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  1. First-principle study of single TM atoms X (X=Fe, Ru or Os) doped monolayer WS2 systems

    Zhu, Yuan-Yan; Zhang, Jian-Min

    2018-05-01

    We report the structural, magnetic and electronic properties of the pristine and single TM atoms X (X = Fe, Ru or Os) doped monolayer WS2 systems based on first-principle calculations. The results show that the W-S bond shows a stronger covalent bond, but the covalency is obviously weakened after the substitution of W atom with single X atoms, especially for Ru (4d75s1) with the easily lost electronic configuration. The smaller total energies of the doped systems reveal that the spin-polarized states are energetically favorable than the non-spin-polarized states, and the smallest total energy of -373.918 eV shows the spin-polarized state of the Os doped monolayer WS2 system is most stable among three doped systems. In addition, although the pristine monolayer WS2 system is a nonmagnetic-semiconductor with a direct band gap of 1.813 eV, single TM atoms Fe and Ru doped monolayer WS2 systems transfer to magnetic-HM with the total moments Mtot of 1.993 and 1.962 μB , while single TM atom Os doped monolayer WS2 systems changes to magnetic-metal with the total moments Mtot of 1.569 μB . Moreover, the impurity states with a positive spin splitting energies of 0.543, 0.276 and 0.1999 eV near the Fermi level EF are mainly contributed by X-dxy and X-dx2-y2 states hybridized with its nearest-neighbor atom W-dz2 states for Fe, Ru and Os doped monolayer WS2 system, respectively. Finally, we hope that the present study on monolayer WS2 will provide a useful theoretical guideline for exploring low-dimensional spintronic materials in future experiments.

  2. Metal Dependence of Signal Transmission through MolecularQuantum-Dot Cellular Automata (QCA: A Theoretical Studyon Fe, Ru, and Os Mixed-Valence Complexes

    Ken Tokunaga

    2010-08-01

    Full Text Available Dynamic behavior of signal transmission through metal complexes [L5M-BL-ML5]5+ (M=Fe, Ru, Os, BL=pyrazine (py, 4,4’-bipyridine (bpy, L=NH3, which are simplified models of the molecular quantum-dot cellular automata (molecular QCA, is discussed from the viewpoint of one-electron theory, density functional theory. It is found that for py complexes, the signal transmission time (tst is Fe(0.6 fs < Os(0.7 fs < Ru(1.1 fs and the signal amplitude (A is Fe(0.05 e < Os(0.06 e < Ru(0.10 e. For bpy complexes, tst and A are Fe(1.4 fs < Os(1.7 fs < Ru(2.5 fs and Os(0.11 e < Ru(0.12 e <Fe(0.13 e, respectively. Bpy complexes generally have stronger signal amplitude, but waste longer time for signal transmission than py complexes. Among all complexes, Fe complex with bpy BL shows the best result. These results are discussed from overlap integral and energy gap of molecular orbitals.

  3. Electronic, structural and magnetic studies of niobium borides of group 8 transition metals, Nb2MB2 (M=Fe, Ru, Os) from first principles calculations

    Touzani, Rachid St.; Fokwa, Boniface P.T.

    2014-01-01

    The Nb 2 FeB 2 phase (U 3 Si 2 -type, space group P4/mbm, no. 127) is known for almost 50 years, but until now its magnetic properties have not been investigated. While the synthesis of Nb 2 OsB 2 (space group P4/mnc, no. 128, a twofold superstructure of U 3 Si 2 -type) with distorted Nb-layers and Os 2 -dumbbells was recently achieved, “Nb 2 RuB 2 ” is still not synthesized and its crystal structure is yet to be revealed. Our first principles density functional theory (DFT) calculations have confirmed not only the experimental structures of Nb 2 FeB 2 and Nb 2 OsB 2 , but also predict “Nb 2 RuB 2 ” to crystalize with the Nb 2 OsB 2 structure type. According to chemical bonding analysis, the homoatomic B–B interactions are optimized and very strong, but relatively strong heteroatomic M–B, B–Nb and M–Nb bonds (M=Fe, Ru, Os) are also found. These interactions, which together build a three-dimensional network, are mainly responsible for the structural stability of these ternary borides. The density-of-states at the Fermi level predicts metallic behavior, as expected, from metal-rich borides. Analysis of possible magnetic structures concluded preferred antiferromagnetic ordering for Nb 2 FeB 2 , originating from ferromagnetic interactions within iron chains and antiferromagnetic exchange interactions between them. -- Graphical abstract: Nb 2 FeB 2 (U 3 Si 2 structure type, space group P4/mbm, no. 127) is predicted to order antiferromagnetically, due to the presence of iron chains which show ferromagnetic interactions in the chains and antiferromagnetic interactions between them. “Nb 2 RuB 2 ” is predicted to crystallize with the recently discovered Nb 2 OsB 2 twofold superstructure (space group P4/mnc, no. 128) of U 3 Si 2 structure type. The building of ruthenium dumbbells instead of chains along [001] is found to be responsible for the stabilization of this superstructure. Highlights: • Nb 2 FeB 2 is predicted to order antiferromagnetically.

  4. EPR of some low-spin dsup(5) tris-chelate complexes of Fe(3), Ru(3), Os(3) in liquid-crystal matrix

    Domracheva, N.E.; Konstantinov, V.N.; Luchkona, S.A.; Ovchinnikov, I.V.

    1985-01-01

    Using the EPR method low-spin trischelate complexes of Fe, Ru, Os with 8-mercaptoquinoline and 8-oxyquinoline in oriented vitrified liquid-crystal matrix have been studied. Analtysis of angular dependences of EPR spectra of the complexes permitted to correlate the main axes of g-tensor with molecular axes and, consequently, to determine unambiguously the main electron states of the systems, as well as the value of crystal splittings. It is shown that in the complexes studied the splitting of energy levels is mainly determined by spin-orbital interaction, and not by axial or rhombic components of crystal field. However, rhombic distortion is responsible for anisotropy of g-tensor in xy plane and anisotropy of x- and y-axes orientation. The way to orient complexes in liquid-crystal matrix is substantiated; symmetry axis of the third order C 3 (Z) is mainly oriented along the director. Parameters of the function of orientational distribution of the complex axes are obtained

  5. Electronic, structural and magnetic studies of niobium borides of group 8 transition metals, Nb{sub 2}MB{sub 2} (M=Fe, Ru, Os) from first principles calculations

    Touzani, Rachid St.; Fokwa, Boniface P.T., E-mail: Boniface.Fokwa@ac.rwth-aachen.de

    2014-03-15

    The Nb{sub 2}FeB{sub 2} phase (U{sub 3}Si{sub 2}-type, space group P4/mbm, no. 127) is known for almost 50 years, but until now its magnetic properties have not been investigated. While the synthesis of Nb{sub 2}OsB{sub 2} (space group P4/mnc, no. 128, a twofold superstructure of U{sub 3}Si{sub 2}-type) with distorted Nb-layers and Os{sub 2}-dumbbells was recently achieved, “Nb{sub 2}RuB{sub 2}” is still not synthesized and its crystal structure is yet to be revealed. Our first principles density functional theory (DFT) calculations have confirmed not only the experimental structures of Nb{sub 2}FeB{sub 2} and Nb{sub 2}OsB{sub 2}, but also predict “Nb{sub 2}RuB{sub 2}” to crystalize with the Nb{sub 2}OsB{sub 2} structure type. According to chemical bonding analysis, the homoatomic B–B interactions are optimized and very strong, but relatively strong heteroatomic M–B, B–Nb and M–Nb bonds (M=Fe, Ru, Os) are also found. These interactions, which together build a three-dimensional network, are mainly responsible for the structural stability of these ternary borides. The density-of-states at the Fermi level predicts metallic behavior, as expected, from metal-rich borides. Analysis of possible magnetic structures concluded preferred antiferromagnetic ordering for Nb{sub 2}FeB{sub 2}, originating from ferromagnetic interactions within iron chains and antiferromagnetic exchange interactions between them. -- Graphical abstract: Nb{sub 2}FeB{sub 2} (U{sub 3}Si{sub 2} structure type, space group P4/mbm, no. 127) is predicted to order antiferromagnetically, due to the presence of iron chains which show ferromagnetic interactions in the chains and antiferromagnetic interactions between them. “Nb{sub 2}RuB{sub 2}” is predicted to crystallize with the recently discovered Nb{sub 2}OsB{sub 2} twofold superstructure (space group P4/mnc, no. 128) of U{sub 3}Si{sub 2} structure type. The building of ruthenium dumbbells instead of chains along [001] is found to be

  6. The role of the [CpM(CO)2](-) chromophore in the optical properties of the [Cp2ThMCp(CO)2](+) complexes, where M = Fe, Ru and Os. A theoretical view.

    Cantero-López, Plinio; Le Bras, Laura; Páez-Hernández, Dayán; Arratia-Pérez, Ramiro

    2015-12-14

    The chemical bond between actinide and the transition metal unsupported by bridging ligands is not well characterized. In this paper we study the electronic properties, bonding nature and optical spectra in a family of [Cp2ThMCp(CO)2](+) complexes where M = Fe, Ru, Os, based on the relativistic two component density functional theory calculations. The Morokuma-Ziegler energy decomposition analysis shows an important ionic contribution in the Th-M interaction with around 25% of covalent character. Clearly, charge transfer occurs on Th-M bond formation, however the orbital term most likely represents a strong charge rearrangement in the fragments due to the interaction. Finally the spin-orbit-ZORA calculation shows the possible NIR emission induced by the [FeCp(CO)2](-) chromophore accomplishing the antenna effect that justifies the sensitization of the actinide complexes.

  7. What is the best bonding model of the (σ-H-BR) species bound to a transition metal? Bonding analysis in complexes [(H)2Cl(PMe3)2M(σ-H-BR)] (M = Fe, Ru, Os).

    Pandey, Krishna K

    2012-03-21

    Density Functional Theory calculations have been performed for the σ-hydroboryl complexes of iron, ruthenium and osmium [(H)(2)Cl(PMe(3))(2)M(σ-H-BR)] (M = Fe, Ru, Os; R = OMe, NMe(2), Ph) at the BP86/TZ2P/ZORA level of theory in order to understand the interactions between metal and HBR ligands. The calculated geometries of the complexes [(H)(2)Cl(PMe(3))(2)Ru(HBNMe(2))], [(H)(2)Cl(PMe(3))(2)Os(HBR)] (R = OMe, NMe(2)) are in excellent agreement with structurally characterized complexes [(H)(2)Cl(P(i)Pr(3))(2)Os(σ-H-BNMe(2))], [(H)(2)Cl(P(i)Pr(3))(2)Os{σ-H-BOCH(2)CH(2)OB(O(2)CH(2)CH(2))}] and [(H)(2)Cl(P(i)Pr(3))(2)Os(σ-H-BNMe(2))]. The longer calculated M-B bond distance in complex [(H)(2)Cl(PMe(3))(2)M(σ-H-BNMe(2))] are due to greater B-N π bonding and as a result, a weaker M-B π-back-bonding. The B-H2 bond distances reveal that (i) iron complexes contain bis(σ-borane) ligand, (ii) ruthenium complexes contain (σ-H-BR) ligands with a stretched B-H2 bond, and (iii) osmium complexes contain hydride (H2) and (σ-H-BR) ligands. The H-BR ligands in osmium complexes are a better trans-directing ligand than the Cl ligand. Values of interaction energy, electrostatic interaction, orbital interaction, and bond dissociation energy for interactions between ionic fragments are very large and may not be consistent with M-(σ-H-BR) bonding. The EDA as well as NBO and AIM analysis suggest that the best bonding model for the M-σ-H-BR interactions in the complexes [(H)(2)Cl(PMe(3))(2)M(σ-H-BR)] is the interaction between neutral fragments [(H)(2)Cl(PMe(3))(2)M] and [σ-H-BR]. This becomes evident from the calculated values for the orbital interactions. The electron configuration of the fragments which is shown for C in Fig. 1 experiences the smallest change upon the M-σ-H-BR bond formation. Since model C also requires the least amount of electronic excitation and geometry changes of all models given by the ΔE(prep) values, it is clearly the most appropriate choice of

  8. Synthesis and magnetic properties of carbon-coated FeRu, CoRu, and NiRu nanoalloys

    El-Gendy, A.A.; Khavrus, V.O.; Hampel, S.; Leonhardt, A.; Klingeler, R.; Buechner, B. [Leibniz Institute for Solid State and Materials Research (IFW) Dresden (Germany)

    2010-07-01

    Carbon coated FeRu, CoRu and NiRu nanoalloys have been synthesised by high pressure chemical vapour deposition (HPCVD). The formation of the core-shell nanoalloys with a mean diameter around 8 nm has been confirmed by means of high resolution transmission electron microscopy imaging (HRTEM), energy dispersive X-ray (EDX) analysis, and X-ray diffraction (XRD). We show the effect of the synthesis parameters on the actual composition of the nanoalloys and on their magnetic properties and we discuss their feasibility for applications in medical hyperthermia.

  9. Systems of OsO4-RuO4 and Re2O7-OsO4

    Nisel'son, L.A.; Sokolova, T.D.; Orlov, A.M.; Shorikov, Yu.S.

    1981-01-01

    The meltability diagrams of the systems OsO 4 -RuO 4 and Re 2 O 7 -OsO 4 are studied using the visual-polythermal method. The OsO 4 -RuO 4 system forms a continuous series of solid solutions with practically rectilinear line of the liquidus. The Re 2 O 7 -OsO 4 system of the eutectic type has the eutectics degenerated from the side of OsO 4 . For the system OsO 4 (basis)-RuO 4 (admixture) the equilibrium coefficient of distribution is determined using the method of directed crystallization [ru

  10. Comparing Ru and Fe-catalyzed olefin metathesis

    Poater, Albert; Chaitanya Vummaleti, Sai Vikrama; Pump, Eva; Cavallo, Luigi

    2014-01-01

    Density functional theory calculations have been used to explore the potential of Fe-based complexes with an N-heterocyclic carbene ligand, as olefin metathesis catalysts. Apart from a less endothermic reaction energy profile, a small reduction in the predicted upper energy barriers (≈ 2 kcal mol -1) is calculated in the Fe catalyzed profile with respect to the Ru catalysed profile. Overall, this study indicates that Fe-based catalysts have the potential to be very effective olefin metathesis catalysts. This journal is © the Partner Organisations 2014.

  11. Study the Polyol Process of Preparing the ru Doped FePt Nanoparticles

    Lee, Chih-Hao; Hsu, Jen-Ho; Su, Hui-Chia; Huang, Tzu Wen

    The structure of Ru doped FePt nanoparticles using polyol process was studied. The particle size grown is around 5 nm, and a shell structure might be formed. By selecting the time and temperature of adding the Ru precursors into solution, three different processes to synthesize the FePtRu particles were studied resulting in different growing mechanics. The possible models during the reaction process are also discussed. The phase transition temperature for the as-grown FCC FePt nanoparticle to transform into L10 FePt nanoparticle is about 823 K which is about the same as the one without doping Ru atoms. From the XAS study of each element, the possible scenario is that: although Ru atoms with the size close to the Pt, they do not totally replace the Pt sites in the FePt alloy. Instead, most of Ru formed a shell outside the FePt nanoparticles and Fe atoms are replaced.

  12. Phase diagrams of Ca(Fe,Ru){sub 2}As{sub 2} system

    Zhao, Kan; Gegenwart, Philipp [Experimentalphysik VI, Elektronische Korrelationen und Magnetismus, Institut fuer Physik, Universitaet Augsburg, D-86135 Augsburg (Germany)

    2015-07-01

    Single crystalline Ca(Fe,Ru){sub 2}As{sub 2} series have been grown and characterized by structural, magnetic, and transport measurements. These measurement shows Ca(Fe,Ru){sub 2}As{sub 2} undergoes successive phase transitions with increasing Ru element doping. The antiferromagnetic phase with orthorhombic structure at x<0.023 (x means the doping concentration of Ru element) is directly driven to a Fermi-liquid type collapsed tetragonal (cT) phase at 0.023Fe{sub 2}As{sub 2} under hydrostatic pressure.

  13. B11 NMR in the layered diborides OsB2 and RuB2

    Suh, B. J.; Zong, X.; Singh, Y.; Niazi, A.; Johnston, D. C.

    2007-10-01

    B11 nuclear magnetic resonance (NMR) measurements have been performed on B11 enriched OsB2 and RuB2 polycrystalline powder samples in an external field of 4.7T and in the temperature range, 4.2KOsB2 and RuB2 , respectively. The experimental results indicate that a p character dominates the conduction electron wave function at the B site with a negligibly small s character in both compounds.

  14. Soft magnetic properties of FeRuGaSi alloy films: SOFMAX

    Hayashi, K.; Hayakawa, M.; Ishikawa, W.; Ochiai, Y.; Iwasaki, Y.; Aso, K.

    1988-01-01

    To advance new soft magnetic materials of an FeGaSi alloy into the commercial world, improvements on various properties were designed by introducing additive elements without sacrificing its high saturation magnetic induction. The detailed studies on the diversified properties, such as saturation magnetic induction, film internal stress, wear resistivity, and so on, were performed. High-frequency permeability of the laminated structure film was also investigated. As a result, the Ru-added FeRuGaSi alloy films, whose typical compositions are Fe 72 Ru 4 Ga 7 Si 17 and Fe 68 Ru 8 Ga 7 Si 17 (at. %), prove to be excellent soft magnetic materials especially appropriate for the magnetic recording/playback head core use

  15. Electrochemical, spectroscopic, and photophysical properties of structurally diverse polyazine-bridged Ru(II),Pt(II) and Os(II),Ru(II),Pt(II) supramolecular motifs.

    Knoll, Jessica D; Arachchige, Shamindri M; Wang, Guangbin; Rangan, Krishnan; Miao, Ran; Higgins, Samantha L H; Okyere, Benjamin; Zhao, Meihua; Croasdale, Paul; Magruder, Katherine; Sinclair, Brian; Wall, Candace; Brewer, Karen J

    2011-09-19

    Five new tetrametallic supramolecules of the motif [{(TL)(2)M(dpp)}(2)Ru(BL)PtCl(2)](6+) and three new trimetallic light absorbers [{(TL)(2)M(dpp)}(2)Ru(BL)](6+) (TL = bpy = 2,2'-bipyridine or phen = 1,10-phenanthroline; M = Ru(II) or Os(II); BL = dpp = 2,3-bis(2-pyridyl)pyrazine, dpq = 2,3-bis(2-pyridyl)quinoxaline, or bpm = 2,2'-bipyrimidine) were synthesized and their redox, spectroscopic, and photophysical properties investigated. The tetrametallic complexes couple a Pt(II)-based reactive metal center to Ru and/or Os light absorbers through two different polyazine BL to provide structural diversity and interesting resultant properties. The redox potential of the M(II/III) couple is modulated by M variation, with the terminal Ru(II/III) occurring at 1.58-1.61 V and terminal Os(II/III) couples at 1.07-1.18 V versus Ag/AgCl. [{(TL)(2)M(dpp)}(2)Ru(BL)](PF(6))(6) display terminal M(dπ)-based highest occupied molecular orbitals (HOMOs) with the dpp(π*)-based lowest unoccupied molecular orbital (LUMO) energy relatively unaffected by the nature of BL. The coupling of Pt to the BL results in orbital inversion with localization of the LUMO on the remote BL in the tetrametallic complexes, providing a lowest energy charge separated (CS) state with an oxidized terminal Ru or Os and spatially separated reduced BL. The complexes [{(TL)(2)M(dpp)}(2)Ru(BL)](6+) and [{(TL)(2)M(dpp)}(2)Ru(BL)PtCl(2)](6+) efficiently absorb light throughout the UV and visible regions with intense metal-to-ligand charge transfer (MLCT) transitions in the visible at about 540 nm (M = Ru) and 560 nm (M = Os) (ε ≈ 33,000-42,000 M(-1) cm(-1)) and direct excitation to the spin-forbidden (3)MLCT excited state in the Os complexes about 720 nm. All the trimetallic and tetrametallic Ru-based supramolecular systems emit from the terminal Ru(dπ)→dpp(π*) (3)MLCT state, λ(max)(em) ≈ 750 nm. The tetrametallic systems display complex excited state dynamics with quenching of the (3)MLCT emission at

  16. FeRu/TiO2 and Fe/TiO2 catalysts after reduction and Fischer-Tropsch synthesis studied by Moessbauer spectroscopy

    Kraan, A.M. van der; Nonnekens, R.C.H.; Niemantsverdriet, J.W.

    1986-01-01

    A series of TiO 2 -supported bimetallic FeRu catalysts with different Fe:Ru ratios (infinity; 10:1; 3:1; 1:1; 1:3) has been studied by means of in situ Moessbauer spectroscopy. The influence of reduction and Fischer-Tropsch synthesis on the state of iron in the FeRu/TiO 2 catalysts is derived. (Auth.)

  17. Lattice dynamics of Ru2FeX (X = Si, Ge) Full Heusler alloys

    Rizwan, M.; Afaq, A.; Aneeza, A.

    2018-05-01

    In present work, the lattice dynamics of Ru2FeX (X = Si, Ge) full Heusler alloys are investigated using density functional theory (DFT) within generalized gradient approximation (GGA) in a plane wave basis, with norm-conserving pseudopotentials. Phonon dispersion curves and phonon density of states are obtained using first-principles linear response approach of density functional perturbation theory (DFPT) as implemented in Quantum ESPRESSO code. Phonon dispersion curves indicates for both Heusler alloys that there is no imaginary phonon in whole Brillouin zone, confirming dynamical stability of these alloys in L21 type structure. There is a considerable overlapping between acoustic and optical phonon modes predicting no phonon band gap exists in dispersion curves of alloys. The same result is shown by phonon density of states curves for both Heusler alloys. Reststrahlen band for Ru2FeSi is found smaller than Ru2FeGe.

  18. Strain effects on electronic structure of Fe{sub 0.75}Ru{sub 0.25}Te

    Winiarski, M.J., E-mail: M.Winiarski@int.pan.wroc.pl [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Okólna 2, 50-422, Wrocław (Poland); Samsel-Czekała, M. [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Okólna 2, 50-422, Wrocław (Poland); Ciechan, A. [Institute of Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668, Warsaw (Poland)

    2017-01-15

    Structural and electronic properties of a hypothetical Fe{sub 0.75}Ru{sub 0.25}Te alloy and the parent FeTe compound have been investigated from first principles within the density functional theory (DFT). For both systems the double-stripe antiferromagnetic ground state is predicted at ambient pressure. The incorporation of Ru atoms into FeTe in the nonmagnetic phase leads to a deep valley of density of states in the vicinity of the Fermi level and the DOS at the Fermi level is significantly diminished in the considered solid solution. The single-stripe antiferromagnetic phase in Fe{sub 0.75}Ru{sub 0.25}Te may be induced by tensile strain. These findings suggest that strained thin films of Fe{sub 1−x}Ru{sub x}Te are good candidates for new superconducting Fe-based materials. - Highlights: • Ru-doped FeTe systems are investigated by density-functional theory methods. • Structural and electronic properties of Fe{sub 0.75}Ru{sub 0.25}Te and parent FeTe are studied. • The double-stripe antiferromagnetic ground state is predicted for both systems. • The single-stripe antiferromagnetic phase may be induced by tensile strain. • Tensile strained Fe{sub 0.75}Ru{sub 0.25}Te is a candidate for a new Fe-based superconductor.

  19. Effect of the leaching of Ru-Se-Fe and Ru-Mo-Fe obtained by mechanical alloying on electrocatalytical behavior for the oxygen reduction reaction

    Ezeta, A.; Arce, E.M.; Solorza, O.; Gonzalez, R.G.; Dorantes, H.

    2009-01-01

    In the present work, Ru-Se-Fe and Ru-Mo-Fe alloyed nanoparticles were synthesized from high purity powders (Ru, Se and Mo) by means of the high-energy mechanical alloying. Fe was integrated to the alloys because of the erosion of the mill balls. The ORR electrocatalytic performance of the alloys (lixiviated or not) was evaluated in a rotating disc electrode (RDE) at room temperature. X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used for the structure characterization of the materials. Small-particle clusters with granular morphology and nanometric sizes were obtained in all the cases. According to the Tafel parameters from the RDE results, a first order ORR is present in both electrocatalytic systems through a 4e - global multielectron transference to form water: O 2 + 4H + + e - → H 2 O. The electrocatalytic activity showed that the mechanical alloying enabled to obtain nanoparticle electrocatalysts with good ORR performance. Lixiviation of the mechanical alloying powders not improves the catalytical responses.

  20. Ionization and photofragmentation of Ru3(CO)12 and Os3(CO)12

    Schalk, Oliver; Josefsson, Ida; Odelius, Michael; Richter, Robert; Prince, Kevin C.; Mucke, Melanie

    2015-01-01

    In this paper, we use a combination of photoelectron spectroscopy, mass spectrometry, and density functional theory calculations to get a detailed understanding of valence single and double ionization and the subsequent dissociation processes. This is exemplified on benchmark systems, trimetallo-dodecacarbonyls M 3 (CO) 12 with M = Ru, Os, where the energy remaining in the molecule after photoionization can be retrieved by measuring the degree of fragmentation of the molecular ion. The intensity of different mass peaks can thus be directly related to ionization cross sections obtained by photoelectron spectroscopy. We find that the M—CO dissociation energy rises as the number of CO ligands decreases due to dissociation. Moreover, ionization of the CO ligands has a higher cross section than that of the metal center for both single and double ionization. After advanced fragmentation, a CO bond can break and the carbon atom remains bonded to the metal core. In addition, we found that the valence ionization cross sections of M 3 (CO) 12 are maximal at about 40 eV photon energy thus showing a more pronounced shape resonance than Ru and Os-complexes with a single metal atom center. Finally, an np → nd giant resonance absorption causes a significant increase of the ionization cross section above 50 eV for Ru 3 (CO) 12

  1. Gas-phase chemistry of Mo, Ru, W, and Os metal carbonyl complexes

    Wang, Y.; Qin, Z.; Fan, F.L.

    2014-01-01

    Metal carbonyl complexes were used for studying the gas-phase chemical behavior of Mo, Ru, W and Os isotopes with an on-line low temperature isothermal gas chromatography apparatus. Short-lived Mo and Ru isotopes were produced by a 252 Cf spontaneous fission source. Short-lived nuclides of W and Os were produced using the heavy ion reactions 19 F + 159 Tb and 165 Ho, respectively. Short-lived products were thermalized in a recoil chamber filled with a gas mixture of helium and carbon monoxide. The carbonyls formed were then transported through capillaries to an isothermal chromatography column for study of the adsorption behavior as a function of temperature. On-line isothermal chromatography (IC) experiments on Teflon (PTFE) and quartz surfaces showed that short-lived isotopes of the listed elements can form carbonyl complexes which are very volatile and interact most likely in physical sorption processes. Deduced adsorption enthalpies of Mo and Ru carbonyls were -38 ± 2 kJ/mol and -36 ± 2 kJ/mol, respectively. These values are in good agreement with literature data, partly obtained with different chromatographic techniques. A validation of the applied Monte Carlo model to deduce adsorption enthalpies with Mo isotopes of different half-lives proved the validity of the underlying adsorption model. The investigations using a gas-jet system coupled to a heavy ion accelerator without any preseparator clearly showed the limitations of the approach. The He and CO gas mixture, which was directly added into the chamber, will result in decomposition of CO gas and produce some aerosol particles. After the experiment of 173 W and 179 Os in the heavy ion experiments, the Teflon column was covered by a yellowish deposit; the adsorption enthalpy of W and Os carbonyls could therefore not be properly deduced using Monte Carlo simulations. (orig.)

  2. Ferromagnetic resonance study of structure and relaxation of magnetization in NiFe/Ru superlattices

    Alayo, W., E-mail: willian.rodriguez@ufpel.edu.br [Depto. de Física, Univ. Federal de Pelotas, Campus Universitário, 96010-900, Pelotas, RS (Brazil); Landi Jr, S. [Instituto Federal Goiano, Rio Verde 75901-970 (Brazil); Pelegrini, F. [Instituto de Física, Universidade Federal de Goiás, Goiânia 74001-970 (Brazil); Baggio-Saitovitch, E. [Centro Brasileiro de Pesquisas Físicas, Rio de Janeiro 22290-180 (Brazil)

    2014-01-15

    The structural properties and relaxation processes of magnetization in [Ni{sub 81}Fe{sub 19}(t{sub 1})/Ru(t{sub 2})]{sub N} superlattices (N=number of bilayers) were analyzed by ferromagnetic resonance (FMR) with a fixed microwave frequency. One series of samples was deposited with constant NiFe layer thickness (t{sub 1}) and variable Ru layer thickness (t{sub 2}); the other series, with constant t{sub 2} and variable t{sub 1}. A single FMR mode was observed for t{sub 2}<15 Å and t{sub 1}>75 Å and it has been attributed to the resonance of the exchange-coupled NiFe layers across the Ru interlayers. For the other values of t{sub 1} and t{sub 2}, several FMR modes appeared and they were associated to non-coupled magnetic phases with different effective magnetization formed during the multilayer growth. The FMR linewidths were analyzed as a function of the magnetic layer thickness and a strong dependence on t{sub 1}{sup −2} was observed. It was attributed to the contribution of the two-magnon scattering mechanism for the linewidth. - Highlights: • We present a study of magnetic properties of NiFe/Ru superlattices by ferromagnetic resonance (FMR). • The FMR spectra show several modes for large Ru thicknesses and for low NiFe thicknesses. • The above behavior is correlated with the interlayer exchange coupling. • The two-magnon scattering mechanism is revealed by the dependence of the FMR linewidth on the NiFe thickness.

  3. Half-Sandwich Ru(II and Os(II Bathophenanthroline Complexes Containing a Releasable Dichloroacetato Ligand

    Pavel Štarha

    2018-02-01

    Full Text Available We report on the preparation and thorough characterization of cytotoxic half-sandwich complexes [Ru(η6-pcym(bphen(dca]PF6 (Ru-dca and [Os(η6-pcym(bphen(dca]PF6 (Os-dca containing dichloroacetate(1– (dca as the releasable O-donor ligand bearing its own cytotoxicity; pcym = 1-methyl-4-(propan-2-ylbenzene (p-cymene, bphen = 4,7-diphenyl-1,10-phenanthroline (bathophenanthroline. Complexes Ru-dca and Os-dca hydrolyzed in the water-containing media, which led to the dca ligand release (supported by 1H NMR and electrospray ionization mass spectra. Mass spectrometry studies revealed that complexes Ru-dca and Os-dca do not interact covalently with the model proteins cytochrome c and lysozyme. Both complexes exhibited slightly higher in vitro cytotoxicity (IC50 = 3.5 μM for Ru-dca, and 2.6 μM for Os-dca against the A2780 human ovarian carcinoma cells than cisplatin (IC50 = 5.9 μM, while their toxicity on the healthy human hepatocytes was found to be IC50 = 19.1 μM for Ru-dca and IC50 = 19.7 μM for Os-dca. Despite comparable cytotoxicity of complexes Ru-dca and Os-dca, both the complexes modified the cell cycle, mitochondrial membrane potential, and mitochondrial cytochrome c release by a different way, as revealed by flow cytometry experiments. The obtained results point out the different mechanisms of action between the complexes.

  4. Multichromophoric hybrid species made of perylene bisimide derivatives and Ru(ii) and Os(ii) polypyridine subunits.

    Nastasi, Francesco; La Ganga, Giuseppina; Campagna, Sebastiano; Syrgiannis, Zois; Rigodanza, Francesco; Vitale, Stefania; Licciardello, Antonino; Prato, Maurizio

    2017-05-31

    Herein, the synthesis and the photophysical and redox properties of a new perylene bisimide (PBI) species (L), bearing two 1,10-phenanthroline (phen) ligands at the two imide positions of the PBI, and its dinuclear Ru(ii) and Os(ii) complexes, [(bpy) 2 Ru(μ-L)Ru(bpy) 2 ](PF 6 ) 4 (Ru2; bpy = 2,2'-bipyridine) and [(Me 2 -bpy) 2 Os(μ-L)Os(Me 2 -bpy) 2 ](PF 6 ) 4 (Os2; Me 2 -bpy = (4,4'-dimethyl)-2,2'-bipyridine), are reported. The absorption spectra of the compounds are dominated by the structured bands of the PBI subunit due to the lowest-energy spin-allowed π-π* transition. The spin-allowed MLCT transitions in Ru2 and Os2 are inferred by the absorption at 350-470 nm, where the PBI absorption is negligible. The absorption band extends towards the red region for Os2 due to the spin-forbidden MLCT transitions, intensified by the heavy osmium center. The reduction processes of the compounds are dominated by two successive mono-electronic PBI-based processes, which in the metal complexes are slightly shifted compared to the free ligand. On oxidation, both metal complexes undergo an apparent bi-electronic process (at 1.31 V vs. SCE for Ru2 and 0.77 V for Os2), attributed to the simultaneous one-electron oxidation of the two weakly-interacting metal centers. In Ru2 and Os2, the intense fluorescence of L subunit (λ max , 535 nm; τ, 4.3 ns; Φ, 0.91) is fully quenched, mainly by photoinduced electron transfer from the metal centers, on the ps timescale (time constant, 11 ps in Ru2 and 3 ps in Os2). Such photoinduced electron transfer leads to the formation of a charge-separated state, which directly decays to the ground state in about 70 ps in Os2, but produces the triplet π-π* state of the PBI subunit in 35 ps in Ru2. The results provide information on the excited-state processes of the hybrid species combining two dominant classes of chromophore/luminophore species, the PBI and the metal polypyridine complexes, and can be used for future design on new hybrid

  5. Study of anodic dissolution of Fe-Ru alloy with the aid of mossbauer spectroscopy

    Khlystov, A.S.; Fasman, A.B.; Kil'dibekova, G.A.

    1986-01-01

    This paper uses Fe 57 Mossbauer spectroscopy, whereby iron compounds may be identified quantitatively and their composition and structure can be determined, for the study of the relationships of slime formation from Fe-Ru binary alloys. Both the products of dissolution and the composition and state of intermediate phases formed at various stages of anodic dissolution were studied simultaneously. It was found that the slimes formed both during chemical and during electrochemical destruction of ruthenium-iron alloys are finely dispersed systems of complex composition, analogous to those formed in the course of electrochemical dissolution of Ni-Ru alloys, which were found to contain oxide phases of ruthenium (by x-ray spectroscopy and ESCA) and of nickel (by x-ray phase analysis). The difference between the slime compositions is determined mainly by kinetic factors

  6. The Design, Synthesis and Study of Mixed-Metal Ru,Rh and Os, Rh Complexes with Biologically Relevant Reactivity

    Wang, Jing

    2013-01-01

    A series of mixed-metal bimetallic complexes [(TL)2M(dpp)RhCl2(TL)]3 (M = Ru and Os, terminal ligands (TL) = phen, Ph2phen, Me2phen and bpy, terminal ligands (TL) = phen, bpy and Me2bpy ), which couple one Ru or Os polyazine light absorber (LA) to a cis-RhIIICl2 center through a dpp bridging ligand (BL), were synthesized using a building block method. These are related to previously studied trimetallic systems [{(TL)2M(dpp)2RhCl2]5+, but the bimetallics are synthetically more complex to prepa...

  7. Electronic and elastic properties of new semiconducting oP12-type RuB2 and OsB2

    Hao Xianfeng; Xu Yuanhui; Gao Faming

    2011-01-01

    Using first-principles total energy calculations we investigate the structural, elastic and electronic properties of new hypothetical oP 12 -type phase RuB 2 and OsB 2 . The calculations indicate that the oP 12 -type phase RuB 2 and OsB 2 are thermodynamically and mechanically stable. Remarkably, the new phases RuB 2 and OsB 2 are predicted to be semiconductors, and the appearance of band gaps is ascribed to the enhanced B-B covalent hybridization. Compared to metallic oP 6 -type RuB 2 and OsB 2 phases, the new phases possess similar mechanical properties and hardness. The combination of the probability of tunable electronic properties, strong stiffness and high hardness make RuB 2 and OsB 2 attractive and interesting for advanced applications.

  8. Electronic and elastic properties of new semiconducting oP(12)-type RuB(2) and OsB(2).

    Hao, Xianfeng; Xu, Yuanhui; Gao, Faming

    2011-03-30

    Using first-principles total energy calculations we investigate the structural, elastic and electronic properties of new hypothetical oP(12)-type phase RuB(2) and OsB(2). The calculations indicate that the oP(12)-type phase RuB(2) and OsB(2) are thermodynamically and mechanically stable. Remarkably, the new phases RuB(2) and OsB(2) are predicted to be semiconductors, and the appearance of band gaps is ascribed to the enhanced B-B covalent hybridization. Compared to metallic oP(6)-type RuB(2) and OsB(2) phases, the new phases possess similar mechanical properties and hardness. The combination of the probability of tunable electronic properties, strong stiffness and high hardness make RuB(2) and OsB(2) attractive and interesting for advanced applications. © 2011 IOP Publishing Ltd

  9. Electronic and elastic properties of new semiconducting oP{sub 12}-type RuB{sub 2} and OsB{sub 2}

    Hao Xianfeng; Xu Yuanhui; Gao Faming, E-mail: xfhao1980@yahoo.com.cn [Key Laboratory of Applied Chemistry, Yanshan University, Qinhuangdao 066004 (China)

    2011-03-30

    Using first-principles total energy calculations we investigate the structural, elastic and electronic properties of new hypothetical oP{sub 12}-type phase RuB{sub 2} and OsB{sub 2}. The calculations indicate that the oP{sub 12}-type phase RuB{sub 2} and OsB{sub 2} are thermodynamically and mechanically stable. Remarkably, the new phases RuB{sub 2} and OsB{sub 2} are predicted to be semiconductors, and the appearance of band gaps is ascribed to the enhanced B-B covalent hybridization. Compared to metallic oP{sub 6}-type RuB{sub 2} and OsB{sub 2} phases, the new phases possess similar mechanical properties and hardness. The combination of the probability of tunable electronic properties, strong stiffness and high hardness make RuB{sub 2} and OsB{sub 2} attractive and interesting for advanced applications.

  10. Crystal growth and characterization of CeFe{sub 1-x}Ru{sub x} PO

    Balle, Tanita; Kliemt, Kristin; Krellner, Cornelius [Goethe Universitaet Frankfurt, Kristall- und Materiallabor (Germany)

    2016-07-01

    CeRuPO is a one of the few heavy fermion systems, which order ferromagnetically at low temperatures (T{sub C} = 15 K), because of dominant RKKY-interaction. CeFePO on the other hand shows no long-range magnetic order even at low temperatures because of dominant Kondo effect (T{sub K} = 10 K). By substituting CeFePO with ruthenium we can reach a quantum critical point, at which the RKKY-interaction and the Kondo effect are equally strong. To study the quantum critical point, and to enlighten the question if the order stays ferromagnetically down to lowest temperatures, high quality crystals are needed. Here, the growth and characterization of the single crystals will be discussed. We obtained mm-sized single crystals of the unsubstituted CeRuPO and CeFePO by a modified Bridgeman method using tin as a flux. The quality of the crystals was verified by Powder-X-Ray-Diffraction, energy dispersive X-ray spectroscopy and Laue backscattering.

  11. Epitaxial growth of unusual 4H hexagonal Ir, Rh, Os, Ru and Cu nanostructures on 4H Au nanoribbons

    Fan, Zhanxi; Chen, Ye; Zhu, Yihan; Wang, Jie; Li, Bing; Zong, Yun; Han, Yu; Zhang, Hua

    2016-01-01

    Metal nanomaterials normally adopt the same crystal structure as their bulk counterparts. Herein, for the first time, the unusual 4H hexagonal Ir, Rh, Os, Ru and Cu nanostructures have been synthesized on 4H Au nanoribbons (NRBs) via solution-phase epitaxial growth under ambient conditions. Interestingly, the 4H Au NRBs undergo partial phase transformation from 4H to face-centered cubic (fcc) structures after the metal coating. As a result, a series of polytypic 4H/fcc bimetallic Au@M (M = Ir, Rh, Os, Ru and Cu) core-shell NRBs has been obtained. We believe that the rational crystal structure-controlled synthesis of metal nanomaterials will bring new opportunities for exploring their phase-dependent physicochemical properties and promising applications.

  12. Epitaxial growth of unusual 4H hexagonal Ir, Rh, Os, Ru and Cu nanostructures on 4H Au nanoribbons

    Fan, Zhanxi

    2016-09-12

    Metal nanomaterials normally adopt the same crystal structure as their bulk counterparts. Herein, for the first time, the unusual 4H hexagonal Ir, Rh, Os, Ru and Cu nanostructures have been synthesized on 4H Au nanoribbons (NRBs) via solution-phase epitaxial growth under ambient conditions. Interestingly, the 4H Au NRBs undergo partial phase transformation from 4H to face-centered cubic (fcc) structures after the metal coating. As a result, a series of polytypic 4H/fcc bimetallic Au@M (M = Ir, Rh, Os, Ru and Cu) core-shell NRBs has been obtained. We believe that the rational crystal structure-controlled synthesis of metal nanomaterials will bring new opportunities for exploring their phase-dependent physicochemical properties and promising applications.

  13. Lattice dynamics and thermophysical properties of h.c.p. Os and Ru from the quasi-harmonic approximation.

    Palumbo, Mauro; Dal Corso, Andrea

    2017-10-04

    We report first-principles phonon frequencies and anharmonic thermodynamic properties of h.c.p. Os and Ru calculated within the quasi-harmonic approximation, including Grüneisen parameters, temperature-dependent lattice parameters, thermal expansion, and isobaric heat capacity. We discuss the differences between a full treatment of anisotropy and a simplified approach with a constant [Formula: see text] ratio. The results are systematically compared with the available theoretical and experimental data and an overall satisfactory agreement is obtained.

  14. New ternary tantalum borides containing boron dumbbells: Experimental and theoretical studies of Ta2OsB2 and TaRuB

    Mbarki, Mohammed; Touzani, Rachid St.; Rehorn, Christian W.G.; Gladisch, Fabian C.; Fokwa, Boniface P.T.

    2016-01-01

    The new ternary transition metal-rich borides Ta 2 OsB 2 and TaRuB have been successfully synthesized by arc-melting the elements in a water-cooled crucible under an argon atmosphere. The crystal structures of both compounds were solved by single-crystal X-ray diffraction and their metal compositions were confirmed by EDX analysis. It was found that Ta 2 OsB 2 and TaRuB crystallize in the tetragonal Nb 2 OsB 2 (space group P4/mnc, no. 128) and the orthorhombic NbRuB (space group Pmma, no. 51) structure types with lattice parameters a=5.878(2) Å, c=6.857(2) Å and a=10.806(2) Å, b=3.196(1) Å, c=6.312(2) Å, respectively. Furthermore, crystallographic, electronic and bonding characteristics have been studied by density functional theory (DFT). Electronic structure relaxation has confirmed the crystallographic parameters while COHP bonding analysis indicates that B 2 -dummbells are the strongest bonds in both compounds. Moreover, the formation of osmium dumbbells in Ta 2 OsB 2 through a Peierls distortion along the c-axis, is found to be the origin of superstructure formation. Magnetic susceptibility measurements reveal that the two phases are Pauli paramagnets, thus confirming the theoretical DOS prediction of metallic character. Also hints of superconductivity are found in the two phases, however lack of single phase samples has prevented confirmation. Furthermore, the thermodynamic stability of the two modifications of AMB (A=Nb, Ta; M =Ru, Os) are studied using DFT, as new possible phases containing either B 4 - or B 2 -units are predicted, the former being the most thermodynamically stable modification. - Graphical abstract: The two new ternary tantalum borides, Ta 2 OsB 2 and TaRuB, have been discovered. Their crystal structures contain boron dumbbells, which are the strongest bonds. Peirls distortion is found responsible for Os 2 -dumbbells formation in Ta 2 OsB 2 . Ta 2 OsB 2 and TaRuB are Pauli paramagnet and potential superconductors. - Highlights:

  15. Electronic structures of three semiconducting intermetallics: RuAl sub 2 , RuGa sub 2 and OsAl sub 2

    Springborg, M

    1998-01-01

    Results of first-principles, density-functional, LMTO-ASA calculations on the closely related C11, C40, and C54 structures of the three title compounds are reported. Only for OsAl sub 2 in the C11 structure were the structural degrees of freedom optimized; this gave results in good agreement with experimental values. On the other hand, the calculations were not capable of reproducing the correct relative stability of the different structures; this was ascribed to the atomic-sphere approximation. All of the compounds were found to be small-gap semiconductors with, however, a slightly larger gap for OsAl sub 2. The occurrence of a gap at the Fermi level is mainly due to hybridization between d functions of Os or Ru and p functions of Al or Ga, but, in particular for OsAl sub 2 , charge-transfer effects can also be considered to be responsible for the occurrence of a gap. Several flat bands just above the Fermi level lead to a corresponding high density of states there, but also to low carrier velocities. As a b...

  16. Structure, elastic stiffness, and hardness of Os 1- xRu xB 2 solid solution transition-metal diborides

    Kanoun, Mohammed; Hermet, Patrick; Goumri-Said, Souraya

    2012-01-01

    On the basis of recent experiments, the solid solution transition-metal diborides were proposed to be new ultra-incompressible hard materials. We investigate using density functional theory based methods the structural and mechanical properties, electronic structure, and hardness of Os 1-xRu xB 2 solid solutions. A difference in chemical bonding occurs between OsB 2 and RuB 2 diborides, leading to significantly different elastic properties: a large bulk, shear moduli, and hardness for Os-rich diborides and relatively small bulk, shear moduli, and hardness for Ru-rich diborides. The electronic structure and bonding characterization are also analyzed as a function of Ru-dopant concentration in the OsB 2 lattice. © 2012 American Chemical Society.

  17. Structure, elastic stiffness, and hardness of Os 1- xRu xB 2 solid solution transition-metal diborides

    Kanoun, Mohammed

    2012-05-31

    On the basis of recent experiments, the solid solution transition-metal diborides were proposed to be new ultra-incompressible hard materials. We investigate using density functional theory based methods the structural and mechanical properties, electronic structure, and hardness of Os 1-xRu xB 2 solid solutions. A difference in chemical bonding occurs between OsB 2 and RuB 2 diborides, leading to significantly different elastic properties: a large bulk, shear moduli, and hardness for Os-rich diborides and relatively small bulk, shear moduli, and hardness for Ru-rich diborides. The electronic structure and bonding characterization are also analyzed as a function of Ru-dopant concentration in the OsB 2 lattice. © 2012 American Chemical Society.

  18. Investigation into transformations of Ru(4) and Os(4) hexafluorocomplexes in aqueous solutions

    Shipachev, V.A.; Zemskov, S.V.

    1982-01-01

    Using the methods of spectrophotometry, 19 NMR and potentiometric titration the study of activation processes of hexafluorocomplexes [RuF 6 ] 2- and Cl - ion substitution for F - in them is carried out. It is shown that Cl - substitution for F - in [RuF 6 ] 2 is limited by the stage of replacement of the first fluorine in the inner sphere, and intermediate mixed forms are less stable. Hydrolytic interactions with formation of polymer oxohydroxofluoride ions in solutions are of great importance in the chemistry of the compounds. The data of potentiometric titration of [RuF 6 ] 2- solutions with reducers point to the formation of Ru(3) aquohydroxocomplexes of indefinite composition

  19. Dual-mode ferromagnetic resonance in an FeCoB/Ru/FeCoB synthetic antiferromagnet with uniaxial anisotropy

    Wang, Cuiling; Zhang, Shouheng; Qiao, Shizhu; Du, Honglei; Liu, Xiaomin; Sun, Ruicong; Chu, Xian-Ming; Miao, Guo-Xing; Dai, Youyong; Kang, Shishou; Yan, Shishen; Li, Shandong

    2018-05-01

    Dual-mode ferromagnetic resonance is observed in FeCoB/Ru/FeCoB trilayer synthetic antiferromagnets with uniaxial in-plane magnetic anisotropy. The optical mode is present in the (0-108 Oe) magnetic field range, where the top and bottom layer magnetizations are aligned in opposite directions. The strong acoustic mode appears, when the magnetic field exceeds the 300 Oe value, which corresponds to the flop transition in the trilayer. Magnetic field and angular dependences of resonant frequencies are studied for both optical (low-field) and acoustic (high field) modes. The low-field mode is found to be anisotropic but insensitive to the magnetic field value. In contrast, the high field mode is quasi-isotropic, but its resonant frequency is tunable by the value of the magnetic field. The coexistence of two modes of ferromagnetic resonance as well as switching between them with the increase in the magnetic field originates from the difference in the sign of interlayer coupling energy at the parallel and antiparallel configurations of the synthetic antiferromagnet. The dual-mode resonance in the studied trilayer structures provides greater flexibility in the design and functionalization of micro-inductors in monolithic microwave integrated circuits.

  20. Structure and magnetic properties of L10-FePt thin films on TiN/RuAl underlayers

    Yang En; Ratanaphan, Sutatch; Zhu Jiangang; Laughlin, David E.

    2011-01-01

    Highly ordered L1 0 FePt-oxide thin films with small grains were prepared by using a RuAl layer as a grain size defining seed layer along with a TiN barrier layer. Different HAMR (Heat Assisted Magnetic Recording) favorable underlayers were studied to encourage perpendicular texture and preferred microstructure. It was found that the epitaxial and small grain growth from the RuAl/TiN underlayer results in small and uniform grains in the FePt layer with perpendicular texture. By introducing the grain size defining underlayers, the FePt grain size can be reduced from 30 to 6 nm with the same volume fraction (9%) of SiO 2 in the film, excellent perpendicular texture, and very high order parameter at 520 deg. C.

  1. OsB 2 and RuB 2, ultra-incompressible, hard materials: First-principles electronic structure calculations

    Chiodo, S.; Gotsis, H. J.; Russo, N.; Sicilia, E.

    2006-07-01

    Recently it has been reported that osmium diboride has an unusually large bulk modulus combined with high hardness, and consequently is a most interesting candidate as an ultra-incompressible and hard material. The electronic and structural properties of the transition metal diborides OsB 2 and RuB 2 have been calculated within the local density approximation (LDA). It is shown that the high hardness is the result of covalent bonding between transition metal d states and boron p states in the orthorhombic structure.

  2. Magnetoresistance Versus Oxygen Deficiency in Epi-stabilized SrRu1 - x Fe x O3 - δ Thin Films

    Dash, Umasankar; Acharya, Susant Kumar; Lee, Bo Wha; Jung, Chang Uk

    2017-03-01

    Oxygen vacancies have a profound effect on the magnetic, electronic, and transport properties of transition metal oxide materials. Here, we studied the influence of oxygen vacancies on the magnetoresistance (MR) properties of SrRu1 - x Fe x O3 - δ epitaxial thin films ( x = 0.10, 0.20, and 0.30). For this purpose, we synthesized highly strained epitaxial SrRu1 - x Fe x O3 - δ thin films with atomically flat surfaces containing different amounts of oxygen vacancies using pulsed laser deposition. Without an applied magnetic field, the films with x = 0.10 and 0.20 showed a metal-insulator transition, while the x = 0.30 thin film showed insulating behavior over the entire temperature range of 2-300 K. Both Fe doping and the concentration of oxygen vacancies had large effects on the negative MR contributions. For the low Fe doping case of x = 0.10, in which both films exhibited metallic behavior, MR was more prominent in the film with fewer oxygen vacancies or equivalently a more metallic film. For semiconducting films, higher MR was observed for more semiconducting films having more oxygen vacancies. A relatively large negative MR ( 36.4%) was observed for the x = 0.30 thin film with a high concentration of oxygen vacancies ( δ = 0.12). The obtained results were compared with MR studies for a polycrystal of (Sr1 - x La x )(Ru1 - x Fe x )O3. These results highlight the crucial role of oxygen stoichiometry in determining the magneto-transport properties in SrRu1 - x Fe x O3 - δ thin films.

  3. High electrochemical performance of RuO_2–Fe_2O_3 nanoparticles embedded ordered mesoporous carbon as a supercapacitor electrode material

    Xiang, Dong; Yin, Longwei; Wang, Chenxiang; Zhang, Luyuan

    2016-01-01

    The electrode materials RuO_2 or RuO_2–Fe_2O_3 nanoparticle embedded OMC (ordered mesoporous carbon) are prepared by the method of impregnation and heating in situ. The mesoporous structure optimized the electron and proton conducting pathways, leading to the enhanced capacitive performances of the composite materials. The average nanoparticle size of RuO_2 and RuO_2–Fe_2O_3 is 2.54 and 1.96 nm, respectively. The fine RuO_2–Fe_2O_3 nanoparticles are dispersed evenly in the pore channel wall of the two-dimensional mesoporous carbon without blocking the mesoporous channel, and they have a higher specific surface area, a larger pore volume, a proper pore size and a small charge transfer impedance value. The special electrochemical capacitance of RuO_2–Fe_2O_3/OMC tested in acid electrolyte (H_2SO_4) is measured to be as high as 1668 F g"−"1, which is higher than that of RuO_2/OMC. Meanwhile, the supercapacitor properties of the RuO_2–Fe_2O_3/OMC composites show a good cycling performance of 93% capacitance retention (3000 cycles), a better reversibility, a higher energy density (134 Wh kg"−"1) and power density (4000 W kg"−"1). The composite electrode of RuO_2–Fe_2O_3/OMC, which combines a double layer capacitance with pseudo-capacitance, is proved to be suitable for ideal high performance electrode material of a hybrid supercapacitor application. - Highlights: • The nanocomposites of RuO_2–Fe_2O_3/OMC are prepared by impregnation and heating in situ. • The fine RuO_2–Fe_2O_3 nanoparticles distribute in the pore channel wall of OMC. • We discuss a reversible redox reaction mechanism of RuO_2–Fe_2O_3/OMC in acid solutions. • RuO_2–Fe_2O_3 nanoparticles embedded OMC shows a higher supercapacitive performance.

  4. Significance of β-dehydrogenation in ethanol electro-oxidation on platinum doped with Ru, Rh, Pd, Os and Ir.

    Sheng, Tian; Lin, Wen-Feng; Hardacre, Christopher; Hu, P

    2014-07-14

    In the exploration of highly efficient direct ethanol fuel cells (DEFCs), how to promote the CO2 selectivity is a key issue which remains to be solved. Some advances have been made, for example, using bimetallic electrocatalysts, Rh has been found to be an efficient additive to platinum to obtain high CO2 selectivity experimentally. In this work, the mechanism of ethanol electrooxidation is investigated using the first principles method. It is found that CH3CHOH* is the key intermediate during ethanol electrooxidation and the activity of β-dehydrogenation is the rate determining factor that affects the completeness of ethanol oxidation. In addition, a series of transition metals (Ru, Rh, Pd, Os and Ir) are alloyed on the top layer of Pt(111) in order to analyze their effects. The elementary steps, α-, β-C-H bond and C-C bond dissociations, are calculated on these bimetallic M/Pt(111) surfaces and the formation potential of OH* from water dissociation is also calculated. We find that the active metals increase the activity of β-dehydrogenation but lower the OH* formation potential resulting in the active site being blocked. By considering both β-dehydrogenation and OH* formation, Ru, Os and Ir are identified to be unsuitable for the promotion of CO2 selectivity and only Rh is able to increase the selectivity of CO2 in DEFCs.

  5. Coupling phenomena and scalability of CoFeB/Ru/CoFeB sandwiches

    Wiese, N.

    2006-02-01

    The work of this thesis has to be seen in the context of magnetoresistive phenomena and their applications. It was the aim of this thesis, to implement a new material system, an amorphous CoFeB alloy, and to study its properties in magnetic tunnel junctions (MTJ). Main focus was the investigation of the coupling phenomena in these materials and the effect for their technical application. The work is relevant for application in magnetoresistive devices and partly has been carried out within the project ''Magnetoresistive logic devices''. In order to compete with the rapid downscaling in feature size of silicon semiconductors, the spin-dependent devices will also have to be scaled down to the sub-micrometer range. In the second part of this thesis, therefore, the concept of an Artificial Ferrimagnet (AFi) has been transferred to elements of sub-micrometer size. In order to get access to this small scale at experiments, patterning has been performed by electron-beam lithography, leading to sizes comparable to recent MRAM devices. In order to characterize the resulting patterns, a magneto-optical Kerr effect setup has been purchased, installed, and modified. A systematic study of the switching behavior as well as the related coupling phenomena at sub-micrometer size is presented. Emphasis is given at the interlayer exchange coupling and the exchange bias effect. Most of the phenomena for spin-dependent devices listed above are relevant for the discussion of the measurements presented in this thesis. Therefore, the first chapter covers a short introduction to most of them. The second chapter highlights the measurement methods used within this thesis. In the third chapter, the experimental results are presented and discussed. This chapter is separated into three main sections, covering the experiments at unpatterned magnetic multilayers, at patterned samples, and the studies of exchange bias effect. In the last chapter, the thesis is summarized and an outlook for further

  6. Study of the ternary alloy systems Al-Ni-Fe and Al-Cu-Ru with special regard to quasicrystalline phases

    Lemmerz, U.

    1996-07-01

    Two ternary alloy-systems, the Al-Ni-Fe system and the Al-Cu-Ru system were studied with special regard to quasicrystalline phases. Isothermal sections were established in both systems in the stoichiometric area of the quasicrystalline phase. In the Al-Ni-Fe system a new stable decagonal phase was found. Its stoichiometric range is very small around Al 71.6 Ni 23.0 Fe 5.4 . The temperature range in which it is stable lies between 847 and 930 C. The decagonal phase undergoes a eutectoid reaction to the three crystalline phases Al 3 Ni 2 , Al 3 Ni and Al 13 Fe 4 at 847 C. It melts peritectically at 930 C forming Al 13 Fe 4 , Al 3 Ni 2 and a liquid. The investigations in the Al-Cu-Ru system concentrated on the phase equilibria between the icosahedral phase and its neighbouring phases in a temperature range between 600 and 1000 C. The icosahedral phase was observed in the whole temperature range. The investigated stoichiometric area extends down to Al contents of 45%, which allows the fields of existence to be determined for the ternary phases α-AlCuRu, the icosahedral phase and Al 7 Cu 2 Ru. Binary phases were determined down to the upper (high Al content) border of AlRu. No hitherto unknown phase was observed in the investigated area. Rietveld analyses were carried out on α-AlCuRu and Al 7 Cu 2 Ru showing some discrepancies from the α-AlMnSi structure taken as a base for α-AlCuRu and confirming the Al 7 Cu 2 Fe structure for Al 7 Cu 2 Ru. (orig.)

  7. Estimation of ΔR/R values by benchmark study of the Mössbauer Isomer shifts for Ru, Os complexes using relativistic DFT calculations

    Kaneko, Masashi [Japan Atomic Energy Agency, Nuclear Science and Engineering Center (Japan); Yasuhara, Hiroki; Miyashita, Sunao; Nakashima, Satoru, E-mail: snaka@hiroshima-u.ac.jp [Hiroshima University, Graduate School of Science (Japan)

    2017-11-15

    The present study applies all-electron relativistic DFT calculation with Douglas-Kroll-Hess (DKH) Hamiltonian to each ten sets of Ru and Os compounds. We perform the benchmark investigation of three density functionals (BP86, B3LYP and B2PLYP) using segmented all-electron relativistically contracted (SARC) basis set with the experimental Mössbauer isomer shifts for {sup 99}Ru and {sup 189}Os nuclides. Geometry optimizations at BP86 theory of level locate the structure in a local minimum. We calculate the contact density to the wavefunction obtained by a single point calculation. All functionals show the good linear correlation with experimental isomer shifts for both {sup 99}Ru and {sup 189}Os. Especially, B3LYP functional gives a stronger correlation compared to BP86 and B2PLYP functionals. The comparison of contact density between SARC and well-tempered basis set (WTBS) indicated that the numerical convergence of contact density cannot be obtained, but the reproducibility is less sensitive to the choice of basis set. We also estimate the values of ΔR/R, which is an important nuclear constant, for {sup 99}Ru and {sup 189}Os nuclides by using the benchmark results. The sign of the calculated ΔR/R values is consistent with the predicted data for {sup 99}Ru and {sup 189}Os. We obtain computationally the ΔR/R values of {sup 99}Ru and {sup 189}Os (36.2 keV) as 2.35×10{sup −4} and −0.20×10{sup −4}, respectively, at B3LYP level for SARC basis set.

