span>/WC(Ni) composite were performed in the Multi-function Crystal Growing Furnace on board the unmanned Chinese Shenzhou II spacecraft and on the ground respectively. The specimens were investigated applying metallographic, SEM, XRD and image analysis techniques. The results show that, for the <span class="hlt">Al-Al</span>3 Ni eutectic alloy, 1) microgravity condition is beneficial to eliminate solidification defects; 2) the <span class="hlt">Al</span>3 Ni rods precipitated in the space sample are short and array somewhat random compared with that in the ground sample, which are longer and parallel to the growth direction; 3) different preferred orientations, <span class="hlt">Al</span>(111) in the sample solidified under microgravity and <span class="hlt">Al</span>3 Ni(200) in the sample solidified in 1g, were observed respectively; 4) the mean spacing between <span class="hlt">Al</span>3 Ni rods obtained under microgravity comes near to that in normal gravity. Moreover, the inter-rod spacing distribution obtained in space is more convergent. In the <span class="hlt">Al</span>/WC(Ni) composite, an obvious migration of WC(Ni) particles in <span class="hlt">Al</span> matrix was observed in the space sample but not in the ground sample. It could be concluded that gravity condition had a strong influence on the solidification behavior of materials .</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/20005991"><span id="translatedtitle">Wear behavior of <span class="hlt">Al-Al</span>{sub 3}Ti composite manufactured by a centrifugal method</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Watanabe, Yoshimi; Yamanaka, Noboru; Fukui, Yasuyoshi</p> <p>1999-12-01</p> <p>The purpose of the present study was to develop a wear-resistant, light <span class="hlt">Al-Al</span>{sub 3}Ti composite material. An <span class="hlt">Al-Al</span>{sub 3}Ti composite specimen was machined from a thick-walled tube of <span class="hlt">Al-Al</span>{sub 3}Ti functionally graded material (FGM) manufactured by the centrifugal method from a commercial ingot of <span class="hlt">Al</span>-5 mass% Ti master alloy. The alloy was heated to a temperature where solid <span class="hlt">Al</span>{sub 3}Ti particles resided in a liquid <span class="hlt">Al</span> matrix, and then the centrifugal method was carried out. <span class="hlt">Al</span>{sub 3}Ti particles in a commercial alloy ingot exist as platelets, and this shape was maintained through the casting. Three kinds of wear specimens were prepared, taking into account the morphology of the <span class="hlt">Al</span>{sub 3}Ti particles in the thick-walled FGM tube; the <span class="hlt">Al</span>{sub 3}Ti particles were arranged with their platelet planes nearly normal to the radial direction as a result of the applied centrifugal force. The wear resistance of the <span class="hlt">Al-Al</span>{sub 3}Ti composite was significantly higher than that of pure <span class="hlt">Al</span>. Wear-resistance anisotropy and dissolution of the <span class="hlt">Al</span>{sub 3}Ti into the <span class="hlt">Al</span> matrix at the near-surface region, around 100 {micro}m in depth, were also observed. The mechanism of the supersaturated-layer formation and the origin of the anisotropic wear resistance are discussed.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASA-TRS&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=PIA07216&hterms=Arabic+Arabic+al-+arab+yah&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DArabic%2B%257C%2B%25C3%2598%25C2%25A7%25C3%2599%25E2%2580%259E%25C3%2598%25C2%25B9%25C3%2598%25C2%25B1%25C3%2598%25C2%25A8%25C3%2599%25C5%25A0%25C3%2598%25C2%25A9%2B%257C%2Bal-%25C3%258A%25C2%25BBarab%25C3%2584%25C2%25AByah%2B%257C%2B%25C3%2598%25C2%25B9%25C3%2598%25C2%25B1%25C3%2598%25C2%25A8%25C3%2599%25C5%25A0%252F%2526"><span id="translatedtitle">Opportunity's 'Rub <span class="hlt">al</span> Khali' Panorama</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2005-01-01</p> <p><p/> [figure removed for brevity, see original site] Click on the image for Opportunity's 'Rub <span class="hlt">al</span> Khali' Panorama (QTVR) <p/> This panoramic image, dubbed 'Rub <span class="hlt">al</span> Khali,' was acquired by NASA's Mars Exploration Rover Opportunity on the plains of Meridiani during the period from the rover's 456th to 464th sols on Mars (May 6 to May 14, 2005). Opportunity was about 2 kilometers (1.2 miles) south of 'Endurance Crater' at a place known informally as 'Purgatory Dune.' <p/> The rover was stuck in the dune's deep fine sand for more than a month. 'Rub <span class="hlt">al</span> Khali' (Arabic translation: 'the empty quarter') was chosen as the name for this panorama because it is the name of a similarly barren, desolate part of the Saudi Arabian desert on Earth. <p/> The view spans 360 degrees. It consists of images obtained in 97 individual pointings of the panoramic camera. The camera took images with five camera filters at each pointing. This 22,780-by-6,000-pixel mosaic is an approximately true-color rendering generated using the images acquired through filters admitting light wavelengths of 750, 530, and 480 nanometers. <p/> Lighting varied during the nine sols it took to acquire this panorama, resulting in some small image seams within the mosaic. These seams have been smoothed in sky parts of the mosaic to better simulate the vista that a person would see if able to view it all at the same time on Mars. <p/> Opportunity's tracks leading back to the north (center of the panorama) are a reminder of the rover's long trek from Endurance Crater. The deep ruts dug by Opportunity's wheels as it became stuck in the sand appear in the foreground. The crest and trough of the last ripple the rover crossed before getting stuck is visible in the center. These wind-formed sand features are only about 10 to 15 centimeters (4 to 6 inches) tall. The crest of the actual ripple where the rover got stuck can be seen just to the right of center. The tracks and a few other places on and near ripple crests can be seen in this color image to be dustier than the undisturbed or 'normal' plains soils in Meridiani. Since the time these ruts were made, some of the dust there has been blown away by the wind, reaffirming the dynamic nature of the martian environment, even in this barren, ocean-like desert of sand.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASA-TRS&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20040087167&hterms=distribution+system+food+industry&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Ddistribution%2Bsystem%2Bfood%2Bindustry"><span id="translatedtitle">Systems Engineering Techniques for <span class="hlt">ALS</span> Decision Making</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rodriquez, Luis F.; Drysdale, Alan E.; Jones, Harry; Levri, Julie A.</p> <p>2004-01-01</p> <p>The Advanced Life Support (<span class="hlt">ALS</span>) Metric is the predominant tool for predicting the cost of <span class="hlt">ALS</span> systems. Metric goals for the <span class="hlt">ALS</span> Program are daunting, requiring a threefold increase in the <span class="hlt">ALS</span> Metric by 2010. Confounding the problem, the rate new <span class="hlt">ALS</span> technologies reach the maturity required for consideration in the <span class="hlt">ALS</span> Metric and the rate at which new configurations are developed is slow, limiting the search space and potentially giving the perspective of a <span class="hlt">ALS</span> technology, the <span class="hlt">ALS</span> Metric may remain elusive. This paper is a sequel to a paper published in the proceedings of the 2003 ICES conference entitled, "Managing to the metric: an approach to optimizing life support costs." The conclusions of that paper state that the largest contributors to the <span class="hlt">ALS</span> Metric should be targeted by <span class="hlt">ALS</span> researchers and management for maximum metric reductions. Certainly, these areas potentially offer large potential benefits to future <span class="hlt">ALS</span> missions; however, the <span class="hlt">ALS</span> Metric is not the only decision-making tool available to the community. To facilitate decision-making within the <span class="hlt">ALS</span> community a combination of metrics should be utilized, such as the Equivalent System Mass (ESM)-based <span class="hlt">ALS</span> metric, but also those available through techniques such as life cycle costing and faithful consideration of the sensitivity of the assumed models and data. Often a lack of data is cited as the reason why these techniques are not considered for utilization. An existing database development effort within the <span class="hlt">ALS</span> community, known as OPIS, may provide the opportunity to collect the necessary information to enable the proposed systems analyses. A review of these additional analysis techniques is provided, focusing on the data necessary to enable these. The discussion is concluded by proposing how the data may be utilized by analysts in the future.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://euro.ecom.cmu.edu/people/faculty/mshamos/7610244.pdf"><span id="translatedtitle">(12) United States Patent Likourezos et <span class="hlt">al</span>.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Shamos, Michael I.</p> <p></p> <p>et <span class="hlt">al</span>. 5,778,178 A 711998 Arunachalam 5,794,207 A 811998 Walker et <span class="hlt">al</span>. 5,794,219 A * 811998 Brown,987,500 A 1111999 Arunachalam 6,021,397 A 212000 Jones et <span class="hlt">al</span>. 6,023,685 A 212000 Brett et <span class="hlt">al</span>. 6,029,150 A 212000/2001 Woolston 6,212,556 Bl 4/2001 Arunachalam 6,246,996 Bl 6/2001 Stein et <span class="hlt">al</span>. 6,260,024 Bl 7/2001 Shkedy 6</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2009bein.book...29D"><span id="translatedtitle">Instandhaltungsmanagement <span class="hlt">als</span> Gestaltungsfeld Ganzheitlicher Produktionssysteme</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dombrowski, Uwe; Schulze, Sven; Otano, Isabel Crespo</p> <p></p> <p>Sich kontinuierlich verändernde Rahmenbedingungen, wie beispielsweise eine steigende Variantenvielfalt, verkürzte Produktlebenszyklen sowie Kundenforderungen nach höherer Qualität, kürzeren Lieferzeiten und geringeren Kosten, fordern von produzierenden Unternehmen eine stetige Anpassung der Prozesse, der Organisation und der Strukturen. Seit den 90er Jahren versuchen immer mehr deutsche Unternehmen diesen veränderten Anforderungen mit der Einführung eines Ganzheitlichen Produktionssystems (GPS) zu begegnen. Ganzheitliche Produktionssysteme sind dabei in ihren Grundlagen an das Toyota Produktionssystem angelehnt, vereinigen aber auch weitere Methoden zu einem unternehmensspezifischen Regelwerk. Im Rahmen des langfristigen Trends zu unternehmensindividuellen Produktionssystemen wird sowohl in der Industrie <span class="hlt">als</span> auch in der Forschung intensiv über das Toyota Produktionssystem, Lean Production, Lean Management und Ganzheitliche Produktionssysteme diskutiert, werden Konzepte zu Implementierung und Betrieb erstellt und die Wirtschaftlichkeit untersucht.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/282257"><span id="translatedtitle">Microstructure and properties of <span class="hlt">Al</span>{sub 2}O{sub 3}-<span class="hlt">Al</span>(Si) and <span class="hlt">Al</span>{sub 2}O{sub 3}-<span class="hlt">Al</span>(Si)-Si composites formed by in situ reaction of <span class="hlt">Al</span> with aluminosilicate ceramics</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ewsuk, K.G.; Glass, S.J.; Loehman, R.E. [Sandia National Labs., Albuquerque, NM (United States); Tomsia, A.P. [Lawrence Berkeley Lab., CA (United States); Fahrenholtz, W.G. [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Chemical and Nuclear Engineering</p> <p>1996-08-01</p> <p><span class="hlt">Al</span>{sub 2}O{sub 3}-<span class="hlt">Al</span>(Si) and <span class="hlt">Al</span>{sub 2}O{sub 3}-<span class="hlt">Al</span>(Si)-Si composites have been formed by in situ reaction of molten <span class="hlt">Al</span> with aluminosilicate ceramics. This reactive metal penetration (RMP) process is driven by a strongly negative Gibbs energy for reaction. In the <span class="hlt">Al</span>/mullite system, <span class="hlt">Al</span> reduces mullite to produce {alpha}-<span class="hlt">Al</span>{sub 2}O{sub 3} and elemental Si. With excess <span class="hlt">Al</span> (i.e., x > 0), a composite of {alpha}-<span class="hlt">Al</span>{sub 2}O{sub 3}, <span class="hlt">Al</span>(Si) alloy, and Si can be formed. Ceramic-metal composites containing up to 30 vol pct <span class="hlt">Al</span>(Si) were prepared by reacting molten <span class="hlt">Al</span> with dense, aluminosilicate ceramic preforms or by reactively hot pressing <span class="hlt">Al</span> and mullite powder mixtures. Both reactive metal-forming techniques produce ceramic composite bodies consisting of a fine-grained alumina skeleton with an interpenetrating <span class="hlt">Al</span>(Si) metal phase. The rigid alumina ceramic skeletal structure dominates composite physical properties such as the Young`s modulus, hardness, and the coefficient of thermal expansion, while the interpenetrating ductile <span class="hlt">Al</span>(Si) metal phase contributes to composite fracture toughness. Microstructural analysis of composite fracture surfaces shows evidence of ductile metal failure of <span class="hlt">Al</span>(Si) ligaments. <span class="hlt">Al</span>{sub 2}O{sub 3}-<span class="hlt">Al</span>(Si) and <span class="hlt">Al</span>{sub 2}O{sub 3}-<span class="hlt">Al</span>(Si)-Si composites produced by in situ reaction of aluminum with mullite have improved mechanical properties and increased stiffness relative to dense mullite, and composite fracture toughness increases with increasing <span class="hlt">Al</span>(Si) content.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/22162790"><span id="translatedtitle">Atom probe analysis of <span class="hlt">Al</span>N interlayers in <span class="hlt">AlGaN/Al</span>N/GaN heterostructures</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Mazumder, Baishakhi; Kaun, Stephen W.; Speck, James S. [Materials Department, University of California, Santa Barbara, California 93106 (United States)] [Materials Department, University of California, Santa Barbara, California 93106 (United States); Lu, Jing; Keller, Stacia; Mishra, Umesh K. [Electrical and Computer Engineering Department, University of California, Santa Barbara, California 93106 (United States)] [Electrical and Computer Engineering Department, University of California, Santa Barbara, California 93106 (United States)</p> <p>2013-03-18</p> <p>Atom probe tomography was used to characterize <span class="hlt">Al</span>N interlayers in <span class="hlt">AlGaN/Al</span>N/GaN heterostructures grown by plasma-assisted molecular beam epitaxy (PAMBE), NH{sub 3}-based molecular beam epitaxy (NH{sub 3}-MBE), and metal-organic chemical vapor deposition (MOCVD). The PAMBE-grown <span class="hlt">Al</span>N interlayer had the highest purity, with nearly 100% of group-III sites occupied by <span class="hlt">Al</span>. The group-III site concentrations of <span class="hlt">Al</span> for interlayers grown by NH{sub 3}-MBE and MOCVD were {approx}85% and {approx}47%, respectively. Hall measurements were performed to determine the two-dimensional electron gas mobility and sheet concentration. Sheet concentrations were {approx}25%-45% higher with molecular beam epitaxy than with MOCVD, and these results matched well with atom probe data.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/41028264"><span id="translatedtitle">The behavior of MCr<span class="hlt">Al</span>Y coatings on Ni 3<span class="hlt">Al</span>-base superalloy</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>B. Wang; J. Gong; C. Sun; R. F. Huang; L. S. Wen</p> <p>2003-01-01</p> <p>This work is concerned with NiCr<span class="hlt">Al</span>Y and NiCoCr<span class="hlt">Al</span>Y coatings deposited on the superalloy IC-6 (Ni3<span class="hlt">Al</span>-base superalloy) by arc ion plating (AIP). The results indicated that the presence of <span class="hlt">Al</span> and Mo in alloy IC-6 impeded Cr atoms moving from coatings to substrates during the deposition process. As a consequence, the distribution of Cr is well proportioned in both NiCr<span class="hlt">Al</span>Y and</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/servlets/purl/10177889"><span id="translatedtitle"><span class="hlt">AISI</span> Direct Steelmaking Program. Final technical report</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Aukrust, E.</p> <p>1994-08-01</p> <p>This final report deals with the results of a 5-yr project for developing a more energy-efficient, environmentally friendly, less costly process for producing hot metal than current coke ovens and blast furnaces. In the process, iron ore pellets are smelted in a foamy slag created by reaction of coal char with molten slag to produce CO. The CO further reacts with oxygen, which also reacts with coal volatile matter, to produce the heat necessary to sustain the endothermic reduction reaction. The uncombusted CO and H{sub 2} from the coal are used to preheat and prereduce hematite pellets for the most efficient use of the energy in the coal. Laboratory programs confirmed that the process steps worked. Pilot plant studies were successful. Economic analysis for a 1 million tpy plant is promising.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/40086017"><span id="translatedtitle">Fretting fatigue in <span class="hlt">AISI</span> 1015 steel</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>R. Gnanamoorthy; R. Rosi Reddy</p> <p>2002-01-01</p> <p>A small oscillatory movement between two contacting surfaces is termed as fretting and on many occasions it acts as the crack\\u000a initiation site leading to catastrophic failure of the overall structure. The occurrence of fretting is observed in many engineering\\u000a structures such as shaft flanges, gas turbines, steel ropes etc. An experimental facility, which can simulate the fretting\\u000a fatigue in</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/18997156"><span id="translatedtitle">Optical properties and electronic structure of the intermetallic phases Ni<span class="hlt">Al</span>, Co<span class="hlt">Al</span>, and Fe<span class="hlt">Al</span></span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>K. Schlemper; L. K. Thomas</p> <p>1994-01-01</p> <p>The dielectric functions of the intermetallic B2 phases Ni<span class="hlt">Al</span>, Co<span class="hlt">Al</span>, and Fe<span class="hlt">Al</span> have been determined by differential reflectometry and the Kramers-Kronig analysis in the energy range of 1.2-5 eV for various compositions near stoichiometry. The experimental absorption maxima are correlated to the band structure of these alloys taken from the literature. All transitions could be assigned to the band structure.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/49443586"><span id="translatedtitle">Effects of <span class="hlt">Al</span> and <span class="hlt">Al</span> 4C 3 contents on combustion synthesis of Cr 2<span class="hlt">Al</span>C from Cr 2O 3–<span class="hlt">Al–Al</span> 4C 3 powder compacts</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>C. L. Yeh; C. W. Kuo</p> <p>2011-01-01</p> <p>Preparation of the ternary carbide Cr2<span class="hlt">Al</span>C was conducted by combustion synthesis in the mode of self-propagating high-temperature synthesis (SHS) from the Cr2O3–<span class="hlt">Al–Al</span>4C3 powder compact. Effects of the contents of <span class="hlt">Al</span> and <span class="hlt">Al</span>4C3 on the product composition and combustion behavior were studied by formulating the reactant mixture with a stoichiometric proportion of Cr2O3:<span class="hlt">Al:Al</span>4C3=3:5x:y, where x and y varied from 1.0 to</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/18519686"><span id="translatedtitle">Thermoluminescence properties of <span class="hlt">Al</span>N ceramics</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>L Trinkler; P Christensen; N. A Larsen; B Berzina</p> <p>1998-01-01</p> <p>The paper describes thermoluminescence (TL) properties of <span class="hlt">Al</span>N:Y2O3 ceramics irradiated with ionising radiation. A high TL sensitivity of <span class="hlt">Al</span>N:Y2O3 ceramics to radiation encouraged a study of the <span class="hlt">Al</span>N ceramics for application as a dosimetric material. The paper presents experimental data on: glow curve, emission spectrum, dose response, energy dependence, influence of heating rate and fading rate. The measured TL characteristics</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/40440606"><span id="translatedtitle">Nanomechanics of Mg–<span class="hlt">Al</span> intermetallic compounds</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>M.-X. Zhang; H. Huang; K. Spencer; Y.-N. Shi</p> <p>2010-01-01</p> <p>Cold spraying of pure <span class="hlt">Al</span> powder on a pure Mg substrate together with subsequent post-spray annealing treatment produced Mg17<span class="hlt">Al</span>12 (?-phase) and Mg2<span class="hlt">Al</span>3 (?-phase) intermetallic layers on the surface of the substrate. These layers showed significantly better nanomechanical properties, including the reduced elastic modulus and nanohardness, which were determined using nanoindentation, than commercial purity Mg and AZ91 alloys. Combined with their</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://aem.asm.org/cgi/reprint/69/7/4057.pdf"><span id="translatedtitle">Toxicity of <span class="hlt">Al</span> to Desulfovibrio desulfuricans</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>James E. Amonette; Colleen K. Russell; Katie A. Carosino; Nicole L. Robinson; Jennifer T. Ho</p> <p>2003-01-01</p> <p>The toxicity of <span class="hlt">Al</span> to Desulfovibrio desulfuricans G20 was assessed over a period of eight weeks in a modified lactate-C medium buffered at four initial pHs (5.0, 6.5, 7.2, and 8.3) and treated with five levels of added <span class="hlt">Al</span> (none, 0.01, 0.1, 1.0, and 10 mM). At pH 5, cell populations decreased significantly and any effect of <span class="hlt">Al</span> was negligible</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://courses.ttu.edu/ppare/Research/PDF%20Articles/tetrahedron%20letter%202002.pdf"><span id="translatedtitle">COOMe Et2<span class="hlt">Al</span>I TETRAHEDRON</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Paré, Paul W.</p> <p></p> <p>RCHO COOMe Et2<span class="hlt">Al</span>I CH2Cl2 O OMe OH R IH + (1.2eq) ( 90%) TETRAHEDRON LETTERS Tetrahedron Letters 43 also obtained by using Et2<span class="hlt">Al</span>I as the promoter and the halogen source.8 Afterwards, Lu and coCl4 (1.2 equiv.), but the success was very limited. However when TiCl4 was replaced by Et2<span class="hlt">Al</span>I</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/142321"><span id="translatedtitle">Creep regimes for directionally solidified <span class="hlt">Al-Al</span>{sub 3}Ni eutectic composite</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Himbeault, D.D. [Atomic Energy of Canada Ltd., Pinawak, Manitoba (Canada); Cahoon, J.R. [Univ. of Manitoba, Winnipeg (Canada). Dept. of Mechanical and Industrial Engineering</p> <p>1993-12-01</p> <p>Creep characteristics of <span class="hlt">Al-Al</span>{sub 3}Ni eutectic composites directionally solidified at 2.2 {times} 10{sup {minus}2} mm/s were determined over a wide range of stress and temperature. Four distinct regions of creep were observed. The rate controlling mechanisms for the four regions appear to be high-temperature dislocation climb in the <span class="hlt">Al</span> matrix, low-temperature climb in the <span class="hlt">Al</span> matrix, boundary sliding, and a mechanism involving deformation of the <span class="hlt">Al</span>{sub 3}Ni fibers. Creep rates of the <span class="hlt">Al-Al</span>{sub 3}Ni composite are several orders of magnitude smaller than for pure <span class="hlt">Al</span>, and apparently, in the regions where deformation of the <span class="hlt">Al</span> matrix is rate controlling, only a very small fraction of the matrix is deforming during creep of the composite.