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Sample records for hariliku mnni okaste

  1. Structure of the c(2x2) Mn/Ni(001) surface alloy by quantitative photoelectron diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, S.; Denlinger, J.; Chen, X. [Univ. of Wisconsin, Milwaukee, WI (United States)] [and others

    1997-04-01

    Surface alloys are two-dimensional metallic systems that can have structures that are unique to the surface, and have no counterpart in the bulk binary phase diagram. A very unusual structure was reported for the Mn-Ni system, based on a quantitative LEED structure determination, which showed that the Mn atoms were displaced out of the surface by a substantial amount. This displacement was attributed to a large magnetic moment on the Mn atoms. The structure of the Mn-Ni surface alloy was proposed to be based on a bulk termination model. Magnetic measurements on the Mn-Ni surface alloys, however, showed conclusively that the magnetic structure of these surface alloys is completely different from the bulk alloy analogs. For example, bulk MnNi is an antiferromagnet, whereas the surface alloy is ferromagnetic. This suggests that the proposed structure based on bulk termination, may not be correct. X-ray Photoelectron Diffraction (XPD) techniques were used to investigate this structure, using both a comparison to multiple scattering calculations and photoelectron holography. In this article the authors present some of the results from the quantitative analysis of individual diffraction patterns by comparison to theory.

  2. The kinetics of phase transformations of undercooled austenite of the Mn-Ni iron based model alloy

    OpenAIRE

    E. Rożniata; R. Dziurka; J. Pacyna

    2011-01-01

    Purpose: Present work corresponds to the research on the kinetics of phase transformations of undercooled austenite of Mn-Ni iron based model alloy. The kinetics of phase transformations of undercooled austenite of investigated alloy was presented on CCT diagram (continuous cooling transformation). Also the methodology of a dilatometric samples preparation and the method of the critical points determination were described.Design/methodology/approach: The austenitising temperature was defined ...

  3. Tuning the magnetocaloric response in half-Heusler/Heusler MnNi1 +xSb solid solutions

    Science.gov (United States)

    Levin, Emily E.; Bocarsly, Joshua D.; Wyckoff, Kira E.; Pollock, Tresa M.; Seshadri, Ram

    2017-12-01

    Materials with a large magnetocaloric response are associated with a temperature change upon the application of a magnetic field and are of interest for applications in magnetic refrigeration and thermomagnetic power generation. The usual metric of this response is the gravimetric isothermal entropy change Δ SM . The use of a simple proxy for the Δ SM that is based on density functional theory (DFT) calculations of the magnetic electronic structure suggests that half-Heusler MnNiSb should be a better magnetocaloric than the corresponding Heusler compound MnNi2Sb . Guided by this observation, we present a study of MnNi1 +xSb (x =0 , 0.25, 0.5, 0.75, and 1.0) to evaluate relevant structural and magnetic properties. DFT stability calculations suggest that the addition of Ni takes place at a symmetrically distinct Ni site in the half-Heusler structure and support the observation using synchrotron x-ray diffraction of a homogeneous solid solution between the half-Heusler and Heusler end members. There is a maximum in the saturation magnetization at x =0.5 and the Curie temperature systematically decreases with increasing x . Δ SM for a maximum magnetic field change of Δ H =5 T monotonically decreases in magnitude from -2.93 J kg-1K-1 in the half-Heusler to -1.35 J kg-1K-1 in the Heusler compound. The concurrent broadening of the magnetic transition results in a maximum in the refrigerant capacity at x =0.75 . The Curie temperature of this system is highly tunable between 350 K and 750 K, making it ideal for low grade waste heat recovery via thermomagnetic power generation. The increase in Δ SM with decreasing x may be extendable to other MnNi2Z Heusler systems that are currently under investigation for use in magnetocaloric refrigeration applications.

  4. Photoelectron diffraction k-space volumes of the c(2x2) Mn/Ni(100) structure

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, S.; Denlinger, J.; Chen, X. [Univ. of Wisconsin, Milwaukee, WI (United States)] [and others

    1997-04-01

    Traditionally, x-ray photoelectron diffraction (XPD) studies have either been done by scanning the diffraction angle for fixed kinetic energy (ADPD), or scanning the kinetic energy at fixed exit angle (EDPD). Both of these methods collect subsets of the full diffraction pattern, or volume, which is the intensity of photoemission as a function of momentum direction and magnitude. With the high density available at the Spectromicroscopy Facility (BL 7.0) {open_quotes}ultraESCA{close_quotes} station, the authors are able to completely characterize the photoelectron diffraction patterns of surface structures, up to several hundred electron volts kinetic energy. This large diffraction `volume` can then be analyzed in many ways. The k-space volume contains as a subset the energy dependent photoelectron diffraction spectra along all emission angles. It also contains individual, hemispherical, diffraction patterns at specific kinetic energies. Other `cuts` through the data set are also possible, revealing new ways of viewing photoelectron diffraction data, and potentially new information about the surface structure being studied. In this article the authors report a brief summary of a structural study being done on the c(2x2) Mn/Ni(100) surface alloy. This system is interesting for both structural and magnetic reasons. Magnetically, the Mn/Ni(100) surface alloy exhibits parallel coupling of the Mn and Ni moments, which is opposite to the reported coupling for the bulk, disordered, alloy. Structurally, the Mn atoms are believed to lie well above the surface plane.

  5. Enhancing pitting corrosion resistance of AlxCrFe1.5MnNi0.5 high-entropy alloys by anodic treatment in sulfuric acid

    International Nuclear Information System (INIS)

    Lee, C.P.; Chen, Y.Y.; Hsu, C.Y.; Yeh, J.W.; Shih, H.C.

    2008-01-01

    High-entropy alloys are a newly developed family of multi-component alloys that comprise various major alloying elements. Each element in the alloy system is present in between 5 and 35 at.%. The crystal structures and physical properties of high-entropy alloys differ completely from those of conventional alloys. The electrochemical impedance spectra (EIS) of the Al x CrFe 1.5 MnNi 0.5 (x = 0, 0.3, 0.5) alloys, obtained in 0.1 M HCl solution, clearly revealed that the corrosion resistance values were determined to increase from 21 to 34 Ωcm 2 as the aluminum content increased from 0 to 0.5 mol, and were markedly lower than that of 304 stainless steel (243 Ωcm 2 ). At passive potential, the corresponding current declined with the anodizing time accounting, causing passivity by the growth of the multi-component anodized film in H 2 SO 4 solution. X-ray photoelectron spectroscopy (XPS) analyses revealed that the surface of anodized Al 0.3 CrFe 1.5 MnNi 0.5 alloy formed aluminum and chromium oxide film which was the main passivating compound on the alloy. This anodic treatment increased the corrosion resistance in the EIS measurements of the CrFe 1.5 MnNi 0.5 and Al 0.3 CrFe 1.5 MnNi 0.5 alloys by two orders of magnitude. Accordingly, the anodic treatment of the Al x CrFe 1.5 MnNi 0.5 alloys optimized their surface structures and minimized their susceptibility to pitting corrosion

  6. Structure and magnetic properties of nanostructured MnNi alloys fabricated by mechanical alloying and annealing treatments

    Science.gov (United States)

    Jalal, T.; Hossein Nedjad, S.; Khalili Molan, S.

    2013-05-01

    A nearly equiatomic MnNi alloy was fabricated from the elemental powders by means of mechanical alloying in a planetary ball milling apparatus. X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and measurements of magnetization were conducted to identify the structural states and properties of the prepared alloys. After ball milling for 20 h, a disordered face-centered cubic (f.c.c.) solid solution was formed which increased in lattice parameter by further milling up to 50 h. An exothermic reaction took place at around 300-400°C during continuous heating of the disordered f.c.c. solid solution. This reaction is attributed to a structural ordering leading to the formation of a face-centered tetragonal (f.c.t.) phase with L10 type ordering. Examination of the magnetic properties indicated that the structural ordering increases remnant magnetization and decreases coerecivity.

