Science.gov

Sample records for nitridov perekhodnykh metallov

  1. Study on Iron Disilicide Thermoelectric Generator

    DTIC Science & Technology

    1988-06-01

    ABRIKOSOV. IZV. Sekt. Fiz. Khim. analiza 27.157 (1956). 2 I.N. STRUKOV and P.V. GELD . Fiz. Metallov i Metallovedenie 4. 190 (1957). 3 F.A. SIDORENKO. P.V... GELD , and L.B. DUBROVSKAYA, Fiz. Metallov Metallovedenie 8, 465 (1959). 4 J.P. PITON and M.F. FAY, C.R. Acad. Sci. C 266, 154 (1968). 5 J. VAN DEN...SIDORENKO, P.V. GELD , and M.A. SHUMILOV. Fiz. Metallov Metallovedenie 9. 861 (1960). 9 I.N. STRUKOV and P.V. GELD , Fiz. Metallov i Metallovedenie 3. 564

  2. The Development of Aluminum-Lithium Alloys.

    DTIC Science & Technology

    1980-07-31

    Metallurgy Sander A. Levy, Director Department of Metallurgical Services and Ingot Casting Technology __j: Grant E. Spangle $, Gereral Director bd...of the Aqeinq Mechanism of the Alloy Al-Li," translated from Fiz. Metal Metalloved., V. 42, N. 3, 1976 , pp. 546-556. [8] B. Noble and G. E. Thompson...34 translated from Fiz. Metal Metalloved., 42, N. 5, 1976 , pp. 1021-1028. -159- [19] Z. A. Sviderskaya, E. S. Kadaner, N. I. Turkina, and V. I

  3. JPRS Report, Science & Technology, USSR: Materials Science.

    DTIC Science & Technology

    2007-11-02

    CONTENTS ANALYSIS, TESTING Structural Characteristics of Fracture Surface of Rolled Al-Zn-Mg Alloy (A.A. Artsruni, N.F. Kuzovova, et al...Nitrogen (V.M. Ledovskikh, H.D. Gonzales Rigotty, et al.; ZASHCHITA METALLOV, No 5, Sep-Oct 87) 2 Corrosion Resistance of Ti-Pd- Alloy Surface...2 - a - Structure and Electrochemical Behavior of Oxide Films of Ni60Nb40 Alloy in Amorphous and Crystalline States (N.D. Tomashov, I.B

  4. Thermophysical and Electronic Properties of Foreign Stainless Steels, A Comprehensive Survey of the World Literature,

    DTIC Science & Technology

    1981-11-01

    AUJMI NUM. 6 2 327-S 196# .,.,iEV. e. V. StIVEDOV, L. 1. PAVLENKO, Z. C. 1 ENGLIS - TRANSLATION LF TEPLCFIZ. VYS. TEMP.. 6 .2. 2tTS, S. L.. 1 2 1, 340s-2...9s69 CA 72 81866 2 113-1. 1968 ENGLIS - TRANSLATIC. CF METALLOVED. TERM. OBRAIS. T62?MT.. (2) . 32-0., 1968; FOR ORIGINAL SEE 060023 3 -FFFCT CF SMALL...3-10-900 DEGREE K TE"I-ERATURE 19 C 1 ). 63-4. 1472. RAN’ E . C ENGLIS )H INANSLAT ICR CF TEPLCEER-ETIA. 19 1 1 I CCJ$KOrIS 01. V. YA. GENcASINA, 6. 2

  5. Core Formation in the Earth: Constraints from Ni and Co

    NASA Technical Reports Server (NTRS)

    Chabot, N. L.; Draper, D. S.; Agee, C. B.

    2004-01-01

    Due to their metal-loving nature, Ni and Co were strongly partitioned into the metallic core and were left depleted in the silicate mantle during core formation in the Earth. Based on experimental liquid metal- liquid silicate partition coefficients (D), studies have suggested that core formation in an early magma Ocean can explain the observed mantle depletions of Ni and Co [l-51. However, the conditions proposed by the magma ocean models have ranged from pressures of 24 to 59 GPa and temperatures of 2200 to < 4000 K. Furthermore, the proposed magma Ocean oxygen fugacities have differed by nearly two orders of magnitude.Chabot and Agee noted that the different models predicted contradictory behaviors for D(Ni) and D(Co) as a function of temperature. With the hope of resolving the discrepancies between the magma ocean models, we conducted a systematic experimental study to constrain the effects of temperature on D(Ni) and D(Co).