  8. The polarized neutron reflectivity and X-ray reflectivity studies of the magnetic profiles of epitaxial Ni80Fe20/Ru multilayers

    Su, H.-C.; Peir, J.-J.; Lee, C.-H.; Lin, M.-Z.; Wu, P.-T.; Huang, J.C.A.; Tun Zin

    2005-01-01

    The depth profiles of the epitaxial Ni 80 Fe 20 (1 1 1)/Ru(0 0 0 1) multilayers were studied by polarized neutron reflectivity and X-ray reflectivity. At the Ru thickness that the anti-ferromagnetic coupling was found, the magnetic moments between two Ni 80 Fe 20 interlayers show a biquadratic coupling effect with a double unit cell at low applied fields. A magnetic dead layer of about 0.3 nm was also found at the interface boundaries. The maximal polarization effect applied to the Ru layer is less than 0.03μ B

  9. New ternary tantalum borides containing boron dumbbells: Experimental and theoretical studies of Ta{sub 2}OsB{sub 2} and TaRuB

    Mbarki, Mohammed; Touzani, Rachid St.; Rehorn, Christian W.G.; Gladisch, Fabian C. [Institute of Inorganic Chemistry, RWTH Aachen University, D-52056 Aachen (Germany); Fokwa, Boniface P.T., E-mail: bfokwa@ucr.edu [Institute of Inorganic Chemistry, RWTH Aachen University, D-52056 Aachen (Germany); Department of Chemistry, University of California Riverside (UCR), Riverside, CA 92521 (United States)

    2016-10-15

    The new ternary transition metal-rich borides Ta{sub 2}OsB{sub 2} and TaRuB have been successfully synthesized by arc-melting the elements in a water-cooled crucible under an argon atmosphere. The crystal structures of both compounds were solved by single-crystal X-ray diffraction and their metal compositions were confirmed by EDX analysis. It was found that Ta{sub 2}OsB{sub 2} and TaRuB crystallize in the tetragonal Nb{sub 2}OsB{sub 2} (space group P4/mnc, no. 128) and the orthorhombic NbRuB (space group Pmma, no. 51) structure types with lattice parameters a=5.878(2) Å, c=6.857(2) Å and a=10.806(2) Å, b=3.196(1) Å, c=6.312(2) Å, respectively. Furthermore, crystallographic, electronic and bonding characteristics have been studied by density functional theory (DFT). Electronic structure relaxation has confirmed the crystallographic parameters while COHP bonding analysis indicates that B{sub 2}-dummbells are the strongest bonds in both compounds. Moreover, the formation of osmium dumbbells in Ta{sub 2}OsB{sub 2} through a Peierls distortion along the c-axis, is found to be the origin of superstructure formation. Magnetic susceptibility measurements reveal that the two phases are Pauli paramagnets, thus confirming the theoretical DOS prediction of metallic character. Also hints of superconductivity are found in the two phases, however lack of single phase samples has prevented confirmation. Furthermore, the thermodynamic stability of the two modifications of AMB (A=Nb, Ta; M =Ru, Os) are studied using DFT, as new possible phases containing either B{sub 4}- or B{sub 2}-units are predicted, the former being the most thermodynamically stable modification. - Graphical abstract: The two new ternary tantalum borides, Ta{sub 2}OsB{sub 2} and TaRuB, have been discovered. Their crystal structures contain boron dumbbells, which are the strongest bonds. Peirls distortion is found responsible for Os{sub 2}-dumbbells formation in Ta{sub 2}OsB{sub 2}. Ta{sub 2}OsB{sub 2} and

  10. Density functional study of electronic, magnetic and hyperfine properties of [M(CN)5 NO]2- (M=Fe, Ru) and reduction products

    Gomez, J.A.; Guenzburger, Diana

    1999-06-01

    The Discrete Variational method (DVM) in density functional theory was employed to investigate the electronic structure of the complexes [Fe(CN) 5 NO] 2- (Nitroprusside), [Fe(CN) 5 NO] 3- , [Fe(CN) 4 NO] 2- , [Ru(CN) 5 NO] 2- and [Ru(CN) 5 NO] 3- . Total energy calculations revealed that in pentacyano nitrosyl ferrate (I) and pentacyano nitrosyl ruthenate (I), which are paramagnetic ions containing one unpaired electron, the M-N-O angle is bent, having values of 152.5 deg and 144 deg, respectively. From self-consistent spin-polarized calculations, the distribution of unpaired electron in the paramagnetic complexes [Fe(CN) 5 NO] 3, [Fe(CN) 4 NO] 2- and [Ru(CN) 5 NO] 3- was obtained as well as spin-density maps. A long-standing controversy regarding the configuration of [Fe(CN) 5 NO] 3- was elucidated, and it was found that the unpaired electron in this complex is in an orbital primarily localized on π * (NO). Moessbauer quadrupole splittings on Fe and Ru were derived from calculations of the electric-field gradients. Magnetic hyperfine coupling constants on No of the NO ligand were also obtained for the paramagnetic complexes. (author)

  11. pH-Dependent isotope exchange and hydrogenation catalysed by water-soluble NiRu complexes as functional models for [NiFe]hydrogenases

    Kure, Bunsho; Matsumoto, Takahiro; Ichikawa, Koji; Fukuzumi, Shunichi; Higuchi, Yoshiki; Yagi, Tatsuhiko; Ogo, Seiji

    2008-01-01

    The pH-dependent hydrogen isotope exchange reaction between gaseous isotopes and medium isotopes and hydrogenation of the carbonyl compounds have been investigated with water-soluble bis(mu-thiolate)(mu-hydride)NiRu complexes, Ni(II)(mu-SR)(2)(mu-H)Ru(II) {(mu-SR)(2) = N,N'-dimethyl-N,N'-bis(2-mercaptoethyl)-1,3-propanediamine}, as functional models for [NiFe]hydrogenases. In acidic media (at pH 4-6), the mu-H ligand of the Ni(II)(mu-SR)(2)(mu-H)Ru(II) complexes has H(+) properties, and the c...

  12. Ionic Liquid Gating Control of RKKY Interaction in FeCoB/Ru/FeCoB and (Pt/Co)2/Ru/(Co/Pt)2 Multilayers.

    Yang, Qu; Wang, Lei; Zhou, Ziyao; Wang, Liqian; Zhang, Yijun; Zhao, Shishun; Dong, Guohua; Cheng, Yuxin; Min, Tai; Hu, Zhongqiang; Chen, Wei; Xia, Ke; Liu, Ming

    2018-03-07

    To overcome the fundamental challenge of the weak natural response of antiferromagnetic materials under a magnetic field, voltage manipulation of antiferromagnetic interaction is developed to realize ultrafast, high-density, and power efficient antiferromagnetic spintronics. Here, we report a low voltage modulation of Ruderman–Kittel–Kasuya–Yosida (RKKY) interaction via ionic liquid gating in synthetic antiferromagnetic multilayers of FeCoB/Ru/FeCoB and (Pt/Co)2/Ru/(Co/Pt)2. At room temperature, the distinct voltage control of transition between antiferromagnetic and ferromagnetic ordering is realized and up to 80% of perpendicular magnetic moments manage to switch with a small-applied voltage bias of 2.5 V. We related this ionic liquid gating-induced RKKY interaction modification to the disturbance of itinerant electrons inside synthetic antiferromagnetic heterostructure and the corresponding change of its Fermi level. Voltage tuning of RKKY interaction may enable the next generation of switchable spintronics between antiferromagnetic and ferromagnetic modes with both fundamental and practical perspectives.

  13. Exploring the Photovoltaic Properties of Metal Bipyridine Complexes (Metal = Fe, Zn, Cr, and Ru) by Density Functional Theory

    Irfan, Ahmad; Abbas, Ghulam

    2018-03-01

    The synthesis and characterisation of mononuclear Fe complexes were carried out by using bipyridine (Compound 1) at ambient conditions. Additionally, three more derivatives were designed by substituting the central Fe metal with Zn, Cr, and Ru (Compound 2, Compound 3, and Compound 4), respectively. The ground state geometry calculations were carried out by using density functional theory (DFT) at B3LYP/6-31G** (LANL2DZ) level of theory. We shed light on the frontier molecular orbitals, electronic properties, photovoltaic parameters, and structure-property relationship. The open-circuit voltage is a promising parameter that considerably affects the photovoltaic performance; thus, we have estimated its value by considering the complexes as donors whereas TiO2 and/or Si were used as acceptors. The solar cell performance behaviour was also studied by shedding light on the band alignment and energy level offset.

  14. In Silico Switch from Second- to First-Row Transition Metals in Olefin Metathesis: From Ru to Fe and from Rh to Co

    Jesús Antonio Luque-Urrutia

    2017-12-01

    Full Text Available Density functional theory (DFT calculations have been used to investigate the behavior of different transition metals from Groups 8 (Fe and Ru and 9 (Co and Rh in an already well-known catalytic mechanism, which is based on an Ru(SIMes(PPh3Cl2=CH(Ph complex. As expected, Ru has proven to perform better than their Fe, Co, and Rh counterparts. Even though the topographic steric maps analysis shows no difference in sterical hindrance for any of the metal centers, geometrically, the Fe-based species show a high rigidity with shorter and stronger bonds confirmed by Mayer Bond Orders. The systems bearing Co as a metallic center might present a reactivity that is, surprisingly, too high according to conceptual DFT, which would consequently be a drawback for the formation of the fundamental species of the reaction pathway: the metallacycle intermediate.

  15. Structural, electronic, magnetic, half-metallic, mechanical, and thermodynamic properties of the quaternary Heusler compound FeCrRuSi: A first-principles study.

    Wang, Xiaotian; Khachai, Houari; Khenata, Rabah; Yuan, Hongkuan; Wang, Liying; Wang, Wenhong; Bouhemadou, Abdelmadjid; Hao, Liyu; Dai, Xuefang; Guo, Ruikang; Liu, Guodong; Cheng, Zhenxiang

    2017-11-23

    In this paper, we have investigated the structural, electronic, magnetic, half-metallic, mechanical, and thermodynamic properties of the equiatomic quaternary Heusler (EQH) compound FeCrRuSi using the density functional theory (DFT) and the quasi-harmonic Debye model. Our results reveal that FeCrRuSi is a half-metallic material (HMM) with a total magnetic moment of 2.0 μ B in agreement with the well-known Slater-Pauling rule M t  = Z t  - 24. Furthermore, the origin of the half-metallic band gap in FeCrRuSi is well studied through a schematic diagram of the possible d-d hybridization between Fe, Cr and Ru elements. The half-metallic behavior of FeCrRuSi can be maintained in a relatively wide range of variations of the lattice constant (5.5-5.8 Å) under uniform strain and the c/a ratio (0.96-1.05) under tetragonal distortion. The calculated phonon dispersion, cohesive and formation energies, and mechanical properties reveal that FeCrRuSi is stable with an EQH structure. Importantly, the compound of interest has been prepared and is found to exist in an EQH type structure with the presence of some B2 disorder. Moreover, the thermodynamic properties, such as the thermal expansion coefficient α, the heat capacity C V , the Grüneisen constant γ, and the Debye temperature Θ D are calculated.

  16. New ternary tantalum borides containing boron dumbbells: Experimental and theoretical studies of Ta2OsB2 and TaRuB

    Mbarki, Mohammed; Touzani, Rachid St.; Rehorn, Christian W. G.; Gladisch, Fabian C.; Fokwa, Boniface P. T.

    2016-10-01

    The new ternary transition metal-rich borides Ta2OsB2 and TaRuB have been successfully synthesized by arc-melting the elements in a water-cooled crucible under an argon atmosphere. The crystal structures of both compounds were solved by single-crystal X-ray diffraction and their metal compositions were confirmed by EDX analysis. It was found that Ta2OsB2 and TaRuB crystallize in the tetragonal Nb2OsB2 (space group P4/mnc, no. 128) and the orthorhombic NbRuB (space group Pmma, no. 51) structure types with lattice parameters a=5.878(2) Å, c=6.857(2) Å and a=10.806(2) Å, b=3.196(1) Å, c=6.312(2) Å, respectively. Furthermore, crystallographic, electronic and bonding characteristics have been studied by density functional theory (DFT). Electronic structure relaxation has confirmed the crystallographic parameters while COHP bonding analysis indicates that B2-dummbells are the strongest bonds in both compounds. Moreover, the formation of osmium dumbbells in Ta2OsB2 through a Peierls distortion along the c-axis, is found to be the origin of superstructure formation. Magnetic susceptibility measurements reveal that the two phases are Pauli paramagnets, thus confirming the theoretical DOS prediction of metallic character. Also hints of superconductivity are found in the two phases, however lack of single phase samples has prevented confirmation. Furthermore, the thermodynamic stability of the two modifications of AMB (A=Nb, Ta; M =Ru, Os) are studied using DFT, as new possible phases containing either B4- or B2-units are predicted, the former being the most thermodynamically stable modification.

  17. Transient field for W ions traversing Fe hosts and for Os ions traversing Fe and Ni hosts

    Stuchbery, A.E.; Bolotin, H.H.; Doran, C.E.

    1987-02-01

    Transient field strengths were measured for 184 W and 186 W ions traversing thin, magnetized Fe foils with velocities in the range 1.8 ≤ v/v>=o ≤ 5.7 (v>=o Bohr velocity) and for 188 Os, 190 Os, 192 Os ions traversing polarized Ni hosts with average velocities =o> ∼ 4. The present measured transient field strengths, together with previously measured results for W, Os ions, are compared with transient-field strength parametrizations, and discussed in terms of microscopic models of the transient field

  18. Platinum-group elements fractionation by selective complexing, the Os, Ir, Ru, Rh-arsenide-sulfide systems above 1020 °C

    Helmy, Hassan M.; Bragagni, Alessandro

    2017-11-01

    The platinum-group element (PGE) contents in magmatic ores and rocks are normally in the low μg/g (even in the ng/g) level, yet they form discrete platinum-group mineral (PGM) phases. IPGE (Os, Ir, Ru) + Rh form alloys, sulfides, and sulfarsenides while Pt and Pd form arsenides, tellurides, bismuthoids and antimonides. We experimentally investigate the behavior of Os, Ru, Ir and Rh in As-bearing sulfide system between 1300 and 1020 °C and show that the prominent mineralogical difference between IPGE (+Rh) and Pt and Pd reflects different chemical preference in the sulfide melt. At temperatures above 1200 °C, Os shows a tendency to form alloys. Ruthenium forms a sulfide (laurite RuS2) while Ir and Rh form sulfarsenides (irarsite IrAsS and hollingworthite RhAsS, respectively). The chemical preference of PGE is selective: IPGE + Rh form metal-metal, metal-S and metal-AsS complexes while Pt and Pd form semimetal complexes. Selective complexing followed by mechanical separation of IPGE (and Rh)-ligand from Pt- and Pd-ligand associations lead to PGE fractionation.

  19. The system Fe-Os-S at 1180°, 1100°and 900°C

    Karup-Møller, Sven; Makovicky, E.

    2002-01-01

    Phase relations in the condensed system Fe-Os-S were investigated by means of dry syntheses from the elements at 1180degrees, 1100degrees and 900degreesC. The Fe-rich sulfide melt dissolves only traces of Os. Fe1-xS dissolves up to 0.7 at.% Os at 1180degreesC; Os solubility decreases to 0.3 at...... partition coefficients for Os. The three-phase association alloy-FeS1-xS-OsS2 involves alloys with less than 1 at.% Fe. The solubility of Fe in OsS2 increases with decreasing temperature and increasing fugacity of sulfur, possibly making analyses of erlichmanite for trace quantities of Fe important....

  20. Complexes superstructurés mixtes Ru/Fe et Ru/Co à ligands polypyridinyles multitopiques : synthèses, caractérisations, propriétés rédox et photorédox.

    Lombard , Jean

    2007-01-01

    This work deals with the synthesis and physico-chemical study of heterobimetallic complexes bearing ruthenium(II)-tris-bipyridine units as photosensitizers covalently linked to a polypyridinic complex unit of iron (II) or cobalt (II), in order to investigate photoinduced electron transfer in such architectures.With bis-bipyridine type ligands, we synthesized a serie of tetranuclear complexes formed by a central complex unit FeII-tris-bipyridine, covalently linked to three RuII-tris-bipyridine...

  1. Synthesis, single-crystal structure refinement and Fe/T site preference in the ternary borides Fe {sub x}T{sub 7-x}B{sub 3} (T = Ru, Rh; 0 < x {<=} 1.5)

    Fokwa, Boniface P.T. [Institut fuer Anorganische Chemie, Rheinisch-Westfaelische Technische Hochschule Aachen, D-52056 Aachen (Germany); Dronskowski, Richard [Institut fuer Anorganische Chemie, Rheinisch-Westfaelische Technische Hochschule Aachen, D-52056 Aachen (Germany)]. E-mail: drons@HAL9000.ac.rwth-aachen.de

    2007-01-31

    Single crystals of the borides Fe {sub x}Rh{sub 7-x}B{sub 3} (1 < x < 1.5) and Fe {sub x}Ru{sub 7-x}B{sub 3} (0 < x < 1) have been synthesized by arc-melting the elements in a water-cooled copper crucible under argon atmosphere. The silver-like products, structurally characterized by single-crystal X-ray analysis, adopt the hexagonal Th{sub 7}Fe{sub 3} structure type (space group P6{sub 3} mc, no. 186) with Z = 2. Their structures consist of layers of boron-centered trigonal prisms of rhodium or ruthenium (Rh;Ru) and iron on the one side, and one-dimensional channels of face-sharing octahedral (Rh;Ru){sub 6} clusters on the other. Unlike in FeRh{sub 6}B{sub 3}, the iron substitution takes place at two (6c and 2b) of the three available rhodium/ruthenium positions, with a preference for the 6c site in the case of the Fe {sub x}Rh{sub 7-x}B{sub 3} compounds but not for Fe {sub x}Ru{sub 7-x}B{sub 3}.

  2. Magnetoresistance Versus Oxygen Deficiency in Epi-stabilized SrRu1 - x Fe x O3 - δ Thin Films.

    Dash, Umasankar; Acharya, Susant Kumar; Lee, Bo Wha; Jung, Chang Uk

    2017-12-01

    Oxygen vacancies have a profound effect on the magnetic, electronic, and transport properties of transition metal oxide materials. Here, we studied the influence of oxygen vacancies on the magnetoresistance (MR) properties of SrRu 1 - x Fe x O 3 - δ epitaxial thin films (x = 0.10, 0.20, and 0.30). For this purpose, we synthesized highly strained epitaxial SrRu 1 - x Fe x O 3 - δ thin films with atomically flat surfaces containing different amounts of oxygen vacancies using pulsed laser deposition. Without an applied magnetic field, the films with x = 0.10 and 0.20 showed a metal-insulator transition, while the x = 0.30 thin film showed insulating behavior over the entire temperature range of 2-300 K. Both Fe doping and the concentration of oxygen vacancies had large effects on the negative MR contributions. For the low Fe doping case of x = 0.10, in which both films exhibited metallic behavior, MR was more prominent in the film with fewer oxygen vacancies or equivalently a more metallic film. For semiconducting films, higher MR was observed for more semiconducting films having more oxygen vacancies. A relatively large negative MR (~36.4%) was observed for the x = 0.30 thin film with a high concentration of oxygen vacancies (δ = 0.12). The obtained results were compared with MR studies for a polycrystal of (Sr 1 - x La x )(Ru 1 - x Fe x )O 3 . These results highlight the crucial role of oxygen stoichiometry in determining the magneto-transport properties in SrRu 1 - x Fe x O 3 - δ thin films.

  3. First-principles study on the structure, elastic properties, hardness and electronic structure of TMB4 (TM=Cr, Re, Ru and Os) compounds

    Pan, Y.; Zheng, W.T.; Guan, W.M.; Zhang, K.H.; Fan, X.F.

    2013-01-01

    The structural formation, elastic properties, hardness and electronic structure of TMB 4 (TM=Cr, Re, Ru and Os) compounds are investigated using first-principles approach. The value of C 22 for these compounds is almost two times bigger than the C 11 and C 33 . The intrinsic hardness, shear modulus and Young's modulus are calculated to be in a sequence of CrB 4 >ReB 4 >RuB 4 >OsB 4 , and the Poisson's ratio and B/G ratio of TMB 4 follow the order of CrB 4 4 4 4 . The intrinsic hardness of CrB 4 and ReB 4 by LDA is bigger than 40 GPa. The high hardness of TMB 4 compounds is derived from the feature of B–B bonds cage and higher C 22 value. The B–B covalent bonds as bonds cage enhances the resistance to shear deformation and improve the hardness. We predict that the TMB 4 compounds with CrB 4 -type are the potential superhard materials. - Graphical abstract: The first-principles calculations show that the intrinsic hardness of CrB 4 and ReB 4 are bigger than 40 GPa, which are the potential superhard materials due to the B–B bonds cage structure. Display Omitted - Highlights: • The intrinsic hardness of CrB 4 and ReB 4 is bigger than 40 GPa. • The hardness of TMB 4 is calculated to be in a sequence of CrB 4 >ReB 4 >RuB 4 >OsB 4 . • The trend of hardness for TMB 4 is consistent with the variation of elastic modulus. • The C 22 value of TMB 4 is bigger than that of C 11 and C 33 . • The high hardness of TMB 4 is originated from the B–B bonds cage

  4. Comparative Study of Electronic Structure and Magnetic Properties of Osmate Double Perovskites: Ca2FeOsO6 versus Ca2Co(Ni)OsO6

    Samanta, Kartik; Saha-Dasgupta, Tanusri

    2018-04-01

    Employing density functional theory, we study the trend in the electronic and magnetic properties of 3d-5d double perovskites, upon varying the 3d element for a fixed choice of 5d element, namely Ca2BOsO6 (B = Fe/Co/Ni). While all three compounds are reported to be ferrimagnets, the magnetic transition temperature of Ca2FeOsO6 is reported to be 2-2.4 times larger than that of Ca2CoOsO6 or Ca2NiOsO6. Our first-principles study provides microscopic insight into this trend. This trend is found to be caused by the downward shift in the position of d level energies of the B site element with respect to that of the Os t2g level upon moving across the 3d series from Fe to Co and Ni. This in turn changes the nominal valence of the Os ion from 5+ in Ca2FeOsO6 to 6+ in Ca2CoOsO6 and Ca2NiOsO6, resulting in differing superexchange paths between Ca2FeOsO6 and Ca2Co(Ni)OsO6, and additionally enabling the hybridization-mechanism-driven magnetism in Ca2FeOsO6. These together significantly enhance the magnetic transition temperature in Ca2FeOsO6 compared with that in Ca2Co(Ni)OsO6.

  5. Lattice dynamical and thermodynamical properties of ReB2, RuB2, and OsB2 compounds in the ReB2 structure

    Deligoz, E.; Colakoglu, K.; Ciftci, Y. O.

    2012-01-01

    Structural and lattice dynamical properties of ReB 2 , RuB 2 , and OsB 2 in the ReB 2 structure are studied in the framework of density functional theory within the generalized gradient approximation. The present results show that these compounds are dynamically stable for the considered structure. The temperature-dependent behaviors of thermodynamical properties such as internal energy, free energy, entropy, and heat capacity are also presented. The obtained results are in good agreement with the available experimental and theoretical data

  6. First-principles study on the structure, elastic properties, hardness and electronic structure of TMB{sub 4} (TM=Cr, Re, Ru and Os) compounds

    Pan, Y. [Department of Materials Science, Key Laboratory of Automobile Materials of MOE and State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012 (China); Zheng, W.T., E-mail: WTZheng@jlu.edu.cn [Department of Materials Science, Key Laboratory of Automobile Materials of MOE and State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012 (China); Guan, W.M.; Zhang, K.H. [State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals, Kunming 650106 (China); Fan, X.F. [Department of Materials Science, Key Laboratory of Automobile Materials of MOE and State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012 (China)

    2013-11-15

    The structural formation, elastic properties, hardness and electronic structure of TMB{sub 4} (TM=Cr, Re, Ru and Os) compounds are investigated using first-principles approach. The value of C{sub 22} for these compounds is almost two times bigger than the C{sub 11} and C{sub 33}. The intrinsic hardness, shear modulus and Young's modulus are calculated to be in a sequence of CrB{sub 4}>ReB{sub 4}>RuB{sub 4}>OsB{sub 4}, and the Poisson's ratio and B/G ratio of TMB{sub 4} follow the order of CrB{sub 4}RuB{sub 4}<OsB{sub 4}. The intrinsic hardness of CrB{sub 4} and ReB{sub 4} by LDA is bigger than 40 GPa. The high hardness of TMB{sub 4} compounds is derived from the feature of B–B bonds cage and higher C{sub 22} value. The B–B covalent bonds as bonds cage enhances the resistance to shear deformation and improve the hardness. We predict that the TMB{sub 4} compounds with CrB{sub 4}-type are the potential superhard materials. - Graphical abstract: The first-principles calculations show that the intrinsic hardness of CrB{sub 4} and ReB{sub 4} are bigger than 40 GPa, which are the potential superhard materials due to the B–B bonds cage structure. Display Omitted - Highlights: • The intrinsic hardness of CrB{sub 4} and ReB{sub 4} is bigger than 40 GPa. • The hardness of TMB{sub 4} is calculated to be in a sequence of CrB{sub 4}>ReB{sub 4}>RuB{sub 4}>OsB{sub 4}. • The trend of hardness for TMB{sub 4} is consistent with the variation of elastic modulus. • The C{sub 22} value of TMB{sub 4} is bigger than that of C{sub 11} and C{sub 33}. • The high hardness of TMB{sub 4} is originated from the B–B bonds cage.

  7. pH-Dependent isotope exchange and hydrogenation catalysed by water-soluble NiRu complexes as functional models for [NiFe]hydrogenases.

    Kure, Bunsho; Matsumoto, Takahiro; Ichikawa, Koji; Fukuzumi, Shunichi; Higuchi, Yoshiki; Yagi, Tatsuhiko; Ogo, Seiji

    2008-09-21

    The pH-dependent hydrogen isotope exchange reaction between gaseous isotopes and medium isotopes and hydrogenation of the carbonyl compounds have been investigated with water-soluble bis(mu-thiolate)(mu-hydride)NiRu complexes, Ni(II)(mu-SR)(2)(mu-H)Ru(II) {(mu-SR)(2) = N,N'-dimethyl-N,N'-bis(2-mercaptoethyl)-1,3-propanediamine}, as functional models for [NiFe]hydrogenases. In acidic media (at pH 4-6), the mu-H ligand of the Ni(II)(mu-SR)(2)(mu-H)Ru(II) complexes has H(+) properties, and the complexes catalyse the hydrogen isotope exchange reaction between gaseous isotopes and medium isotopes. A mechanism of the hydrogen isotope exchange reaction between gaseous isotopes and medium isotopes through a low-valent Ni(I)(mu-SR)(2)Ru(I) complex is proposed. In contrast, in neutral-basic media (at pH 7-10), the mu-H ligand of the Ni(II)(mu-SR)(2)(mu-H)Ru(II) complexes acts as H(-), and the complexes catalyse the hydrogenation of carbonyl compounds.

  8. Perovskites with noble metals of type Ba/sub 3/BM/sub 2/O/sub 9/; B = Mg, Fe, Co, Ni, Zn, Cd; M = Ru, Ir

    Treiber, U; Kemmler-Sack, S; Ehmann, A [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

    1982-04-01

    The perovskites Ba/sub 3/BM/sub 2/O/sub 9/ crystallize in a hexagonal BaTiO/sub 3/ structure and could be prepared for M = Ru; B = Mg, Fe, Co, Ni, Zn, Cd and M = Ir; B = Co, Ni. According to intensity calculations on powder data of Ba/sub 3/MgRu/sub 2/O/sub 9/ and Ba/sub 3/NiIr/sub 2/O/sub 9/ (refined intensity related R' value 6.7% (Ba/sub 3/MgRu/sub 2/O/sub 9/) and 6.9% (Ba/sub 3/NiIr/sub 2/O/sub 9/)) an 1:2 order is present and both lattices contain face connected M/sub 2/O/sub 9/ double octahedra linked by another via common corners through BO/sub 6/ single octahedra. The occurrence of this typ of cationic order results for B = Mg, Co, Ni, Zn, Cd from the analysis of the vibrational spectra. For B = Mg, Zn, Cd and presumable with B = Ni the charge distribution is B/sup 2 +// 2 M/sup 5 +/; for B = Co deviation can not be excluded. On the opposite in Ba/sub 3/FeRu/sub 2/O/sub 9/ an electron delocalisation is present.

  9. Carbometalates. Intermediate phases in the ternary systems RE-T-C (RE = Y, La, Gd-Er; T = Cr, Fe, Ru)

    Davaasuren, Bambar

    2010-07-01

    The main motivation of this work was the preparation and characterization of novel compounds in the ternary systems RE-T-C with T = Cr, Fe and Ru with a special focus on compounds containing C{sub 2}{sup n-} and C{sub 3}{sup m-} or mixed C and C{sub 2}{sup n-} as structural units. This would allow to investigate the applicability of the concept of complex anions to this class of materials.

  10. Study on oxidization of Ru and its application as electrode of PZT capacitor for FeRAM

    Jia Ze; Ren Tianling; Liu Tianzhi; Hu Hong; Zhang Zhigang; Xie Dan; Liu Litian

    2007-01-01

    Oxidization for Ru through anneal with plenteous oxygen atmosphere and its application as the top electrode of sol-gel PZT capacitor are investigated in this study. PZT capacitor with RuO 2 or oxygen-doped Ru as top electrode can be obtained from Ru/PZT/Pt capacitor through slow-rate anneal at 650 deg. C for 20 min in cannulation furnace. It has larger remanent polarization, better rectangle shape, better fatigue properties and lower leakage current than the other capacitors with PZT film prepared by the same process and different top electrodes in this study. Plenteous oxygen atmosphere and 650 deg. C in cannulation furnace are important conditions for the oxidation of Ru and renewed crystallization of PZT in this capacitor. Plenteous oxygen at interface can compensate the oxygen vacancies at PZT/electrode interface, which results in the above good characteristics

  11. Investigation of energy band alignments and interfacial properties of rutile NMO2/TiO2 (NM = Ru, Rh, Os, and Ir) by first-principles calculations.

    Yang, Chen; Zhao, Zong-Yan

    2017-11-08

    In the field of photocatalysis, constructing hetero-structures is an efficient strategy to improve quantum efficiency. However, a lattice mismatch often induces unfavorable interfacial states that can act as recombination centers for photo-generated electron-hole pairs. If the hetero-structure's components have the same crystal structure, this disadvantage can be easily avoided. Conversely, in the process of loading a noble metal co-catalyst onto the TiO 2 surface, a transition layer of noble metal oxides is often formed between the TiO 2 layer and the noble metal layer. In this article, interfacial properties of hetero-structures composed of a noble metal dioxide and TiO 2 with a rutile crystal structure have been systematically investigated using first-principles calculations. In particular, the Schottky barrier height, band bending, and energy band alignments are studied to provide evidence for practical applications. In all cases, no interfacial states exist in the forbidden band of TiO 2 , and the interfacial formation energy is very small. A strong internal electric field generated by interfacial electron transfer leads to an efficient separation of photo-generated carriers and band bending. Because of the differences in the atomic properties of the components, RuO 2 /TiO 2 and OsO 2 /TiO 2 hetero-structures demonstrate band dividing, while RhO 2 /TiO 2 and IrO 2 /TiO 2 hetero-structures have a pseudo-gap near the Fermi energy level. Furthermore, NMO 2 /TiO 2 hetero-structures show upward band bending. Conversely, RuO 2 /TiO 2 and OsO 2 /TiO 2 hetero-structures present a relatively strong infrared light absorption, while RhO 2 /TiO 2 and IrO 2 /TiO 2 hetero-structures show an obvious absorption edge in the visible light region. Overall, considering all aspects of their properties, RuO 2 /TiO 2 and OsO 2 /TiO 2 hetero-structures are more suitable than others for improving the photocatalytic performance of TiO 2 . These findings will provide useful information

  12. Quaternary Pt{sub 2}Ru{sub 1}Fe{sub 1}M{sub 1}/C (M=Ni, Mo, or W) catalysts for methanol electro-oxidation reaction

    Jeon, Min Ku; Lee, Ki Rak; Kang, Kweon Ho; Park, Geun Il [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Jeon, Hyung Joon [Kyoto University, Kyoto (Japan); McGinn, Paul J. [University of Notre Dame, Indiana (United States)

    2015-02-15

    Quaternary Pt{sub 2}Ru{sub 1}Fe{sub 1}M{sub 1}/C (M=Ni, Mo, or W) catalysts were investigated for the methanol electro-oxidation reaction (MOR). Electrocatalytic activities of the quaternary catalysts for CO electro-oxidation were studied via CO stripping experiments, and the Pt{sub 2}Ru{sub 1}Fe{sub 1}Ni{sub 1}/C and Pt{sub 2}Ru{sub 1}Fe{sub 1}W{sub 1}/C catalysts exhibited lowered on-set potential compared to that of a commercial PtRu/C catalyst. MOR activities of the quaternary catalysts were determined by linear sweep voltammetry (LSV) experiments, and the Pt{sub 2}Ru{sub 1}Fe{sub 1}W{sub 1}/C catalyst outperformed the commercial PtRu/C catalyst by 170 and 150% for the mass and specific activities, respectively. X-ray photoelectron spectroscopy (XPS) was employed to analyze surface oxidation states of constituent atoms, and it was identified that the structure of the synthesized catalysts are close to a nano-composite of Pt and constituent metal hydroxides and oxides. In addition, the XPS results suggested that the bi-functional mechanism accounts for the improved performance of the Pt{sub 2}Ru{sub 1}Fe{sub 1}Ni{sub 1}/C and Pt{sub 2}Ru{sub 1} Fe{sub 1}W{sub 1}/C catalysts.

  13. DFT calculations of the structures and vibrational spectra of the [Fe(bpy){sub 3}]{sup 2+} and [Ru(bpy){sub 3}]{sup 2+} complexes

    Alexander, Bruce D. [School of Science, University of Greenwich at Medway, Central Avenue, Chatham Maritime, Kent ME4 4TB (United Kingdom); Dines, Trevor J. [Division of Electronic Engineering and Physics, University of Dundee, Dundee DD1 4HN (United Kingdom)], E-mail: t.j.dines@dundee.ac.uk; Longhurst, Rayne W. [Division of Electronic Engineering and Physics, University of Dundee, Dundee DD1 4HN (United Kingdom)

    2008-09-03

    Structures of the [M(bpy){sub 3}]{sup 2+} complexes (M = Fe and Ru) have been calculated at the B3-LYP/DZVP level. IR and Raman spectra were calculated using the optimised geometries, employing a scaled quantum chemical force field, and compared with an earlier normal coordinate analysis of [Ru(bpy){sub 3}]{sup 2+} which was based upon experimental data alone, and the use of a simplified model. The results of the calculations provide a highly satisfactory fit to the experimental data and the normal coordinate analyses, in terms of potential energy distributions, allow a detailed understanding of the vibrational spectra of both complexes. Evidence is presented for Jahn-Teller distortion in the {sup 1}E MLCT excited state.

  14. DFT calculations of the structures and vibrational spectra of the [Fe(bpy)3]2+ and [Ru(bpy)3]2+ complexes

    Alexander, Bruce D.; Dines, Trevor J.; Longhurst, Rayne W.

    2008-01-01

    Structures of the [M(bpy) 3 ] 2+ complexes (M = Fe and Ru) have been calculated at the B3-LYP/DZVP level. IR and Raman spectra were calculated using the optimised geometries, employing a scaled quantum chemical force field, and compared with an earlier normal coordinate analysis of [Ru(bpy) 3 ] 2+ which was based upon experimental data alone, and the use of a simplified model. The results of the calculations provide a highly satisfactory fit to the experimental data and the normal coordinate analyses, in terms of potential energy distributions, allow a detailed understanding of the vibrational spectra of both complexes. Evidence is presented for Jahn-Teller distortion in the 1 E MLCT excited state

  15. DFT calculations of the structures and vibrational spectra of the [Fe(bpy) 3] 2+ and [Ru(bpy) 3] 2+ complexes

    Alexander, Bruce D.; Dines, Trevor J.; Longhurst, Rayne W.

    2008-09-01

    Structures of the [M(bpy) 3] 2+ complexes (M = Fe and Ru) have been calculated at the B3-LYP/DZVP level. IR and Raman spectra were calculated using the optimised geometries, employing a scaled quantum chemical force field, and compared with an earlier normal coordinate analysis of [Ru(bpy) 3] 2+ which was based upon experimental data alone, and the use of a simplified model. The results of the calculations provide a highly satisfactory fit to the experimental data and the normal coordinate analyses, in terms of potential energy distributions, allow a detailed understanding of the vibrational spectra of both complexes. Evidence is presented for Jahn-Teller distortion in the 1E MLCT excited state.

  16. Zeolite-Y entrapped Ru(III and Fe(III complexes as heterogeneous catalysts for catalytic oxidation of cyclohexane reaction

    Chetan K. Modi

    2017-02-01

    Full Text Available Catalysis is probably one of the greatest contributions of chemistry to both economic growth and environmental protection. Herein we report the catalytic behavior of zeolite-Y entrapped Ru(III and Fe(III complexes with general formulae [M(VTCH2·2H2O]+-Y and [M(VFCH2·2H2O]+-Y [where, VTCH = vanillin thiophene-2-carboxylic hydrazone and VFCH = vanillin furoic-2-carboxylic hydrazone] over the oxidation of cyclohexane forming cyclohexanone and cyclohexanol. The samples were corroborated by various physico-chemical techniques. These zeolite-Y based complexes are stable and recyclable under current reaction conditions. Amongst them, [Ru(VTCH2⋅2H2O]+-Y showed higher catalytic activity (41.1% with cyclohexanone (84.6% selectivity.

  17. Systematic measurements of transient fields for W, Os and Pt ions traversing Fe

    Stuchbery, A.E.; Heseltine, T.H.; Anderssen, S.S.; Bolotin, H.H.; Byrne, A.P.; Fabricius, B.; Kibedi, T.

    1994-01-01

    Transient magnetic fields were measured for W, Os and Pt ions traversing iron hosts with average velocities in the range from approximately 1.6 v 0 to 4.8 v 0 (v 0 = c/137, Bohr velocity). Transient fields for W and Os in Fe are consistent with behaviour found for lighter rare-earth ions and are about 20% stronger than those for Pt in Fe over the majority of the velocity range examined. A measurement was made to confirm that possible heavy-ion beam induced attenuations of the transient field are negligible for low-velocity Pt ions excited by Ni beams. Results are discussed in terms of both empirical and model-based parameterizations of the transient field strength. (orig.)

  18. Highly textured Sr, Nb co-doped BiFeO3 thin films grown on SrRuO3/Si substrates by rf- sputtering

    Ostos, C.; Raymond, O.; Siqueiros, J. M.; Suarez-Almodovar, N.; Bueno-Baques, D.; Mestres, L.

    2011-01-01

    In this study, (011)-highly oriented Sr, Nb co-doped BiFeO 3 (BFO) thin films were successfully grown on SrRuO 3 /Si substrates by rf-magnetron sputtering. The presence of parasite magnetic phases was ruled out based on the high resolution x-ray diffraction data. BFO films exhibited a columnar-like grain growth with rms surface roughness values of ≅5.3 nm and average grain sizes of ≅65-70 nm for samples with different thicknesses. Remanent polarization values (2P r ) of 54 μC cm -2 at room temperature were found for the BFO films with a ferroelectric behavior characteristic of an asymmetric device structure. Analysis of the leakage mechanisms for this structure in negative bias suggests Schottky injection and a dominant Poole-Frenkel trap-limited conduction at room temperature. Oxygen vacancies and Fe 3+ /Fe 2+ trap centers are consistent with the surface chemical bonding states analysis from x-ray photoelectron spectroscopy data. The (011)-BFO/SrRuO 3 /Si film structure exhibits a strong magnetic interaction at the interface between the multiferroic film and the substrate layer where an enhanced ferromagnetic response at 5 K was observed. Zero-field cooled (ZFC) and field cooled (FC) magnetization curves of this film system revealed a possible spin glass behavior at spin freezing temperatures below 30 K depending on the BFO film thickness.

  19. Chiral analysis of alpha-diimine Ru(II) and Fe(II) complexes by capillary electrophoresis using sulfated cyclodextrins as stereoselectors

    Sázelová, Petra; Koval, Dušan; Severa, Lukáš; Teplý, Filip; Kašička, Václav

    2017-01-01

    Roč. 38, č. 15 (2017), s. 1913-1921 ISSN 0173-0835 R&D Projects: GA ČR(CZ) GA15-01948S; GA ČR GA13-32974S; GA ČR GA13-19213S Institutional support: RVO:61388963 Keywords : binding constant * capillary electrophoresis * chiral separation * polypyridyl Fe(II) complex * polypyridyl Ru(II) complex Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 2.744, year: 2016

  20. Peierls-distorted Ru-chains and boron dumbbells in Nb{sub 2}RuB{sub 2} and Ta{sub 2}RuB{sub 2} from first-principles calculations and experiments

    Touzani, Rachid S.; Mbarki, Mohammed; Chen, Ximeng [Institute of Inorganic Chemistry, RWTH Aachen University (Germany); Fokwa, Boniface P.T. [Institute of Inorganic Chemistry, RWTH Aachen University (Germany); Department of Chemistry, University of California Riverside (UCR), Riverside, CA (United States)

    2016-09-15

    Nb{sub 2}RuB{sub 2} and Ta{sub 2}RuB{sub 2} phases were recently predicted by GGA-VASP structure optimization to crystallize in the Nb{sub 2}OsB{sub 2}-type structure. Although the Fe-based (Mo{sub 2}FeB{sub 2} type) and Os-based (Nb{sub 2}OsB{sub 2} type, superstructure variant of Mo{sub 2}FeB{sub 2} type) analogues have been synthesized and characterized successfully, the Ru-based phases remained unknown. Crystal structure prediction of Nb{sub 2}RuB{sub 2} and Ta{sub 2}RuB{sub 2} phases, using an evolutionary algorithm, led to the AlMn{sub 2}B{sub 2}-type structure in contrast to the aforementioned optimization; however, phonon calculations showed that the Nb{sub 2}OsB{sub 2}-type phases are dynamically more stable than the AlMn{sub 2}B{sub 2}-type phases. A slightly modified synthetic strategy finally led to the successful preparation of the predicted phases. The extremely quick arc-melting procedure, under argon atmosphere, not only led to a quantitative amount of the phases but also to single crystals suitable for structure determination. Powder and single-crystal X-ray diffraction as well as EDX analysis of the metal ratio have confirmed the GGA-VASP structure optimization: Nb{sub 2}RuB{sub 2} and Ta{sub 2}RuB{sub 2} compounds indeed crystallize isotypically with Nb{sub 2}OsB{sub 2} structure, a superstructure variant of Mo{sub 2}FeB{sub 2} type, in which B-dumbbells and Peierls-distorted Ru-chains are found. Susceptibility measurements on a Ta{sub 2}RuB{sub 2} single crystal reveal no superconducting transition down to 2 K, even though some features in the band structures of both phases, similar to those reported in superconducting NbRuB, hinted at possible superconductivity. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  1. A DFT study of Ru, Rh, Pd, Os, Ir, and Pt clusters as catalysts for methane dissociation in a direct methane fuel cell (DMHFC)

    Psofogiannakisa, G. [Ottawa Univ., Ottawa, ON (Canada). Dept. of Chemical Engineering; Ottawa, Univ., Ottawa, ON (Canada). Centre for Catalysis Research and Innovation; St-Amant, A. [Ottawa Univ., Ottawa, ON (Canada). Dept. of Chemistry; Ternan, M. [Ottawa Univ., Ottawa, ON (Canada). Centre for Catalysis Research and Innovation; EnPross Inc., Ottawa, ON (Canada)

    2008-07-01

    The rate limiting step in a direct methane hydrocarbon fuel cell (DMHFC) is the dissociative chemisorption of methane. Quantum mechanical computations were used to examine the terrace, kink, and step sites on 6 different clusters of group 8 transition metals, notably Ru, Rh, Pd, Os, Ir, and Pt. The computations involved the anodic reaction of a DMHFC with a polymer electrolyte that operates at atmospheric pressure and temperatures higher than 120 degrees C. The interaction between molecular fragments and a surface (Pt) were described and density functional theory (DFT) calculations were performed using Guassian software. The geometries of 5 different platinum clusters were examined along with their electronic energy barriers. The biggest contribution to the stabilization energy came from the overlap between the sigma bond in methane and unoccupied sd hybrid orbitals in the Pt bonding atom. The study showed that when relaxation was allowed, the displacement of the bonding metal atom was 0.36 to 0.52 A. The electronic energy barrier often increased as d-orbital occupancy increased. For the kink surface sites, the energy barriers were considerably smaller for the 5d transition metals than for the 4d transition metals. 5 refs., 1 tab.

  2. Anti-Inflammatory Oxicams as Multi-donor Ligand Systems: pH- and Solvent-Dependent Coordination Modes of Meloxicam and Piroxicam to Ru and Os.

    Aman, Farhana; Hanif, Muhammad; Kubanik, Mario; Ashraf, Adnan; Söhnel, Tilo; Jamieson, Stephen M F; Siddiqui, Waseeq Ahmad; Hartinger, Christian G

    2017-04-06

    The nitrogen- and sulfur-containing 1,2-benzothiazines meloxicam and piroxicam are widely used as nonsteroidal anti-inflammatory drugs. Intrigued by the presence of multiple donor atoms and therefore potentially rich coordination chemistry, we prepared a series of organometallic Ru and Os compounds with meloxicam and piroxicam featuring either as mono- or bidentate ligand systems. The choice of the solvent and the pH value was identified as the critical parameter to achieve selectively mono- or bidentate coordination. The coordination modes were confirmed experimentally by NMR spectroscopy and single crystal X-ray diffraction analysis. Using DFT calculations, it was established that complexes in which meloxicam acts as a bidentate N,O donor are energetically more favorable than coordination as O,O and S,O donor systems. Since meloxicam and piroxicam derivatives have shown anticancer activity in the past, we aimed to compare the complexes with mono- and bidentate ligands on their in vitro anticancer activity. However, stability studies revealed that only the latter complexes were stable in [D 6 ]DMSO/D 2 O (5:95) and therefore no direct comparisons could be made. The meloxicam complexes 1 and 2 showed moderate cytotoxicity, whereas the piroxicam derivatives 5 and 6 were hardly active against the utilized cell lines. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. NMR and NQR study of the electronic and structural properties of Al-Cu-Fe and Al-Cu-Ru quasicrystals

    Shastri, A.; Borsa, F.; Torgeson, D.R.; Shield, J.E.; Goldman, A.I.

    1994-01-01

    27 Al and 63,65 Cu NMR is reported for powdered stable Al-Cu-Fe and Al-Cu-Ru icosahedral quasicrystals and crystalline approximants, and for an Al-Pd-Mn single-grain quasicrystal. 27 Al NQR spectra at 4.2 K were observed in Al-Cu-Fe and Al-Cu-Ru samples. From quadrupole-perturbed NMR spectra at different magnetic fields, and from zero-field NQR spectra, a wide distribution of local electric-field gradient (EFG) tensor components and principal-axis-system orientations was found at the Al site. A model EFG calculation based on a 1/1 Al-Cu-Fe approximant successfully explained the observed NQR spectra. The average local gradient is largely determined by the p-electron wave function at the Al site, while the width of the distribution is due to EFG lattice contribution. Comparison of 63 Cu and 27 Al NMR shows the EFG distribution at the two sites is similar, but the electronic contribution to the EFG is considerably smaller at the Cu site, in agreement with a more s-type wave function of the conduction electrons. Overall spread of EFG values is well reproduced by calculation based on the approximant. However, the experimental spectra indicate a much larger number of nonequivalent sites when compared with the simulated NQR spectra based on the 1/1 approximant. The short-range, local chemical order is well represented by the approximant, but differences in coordination must be included at intermediate range in the quasicrystal. Measured 27 Al Knight shift, magnetic susceptibility, and nuclear spin-lattice relaxation time as a function of temperature indicate reduced density of states at the Fermi level by a factor of 7 or 8 from the value in Al metal, consistent with the notion of a pseudogap for these quasicrystals. No differences in measured parameters were detected as a function of composition of the quasicrystalline alloys

  4. Removal of radioactive material by so-called manganese-zeolite. [Mn-54, Fe-59, Co-60, Cs-137, Ru-complexes

    Matsumura, T; Ishiyama, T [Radiation Center of Osaka Prefecture, Sakai (Japan)

    1975-03-01

    Decontamination property of the so-called manganese-zeolite which was made from montmorillonite was studied by a column method. The following results were obtained: (1) /sup 54/Mn or /sup 59/Fe is removed completely. (2) /sup 60/Co or /sup 137/Cs is removed effectively. It is attributed to the adsorption on a broken-bond of quartz or feldsper. (3) Nitro nitrosylruthenium and (RuORu) nitrate are hardly removed, however, a little amount of nitrato nitrosylruthenium is removed. (4) Contact time of radioactive material with manganese-zeolite is the important factor for the removal of radioactive material. Each radioactive material was hardly removed at the contact time less than 20 min.

  5. Magnetic and electronic properties of La3 M O7 and possible polaron formation in hole-doped La3 M O7 (M   =  Ru and Os)

    Gao, Bin; Weng, Yakui; Zhang, Jun-Jie; Zhang, Huimin; Zhang, Yang; Dong, Shuai

    2017-01-01

    Oxides with 4 d /5 d transition metal ions are physically interesting for their particular crystalline structures as well as the spin–orbit coupled electronic structures. Recent experiments revealed a series of 4 d /5 d transition metal oxides R 3 M O 7 (R : rare earth; M : 4 d /5 d transition metal) with unique quasi-one-dimensional M chains. Here first-principles calculations have been performed to study the electronic structures of La 3 OsO 7 and La 3 RuO 7 . Our study confirm both of them to be Mott insulating antiferromagnets with identical magnetic order. The reduced magnetic moments, which are much smaller than the expected value for ideal high-spin state (3 t 2g orbitals occupied), are attributed to the strong p   −   d hybridization with oxygen ions, instead of the spin–orbit coupling. The Ca-doping to La 3 OsO 7 and La 3 RuO 7 can not only modulate the nominal carrier density but also affect the orbital order as well as the local distortions. The Coulombic attraction and particular orbital order would prefer to form polarons, which might explain the puzzling insulating behavior of doped 5 d transition metal oxides. In addition, our calculations predict that the Ca-doping can trigger ferromagnetism in La 3 RuO 7 but not in La 3 OsO 7 . (paper)

  6. Tunnel magnetoresistance of an as-deposited Co2FeAl0.5Si0.5-based magnetic tunnel junction on a Ta/Ru buffer layer

    Hwang, Jae Youn; Lee, Gae Hun; Song, Yun Heub; Yim, Hae In

    2010-01-01

    A magnetic tunnel junction (MTJ) with a Co 2 FeAl 0.5 Si 0.5 (CFAS) heusler film on a conductive Ta/Ru buffer layer was fabricated for the first time. In the as-deposited state, a highly B2-ordered CFAS film was obtained by using the Ta/Ru buffer layer. The Ta (110) buffer layer causes a Ru (002) buffer layer, which leads to the growth of CFAS with a B2 structure and a completely flat CFAS film. After 600 .deg. C annealing, strain relaxation occurred in the Ta/Ru interface, and the surface roughness decreased; however, the B2-ordered CFAS film remained. Also, in the as-deposited state, a exchange-biased CFAS/AlO x /CFAS MTJ deposited on a Ta/Ru buffer layer exhibited a relatively high tunnel magnetoresistance (TMR) of 13% at room temperature, which resulted from the highly B2-ordered CFAS layer and the perfectly flat surface roughness resulting from the use of the Ta/Ru buffer layer.

  7. Magnetic properties of RT2Zn20; R = rare earth, T = Fe, Co, Ru, Rh, Os and Ir

    Jia, Shuang

    2008-01-01

    It is well known that rare earth intermetallic compounds have versatile, magnetic properties associated with the 4f electrons: a local moment associated with the Hund's rule ground state is formed in general, but a strongly correlated, hybridized state may also appear for specific 4f electronic configuration (eg. for rare earth elements such as Ce or Yb). On the other hand, the conduction electrons in rare earth intermetallic compounds, certainly ones associated with non hybridizing rare earths, usually manifest non-magnetic behavior and can be treated as a normal, non-interacted Fermi liquid, except for some 3d-transition metal rich binary or ternary systems which often manifest strong, itinerant, d electron dominant magnetic behavior. Of particular interest are examples in which the band filling of the conduction electrons puts the system in the vicinity of a Stoner transition: such systems, characterized as nearly or weakly ferromagnet, manifest strongly correlated electronic properties (Moriya, 1985). For rare earth intermetallic compounds, such systems provide an additional versatility and allow for the study of the behaviors of local moments and hybridized moments which are associated with 4f electron in a correlated conduction electron background.

  8. Control of oxygen octahedral rotation in BiFeO3 films using modulation of SrRuO3 bottom electrode layer

    Lee, Sungsu; Jo, Ji Young

    2015-03-01

    Oxygen octahedral rotation of multiferroic BiFeO3 (BFO) has attracted great attention due to changes of electrical and magnetic properties. Coupling of octahedral rotation in BFO-bottom electrode layer interface remains unexplored. Recently, there have been reported the control of octahedral rotation in SrRuO3 (SRO) film on SrTiO3 (001) substrate by coherently controlling the oxygen pressure during growth and interfacial coupling. Here we demonstrate that the octahedral rotation of BFO film is changed using tetragonal a0a0c- tilted-SRO bottom electrodes. In this work, BFO/SRO heterostructure is fabricated to SrTiO3 (001) single crystal substrates by pulsed laser deposition at different oxygen partial pressures. The rotation pattern of FeO6 and the structural symmetry are identified from half-integer reflections using high-resolution X-ray diffraction. The effects depending on octahedral tilting of BFO films on the magnetic and ferroelectric properties will be presented.

  9. Metal induced B-Y activation in semisandwich Cp*Rh-, Cp*Ir-, (p-cumene)Ru-, and (p-cumene)Os complexes containing 1,2-dicarba-closo-dodecaborane(12)-1,2-dichalcogenide ligand

    Bernd Vrakmejer; Khong Yan; Vol'fgang Milius; Maks Kherberkhol'd

    2001-01-01

    Reactivity of 16e-semisandwich Cp*M[E 2 C 2 (B 10 H 10 )] and (p-cumene) M' [S 2 C 2 (B 10 H 10 )] complexes (Cp = cyclopentadienyl-ion; M = Rh, Ir; M' Ru, Os; E = S, Se) towards various alkynes was studied using data of NMR and X-ray diffraction analyses of intermediate and final products of the reactions. It is shown that the reactions initiate from introduction of alkyne molecule in one of metal-E bonds, then intramolecular metal-induced B-H activation occurs along with metal-B bond formation, followed by simultaneous hydrogen atom transfer from boron atom through metal atom to alkyne [ru

  10. Synthesis and Electronic Structure of Dissymmetrical, Naphthalene-Bridged Sandwich Complexes [Cp ' Fe(mu-C10H8)MCp*](x) (x=0,+1; M = Fe, Ru; Cp ' = eta(5)-C5H2-1,2,4-tBu(3); Cp* = eta(5)-C5Me5)

    Malberg, J.; Lupton, E.; Schnöckelborg, E.M.; de Bruin, B.; de Sutter, J.; Meyer, K.; Hartl, F.; Wolf, R.

    2013-01-01

    The dissymmetrical naphthalene-bridged complexes [Cp'Fe(mu-C10H8)FeCp*] (3; Cp* = eta(5)-C5Me5, Cp' = eta(5)-C5H2-1,2,4-tBu(3)) and [Cp'Fe(mu-C10H8)RuCp*] (4) were synthesized via a one-pot procedure from FeCl2(thf)(1.5), Cp'K, KC10H8, and [Cp*FeCl(tmeda)] (tmeda =

  11. Electrical and piezoelectric properties of BiFeO3 thin films grown on SrxCa1−xRuO3-buffered SrTiO3 substrates

    Yao, Yingbang

    2012-06-01

    (001)-oriented BiFeO 3 (BFO) thin films were grown on Sr xCa 1-xRuO 3- (SCRO; x = 1, 0.67, 0.33, 0) buffered SrTiO 3 (001) substrates using pulsed laser deposition. The microstructural, electrical, ferroelectric, and piezoelectric properties of the thin films were considerably affected by the buffer layers. The interface between the BFO films and the SCRO-buffer layer was found to play a dominant role in determining the electrical and piezoelectric behaviors of the films. We found that films grown on SrRuO 3-buffer layers exhibited minimal electrical leakage while films grown on Sr 0.33Ca 0.67RuO 3-buffer layers had the largest piezoelectric response. The origin of this difference is discussed. © 2012 American Institute of Physics.

  12. The effect of hydrogen absorption on the structural, electronic and magnetic properties of the C15 Friauf-Laves phase compounds CeFe2, CeRu2 and LaRu2 : an x-ray absorption spectroscopy (XAS) study

    Chaboy, J.; Garcia, J.; Marcelli, A.

    1995-08-01

    An x-ray absorption spectroscopy (XAS) investigation of the structural changes occurred upon hydriding in the Friauf-Laves phase compounds CeFe 2 , CeRu 2 and LaRu 2 compounds is presented. The analysis of the extended x-ray absorption spectroscopy (EXAFS) spectra at the L-edges of the rare-earth and at the Fe K-edge indicates that the hydrogenation process leads to the suppression of the long-range crystalline order in all the hydride derivates investigated, as well as the different influence of H 2 in both the rare earth and transition metal sublattices. The correlation between the structural and magnetic changes induced by the hydrogen in the lost matrix is discussed in terms of the modification of the electronic properties, i.e., intermediate-valence of Ce, and of the hybridization between the transition metal and rare-earth

  13. Ruthenium and osmium carbonyl nitrosyl complexes: Matrix infrared spectra and density functional calculations for M(CO){sub 2}(NO){sub 2} and M(CO)(NO) (M = Ru, Os)

    Song, Zhenjun [Department of Chemistry, Tongji University, Shanghai 200092 (China); Wang, Xuefeng, E-mail: xfwang@tongji.edu.cn [Department of Chemistry, Tongji University, Shanghai 200092 (China); Key Laboratory of Yangtze River Water Environment, Ministry of Education, Tongji University (China)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer Laser-ablated ruthenium or osmium atom reactions with CO and NO mixtures in solid argon. Black-Right-Pointing-Pointer Metal carbonyl nitrosyls including M(CO)(NO) and 18-electron configuration M(CO){sub 2}(NO){sub 2} molecules (M = Ru, Os). Black-Right-Pointing-Pointer The observed absorption bands of reaction products are identified by isotopic substitution and DFT calculations. Black-Right-Pointing-Pointer The bonding and reaction mechanism are discussed in detail. -- Abstract: Laser-ablated ruthenium or osmium atom reactions with CO and NO mixtures in solid argon produce unsaturated metal carbonyl nitrosyls including M(CO)(NO) and 18-electron configuration M(CO){sub 2}(NO){sub 2} molecules (M = Ru, Os). The observed absorption bands of reaction products are identified by isotopic substitution, isotopic ratios and isotopic distributions ({sup 13}CO, {sup 15}NO, and mixtures). DFT (B3LYP and BP86) vibrational fundamental calculations reproduce observed frequencies and isotopic shifts very well. The bonding and reaction mechanism are discussed.