  7. Nonlinear elastic properties of superconducting antiperovskites MNNi 3 (M =Zn, Cd, Mg, Al, Ga, and In) from first principles

    KAUST Repository

    Liu, Lili

    2014-05-22

    We present theoretical studies for the third-order elastic constants (TOECs) of superconducting antiperovskites MNNi 3 (M = Zn, Cd, Mg, Al, Ga, and In) using the density functional theory (DFT) and homogeneous deformation method. From the nonlinear least-square fitting, the elastic constants are extracted from a polynomial fit to the calculated strain-energy data. Calculated second-order elastic constants (SOECs) are compared with the previous theoretical calculations, and a very good agreement was found. The nonlinear effects often play an important role when the finite strains are larger than approximately 2.5 %. Besides, we have computed the pressure derivatives of SOECs and provided rough estimations for the Grüneisen constants of long-wavelength acoustic modes by using the calculated TOECs. © 2014 Springer Science+Business Media New York.

  8. Nonlinear elastic properties of superconducting antiperovskites MNNi 3 (M =Zn, Cd, Mg, Al, Ga, and In) from first principles

    KAUST Repository

    Liu, Lili; Wu, Xiaozhi; Wang, Rui; Gan, Liyong; Wei, Qunyi

    2014-01-01

    We present theoretical studies for the third-order elastic constants (TOECs) of superconducting antiperovskites MNNi 3 (M = Zn, Cd, Mg, Al, Ga, and In) using the density functional theory (DFT) and homogeneous deformation method. From the nonlinear least-square fitting, the elastic constants are extracted from a polynomial fit to the calculated strain-energy data. Calculated second-order elastic constants (SOECs) are compared with the previous theoretical calculations, and a very good agreement was found. The nonlinear effects often play an important role when the finite strains are larger than approximately 2.5 %. Besides, we have computed the pressure derivatives of SOECs and provided rough estimations for the Grüneisen constants of long-wavelength acoustic modes by using the calculated TOECs. © 2014 Springer Science+Business Media New York.

  9. Hariliku pliiatsi kaks otsa / Tõnu Kaalep

    Index Scriptorium Estoniae

    Kaalep, Tõnu, 1966-

    2011-01-01

    Näitus "Harilik" Tallinna Kunstihoone galeriis 6. märtsini 2011, kuraator Margot Kask. MariaUNDmaria (Maria Juur, Maria Arusoo) näitus "Everything Counts In Large Amounts" Tallinna Linnagaleriis 13. märtsini 2011

  10. Enhancement of magnetocaloric effect by external hydrostatic pressure in MnNi0.75Fe0.25Ge alloy

    Science.gov (United States)

    Mandal, K.; Dutta, P.; Dasgupta, P.; Pramanick, S.; Chatterjee, S.

    2018-06-01

    A systematic investigation on the structural and magnetic properties of an Fe-doped MnNiGe alloy with nominal composition MnNi0.75Fe0.25Ge has been performed. Temperature dependent x-ray diffraction studies indicate a clear structural phase transition (martensitic type) from the high temperature hexagonal austenite phase (space group P63/mmc) to the low temperature orthorhombic martensite phase (space group Pnma). Interestingly, about 1.4% of the high temperature hexagonal phase has been observed at 15 K, which is well below the martensitic phase transition (MPT) temperature. The studied alloy is found to be ferromagnetic in nature at the lowest temperature of measurement and the saturation moment increases in the presence of external hydrostatic pressure (P). In addition, it shows a significantly large conventional (negative) magnetocaloric effect with an adiabatic entropy change () of about ‑16.2 J kg‑1 K‑1 around the MPT for a magnetic field changing from 0  →  5 T. The most interesting observation is the  ∼40.1% increase in the peak value of on application of 6 kbar of external P. A considerable increment in the refrigeration capacity has also been noted with the applied P.

  11. The effect of noble metals on catalytic methanation reaction over supported Mn/Ni oxide based catalysts

    Directory of Open Access Journals (Sweden)

    Wan Azelee Wan Abu Bakar

    2015-09-01

    Full Text Available Carbon dioxide (CO2 in sour natural gas can be removed using green technology via catalytic methanation reaction by converting CO2 to methane (CH4 gas. Using waste to wealth concept, production of CH4 would increase as well as creating environmental friendly approach for the purification of natural gas. In this research, a series of alumina supported manganese–nickel oxide based catalysts doped with noble metals such as ruthenium and palladium were prepared by wetness impregnation method. The prepared catalysts were run catalytic screening process using in-house built micro reactor coupled with Fourier Transform Infra Red (FTIR spectroscopy to study the percentage CO2 conversion and CH4 formation analyzed by GC. Ru/Mn/Ni(5:35:60/Al2O3 calcined at 1000 °C was found to be the potential catalyst which gave 99.74% of CO2 conversion and 72.36% of CH4 formation at 400 °C reaction temperature. XRD diffractogram illustrated that the supported catalyst was in polycrystalline with some amorphous state at 1000 °C calcination temperature with the presence of NiO as active site. According to FESEM micrographs, both fresh and used catalysts displayed spherical shape with small particle sizes in agglomerated and aggregated mixture. Nitrogen Adsorption analysis revealed that both catalysts were in mesoporous structures with BET surface area in the range of 46–60 m2/g. All the impurities have been removed at 1000 °C calcination temperature as presented by FTIR, TGA–DTA and EDX data.

  12. Tüütu tegelane helvik / Eva Luigas

    Index Scriptorium Estoniae

    Luigas, Eva

    2015-01-01

    Sageli võib aiakeskustes näha taimepotte, kus mullapinda katab kummaline roheline sammal - nagu plaaditaoline, korrapäraselt harunenud leht oleks tihedalt vastu mulda surutud. Tegemist on hariliku helvikuga (Marchantia polymorpha), rahvas nimetab teda ka maksasamblaks. Koduaeda sattudes võib helvik ruttu levima hakata ja siis on temast lahti saada üsna vaevarikas

  13. Riiulifilmide taassünd / Jaan Ruus

    Index Scriptorium Estoniae

    Ruus, Jaan, 1938-2017

    2009-01-01

    Ülevaade kunstnik Evald Okase poja Jüri Okase ja dokumentaalfilmi "Seal, kus lõpeb luule" (rež. Arko Okk) tegijate, levitajate ja vastutavate ametnike vahel toimunud kirjavahetusest, mille sisuks on J. Okase nõudmine keelustada filmi levitamine, kuni sealt pole eemaldatud E. Okast käsitlev osa

  14. Electrodeposition of Manganese-Nickel Oxide Films on a Graphite Sheet for Electrochemical Capacitor Applications

    Directory of Open Access Journals (Sweden)

    Hae-Min Lee

    2014-01-01

    Full Text Available Manganese-nickel (Mn-Ni oxide films were electrodeposited on a graphite sheet in a bath consisting of manganese acetate and nickel chloride, and the structural, morphological, and electrochemical properties of these films were investigated. The electrodeposited Mn-Ni oxide films had porous structures covered with nanofibers. The X-ray diffractometer pattern revealed the presence of separate manganese oxide (g-MnO2 and nickel oxide (NiO in the films. The electrodeposited Mn-Ni oxide electrode exhibited a specific capacitance of 424 F/g in Na2SO4 electrolyte. This electrode maintained 86% of its initial specific capacitance over 2000 cycles of the charge-discharge operation, showing good cycling stability.

  15. Effect of Pressure on Elastic Constants, Generalized Stacking Fault Energy, and Dislocation Properties in Antiperovskite-Type Ni-Rich Nitrides ZnNNi3 and CdNNi3

    KAUST Repository

    Liu, Lili

    2014-07-31

    The elastic properties and generalized stacking fault energy curves of antiperovskite-type Ni-rich nitrides MNNi3 (M = Zn, Cd) under different pressure have been obtained from the first-principles calculations. By using the variational method, the core width and Peierls stresses of (Formula presented.) edge dislocation and screw dislocation in ZnNNi3 and CdNNi3 within the improved Peierls-Nabarro (P-N) model in which the lattice discrete effect is taken into account have been investigated. Whatever the material or the pressure range, the Peierls stress of edge dislocation is smaller than that of screw dislocation. This also demonstrates that the edge dislocation is considered to be the dominant factor in determining the plastic behavior of MNNi3 (M = Zn, Cd) in the pressure range of 0–30 GPa.

  16. Determination flux in the Reactor JEN-1; Medida de flujos de neutrones en el nucleo del Reactor JEN-1

    Energy Technology Data Exchange (ETDEWEB)

    Manas Diaz, L; Montes Ponce de leon, J.