  6. Cumulate causes for the low contents of sulfide-loving elements in the continental crust

    NASA Astrophysics Data System (ADS)

    Jenner, Frances Elaine

    2017-07-01

    Despite the economic importance of chalcophile (sulfide-loving) and siderophile (metal-loving) elements (CSEs), it is unclear how they become enriched or depleted in the continental crust, compared with the oceanic crust. This is due in part to our limited understanding of the partitioning behaviour of the CSEs. Here I compile compositional data for mid-ocean ridge basalts and subduction-related volcanic rocks. I show that the mantle-derived melts that contribute to oceanic and continental crust formation rarely avoid sulfide saturation during cooling in the crust and, on average, subduction-zone magmas fractionate sulfide at the base of the continental crust prior to ascent. Differentiation of mantle-derived melts enriches lower crustal sulfide- and silicate-bearing cumulates in some CSEs compared with the upper crust. This storage predisposes the cumulate-hosted compatible CSEs (such as Cu and Au) to be recycled back into the mantle during subduction and delamination, resulting in their low contents in the bulk continental crust and potentially contributing to the scarcity of ore deposits in the upper continental crust. By contrast, differentiation causes the upper oceanic and continental crust to become enriched in incompatible CSEs (such as W) compared with the lower oceanic and continental crust. Consequently, incompatible CSEs are predisposed to become enriched in subduction-zone magmas that contribute to continental crust formation and are less susceptible to removal from the continental crust via delamination compared with the compatible CSEs.

  7. Orientation and temperature dependence of the anomalous Hall effect in hcp cobalt

    NASA Astrophysics Data System (ADS)

    Souza, Ivo; Roman, Eric; Mokrousov, Yuriy

    2009-03-01

    We calculate from first-principles the evolution of the intrinsic anomalous Hall conductivity vector â of hcp Co as the spin magnetization direction M is tilted away from the c-axis. We find that â varies smoothly with the tilt angle θ, and that its magnitude is strongly reduced, by a factor of about four, between θ=0 and θ=π/2, in good agreement with the measured anisotropy ratio of about three.ootnotetextN. V. Volkenshtein et al., Fiz. Metal. Metalloved. 11, 152 (1961). In addition to the anisotropic linear magnetization dependence (âz/Mz=âx/Mx) expected for any uniaxial crystal, there is a considerable nonlinearity in the dependence of σx^a on Mx=Mθ, while the relation between σz^a and Mz=Mθ is essentially linear, as in Mn5Ge3.ootnotetextC. Zeng et al., Phys. Rev. Lett. 96, 037204 (2006). The overall angular dependence of â is well-described by an expansion in terms of l=1 and l=3 spherical harmonics. From Zener's model for the influence of thermal fluctuations of M(r) on the temperature dependence of magnetic anisotropies,ootnotetextC. Zener, Phys. Rev. 96, 1335 (1954). we predict that the l=3 terms give rise to an appreciable increase with temperature of the anisotropy ratio.

  8. Investigation of various equations of state for high current, pulsed power load modeling

    NASA Astrophysics Data System (ADS)

    Luginsland, John; Parkinson, Roland; Rigby, Fred; Toepfer, Alan

    2002-08-01

    A number of technologies utilize the increasing availability of modern pulsed power systems to produce high currents to resistively drive solid, metallic loads into the plasma state. Examples include ablation plasma deposition, circuit breakers, fuses, exploding and imploding wires, and high velocity jet disruption. One important feature in any computational model of these phenomena is the equation of state (EOS). The equations of state used in these models are typically as varied as the range of applications. In this work, using a segmented wire experiment performed at the Army Research Laboratory [1] as a benchmark, we investigate three equations of state [2-4]. We assess the merits of the EOS for both their physical accuracy and easy of use computationally. Finally, we comment on the availability of the information necessary to build the EOS, given the wide variety of materials that are used in this applied field. [1] C.E. Hollandsworth et al., J. Appl. Phys., vol. 84, no. 9, 4992-5000, 1998. [2] SESAME tables, LANL T-1 Division, Equation of State and Strength of Materials. [3] Zhukov, Demidov, and Ryabenko, Fiz. Metal. Metalloved., vol. 57, no. 2, 224-229, 1984. [4] Chittenden et al., Laser and Particle Beams, vol. 19, issue 3, 323-343, 2001, and references therein.

  9. Sulfur in Earth's Mantle and Its Behavior During Core Formation

    NASA Technical Reports Server (NTRS)