  14. Room temperature magnetism of few-nanometers-thick Fe{sub 3}O{sub 4}(111) films on Pt(111) and Ru(0001) studied in ambient conditions

    Lewandowski, M., E-mail: lewandowski@amu.edu.pl [NanoBioMedical Centre, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland); Institute of Molecular Physics, Polish Academy of Sciences, M. Smoluchowskiego 17, 60-179 Poznań (Poland); Miłosz, Z.; Michalak, N.; Ranecki, R. [Institute of Molecular Physics, Polish Academy of Sciences, M. Smoluchowskiego 17, 60-179 Poznań (Poland); Sveklo, I.; Kurant, Z.; Maziewski, A. [Faculty of Physics, University of Białystok, Lipowa 41, 15-424 Białystok (Poland); Mielcarek, S. [Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland); Luciński, T. [Institute of Molecular Physics, Polish Academy of Sciences, M. Smoluchowskiego 17, 60-179 Poznań (Poland); Jurga, S. [NanoBioMedical Centre, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland)

    2015-09-30

    Few-nanometers-thick Fe{sub 3}O{sub 4}(111) films were epitaxially grown on Pt(111) and Ru(0001) single crystal supports by sequential iron deposition and oxidation in an ultra-high vacuum chamber. The growth of well-ordered magnetite films was confirmed by low energy electron diffraction. The films were covered with a protective Au layer and subjected to magnetic and structural studies in ambient conditions. Magnetic hysteresis loops, recorded using magneto-optical Kerr effect apparatus, confirmed magnetic ordering in both films at room temperature. The Kerr measurements indicated in-plane orientation of magnetization, which was supported by the lack of magnetic contrast in magnetic force microscopy images. Atomic force microscopy revealed significant differences in morphology of the films, tentatively attributed to different lattice mismatch with Pt(111) and Ru(0001) single crystal supports. - Highlights: • Few-nanometers-thick Fe{sub 3}O{sub 4}(111) films were grown on Pt(111) and Ru(0001). • Magnetic properties were studied using MOKE and AFM/MFM in ambient conditions. • The films exhibited in-plane magnetic ordering at room temperature. • Differences in magnetic properties were tentatively assigned to structural differences.

  15. Photomagnetic studies on spin-crossover solid solutions containing two different metal complexes, [Fe(1-bpp)(2)](x)[M(terpy)2](1-x)[BF4]2 (M = Ru or Co).

    Chastanet, Guillaume; Tovee, Clare A; Hyett, Geoffrey; Halcrow, Malcolm A; Létard, Jean-François

    2012-04-28

    The photomagnetic properties of two series of spin-crossover solid solutions, [Fe(1-bpp)(2)](x)[Ru(terpy)(2)](1-x)(BF(4))(2) and [Fe(1-bpp)(2)](x)[Co(terpy)(2)](1-x)(BF(4))(2) (1-bpp = 2,6-bis[pyrazol-1-yl]pyridine), have been investigated. For all the materials, the evolution of the T(LIESST) value, the high-spin → low-spin relaxation parameters and the LITH loops were thoroughly studied. Interestingly in the Fe:Co series, along the photo-excitation, cobalt ions are concomitantly converted from low-spin to high-spin states with the iron centres, and also fully relax after light excitation. This journal is © The Royal Society of Chemistry 2012

  16. Photogeneration of metastable side-on N2 linkage isomers in [Ru(NH3)5N2]Cl2, [Ru(NH3)5N2]Br2 and [Os(NH3)5N2]Cl2.

    Schaniel, Dominik; Woike, Theo; Delley, Bernard; Boskovic, Colette; Güdel, Hans-Ueli

    2008-09-28

    Photogeneration of side-on N2 linkage isomers in [Ru(NH3)5N2]2+ and [Os(NH3)5N2]2+ is achieved by irradiation with lambda = 325 nm of powder samples at T = 80 K and detected by the downshift of the nu(N-N) vibration and by the heat release at elevated temperature due to the back switching of the side-on configuration to the ground state. The concentration of the transferred molecules is evaluated by the decrease of the area of the nu(N-N) or 2nu(N-N) vibrational bands. All characteristic changes between the linear Ru-N-N and side-on configuration are predicted by DFT calculations: the structure of the anion, shifts of the vibrations, electronic excitation energy, energetic position and sequence of the electronic orbitals, the potentials of the ground and relaxed metastable state with the activation energy, saddle points and energetic position of the minimum.

  17. Phlebotominae: Vectores de Leishmaniasis en las provincias de Santa Fe y Entre Ríos, Argentina Phlebotominae: vectors of leishmaniasis in the provinces of Santa Fe and Entre Ríos, Argentina

    Oscar D. Salomón

    2006-06-01

    Full Text Available La transmisión de leishmaniasis tegumentaria (LT se incrementó desde 1985 en 9 provincias argentinas. Santa Fe y Entre Ríos en dicho período no notificaron casos de transmisión autóctona comprobada, sin embargo en el año 2003 ocurrió un brote epidémico en Bella Vista, Corrientes, localidad que se encuentra en un área con continuidad ecológica y contigüidad geográfica con ambas provincias. Por ello, para determinar el riesgo potencial de transmisión de LT en las áreas próximas y al sur de Bella Vista se realizaron capturas de Phlebotominae en febrero del 2004, colectándose sobre las márgenes del río Paraná en Santa Fe (El Rabón, Villa Ocampo, Cayastá y en Entre Ríos (La Paz, La Celina-Villa Urquiza 860 ejemplares de Lutzomyia neivai (99.5% y Lu. migonei (0.5 %, ambas especies con capacidad vectorial para Leishmania (V. braziliensis. En Tartagal, Santa Fe, las capturas fueron consistentes con el paisaje de «chaco» residual: 7 ejemplares de Lu. nerivai, Lu. migonei y Lu. cortelezzii. Se destaca el riesgo potencial de transmisión epidémica de LT en estas provincias, especialmente por la tropicalización progresiva hacia el sur de la selva en galeria paranaense. Se recomiendan actividades de vigilancia clínica y vectorial.The transmission of tegumentary leishmaniasis (TL has increased in 9 provinces of Argentina since 1985. Santa Fe and Entre Ríos did not record in this period autochtonous probed cases: however, an epidemic outbreak took place in 2003 in Bella Vista, Corrientes, located in an area with ecological continuity and contiguous to both provinces. In order to evaluate the potential risk of transmission of LT, Phlebotominae were captured at locations close to and southern from Bella Vista during February 2004. The traps located on the shores of Parana river in Santa Fe (El Rabón, Villa Ocampo, Cayastá, and Entre Ríos (La Paz. La Celina-Villa Urquiza captured 860 individuals of Lutzomyia neivai (99.5% and Lu

  18. Oxygen trapped by rare earth tetrahedral clusters in Nd4FeOS6: Crystal structure, electronic structure, and magnetic properties

    Lin, Qisheng; Taufour, Valentin; Zhang, Yuemei; Wood, Max; Drtina, Thomas; Bud’ko, Sergey L.; Canfield, Paul C.; Miller, Gordon J.

    2015-01-01

    Single crystals of Nd 4 FeOS 6 were grown from an Fe–S eutectic solution. Single crystal X-ray diffraction analysis revealed a Nd 4 MnOSe 6 -type structure (P6 3 mc, a=9.2693(1) Å, c=6.6650(1)Å, V=495.94(1) Å 3 , Z=2), featuring parallel chains of face-sharing [FeS 6×1/2 ] 4− trigonal antiprisms and interlinked [Nd 4 OS 3 ] 4+ cubane-like clusters. Oxygen atoms were found to be trapped by Nd 4 clusters in the [Nd 4 OS 3 ] 4 + chains. Structural differences among Nd 4 MnOSe 6 -type Nd 4 FeOS 6 and the related La 3 CuSiS 7 − and Pr 8 CoGa 3 -type structures have been described. Magnetic susceptibility measurements on Nd 4 FeOS 6 suggested the dominance of antiferromagnetic interactions at low temperature, but no magnetic ordering down to 2 K was observed. Spin-polarized electronic structure calculations revealed magnetic frustration with dominant antiferromagnetic interactions. - Graphical abstract: Trapping of oxygen in Nd 4 tetrahedral clusters results in the formation of the Nd 4 MnOSe 6 -type Nd 4 FeOS 6 , in contrast to the La 3 CuSiS 7 -type oxygen-free Nd 4 FeS 7 and related Pr 8 CoGa 3 -type structures. Complex magnetic frustration inhibits magnetic ordering at low temperature. - Highlights: • Single crystals of Nd 4 FeOS 6 were grown using self-flux method. • Oxygen was found trapped by Nd 4 tetrahedral clusters. • Comparison with two closely related structural types were discussed. • Magnetic measurements revealed antiferromagnetic (AFM) interaction. • VASP calculations confirmed strong magnetic frustration in AFM model

  19. Structural and physical properties of new uranium and transition element ternary stannides (Fe, Co, Ni, Ru, Rh, Pd, Ir, Pt); Proprietes structurales et physiques de nouveaux stannures ternaires a base d'uranium et d'element de transition (Fe, Co, Ni, Rh, Pd, Ir, Pt)

    Mirambet, F

    1993-12-15

    This work is dedicated to the study of ternary stannides based on uranium. The author reviews the structural, magnetic and electric properties of different families of stannides. The study of the U{sub 2}M{sub 2}Sn family where M stands for Fe, Co, Ni, Ru, Rh, Pd, Ir and Pt shows that the magnetic behaviour of uranium in these compounds is strongly influenced by the transition element M, which is explained by the hybridization force 5f(U) - nd(M) that depends on the number of electrons on the d shell of the M element. For instance, for the elements whose d shell is low filled (Fe, Ru), the U{sub 2}M{sub 2}Sn stannides show no magnetic order. On the other hand, when the number of d-electrons increases, a magnetic order appears progressively.

  20. Sandwich-Type Electrochemiluminescence Sensor for Detection of NT-proBNP by Using High Efficiency Quench Strategy of Fe3O4@PDA toward Ru(bpy)32+ Coordinated with Silver Oxalate.

    Shi, Li; Li, Xiaojian; Zhu, Wenjuan; Wang, Yaoguang; Du, Bin; Cao, Wei; Wei, Qin; Pang, Xuehui

    2017-12-22

    Heart failure (HF) is a burgeoning public health problem trigged by a heart circulation disorder. N-terminal pro-B-type natriuretic peptide (NT-proBNP) has been acknowledged as a prognostic biomarker for cardiac disease. Herein, a sandwich-type electrochemiluminescence (ECL) immunosensor was introduced for sensitive detection of NT-proBNP. Gold nanoparticle modified graphene oxide-Ru(bpy) 3 2+ /Ag 2 C 2 O 4 was used as a luminophore and a desirable platform for immobilization of the captured antibodies. The more stable immobilization of plentiful Ru(bpy) 3 2+ could be implemented by direct covalent bonding chelation with Ag 2 C 2 O 4 . More importantly, significant quenching can be achieved by introducing polydopamine (PDA) coated Fe 3 O 4 onto the electrode via sandwich immunoreactions. The quenching mechanism mainly showed that the excited states of Ru(bpy) 3 2+ could be annihilated by quinone units in PDA via energy transfer. The ECL quenching efficiency was logarithmically related to the concentration of the NT-proBNP in the range from 0.0005 ng/mL to 100.0 ng/mL with a detection limit of 0.28 pg/mL. Furthermore, this specific immunosensor presented good stability and repeatability as well as selectivity, which offers a guiding significance in both fundamental and clinical diagnosis of NT-proBNP.

  1. Electrochemical Behavior of Nanocrystalline Ru1-xMexO2-y (Me=Fe, Co, Ni) Oxide Elektrodes in Double –Layer Region

    Macounová, Kateřina; Jirka, Ivan; Trojánek, Antonín; Makarova, Marina; Samec, Zdeněk; Krtil, Petr

    2007-01-01

    Roč. 154, č. 12 (2007), A1077-A1082 ISSN 0013-4651 R&D Projects: GA AV ČR 1ET400400413 Institutional research plan: CEZ:AV0Z40400503 Keywords : Ruthenium oxide * RuO2 * supercapacitos Subject RIV: CG - Electrochemistry Impact factor: 2.483, year: 2007

  2. Multiple episodes of mineralization revealed by Re-Os molybdenite geochronology in the Lala Fe-Cu deposit, SW China

    Zhu, Zhimin; Tan, Hongqi; Liu, Yingdong; Li, Chao

    2018-03-01

    The Lala Fe-Cu deposit is one of the largest iron oxide-copper-gold (IOCG) deposits in the Kangdian copper belt, southwest China. The paragenetic sequence of the Lala deposit includes six hydrothermal stages: pre-ore pervasive Na alteration (I); magnetite stage with K-feldspar and apatite (II); polymetallic disseminated/massive magnetite-sulfide stage (III); banded magnetite-sulfide stage (IV); sulfide vein stage (V); and late quartz-carbonate vein stage (VI). Fifteen molybdenite separates from stages III to VI were analyzed for Re-Os dating. Our new Re-Os data, together with previous studies, identify four distinct hydrothermal events at the Lala deposit. Molybdenite from the stage III disseminated to massive chalcopyrite-magnetite ores yielded a weighted average Re-Os age of 1306 ± 8 Ma (MSWD = 1.1, n = 6) which represents the timing of main ore formation. Molybdenite from the stage IV-banded magnetite-chalcopyrite ores yielded a weighted average Re-Os age of 1086 ± 8 Ma (MSWD = 2.2, n = 7), i.e., a second ore-forming event. Molybdenite from the stage V sulfide veins yielded a weighted average Re-Os age of 988 ± 8 Ma (MSWD = 1.3, n = 7) which represents the timing of a third hydrothermal event. Molybdenite from the quartz-carbonate veins (stage VI) yielded a weighted average Re-Os age at 835 ± 4 Ma (MSWD = 0.66, n = 10) and documented the timing of a late hydrothermal event. Our results indicate that the Lala deposit formed during multiple, protracted mineralization events over several hundred million years. The first three Mesoproterozoic mineralization events are coeval with intra-continental rifting (breakup of the supercontinent Nuna) and share a temporal link to other IOCG-style deposits within the Kangdian Copper Belt, and the last Neoproterozoic hydrothermal event is coeval with the Sibao orogeny which culminated with the amalgamation of the Yangtze Block with the Cathaysia Block at 860-815 Ma.

  3. Excitation functions and yields of proton induced reactions at intermediate energies leading to important diagnostics radioisotopes of 52Fe, 77Br, 82Rb, 97Ru, 111In, 123I, 127Xe, 128Cs, 178Ta and 201Tl

    Rurarz, E.

    1994-01-01

    This report describes investigations of the excitation functions of the proton induced reactions on 14 targets (Mn, Co, Br, Rb, 99 Tc, 113 Cd, 114 Cd, Cd, I, Cs, Ta, 206,207,208 Pb) leading directly or indirectly to the formation of radionuclides 52 Fe, 77 Br, 82 Rb, 97 Ru, 111 In, 123 I, 127 Xe, 128 Cs, 178 Ta and 201 Tl frequently used in diagnostic procedures of nuclear medicine. The measurements of the excitation functions were made over a wide proton energy range from the reaction threshold up to 100 MeV using the stacked foil (or pellet) technique. Small energy steps were used to allow for accurate determination of the structure of excitation functions. For 97 Ru, 111 In and 127 Xe formation with protons, new reaction channels and targets were used and data concerning this method are published for the first time. The data for 52 Fe, 77 Br, 82 Rb, 123 I, 128 Cs and 201 Tl obtained in the present work for the E p =70-100 MeV region are also published for the first time. The measured excitation functions for the formation of desired (and undesired) radionuclides (altogether 28 excitation functions) are compared with the theoretical ones calculated on the basis of a hybrid model of nuclear reactions in the form of the Overlaid Alice computer code. In order to determine the contribution of the competitive reaction channels to the purity of the produced, desired radionuclide, the excitation functions of the accompanying reactions were also calculated. The 122 calculated excitation functions for the possible contaminant are given in the present work. The comparison of experimental excitation functions with the results of model calculations showed satisfactory agreement, especially if one considers, that no parameter adjustment for individual reaction products was undertaken. From the measured excitation functions the production yields for 28 radionuclides mentioned above have been determined (author). 262 refs, 65 figs, 34 tabs

  4. Complex transition metal hydrides incorporating ionic hydrogen: Synthesis and characterization of Na{sub 2}Mg{sub 2}FeH{sub 8} and Na{sub 2}Mg{sub 2}RuH{sub 8}

    Humphries, Terry D., E-mail: terry_humphries81@hotmail.com [WPI-Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Takagi, Shigeyuki; Li, Guanqiao; Matsuo, Motoaki; Sato, Toyoto [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Sørby, Magnus H.; Deledda, Stefano; Hauback, Bjørn C. [Physics Department, Institute for Energy Technology, Kjeller NO-2027 (Norway); Orimo, Shin-ichi [WPI-Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan)

    2015-10-05

    Highlights: • Structures of Na{sub 2}Mg{sub 2}FeH{sub 8} and Na{sub 2}Mg{sub 2}RuH{sub 8} have been determined by XRD and PND. • Compounds incorporate independently coordinated ionic and covalent hydrogen. • [TH{sub 6}]{sup 4−} anion is surrounded by a cubic array of four Mg{sup 2+} and four Na{sup +} cations. • H{sup −} anions are octahedrally coordinated by four Na{sup +} and two Mg{sup 2+} cations. • Vibrational modes of the H{sup −} anions and complex hydride anion are observed. - Abstract: A new class of quaternary complex transition metal hydrides (Na{sub 2}Mg{sub 2}TH{sub 8} (T = Fe, Ru)) have been synthesized and their structures determined by combined synchrotron radiation X-ray and powder neutron diffraction. The compounds can be considered as a link between ionic and complex hydrides in terms of incorporating independently coordinated ionic and covalent hydrogen. These novel isostructural complex transition metal hydrides crystallize in the orthorhombic space group Pbam, where the octahedral complex hydride anion is surrounded by a cubic array of four Mg{sup 2+} and four Na{sup +} cations, forming distinct two-dimensional layers. An intriguing feature of these materials is the distorted octahedral coordination of the isolated H{sup −} anions by four Na{sup +} and two Mg{sup 2+} cations, which form layers between the transition metal containing layers. The vibrational modes of the H{sup −} anions and complex hydride anion are independently observed for the first time in a quaternary complex transition metal hydride system by Raman and IR spectroscopy.

  5. Ru/Fe bimetallic complexes: Synthesis, characterization, cytotoxicity and study of their interactions with DNA/HSA and human topoisomerase IB.

    Takarada, Jessica E; Guedes, Adriana P M; Correa, Rodrigo S; Silveira-Lacerda, Elisângela de P; Castelli, Silvia; Iacovelli, Federico; Deflon, Victor Marcelo; Batista, Alzir Azevedo; Desideri, Alessandro

    2017-12-15

    Three ruthenium/iron-based compounds, 1: [Ru(MIm)(bipy)(dppf)]PF 6 (MIm = 2-mercapto-1-methylimidazole anion), 2: [RuCl(Im)(bipy)(dppf)]PF 6 (Im = imidazole), and 3: [Ru(tzdt)(bipy)(dppf)]PF 6 (tzdt = 1,3-thiazolidine-2-thione anion) (dppf = 1,1'-bis(diphenylphosphine)ferrocene and bipy = 2,2'-bipyridine), were synthesized, and characterized by elemental analyses, conductivity, UV/Vis, IR, 1 H, 13 C and 31 P{1H} NMR spectroscopies, and by electrochemical technique. The complex 3 was also characterized by single-crystal X-ray. The three ruthenium(II) complexes show cytotoxicity against DU-145 (prostate carcinoma cells) and A549 (lung carcinoma cells) tumor cells. The free ligands do not exhibit any cytotoxic activity, such as evident by the IC 50 values higher than 200 μM. UV/Vis and viscosity experiments showed that the complexes interact weakly with the DNA molecule, via electrostatic forces. The interaction of the complexes 1-3 with the HSA is moderate, with K b values in range of 10 5 -10 7  M -1 , presenting a static mechanism of interaction stabilized by hydrophobic. Complexes 2 and 3 showed high affinity for the FA7 HSA site as evidenced by fluorescence spectroscopy and molecular docking. Complexes 1-3 were tested as potential human Topoisomerase IB inhibitors by analysing the different steps of the enzyme catalytic cycle. The results indicate that all compounds efficiently inhibit the DNA relaxation and the cleavage reaction, in which the effect increases upon pre-incubation. Complexes 1 and 2 are also able to slow down the religation reaction. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Bioleaching of Zn, Ni and Fe from contaminated sediments of water reservoir Ružín I with using heterotrophic bacterial strains

    Katarína Jablonovská

    2012-12-01

    Full Text Available This study investigates the bioleaching of the zinc polluted sediment from water reservoir Ružín I using heterotrophic bacterialstrains ubiquitous in sediment environment. The effect of bacterial activity, pH, iron solubilization and precipitation and bioleachingmedium were evaluated. The pH value controls the bacterial activity during the leaching process. Addition of glucose to the bioleachingmedium accelerated the bioleaching rate. The results indicates, that the leachibility of zinc depend on the geochemical formsand surface interaction between metal and sediment fraction. Sequential chemical extraction confirm, that Zn was predominantly boundto the iron-manganese oxides.

  7. Syntheses, structures and redox properties of some complexes containing the Os(dppe)Cp* fragment, including [{Os(dppe)Cp*}2(mu-C triple bondCC triple bond C)].

    Bruce, Michael I; Costuas, Karine; Davin, Thomas; Halet, Jean-François; Kramarczuk, Kathy A; Low, Paul J; Nicholson, Brian K; Perkins, Gary J; Roberts, Rachel L; Skelton, Brian W; Smith, Mark E; White, Allan H

    2007-12-14

    The sequential conversion of [OsBr(cod)Cp*] (9) to [OsBr(dppe)Cp*] (10), [Os([=C=CH2)(dppe)Cp*]PF6 ([11]PF6), [Os(C triple bond CH)(dppe)Cp*] (12), [{Os(dppe)Cp*}2{mu-(=C=CH-CH=C=)}][PF6]2 ([13](PF6)2) and finally [{Os(dppe)Cp*}(2)(mu-C triple bond CC triple bond C)] (14) has been used to make the third member of the triad [{M(dppe)Cp*}2(mu-C triple bond CC triple bond C)] (M = Fe, Ru, Os). The molecular structures of []PF6, 12 and 14, together with those of the related osmium complexes [Os(NCMe)(dppe)Cp*]PF6 ([15]PF6) and [Os(C triple bond CPh)(dppe)Cp*] (16), have been determined by single-crystal X-ray diffraction studies. Comparison of the redox properties of 14 with those of its iron and ruthenium congeners shows that the first oxidation potential E1 varies as: Fe approximately Os < Ru. Whereas the Fe complex has been shown to undergo three sequential 1-electron oxidation processes within conventional electrochemical solvent windows, the Ru and Os compounds undergo no fewer than four sequential oxidation events giving rise to a five-membered series of redox related complexes [{M(dppe)Cp*}2(mu-C4)]n+ (n = 0, 1, 2, 3 and 4), the osmium derivatives being obtained at considerably lower potentials than the ruthenium analogues. These results are complimented by DFT and DT DFT calculations.

  8. Magnetic properties of RT2Zn20; R = rare earth, T = Fe, Co, Ru, Os and Ir

    Jia, Shuang [Ames Lab. and Iowa State Univ., Ames, IA (United States)

    2008-01-01

    It is well known that rare earth intermetallic compounds have versatile, magnetic properties associated with the 4f electrons: a local moment associated with the Hund's rule ground state is formed in general, but a strongly correlated, hybridized state may also appear for specific 4f electronic configuration (eg. for rare earth elements such as Ce or Yb). On the other hand, the conduction electrons in rare earth intermetallic compounds, certainly ones associated with non hybridizing rare earths, usually manifest non-magnetic behavior and can be treated as a normal, non-interacted Fermi liquid, except for some 3d-transition metal rich binary or ternary systems which often manifest strong, itinerant, d electron dominant magnetic behavior. Of particular interest are examples in which the band filling of the conduction electrons puts the system in the vicinity of a Stoner transition: such systems, characterized as nearly or weakly ferromagnet, manifest strongly correlated electronic properties [Moriya, 1985]. For rare earth intermetallic compounds, such systems provide an additional versatility and allow for the study of the behaviors of local moments and hybridized moments which are associated with 4f electron in a correlated conduction electron background.

  9. X = Pt, Os, Ru, Ir, Rh

    Timothy Ademakinwa

    The compressibility of five compounds in the stoichiometry X Al was evaluated from 0K to 2000K using the. 3 ... atom model framework, using the Sutton and Chen potentials. Keywords: ... However, alloys based on these ... computer code (Turodov et al., 2006). DL-POLY is a molecular dynamics (MD) simulation package.

  10. Fragility of ferromagnetic double exchange interactions and pressure tuning of magnetism in 3 d -5 d double perovskite Sr2FeOsO6

    Veiga, L. S. I.; Fabbris, G.; van Veenendaal, M.; Souza-Neto, N. M.; Feng, H. L.; Yamaura, K.; Haskel, D.

    2015-06-01

    The ability to tune exchange (magnetic) interactions between 3 d transition metals in perovskite structures has proven to be a powerful route to discovery of novel properties. Here we demonstrate that the introduction of 3 d -5 d exchange pathways in double perovskites enables additional tunability, a result of the large spatial extent of 5 d wave functions. Using x-ray probes of magnetism and structure at high pressure, we show that compression of Sr2FeOsO6 drives an unexpected continuous change in the sign of Fe-Os exchange interactions and a transition from antiferromagnetic to ferrimagnetic order. We analyze the relevant electron-electron interactions, shedding light into fundamental differences with the more thoroughly studied 3 d -3 d systems.

  11. The End of Monterey Submarine Canyon Incision and Potential River Source Areas-Os, Nd, and Pb Isotope Constraints from Hydrogenetic Fe-Mn Crusts

    Conrad, T. A.; Nielsen, S.; Ehrenbrink, B. P. E.; Blusztajn, J.; Hein, J. R.; Paytan, A.

    2015-12-01

    The Monterey Canyon off central California is the largest submarine canyon off North America and is comparable in scale to the Grand Canyon. The age and history of the Monterey Canyon are poorly constrained due to thick sediment cover and sediment disruption from turbidity currents. To address this deficit we analyzed isotopic proxies (Os, Pb, Nd) from hydrogenetic ferromanganese (Fe-Mn) crusts, which grow over millions of years on elevated rock surfaces by precipitation of metals from seawater. Fe-Mn crusts were studied from Davidson Seamount near the base of the Monterey submarine fan, the Taney Seamount Chain, and from Hoss Seamount, which serves as a regional control (Fig.). Fe-Mn crusts were dated using Os isotope ratios compared to those that define the Cenozoic Os isotope seawater curve. Four Fe-Mn crust samples from Davidson and Taney Seamounts deviate from the Os isotopic seawater curve towards radiogenic values after 4.5±1 Ma. Osmium is well mixed in the global ocean and is not subject to significant diffusive reequilibration in Fe-Mn crusts. We therefore attribute deviations from the Os isotope seawater curve to large-scale terrestrial input that ended about 4.5±1 Ma. The two Davidson samples also show more radiogenic Nd isotope values from about 4.5±1 Ma. Lead isotopes in one Davidson Seamount crust, measured by LA-ICPMS, deviate from regional values after 4.5±1 Ma for about 500 ka towards terrestrial sources. The Taney Seamount Fe-Mn crust does not deviate from regional Nd nor Pb isotope values due to its greater distance from Monterey Canyon and the shorter marine residence times of Nd and Pb. Isotope plots of our crust data and compiled data for potential source rocks indicate that the river that carved Monterey Canyon carried sediment with values closer to the Sierra Nevada than to a Colorado Plateau source, with cessation of major riverine input occurring approximately 4.5±1 Ma, an age that we interpret as the end of the Monterey Canyon

  12. Synthesis, crystal structure investigation and magnetism of the complex metal-rich boride series Cr{sub x}(Rh{sub 1-y}Ru{sub y}){sub 7-x}B{sub 3} (x=0.88-1; y=0-1) with Th{sub 7}Fe{sub 3}-type structure

    Misse, Patrick R.N.; Mbarki, Mohammed [Institute of Inorganic Chemistry, RWTH Aachen University, 52066 Aachen (Germany); Fokwa, Boniface P.T., E-mail: boniface.fokwa@ac.rwth-aachen.de [Institute of Inorganic Chemistry, RWTH Aachen University, 52066 Aachen (Germany)

    2012-08-15

    Powder samples and single crystals of the new complex boride series Cr{sub x}(Rh{sub 1-y}Ru{sub y}){sub 7-x}B{sub 3} (x=0.88-1; y=0-1) have been synthesized by arc-melting the elements under purified argon atmosphere on a water-cooled copper crucible. The products, which have metallic luster, were structurally characterized by single-crystal and powder X-ray diffraction as well as EDX measurements. Within the whole solid solution range the hexagonal Th{sub 7}Fe{sub 3} structure type (space group P6{sub 3}mc, no. 186, Z=2) was identified. Single-crystal structure refinement results indicate the presence of chromium at two sites (6c and 2b) of the available three metal Wyckoff sites, with a pronounced preference for the 6c site. An unexpected Rh/Ru site preference was found in the Ru-rich region only, leading to two different magnetic behaviors in the solid solution: The Rh-rich region shows a temperature-independent (Pauli) paramagnetism whereas an additional temperature-dependent paramagnetic component is found in the Ru-rich region. - Graphical abstract: The new complex boride series Cr{sub x}(Rh{sub 1-y}Ru{sub y}){sub 7-x}B{sub 3} (x=0.88-1; y=0-1) has been synthesized by arc melting the elements under purified argon atmosphere. Beside the 3d/4d site preference within the whole solid solution, an unexpected Rh/Ru site preference was found in the Ru-rich region only, leading to two different magnetic behaviors: The Rh-rich region shows a temperature-independent (Pauli) paramagnetism whereas an additional temperature-dependent paramagnetic component is found in the Ru-rich region. Highlights: Black-Right-Pointing-Pointer Synthesis of a new boride series fulfilling Vegard Acute-Accent s rule. Black-Right-Pointing-Pointer 3d/4d site preference. Black-Right-Pointing-Pointer Unexpected Ru/Rh site preference. Black-Right-Pointing-Pointer Rh-rich region is Pauli paramagnetic. Black-Right-Pointing-Pointer Ru-rich region is Pauli and temperature-dependent paramagnetic.

  13. London penetration depth measurements in Ba (Fe1-xTx)2As2(T=Co,Ni,Ru,Rh,Pd,Pt,Co+Cu) superconductors

    Gordon, Ryan T. [Iowa State Univ., Ames, IA (United States)

    2011-01-01

    The London penetration depth has been measured in various doping levels of single crystals of Ba(Fe1-xTx)2As2 (T=Co,Ni,Ru,Rh,Pd,Pt,Co+Cu) superconductors by utilizing a tunnel diode resonator (TDR) apparatus. All in-plane penetration depth measurements exhibit a power law temperature dependence of the form Δλab(T) = CTn, indicating the existence of low-temperature, normal state quasiparticles all the way down to the lowest measured temperature, which was typically 500 mK. Several different doping concentrations from the Ba(Fe1-xTx)2As2 (T=Co,Ni) systems have been measured and the doping dependence of the power law exponent, n, is compared to results from measurements of thermal conductivity and specific heat. In addition, a novel method has been developed to allow for the measurement of the zero temperature value of the in-plane penetration depth, λab(0), by using TDR frequency shifts. By using this technique, the doping dependence of λab(0) has been measured in the Ba(Fe1-xCox)2As2 series, which has allowed also for the construction of the doping-dependent superfluid phase stiffness, ρs(T) = [λ(0)/λ(T)]2. By studying the effects of disorder on these superconductors using heavy ion irradiation, it has been determined that the observed power law temperature dependence likely arises from pair-breaking impurity scattering contributions, which is consistent with the proposed s±-wave symmetry of the superconducting gap in the dirty scattering limit. This hypothesis is supported by the measurement of an exponential temperature dependence of the penetration depth in the intrinsically clean LiFeAs, indicative of a nodeless superconducting gap.

  14. Standard enthalpies of formation of selected Ru{sub 2}YZ Heusler compounds

    Yin, Ming, E-mail: myin1@hawk.iit.edu; Nash, Philip

    2015-06-15

    Highlights: • Standard enthalpies of formation of Ru{sub 2}YZ were measured using a drop calorimeter. • Result of L2{sub 1} structured compounds agrees with first principles data. • Lattice parameters and related phase relationships were consistent with literature data. • Ru{sub 2}HfSn, Ru{sub 2}TiSn, Ru{sub 2}VGa, Ru{sub 2}VSi, Ru{sub 2}VSn of L2{sub 1} structure were reported for the first time. - Abstract: The standard enthalpies of formation of selected ternary Ru-based Heusler compounds Ru{sub 2}YZ (Y = Fe, Hf, Mn, Ti, V; Z = Al, Ga, In, Si, Ge, Sn) were measured using high temperature direct reaction calorimetry. The measured enthalpies of formation (in kJ/mole of atoms) of the Heusler compounds are, Ru{sub 2}FeGe (−19.7 ± 3.3); Ru{sub 2}HfSn (−24.9 ± 3.6); Ru{sub 2}MnSi (−46.0 ± 2.6); Ru{sub 2}MnGe (−29.7 ± 1.0); Ru{sub 2}MnSn (−20.6 ± 2.4); Ru{sub 2}TiSi (−94.9 ± 4.0); Ru{sub 2}TiGe (−79.1 ± 3.2); Ru{sub 2}TiSn (−60.6 ± 1.8); Ru{sub 2}VSi (−55.9 ± 1.7);for the B2-structured compounds, Ru{sub 2}FeSi (−28.5 ± 0.8); Ru{sub 2}HfAl (−70.8 ± 1.9); Ru{sub 2}MnAl (−32.3 ± 1.9); Ru{sub 2}MnGa (−25.3 ± 3.0); Ru{sub 2}TiAl (−62.7 ± 3.5); Ru{sub 2}VAl (−30.9 ± 1.6); Ru{sub 2}ZrAl (−64.5 ± 1.5). Values were compared with those from published first principles calculations and the OQMD (Open Quantum Materials Database). Lattice parameters of these compounds were determined using X-ray diffraction analysis (XRD). Microstructures were identified using scanning electron microscopy (SEM) and Energy Dispersive Spectroscopy (EDS)

  15. Effect of Silicon on the Activity Coefficient of Rhenium in Fe-Si Liquids: Implications for HSE and Os Isotopes in Planetary Mantles

    Righter, K.; Pando, K.; Yang, S.; Humayun, M.

    2018-01-01

    Metallic cores contain light alloying elements that can be a combination of S, C, Si, and O, all of which have important chemical and physical influences. For Earth, Si may be the most abundant light element in the core. Si dissolved into Fe liquids can have a large effect on the magnitude of the activity coefficient of siderophile elements (SE), and thus the partitioning behavior of those elements between core and mantle. The effect of Si on the highly siderophile elements is only beginning to be studied and the effects on Au, Pd and Pt are significant. Here we report new experiments designed to quantify the effect of Si on the partitioning of Re between metal and silicate melt. A solid understanding of Re partitioning is required for a complete understanding of the Re-Os isotopic systems. The results will be applied to understanding the HSEs and Os isotopic data for planetary mantles, and especially Earth.

  16. Electrical and piezoelectric properties of BiFeO3 thin films grown on SrxCa1−xRuO3-buffered SrTiO3 substrates

    Yao, Yingbang; Chen, Long; Wang, Zhihong; Alshareef, Husam N.; Zhang, Xixiang

    2012-01-01

    on SrRuO 3-buffer layers exhibited minimal electrical leakage while films grown on Sr 0.33Ca 0.67RuO 3-buffer layers had the largest piezoelectric response. The origin of this difference is discussed. © 2012 American Institute of Physics.

  17. All-atom force field for molecular dynamics simulations on organotransition metal solids and liquids. Application to M(CO)(n) (M = Cr, Fe, Ni, Mo, Ru, or W) compounds.

    Bernardes, Carlos E S; Canongia Lopes, José N; Minas da Piedade, Manuel E

    2013-10-31

    A previously developed OPLS-based all-atom force field for organometallic compounds was extended to a series of first-, second-, and third-row transition metals based on the study of M(CO)(n) (M = Cr, Fe, Ni, Mo, Ru, or W) complexes. For materials that are solid at ambient temperature and pressure (M = Cr, Mo, W) the validation of the force field was based on reported structural data and on the standard molar enthalpies of sublimation at 298.15 K, experimentally determined by Calvet-drop microcalorimetry using samples corresponding to a specific and well-characterized crystalline phase: Δ(sub)H(m)° = 72.6 ± 0.3 kJ·mol(–1) for Cr(CO)(6), 73.4 ± 0.3 kJ·mol(–1) for Mo(CO)(6), and 77.8 ± 0.3 kJ·mol(–1) for W(CO)(6). For liquids, where problems of polymorphism or phase mixtures are absent, critically analyzed literature data were used. The force field was able to reproduce the volumetric properties of the test set (density and unit cell volume) with an average deviations smaller than 2% and the experimentally determined enthalpies of sublimation and vaporization with an accuracy better than 2.3 kJ·mol(–1). The Lennard-Jones (12-6) potential function parameters used to calculate the repulsive and dispersion contributions of the metals within the framework of the force field were found to be transferable between chromium, iron, and nickel (first row) and between molybdenum and ruthenium (second row).

  18. Two crystalline modifications of RuO4

    Pley, Martin; Wickleder, Mathias S.

    2005-01-01

    RuO 4 was prepared by oxidation of elemental ruthenium. Two different modifications were obtained and investigated by X-ray single crystal diffraction. RuO 4 -I has cubic symmetry (P4; - 3n,Z=8,a=8.509(1)A), and two independent tetrahedral molecules are present in the unit cell. Within the standard uncertainties in both molecules the distances Ru-O are 1.695A. The second modification, RuO 4 -II, is monoclinic (C2/c,Z=4,a=9.302(4)A,b=4.3967(10)A,c=8.454(4)A,β=116.82(3) o ) and isotypic with OsO 4 . There is one independent molecule in the unit cell, which shows distances Ru-O of 1.697 and 1.701A, respectively

  19. Rare earth ruthenium gallides with the ideal composition Ln_2Ru_3Ga_5 (Ln = La-Nd, Sm) crystallizing with U_2Mn_3Si_5 (Sc_2Fe_3Si_5) type structure

    Jeitschko, Wolfgang; Schlueter, Martin

    2010-01-01

    The rare earth ruthenium gallides Ln_2Ru_3Ga_5 (Ln = La, Ce, Pr, Nd, Sm) were prepared by arc-melting of cold-pressed pellets of the elemental components. They crystallize with a tetragonal structure (P4/mnc, Z = 4) first reported for U_2Mn_3Si_5. The crystal structures of the cerium and samarium compounds were refined from single-crystal X-ray data, resulting in significant deviations from the ideal compositions: Ce_2Ru_2_._3_1_(_1_)Ga_5_._6_9_(_1_), a = 1135.10(8) pm, c = 580.58(6) pm, R_F = 0.022 for 742 structure factors; Sm_2Ru_2_._7_3_(_2_)Ga_5_._2_7_(_2_), a = 1132.95(9) pm, c = 562.71(6) pm, R_F = 0.026 for 566 structure factors and 32 variable parameters each. The deviations from the ideal compositions 2:3:5 are discussed. A mixed Ru/Ga occupancy occurs only for one atomic site. The displacement parameters are relatively large for atoms with mixed occupancy within their coordination shell and small for atoms with no neighboring sites of mixed occupancy. Chemical bonding is analyzed on the basis of interatomic distances. Ln-Ga bonding is stronger than Ln-Ru bonding. Ru-Ga bonding is strong and Ru-Ru bonding is weak. The Ga-Ga interactions are of similar strength as in elemental gallium. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  20. Development of metal-carbon eutectic cells for application as high temperature reference points in nuclear reactor severe accident tests: Results on the Fe-C, Co-C, Ti-C and Ru-C alloys' melting/freezing transformation temperature under electromagnetic induction heating

    Parga, Clemente J.; Journeau, Christophe; Parga, Clemente J.; Tokuhiro, Akira

    2012-01-01

    With the aim of reducing the high temperature measurement uncertainty of nuclear reactor severe accident experimental tests at the PLINIUS platform in Cadarache Research Centre, France, a variety of graphite cells containing a metal-carbon eutectic mix have been tested to assess the melting/freezing temperature reproducibility and their feasibility as calibration cells for thermometers. The eutectic cells have been thermally cycled in an induction furnace to assess the effect of heating/cooling rate, metal purity, graphite crucible design, and binary system constituents on the eutectic transformation temperature. A bi-chromatic pyrometer was used to perform temperature measurements in the graphite cell black cavity containing the metal-carbon eutectic mix. The eutectic points analyzed are all over 1100 C and cover an almost thousand degree span, i.e. from the Fe-Fe 3 C to the Ru-C eutectic. The induction heating permitted the attainment of heating and cooling rates of over 200 C/min under an inert atmosphere. The conducted tests allowed the determination of general trends and peculiarities of the solid. liquid transformation temperature under non-equilibrium and non-steady-state conditions of a variety of eutectic alloys (Fe-C, Co-C, Ti-C and Ru-C binary systems). (authors)

  1. RESONANCEI--Fe-b-ru-a

    experiment has been that amino acids are formed readily in simulated pre-biotic conditions but nucleic acid bases, let alone nucleotides, are much harder to come by. If only proteins needed to have been produced pre-biotically and nucleic acids originated inside primitive 'cells' already containing proteins, the experimental ...

  2. RESONANCE--I--Fe-b-ru-a

    fih, accounting for the observed high wave speed of700 kmph corresponding to an ocean depth (h) of 4 km and acceleration due to gravity (g) of 9.8 rn/s2. • Nearing the coast, the depth and the wave speed reduce, but the height of the wave rapidly builds up. The article by Shetye ofNIO, Goa, written at short notice, lucidly.

  3. Origin of the volcanic-hosted Yamansu Fe deposit, Eastern Tianshan, NW China: constraints from pyrite Re-Os isotopes, stable isotopes, and in situ magnetite trace elements

    Huang, Xiao-Wen; Zhou, Mei-Fu; Beaudoin, Georges; Gao, Jian-Feng; Qi, Liang; Lyu, Chuan

    2018-01-01

    The Yamansu Fe deposit (32 Mt at 51% Fe) in the Eastern Tianshan Orogenic Belt of NW China is hosted in early Carboniferous volcano-sedimentary rocks and spatially associated with skarn. The paragenetic sequence includes garnet-diopside (I), magnetite (II), hydrous silicate-sulfide (III), and calcite-quartz (IV) stages. Pyrite associated with magnetite has a Re-Os isochron age of 322 ± 7 Ma, which represents the timing of pyrite and, by inference, magnetite mineralization. Pyrite has δ 34SVCDT values of - 2.2 to + 2.9‰, yielding δ 34SH2S values of - 3.1 to 2‰, indicating the derivation of sulfur from a magmatic source. Calcite from stages II and IV has δ 13CVPDB values from - 2.5 to - 1.2‰, and - 1.1 to 1.1‰, and δ 18OVSMOW values from 11.8 to 12.0‰ and - 7.7 to - 5.2‰, respectively. Calculated δ 13C values of fluid CO2 and water δ 18O values indicate that stage II hydrothermal fluids were derived from magmatic rocks and that meteoric water mixed with the hydrothermal fluids in stage IV. Some ores contain magnetite with obvious chemical zoning composed of dark and light domains in BSE images. Dark domains have higher Mg, Al, Ca, Mn, and Ti but lower Fe and Cr contents than light domains. The chemical zoning resulted from a fluctuating fluid composition and/or physicochemical conditions (oscillatory zoning), or dissolution-precipitation (irregular zoning) via infiltration of magmatic-hydrothermal fluids diluted by late meteoric water. Iron was mainly derived from fluids similar to that in skarn deposits.

  4. Local distortion induced metal-to-insulator phase transition in PrRu4P12

    Cao, D.; Heffner, R.H.; Jeong, I.-K.; Bauer, E.D.; Bridges, F.; Yuhasz, W.M.; Maple, M.B.

    2005-01-01

    Extended x-ray absorption fine structure (EXAFS) experiments have been carried out on PrRu 4 P 12 and PrOs 4 P 12 to study the metal-to-insulator (MI) phase transition in PrRu 4 P 12 . No Pr displacement was observed across the MI transition temperature from the EXAFS data. Instead, our EXAFS data clearly show that a Ru displacement is associated with this MI transition. The very high Debye temperature for the Ru-P bond (Θ D =690 K) suggests that a slight rotation/displacement of relatively rigid RuP 6 octahedra leads to this small Ru displacement, which accompanies the MI transition at 62 K in PrRu 4 P 12

  5. Inelastic scattering on 100Ru

    Sirota, S.

    1987-01-01

    Aspects of the nuclear structure of 100 Ru whe investigated by means of the scattering of 100 Ru (p,p') 100 Ru* with 16 MeV protons, where 21 states were investigated. The emergent protons were analysed by a magnetic spectrograph, of the enge type with a typical resolution of ≅ 9 KeV. (A.C.A.S.) [pt

  6. La mortalidad infantil en Santa Fe, Argentina (2007-2011. Un aporte al monitoreo de los derechos de los niños

    Ana Cecilia Augsburger

    2015-07-01

    Full Text Available La mortalidad infantil en Santa Fe tuvo un comportamiento similar al de Argentina, acompañando el descenso que se presentó para el país, aunque siempre con valores inferiores al indicador nacional. Pese a ello, mereció particular preocupación la elevada proporción de defunciones cuyas causas se consideran reducibles con valores históricos superiores al 50%. El establecimiento de las metas internacionales conocidas como Objetivos de Desarrollo del Milenio, que bregó por la protección de los derechos de la niñez, contó con la ratificación nacional al tiempo que la provincia se comprometió con estos fijándolos como política socio-sanitaria estratégica. El estudio construyó el perfil de la mortalidad infantil de la provincia de Santa Fe durante el quinquenio 2007-2011. Se realizó un estudio epidemiológico descriptivo y transversal. La población incluyó las defunciones en menores de un año del período estudiado. Se analizó su distribución según la edad al morir, peso al nacer y lugar de ocurrencia, causas de muerte y criterios de reducibilidad. Ocurrieron 2.904 muertes de niños, obteniendo una tasa del 10,9‰, que mantuvo el comportamiento descendente previo. Las muertes neonatales duplicaron la mortalidad posneonatal y se concentraron en la primera semana de vida. Las causas más frecuentes estuvieron asociadas a los problemas perinatales. El mayor riesgo de morir fue para los niños de menos de 1.000 gramos o inmadurez extrema. El 60% de los eventos podría haberse evitado. La persistencia de muertes consideradas reducibles debería estimular para incentivar estrategias de intervenciones sociales y sanitarias más equitativas y de protección de la infancia.

  7. La mortalidad infantil en Santa Fe, Argentina (2007-2011. Un aporte al monitoreo de los derechos de los niños

    Ana Cecilia Augsburger

    2015-01-01

    Full Text Available La mortalidad infantil en Santa Fe tuvo un comportamiento similar al de Argentina, acompañando el descenso que se presentó para el país, aunque siempre con valores inferiores al indicador nacional. Pese a ello, mereció particular preocupación la elevada proporción de defunciones cuyas causas se consideran reducibles con valores históricos superiores al 50%. El establecimiento de las metas internacionales conocidas como Objetivos de Desarrollo del Milenio, que bregó por la protección de los derechos de la niñez, contó con la ratificación nacional al tiempo que la provincia se comprometió con estos fijándolos como política socio-sanitaria estratégica. El estudio construyó el perfil de la mortalidad infantil de la provincia de Santa Fe durante el quinquenio 2007-2011. Se realizó un estudio epidemiológico descriptivo y transversal. La población incluyó las defunciones en menores de un año del período estudiado. Se analizó su distribución según la edad al morir, peso al nacer y lugar de ocurrencia, causas de muerte y criterios de reducibilidad. Ocurrieron 2.904 muertes de niños, obteniendo una tasa del 10,9‰, que mantuvo el comportamiento descendente previo. Las muertes neonatales duplicaron la mortalidad posneonatal y se concentraron en la primera semana de vida. Las causas más frecuentes estuvieron asociadas a los problemas perinatales. El mayor riesgo de morir fue para los niños de menos de 1.000 gramos o inmadurez extrema. El 60% de los eventos podría haberse evitado. La persistencia de muertes consideradas reducibles debería estimular para incentivar estrategias de intervenciones sociales y sanitarias más equitativas y de protección de la infancia.

  8. The ternary rare earth ruthenium gallides R3Ru4Ga15 (R=Y, Tb-Er) with a new structure type, a further example of a recently recognized large family of structures

    Schlueter, Martin; Jeitschko, Wolfgang

    2003-01-01

    The title compounds were prepared by reaction of the elemental components at high temperature. They crystallize with a new orthorhombic structure type which was determined from single-crystal diffractometer data of Ho 3 Ru 4 Ga 15 : Pnma, a=871.7(1) pm, b=956.4(1) pm, c=1765.9(3) pm, Z=4, R=0.040 for 1039 structure factors and 114 variable parameters. The structure may be viewed as consisting of two kinds of atomic layers, although atomic bonding within and between the layers is comparable strength, as can be judged from the near-neighbor environments, where all of the 15 atomic sites have high coordination numbers. One kind of atomic layers (A) contains all of the holmium and additional gallium atoms in the ratio Ho:Ga=3:5 with a unit mesh content of 2Ho 3 Ga 5 ; these layers are flat. The other layers (B) consist of sheets of corner- and edge-sharing condensed RuGa 6 octahedra, which are extremely compressed resulting in a hexagonal close-packed, puckered net with a Ru:Ga ratio of 2:5 and a unit mesh content of 4Ru 2 Ga 5 . These nets alternate in the sequence ABAB, ABAB, thus yielding the formula 4Ho 3 Ga 5 ·8Ru 2 Ga 5 =4Ho 3 Ru 4 Ga 15 . Similar layers are observed in the structures of Y 2 Co 3 Ga 9 , Gd 3 Ru 4 Al 12 , Er 4 Pt 9 Al 24 , CeOsGa 4 , CaCr 2 Al 10 , and the four stacking variants with the compositions TbRe 2 Al 10 , DyRe 2 Al 10 , YbFe 2 Al 10 , and LuRe 2 Al 10

  9. X-ray fluorescence analysis of Fe - Ni - Mo systems

    Belyaev, E.E.; Ershov, A.V.; Mashin, A.I.; Mashin, N.I.; Rudnevskij, N.K.

    1998-01-01

    Procedures for the X-ray fluorescence determination of the composition and thickness of Fe - Ni - Mo thin films and the concentration of elements in thick films of the Fe - Ni - Mo alloy are developed [ru

  10. Reactions of ethanol on Ru

    Sturm, Jacobus Marinus; Liu, Feng; Lee, Christopher James; Bijkerk, Frederik

    2012-01-01

    The adsorption and reactions of ethanol on Ru(0001) were studied with temperatureprogrammed desorption (TPD) and reflection-absorption infrared spectroscopy (RAIRS). Ethanol was found to adsorb intact onto Ru(0001) below 100 K. Heating to 250 K resulted in formation of ethoxy groups, which undergo

  11. Synthesis, characterization and use of Ru-Fc intercalation complex as an electrochemical label for the detection of pathogen-DNA

    Díaz-Serrano, M; Rosado, A; Guadalupe, A R; Santana, D; Vega, E Z

    2013-01-01

    This report describes the synthesis of [Ru(Fe-Phen) 2 dppz](PF 6 ) 2 (Ru-Fe complex) for a label-free approach to detect DNA hybridization. The Ru-Fe complex showed oxidation signals at +608 mV and +1192 mV corresponding to the RuII/III and FeII/III centers, respectively. We used the Ru-Fe complex and the Ferrocene covalently attached to the target to monitor the hybridization event of a 70-mer oligo immobilized in 10.3KD NHS-PS-NHS. The lowest target detectable concentration for the DNA fragment was around 0.4 μM.

  12. Distribución de serotipos de Streptococcus pneumoniae aislados de infecciones invasoras en el Hospital de Niños de Santa Fe Serotype distribution of Streptococcus pneumoniae isolated from invasive infections at the Hospital de Niños of Santa Fe.

    C. Mayoral

    2008-03-01

    Full Text Available Con la introducción de vacunas conjugadas antineumocócicas se observó, en muchos países, disminución de aislamientos de Streptococcus pneumoniae del serotipo 14 y aumento de aislamientos correspondientes a serotipos no incluidos en esas vacunas. En 1993, el Hospital de Niños de Santa Fe comenzó la vigilancia de la distribución de serotipos de Streptococcus pneumoniae invasores. En este trabajo se estudió la correlación entre serotipo y a patología (neumonía/meningitis, b edad (menor o mayor de dos años, y c CIM de penicilina, para los serotipos aislados en el período 2003-2005. El serotipo predominante fue el 14, seguido del 1, 6B, 18C, 7F, 19F y 5. El serotipo 14 mostró asociación estadísticamente significativa con valores de CIM de penicilina entre 0,5 y 2 mg/l, no así con alguna patología, aunque se lo halló con mayor frecuencia en neumonías que en meningitis. Los serotipos 14 y 1 prevalecieron en niños menores y mayores de 2 años, respectivamente. La CIM de penicilina = 2 mg/l se observó más en neumonías que en meningitis. La frecuencia relativa de los diferentes serotipos hallados fue semejante a la observada en el período 1993-99; no obstante, los serotipos 18C, 4, 12F y 22F no se habían encontrado antes. La aparición de nuevos serotipos convierte en importante la vigilancia, dada la necesidad de formular vacunas que los incluyan y que efectivamente prevengan las infecciones neumocócicas más comunes.The serotype distribution of Streptococcus pneumoniae varies through time. The introduction of pneumococcal conjugate vaccines showed a decreased prevalence of pneumococcal invasive isolates belonging to serotype 14 and an increase of serotypes not therein included. In 1993, the Hospital de Niños of Santa Fe began surveillance of the serotype distribution of invasive S. pneumoniae disease. In the period 2003 - 2005, 76 isolates were analysed by studying the correlation between serotype and pathology, age and MIC

  13. The effect of CF4 addition on Ru etching with inductively coupled plasma

    Lim, Kyu Tae; Kim, Dong Pyo; Kim, Kyoung Tae; Kim, Chang Il

    2003-01-01

    Ru thin films were etched in CF 4 /O 2 plasma using an ICP (inductively coupled plasma etching) system. The etch rate of Ru thin films was examined as a function of gas mixing ratio. The maximum etch rate of Ru thin films was 168 nm/min at a CF 4 /O 2 gas mixing ratio of 10 %. The selectivity of Ru over SiO 2 was 1.3. From the OES (optical emission spectroscopy), the optical emission intensity of the O radical had a maximum value at 10 % of CF 4 gas concentration and decrease with further addition of CF 4 gas. From XPS (x-ray photoelectron spectroscopy) analysis, Ru-F bonds by the chemical reaction of Ru and F appeared in the surface of the etched Ru thin film in CF 4 /O 2 chemistry. RuF 3-4 compounds were suggested as a surface passivation layer that reduces the chemical reactions between Ru and O radicals. In a FE-SEM (field emission scanning electron microscope) micrograph, we had an almost perpendicular taper angle of 89 .deg.

  14. 101Ru NQR study in superconducting CeRu2

    Matsuda, Kazuyuki; Kohori, Yoh; Kohara, Takao

    1995-01-01

    We present measurements of the NQR spectrum and the nuclear spin lattice relaxation rate, 1/T 1 , of 101 Ru in superconducting CeRu 2 from 1.9 K to 10 K. From the NQR spectrum, the electric quadrupole interaction parameters were determined to be ν Q =13.2 MHz and η=0.1/T 1 varies in proportion to temperature in the normal state, and has the Hebel-Slichter coherence peak just below the superconducting transition temperature, T C , of 6.2 K, and decreases exponentially at low temperatures with the energy gap of 2Δ=4.0k B T C . 101 Ru NQR study indicates that CeRu 2 is an s-wave and strong-coupling superconductor. (author)

  15. Influence of ruthenium ions on the precipitation of α-FeOOH, α-Fe2O3 and Fe3O4 in highly alkaline media

    Krehula, Stjepko; Music, Svetozar

    2006-01-01

    The influence of ruthenium ions on the precipitation of goethite (α-FeOOH), α-Fe 2 O 3 and Fe 3 O 4 in highly alkaline media was investigated by 57 Fe Moessbauer and FT-IR spectroscopies, thermal field emission scanning electron microscope (FE SEM) and EDS. The presence of Ru-dopant strongly affected the precipitation of α-FeOOH at highly alkaline pH, i.e. the formation of α-Fe 2 O 3 was also noticed. A decrease of hyperfine magnetic field (HMF) at RT from 35.1 T (undoped α-FeOOH) to 31.3 T for sample with [Ru]/([Ru] + [Fe]) = 0.0196 was assigned to the incorporation of ruthenium ions into the α-FeOOH structure. Moessbauer spectroscopy showed the formation of stoichiometric Fe 3 O 4 for [Ru]/([Ru] + [Fe]) = 0.0291-0.0909. α-Fe 2 O 3 and Fe 3 O 4 did not show a tendency to the formation of solid solutions with ruthenium ions. FE SEM observations of the samples showed that reference α-FeOOH sample contained acicular particles of good uniformity, which increased the length up to ∼5 times with increase of concentration of ruthenium ions. On the other hand, large octahedral Fe 3 O 4 crystals (particles) were associated with small particles of ruthenium (hydrous) oxide with a size in the range ∼100 nm or less. A possible catalytic action of ruthenium that created reduction conditions for Fe 3+ ions and formation of Fe 2+ ions for precipitation of Fe 3 O 4 was discussed

  16. Modulation of transport properties of RuO2 with 3d transition metals

    Music, Denis; Chen, Yen-Ting; Geyer, Richard W; Bliem, Pascal; Schneider, Jochen M

    2014-01-01

    Using density functional theory, we have demonstrated that alloying of RuO 2 (P4 2 /mnm) with 3d transition metals (Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn) gives rise to a substantial increase in the Seebeck coefficient probably due to quantum confinement. As Fe yields the largest enhancement, it was selected for experimental verification. We synthesized combinatorial Ru–Fe–O thin films and subsequently measured their transport properties at elevated temperatures. The Fe-alloyed samples increase the Seebeck coefficient threefold with respect to the unalloyed RuO 2 specimen thereby verifying the theoretical prediction. The here obtained power factor of 274 μW K −2 m −1 is not only the largest reported value for RuO 2 based compounds but it also occurs at ∼600 °C thus increasing the Carnot efficiency significantly. (paper)

  17. Excitation functions and yields of proton induced reactions at intermediate energies leading to important diagnostics radioisotopes of {sup 52}Fe, {sup 77}Br, {sup 82}Rb, {sup 97}Ru, {sup 111}In, {sup 123}I, {sup 127}Xe, {sup 128}Cs, {sup 178}Ta and {sup 201}Tl

    Rurarz, E. [Soltan Inst. for Nuclear Studies, Otwock-Swierk (Poland)

    1994-12-31

    This report describes investigations of the excitation functions of the proton induced reactions on 14 targets (Mn, Co, Br, Rb, {sup 99}Tc, {sup 113}Cd, {sup 114}Cd, Cd, I, Cs, Ta, {sup 206,207,208}Pb) leading directly or indirectly to the formation of radionuclides {sup 52}Fe, {sup 77}Br, {sup 82}Rb, {sup 97}Ru, {sup 111}In, {sup 123}I, {sup 127}Xe, {sup 128}Cs, {sup 178}Ta and {sup 201}Tl frequently used in diagnostic procedures of nuclear medicine. The measurements of the excitation functions were made over a wide proton energy range from the reaction threshold up to 100 MeV using the stacked foil (or pellet) technique. Small energy steps were used to allow for accurate determination of the structure of excitation functions. For {sup 97}Ru, {sup 111}In and {sup 127}Xe formation with protons, new reaction channels and targets were used and data concerning this method are published for the first time. The data for {sup 52}Fe, {sup 77}Br, {sup 82}Rb, {sup 123}I, {sup 128}Cs and {sup 201}Tl obtained in the present work for the E{sub p}=70-100 MeV region are also published for the first time. The measured excitation functions for the formation of desired (and undesired) radionuclides (altogether 28 excitation functions) are compared with the theoretical ones calculated on the basis of a hybrid model of nuclear reactions in the form of the Overlaid Alice computer code. In order to determine the contribution of the competitive reaction channels to the purity of the produced, desired radionuclide, the excitation functions of the accompanying reactions were also calculated. The 122 calculated excitation functions for the possible contaminant are given. The comparison of experimental excitation functions with the results of model calculations showed satisfactory agreement; no parameter adjustment for individual reaction products was undertaken. Production yields for 28 radionuclides mentioned above were determined (author). 262 refs, 65 figs, 34 tabs.