    1960-07-01

    This report summarized several irradiations that have been made to determine the neutron flux distributions in the core of the JEN-1 reactor. Gold foils of 380 {mu} gr and Mn-Ni (12% de Ni) of 30 mg have been employed. the epithermal flux has been determined by mean of the Cd radio. The resonance integral values given by Macklin and Pomerance have been used. (Author) 9 refs.

  17. Determination flux in the Reactor JEN-1

    International Nuclear Information System (INIS)

    Manas Diaz, L.; Montes Ponce de leon, J.

    1960-01-01

    This report summarized several irradiations that have been made to determine the neutron flux distributions in the core of the JEN-1 reactor. Gold foils of 380 μ gr and Mn-Ni (12% de Ni) of 30 mg have been employed. the epithermal flux has been determined by mean of the Cd radio. The resonance integral values given by Macklin and Pomerance have been used. (Author) 9 refs

  18. High-resolution structural studies of ultra-thin magnetic, transition metal overlayers and two-dimensional transition metal oxides using synchrotron radiation

    International Nuclear Information System (INIS)

    Kellar, S.A.; Lawrence Berkeley National Lab., CA

    1997-05-01

    This thesis report the surface-structure determination of three, ultra-thin magnetic transition-metal films, Fe/Au(100), Mn/Ni(100), and Mn/Cu(100) using Angle-Resolved Photoemission Extended Fine Structure (ARPEFS) and photoelectron holography. These structural studies are the first to use non-s initial states in the ARPEFS procedure. This thesis also reports an ARPEFS surface-structure determination of a two-dimensional transition-metal oxide, [(1 x 1)O/W(110)] x 12. The authors have analyzed the ARPFES signal from the Au 4f 7/5 core level of the Au(1 ML)/Fe(15 ML)/Au(100) system. The analysis shows that the Fe grows layer by layer with one monolayer of gold, acting as a surfactant, remaining on top of the growing Fe layers. These surface gold atoms sit in the four-fold hollow site, 1.67 ± 0.02 A above the iron surface. The grown Fe layer is very much like the bulk, bcc iron, with an interlayer spacing of 1.43 ± 0.03 A. Analysis of the Mn 3p ARPEFS signals from c(2 x 2)Mn/Ni(100) and c(2 x 2)Mn/Cu(100) shows that the Mn forms highly corrugated surface alloys. The corrugation of the Mn/Ni(100) and Mn/Cu(100) systems are 0.24 ± 0.02 A and 0.30 ± 0.04 A respectively. In both cases the Mn is sticking above the plane of the surface substrate atoms. For the Mn/Ni(100) system the first layer Ni is contracted 4% from the bulk value. The Mn/Cu(100) system shows bulk spacing for the substrate Cu. Photoelectron holography shows that the Mn/Ni interface is very abrupt with very little Mn leaking into the second layer, while the Mn/Cu(100) case has a significant amount of Mn leaking into the second layer. A new, five-element electrostatic electron lens was developed for hemispherical electron-energy analyzers. This lens system can be operated at constant transverse or constants angular magnification, and has been optimized for use with the very small photon-spot sizes. Improvements to the hemispherical electron-energy analyzer are also discussed

  19. High-resolution structural studies of ultra-thin magnetic, transition metal overlayers and two-dimensional transition metal oxides using synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kellar, S.A. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry]|[Lawrence Berkeley National Lab., CA (United States). Advanced Light Source Div.

    1997-05-01

    This thesis report the surface-structure determination of three, ultra-thin magnetic transition-metal films, Fe/Au(100), Mn/Ni(100), and Mn/Cu(100) using Angle-Resolved Photoemission Extended Fine Structure (ARPEFS) and photoelectron holography. These structural studies are the first to use non-s initial states in the ARPEFS procedure. This thesis also reports an ARPEFS surface-structure determination of a two-dimensional transition-metal oxide, [(1 x 1)O/W(110)] x 12. The authors have analyzed the ARPFES signal from the Au 4f{sub 7/5} core level of the Au(1 ML)/Fe(15 ML)/Au(100) system. The analysis shows that the Fe grows layer by layer with one monolayer of gold, acting as a surfactant, remaining on top of the growing Fe layers. These surface gold atoms sit in the four-fold hollow site, 1.67 {+-} 0.02 A above the iron surface. The grown Fe layer is very much like the bulk, bcc iron, with an interlayer spacing of 1.43 {+-} 0.03 A. Analysis of the Mn 3p ARPEFS signals from c(2 x 2)Mn/Ni(100) and c(2 x 2)Mn/Cu(100) shows that the Mn forms highly corrugated surface alloys. The corrugation of the Mn/Ni(100) and Mn/Cu(100) systems are 0.24 {+-} 0.02 A and 0.30 {+-} 0.04 A respectively. In both cases the Mn is sticking above the plane of the surface substrate atoms. For the Mn/Ni(100) system the first layer Ni is contracted 4% from the bulk value. The Mn/Cu(100) system shows bulk spacing for the substrate Cu. Photoelectron holography shows that the Mn/Ni interface is very abrupt with very little Mn leaking into the second layer, while the Mn/Cu(100) case has a significant amount of Mn leaking into the second layer. A new, five-element electrostatic electron lens was developed for hemispherical electron-energy analyzers. This lens system can be operated at constant transverse or constants angular magnification, and has been optimized for use with the very small photon-spot sizes. Improvements to the hemispherical electron-energy analyzer are also discussed.

  20. Topic 1. Steels for light water reactor pressure vessels

    International Nuclear Information System (INIS)

    Brumovsky, M.; Brynda, J.; Kepka, M.; Barackova, L.; Vacek, M.; Havel, S.; Cukr, B.; Protiva, K.; Petrman, I.; Tvrdy, M.; Hyspecka, L.; Mazanec, K.; Kupca, L.; Brezina, M.

    1980-01-01

    Part 1 of the Proceedings consists of papers on the criteria for the selection and comparison of the properties of steel for pressure vessels and on the metallurgy of the said steels, the selection of suitable material for internal tubing systems, the manufacture of high-alloy steels for WWER components, the mechanical and metallurgical properties of steel 22K for WWER 440 pressure components, and of steel 10MnNi2Mo for the WWER primary coolant circuit, and the metallographic assessment of steel 0Kh18N10T. (J.P.)

  1. MnNi-based spin valve sensors combining high thermal stability, small footprint and pTesla detectivities

    Science.gov (United States)

    Silva, Marília; Leitao, Diana C.; Cardoso, Susana; Freitas, Paulo

    2018-05-01

    Magnetoresistive sensors with high thermal robustness, low noise and high spatial resolution are the answer to a number of challenging applications. Spin valve sensors including MnNi as antiferromagnet layer provide higher exchange bias field and improved thermal stability. In this work, the influence of the buffer layer type (Ta, NiFeCr) and thickness on key sensor parameters (e.g. offset field, Hf) is investigated. A Ta buffer layer promotes a strong (111) texture which leads to a higher value of MR. In contrast, Hf is lower for NiFeCr buffer. Micrometric sensors display thermal noise levels of 1 nT/Hz1/2 and 571 pT/Hz1/2 for a sensor height (h) of 2 and 4 μm, respectively. The temperature dependence of MR and sensitivity is also addressed and compared with MnIr based spin valves. In this case, MR abruptly decreases after heating at 160°C (without magnetic field), contrary to MnNi-based spin valves, where only a 10% MR decrease (relative to the initial value) is seen at 275°C. Finally, to further decrease the noise levels and improve detectivity, MnNi spin-valves are deposited vertically, and connected in parallel and series (in-plane) to create a device with low resistance and high sensitivity. A field detection at thermal level of 346 pT/Hz1/2 is achieved for a device with a total of 300 SVs (4 vertical, 15 in series, 5 in parallel).