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2014JMEP...23.1614P"><span id="translatedtitle">Interfacial Phenomena in <span class="hlt">Al/Al</span>, <span class="hlt">Al</span>/Cu, and Cu/Cu Joints Soldered Using an <span class="hlt">Al</span>-Zn Alloy with Ag or Cu Additions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pstru?, Janusz; Gancarz, Tomasz</p> <p>2014-05-01</p> <p>The studies of soldered joints were carried out in systems: <span class="hlt">Al/solder/Al</span>, <span class="hlt">Al</span>/solder/Cu, Cu/solder/Cu, where the solder was (<span class="hlt">Al</span>-Zn)EUT, (<span class="hlt">Al</span>-Zn)EUT with 0.5, 1.0, and 1.5 at.% of Ag and (<span class="hlt">Al</span>-Zn)EUT with 0.5, 1.0, and 1.5 at.% of Cu addition. Brazing was performed at 500 °C for 3 min. The EDS analysis indicated that the composition of the layers starting from the Cu pad was CuZn, Cu5Zn8, and CuZn4, respectively. Wetting tests were performed at 500 °C for 3, 8, 15, and 30 min, respectively. Thickness of the layers and their kinetics of growth were measured based on the SEM micrographs. The formation of interlayers was not observed from the side of <span class="hlt">Al</span> pads. On the contrary, dissolution of the <span class="hlt">Al</span> substrate and migration of <span class="hlt">Al</span>-rich particles into the bulk of the solder were observed.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://euro.ecom.cmu.edu/people/faculty/mshamos/7627528.pdf"><span id="translatedtitle">(12) United States Patent Likourezos et <span class="hlt">al</span>.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Shamos, Michael I.</p> <p></p> <p>/1998 Mandler et <span class="hlt">al</span>. 5,778,178 A 7/1998 Arunachalam 5,794,207 A 8/1998 Walker et <span class="hlt">al</span>. 5,794,219 A 8/1998 Brown 5. 5,966,698 A 1011999 Pollin 5,987,500 A 1111999 Arunachalam 6,021,397 A 212000 Jones et <span class="hlt">al</span>. 6/2001 Arunachalam 6,246,996 Bl 6/2001 Stein et <span class="hlt">al</span>. 6,260,024 Bl 7/2001 Shkedy 6,266,651 Bl 7/2001 Woolston 6</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2011JNuM..410....1K"><span id="translatedtitle">Interdiffusion in U 3Si-<span class="hlt">Al</span>, U 3Si 2-<span class="hlt">Al</span>, and USi-<span class="hlt">Al</span> dispersion fuels during irradiation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kim, Yeon Soo; Hofman, Gerard L.</p> <p>2011-03-01</p> <p>Uranium-silicide compound fuel dispersion in an <span class="hlt">Al</span> matrix is used in research and test reactors worldwide. Interaction layer (IL) growth between fuel particles and the matrix is one of performance issues. The interaction layer growth data for U 3Si, U 3Si 2 and USi dispersions in <span class="hlt">Al</span> were obtained from both out-of-pile and in-pile tests. The IL is dominantly U(<span class="hlt">Al</span>Si) 3 from out-of-pile tests, but its (<span class="hlt">Al</span> + Si)/U ratio from in-pile tests is higher than the out-of-pile data, because of amorphous behavior of the ILs. IL growth correlations were developed for U 3Si-<span class="hlt">Al</span> and U 3Si 2-<span class="hlt">Al</span>. The IL growth rates were dependent on the U/Si ratio of the fuel compounds. During irradiation, however, the IL growth rates did not decrease with the decreasing U/Si ratio by fission. It is reasoned that transition metal fission products in the IL compensate the loss of U atoms by providing chemical potential for <span class="hlt">Al</span> diffusion and volume expansion by solid swelling and gas bubble swelling. The addition of Mo in U 3Si 2 reduces the IL growth rate, which is similar to that of UMo alloy dispersion in a silicon-added <span class="hlt">Al</span> matrix.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/20016104"><span id="translatedtitle"><span class="hlt">AlN\\/Al</span>GaN\\/GaN Metal Insulator Semiconductor Heterostructure Field Effect Transistor</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Dong-Hyun Cho; Mitsuaki Shimizu; Toshihide Ide; Hideyuki Ookita; Hajime Okumura</p> <p>2002-01-01</p> <p>We present the characteristics of a novel <span class="hlt">AlN\\/Al</span>GaN\\/GaN metal insulator semiconductor heterostructure field-effect transistor (MIS-HFET) structure with an <span class="hlt">Al</span>N cap layer as a gate insulating layer. The gate leakage current for the <span class="hlt">AlN\\/Al</span>GaN\\/GaN MIS-HFET was shown to be more than three orders of magnitude smaller than that for the <span class="hlt">Al</span>GaN\\/GaN HFET at around -20 V gate bias. This demonstrates that</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASA-TRS&redirectUrl=http://hdl.handle.net/2060/19970022133"><span id="translatedtitle">Processing and Mechanical Properties of Directionally Solidified Ni<span class="hlt">Al/NiAl</span>Ta Alloys</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Johnson, D. R.; Oliver, B. F.; Noebe, R. D.; Whittenberger, J. D.</p> <p>1994-01-01</p> <p>Promising creep strengths were found for a directionally solidified Ni<span class="hlt">Al-NiAl</span>Ta alloy when compared to other Ni<span class="hlt">Al</span> based intermetallics. The directionally solidified alloy had an off-eutectic composition that resulted in microstructures consisting of Ni<span class="hlt">Al</span> dendrites surrounded by aligned eutectic regions. The room temperature toughness of the two phase alloy was similar to that of polycrystalline Ni<span class="hlt">Al</span> even with the presence of the brittle Laves phase Ni<span class="hlt">Al</span>Ta. Alloying additions that may improve the room temperature toughness by producing multiphase alloys are discussed.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/1050922"><span id="translatedtitle">Effects of the <span class="hlt">Al</span> content on pore structures of porous Tie<span class="hlt">Al</span> alloys</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Jiang, Y [State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China; He, Y H [State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China; Zou, J [School of Engineering and Centre for Microscopy and Microanalysis, The University of Queensland, QLD; Huang, B [State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China; Liu, C [Oak Ridge National Laboratory (ORNL)</p> <p>2008-01-01</p> <p>PorousTi Alalloys with different nominal compositions were fabricated through a reactive synthesis of Ti and <span class="hlt">Al</span> elemental powders. It has been found that the pore parameters vary with the <span class="hlt">Al</span> contents, indicating that the nature of the pores can be manipulated through changing the <span class="hlt">Al</span> contents. In addition, detailed structural characterizations showed that the fabricated porousTi Alalloys can have three crystalline phases (i.e., 2-Ti3<span class="hlt">Al</span>, -Ti<span class="hlt">Al</span>, and Ti<span class="hlt">Al</span>3) when using different compositions. The fundamental reasons behind these phenomena have been explored.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/16706418"><span id="translatedtitle">Observation of triatomic species with conflicting aromaticity: <span class="hlt">Al</span>Si2- and <span class="hlt">Al</span>Ge2-.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zubarev, Dmitry Yu; Boldyrev, Alexander I; Li, Xi; Wang, Lai-Sheng</p> <p>2006-05-25</p> <p>We created mixed triatomic clusters, <span class="hlt">Al</span>CGe(-), <span class="hlt">Al</span>Si(2)(-), and <span class="hlt">Al</span>Ge(2)(-), and studied their electronic structure and chemical bonding using photoelectron spectroscopy and ab initio calculations. Excellent agreement between theoretical and experimental photoelectron spectra confirmed the predicted global minimum structures for these species. Chemical bonding analysis revealed that the <span class="hlt">Al</span>Si(2)(-) and <span class="hlt">Al</span>Ge(2)(-) anions can be described as species with conflicting (sigma-antiaromatic and pi-aromatic) aromaticity. The <span class="hlt">Al</span>CGe(-) anion represents an interesting example of chemical species which is between classical and aromatic. PMID:16706418</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://www.uni-greifswald.de/fileadmin/mp/e_dez4/zpa/PO/Bachelor_of_Arts/Deutsch_als_Fremdsprache/PO_B_A__DaF-2009.pdf"><span id="translatedtitle">Fachprfungsordnung fr den Bachelor-Teilstudiengang Deutsch <span class="hlt">als</span> Fremdsprache</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Greifswald, Ernst-Moritz-Arndt-Universität</p> <p></p> <p>Fachprüfungsordnung für den Bachelor-Teilstudiengang Deutsch <span class="hlt">als</span> Fremdsprache an der Ernst Bachelor-Teilstudiengang Deutsch <span class="hlt">als</span> Fremd- sprache <span class="hlt">als</span> Satzung: Inhaltsverzeichnis § 1 Geltungsbereich § 2- Teilstudiengang Deutsch <span class="hlt">als</span> Fremdsprache. Ergänzend gilt die Gemeinsa- me Prüfungsordnung für Bachelor- und Master</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2015JEMat..44.1919H"><span id="translatedtitle">Preparation and Thermoelectric Properties of Yb<span class="hlt">Al</span>3 Thermoelectric Materials with Excessive <span class="hlt">Al</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>He, Dan-qi; Zhao, Wen-Yu; Mu, Xin; Zhou, Hong-yu; Zhang, Qing-jie</p> <p>2015-06-01</p> <p>A method to prepare Yb<span class="hlt">Al</span>3 sample with an accurate stoichiometric ratio has been developed by a melting, quenching, annealing and spark plasma sintering (SPS) method. A series of Yb<span class="hlt">Al</span>3 thermoelectric materials with nominal compositions Yb<span class="hlt">Al</span>3+ x ( x = 0-0.3, ? x = 0.1) have been prepared using the method. We have explored the effects of the excessive <span class="hlt">Al</span> on phase compositions, microstructure and transport properties. The quenched samples are composed of Yb<span class="hlt">Al</span>3, Yb<span class="hlt">Al</span>2, Yb, and <span class="hlt">Al</span>. All the annealed samples are composed of main phase Yb<span class="hlt">Al</span>3 and a trace of <span class="hlt">Al</span>; some annealed samples with x = 0 and x = 0.1 still contain a trace of Yb<span class="hlt">Al</span>2. The SPSed samples with x ? 0.1 are composed of single-phase Yb<span class="hlt">Al</span>3, though a trace of Yb<span class="hlt">Al</span>2 still occured in the SPSed sample with x = 0. The electrical conductivity, Seebeck coefficient, power factor, thermal conductivity and ZT values are first increased with increasing x in the range of 0-0.2 and then decreased when x > 0.2. These thermoelectric properties evolutions originate from the change of densities and chemical composition induced by the excessive <span class="hlt">Al</span>. The highest ZT value reaches 0.28 at 300 K for the SPSed sample with x = 0.2.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/40939800"><span id="translatedtitle">Formation of nickel aluminide coating on ?-Ti<span class="hlt">Al</span> alloy</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Takeshi Izumi; Takumi Nishimoto; Toshio Narita</p> <p>2003-01-01</p> <p>A nickel aluminide coating process was developed on ?-Ti<span class="hlt">Al</span> alloy by electroplating a Ni film followed by a high <span class="hlt">Al</span> activity pack cementation carried out in a vacuum with a mixture of fine <span class="hlt">Al</span>, NH4Cl, and <span class="hlt">Al</span>2O3 powders at 1273 K for 18 ks. The coating has a duplex layer structure, an outer Ni2<span class="hlt">Al</span>3 layer and an inner Ti<span class="hlt">Al</span>3\\/Ti<span class="hlt">Al</span>2\\/TiNi<span class="hlt">Al</span>2 layer.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://psi.ece.jhu.edu/~kaplan/PUBL/AEK.pubs/Kap_Bjo_Sm_Tom.Pat.US4410239.pdf"><span id="translatedtitle">United States Patent [191 Kaplan et <span class="hlt">al</span>.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Kaplan, Alexander</p> <p></p> <p>..................................... .. 372/96 _ `1 OTHER PUBLICATIONS Javan et <span class="hlt">al</span>., "Possibility of Self-Focusing Due to Inten NONLINEAR", IEEE Jr. Quantum Electronics, QE 2, 9/66, pp. 470-475. Bjorkholm et <span class="hlt">al</span>., "CW Self-Focusing & Self is based on self focusing of light. Self-focusing occurs when a light beam having a nonuniform spatial pro</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://www.astro.umd.edu/~white/WG3/HESSI6_Bastian_submm.pdf"><span id="translatedtitle">4 November 2003 Kaufmann et <span class="hlt">al</span>. 2005</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>White, Stephen</p> <p></p> <p>SST 405 GHz SST 212 GHz OVSA Largest SXR flare recorded: X28, possibly as large as X45 (Neil et <span class="hlt">al</span>-emitting values. #12;Kaufmann et <span class="hlt">al</span>. 2004 4 November 2003 SST 405 GHz SST 212 GHz OVSA Largest SXR flare recorded</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://arep.med.harvard.edu/pdf/Church98_opore.pdf"><span id="translatedtitle">United States Patent [19] Church et <span class="hlt">al</span>.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Church, George M.</p> <p></p> <p>United States Patent [19] Church et <span class="hlt">al</span>. [54] CHARACTERIZATION OF INDIVIDUAL POLYMER MOLECULES BASED of Search ............................ 435/6. 4. 5; 43612. 436/151 [56] References Cited PUBUCATIONS Auld et of the Volt- age-Dependent Sodium Channel". 1990, Proc. Natl. Acad. Sci. USA, 87:323-27. Bensirnon. A.. et <span class="hlt">al</span></p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://www.photonics.ucla.edu/media/publication/patent/US5793907.pdf"><span id="translatedtitle">United States Patent [191 Jalali et <span class="hlt">al</span>.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Jalali. Bahram</p> <p></p> <p>antennas: SPIE vol. 1703 (1992) 264-271. GA Magel et <span class="hlt">al</span>.: "Phosphosilicate Glass waveguides for phased-Loss Fiber Optic Time-Delay Ele ment for Phased-Array Antennas." SPIE 194/1450-6/94 vol. 2155. pp. 13/vol. 31 No. 35 pp. 7395-7397. Goutzoulis et <span class="hlt">al</span>.; Hardware-compressive 2-D ?ber optic delay line</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://hal.inria.fr/docs/00/29/83/74/PDF/osd-3-165-2006.pdf"><span id="translatedtitle">3, 165198, 2006 G. Petihakis et <span class="hlt">al</span>.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Boyer, Edmond</p> <p></p> <p>for the Mediterranean Sea took place under the Mediterranean 166 #12;OSD 3, 165­198, 2006 M3A system G. Petihakis et <span class="hlt">al</span>-ocean conditions in the Mediterranean Sea (Nittis et5 <span class="hlt">al</span>., 2003). This first phase was devoted to the design Abstract During the Pilot Phase of the Mediterranean Forecasting System (MFSPP) (1998­ 2001) a prototype</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://www.mol.biol.ethz.ch/groups/wider_group/publications/WIDER_jbc282.33859s.pdf"><span id="translatedtitle">Supplementary Material -Haugstetter et <span class="hlt">al</span>. SUPPLEMENTARY MATERIAL</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Wider, Gerhard</p> <p></p> <p>Supplementary Material - Haugstetter et <span class="hlt">al</span>. 1 SUPPLEMENTARY MATERIAL Molecular Modeling of the TMX3 by a row of dots). The dots above the sequence mark every tenth residue in TMX3. #12;Supplementary Material;Supplementary Material - Haugstetter et <span class="hlt">al</span>. 3 Determination of the rate-limiting step in peptide oxidation</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://www.ldeo.columbia.edu/~jsmerdon/papers/2011_grl_smerdonetal_am.pdf"><span id="translatedtitle">SMERDON ET <span class="hlt">AL</span>.: AUXILIARY MATERIAL Auxiliary Material</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Smerdon, Jason E.</p> <p></p> <p>SMERDON ET <span class="hlt">AL</span>.: AUXILIARY MATERIAL 1 Auxiliary Material Spatial Performance of Four Climate Field). We nevertheless perform additional PPEs later in this Auxiliary Material that test CFR performance;SMERDON ET <span class="hlt">AL</span>.: AUXILIARY MATERIAL 2 ECHO-g simulations, respectively. The above conventions</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=ERIC&redirectUrl=http://eric.ed.gov/?q=sculpture&id=EJ997797"><span id="translatedtitle">Diana <span class="hlt">Al</span>-Hadid: Identity and Heritage</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Jungerberg, Tom; Smith, Anna; Borsh, Colleen</p> <p>2012-01-01</p> <p>Diana <span class="hlt">Al</span>-Hadid's sculptures reflect the many locations, cultures, histories, and mythologies that have shaped her as an artist. In large-scale works which have the appearance of architectural ruins, <span class="hlt">Al</span>-Hadid employs imagery drawn from many diverse interests including science and technology, history, and literature. She also incorporates images and…</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/15020715"><span id="translatedtitle">Stress Corrosion Cracking of <span class="hlt">Al</span>-Mg and Mg-<span class="hlt">Al</span> Alloys</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Jones, Russell H.; Vetrano, John S.; Windisch, Charles F.</p> <p>2004-12-01</p> <p>Aluminum and magnesium based alloys are being used for reducing the weight of automobiles. For structural applications they must have adequate stress corrosion resistance and yet, under some circumstances, stress corrosion cracking can occur in both alloy systems. Precipitation of the Mg rich Beta-phase (<span class="hlt">Al</span>3Mg2) at grain boundaries of <span class="hlt">Al</span>-Mg alloys and the Beta-phase (Mg17<span class="hlt">Al</span>12) at grain boundaries of the Mg-<span class="hlt">Al</span> alloys are critical factors in their stress corrosion performance. In Mg-<span class="hlt">Al</span>, the Beta-phase is cathodic to the matrix while in the <span class="hlt">Al</span>-Mg case, the Beta-phase is anodic to the matrix. These phases produce localized galvanic induced-corrosion that leads to intergranular stress corrosion cracking and cracking growth rates of 5 and 103 times faster than the solution treated condition, for <span class="hlt">Al</span>-Mg and Mg-<span class="hlt">Al</span>, respectively.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://eprint.iacr.org/2008/297.pdf"><span id="translatedtitle">Attack on Kang et <span class="hlt">al.'s</span> Identity-Based Strong Designated Verifier Signature Scheme</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p></p> <p></p> <p>, China 2 Mathematics Department, Baoji University of Arts and Sciences, Baoji 721007, China E-mail: duhongzhen@gmail.com Abstract: In this paper, we present a universal forgery attack on Kang et <span class="hlt">al.'s</span> identity</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/40280131"><span id="translatedtitle">Formation of Ti 3<span class="hlt">Al</span>C 2\\/<span class="hlt">Al</span> 2O 3 and Ti 2<span class="hlt">AlC\\/Al</span> 2O 3 composites by combustion synthesis in Ti–<span class="hlt">Al</span>–C–TiO 2 systems</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>C. L. Yeh; C. W. Kuo; Y. C. Chu</p> <p>2010-01-01</p> <p>Preparation of Ti3<span class="hlt">Al</span>C2\\/<span class="hlt">Al</span>2O3 and Ti2<span class="hlt">AlC\\/Al</span>2O3 in situ composites was conducted by combustion synthesis in the mode of self-propagating high-temperature synthesis (SHS). The SHS process incorporates the thermite reaction of <span class="hlt">Al</span> with TiO2 into solid state combustion of the Ti–<span class="hlt">Al</span>–C system. The extent of thermite reaction involved in the SHS process was studied on the product composition and combustion behavior. It</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=FEDREG&redirectUrl=http://www.gpo.gov:80/fdsys/pkg/FR-2011-06-14/pdf/2011-14629.pdf"><span id="translatedtitle">76 FR 34750 - United States et <span class="hlt">al</span>. v. Comcast Corp., et <span class="hlt">al</span>.; Public Comments and Response on Proposed Final...</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2011-06-14</p> <p>...DEPARTMENT OF JUSTICE Antitrust Division United States et <span class="hlt">al</span>. v. Comcast Corp., et <span class="hlt">al</span>.; Public Comments and Response on Proposed Final...received on the proposed Final Judgment in United States et <span class="hlt">al</span>. v. Comcast Corp. et <span class="hlt">al</span>., Civil Action...</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://xray.engr.wisc.edu/publications/Imhoff%20et%20al%20J%20Appl%20Phys%202012.pdf"><span id="translatedtitle">Kinetic transition in the growth of <span class="hlt">Al</span> nanocrystals in <span class="hlt">Al</span>-Sm alloys S. D. Imhoff, J. Ilavsky, F. Zhang, P. Jemian, P. G. Evans et <span class="hlt">al</span>.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Evans, Paul G.</p> <p></p> <p>Kinetic transition in the growth of <span class="hlt">Al</span> nanocrystals in <span class="hlt">Al</span>-Sm alloys S. D. Imhoff, J. Ilavsky, F://jap.aip.org/authors #12;Kinetic transition in the growth of <span class="hlt">Al</span> nanocrystals in <span class="hlt">Al</span>-Sm alloys S. D. Imhoff,1 J. Ilavsky,2 F January 2012; accepted 22 February 2012; published online 29 March 2012) The formation of <span class="hlt">Al</span> nanocrystals</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2010JPhCS.240a2084S"><span id="translatedtitle">High temperature creep behaviour of <span class="hlt">Al</span>-rich Ti-<span class="hlt">Al</span> alloys</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sturm, D.; Heilmaier, M.; Saage, H.; Aguilar, J.; Schmitz, G. J.; Drevermann, A.; Palm, M.; Stein, F.; Engberding, N.; Kelm, K.; Irsen, S.</p> <p>2010-07-01</p> <p>Compared to Ti-rich ?-Ti<span class="hlt">Al</span>-based alloys <span class="hlt">Al</span>-rich Ti-<span class="hlt">Al</span> alloys offer an additional reduction of in density and a better oxidation resistance which are both due to the increased <span class="hlt">Al</span> content. Polycrystalline material was manufactured by centrifugal casting. Microstructural characterization was carried out employing light-optical, scanning and transmission electron microscopy and XRD analyses. The high temperature creep of two binary alloys, namely <span class="hlt">Al</span>60Ti40 and <span class="hlt">Al</span>62Ti38 was comparatively assessed with compression tests at constant true stress in a temperature range between 1173 and 1323 K in air. The alloys were tested in the cast condition (containing various amounts of the metastable phases <span class="hlt">Al</span>5Ti3 and h-<span class="hlt">Al</span>2Ti) and after annealing at 1223 K for 200 h which produced (thermodynamically stable) lamellar ?