    Chabot, Nancy L.; Righter,Kevin

    2006-01-01

    The density of Earth's outer core requires that about 5-10% of the outer core be composed of elements lighter than Fe-Ni; proposed choices for the "light element" component of Earth's core include H, C, O, Si, S, and combinations of these elements [e.g. 1]. Though samples of Earth's core are not available, mantle samples contain elemental signatures left behind from the formation of Earth's core. The abundances of siderophile (metal-loving) elements in Earth's mantle have been used to gain insight into the early accretion and differentiation history of Earth, the process by which the core and mantle formed, and the composition of the core [e.g. 2-4]. Similarly, the abundance of potential light elements in Earth's mantle could also provide constraints on Earth's evolution and core composition. The S abundance in Earth's mantle is 250 ( 50) ppm [5]. It has been suggested that 250 ppm S is too high to be due to equilibrium core formation in a high pressure, high temperature magma ocean on early Earth and that the addition of S to the mantle from the subsequent accretion of a late veneer is consequently required [6]. However, this earlier work of Li and Agee [6] did not parameterize the metalsilicate partitioning behavior of S as a function of thermodynamic variables, limiting the different pressure and temperature conditions during core formation that could be explored. Here, the question of explaining the mantle abundance of S is revisited, through parameterizing existing metal-silicate partitioning data for S and applying the parameterization to core formation in Earth.

  10. Carbon solution and partitioning between metallic and silicate melts in a shallow magma ocean: Implications for the origin and distribution of terrestrial carbon

    NASA Astrophysics Data System (ADS)

    Dasgupta, Rajdeep; Chi, Han; Shimizu, Nobumichi; Buono, Antonio S.; Walker, David

    2013-02-01

    The origin of bulk silicate Earth carbon inventory is unknown and the fate of carbon during the early Earth differentiation and core formation is a missing link in the evolution of the terrestrial carbon cycle. Here we present high pressure (P)-temperature (T) experiments that offer new constraints upon the partitioning of carbon between metallic and silicate melt in a shallow magma ocean. Experiments were performed at 1-5 GPa, 1600-2100 °C on mixtures of synthetic or natural silicates (tholeiitic basalt/alkali basalt/komatiite/fertile peridotite) and Fe-Ni-C ± Co ± S contained in graphite or MgO capsules. All the experiments produced immiscible Fe-rich metallic and silicate melts at oxygen fugacity (fO2) between ˜IW-1.5 and IW-1.9. Carbon and hydrogen concentrations of basaltic glasses and non-glassy quenched silicate melts were determined using secondary ionization mass spectrometry (SIMS) and speciation of dissolved C-O-H volatiles in silicate glasses was studied using Raman spectroscopy. Carbon contents of metallic melts were determined using both electron microprobe and SIMS. Our experiments indicate that at core-forming, reduced conditions, carbon in deep mafic-ultramafic magmas may dissolve primarily as various hydrogenated species but the total carbon storage capacity, although is significantly higher than solubility of CO2 under similar conditions, remains low (<500 ppm). The total carbon content in our reduced melts at graphite saturation increases with increasing melt depolymerization (NBO/T), consistent with recent spectroscopic studies, and modestly with increasing hydration. Carbon behaves as a metal-loving element during core-mantle separation and our experimental DCmetal/silicate varies between ˜4750 and ⩾150 and increases with increasing pressure and decreases with increasing temperature and melt NBO/T. Our data suggest that if only a trace amount of carbon (˜730 ppm C) was available during early Earth differentiation, most of it was

  11. Impact of Acid Mine Drainage on the hydrogeological system at Sia, Cyprus

    NASA Astrophysics Data System (ADS)

    Ng, Stephen; Malpas, John

    2013-04-01

    Discontinued mining of the volcanogenic massive sulphide ore bodies of Cyprus has left significant environmental concerns including Acid Mine Drainage. Remnant sulphide ore and tailings in waste dumps react with oxygenated rainwater to produce sulphuric acid, a process which is multiplied when metal-loving acidophilic bacteria are present. Given that Cyprus has a Mediterranean climate, characterized by its warm and dry summers and cool and wet winters, the low pH effluent with high levels of trace elements, particularly metals, is leached out of the waste tips particularly during the wet season. The Sia site includes an open mine-pit lake, waste rock and tailings dumps, a river leading to a downstream dam-lake, and a localised groundwater system. The study intends to: identify the point source and nature of contamination; analyze the mechanism and results of local acid generation; and understand how the hydrogeological system responds to seasonal variations. During two sampling campaigns, in the wet and dry seasons of 2011, water samples were collected from the mine pit lake, from upstream of the adjacent river down to the dam catchment, and from various boreholes close to the sulphide mine. The concentration of ions in waters varies between wet and dry seasons but, in both, relative amounts are directly related to pH. In the mine-pit lake, Fe, Mn, Mg, Cu, Pb, Zn, Ni, Co and Cd are found in higher concentrations in the dry season, as a result of substantial evaporation of water. The Sia River runs continuously in the wet season, and waters collected close to the waste tips have pH as low as 2.5 and higher concentrations of Al, Cu, Fe and Zn. Further downstream there is a significant decrease in trace metal contents with a concomitant rise of pH. Al and Fe dominate total cation content when pH is lower than 4. Al is derived from the weathering of clay minerals, especially during the wet season. Fe is derived from the oxidation of pyrite. Once pH's exceed 4, a white