  2. Ni And Co Segregations On Selective Surface Facets And Rational Design Of Layered Lithium Transition-metal Oxide Cathodes

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Pengfei; Zheng, Jianming; Zheng, Jiaxin; Wang, Zhiguo; Teng, Gaofeng; Kuppan, Saravanan; Xiao, Jie; Chen, Guoying; Zhang, Jiguang; Wang, Chong M.; Pan, Feng

    2016-05-05

    The chemical processes occurring on the surface of cathode materials during battery cycling play a crucial role in determining battery’s performance. However, our understanding on such surface chemistry is far from clear due to the complexity of redox chemistry during battery charge/discharge. In this work, through intensive aberration corrected STEM investigation on eight layered oxide cathode materials, we report two important findings on the pristine oxides. First, Ni and Co show strong plane selectivity when building up their respective surface segregation layers (SSL). Specifically, Ni-SSL is exclusively developed on (200)m facet in Li-Mn-rich oxides (monoclinic C2/m symmetry) and (012)h facet in Mn-Ni equally rich oxides (hexagonal R-3m symmetry), while Co-SSL has a strong preference to (20-2)m plane with minimal Co-SSL also developed on some other planes in LMR cathodes. Structurally, Ni-SSLs tend to form spinel-like lattice while Co-SSLs are in a rock-salt-like structure. Secondly, by increasing Ni concentration in these layered oxides, Ni and Co SSLs can be suppressed and even eliminated. Our findings indicate that Ni and Co SSLs are tunable through controlling particle morphology and oxide composition, which opens up a new way for future rational design and synthesis of cathode materials.

  3. Corrosion studies on selected metallic materials for application in nuclear waste disposal containers

    International Nuclear Information System (INIS)

    Smailos, E.; Fiehn, B.; Gago, J.A.; Azkarate, I.

    1994-03-01

    In previous corrosion studies, carbon steels and the alloy Ti 99.8-Pd were identified as promising materials for heat-generating nuclear waste containers acting as a radionuclide barrier in a rock-salt repository. To characterize the long-term corrosion behaviour of these materials in more detail, a research programme including laboratory-scale and in-situ corrosion studies has been undertaken jointly by KfK and ENRESA/INASMET. In the period under review, gamma irradiation corrosion studies of up to about 6 months at 10 Gy/h and stress corrosion cracking studies at slow strain rates (10 -4 -10 -7 s -1 ) were performed on three preselected carbon steels in disposal relevant brines (NaCl-rich, MgCl 2 -rich) at 90 C and 150 C (TStE 355, TStE 460, 15 MnNi 6.3). Moreover, results were obtained from long-term in-situ corrosion studies (maximum test duration 9 years) conducted on carbon steel, Ti 99.8-Pd, Hastelloy C4, Ni-resist D4, and Si-cast iron in boreholes in the Asse salt mine. (orig./MM) [de

  4. Whole-plant mineral partitioning during the reproductive development of rice (Oryza sativa L.)

    Energy Technology Data Exchange (ETDEWEB)

    Sperotto, R.A.; Vasconcelos, M.W.; Grusak, M.A.; Fett, J.

    2017-07-01

    Minimal information exists on whole-plant dynamics of mineral flow. Understanding these phenomena in a model plant such as rice could help in the development of nutritionally enhanced cultivars. A whole-plant mineral accumulation study was performed in rice (cv. Kitaake), using sequential harvests during reproductive development panicle exertion, grain filling, and full maturity stages in order to characterize mineral accumulation in roots, non-flag leaves, flag leaves, stems/sheaths, and panicles. Partition quotient analysis showed that Fe, Zn, Cu and Ni are preferentially accumulated in roots; Mn and Mg are accumulated in leaves; Mo, Ca, and S in roots and leaves; and K in roots, leaves and stems/sheaths. Correlation analysis indicated that changes in the concentrations of mineral pairs Fe-Mn, K-S, Fe-Ni, Cu-Mg, Mn-Ni, S-Mo, Mn-Ca, and Mn-Mg throughout the reproductive development of rice were positively correlated in all four of the above ground organs evaluated, with Fe-Mn and K-S being positively correlated also in roots, which suggest that root-to-shoot transfer is not driven simply by concentrations in roots. These analyses will serve as a starting point for a more detailed examination of mineral transport and accumulation in rice plants.

  5. Crack behaviour of ferritic pressure vessels steels in oxygenated high temperature water under transient loadings. Crack corrosion phase 2. Crack development and fatigue. Final report; Rissverhalten ferritischer Druckbehaelterstaehle in sauerstoffhaltigem Hochtemperaturwasser bei transienten Vorgaengen. Risskorrosion Phase 2. Rissentstehung und Ermuedung. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Weissenberg, Thomas

    2014-03-15

    Using the example of the ferritic steels 22NiMoCr3-7 and 15MnNi6-3 representative for Nuclear Power Plants experimental data for the evaluation of the influence of the light water reactor (LWR) coolant environment and postulated chloride contaminations on crack development and fatigue have been determined in order to verify and extend the basis for a reliable estimation of the residual service life of reactor components. The aim of the research project was the investigation of the environmental effects at low strain rate conditions and the determination of the fatigue life under cyclic loading at uniaxial and multiaxial stress state. The quasi-static tensile tests (Constant Extension Rate Test, CERT) were performed using 3 low strain rates, each differing by about one order of magnitude (2.5.10{sup -3}, 3.1.10{sup -4} and 2.3.10{sup -5} %/s). The low cycle fatigue (LCF) experiments were conducted applying alternating tensile-compression loading with strain amplitudes of 0.3, 0.5 and 0.9 % at strain rates of 0.1 and 0.01 %/s (tests in air primarily 0.1 %/s). The cyclic notched tensile tests were carried out with a nominal axial strain in the notch root of 0.5 % at a strain rate of 0.1 %/s. The experiments in each case were performed in air, high purity water and chloride containing water at a testing temperature of 240 C, the oxygen content of the liquid medium was set to 0.4 ppm (simulated boiling water reactor coolant). In the CERT experiments chloride contents of 30, 50 and 100 ppb were applied, in the LCF tests the chloride content was 50 ppb which can be regarded as an upper realistic limit for a postulated chloride contamination of the reactor coolant. All experiments in liquid environment were preceded by a pre-autoclaving phase of at least 100 h in order to allow the formation of a stable oxide layer (magnetite). The testing material 22NiMoCr3-7 was available in form of an original reactor pressure vessel shell primarily designated for the German nuclear

  6. Solvent Extraction of Co, Ni and Mn from NCM Sulfate Leaching Solution of Li(NCMO2 Secondary Battery Scraps

    Directory of Open Access Journals (Sweden)

    Hong Hyun Seon

    2017-06-01

    Full Text Available As a part of the study on recycling Li(NCMO2 lithium-ion battery scraps, solvent extraction experiments were performed using different extraction agents such as PC88A, Cyanex272 and D2EHPA to separate Co, Ni and Mn from the leaching solution. When the ratio of Mn to Ni was about 0.4 in the leaching solution, the separation factor for Co and Mn was found to be less than 10 so that the separation of Co and Ni was insufficient. When solvent extraction was done using the solution with the lower Mn/Ni ratio of 0.05 where Mn was removed by potassium permanganate and chlorine dioxide, more than 99% of Mn could be extracted through five courses of extraction using 30vol% D2EHPA while the extraction rates of Co and Ni were around 17% and 11%, respectively. In the case that Mn was removed from the solution, the extraction rate of Co was higher than 99% whereas less than 7% Ni was extracted using Cyanex272 suggesting that Co and Ni elements were effectively separated.

  7. Negative Thermal Expansion over a Wide Temperature Range in Fe-Doped MnNiGe Composites.

    Science.gov (United States)

    Zhao, Wenjun; Sun, Ying; Liu, Yufei; Shi, Kewen; Lu, Huiqing; Song, Ping; Wang, Lei; Han, Huimin; Yuan, Xiuliang; Wang, Cong

    2018-01-01

    Fe-doped MnNiGe alloys were successfully synthesized by solid-state reaction. Giant negative thermal expansion (NTE) behaviors with the coefficients of thermal expansion (CTE) of -285.23 × 10 -6 K -1 (192-305 K) and -1167.09 × 10 -6 K -1 (246-305 K) have been obtained in Mn 0.90 Fe 0.10 NiGe and MnNi 0.90 Fe 0.10 Ge, respectively. Furthermore, these materials were combined with Cu in order to control the NTE properties. The results indicate that the absolute value of CTE gradually decreases with increasing Cu contents. In Mn 0.92 Fe 0.08 NiGe/ x %Cu, the CTE gradually changes from -64.92 × 10 -6 K -1 (125-274 K) to -4.73 × 10 -6 K -1 (173-229 K) with increasing value of x from 15 to 70. The magnetic measurements reveal that the NTE behaviors in this work are strongly correlated with the process of the magnetic phase transition and the introduction of Fe atoms could also change the spiral anti-ferromagnetic (s-AFM) state into ferromagnetic (FM) state at low temperature. Our study launches a new candidate for controlling thermal expansion properties of metal matrix materials which could have potential application in variable temperature environment.