-Ti<span class="hlt">Al</span> + r-<span class="hlt">Al</span>2Ti microstructures. In general, already the as-cast alloys exhibit a reasonable creep resistance at 1173 K. Compared with <span class="hlt">Al</span>60Ti40, both, the as-cast and the annealed <span class="hlt">Al</span>62Ti38 alloy exhibit better creep resistance up to 1323 K which can be rationalized by the reduced lamella spacing. The assessment of creep tests conducted at identical stress levels and varying temperatures yielded apparent activation energies for creep of Q = 430 kJ/mol for the annealed <span class="hlt">Al</span>60Ti40 alloy and of Q = 383 kJ/mol for the annealed <span class="hlt">Al</span>62Ti38 material. The latter coincides well with that of <span class="hlt">Al</span> diffusion in ?-Ti<span class="hlt">Al</span>, whereas the former can be rationalized by the instability of the microstructure containing metastable phases.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/55062997"><span id="translatedtitle">The nature of the Fe<span class="hlt">Al</span>3 liquid-(FeMn)<span class="hlt">Al</span>6</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>W. T. Denholm; J. D. Esdaile; N. G. Siviour; B. W. Wilson</p> <p>1987-01-01</p> <p>Crystallization studies using an inverted L pattern of liquid aluminum alloys of compositions just to the right of the ternary point, and the application of a theoretical analysis of the behavior of a hypothetical system, show that the Fe<span class="hlt">Al</span>3-(FeMn)<span class="hlt">Al</span>6-liquid reaction is peritectic close to the ternary point, and that the invariant reaction is eutectic, i.e., L = Fe<span class="hlt">Al</span>3 + (FeMn)<span class="hlt">Al</span>6</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASA-TRS&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19980019510&hterms=alternating+current+corrosion&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dalternating%2Bcurrent%2Bcorrosion"><span id="translatedtitle">Corrosion Studies of 2195 <span class="hlt">Al</span>-Li Alloy and 2219 <span class="hlt">Al</span> Alloy with Differing Surface Treatments</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Danford, M. D.; Mendrek, M. J.</p> <p>1998-01-01</p> <p>Corrosion studies of 2195 <span class="hlt">Al</span>-Li and 2219 <span class="hlt">Al</span> alloys have been conducted using the scanning reference electrode technique (SRET) and the polarization resistance (PR) technique. The SRET was used to study corrosion mechanisms, while corrosion rate measurements were studied with the PR technique. Plates of <span class="hlt">Al</span>203 blasted, soda blasted and conversion coated 2219 <span class="hlt">Al</span> were coated with Deft primer and the corrosion rates studied with the EIS technique. Results from all of these studies are presented.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/19441466"><span id="translatedtitle">Thermal stability of Ti<span class="hlt">Al</span>N and nanocomposite Ti<span class="hlt">Al</span>SiN thin films.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yang, Sheng-Min; Chang, Yin-Yu; Lin, Dong-Yih; Wang, Da-Yung; Wu, Weite</p> <p>2009-02-01</p> <p>Ti<span class="hlt">Al</span>N and Ti<span class="hlt">Al</span>SiN coatings were synthesized by a cathodic arc deposition process. Titanium, Ti50<span class="hlt">Al</span>50 alloy and <span class="hlt">Al</span>Si (88 at.% of <span class="hlt">Al</span> and 12 at.% of Si) alloy targets were adopted as the cathode materials. X-ray diffraction analyses revealed that Ti0.5<span class="hlt">Al</span>0.5N and Ti49<span class="hlt">Al</span>0.44Si0.07N possess a B1-NaCl crystal structure. The lattice constants of the Ti0.5<span class="hlt">Al</span>0.5N and Ti0.49<span class="hlt">Al</span>0.44Si0.07N calculated from XRD pattern were 0.418 nm and 0.422 nm, respectively. For the high temperature oxidation test, the coated samples were annealed at 900 degrees C in air atmosphere for 2 hours. In this study, the deposited Ti0.5<span class="hlt">Al</span>0.5N had completely transformed to TiO2 and <span class="hlt">Al</span>2O3, and Ti0.49<span class="hlt">Al</span>0.44Si0.07N remained the as-deposited structure after oxidation treatment. It indicated that Ti0.49<span class="hlt">Al</span>0.44Si0.07N possesses superior oxidation resistance than Ti0.5<span class="hlt">Al</span>0.5N, due to the amorphous SiNx phase existed in the nanocomposite structure. The different oxidation mechanisms of Ti50<span class="hlt">Al</span>50N and Ti0.49<span class="hlt">Al</span>0.44Si0.07N at high temperature of 900 degrees C are developed in this study. PMID:19441466</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/46502444"><span id="translatedtitle">The structure of interphase boundaries in <span class="hlt">Al-CuAl</span> 2 curved eutectic crystals</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>G. G. Rmong; C. G. Rhodes</p> <p>1974-01-01</p> <p>Direction lly solidified crystals were grown in which the <span class="hlt">Al-CuAl</span>2 interphase boundary was uniformly misoriented by 6-8 deg with respect to the usual crystallographic relations interface \\u000a $$\\\\left\\\\| {(1\\\\overline 1 1)_{<span class="hlt">Al</span>} } \\\\right.\\\\left\\\\| {(21\\\\overline 1 )_{Cu<span class="hlt">Al</span>_2 } } \\\\right.$$\\u000a . The rrays of features then found in the boundary were shown to be ledges by transmission electron microscopy. These ledges\\u000a could</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/26350159"><span id="translatedtitle">Examination of wire electrical discharge machining of <span class="hlt">Al</span> 2O 3p\\/6061<span class="hlt">Al</span> composites</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Biing Hwa Yan; Hsien Chung Tsai; Fuang Yuan Huang; Long Chorng Lee</p> <p>2005-01-01</p> <p>Alumina particle reinforced 6061 aluminum matrix composites (<span class="hlt">Al</span>2O3p\\/6061<span class="hlt">Al</span>) have excellent physical and chemical properties than those of a traditional metal; however, their poor machinability lead to worse surface quality and serious cutting tool wear. In this study, wire electrical discharge machining (WEDM) is adopted in machining <span class="hlt">Al</span>2O3p\\/6061<span class="hlt">Al</span> composite. In the experiments, machining parameters of pulse-on time were changed to explore</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2003EAEJA....14868S"><span id="translatedtitle"><span class="hlt">AL</span>(0) in municipal waste incinerator ash</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stipp, S. L.; Ronsbo, J. G.; Zunic, T. B.; Christensen, T. H.</p> <p>2003-04-01</p> <p>Disposal of municipal waste is a challenge to society. Waste volume is substantially decreased by incineration but residual ash usually contains a number of toxic components which must be immobilised to insure environmental protection. One element, chromium, is mobile and toxic in its oxidised state as Cr(VI) but it can be reduced to Cr(III) and immobilised. Reduction can be promoted by ash treatment with Fe(0) or Fe(II), but recent evidence shows that at least some Cr(VI) is reduced spontaneously in the ash. Aspects of ash behaviour suggest metallic aluminium as the reducing agent, but no direct evidence of <span class="hlt">Al</span>(0) has been found until now. We examined filter ash from an energy-producing, municipal-waste incinerator (Vest-forbrænding) near Copenhagen. X-ray diffraction (XRD) identified expected salts of Na, K and Ca such as halite, sylvite, calcite, anhydrite and gypsum as well as quartz, feldspar and some hematite. Wave-dispersive electron microprobe produced elemen-tal maps of the ash; <span class="hlt">Al</span>-rich areas were analysed quantitatively by comparison with standards. We identified metallic <span class="hlt">Al</span> particles, averaging 50 to 100 micrometers in di-ameter, often with a fractured, glassy border of aluminum oxide. The particles were porous, explaining fast Cr(VI) reduction and they contained thin exsolution lamellae of <span class="hlt">Al</span>-alloys of Pb and Cu or Mn, Fe and Ag, which provide clues of the <span class="hlt">Al</span>(0) origin in the waste. Sometimes <span class="hlt">Al</span>(0) occurred inside glassy globes of <span class="hlt">Al</span>2O3. Time-of-flight secondary ion mass spectroscopy (TOF-SIMS) and X-ray photoelectron spectroscopy (XPS) proved that surface <span class="hlt">Al</span> concentrations on ash particles were below detection, confirming reactivity of the <span class="hlt">Al</span>(0) bulk. The persistence of reduced <span class="hlt">Al</span> through the highly oxidising combustion procedure comes as a surprise and is a benefit in the immobilisation of Cr(VI) from municipal-waste incineration residues.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://www.bu.edu/admissions/files/library/media/accelerated_eval.pdf"><span id="translatedtitle">Boston University AccelerAted Medic<span class="hlt">Al</span> And dent<span class="hlt">Al</span> ProgrAMs</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Finzi, Adrien</p> <p></p> <p>Boston University AccelerAted Medic<span class="hlt">Al</span> And dent<span class="hlt">Al</span> ProgrAMs teAcher ev<span class="hlt">Al</span>UAtion To the applicant: Applicants to any of the College of Arts & Sciences' accelerated medical or dental programs must submit three</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/5875445"><span id="translatedtitle"><span class="hlt">Al</span>-Cu-Fe-Pd-Mn and <span class="hlt">Al</span>-Cr-Pd-Mn quasicrystalline alloys</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chen Zhenhua (Univ. of Technology, Hunan (China). Powder Metallurgy Research Inst.); Inoue, Akihisa; Masumoto, Tsuyoshi (Tohoku Univ. (Japan). Metal Research Inst.)</p> <p>1993-12-15</p> <p>While searching for new multicomponent quasicrystalline alloys, the authors have suggested a principle of composition activity in the quasicrystal constitution. This means that some new quasicrystals can be constituted by adding several quasicrystalline alloy compositions, and these alloys can be obtained by means of rapid solidification or ingot processing. Guided by this principle, <span class="hlt">Al</span>-Mn-Cr, <span class="hlt">Al</span>-Cu-Fe-Mn, <span class="hlt">Al</span>-Cu-Fe-Cr, <span class="hlt">Al</span>-Cu-Fe-Cr-Mn, <span class="hlt">Al</span>-Mn-Ni-Ti, <span class="hlt">Al</span>-Mn-Fe-Ti, <span class="hlt">Al</span>-Cu-Fe-Ni-Ti and other multicomponent quasicrystalline alloys have been found. A recent study used <span class="hlt">Al</span>[sub 70]Pd[sub 20]Mn[sub 10], <span class="hlt">Al</span>[sub 65]Cu[sub 20]Fe[sub 15] and <span class="hlt">Al</span>[sub 85]Cr[sub 15] quasicrystalline alloys to formulate new alloys. Both <span class="hlt">Al</span>-Cu-Fe-Pd-Mn and <span class="hlt">Al</span>-Cr-Pd-Mn alloys are quasicrystalline. In this paper, they discuss these two quasicrystals, their formation, electronic diffraction and composition scope and thermal stability in detail.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/41024964"><span id="translatedtitle">An in situ composite of <span class="hlt">Al</span> (graphite, <span class="hlt">Al</span> 4C 3) produced by reciprocating extrusion</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Hsu-Shen Chu; Kuo-Shung Liu; Jien-Wei Yeh</p> <p>2000-01-01</p> <p>A reciprocating extrusion process was used to produce an in situ composite of <span class="hlt">Al</span> (graphite, <span class="hlt">Al</span>4C3). 6061 <span class="hlt">Al</span> alloy powder was first dehydrated at 450°C in vacuum, and then mixed with graphite powder in various volume fractions up to 20%. The mixed powder was hot pressed as a billet and finally consolidated by a reciprocating extrusion machine. Each billet was</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://defects.physics.wsu.edu/Al3Zr-ppt.pdf"><span id="translatedtitle">Site preferences of indium impurity atoms in intermetallics having <span class="hlt">Al</span>3Ti and <span class="hlt">Al</span>3Zr crystal structures</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Collins, Gary S.</p> <p></p> <p>Site preferences of indium impurity atoms in intermetallics having <span class="hlt">Al</span>3Ti and <span class="hlt">Al</span>3Zr crystal · Indium was doped in samples of <span class="hlt">Al</span>3V and <span class="hlt">Al</span>3Ti (<span class="hlt">Al</span>3Ti structure) and <span class="hlt">Al</span>3Zr (<span class="hlt">Al</span>3Zr structure) by arc-melting; doping at 10 ppb level. · Inequivalent <span class="hlt">Al</span>-sites occupied by indium solutes were identified by measuring</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2003AdSpR..32..225L"><span id="translatedtitle"><span class="hlt">Al?Al</span> 3Ni eutectic alloy and <span class="hlt">AL</span>/WC(NI) composite directionally solidified under microgravity and normal gravity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Luo, X.-H.; Huang, Q.; Liu, B.-D.; Zhang, X.-M.; Li, Y.-Y.</p> <p>2003-07-01</p> <p>Directional solidification of <span class="hlt">Al?Al</span> 3Ni eutectic alloy and <span class="hlt">Al</span>/WC(Ni) composite were performed in the Multi-functional Crystal Growing Furnace on board the unmanned Chinese Shenzhou II spacecraft and on the ground respectively. The microstructures of the samples were investigated applying metallographic, SEM, XRD and image analysis techniques. Many differences were found between the space samples and the ground samples. It could be concluded that gravity condition had a strong influence on the solidification behavior of materials. The temperature gradient driven convection, i.e. Marangoni Convection, played an apparent role on the formation of solidification microstructure under microgravity.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2009JNuM..394..160P"><span id="translatedtitle">Phase constituents of <span class="hlt">Al</span>-rich U-Mo-<span class="hlt">Al</span> alloys examined by transmission electron microscopy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Perez, E.; Ewh, A.; Liu, J.; Yuan, B.; Keiser, D. D., Jr.; Sohn, Y. H.</p> <p>2009-11-01</p> <p>To supplement the understanding of diffusional interactions involving <span class="hlt">Al</span>-rich region of the U-Mo-<span class="hlt">Al</span> system, alloys with composition 85.7<span class="hlt">Al</span>-11.44U-2.86Mo and 87.5<span class="hlt">Al</span>-10U-2.5Mo in at.%, were examined to determine the equilibrium phase constituents at 500 °C. These alloys were triple arc-melted, homogenized at 500 °C for 200 h, and water-quenched to preserve the high temperature microstructure. X-ray diffraction, scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (XEDS), and transmission electron microscopy (TEM) with high angle annular dark field (HAADF) imaging via scanning transmission electron microscopy (STEM) were employed for the characterization. Alloy specimens for TEM/STEM were prepared using site-specific focused ion beam (FIB) in situ lift-out (INLO) technique. Despite the homogenization time and temperature, five different phases, namely fcc-<span class="hlt">Al</span> solid solution, cubic-UAl 3, orthorhombic-UAl 4, hexagonal-U 6Mo 4<span class="hlt">Al</span> 43 and diamond cubic-UMo 2<span class="hlt">Al</span> 20, were observed. Based on U-<span class="hlt">Al</span>, U-Mo and <span class="hlt">Al</span>-Mo binary phase diagrams, previously proposed U-Mo-<span class="hlt">Al</span> isotherms, and the solidification microstructure of these alloys, the <span class="hlt">Al</span>-rich region of the equilibrium ternary isotherm at 500 °C was constructed. The fcc-<span class="hlt">Al</span> solid solution, orthorhombic-UAl 4, and diamond cubic-UMo 2<span class="hlt">Al</span> 20 which were determined to be the equilibrium phases in 85.7<span class="hlt">Al</span>-11.44U-2.86Mo and 87.5<span class="hlt">Al</span>-10U-2.5Mo alloys.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/974421"><span id="translatedtitle">Phase Constituents of <span class="hlt">Al</span>-rich U-Mo-<span class="hlt">Al</span> Alloys Examined by Transmission Electron Microscopy</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>E. Perez; A. Ewh; J. Liu; B. Yuan; D. D. Keiser, Jr.; Y. H. Sohn</p> <p>2009-11-01</p> <p>To supplement the understanding of diffusional interactions involving <span class="hlt">Al</span>-rich region of the U-Mo-<span class="hlt">Al</span> system, alloys with composition 85.7<span class="hlt">Al</span>-11.44U-2.86Mo and 87.5<span class="hlt">Al</span>-10U-2.5Mo in at.%, were examined to determine the equilibrium phase constituents at 500?C. These alloys were triple arc-melted, homogenized at 500?C for 200 hours, and water-quenched to preserve the high temperature microstructure. X-ray diffraction, scanning electron microscopy (SEM) with energy dispersive x-ray spectroscopy (XEDS), and transmission electron microscopy (TEM) with high angle annular dark field (HAADF) imaging via scanning transmission electron microscopy (STEM) were employed for the characterization. Alloy specimens for TEM/STEM were prepared using site-specific focused ion beam (FIB) in-situ lift-out (INLO) technique. Despite the homogenization time and temperature, five different phases, namely fcc-<span class="hlt">Al</span> solid solution, cubic-UAl3, orthorhombic-UAl4, hexagonal-U6Mo4<span class="hlt">Al</span>43 and diamond cubic-UMo2<span class="hlt">Al</span>20, were observed. Based on U-<span class="hlt">Al</span>, U-Mo and <span class="hlt">Al</span>-Mo binary phase diagrams, previously proposed U-Mo-<span class="hlt">Al</span> isotherms, and the solidification microstructure of these alloys, the <span class="hlt">Al</span>-rich region of the equilibrium ternary isotherm at 500?C was constructed. The fcc-<span class="hlt">Al</span> solid solution, orthorhombic-UAl4, and diamond cubic-UMo2<span class="hlt">Al</span>20, which were determined to be the equilibrium phases in 85.7<span class="hlt">Al</span>-11.44U-2.86Mo and 87.5<span class="hlt">Al</span>-10U-2.5Mo alloys.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASA-TRS&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19910043314&hterms=Alumina&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DAlumina"><span id="translatedtitle">Reaction of Ti and Ti-<span class="hlt">Al</span> alloys with alumina</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Misra, Ajay K.</p> <p>1991-01-01</p> <p>The reaction of single-crystal <span class="hlt">Al</span>2O3 with pure Ti and Ti-<span class="hlt">Al</span> alloys with different <span class="hlt">Al</span> concentrations was examined in the temperature range of 1173 to 1573 K. Significant reaction occurred between <span class="hlt">Al</span>2O3 and the Ti-<span class="hlt">Al</span> alloys with <span class="hlt">Al</span> concentrations lower than that corresponding to the gamma-Ti<span class="hlt">Al</span> phase. The reaction mechanism was determined to be simultaneous diffusion of <span class="hlt">Al</span> and atomic oxygen from <span class="hlt">Al</span>2O3 into Ti and the Ti-<span class="hlt">Al</span> alloys.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/servlets/purl/296638"><span id="translatedtitle">Effects of hydrogen absorption in TbNi<span class="hlt">Al</span> and UNi<span class="hlt">Al</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bordallo, H.N. [Los Alamos National Lab., NM (United States). Manuel Lujan Jr. Neutron Scattering Center; Nakotte, H. [New Mexico State Univ., Las Cruces, NM (United States); Schultz, A. [Argonne National Lab., IL (United States). Intense Pulsed Neutron Source; Kolomiets, A.V.; Havela, L.; Andreev, A.V. [Charles Univ., Prague (Czech Republic). Dept. of Metal Physics</p> <p>1998-12-31</p> <p>Although hydrides of intermetallic compounds are used extensively as hydrogen-storage media, little is known about the exact nature of metal-hydrogen interactions. However, this knowledge is of essential importance for the understanding of thermodynamics and other properties. Hydrides (deuterides) of TbNi<span class="hlt">Al</span> and UNi<span class="hlt">Al</span> have been widely studied because of drastic increase of magnetic ordering temperature under hydrogenation. Here the authors report neutron-diffraction results of the three deuterides, TbNi<span class="hlt">Al</span>D{sub 1.28}, TbNi<span class="hlt">Al</span>D{sub 0.8}a nd UNi<span class="hlt">Al</span>D{sub 2.23}.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://www.springerlink.com/index/ug5rq8u235503375.pdf"><span id="translatedtitle">The nature of the Fe<span class="hlt">Al</span> 3 liquid-(FeMn)<span class="hlt">Al</span> 6</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>W. T. Denholm; J. D. Esdaile; N. G. Siviour; B. W. Wilson</p> <p>1987-01-01</p> <p>Crystallization studies using an invertedL pattern of liquid aluminum alloys of compositions just to the right of the ternary point, and the application of a theoretical\\u000a analysis of the behavior of a hypothetical system, show that the Fe<span class="hlt">Al</span>3-(FeMn)<span class="hlt">Al</span>6-liquid reaction is peritectic close to the ternary point, and that the invariant reaction is eutectic,i.e., L = Fe<span class="hlt">Al</span>3 + (FeMn)<span class="hlt">Al</span>6 + <span class="hlt">Al</span>(C).</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/1540232"><span id="translatedtitle">High <span class="hlt">Al</span>-content <span class="hlt">Al</span>GaN\\/GaN MODFETs for ultrahigh performance</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Y.-F. Wu; B. P. Keller; P. Fini; S. Keller; T. J. Jenkins; L. T. Kehias; S. P. Denbaars; U. K. Mishra</p> <p>1998-01-01</p> <p>The use of an <span class="hlt">Al</span>GaN layer with high <span class="hlt">Al</span> mole-fraction is proposed to increase the equivalent figures of merit of the <span class="hlt">Al</span>GaN\\/GaN MODFET structure. It is shown that the room temperature mobility has little degradation with increasing <span class="hlt">Al</span> mole-fraction up to 50%. 0.7-?m gate-length <span class="hlt">Al</span>0.5Ga0.5N\\/GaN MODFETs by optical lithography exhibit a current density of 1 A\\/mm and three-terminal breakdown voltages</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/697075"><span id="translatedtitle">Evaluating Zn, <span class="hlt">Al</span> and <span class="hlt">Al</span>-Zn coatings on carbon steel in a special atmosphere</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Troconis de Rincon, O.; Delgado, R.; Lopez, B. [Univ. del Zulia, Maracaibo (Venezuela). Centro de Estudios de Corrosion; Uruchutu, J. [Univ. de Cuernavaca (Mexico)</p> <p>1999-11-01</p> <p>This paper presents a comparative evaluation of <span class="hlt">Al</span>, Zn and <span class="hlt">Al</span>-Zn coatings on carbon steel exposed to a coastal-marine atmosphere. It is a very aggressive atmosphere with high wind velocities (corrosion-erosion rate = 1.4 mm/year for ASTM 1029 steel). A metallized zinc coating with a pore sealer was also evaluated. ISO and ASTM standards were used for the evaluation. After a two-year exposure the best performance was achieved by the <span class="hlt">Al</span> and <span class="hlt">Al</span> rich alloy (85%<span class="hlt">Al</span>-15%Zn) with some damage of the coatings. But the Zn metallized coating, with a pore sealer, did not show signs of damage.