  18. The effect of diluting ruthenium by iron in Ru{sub x}Se{sub y} catalyst for oxygen reduction

    Delacote, Cyril [Laboratory of Electrocatalysis, CNRS, University of Poitiers, F-86022 Poitiers Cedex (France); CEISAM, CNRS, University of Nantes, F-44322 Nantes Cedex 3 (France); Lewera, Adam [University of Warsaw, Department of Chemistry, ul. Pasteura 1, 02-093 Warsaw (Poland); Pisarek, Marcin [Institute of Physical Chemistry, Polish Academy of Sciences, ul. Kasprzaka 44/52, 01-224 Warsaw (Poland); Kulesza, Pawel J. [University of Warsaw, Department of Chemistry, ul. Pasteura 1, 02-093 Warsaw (Poland); Zelenay, Piotr [Materials Physics and Applications, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Alonso-Vante, Nicolas, E-mail: nicolas.alonso.vante@univ-poitiers.f [Laboratory of Electrocatalysis, CNRS, University of Poitiers, F-86022 Poitiers Cedex (France)

    2010-11-01

    This study has focused on the synthesis of novel oxygen reduction reaction (ORR) chalcogenide catalysts, with Ru partially replaced by Fe in a cluster-type Ru{sub x}Se{sub y}. The catalysts were obtained by thermal decomposition of Ru{sub 3}(CO){sub 12} and Fe(CO){sub 5} in the presence of Se. As indicated by the XPS data, the composition of catalyst nanoparticles depends on the solvent used (either p-xylene or dichlorobenzene). The presence of iron in synthesized catalysts has been confirmed by both EDAX and XPS. Voltammetric activation of the catalysts results in a partial removal of iron and unreacted selenium from the surface. The ORR performance of electrochemically pre-treated catalysts was evaluated using rotating disk and ring-disk electrodes in a sulfuric acid solution. No major change in the ORR mechanism relative to the Se/Ru catalyst has been observed with Fe-containing catalysts.

  19. Round table on RU486.

    Shallat, L

    1993-01-01

    As a non-invasive means of early abortion, RU-486 has the potential to increase women's reproductive options; at the same time, the "abortion pill" has stimulated debate about the ethics and safety of new medical technologies. When combined with a prostaglandin (PG), the success rate for RU-486 is 96% for pregnancies of up to 9 weeks' gestation. In France, over 120,000 women have used RU-486/PG to terminate pregnancy, and this regimen is now used in about 25% of abortions. Clinical trials of RU-486 are underway in Cuba, China, India, Singapore, and Zambia. The Program for Appropriate Technology has identified four considerations for introducing RU-486 to developing countries: whether abortion or menstrual regulation is legal; whether women find the method acceptable and can comply with the multiple visit treatment regimen; whether the health infrastructure can support safe method use, including prevention of misuse and provision of appropriate medical backup personnel and facilities; and whether the cost of the regimen is affordable to individuals and/or programs --conditions unlikely to be met in most such countries. Ideal would be development of a medical abortifacient that is single dose and the lowest possible dose of each drug, provokes miscarriage within a more predictable time frame with less acute and prolonged bleeding, is safe and effective beyond two months, has minimal side effects, and maximizes short-term safety and minimizes long-term effects. Technological advances are being undermined, however, by political and religious attacks on the method. Even some feminists have expressed concerns about potential long-term effects of RU-486 use.

  20. Diseño de un plan lector dirigido a niños de 4 a 5 años del proyecto Cuéntamelo Todo – Fe y Alegría.

    Rueda Ramírez, Lisbeth Carolina

    2014-01-01

    This learning product is based on the design of a reading plan aimed at children from 4 to 5 years old, from the project “Cuéntamelo Todo-Fe y Alegría” from Quito. This was created because of the need to teach kids how to read at a young age, through playful, fun and creative activities which make kids enjoy written texts. The idea is born of a previous experience which took place at a university level in the previously mentioned project; this tool is designed so project collab...

  1. 103Ru for tumor scanning, 2

    Mizukawa, Kiichiro

    1979-01-01

    The mechanism of 103 Ru-uptake in tumors was investigated through the incubation of rat ascites hepatoma cells (AH-130) in vitro with various concentrations of Ru-chloride containing 103 Ru-chloride as a tracer. Quantitative analysis of Ru binding to the cells indicated that ascites hepatoma cells contained high- and low-affinity binding sites for Ru. When ascites hepatoma cells were incubated with Ru after incubation with a low concentration of papain, most of the Ru was not bound to the cells but was found in the medium containing solubilized glycoproteins. However Ru bound mainly to washed cells after the incubation with papain. About 65% of the Ru bound to ascites hepatoma cells was liberated by the papain treatment, and about 45% of the liberated Ru was precipitated by cetyltrimethylammonium bromide, indicating that Ru bound tightly to glycopeptides. These results suggest that the tumor affinity of 103 Ru is related to specific binding to glycopeptides on the tumor cell surface. (author)

  2. Ru (amp)(bipy)Cl

    Administrator

    [RuV(amp)(bipy)O]+ intermediate complex which leads to the high affinity for hydrogen atom/hydride abstraction. Acknowledgement. We gratefully acknowledge the financial support from the Department of Science &. Technology, Government of India. We are thankful to Shri Hardyal Singh for his encouragement. Reference.

  3. Engineering of RuMb: Toward a Green Catalyst for Carbene Insertion Reactions.

    Wolf, Matthew W; Vargas, David A; Lehnert, Nicolai

    2017-05-15

    The small, stable heme protein myoglobin (Mb) was modified through cofactor substitution and mutagenesis to develop a new catalyst for carbene transfer reactions. The native heme was removed from wild-type Mb and several Mb His64 mutants (H64D, H64A, H64V), and the resulting apoproteins were reconstituted with ruthenium mesoporphyrin IX (RuMpIX). The reconstituted proteins (RuMb) were characterized by UV-vis and circular dichroism spectroscopy and were used as catalysts for the N-H insertion of aniline derivatives and the cyclopropanation of styrene derivatives. The best catalysts for each reaction were able to achieve turnover numbers (TON) up to 520 for the N-H insertion of aniline, and 350 TON for the cyclopropanation of vinyl anisole. Our results show that RuMb is an effective catalyst for N-H insertion, with the potential to further increase the activity and stereoselectivity of the catalyst in future studies. Compared to native Mb ("FeMb"), RuMb is a more active catalyst for carbene transfer reactions, which leads to both heme and protein modification and degradation and, hence, to an overall much-reduced lifetime of the catalyst. This leads to lower TONs for RuMb compared to the iron-containing analogues. Strategies to overcome this limitation are discussed. Finally, comparison is also made to FeH64DMb and FeH64AMb, which have not been previously investigated for carbene transfer reactions.

  4. Studies on Kondo insulating FeSi

    Bharathi, A.; Mani, Awadhesh; Ravindran, Nithya; Mathi Jaya, S.; Sundar, C.S.; Hariharan, Y.

    2000-01-01

    Temperature dependent electrical resistivity measurements have been carried out in Fe (1-x) Ru x Si and FeSi (1-x) Ge x to examine the robustness of the Kondo Insulating gap to substitution in the Fe and Si sublattices. The gap is seen to decrease with Ge substitution, while for Ru substitution the gap shows an initial decrease followed by an increase at higher concentration. The results can be understood in terms of the shift in the mobility edge due to disorder and/or pressure effects in combination with changes in band structure

  5. Simulating Ru L3-edge X-ray absorption spectroscopy with time-dependent density functional theory: model complexes and electron localization in mixed-valence metal dimers.

    Van Kuiken, Benjamin E; Valiev, Marat; Daifuku, Stephanie L; Bannan, Caitlin; Strader, Matthew L; Cho, Hana; Huse, Nils; Schoenlein, Robert W; Govind, Niranjan; Khalil, Munira

    2013-05-30

    Ruthenium L3-edge X-ray absorption (XA) spectroscopy probes unoccupied 4d orbitals of the metal atom and is increasingly being used to investigate the local electronic structure in ground and excited electronic states of Ru complexes. The simultaneous development of computational tools for simulating Ru L3-edge spectra is crucial for interpreting the spectral features at a molecular level. This study demonstrates that time-dependent density functional theory (TDDFT) is a viable and predictive tool for simulating ruthenium L3-edge XA spectroscopy. We systematically investigate the effects of exchange correlation functional and implicit and explicit solvent interactions on a series of Ru(II) and Ru(III) complexes in their ground and electronic excited states. The TDDFT simulations reproduce all of the experimentally observed features in Ru L3-edge XA spectra within the experimental resolution (0.4 eV). Our simulations identify ligand-specific charge transfer features in complicated Ru L3-edge spectra of [Ru(CN)6](4-) and Ru(II) polypyridyl complexes illustrating the advantage of using TDDFT in complex systems. We conclude that the B3LYP functional most accurately predicts the transition energies of charge transfer features in these systems. We use our TDDFT approach to simulate experimental Ru L3-edge XA spectra of transition metal mixed-valence dimers of the form [(NC)5M(II)-CN-Ru(III)(NH3)5](-) (where M = Fe or Ru) dissolved in water. Our study determines the spectral signatures of electron delocalization in Ru L3-edge XA spectra. We find that the inclusion of explicit solvent molecules is necessary for reproducing the spectral features and the experimentally determined valencies in these mixed-valence complexes. This study validates the use of TDDFT for simulating Ru 2p excitations using popular quantum chemistry codes and providing a powerful interpretive tool for equilibrium and ultrafast Ru L3-edge XA spectroscopy.

  6. Metalloradical Reactivity of RuI and Ru0 Stabilized by an Indole-Based Tripodal Tetraphosphine Ligand

    van de Watering, F.F.; van der Vlugt, J.I.; Dzik, W.I.; de Bruin, B.; Reek, J.N.H.

    2017-01-01

    The tripodal, tetradentate tris(1-(diphenylphosphanyl)-3-methyl-1H-indol-2-yl)phosphane PP3-ligand 1 stabilizes Ru in the RuII, RuI, and Ru0 oxidation states. The octahedral [(PP3)RuII(Cl)2] ( 2 ), distorted trigonal bipyramidal [(PP3)RuI(Cl)] ( 3 ), and trigonal bipyramidal [(PP3)Ru0(N2)] ( 4 )

  7. Associação entre perda auditiva induzida pelo ruído e zumbidos

    Dias Adriano

    2006-01-01

    Full Text Available O estudo verificou a associação entre perda auditiva induzida por ruído (PAIR e queixa de zumbido em trabalhadores expostos ao ruído ocupacional. Foram entrevistados e avaliados trabalhadores com histórico de exposição ao ruído ocupacional atendidos em dois ambulatórios de audiologia. Estudou-se a existência de associação entre PAIR e ocorrência de zumbido por intermédio do ajuste de modelo de regressão logística, tendo como variável dependente o zumbido e como variável independente a PAIR, classificada em seis graus, controlada pelas co-variáveis idade e tempo de exposição ao ruído. Os dados foram coletados entre abril e outubro de 2003, na Cidade de Bauru, Estado de São Paulo, Brasil, contemplando 284 trabalhadores. Estimou-se que a prevalência de zumbido aumenta de acordo com a evolução do dano auditivo, controlado para a idade e tempo de exposição ao ruído. Os achados justificam o investimento em programas de conservação auditiva particularmente voltados para o controle da emissão de ruídos na fonte e para a intervenção na evolução das perdas auditivas geradas pela exposição ao ruído visando à manutenção da saúde auditiva e à diminuição dos sintomas associados.

  8. Functional properties of electrospun NiO/RuO{sub 2} composite carbon nanofibers

    Wu Yongzhi [Healthcare and Energy Materials Laboratory, Nanoscience and Nanotechnology Initiative, National University of Singapore, Singapore 117576 (Singapore); Physics Department, National University of Singapore, Singapore 117542 (Singapore); NUS Graduate School for Integrated Science and Engineering, 10 Kent Ridge Crescent, National University of Singapore, Singapore 119260 (Singapore); Balakrishna, Rajiv [Healthcare and Energy Materials Laboratory, Nanoscience and Nanotechnology Initiative, National University of Singapore, Singapore 117576 (Singapore); Physics Department, National University of Singapore, Singapore 117542 (Singapore); Reddy, M.V., E-mail: phymvv@nus.edu.sg [Physics Department, National University of Singapore, Singapore 117542 (Singapore); Nair, A. Sreekumaran, E-mail: nniansn@nus.edu.sg [Healthcare and Energy Materials Laboratory, Nanoscience and Nanotechnology Initiative, National University of Singapore, Singapore 117576 (Singapore); Chowdari, B.V.R. [Physics Department, National University of Singapore, Singapore 117542 (Singapore); Ramakrishna, S. [Healthcare and Energy Materials Laboratory, Nanoscience and Nanotechnology Initiative, National University of Singapore, Singapore 117576 (Singapore); Kind Saud University, Riyadh 11451 (Saudi Arabia)

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer Fabrication of carbon nanofibers with nickel-ruthenium composites by electrospinning. Black-Right-Pointing-Pointer An interesting observation of increase in capacitance with increase in the number of cycles for supercapacitor applications. Black-Right-Pointing-Pointer Li ion battery testing showed a stable capacity ranging from 350 mAh g{sup -1} to 400 mAh g{sup -1}. Black-Right-Pointing-Pointer Lower impedance with the incorporation of 15 wt% Ru precursor than those without Ru. - Abstract: One-dimensional (1D) nickel oxide/ruthenium oxide (NiO/RuO{sub 2})-carbon composite nanofibers (NiRu-C-NFs) were fabricated via electrospinning of a homogenous mixture of polyacrylonitrile (PAN) and Ni/Ru salt precursors at different ratios followed by heat treatments. The 1D nanostructures of the composite material were characterized by field-emission scanning electron microscopy (FE-SEM), powder X-ray diffraction (XRD), Rietveld refinement and Brunauer-Emmett-Teller (BET) surface area measurements. Li-cycling properties were evaluated using cyclic voltammetry and galvanostatic properties. The asymmetric hybrid supercapacitor studies were carried out with activated carbon as a cathode and NiRu-C-NFs composites as anodes in the cycling range, 0.005-3.0 V using 1 M LiPF{sub 6} (EC;DMC) electrolyte. NiRu-C-NFs fabricated from 5 wt% nickel (II) and 15 wt% ruthenium (III) precursors showed a capacitance up to {approx}60 F g{sup -1} after 30 cycles. Anodic Li-cycling studies of NiRu-C-NF-0 and NiRu-C-NF-2 composite samples showed a reversible capacity of 230 and 350 m Ahg{sup -1} at current rate of 72 mA g{sup -1} at the end of 40th cycle in the voltage range of 0.005-3.0 V. Electrochemical impedance studies (EIS) on NiRu-C-NFs showed lower impedance value for 15 wt% Ru than the bare sample.

  9. Estudio en niños con diagnóstico presuntivo de toxocariasis en Santa Fe, Argentina Analysis of children with a presumptive diagnosis of toxocariasis in Santa Fe, Argentina

    Ubaldo O. Martín

    2008-10-01

    Full Text Available La toxocariasis humana es una parasitosis de amplia distribución en el mundo, cuyo agente etiológico más importante es el Toxocara canis, parásito del perro. El hombre adquiere esta zoonosis mediante la ingesta de huevos infectivos; en el intestino delgado desarticulan sus envolturas y las larvas se liberan atravesando la mucosa, ubicándose en diversos tejidos. Los niños son la población de mayor riesgo. El diagnostico clínico es dificultoso. El test de ELISA usando antígenos de excreción-secreción de la larva, es la técnica de elección. Se estudiaron por esta técnica inmunoserológica 100 niños con diagnóstico presuntivo de toxocariasis y se revisaron posteriormente sus historias clínicas de Hospital. La técnica de diagnóstico fue estandarizada y validada en el laboratorio. Su aplicación permitió identificar dos poblaciones de niños: infectados (59 y no infectados (41. La eosinofilia fue más frecuente en la población infectada (100% vs. 85.2%, p = 0.017; no así la leucocitosis (p = 0.950. La fuerza de asociación de ambos parámetros fue mayor en la población positiva (R = 0.918. La dificultad respiratoria se presentó más frecuentemente en pacientes con ELISA positiva, considerados como infectados (p = 0.05. La edad promedio de los positivos fue significativamente mayor que la de los negativos (p = 0.009. Se halló eosinofilia en el 100% de los infectados y en el 85.2% de los no infectados. La tenencia de canes en los domicilios no fue significativamente mayor entre los casos positivos que entre los negativos (p = 0.53. Sería necesario investigar esta enfermedad en niños consultantes con sospecha clínica, y promover las medidas de prevención, diagnóstico temprano y su correcto tratamiento.Human toxocariasis is a parasitic disease found worldwide. The most important etiological agent is Toxocara canis, a dog parasite. Humans are infected by the ingestion of their eggs; the eggs hatch in the small intestine and

  10. Estrategia de actividades de educación medio ambiental que contribuyan a elevar el conocimiento de los pobladores entre 30 y 40 años de la base de pesca de la Fe del Municipio Sandino

    Liuba Berra Hernández

    2011-12-01

    Full Text Available El presente trabajo aborda un problema de gran interés para la sociedad y para el mundo en general, como es la Educación Ambiental, una vía para ponerle fin a los problemas globales del medio ambiente. Se propone una estrategia de actividades físico- recreativas de Educación Medio Ambiental que contribuyan a elevar el conocimiento de los pobladores entre 30 y 40 años de la base de pesca de La Fe del municipio Sandino. Una vez identificado el problema se hace el análisis de la literatura y documentos existente sobre el tema, en el cual se incluye también visitas a las zonas priorizadas para la investigación. Este trabajo permite a los pobladores elevar su nivel de conciencia en cuanto al tema y la búsqueda de alternativas para cuidar y proteger el medio ambiente. La investigación se realizó con la colaboración de el organismo beneficiado con la misma, en ella se aplicaron observaciones al lugar, entrevistas y encuestas a pobladores y al administrador de la base de pesca para que la temática pueda ser resuelta. Con la estrategia de actividades físico-recreativas se logró que los pobladores adquirieran una educación ambiental y se concientizaran en vistas del proceso de protección y conservación del entorno natural de la base de pesca de La Fe de Sandino.

  11. Inner-shell photodetachment from Ru-

    Dumitriu, I.; Gorczyca, T. W.; Berrah, N.; Bilodeau, R. C.; Pesic, Z. D.; Rolles, D.; Walter, C. W.; Gibson, N. D.

    2010-01-01

    Inner-shell photodetachment from Ru - was studied near and above the 4p excitation region, 29-to-91-eV photon energy range, using a merged ion-photon-beam technique. The absolute photodetachment cross sections of Ru - ([Kr]4d 7 5s 2 ) leading to Ru + , Ru 2+ , and Ru 3+ ion production were measured. In the near-threshold region, a Wigner s-wave law, including estimated postcollision interaction effects, locates the 4p 3/2 detachment threshold between 40.10 and 40.27 eV. Additionally, the Ru 2+ product spectrum provides evidence for simultaneous two-electron photodetachment (likely to the Ru + 4p 5 4d 6 5s 2 state) located near 49 eV. Resonance effects are observed due to interference between transitions of the 4p electrons to the quasibound 4p 5 4d 8 5s 2 states and the 4d→εf continuum. Despite the large number of possible terms resulting from the Ru - 4d open shell, the cross section obtained from a 51-state LS-coupled R-matrix calculation agrees qualitatively well with the experimental data.

  12. Formation of graphene on Ru(0001) surface

    Pan Yi; Shi Dong-Xia; Gao Hong-Jun

    2007-01-01

    We report on the formation of a graphene monolayer on a Ru(0001) surface by annealing the Ru(0001) crystal.The samples are characterized by scanning tunnelling microscopy (STM) and Auger electron spectroscopy (AES). STM images show that the Moiré pattern is caused by the graphene layer mismatched with the underlying Ru(0001) surface and has an N × N superlattice. It is further found that the graphene monolayer on a Ru(0001) surface is very stable at high temperatures. Our results provide a simple and convenient method to produce a graphene monolayer on the Ru(0001) surface, which is used as a template for fabricating functional nanostructures needed in future nano devices and catalysis.

  13. Produção de grãos e absorção de Cu, Fe, Mn e Zn pelo milho em solo adubado com lodo de esgoto, com e sem calcário Corn yield and uptake of Cu, Fe, Mn and Zn from sewage sludge-amended soil with and without liming

    A. L. C. Martins

    2003-06-01

    Full Text Available O lodo de esgoto (LE, apesar do seu reconhecido valor como fertilizante, ainda é motivo de preocupação quando usado na agricultura, em virtude do potencial de absorção excessiva de metais pesados pelas plantas e entrada na cadeia alimentar. Para avaliar o efeito da adição de 0, 20, 40, 60 e 80 Mg ha-1 (com base no material seco de LE, aplicado de forma única ou parcelada em 2, 3 e 4 anos nas doses de 40, 60 e 80 Mg ha-1, respectivamente, com e sem calcário, na produção de grãos e massa seca da parte aérea e na absorção de Cu, Fe, Mn e Zn pelo milho, foi realizado, em Cordeirópolis (SP, um experimento em condições de campo, utilizando um Latossolo Vermelho distrófico típico, no período de 1983 a 1987. Foi utilizado o experimento em faixas ("split block" com quatro repetições. A maior dose de LE adicionou ao solo, em kg ha-1, 63, 3040, 25 e 152 de Cu, Fe, Mn e Zn, respectivamente. A produção de grãos e de massa seca da parte aérea aumentou linearmente com a adição de LE nos anos estudados. O LE aumentou significativamente as concentrações de Zn nas folhas e na parte aérea e provocou a redução nas concentrações de Fe e Mn, mas não alterou as de Cu. As concentrações dos metais nos grãos não foram influenciadas de forma significativa pela adição de LE, estando mesmo nas maiores doses, dentro dos níveis aceitáveis, sem causar restrição ao consumo humano. A absorção de Zn, Fe e Mn pelo milho foi significativamente reduzida pela adição de calcário. O Zn foi o metal que mais teve reduzida sua concentração na parte aérea pela adição de calcário. O parcelamento das doses de lodo de 40 a 80 Mg ha-1 provocou, de modo geral, aumento das quantidades absorvidas de metais pelo milho, sendo o Fe e o Zn os elementos que mais se acumularam na planta em resposta a esse parcelamento.Although the value of sewage sludge (SS as a fertilizer has long been recognized, it is still a matter of considerable concern

  14. The Effect of pH on Slurry Erosion-Corrosion of Tungsten Carbide Overlays Alloyed with Ru

    Nelwalani, Ndivhuwo B.; van der Merwe, Josias W.

    2018-02-01

    The aim of the study was to determine the effect of Ru additions to WC-Fe overlays when exposed to low pH slurry erosion conditions. These overlays were applied through Plasma Transferred Arc, and the original bulk Ru powder concentrations varied from 0.5 to 5 wt.%. A slurry jet impingement erosion-corrosion test rig was used to evaluate wear, and electrochemical measurements were performed to characterize the corrosion properties. The slurry mixtures contained silica sand and synthetic mine water. The pH was varied between 3 and 6.5 for the slurry erosion tests and lowered further for the corrosion characterization. Samples were examined optically and with a scanning electron microscope using energy-dispersive x-ray spectroscopy. X-ray diffraction analysis was used to determine the phases present. For the slurry erosion-corrosion results at the pH of 6.5, addition of Ru did not show a decrease in erosion-corrosion rates. However, when the pH was decreased to 3, by the addition of HCl, Ru improved the resistance. From the electrochemistry, it was also clear that Ru additions improved the corrosion resistance, but more than 1 wt.% Ru was required. At very low pH levels, the presence of Ru was not able to prevent corrosion.

  15. RE-SONANCE--I--Fe-b-ru-arY

    ... Everyone's Guide to. Science: The Universe, Life ... Universe, life and Everything ... science writer with a large numberofbooks to his credit. ... explanation of the whole of science in a ... or he would cetainly benefit from this book as it would ...

  16. Novel Electronic Structures of Ru-pnictides RuPn (Pn = P, As, Sb)

    Goto, H.; Toriyama, T.; Konishi, T.; Ohta, Y.

    Density-functional-theory-based electronic structure calculations are made to consider the novel electronic states of Ru-pnictides RuP and RuAs where the intriguing phase transitions and superconductivity under doping of Rh have been reported. We find that there appear nearly degenerate flat bands just at the Fermi level in the high-temperature metallic phase of RuP and RuAs; the flat-band states come mainly from the 4dxy orbitals of Ru ions and the Rh doping shifts the Fermi level just above the flat bands. The splitting of the flat bands caused by their electronic instability may then be responsible for the observed phase transition to the nonmagnetic insulating phase at low temperatures. We also find that the band structure calculated for RuSb resembles that of the doped RuP and RuAs, which is consistent with experiment where superconductivity occurs in RuSb without Rh doping.

  17. Antiferromagnetic order in (Lu.sub.0.8./sub.Ce.sub.0.2./sub.).sub.2./sub.Fe.sub.17./sub. and Lu.sub.2./sub.Fe.sub.16.5./sub.Ru.sub.0.5./sub.: high pressure study

    Tereshina, Evgeniya; Andreev, Alexander V.; Kamarád, Jiří; Isnard, O.

    2009-01-01

    Roč. 105, č. 7 (2009), 07A747/1-07A747/3 ISSN 0021-8979 R&D Projects: GA ČR GA202/09/0339 Grant - others:GA UK(CZ) GAUK 7015/2007; EC(XE) COST-STSM-P16-03025 Institutional research plan: CEZ:AV0Z10100520 Keywords : neutron-diffraction * magnetic-properties * LU 2 FE 17 Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.072, year: 2009

  18. Pressure study of magnetism in (Lu.sub.0.8./sub.Ce.sub.0.2./sub.).sub.2./sub.Fe.sub.17./sub. and Lu.sub.2./sub.Fe.sub.16.5./sub.Ru.sub.0.5./sub. single crystals

    Andreev, Alexander V.; Kamarád, Jiří; Tereshina, Evgeniya; Komatsubara, T.; Satoh, I.

    2008-01-01

    Roč. 121, č. 3 (2008), 032010/1-032010/4 ISSN 1742-6588. [Joint AIRAPT /21./ and EHPRG /45./ International Conference on High Pressure Science and Technology. Catania, 17.09.2007-21.09.2007] R&D Projects: GA ČR GA202/06/0178; GA ČR(CZ) GA202/06/0185 Grant - others:GAUK(CZ) 1507/2007 Institutional research plan: CEZ:AV0Z10100520 Keywords : pressure effect * magnetic moment * anisotropy * intermetallic compounds * Fe Subject RIV: BM - Solid Matter Physics ; Magnetism

  19. CoFeRh alloys

    Tabakovic, Ibro [Seagate Technology, Research and Development, Bloomington, MN 55435 (United States)], E-mail: ibro.m.tabakovic@seagate.com; Qiu Jiaoming; Riemer, Steve; Sun Ming; Vas' ko, Vlad; Kief, Mark [Seagate Technology, Research and Development, Bloomington, MN 55435 (United States)

    2008-01-01

    The electrochemical behavior of Rh(III) species in CoFe solution containing RhCl{sub 3}, NH{sub 4}Cl, H{sub 3}BO{sub 3}, CoSO{sub 4}, FeSO{sub 4}, saccharin, and NaLS (Na lauryl sulfate) has been investigated. The electrochemistry of Rh(III) species is influenced by each of the compounds present in CoFe plating solution, but especially by addition of saccharin and H{sub 3}BO{sub 3} to the RhCl{sub 3}-NH{sub 4}Cl solution. The nucleation and growth of Rh on GC (glassy carbon), Ru, and Cu electrodes from NH{sub 4}Cl solution was studied using the potentiostatic current-transient methods. The results support a predominantly progressive nucleation of Rh on all three-electrode surfaces. The nucleation kinetic parameters ANo (steady state nucleation rate) and Ns (saturation nuclear number density) were found to vary with potential and are electrode-dependent in order: GC > Ru{approx}Cu. The electrodeposited Rh films obtained from NH{sub 4}Cl solution and nonmagnetic CoFeRh film obtained from CoFe solution were characterized in terms of the following properties: morphology, surface roughness, crystal structure and chemical composition. The origin of light elements found in Rh and CoFeRh films (O, Cl, S, C, N) was discussed.

  20. Possible multigap type-I superconductivity in the layered boride RuB2

    Singh, Jaskaran; Jayaraj, Anooja; Srivastava, D.; Gayen, S.; Thamizhavel, A.; Singh, Yogesh

    2018-02-01

    The structure of the layered transition-metal borides A B2 (A =Os,Ru ) is built up by alternating T and B layers with the B layers forming a puckered honeycomb. Here we report superconducting properties of RuB2 with a Tc≈1.5 K using measurements of the magnetic susceptibility versus temperature T , magnetization M versus magnetic field H , resistivity versus T , and heat capacity versus T at various H . We observe a reduced heat capacity anomaly at Tc given by Δ C /γ Tc≈1.1 suggesting multigap superconductivity. Strong support for this is obtained by the successful fitting of the electronic specific heat data to a two-gap model with gap values Δ1/kBTc≈1.88 and Δ2/kBTc≈1.13 . Additionally, M versus H measurements reveal a behavior consistent with type-I superconductivity. This is confirmed by comparing the experimental critical field ≈122 Oe obtained from extrapolation to T =0 of the H -T phase diagram, with an estimate of the T =0 thermodynamic critical field ≈114 Oe. Additionally, the Ginzburg-Landau parameter was estimated to be κ ≈0.1 -0.66 . These results strongly suggest multigap type-I superconductivity in RuB2. We also calculate the band structure and obtain the Fermi surface for RuB2. The Fermi surface consists of one quasi-two-dimensional sheet and two concentric ellipsoidal sheets very similar to OsB2. An additional small fourth sheet is also found for RuB2. RuB2 could thus be an example of a multigap type-I superconductor.

  1. Thermodynamic assessment of the Al-Ru system

    Prins, SN

    2003-03-01

    Full Text Available describes the order disorder transformation with one Gibbs energy function. The RuAl6 phase was described as a stoichiometric phase and the remaining intermetallic phases (Ru4Al13, RuAl2 and Ru2Al3) were modelled with the sublattice model. The solubility...

  2. Pseudogap behavior of RuP probed by photoemission spectroscopy

    Sato, K.; Ootsuki, D.; Wakisaka, Y.; Saini, N. L.; Mizokawa, T.; Arita, M.; Anzai, H.; Namatame, H.; Taniguchi, M.; Hirai, D.; Takagi, H.

    2012-01-01

    We have studied the electronic structure of RuP and related Ru pnictides using photoemission spectroscopy. Ru 3d core-level and valence-band spectra of RuP show that the Ru valence is +3 with t_{2g}^5 configuration. The photoemisson spectral weight near the Fermi level is moderately suppressed in the pseudogap phase of RuP, consistent with the pseudogap opening of 2\\Delta/k_BT_c ~ 3 (gap size \\Delta ~ 50 meV and transition temperature T_c ~ 330 K). The Ru 3d peak remains sharp in the pseudoga...

  3. Nanoscale decomposition of Nb-Ru-O

    Music, Denis; Geyer, Richard W.; Chen, Yen-Ting

    2016-11-01

    A correlative theoretical and experimental methodology has been employed to explore the decomposition of amorphous Nb-Ru-O at elevated temperatures. Density functional theory based molecular dynamics simulations reveal that amorphous Nb-Ru-O is structurally modified within 10 ps at 800 K giving rise to an increase in the planar metal - oxygen and metal - metal population and hence formation of large clusters, which signifies atomic segregation. The driving force for this atomic segregation process is 0.5 eV/atom. This is validated by diffraction experiments and transmission electron microscopy of sputter-synthesized Nb-Ru-O thin films. Room temperature samples are amorphous, while at 800 K nanoscale rutile RuO2 grains, self-organized in an amorphous Nb-O matrix, are observed, which is consistent with our theoretical predictions. This amorphous/crystalline interplay may be of importance for next generation of thermoelectric devices.

  4. New upper limit to the coronal line emission from the T Tauri star RU Lupi

    Gahm, G F [Stockholm Observatory (Sweden); Lago, M T.V.T. [Universidade do Porto (Portugal). Grupo de Matematica Aplicada; Penston, M V [ESTEC, European Space Agency, Villafranca Satellite Tracking Station, Madrid, (Spain)

    1981-05-01

    A high dispersion AAT spectrogram sets an upper limit on the (Fe x) emission line lambda 6374.5 A in the T Tauri star RU Lupi. The intensity of any 10/sup 6/ K corona in this star is less than 600 times that of the Sun compared to a chromosphere and transition region of 3 x 10/sup 3/ to 2 x 10/sup 5/ K gas 10/sup 6/ times stronger than the Sun's. The important theoretical implications are noted.

  5. Interface Control of Ferroelectricity in an SrRuO3 /BaTiO3 /SrRuO3 Capacitor and its Critical Thickness.

    Shin, Yeong Jae; Kim, Yoonkoo; Kang, Sung-Jin; Nahm, Ho-Hyun; Murugavel, Pattukkannu; Kim, Jeong Rae; Cho, Myung Rae; Wang, Lingfei; Yang, Sang Mo; Yoon, Jong-Gul; Chung, Jin-Seok; Kim, Miyoung; Zhou, Hua; Chang, Seo Hyoung; Noh, Tae Won

    2017-05-01

    The atomic-scale synthesis of artificial oxide heterostructures offers new opportunities to create novel states that do not occur in nature. The main challenge related to synthesizing these structures is obtaining atomically sharp interfaces with designed termination sequences. In this study, it is demonstrated that the oxygen pressure (PO2) during growth plays an important role in controlling the interfacial terminations of SrRuO 3 /BaTiO 3 /SrRuO 3 (SRO/BTO/SRO) ferroelectric (FE) capacitors. The SRO/BTO/SRO heterostructures are grown by a pulsed laser deposition method. The top SRO/BTO interface, grown at high PO2 (around 150 mTorr), usually exhibits a mixture of RuO 2 -BaO and SrO-TiO 2 terminations. By reducing PO2, the authors obtain atomically sharp SRO/BTO top interfaces with uniform SrO-TiO 2 termination. Using capacitor devices with symmetric and uniform interfacial termination, it is demonstrated for the first time that the FE critical thickness can reach the theoretical limit of 3.5 unit cells. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Simulating Ru L 3 -Edge X-ray Absorption Spectroscopy with Time-Dependent Density Functional Theory: Model Complexes and Electron Localization in Mixed-Valence Metal Dimers

    Van Kuiken, Benjamin E.; Valiev, Marat; Daifuku, Stephanie L.; Bannan, Caitlin; Strader, Matthew L.; Cho, Hana; Huse, Nils; Schoenlein, Robert W.; Govind, Niranjan; Khalil, Munira

    2013-05-30

    Ruthenium L3-edge X-ray absorption (XA) spectroscopy probes unoccupied 4d orbitals of the metal atom and is increasingly being used to investigate the local electronic structure in ground and excited electronic states of Ru complexes. The simultaneous development of computational tools for simulating Ru L3-edge spectra is crucial for interpreting the spectral features at a molecular level. This study demonstrates that time-dependent density functional theory (TDDFT) is a viable and predictive tool for simulating ruthenium L3-edge XA spectroscopy. We systematically investigate the effects of exchange correlation functional and implicit and explicit solvent interactions on a series of RuII and RuIII complexes in their ground and electronic excited states. The TDDFT simulations reproduce all of the experimentally observed features in Ru L3-edge XA spectra within the experimental resolution (0.4 eV). Our simulations identify ligand-specific charge transfer features in complicated Ru L3-edge spectra of [Ru(CN)6]4- and RuII polypyridyl complexes illustrating the advantage of using TDDFT in complex systems. We conclude that the B3LYP functional most accurately predicts the transition energies of charge transfer features in these systems. We use our TDDFT approach to simulate experimental Ru L3-edge XA spectra of transition metal mixed-valence dimers of the form [(NC)5MII-CN-RuIII(NH3)5] (where M = Fe or Ru) dissolved in water. Our study determines the spectral signatures of electron delocalization in Ru L3-edge XA spectra. We find that the inclusion of explicit solvent molecules is necessary for reproducing the spectral features and the experimentally determined valencies in these mixed-valence complexes. This study validates the use of TDDFT for simulating Ru 2p excitations using popular quantum chemistry codes and providing a powerful interpretive tool for equilibrium and ultrafast Ru L3-edge XA spectroscopy.

  7. Characterization and methanol electrooxidation studies of Pt(111)/Os surfaces prepared by spontaneous deposition.

    Johnston, Christina M; Strbac, Svetlana; Lewera, Adam; Sibert, Eric; Wieckowski, Andrzej

    2006-09-12

    Catalytic activity of the Pt(111)/Os surface toward methanol electrooxidation was optimized by exploring a wide range of Os coverage. Various methods of surface analyses were used, including electroanalytical, STM, and XPS methods. The Pt(111) surface was decorated with nanosized Os islands by spontaneous deposition, and the Os coverage was controlled by changing the exposure time to the Os-containing electrolyte. The structure of Os deposits on Pt(111) was characterized and quantified by in situ STM and stripping voltammetry. We found that the optimal Os surface coverage of Pt(111) for methanol electrooxidation was 0.7 +/- 0.1 ML, close to 1.0 +/- 0.1 Os packing density. Apparently, the high osmium coverage Pt(111)/Os surface provides more of the necessary oxygen-containing species (e.g., Os-OH) for effective methanol electrooxidation than the Pt(111)/Os surfaces with lower Os coverage (vs e.g., Ru-OH). Supporting evidence for this conjecture comes from the CO electrooxidation data, which show that the onset potential for CO stripping is lowered from 0.53 to 0.45 V when the Os coverage is increased from 0.2 to 0.7 ML. However, the activity of Pt(111)/Os for methanol electrooxidation decreases when the Os coverage is higher than 0.7 +/- 0.1 ML, indicating that Pt sites uncovered by Os are necessary for sustaining significant methanol oxidation rates. Furthermore, osmium is inactive for methanol electrooxidation when the platinum substrate is absent: Os deposits on Au(111), a bulk Os ingot, and thick films of electrodeposited Os on Pt(111), all compare poorly to Pt(111)/Os. We conclude that a bifunctional mechanism applies to the methanol electrooxidation similarly to Pt(111)/Ru, although with fewer available Pt sites. Finally, the potential window for methanol electrooxidation on Pt(111)/Os was observed to shift positively versus Pt(111)/Ru. Because of the difference in the Os and Ru oxophilicity under electrochemical conditions, the Os deposit provides fewer

  8. Effect of heavy-metal insertions at Fe/MgO interfaces on electric-field-induced modification of magnetocrystalline anisotropy

    Nakamura, K.; Nomura, T. [Department of Physics Engineering, Mie University, Tsu, Mie 514-8507 (Japan); Pradipto, A.-M. [Department of Physics Engineering, Mie University, Tsu, Mie 514-8507 (Japan); Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan); Nawa, K.; Akiyama, T.; Ito, T. [Department of Physics Engineering, Mie University, Tsu, Mie 514-8507 (Japan)

    2017-05-01

    Magnetocrystalline anisotropy (MCA) at Fe/MgO interfaces with insertions of 3d (Co, Ni), 4d (Ru, Rh, Pd), and 5d (Os, Ir, Pt) elements in external electric fields was investigated from first-principles calculations. The MCA energy and the electric-field-induced MCA modification dramatically depend on the inserted elements. Large MCA modification may be achieved by heavy-metal insertions, in which the strength of spin-orbit coupling of inserted elements and the position of the Fermi level relative to d band level play key roles. - Highlights: • MCA at Fe/MgO interface dramatically depends on insertions of 3d, 4d, and 5d elements. • Large electric-field-induced MCA modification is achieved by heavy-metal insertions. • Position of Fermi level relative to d band level plays key role in determining MCA.

  9. DETERMINACIÓN DEL ESTADO NUTRICIONAL EN PACIENTES CON ENFERMEDAD PULMONAR OBSTRUCTIVA CRÓNICA DEL PROGRAMA DE REHABILITACIÓN PULMONAR DEL HOSPITAL UNIVERSITARIO FUNDACIÓN SANTA FE DE BOGOTÁ DURANTE LOS AÑOS 2014-2015

    Estefanía Zuluaga

    2017-11-01

    Full Text Available Introducción: La Organización Mundial de la Salud (OMS estima que 65 millones de personas sufren de Enfermedad Pulmonar Obstructiva Crónica (EPOC moderada o severa siendo una enfermedad crónica cuyos fenotipos se encuentran relacionados con el estado nutricional y generan efectos metabólicos, y también sistémica multiorgánica progresiva, presenciando cambios estructurales y funcionales adversos en tejidos coronarios y musculo-esqueléticos. En 1968 Filley describió dos fenotipos en la enfermedad pulmonar avanzada: el llamado soplador azul, hoy denominado bronquítico y el soplador rosado, conocido como enfisematoso. El enfisematoso es un paciente desnutrido tendiendo hacia la caquexia; mientras que el bronquítico en su mayoría se encuentra en sobrepeso u obesidad, y presenta comorbilidades metabólicas. Objetivo: determinar el estado nutricional en pacientes con EPOC mediante la antropometría y el fenotipo para establecer una terapia multimodal caracterizada por tratamiento médico, nutricional y un plan de ejercicio que mejore las condiciones generales del paciente. Metodología: Se realizó un estudio observacional transversal, con recolección de la información de manera retrospectiva, analizando los registros clínicos de los pacientes del programa de Rehabilitación Pulmonar en el Hospital Universitario de la Fundación Santa Fe de Bogotá con EPOC en los años 2014 a 2015, con edad mayor de 18 años, el total de pacientes es de 37, 62% (n=23 mujeres; 38% (n= 14 hombres. Resultados: Hubo una mayor prevalencia de EPOC en mujeres no fumadoras y exfumadoras. Los pacientes, independientes del género, se encontraban en un 43,24% (n=16 en sobrepeso u obesidad, con un WHtR mayor o igual a 0.6, implicando el aumento en el riesgo cardiovascular, diabetes y síndrome metabólico. Los pacientes que presentaron bajo peso fueron un 10,81%(n=4, diferente a lo reportado en la literatura. Conclusión: Es necesario realizar estudios con

  10. Hydrogen solubility in austenite of Fe-Ni-Cr alloys

    Zhirnova, V.V.; Mogutnov, B.M.; Tomilin, I.A.

    1981-01-01

    Hydrogen solubility in Fe-Ni-Cr alloys at 600-1000 deg C is determined. Hydrogen solubility in ternary alloys can not be predicted on the basis of the data on its solubility in binary Fe-Ni, Fe-Cr alloys. Chromium and nickel effect on hydrogen solubility in iron is insignificant in comparison with the effect of these elements on carbon or nitrogen solubility [ru

  11. Carbon supported nanoparticles Pt Ru (Pt Ru/C electrocatalysts) prepared using electron beam irradiation; Preparacao de nanoparticulas de PtRu suportadas em carbono (eletrocatalisadores PtRu/C) utilizando feixe de eletrons

    Silva, Dionisio F. da; Oliveira Neto, Almir; Pino, Eddy S.; Linardi, Marcelo; Spinace, Estevam V. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Programa de Celulas a Combustivel], e-mail: espinace@ipen.br, e-mail: dfsilva@ipen.br

    2006-07-01

    Carbon-supported Pt Ru (electrocatalysts PtRu/C nanoparticles) were prepared submitting a water/ethylene glycol mixture containing Pt(IV) and Ru(III) ions and the carbon support to electron beam irradiation. The PtRu/C electrocatalysts were characterized by EDX, XRD and cyclic voltammetry and tested for methanol electro-oxidation aiming fuel cell application. The obtained PtRu/C electrocatalysts were more active for methanol electro-oxidation than the commercial PtRu/C ETEK electrocatalyst at ambient temperature. (author)

  12. Magnetic properties of Heusler alloy Mn2RuGe and Mn2RuGa ribbons

    Yang, Ling; Liu, Bohua; Meng, Fanbin; Liu, Heyan; Luo, Hongzhi; Liu, Enke; Wang, Wenhong; Wu, Guangheng

    2015-01-01

    Heusler alloys Mn 2 RuGe and Mn 2 RuGa have been prepared by melt-spinning method successfully. Theoretical and experimental studies reveal a ferrimagnetic ground state in the two alloys. The Curie temperatures are 303 K for Mn 2 RuGe and 272 K for Mn 2 RuGa. The calculated total spin moments of Mn 2 RuGe and Mn 2 RuGa are integral values of 2.00 μ B and 1.03 μ B , respectively. And the theoretical spin polarization ratio is also quite high. However, due to the atomic disorder in the ribbons, the saturation moments of them measured at 5 K are smaller than the calculated values, especially that of Mn 2 RuGa. This coincides with the disappearance of the superlattice reflection (111) and (200) peaks in the XRD pattern of Mn 2 RuGa. Annealing Mn 2 RuGa ribbon at 773 K can enhance the atomic ordering. Both saturation magnetic moment and Curie temperature increase obviously after the heat treatment. - Highlights: • Mn 2 RuGe and Mn 2 RuGa have been prepared by melt-spinning successfully. • Ferrimagnetic ground state has been confirmed in Mn 2 RuGe and Mn 2 RuGa. • High spin polarization has been predicted in Mn 2 RuGe. • Melt-spinning can be a possible way to adjust the atomic order of Heusler alloys

  13. Metabolism and dosimetry of 106Ru inhaled as 106RuO4 by beagle dogs

    Snipes, M.B.

    1981-01-01

    This report provides metabolism and dosimetry data for inhaled ruthenium developed from studies in Beagle dogs that were exposed by inhalation to 106 RuO 4 . Twenty-six dogs were exposed nose-only to 106 RuO 4 and sacrificed at times from 2 hr to 512 days after inhalation exposure. Ninety-nine percent of the initial body burden was retained with an effective half-time of 1.2 days, 0.7% with a half-time of 14 days and 0.3% with a half-time of 170 days. Initial deposition was primarily in the nasopharyngeal and tracheobronchial regions. Results for deposition and retention of 106 Ru inhaled as 106 RuO 4 in dogs were similar to what has been observed for humans. The data for dogs were used to develop a model to predict potential radiation exposure patterns for humans after inhalation exposure to 106 RuO 4 . The model indicates that for humans the nasopharyngeal region, lower large intestine, and tracheobronchial epithelium would receive approx. 36, 13 and 10 times, respectively, the dose to 500 days after inhalation exposure to 106 RuO 4 that the lung would receive. The nasopharyngeal region should be considered the critical region for inhalation exposures to 106 RuO 4 . (author)

  14. iOS app development portable genius

    Wentk, Richard

    2012-01-01

    The essential skills and technologies needed for iOS development in one handy guide! The unprecedented popularity of iOS devices, such as the iPhone, iPad, and iPod touch, has led to a development boom. If you’re eager to become part of the action, then this is the book for you! Packed with must-have information on iOS development, this handy guide covers Objective-C, Xcode, Frameworks, and sound design principles and explains how to upload an app to the app store and integrate apps with the latest advances that Apple offers developers. The featured tips and tricks will get you up and ru

  15. Incômodo causado pelo ruído urbano à população de Curitiba, PR

    Paulo Henrique Trombetta Zannin

    2002-08-01

    Full Text Available Descreve-se a reação da população de Curitiba, PR -- cidade com aproximadamente 1,6 milhões de habitantes --, ao ruído ambiental . Os dados foram coletados por meio de questionários distribuídos aleatoriamente a moradores da cidade. Dos 1.000 questionários distribuídos, 860 (86% foram avaliados. As principais fontes de ruído causadoras de incômodo identificadas foram o tráfego de veículos (73% e os vizinhos (38%, sendo que estes foram classificados como a principal fonte de desconforto. Todos os respondentes apontaram pelo menos um dos seguintes itens como geradores de ruído: vizinhos, animais, sirenes, construção civil, templos religiosos, casas noturnas, brinquedos e aparelhos domésticos. As principais reações ao ruído foram: irritabilidade (58%, baixa concentração (42%, insônia (20% e dores de cabeça (20%.

  16. Chalcogenide oxygen reduction reaction catalysis: X-ray photoelectron spectroscopy with Ru, Ru/Se and Ru/S samples emersed from aqueous media

    Lewera, A. [Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Department of Chemistry, Warsaw University, Pasteura 1, 02-093 Warsaw (Poland); Inukai, J. [Clean Energy Research Center, University of Yamanashi, 7-32 Miyamae-cho, Kofu 400-0006 (Japan); Zhou, W.P. [Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Cao, D. [Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin 150001 (China); Duong, H.T. [Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Alonso-Vante, N. [Laboratory of Electrocatalysis, UMR-CNRS 6503, University of Poitiers, F-86022 Poitiers (France)]. E-mail: Nicolas.Alonso.Vante@univ-poitiers.fr; Wieckowski, A. [Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States)]. E-mail: andrzej@scs.uiuc.edu

    2007-05-10

    Oxygen reduction Ru/Se and Ru/S fuel cell surface chalcogenide catalysts were prepared via chemical reaction of reduced Ru nanoparticles with selenium and sulfur in xylenes [D. Cao, A. Wieckowski, J. Inukai, N. Alonso-Vante, J. Electrochem. Soc. 153 (2006) A869]. The chalcogenide samples - as well as the starting chalcogens-free Ru nanoparticle material - were immobilized on a gold disk for X-ray Photoelectron Spectroscopy (XPS) characterization. While we found oxygen in most of the samples, predominantly from Ru oxides, we conclude that the oxygen on Ru/S may be located in subsurface sites: the subsurface oxygen. We also found that the transformation of the oxidized Ru black to metallic Ru required intensive electrochemical treatment, including hydrogen evolution. In contrast, five cyclic voltammetric scans in the potential range from 0.00 and 0.75 V versus RHE were sufficient to remove the oxygen forms from Ru/Se and, to a large extent, from Ru/S. We therefore conclude that Ru metal is protected against oxidation to Ru oxides by the chalcogens additives. The voltammetric treatment in the 0.00 and 0.75 V range also removed the SeO{sub 2} or SO {sub x} forms leaving anionic/elemental Se or S on the surface. Upon larger amplitude voltammetric cycling, from 0.00 to 1.20 V versus RHE, both Se and S were dissolved and the dissolution process was coincidental with the oxygen growth in/on the Ru samples.

  17. Chalcogenide oxygen reduction reaction catalysis: X-ray photoelectron spectroscopy with Ru, Ru/Se and Ru/S samples emersed from aqueous media

    Lewera, A.; Inukai, J.; Zhou, W.P.; Cao, D.; Duong, H.T.; Alonso-Vante, N.; Wieckowski, A.

    2007-01-01

    Oxygen reduction Ru/Se and Ru/S fuel cell surface chalcogenide catalysts were prepared via chemical reaction of reduced Ru nanoparticles with selenium and sulfur in xylenes [D. Cao, A. Wieckowski, J. Inukai, N. Alonso-Vante, J. Electrochem. Soc. 153 (2006) A869]. The chalcogenide samples - as well as the starting chalcogens-free Ru nanoparticle material - were immobilized on a gold disk for X-ray Photoelectron Spectroscopy (XPS) characterization. While we found oxygen in most of the samples, predominantly from Ru oxides, we conclude that the oxygen on Ru/S may be located in subsurface sites: the subsurface oxygen. We also found that the transformation of the oxidized Ru black to metallic Ru required intensive electrochemical treatment, including hydrogen evolution. In contrast, five cyclic voltammetric scans in the potential range from 0.00 and 0.75 V versus RHE were sufficient to remove the oxygen forms from Ru/Se and, to a large extent, from Ru/S. We therefore conclude that Ru metal is protected against oxidation to Ru oxides by the chalcogens additives. The voltammetric treatment in the 0.00 and 0.75 V range also removed the SeO 2 or SO x forms leaving anionic/elemental Se or S on the surface. Upon larger amplitude voltammetric cycling, from 0.00 to 1.20 V versus RHE, both Se and S were dissolved and the dissolution process was coincidental with the oxygen growth in/on the Ru samples

  18. Ru-assisted synthesis of Pd/Ru nanodendrites with high activity for ethanol electrooxidation

    Zhang, Ke; Bin, Duan; Yang, Beibei; Wang, Caiqin; Ren, Fangfang; Du, Yukou

    2015-07-01

    Due to the specific physical and chemical properties of a highly branched noble metal, the controllable synthesis has attracted much attention. This article reports the synthesis of Pd/Ru nanodendrites by a facile method using an oil bath in the presence of polyvinyl pyrrolidone, potassium bromide and ascorbic acid. The morphology, structure, and composition of the as-prepared catalysts were characterized by means of X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy. In the electrochemical measurement, the as-prepared Pd7/Ru1 bimetallic nanodendrites provide a large electrochemically active surface area and exhibit high peak current density in the forward scan toward ethanol electrooxidation, which is nearly four times higher than those of a pure Pd catalyst. The as-prepared Pd7/Ru1 catalysts also exhibit significantly enhanced cycling stability toward ethanol oxidation in alkaline medium, which are mainly ascribed to the synergetic effect between Pd and Ru. This indicates that the Pd7/Ru1 catalysts should have great potential applications in direct ethanol fuel cells.Due to the specific physical and chemical properties of a highly branched noble metal, the controllable synthesis has attracted much attention. This article reports the synthesis of Pd/Ru nanodendrites by a facile method using an oil bath in the presence of polyvinyl pyrrolidone, potassium bromide and ascorbic acid. The morphology, structure, and composition of the as-prepared catalysts were characterized by means of X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy. In the electrochemical measurement, the as-prepared Pd7/Ru1 bimetallic nanodendrites provide a large electrochemically active surface area and exhibit high peak current density in the forward scan toward ethanol electrooxidation, which is nearly four times higher than those of a pure Pd catalyst. The as-prepared Pd7/Ru1 catalysts also exhibit significantly

  19. Carbon monoxide oxidation on bimetallic Ru/Au(111 surfaces

    ROLF-JÜRGEN BEHM

    2001-02-01

    Full Text Available The electrochemical deposition of Ru on Au(111 was performed in 0.5 M H2SO4+10-4 M RuCl3 . The obtained bimetallic Ru/Au(111 surfaces were character-ised by cyclic voltammetry and in situ STM in 0.5 MH2SO4. The Ru deposit consists of nanoscale islands, which merge with increasing coverage. Two different types of bimetallic Ru/Au(111 surfaces with respect to the distribution of Ru islands over the Au(111 substrate surface were obtained. When the deposition was performed at potentials more positive than the range of Au(111 reconstruction, homogeneous nucleation occured resulting in a random distribution of Ru islands. When the deposition was performed on reconstructed Au(111 at low overpotentials, selective nucleation occured resulting in the replication of the Au(111 reconstruction. Only at higher deposition overpotentials, can multilayer deposits be formed, which exhibit a very rough surface morphology. The electrocatalytic activity of such structurally well defined Ru/Au(111 bimetallic surfaces was studied towards CO oxidation with the Ru coverage ranging from submonolayer to several monolayer. COstripping commences at about 0.2 Vand occurs over a broad potential range. The observed influence of the Ru structure on the CO stripping voltammetry is explained by local variations in the COadsorption energy, caused by differences in the local Ru structure and by effects induced by the Au(111 substrate.

  20. The provenance investigation on ancient chinese Ru porcelains by NAA

    Gao Zhengyao; Wang Jie; Chen Songhua

    1997-01-01

    The 28 samples of glazes and bodies of ancient Chinese Ru porcelains are analyzed by neutron activation. The 36 element contents in each sample are determined. The neutron activation analysis (NAA) data are analyzed by fuzzy cluster. The trend cluster diagram is obtained. The result shows that the ancient Chinese Ru porcelains were most probably from the same raw material source though they were from different time, fired in different kilns and in different colors. The near provenance relation between ancient Jun porcelain and ancient Ru porcelain is preliminarily analyzed. The two modern Ru porcelains approximate to ancient Ru porcelains, one becomes estranged from ancient Ru porcelains. Jingdezhen porcelain is unconcerned with Ru porcelains

  1. CoFeRh alloys

    Tabakovic, Ibro; Qiu Jiaoming; Riemer, Steve; Sun Ming; Vas'ko, Vlad; Kief, Mark

    2008-01-01

    The electrochemical behavior of Rh(III) species in CoFe solution containing RhCl 3 , NH 4 Cl, H 3 BO 3 , CoSO 4 , FeSO 4 , saccharin, and NaLS (Na lauryl sulfate) has been investigated. The electrochemistry of Rh(III) species is influenced by each of the compounds present in CoFe plating solution, but especially by addition of saccharin and H 3 BO 3 to the RhCl 3 -NH 4 Cl solution. The nucleation and growth of Rh on GC (glassy carbon), Ru, and Cu electrodes from NH 4 Cl solution was studied using the potentiostatic current-transient methods. The results support a predominantly progressive nucleation of Rh on all three-electrode surfaces. The nucleation kinetic parameters ANo (steady state nucleation rate) and Ns (saturation nuclear number density) were found to vary with potential and are electrode-dependent in order: GC > Ru∼Cu. The electrodeposited Rh films obtained from NH 4 Cl solution and nonmagnetic CoFeRh film obtained from CoFe solution were characterized in terms of the following properties: morphology, surface roughness, crystal structure and chemical composition. The origin of light elements found in Rh and CoFeRh films (O, Cl, S, C, N) was discussed

  2. Iron deficiency regulated OsOPT7 is essential for iron homeostasis in rice.

    Bashir, Khurram; Ishimaru, Yasuhiro; Itai, Reiko Nakanishi; Senoura, Takeshi; Takahashi, Michiko; An, Gynheung; Oikawa, Takaya; Ueda, Minoru; Sato, Aiko; Uozumi, Nobuyuki; Nakanishi, Hiromi; Nishizawa, Naoko K

    2015-05-01

    The molecular mechanism of iron (Fe) uptake and transport in plants are well-characterized; however, many components of Fe homeostasis remain unclear. We cloned iron-deficiency-regulated oligopeptide transporter 7 (OsOPT7) from rice. OsOPT7 localized to the plasma membrane and did not transport Fe(III)-DMA or Fe(II)-NA and GSH in Xenopus laevis oocytes. Furthermore OsOPT7 did not complement the growth of yeast fet3fet4 mutant. OsOPT7 was specifically upregulated in response to Fe-deficiency. Promoter GUS analysis revealed that OsOPT7 expresses in root tips, root vascular tissue and shoots as well as during seed development. Microarray analysis of OsOPT7 knockout 1 (opt7-1) revealed the upregulation of Fe-deficiency-responsive genes in plants grown under Fe-sufficient conditions, despite the high Fe and ferritin concentrations in shoot tissue indicating that Fe may not be available for physiological functions. Plants overexpressing OsOPT7 do not exhibit any phenotype and do not accumulate more Fe compared to wild type plants. These results indicate that OsOPT7 may be involved in Fe transport in rice.

  3. Average resonance capture studies of 102Ru

    Shi, Z.R.; Casten, R.F.; Stachel, J.; Bruce, A.M.