  8. Negative Thermal Expansion over a Wide Temperature Range in Fe-Doped MnNiGe Composites

    Directory of Open Access Journals (Sweden)

    Wenjun Zhao

    2018-02-01

    Full Text Available Fe-doped MnNiGe alloys were successfully synthesized by solid-state reaction. Giant negative thermal expansion (NTE behaviors with the coefficients of thermal expansion (CTE of −285.23 × 10−6 K−1 (192–305 K and −1167.09 × 10−6 K−1 (246–305 K have been obtained in Mn0.90Fe0.10NiGe and MnNi0.90Fe0.10Ge, respectively. Furthermore, these materials were combined with Cu in order to control the NTE properties. The results indicate that the absolute value of CTE gradually decreases with increasing Cu contents. In Mn0.92Fe0.08NiGe/x%Cu, the CTE gradually changes from −64.92 × 10−6 K−1 (125–274 K to −4.73 × 10−6 K−1 (173–229 K with increasing value of x from 15 to 70. The magnetic measurements reveal that the NTE behaviors in this work are strongly correlated with the process of the magnetic phase transition and the introduction of Fe atoms could also change the spiral anti-ferromagnetic (s-AFM state into ferromagnetic (FM state at low temperature. Our study launches a new candidate for controlling thermal expansion properties of metal matrix materials which could have potential application in variable temperature environment.

  9. Full k-space visualization of photoelectron diffraction

    International Nuclear Information System (INIS)

    Denlinger, J.D.; Rotenberg, E.; Kevan, S.D.; Tonner, B.P.

    1997-01-01

    The development of photoelectron holography has promoted the need for larger photoelectron diffraction data sets in order to improve the quality of real-space reconstructed images (by suppressing transformational artifacts and distortions). The two main experimental and theoretical approaches to holography, the transform of angular distribution patterns for a coarse selection of energies or the transform of energy-scanned profiles for several directions, represent two limits to k-space sampling. The high brightness of third-generation soft x-ray synchrotron sources provides the opportunity to rapidly measure large high-density x-ray photoelectron diffraction (XPD) data sets with approximately uniform k-space sampling. In this abstract, the authors present such a photoelectron data set acquired for Cu 3p emission from Cu(001). Cu(001) is one of the most well-studied systems for understanding photoelectron diffraction structure and for testing photoelectron holography methods. Cu(001) was chosen for this study in part due to the relatively inert and unreconstructed clean surface, and it served to calibrate and fine-tune the operation of a new synchrotron beamline, electron spectrometer and sample goniometer. In addition to Cu, similar open-quotes volumeclose quotes XPD data sets have been acquired for bulk and surface core-level emission from W(110), from reconstructed Si(100) and Si(111) surfaces, and from the adsorbate system of c(2x2) Mn/Ni(100)

  10. Summary reports of activities under visiting research program

    International Nuclear Information System (INIS)

    1984-01-01

    Technical Report of the Research Reactor Institute, Kyoto University, is published any time as a prompt report as occasion requires. In this report, the title, names of reporters and summary of each of 53 researches which were carried out under the visiting research program in the first half of 1983 are given. The titles are, for example, a mechanism for the anodic oxidation of GaAs, gamma-gamma perturbed angular correlation study of relaxation phenomena, the studies on the genesis of volcanic rocks by partition of trace elements, neutron activation analysis of geochemical standard rock samples, studies on the changes of elements in the fur of rats with various disease, neutron activation analysis on glacier ice strata and glaciegla lake sediments in Nepal Himalayas, low temperature irradiation effects on bcc metals, organ and its subcellular distribution of manganese ion in animals, structure analysis of orthorhombic BaTiO 3 by profile analysis method, regional distribution of Mn, Zn and Cu in human brain, neutron diffraction study of Mn-Ni alloy, structural change of KCoF 3 in the vicinity of the critical region, activation analysis of trace elements in tumor tissues (thyroid) and so on. (Kako, I.)

  11. Irradiation-Induced Solute Clustering in a Low Nickel FeMnNi Ferritic Alloy

    International Nuclear Information System (INIS)

    Meslin, E.; Barbu, A.; Radiguet, B.; Pareige, P.; Toffolon, C.

    2011-01-01

    Understanding the radiation embrittlement of reactor pressure vessel (RPV) steels is required to be able to operate safely a nuclear power plant or to extend its lifetime. The mechanical properties degradation is partly due to the clustering of solute under irradiation. To gain knowledge about the clustering process, a Fe-1.1 Mn-0.7 Ni (at.%) alloy was irradiated in a test reactor at two fluxes of 0.15 and 9 *10 17 n E≥1MeV . m -2 .s -1 and at increasing doses from 0.18 to 1.3 *10 24 n E≥1MeV ) . m -2 at 300 degrees C. Atom probe tomography (APT) experiments revealed that the irradiation promotes the formation in the α iron matrix of Mn/Mn and/or Ni/Ni pair correlations at low dose and Mn-Ni enriched clusters at high dose. These clusters dissolve partially after a thermal treatment at 400 degrees C. Based on a comparison with thermodynamic calculations, we show that the solute clustering under irradiation can just result from an induced mechanism. (authors)

  12. Environmental contamination in the K eban Mining District, Eastern Turkey

    International Nuclear Information System (INIS)

    Bolucek, C.

    2007-01-01

    The present research is focused on the contribution of base-metal mining to heavy metal contamination of the environment. Mining wastes and unworked ore-mineral concentrations present in the Keban region (eastern Turkey) are the main sources of environmental contamination in the area via leaching of the potentially toxic elements. Total-element concentrations of several different sampling media, such as sediment, waters and plants were measured. Analyses of metal and metalloid concentrations of sediment samples indicate high As, F, Mo and Zn contents, which decrease exponentially with distance from the mine and mineralized zones, mainly due to dilution by water and barren material. The average concentrations of As, Cd, Cr, Pb and Ta in the water samples are higher than the average natural background values for these heavy metals. The most significant components of water samples under study are (>1 mg/1) Ca, Cl, K, Mg, Mn, Na, Zn and S and (1 mg/1) Ba, Fe and Mo; these samples are also enriched in some toxic elements such as As, Cd, Cr, Pb and Sb. Red algae have a higher capacity for absorption of Cr, Cu, Mn,Ni, Pb and S, whereas green algae are enriched in Co, Hg, La, Se and V. However, the highest heavy-metal and toxic element contents are found in moss collected at the mine adit. (author)

  13. Investigation program on PWR-steel-containment behavior under accident conditions

    International Nuclear Information System (INIS)

    Krieg, R.; Eberle, F.; Goeller, B.; Gulden, W.; Kadlec, J.; Messemer, G.; Mueller, S.; Wolf, E.