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25753730"><span id="translatedtitle">RNA-targeted Therapeutics for <span class="hlt">ALS</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Reddy, Linga V; Miller, Timothy M</p> <p>2015-04-01</p> <p>Amyotrophic lateral sclerosis (<span class="hlt">ALS</span>) is a neurodegenerative disease leading to cell death of predominantly motor neurons. Despite extensive research in this disease, finding a way to slow the progress of the disease has been challenging. RNA-targeted therapeutic approaches, including small interfering RNA and antisense oligonucleotides are being developed for genetic forms of <span class="hlt">ALS</span>. <span class="hlt">ALS</span> provides an unique opportunity for the use of RNA inhibition strategies given a well-defined animal model, extensive available information regarding the causative genes, and recent experience in phase 1 clinical trial. PMID:25753730</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/servlets/purl/10191071"><span id="translatedtitle">Ni{sub 3}<span class="hlt">Al</span> aluminide alloys</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Liu, C.T.</p> <p>1993-10-01</p> <p>This paper provides a brief review of the recent progress in research and development of Ni{sub 3}<span class="hlt">Al</span> and its alloys. Emphasis has been placed on understanding low ductility and brittle fracture of Ni{sub 3}<span class="hlt">Al</span> alloys at ambient and elevated temperatures. Recent studies have resulted in identifying both intrinsic and extrinsic factors governing the fracture behavior of Ni{sub 3}<span class="hlt">Al</span> alloys. Parallel efforts on alloy design using physical metallurgy principles have led to properties for structural use. Industrial interest in these alloys is high, and examples of industrial involvement in processing and utilization of these alloys are briefly mentioned.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/22116017"><span id="translatedtitle">Thermal diffusion in Ni/<span class="hlt">Al</span> multilayer</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Swain, M.; Bhattacharya, D.; Singh, S.; Basu, S. [Solid State Physics Division, Bhabha Atomic Research Center, Mumbai 400085 (India); Gupta, M. [UGC-DAE-Consortium for Scientific Research, University Campus, Khandwa Road, Indore 452017 (India)</p> <p>2013-02-05</p> <p>Two Ni/<span class="hlt">Al</span> multilayers deposited by ion beam sputtering of nominal design [Ni(200A)/<span class="hlt">Al</span>(100A)] Multiplication-Sign 5 and [Ni(50A)/<span class="hlt">Al</span>(227A)] Multiplication-Sign 5 on Si substrates were annealed at 200 Degree-Sign C. As-deposited and annealed samples were characterized by x-ray diffraction (XRD) and x-ray reflectometry (XRR). The effort was to study the path of alloying in the above two multilayers of same elements but of opposite stoichiometric ratio. We find distinct differences in alloying of these samples.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2013AIPC.1512..678S"><span id="translatedtitle">Thermal diffusion in Ni/<span class="hlt">Al</span> multilayer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Swain, M.; Bhattacharya, D.; Singh, S.; Gupta, M.; Basu, S.</p> <p>2013-02-01</p> <p>Two Ni/<span class="hlt">Al</span> multilayers deposited by ion beam sputtering of nominal design [Ni(200Å)/<span class="hlt">Al</span>(100Å)]×5 and [Ni(50Å)/<span class="hlt">Al</span>(227Å)]×5 on Si substrates were annealed at 200°C. As-deposited and annealed samples were characterized by x-ray diffraction (XRD) and x-ray reflectometry (XRR). The effort was to study the path of alloying in the above two multilayers of same elements but of opposite stoichiometric ratio. We find distinct differences in alloying of these samples.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2012JChPh.137m4303K"><span id="translatedtitle"><span class="hlt">Al</span>6H18: A baby crystal of ?-<span class="hlt">Al</span>H3</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kiran, B.; Kandalam, Anil K.; Xu, Jing; Ding, Y. H.; Sierka, M.; Bowen, K. H.; Schnöckel, H.</p> <p>2012-10-01</p> <p>Using global-minima search methods based on the density functional theory calculations of (<span class="hlt">Al</span>H3)n (n = 1-8) clusters, we show that the growth pattern of alanes for n ? 4 is dominated by structures containing hexa-coordinated <span class="hlt">Al</span> atoms. This is in contrast to the earlier studies where either linear or ring structures of <span class="hlt">Al</span>H3 were predicted to be the preferred structures in which the <span class="hlt">Al</span> atoms can have a maximum of five-fold coordination. Our calculations also reveal that the <span class="hlt">Al</span>6H18 cluster, with its hexa-coordination of the <span class="hlt">Al</span> atoms, resembles the unit-cell of ?-<span class="hlt">Al</span>H3, thus <span class="hlt">Al</span>6H18 is designated as the "baby crystal." The fragmentation energies of the (<span class="hlt">Al</span>H3)n (n = 2-8) along with the dimerization energies for even n clusters indicate an enhanced stability of the <span class="hlt">Al</span>6H18 cluster. Both covalent (hybridization) and ionic (charge) contribution to the bonding are the driving factors in stabilizing the isomers containing hexa-coordinated <span class="hlt">Al</span> atoms.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2008ApSS..254.1636Y"><span id="translatedtitle">Microstructure and mechanical properties of <span class="hlt">Al</span> 2O 3-<span class="hlt">Al</span> composite coatings deposited by plasma spraying</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yin, Zhijian; Tao, Shunyan; Zhou, Xiaming; Ding, Chuanxian</p> <p>2008-01-01</p> <p><span class="hlt">Al</span> 2O 3 and <span class="hlt">Al</span> 2O 3-<span class="hlt">Al</span> composite coatings were prepared by plasma spraying. Phase composition of powders and as-sprayed coatings was determined by X-ray diffraction (XRD), while optical microscopy (OM) and scanning electron microscopy (SEM) were employed to investigate the morphology of impacted droplets, polished and fractured surface, and the element distribution in terms of wavelength-dispersive spectrometer (WDS). Mechanical properties including microhardness, adhesion and bending strength, fracture toughness and sliding wear rate were evaluated. The results indicated that the addition of <span class="hlt">Al</span> into <span class="hlt">Al</span> 2O 3 was beneficial to decrease the splashing of impinging droplets and to increase the deposition efficiency. The <span class="hlt">Al</span> 2O 3-<span class="hlt">Al</span> composite coating exhibited homogeneously dispersed pores and the co-sprayed <span class="hlt">Al</span> particles were considered to be distributed in the splat boundary. Compared with <span class="hlt">Al</span> 2O 3 coating, the composite coating showed slightly lower hardness, whereas the coexistence of metal <span class="hlt">Al</span> phase and <span class="hlt">Al</span> 2O 3 ceramic phase effectively improved the toughness, strength and wear resistance of coatings.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2015APExp...8d2603R"><span id="translatedtitle">Optical characterization of <span class="hlt">Al</span>- and N-polar <span class="hlt">Al</span>N waveguides for integrated optics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rigler, Martin; Buh, Jože; Hoffmann, Marc P.; Kirste, Ronny; Bobea, Milena; Mita, Seiji; Gerhold, Michael D.; Collazo, Ramon; Sitar, Zlatko; Zgonik, Marko</p> <p>2015-04-01</p> <p>Dispersion of the extraordinary and ordinary refractive indices of <span class="hlt">Al</span>- and N-polar <span class="hlt">Al</span>N waveguides is measured by multiple angle-of-incidence and spectroscopic ellipsometry techniques. The polarity-controlled <span class="hlt">Al</span>N layers are grown by metal–organic chemical vapor deposition on (0001)-sapphire substrates. Taking into consideration the different surface morphologies of the <span class="hlt">Al</span>- and N-polar <span class="hlt">Al</span>N waveguides, we propose two optical models to describe the measured ellipsometry data. The results indicate that there is no difference between the refractive indices of the <span class="hlt">Al</span>N grown in opposite directions, which confirms the potential of the <span class="hlt">Al</span>N lateral polar structures for use in nonlinear optical applications based on quasi phase matching.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/286891"><span id="translatedtitle">Selective oxidation of buried <span class="hlt">Al</span>GaAs versus <span class="hlt">Al</span>As layers</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Choquette, K.D.; Geib, K.M.; Chui, H.C.; Hammons, B.E.; Hou, H.Q.; Drummond, T.J. [Photonics Research Department, Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)] [Photonics Research Department, Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Hull, R. [Department of Materials Science, University of Virginia, Charlottesville, Virginia 22903 (United States)] [Department of Materials Science, University of Virginia, Charlottesville, Virginia 22903 (United States)</p> <p>1996-09-01</p> <p>We report significant differences between the properties of buried oxides converted from <span class="hlt">Al</span>GaAs and <span class="hlt">Al</span>As layers using selective wet oxidation. Layers of <span class="hlt">Al</span>{sub {ital x}}Ga{sub 1{minus}{ital x}}As with {ital x}{ge}0.96 exhibit crystallographic dependent oxidation rates, while for layers with {ital x}{le}0.92 the oxidation rate is isotropic. Mesas containing partially oxidized layers of <span class="hlt">Al</span>As are unstable to rapid thermal cycling and exhibit excessive strain at the oxide terminus, while mesas containing partially oxidized layers of <span class="hlt">Al</span>GaAs are robust and lack evidence of strain. Finally, the oxidation of <span class="hlt">Al</span>GaAs layers, rather than <span class="hlt">Al</span>As, is found to provide robust oxide apertures for reliable vertical-cavity surface emitting lasers. {copyright} {ital 1996 American Institute of Physics.}</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/40280672"><span id="translatedtitle">An investigation on formation of Nb 2<span class="hlt">Al</span>C by combustion synthesis of Nb 2O 5–<span class="hlt">Al–Al</span> 4C 3 powder compacts</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>C. L. Yeh; C. W. Kuo</p> <p>2010-01-01</p> <p>Preparation of layered ternary carbide Nb2<span class="hlt">Al</span>C was conducted by combustion synthesis in the mode of self-propagating high-temperature synthesis (SHS) from Nb2O5–<span class="hlt">Al–Al</span>4C3 powder compacts. Effects of the contents of <span class="hlt">Al</span> and <span class="hlt">Al</span>4C3 on the product composition and combustion behavior were studied by adopting two series of sample stoichiometries with Nb2O5:<span class="hlt">Al:Al</span>4C3 varying from 3:9:1 to 3:13:1 (for supplying additional <span class="hlt">Al</span>) and 3:9:1</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/servlets/purl/971365"><span id="translatedtitle">Interdiffusion in Diffusion Couples: U-Mo v. <span class="hlt">Al</span> and <span class="hlt">Al</span>-Si</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>D. D. Keiser, Jr.; E. Perez; B. Yao; Y. H. Sohn</p> <p>2009-11-01</p> <p>Interdiffusion and microstructural development in the U-Mo-<span class="hlt">Al</span> system was examined using solid-tosolid diffusion couples consisting of U-7wt.%Mo, U-10wt.%Mo and U-12wt.%Mo vs. pure <span class="hlt">Al</span>, annealed at 600°C for 24 hours. The influence of Si alloying addition (up to 5 wt.%) in <span class="hlt">Al</span> on the interdiffusion microstructural development was also examined using solid-to-solid diffusion couples consisting of U-7wt.%Mo, U-10wt.%Mo and U-12wt.%Mo vs. pure <span class="hlt">Al</span>, <span class="hlt">Al</span>-2wt.%Si, and <span class="hlt">Al</span>-5wt.%Si annealed at 550°C up to 20 hours. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electron probe microanalysis (EPMA) were employed to examine the development of a very fine multiphase intermetallic layer. In ternary U-Mo-<span class="hlt">Al</span> diffusion couples annealed at 600°C for 24 hours, interdiffusion microstructure varied of finely dispersed UAl3, UAl4, U6Mo4<span class="hlt">Al</span>43, and UMo2<span class="hlt">Al</span>20 phases while the average composition throughout the interdiffusion zone remained constant at approximately 80 at.% <span class="hlt">Al</span>. Interdiffusion microstructure observed by SEM/TEM analyses and diffusion paths drawn from concentration profiles determined by EPMA appear to deviate from the assumption of “local thermodynamic equilibrium,” and suggest that interdiffusion occurs via supersaturated UAl4 followed by equilibrium transformation into UAl3, U6Mo4<span class="hlt">Al</span>43, UAl4 and UMo2<span class="hlt">Al</span>20 phases. Similar observation was made for U-Mo vs. <span class="hlt">Al</span> diffusion couples annealed at 550°C. The addition of Si (up to 5 wt.%) in <span class="hlt">Al</span> significantly reduced the thickness of the intermetallic layer by changing the constituent phases of the interdiffusion zone developed in U-Mo vs. <span class="hlt">Al</span>-Si diffusion couples. Specifically, the formation of (U,Mo)(<span class="hlt">Al</span>,Si)3 with relatively large solubility for Mo and Si, along with UMo2<span class="hlt">Al</span>20 phases was observed along with disappearance of U6Mo4<span class="hlt">Al</span>43 and UAl4 phases. Simplified understanding based on U-<span class="hlt">Al</span>, U-Si, and Mo-Si binary phase diagrams is discussed in the light of the beneficial effect of Si alloying addition.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://www.materia.coppe.ufrj.br/sarra/artigos/artigo10606/10606.pdf"><span id="translatedtitle">Resistência ao Cisalhamento do Compósito <span class="hlt">Carbono</span> Reforçado com Fibras de <span class="hlt">Carbono</span>\\/Tecido tipo Twill</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>J. C. Dias</p> <p>2004-01-01</p> <p>The prediction of the strength of structures made of composites materials is the great importance when designing with Carbon Fiber Reinforced Carbon composite-CRFC\\/twill. This paper addresses the issue of the measurement of in-plane shear strengths of CRFC\\/twill composites from Iosipescu specimens. Among the important design parameters for this composite is the in-plane shear strength. The purpose of this present paper</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://www.jatm.com.br/papers/vol1_n2/JATMv1n2_p231-241_Processing_of_thermo-structural_carbon-fiber_reinforced_carbon_composites.pdf"><span id="translatedtitle">Processamento de compósitos termoestruturais de <span class="hlt">carbono</span> reforçado com fibras de <span class="hlt">carbono</span></span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Luiz Cláudio Pardini; Adriano Gonçalves</p> <p>2009-01-01</p> <p>The present work describes the processes used to obtain thermostructural Carbon\\/Carbon composites. The processing of these materials begins with the definition of the architecture of the carbon fiber reinforcement, in the form of stacked plies or in the form of fabrics or multidirectional reinforcement. Incorporating fiber reinforcement into the carbon matrix, by filling the voids and interstices, leads to the</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://www.springerlink.com/index/8718001096w31471.pdf"><span id="translatedtitle">Separating method and dynamic processes of Nano-<span class="hlt">Al</span> 13</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Baoyu Gao; Yongbao Chu; Qinyan Yue; Chunyan Kong; Xiaona Wang</p> <p>2007-01-01</p> <p>In order to investigate the characteristics of pure Nano-<span class="hlt">Al</span>13, Nano-<span class="hlt">Al</span>13 was separated and purified from a series of poly-aluminum chloride (PAC) solutions which had the same <span class="hlt">Al</span>13 percentage but different total <span class="hlt">Al</span> concentrations, by using column chromatography, ethanol-acetone resolving and SO2?\\u000a 4\\/Ba2+ displacement. The <span class="hlt">Al</span>13 species yield was characterized by <span class="hlt">Al</span>-ferron timed complexation spectrophotometry and 27<span class="hlt">Al</span>-NMR (nuclear magnetic resonance). The</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3866720"><span id="translatedtitle"><span class="hlt">ALS</span> and Oxidative Stress: The Neurovascular Scenario</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Thakur, Keshav; Gupta, Pawan Kumar</p> <p>2013-01-01</p> <p>Oxidative stress and angiogenic factors have been placed as the prime focus of scientific investigations after an establishment of link between vascular endothelial growth factor promoter (VEGF), hypoxia, and amyotrophic lateral sclerosis (<span class="hlt">ALS</span>) pathogenesis. Deletion of the hypoxia-response element in the vascular endothelial growth factor promoter and mutant superoxide dismutase 1 (SOD1) which are characterised by atrophy and muscle weakness resulted in phenotype resembling human <span class="hlt">ALS</span> in mice. This results in lower motor neurodegeneration thus establishing an important link between motor neuron degeneration, vasculature, and angiogenic molecules. In this review, we have presented human, animal, and in vitro studies which suggest that molecules like VEGF have a therapeutic, diagnostic, and prognostic potential in <span class="hlt">ALS</span>. Involvement of vascular growth factors and hypoxia response elements also highlights the converging role of oxidative stress and neurovascular network for understanding and treatment of various neurodegenerative disorders like <span class="hlt">ALS</span>. PMID:24367722</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2012NIMPB.289...43M"><span id="translatedtitle">Cd ion implantation in <span class="hlt">Al</span>N</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Miranda, S. M. C.; Franco, N.; Alves, E.; Lorenz, K.</p> <p>2012-10-01</p> <p><span class="hlt">Al</span>N thin films were implanted with cadmium, to fluences of 1 × 1013 and 8 × 1014 at/cm2. The implanted samples were annealed at 950 °C under flowing nitrogen. Although implantation damage in <span class="hlt">Al</span>N is known to be extremely stable the crystal could be fully recovered at low fluences. At high fluences the implantation damage was only partially removed. Implantation defects cause an expansion of the c-lattice parameter. For the high fluence sample the lattice site location of the ions was studied by Rutherford Backscattering/Channelling Spectrometry. Cd ions are found to be incorporated in substitutional <span class="hlt">Al</span> sites in the crystal and no significant diffusion is seen upon thermal annealing. The observed high solubility limit and site stability are prerequisite for using Cd as p-type dopant in <span class="hlt">Al</span>N.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2650295"><span id="translatedtitle">Substitutional alloy of Ce and <span class="hlt">Al</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zeng, Qiao-Shi; Ding, Yang; Mao, Wendy L.; Luo, Wei; Blomqvist, Andreas; Ahuja, Rajeev; Yang, Wenge; Shu, Jinfu; Sinogeikin, Stas V.; Meng, Yue; Brewe, Dale L.; Jiang, Jian-Zhong; Mao, Ho-kwang</p> <p>2009-01-01</p> <p>The formation of substitutional alloys has been restricted to elements with similar atomic radii and electronegativity. Using high-pressure at 298 K, we synthesized a face-centered cubic disordered alloy of highly dissimilar elements (large Ce and small <span class="hlt">Al</span> atoms) by compressing the Ce3<span class="hlt">Al</span> intermetallic compound >15 GPa or the Ce3<span class="hlt">Al</span> metallic glass >25 GPa. Synchrotron X-ray diffraction, Ce L3-edge absorption spectroscopy, and ab initio calculations revealed that the pressure-induced Kondo volume collapse and 4f electron delocalization of Ce reduced the differences between Ce and <span class="hlt">Al</span> and brought them within the Hume-Rothery (HR) limit for substitutional alloying. The alloy remained after complete release of pressure, which was also accompanied by the transformation of Ce back to its ambient 4f electron localized state and reversal of the Kondo volume collapse, resulting in a non-HR alloy at ambient conditions. PMID:19188608</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4439492"><span id="translatedtitle"><span class="hlt">AL</span> Amyloidosis Complicated by Persistent Oral Bleeding</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Marconcini, Luiz Antonio Liarte; Stewart, Forrest Marc; Sonntag, Lisa; Stevens, Emily; Burwick, Nicholas</p> <p>2015-01-01</p> <p>A case of amyloid light chain (<span class="hlt">AL</span>) amyloidosis is presented here with uncontrolled bleeding after a nonsurgical dental procedure, most likely multifactorial in nature, and consequently treated with a multidisciplinary approach.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://www.utwente.nl/abvakabo/grensarbeid/persinformatie.pdf"><span id="translatedtitle">Binnenkort verschijnt <span class="hlt">Als</span> verhuizen emigreren is</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Al Hanbali, Ahmad</p> <p></p> <p>kinderen de Duitse taal beter beheersen dan hun ouders. De schrijvers van dit boek hebben grote waardering. Het boek is geschreven voor Nederlanders, die <span class="hlt">al</span> in Duitsland wonen of naar Duitsland willen verhuizen</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/servlets/purl/6143418"><span id="translatedtitle">Half life of /sup 26/<span class="hlt">Al</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Norris, T.L.; Gancarz, A.J.; Rokop, D.J.; Thomas, K.W.</p> <p>1983-01-01</p> <p>The half-life of /sup 26/<span class="hlt">Al</span> has been redetermined because of suggestions of an error in the accepted value based on its use in calculating /sup 21/Ne production rates from cosmic rays in meteorites. Two solutions of /sup 26/<span class="hlt">Al</span> were analyzed for the specific radioactivity and mass spectrometric determination of the /sup 26/<span class="hlt">Al</span> concentration. The half-life obtained for /sup 26/<span class="hlt">Al</span> was 7.05 x 10/sup 5/ years +- 3.7% at the two sigma level. This is identical to the accepted value of 7.16 x 10/sup 5/ years and indicates that problems with the /sup 21/Ne production rate is not due to an erroneous half-life.