    1984-01-01

    The 102 Ru nucleus has been investigated via the ARC technique which ensures a complete set of J/sup π/ = 0 + , 1 +- , 2 +- , 3 +- , 4 +- , and 5 + levels up to 2 MeV. The results are discussed in the framework of the IBA-1 with Consistent Q. The calculations show good agreement with the empirical data especially for the O 2 + state, suggesting that it can be described in terms of collective degrees of freedom

  4. Laser Spectroscopy of Ruthenium Containing Diatomic Molecules: RuH/D and RuP.

    Adam, Allan G.; Konder, Ricarda M.; Nickerson, Nicole M.; Linton, Colan; Tokaryk, D. W.

    2015-06-01

    In the last few years, the Cheung group in Hong Kong and the Steimle group in Arizona have successfully studied several ruthenium containing diatomic molecules, RuX (X =C, O, N, B, using the laser-ablation molecular jet technique. Based on this success, the UNB spectroscopy group decided to try and find the optical signatures of other RuX molecules. Using CH_3OH and PH_3 as reactant gases, the RuH and RuP diatomic molecules have been detected in surveys of the 420 - 675 nm spectral region. RuD has also been made using fully deuterated methanol as a reactant. Dispersed fluorescence experiments have been performed to determine ground state vibrational frequencies and the presence of any low-lying electronic states. Rotationally resolved spectra for these molecules have also been taken and the analysis is proceeding. The most recent results will be presented. F. Wang et al., Journal of Chemical Physics 139, 174318 (2013). N. Wang et al., Journal of Physical Chemistry A 117, 13279 (2013). T. Steimle et al., Journal of Chemical Physics 119, 12965 (2003). N. Wang et al., Chemical Physics Letters 547, 21 (2012).

  5. Ru nanostructure fabrication using an anodic aluminum oxide nanotemplate and highly conformal Ru atomic layer deposition

    Kim, Woo-Hee; Park, Sang-Joon; Son, Jong-Yeog; Kim, Hyungjun [Department of Material Science and Engineering, POSTECH Pohang University of Science and Technology, San 31, Hyoja-Dong, Nam-Gu, Pohang 790-784 (Korea, Republic of)

    2008-01-30

    We fabricated metallic nanostructures directly on Si substrates through a hybrid nanoprocess combining atomic layer deposition (ALD) and a self-assembled anodic aluminum oxide (AAO) nanotemplate. ALD Ru films with Ru(DMPD)(EtCp) as a precursor and O{sub 2} as a reactant exhibited high purity and low resistivity with negligible nucleation delay and low roughness. These good growth characteristics resulted in the excellent conformality for nanometer-scale vias and trenches. Additionally, AAO nanotemplates were fabricated directly on Si and Ti/Si substrates through a multiple anodization process. AAO nanotemplates with various hole sizes (30-100 nm) and aspect ratios (2:1-20:1) were fabricated by controlling the anodizing process parameters. The barrier layers between AAO nanotemplates and Si substrates were completely removed by reactive ion etching (RIE) using BCl{sub 3} plasma. By combining the ALD Ru and the AAO nanotemplate, Ru nanostructures with controllable sizes and shapes were prepared on Si and Ti/Si substrates. The Ru nanowire array devices as a platform for sensor devices exhibited befitting properties of good ohmic contact and high surface/volume ratio.

  6. Spectroscopy of {sup 96}Ru and {sup 98}Ru: structures of varied character at N {>=} 52

    Reviol, W; Garg, U; Aprahamian, A; Davis, B F; Herr, M C; Naguleswaran, S; Walpe, J C; Ye, D [Notre Dame Univ., IN (United States); Ahmad, I; Carpenter, M P; Janssens, R V.F.; Khoo, T L; Lauritsen, T; Liang, Y [Argonne National Lab., IL (United States)

    1992-08-01

    The authors have investigated the onset of deformation at N {>=} 52 by performing high-spin gamma spectroscopy of {sup 96-98}Ru using the {sup 65}Cu({sup 36}S,pxn) reaction with the Argonne-Notre Dame {gamma}-ray facility. From the coincidence data associated with high multiplicity (k {>=} 8) events, they have established two main band structures in {sup 96-98}Ru which extend the previously-known level schemes significantly (up to > 20 {Dirac_h}). In {sup 96}Ru, one of the newly observed structures consists of five rotation-like E2 transitions and feeds into the known 9{sup (-)} state; the other structure bypasses the first one, and based on the observed level-spacings, is tentatively described as vibration-like. A rotational-like structure above a spin of 8 {Dirac_h}, along with a parallel vibration-like structure, has been observed in {sup 98}Ru as well. The data also contain some evidence for a weak sequence of dipole (presumably M1) transitions in {sup 96}Ru. This structure might be similar to the high-K oblate bands recently observed in {sup 119-123}I and {sup 198-20P}b. 9 refs., 3 figs.

  7. Magnetic phase transitions and magnetization reversal in MnRuP

    Lampen-Kelley, P.; Mandrus, D.

    The ternary phosphide MnRuP is an incommensurate antiferromagnetic metal crystallizing in the non-centrosymmetric Fe2P-type crystal structure. Below the Neel transition at 250 K, MnRuP exhibits hysteretic anomalies in resistivity and magnetic susceptibility curves as the propagation vectors of the spiral spin structure change discontinuously across T1 = 180 K and T2 = 100 K. Temperature-dependent X-ray diffraction data indicate that the first-order spin reorientation occurs in the absence of a structural transition. A strong magnetization reversal (MR) effect is observed upon cooling the system through TN in moderate dc magnetic fields. Positive magnetization is recovered on further cooling through T1 and maintained in subsequent warming curves. The field dependence and training of the MR effect in MnRuP will be discussed in terms of the underlying magnetic structures and compared to anomalous MR observed in vanadate systems. This work is supported by the Gordon and Betty Moore Foundation GBMF4416 and U.S. DOE, Office of Science, BES, Materials Science and Engineering Division.

  8. Substituent-directed structural and physicochemical controls of diruthenium catecholate complexes with ligand-unsupported Ru-Ru bonds.

    Chang, Ho-Chol; Mochizuki, Katsunori; Kitagawa, Susumu

    2005-05-30

    A family of diruthenium complexes with ligand-unsupported Ru-Ru bonds has been systematically synthesized, and their crystal structures and physical properties have been examined. A simple, useful reaction between Ru2(OAc)4Cl (OAc- = acetate) and catechol derivatives in the presence of bases afforded a variety of diruthenium complexes, generally formulated as [Na(n){Ru2(R4Cat)4}] (n = 2 or 3; R4 = -F4, -Cl4, -Br4, -H4, -3,5-di-t-Bu, and -3,6-di-t-Bu; Cat(2-) = catecholate). The most characteristic feature of the complexes is the formation of short ligand-unsupported Ru-Ru bonds (2.140-2.273 A). These comprehensive studies were carried out to evaluate the effects of the oxidation states and the substituents governing the molecular structures and physicochemical properties. The Ru-Ru bond distances, rotational conformations, and bending structures of the complexes were successfully varied. The results presented in this manuscript clearly demonstrate that the complexes with ligand-unsupported Ru-Ru bonds can sensitively respond to redox reactions and ligand substituents on the basis of the greater degree of freedom in their molecular structures.

  9. Sideward flow of K+ in Ru+Ru and Ni+Ni reactions sat SIS energies

    Crochet, P.; Herrmann, N.; Wisniewski, K.

    2000-01-01

    Experimental data on K + and proton sideward flow measured with the FOPI detector at SIS/GSI in the reactions Ru+Ru at 1.69 A GeV and Ni+Ni at 1.93 A GeV are presented. The K + sideward flow is found to be anti-correlated (correlated) with the one of protons at low (high) transverse momenta. When compared to the predictions of a transport model, the data favour the existence of an in-medium repulsive K + -nucleon potential. (author)

  10. Electron correlation in CaRuO3 and SrRuO3

    Singh, Ravi Shankar; Maiti, Kalobaran

    2005-01-01

    We investigate the role of electron correlation in the electronic structure of 4d transition-metal oxides CaRuO 3 and SrRuO 3 . The photoemission spectra collected at different surface sensitivities reveal qualitatively different surface and bulk electronic structures in these systems. Extracted bulk spectra could be simulated using first principle approaches consistently with their thermodynamic parameters within the same model. The estimated electron correlation strength (U/W ∼ 0.2) is significantly weak as expected in 4d systems and resolves the long-standing issue that arose due to the prediction of large U/W similar to 3d systems. (author)

  11. Gamma-gamma angular correlation measurement in the 100 Ru

    Kenchian, G.

    1990-01-01

    An angular correlation automatic spectrometer with two Ge(Li) detectors has been developed. The spectrometer moves automatically, controlled by a microcomputer. The gamma-gamma directional angular correlations of coincidence transitions have been measured in 100 Ru nuclide, following the β + and electron capture of 100 Rh. The 100 Rh source has been produced with 100 Ru(p,n) 100 Rh reaction, using the proton beam of the Cyclotron Accelerator insiding in 100 Ru isotope. (author)

  12. Enhanced anodic Ru(bpy)32+ electrogenerated chemiluminescence by polyphenols

    Lei Rong; Xu Xiao; Xu Da; Zhu Gang; Li Na; Liu Huwei; Li Kean

    2008-01-01

    Anodic Ru(bpy) 3 2+ electrogenerated chemiluminescence (ECL) can be enhanced by polyphenols in alkaline solution. Spin trapping-electron spin resonance (ESR) experiments verified that reactive oxygen species (ROS) were generated during the electrolysis of Ru(bpy) 3 2+ in alkaline solution, and oxidation of quercetin enhanced Ru(bpy) 3 2+ ECL at anodic potential by producing additional ROS. This ECL enhancement can be used to analyze real sample and evaluate antioxidant activity of polyphenols

  13. Several novel Ru(II) and Ru(III) complexes formed by reduction of (RuO4bipy) and (RuO3phen)2O with hydroquinone and methanol

    Ishiyama, Toshio

    1975-01-01

    The geometrical isomers, cis-dichloro-trans-(methanol)(hydroquinone)(2,2'-bipyridine)ruthenium(II) and cis-dichloro-cis-(methanol)(hydroquinone)(2,2'-bipyridine)ruthenium(II), [RuCl 2 (MeOH)(QH 2 )bipy] (complex I and II), were synthesized by reduction and substitution reactions of [RuO 4 bipy] and [RuO 2 (OH) 2 bipy] with hydroquinone in hydrochloric acid solution, and methanol. cis-Chloro(hydroquinonato)bis(2,2'-bipyridine)ruthenium(II), cis-[RuCl(QH)(bipy) 2 ], was obtained from the substitution reaction of complex I or II with 2,2'-bipyridine in methanol, and cis-chloro(hydroquinone)bis(2,2'-bipyridine)ruthenium(II) chloride, cis-[RuCl(QH 2 )(bipy) 2 ]Cl, was also obtained from the substitution of cis-trans-[RuCl 2 (MeOH)(QH 2 )bipy] in methanol containing hydrochloric acid. cis-Dihydroxobis(2,2'-bipyridine)ruthenium(II), cis-[Ru(OH) 2 (bipy) 2 ], was obtained by heating an aqueous solution of cis-[RuCl(QH)(bipy) 2 ]. Trihydroxoaquo(1,10-phenanthroline)ruthenium(III), [Ru(OH) 3 (H 2 O)phen] was also synthesized from [RuO 3 phen] 2 O and [Ru(OH) 3 phen] 2 O by reduction reactions similar to those used for [RuCl 2 (MeOH)(QH 2 )bipy]. These complexes were characterized by the infrared, visible and ultraviolet absorption spectra, and also by polarographic and magnetic measurements. The structures are discussed. (auth.)

  14. Percepção de fala no ruído em músicos

    Quental,Sávia Leticia Menuzzo; Colella-Santos,Maria Francisca; Couto,Christiane Marques do

    2014-01-01

    Objetivo Verificar se o estudo de música pode aprimorar a habilidade de compreensão de fala em presença de ruído. Métodos Participaram deste estudo 43 sujeitos de ambos os gêneros, com idade entre 18 e 33 anos, distribuídos em três grupos: o Grupo de Músicos, composto por 15 sujeitos com estudo formal de música; o Grupo de Intermediários, composto por 13 sujeitos com estudo informal de música e o Grupo de Não Músicos, c...

  15. The knockdown of OsVIT2 and MIT affects iron localization in rice seed.

    Bashir, Khurram; Takahashi, Ryuichi; Akhtar, Shamim; Ishimaru, Yasuhiro; Nakanishi, Hiromi; Nishizawa, Naoko K

    2013-11-20

    The mechanism of iron (Fe) uptake in plants has been extensively characterized, but little is known about how Fe transport to different subcellular compartments affects Fe localization in rice seed. Here, we discuss the characterization of a rice vacuolar Fe transporter 2 (OsVIT2) T-DNA insertion line (osvit2) and report that the knockdown of OsVIT2 and mitochondrial Fe transporter (MIT) expression affects seed Fe localization. osvit2 plants accumulated less Fe in their shoots when grown under normal or excess Fe conditions, while the accumulation of Fe was comparable to that in wild-type (WT) plants under Fe-deficient conditions. The accumulation of zinc, copper, and manganese also changed significantly in the shoots of osvit2 plants. The growth of osvit2 plants was also slow compared to that of WT plants. The concentration of Fe increased in osvit2 polished seeds. Previously, we reported that the expression of OsVIT2 was higher in MIT knockdown (mit-2) plants, and in this study, the accumulation of Fe in mit-2 seeds decreased significantly. These results suggest that vacuolar Fe trafficking is important for plant Fe homeostasis and distribution, especially in plants grown in the presence of excess Fe. Moreover, changes in the expression of OsVIT2 and MIT affect the concentration and localization of metals in brown rice as well as in polished rice seeds.

  16. Nonalloyed carbon-supported PtRu catalysts for PEMFC applications

    Papageorgopoulos, D.C.; De Heer, M.P.; Keijzer, M.; Pieterse, J.A.Z.; de Bruijn, F. A.

    2004-01-01

    PtRu(1:1)/C catalysts were prepared by a process that was claimed previously to lead to non-alloyed Pt and Ru particles, using two different precursors, Ru nitrosyl nitrate and Ru chloride hydrate. Both X-ray diffraction and characterization by cyclic voltammetry point toward Pt and Ru being present

  17. Nonalloyed carbon-supported PtRu catalysts for PEMFC applications

    Papageorgopoulos, D.C.; Heer, de M.P.; Keijzer, M.; Pieterse, J.A.Z.; Bruijn, de F.A.

    2004-01-01

    PtRu(1:1)/C catalysts were prepared by a process that was claimed previously to lead to nonalloyed Pt and Ru particles, using twodifferent precursors, Ru nitrosyl nitrate and Ru chloride hydrate. Both X-ray diffraction and characterization by cyclic voltammetrypoint toward Pt and Ru being present as

  18. O impacto ergonômico do ruído em docentes da rede pública

    Marco Túlio Domingues Costa

    2018-01-01

    Full Text Available Embora pouco seja abordado, o ambiente escolar também pode ser um local propício ao desenvolvimento de doenças ocupacionais nos profissionais que ali atuam, sobretudo em relação ao aspecto ergonômico cognitivo. Entre os principais agentes geradores do risco está a incidência do ruído. A presença do ruído em salas de aulas pode ocasionar diversos danos à saúde dos docentes e, quando acima dos limites estabelecidos normativamente, pode causar transtornos comportamentais e psicológicos. Neste sentido, o estudo realizado tem por objetivo investigar, através de análises quantitativa e qualitativa, a capacidade de dano gerado pelo ruído a partir do ponto de vista ergonômico. Os métodos utilizados na pesquisa incluem uma entrevista semiestruturada com docentes de uma instituição pública específica localizada na cidade de João Monlevade. Além disso, foi também realizada a avaliação quantitativa do nível de ruído contínuo e intermitente através do uso de um dosímetro de ruído. As análises partiram do pressuposto das condições de conforto acústico, não tendo sido considerado os aspectos relacionados à insalubridade.  Os resultados obtidos foram confrontados com os níveis estabelecidos para conforto acústico pelas normas brasileiras e relacionados às informações obtidas através do questionário. Os resultados alcançados demonstram a necessidade de adequação das atividades dos referidos profissionais para a instituição estudada.

  19. A preliminary study on Fe valence of porcelain glaze by XAFS

    Zhang Maolin; Wang Changsui; Jin Pujun; Wei Shiqiang; Xu Wei; Chen Dongliang; Wu Ziyu

    2008-01-01

    Ru ware was a famous celadon in Song dynasty, whose structure analysis of glaze had always been a difficulty in scientifically analysis of ancient porcelains. The X-ray absorption fine structure spectrum (XAFS) of Fe element in glaze of Ru ware excavated in Qingliang temple was obtained. Fe valence state in porcelain glaze samples was stud/ed by Principle Component Analysis (PCA) along with linear combination fitting method. The main wavelength of the samples was also obtained by color/meter. The results show that the cyan glaze samples have great Fe 2+ /Fe 3+ , while the yellow glaze samples have small Fe 2+ /Fe 3+ . The work also showed that X-ray absorption fine structure spectrum was very suitable in nondestructive analysis of ancient ceramics. (authors)

  20. 103Ru/103mRh generator

    Bartos, B.; Kowalska, E.; Bilewicz, A.; Skarnemark, G.

    2009-01-01

    103m Rh is a very promising radionuclide for Auger electron therapy due to its very low photon/electron ratio. The goal of the present work was the elaboration a method for production of large quantities of 103m Rh for generator system. It was found that the combination of solvent extraction with evaporation of 103 RuO 4 followed by decomposition of H 5 IO 6 makes it possible to produce 103m Rh of high radionuclidic and chemical purity. (author)

  1. In situ Ru K-edge EXAFS of CO adsorption on a Ru modified Pt/C fuel cell catalyst

    Rose, Abigail; Bilsborrow, Robert; King, Colin R.; Ravikumar, M.K.; Qian Yangdong; Wiltshire, Richard J.K.; Crabb, Eleanor M.; Russell, Andrea E.

    2009-01-01

    The Ru-CO bond of CO adsorbed on a Ru modified Pt/C fuel cell catalyst has been directly probed by in situ EXAFS at the Ru K-edge, providing evidence of a CO:metal surface atom ratio greater than 1:1 and that CO is adsorbed at bridging sites associated with Ru atoms at the surface of the catalyst nanoparticles. This result illustrates the limitations of single crystal models as representations of the bonding of adsorbed species at nanoparticle surfaces.

  2. Mössbauer analysis of the firing process of the sky-green glaze of the imitative ancient Chinese Ru porcelain

    Songhua, Chen; Zhengyao, Gao; Guoju, Hu; Xiande, Chen

    1994-12-01

    The variation of the Mössbauer parameters of the imitative ancient Ru porcelain skygreen glaze with the firing conditions is studied in detail in the present paper. The Mössbauer spectra show that the sky-green glaze contains three kinds of iron minerals, i.e. the structural iron (Fe2+ and Fe3+); Fe2O3 and Fe3O4. The relative intensity of the paramagnetic peak Fe2+ increases and the magnetic ratio of the magnetic peak decreases with increasing temperature. Based on the variation of the quadrupole splitting ( QS) of the paramagnetic peak Fe2+, the phase transformation characteristics of the sky-green glaze in the firing process is discussed. The coloring mechanism of the sky-green glaze and the variation of its magnetism in the firing process are also investigated in the present paper.

  3. Electrochemiluminescence resonance energy transfer system between GNRs and Ru(bpy)32+: Application in magnetic aptasensor for β-amyloid.

    Ke, Hong; Sha, Haifeng; Wang, Yinfang; Guo, Weiwei; Zhang, Xin; Wang, Zhiming; Huang, Chusen; Jia, Nengqin

    2018-02-15

    Electrochemiluminescent (ECL) assay has gradually drawn increasing interest in the biomedical analysis. This paper proposed a new methodology for ultrasensitive and facile detection of Alzheimer's disease marker β-amyloid (Aβ) by fabricating a sandwich-type ECL sensing platform. Herein, electrochemiluminescence resonance energy transfer (ECL-RET) was employed to determine Aβ concentration, which can be attributed to the quenching effect from RET between Ru(bpy) 3 2+ and gold nanorods (GNRs) acting as ECL-RET electron donor and acceptor, respectively. In this protocol, mesoporous carbon nanospheres were adopted to immobilize ECL reactant Ru(bpy) 3 2+ and antibody via nafion to acquire the RET donor nanocomposites (MOCs/nafion/Ru(bpy) 3 2+ /antibody), which were tightly interconnected with epoxy group functionalized Fe 3 O 4 nanoparticles. It is of vital importance that GNRs with exquisite rod shape were synthesized and exhibited a typical absorption peak at 650nm to quench ECL signal of Ru(bpy) 3 2+ effectively. In addition, the ECL emission decreased linearly with the logarithm of Aβ concentration in a wide linear range from 1.0 × 10 -5 to 100ng/mL with a detection limit of 4.2 × 10 -6 ng/mL. Furthermore, distinctive and desirable properties were verified to declare the promise for being applicable to analyze the Aβ content in real Alzheimer's cerebrospinal fluid samples with satisfactory results. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Biodistribution of Ru-97-labeled DTPA, DMSA and transferrin

    Som, P.; Oster, Z.H.; Fairchild, R.G.; Atkins, H.L.; Brill, A.B.; Gil, M.C.; Srivastava, S.C.; Meinken, G.E.; Goldman, A.G.; Richards, P.

    1980-01-01

    Ruthenium-97 is being produced at the Brookhaven Linac Isotope Producer (BLIP). The favorable physical properties of Ru-97 and chemical reactivity of ruthenium offer a potential for using this isotope to label compounds useful for delayed scanning. Diethylenetriamine pentaacetic acid (DTPA), 2,3-Dimercaptosuccinic acid (DMSA), and Transferrin (TF) were labeled with Ru-97-chloride. Ru-97-DTPA and In-111-DTPA, injected intravenously, showed similar organ distribution, kinetics, and more than 80% excretion by 0.5 h. Ru-97-DTPA and In-111-DTPA injected into the cisterna magna of dogs showed similar kinetics in brain, blood, and urinary bladder. The energy deposited by 1 mCi In-111-DTPA is twice that from 1 mCi Ru-97-DTPA. High quality camera images of the CSF space in the dog were obtained with both isotopes. Ru-97-DMSA was prepared with and without the addition of SnCl 2 .2H 2 O. Tin-free DMSA was rapidly excreted via the kidneys, whereas for maximum cortical deposition, the tin-containing preparation was superior. This compound is suitable for delayed imaging of both normal and impaired kidneys. Tissue distribution studies were performed in abscess-bearing rats with Ru-97-transferrin. Although blood levels were higher than with Ga-67-citrate, the abscess had twice as much Ru-97-TF as Ga-67-citrate and the Ru-97 muscle activity was one-third that of Ga-67. Imaging of abscess-bearing rabbits with Ru-97-TF visualized the abscesses as early as 1/2 hr after injection. Since the initial images visualize the abscess so clearly and since the TF portion of the compound binds to the abscess, Tc-99m-TF is being studied for the same purpose. Ru-97-labeled compounds are a promising replacement for In-111 and possibly also for Ga-67 compounds with the advantages of lower radiation dose and high quality image

  5. Interfacial mixing in double-barrier magnetic tunnel junctions with amorphous NiFeSiB layers

    Chun, B.S.; Ko, S.P.; Hwang, J.Y.; Rhee, J.R.; Kim, T.W.; Kim, Y.K.

    2007-01-01

    Double-barrier magnetic tunnel junctions (DMTJs) comprising Ta 45/Ru 9.5/IrMn 10/CoFe 7/AlO x /free layer (CoFe 4/NiFeSiB 2/CoFe 4, CoFe 10, or NiFeSiB 10)/AlO x /CoFe 7/IrMn 10/Ru 60 (nm) have been examined with an emphasis given on understanding the interfacial mixing effects. The DMTJ, consisted of NiFeSiB, shows low switching field and low bias voltage dependence because the amorphous NiFeSiB has lower M S (=800 emu/cm 3 ) and offers smoother interfaces than polycrystalline CoFe. An interesting feature observed in the CoFe/NiFeSiB/CoFe sandwich free layered DMTJ is the presence of a wavy MR transfer curve at high-resistance region. Because the polycrystalline CoFe usually grows into a columnar structure, diamagnetic CoSi, paramagnetic FeSi, and/or diamagnetic CoB might have been formed during the sputter-deposition process. By employing electron energy loss spectrometry (EELS) and Auger electron spectroscopy (AES), we were able to confirm that Si and B atoms were arranged evenly in the top and bottom portions of AlO x /CoFe interfaces. This means that the interfacial mixing resulted in a distorted magnetization reversal process

  6. Colonización nasofaríngea y resistencia antimicrobiana de Streptococcus pneumoniae en niños de una guardería en Santa Fe de Bogotá.

    lngrid J. Peñuela

    1999-09-01

    Full Text Available Streptococcus pneumoniae es el principal agente etiológico bacteriano de infección respiratoria aguda en niños. Esta bacteria coloniza la nasofaringe desde el momento del nacimiento, y el hombre se constituye, así, en el reseworio de la infección. La atención mundial se centra actualmente en la propagación de los aislamientos de S. pneumoniae resistentes a los antimicrobianos. El objetivo de este estudio fue el de establecer, mediante un seguimiento de seis meses, el porcentaje de colonización por Spneumoniae en un grupo de 20 niños menores de 2 años que asistían a una guardería, así como la distribución de los tipos capsulares de los aislamientos recuperados y los patrones de susceptibilidad antimicrobiana. Se obtuvieron 98 muestras nasofaríngeas con las que se estableció un porcentaje global de colonización por S. pneumoniae de 69%. Todos los niños fueron colonizados, por lo menos una vez durante el tiempo de estudio. Los serotipos más frecuentes fueron: 23F (41%, 19F (26%, 6A (10% y 10A (6% y la susceptibilidad disminuida a la penicilina (SDP se estableció en 53%. La resistencia global al trimetoprimsulfametoxazol (TMS fue de 68%, al cloranfenicol de 43% y a la eritromicina de 3%. Los porcentajes de resistencia presentaron variaciones durante los meses de estudio. El 42% de los aislamientos fue multirresistente y el patrón predominante fue la asociación penicilina, TMS y cloranfenicol. Los serotipos con SDP fueron 23F (72%, 19F (1 1%, 23A (8%, 6A (6% y 15 (3%. En la guardería en estudio, los datos obtenidos señalan el alto porcentaje de circulación de aislamientos con resistencia antimicrobiana, lo que constituye un factor de riesgo para su diseminación en la comunidad; también destacan la importancia de implementar un sistema de vigilancia con portadores, lo que permite monitorizar la susceptibilidad antimicrobiana de este patógeno.

  7. Supercapacitive performance of hydrous ruthenium oxide (RuO2 ...

    2016-08-26

    SO4 electrolyte. RuO2.H2O film showed maximum specific capacitance of 192 F.g-1 at a scan rate of 20 mV.s-1. The charge–discharge studies of RuO2.H2O carried out at 300 A.cm-2 current density revealed the specific ...

  8. NOVEL RU-NI-S ELECTRODE CATALYST FOR PEMFC

    The expected results from this project include: a new formula and preparation procedures for Ru-Ni-S catalyst; demonstration of CO and S tolerance of the new catalyst; a small size PEMFC with Ru-Ni-S catalyst and good performance; an...

  9. bond activation and catalysis by Ru -pac complexes

    and their reactivity towards oxidation of a few organic compounds. Keywords. Kinetics; catalysis; -O–O- bond activation; Ru-pac complex; oxidation. 1. Introduction. Ru-pac complexes exhibit catalytic properties,1 in homogeneous conditions in the presence of oxygen atom donors, that mimic the biological enzymatic oxi-.

  10. Identificação e estimação de ruído em redes DSL: uma abordagem baseada em inteligência computacional

    FARIAS, Fabrício de Souza

    2012-01-01

    Este trabalho propõe a utilização de técnicas de inteligência computacional objetivando identificar e estimar a potencia de ruídos em redes Digital Subscriber Line ou Linhas do Assinante Digital (DSL) em tempo real. Uma metodologia baseada no Knowledge Discovery in Databases ou Descobrimento de Conhecimento em Bases de Dados (KDD) para detecção e estimação de ruídos em tempo real, foi utilizada. KDD é aplicado para selecionar, pré-processar e transformar os dados antes da etapa de aplicação d...

  11. Relação da perda auditiva induzida por ruído e o uso de tabaco em trabalhadores de uma indústria alimentícia

    Eliziane Gai Menin

    2014-04-01

    Full Text Available Objetivo verificar se o uso do tabaco potencializa os efeitos do ruído causados na audição. Métodos 153 trabalhadores de ambos os sexos, fumantes e não-fumantes, de uma indústria do ramo alimentício, escolhidos aleatoriamente dentre 14 setores da empresa, cuja faixa de ruído apresentada teve uma variação de 85 a 109 dBNA, responderam a um questionário sobre tempo e exposição ao ruído bem como hábitos sobre fumo e passaram por exame de audiometria. Resultados os limiares auditivos da via aérea nas frequências de 4.000 Hz e 6.000Hz foram significantemente mais altos no grupo de fumantes/ex-fumantes quando comparados aos não-fumantes tanto na orelha direita quanto na orelha esquerda; limiares estes, característicos da perda auditiva induzida por ruído. Essas diferenças se mantiveram significantes após o ajuste pela idade e pelo tempo de exposição. Conclusão por meio dos resultados obtidos, concluiu-se que o uso do tabaco pode potencializar os danos causados pelo ruído à audição.

  12. Flotation-spectrophotometric determination of ruthenium in the Ru(IV)-chloride-rhodamine 6G-toluene system

    Balcerzak, M.

    1985-01-01

    The reduction of RuO 4 in hydrochloric acid has been examined. A sensitive flotation-spectrophotometric method of the determination of ruthenium based on the ion associate formed by the anionic chlorid complex of ruthenium RuCl 2- 6 with the basic dye Rhodamine 6G (R6G) has been developed. The solution of the ion associate obeys Beer's law up to the concentration of 0.25 μg Ru/ml. The ion associate precipitates when the aqueous solution is shaken with toluene. The separated compound is dissolved in acetone. The molar absorptivity (epsilon) at 530 nm is 5.1 x 10 5 l x mole -1 x cm -1 . The relative standard deviation is 3-7%. The mole ratio of Ru:R6G in the complex is 1:5. Osmium reacts similarly. The determination of ruthenium can be selective after the preliminary separation of osmium as OsO 4 . The method was applied to the determination of microgram amounts of ruthenium in crucible platinum. (Author)

  13. Electronic structure of LaFe{sub 2}X{sub 2} (X = Si,Ge)

    Hase, I., E-mail: i.hase@aist.go.jp [Electronics and Photonics Research Institute, AIST, Tsukuba, Ibaraki 305-8568 (Japan); Yanagisawa, T. [Electronics and Photonics Research Institute, AIST, Tsukuba, Ibaraki 305-8568 (Japan)

    2011-11-15

    We have calculated the electronic structure of LaFe{sub 2}Si{sub 2} and LaFe{sub 2}Ge{sub 2} from first-principles. The obtained Fermi surfaces of LaFe{sub 2}Si{sub 2} and LaFe{sub 2}Ge{sub 2} resemble those of LaRu{sub 2}Ge{sub 2}, which well explains the result of the dHvA experiments of CeRu{sub 2}Ge{sub 2}. Their density of states curves show the common feature with CaFe{sub 2}As{sub 2}. D(E{sub F}) strongly depends on the distortion of the FeX{sub 4} tetrahedra and/or the height of the X atom, as also found in iron-pnictide system. Recently found iron-pnictide superconductor (Ba,K)Fe{sub 2}As{sub 2} and the heavy-fermion superconductor CeCu{sub 2}Si{sub 2} both have the same crystal structure. In this paper we have calculated the electronic structure of LaFe{sub 2}Si{sub 2} and LaFe{sub 2}Ge{sub 2} from first-principles. These compounds also have the same crystal structure and closely related to both of (Ba,K)Fe{sub 2}As{sub 2} and CeRu{sub 2}Ge{sub 2}. The obtained Fermi surfaces of LaFe{sub 2}Si{sub 2} and LaFe{sub 2}Ge{sub 2} resemble those of LaRu{sub 2}Ge{sub 2}, which are already found that they well explain the results of the dHvA experiments of CeRu{sub 2}Ge{sub 2}. Their density of states curves show the common feature with CaFe{sub 2}As{sub 2}. The density of states at the Fermi level strongly depends on the distortion of the FeX{sub 4} tetrahedra and/or the height of the X atom from the two-dimensional Fe plane, as also found in iron-pnictide system. The electronic specific heat coefficient is 11.8 mJ/mol K{sup 2} for LaFe{sub 2}Si{sub 2} and 12.5 mJ/mol K{sup 2} for LaFe{sub 2}Ge{sub 2}, which is about 1/3 and 1/2 of experimental results, respectively.

  14. High-Density Stacked Ru Nanocrystals for Nonvolatile Memory Application

    Ping, Mao; Zhi-Gang, Zhang; Li-Yang, Pan; Jun, Xu; Pei-Yi, Chen

    2009-01-01

    Stacked ruthenium (Ru) nanocrystals (NCs) are formed by rapid thermal annealing for the whole gate stacks and embedded in memory structure, which is compatible with conventional CMOS technology. Ru NCs with high density (3 × 10 12 cm −2 ), small size (2–4 nm) and good uniformity both in aerial distribution and morphology are formed. Attributed to the higher surface trap density, a memory window of 5.2 V is obtained with stacked Ru NCs in comparison to that of 3.5 V with single-layer samples. The stacked Ru NCs device also exhibits much better retention performance because of Coulomb blockade and vertical uniformity between stacked Ru NCs

  15. Methanol electro-oxidation on Pt-Ru-P/C and Pt-Ru-P/MWCNT in acidic medium

    Modibedi, M

    2009-06-01

    Full Text Available . The electro-catalytic activity towards methanol oxidation in acidic medium was studied by cyclic voltammetry and linear sweep voltammetry. Pt-Ru-P/MWCNT showed excellent activity compared to that of Pt-Ru-P/C. This may be attributed to the effectiveness...

  16. Methanol oxidation reaction on Ti/RuO{sub 2(x)}Pt{sub (1-x)} electrodes prepared by the polymeric precursor method

    Freitas, R.G.; Marchesi, L.F.; Mattos-Costa, F.I.; Pereira, E.C. [Laboratorio Interdisciplinar de Eletroquimica e Ceramica, Centro Multidisciplinar para o Desenvolvimento de Materiais Ceramicos, Departamento de Quimica, Universidade Federal de Sao Carlos, Caixa Postal 676, 13560-905 Sao Carlos, SP (Brazil); Oliveira, R.T.S. [Laboratorio Interdisciplinar de Eletroquimica e Ceramica, Centro Multidisciplinar para o Desenvolvimento de Materiais Ceramicos, Departamento de Quimica, Universidade Federal de Sao Carlos, Caixa Postal 676, 13560-905 Sao Carlos, SP (Brazil); Grupo de Materiais Eletroquimicos e Metodos Eletroanaliticos, Instituto de Quimica de Sao Carlos, Universidade de Sao Paulo, Caixa Postal 780, 13566-590 Sao Carlos, SP (Brazil); LEMN, Laboratorio de Eletroquimica e Materiais Nanoestruturados, CCNH-Centro de Ciencias Naturais e Humanas, UFABC-Universidade Federal do ABC, CEP 09.210-170, Rua Santa Adelia 166, Bairro Bangu, Santo Andre, SP (Brazil); Bulhoes, L.O.S. [Laboratorio Interdisciplinar de Eletroquimica e Ceramica, Centro Multidisciplinar para o Desenvolvimento de Materiais Ceramicos, Departamento de Quimica, Universidade Federal de Sao Carlos, Caixa Postal 676, 13560-905 Sao Carlos, SP (Brazil); CENIP, Centro Universitario Central Paulista, UNICEP, Rua Miguel Petroni, 5111, CEP 13563-470, Sao Carlos, SP (Brazil); Santos, M.C. [Laboratorio Interdisciplinar de Eletroquimica e Ceramica, Centro Multidisciplinar para o Desenvolvimento de Materiais Ceramicos, Departamento de Quimica, Universidade Federal de Sao Carlos, Caixa Postal 676, 13560-905 Sao Carlos, SP (Brazil); LEMN, Laboratorio de Eletroquimica e Materiais Nanoestruturados, CCNH-Centro de Ciencias Naturais e Humanas, UFABC-Universidade Federal do ABC, CEP 09.210-170, Rua Santa Adelia 166, Bairro Bangu, Santo Andre, SP (Brazil)

    2007-09-27

    In this work, ruthenium oxide films containing platinum nanoparticles were prepared using the polymeric precursor method on Ti substrates with several molar ratios. This paper aims at presenting the characterization of the Pt content effect in the methanol electrochemical oxidation reaction. The films were physically characterized using X-ray diffraction and both Pt and RuO{sub 2} (rutile) phases were observed. The mean crystallite sizes were 6 nm for Pt and 25 nm for RuO{sub 2}. The X-ray photoelectronic results indicated that on the electrodes surfaces, depending on the substrate, there was RuO{sub 2}, Ru metal and Pt metal. Besides, it was not observed the formation of PtRu alloys. The atomic force microscopy images of the films showed highly rough surfaces. A decrease in the roughness mean square values is observed as the Pt content increases. These last results are similar to electroactive surface area values calculated by redox-couple (K{sub 4}FeCN{sub 6}/K{sub 3}FeCN{sub 6}). There was an increase in the globular size observed on the electrode surface and lower particle dispersion as the Pt content is increased from 12.5 to 75 mol%. Regarding the eletrode electrocatalytical behavior for methanol oxidation, it was observed that the onset oxidation overpotential is displaced towards more negative values as Pt content is decreased. Besides, an increase has been shown in the current density for methanol oxidation of 600% using a Ti/RuO{sub 2}-Pt (87.5:12.5) electrode compared to polycrystalline Pt. (author)

  17. Functional properties of electrospun NiO/RuO2 composite carbon nanofibers

    Wu Yongzhi; Balakrishna, Rajiv; Reddy, M.V.; Nair, A. Sreekumaran; Chowdari, B.V.R.; Ramakrishna, S.

    2012-01-01

    Highlights: ► Fabrication of carbon nanofibers with nickel–ruthenium composites by electrospinning. ► An interesting observation of increase in capacitance with increase in the number of cycles for supercapacitor applications. ► Li ion battery testing showed a stable capacity ranging from 350 mAh g −1 to 400 mAh g −1 . ► Lower impedance with the incorporation of 15 wt% Ru precursor than those without Ru. - Abstract: One-dimensional (1D) nickel oxide/ruthenium oxide (NiO/RuO 2 )–carbon composite nanofibers (NiRu–C–NFs) were fabricated via electrospinning of a homogenous mixture of polyacrylonitrile (PAN) and Ni/Ru salt precursors at different ratios followed by heat treatments. The 1D nanostructures of the composite material were characterized by field-emission scanning electron microscopy (FE-SEM), powder X-ray diffraction (XRD), Rietveld refinement and Brunauer–Emmett–Teller (BET) surface area measurements. Li-cycling properties were evaluated using cyclic voltammetry and galvanostatic properties. The asymmetric hybrid supercapacitor studies were carried out with activated carbon as a cathode and NiRu–C–NFs composites as anodes in the cycling range, 0.005–3.0 V using 1 M LiPF 6 (EC;DMC) electrolyte. NiRu–C–NFs fabricated from 5 wt% nickel (II) and 15 wt% ruthenium (III) precursors showed a capacitance up to ∼60 F g −1 after 30 cycles. Anodic Li-cycling studies of NiRu–C–NF-0 and NiRu–C–NF-2 composite samples showed a reversible capacity of 230 and 350 m Ahg −1 at current rate of 72 mA g −1 at the end of 40th cycle in the voltage range of 0.005–3.0 V. Electrochemical impedance studies (EIS) on NiRu–C–NFs showed lower impedance value for 15 wt% Ru than the bare sample.

  18. O uso de geotecnologias na elaboração de mapas de ruído The use of geotechnologies in the noise mapping

    Évely Mara Scariot

    2012-03-01

    Full Text Available A elaboração de mapas de ruído com o apoio das geotecnologias é uma poderosa ferramenta para visualização e compreensão do comportamento do ruído em determinada área. Nesta pesquisa avaliaram-se os níveis de pressão sonora em uma região de aproximadamente 18 ha, composta por indústrias, residências, criação de animais e uma avenida movimentada no entorno do município de Campo Grande (MS. Efetuaram-se análises semivariográficas das amostras e os mapas de ruído foram desenvolvidos utilizando-se krigagem, que se mostrou adequada, desde que os dados coletados fossem representativos e os pontos de amostragem coerentes com a situação que se queria avaliar. Os mapas de ruído permitiram identificar as regiões mais críticas, as fontes e suas respectivas áreas de influência, além de verificar onde são ultrapassados os limites normativos de pressão sonora.Geotechnologies application in noise mapping consists in a powerful tool to visualize and understand the sound distribution in a specific area. This research was done at the city of Campo Grande, Mato Grosso do Sul, Brazil, in an area of approximately 18 ha, where there are industries, residences, animal breeding and an avenue. Sound level pressures were explored, semivariografic analysis were done and noise maps were developed using kriging, that demonstrated to be appropriated, since that the collected data were representative and the sampling points coherent with the situation that needed to be evaluated. The noise maps permitted to identify the most critical regions, the sources and their influence areas, as verify where the normative limit values for sound pressure exceed.

  19. Programa para incentivar el consumo de soya en niños y niñas del Plantel central de la Red Educativa "Santa Fe de Galán"

    Pilataxi Tiumaico, América Beatríz

    2010-01-01

    "El desafío es muy grande, ya que en 2006 la tasa de desnutrición de la infancia menor a un año era de 12 por ciento, una de las más altas de América Latina", dijo este miércoles en rueda de prensa con las agencias extranjeras la ministra Coordinadora de Desarrollo Social, Jeannette Sánchez. Ese porcentaje se mantuvo hasta 2008. "Hay que caer en cuenta que el problema de la desnutrición no es estático sino que tiene repercusiones en las posibilidades cognitivas de los niños y niñas, en el ...

  20. Oxidation study of Cr-Ru hard coatings

    Chen, Yung-I, E-mail: yichen@mail.ntou.edu.tw; Kuo, Yu-Chu; Chen, Sin-Min

    2012-01-01

    Cr-Ru alloy coatings with Cr content ranging from 47 to 83 at.% were deposited at 400 Degree-Sign C by direct current magnetron co-sputtering with a Ti interlayer on silicon substrates. With a total input power of 300 W, the Cr content in the Cr-Ru coatings increased linearly with the increasing input power of Cr. The intermetallic compound phase Cr{sub 2}Ru with columnar structure was identified for the as-deposited Cr{sub 56}Ru{sub 44} and Cr{sub 65}Ru{sub 35} coatings, resulting in an increase of hardness up to 15-16 GPa. To evaluate the performance of Cr-Ru coatings as a protective coating on glass molding dies, the annealing treatment was conducted at 600 Degree-Sign C in a 50 ppm O{sub 2}-N{sub 2} atmosphere. The outward diffusion and preferential oxidization of Cr in the Cr-Ru coatings resulted in the variations of the crystalline structure, chemical composition distribution, and surface hardness after annealing. X-ray diffraction and transmission electron microscopy (TEM) proved that an oxide scale consisting of Cr{sub 2}O{sub 3} formed on the free surface. Scanning electron microscopy and TEM observed the surface morphology and structural variation. The chemical composition depth profiles were analyzed by Auger electron microscopy, verifying the presence of a Cr-depleted zone beneath the oxide scale. The hardness of Cr{sub 56}Ru{sub 44} and Cr{sub 65}Ru{sub 35} coatings decreased to 11-12 GPa after annealing, accompanied by the replacement of the Cr{sub 2}Ru phase by the Ru phase. - Highlights: Black-Right-Pointing-Pointer We prepared crystalline Cr-Ru alloy coatings by direct current magnetron sputtering. Black-Right-Pointing-Pointer Cr-Ru coatings were annealed at 600 Degree-Sign C for 2 h in a 50 ppm O{sub 2}-N{sub 2} atmosphere. Black-Right-Pointing-Pointer Cr diffused outwardly and oxidized to form a stable and protective oxide scale. Black-Right-Pointing-Pointer The original columnar grains recrystallized to polycrystalline grains.

  1. Analysis of the width correlation in 54Fe(nγ)55Fe reaction

    Knat'ko, V.A.; Shimanovich, E.A.

    1982-01-01

    To find out structural effects manifesting themselves in the form of correlation between widths of different channels of γ decay of levels and violation of Porter-Thomas distribution, calculated are partial widths of levels for 20 high-energy γ transitions in the 54 Fe(nγ) 55 Fe reaction. Calculations are carried out for widths in relation to γ transitions on 8 low p levels of 55 Fe, for 100 sets of partial γ widths (20 widths in a set). Results of analysis of theoretical values of partial γ widths of s resonances are presented in the form of the table. Results, obtained, show that consideration of contributions into γ decay of one-particle-vibrational configurations improve the accordance with experimental data, in comparison with calculations according to the model of valent capture. It is concluded that properties of γ widths of 55 Fe resonances, calculated in studied model, agree satisfactorily with properties of experimental γ widths [ru

  2. APPLIED SCIENTOMETRICS: ELIBRARY.RU VS GOOGLE

    А В Юрков

    2015-12-01

    Full Text Available The practical issues associated with searching reliable information about the publication activity of Russian scientist are discussed in the article. The examples in [1] show that the effective solution of this problem requires the using of different scientometric services: both the domestic eLIBRARY.RU and its Russian Science Citation Index, and the Google Scholar as an alternative. At the time the work is published comparison was not in favor of the domestic resource. However, due to the RSCI project within a short period the eLibrary’s tools for building database of scientific publications have grown significantly and the opportunities to improve the quality of scientometric information become real. The article gives the examples.

  3. Ruído emitido por conjunto trator-carreta cafeeira em função da rotação, do raio de afastamento, da velocidade e do tipo de pista

    Paulo da Silva Lima Júnior

    2014-07-01

    Full Text Available Apesar dos benefícios, o uso de máquinas expõe, muitas vezes, o operador a níveis elevados de ruído e desta forma pode gerar problemas no sistema auditivo. O objetivo da pesquisa foi avaliar o nível de ruído emitido por conjunto mecanizado utilizado na operação de transporte de grãos de café (Coffea arabica L.. As análises foram realizadas numa propriedade na cidade de Romaria – MG. Na condição estática foi avaliado o nível de ruído em função da rotação do motor e do raio de afastamento considerando as posições (direita, esquerda, anterior e posterior na distância de zero a 10 m. Na condição dinâmica foi avaliado o nível de ruído emitido pelo conjunto trator-carreta em função dos fatores pista e marchas de trabalho. Foi utilizado o delineamento inteiramente casualizado, e quando significativo no teste de F os dados foram submetidos ao teste de Tukey a 5% de probabilidade para comparação de médias, a análise de regressão quando foi significativo o fator quantitativo (distâncias e marchas e a geoestatística para a verificar a propagação do ruído. Os resultados mostraram que os níveis de ruído no trator aumentam conforme aumenta à rotação do motor, e os maiores níveis de ruído foram na posição direita do trator. À medida que se afasta do posto de operação, os níveis de ruído vão reduzindo. O conjunto trator-carreta apresentou maiores riscos à audição na segunda, terceira e quarta marcha reduzida, respectivamente. Não houve diferença nos níveis de ruído em relação às pistas de asfalto e terra batida.

  4. Single hole spectroscopic strength in 98Ru through the 99Ru(d,t) reaction

    Rodrigues, M.R.D.; Borello-Lewin, T.; Horodynski-Matsushigue, L.B.; Duarte, J.L.M.; Rodrigues, C.L.; Barbosa, M.D.L.; Silva, G.B. da; Ukita, G.M.

    2002-01-01

    The 99 Ru(d,t) 98 Ru reaction was measured for the first time at 16 MeV incident energy with the Sao Paulo Pelletron-Enge-spectrograph facility employing the nuclear emulsion technique. In all, up to 3.5 MeV, 23 levels were detected, eight of them new; angular distributions are presented for all of them. Least squares fits of distorted wave Born approximation one-neutron pickup predictions to the rather well structured experimental angular distributions enabled the determination of l transfers and of the corresponding spectroscopic factors for 19 of these states, some being tentative attributions. Only transfers of l=0, 2, and 4 were observed. Several states were populated through single l transfers. A pure l=2 transfer is associated with the 2 1 + level and with several other states which are considered collective, as well as with the (4 + ) state at 2.277 MeV, which presents the highest spectroscopic strength. Considering five valence neutrons above the N=50 core, only 41% of the spectroscopic strength expected for 99 Ru was detected

  5. Determination of Au, Ir, Os, Pd, Pt, Ru in high-purity metals by neutron activation

    Samadi, A.A.; Fedoroff, M.

    1978-01-01

    This determination was achieved by thermal neutron activation, chemical separations and radioactivity measurements by γ spectrometry. In order to develop chemical separations, some studies on the distillation and ion exchange of platinum group elements were perfomed. The fixation of these elements on an anion exchange resin in a nitrite medium was studied more particularly. This method enables a fully quantitative fixation. The detection limits in these irradiation conditions ranges from 10 -12 g for Ir to 10 -8 g for Pd [fr

  6. One-Pot Process for Hydrodeoxygenation of Lignin to Alkanes Using Ru-Based Bimetallic and Bifunctional Catalysts Supported on Zeolite Y.

    Wang, Hongliang; Ruan, Hao; Feng, Maoqi; Qin, Yuling; Job, Heather; Luo, Langli; Wang, Chongmin; Engelhard, Mark H; Kuhn, Erik; Chen, Xiaowen; Tucker, Melvin P; Yang, Bin

    2017-04-22

    The synthesis of high-efficiency and low-cost catalysts for hydrodeoxygenation (HDO) of waste lignin to advanced biofuels is crucial for enhancing current biorefinery processes. Inexpensive transition metals, including Fe, Ni, Cu, and Zn, were severally co-loaded with Ru on HY zeolite to form bimetallic and bifunctional catalysts. These catalysts were subsequently tested for HDO conversion of softwood lignin and several lignin model compounds. Results indicated that the inexpensive earth-abundant metals could modulate the hydrogenolysis activity of Ru and decrease the yield of low-molecular-weight gaseous products. Among these catalysts, Ru-Cu/HY showed the best HDO performance, affording the highest selectivity to hydrocarbon products. The improved catalytic performance of Ru-Cu/HY was probably a result of the following three factors: (1) high total and strong acid sites, (2) good dispersion of metal species and limited segregation, and (3) high adsorption capacity for polar fractions, including hydroxyl groups and ether bonds. Moreover, all bifunctional catalysts proved to be superior over the combination catalysts of Ru/Al 2 O 3 and HY zeolite. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. One-Pot Process for Hydrodeoxygenation of Lignin to Alkanes Using Ru-Based Bimetallic and Bifunctional Catalysts Supported on Zeolite Y

    Wang, Hongliang [Department of Biological Systems Engineering, Washington State University, Richland WA 99354 USA; Ruan, Hao [Department of Biological Systems Engineering, Washington State University, Richland WA 99354 USA; Feng, Maoqi [Chemistry & Chemical Engineering Division, Southwest Research Institute, San Antonio TX 78238 USA; Qin, Yuling [Department of Biological Systems Engineering, Washington State University, Richland WA 99354 USA; Job, Heather [Pacific Northwest National Laboratory, 902 Battelle Blvd Richland WA 99354 USA; Luo, Langli [Environmental Molecular Sciences Laboratory, 3335 Q Ave Richland WA 99354 USA; Wang, Chongmin [Environmental Molecular Sciences Laboratory, 3335 Q Ave Richland WA 99354 USA; Engelhard, Mark H. [Environmental Molecular Sciences Laboratory, 3335 Q Ave Richland WA 99354 USA; Kuhn, Erik [National Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver West Parkway Golden CO. 80401 USA; Chen, Xiaowen [National Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver West Parkway Golden CO. 80401 USA; Tucker, Melvin P. [National Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver West Parkway Golden CO. 80401 USA; Yang, Bin [Department of Biological Systems Engineering, Washington State University, Richland WA 99354 USA

    2017-03-16

    The synthesis of high-efficiency and low-cost multifunctional catalysts for hydrodeoxygenation (HDO) of waste lignin into advanced biofuels is crucial for enhancing current biorefinery processes. Inexpensive transition metals, including Fe, Ni, Cu, Zn, were severally co-loaded with Ru on HY zeolite to form bimetallic and bifunctional catalysts. These catalysts were subsequently tested for HDO conversion of softwood lignin and several lignin model compounds. Results indicated that the inexpensive earth abundant metals could modulate the hydrogenolysis activity of Ru and decrease the yield of low molecular weight gaseous side-products. Among all the prepared catalysts, Ru-Cu/HY showed the best HDO performance, giving the highest selectivity to hydrocarbon products. The improved catalytic performance of Ru-Cu/HY was probably due to the following three factors: (1) high total and strong acid sites, (2) good dispersion of metal species and limited segregation, (3) high adsorption capacity for polar fractions, including hydroxyl groups and ether bonds. Moreover, all the bifunctional catalysts were proven to be superior over the combination catalysts of Ru/Al2O3 and HY zeolite, and this could be attributed to the “intimacy criterion”. The practical use of the designed catalysts would be promising in lignin valorization.

  8. Saúde auditiva de trabalhadores expostos a ruído e inseticidas

    Teixeira Cleide Fernandes

    2003-01-01

    Full Text Available OBJETIVO: Avaliar as alterações auditivas periféricas em um grupo de trabalhadores exposto a inseticidas, organofosforados e piretróides, utilizados em campanhas de controle de vetores. MÉTODOS: Estudo de prevalência de uma população de 98 indivíduos que pulverizavam venenos nas campanhas de prevenção do dengue, da febre amarela e da doença de Chagas. A amostra foi de tipo finalística, considerando o universo dos trabalhadores de um distrito sanitário, em Pernambuco, no ano de 2000. Utilizou-se questionário contendo questões de identificação de riscos ocupacional e não ocupacional, medidas de segurança utilizadas, antecedentes de problemas auditivos e sintomas referidos. Foi investigada a historia pregressa de exposição ao ruído, por ser um fator de confusão para a perda auditiva. Todos os indivíduos foram avaliados pelo teste de audiometria tonal. RESULTADOS: Dos expostos apenas aos inseticidas, 63,8% apresentaram perda auditiva. Para o grupo com exposição concomitantemente aos inseticidas e ao ruído, a perda auditiva foi de 66,7%. O tempo mediano para o desenvolvimento de alterações auditivas nas freqüências médias altas, para as exposições combinadas de inseticidas e ruído, foi de 3,4 anos e para as exposições apenas aos inseticidas foi de 7,3 anos. A perda auditiva para as exposições concomitantes aos dois fatores foi de maior intensidade nessas freqüências, do que o observado na exposição apenas aos inseticidas. CONCLUSÕES: Há evidência de que a exposição aos inseticidas induz dano auditivo periférico e que o ruído é um fator que interage com os inseticidas, potencializando seus efeitos ototóxicos. Faz-se necessário avaliar essa possível associação através de estudos epidemiológicos de caráter analítico.

  9. Saúde auditiva de trabalhadores expostos a ruído e inseticidas

    Cleide Fernandes Teixeira

    2003-08-01

    Full Text Available OBJETIVO: Avaliar as alterações auditivas periféricas em um grupo de trabalhadores exposto a inseticidas, organofosforados e piretróides, utilizados em campanhas de controle de vetores. MÉTODOS: Estudo de prevalência de uma população de 98 indivíduos que pulverizavam venenos nas campanhas de prevenção do dengue, da febre amarela e da doença de Chagas. A amostra foi de tipo finalística, considerando o universo dos trabalhadores de um distrito sanitário, em Pernambuco, no ano de 2000. Utilizou-se questionário contendo questões de identificação de riscos ocupacional e não ocupacional, medidas de segurança utilizadas, antecedentes de problemas auditivos e sintomas referidos. Foi investigada a historia pregressa de exposição ao ruído, por ser um fator de confusão para a perda auditiva. Todos os indivíduos foram avaliados pelo teste de audiometria tonal. RESULTADOS: Dos expostos apenas aos inseticidas, 63,8% apresentaram perda auditiva. Para o grupo com exposição concomitantemente aos inseticidas e ao ruído, a perda auditiva foi de 66,7%. O tempo mediano para o desenvolvimento de alterações auditivas nas freqüências médias altas, para as exposições combinadas de inseticidas e ruído, foi de 3,4 anos e para as exposições apenas aos inseticidas foi de 7,3 anos. A perda auditiva para as exposições concomitantes aos dois fatores foi de maior intensidade nessas freqüências, do que o observado na exposição apenas aos inseticidas. CONCLUSÕES: Há evidência de que a exposição aos inseticidas induz dano auditivo periférico e que o ruído é um fator que interage com os inseticidas, potencializando seus efeitos ototóxicos. Faz-se necessário avaliar essa possível associação através de estudos epidemiológicos de caráter analítico.

  10. Superconductivity and transport properties in LaRu4Sb12 single crystals probed by radiation-induced disordering

    Goshchitskii, B.; Naumov, S.; Kostromitina, N.; Karkin, A.

    2007-01-01

    Resistivity ρ(T) and Hall coefficient R H (T) in magnetic fields H up to 14 T were studied in superconducting (T c = 3.3 K) LaRu 4 Sb 12 single crystals disordered by fast neutron irradiation. Atomic disordering leads to increase in residual resistivity ρ 0 , decrease of Hall number and suppression of superconductivity. The upper critical field slope -dH c2 /dT increases approximately linear with ρ 0 . The irradiation effects are almost recovered after annealing at 500 deg. C. The observed radiation-induced effects in LaRu 4 Sb 12 are compared with those in PrOs 4 Sb 12 in terms of unconventional mechanisms of superconductivity

  11. Magnetic properties of the filled skutterudite-type structure compounds GdRu4P12 and TbRu4P12 synthesized under high pressure

    Sekine, C; Uchiumi, T; Shirotani, I; Matsuhira, kazuyuki; Sakakibara, T; Goto, T; Yagi, T

    2000-01-01

    We have succeeded in synthesizing filled skutterudite-type structure compounds GdRu4P12 and TbRu4P12 under high pressure. The magnetic properties of GdRu4P12 and TbRu4P12 have been studied by means of electrical resistivity, magnetic susceptibility, and magnetization measurements. Magnetic experiments suggest that the Gd and Tb ions in the compounds have trivalent state. The compound GdRu4P12 displays features that suggest the occurrence of antiferromagnetic ordering below TN=22 K. In TbRu4P1...