    1983-10-01

    This report is a first documentation of the KfK/PNS activities and plans to investigate the behaviour of steel containments under accident conditions. The investigations will deal with a free standing spherical containment shell built for the latest type of a German pressurized water reactor. The diameter of the containment shell is 56 m. The minimum wall thickness is 38 mm. The material used is the ferritic steel 15MnNi63. According to the actual planning the program is concerned with four different problems which are beyond the common design and licensing practice: Containment behavior under quasi-static pressure increase up to containment failure. Containment behavior under high transient pressures. Containment oscillations due to earthquake loadings; consideration of shell imperfections. Containment buckling due to earthquake loadings. The investigation program consists of both theoretical and experimental activities including membrane tests allowing for very high plastic strains and oscillation tests with a thin-walled, high-accurate spherical shell. (orig.) [de

  14. Crack behaviour of ferritic pressure vessels steels in oxygenated high temperature water under transient loadings. Crack corrosion phase 2. Crack development and fatigue. Final report

    International Nuclear Information System (INIS)

    Weissenberg, Thomas

    2014-03-01

    Using the example of the ferritic steels 22NiMoCr3-7 and 15MnNi6-3 representative for Nuclear Power Plants experimental data for the evaluation of the influence of the light water reactor (LWR) coolant environment and postulated chloride contaminations on crack development and fatigue have been determined in order to verify and extend the basis for a reliable estimation of the residual service life of reactor components. The aim of the research project was the investigation of the environmental effects at low strain rate conditions and the determination of the fatigue life under cyclic loading at uniaxial and multiaxial stress state. The quasi-static tensile tests (Constant Extension Rate Test, CERT) were performed using 3 low strain rates, each differing by about one order of magnitude (2.5.10 -3 , 3.1.10 -4 and 2.3.10 -5 %/s). The low cycle fatigue (LCF) experiments were conducted applying alternating tensile-compression loading with strain amplitudes of 0.3, 0.5 and 0.9 % at strain rates of 0.1 and 0.01 %/s (tests in air primarily 0.1 %/s). The cyclic notched tensile tests were carried out with a nominal axial strain in the notch root of 0.5 % at a strain rate of 0.1 %/s. The experiments in each case were performed in air, high purity water and chloride containing water at a testing temperature of 240 C, the oxygen content of the liquid medium was set to 0.4 ppm (simulated boiling water reactor coolant). In the CERT experiments chloride contents of 30, 50 and 100 ppb were applied, in the LCF tests the chloride content was 50 ppb which can be regarded as an upper realistic limit for a postulated chloride contamination of the reactor coolant. All experiments in liquid environment were preceded by a pre-autoclaving phase of at least 100 h in order to allow the formation of a stable oxide layer (magnetite). The testing material 22NiMoCr3-7 was available in form of an original reactor pressure vessel shell primarily designated for the German nuclear power plant

  15. Thermodynamic investigations of the Mn-Ni-C-N quarternary alloys by solid-state galvanic cell technique

    International Nuclear Information System (INIS)

    Teng Lidong; Aune, Ragnhild; Seetharaman, Seshadri

    2005-01-01

    In view of the important applications of carbides and nitrides of transition metals in the hard materials industries, the thermodynamic activities of manganese in Mn-Ni-C-N alloys have been studied by solid-state galvanic cell technique with CaF 2 as the solid electrolyte. The phase compositions and microstructure of various alloys have been analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Nitrogen was introduced into the alloy by equilibrating with N 2 gas. It was established during the experiments that the solubility of nitrogen in the alloys was affected by the carbon content. A (Mn,Ni) 4 (N,C) nitride was formed during the nitriding procedure in the alloys. The electromotive force (EMF) measurements were carried out in the temperature range 940-1127 K in order to determine the activities of Mn in the alloys. The activities of manganese were calculated and compared with those of the corresponding Mn-Ni-C ternary alloys

  16. The Al-rich region of the Al-Mn-Ni alloy system. Part II. Phase equilibria at 620-1000 oC

    International Nuclear Information System (INIS)

    Balanetskyy, S.; Meisterernst, G.; Grushko, B.; Feuerbacher, M.

    2011-01-01

    Research highlights: → Phase equilibria in the Al-rich region of the Al-Mn-Ni alloy system were studied at 1000, 950, 850, 750, 700, 645 and 620 deg. C by means of SEM, TEM, powder XRD and DTA. → Three ternary thermodynamically stable intermetallics, the φ-phase (Al 5 Co 2 -type, hP26, P63/mmc; a = 0.76632(16), c = 0.78296(15) nm), the κ-phase (κ-Al 14.4 Cr 3.4 Ni l.1 -type, hP227, P63/m; a = 1.7625(10), c = 1.2516(10) nm), and the O-phase (O-Al 77 Cr 14 Pd 9 -type, Pmmn, oP650,: a = 2.3316(16), b = 1.2424(15), c = 3.2648(14) nm), as well as three ternary metastable phases, the decagonal D 3 -phase with periodicity about 1.25 nm, the Al 9 (Mn,Ni) 2 -phase (Al 9 Co 2 -type, P1121/a, mP22; a = 0.8585(16), b = 0.6269(9), c = 0.6205(11) nm, β = 95.34(10) o ) and the O 1 -phase (basecentered orthorhombic, a ∼ 23.8, b ∼ 12.4, c ∼ 32.2 nm) were revealed. → The existence of a thermodynamically stable R-phase of stoichiometry Al 60 Mn 11 Ni 4 , reported earlier in literature, was not confirmed in the present study. - Abstract: Phase equilibria in the Al-rich region of the Al-Mn-Ni alloy system were studied at 1000, 950, 850, 750, 700, 645 and 620 o C. Three ternary thermodynamically stable intermetallics, the φ-phase (Al 5 Co 2 -type, hP26, P6 3 /mmc; a = 0.76632(16), c = 0.78296(15) nm), the κ-phase (κ-Al 14.4 Cr 3.4 Ni l.1 -type, hP227, P6 3 /m; a = 1.7625(10), c = 1.2516(10) nm), and the O-phase (O-Al 77 Cr 14 Pd 9 -type, Pmmn, oP650,: a = 2.3316(16), b = 1.2424(15), c = 3.2648(14) nm), as well as three ternary metastable phases, the decagonal D 3 -phase with periodicity about 1.25 nm, the Al 9 (Mn,Ni) 2 -phase (Al 9 Co 2 -type, P112 1 /a, mP22; a = 0.8585(16), b = 0.6269(9), c = 0.6205(11) nm, β = 95.34(10) o ) and the O 1 -phase (base-centered orthorhombic, a ∼ 23.8, b ∼ 12.4, c ∼ 32.2 nm) were revealed. Their physicochemical behaviour in the Al-Mn-Ni alloy system was studied.

  17. MAG narrow gap welding - an economic way to minimize welding expenses

    International Nuclear Information System (INIS)

    Kast, W.; Scholz, E.; Weyland, F.

    1982-01-01

    The thicker structural components are, the more important it is to take measures to reduce the volume of the weld. The welding process requiring the smallest possible weld section is the so-called narrow gap process. In submerged arc narrow gap welding as well as in MAG narrow gap welding different variants are imaginable, some of them already in practical use. With regard to efficiency and weld quality an optimum variant of the MAG narrow gap welding process is described. It constitutes a two wire system in which two wire electrodes of 1.2 mm diameter are arranged one behind the other. In order to avoid lack of fusion, the wire guides are slightly pointed towards each groove face. Thus, by inclining the two arcs burning one behind the other in the direction of weld progress, it is achieved that two separately solidifying weld pools and two beads per layer are simultaneously formed. Welding parameters are selected in such a way that a heat input of 16-20 kJ/cm and a deposition rate of 11-16 kgs/h are obtained. In spite of this comparatively high deposition rate, good impact values are found both in the weld and HAZ (largely reduced coarse-grain zone) which is due to an optimum weld build-up. With the available welding equipment the process can be applied to structural members having a thickness of 40-400 mm. The width of gap is 13 mm (root section) with a bevel angle of 1 0 . As filler metal, basic flux-cored wires are used which, depending on the base metal to be welded and the required tensile properties, can be of the Mn-, MnMo-, MnCrMo-, MnNi-, or MnNiMo-alloyed types. (orig.)

  18. Determination of pollutant elements and heavy metals in petroleum sludge and scale at Heglig field Sudan

    International Nuclear Information System (INIS)

    Amir, N. T.