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://www.uni-regensburg.de/studium/koordinierungsstelle-leistungspunkte/medien/fra_ita_kommentare_ss12.pdf"><span id="translatedtitle">Franzsische Sprachgeschichte <span class="hlt">als</span> Kulturgeschichte: Renaissance und Klassik</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Schubart, Christoph</p> <p></p> <p>36 000 VL Französische Sprachgeschichte <span class="hlt">als</span> Kulturgeschichte: Renaissance und Klassik 2st., Fr 10 ,,questione" in der Renaissance sollen die verschiedenen Etappen dieser Suche von der frühen Neuzeit bis</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/53441860"><span id="translatedtitle">Hydrogen diffusion in <span class="hlt">Al</span>-Li alloys</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>P. N. Anyalebechi</p> <p>1990-01-01</p> <p>The diffusion coefficients of hydrogen in binary <span class="hlt">Al</span>-Li alloys containing 1,2, and 3 wt pct Li have been determined from desorption curves of samples saturated with hydrogen at 473 to 873 K. Within this temperature range, the diffusivity of hydrogen in the binary <span class="hlt">Al</span>-Li alloys investigated has an Arrhenius-type temperature dependence and follows the equation of the general form D</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://www.springerlink.com/index/uh68186664266xj6.pdf"><span id="translatedtitle">Hydrogen diffusion in <span class="hlt">Al</span>-Li alloys</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>P. N. Anyalebechi</p> <p>1990-01-01</p> <p>The diffusion coefficients of hydrogen in binary <span class="hlt">Al</span>-Li alloys containing 1,2, and 3 wt pct Li have been determined from desorption\\u000a curves of samples saturated with hydrogen at 473 to 873 K. Within this temperature range, the diffusivity of hydrogen in the\\u000a binary <span class="hlt">Al</span>-Li alloys investigated has an Arrhenius-type temperature dependence and follows the equation of the general formD =</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/40789047"><span id="translatedtitle">High temperature deformation of 6061 <span class="hlt">Al</span></span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Kyungtae Park; E. J. Lavernia; F. A. Mohamed</p> <p>1994-01-01</p> <p>The creep behavior of powder metallurgy (PM) 6061 <span class="hlt">Al</span>, which has been used as a metal matrix alloy in the development of discontinuous silicon carbide reinforced aluminum (SiC-<span class="hlt">Al</span>) composites, has been studied over six orders of magnitude of strain rate. The experimental data show that the steady-state stage of the creep curve is of short duration; that the stress dependence</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/servlets/purl/862324"><span id="translatedtitle">17th Annual <span class="hlt">ALS</span> Users' Association Meeting</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Robinson, Art; Tamura, Lori</p> <p>2004-11-29</p> <p>It's not exactly Russian roulette, but scheduling October events outdoors is not risk-free, even in usually sunny California. An overflow crowd of more than 400 registered users, <span class="hlt">ALS</span> staff, and vendors enjoyed a full indoor program featuring science highlights and workshops spread over two and a half days from October 18 to October 20. However, a major storm, heralding the onset of the San Francisco Bay Area rainy season, posed a few weather challenges for the events on the <span class="hlt">ALS</span> patio.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25080252"><span id="translatedtitle">Structure of decagonal <span class="hlt">Al</span>-Ni-Rh.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Logvinovich, Dmitry; Simonov, Arkadiy; Steurer, Walter</p> <p>2014-08-01</p> <p>The crystal structure of the decagonal phase in the system <span class="hlt">Al</span>-Ni-Rh (d-<span class="hlt">Al</span>-Ni-Rh) was analyzed in the five-dimensional embedding approach based on single-crystal synchrotron X-ray diffraction data. The structure can be described as a quasiperiodic packing of partially overlapping decagonal and pentagonal columnar clusters with ??21?Å diameter and ??4?Å period along the tenfold axis. PMID:25080252</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/servlets/purl/516447"><span id="translatedtitle">Modeling of precipitation in <span class="hlt">Al</span> alloys</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Asta, M.; Foiles, S.M.; Wolfer, W.G. [Sandia National Labs., Livermore, CA (United States)] [and others</p> <p>1996-10-01</p> <p>Objective was the development of a computational model of precipitation from a supersaturated alloy solid solution. The model is based on the formalism of chemical-reaction-rate theory combined with classical descriptions of precipitate thermodynamic properties and a mean-field treatment of diffusion-limited growht and coarsening. For the case of precipitation of <span class="hlt">Al</span>{sub 3}Sc in supersaturated <span class="hlt">Al</span>-Sc alloys, it is demonstrated how the model can be used to calculate number densities and size distributions of precipitates as a function of aging time and temperature, including effects of continuous cooling and thermally generated point defects. Application of the model to a specific alloy system requires knowledge of diffusion data, point defect energetics, and thermodynamic properties for bulk phases and interphase interfaces. For interfaces and point defects, thermodynamic data can be difficult to measure and reliable values of defect free energies are often unavailable. For this reason, part of the efforts were devoted to applying semiempirical and first-principles atomistic techniques to the calculation of interfacial and point-defect thermodynamic properties. This report discusses applications for interphase interfaces in the <span class="hlt">Al</span>-Ag, <span class="hlt">Al</span>-Sc, and <span class="hlt">Al</span>-Li alloy systems. We also describe atomistic work aimed at understanding the energetics of vacancy clusters in <span class="hlt">Al</span>. These clusters serve as sinks for isolated vacancies during aging and their growth can lead to more complex defects, such as dislocation loops, that act as heterogeneous nucleation sites.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/552877"><span id="translatedtitle">Incorporation of Cu and <span class="hlt">Al</span> in thin layer silicon grown from Cu-<span class="hlt">Al</span>-Si</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wang, T.H.; Ciszek, T.F. [National Renewable Energy Laboratory, 1617 Cole Blvd., Golden, Colorado 80401 (United States of America)</p> <p>1997-02-01</p> <p>Cu and <span class="hlt">Al</span> concentrations in silicon thin layers grown from Cu-<span class="hlt">Al</span>-Si are determined by segregation at the solid-liquid interface, and for the fast diffusing Cu, also at the free silicon surface. Using the multicomponent regular solution model and experimental results, we found that Si-<span class="hlt">Al</span> and Si-Cu interactions in the liquid solution are repulsive, and <span class="hlt">Al</span>-Cu interaction is attractive. As a result, <span class="hlt">Al</span> incorporation as a function of Cu and <span class="hlt">Al</span> compositions in the growth solution is determined at about 900{degree}C. Up to 0.2{Omega}{center_dot}cm P-type resistivities caused by <span class="hlt">Al</span> doping are achieved because of suppression of <span class="hlt">Al</span> incorporation by Cu, yet with a substantial amount of <span class="hlt">Al</span> still present in the liquid for substrate surface-oxide removal. On the other hand, Cu concentration in the grown layers is reduced by <span class="hlt">Al</span> in the liquid during growth and by surface segregation after growth. The surface segregation phenomenon can be conveniently used to getter Cu from the bulk of silicon layers so that its concentration ({approximately}10{sup 16}cm{sup {minus}3}) is much lower than its solubility (2.5{times}10{sup 17}cm{sup {minus}3}) at the layer growth temperature and the reported 10{sup 17}cm{sup {minus}3} degradation onset for solar-cell performance. {copyright} {ital 1997 American Institute of Physics.}</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2012AIPC.1426..275Z"><span id="translatedtitle">Air blast characteristics of laminated <span class="hlt">al</span> and NI-<span class="hlt">AL</span> casings</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Fan; Ripley, Robert; Wilson, William</p> <p>2012-03-01</p> <p>Air blast characteristics of <span class="hlt">Al</span> and Ni-<span class="hlt">Al</span> laminated materials were experimentally investigated in a 23 m3 closed chamber. Ni and <span class="hlt">Al</span> foils, 50 to 100 micrometers in thickness, were rolled and compacted to form a cylindrical casing with a density of 95% TMD through an explosive formation technique. Charges were prepared using 2 kg C4 explosive packed in the laminated casing to a metal-explosive mass ratio of 1.75. The blast pressure history measured on the chamber wall showed a double-shock front structure with a precursor shock followed by the primary blast. The front peak pressure for the Ni-<span class="hlt">Al</span> cased charge reaches 1.5-2 times that of the <span class="hlt">Al</span> cased, consistent with the larger fireball recorded for the Ni-<span class="hlt">Al</span> cased. The long time quasi-static explosion pressure (QSP) from the Ni- <span class="hlt">Al</span> cased charge is 0.8 of that of the <span class="hlt">Al</span> cased, due to half of <span class="hlt">Al</span> mass in the Ni-<span class="hlt">Al</span>.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/1185327"><span id="translatedtitle">Metastability in the Mg<span class="hlt">Al</span>2O4-<span class="hlt">Al</span>2O3 System</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wilkerson, Dr. Kelley R. [Missouri University of Science and Technology; Smith, Jeffrey D [ORNL; Hemrick, James Gordon [ORNL</p> <p>2014-01-01</p> <p>Aluminum oxide must take a spinel form ( -<span class="hlt">Al</span>2O3) at elevated temperatures in order for extensive solid solution to form between Mg<span class="hlt">Al</span>2O4 and -<span class="hlt">Al</span>2O3. The solvus line between Mg<span class="hlt">Al</span>2O4 and <span class="hlt">Al</span>2O3 has been dened at 79.6 wt% <span class="hlt">Al</span>2O3 at 1500C, 83.0 wt% <span class="hlt">Al</span>2O3 at 1600C, and 86.5 wt% <span class="hlt">Al</span>2O3 at 1700C. A metastable region has been dened at temperatures up to 1700C which could have signicant implications for material processing and properties. Additionally, initial processing could have major implications on nal chemistry. The spinel solid solution region has been extended to form an innite solid solution with <span class="hlt">Al</span>2O3 at elevated temperatures. A minimum in melting at 1975C and a chemistry of 96 wt% <span class="hlt">Al</span>2O3 rather than a eutectic is present, resulting in no eutectic crystal formation during solidication.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/1994JChPh.101.6487B"><span id="translatedtitle">Spectroscopic analysis of the open 3d subshell transition metal aluminides: <span class="hlt">Al</span>V, <span class="hlt">Al</span>Cr, and <span class="hlt">Al</span>Co</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Behm, Jane M.; Brugh, Dale J.; Morse, Michael D.</p> <p>1994-10-01</p> <p>Three open 3d subshell transition metal aluminides, <span class="hlt">Al</span>V, <span class="hlt">Al</span>Cr, and <span class="hlt">Al</span>Co, have been investigated by resonant two-photon ionization spectroscopy to elucidate the chemical bonding in these diatomic molecules. The open nature of the 3d subshell results in a vast number of excited electronic states in these species, allowing bond strengths to be measured by the observation of abrupt predissociation thresholds in a congested optical spectrum, giving D00(<span class="hlt">Al</span>V)=1.489±0.010 eV, D00(<span class="hlt">Al</span>Cr)=2.272±0.009 eV, and D00(<span class="hlt">Al</span>Co)=1.844±0.002 eV. At lower excitation energies the presence of discrete transitions has permitted determinations of the ground state symmetries and bond lengths of <span class="hlt">Al</span>V and <span class="hlt">Al</span>Co through rotationally resolved studies, giving r0` (<span class="hlt">Al</span>V, ?`=0)=2.620±0.004 Å and r0` (<span class="hlt">Al</span>Co, ?`=3)=2.3833±0.0005 Å. Ionization energies were also measured for all three species, yielding IE(<span class="hlt">Al</span>V)=6.01±0.10 eV, IE(<span class="hlt">Al</span>Cr)=5.96±0.04 eV, and IE(<span class="hlt">Al</span>Co)=6.99±0.17 eV. A discussion of these results is presented in the context of previous work on <span class="hlt">Al</span>Cu, <span class="hlt">Al</span>Ni, <span class="hlt">Al</span>Ca, and <span class="hlt">Al</span>Zn.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2013JAP...114w3702H"><span id="translatedtitle">Optical microcavities and enhanced electroluminescence from electroformed <span class="hlt">Al-Al</span>2O3-Ag diodes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hickmott, T. W.</p> <p>2013-12-01</p> <p>Electroluminescence (EL) and electron emission into vacuum (EM) occur when a non-destructive dielectric breakdown of <span class="hlt">Al-Al</span>2O3-Ag diodes, electroforming, results in the development of a filamentary region in which current-voltage (I-V) characteristics exhibit voltage-controlled negative resistance. The temperature dependence of I-V curves, EM, and, particularly, EL of <span class="hlt">Al-Al</span>2O3-Ag diodes with anodic <span class="hlt">Al</span>2O3 thicknesses between 12 nm and 30 nm, has been studied. Two filters, a long-pass (LP) filter with transmission of photons with energies less than 3.0 eV and a short-pass (SP) filter with photon transmission between 3.0 and 4.0 eV, have been used to characterize EL. The voltage threshold for EL with the LP filter, VLP, is ˜1.5 V. VLP is nearly independent of <span class="hlt">Al</span>2O3 thickness and of temperature and is 0.3-0.6 V less than the threshold voltage for EL for the SP filter, VSP. EL intensity is primarily between 1.8 and 3.0 eV when the bias voltage, VS ? 7 V. EL in the thinnest diodes is enhanced compared to EL in thicker diodes. For increasing VS, for diodes with the smallest <span class="hlt">Al</span>2O3 thicknesses, there is a maximum EL intensity, LMX, at a voltage, VLMX, followed by a decrease to a plateau. LMX and EL intensity at 4.0 V in the plateau region depend exponentially on <span class="hlt">Al</span>2O3 thickness. The ratio of LMX at 295 K for a diode with 12 nm of <span class="hlt">Al</span>2O3 to LMX for a diode with 25 nm of <span class="hlt">Al</span>2O3 is ˜140. The ratio of EL intensity with the LP filter to EL intensity with the SP filter, LP/SP, varies between ˜3 and ˜35; it depends on <span class="hlt">Al</span>2O3 thickness and VS. Enhanced EL is attributed to the increase of the spontaneous emission rate of a dipole in a non-resonant optical microcavity. EL photons interact with the Ag and <span class="hlt">Al</span> films to create surface plasmon polaritons (SPPs) at the metal-<span class="hlt">Al</span>2O3 interfaces. SPPs generate large electromagnetic fields in the filamentary region of the electroformed <span class="hlt">Al-Al</span>2O3-Ag diode, which then acts as an optical microcavity. A model is proposed for electronic processes in electroformed <span class="hlt">Al-Al</span>2O3-Ag diodes.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASA-TRS&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19920049226&hterms=protective+effect&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dprotective%2Beffect"><span id="translatedtitle">Protective <span class="hlt">Al</span>2O3 scale formation on Nb<span class="hlt">Al</span>3-base alloys</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Doychak, J.; Hebsur, M. G.</p> <p>1991-01-01</p> <p>The oxidation of Nb<span class="hlt">Al</span>3 with additions of Cr and Y was studied to determine the mechanisms of the beneficial effects of these elements upon oxidation. Cr additions to the binary Nb<span class="hlt">Al</span>3 alloy of up to 6.8 at. percent reduced the scale growth rates and promoted alpha-<span class="hlt">Al</span>2O3 formation over much longer times relative to binary Nb<span class="hlt">Al</span>3. A major effect of Cr is to form a layer of <span class="hlt">Al</span>NbCr at the metal/scale interface, which is inherently more oxidation-resistant than the matrix alloy in the long term. Yttrium additions to a Cr-containing alloy improved the scale growth rate and adherence and changed the scale microstructure to mimic that of a typical protective <span class="hlt">Al</span>2O3 scale.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/1996ApPhL..69.1385C"><span id="translatedtitle">Selective oxidation of buried <span class="hlt">Al</span>GaAs versus <span class="hlt">Al</span>As layers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Choquette, Kent D.; Geib, K. M.; Chui, H. C.; Hammons, B. E.; Hou, H. Q.; Drummond, T. J.; Hull, Robert</p> <p>1996-09-01</p> <p>We report significant differences between the properties of buried oxides converted from <span class="hlt">Al</span>GaAs and <span class="hlt">Al</span>As layers using selective wet oxidation. Layers of AlxGa1-xAs with x?0.96 exhibit crystallographic dependent oxidation rates, while for layers with x?0.92 the oxidation rate is isotropic. Mesas containing partially oxidized layers of <span class="hlt">Al</span>As are unstable to rapid thermal cycling and exhibit excessive strain at the oxide terminus, while mesas containing partially oxidized layers of <span class="hlt">Al</span>GaAs are robust and lack evidence of strain. Finally, the oxidation of <span class="hlt">Al</span>GaAs layers, rather than <span class="hlt">Al</span>As, is found to provide robust oxide apertures for reliable vertical-cavity surface emitting lasers.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/244977"><span id="translatedtitle">Relationship between electrical conductivity and stress corrosion cracking susceptibility of <span class="hlt">Al</span> 7075 and <span class="hlt">Al</span> 7475 alloys</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Tsai, T.C.; Chuang, T.H. [National Taiwan Univ., Taipei (Taiwan, Province of China). Inst. of Materials Science and Engineering</p> <p>1996-06-01</p> <p>A relationship between electrical conductivity and stress corrosion cracking (SCC) resistance of the 7,000-series <span class="hlt">Al</span>-Zn-Mg alloys has been established, although only from the near-peak strength T6 temper to the overaged T73 tempered condition. The present work investigated whether this relationship exists for all periods of aging and for <span class="hlt">Al</span> alloys with different compositions and grain structures. The materials studied were commercial 2-mm thick <span class="hlt">Al</span> 7075 (<span class="hlt">Al</span>-5.76% Zn-2.46% Mg-1.70% Cu-0.20% Cr-0.12% Fe-0.09% Si-0.06% Mn-0.04% Ti) and <span class="hlt">Al</span> 7475 (<span class="hlt">Al</span>-5.80% Zn-2.24% Mg-1.53% Cu-0.19% Cr-0.08% Fe-0.02% Si-0.01% Mn-0.02% Ti) alloy plates.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASA-TRS&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19890059135&hterms=incoherent+metal&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dincoherent%2Bmetal"><span id="translatedtitle">TEM studies of oxidized Ni<span class="hlt">Al</span> and Ni3<span class="hlt">Al</span> cross sections</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Doychak, J.; Ruhle, M.</p> <p>1989-01-01</p> <p>Cross sections of oxide scale/(Ni-<span class="hlt">Al</span>) intermetallics were prepared by a new method and studied using primarily TEM. The cross sections were prepared by encasing an oxidized metal specimen sandwich in a low-melting-temperature zinc alloy. Observations of oxidized zirconium-doped beta-Ni<span class="hlt">Al</span> cross sections revealed crystallographic voids beneath an adherent <span class="hlt">Al</span>2O3 scale. The oxide-metal interface was incoherent, but a high dislocation density in the metal near the interface suggested that a large tensile stress was induced by the attached oxide scale. A duplex <span class="hlt">Al</span>2O3-Ni<span class="hlt">Al</span>2O4 scale formed on zirconium-doped and zirconium/boron-doped gamma-prime-Ni3<span class="hlt">Al</span> alloys. Additional results are presented involving oxidation mechanisms and oxide-metal interface structures.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2005JaJAP..44L.760O"><span id="translatedtitle">Temperature Dependence of Tunnel Magnetoresistance in Co-Mn-<span class="hlt">Al/Al</span>-Oxide/Co-Fe Junctions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Oogane, Mikihiko; Nakata, Jun; Kubota, Hitoshi; Ando, Yasuo; Sakuma, Akimasa; Miyazaki, Terunobu</p> <p>2005-06-01</p> <p>We investigated the temperature dependence of the tunnel magnetoresistance (TMR) effect in Co-Mn-<span class="hlt">Al/Al</span>-oxide/Co-Fe tunnel junctions. The junction prepared without exposure to air during deposition showed very large TMR ratios of 65% at 10 K and 40% at room temperature. In contrast, the junction prepared with air exposure before and after <span class="hlt">Al</span>-oxide layer fabrication showed a maximum TMR ratio of only 40% at a low temperature. Temperature dependences of tunnel conductance of these junctions were analyzed using a simple model that incorporates two contributions: elastic tunneling with decreasing spin polarization as temperature increases and spin-independent hopping tunneling through trap states in <span class="hlt">Al</span>-oxide tunnel barriers. Results of analyses indicated that air exposure drastically reduced spin polarization and Curie temperature. It also created an inferior insulating layer at the Co-Mn-<span class="hlt">Al/Al</span>-oxide interface.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASA-TRS&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19990008594&hterms=titanium+microstructure&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dtitanium%2Bmicrostructure"><span id="translatedtitle">Two-Phase (Ti<span class="hlt">Al+TiCrAl</span>) Coating Alloys for Titanium Aluminides</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Brady, Michael P. (Inventor); Smialek, James L. (Inventor); Brindley, William J. (Inventor)</p> <p>1998-01-01</p> <p>A coating for protecting titanium aluminide alloys, including the Ti<span class="hlt">Al</span> gamma + Ti3<span class="hlt">Al</span> (alpha(sub 2)) class, from oxidative attack and interstitial embrittlement at temperatures up to at least 1000 C. is disclosed. This protective coating consists essentially of titanium, aluminum. and chromium in the following approximate atomic ratio: Ti(41.5-34.5)<span class="hlt">Al</span>(49-53)Cr(9.5-12.5)</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/26495778"><span id="translatedtitle">Structure and mechanical properties of Ni<span class="hlt">Al</span> and Ni 3<span class="hlt">Al</span>-based alloys</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Tomasz Czeppe; Stanislaw Wierzbinski</p> <p>2000-01-01</p> <p>The investigation of Ni–<span class="hlt">Al</span>–Fe–Ti–B alloys was carried out to determine the influence of iron and small titanium and boron additions on the phase composition, microstructure and mechanical characteristic, particularly with respect to high-temperature deformation conditions. These alloys, containing <span class="hlt">Al</span> 35.8 at% and Fe 3.6–8.6–17.6 at% were prepared from high-purity components and <span class="hlt">Al</span> master alloy containing Ti2B particles. The influence of</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/46502015"><span id="translatedtitle">Stability of the directionally solidified eutectics Ni<span class="hlt">Al</span>-Cr and Ni<span class="hlt">Al</span>-Mo</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>J. L. Walter; H. E. Cline</p> <p>1973-01-01</p> <p>The eutectics Ni<span class="hlt">Al</span>-Cr with cylindrical chromium fibers and Ni<span class="hlt">Al</span>-Mo with faceted molybdenum fibers were heated at 1400?C to\\u000a determine the stability of the composite structure and to compare the stability of the nonfaceted fibers with that of the\\u000a faceted fibers in the Ni<span class="hlt">Al</span> matrix. Fiber size and size distribution and number of fibers per unit area were measured as a</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25781510"><span id="translatedtitle">Remarks on Peinado et <span class="hlt">al.'s</span> Analysis of J3Gen.