  12. Preparation of PtRu/Carbon hybrid materials by hydrothermal carbonization: A study of the Pt:Ru atomic ratio

    Tusi, Marcelo Marques; Brandalise, Michele; Correa, Olandir Vercino; Oliveira Neto, Almir; Linardi, Marcelo; Spinace, Estevam Vitorio; Villalba, Juan Carlo

    2009-01-01

    PtRu/Carbon materials with different Pt:Ru atomic ratios (30:70, 50:50, 60:40, 80:20 and 90:10) and 5 wt% of nominal metal load were prepared by hydrothermal carbonization using H 2 PtCl 6.6 H 2 O and RuCl 3. xH 2 O as metals sources and catalysts of the carbonization process and starch as carbon source and reducing agent. The obtained materials were treated at 900 deg C under argon and characterized by EDX, XRD and cyclic voltammetry. The electro-oxidation of methanol was studied by cyclic voltammetry and chronoamperometry using thin porous coating technique. The PtRu/Carbon materials showed Pt:Ru atomic ratios obtained by EDX similar to the nominal ones. XRD analysis showed that Pt face-cubic centered (FCC) and Ru hexagonal close-packed (HCP) phases coexist in the obtained materials. The average crystallite sizes of the Pt (FCC) phase were in the range of 8-12 nm. The material prepared with Pt:Ru atomic ratio of 50:50 showed the best performance for methanol electro-oxidation. (author)

  13. Buffer layer dependence of magnetoresistance effects in Co2Fe0.4Mn0.6Si/MgO/Co50Fe50 tunnel junctions

    Sun, Mingling; Kubota, Takahide; Takahashi, Shigeki; Kawato, Yoshiaki; Sonobe, Yoshiaki; Takanashi, Koki

    2018-05-01

    Buffer layer dependence of tunnel magnetoresistance (TMR) effects was investigated in Co2Fe0.4Mn0.6Si (CFMS)/MgO/Co50Fe50 magnetic tunnel junctions (MTJs). Pd, Ru and Cr were selected for the buffer layer materials, and MTJs with three different CFMS thicknesses (30, 5, and 0.8 nm) were fabricated. A maximum TMR ratio of 136% was observed in the Ru buffer layer sample with a 30-nm-thick CFMS layer. TMR ratios drastically degraded for the CFMS thickness of 0.8 nm, and the values were 26% for Cr buffer layer and less than 1% for Pd and Ru buffer layers. From the annealing temperature dependence of the TMR ratios, amounts of interdiffusion and effects from the lattice mismatch were discussed.

  14. Adsorption and diffusion of Ru adatoms on Ru(0001)-supported graphene: Large-scale first-principles calculations

    Han, Yong; Evans, James W. [Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA and Ames Laboratory—U.S. Department of Energy, Iowa State University, Ames, Iowa 50011 (United States)

    2015-10-28

    Large-scale first-principles density functional theory calculations are performed to investigate the adsorption and diffusion of Ru adatoms on monolayer graphene (G) supported on Ru(0001). The G sheet exhibits a periodic moiré-cell superstructure due to lattice mismatch. Within a moiré cell, there are three distinct regions: fcc, hcp, and mound, in which the C{sub 6}-ring center is above a fcc site, a hcp site, and a surface Ru atom of Ru(0001), respectively. The adsorption energy of a Ru adatom is evaluated at specific sites in these distinct regions. We find the strongest binding at an adsorption site above a C atom in the fcc region, next strongest in the hcp region, then the fcc-hcp boundary (ridge) between these regions, and the weakest binding in the mound region. Behavior is similar to that observed from small-unit-cell calculations of Habenicht et al. [Top. Catal. 57, 69 (2014)], which differ from previous large-scale calculations. We determine the minimum-energy path for local diffusion near the center of the fcc region and obtain a local diffusion barrier of ∼0.48 eV. We also estimate a significantly lower local diffusion barrier in the ridge region. These barriers and information on the adsorption energy variation facilitate development of a realistic model for the global potential energy surface for Ru adatoms. This in turn enables simulation studies elucidating diffusion-mediated directed-assembly of Ru nanoclusters during deposition of Ru on G/Ru(0001)

  15. Pd-RuSe/C as ORR specific catalyst in alkaline solution containing methanol

    Maheswari, S.; Sridhar, P.; Pitchumani, S. [CSIR-Central Electrochemical Research Institute-Madras Unit, CSIR Complex, Chennai 600 113 (India)

    2012-12-15

    Carbon supported RuSe (RuSe/C) catalyst in varying atomic ratios of Ru to Se, namely, 1:1, 2:1, and 3:1 were prepared and their performances were compared with carbon supported Ru (Ru/C). Based on the performance, Palladium was incorporated into as prepared RuSe(2:1)/C and heat treated HTRuSe(2:1)/C. Ru/C, RuSe/C, and Pd-RuSe/C were characterized by X-ray diffraction (XRD) and transmission electron microscopy techniques. The XRD analyses of Ru/C, RuSe/C and Pd-HTRuSe/C show the formation of the hcp structure of Ru particles and the mean particle size was obtained from Ru(101) peak. The electrochemical characterizations of Ru/C, RuSe/C, Pd-HTRuSe(2:1)/C and Pd-RuSe(2:1)/C were conducted by cyclic voltammetry. Linear Sweep Voltammetric studies showed that incorporation of Pd in HTRu-Se(2:1)/C resulted in better catalytic activity toward oxygen reduction with resistance to methanol oxidation. The quantity of hydrogen peroxide produced was obtained from rotating ring disk electrode studies. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. U-Pb, Re-Os, and Ar/Ar geochronology of rare earth element (REE)-rich breccia pipes and associated host rocks from the Mesoproterozoic Pea Ridge Fe-REE-Au deposit, St. Francois Mountains, Missouri

    Aleinikoff, John N.; Selby, David; Slack, John F.; Day, Warren C.; Pillers, Renee M.; Cosca, Michael A.; Seeger, Cheryl; Fanning, C. Mark; Samson, Iain

    2016-01-01

    Rare earth element (REE)-rich breccia pipes (600,000 t @ 12% rare earth oxides) are preserved along the margins of the 136-million metric ton (Mt) Pea Ridge magnetite-apatite deposit, within Mesoproterozoic (~1.47 Ga) volcanic-plutonic rocks of the St. Francois Mountains terrane in southeastern Missouri, United States. The breccia pipes cut the rhyolite-hosted magnetite deposit and contain clasts of nearly all local bedrock and mineralized lithologies.Grains of monazite and xenotime were extracted from breccia pipe samples for SHRIMP U-Pb geochronology; both minerals were also dated in one polished thin section. Monazite forms two morphologies: (1) matrix granular grains composed of numerous small (minerals includes Re-Os on fine-grained molybdenite and 40Ar/39Ar on muscovite, biotite, and K-feldspar.Ages (±2σ errors) obtained by SHRIMP U-Pb analysis are as follows: (1) zircon from the two host rhyolite samples have ages of 1473.6 ± 8.0 and 1472.7 ± 5.6 Ma; most zircon in late felsic dikes is interpreted as xenocrystic (age range ca. 1522–1455 Ma); a population of rare spongy zircon is likely of igneous origin and yields an age of 1441 ± 9 Ma; (2) pale-yellow granular monazite—1464.9 ± 3.3 Ma (no dated xenotime); (3) reddish matrix granular monazite—1462.0 ± 3.5 Ma and associated xenotime—1453 ± 11 Ma; (4) coarse glassy-yellow monazite—1464.8 ± 2.1, 1461.7 ± 3.7 Ma, with rims at 1447.2 ± 4.7 Ma; and (5) matrix monazite (in situ)—1464.1 ± 3.6 and 1454.6 ± 9.6 Ma, and matrix xenotime (in situ)—1468.0 ± 8.0 Ma. Two slightly older ages of cores are about 1478 Ma. The young age of rims on the coarse glassy monazite coincides with an Re-Os age of 1440.6 ± 9.2 Ma determined in this study for molybdenite intergrown with quartz and allanite, and with the age of monazite inclusions in apatite from the magnetite ore (Neymark et al., 2016). A 40Ar/39Ar age of 1473 ± 1 Ma was obtained for muscovite from a breccia pipe sample.Geochronology and

  17. Surface studies by low energy ion beams: Cu/Ru(0001) and Cu/O/Ru(0001)

    Shen, Y G; O` Connor, D J; MacDonald, R J [Newcastle Univ., NSW (Australia). Dept. of Physics; Wandelt, H [Institut fur Physikalische und Theoretische Chemie der Universitat Bonn, Bonn (Germany).; Zee, H van [Eindhoven University of Technology, Eindhoven (Netherlands) Dept. of Physics

    1994-12-31

    The surface structure of Cu on Ru(OOO1) has been studied by low energy Li{sup +} ion scattering. It was found that Cu forms pseudomorphic islands for two layers. The effects of Cu on an O-precovered RU(OOO1) surface has also been investigated using keV He{sup +} ions. The results show that during the deposition of Cu, O is displaced from the Ru surface and migrated onto the top of the surface of the growing overlayer. The floated out O has been tested, showing a disordered overlayer. 5 refs., 3 figs.

  18. Surface studies by low energy ion beams: Cu/Ru(0001) and Cu/O/Ru(0001)

    Shen, Y.G.; O`Connor, D.J.; MacDonald, R.J. [Newcastle Univ., NSW (Australia). Dept. of Physics; Wandelt, H. [Institut fur Physikalische und Theoretische Chemie der Universitat Bonn, Bonn (Germany).; Zee, H. van [Eindhoven University of Technology, Eindhoven (Netherlands) Dept. of Physics

    1993-12-31

    The surface structure of Cu on Ru(OOO1) has been studied by low energy Li{sup +} ion scattering. It was found that Cu forms pseudomorphic islands for two layers. The effects of Cu on an O-precovered RU(OOO1) surface has also been investigated using keV He{sup +} ions. The results show that during the deposition of Cu, O is displaced from the Ru surface and migrated onto the top of the surface of the growing overlayer. The floated out O has been tested, showing a disordered overlayer. 5 refs., 3 figs.

  19. An investigation of the Pd-Ag-Ru-Gd quaternary system phase diagram

    Zhang Kanghou; Xu Yun

    2005-01-01

    On the basis of the Ag-Pd-Gd, Ag-Ru-Gd and Pd-Ru-Gd ternary systems, the partial phase diagram of Pd-Ag-Ru-Gd (Gd 3 Gd and Ag 51 Gd 14 ; five two-phase regions: Pd(Ag) + (Ru), Pd(Ag) + Ag 51 Gd 14 (Ru) + Ag 51 Gd 14 , Pd(Ag) + Pd 3 Gd and (Ru) + Pd 3 Gd; three three-phase regions: Pd(Ag) + Pd 3 Gd + (Ru), Pd(Ag) + Ag 51 Gd 14 + (Ru) and (Ru) + Ag 51 Gd 14 + Pd 3 Gd; one four-phase region Pd(Ag) + (Ru) + Ag 51 Gd 14 + Pd 3 Gd. No new quaternary intermetallic phase has been found

  20. Optimum Pt and Ru atomic composition of carbon-supported Pt-Ru alloy electrocatalyst for methanol oxidation studied by the polygonal barrel-sputtering method

    Hiromi, Chikako; Inoue, Mitsuhiro; Taguchi, Akira; Abe, Takayuki

    2011-01-01

    Highlights: → The sputtered Pt and Ru form the Pt-Ru alloy nanoparticles on the carbon support. → The deposited Pt-Ru alloy particles have uniform Pt:Ru atomic ratios. → The optimum Pt:Ru ratio of the Pt-Ru/C for methanol oxidation is 58:42 at.% at 25 deg. C. → The optimum Pt:Ru ratio of 58:42 shifts to 50:50 at.% at 40 and 60 deg. C. → The polygonal barrel-sputtering method is useful to prepare the DMFC anode catalyst. - Abstract: The optimum Pt and Ru atomic composition of a carbon-supported Pt-Ru alloy (Pt-Ru/C) used in a practical direct methanol fuel cell (DMFC) anode was investigated. The samples were prepared by the polygonal barrel-sputtering method. Based on the physical properties of the prepared Pt-Ru/C samples, the Pt-Ru alloy was found to be deposited on a carbon support. The microscopic characterization showed that the deposited alloy forms nanoparticles, of which the atomic ratios of Pt and Ru (Pt:Ru ratios) are uniform and are in accordance with the overall Pt:Ru ratios of the samples. The formation of the Pt-Ru alloy is also supported by the electrochemical characterization. Based on these results, methanol oxidation on the Pt-Ru/C samples was measured by cyclic voltammetry and chronoamperometry. The results indicated that the methanol oxidation activities of the prepared samples depended on the Pt:Ru ratios, of which the optimum Pt:Ru ratio is 58:42 at.% at 25 deg. C and 50:50 at.% at 40 and 60 deg. C. This temperature dependence of the optimum Pt:Ru ratio is well explained by the relationship between the methanol oxidation reaction process and the temperature, which is reflected in the rate-determining steps considered from the activation energies. It should be noted that at 25-60 deg. C, the Pt-Ru/C with Pt:Ru = 50:50 at.% prepared by our sputtering method has the higher methanol oxidation activity than that of a commercially available sample with the identical overall Pt:Ru ratio. Consequently, the polygonal barrel-sputtering method

  1. Synthesis and thermoelectric properties of RuO2 nanorods

    Music, Denis; Basse, Felix H.-U.; Schneider, Jochen M.; Hassdorf, Ralf

    2010-01-01

    We have explored the effect of the O/Ru ratio on the morphology and the Seebeck coefficient of RuO 2 nanorods (space group P4 2 /mnm) synthesized by reactive sputtering. At an O/Ru ratio of 1.69, a faceted surface is observed, while nanorod formation occurs at O/Ru ratios of 2.03 and 2.24. Using classical molecular dynamics with the potential parameters derived in this work, we show that volatile species enable nanorod formation. Based on ab initio calculations, two effects of the nanorod formation on the Seebeck coefficient are observed: (i) increase due to additional states in the vicinity of the Fermi level and (ii) decrease due to oxygen point defects (volatile species). These two competing effects give rise to a moderate increase in the Seebeck coefficient upon nanorod formation.

  2. Fingerprint elements scatter analysis on ancient chinese Ru porcelains samples

    Gao Zhengyao; Wang Jie; Chen Xiande

    1997-01-01

    Altogether 28 samples, mainly including glazes and bodies of ancient Chinese Ru porcelain, were analyzed by NAA technique and the contents of 36 elements were compared. The scatter analysis for nine fingerprint-elements indicates that almost all ancient Chinese Ru porcelain samples had nearly identical and long-term stable source of raw materials although they were fired in different kilns, at varying time and with distinct colors, and moreover, the source of raw materials for modern Ru porcelain seems to approach that for ancient one. The close provenance relation between ancient Jun porcelain and ancient Ru porcelain is also preliminarily verified. The glaze material of Jingdezhen white porcelain is totally different from all other samples. It shows that the former came from a separate source

  3. Isomer spectroscopy in 92Ru and 95Pd

    Gorska, M.; Rejmund, M.; Schubart, R.; Grawe, H.; Heese, J.; Maier, K.H.; Spohr, K.; Fitzgerald, J.B.; Fossan, D.B.

    1996-01-01

    The parity changing γ-transitions like E1, M2, E3 in 92 Ru and 95 Pd nuclei have been investigated to probe the purity of the Shell Model. Two isomers of 92 Ru and 95 Pd have been produced in the 58 Ni + 40 Ca heavy ion reaction at 58 Ni beams energy 215 MeV. The gamma-ray transition strength have been deduced

  4. RDM Lifetime measurement in "1"0"0Ru

    Gupta, C.K.; Rohilla, Aman; Chamoli, S.K.; Singh, R.P.; Murlithar, S.; Chakraborty, S.; Sharma, H.P.; Rai, S.; Kumar, A.; Govil, I.M.

    2016-01-01

    The energy level sequences of nuclei in A ∼ 100 mass region show an interesting interplay between single-particle and collective degrees of freedom. The measured transition probabilities in "9"8Ru suggest that the nucleus has both single-particle and vibrational character. To see how the nature of this nucleus changes with addition of 2 neutrons, we performed RDM lifetime measurement in yrast sequence of "1"0"0Ru at Inter University Accelerator Center (IUAC), New Delhi

  5. Alkali promotion of N-2 dissociation over Ru(0001)

    Mortensen, Jens Jørgen; Hammer, Bjørk; Nørskov, Jens Kehlet

    1998-01-01

    Using self-consistent density functional calculations, we show that adsorbed Na and Cs lower the barrier for dissociation of N2 on Ru(0001). Since N2 dissociation is a crucial step in the ammonia synthesis reaction, we explain in this way the experimental observation that alkali metals promote th...... the ammonia synthesis reaction over Ru catalysts. We also show that the origin of this effect is predominantly a direct electrostatic attraction between the adsorbed alkali atoms and the dissociating molecule....

  6. ScreenOS Cookbook

    Brunner, Stefan; Delcourt, David

    2008-01-01

    In the only book that completely covers ScreenOS, six key members of Juniper Network's ScreenOS development team help you troubleshoot secure networks using ScreenOS firewall appliances. Over 200 recipes address a wide range of security issues, provide step-by-step solutions, and include discussions of why the recipes work, so you can easily set up and keep ScreenOS systems on track. The easy-to-follow format enables you to find the topic and specific recipe you need right away.

  7. The activation mechanism of Fe-based olefin metathesis catalysts

    Poater, Albert

    2014-08-01

    Density functional theory calculations have been used to describe the first turnover for olefin metathesis reaction of a homogenous Fe-based catalyst bearing a N-heterocyclic carbene ligand with methoxyethene as a substrate. Equal to conventional Ru-based catalysts, the activation of its Fe congener occurs through a dissociative mechanism, however with a more exothermic reaction energy profile. Predicted upper energy barriers were calculated to be on average ∼2 kcal/mol more beneficial for Fe catalyzed metathesis. Overall, this present computational study emphasises on advantages of Fe-based metathesis and gives a potential recipe for the design of an efficient Fe-based olefin metathesis catalysts. © 2014 Elsevier B.V.

  8. The activation mechanism of Fe-based olefin metathesis catalysts

    Poater, Albert; Pump, Eva; Vummaleti, Sai V. C.; Cavallo, Luigi

    2014-01-01

    Density functional theory calculations have been used to describe the first turnover for olefin metathesis reaction of a homogenous Fe-based catalyst bearing a N-heterocyclic carbene ligand with methoxyethene as a substrate. Equal to conventional Ru-based catalysts, the activation of its Fe congener occurs through a dissociative mechanism, however with a more exothermic reaction energy profile. Predicted upper energy barriers were calculated to be on average ∼2 kcal/mol more beneficial for Fe catalyzed metathesis. Overall, this present computational study emphasises on advantages of Fe-based metathesis and gives a potential recipe for the design of an efficient Fe-based olefin metathesis catalysts. © 2014 Elsevier B.V.

  9. Comparison of Os-Os and Re-Os dating results of molybdenites

    Xie Zhi; Sun Weidong; Chen Jiangfeng

    2002-01-01

    Two molybdenite samples from the Middle-Low Reaches of the Yangtze River were dated by both Os-Os and Re-Os methods. Os-Os and Re-Os dating give identical age results for the two samples. An experiment of step distillation of Os-Os method suggests that no isotopic fractionation is observed between fractions obtained by the experiment. The results prove that the Os-Os method can avoid the problems in the Re-Os method, simplify the experimental procedure, give creditable age data, and have unique advantage that no quantitative extracting of Os is required

  10. Reduction of RuVI≡N to RuIII-NH3 by Cysteine in Aqueous Solution.

    Wang, Qian; Man, Wai-Lun; Lam, William W Y; Yiu, Shek-Man; Tse, Man-Kit; Lau, Tai-Chu

    2018-05-21

    The reduction of metal nitride to ammonia is a key step in biological and chemical nitrogen fixation. We report herein the facile reduction of a ruthenium(VI) nitrido complex [(L)Ru VI (N)(OH 2 )] + (1, L = N, N'-bis(salicylidene)- o-cyclohexyldiamine dianion) to [(L)Ru III (NH 3 )(OH 2 )] + by l-cysteine (Cys), an ubiquitous biological reductant, in aqueous solution. At pH 1.0-5.3, the reaction has the following stoichiometry: [(L)Ru VI (N)(OH 2 )] + + 3HSCH 2 CH(NH 3 )CO 2 → [(L)Ru III (NH 3 )(OH 2 )] + + 1.5(SCH 2 CH(NH 3 )CO 2 ) 2 . Kinetic studies show that at pH 1 the reaction consists of two phases, while at pH 5 there are three distinct phases. For all phases the rate law is rate = k 2 [1][Cys]. Studies on the effects of acidity indicate that both HSCH 2 CH(NH 3 + )CO 2 - and - SCH 2 CH(NH 3 + )CO 2 - are kinetically active species. At pH 1, the reaction is proposed to go through [(L)Ru IV (NHSCH 2 CHNH 3 CO 2 H)(OH 2 )] 2+ (2a), [(L)Ru III (NH 2 SCH 2 CHNH 3 CO 2 H)(OH 2 )] 2+ (3), and [(L)Ru IV (NH 2 )(OH 2 )] + (4) intermediates. On the other hand, at pH around 5, the proposed intermediates are [(L)Ru IV (NHSCH 2 CHNH 3 CO 2 )(OH 2 )] + (2b) and [(L)Ru IV (NH 2 )(OH 2 )] + (4). The intermediate ruthenium(IV) sulfilamido species, [(L)Ru IV (NHSCH 2 CHNH 3 CO 2 H)(OH 2 )] 2+ (2a) and the final ruthenium(III) ammine species, [(L)Ru III (NH 3 )(MeOH)] + (5) (where H 2 O was replaced by MeOH) have been isolated and characterized by various spectroscopic methods.

  11. Effect of the structural characteristics of binary Pt-Ru and ternary Pt-Ru-M fuel cell catalysts on the activity of ethanol electrooxidation in acid medium.

    Antolini, Ermete

    2013-06-01

    In view of their possible use as anode materials in acid direct ethanol fuel cells, the electrocatalytic activity of Pt-Ru and Pt-Ru-M catalysts for ethanol oxidation has been investigated. This minireview examines the effects of the structural characteristics of Pt-Ru, such as the degree of alloying and Ru oxidation state, on the electrocatalytic activity for ethanol oxidation. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Pt and Ru X-ray absorption spectroscopy of PtRu anode catalysts in operating direct methanol fuel cells.

    Stoupin, Stanislav; Chung, Eun-Hyuk; Chattopadhyay, Soma; Segre, Carlo U; Smotkin, Eugene S

    2006-05-25

    In situ X-ray absorption spectroscopy, ex situ X-ray fluorescence, and X-ray powder diffraction enabled detailed core analysis of phase segregated nanostructured PtRu anode catalysts in an operating direct methanol fuel cell (DMFC). No change in the core structures of the phase segregated catalyst was observed as the potential traversed the current onset potential of the DMFC. The methodology was exemplified using a Johnson Matthey unsupported PtRu (1:1) anode catalyst incorporated into a DMFC membrane electrode assembly. During DMFC operation the catalyst is essentially metallic with half of the Ru incorporated into a face-centered cubic (FCC) Pt alloy lattice and the remaining half in an amorphous phase. The extended X-ray absorption fine structure (EXAFS) analysis suggests that the FCC lattice is not fully disordered. The EXAFS indicates that the Ru-O bond lengths were significantly shorter than those reported for Ru-O of ruthenium oxides, suggesting that the phases in which the Ru resides in the catalysts are not similar to oxides.

  13. A model system for carbohydrates interactions on single-crystalline Ru surfaces

    Nguyen, Thanh Nam

    2015-07-01

    In this thesis, I present a model system for carbohydrate interactions with single-crystalline Ru surfaces. Geometric and electronic properties of copper phthalocyanine (CuPc) on top of graphene on hexagonal Ru(0001), rectangular Ru(10 anti 10) and vicinal Ru(1,1, anti 2,10) surfaces have been studied. First, the Fermi surfaces and band structures of the three Ru surfaces were investigated by high-resolution angle-resolved photoemission spectroscopy. The experimental data and theoretical calculations allow to derive detailed information about the momentum-resolved electronic structure. The results can be used as a reference to understand the chemical and catalytic properties of Ru surfaces. Second, graphene layers were prepared on the three different Ru surfaces. Using low-energy electron diffraction and scanning tunneling microscopy, it was found that graphene can be grown in well-ordered structures on all three surfaces, hexagonal Ru(0001), rectangular Ru(10 anti 10) and vicinal Ru(1,1, anti 2,10), although they have different surface symmetries. Evidence for a strong interaction between graphene and Ru surfaces is a 1.3-1.7 eV increase in the graphene π-bands binding energy with respect to free-standing graphene sheets. This energy variation is due to the hybridization between the graphene pi bands and the Ru 4d electrons, while the lattice mismatch does not play an important role in the bonding between graphene and Ru surfaces. Finally, the geometric and electronic structures of CuPc on Ru(10 anti 10), graphene/Ru(10 anti 10), and graphene/Ru(0001) have been studied in detail. CuPc molecules can be grown well-ordered on Ru(10 anti 10) but not on Ru(0001). The growth of CuPc on graphene/Ru(10 anti 10) and Ru(0001) is dominated by the Moire pattern of graphene. CuPc molecules form well-ordered structures with rectangular unit cells on graphene/Ru(10 anti 10) and Ru(0001). The distance of adjacent CuPc molecules is 15±0.5 Aa and 13±0.5 Aa on graphene/Ru(0001

  14. Measurement of the Ru surface content of electrodeposited PtRu electrodes with the electrochemical quartz crystal microbalance: implications for methanol and CO electrooxidation

    Frelink, T.; Visscher, W.; Veen, van J.A.R.

    1996-01-01

    To obtain the surface content of Ru in rough electrocodeposited PtRu electrodes, the mass change of a Pt electrode during Ru deposition was measured with the electrochemical quartz crystal microbalance (EQCMB). It is shown that there is a correlation between the potential of the surface oxide

  15. Reactivity toward alcohols of (Ru/sup IV/ = O/sup 2-/) unit in trans-(RuCl(O)(py)/sub 4/)/sup +/

    Aoyagi, Kimitake; Nagao, Hirotaka; Yukawa, Yasuhiko; Ogura, Mariko; Kuwayama, Akito; Howell, F S; Mukaida, Masao; Kakihana, Hidetake

    1986-12-01

    The reactivity with alcohol of trans-(RuCl(O)(py)/sub 4/)/sup +/ was investigated. In MeOH, trans-(RuCl(OH)(py)/sub 4/)/sup +/ was confirmed to exist as a precursor in the formation of trans-(RuCl(OMe)(py)/sub 4/)/sup +/. The reaction progress was traced by spectrometrical and /sup 18/O-labelling experiments.

  16. [Population Council responsible for RU486 clinical trials in USA].

    Aguillaume, C J

    1993-04-01

    As a result of the sudden political change that came with the Clinton Administration, RU-486's manufacturer, Roussel-Uclaf, and the Population Council agreed on April 20, 1992, on the manufacture and distribution of RU-486 in the US. In the US, there are less than 1.6 million induced abortions annually. From now on, US women will be able to have a choice between medical and surgical abortion. The Population Council and Roussel-Uclaf have had a contract since 1982. The Council is solely responsible for the phase 2 clinical trial of RU-486 in the US and other countries. It must present to the US Food and Drug Administration (FDA) an amendment allowing it to begin phase 3 clinical trials. The Council will also lead the US medical facilities in this study. It will identify partners for future production of RU-486 and its distribution in the US. It will also submit to FDA a New Drug Application (NDA). FDA will review the scientific literature on RU-486 and evaluate all data submitted by the Population Council. There are still obstacles to be surmounted. The Population Council must demonstrate good judgment when selecting the criteria for choosing a pharmaceutical firm before a Technical Committee which will be part of a group of players promoting women's health, scientific experts, and other interested parties. It must find the necessary funds to conduct the clinical trials and prepare the NDA. Phase 3 clinical trials in the US must have at least 2000 women. They will test RU-486's efficacy, safety, and acceptability among women choosing medical abortion over surgical abortion. Since the Council operates in almost all countries in the world, has innovated contraceptive research and development activities, and has been endorsed by the UN, product approval of RU-486 in the US will affect policy in all countries concerned about abortion.

  17. Effect of noble metals in the decomposition of nitrous oxide over Fe-ferrierites

    Sobalík, Zdeněk; Jíša, Kamil; Kaucký, Dalibor; Vondrová, Alena; Tvarůžková, Zdenka; Nováková, Jana

    2007-01-01

    Roč. 113, 3-4 (2007), s. 124-129 ISSN 1011-372X R&D Projects: GA AV ČR 1ET400400413 Institutional research plan: CEZ:AV0Z40400503 Keywords : Fe, Pt, Rh, Ru-ferrierite * synergy effects in Fe/Me-ferrierites * N2O decomposition Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.883, year: 2007

  18. Advanced OS deployment system

    Galiano Molina, Sebastián

    2007-01-01

    The main project’s objective is to design and build an OS deployment system taking advantage of the Linux OS and the Open Source community developments. This means to use existing technologies that modularize the system. With this philosophy in mind, the number of developed code lines within the project is keeping as small as possible. As REMBO, the OS deployment system to develop has to be transparent to the user. This means a system with a friendly user interface and no te...

  19. Firefox OS Overview

    JANCZUKOWICZ , Ewa

    2013-01-01

    Firefox OS is an operating system for mobile devices such as smartphones and tablets. It is developed by Mozilla but it aims to be free from any proprietary technology. It lets users run applications developed entirely using web technologies, like HTML5, JavaScript, CSS. It is not directly competing with iOS. It has some common target markets with Android. For now Firefox OS targets specific type of clients - people that don't have smartphones yet. Available devices are low-end and as a resul...

  20. Laminated structure in internally oxidized Ru-Ta coatings

    Chen, Yung-I, E-mail: yichen@mail.ntou.edu.tw

    2012-12-01

    During the development of refractory alloy coatings for protective purposes at high temperature under oxygen-containing atmospheres, previous studies noted and examined the internal oxidation phenomenon for Mo-Ru and Ru-Ta coatings. The internally oxidized zone shows a laminated structure, consisting of alternating oxygen-rich and deficient layers stacked with a general orientation. Previous studies proposed a forming mechanism. To investigate in detail, Ru-Ta coatings were prepared with various rotating speeds of a substrate-holder. The coatings were annealed at 600 Degree-Sign C in an atmosphere continuously purged with 1% O{sub 2}-99% Ar mixed gas for 30 min. Transmission electron microscopy was used to examine the laminated-layer periods. Auger electron spectroscopy depth profiles certified the periodical variation of the related constituents. X-ray photoelectron spectroscopy proved the valence variation of Ta in the near surface, accompanied by the introduction of oxygen ions. The inward diffusion of oxygen was dominated by lattice diffusion. - Highlights: Black-Right-Pointing-Pointer Laminated Ru-Ta coatings consisted of a cyclical gradient concentration. Black-Right-Pointing-Pointer The as-deposited coatings showed a laminated structure with a period of 4-34 nm. Black-Right-Pointing-Pointer Internal oxidation of Ru-Ta coatings executed after annealing in 1% O{sub 2}-Ar atmosphere. Black-Right-Pointing-Pointer Oxygen inward diffusion was dominated by lattice diffusion.

  1. Syntheses, structures, and physicochemical properties of diruthenium compounds of tetrachlorocatecholate with metal-metal bonded Ru(3+)(mu-OR)(2)Ru(3+) and Ru(3.5+)(mu-OR)(2)Ru(3.5+) cores (R = CH(3) and C(2)H(5)).

    Miyasaka, H; Chang, H C; Mochizuki, K; Kitagawa, S

    2001-07-02

    Metal-metal bonded Ru(3+)(mu-OR)(2)Ru(3+) and Ru(3.5+)(mu-OR)(2)Ru(3.5+) (R = CH(3) and CH(3)CH(2)) compounds with tetrachlorocatecholate (Cl(4)Cat) have been synthesized in the corresponding alcohol, MeOH and EtOH, from a nonbridged Ru(2+)-Ru(3+) compound, Na(3)[Ru(2)(Cl(4)Cat)(4)(THF)].3H(2)O.7THF (1). In alcohol solvents, compound 1 is continuously oxidized by oxygen to form Ru(3+)(mu-OR)(2)Ru(3+) and Ru(3.5+)(mu-OR)(2)Ru(3.5+) species. The presence of a characteristic countercation leads to selective isolation of either Ru(3+)(mu-OR)(2)Ru(3+) or Ru(3.5+)(mu-OR)(2)Ru(3.5+) as a stable adduct species. In methanol, Ph(4)PCl and dibenzo-18-crown-6-ether afford Ru(3+)(mu-OMe)(2)Ru(3+) species, [A](2)[Ru(2)(Cl(4)Cat)(4)(mu-OMe)(2)Na(2)(MeOH)(6)] ([A](+) = Ph(4)P(+) (2), [Na(dibenzo-18-crown-6)(H(2)O)(MeOH)](+) (3)), while benzo-15-crown-5-ether provides a Ru(3.5+)(mu-OMe)(2)Ru(3.5+) species, [Na(benzo-15-crown-5)(2)][Ru(2)(Cl(4)Cat)(4)(mu-OMe)(2)Na(2)(MeOH)(6)] (4). The air oxidation of 1 in a MeOH/EtOH mixed solvent (1:1 v/v) containing benzo-15-crown-5-ether provides a Ru(3.5+)(mu-OMe)(2)Ru(3.5+) species, [Na(benzo-15-crown-5)(H(2)O)][Ru(2)(Cl(4)Cat)(2)(mu-OMe)(2)Na(2)(EtOH)(2)(H(2)O)(2)(MeOH)(2)].(benzo-15-crown-5) (5). Similarly, the oxidation of 1 in ethanol with Ph(4)PCl provides a Ru(3.5+)(mu-OEt)(2)Ru(3.5+) species, (Ph(4)P)[Ru(2)(Cl(4)Cat)(4)(mu-OEt)(2)Na(2)(EtOH)(6)] (7). A selective formation of a Ru(3+)(mu-OEt)(2)Ru(3+) species, (Ph(4)P)(2)[Ru(2)(Cl(4)Cat)(4)(mu-OEt)(2)Na(2)(EtOH)(2)(H(2)O)(2)] (6), is found in the presence of pyrazine or 2,5-dimethylpyrazine. The crystal structures of these compounds, except 2 and 7, have been determined by X-ray crystallography, and all compounds have been characterized by several spectroscopic and magnetic investigations. The longer Ru-Ru bonds are found in the Ru(3+)(mu-OR)(2)Ru(3+) species (2.606(1) and 2.628(2) A for 3 and 6, respectively) compared with those of Ru(3.5+)(mu-OMe)(2)Ru(3.5+) species (2.5260(6) A and 2

  2. Mac OS X Forensics

    Craiger, Philip; Burke, Paul

    This paper describes procedures for conducting forensic examinations of Apple Macs running Mac OS X. The target disk mode is used to create a forensic duplicate of a Mac hard drive and preview it. Procedures are discussed for recovering evidence from allocated space, unallocated space, slack space and virtual memory. Furthermore, procedures are described for recovering trace evidence from Mac OS X default email, web browser and instant messaging applications, as well as evidence pertaining to commands executed from a terminal.

  3. Direct methanol fuel cell with extended reaction zone anode: PtRu and PtRuMo supported on graphite felt

    Bauer, Alex; Gyenge, Előd L.; Oloman, Colin W.

    Pressed graphite felt (thickness ∼350 μm) with electrodeposited PtRu (43 g m -2, 1.4:1 atomic ratio) or PtRuMo (52 g m -2, 1:1:0.3 atomic ratio) nanoparticle catalysts was investigated as an anode for direct methanol fuel cells. At temperatures above 333 K the fuel cell performance of the PtRuMo catalyst was superior compared to PtRu. The power density was 2200 W m -2 with PtRuMo at 5500 A m -2 and 353 K while under the same conditions PtRu yielded 1925 W m -2. However, the degradation rate of the Mo containing catalyst formulation was higher. Compared to conventional gas diffusion electrodes with comparable PtRu catalyst composition and load, the graphite felt anodes gave higher power densities mainly due to the extended reaction zone for methanol oxidation.

  4. Linear thermal expansion coefficient of cast Fe-Ni invar and Fe-Ni-Co superinvar alloys

    Ogorodnikova, O.M.; Chermenskaya, E.V.; Rabinovich, S.V.; Grachev, S.V.

    1999-01-01

    Cast invar alloys Fe-Ni (28-35 wt. % Ni) are investigated using metallography, dilatometry and X-ray methods as soon as the crystallization is completed and again after low-temperature treatment resulting in martensitic transformation in low nickel alloys. Nickel distribution in a cast superinvar Fe-32% Ni-4% Co is studied by means of X-ray spectrum microanalysis. The results obtained permit the correction of model concepts about cast invars and the estimate of a coefficient of linear expansion depending on phase composition and nickel microsegregation [ru

  5. O ruído e o aparelho respiratório

    Mariana Alves-Pereira

    2003-09-01

    Full Text Available RESUMO: Apesar do importante acervo de evidência científica já existente, a patologia respiratória provocada pela exposição crónica a ruído de baixa frequência (RBF continua por reconhecer. O objectivo deste trabalho de revisão consiste em: a descrever o fenómeno acústico como agente de doença, demonstrando a inépcia da legislação no que diz respeito à patologia extra-auditiva; b esclarecer os motivos que conduziram ao interesse na patologia respiratória nos indivíduos expostos a RBF; e c enaltecer outros estudos que denunciam o efeito deletério do ruído sobre o aparelho respiratório. Por último, apresentar e discutir as perspectivas futuras sobre os estudos dirigidos à caracterização dos efeitos do RBF e da necessidade de reproduzir estes efeitos em modelos animais.REV PORT PNEUMOL 2003; IX (5: 367-379 ABSTRACT: Noise-induced pulmonary pathology is still an issue that is regarded with much suspicion despite the significant body of evidence demonstrating that acoustic phenomena target the respiratory tract. The goal of this review paper is threefold: a to describe acoustic phenomena as an agent of disease, and the inadequacies of current legislation regarding noise-induced, non-auditory pathology; b to trace how the interest in noise-induced pulmonary pathology emerged within the scope of studies on vibroacoustic disease; and c to bring to light other studies denouncing noise as an agent of disease that impinges on the respiratory tract. As concluding remarks, future perspectives in LFN-related research will be discussed. The need for animal models will be emphasized.REV PORT PNEUMOL 2003; IX (5: 367-379 Palavras-chave: ruído de baixa frequência, derrame pleural, bronquite, fibrose pulmonar, audição, decibel, ocupacional, ambiental, Key-words: low frequency noise, pleural effusion, bronchitis, pulmonary fibrosis, hearing, decibel, occupational, environmental

  6. Ethylene glycol oxidation on Pt and Pt-Ru nanoparticle decorated polythiophene/multiwalled carbon nanotube composites for fuel cell applications

    Selvaraj, Vaithilingam; Alagar, Muthukaruppan

    2008-01-01

    A novel supporting material containing polythiophene (PTh) and multiwalled carbon nanotubes (MWCNTs) (PTh-CNTs) is prepared by in situ polymerization of thiophene on carbon nanotubes using FeCl 3 as oxidizing agent under sonication. The prepared polythiophene/CNT composites are further decorated with Pt and Pt-Ru nanoparticles by chemical reduction of the corresponding metal salts using HCHO as reducing agent at pH = 11 (Pt/PTh-CNT and Pt-Ru/PTh-CNT). The fabricated composite films decorated with nanoparticles were investigated towards the electrochemical oxidation of ethylene glycol (EG). The presence of carbon nanotubes in conjugation with a conducting polymer produces a good catalytic effect, which might be due to the higher electrochemically accessible surface areas, electronic conductivity and easier charge-transfer at polymer/electrolyte interfaces, which allows higher dispersion of Pt and Pt-Ru nanoparticles. Such nanoparticle modified PTh-CNT electrodes exhibit better catalytic behavior towards ethylene glycol oxidation. Results show that Pt/PTh-CNT and Pt-Ru/PTh-CNT modified electrodes show enhanced electrocatalytic activity and stability towards the electro-oxidation of ethylene glycol than the Pt/PTh electrodes, which shows that the composite film is more promising for applications in fuel cells

  7. Addition of IrO2 to RuO2+TiO2 coated anodes and its effect on electrochemical performance of anodes in acid media

    Farhad Moradi

    2014-04-01

    Full Text Available Ternary mixed metal oxide coatings with the nominal composition IrxRu(0.6−xTi0.4O2 (x=0, 0.1, 0.2, 0.3 on the titanium substrate were prepared by thermal decomposition of a chloride precursor mixture. Surface morphology and microstructure of the coatings were investigated by Scanning electron microscopy (SEM, Field emission scanning electron microscopy (FE-SEM and X-ray diffraction (XRD analysis. Systematic study of electrochemical properties of these coatings was performed by cyclic voltammetry (CV and polarization measurements. The corrosion behavior of the coatings was evaluated under accelerated conditions (j=2 A cm−2 in acidic electrolyte. The role of iridium oxide admixture in the change of electrocatalytic activity and stability of Ru0.6Ti0.4O2 coating was discussed. Small addition of IrO2 can improve the stability of the RuO2+TiO2 mixed oxide, while the electrocatalytic activity for oxygen evolution reaction (OER is decreased. The shift of redox potentials for Ru0.6Ti0.4O2 electrode that is slightly activated with IrO2 and improvement in the stability can be attributed to the synergetic effect of mixed oxide formation.

  8. Anisotropic electrical, thermal and magnetic properties of Al{sub 13}Ru{sub 4} decagonal quasicrystalline approximant

    Wencka, Magdalena [Polish Academy of Sciences, Poznan (Poland). Inst. of Molecular Physics; Vrtnik, Stanislav; Kozelj, Primoz; Dolinsek, Janez [Ljubljana Univ. (Slovenia). Faculty of Mathematics and Physics; Jozef Stefan Institute, Ljubljana (Slovenia); Jaglicic, Zvonko [Ljubljana Univ. (Slovenia). Inst. of Mathematics, Physics and Mechanics; Gille, Peter [Muenchen Univ. (Germany). Crystallography Section

    2017-09-01

    We present measurements of the anisotropic electrical and thermal transport coefficients (the electrical resistivity, the thermoelectric power, the thermal conductivity), the magnetization and the specific heat of the Al{sub 13}Ru{sub 4} monoclinic approximant to the decagonal quasicrystal, in comparison to the isostructural Al{sub 13}Fe{sub 4}. The electrical and thermal transport parameters of Al{sub 13}Ru{sub 4} were found to exhibit significant anisotropy, qualitatively similar to that found previously in the Al{sub 13}Fe{sub 4} (P. Popcevic, et al., Phys. Rev. B 2010, 81, 184203). The crystallographic b direction, corresponding to the stacking direction of the (a,c) atomic planes, is the most conducting direction for the electricity and heat. The thermopower is strongly anisotropic with a complicated temperature dependence, exhibiting maxima, minima, crossovers and sign change. The electronic density of states (DOS) at the Fermi energy is reduced to 35% of the DOS of Al metal. The magnetic susceptibility is diamagnetic and the diamagnetism is by a factor of 2 stronger for the magnetic field along the stacking b direction.

  9. Dynamical spin structure factors of α-RuCl3

    Suzuki, Takafumi; Suga, Sei-ichiro

    2018-03-01

    Honeycomb-lattice magnet α-RuCl3 is considered to be a potential candidate of realizing Kitaev spin liquid, although this material undergoes a phase transition to the zigzag magnetically ordered state at T N ∼ 7 K. Quite recently, inelastic neutron-scattering experiments using single crystal α-RuCl3 have unveiled characteristic dynamical properties. We calculate dynamical spin structure factors of three ab-initio models for α-RuCl3 with an exact numerical diagonalization method. We also calculate temperature dependences of the specific heat by employing thermal pure quantum states. We compare our numerical results with the experiments and discuss characteristics obtained by using three ab-initio models.

  10. Growth model of Au films on Ru(001)

    Canessa, E.; Calmetta, A.

    1992-06-01

    In an attempt to find generic features on the fractal growth of Au films deposited on Ru(001), a simple simulation model based on irreversible diffusion-limited aggregation (DLA) is discussed. Highly irregular two-dimensional dentritic islands of Au particles that gradually grow on a larger host lattice of Ru particles and have fractal dimension d f approx. 1.70 each, are generated via a multiple had-hoc version of the DLA algorithm for single aggregates. Annealing effects on the islands morphology are reproduced assuming different sticking probabilities at nearest-neighbour lattice sites of Au films on Ru(001). Using simulation data, islands growth are described in analogy to diffusion-limited, precipitate growth with soft impingement of precipities. This leads to analyse thin film island growth kinetics in such fractal systems and to predict a main peak in scattering intensity patterns due to interisland interference. (author). 12 refs, 4 figs

  11. On the solubility of yttrium in RuO2

    Music, Denis; Zumdick, Naemi A.; Hallstedt, Bengt; Schneider, Jochen M.

    2011-01-01

    We have investigated the solubility of Y in rutile RuO 2 using experimental and theoretical methods. Nanostructured Ru-Y-O thin films were synthesized via combinatorial reactive sputtering with an O/metal ratio of 2.6 and a Y content of 0.3 to 12.6 at. %. A solubility limit of 1.7 at. % was identified using x-ray photoelectron spectroscopy and x-ray diffraction. Based on ab initio and thermodynamic modeling, the solubility of Y can be understood. Smaller Y amounts are incorporated into the lattice, forming a metastable film, with local structural deformations due to size effects. As the Y content is increased, extensive local structural deformations are observed, but phase separation does not occur due to kinetic limitations. Nanostructured RuO 2 alloyed with Y might lead to enhanced phonon scattering and quantum confinement effects, which in turn improve the thermoelectric efficiency.

  12. O ruído causando danos e estresse: possibilidade de atuação para a enfermagem do trabalho

    Jorge Luiz Lima da Silva

    2014-01-01

    Full Text Available A exposição ao ruído vem sendo problema de saúde ocupacional cada vez mais presente na vida de profissionais, e reclamado como fator de estresse no trabalho. Diante disto, este estudo objetivou identificar os riscos ocupacionais que acometem trabalhadores que atuam em ambientes ruidosos, discutindo as consequências à saúde do trabalhador. A presente é uma pesquisa de natureza descritiva, que se deu por meio de revisão bibliográfica analítica baseada em obras publicadas no período de 1978 a 2010. Foi construído um quadro comparativo para discussão dos principais achados. Os riscos encontrados foram: estresse, distúrbios do sono, problemas em vários sistemas fisiológicos, com destaque para o neurológico e circulatório e risco de acidentes laborais. O papel educativo do enfermeiro deve ser contínuo e com avaliação de risco das ações executadas pelo trabalhador. A enfermagem do trabalho, como especialidade, vem buscando desenvolver e aprofundar conhecimentos e ampliar seu papel junto à área de saúde do trabalhador. Os profissionais conhecem os riscos do ruído, classificam-no como a principal causa de incômodo e conhecem estratégias coletivas e individuais para diminuir os riscos ocupacionais.

  13. Fuel management simulation for CANFLEX-RU in CANDU 6

    Jeong, Chang Joon; Suk, Ho Chun [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1997-12-31

    Fuel management simulations have been performed for CANFLEX-09% RU fuel in the CANDU 6 reactor. In this study, the bi-directional 4-bundle shift fuelling scheme was assumed. The lattice cell and time-average calculation were carried out. The refuelling simulation calculations were performed for 600 full power days. Time-averaged results show good axial power profile with the CANFLEX-RU fuel. During the simulation period, the maximum channel and bundle power were maintained below the licensing limit of CANDU 6 reactor. 7 refs., 4 figs. (Author)

  14. Role of steps in N-2 activation on Ru(0001)

    Dahl, Søren; Logadottir, Ashildur; Egeberg, Rasmus

    1999-01-01

    Using adsorption experiments and density functional calculations we show that N-2 dissociation on the Ru(0001) surface is totally dominated by steps. The measured adsorption rate at the steps is at least 9 orders of magnitude higher than on the terraces at 500 K, and the corresponding calculated ...... difference in activation energy is 1.5 eV. The low barrier at the step is shown to be due to a combination of electronic and geometrical effects. The consequences for Ru as a catalyst for ammonia synthesis are discussed....

  15. Fuel management simulation for CANFLEX-RU in CANDU 6

    Jeong, Chang Joon; Suk, Ho Chun [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1998-12-31

    Fuel management simulations have been performed for CANFLEX-09% RU fuel in the CANDU 6 reactor. In this study, the bi-directional 4-bundle shift fuelling scheme was assumed. The lattice cell and time-average calculation were carried out. The refuelling simulation calculations were performed for 600 full power days. Time-averaged results show good axial power profile with the CANFLEX-RU fuel. During the simulation period, the maximum channel and bundle power were maintained below the licensing limit of CANDU 6 reactor. 7 refs., 4 figs. (Author)

  16. Tuning the reactivity of Ru nanoparticles by defect engineering of the reduced graphene oxide support

    Liu, Xin; Sui, Yanhui; Meng, Changgong; Han, Yu

    2014-01-01

    We systematically investigated the electronic structure of Ru nanoparticles supported on various local structures on reduced graphene oxide (rGO) by first-principles-based calculations. We showed that Ru nanoparticles prefer to nucleate

  17. Graphene substrate-mediated catalytic performance enhancement of Ru nanoparticles: A first-principles study

    Liu, Xin; Yao, Kexin; Meng, Changgong; Han, Yu

    2012-01-01

    The structural, energetic and magnetic properties of Ru nanoparticles deposited on pristine and defective graphene have been thoroughly studied by first-principles based calculations. The calculated binding energy of a Ru 13 nanoparticle on a single

  18. Ru-core/Cu-shell bimetallic nanoparticles with controlled size formed in one-pot synthesis.

    Helgadottir, I; Freychet, G; Arquillière, P; Maret, M; Gergaud, P; Haumesser, P H; Santini, C C

    2014-12-21

    Suspensions of bimetallic nanoparticles (NPs) of Ru and Cu have been synthesized by simultaneous decomposition of two organometallic compounds in an ionic liquid. These suspensions have been characterized by Anomalous Small-Angle X-ray Scattering (ASAXS) at energies slightly below the Ru K-edge. It is found that the NPs adopt a Ru-core, a Cu-shell structure, with a constant Ru core diameter of 1.9 nm for all Ru : Cu compositions, while the Cu shell thickness increases with Cu content up to 0.9 nm. The formation of RuCuNPs thus proceeds through rapid decomposition of the Ru precursor into RuNPs of constant size followed by the reaction of the Cu precursor and agglomeration as a Cu shell. Thus, the different decomposition kinetics of precursors make possible the elaboration of core-shell NPs composed of two metals without chemical affinity.

  19. The microstructural evolution of nanometer ruthenium films in Ru/C multilayers with thermal treatments

    Nguyen, T.D.; Gronsky, R.; Kortright, J.B.

    1991-04-01

    The evolution of nanometer Ru films sandwiched between various C layer thickness with thermal treatments was studied by plan-view and cross-sectional Transmission Electron Microscopy. Plan-view observation provides information on the Ru grain size, while cross- sectional studies allow examination of the multilayer morphology. After annealing at 800 degrees C for 30 minutes, the grain size in the 2 and 4 nm Ru layers show little difference from each other, while that in the 1 nm Ru layers depends strongly on the thickness of the C layers in the multilayers. It increases with decreasing C layer thickness. Agglomeration of the Ru layers is observed in 1nm Ru/1nm C multilayers after annealing at 600 degrees C for 30 minutes. The evolution of the microstructures and layered structure stability of the Ru/C system is compared to that of W/C and Ru/B 4 C systems. 10 refs., 2 figs

  20. Minatom.ru - A nuclear information repository

    Fateyev, Eugene

    2002-01-01

    irradiated fuel as spent nuclear fuel and thus started threatening the population saying that Russia would be transformed into a nuclear garbage ground. - In such a situation a new column was started on the site - 'Discussing the Bills'. The column gave the answers to frequently asked questions and that was a due response to the opponents of importing of foreign irradiated fuel in Russia. After that a permanent column was started - 'Irradiated fuel is the Fuel of the Future'. In this column specialists in atomic energy and radiological safety very clearly explain on a step-by-step basis all the problems concerning the irradiated fuel. - We consider the minatom.ru web-site an instrument that will help us to achieve the following goals: - creating of a single information area of Minatom in Russia; - achieving favorable public opinion about the nuclear; - supporting the image of Minatom as one of the main branches of economy; - propaganda of the benefits of the atomic energy, stressing the fact that it has no alternative; - propaganda of using radiation in medicine as well as other socially valuable aspects of the nuclear science and the atomic energy; - closer contacts with the regions of the country where nuclear sites are located or planned; - giving the possibility to the negatively orientated part of the population to express their point of view; - giving maximum access to the information available within the industry; - establishing of interactive dialogue between the public and the head of the industry. (author)

  1. Synthesis, characterization, and magnetic properties of the new boride solid solutions M{sub 0.5}Ru{sub 6.5}B{sub 3} (M = Cr, Mn, Co, Ni)

    Misse, Patrick R.N.; Fokwa, Boniface P.T. [Institute of Inorganic Chemistry, RWTH Aachen University (Germany)

    2010-05-15

    Powder samples and single crystals of the borides M{sub 0.5}Ru{sub 6.5}B{sub 3} (M = Cr, Mn, Co, Ni) were synthesized by arc-melting the elements in a water-cooled copper crucible under argon. The new phases were structurally characterized by single-crystal and powder X-ray diffraction as well as EDX-Analyses. They crystallize in the hexagonal Th{sub 7}Fe{sub 3} structure type (space group P6{sub 3}mc, no. 186, Z = 2) and a pronounced site preferential M/Ru substitution is observed. Magnetic properties of the compounds were investigated and Pauli paramagnetism was observed in all cases. However, a strong temperature dependency is subsequently observed in Mn{sub 0.5}Ru{sub 6.5}B{sub 3} below 250 K, but no hint of magnetic ordering was found. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  2. Moessbauer study of the Ru porcelain of Chinese Song Dynasty and Yuan Dynasty

    Gao Zhengyao; Chen Xiande

    1994-01-01

    The Moessbauer spectra from the glazes of the Song Dynasty and the Yuan Dynasty Ru porcelains and the imitative ancient Ru porcelain are compared and analyzed. It is determined that the original firing atmosphere of the Yuan Dynasty Ru porcelain was reductive. The firing temperature was 1250 ± 20 C. The original firing atmosphere of the Song Dynasty Ru porcelain was also reductive; the firing temperature was above 1200 C. The coloring mechanism of these glazes is discussed. (orig.)

  3. Unconventional transport characteristics of p-wave superconducting junctions in Sr2RuO4-Ru eutectic system

    Kambara, H.; Kashiwaya, S.; Yaguchi, H.; Asano, Y.; Tanaka, Y.; Maeno, Y.

    2010-01-01

    We report on novel local transport characteristics of naturally formed p-wave superconducting junctions of Sr 2 RuO 4 -Ru eutectic system by using microfabrication technique. We observed quite anomalous voltage-current (differential resistance-current) characteristics for both I//ab and I//c directions, which are not seen in conventional Josephson junctions. The anomalous features suggest the internal degrees of freedom of the superconducting state, possibly due to chiral p-wave domain. The dc current acts as a driving force to move chiral p-wave domain walls and form larger critical current path to cause the anomalous hysteresis.

  4. Photoinduced reduction of the medial FeS center in the hydrogenase small subunit HupS from Nostoc punctiforme.

    Raleiras, Patrícia; Hammarström, Leif; Lindblad, Peter; Styring, Stenbjörn; Magnuson, Ann

    2015-07-01

    The small subunit from the NiFe uptake hydrogenase, HupSL, in the cyanobacterium Nostoc punctiforme ATCC 29133, has been isolated in the absence of the large subunit (P. Raleiras, P. Kellers, P. Lindblad, S. Styring, A. Magnuson, J. Biol. Chem. 288 (2013) 18,345-18,352). Here, we have used flash photolysis to reduce the iron-sulfur clusters in the isolated small subunit, HupS. We used ascorbate as electron donor to the photogenerated excited state of Ru(II)-trisbipyridine (Ru(bpy)3), to generate Ru(I)(bpy)3 as reducing agent. Our results show that the isolated small subunit can be reduced by the Ru(I)(bpy)3 generated through flash photolysis. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. H2-splitting on Pt/Ru alloys supported on sputtered HOPG

    Fiordaliso, Elisabetta Maria; Dahl, Søren; Chorkendorff, Ib

    2011-01-01

    to strain and ligand effects, caused by the compression of the surface due to the presence of the larger Pt atoms in the neighboring Ru atoms. The apparent energy of desorption at equilibrium, Eapp, for the three Pt-Ru systems is found to decrease with an increasing amount of Ru in the alloys...

  6. In situ EXAFS study of Ru-containing electrocatalysts of oxygen reduction

    Malakhov, I.V.; Nikitenko, S.G.; Savinova, E.R.; Kochubey, D.I.; Alonso-Vante, N.

    2000-01-01

    The series of Ru chalcogenide compounds is obtained by varying the nature of the chalcogen with the transition metal (Ru) matrix. The EXAFS technique reveals that the electrocatalytic centre is Ru in a cluster matrix. Furthermore, a reversible change in the structure of the active centre as a function of the applied electrode potential appears

  7. Production of ruthenium aluminide by reaction sintering of Ru and Al powder mix

    Povarova, K.B.; Kazanskaya, N.K.; Drozdov, A.A.; Skachkov, O.A.; Levin, V.P.

    2002-01-01

    The physicochemical processes, taking place by the RuAl alloy formation from the ruthenium and aluminium powder mixture within the temperature range of 250-1400 deg C in the vacuum from 10 -2 up to 10 -5 mm mercury column are studied on the alloys of the Ru 50 Al 50 stoichiometric and Ru 52 Al 48 hyperstoichiometric composition. The Ru + Al → RuAl interaction with the exothermal effect begins in the solid phase at the temperatures below the aluminium t melt . The Ru 2 Al 3 , RuAl 2 and RuAl traces rich in aluminium are formed already at 600 deg C; at 1000-1400 deg C the RuAl becomes the basic phase; the precipitates of the ruthenium-based solid solution are additionally present in the hyperstoichiometric Ru 52 Al 48 alloy. The Ru 52 Al 48 crystalline lattice period increases with the growth of the caking temperature from 0.29906 (660 deg C) up to 0.22955 nm (1400 deg C). The Al 2 O 3 inclusions up to 1 μm in diameter are identified in the caked alloys in vacuum after the reaction caking [ru

  8. Ab-initio calculations of electric field gradient in Ru compounds and ...

    Home; Journals; Pramana – Journal of Physics; Volume 89; Issue 2. A b − i n i t i o calculations of electric field gradient in Ru compounds and their implication on the nuclear quadrupole moments of 99 Ru and 101 Ru. S N MISHRA. Research Article Volume 89 Issue 2 August 2017 Article ID 22 ...

  9. Electrocatalytic activity of atomic layer deposited Pt-Ru catalysts onto N-doped carbon nanotubes

    Johansson, A.-C.; Larsen, J.V.; Verheijen, M.A.; Haugshøj, K.B.; Clausen, H.; Kessels, W.M.M.; Christensen, L.H.; Thomsen, E.V.

    2014-01-01

    Pt-Ru catalysts of various compositions, between 0 and 100 at.% of Ru, were deposited onto N-doped multi-walled carbon nanotubes (N-CNTs) by atomic layer deposition (ALD) at 250 C. The Pt and Ru precursors were trimethyl(methylcyclopentadienyl)platinum (MeCpPtMe3) and

  10. RuBee and RFID A confidential summary,May 2009

    2009-01-01

    The letters"RFID"have become a negative to many of our end-customers,so we have had to distance RuBee from the entire category and discourage any attempt to characterize RuBee as just another RFID technology.We never engage in pilots or trials where RFID is seen as a competing technology to RuBee.Most

  11. Polarized Raman study on the lattice structure of BiFeO3 films prepared by pulsed laser deposition

    Yang, Yang

    2014-11-01

    Polarized Raman spectroscopy was used to study the lattice structure of BiFeO3 films on different substrates prepared by pulsed laser deposition. Interestingly, the Raman spectra of BiFeO3 films exhibit distinct polarization dependences. The symmetries of the fundamental Raman modes in 50-700 cm-1 were identified based on group theory. The symmetries of the high order Raman modes in 900-1500 cm-1 of BiFeO3 are determined for the first time, which can provide strong clarifications to the symmetry of the fundamental peaks in 400-700 cm-1 in return. Moreover, the lattice structures of BiFeO3 films are identified consequently on the basis of Raman spectroscopy. BiFeO3 films on SrRuO3 coated SrTiO3 (0 0 1) substrate, CaRuO3 coated SrTiO3 (0 0 1) substrate and tin-doped indium oxide substrate are found to be in the rhombohedral structure, while BiFeO3 film on SrRuO3 coated Nb: SrTiO3 (0 0 1) substrate is in the monoclinic structure. Our results suggest that polarized Raman spectroscopy would be a feasible tool to study the lattice structure of BiFeO3 films.