    2012-02-01

    The release of pollutant metals from petroleum industry in to ecosystems represents a serious hazard for the biosphere, because of their toxicity. The objective of this study was to determine the levels of some elements in petroleum sludge and scales collected from petroleum production area in Heglig oil field located in South Kordofan State. The concentration of Ca, Fe, V, Mn,Ni, Cu, Zn, Cs, Sr, Zr, Y and Pb in sludge and scale samples have been determined using energy dispersive x-ray fluorescence (EDXRF) equipped with a point source of 1 09C d. The concentration of Ca and Fe in scale samples were found to fall in range of 15,49-23.28% and 0.98-5.13%, respectively. The a verge elemental concentrations of Ti, Mn, Ni, Cu, Zn, Sr,Y, and Pb in scale samples were 2917.8, 567.74, 23.21, 23.05, 101.67, 31.38, 177.06 and 24.12 (mg/kg), respectively. The concentrations of Ca and Fe in sludge samples ranged from 1.98-8.82% and 0.71-5.19%, respectively and the a verge elemental concentrations of Cs, V, Mn,Cu, Zn, Pb, Sr, Y and Zr were 7.44, 92,59, 557.36, 7.67, 162.72,28.67, 65.02, 45.64 and 52.15 (mg/kg), respectively. Correlation analysis revealed lock of any significant correlation between elemental concentrations in sludge and scales. (Author)

  19. Explosive device of conduit using Ti Ni alloy

    Directory of Open Access Journals (Sweden)

    A. Yu. Kolobov

    2014-01-01

    Full Text Available Presently, materials have been developed which are capable at changing temperate to return significant inelastic deformations, exhibit rubber-like elasticity, convert heat into mechanical work, etc. The aggregate of these effects is usually called the shape memory effect.At present a great number of compounds and alloys with a shape memory effect has been known.These are alloys based on titanium nickelide (TiNi, copper-based alloys (Cu-Al, Cu-Sn, Cu-Al-Ni, Cu-Zn-Si, etc., gold and silver (Ag-Cd, Au-Ag-Cd, Au-Cd-Cu, Au-Zn-Cu, etc., manganese (Mn-Cr, Fe-Cu, Mn-Cu-Ni, Mn-Cu-Zr, Mn-Ni, etc., iron (Fe-Mn, Fe-Ni, Fe-Al, etc., and other compounds.The alloys based on titanium nickelide (nitinol are the most widely used.Alloys with shape memory effect find various applications in engineering and medicine, namely connecting devices, actuators, transformable design, multipurpose medical implants, etc.There is a task of breaking fuel conduit during separating the spacecraft from the rocket in space technology.The paper examines the procedure for design calculation of the separating device of conduit with the use of Ti-Ni alloy. This device can be used instead of the pyro-knives.The device contains two semi-rings from Ti-Ni alloy. In the place of break on the conduit an annular radius groove is made.At a temperature of martensite passage the semi-rings undergo deformation and in the strained state are set in the device. With heating to the temperature of the austenitic passage of bushing macro-deformation the energy stored by the nitinol bushing is great enough to break the conduit on the neck.The procedures of design calculation and response time of device are given.

  20. Statistical analysis of trace metals in the plasma of cancer patients versus controls

    International Nuclear Information System (INIS)

    Pasha, Qaisara; Malik, Salman A.; Shah, Munir H.

    2008-01-01

    The plasma of cancer patients (n = 112) and controls (n = 118) were analysed for selected trace metals (Al, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Sb, Sr and Zn) by flame atomic absorption spectroscopy. In the plasma of cancer patients, mean concentrations of macronutrients/essential metals, Na, K, Ca, Mg, Fe and Zn were 3971, 178, 44.1, 7.59, 4.38 and 3.90 ppm, respectively, while the mean metal levels in the plasma of controls were 3844, 151, 74.2, 18.0, 6.60 and 2.50 ppm, respectively. Average concentrations of Cd, Cr, Cu, Mn, Mo, Ni, Pb, Sb, Sr and Zn were noted to be significantly higher in the plasma of cancer patients compared with controls. Very strong mutual correlations (r > 0.70) in the plasma of cancer patients were observed between Fe-Mn, Ca-Mn, Ca-Ni, Ca-Co, Cd-Pb, Co-Ni, Mn-Ni, Mn-Zn, Cr-Li, Ca-Zn and Fe-Ni, whereas, Ca-Mn, Ca-Mg, Fe-Zn, Ca-Zn, Mg-Mn, Mg-Zn, Cd-Sb, Cd-Co, Cd-Zn, Co-Sb and Sb-Zn exhibited strong relationships (r > 0.50) in the plasma of controls, all were significant at p < 0.01. Principal component analysis (PCA) of the data extracted five PCs, both for cancer patients and controls, but with considerably different loadings. The average metals levels in male and female donors of the two groups were also evaluated and in addition, the general role of trace metals in the carcinogenesis was discussed. The study indicated appreciably different pattern of metal distribution and mutual relationships in the plasma of cancer patients in comparison with controls

  1. Statistical analysis of trace metals in the plasma of cancer patients versus controls

    Energy Technology Data Exchange (ETDEWEB)

    Pasha, Qaisara; Malik, Salman A. [Department of Biochemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Shah, Munir H. [Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan)], E-mail: munir_qau@yahoo.com

    2008-05-30

    The plasma of cancer patients (n = 112) and controls (n = 118) were analysed for selected trace metals (Al, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Sb, Sr and Zn) by flame atomic absorption spectroscopy. In the plasma of cancer patients, mean concentrations of macronutrients/essential metals, Na, K, Ca, Mg, Fe and Zn were 3971, 178, 44.1, 7.59, 4.38 and 3.90 ppm, respectively, while the mean metal levels in the plasma of controls were 3844, 151, 74.2, 18.0, 6.60 and 2.50 ppm, respectively. Average concentrations of Cd, Cr, Cu, Mn, Mo, Ni, Pb, Sb, Sr and Zn were noted to be significantly higher in the plasma of cancer patients compared with controls. Very strong mutual correlations (r > 0.70) in the plasma of cancer patients were observed between Fe-Mn, Ca-Mn, Ca-Ni, Ca-Co, Cd-Pb, Co-Ni, Mn-Ni, Mn-Zn, Cr-Li, Ca-Zn and Fe-Ni, whereas, Ca-Mn, Ca-Mg, Fe-Zn, Ca-Zn, Mg-Mn, Mg-Zn, Cd-Sb, Cd-Co, Cd-Zn, Co-Sb and Sb-Zn exhibited strong relationships (r > 0.50) in the plasma of controls, all were significant at p < 0.01. Principal component analysis (PCA) of the data extracted five PCs, both for cancer patients and controls, but with considerably different loadings. The average metals levels in male and female donors of the two groups were also evaluated and in addition, the general role of trace metals in the carcinogenesis was discussed. The study indicated appreciably different pattern of metal distribution and mutual relationships in the plasma of cancer patients in comparison with controls.

  2. Periodic table of 3d-metal dimers and their ions.

    Science.gov (United States)

    Gutsev, G L; Mochena, M D; Jena, P; Bauschlicher, C W; Partridge, H

    2004-10-08

    The ground states of the mixed 3d-metal dimers TiV, TiCr, TiMn, TiFe, TiCo, TiNi, TiCu, TiZn, VCr, VMn, VFe, VCo, VNi, VCu, VZn, CrMn, CrFe, CrCo, CrNi, CrCu, CrZn, MnFe, MnCo, MnNi, MnCu, MnZn, FeCo, FeNi, FeCu, FeZn, CoNi, CoCu, CoZn, NiCu, NiZn, and CuZn along with their singly negatively and positively charged ions are assigned based on the results of computations using density functional theory with generalized gradient approximation for the exchange-correlation functional. Except for TiCo and CrMn, our assignment agrees with experiment. Computed spectroscopic constants (r(e),omega(e),D(o)) are in fair agreement with experiment. The ground-state spin multiplicities of all the ions are found to differ from the spin multiplicities of the corresponding neutral parents by +/-1. Except for TiV, MnFe, and MnCu, the number of unpaired electrons, N, in a neutral ground-state dimer is either N(1)+N(2) or mid R:N(1)-N(2)mid R:, where N(1) and N(2) are the numbers of unpaired 3d electrons in the 3d(n)4s(1) occupation of the constituent atoms. Combining the present and previous results obtained at the same level of theory for homonuclear 3d-metal and ScX (X=Ti-Zn) dimers allows one to construct "periodic" tables of all 3d-metal dimers along with their singly charged ions.

  3. Wavelengths, energy levels and hyperfine structure of Mn II and Sc II.

    Science.gov (United States)

    Nave, Gillian; Pickering, Juliet C.; Townley-Smith, Keeley I. M.; Hala, .