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Garcia-Alfaro, Joaquin; Herrera-Joancomartí, Jordi; Melià-Seguí, Joan</p> <p>2015-01-01</p> <p>Peinado et <span class="hlt">al</span>. analyzed the security of the J3Gen pseudorandom number generator proposed by Melià-Seguí et <span class="hlt">al</span>., and claimed weaknesses regarding its security properties. They also presented a deterministic attack based on the decimation of the J3Gen output sequences. We show that the assumptions made by Peinado et <span class="hlt">al</span>. are not correct and that the proposed deterministic attack against J3Gen does not hold in practice. PMID:25781510</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://www.springerlink.com/index/5x3374tr35464r94.pdf"><span id="translatedtitle">Combustion Synthesis Reactions in Cold-Rolled Ni\\/<span class="hlt">Al</span> and Ti\\/<span class="hlt">Al</span> Multilayers</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Xiaotun Qiu; Ranran Liu; Shengmin Guo; Jesse Harris Graeter; Laszlo Kecskes; Jiaping Wang</p> <p>2009-01-01</p> <p>In this article, a cold rolling method was developed to fabricate Ni\\/<span class="hlt">Al</span> and Ti\\/<span class="hlt">Al</span> multilayer foils, and the combustion synthesis\\u000a reactions in the cold-rolled foils were investigated. Combustion synthesis reactions were initiated by heating one end of\\u000a the cold-rolled foil in a flame for several seconds. The Ni\\/<span class="hlt">Al</span> foils went through three reaction stages. The first reaction\\u000a stage was a</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/55839621"><span id="translatedtitle">Combustion synthesis of Ni3<span class="hlt">Al</span> and Ni3<span class="hlt">Al</span>-matrix composites</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>J. P. Lebrat; A. Varma; A. E. Miller</p> <p>1992-01-01</p> <p>The self-propagating mode of combustion synthesis (SHS) of Ni3<span class="hlt">Al</span> starting from compacts of stoichiometrically mixed Ni and <span class="hlt">Al</span> powders readily forms fully reacted structures with about 3 to 5 pct porosity, if green density of the compacts is greater than about 75 pct of theoretical. SHS-produced Ni3<span class="hlt">Al</span> matrix composites with up to 2 wt pct A12O3 whiskers also have relatively</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/46500144"><span id="translatedtitle">Combustion synthesis of Ni 3 <span class="hlt">Al</span> and Ni 3 <span class="hlt">Al</span>-matrix composites</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>J. P. Lebrat; A. Varma; A. E. Miller</p> <p>1992-01-01</p> <p>The self-propagating mode of combustion synthesis (SHS) of Ni3<span class="hlt">Al</span> starting from compacts of stoichiometrically mixed Ni and <span class="hlt">Al</span> powders readily forms fully reacted structures with about\\u000a 3 to 5 pct porosity, if green density of the compacts is greater than about 75 pct of theoretical. SHS-produced Ni3<span class="hlt">Al</span> matrix composites with up to 2 wt pct A12O3 whiskers also have relatively</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/21055234"><span id="translatedtitle">High Performance <span class="hlt">AlInGaAs/Al</span>GaAs Photocathode</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Mamaev, Yu. A.; Gerchikov, L. G.; Yashin, Yu. P.; Vasiliev, D. A.; Kuzmichev, V. V. [State Polytechnic University, 195251, St. Petersburg (Russian Federation); Ustinov, V. M.; Zhukov, A. E. [St. Petersburg Scientific-Educational Center RAS, 195251, St. Petersburg (Russian Federation); Mikhrin, V. S. [Ioffe Physico-Technical Institute, RAS, 194021, St. Petersburg (Russian Federation)</p> <p>2008-02-06</p> <p>New photocathode for highly polarized electron emission has been developed, fabricated and studied. Polarized electron source is based on short-period strained <span class="hlt">AlInGaAs/Al</span>GaAs superlattice grown by MBE method. Deformation of <span class="hlt">Al</span>InGaAs quantum well results in 85 meV energy splitting between heavy hole and light hole minibands. Electron emission from the developed photocathode demonstrates maximal polarization of 92% with quantum efficiency of 0.85%.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/1540360"><span id="translatedtitle"><span class="hlt">AlGaN\\/Al</span>N\\/GaN high-power microwave HEMT</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>L. Shen; S. Heikman; B. Moran; R. Coffie; N.-Q. Zhang; D. Buttari; I. P. Smorchkova; S. Keller; S. P. DenBaars; U. K. Mishra</p> <p>2001-01-01</p> <p>In this letter, a novel heterojunction <span class="hlt">AlGaN\\/Al</span>N\\/GaN high-electron mobility transistor (HEMT) is discussed. Contrary to normal HEMTs, the insertion of the very thin <span class="hlt">Al</span>N interfacial layer (~1 nm) maintains high mobility at high sheet charge densities by increasing the effective ?EC and decreasing alloy scattering. Devices based on this structure exhibited good DC and RF performance. A high peak current</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://hotmetals.ms.northwestern.edu/refs/files/am04_superalloy_foams.pdf"><span id="translatedtitle">Synthesis, structure, and mechanical properties of Ni–<span class="hlt">Al</span> and Ni–Cr–<span class="hlt">Al</span> superalloy foams</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Heeman Choe; David C. Dunand</p> <p>2004-01-01</p> <p>Reticulated nickel foams were alloyed with 8–9 wt% <span class="hlt">Al</span> or 14–18 wt% Cr and 5–9 wt% <span class="hlt">Al</span> in a three-step method consisting of (i) gas-phase deposition of Cr and\\/or <span class="hlt">Al</span> onto the struts of a pure Ni foam by pack-cementation at 1000 °C; (ii) homogenization at 1200 °C to remove concentration gradients and to solutionize the alloyed struts; (iii) aging</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/40274889"><span id="translatedtitle">On the properties of the eutectic alloy <span class="hlt">Al</span> 3(Nb,Cr) + Cr(<span class="hlt">Al</span>,Nb)</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>S. A. Souza; P. L. Ferrandini; E. A. Souza; A. O. dos Santos; R. Caram</p> <p>2008-01-01</p> <p>The eutectic alloy <span class="hlt">Al</span>3(Nb,Cr)+Cr(<span class="hlt">Al</span>,Nb) forms an in situ composite and the <span class="hlt">Al</span>3Nb presents high specific strength and low oxidation rate that may be improved by the combination with other phases. The purpose of this work is to investigate physical, mechanical and oxidation properties of the eutectic alloy. Therefore, Rietveld analysis was carried out for furnace cooled and water quenched samples</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/203536"><span id="translatedtitle">Synthesis of <span class="hlt">Al</span>{sub 2}O{sub 3}-<span class="hlt">Al</span> composites by reactive metal penetration</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Loehman, R.E.; Ewsuk, K. [Sandia National Labs., Albuquerque, NM (United States). Advanced Materials Lab.; Tomsia, A.P. [Pask Research and Engineering, Berkeley, CA (United States)</p> <p>1996-01-01</p> <p>Ceramic-metal composites have been made to near net-shape by reactive penetration of dense ceramic preforms by molten <span class="hlt">Al</span>. Ceramic-metal composite formation by reactive metal penetration is driven by a strongly negative Gibbs energy for reaction. For <span class="hlt">Al</span>, the general form of the reaction is (x + 2)<span class="hlt">Al</span> + (3/y)MO{sub y} {yields} <span class="hlt">Al</span>{sub 2}O{sub 3} + M{sub 3/y}<span class="hlt">Al</span>{sub x}, where MO{sub y} is an oxide that is wet by molten <span class="hlt">Al</span>. In low P{sub O{sub 2}} atmospheres and at temperatures above about 900 C, molten <span class="hlt">Al</span> reduces mullite to produce <span class="hlt">Al</span>{sub 2}O{sub 3} and silicon. The <span class="hlt">Al</span>/mullite reaction has a {Delta}G{degree}{sub r} (1,200 K) of {minus}1,014 kJ/mol and, if the mullite is fully dense, the theoretical volume change on reaction is less than 1%. Experiments with commercial mullite containing a silicate grain boundary phase average less than 2% volume change on reaction. In the <span class="hlt">Al</span>/mullite system, reactive metal penetration produces a fine-grained alumina skeleton with an interspersed metal phase. With enough excess aluminum, mutually interpenetrating ceramic-metal composites are produced. Properties measurements show that ceramic-metal composites produced by reactive metal penetration of mullite by <span class="hlt">Al</span> have a Young`s modulus and hardness similar to that of <span class="hlt">Al</span>{sub 2}O{sub 3}, with improved fracture toughness ranging from5 to 9 MPa {center_dot} m{sup 1/2}. For penetration times less than 1 h, reaction layer thickness varies as the square root of time, which allows ceramic-metal composite coatings to be fabricated by controlling the penetration time.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/919660"><span id="translatedtitle">The Stability of <span class="hlt">Al</span> 11Sm3 (<span class="hlt">Al</span>4Sm) Phases in the <span class="hlt">Al</span>-Sm Binary System</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>S.H.Zhou; R.E. Napolitano</p> <p>2007-06-01</p> <p>The relative stability of <span class="hlt">Al</span>{sub 11}Sm{sub 3} (<span class="hlt">Al</span>{sub 4}Sm) intermetallic phases was experimentally investigated through a series of heat treatments followed by microstructural, microchemical, and X-ray diffraction (XRD) analyses. The principal findings are that the high-temperature tetragonal phase is stable from 1655 to 1333 K and that the low-temperature orthorhombic phases, {alpha} and {gamma}, have no range of full stability but are metastable with respect to the crystalline <span class="hlt">Al</span> and Sm reference states down to 0 K. Thermodynamic modeling is used to describe the relative energetics of stable and metastable phases along with the associated two-phase mixtures. Issues regarding transition energetics and kinetics are discussed.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASA-TRS&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20020041465&hterms=dissociation+H2&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Ddissociation%2BH2"><span id="translatedtitle">The Dissociation Energies of <span class="hlt">Al</span>H2 and <span class="hlt">Al</span>Ar</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ricca, Alessandra; Partridge, Harry; Bauschlicher, Charles W., Jr.; Visscher, Luuk; Langhoff, Stephen R. (Technical Monitor)</p> <p>1995-01-01</p> <p>The D(sub 0) values for <span class="hlt">Al</span>H2 and <span class="hlt">Al</span>Ar are computed using the coupled cluster approach in conjunction with large basis sets. Basis set superposition and spin-orbit effects are accounted for as they are sizeable due to the small binding energy. The computed dissociation energy for <span class="hlt">Al</span>Ar is 101 /cm , which is 83% of the experimental value (122.4/ cm). Our best estimate for the H2 binding energy in <span class="hlt">Al</span>H2 is 40 +/- 28 /cm.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2014SRL....2150034M"><span id="translatedtitle">HYDROGEN ADSORPTION ON ?-Ti<span class="hlt">Al</span> (001) AND Ni/Ti<span class="hlt">Al</span> (001) SURFACES</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mubarak, A. A. Karim; Alelaimi, Mahmoud</p> <p>2014-04-01</p> <p>In this paper, we present first principles calculations of the energetic, electronic and magnetic properties of the variant termination of Ti<span class="hlt">Al</span> (001) and Ni/Ti<span class="hlt">Al</span> (001) surfaces with and without hydrogen atoms. The calculations have been performed within the density functional theory using full-potential linearized augmented plane wave method. The generalized gradient approximation (GGA) is utilized as the exchange-correlation energy. The octahedral site is the stable absorption site of H atom in the ?-Ti<span class="hlt">Al</span> system. This absorption reduces the cohesive energy of ?-Ti<span class="hlt">Al</span> system due to increase in the lattice constant. The surface energy for both Ti<span class="hlt">Al</span> (001) terminations is calculated. The stable adsorption site of H atoms on the variant termination of Ti<span class="hlt">Al</span> (001) surface is performed. The adsorption energy of hydrogen on Ti is more energetic than that on <span class="hlt">Al</span>. The adsorption of H atom on both terminations of H/Ni/Ti<span class="hlt">Al</span> (001) is more preferable at the bridge site. The adsorption energies are enhanced on Ni atom due to the contraction between d-Ni bands and Ti<span class="hlt">Al</span> substrate band.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2010PhLA..374.3230Y"><span id="translatedtitle">Glassy ferromagnetism in <span class="hlt">Al</span>-doped 4H-SiC: <span class="hlt">Al</span>Si-V complexes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, Mao; Shi, Jun-jie</p> <p>2010-07-01</p> <p>The recent observed glassy ferromagnetism in <span class="hlt">Al</span>-doped 4 H-SiC is investigated using first principles calculations. We find that the formation energy of V is significantly reduced by <span class="hlt">Al</span> atoms doped in SiC. The <span class="hlt">Al</span> Si- V complex induces a half-filled narrow a level in the band gap and contributes a net local moment of 1 ?. The exchange parameter J can be either positive or negative along different directions. Both the strong anisotropy of J and the correlation effects of the a level can lead to a glassy ferromagnetism in <span class="hlt">Al</span>-doped 4 H-SiC.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASA-TRS&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19920053767&hterms=chemistry+synthesis&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dchemistry%2Bsynthesis"><span id="translatedtitle">Combustion synthesis of TiB2-<span class="hlt">Al</span>2O3-<span class="hlt">Al</span> composite materials</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Feng, H. J.; Moore, J. J.; Wirth, D. G.</p> <p>1991-01-01</p> <p>The oxide-aluminum exothermic reduction reaction is presently used in the combustion-synthesis of ceramic/metal composites. An excess of <span class="hlt">Al</span> is used in the reacting materials, which rapidly generate enough heat to exceed <span class="hlt">Al</span>'s melting point. The molten <span class="hlt">Al</span> thus evolved is allowed to infiltrate the porous ceramic matrix as the exothermic reaction proceeds; this feature of the process turns the disadvantage of high porosity levels in combustion-synthesized materials into an advantage. Attention is given to the system obtained with 3TiO2 + 3B2O3 + (10-x)<span class="hlt">Al</span> starting materials.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://irvinginstitute.columbia.edu/2012/pdf/prize4life_press_release_v13_ccaNrc.pdf"><span id="translatedtitle">THE NEXT <span class="hlt">ALS</span> BREAKTHROUGH COULD BE YOURS Prize4Life Awards Prizes for <span class="hlt">ALS</span> Biomarker Challenge to InnoCentive</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Grishok, Alla</p> <p></p> <p>THE NEXT <span class="hlt">ALS</span> BREAKTHROUGH COULD BE YOURS Prize4Life Awards Prizes for <span class="hlt">ALS</span> Biomarker Challenge to InnoCentive Solvers Extends $1Million Challenge Seeking <span class="hlt">ALS</span> Biomarker WALTHAM, Mass. ­ April 28, 2009 for the Prize4Life <span class="hlt">ALS</span> Biomarker Challenge, which seeks a biomarker for measuring disease progression in <span class="hlt">ALS</span></p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://hal.archives-ouvertes.fr/docs/00/67/69/13/PDF/GRL_2010_37_L20306.pdf"><span id="translatedtitle">Elasticity of <span class="hlt">Al</span>FeO3 and Fe<span class="hlt">Al</span>O3 perovskite and postperovskite from firstprinciples calculations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Paris-Sud XI, Université de</p> <p></p> <p>Elasticity of <span class="hlt">Al</span>FeO3 and Fe<span class="hlt">Al</span>O3 perovskite and postperovskite from firstprinciples calculations R constants tensor of perovskite and postperovskite with formulas <span class="hlt">Al</span>FeO3 and Fe<span class="hlt">Al</span>O3 in which Fe or <span class="hlt">Al</span> perovskite and postperovskite is associated with a site exchange, during which Fe from the interoctahedral</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/616445"><span id="translatedtitle">Long range order and vacancy properties in <span class="hlt">Al</span>-rich Fe{sub 3}<span class="hlt">Al</span> and Fe{sub 3}<span class="hlt">Al</span>(Cr) alloys</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kim, S.M. [AECL, Chalk River, Ontario (Canada). Chalk River Labs.] [AECL, Chalk River, Ontario (Canada). Chalk River Labs.; Morris, D.G. [Univ. of Neuchatel (Switzerland). Inst. of Structural Metallurgy] [Univ. of Neuchatel (Switzerland). Inst. of Structural Metallurgy</p> <p>1998-05-01</p> <p>Neutron powder diffraction measurements have been carried out in situ from room temperature to about 100 C in Fe28<span class="hlt">Al</span> (28 at.% <span class="hlt">Al</span>), Fe32.5<span class="hlt">Al</span> (32.5 at.% <span class="hlt">Al</span>) and Fe28<span class="hlt">Al</span>15Cr (28 at.% <span class="hlt">Al</span>, 5 at.% Cr) alloys. X-ray diffraction and TEM studies provided supporting information. The data were analyzed to obtain information about the temperature dependence of the DO{sub 3} and B2 long range order parameters, the location of the Cr atoms and their effect on the ordering energies, and on the vacancy formation and migration properties in Fe28<span class="hlt">Al</span> and Fe32.5<span class="hlt">Al</span> alloys. The location of the ternary alloying addition in DO{sub 3} and B2 ordered <span class="hlt">Al</span>-rich Fe{sub 3}<span class="hlt">Al</span> is shown to be consistent with considerations of interatomic bond energies.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=FEDREG&redirectUrl=http://www.gpo.gov:80/fdsys/pkg/FR-2012-11-13/pdf/2012-27494.pdf"><span id="translatedtitle">77 FR 67689 - Fidelity Aberdeen Street Trust, et <span class="hlt">al</span>.;</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2012-11-13</p> <p>...812-13731] Fidelity Aberdeen Street Trust, et <span class="hlt">al</span>.; Notice of Application November 6...1\\ Colchester Street Trust, et <span class="hlt">al</span>., Investment Company Act Release Nos...amending, Colchester Street Trust, et <span class="hlt">al</span>., Investment Company Act Release...</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2009PhRvB..79h5423K"><span id="translatedtitle">Coating of a layer of Au on <span class="hlt">Al</span>13 : The findings of icosahedral <span class="hlt">Al@Al</span>12Au20- and <span class="hlt">Al</span>12Au202- fullerenes using ab initio pseudopotential calculations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kumar, Vijay</p> <p>2009-02-01</p> <p>We report results of ab initio pseudopotential calculations on the nanocoating of gold on an icosahedral <span class="hlt">Al</span>13 cluster and the findings of icosahedrally symmetric endohedral <span class="hlt">Al@Al</span>12Au20- and empty cage <span class="hlt">Al</span>12Au202- compound fullerenes formed of metal atoms. Twelve <span class="hlt">Al</span> atoms cap the pentagonal faces of a dodecahedral Au20 cage in which each Au atom has three <span class="hlt">Al</span> atoms and three Au atoms as nearest neighbors. Mixing of <span class="hlt">Al</span>13 and Au20 magic clusters leads to a large heat of formation of 0.55 eV/atom and high stability of the <span class="hlt">Al@Al</span>12Au20 compound fullerene. The binding energies of <span class="hlt">Al</span>12Au20 and <span class="hlt">Al@Al</span>12Au20 are 3.017 and 3.007 eV/atom, respectively, which are much larger than 2.457 eV/atom for Au32 fullerene, leading to the possibility of their high abundance.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://www.uni-regensburg.de/studium/pruefungsordnungen/medien/zusatzausbildung/903daz2.pdf"><span id="translatedtitle">Ordnung fr die Studienbegleitende Ausbildung Deutsch <span class="hlt">als</span> Zweitsprache</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Schubart, Christoph</p> <p></p> <p>Ordnung für die Studienbegleitende Ausbildung Deutsch <span class="hlt">als</span> Zweitsprache an der Universität Literaturwissenschaften der Universität Regensburg bietet die studienbegleitende Ausbildung Deutsch <span class="hlt">als</span> Zweitsprache (im Fachbereichs Deutschs <span class="hlt">als</span> Zweitsprache zu einer Unterrichtstätigkeit in diesem Bereich zu befähigen. (3) 1 Die</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/1987MTA....18..393D"><span id="translatedtitle">The nature of the Fe<span class="hlt">Al</span>3 liquid-(FeMn)<span class="hlt">Al</span>6 reaction in the <span class="hlt">Al</span>-Fe-Mn system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Denholm, W. T.; Esdaile, J. D.; Siviour, N. G.; Wilson, B. W.</p> <p>1987-03-01</p> <p>Crystallization studies using an inverted L pattern of liquid aluminum alloys of compositions just to the right of the ternary point, and the application of a theoretical analysis of the behavior of a hypothetical system, show that the Fe<span class="hlt">Al</span>3-(FeMn)<span class="hlt">Al</span>6-liquid reaction is peritectic close to the ternary point, and that the invariant reaction is eutectic, i.e., L = Fe<span class="hlt">Al</span>3 + (FeMn)<span class="hlt">Al</span>6 + <span class="hlt">Al</span>( C).</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2015AIPC.1653b0023B"><span id="translatedtitle">The formation of (<span class="hlt">Al</span>8Fe2Si, <span class="hlt">Al</span>13Fe4) phases from <span class="hlt">Al</span>-Fe-Si system by TE mode</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Boulouma, A.; Drici, A.; Benaldjia, A.; Guerioune, M.; Vrel, D.</p> <p>2015-03-01</p> <p>This work prepared <span class="hlt">Al</span>8Fe2Si, <span class="hlt">Al</span>13Fe4 mixed sample by ball milling and thermal explosion techniques applying <span class="hlt">Al</span>, Fe and Si powders as precursors. Thermal combustion of powder mixes of composition 24, 37 <span class="hlt">Al</span>+ 50, 36 Fe + 25, 27 Si in mass reveals production of several binary and ternary intermetallic phases such: A113Fe4 and <span class="hlt">Al</span>8Fe2Si.. Synthesis conditions were optimized to fabricate these phases having many potential applications.