  12. Resonant photoemission study of CeRu4Sb12

    Ishii, Hiroyoshi; Miyahara, Tsuneaki; Takayama, Yasuhiro; Shiozawa, Hidetsugu; Obu, Kenji; Matsuda, Tatsuma D.; Aoki, Yuji; Sugawara, Hitoshi; Sato, Hideyuki

    2005-01-01

    We have measured the Ce 4d-4f and Ce 3d-4f resonant photoemission spectra of CeRu 4 Sb 12 . The Ce 4f spectra show the spectral features corresponding to a weakly hybridized system. The number of 4f electrons is estimated to be ∼1.0

  13. Preparation of Pt–Ru bimetallic catalyst supported on carbon

    The template carbonization of polyphenyl acetylene yields hollow, uniform cylindrical carbon nanotubes with outer diameter almost equal to pore diameter of the template used. High resolution transmission electron microscopic investigation reveals that Pt–Ru nanoparticles are highly dispersed inside the tube with an ...

  14. Catalytic properties of Ru-mordenite for NO reduction

    Labhsetwar, NK.; Minamino, H.; Mukherjee, M.; Mitsuhashi, T.; Rayalu, S.; Dhakad, M.; Haneda, H.; Šubrt, Jan; Devotta, S.

    2007-01-01

    Roč. 261, č. 2 (2007), s. 213-217 ISSN 1381-1169 Grant - others:CSIR(IN) CORE(08) Institutional research plan: CEZ:AV0Z40320502 Keywords : NO reduction * catalyst * Ru-zeolite Subject RIV: CA - Inorganic Chemistry Impact factor: 2.707, year: 2007

  15. STUDY OF THE Pt/Ru(0001) INTERFACE

    Godowski, P.J.; Li, Zheshen; Bork, J.

    2007-01-01

    to the different stages of the deposition were analyzed. Up to ca. two adsorbate monolayers, the intensity changes of the peaks indicated layer-by-layer growth mode. The surface core level shifts of Ru and Pt levels were evaluated as -0.33 and -0.476 eV, respectively. The valence band spectra show a rather weak...

  16. Magnetic Excitations in α-RuCl3

    Nagler, Stephen; Banerjee, Arnab; Bridges, Craig; Yan, Jiaqiang; Mandrus, David; Stone, Matthew; Aczel, Adam; Li, Ling; Yiu, Yuen; Lumsden, Mark; Knolle, Johannes; Moessner, Roderich; Tennant, Alan

    2015-03-01

    The layered material α-RuCl3 is composed of stacks of weakly coupled honeycomb lattices of octahedrally coordinated Ru3+ ions. The Ru ion ground state has 5 d electrons in the low spin state, with spin-orbit coupling very strong compared to other terms in the single ion Hamiltonian. The material is therefore an excellent candidate for investigating possible Heisenberg-Kitaev physics. In addition, this compound is very amenable to investigation by neutron scattering to explore the magnetic ground state and excitations in detail. Here we discuss new time-of-flight inelastic neutron scattering data on α-RuCl3. A high energy excitation near 200 meV is identified as a transition from the single ion J=1/2 ground state to the J=3/2 excited state, yielding a direct measurement of the spin orbit coupling energy. Higher resolution measurements reveal two collective modes at much lower energy scales. The results are compared with the theoretical expectations for excitations in the Heisenberg - Kitaev model on a honeycomb lattice, and show that Kitaev interactions are important. Research at SNS supported by the DOE BES Scientific User Facilities Division.

  17. A Renewable and Ultrasensitive Electrochemiluminescence Immunosenor Based on Magnetic RuL@SiO2-Au~RuL-Ab2 Sandwich-Type Nano-Immunocomplexes

    Ning Gan

    2011-08-01

    Full Text Available An ultrasensitive and renewable electrochemiluminescence (ECL immunosensor was developed for the detection of tumor markers by combining a newly designed trace tag and streptavidin-coated magnetic particles (SCMPs. The trace tag (RuL@SiO2-Au~RuL-Ab2 was prepared by loading Ru(bpy32+(RuL-conjuged secondary antibodies (RuL-Ab2 on RuL@SiO2 (RuL-doped SiO2 doped Au (RuL@SiO2-Au. To fabricate the immunosensor, SCMPs were mixed with biotinylated AFP primary antibody (Biotin-Ab1, AFP, and RuL@SiO2-Au~RuL-Ab2 complexes, then the resulting SCMP/Biotin-Ab1/AFP/RuL@SiO2-Au~RuL-Ab2 (SBAR sandwich-type immunocomplexes were absorbed on screen printed carbon electrode (SPCE for detection. The immunocomplexes can be easily washed away from the surface of the SPCE when the magnetic field was removed, which made the immunosensor reusable. The present immunosensor showed a wide linear range of 0.05–100 ng mL–1 for detecting AFP, with a low detection limit of 0.02 ng mL–1 (defined as S/N = 3. The method takes advantage of three properties of the immunosensor: firstly, the RuL@SiO2-Au~RuL-Ab2 composite exhibited dual amplification since SiO2 could load large amount of reporter molecules (RuL for signal amplification. Gold particles could provide a large active surface to load more reporter molecules (RuL-Ab2. Accordingly, through the ECL response of RuL and tripropylamine (TPA, a strong ECL signal was obtained and an amplification analysis of protein interaction was achieved. Secondly, the sensor is renewable because the sandwich-type immunocomplexes can be readily absorbed or removed on the SPCE’s surface in a magnetic field. Thirdly, the SCMP modified probes can perform the rapid separation and purification of signal antibodies in a magnetic field. Thus, the present immunosensor can simultaneously realize separation, enrichment and determination. It showed potential application for the detection of AFP in human sera.

  18. De como os alunos entendem os textos

    Peronard Th, Marianne

    1991-01-01

    Full Text Available Nosso interesse na compreensão do texto escrito apresenta uma tendência pedagógica. Tal perspectiva guiou a seleção de nossa estrutura teórica, os limites de nosso trabalho experimental e a natureza dos instrumentos que usamos, tanto durante a avaliação das habilidades de compreensão dos alunos como durante as aplicações instrucionais. Nosso foco tem se localizado na compreensão inferencial, a qual medimos pedindo aos estudantes que verbalizassem as inferências necessárias para conbstruir uma interpretação coerente. Para garantir uma sanidade ecológica, temos nos mantido o mais próximo possível de uma situação escolar, um fato que, em resumo, parece ter sido autodestruidor. Nossos resultados mostram fracas habilidades de compreensão por parte dos sujeitos (aproximadamente 2600 alunos. Suas respostas manifestam pouco raciocínio inferencial e suas estratégias, baixa adaptação à estrutura ou conteúdo do texto. De fato a estratégia mais comum parece ser a que nós chamamos de "estratégia lexical restrita", que é mais uma "estratégia de resposta" do que uma estratégia de compreensão

  19. OS Friendly Microprocessor Architecture

    2017-04-01

    NOTES Patrick La Fratta is now affiliated with Micron Technology, Inc., Boise, Idaho. 14. ABSTRACT We present an introduction to the patented ...Operating System Friendly Microprocessor Architecture (OSFA). The software framework to support the hardware-level security features is currently patent ...Army is assignee. OS Friendly Microprocessor Architecture. United States Patent 9122610. 2015 Sep. 2. Jungwirth P, inventor; US Army is assignee

  20. Os Trigonum Syndrome

    ... other conditions, such as an Achilles tendon injury, ankle sprain or talus fracture. Diagnosis of os trigonum syndrome begins with questions from the doctor about the development of symptoms. After the foot and ankle are examined, x-rays or other imaging tests ...

  1. Superconductivity in the Nb-Ru-Ge σ phase

    Carnicom, Elizabeth M.; Xie, Weiwei; Sobczak, Zuzanna; Kong, Tai; Klimczuk, Tomasz; Cava, R. J.

    2017-12-01

    We show that the previously unreported ternary σ -phase material N b20.4R u5.7G e3.9 (N b0.68R u0.19G e0.13 ) is a superconductor with a critical temperature of 2.2 K. Temperature-dependent magnetic susceptibility, resistance, and specific-heat measurements were used to characterize the superconducting transition. The Sommerfeld constant γ for N b20.4R u5.7G e3.9 is 91 mJ mol f .u .-1K-2 (˜3 mJ mol ato m-1K-2 ) and the specific-heat anomaly at the superconducting transition, Δ C /γ Tc , is approximately 1.38. The zero-temperature upper critical field [μ0H c2(0 ) ] was estimated to be 2 T by resistance data. Field-dependent magnetization data analysis estimated μ0H c1(0 ) to be 5.5 mT. Thus, the characterization shows N b20.4R u5.7G e3.9 to be a type-II BCS superconductor. This material appears to be the first reported ternary phase in the Nb-Ru-Ge system, and the fact that there are no previously reported binary Nb-Ru, Nb-Ge, or Ru-Ge σ phases shows that all three elements are necessary to stabilize the material. An analogous σ phase in the Ta-Ru-Ge system did not display superconductivity above 1.7 K, which suggests that electron count cannot govern the superconductivity observed. Preliminary characterization of a possible superconducting σ phase in the Nb-Ru-Ga system is also reported.

  2. Hoechst reportedly stalls RU-486 in U.S.

    1994-05-16

    President Clinton's administration would like RU-486 to be widely available in the US, but its manufacturer has been procrastinating about introducing RU-486 in the US. President Clinton lifted the ban on it shortly after ascending to the presidency. After 13 months of negotiations, the parent company of Roussel Uclaf, Hoechst, blocked efforts. It appears to be thwarting Ru-486's manufacture in the US because it fears that antiabortion groups will boycott its other products (textiles, rug fibers, and drugs for diabetics and heart patients). Its annual sales in the US are $7 billion. In April, 1993, Roussel Uclaf said that it would transfer its patent to the Population Council. The Council agreed to perform the clinical trials required to obtain US Food and Drug Administration approval and to find a domestic manufacturer to produce RU-486. Before handing the patent over to the Population Council, Hoechst wants protection from potential product liability or losses from antiabortion protests. US Health and Human Services officials have been trying to promote progress in the negotiations between the Population Council and Hoechst. A US member of Congress has set up a subcommittee hearing to look into the delays, specifically Hoechst's role in the delays. Women's groups want US women to have access to an alternative to surgical abortion. If progress is not made soon, they intend to push the government to revoke Roussel Uclaf's patent or support development of a similar drug. They stress that Hoechst's actions, be they for economic or political reasons, have slowed medical research and have hurt women's well being. RU-486 can also be used to treat breast cancer, some brain tumors, and other diseases.

  3. Enantioselective light switch effect of Δ- and Λ-[Ru(phenanthroline)2 dipyrido[3,2-a:2', 3'-c]phenazine]2+ bound to G-quadruplex DNA.

    Park, Jin Ha; Lee, Hyun Suk; Jang, Myung Duk; Han, Sung Wook; Kim, Seog K; Lee, Young-Ae

    2018-06-01

    The interaction of Δ- and Λ-[Ru(phen) 2 DPPZ] 2+ (DPPZ = dipyrido[3,2-a:2', 3'-c]phenazine, phen = phenanthroline) with a G-quadruplex formed from 5'-G 2 T 2 G 2 TGTG 2 T 2 G 2-3 '(15-mer) was investigated. The well-known enhancement of luminescence intensity (the 'light-switch' effect) was observed for the [Ru(phen) 2 DPPZ] 2+ complexes upon formation of an adduct with the G-quadruplex. The emission intensity of the G-quadruplex-bound Λ-isomer was 3-fold larger than that of the Δ-isomer when bound to the G-quadruplex, which is opposite of the result observed in the case of double stranded DNA (dsDNA); the light switch effect is larger for the dsDNA-bound Δ-isomer. In the job plot of the G-quadruplex with Δ- and Λ-[Ru(phen) 2 DPPZ] 2+ , a major inflection point for the two isomers was observed at x ≈ .65, which suggests a binding stoichiometry of 2:1 for both enantiomers. When the G base at the 8th position was replaced with 6-methyl isoxanthopterin (6MI), a fluorescent guanine analog, the excited energy of 6-MI transferred to bound Δ- or Λ-[Ru(phen) 2 DPPZ] 2+ , which suggests that at least a part of both Ru(II) enantiomers is close to or in contact with the diagonal loop of the G-quadruplex. A luminescence quenching experiment using [Fe(CN) 6 ] 4- for the G-quadruplex-bound Ru(II) complex revealed downward bending curves for both enantiomers in the Stern-Volmer plot, which suggests the presence of Ru(II) complexes that are both accessible and inaccessible to the quencher and may be related to the 2:1 binding stoichiometry.

  4. PtRu nanoparticles dispersed on nitrogen-doped carbon nanohorns as an efficient electrocatalyst for methanol oxidation reaction

    Zhang, Linwei; Gao, Ang; Liu, Yan; Wang, Yuan; Ma, Jiantai

    2014-01-01

    Highlights: • A novel anode catalyst is synthesized using N-doped carbon nanohorns as support. • PtRu/NCNHs exhibits an excellent activity for MOR relative to PtRu/C catalysts. • The enhancement is due to the electronic interaction between NCNHs and PtRu NPs. - Abstract: A novel anode catalyst (PtRu/NCNHs) assembled with nitrogen-doped carbon nanohorns (NCNHs) and PtRu nanoparticles (1.9 nm) exhibits an obvious enhancement in the tolerance to carbonaceous intermediates and the electocatalytic activity for methanol oxidation reaction (MOR) in comparison to a commercial PtRu/C-JM catalyst and a home-made PtRu/Vulcan catalyst. The MOR mass activity of PtRu/NCNHs (850 mA mg −1 PtRu ) is 2.5 times as high as that of PtRu/C-JM (341 mA mg −1 PtRu ). The MOR specific activity of PtRu/NCNHs is 1.8 times as high as that of PtRu/Vulcan having similar Pt/Ru atomic ratios, specific electrochemical surface areas and particle sizes of PtRu NPs. The electronic interaction between PtRu NPs and NCNHs is responsible for the enhancement in the MOR activity of PtRu/NCNHs

  5. Avaliação do ruído através do SPBI (Statistical Pass-By Index) em diferentes pavimentos Noise evaluation using the SPBI (Statistical Pass-By Index) for different pavements

    Luciano Pivoto Specht; Sérgio C. Callai; Oleg A. Khatchatourian; Raquel Kohler

    2009-01-01

    O transporte rodoviário causa grande impacto no meio ambiente, tanto pelo grande consumo de energia quanto pela infra-estrutura física necessária a sua operação. A emissão de gases e os ruídos causados pelo tráfego causam danos irreversíveis ao meio ambiente e têm sido alvo de inúmeros estudos e pesquisas. Sabe-se que o atrito pneu/pavimento e as propriedades acústicas dos revestimentos influenciam de sobremaneira a geração e a propagação do ruído. Essa pesquisa tem como objetivo avaliar o ru...

  6. Mechanism study on inorganic oxidants induced inhibition of Ru(bpy)₃²+ electrochemiluminescence and its application for sensitive determination of some inorganic oxidants.

    Qiu, Bin; Xue, Lingling; Wu, Yanping; Lin, Zhenyu; Guo, Longhua; Chen, Guonan

    2011-07-15

    Inhibited Ru(bpy)(3)(2+) electrochemiluminescence by inorganic oxidants is investigated. Results showed that a number of inorganic oxidants can quench the ECL of Ru(bpy)(3)(2+)/tri-n-propylamine (TPrA) system, and the logarithm of the decrease in ECL intensity (ΔI) was proportional to the logarithm of analyte concentrations. Based on which, a sensitive approach for detection of these inorganic oxidants was established, e.g. the log-log plots of ΔI versus the concentration of MnO(4)(-), Cr(2)O(7)(2-) and Fe(CN)(6)(3-) are linear in the range of 1×10(-7) to 3×10(-4)M for MnO(4)(-) and Cr(2)O(7)(2-), and 1×10(-7) to 1×10(-4)M for Fe(CN)(6)(3-), with the limit of detection (LOD) of 8.0×10(-8)M, 2×10(-8)M, and 1×10(-8)M, respectively. A series of experiments such as a comparison of the inhibitory effect of different compounds on Ru(bpy)(3)(2+)/TPrA ECL, ECL emission spectra, UV-Vis absorption spectra etc. were investigated in order to discover how these inorganic analytes quench the ECL of Ru(bpy)(3)(2+)/TPrA system. A mechanism based on consumption of TPrA intermediate (TPrA(·)) by inorganic oxidants was proposed. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. A Ru(II) complex with 2-(4-(methylsulfonyl)phenyl)-1H-imidazo[4,5- f][1,10]phenanthroline: Synthesis, characterization, and acid-base and DNA-binding properties

    Gao, Jie; Wang, Zhi-Ping; Yuan, Cui-Li; Jia, Hai-Shun; Wang, Ke-Zhi

    2011-09-01

    A new Ru(II) complex of [Ru(bpy) 2(Hmspip)]Cl 2 {in which bpy = 2,2'-bipyridine, Hmspip = 2-(4-(methylsulfonyl)phenyl)-1 H-imidazo[4,5- f][1,10]phenanthroline} have been synthesized and characterized. The ground- and excited-state acid-base properties of [Ru(bpy) 2(Hmspip)]Cl 2 and its parent complex of [Ru(bpy) 2(Hpip)]Cl 2 {Hpip = 2-phenyl-1H-imidazo[4,5- f][1,10]phenanthroline} have been studied by UV-visible (UV-vis) and emission spectrophotometric pH titrations. [Ru(bpy) 2(Hmspip)]Cl 2 acts as a calf thymus DNA intercalators with a binding constant of 4.0 × 10 5 M -1 in buffered 50 mM NaCl, as evidenced by UV-vis and luminescence titrations, steady-state emission quenching by [Fe(CN) 6] 4-, DNA competitive binding with ethidium bromide, reverse salt titrations and viscosity measurements.

  8. Parallel ferromagnetic resonance and spin-wave excitation in exchange-biased NiFe/IrMn bilayers

    Sousa, Marcos Antonio de, E-mail: marcossharp@gmail.com [Instituto de Física, Universidade Federal de Goiás, Goiânia, 74001-970 (Brazil); Pelegrini, Fernando [Instituto de Física, Universidade Federal de Goiás, Goiânia, 74001-970 (Brazil); Alayo, Willian [Departamento de Física, Universidade Federal de Pelotas, Pelotas, 96010-900 (Brazil); Quispe-Marcatoma, Justiniano; Baggio-Saitovitch, Elisa [Centro Brasileiro de Pesquisas Físicas, Rio de Janeiro, 22290-180 (Brazil)

    2014-10-01

    Ferromagnetic Resonance study of sputtered Ru(7 nm)/NiFe(t{sub FM})/IrMn(6 nm)/Ru(5 nm) exchange-biased bilayers at X and Q-band microwave frequencies reveals the excitation of spin-wave and NiFe resonance modes. Angular variations of the in-plane resonance fields of spin-wave and NiFe resonance modes show the effect of the unidirectional anisotropy, which is about twice larger for the spin-wave mode due to spin pinning at the NiFe/IrMn interface. At Q-band frequency the angular variations of in-plane resonance fields also reveal the symmetry of a uniaxial anisotropy. A modified theoretical model which also includes the contribution of a rotatable anisotropy provides a good description of the experimental results.

  9. Formation of pyroxenite layers in the Totalp ultramafic massif (Swiss Alps) - Insights from highly siderophile elements and Os isotopes

    van Acken, David; Becker, Harry; Walker, Richard J.; McDonough, William F.; Wombacher, Frank; Ash, Richard D.; Piccoli, Phil M.

    2010-01-01

    Pyroxenitic layers are a minor constituent of ultramafic mantle massifs, but are considered important for basalt generation and mantle refertilization. Mafic spinel websterite and garnet-spinel clinopyroxenite layers within Jurassic ocean floor peridotites from the Totalp ultramafic massif (eastern Swiss Alps) were analyzed for their highly siderophile element (HSE) and Os isotope composition. Aluminum-poor pyroxenites (websterites) display chondritic to suprachondritic initial γOs (160 Ma) of -2 to +27. Osmium, Ir and Ru abundances are depleted in websterites relative to the associated peridotites and to mantle lherzolites worldwide, but relative abundances (Os/Ir, Ru/Ir) are similar. Conversely, Pt/Ir, Pd/Ir and Re/Ir are elevated. Aluminum-rich pyroxenites (clinopyroxenites) are characterized by highly radiogenic 187Os/ 188Os with initial γOs (160 Ma) between +20 and +1700. Their HSE composition is similar to that of basalts, as they are more depleted in Os, Ir and Ru compared to Totalp websterites, along with even higher Pt/Ir, Pd/Ir and Re/Ir. The data are most consistent with multiple episodes of reaction of mafic pyroxenite precursor melts with surrounding peridotites, with the highest degree of interaction recorded in the websterites, which typically occur in direct contact to peridotites. Clinopyroxenites, in contrast, represent melt-dominated systems, which retained the precursor melt characteristics to a large extent. The melts may have been derived from a sublithospheric mantle source with high Pd/Ir, Pt/Ir and Re/Os, coupled with highly radiogenic 187Os/ 188Os compositions. Modeling indicates that partial melting of subducted, old oceanic crust in the asthenosphere could be a possible source for such melts. Pentlandite and godlevskite are identified in both types of pyroxenites as the predominant sulfide minerals and HSE carriers. Heterogeneous HSE abundances within these sulfide grains likely reflect subsolidus processes. In contrast, large grain

  10. Análise do risco ruído em indústria de confecção de roupa

    Daniela Dalapicula Barcelos

    2014-03-01

    Full Text Available Objetivo : verificar a presença do ruído em indústria de confecção de roupas, visto que este risco é pouco difundido nas pesquisas relacionadas a este ambiente de trabalho.Métodos : a empresa escolhida foi uma fábrica de confecção de roupa localizada em Colatina no Espírito Santo/Brasil. Foram analisados os dois setores com maior risco ruído na empresa, após a exclusão dos funcionários com menos de cinco anos de trabalho neste local, totalizamos uma amostra de seis funcionários. Os trabalhadores selecionados responderam questionário sobre informações e sintomas auditivos e posteriormente, foram analisadas as audiometrias realizadas nos últimos cinco anos.Resultados : por meio de medições realizadas nos setores analisados, constatou-se produção de ruído de 83,5 a 97,8 dB(A. Após observar o histórico das audiometrias, obteve-se 83% dos trabalhadores, destes setores, sem perda auditiva, 16% com perda ocupacional, sendo classificada como estável. Os dados levantados no questionário revelaram que 33% dos trabalhadores sentem-se irritados quando expostos a sons elevados, 50% sentem-se estressados após a jornada de trabalho, e nenhum trabalhador relatou queixa de zumbido, insônia ou dificuldade em entender as pessoas.Conclusão : este ambiente de trabalho apresenta risco ruído, uma vez constatados os níveis de pressão sonora no qual os trabalhadores são expostos durante a jornada de trabalho, bem como a presença de perda auditiva ocupacional, mesmo em menor escala – atribuído ao tempo mínimo de cinco anos de serviços prestados utilizado na pesquisa.

  11. Characterisation and catalytic properties of Ni, Co, Ce and Ru nanoparticles in mesoporous carbon spheres

    Barros, Francisco A. A.; Castro, Antonio J. R.; Filho, Josue M.; Viana, Bartolomeu C.; Campos, Adriana; Oliveira, Alcineia C.

    2012-01-01

    Ni, Co, Ce and Ru nanoparticles were inserted into templated carbon using a nanocasting technique and evaluated for the dehydration of glycerol. NiO and CeO 2 preferentially yielded 5 nm uniformly sized particles that filled the mesoporous carbon via a geometric confinement effect. Ru generated Ru o and RuO 2 nanoparticles that selectively migrated towards the carbon surface and did not undergo sintering, whereas Co nanoparticles containing CoO and Co 3 O 4 showed the opposite behaviour. The stabilising effects of the Ce and Ru nanoparticles on the carbon matrix effectively prevented the aggregation of small particles, resulting in superior catalytic performance in glycerol dehydration.

  12. Elaboration of a Highly Porous RuII,II Analogue of HKUST-1.

    Zhang, Wenhua; Freitag, Kerstin; Wannapaiboon, Suttipong; Schneider, Christian; Epp, Konstantin; Kieslich, Gregor; Fischer, Roland A

    2016-12-19

    When the dinuclear Ru II,II precursor [Ru 2 (OOCCH 3 ) 4 ] is employed under redox-inert conditions, a Ru II,II analogue of HKUST-1 was successfully prepared and characterized as a phase-pure microcrystalline powder. X-ray absorption near-edge spectroscopy confirms the oxidation state of the Ru centers of the paddle-wheel nodes in the framework. The porosity of 1371 m 2 /mmol of Ru II,II -HKUST-1 exceeds that of the parent compound HKUST1 (1049 m 2 / mmol).

  13. Activity of carbon supported Pt3Ru2 nanocatalyst in CO oxidation

    KSENIJA DJ. POPOVIĆ

    2009-08-01

    Full Text Available The electrocatalytic activity of Pt3Ru2/C nanocatalyst toward the electro-oxidation of bulk CO was examined in acid and alkaline solution at ambient temperature using the thin-film, rotating disk electrode (RDE method. The catalyst was characterized by XRD analysis. The XRD pattern revealed that the Pt3Ru2/C catalyst consisted of two structures, i.e., Pt–Ru-fcc and Ru-hcp (a solid solution of Ru in Pt and a small amount of Ru or a solid solution of Pt in Ru. Electrocatalytic activities were measured by applying potentiodynamic and steady state techniques. The oxidation of CO on the Pt3Ru2/C catalyst was influenced by pH and anions from the supporting electrolytes. The Pt3Ru2/C was more active in alkaline than in acid solution, as well as in perchloric than in sulfuric acid. Comparison of CO oxidation on Pt3Ru2/C and Pt/C revealed that the Pt3Ru2/C was more active than Pt/C in acid solution, while both catalysts had a similar activity in alkaline solution.

  14. Substrate-mediated enhanced activity of Ru nanoparticles in catalytic hydrogenation of benzene

    Liu, Xin

    2012-01-01

    The impact of carbon substrate-Ru nanoparticle interactions on benzene and hydrogen adsorption that is directly related to the performance in catalytic hydrogenation of benzene has been investigated by first-principles based calculations. The stability of Ru 13 nanoparticles is enhanced by the defective graphene substrate due to the hybridization between the dsp states of the Ru 13 particle with the sp 2 dangling bonds at the defect sites. The local curvature formed at the interface will also raise the Ru atomic diffusion barrier, and prohibit the particle sintering. The strong interfacial interaction results in the shift of averaged d-band center of the deposited Ru nanoparticle, from -1.41 eV for a freestanding Ru 13 particle, to -1.17 eV for the Ru/Graphene composites, and to -1.54 eV on mesocellular foam carbon. Accordingly, the adsorption energies of benzene are increased from -2.53 eV for the Ru/mesocellular foam carbon composites, to -2.62 eV on freestanding Ru 13 particles, to -2.74 eV on Ru/graphene composites. A similar change in hydrogen adsorption is also observed, and all these can be correlated to the shift of the d-band center of the nanoparticle. Thus, Ru nanoparticles graphene composites are expected to exhibit both high stability and superior catalytic performance in hydrogenation of arenes. © 2012 The Royal Society of Chemistry.

  15. Magnetic Properties and Microstructure of FeOx/Fe/FePt and FeOx/FePt Films

    Jai-Lin Tsai

    2013-01-01

    Full Text Available The Fe(6 nm/FePt film with perpendicular magnetization was deposited on the glass substrate. To study the oxygen diffusion effect on the coupling of Fe/FePt bilayer, the plasma oxidation with 0.5~7% oxygen flow ratio was performed during sputtered part of Fe layer and formed the FeOx(3 nm/Fe(3 nm/FePt trilayer. Two-step magnetic hysteresis loops were found in trilayer with oxygen flow ratio above 1%. The magnetization in FeOx and Fe/FePt layers was decoupled. The moments in FeOx layer were first reversed and followed by coupled Fe/FePt bilayer. The trilayer was annealed again at 500°C and 800°C for 3 minutes. When the FeOx(3 nm/Fe(3 nm/FePt trilayer was annealed at 500°C, the layers structure was changed to FeOx(6 nm/FePt bilayer due to oxygen diffusion. The hard-magnetic FeOx(6 nm/FePt film was coupled with single switching field. The FeOx/(disordered FePt layer structure was observed with further annealing at 800°C and presented soft-magnetic loop. In summary, the coupling between soft-magnetic Fe, FeOx layer, and hard-magnetic L10 FePt layer can be controlled by the oxygen diffusion behavior, and the oxidation of Fe layer was tuned by the annealing temperature. The ordered L10 FePt layer was deteriorated by oxygen and became disordered FePt when the annealed temperature was up to 800°C.

  16. A re-examination of thermodynamic modelling of U-Ru binary phase diagram

    Wang, L.C.; Kaye, M.H., E-mail: matthew.kaye@uoit.ca [University of Ontario Institute of Technology, Oshawa, ON (Canada)

    2015-07-01

    Ruthenium (Ru) is one of the more abundant fission products (FPs) both in fast breeder reactors and thermal reactors. Post irradiation examinations (PIE) show that both 'the white metallic phase' (MoTc-Ru-Rh-Pd) and 'the other metallic phase' (U(Pd-Rh-Ru)3) are present in spent nuclear fuels. To describe this quaternary system, binary subsystems of uranium (U) with Pd, Rh, and Ru are necessary. Presently, only the U-Ru system has been thermodynamically described but with some problems. As part of research on U-Ru-Rh-Pd quaternary system, an improved consistent thermodynamic model describing the U-Ru binary phase diagram has been obtained. (author)

  17. Semiconductor-metal transition of Se in Ru-Se Catalyst Nanoparticles

    Babu, P. K.; Lewera, Adam; Oldfield, Eric; Wieckowski, Andrzej

    2009-03-01

    Ru-Se composite nanoparticles are promising catalysts for the oxygen reduction reaction (ORR) in fuel cells. Though the role of Se in enhancing the chemical stability of Ru nanoparticles is well established, the microscopic nature of Ru-Se interaction was not clearly understood. We carried out a combined investigation of ^77Se NMR and XPS on Ru-Se nanoparticles and our results indicate that Se, a semiconductor in elemental form, becomes metallic when interacting with Ru. ^77Se spin-lattice relaxation rates are found to be proportional to T, the well-known Korringa behavior characteristic of metals. The NMR results are supported by the XPS binding energy shifts which suggest that a possible Ru->Se charge transfer could be responsible for the semiconductor->metal transition of Se which also makes Ru less susceptible to oxidation during ORR.

  18. Electronic Structure of the Pyrochlore-Type Ru Oxides through the Metal--Insulator Transition

    Okamoto, J.; Fujimori, S.I.; Okane, T.; Fujimori, A.; Abbate, M.; Yoshii, S.; Sato, M.

    2003-01-01

    The electronic structures of the pyrochlore-type Ru oxides Sm 2-x Ca x Ru 2 O 7 and Sm 2-x Bi x Ru 2 O 7 , which show metal-insulator transition with increasing Ca or Bi concentration, have been studied by ultraviolet photoemission spectroscopy. Spectral changes near the Fermi level are different but reflect the tendency of their transport properties in both systems. The Sm 2-x Ca x Ru 2 O 7 system shows an energy shift, which is expected from the increase of hole in the Ru 4d t 2g band and the Sm 2 - x Bi x Ru 2 O 7 system shows spectral weight transfer within the Ru 4d t 2g band, which is expected to be observed in bandwidth-control Mott-Hubbard system. (author)

  19. Interaction of electron neutrinos with 56Fe in the LSD for Eνe≤50 MeV

    Gaponov, Yu.V.; Semenov, S.V.; Ryazhskaya, O.G.

    2004-01-01

    The neutrino pulses, detected by LSD (liquid scintillator detector) on February 23, 1987, are analyzed on the base of two-stage model of supernova explosion. The number of events due to the electron neutrino interaction with 56 Fe in the LSD is calculated. The obtained results is in a agreement with experimental data [ru

  20. Investigation of finely dispersed grind of magnetically hard SmCo5 and Nd2Fe14B alloys

    Balalaev, Yu.N.; Kosobudskij, I.D.

    2000-01-01

    Possibility of preparation of finely dispersed powders of SmCo 5 and Nd 2 Fe 14 B allays investigated and comparison of different types of grinding processes is conducted. Results of comparison of the processes in vibrational mills and disintegrators permit to conclude that density and structure of grindable materials effect on the rate and quality of grinding of magnetically hard alloys [ru

  1. Local conductivity and the role of vacancies around twin walls of (001)-BiFeO3 thin films

    Farokhipoor, S.; Noheda, Beatriz

    2012-01-01

    BiFeO3 thin films epitaxially grown on SrRuO3-buffered (001)-oriented SrTiO3 substrates show orthogonal bundles of twin domains, each of which contains parallel and periodic 71 degrees domain walls. A smaller amount of 109 degrees domain walls are also present at the boundaries between two adjacent

  2. Efeitos auditivos da exposição combinada: interação entre monóxido de carbono, ruído e tabagismo Auditory effects of combined exposure: interaction between carbon monoxide, noise and smoking

    Débora Gonçalves Ferreira

    2012-12-01

    Full Text Available OBJETIVO: Analisar os efeitos auditivos da exposição combinada ao monóxido de carbono (CO e ao ruído, e o impacto do tabagismo. MÉTODOS: Participaram da pesquisa 80 trabalhadores fumantes e não fumantes, do gênero masculino, oriundos de uma empresa siderúrgica, sendo que 40 estavam expostos ao CO e ao ruído e 40 somente ao ruído. Realizou-se análise retrospectiva dos dados referentes aos riscos ambientais (CO e ruído e das informações contidas nos prontuários médicos relacionadas à saúde auditiva e às concentrações biológicas do CO no sangue (COHb. Analisou-se a audiometria tonal de referência e a última, e os limiares auditivos em função do tabagismo, do tipo de exposição (CO e ruído ou somente ao ruído, do tempo de exposição, do nível de ruído e da idade. RESULTADOS: Tanto a concentração de CO como os níveis de ruído encontraram-se acima do limite de tolerância previsto na norma regulamentadora de número 15 do Ministério do Trabalho. O grupo exposto ao CO e ao ruído apresentou mais casos de PAIR (22,5%, comparativamente ao grupo exposto somente ao ruído (7,5% e também apresentou piora significativa nos limiares auditivos de 3, 4 e 6 kHz. Foram encontradas diferenças significativas entre a idade, o tempo de serviço, o tipo de exposição, o nível de ruído e o hábito de fumar influenciando nos limiares auditivos dos participantes. O hábito de fumar potencializou o efeito tanto do CO quanto do ruído no sistema auditivo. CONCLUSÃO: Efeitos auditivos significativos foram identificados na audição dos trabalhadores de uma siderúrgica expostos ao CO.PURPOSE: To analyze the auditory effects of the combined exposure to carbon monoxide (CO and noise, and the impact of smoking. METHODS: Participants were 80 male workers, smokers and non-smokers, from a steel industry - 40 exposed to CO and noise simultaneously, and 40 exposed only to noise. A retrospective data analysis was conducted regarding the

  3. A rechargeable hydrogen battery based on Ru catalysis.

    Hsu, Shih-Fan; Rommel, Susanne; Eversfield, Philipp; Muller, Keven; Klemm, Elias; Thiel, Werner R; Plietker, Bernd

    2014-07-01

    Apart from energy generation, the storage and liberation of energy are among the major problems in establishing a sustainable energy supply chain. Herein we report the development of a rechargeable H2 battery which is based on the principle of the Ru-catalyzed hydrogenation of CO2 to formic acid (charging process) and the Ru-catalyzed decomposition of formic acid to CO2 and H2 (discharging process). Both processes are driven by the same catalyst at elevated temperature either under pressure (charging process) or pressure-free conditions (discharging process). Up to five charging-discharging cycles were performed without decrease of storage capacity. The resulting CO2/H2 mixture is free of CO and can be employed directly in fuel-cell technology. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. New bands and spin-parity assignments in 111Ru

    Urban, W.; Rzaca-Urban, T.; Droste, C.; Rohozinski, S.G.; Durell, J.L.; Phillips, W.R.; Smith, A.G.; Varley, B.J.; Schulz, N.; Ahmad, I.; Pinston, J.A.

    2004-01-01

    The 111 Ru nucleus, populated in the spontaneous fission of 248 Cm has been studied by means of prompt gamma spectroscopy using the EUROGAM2 array. Spin and parity assignments, based on angular correlations, linear polarization, and conversion coefficient measurements differ from those available in the literature. New bands are reported, which incorporate γ transitions seen previously but not placed in the scheme of 111 Ru or placed incorrectly. The bands are interpreted as neutron excitations into subshells originating predominantly from the h 11/2 , g 7/2 and s 1/2 spherical orbitals. The s 1/2 band, strongly mixed with the d 3/2 , d 5/2 and g 7/2 configurations, is observed for the first time in this region. (orig.)

  5. Bias voltage dependence of magnetic tunnel junctions comprising amorphous ferromagnetic CoFeSiB layer with double barriers

    Yim, H.I.; Lee, S.Y.; Hwang, J.Y.; Rhee, J.R.; Chun, B.S.; Wang, K.L.; Kim, Y.K.; Kim, T.W.; Lee, S.S.; Hwang, D.G.

    2008-01-01

    Double-barrier magnetic tunnel junctions (DMTJs) with and without an amorphous ferromagnetic material such as CoFeSiB 10, CoFe 5/CoFeSiB 5, and CoFe 10 (nm) were prepared and compared to investigate the bias voltage dependence of the tunneling magnetoresistance (TMR) ratio. Typical DMTJ structures were Ta 45/Ru 9.5/IrMn 10/CoFe 7/AlO x /free layer 10/AlO x /CoFe 7/IrMn 10/Ru 60 (in nanometers). The interlayer coupling field and the normalized TMR ratios at the applied voltages of +0.4 and -0.4 V of the amorphous CoFeSiB free-layer DMTJ offer lower and higher values than that of the polycrystalline CoFe free-layer DMTJ, respectively. An amorphous ferromagnetic CoFeSiB layer improves the interface roughness of the free layer/tunnel barrier and, as a result, the interlayer coupling field and bias voltage dependence of the TMR ratio are suppressed at a given voltage. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  6. Benten v. Kessler: the RU 486 import case.

    Pine, R N

    1992-01-01

    On July 1, 1992, the case of Benten v. Kessler was filed in the US District Court in New York. The case arose out of an attempt by abortion rights activist Lawrence Lader to call public attention to the US Food and Drug Administration's (FDA) ban on importation of the abortifacient drug mifepristone known as RU-486. The ban expresses the anti abortion stance of the Reagan and Bush administrations and creates a hostile climate for the development of new drugs related to reproductive health and reproductive choice. Plaintiffs in the Benten case sought public accountability by the FDA for its adoption of a ban of a safe and effective drug for unwanted pregnancy. Although the case did not succeed in retrieving the confiscated RU-486 pills for Leona Benten, in its opinion issued on July 14, 1992, the New York district court judge concluded that the import ban did not appear to be based on concern with the safety or effectiveness of RU-486, describing the FDA's process of adopting the import ban as a sink of illegality. On July 17, 1992, 7 Justices of the Supreme Court, with justices Blackmun and Stevens dissenting, joined in a per curiam opinion denying the application and foreclosing further personal relief for Leona Benten. This was the best result possible short of an all out victory for Leona Benten. The Court ruled against plaintiffs in their argument that notice and comment were required, but left entirely open plaintiffs' claims that the import ban is arbitrary and capricious under the Administrative Procedure Act and that the ban is unconstitutional in that it unduly burdens the right to terminate pregnancy. This backdrop creates a healthy skepticism about the prospects for the introduction of RU-486 into the US in the near future as well as about the fairness of government processes in areas of concern to women. Public health considerations, not politics, should determine access to health care.

  7. Thermoelectric properties of RuSb2Te ternary skutterudites

    Navrátil, Jiří; Plecháček, T.; Drašar, Č.; Laufek, F.

    2013-01-01

    Roč. 42, č. 7 (2013), s. 1864-1869 ISSN 0361-5235 R&D Projects: GA ČR GAP108/10/1315 Institutional support: RVO:61389013 Keywords : RuSb2Te * ternary skutterudite * doping Subject RIV: CA - Inorganic Chemistry Impact factor: 1.675, year: 2013 http://link.springer.com/article/10.1007/s11664-012-2451-5

  8. Enhanced antiferromagnetic coupling in dual-synthetic antiferromagnet with Co2FeAl electrodes

    Zhang, D.L.; Xu, X.G.; Wu, Y.; Li, X.Q.; Miao, J.; Jiang, Y.

    2012-01-01

    We study dual-synthetic antiferromagnets (DSyAFs) using Co 2 FeAl (CFA) Heusler electrodes with a stack structure of Ta/CFA/Ru/CFA/Ru/CFA/Ta. When the thicknesses of the two Ru layers are 0.45 nm, 0.65 nm or 0.45 nm, 1.00 nm, the CFA-based DSyAF has a strong antiferromagnetic coupling between adjacent CFA layers at room temperature with a saturation magnetic field of ∼11,000 Oe, a saturation magnetization of ∼710 emu/cm 3 and a coercivity of ∼2.0 Oe. Moreover, the DSyAF has a good thermal stability up to 400 °C, at which CFA films show B2-ordered structure. Therefore, the CFA-based DSyAFs are favorable for applications in future spintronic devices. - Graphical abstract: Display Omitted Highlights: ► Co 2 FeAl can be applied in room temperature dual-synthetic antiferromagnets. ► Co 2 FeAl dual-synthetic antiferromagnets have a good thermal stability up to 400 °C. ► The Co 2 FeAl has B2-ordered structure in annealed dual-synthetic antiferromagnets.

  9. Os primeiros Folhetins

    Marco Antonio Maschio Cardozo Chaga

    1997-12-01

    Full Text Available Num texto anterior - publicado no Boletim Nelic, n. 1 -, destaquei os pressupostos editoriais que visavam a execução do "Projeto Folhetim", apontando também as razões pedagógicas e a veia esclarecedora que a publicação pretendia atingir. Neste sentido, o imperativo deveria ser a formação de um suplemento com a finalidade principal de proporcionar ao leitor uma massa de textos capazes de refletir e questionar a recente história brasileira.

  10. CtOS Enabler

    Crespo Cepeda, Rodrigo; El Yamri El Khatibi, Meriem; Carrera García, Juan Manuel

    2015-01-01

    Las Smart Cities son, indudablemente, el futuro próximo de la tecnología al que nos acercamos cada día, lo que se puede observar en la abundancia de dispositivos móviles entre la población, que informatizan la vida cotidiana mediante el uso de la geolocalización y la información. Pretendemos unir estos dos ámbitos con CtOS Enabler para crear un estándar de uso que englobe todos los sistemas de Smart Cities y facilite a los desarrolladores de dicho software la creación de nuevas herramientas. ...

  11. Os limites da cidade

    Borges Abel, António

    2008-01-01

    A porta, na sua qualidade de fronteira entre espaços e como elemento fundamental na definição do "dentro" e do "fora", do caos e do Cosmos, na definição do "círculo fronteiriço" e, consequentemente, do "ser fronteiriço". Morfologias urbanas: Évora como estudo de caso. Propostas genéricas de desenvolvimento/crescimento urbano, tendo como princípio orientador a relação dicotómica com o território.

  12. Crystalline-electric field of Pr(Os1-xRux)4Sb12

    Akita, H.; Yoshino, G.; Ochiai, A.

    2006-01-01

    High-quality single crystals of Pr(Os 1-x Ru x ) 4 Sb 12 were grown by the Sb self-flux method. Magnetic susceptibility χ(T) was measured precisely. The characteristic temperature T max , where χ(T) exhibits a maximum, varies as a function of Ru-content x but its functional form changes at around x=0.6 where competition of two types of superconductivity is suggested. Since T max is thought to be relevant to the splitting energy between a ground state and a first excited state, we analyzed χ(T) considering the crystalline electric field (CEF) of the T h symmetry. χ(T) is well fitted assuming a Γ 1 singlet ground state for all x values. As expected from T max , the energy of the first excited state (Γ 4 (2) ) changes its functional form at around x=0.6. Furthermore, the energies of the second and third excited states (Γ 4 (1) and Γ 23 ) exhibit a minimum at almost the same value of x=0.6. These results suggest that the CEF is related to the superconductivity in Pr(Os 1-x Ru x ) 4 Sb 12

  13. γ - γ angular correlation in sup(100)Ru

    Kenchian, G.; Leljbman, I.D.G.; Cruz, M.T.F.

    1990-01-01

    The gamma-gamma directional angular correlations of coincident transitions have been measured in sup(100)Ru nuclide, following the β sup(+) and electron capture of sup(100)Rh using an angular correlation automatic spectrometer with two Ge(Li) detectors. The sup(100)Rh source has been produced with sup(100)Ru(p,n) sup(100)Rh reaction, using the proton beam of the Cyclotron Acelerator and enriched sup(100)Ru isotope. We have measured 30 direct cascades and 11 triple cascades. The spin and the parity of the 1865 KeV, 1881 KeV, 2099 KeV, 2167 KeV, 2241 KeV, 2517 KeV, and 3070 KeV levels have been established and multipole mixing ratios (δ) for 21 transitions have been obtained, 12 for the first time. Multipole mixing ratios Q sup(2)(E0/E2) has been also measured in the 2 sup(+) sub(2) → 2 sup(+) sub(1) transition. (author)

  14. Ni@Ru and NiCo@Ru Core-Shell Hexagonal Nanosandwiches with a Compositionally Tunable Core and a Regioselectively Grown Shell.

    Hwang, Hyeyoun; Kwon, Taehyun; Kim, Ho Young; Park, Jongsik; Oh, Aram; Kim, Byeongyoon; Baik, Hionsuck; Joo, Sang Hoon; Lee, Kwangyeol

    2018-01-01

    The development of highly active electrocatalysts is crucial for the advancement of renewable energy conversion devices. The design of core-shell nanoparticle catalysts represents a promising approach to boost catalytic activity as well as save the use of expensive precious metals. Here, a simple, one-step synthetic route is reported to prepare hexagonal nanosandwich-shaped Ni@Ru core-shell nanoparticles (Ni@Ru HNS), in which Ru shell layers are overgrown in a regioselective manner on the top and bottom, and around the center section of a hexagonal Ni nanoplate core. Notably, the synthesis can be extended to NiCo@Ru core-shell nanoparticles with tunable core compositions (Ni 3 Co x @Ru HNS). Core-shell HNS structures show superior electrocatalytic activity for the oxygen evolution reaction (OER) to a commercial RuO 2 black catalyst, with their OER activity being dependent on their core compositions. The observed trend in OER activity is correlated to the population of Ru oxide (Ru 4+ ) species, which can be modulated by the core compositions. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Methanol Electro-Oxidation on Pt-Ru Alloy Nanoparticles Supported on Carbon Nanotubes

    Yangchuan Xing

    2009-09-01

    Full Text Available Carbon nanotubes (CNTs have been investigated in recent years as a catalyst support for proton exchange membrane fuel cells. Improved catalyst activities were observed and attributed to metal-support interactions. We report a study on the kinetics of methanol electro-oxidation on CNT supported Pt-Ru alloy nanoparticles. Alloy catalysts with different compositions, Pt53Ru47/CNT, Pt69Ru31/CNT and Pt77Ru23/CNT, were prepared and investigated in detail. Experiments were conducted at various temperatures, electrode potentials, and methanol concentrations. It was found that the reaction order of methanol electro-oxidation on the PtRu/CNT catalysts was consistent with what has been reported for PtRu alloys with a value of 0.5 in methanol concentrations. However, the electro-oxidation reaction on the PtRu/CNT catalysts displayed much lower activation energies than that on the Pt-Ru alloy catalysts unsupported or supported on carbon black (PtRu/CB. This study provides an overall kinetic evaluation of the PtRu/CNT catalysts and further demonstrates the beneficial role of CNTs.

  16. TinyOS Alliance Structure

    Bonnet, Philippe; Culler, David; Estrin, Deborah

    2006-01-01

    This memo describes the goals and organization structure of the TinyOS Alliance. It covers membership, the working group forums for contribution, intellectual property, source licensing, and the TinyOS Steering Committee (TSC)....

  17. RuPd, RuCo, PdCo and RuPdCo materials as candidates for cathode catalyzers in PEM fuel cells; Materiales RuPd, RuCo, PdCo y RuPdCo como candidatos a catalizadores catodicos en celdas de combustible tipo PEM

    Leyva Noyola, Fatima; Solorza Feria, Omar [Centro de Investigacion y Estudios Superiores del IPN, Mexico, D.F. (Mexico)]. E-mail: fleyva@cinvestav.mx

    2009-09-15

    This work reports on the catalytic activity of RuPd, RuCo, PdCo and RuPdCo material for oxygen reduction reaction (ORR). These materials were synthesized using chemical reduction with NaBH{sub 4} as a reducing agent in THF, in ambient temperature and pressure conditions. The evaluation of the catalytic activity was done using cyclic voltamperometry (CV) and rotary disc electrode (RDE) in H{sub 2}SO{sub 4} 0.5 M. The kinetic results showed that the electrochemical reaction involves 4 electrons and the transfer of the first electron is the determinant stage. The values of {alpha}, i0 and the Tafel slope were very similar for the four materials studied, around 0.4, 5x10{sup -6} mA cm{sup -2} and 60 mV dec-1, respectively. Although these values are less than those reported for nanostructured platinum, they are better than those reported for other materials such as pure Pd, which enables them to be considered as cathode catalysts for a proton exchange membrane fuel cell. [Spanish] En este trabajo se reporta la actividad catalitica de los materiales RuPd, RuCo, PdCo y RuPdCo para la reaccion de reduccion de oxigeno (RRO). Estos materiales fueron sintetizados por el metodo de reduccion quimica, usando NaBH{sub 4} como agente reductor en THF, en condiciones de temperatura y presion ambiental. La evaluacion de la actividad catalitica fue realizada usando Voltamperometria Ciclica (VC) y Electrodo Disco Rotatorio (EDR) en H{sub 2}SO{sub 4} 0.5 M. Los resultados cineticos mostraron que la reaccion electroquimica procede por la via de 4 electrones y la etapa determinante es la transferencia del primer electron. Los valores de {alpha}, i0 y pendiente de Tafel fueron muy similares para los 4 materiales estudiados, siendo estos de alrededor de 0.4, 5x10{sup -6} mA cm{sup -2} y 60 mV dec{sup -1}, respectivamente. Sin embargo, aun cuando estos valores son menores que los reportados para platino nanoestructurado, son mejores que los reportados para otros materiales como el Pd puro

  18. Boycott threat forces French company to abandon RU486.

    Dorozynski, A

    1997-04-19

    Threatened boycotts by American anti-abortion groups have forced the French pharmaceutical company Roussel-Uclaf, a subsidiary of the German company Hoechst, to stop production and distribution of mifepristone (RU-486), which the protesters call "the abortion pill." All patent rights have been transferred, without charge, to Dr. Edouard Sarkiz, one of the pill's developers. Hoechst, which had acquired Marion Pharmaceuticals to form a new group, Hoechst-Marion-Roussel, had increased its share of the US pharmaceutical market from 1% to 4% in doing so and could not tolerate a boycott. RU-486, which was discovered by Professor Etienne Baulieu, was introduced in France in 1987 as an alternative to surgical abortion. Although Hoechst, then a majority stockholder of Roussel-Uclaf, had asked the French firm to interrupt production of the pill in 1988, the French minister of health and social affairs at that time, Claude Evin, ordered production to be continued. Approximately 25% of French women seeking abortion use RU-486; it is also used in Britain, Sweden, and China (women in China must pay for the drug, while surgical abortion is free). All American firms have refused to buy the drug from Roussel-Uclaf. An offer to the World Health Organization was ignored. The American Population Council obtained the right to use RU-486 in 1993. Dr. Sarkiz has formed Exelgyn, a small nonprofit company, to produce and distribute RU-486; research into other uses for the drug will also be conducted. There has been limited research into its use as an emergency contraceptive and as a treatment for endometriosis, uterine fibroma, and breast cancer. According to Professor Baulieu, the drug could be used in treating wounds and burns because of its antiglucocorticoid and immunosuppressive properties; preliminary research by the professor indicates the drug could also possibly be used as a reversible male contraceptive because of its action on the membranes of spermatozoa. The drug's use in

  19. Spontaneous deposition of Ru on Pt (100: morphological and electrochemical studies. Preliminary results of ethanol oxidation at Pt(100/Ru

    Colle Vinicius D.

    2003-01-01

    Full Text Available In the present work ruthenium was deposited in submonolayer amounts on Pt(100 by spontaneous deposition at several deposition times. The Pt (100/Ru surfaces were analyzed using ex-situ STM to image the deposits characteristic of ruthenium on Pt (100. It was observed the formation of ruthenium islands with diameters between 1.0 and 4.5 nm with bi-atomic thickness in the center of the islands. A homogeneous distribution of the ruthenium islands on the platinum terraces was found, with no preferential deposition on steps or surface defect sites. The ruthenium coverage degree had been calculated by the decrease of charge of the hydrogen adsorption-desorption peaks in the cyclic voltammograms of the Pt(100/Ru electrodes. The Pt(100/Ru electrodes with a ruthenium coverage degree of ca. 0.3 showed a high activity for the ethanol electrooxidation. The electrochemical experimental results support strongly the bifunctional mechanism for the enhanced ethanol oxidation.

  20. Alloyed Ni-Fe nanoparticles as catalysts for NH3 decomposition

    Simonsen, Søren Bredmose; Chakraborty, Debasish; Chorkendorff, Ib

    2012-01-01

    A rational design approach was used to develop an alloyed Ni-Fe/Al2O3 catalyst for decomposition of ammonia. The dependence of the catalytic activity is tested as a function of the Ni-to-Fe ratio, the type of Ni-Fe alloy phase, the metal loading and the type of oxide support. In the tests with high...... temperatures and a low NH3-to-H2 ratio, the catalytic activity of the best Ni-Fe/Al2O3 catalyst was found to be comparable or even better to that of a more expensive Ru-based catalyst. Small Ni-Fe nanoparticle sizes are crucial for an optimal overall NH3 conversion because of a structural effect favoring...

  1. Superconductivity and Competing Ordered Phase in RuPn (Pn = As, P)

    Hirai, Daigorou; Takayama, Tomohiro; Hashizume, Daisuke; Yamamoto, Ayako; Takagi, Hidenori

    2011-03-01

    Unconventional superconductivity likely manifests itself when some competing electronic phases are suppressed down to zero temperature such as cuprates and iron-pnictide superconductors. Therefore, the correlated metallic state neighboring a competing electronic ordering can be a promising playground for unconventional superconductivity. Here we report superconductivity emerging adjacent to electronically ordered phases of RuPn (Pn = As, P). We found that RuAs(P) exhibits phase transitions at 240 (265) K, which is discerned as a drop of magnetic susceptibility or a resistivity upturn. Such anomalies can be suppressed by substituting Rh to the Ru site. Accompanied by the disappearance of the electronic order, superconductivity was found to emerge below 1.8 K and 3.8 K for RuAs and RuP, respectively. The superconductivity in Rh substituted RuPn, which neighbors a competing electronic order, might exhibit an exotic pairing state as seen in the unconventional superconductors known to date.

  2. Kinetic study of methanol oxidation on Pt2Ru3/C catalyst in the alkaline media

    A. V. TRIPKOVIC

    2007-11-01

    Full Text Available The interaction of acridine orange (AO with double-stranded (ds The electrochemical oxidation of methanol in NaOH solution was examined on a thin film Pt2Ru3/C electrode. The XRD pattern revealed that the Pt2Ru3 alloy consisted of a solid solution of Ru in Pt and a small amount of Ru or a solid solution of Pt in Ru. It was shown that in alkaline solution, the difference in activity between Pt/C and Pt2Ru3/C is significantly smaller than in acid solution. It is proposed that the reaction follows a quasi bifunctional mechanism. The kinetic parameters indicated that the chemical reaction between adsorbed COad and OHad species could be the rate limiting step.

  3. Methanol oxidation catalysis and substructure of PtRu bimetallic nanoparticles

    Nitani, Hiroaki; Nakagawa, Takashi; Ono, Takahiro; Honda, Yusuke; Koizumi, Akiko; Seino, Satoshi; Yamamoto, Takao A. [Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Daimon, Hideo; Kurobe, Yukiko [Development and Technology Division, Hitachi Maxell Ltd., 6-20-1 Kinunodai, Tsukubamirai, Ibaraki 300-2496 (Japan)

    2007-07-15

    Catalytic material of PtRu nanoparticles supported on carbon (PtRu/C) for direct methanol fuel cells was synthesized by a polyol reduction method. Addition of phosphorus was effective for downsizing PtRu particles and improving their catalytic activity. The activity obtained was six times of that of a commercial catalysis. The samples were analyzed by techniques of X-ray absorption fine structure (XAFS) at Pt L{sub III}-edge and Ru K-edge, transmission electron microscope (TEM), X-ray diffraction (XRD) and X-ray fluorescence (XRF). These results indicated a core-shell structure consisting of a Pt-rich core and Ru-rich shell. By examining coordination numbers determined by XAFS analysis, we found a clear correlation between the catalytic activity and the Pt-Ru atomic pair frequency occurring on the particle surface, which supports the 'bi-functional mechanism'. (author)

  4. The fingerprint elements analysis on the provenance relation between ancient chinese Ru porcelain and Jun porcelain

    Zhao Weijuan; Xie Jianzhong; Li Guoxia; Gao Zhengyao; Li Rongwu; Zhang Bin; Feng Songlin; Huang Zhongxiang; Jia Xiuqin; Han Song

    2002-01-01

    The 46 samples of glazes and bodies of the ancient Chinese Ru porcelain, Jun Porcelain and imitative porcelain were analyzed by neutron activation analysis (NAA). The contents of 36 elements for each sample were measured, the eight elements were chosen as the fingerprint elements to complete scatter analysis. The result showed that the ancient Chinese Ru porcelain and Jun porcelain had almost identical and stable sources of raw materials. The close provenance relation between ancient Chinese Ru porcelain and Jun porcelain was preliminarily verified. It is found that most modern Jun porcelain samples were similar to the ancient Chinese Jun porcelain, three modern Ru porcelain samples were similar to the ancient Chinese Ru porcelain. Jingdezhen porcelain has no relation to Ru porcelain and Jun porcelain

  5. Interaction of cis-[Ru(DMSO)4Cl2] with acetate-ion in solutions

    Buslaeva, T.M.; Rudnitskaya, O.V.; Kabanova, A.G.; Fedorova, G.A.

    2000-01-01

    Solutions of cis-[Ru(DMSO) 4 Cl 2 ] in water and alcohols in the presence of CH 3 COONa in dependence on concentration and relation of reagents are studied. It is shown that introduction of acetate-ion in solution of cis-[Ru(DMSO) 4 Cl 2 ] in methanol directs to formation of fac-[Ru(DMSO) 3 Cl 3 ] - which can be separated as sodium salt insoluble in methanol. It is necessary to mention that spectrum of solution of cis-[Ru(DMSO) 4 Cl 2 ] in methanol varies in time but these changes are insignificant in comparison with changes taking place in the presence of CH 3 COONa. Compound Na[Ru(DMSO) 3 (CH 3 COO) 2 Cl] is prepared and characterized spectrally for the first time [ru

  6. Palm webOS

    Allen, Mitch

    2009-01-01

    A Note from the Author and from O'Reilly Media about what this bookdoes--and doesn't--do: Palm webOS is a brand new platform and represents a very different type ofoperating system where the web runtime is used as the basis for the UI andApplication model. Palm and O'Reilly felt that it was important to have abook available to help developers get a basic understanding of the new Palmplatform at the time that the SDK was released; this timing played a majorrole in the content and structure of the book. Ideally this book would have been a complete reference of the new platformbut that wasn't

  7. os interesses comuns

    Guimarães, Maria Helena

    2008-01-01

    Os interesses comuns da União Europeia e da América Latina em matéria de integração bi-regional emanam, em grande medida, de factores exógenos, e em particular da crescente concorrência económica a nível global, do impasse negocial do Ciclo de Doha e da política de bilateralismo dos Estados Unidos da América. Com base numa abordagem de cariz sistémico argumenta-se que uma parceria entre as duas regiões é instrumental para enfrentar a concorrência global, sustenta-se que tal ...