    2015-08-01

    For many decades, the Atomic Spectroscopy Groups at the National Institute of Standards and Technology (NIST) and Imperial College London (ICL) have measured atomic data of astronomical interest. Our spectrometers include Fourier transform (FT) spectrometers at NIST and ICL covering the region 1350 Å to 5.5 μm and a 10.7-m grating spectrometer at NIST covering wavelengths from 300 - 5000 Å. Sources for these spectra include high-current continuous and pulsed hollow cathode (HCL) lamps, Penning discharges, and sliding spark discharges. Recent work has focused on the measurement and analysis of wavelengths, energy levels, and hyperfine structure (HFS) constants for iron-group elements. The analysis of FT spectra of Cr I, Mn I, and Mn II is being led by ICL and is described in a companion poster [1]. Current work being led by NIST includes the analysis of HFS in Mn II, analysis of Mn II in the vacuum ultraviolet, and a comprehensive analysis of Sc II.Comprehensive HFS constants for Mn II are needed for the interpretation of stellar spectra and incorrect abundances may be obtained when HFS is omitted. Holt et al. [2] have measured HFS constants for 59 levels of Mn II using laser spectroscopy. We used FT spectra of Mn/Ni and Mn/Cu HCLs covering wavelength ranges from 1350 Å to 5.4 μm to confirm 26 of the A constants of Holt et al. and obtain values for roughly 40 additional levels. We aim to obtain HFS constants for the majority of lines showing significant HFS that are observed in chemically-peculiar stars.Spectra of Sc HCLs have been recorded from 1800 - 6700 Å using a vacuum ultraviolet FT spectrometer at NIST. Additional measurements to cover wavelengths above 6700 Å and below 1800 Å are in progress. The spectra are being analyzed by NIST and Alighar Muslim University, India in order to derive improved wavelengths, energy levels, and hyperfine structure parameters.This work was partially supported by NASA, the STFC and PPARC (UK), the Royal Society of the UK

  4. Microbially-induced Fe and Mn oxides in condensed pelagic sediments (Middle-Upper Jurassic, Western Sicily)

    Science.gov (United States)

    Préat, A.; Mamet, B.; Di Stefano, P.; Martire, L.; Kolo, K.

    2011-06-01

    This article presents a petrographic comparison of the Rosso Ammonitico facies of Western Sicily and the original Rosso Ammonitico Veronese of Northern Italy based on a total of 27 sections. The Rosso Ammonitico has been the subject of numerous controversies that range from bathyal to shallow-water platform sedimentation. Therefore it seemed interesting to verify if the term Rosso Ammonitico has the same geologic connotation from region to region. The Middle-Upper Jurassic Rosso Ammonitico of Western Sicily is a condensed succession formed during a period of extensional synsedimentary tectonics related to the spreading of the Ionian Ocean. Slope-to-basin or pelagic carbonate deposits characterize the sedimentation which consists of reddish mudstones and wackestones. The abundant fauna is composed of radiolarians, protoglobigerinids, Saccocoma, Bositra associated with ammonites. A few ferruginous hardgrounds, Fe-Mn oxide crusts and Mn-coated condensation horizons are also present. The red matrices contain abundant Fe-Mn encrusted, microbored and bioeroded bioclasts. Sporadic Fe-Mn oncolites composed of amorphous Mn-minerals and goethite are also conspicuous. The matrix, as well as the shells and the fillings of the complex associated veinlets, are frequently altered into calcite microsparite. Submicronic iron bacterial and fungal filaments associated with mineralized extracellular polymeric substances (EPS) are observed in the matrix. They record dysaerobic microenvironments at or near the sediment-water interfaces. Early mineralized discontinuities enhanced by subsequent pressure dissolution are reported in the succession. Mn-(Ni) bacterial filaments are exceptionally observed in the cortex of the Fe-Mn oncolites. As a consequence of an early lithification, the Mn filaments are poorly preserved. The pigmentation of the rock is due to the dispersion of submicronic oxyhydroxides (now goethite and amorphous iron) formed by bacterial mediation during early diagenesis

  5. A new family of 1D exchange biased heterometal single-molecule magnets: observation of pronounced quantum tunneling steps in the hysteresis loops of quasi-linear {Mn2Ni3} clusters.

    Science.gov (United States)

    Das, Animesh; Gieb, Klaus; Krupskaya, Yulia; Demeshko, Serhiy; Dechert, Sebastian; Klingeler, Rüdiger; Kataev, Vladislav; Büchner, Bernd; Müller, Paul; Meyer, Franc

    2011-03-16

    First members of a new family of heterometallic Mn/Ni complexes [Mn(2)Ni(3)X(2)L(4)(LH)(2)(H(2)O)(2)] (X = Cl: 1; X = Br: 2) with the new ligand 2-{3-(2-hydroxyphenyl)-1H-pyrazol-1-yl}ethanol (H(2)L) have been synthesized, and single crystals obtained from CH(2)Cl(2) solutions have been characterized crystallographically. The molecular structures feature a quasi-linear Mn(III)-Ni(II)-Ni(II)-Ni(II)-Mn(III) core with six-coordinate metal ions, where elongated axes of all the distorted octahedral coordination polyhedra are aligned parallel and are fixed with respect to each other by intramolecular hydrogen bonds. 1 and 2 exhibit quite strong ferromagnetic exchange interactions throughout (J(Mn-Ni) ≈ 40 K (1) or 42 K (2); J(Ni-Ni) ≈ 22 K (1) or 18 K (2)) that lead to an S(tot) = 7 ground state, and a sizable uniaxial magnetoanisotropy with D(mol) values -0.55 K (1) and -0.45 K (2). These values are directly derived also from frequency- and temperature-dependent high-field EPR spectra. Slow relaxation of the magnetization at low temperatures and single-molecule magnet (SMM) behavior are evident from frequency-dependent peaks in the out-of-phase ac susceptibilities and magnetization versus dc field measurements, with significant energy barriers to spin reversal U(eff) = 27 K (1) and 22 K (2). Pronounced quantum tunnelling steps are observed in the hysteresis loops of the temperature- and scan rate-dependent magnetization data, but with the first relaxation step shifted above (1) or below (2) the zero crossing of the magnetic field, despite the very similar molecular structures. The different behavior of 1 and 2 is interpreted in terms of antiferromagnetic (1) or ferromagnetic (2) intermolecular interactions, which are discussed in view of the subtle differences of intermolecular contacts within the crystal lattice.

  6. Advanced characterization techniques in understanding the roles of nickel in enhancing strength and toughness of submerged arc welding high strength low alloy steel multiple pass welds in the as-welded condition

    Science.gov (United States)

    Sham, Kin-Ling

    refined. Austenite decomposition temperatures into different ferrite products were also suppressed to refine the effective ferrite grain size with increasing nickel. Finally, dislocation density and strain increased and a more preferred orientation behavior was observed. At five wt. pct nickel, a precipitate in the form of MnNi3 or FeNi3 was observed. Its presence in both inter and intragranular regions enhanced strength and toughness by limiting the ferrite grain size and precipitation strengthening.

  7. Thin film Heusler compounds manganese nickel gallium

    Science.gov (United States)

    Jenkins, Catherine Ann

    Multiferroic Heusler compounds Mn3--xNi xGa (x=0,1,2) have a tetragonal unit cell that can variously be used for magneto-mechanically coupled shape memory ( x=1,2) and spin-mechanical applications (x=0). The first fabrication of fully epitaxial thin films of these and electronically related compounds by sputtering is discussed. Traditional and custom lab characterization of the magnetic and temperature driven multiferroic behavior is augmented by more detailed synchrotron-based high energy photoemission spectroscopic techniques to describe the atomic and electronic structure. Integration of the MnNi2Ga magnetic shape memory compound in microwave patch antennas and active free-standing structures represents a fraction of the available and promising applications for these compounds. Prototype magnetic tunnel junctions are demonstrated by Mn3Ga electrodes with perpendicular anisotropy for spin torque transfer memory structures. The main body of the work concentrates on the definition and exploration of the material series Mn3--xNi xGa (x=0,1,2) and the relevant multiferroic phenomena exhibited as a function of preparation and external stimuli. Engineering results on each x=0,1,2 are presented with device prototypes where relevant. In the appendices the process of the materials design undertaken with the goal of developing new ternary intermetallics with enhanced properties is presented with a full exploration of the road from band structure calculations to device implementation. Cobalt based compounds in single crystal and nanoparticle form are fabricated with an eye to developing the production methods for new cobalt- and iron-based magnetic shape memory compounds for device applications in different forms. Mn2CoSn, a compound isolectronic and with similar atomic ordering to Mn2NiGa is experimentally determined to be a nearly half-metallic ferromagnet in contrast to the metallic ferrimagnetism in the parent compound. High energy photoemission spectroscopy is shown to