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/41025655"><span id="translatedtitle">New approximant phases in <span class="hlt">Al</span>–Cr–Fe</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>V Demange; J. S Wu; V Brien; F Machizaud; J. M Dubois</p> <p>2000-01-01</p> <p>Recently, new approximant phases were pointed out in the <span class="hlt">Al</span>–Cr–Fe system, namely orthorhombic O-<span class="hlt">Al</span>–Cr–Fe, hexagonal H-<span class="hlt">Al</span>–Cr–Fe and monoclinic M-<span class="hlt">Al</span>–Cr–Fe. In the corresponding analysed samples, the new approximant phases were always coexisting with metallic aluminium. We have studied the <span class="hlt">Al</span>–Cr–Fe system within a broad composition range. In one alloy with composition <span class="hlt">Al</span>81Cr11Fe8, two new crystalline approximants of the decagonal phase were</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/6542417"><span id="translatedtitle">Combustion synthesis of Ti<span class="hlt">Al</span>-matrix composites in the Ti-<span class="hlt">Al</span>-BN system</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Mabuchi, H.; Tsuda, H.; Nakayama, Y. (Univ. of Osaka Prefecture, Osaka (Japan). Dept. of Metallurgy and Materials Science)</p> <p>1995-01-15</p> <p>The intermetallic compound Ti<span class="hlt">Al</span> has attracted much attention for its potential use as a structural high-temperature material. However, its use has been limited because of its negligible low-temperature ductility and fracture toughness and low high-temperature strength and creep. To improve these properties, recently this compound has been made as a composite material containing a secondary phase such as boride, carbide, nitride, or oxide. Recently, combustion synthesis or self-propagating, high-temperature synthesis (SHS) using powder compacts has been developed to produce intermetallics or ceramics. It is also possible to form intermetallic-intermetallic, intermetallic-ceramic, or ceramic-ceramic composites from combustion reactions between corresponding elemental constituents. It has the advantage of an in-situ forming technique compared with conventional artificial composite production approaches. In the previous studies using elemental powders, combustion reaction was carried out to form intermetallic-ceramic composites in the Ti-<span class="hlt">Al</span>-C, or Ti-<span class="hlt">Al</span>-N system. The compacts of Ti and <span class="hlt">Al</span> powders with carbon powder or in gaseous nitrogen reacted exothermically, and formed a mixture product which had a fine distribution of the Ti[sub 2]<span class="hlt">Al</span>C or Ti[sub 2]<span class="hlt">Al</span>N particles in the matrix Ti<span class="hlt">Al</span> with a small amount of Ti[sub 3]<span class="hlt">Al</span>. The processing technique, therefore, is of interest as a combustion reaction synthesis to make in-situ intermetallic-based composite materials. In the present work, to investigate the effect of BN addition on the reaction of Ti And <span class="hlt">Al</span> powder mixtures, combustion synthesis of Ti<span class="hlt">Al</span>-matrix composites has been performed for the Ti-<span class="hlt">Al</span>-BN system.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/servlets/purl/676870"><span id="translatedtitle">Boron strengthening in Fe<span class="hlt">Al</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Baker, I.; Li, X.; Xiao, H.; Klein, O.; Nelson, C. [Dartmouth Coll., Hanover, NH (United States). Thayer School of Engineering; Carleton, R.L.; George, E.P. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.</p> <p>1998-11-01</p> <p>The effect of boron on the strength of B2-structured Fe<span class="hlt">Al</span> is considered as a function of composition, grain size and temperature. Boron does not affect the concentrations of antisite atoms or vacancies present, with the former increasing and the latter decreasing with increasing deviation from the stoichiometric composition. When vacancies are absent, the strength increase per at. % B per unit lattice strain, {Delta}{sigma}/({Delta}c x {epsilon}) increases with increasing aluminum concentration, but when vacancies are present (>45 at. % <span class="hlt">Al</span>), {Delta}{sigma}/({Delta}c x {epsilon}) decreases again. Boron increases grain size strengthening in Fe<span class="hlt">Al</span>. B strengthening is roughly independent of temperature up to the yield strength peak but above the point, when diffusion-assisted deformation occurs, boron strengthening increases dramatically.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3639398"><span id="translatedtitle">Stress granules as crucibles of <span class="hlt">ALS</span> pathogenesis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>King, Oliver D.</p> <p>2013-01-01</p> <p>Amyotrophic lateral sclerosis (<span class="hlt">ALS</span>) is a fatal human neurodegenerative disease affecting primarily motor neurons. Two RNA-binding proteins, TDP-43 and FUS, aggregate in the degenerating motor neurons of <span class="hlt">ALS</span> patients, and mutations in the genes encoding these proteins cause some forms of <span class="hlt">ALS</span>. TDP-43 and FUS and several related RNA-binding proteins harbor aggregation-promoting prion-like domains that allow them to rapidly self-associate. This property is critical for the formation and dynamics of cellular ribonucleoprotein granules, the crucibles of RNA metabolism and homeostasis. Recent work connecting TDP-43 and FUS to stress granules has suggested how this cellular pathway, which involves protein aggregation as part of its normal function, might be coopted during disease pathogenesis. PMID:23629963</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/47771837"><span id="translatedtitle">Customer Perceived Value Accounting <span class="hlt">als</span> zentrale Komponente des Dienstleistungscontrolling</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Friederike Wall; Regina Schröder</p> <p></p> <p>Dienstleistungen besitzen in zweifacher Hinsicht Prozesscharakter: zum einen <span class="hlt">als</span> unternehm erischer Erstellungsprozess, zum\\u000a anderen <span class="hlt">als</span> kundenseitiger Nutzungsprozess der Leistung (Stauss 1995).</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2014APS..MARL34003N"><span id="translatedtitle">Individual two level fluctuators in the tunneling conductance of <span class="hlt">Al/AlOx/Al</span> Josephson junctions for superconducting qubits</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nugroho, Christopher; Orlyanchik, Vladimir; van Harlingen, Dale</p> <p>2014-03-01</p> <p>Two level system (TLS) defects in <span class="hlt">Al</span>Ox tunnel barriers can lead to low-frequency 1 / f critical current noise and losses in coherent superconducting circuits. Understanding the nature of these defects and how to eliminate them are critical in order to achieve ultra-long coherence times. We present measurements of the tunneling conductance of ultrasmall, A <(100nm) 2 , <span class="hlt">Al/AlOx/Al</span> shadow evaporated junctions. The tunneling conductance of these junctions exhibits several isolated TLSs, which permitted the detailed analysis of the individual switching rates and behavior of the TLSs. We have studied the thermal activation behavior of these TLSs, and in some cases observe a crossover into quantum-limited tunneling at lower temperatures. Tracking the TLS switching rates as a function of the applied voltage bias provides an estimate of the TLS charge dipole moment. In some quantum tunneling limited TLSs we have observed a non-equilibrium enhancement of the switching rates that cannot be explained by simple dissipative heating of the TLSs. Further investigations into these TLS defects may lead to the identification of their physical origins and strategies to eliminate them. Research funded by the Intelligence Advanced Research Projects Activity (IARPA).</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=FEDREG&redirectUrl=http://www.gpo.gov:80/fdsys/pkg/FR-2011-11-17/pdf/2011-29656.pdf"><span id="translatedtitle">76 FR 71355 - United States et <span class="hlt">al</span>. v. Blue Cross and Blue Shield of Montana, Inc. et <span class="hlt">al</span>.; Proposed Final...</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2011-11-17</p> <p>...OF JUSTICE Antitrust Division United States et <span class="hlt">al</span>. v. Blue Cross and Blue Shield of Montana, Inc. et <span class="hlt">al</span>.; Proposed Final Judgment and Competitive...Montana, Billings Division, in United States et <span class="hlt">al</span>. v. Blue Cross and Blue Shield of...</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=FEDREG&redirectUrl=http://www.gpo.gov:80/fdsys/pkg/FR-2012-08-23/pdf/2012-20740.pdf"><span id="translatedtitle">77 FR 51048 - United States et <span class="hlt">al</span>. v. Verizon Communications Inc. et <span class="hlt">al</span>.; Proposed Final Judgment and...</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2012-08-23</p> <p>...DEPARTMENT OF JUSTICE Antitrust Division United States et <span class="hlt">al</span>. v. Verizon Communications Inc. et <span class="hlt">al</span>.; Proposed Final Judgment and Competitive Impact...District of Columbia in United States of America et <span class="hlt">al</span>. v. Verizon Communications Inc. et...</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/1624947"><span id="translatedtitle">Cholinergic markers in <span class="hlt">ALS</span> spinal cord.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Berger, M L; Veitl, M; Malessa, S; Sluga, E; Hornykiewicz, O</p> <p>1992-03-01</p> <p>We analyzed binding sites for quinuclidinyl benzilate (QNB) and hemicholinium-3 (HC-3) by quantitative slice autoradiography and the activities of choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) in spinal cord of 5-7 patients with amyotrophic lateral sclerosis (<span class="hlt">ALS</span>). In the ventral horn, QNB binding sites were markedly reduced (38% of controls; P less than 0.001), whereas HC-3 binding sites were only moderately affected (76%, P less than 0.01). Losses in cholinergic marker enzymes were inconsistent. The loss of muscarinic binding sites in the ventral horn was the most reliable cholinergic disease marker in <span class="hlt">ALS</span>. PMID:1624947</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://arxiv.org/pdf/nucl-ex/0608001v1"><span id="translatedtitle">The beta-decay of 22<span class="hlt">Al</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>N. L. Achouri; F. de Oliveira Santos; M. Lewitowicz; B. Blank; J. Aysto; G. Canchel; S. Czajkowski; P. Dendooven; A. Emsallem; J. Giovinazzo; N. Guillet; A. Jokinen; A. M. Laird; C. Longour; K. Perajarvi; N. Smirnova; M. Stanoiu; J. C. Thomas</p> <p>2006-08-01</p> <p>In an experiment performed at the LISE3 facility of GANIL, we studied the decay of 22<span class="hlt">Al</span> produced by the fragmentation of a 36Ar primary beam. A beta-decay half-life of 91.1 +- 0.5 ms was measured. The beta-delayed one- and two-proton emission as well as beta-alpha and beta-delayed gamma decays were measured and allowed us to establish a partial decay scheme for this nucleus. New levels were determined in the daughter nucleus 22Mg. The comparison with model calculations strongly favours a spin-parity of 4+ for the ground state of 22<span class="hlt">Al</span>.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://kuscholarworks.ku.edu/handle/1808/5722"><span id="translatedtitle">Nominalization in Q'anjob'<span class="hlt">al</span> (Maya)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Mateo, Pedro</p> <p>2010-01-01</p> <p>is widespread across the Mayan language family; and that intransitivization must come first before nominalization. In section 4 I present my conclusion. 1. Ergative system in Q’anjob’<span class="hlt">al</span> Inflection is marked on the verb as shown in the template in (2...). Transitive verbs take aspect, absolutive, ergative and status suffix, as in (3)a, while intransitive verbs take aspect, absolutive, and status suffix, as in (3)b. Thre aspects are marked in Q’anjob’<span class="hlt">al</span>: ch- incompletive, max- completive, and hoq- potential...</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://www.inf.u-szeged.hu/~csendes/go.pdf"><span id="translatedtitle">BEVEZETES A GLOB ALIS OPTIMALIZ <span class="hlt">AL</span> ASBA</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Csendes, Tibor</p> <p></p> <p>BEVEZET´ES A GLOB ´ALIS OPTIMALIZ ´<span class="hlt">AL</span> ´ASBA Csendes Tibor Szeged, 2012. #12;Lektor´alta: (M´anos.) #12;Elosz´o A jelen jegyzet1 a Szegedi Tudom´anyegyetemen 2002-tol tartott Bevezet´es a Glob´alis´itett szakir´any r´esze). Ezek felv´etel´enek ide´alis sorrendje: Nemline´aris optimaliz´<span class="hlt">al</span>´as, majd Glob´alis</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2015JMoSp.311...49M"><span id="translatedtitle">The semi-experimental equilibrium structures of <span class="hlt">Al</span>CCH and <span class="hlt">Al</span>NC</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mück, Leonie Anna; Thorwirth, Sven; Gauss, Jürgen</p> <p>2015-05-01</p> <p>Based on experimental rotational constants available in the literature (Walker and Gerry, Chem. Phys. Lett. 278, 9 (1997); Walker et <span class="hlt">al</span>., J. Mol. Spectrosc. 209, 178 (2001); Sun et <span class="hlt">al</span>., Chem. Phys. Lett. 553, 11 (2012)) [14,17,19] for five isotopologues of <span class="hlt">Al</span>CCH and three isotopologues of <span class="hlt">Al</span>NC as well as quantum-chemical computations for the vibrational corrections to rotational constants, the semi-experimental structures of these two aluminum compounds are determined. These empirical equilibrium structures (<span class="hlt">Al</span>CCH: re (Alsbnd C) = 1.957 Å, re (Csbnd C) = 1.222 Å, re (Csbnd H) = 1.065 Å; <span class="hlt">Al</span>NC: re (Alsbnd N) = 1.850 Å, re (Nsbnd C) = 1.181 Å) compare favorably with theoretical best-estimate structures obtained using highly accurate coupled-cluster calculations in combination with sophisticated extrapolation and additivity schemes, i.e., the deviations are smaller than 0.002 Å, but significant deviations are noted in comparison with previously determined experimental structures. Good agreement is also reached between calculations and experimental values for the relevant spectroscopic parameters of <span class="hlt">Al</span>CCH and <span class="hlt">Al</span>NC, indicating the predictive power of state-of-the-art high-level quantum-chemical calculations.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=DOE-PATENT-XML&redirectUrl=http://www.osti.gov/doepatents/biblio/872577"><span id="translatedtitle">Electronic circuits having Ni<span class="hlt">Al</span> and Ni.sub.3 <span class="hlt">Al</span> substrates</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Deevi, Seetharama C. (Midlothian, VA); Sikka, Vinod K. (Oak Ridge, TN)</p> <p>1999-01-01</p> <p>An electronic circuit component having improved mechanical properties and thermal conductivity comprises Ni<span class="hlt">Al</span> and/or Ni.sub.3 <span class="hlt">Al</span>, upon which an alumina layer is formed prior to applying the conductive elements. Additional layers of copper-aluminum alloy or copper further improve mechanical strength and thermal conductivity.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://www.csg.is.titech.ac.jp/paper/shiota-pro2013-5.pdf"><span id="translatedtitle">Pregel [Malewicz et <span class="hlt">al</span>.'10] Green-Marl [Hong et <span class="hlt">al</span>.'12</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Chiba, Shigeru</p> <p></p> <p>· : JavaracJava · ­ : ­ : · · ­ 64(40) ­ GC ­ FUJITSU FX10 SPARC64 Ixfx 1.848GHz 16 core, RAM32GB 1. 2 Java 1 #12; · ­ ­ ­ · ­ DSL · Pregel [Malewicz et <span class="hlt">al</span>.'10] · Green-Marl [Hong et <span class="hlt">al</span>.'12] 2 #12; · ­ e.g. · ­ 5 3 7 2 3 #12;Java · ­ ­ 4 #12;` Java · ­ JavaVM ­ C</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2014JOM....66i1785S"><span id="translatedtitle">Melting, Processing, and Properties of Disordered Fe-<span class="hlt">Al</span> and Fe-<span class="hlt">Al</span>-C Based Alloys</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Satya Prasad, V. V.; Khaple, Shivkumar; Baligidad, R. G.</p> <p>2014-09-01</p> <p>This article presents a part of the research work conducted in our laboratory to develop lightweight steels based on Fe-<span class="hlt">Al</span> alloys containing 7 wt.% and 9 wt.% aluminum for construction of advanced lightweight ground transportation systems, such as automotive vehicles and heavy-haul truck, and for civil engineering construction, such as bridges, tunnels, and buildings. The melting and casting of sound, porosity-free ingots of Fe-<span class="hlt">Al</span>-based alloys was accomplished by a newly developed cost-effective technique. The technique consists of using a special flux cover and proprietary charging schedule during air induction melting. These alloys were also produced using a vacuum induction melting (VIM) process for comparison purposes. The effect of aluminum (7 wt.% and 9 wt.%) on melting, processing, and properties of disordered solid solution Fe-<span class="hlt">Al</span> alloys has been studied in detail. Fe-7 wt.% <span class="hlt">Al</span> alloy could be produced using air induction melting with a flux cover with the properties comparable to the alloy produced through the VIM route. This material could be further processed through hot and cold working to produce sheets and thin foils. The cold-rolled and annealed sheet exhibited excellent room-temperature ductility. The role of carbon in Fe-7 wt.% <span class="hlt">Al</span> alloys has also been examined. The results indicate that Fe-<span class="hlt">Al</span> and Fe-<span class="hlt">Al</span>-C alloys containing about 7 wt.% <span class="hlt">Al</span> are potential lightweight steels.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2009MMTA...40.1541Q"><span id="translatedtitle">Combustion Synthesis Reactions in Cold-Rolled Ni/<span class="hlt">Al</span> and Ti/<span class="hlt">Al</span> Multilayers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Qiu, Xiaotun; Liu, Ranran; Guo, Shengmin; Graeter, Jesse Harris; Kecskes, Laszlo; Wang, Jiaping</p> <p>2009-07-01</p> <p>In this article, a cold rolling method was developed to fabricate Ni/<span class="hlt">Al</span> and Ti/<span class="hlt">Al</span> multilayer foils, and the combustion synthesis reactions in the cold-rolled foils were investigated. Combustion synthesis reactions were initiated by heating one end of the cold-rolled foil in a flame for several seconds. The Ni/<span class="hlt">Al</span> foils went through three reaction stages. The first reaction stage was a displacement of reaction zone with <span class="hlt">Al</span>3Ni as the reaction product. During the second stage, the part of the foil in the flame underwent thermal explosion. In the last stage, the heat released by thermal explosion triggered a self-propagating high-temperature synthesis (SHS) reaction across the foil that resulted in the formation of <span class="hlt">Al</span>Ni. In contrast, the Ti/<span class="hlt">Al</span> foils experienced only two reaction stages. First, a displacement of the reaction zone propagated across the foil with formation of <span class="hlt">Al</span>3Ti at the Ti/<span class="hlt">Al</span> interface. Then a thermal explosion reaction occurred in the part of foil that was heated in the flame, resulting in many different phases in the reacted foil.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/22150063"><span id="translatedtitle">Synthesis of nanostructured <span class="hlt">Al</span>N by solid state reaction of <span class="hlt">Al</span> and diaminomaleonitrile</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Rounaghi, S.A., E-mail: s.a.rounaghi@gmail.com [Department of Materials Engineering, Ferdowsi University of Mashhad. P.O. Box no. 91775-1111, Mashhad (Iran, Islamic Republic of); IFW Dresden, Institut fuer Komplexe Materialien, Postfach 27 01 16, Dresden D-01171 (Germany); Eshghi, H., E-mail: heshghi@ferdowsi.um.ac.ir [Department of Chemistry, Ferdowsi University of Mashhad. P.O. Box no. 91775-1436, Mashhad (Iran, Islamic Republic of); Kiani Rashid, A.R.; Vahdati Khaki, J. [Department of Materials Engineering, Ferdowsi University of Mashhad. P.O. Box no. 91775-1111, Mashhad (Iran, Islamic Republic of)] [Department of Materials Engineering, Ferdowsi University of Mashhad. P.O. Box no. 91775-1111, Mashhad (Iran, Islamic Republic of); Samadi Khoshkhoo, M.; Scudino, S. [IFW Dresden, Institut fuer Komplexe Materialien, Postfach 27 01 16, Dresden D-01171 (Germany)] [IFW Dresden, Institut fuer Komplexe Materialien, Postfach 27 01 16, Dresden D-01171 (Germany); Eckert, J. [IFW Dresden, Institut fuer Komplexe Materialien, Postfach 27 01 16, Dresden D-01171 (Germany) [IFW Dresden, Institut fuer Komplexe Materialien, Postfach 27 01 16, Dresden D-01171 (Germany); TU Dresden, Institut fuer Werkstoffwissenschaft, Dresden D-01062 (Germany)</p> <p>2013-02-15</p> <p>The solid state reaction of diaminomaleonitrile (DAMN) with aluminum via both mechanochemical and thermal treatment routes was studied by X-ray diffraction and Fourier transform infrared spectroscopy. During the milling process, the reaction starts with the deammoniation of the DAMN molecules, followed by the formation of nanostructured <span class="hlt">Al</span>N powder as the main solid product after milling for 7 h. The reactivity of the mixed powder was also investigated during the conventional thermal treatment process using differential scanning calorimetry, derivative thermogravimetry and thermogravimetric analysis. The results reveal that DAMN starts to polymerize at 192 Degree-Sign C by the elimination of the amine groups. Furthermore, increasing the annealing temperature leads to the formation of a nitrogen-containing carbonaceous material with the structure similar to non-crystalline carbon. However, no evidence for the formation of <span class="hlt">Al</span>N was observed in the annealed samples even at temperatures as high as the <span class="hlt">Al</span> melting point. - Graphical abstract: <span class="hlt">Al</span>N nanoparticles obtained after milling of <span class="hlt">Al</span> and diaminomaleonitrile (DAMN) for 12 h. Highlights: Black-Right-Pointing-Pointer Solid state reaction of diaminomaleonitrile (DAMN) with <span class="hlt">Al</span> was studied via mechanochemical and thermal treatment routs. Black-Right-Pointing-Pointer Nanocrystalline <span class="hlt">Al</span>N was successfully synthesized by the mechanochemical process. Black-Right-Pointing-Pointer The C/N material was formed by polymerization of DAMN during the thermal treatment process. Black-Right-Pointing-Pointer No reaction between DAMN and <span class="hlt">Al</span> was detected during the thermal treatment method.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/40681478"><span id="translatedtitle">The origin of <span class="hlt">Al</span>(OH) 3-rich and <span class="hlt">Al</span> 13-aggregate flocs composition in PACl coagulation</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Jr-Lin Lin; Chihpin Huang; Ching-Ju M. Chin; Jill R. Pan</p> <p>2009-01-01</p> <p>The composition of hydrolyzed <span class="hlt">Al</span> species is essential for the understanding of coagulation with <span class="hlt">Al</span>-based coagulants. Surface characteristics of flocs formed by coagulation with two distinct polyaluminum chloride (PACl) coagulants were identified. One commercial coagulant (PACl-C) with voluminous monomeric <span class="hlt">Al</span> and colloidal <span class="hlt">Al</span>(OH)3 and a custom-made PACl (PACl-<span class="hlt">Al</span>13) containing high <span class="hlt">Al</span>13 content were applied to destabilize kaolin particles. The flocs</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2014SeScT..29i5011Z"><span id="translatedtitle">Analysis of interface trap states in In<span class="hlt">AlN/Al</span>N/GaN heterostructures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhou, Yang; Lin, Zhaojun; Luan, Chongbiao; Zhao, Jingtao; Yang, Qihao; Yang, Ming; Wang, Yutang; Feng, Zhihong; Lv, Yuanjie</p> <p>2014-09-01</p> <p>Gate-source frequency-dependent capacitance and conductance measurements were performed on the In0.17<span class="hlt">Al</span>0.83N/<span class="hlt">Al</span>N/GaN heterostructure field-effect transistor with side-Ohmic contacts to study the characteristics of trap states at the interface between In<span class="hlt">Al</span>N and GaN. The values of interface trap state density and time constant were determined to be (0.96-3.36) × 1013 cm-2 eV-1 and (0.29-1.61) ?s, respectively. We calculated the strain in the In<span class="hlt">Al</span>N barrier layer under the gate and found that the In<span class="hlt">Al</span>N barrier layer was compressively strained with the in-plane strain of 1.31%. This is a possible reason for such a high interface trap state density which is not as low as supposed in the lattice-matched heterostructures.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASA-TRS&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19910034051&hterms=stuttgart&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dstuttgart"><span id="translatedtitle">1300 K compressive properties of a reaction milled Ni<span class="hlt">Al-Al</span>N composites</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Whittenberger, J. Daniel; Arzt, Eduard; Luton, Michael J.</p> <p>1990-01-01</p> <p>When B2 crystal-structure nickel aluminide is subjected to high-intensity mechanical ball milling in a liquid nitrogen bath, or 'cryomilling', an Ni<span class="hlt">Al</span> composite is obtained which contains about 10 vol pct <span class="hlt">Al</span>N particles. This composition arises from the incorporation of N during cryomilling; during subsequent thermomechanical processing, the N reacts with <span class="hlt">Al</span>. While compressive testing of extruded or isostatically pressed specimens at 1300 K indicated that strength at relatively fast strain rates is slightly dependent on consolidation method, slower strain rates indicate no clear dependency on densification technique: four different consolidation methods were found to yield similar creep strengths. The creep properties of Ni<span class="hlt">Al-Al</span>N are similar to those of the single-crystal Ni-base superalloy NASAIR 100.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2011JAP...109b4502P"><span id="translatedtitle">Aging- and annealing-induced variations in Nb/<span class="hlt">Al-Al</span>Ox/Nb tunnel junction properties</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pavolotsky, Alexey B.; Dochev, Dimitar; Belitsky, Victor</p> <p>2011-01-01</p> <p>In this paper, we present studies of room temperature aging and annealing of Nb/<span class="hlt">Al-Al</span>Ox/Nb tunnel junctions with the size of 2-3 ?m2. We observed a noticeable drop of junction normal resistance Rn unusually combined with increase in subgap resistance Rj as a result of aging. Variation in both Rn and Rj are subject to the junction size effect. An effect of aging history on the junction degradation after consequent annealing was discovered. Discussion and interpretation of the observed phenomena are presented in terms of structural ordering and reconstruction in the <span class="hlt">Al</span>Ox layer, driven by diffusion flows enhanced due to stress relaxation processes in the <span class="hlt">Al</span> layer interfacing the <span class="hlt">Al</span>Ox layer.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2012NJPh...14f5007L"><span id="translatedtitle">Radiative cooling of <span class="hlt">Al</span>-4 and <span class="hlt">Al</span>-5 in a cryogenic environment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lange, M.; Froese, M. W.; Menk, S.; Bing, D.; Fellenberger, F.; Grieser, M.; Laux, F.; Orlov, D. A.; Repnow, R.; Sieber, T.; Toker, Y.; von Hahn, R.; Wolf, A.; Blaum, K.</p> <p>2012-06-01</p> <p>We have investigated the radiative cooling of initially hot <span class="hlt">Al</span>-4 and <span class="hlt">Al</span>-5 cluster anions during storage in a cryogenic ion beam trap at an ambient temperature of <15 K. By applying a statistical rate model to the ions' measured delayed detachment rate following excitation with a laser, we have obtained their vibrational temperature as a function of cooling time. The temperature curves for <span class="hlt">Al</span>-4 suggest that the vibrational cooling slows down considerably once the ion reaches approximately room temperature. This suggests the participation of transitions from recently found low-lying electronic states of the anion in the cooling process, prior to reaching approximately room temperature. The experimental results for <span class="hlt">Al</span>-5 suggest slightly slower radiative cooling than for <span class="hlt">Al</span>-4.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/1048747"><span id="translatedtitle">26<span class="hlt">Al</span>+ p elastic and inelastic scattering reactions and galactic abundances of 26<span class="hlt">Al</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Pittman, S. T. [University of Tennessee, Knoxville (UTK); Bardayan, Daniel W [ORNL; Chae, K. Y. [University of Tennessee, Knoxville (UTK); Chipps, K. [Colorado School of Mines, Golden; Jones, K. L. [Rutgers University; Kozub, R. L. [Tennessee Technological University; Matei, Catalin [Oak Ridge Associated Universities (ORAU); Matos, M. [Louisiana State University; Moazen, Brian [University of Tennessee, Knoxville (UTK); Nesaraja, Caroline D [ORNL; O'Malley, Patrick [Rutgers University; Pain, Steven D [ORNL; Parker, P.D. [Yale University; Peters, W. A. [Rutgers University; ShrinerJr., J. F. [Tennessee Technological University; Smith, Michael Scott [ORNL</p> <p>2012-01-01</p> <p>Galactic 26<span class="hlt">Al</span> is the first radioactive nucleus to be positively identified by -ray astronomy with detection of the 1.809 MeV ray associated with its decay. This nucleus is destroyed in astrophysical environments in the 26<span class="hlt">Al</span>(p, )27Si and inelastic 26<span class="hlt">Al</span>+p scattering reactions where properties of 27Si levels determine reaction rates. To investigate these properties, elastic and inelastic 26<span class="hlt">Al</span>+p scattering reactions were measured between Ec.m. = 0.5 1.5 MeV at the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory (ORNL). A candidate for a new resonance in the 26<span class="hlt">Al</span>(p, )27Si reaction was identified. Upper limits were also set on the strengths of postulated resonances and on the cross section of the inelastic reaction, but there is little effect on current reaction rate calculations.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2014ApPhL.105x1908H"><span id="translatedtitle">Alloy inhomogeneity and carrier localization in <span class="hlt">Al</span>GaN sections and <span class="hlt">AlGaN/Al</span>N nanodisks in nanowires with 240-350 nm emission</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Himwas, C.; den Hertog, M.; Dang, Le Si; Monroy, E.; Songmuang, R.</p> <p>2014-12-01</p> <p>We present structural and optical studies of <span class="hlt">Al</span>GaN sections and <span class="hlt">AlGaN/Al</span>N nanodisks (NDs) in nanowires grown by plasma-assisted molecular beam epitaxy. The <span class="hlt">Al</span>-Ga intermixing at <span class="hlt">Al</span>(Ga)N/GaN interfaces and the chemical inhomogeneity in <span class="hlt">Al</span>GaN NDs evidenced by scanning transmission electron microscopy are attributed to the strain relaxation process. This interpretation is supported by the three-dimensional strain distribution calculated by minimizing the elastic energy in the structure. The alloy inhomogeneity increases with the <span class="hlt">Al</span> content, leading to enhanced carrier localization signatures in the luminescence characteristics, i.e., red shift of the emission, s-shaped temperature dependence, and linewidth broadening. Despite these effects, the emission energy of <span class="hlt">AlGaN/Al</span>N NDs can be tuned in the 240-350 nm range with internal quantum efficiencies around 30%.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://faculty.kfupm.edu.sa/EE/husainm/EE%20340/Research%20Projects/Students%20Reports/6-%20Railguns-%20Al-Khaldi.pdf"><span id="translatedtitle">The Rail Gun Muad <span class="hlt">Al</span> Khaldi</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Masoudi, Husain M.</p> <p></p> <p>The Rail Gun Muad <span class="hlt">Al</span> Khaldi Department of Electrical Engineering King Fahd University of Petroleum and Minerals Abstract- The rail gun is one of promising ways of launching projectiles. Recently, many. In this project, I am going to investigate the construction of electromagnetic rail guns, the way the function</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://physics.nyu.edu/grierlab/US8502132.pdf"><span id="translatedtitle">(12) United States Patent Grier et <span class="hlt">al</span>.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Grier, David</p> <p></p> <p>(12) United States Patent Grier et <span class="hlt">al</span>. US008502132B2 US 8,502,132 B2 Aug. 6, 2013 (10) Patent N0.: (45) Date of Patent: (54) (75) (73) (*) (21) (22) (65) (62) (60) (51) (52) MANIPULATION OF OBJECTS) Assignee: New York University, NeW York, NY (Us) Notice: Subject to any disclaimer, the term ofthis patent</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://physics.nyu.edu/grierlab/US8791985.pdf"><span id="translatedtitle">(12) United States Patent Grier et <span class="hlt">al</span>.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Grier, David</p> <p></p> <p>(12) United States Patent Grier et <span class="hlt">al</span>. US008791985B2 US 8,791,985 B2 Jul. 29, 2014 (10) Patent N0.: (45) Date of Patent: (54) (75) (73) (21) (22) (86) (87) (65) (60) (51) (52) TRACKING to any disclaimer, the term ofthis patent is extended or adjusted under 35 U.S.C. 154(b) by 744 days. 12</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=DOE-PATENT-XML&redirectUrl=http://www.osti.gov/doepatents/biblio/87741"><span id="translatedtitle">Ternary Dy-Er-<span class="hlt">Al</span> magnetic refrigerants</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Gschneidner, K.A. Jr.; Takeya, Hiroyuki</p> <p>1995-07-25</p> <p>A ternary magnetic refrigerant material comprising (Dy{sub 1{minus}x}Er{sub x})<span class="hlt">Al</span>{sub 2} for a magnetic refrigerator using the Joule-Brayton thermodynamic cycle spanning a temperature range from about 60K to about 10K, which can be adjusted by changing the Dy to Er ratio of the refrigerant. 29 figs.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://plantbio.berkeley.edu/~bruns/espm131/powerpoints/arbuscular.pdf"><span id="translatedtitle">Schler et <span class="hlt">al</span> 2001 Mycol Arbuscular mycorrhiza</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>California at Berkeley, University of</p> <p></p> <p>vulgaris colonized by arbuscular mycorrhizal fungi vesicle arbuscules (c) D. Redecker 10µm #12;Auxilary. Redecker, K. Wex10µm #12;SEM of arbuscles From Mycorrhizal Symbiosis #12;Devonian Fossil Modern Glomales Remy, Taylor et <span class="hlt">al</span>. 1994 #12;From Gallaud 1905Arum type Paris type #12;AM Hyphae From Mycorrhizal</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/23114496"><span id="translatedtitle">Novel <span class="hlt">Al</span>-based FLP systems.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Uhl, Werner; Würthwein, Ernst-Ulrich</p> <p>2013-01-01</p> <p><span class="hlt">Al</span>/P based frustrated Lewis pairs (FLPs) having coordinatively unsaturated aluminium and phosphorus atoms in a single molecule were obtained on a multigram scale by hydroalumination of alkynylphosphines. Steric shielding prevented the formation of adducts and the quenching of the conflicting Lewis acidic and basic functionalities. These FLPs reacted with terminal alkynes by C-H bond cleavage with the protons bonded to phosphorus and the alkynido groups coordinated to aluminium. Alternatively, a five-membered heterocycle was formed by C?C triple bond activation. Similar heterocycles resulted from the reversible coordination of carbon dioxide. Particularly interesting is their unique propensity to react as effective ion pair receptors for the complexation of alkali metal hydrides and their capability to activate such ionic hydrides as phase transfer catalysts. Sterically less shielded compounds gave dimers via <span class="hlt">Al</span>-P interactions. These compounds are still active as masked FLPs and form complexes with carbon dioxide or phenyl isocyanate. Alternative routes gave methylene bridged <span class="hlt">Al</span>-P compounds which were also shown to coordinate CO2. Bimolecular systems exhibit similar properties. They activate terminal alkynes and isobutene or reduce CO2 to methanol and carbon monoxide. Hydroalumination of ynamines proved to be an excellent method for the generation of <span class="hlt">Al</span>/N based Lewis pairs. These compounds were shown to activate phenylethyne reversibly or to undergo insertion reactions with carbodiimide. The constitution of the latter products is determined by cooperative interactions between aluminium and nitrogen. PMID:23114496</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/56496475"><span id="translatedtitle">Microbial Bioreactor Development in the <span class="hlt">ALS</span> NSCORT</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Cary Mitchell; Dawn Whitaker; M. Katherine Banks; Albert J. Heber; Ronald F. Turco; Loring F. Nies; James E. Alleman; Sybil E. Sharvelle; Congna Li; Megan Heller</p> <p>2008-01-01</p> <p>The NASA Specialized Center of Research and Training in Advanced Life Support (the <span class="hlt">ALS</span> NSCORT), a partnership of Alabama A & M, Howard, and Purdue Universities, was established by NASA in 2002 to develop technologies that will reduce the Equivalent System Mass (ESM) of regenerative processes within future space life-support systems. A key focus area of NSCORT research has been</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://euro.ecom.cmu.edu/people/faculty/mshamos/7702541.pdf"><span id="translatedtitle">(12) United States Patent Black et <span class="hlt">al</span>.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Shamos, Michael I.</p> <p></p> <p>Alamos, New Mexico. After one test explos:ion, two atomic .bombs: were dropped on the Japanese cities of Hiroshima (6 Aug 1945) and Nagasaki (9 _:Aug 1945); the bomb dropped on - .Hiroshima was as. powerful as metric tons of TNT, that on equivalent to 22.000 metrie tOI"ll The USSR first detbnated <span class="hlt">al</span>'l atomic 1949</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://spo.nwr.noaa.gov/olo6thedition/24--Unit%2013.pdf"><span id="translatedtitle"><span class="hlt">AL</span> ASK A SALMON alaska Salmon</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p></p> <p></p> <p>189 <span class="hlt">AL</span> ASK A SALMON UNIT 13 alaska Salmon INTRODUCTION Pacific salmon have played an important and pivotal role in the history of Alaska. Salmon, along with mining, timber, and furs, were the keystone now, the abundant salmon resources of this region continue to shape much of the con- temporary lives</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/503734"><span id="translatedtitle">Bierman {ital et <span class="hlt">al</span>.}Reply:</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bierman, J.D.; Chan, P.; Liang, J.F.; Kelly, M.P.; Sonzogni, A.A.; Vandenbosch, R. [Nuclear Physics Laboratory University of Washington Seattle, Washington 98195 (United States)] [Nuclear Physics Laboratory University of Washington Seattle, Washington 98195 (United States)</p> <p>1997-05-01</p> <p>reply to the Comment by C.H.Dasso et <span class="hlt">al</span>., Phys. Rev. Lett. 78,XXX(1997). A Reply to the Comment by C.H. Dasso and J. Fern{acute a}ndez-Niello. {copyright} {ital 1997} {ital The American Physical Society}</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/5120654"><span id="translatedtitle">High temperature deformation of 6061 <span class="hlt">Al</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kyungtae Park; Lavernia, E.J.; Mohamed, F.A. (Univ. of California, Irvine (United States). Dept. of Mechanical and Aerospace Engineering)</p> <p>1994-03-01</p> <p>The creep behavior of powder metallurgy (PM) 6061 <span class="hlt">Al</span>, which has been used as a metal matrix alloy in the development of discontinuous silicon carbide reinforced aluminum (SiC-<span class="hlt">Al</span>) composites, has been studied over six orders of magnitude of strain rate. The experimental data show that the steady-state stage of the creep curve is of short duration; that the stress dependence of creep rate is high and variable; and that the temperature dependence of creep rate is much higher than that for self-diffusion in aluminum. The above creep characteristics are different from those documented for aluminum based solid-solution alloys but are similar to those reported for discontinuous SiC-<span class="hlt">Al</span> composites and dispersion-strengthened (DS) alloys. Analysis of the experimental data shows that while the high stress dependence of creep rate in 6061 <span class="hlt">Al</span>, like that in DS alloys, can be explained in terms of a threshold stress for creep, the strong temperature dependence of creep rate in the alloy is incompatible with the predictions of available threshold stress models and theoretical treatments proposed for DS alloys.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=ERIC&redirectUrl=http://eric.ed.gov/?q=safety+AND+work&pg=4&id=EJ1019783"><span id="translatedtitle">Hughes et <span class="hlt">al</span>.: Science or Promotion?</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Loman, L. Anthony; Siegel, Gary L.</p> <p>2013-01-01</p> <p>The Hughes et <span class="hlt">al</span>. paper is critiqued generally and in specific areas. The weak nature of the authors' empirical work is discussed along with their enigmatic writing and vague and incorrect use of references, and their simultaneous use of sweeping statements of opinion and narrow analytical focus. This review examines the authors' errors…</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://www.mi.informatik.uni-frankfurt.de/research/phdtheses/rfischlin.dissertation.2002.ps"><span id="translatedtitle">Das Faktorisierungsrepr asentationsproblem <span class="hlt">als</span> Basis kryptographischer Protokolle</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p></p> <p></p> <p>Wolfgang Goethe-Universit at in Frankfurt am Main | von Roger Fischlin aus O#11;enbach am Main | Frankfurt am Main 2002 D F 1 #12; ii Vom Fachbereich Mathematik der Johann Wolfgang Goethe-Universit at <span class="hlt">als</span> Mitarbeit von 1998 bis 2001 in der Gruppe von Prof. Dr.Schnorr am Fachbereich Ma- thematik der J.W.Goethe</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=ERIC&redirectUrl=http://files.eric.ed.gov/fulltext/ED542783.pdf"><span id="translatedtitle">U-<span class="hlt">ALS</span>: A Ubiquitous Learning Environment</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Piovesan, Sandra Dutra; Passerino, Liliana Maria; Medina, Roseclea Duarte</p> <p>2012-01-01</p> <p>The diffusion of the use of the learning virtual environments presents a great potential for the development of an application which meet the necessities in the education area. In view of the importance of a more dynamic application and that can adapt itself continuously to the students' necessities, the "U-<span class="hlt">ALS</span>" (Ubiquitous Adapted Learning…</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=ERIC&redirectUrl=http://eric.ed.gov/?q=mystic&id=EJ775716"><span id="translatedtitle"><span class="hlt">Al</span>-Ghazali on Moral Education</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Alavi, Hamid Reza</p> <p>2007-01-01</p> <p><span class="hlt">Al</span>-Ghazali (1058-1111 CE) is probably the most influential scholar, philosopher, theologian, legal expert, religious reformer and mystic in the history of Islam. Although he wrote extensively about education, and particularly about moral education, this writing is scattered through a number of different works and has received less scholarly…</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://archives.evergreen.edu/webpages/curricular/2005-2006/fieldecology/field_eco_files/kate_Birdsdraft5_10.24-fischer-Wimp.pdf"><span id="translatedtitle">Halstead et <span class="hlt">al</span>. For: Restoration Ecology1</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p></p> <p></p> <p>and native avifauna which may be sensitive to variation in stand7 structure and age. However, little is know associated with the suitability of9 restored habitat for avifauna. We sampled bird communities and aphid et <span class="hlt">al</span>. 2 Keywords: Populus fremontii, riparian restoration, avifauna, galling arthropods,24</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/23490503"><span id="translatedtitle">Oxidation of Volatile Organic Compounds on <span class="hlt">Al</span> 2O 3, Pd\\/<span class="hlt">Al</span> 2O 3, and PdO\\/<span class="hlt">Al</span> 2O 3Catalysts</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Eric M Cordi; John L Falconer</p> <p>1996-01-01</p> <p>Temperature-programmed desorption (TPD) and oxidation (TPO) were used to study the decomposition and oxidation of methanol, ethanol, acetaldehyde, formic acid, and acetic acid on <span class="hlt">Al</span>2O3, Pd\\/<span class="hlt">Al</span>2O3, and PdO\\/<span class="hlt">Al</span>2O3catalysts. The oxidation and decomposition rates were much higher on Pd\\/<span class="hlt">Al</span>2O3than on <span class="hlt">Al</span>2O3, even though the volatile organic compounds (VOCs) were adsorbed on the <span class="hlt">Al</span>2O3support in both cases. The VOCs surface-diffused to Pd</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/11848377"><span id="translatedtitle">Short-period superlattices of <span class="hlt">AlN\\/Al</span>0.08Ga0.92N grown on <span class="hlt">Al</span>N substrates</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>S. A. Nikishin; B. A. Borisov; A. Chandolu; V. V. Kuryatkov; H. Temkin; M. Holtz; E. N. Mokhov; Yu. Makarov; H. Helava</p> <p>2004-01-01</p> <p>High-quality short-period superlattices of <span class="hlt">AlN\\/Al</span>0.08Ga0.92N have been grown by gas-source molecular-beam epitaxy with ammonia on <span class="hlt">Al</span> face of <span class="hlt">Al</span>N (0001) substrates. A significant reduction was achieved in the dislocation density, down to 3×108 cm-2. Complete removal of residual <span class="hlt">Al</span>2O3 surface oxide is needed in order to obtain low dislocation density in homoepitaxy on <span class="hlt">Al</span>N. We show that the presence of</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://mitralab.org/_uploads/partha.pdf"><span id="translatedtitle">Partha P. Mitra's Publications (Erlich, Mitra et <span class="hlt">al</span>. 2008; Saar and Mitra 2008; DeCoteau, Thorn et <span class="hlt">al</span>. 2007; DeCoteau,</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p></p> <p></p> <p>. 1996; Kupferman, Mitra et <span class="hlt">al</span>. 1996; Schwartz, Bergman et <span class="hlt">al</span>. 1996; Bergman, Dunn et <span class="hlt">al</span>. 1995; Latour, Kleinberg et <span class="hlt">al</span>. 1995; Mitra 1995; Mitra and Halperin 1995; Mitra, Latour et <span class="hlt">al</span>. 1995; Svoboda, Mitra et <span class="hlt">al</span>. 1995; Kleinberg, Kenyon et <span class="hlt">al</span>. 1994; Latour, Svoboda et <span class="hlt">al</span>. 1994; Mitra and Halperin 1994; Schwartz</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <center> <div class="footer-extlink text-muted"><small>Some links on this page may take you to non-federal websites. 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