  8. Evaluation of 54Fe(n,2n)53m+gFe reaction cross sections for high energy dosimetry applications

    Zolotarev, K.I.; Pashchenko, A.B.

    2001-01-01

    The new evaluation of excitation function for the high energy threshold 54 Fe(n,2n) 53m+g Fe dosimetry reaction in the energy range from the threshold to 20 MeV is briefly described. The cross section uncertainties and the covariance matrix were estimated simultaneously from the analysis. The adopted curve is compared to the available processed experimental data and the existing FEI-93, ENDF/B-VI and JENDL-3.2 evaluations. The ENDF-6 formatted data file is available from the Web site of the Russian Nuclear Data Center (RNDC) online (http://www.rndc.ippe.obninsk.ru). (author)

  9. Microstructural and magnetic properties of L10 FePt-C (0 0 1) textured nanocomposite films grown on different intermediate layers

    Chen, J S; Chow, G M; Lim, B C; Hu, J F; Ding, Y F; Ju, G

    2008-01-01

    The FePt : C films with different volume fractions of carbon and different thicknesses were epitaxially grown on a CrRu(2 0 0) underlayer with Pt and MgO intermediate layers. The magnetic properties and microstructure of these FePt : C films were investigated. The FePt : C films grown on the Pt intermediate layer consisted of a continuous layer of FePt, with overlying granular FePt grains, while the FePt : C films grown on the MgO intermediate layer consisted of granular FePt : C layers with overlying granular grains. The formation of the overlying granular FePt grains was attributed to carbon diffusion to the surface which resulted in the second nucleation of FePt. The different interface energies and surface energies of FePt on Pt and MgO intermediate layers caused the formation of an initial continuous FePt layer on the Pt intermediate layer and initial granular FePt layers on the MgO intermediate layer. The coupling between the continuous FePt layer or the granular FePt layer and the overlying granular FePt grains resulted in simultaneous magnetization reversal and thus strong exchange coupling in FePt : C films.

  10. Adsorption of RuSex (x =1–5) cluster on Se-doped graphene: First principle calculations

    Üzengi Aktürk, O.; Tomak, M.

    2015-01-01

    Highlights: • Electronic properties of adsorption of RuSe x (x =1–5) cluster on Se-doped graphene are investigated. • It is found that RuSe, RuSe 4 , RuSe 5 adsorbate make substrate metallic. • RuSe 2 makes it half metallic and RuSe 3 makes semiconductor. - Abstract: We have investigated the adsorption of RuSe x (x =1–5) cluster on Se-doped graphene. The change of the adsorption energy with the number of Se atoms and magnetization values are investigated. Electronic properties of adsorption of RuSe x (x =1–5) cluster on Se-doped graphene are investigated. The highest adsorption energy belongs to RuSe adsorbate. The biggest magnetization value belongs to RuSe 2 adsorbate. This adsorbate makes the substrate half metallic. This property is important in electronic device applications. It is observed that substitutional Se atom changes the electronic properties of graphene. This substitution makes graphene metallic. While RuSe, RuSe 4 , RuSe 5 adsorbate make substrate metallic, RuSe 3 makes it semiconducting. Generally, it is found that there is a charge transfer from the substrate to clusters within the Löwdin analysis. This is in line with the charge difference results

  11. Ultrathin Cr added Ru film as a seedless Cu diffusion barrier for advanced Cu interconnects

    Hsu, Kuo-Chung; Perng, Dung-Ching; Yeh, Jia-Bin; Wang, Yi-Chun

    2012-07-01

    A 5 nm thick Cr added Ru film has been extensively investigated as a seedless Cu diffusion barrier. High-resolution transmission electron microscopy micrograph, X-ray diffraction (XRD) pattern and Fourier transform-electron diffraction pattern reveal that a Cr contained Ru (RuCr) film has a glassy microstructure and is an amorphous-like film. XRD patterns and sheet resistance data show that the RuCr film is stable up to 650 °C, which is approximately a 200 °C improvement in thermal stability as compared to that of the pure Ru film. X-ray photoelectron spectroscopy depth profiles show that the RuCr film can successfully block Cu diffusion, even after a 30-min 650 °C annealing. The leakage current of the Cu/5 nm RuCr/porous SiOCH/Si stacked structure is about two orders of magnitude lower than that of a pristine Ru sample for electric field below 1 MV/cm. The RuCr film can be a promising Cu diffusion barrier for advanced Cu metallization.

  12. Synthesis and characterization of [Ru(η6-C6Me6)Cl2(CNPy)] and [Cl2(η6-C6Me6)Ru-(μ-CNPy)-Ru(η6-C6Me6)Cl2] and reactivity of [Ru(η6-C6Me6)Cl2(CNPy)] with various bases

    Pandey, D.S.; Sahay, A.N.; Agarwala, U.C.

    1996-01-01

    Reactions of [(Ru(η 6 -C 6 Me 6 )Cl 2 ) 2 ] with 4-cyanopyridine leads to the formation of neutral mono and dimeric complexes viz., [Ru(η 6 C 6 Me 6 )Cl 2 (CNPy)] (I) and [Cl 2 (η 6 -C 6 Me 6 ) Ru-(μ-CNPy)-Ru(η 6 -C 6 Me 6 )Cl 2 ] (II). Complex (I) undergoes metathetical reactions with EPh 3 (E=P, As and Sb) and N-donor heterocyclic bases yielding corresponding substitutional products which have been characterized by elemental analyses and spectroscopic: (IR, UV/vis, 1 H and 13 C NMR) studies. (author). 21 refs., 1 tab

  13. Studies on transfer and accumulation of 106Ru from seaweed to fish through crustacea, 2

    Izumo, Yoshiro

    1982-01-01

    This paper deals with transfer and accumulation of 106 Ru in a model of the graizing food chain of marine organisms: the radioactive sea water → seaweed (Chondrus crispus) → crustacea (prawn, Palaemon serratus) → fish (plaice, Pleuronectes platessa). The seaweeds were cultured in the radioactive sea waters A (filtrated and circulated through sandy mud, the radioactive concentration decreased and atteined to constant after addition of 106 Ru), B (not filtrated and circulated, the radioactive concentration decreased and atteined to constant) and C (not filtrated and circulated, the radioactive concentration decreased, but did not attein to constant), respectively, and investigated accumulations of 106 Ru. Thereafter, accumulations of 106 Ru in prawns and plaice by the ingestions of their diets (the seaweeds contaminated with 106 Ru in each water and the meats of prawns accumulated 106 Ru from each diet, respectively), were investigated and compared with those from the radioactive sea waters reported previously. It was shown that 106 Ru would be accumulated by the prawns from the sea water A about 3 times higher than from the contaminated diet in this water, however from the contaminated diets in the waters B and C about 2 times, respectively, higher than from each water. While, accumulations of 106 Ru by the plaice from each diet were negligible in comparison with those from each water. No higher concentrations of 106 Ru were observed in these organisms from lower to higher in the trophic level. (author)

  14. Generator separation of 103Ru//sup 103m/Rh

    Epperson, C.E.

    1975-01-01

    A generator for producing carrier-free Rh-103m was developed using a liquid extraction technique. Initially, Ru-103 chloride was converted to the sulfate by moderate fuming for 80 minutes in 1:1 sulfuric acid. The Ru-103 was then brought to its highest oxidation state with 0.2 N ceric sulfate. Ru-103 tetroxide was removed from an aqueous equilibrium solution of Ru-103/Rh-103m by three one-minute extractions into CCl 4 . The Rh-103m daughter was not extracted under these conditions. Yields of Rh-103m exceeded 90 percent theoretical. The Ru-103 removed by CCl 4 could be recovered by two hours of back-extraction into 2 M sulfuric acid containing 5 mg of sodium sulfite. A cyclic extraction system was made possible by employing sulfate media. Equilibrium Ru-103 could be repeatedly extracted and recovered, thereby producing a ''generator'' system for the production of Rh-103m. Ru-103 chloride can be converted to the sulfate and then stored for at least 38 days prior to extraction. By performing the fuming step whenever convenient, the time required to perform an extraction separation was reduced to 15 minutes. Prior treatment of glassware surfaces with dilute sulfuric acid prevented Ru-103 glass adsorption losses and made glassware much easier to decontaminate. Off-the-shelf reagent-grade CCl 4 could be used without further purification. Efforts to separate Rh-103m from Ru-103 by chromatography techniques were unsuccessful

  15. RuO2 pH Sensor with Super-Glue-Inspired Reference Electrode

    Lonsdale, Wade; Wajrak, Magdalena; Alameh, Kamal

    2017-01-01

    A pH-sensitive RuO2 electrode coated in a commercial cyanoacrylate adhesive typically exhibits very low pH sensitivity, and could be paired with a RuO2 working electrode as a differential type pH sensor. However, such sensors display poor performance in real sample matrices. A pH sensor employing a RuO2 pH-sensitive working electrode and a SiO2-PVB junction-modified RuO2 reference electrode is developed as an alternative high-performance solution. This sensor exhibits a performance similar to...

  16. PtRu nanoparticles embedded in nitrogen doped carbon with highly stable CO tolerance and durability

    Ling, Ying; Yang, Zehui; Yang, Jun; Zhang, Yunfeng; Zhang, Quan; Yu, Xinxin; Cai, Weiwei

    2018-02-01

    As is well known, the lower durability and sluggish methanol oxidation reaction (MOR) of PtRu alloy electrocatalyst blocks the commercialization of direct methanol fuel cells (DMFCs). Here, we design a new PtRu electrocatalyst, with highly stable CO tolerance and durability, in which the PtRu nanoparticles are embedded in nitrogen doped carbon layers derived from carbonization of poly(vinyl pyrrolidone). The newly fabricated electrocatalyst exhibits no loss in electrochemical surface area (ECSA) and MOR activity after potential cycling from 0.6-1.0 V versus reversible hydrogen electrode, while commercial CB/PtRu retains only 50% of its initial ECSA. Meanwhile, due to the same protective layers, the Ru dissolution is decelerated, resulting in stable CO tolerance. Methanol oxidation reaction (MOR) testing indicates that the activity of newly fabricated electrocatalyst is two times higher than that of commercial CB/PtRu, and the fuel cell performance of the embedded PtRu electrocatalyst was comparable to that of commercial CB/PtRu. The embedded PtRu electrocatalyst is applicable in real DMFC operation. This study offers important and useful information for the design and fabrication of durable and CO tolerant electrocatalysts.

  17. Structural, optical and magnetic characterization of Ru doped ZnO nanorods

    Kumar, Sanjeev; Kaur, Palvinder; Chen, C.L.; Thangavel, R.; Dong, C.L.; Ho, Y.K.; Lee, J.F.; Chan, T.S.; Chen, T.K.; Mok, B.H.; Rao, S.M.; Wu, M.K.

    2014-01-01

    Graphical abstract: Ruthenium (Ru = 0%, 1% and 2%) doped nano-crystalline zinc oxide (ZnO) nanorods were synthesized by using well-known sol–gel technique. X-ray diffraction (XRD) results show that Ru (0%, 1% and 2%) doped ZnO nanorods crystallized in the wurtzite structure having space group C 3v (P6 3 mc). Williamson and Hall plot reveal that in the nanoscale dimensions, incorporation of Ru induced the tensile strain in ZnO host matrix. Photoluminescence (PL) and Raman studies of Ru doped ZnO nanorods show the formation of singly ionized oxygen vacancies which may account for the observed room temperature ferromagnetism (RTFM) in 2% Ru doped ZnO. X-ray absorption spectroscopy (XAS) reveals that Ru replace the Zn atoms in the host lattice and maintain the crystal symmetry with slightly lattice distortion. Highlights: • Ru doped ZnO nanorods crystallized in the wurtzite structure having space group C 3v (P6 3 mc). • PL and Raman studies show the formation of singly ionized oxygen vacancies in 2% Ru doped ZnO. • XAS reveals that Ru replace the Zn atoms in the host lattice with slightly lattice distortion. • Doping of Ru in ZnO nanostructures gives rise to RTFM ordering. -- Abstract: Ruthenium (Ru = 0%, 1% and 2%) doped nano-crystalline zinc oxide (ZnO) nanorods were synthesized by using well-known sol–gel technique. X-ray diffraction (XRD) results show that Ru (0%, 1% and 2%) doped ZnO nanorods crystallized in the wurtzite structure having space group C 3v (P6 3 mc). Williamson and Hall plot reveal that in the nanoscale dimensions, incorporation of Ru induced the tensile strain in ZnO host matrix. Photoluminescence (PL) and Raman studies of Ru doped ZnO nanorods show the formation of singly ionized oxygen vacancies which may account for the observed room temperature ferromagnetism (RTFM) in 2% Ru doped ZnO. X-ray absorption spectroscopy (XAS) reveals that Ru replace the Zn atoms in the host lattice and maintain the crystal symmetry with slightly lattice

  18. Triaxial shapes in the ground states of even-even neutron-rich Ru isotopes

    Ahmad, I.; Lister, C.J.; Morss, L.R. [and others

    1995-08-01

    Partial level schemes for {sup 108,110,112}Ru, and {sup 114}Ru about which nothing was previously known, were determined from the measurement of prompt, triple-gamma coincidences in {sup 248}Cm fission fragments. A 5-mg {sup 249}Cm source, mixed with 65-mg KCl and pressed in the form of a 7-mm diameter pellet, was used for the experiment. Prompt {gamma} rays emitted from the fission fragments were detected with the Eurogam array at Daresbury, which at that time consisted of 45 Compton suppressed Ge detectors and 5 LEPS spectrometers. Transitions in Ru were identified by gating on {gamma} rays in the complementary Te fragments. Figure I-25 shows the technique used to identify the previously unknown transitions in {sup 114}Ru and its partial level scheme. High spin states up to spin 10 h were observed and the {gamma}-ray branching ratios were determined. The ratios of electric quadrupole transition probabilities deduced from the experimental branching ratios were found to be in good agreement with the predictions of a simple model of rigid triaxial rotor. Our analysis shows that gamma deformation in Ru isotopes is increasing with the neutron number and the gamma value for {sup 112}Ru and {sup 114}Ru is {approximately} 25 degrees. This is one of the highest gamma values encountered in nuclei, suggesting soft triaxial shapes for {sup 112}Ru and {sup 114}Ru. The results of this investigation were published.

  19. Mössbauer study of the Ru porcelain of Chinese Song Dynasty and Yuan Dynasty

    Zhengyao, Gao; Songhua, Chen; Xiande, Chen

    1994-12-01

    The Mössbauer spectra from the glazes of the Song Dynasty and the Yuan Dynasty Ru porcelains and the imitative ancient Ru porcelain are compared and analyzed. It is determined that the original firing atmosphere of the Yuan Dynasty Ru porcelain was reductive. The firing temperature was 1250±20 ‡C. The original firing atmosphere of the Song Dynasty Ru porcelain was also reductive; the firing temperature was above 1200 ‡C. The coloring mechanism of these glazes is discussed.

  20. Direct methanol fuel cell with extended reaction zone anode: PtRu and PtRuMo supported on graphite felt

    Bauer, Alex; Gyenge, Elod L.; Oloman, Colin W. [Department of Chemical and Biological Engineering, The University of British Columbia, 2360 East Mall, Vancouver, BC (Canada)

    2007-05-15

    Pressed graphite felt (thickness {proportional_to}350 {mu}m) with electrodeposited PtRu (43 g m{sup -2}, 1.4:1 atomic ratio) or PtRuMo (52 g m{sup -2}, 1:1:0.3 atomic ratio) nanoparticle catalysts was investigated as an anode for direct methanol fuel cells. At temperatures above 333 K the fuel cell performance of the PtRuMo catalyst was superior compared to PtRu. The power density was 2200 W m{sup -2} with PtRuMo at 5500 A m{sup -2} and 353 K while under the same conditions PtRu yielded 1925 W m{sup -2}. However, the degradation rate of the Mo containing catalyst formulation was higher. Compared to conventional gas diffusion electrodes with comparable PtRu catalyst composition and load, the graphite felt anodes gave higher power densities mainly due to the extended reaction zone for methanol oxidation. (author)

  1. PtRu/C and PtRuBi/C electrocatalysts prepared by two different methodologies of borohydride reduction process for ethanol electro-oxidation

    Brandalise, Michele; Tusi, Marcelo Marques; Piasentin, Ricardo Marcelo; Correa, Olandir Vercino; Linardi, Marcelo; Spinace, Estevam Vitorio; Oliveira Neto, Almir, E-mail: brandalise@usp.br, E-mail: mmtusi@usp.br, E-mail: rmpiasen@ipen.br, E-mail: ovcorrea@ipen.br, E-mail: mlinardi@ipen.br, E-mail: espinace@ipen.br, E-mail: aolivei@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    PtRu/C (50:50) and PtRuBi/C (50:40:10) electrocatalysts were prepared by borohydride reduction using H{sub 2}PtCl{sub 6.6}H{sub 2}O, RuCl{sub 3.x}H{sub 2}O and Bi(NO{sub 3}){sub 3.5}H{sub 2}O as metals sources and Vulcan XC72 as support. The borohydride solution was added in two different ways: drop by drop and rapid addition of all the solution. The obtained electrocatalysts were characterized by EDX, XRD and cyclic voltammetry. The electro-oxidation of ethanol was studied by cyclic voltammetry and chronoamperometry at room temperature and on a single cell of a direct ethanol fuel cell (DEFC) at 100 deg C. PtRuBi/C electrocatalysts showed superior performance for ethanol electro-oxidation than PtRu/C electrocatalysts prepared in a similar way. However, PtRuBi/C electrocatalyst prepared by rapid addition of the borohydride solution showed superior performance for ethanol electro oxidation at room temperature, while PtRuBi/C electrocatalyst prepared by addition drop by drop of borohydride solution showed superior performance on DEFC at 100 deg C. (author)

  2. PtRu/C and PtRuBi/C electrocatalysts prepared by two different methodologies of borohydride reduction process for ethanol electro-oxidation

    Brandalise, Michele; Tusi, Marcelo Marques; Piasentin, Ricardo Marcelo; Correa, Olandir Vercino; Linardi, Marcelo; Spinace, Estevam Vitorio; Oliveira Neto, Almir

    2009-01-01

    PtRu/C (50:50) and PtRuBi/C (50:40:10) electrocatalysts were prepared by borohydride reduction using H 2 PtCl 6.6 H 2 O, RuCl 3.x H 2 O and Bi(NO 3 ) 3.5 H 2 O as metals sources and Vulcan XC72 as support. The borohydride solution was added in two different ways: drop by drop and rapid addition of all the solution. The obtained electrocatalysts were characterized by EDX, XRD and cyclic voltammetry. The electro-oxidation of ethanol was studied by cyclic voltammetry and chronoamperometry at room temperature and on a single cell of a direct ethanol fuel cell (DEFC) at 100 deg C. PtRuBi/C electrocatalysts showed superior performance for ethanol electro-oxidation than PtRu/C electrocatalysts prepared in a similar way. However, PtRuBi/C electrocatalyst prepared by rapid addition of the borohydride solution showed superior performance for ethanol electro oxidation at room temperature, while PtRuBi/C electrocatalyst prepared by addition drop by drop of borohydride solution showed superior performance on DEFC at 100 deg C. (author)

  3. Effects of countercations on the structures and redox and spectroscopic properties of diruthenium catecholate complexes with ligand-unsupported Ru-Ru bonds.

    Chang, Ho-Chol; Mochizuki, Katsunori; Kitagawa, Susumu

    2005-05-30

    The molecular structures and physicochemical properties of diruthenium complexes with ligand-unsupported Ru-Ru bonds, generally formulated as [A2{Ru2(DTBCat)4}] (DTB = 3,5- or 3,6-di-tert-butyl; Cat(2-) = catecholate), were studied in detail by changing the countercations. First, the binding structures of the cations in a family of [{A(DME)n}2{Ru2(3,5-DTBCat)4}] (n = 2 for A+ = Li+ and Na+ and n = 1 for A+ = K+ and Rb+) were systematically examined to reveal the effects of the cations on the molecular structures and electrochemical properties. Second, the complex (n-Bu4N)2[Ru2(3,6-DTBCat)4] with a cation-free structure was synthesized using tetra-n-butylammonium cations. The complex clearly demonstrates first that the ligand-unsupported Ru-Ru bonds are essentially stabilized by the dianionic nature of the catecholate derivatives without any other bridging or supporting species. In contrast, the redox potentials and absorption spectra of the complexes can sensitively respond to the countercations depending upon the polarity of the solvents.

  4. Nível de ruídos em uma unidade de cuidados intensivos pediátricos Noise level in a pediatric intensive care unit

    Werther B. Carvalho

    2005-12-01

    Full Text Available OBJETIVO: Verificar o nível de ruídos em uma unidade de cuidados intensivos pediátricos. MÉTODOS: Estudo observacional e prospectivo realizado em uma unidade de cuidados intensivos pediátricos de 10 leitos de um hospital universitário da cidade de São Paulo, Brasil. Os níveis de ruídos foram medidos por meio de equipamento instalado no corredor de acesso à unidade de cuidados intensivos pediátricos, posto de enfermagem, duas salas com três e cinco leitos, bem como nas unidades de isolamento. O equipamento utilizado foi calibrado para registrar a pressão do som em dBA, durante 24 horas, por 6 dias. Os dados foram analisados de acordo com as curvas gráficas registradas pelo equipamento. RESULTADOS: Foi identificado um nível basal de ruídos de 60 a 70 dBA, com pico de 120 dBA. Os níveis mais elevados foram identificados no período diurno, decorrentes da atividade e comunicação dos profissionais. CONCLUSÃO: Os níveis de ruídos identificados excederam as recomendações do International Noise Council, da Organização Mundial da Saúde. A educação sobre os efeitos prejudiciais de ruídos na audição humana e sua relação com o estresse constituem as bases para a implementação de programas de redução de ruídos.OBJECTIVE: The purpose of this study was to verify the noise level at a PICU. METHODS: This prospective observational study was performed in a 10 bed PICU at a teaching hospital located in a densely populated district within the city of São Paulo, Brazil. Sound pressure levels (dBA were measured 24 hours during a 6-day period. Noise recording equipment was placed in the PICU access corridor, nursing station, two open wards with three and five beds, and in isolation rooms. The resulting curves were analyzed. RESULTS: A basal noise level variation between 60 and 70 dBA was identified, with a maximum level of 120 dBA. The most significant noise levels were recorded during the day and were produced by the staff

  5. Phase composition of iron-rich R-Fe-Si (R=Dy, Ho, Er) alloys

    Ivanova, G.V.; Makarova, G.M.; Shcherbakova, E.V.; Belozerov, E.V.

    2005-01-01

    Phase composition is studied in iron-rich alloys of R-Fe-Si (R=Dy, Ho, Er). In the as-cast state R 2 (Fe, Si) 17 of type Th 2 Ni 17 and R(Fe, Si) 12 compounds are observed; in the alloys of rated composition of R(Fe 0.85 Si 0.15 ) 8.5 (R=Dy, Er) a compound R 2 (Fe, Si) 17 of Th 2 Zn 17 -type is revealed as well. The annealing at 1273 K results in formation of Dy 3 (Fe, Si) 29 and also the compounds with the presumed composition of Dy 4 (Fe, Si) 41 and Ho 4 (Fe, Si) 41 . As this takes place the alloys contain a transition structure as well that represents a set of small-sized areas with various type short-range order in mutual displacement of Fe-Fe(Si) dumpbell chains. The process of phase formation at 1273 K is faced with difficulties. Even the annealing for 1000 h does not result in the state of equilibrium [ru

  6. Potências do ruído nas interfaces gráficas dos countergames

    Eduardo Luersen

    2017-08-01

    Full Text Available Proponho neste artigo apresentar de que se tratam as construções imagéticas dos countergames, de modo a dar a ver como estes se inscrevem enquanto tendências experimentais dos videogames e verificar de que maneira se configuram como objetos pertinentes para pensar sobre as imagens ruidosas que tensionam e que convergem e/ou divergem com as imagens das interfaces culturais dos jogos de computador. Pretendo com isso demarcar fricções entre o design das interfaces gráficas de estéticas ruidosas e os constructos audiovisuais dos games, em uma relação ambivalente entre apagamento e permanência dos rastros da cultura audiovisual nestas superfícies. Busco, através disso, realizar uma angulação teórica entre a estética do ruído conforme proposta por Giselle Beiguelman, a abordagem de Alexander Galloway sobre art game mods, as interfaces culturais de que fala Lev Manovich e a pesquisa crítica e especulativa em software studies de Matthew Fuller, para discutir potências resultantes da interação entre estas perspectivas que compõem parte do tecido da tecnocultura contemporânea. Assim, a partir da comunicação audiovisual, mas explorando os limiares desta com o design de interface dos games, sugiro iniciar um debate passível de ampliação em discussões vindouras análogas ao tema.

  7. Os perigos da utopia

    Larry Hufford

    2009-06-01

    Full Text Available

    A utopia pode ter um lado que eleva e um lado sinistro, mas geralmente o lado sinistro acaba destruindo o idealismo inicial. A razão para isto é que os utópicos inevitavelmente adotam uma imagem messiânica do mundo. As três revoluções messiânicas na história—a americana, a francesa e a bolchevique—foram lideradas por homens que pensavem que suas idéias eram universais. Este ensaio examina os escritos do existencialista francês Albert Camus, que argumenta que não existem valores transcendentais, ao mesmo tempo que ele não aceita o niilismo. Camus faz uma distinção entre um rebelde e um revolucionário, e conclui que uma rebelião tentará terminar com uma opressão espedífica, enquanto que uma revolução tentará criar “um novo

  8. Os limites da competitividade

    Henrique Rattner

    2009-08-01

    Full Text Available

    Costuma-se destacar os aspectos aparentemente positivos e as vantagens hipotéticas da concorrência e da competitividade entre empresas e também entre nações. Não se pode negar que a concorrência nos mercados tenha exercido uma função central e fundamental na gênese e na expansão do sistema de produção capitalista. Ela contribuiu para a geração e acumulação de riquezas materiais. Também estimulou e fortaleceu as aspirações de seus principais atores sociais, os empreendedores, de exigir uma organização política mais democrática em oposição ao regime feudal ou absolutista, em determinado período da história do mundo ocidental.

  9. OS X and iOS Kernel Programming

    Halvorsen, Ole Henry

    2011-01-01

    OS X and iOS Kernel Programming combines essential operating system and kernel architecture knowledge with a highly practical approach that will help you write effective kernel-level code. You'll learn fundamental concepts such as memory management and thread synchronization, as well as the I/O Kit framework. You'll also learn how to write your own kernel-level extensions, such as device drivers for USB and Thunderbolt devices, including networking, storage and audio drivers. OS X and iOS Kernel Programming provides an incisive and complete introduction to the XNU kernel, which runs iPhones, i

  10. Magnetic and Crystal Structure of α-RuCl3

    Sears, Jennifer

    The layered honeycomb material α-RuCl3 has been proposed as a candidate material to show significant bond-dependent Kitaev type interactions. This has prompted several recent studies of magnetism in this material that have found evidence for multiple magnetic transitions in the temperature range of 8-14 K. We will present elastic neutron scattering measurements collected using a co-aligned array of α-RuCl3 crystals, identifying zigzag magnetic order within the honeycomb planes with an ordering temperature of ~8 K. It has been reported that the ordering temperature depends on the c axis periodicity of the layered structure, with ordering temperatures of 8 and 14 K for three and two-layer periodicity respectively. While the in-plane magnetic order has been identified, it is clear that a complete understanding of magnetic ordering and interactions will depend on the three dimensional structure of the crystal. Evidence of a structural transition at ~150 K has been reported and questions remain about the structural details, in particular the stacking of the honeycomb layers. We will present x-ray diffraction measurements investigating the low and high temperature structures and stacking disorder in α-RuCl3. Finally, we will present inelastic neutron scattering measurements of magnetic excitations in this material. Work done in collaboration with K. W. Plumb (Johns Hopkins University), J. P. Clancy, Young-June Kim (University of Toronto), J. Britten (McMaster University), Yu-Sheng Chen (Argonne National Laboratory), Y. Qiu, Y. Zhao, D. Parshall, and J. W. Lynn (NCNR).

  11. A reagentless electrochemiluminescent immunosensor for apurinic/apyrimidinic endonuclease 1 detection based on the new Ru(bpy){sub 3}{sup 2+}/bi-arginine system

    Zhao, Min; Chai, Xi Deng Ya-Qin; Han, Jing; Gui, Guo-Feng; Yuan, Ruo, E-mail: yuanruo@swu.edu.cn; Zhuo, Ying, E-mail: yingzhuo@swu.edu.cn

    2014-10-10

    Highlights: • A reagentless ECL biosensor based on the new Ru(bpy){sub 3}{sup 2+}/bi-arginine system. • The successful preparation of bi-Arg/Au@Fe3O4–rGO as enhancer. • Using the APE-1 as target by the sandwich-type immunoassay format. - Abstract: Apurinic/apyrimidinic endonuclease 1 (APE-1), a kind of multifunctional protein widely-distributed in the body, plays an essential role in the DNA base excision repair and serves as multiple possible roles in the response of human cancer to radiotherapy and chemotherapy. In this work, an ultrasensitive solid-state electrochemiluminescence (ECL) immunosensor is designed to determine APE-1 based on the new Ru(bpy){sub 3}{sup 2+}/bi-arginine system. The bi-arginine (bi-Arg) is decorated on the Au nanoparticles functionalized magnetic Fe{sub 3}O{sub 4}/reduced graphene oxide (bi-Arg/Au@Fe{sub 3}O{sub 4}–rGO) according to the self-assembling and covalent cross-linking interaction to obtain the functionalized nanocomposite of bi-Arg/Au@Fe{sub 3}O{sub 4}–rGO. Herein, the bi-Arg/Au@Fe{sub 3}O{sub 4}–rGO plays not only an amplification label to enhance the ECL signal of Ru(bpy){sub 3}{sup 2+} due to the coreactant of bi-Arg but also an ideal nanocarrier to load numerous secondary antibody. Based on sandwich-type immunoassay format, this proposed method offers a linear range of 1.0 fg mL{sup −1}–5.0 pg mL{sup −1} and an estimated detection limit of 0.3 fg mL{sup −1} for the APE-1. Moreover, the reagentless ECL immunosensor also exhibits high sensitivity, excellent selectivity and good stability, which has greatly potential development and application in clinical diagnostics, immunology and biomedical research.

  12. Characterization of a trinuclear ruthenium species in catalytic water oxidation by Ru(bda)(pic)2 in neutral media.

    Zhang, Biaobiao; Li, Fei; Zhang, Rong; Ma, Chengbing; Chen, Lin; Sun, Licheng

    2016-06-30

    A Ru(III)-O-Ru(IV)-O-Ru(III) type trinuclear species was crystallographically characterized in water oxidation by Ru(bda)(pic)2 (H2bda = 2,2'-bipyridine-6,6'-dicarboxylic acid; pic = 4-picoline) under neutral conditions. The formation of a ruthenium trimer due to the reaction of Ru(IV)[double bond, length as m-dash]O with Ru(II)-OH2 was fully confirmed by chemical, electrochemical and photochemical methods. Since the oxidation of the trimer was proposed to lead to catalyst decomposition, the photocatalytic water oxidation activity was rationally improved by the suppression of the formation of the trimer.

  13. Dissociative sticking of CH4 on Ru(0001)

    Nielsen, Jane Hvolbæk; Holmblad, Peter Mikal; Chorkendorff, Ib

    1999-01-01

    In this study the CH4 dissociation probability on Ru(0001) is found for various translational and vibrational energies. The absolute sticking values are determined from King and Wells experiments and carbon uptake curves. The carbon amount is determined from the recombination signal of carbon...... with oxygen obtained after the beam exposure when heating in an oxygen atmosphere. The measured sticking coefficient of CH4 is strongly enhanced both by increasing the translational and the vibrational energy of the CH4 molecule. A model is applied to the data and an estimate of the thermal activation energy...

  14. Progress in doping of ruthenium silicide (Ru2Si3)

    Vining, C.B.; Allevato, C.E.

    1992-01-01

    This paper reports that ruthenium silicide (Ru 2 Si 3 ) is currently under development as a promising thermoelectric material suitable for space power applications. Key to realizing the potentially high figure of merit values of this material is the development of appropriate doping techniques. In this study, manganese and iridium have been identified as useful p- and n-type dopants, respectively. Resistivity values have been reduced by more than 3 orders of magnitude. Anomalous Hall effect results, however, complicate interpretation of some of the results and further effort is required to achieve optimum doping levels

  15. Multidimensional effects on dissociation of N-2 on Ru(0001)

    Diaz, C.; Vincent, J.K.; Krishnamohan, G.P.

    2006-01-01

    on density functional theory. The computed reaction probabilities are in good agreement with molecular beam experiments. Comparison to previous calculations shows that the rotation of N-2 and its motion along the surface affect the reactivity of N-2 much more than nonadiabatic effects.......The applicability of the Born-Oppenheimer approximation to molecule-metal surface reactions is presently a topic of intense debate. We have performed classical trajectory calculations on a prototype activated dissociation reaction, of N-2 on Ru(0001), using a potential energy surface based...

  16. Os (descaminhos da identidade

    Oliveira Roberto Cardoso de

    2000-01-01

    Full Text Available A conferência procurou apresentar uma interpretação das vicissitudes da identidade étnica e/ou nacional quando observada em situações de ambigüidade. É quando o processo identitário expressa crises reais ou virtuais, como as que têm lugar entre imigrantes latino-americanos nos Estados Unidos, entre povos de diferentes regiões da Espanha emigrados para Barcelona, entre catalães espanhóis, franceses e andorranos residentes em Andorra, e entre povos indígenas em regiões de fronteira do Brasil com países vizinhos. O exame do processo identitário que tem lugar em diferentes latitudes, nas Américas e na Europa, sugere que os fenômenos socioculturais de etnicidade e de nacionalidade possuem em comum características tais como a busca de reconhecimento da pessoa moral, o respeito à diferença e, como corolário ético, a elevação do que se pode definir como "taxa de consideração".

  17. Desvíos

    Sánchez Doblado, Manuel

    1992-08-01

    Full Text Available In order to establish connections between the general circulation tracks, and between these and station tracks, devices must be installed on the track which are able to move in a crosswise direction, there by permitting the choice of the appropriate path for the treads. This device in general, is complex and its complexity increases at high speeds (> 200 km/h. Following this, the article deals briefly with some of the solutions adopted to ensure movement on the shunts under optimal safety and comfort conditions, along with the extended useful life of this device in comparison with the conventional railroad.

    Para el establecimiento de las comunicaciones entre las vías generales de circulación, y entre éstas y las del apartado de estaciones, se requiere la instalación de unos aparatos de vía que, dotados de movimiento transversal, permiten establecer adecuadamente la elección del camino de rodadura. El aparato, en general, es complejo, y dicha complejidad se incrementa con la circulación a alta velocidad (V > 200 km/h. A continuación se abordan, de forma sucinta, algunas de las soluciones adoptadas que permiten la circulación por los desvíos en condiciones de seguridad y confort elevados, junto con el alargamiento de su vida útil respecto al ferrocarril convencional.

  18. Os usos da diversidade

    Clifford Geertz

    1999-05-01

    Full Text Available Resumo Ao discorrer sobre o “Futuro do Etnocentrismo”, este artigo parte da premissa de que a globalização, apesar de ter – em muitos casos – diminuído as diferenças entre povos, não tem amenizado os preconceitos e as formas de discriminação que ocorrem em nome dessas diferenças. Ele resgata a importância do antropólogo neste cenário lembrando que a diversidade cultural faz parte da sociedade complexa, remetendo-se não apenas a grupos étnicos ou nacionais bem delimitados, mas também a diferenças de geração, gênero, sexo e classe, entre outros. Neste contexto, a tolerância passiva de modos distantes de vida assim como a aceitação pragmática de nosso próprio paroquialismo são atitudes não somente intelectualmente desonestas mas também moralmente repreensíveis. É no encontro incômodo de subjetividades variantes na sua própria sociedade que o antropólogo define seu lugar.

  19. Efeito do ruído na voz de educadoras de instituições de educação infantil

    Marcia Simões-Zenari

    2012-08-01

    Full Text Available OBJETIVO: Avaliar a associação entre níveis de ruído presentes em centros de educação infantil e alterações vocais em educadoras. MÉTODOS: Estudo transversal com 28 educadoras de três instituições de educação infantil de São Paulo, SP, em 2009. Os níveis de pressão sonora foram mensurados segundo a Associação Brasileira de Normas Técnicas, com uso de medidor de nível de pressão sonora. As médias foram classificadas de acordo com os níveis de conforto, desconforto e dano auditivo propostos pela Organização Panamericana de Saúde. As educadoras tiveram a voz avaliada com: autoavaliação com escala analógica visual, avaliação perceptivo-auditiva com escala GRBAS e análise acústica com o programa Praat. Estatística descritiva e teste do qui-quadrado, com 10% de significância devido ao tamanho da amostra, foram usados para análise da associação entre ruído e avaliação vocal. RESULTADOS: As educadoras possuíam idades entre 21 e 56 anos. A média de ruído foi 72,7 dB, considerado dano 2. A autoavaliação vocal das profissionais apresentou média de 5,1 na escala, considerada alteração moderada. Na avaliação perceptivo-auditiva, 74% apresentaram alteração vocal, principalmente rouquidão; destas, 52% foram consideradas alterações leves. A maior parte apresentou frequência fundamental abaixo do esperado na avaliação acústica. Médias de jitter, shimmer e proporção harmônico-ruído estavam alteradas. Presença de ruído entre os harmônicos associou-se a alteração vocal. CONCLUSÕES: Há associação entre presença de ruído entre harmônicos e alteração vocal, com elevados níveis de ruído. Apesar de a maioria das educadoras ter apresentado voz alterada em grau leve, a autoavaliação mostrou alteração moderada, provavelmente pela dificuldade de projeção.

  20. O2-enhanced methanol oxidation reaction at novel Pt-Ru-C co-sputtered electrodes

    Umeda, Minoru; Matsumoto, Yosuke; Inoue, Mitsuhiro; Shironita, Sayoko

    2013-01-01

    Highlights: ► Novel Pt-Ru-C electrodes were prepared by a co-sputtering technique. ► Co-sputtered electrodes with C result in highly efficient O 2 -enhanced methanol oxidation. ► Pt–Ru-alloy-based co-sputtered electrode induces a negative onset potential of methanol oxidation. ► The Pt-Ru-C electrodes allow a negative onset potential of O 2 -enhanced methanol oxidation. ► The optimum atomic ratios of Pt-Ru-C are Pt: 0.24–0.80, Ru: 0.14–0.61, C: 0.06–0.37. -- Abstract: A Pt-Ru-C electrode has been developed using a co-sputtering technique for use as the anode catalyst of a mixed-reactant fuel cell. The physical and electrochemical characteristics of the electrodes demonstrate that co-sputtered Pt and Ru form a Pt–Ru alloy. The crystallite sizes of the catalysts investigated in this study are reduced by the addition of C to the Pt–Ru alloy. Cu stripping voltammograms suggest that the sputtering of C and the formation of the Pt–Ru alloy synergically increase the electrochemical surface area of the electrodes. The methanol oxidation performances of the prepared electrodes were evaluated in N 2 and O 2 atmospheres; the Pt-Ru-C electrodes achieve an O 2 -induced negative shift in the onset potential of the methanol oxidation (E onset ) and enhance the methanol oxidation current density in the O 2 atmosphere. The mechanism of O 2 -enhanced methanol oxidation with a negative E onset at the Pt-Ru-C electrodes is attributed to a change in the electronic structure of Pt due to the formation of Pt–Ru alloy and the generation of O-based adsorption species by the reduction of O 2 . Finally, the composition of the Pt-Ru-C electrode for the O 2 -enhanced methanol oxidation with a negative E onset was found to be optimal at an atomic ratio of Pt: 0.24–0.80, Ru: 0.14–0.61, and C: 0.06–0.37

  1. Robust ultra-thin RuMo alloy film as a seedless Cu diffusion barrier

    Hsu, Kuo-Chung; Perng, Dung-Ching; Wang, Yi-Chun

    2012-01-01

    Highlights: ► A 5 nm-thick Mo added Ru film has been investigated as a Cu diffusion barrier layer. ► RuMo film provides over 175 °C improvement in thermal stability than that of pure Ru layer. ► The 5 nm-thick RuMo film shows excellent barrier performance against Cu diffusion upon 725 °C. - Abstract: This study investigated the properties of 5 nm-thick RuMo film as a Cu diffusion barrier. The sheet resistance variation and X-ray diffraction patterns show that the RuMo alloy film has excellent barrier performance and that it is stable upon annealing at 725 °C against Cu. The transmission electron microscopy micrograph and diffraction patterns show that the RuMo film is an amorphous-like structure, whereas pure Ru film is a nano-crystalline structure. The elements’ depth profiles, analyzed by X-ray photoelectron spectroscopy, indicate no inter-diffusion behavior between the Cu and Si layer, even annealing at 700 °C. Lower leakage current has been achieved from the Cu/barrier/insulator/Si test structure using RuMo film as the barrier layer. A 5 nm ultrathin RuMo film provided two orders of magnitude improvement in leakage current and also exhibited a 175 °C improvement in thermal stability than that of the pure Ru film. It is a potential candidate as a seedless Cu diffusion barrier for advanced Cu interconnects.

  2. Ru(III) catalyzed permanganate oxidation of aniline at environmentally relevant pH.

    Zhang, Jing; Zhang, Ying; Wang, Hui; Guan, Xiaohong

    2014-07-01

    Ru(III) was employed as catalyst for aniline oxidation by permanganate at environmentally relevant pH for the first time. Ru(III) could significantly improve the oxidation rate of aniline by 5-24 times with its concentration increasing from 2.5 to 15 μmol/L. The reaction of Ru(III) catalyzed permanganate oxidation of aniline was first-order with respect to aniline, permanganate and Ru(III), respectively. Thus the oxidation kinetics can be described by a third-order rate law. Aniline degradation by Ru(III) catalyzed permanganate oxidation was markedly influenced by pH, and the second-order rate constant (ktapp) decreased from 643.20 to 2.67 (mol/L)⁻¹sec⁻¹ with increasing pH from 4.0 to 9.0, which was possibly due to the decrease of permanganate oxidation potential with increasing pH. In both the uncatalytic and catalytic permanganate oxidation, six byproducts of aniline were identified in UPLC-MS/MS analysis. Ru(III), as an electron shuttle, was oxidized by permanganate to Ru(VI) and Ru(VII), which acted the co-oxidants for decomposition of aniline. Although Ru(III) could catalyze permanganate oxidation of aniline effectively, dosing homogeneous Ru(III) into water would lead to a second pollution. Therefore, efforts would be made to investigate the catalytic performance of supported Ru(III) toward permanganate oxidation in our future study. Copyright © 2014. Published by Elsevier B.V.

  3. Ternary Pt-Ru-Ni catalytic layers for methanol electrooxidation prepared by electrodeposition and galvanic replacement

    Athanasios ePapaderakis

    2014-06-01

    Full Text Available Ternary Pt-Ru-Ni deposits on glassy carbon substrates, Pt-Ru(Ni/GC, have been formed by initial electrodeposition of Ni layers onto glassy carbon electrodes, followed by their partial exchange for Pt and Ru, upon their immersion into equimolar solutions containing complex ions of the precious metals. The overall morphology and composition of the deposits has been studied by SEM microscopy and EDS spectroscopy. Continuous but nodular films have been confirmed, with a Pt÷Ru÷Ni % bulk atomic composition ratio of 37÷12÷51 (and for binary Pt-Ni control systems of 47÷53. Fine topographical details as well as film thickness have been directly recorded using AFM microscopy. The composition of the outer layers as well as the interactions of the three metals present have been studied by XPS spectroscopy and a Pt÷Ru÷Ni % surface atomic composition ratio of 61÷12÷27 (and for binary Pt-Ni control systems of 85÷15 has been found, indicating the enrichment of the outer layers in Pt; a shift of the Pt binding energy peaks to higher values was only observed in the presence of Ru and points to an electronic effect of Ru on Pt. The surface electrochemistry of the thus prepared Pt-Ru(Ni/GC and Pt(Ni/GC electrodes in deaerated acid solutions (studied by cyclic voltammetry proves the existence of a shell consisting exclusively of Pt-Ru or Pt. The activity of the Pt-Ru(Ni deposits towards methanol oxidation (studied by slow potential sweep voltammetry is higher from that of the Pt(Ni deposit and of pure Pt; this enhancement is attributed both to the well-known Ru synergistic effect due to the presence of its oxides but also (based on the XPS findings to a modification effect of Pt electronic properties.

  4. Status of the development of RU-43 fuel at INR Pitesti

    Horhoianu, G.

    2008-01-01

    More than 50000 fuel bundles containing natural uranium fuel have been irradiated in the CANDU-6 reactors of Cernavoda-Romania NPP, with a very low defect rate, to a core-average discharge burnup of 170-190 Mwh/kgU. Recovered uranium (RU) is a by-product of many light-water reactor (LWR) fuel recycling programs. After fission products and plutonium (Pu) have been removed from spent LWR fuel, RU is left. A fissile content in the RU of 0.9 to 1.1% makes it impossible for reuse in an LWR without re-enrichment, but CANDU reactors have a sufficiently high neutron economy to use RU as fuel. RU from spent LWR fuel can be considered as a lower cost source of enrichment at the optimal enrichment level for CANDU fuel pellets. In Europe the feedstock of RU is approaching thousands tones and would provide sufficient fuel for hundreds CANDU-6 reactors years of operation. The use of RU fuel offers significant benefits to CANDU reactor operators. RU fuels improves fuel cycle economics by increasing the fuel burnup, which enables large cost reductions in fuel consumption and in spent fuel disposal. RU fuel offers enhanced operating margins that can be applied to increase reactor power. These benefits can be realized using existing fuel production technologies and practices, and with almost negligible changes to fuel receipt and handling procedures at the reactor. The application of RU fuel could be an important element in Cernavoda NPP. For this reason the Institute for Nuclear Research (INR), Pitesti has started a research programme aiming to develop a new fuel bundle RU-43 for extended burnup operation. The most relevant calculations performed on this fuel bundle design version are presented. Also, the stages of an experimental program aiming to verify the operating performance are briefly described in this paper. (orig.)

  5. Java and Mac OS X

    Davis, T Gene

    2010-01-01

    Learn the guidelines of integrating Java with native Mac OS X applications with this Devloper Reference book. Java is used to create nearly every type of application that exists and is one of the most required skills of employers seeking computer programmers. Java code and its libraries can be integrated with Mac OS X features, and this book shows you how to do just that. You'll learn to write Java programs on OS X and you'll even discover how to integrate them with the Cocoa APIs.: Shows how Java programs can be integrated with any Mac OS X feature, such as NSView widgets or screen savers; Re

  6. OS X Mavericks for dummies

    LeVitus, Bob

    2013-01-01

    Coast through OS X Mavericks with help from Dr. Mac and For Dummies Ready to make friends with Mavericks? Then, Dr. Mac's your man. Author and longtime Mac guru, Bob "Dr. Mac" LeVitus shares his witty insights and helpful tips in this full-color update to his bestselling OS X guide. You'll learn the basics of working with the Dock, Launchpad, and Mission Control before moving on to setting up your e-mail, surfing with Safari, organizing your files, and customizing OS X Mavericks for all you need your Mac to do. Familiarizes you with OS X essentials like navigating the desktop, connecting to

  7. Adsorption of n-butane on graphene/Ru(0001)—A molecular beam scattering study

    Sivapragasam, Nilushni; Nayakasinghe, Mindika T.; Burghaus, Uwe, E-mail: uwe.burghaus@ndsu.edu [Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108 (United States)

    2016-07-15

    Adsorption kinetics/dynamics of n-butane on graphene, physical vapor deposited on Ru(0001) (hereafter G/Ru), and bare Ru(0001) (hereafter Ru) are discussed. The chemical activity of the supported-graphene as well as the support was probed by thermal desorption spectroscopy (adsorption kinetics). In addition and to the best of our knowledge, for the first time, molecular beam scattering data of larger molecules were collected for graphene (probing the adsorption dynamics). Furthermore, samples were inspected by x-ray photoelectron spectroscopy and Auger electron spectroscopy. At the measuring conditions used here, n-butane adsorption kinetics/dynamics are molecular and nonactivated. Binding energies of butane on Ru and G/Ru are indistinguishable within experimental uncertainty. Thus, G/Ru is “kinetically transparent.” Initial adsorption probabilities, S{sub 0}, of n-butane decrease with increasing impact energy (0.76–1.72 eV) and are adsorption temperature independent for both Ru and G/Ru, again consistent with molecular adsorption. Also, S{sub 0} of Ru and G/Ru are indistinguishable within experimental uncertainty. Thus, G/Ru is “dynamically transparent.” Coverage dependent adsorption probabilities indicate precursor effects for graphene/Ru.

  8. Adsorption of n-butane on graphene/Ru(0001)—A molecular beam scattering study

    Sivapragasam, Nilushni; Nayakasinghe, Mindika T.; Burghaus, Uwe

    2016-01-01

    Adsorption kinetics/dynamics of n-butane on graphene, physical vapor deposited on Ru(0001) (hereafter G/Ru), and bare Ru(0001) (hereafter Ru) are discussed. The chemical activity of the supported-graphene as well as the support was probed by thermal desorption spectroscopy (adsorption kinetics). In addition and to the best of our knowledge, for the first time, molecular beam scattering data of larger molecules were collected for graphene (probing the adsorption dynamics). Furthermore, samples were inspected by x-ray photoelectron spectroscopy and Auger electron spectroscopy. At the measuring conditions used here, n-butane adsorption kinetics/dynamics are molecular and nonactivated. Binding energies of butane on Ru and G/Ru are indistinguishable within experimental uncertainty. Thus, G/Ru is “kinetically transparent.” Initial adsorption probabilities, S 0 , of n-butane decrease with increasing impact energy (0.76–1.72 eV) and are adsorption temperature independent for both Ru and G/Ru, again consistent with molecular adsorption. Also, S 0 of Ru and G/Ru are indistinguishable within experimental uncertainty. Thus, G/Ru is “dynamically transparent.” Coverage dependent adsorption probabilities indicate precursor effects for graphene/Ru.

  9. Particle size dependence of CO tolerance of anode PtRu catalysts for polymer electrolyte fuel cells

    Yamanaka, Toshiro; Takeguchi, Tatsuya; Wang, Guoxiong; Muhamad, Ernee Noryana; Ueda, Wataru

    An anode catalyst for a polymer electrolyte fuel cell must be CO-tolerant, that is, it must have the function of hydrogen oxidation in the presence of CO, because hydrogen fuel gas generated by the steam reforming process of natural gas contains a small amount of CO. In the present study, PtRu/C catalysts were prepared with control of the degree of Pt-Ru alloying and the size of PtRu particles. This control has become possible by a new method of heat treatment at the final step in the preparation of catalysts. The CO tolerances of PtRu/C catalysts with the same degree of Pt-Ru alloying and with different average sizes of PtRu particles were thus compared. Polarization curves were obtained with pure H 2 and CO/H 2 (CO concentrations of 500-2040 ppm). It was found that the CO tolerance of highly dispersed PtRu/C (high dispersion (HD)) with small PtRu particles was much higher than that of poorly dispersed PtRu/C (low dispersion (LD)) with large metal particles. The CO tolerance of PtRu/C (HD) was higher than that of any commercial PtRu/C. The high CO tolerance of PtRu/C (HD) is thought to be due to efficient concerted functions of Pt, Ru, and their alloy.

  10. X-ray Lβ215 emission spectrum of Ru in Ru(NH3)6Cl3

    Perera, R.C.C.; Barth, J.; LaVilla, R.E.; Nordling, C.

    1984-07-01

    One of the broader applications of synchrotron radiation has been to EXAFS studies for material structure determination, i.e., for an analysis of x-ray absorption over an extended energy region beyond a core ionization limit. Studies of the near edge structure (XANES) give a different type of information, characteristic of the local symmetry and electronic configuration of the absorbing atom. This type of information is reflected also in the x-ray emission spectra, in particular for transitions involving the valence levels. Examination of the near edge absorption or the emission spectrum does not require an instrument capable of scanning a wide energy range with high counting statistics, as does EXAFS; the needs are rather for good resolution and a reliable calibration of the energy scale. Some of the problems of near edge spectra were particularly evident in our investigation of Ru-Lβ 2 15 emission from Ru(NH 3 ) 6 Cl 3 . The Ru-Lβ 2 15 emission was measured with a laboratory Rowland circle x-ray spectrometer with a curved quartz (1010) crystal (radius = 22 inches) in a fixed position appropriate to the energy range, and a position sensitive detector which can be positioned along the Rowland circle. The Ru spectrum was excited mainly by Sn-L/sub α/ primary radiation from a Sn anode in a demountable x-ray tube operating at 13 kV and 120 mA. The resolution of the instrument in this region is 1.5 eV. An accurate calibration of the energy scale was conveniently obtained by measuring a reference x-ray emission line in the same instrumental configuration. In the present case the Pd-L/sub α/ emission line at 2838 eV was used to establish the energy scale. The energy dispersion of the instrument was determined from the Cl-K/sub β/ emission spectrum of CH 3 Cl between 2810 eV and 2830 eV and Pd-Lα 1 2 and extrapolated to the energy region of the recorded emission spectrum. 6 references, 1 figure

  11. Synthesis, structure, and electronic properties of a dimer of Ru(bpy)2 doubly bridged by methoxide and pyrazolate.

    Jude, Hershel; Rein, Francisca N; White, Peter S; Dattelbaum, Dana M; Rocha, Reginaldo C

    2008-09-01

    The heterobridged dinuclear complex cis,cis-[(bpy) 2Ru(mu-OCH 3)(mu-pyz)Ru(bpy) 2] (2+) ( 1; bpy = 2,2'-bipyridine; pyz = pyrazolate) was synthesized and isolated as a hexafluorophosphate salt. Its molecular structure was fully characterized by X-ray crystallography, (1)H NMR spectroscopy, and ESI mass spectrometry. The compound 1.(PF 6) 2 (C 44H 38F 12N 10OP 2Ru 2) crystallizes in the monoclinic space group P2 1/ c with a = 13.3312(4) A, b = 22.5379(6) A, c = 17.2818(4) A, beta = 99.497(2) degrees , V = 5121.3(2) A (3), and Z = 4. The meso diastereoisomeric form was exclusively found in the crystal structure, although the NMR spectra clearly demonstrated the presence of two stereoisomers in solution (rac and meso forms at approximately 1:1 ratio). The electronic properties of the complex in acetonitrile were investigated by cyclic voltammetry and UV-vis and NIR-IR spectroelectrochemistries. The stepwise oxidation of the Ru (II)-Ru (II) complex into the mixed-valent Ru (II)-Ru (III) and fully oxidized Ru (III)-Ru (III) states is fully reversible on the time scale of the in situ (spectro)electrochemical measurements. The mixed-valent species displays strong electronic coupling, as evidenced by the large splitting between the redox potentials for the Ru(III)/Ru(II) couples (Delta E 1/2 = 0.62 V; K c = 3 x 10 (10)) and the appearance of an intervalence transfer (IT) band at 1490 nm that is intense, narrow, and independent of solvent. Whereas this salient band in the NIR region originates primarily from highest-energy of the three IT transitions predicted for Ru(II)-Ru(III) systems, a weaker absorption band corresponding to the lowest-energy IT transition was clearly evidenced in the IR region ( approximately 3200 cm (-1)). The observation of totally coalesced vibrational peaks in the 1400-1650 cm (-1) range for a set of five bpy spectator vibrations in Ru (II)-Ru (III) relative to Ru (II)-Ru (II) and Ru (III)-Ru (III) provided evidence for rapid electron transfer and

  12. Thiolato-bridged RuIIAgIRuII trinuclear complex composed of bis(bipyridine)ruthenium(II) units with chelating 2-aminoethanethiolate: conversion to a disulfide-bridged RuIIRuII dinuclear complex.

    Tamura, Motoshi; Matsuura, Noriyuki; Kawamoto, Tatsuya; Konno, Takumi

    2007-08-20

    The reaction of [Ru(solvent)2(bpy)2]2+ (bpy = 2,2'-bipyridine) with Haet (2-aminoethanethiol) in ethanol/water in the presence of Ag+ gave a thiolato-bridged RuIIAgIRuII trinuclear complex, [Ag{Ru(aet)(bpy)2}2]3+, in which two [RuII(aet)(bpy)2]+ units are linked by an AgI atom. When this complex was treated with HCl in acetonitrile/water, a disulfide-bridged RuIIRuII dinuclear complex, [Ru2(cysta)(bpy)4]4+ (cysta = cystamine), was produced as a result of the removal of an AgI atom and the autoxidation of thiolato groups. It was found that the dinuclear structure in [Ru2(cysta)(bpy)4]4+ is reverted back to [Ag{Ru(aet)(bpy)2}2]3+ by treatment with Ag+ assisted by Zn reduction.

  13. All Pseudocapacitive MXene-RuO2 Asymmetric Supercapacitors

    Jiang, Qiu

    2018-01-23

    2D transition metal carbides and nitrides, known as MXenes, are an emerging class of 2D materials with a wide spectrum of potential applications, in particular in electrochemical energy storage. The hydrophilicity of MXenes combined with their metallic conductivity and surface redox reactions is the key for high-rate pseudocapacitive energy storage in MXene electrodes. However, symmetric MXene supercapacitors have a limited voltage window of around 0.6 V due to possible oxidation at high anodic potentials. In this study, the fact that titanium carbide MXene (Ti3C2Tx) can operate at negative potentials in acidic electrolyte is exploited, to design an all-pseudocapacitive asymmetric device by combining it with a ruthenium oxide (RuO2) positive electrode. This asymmetric device operates at a voltage window of 1.5 V, which is about two times wider than the operating voltage window of symmetric MXene supercapacitors, and is the widest voltage window reported to date for MXene-based supercapacitors. The complementary working potential windows of MXene and RuO2, along with proton-induced pseudocapacitance, significantly enhance the device performance. As a result, the asymmetric devices can deliver an energy density of 37 µW h cm−2 at a power density of 40 mW cm−2, with 86% capacitance retention after 20 000 charge–discharge cycles. These results show that pseudocapacitive negative MXene electrodes can potentially replace carbon-based materials in asymmetric electrochemical capacitors, leading to an increased energy density.

  14. Schweizer RU-38A Twin-Condor: covert surveillance aircraft

    O'Toole, Michael J.; Schweizer, Paul H.

    1997-11-01

    The world order has changed and with it, governments are now faced with waging a new type of `ware.' Regional instability, drug trafficking, environmental issues, international terrorism, and illegal immigration are examples of escalating problems that cross international boundaries and threaten the security of nations. The first and most important element in coping with these illegal activities is the ability to detect and monitor events in a timely and secure fashion. Conventional means of gathering intelligence such as large airborne collection systems and satellites lack the flexibility, dwell times, and cost effectiveness to meet many of today's needs. There is a growing requirement for airborne platforms that can covertly perform surveillance missions during either day or night and in a cost effective manner. To meet this need, Schweizer Aircraft has recently developed the RU-38A twin-engine surveillance aircraft. This paper discusses the evolution and principle design concepts of this aircraft and how its unique performance enables the RU-38A to achieve new levels of surveillance capability.

  15. Magnetic Phase Diagram of α-RuCl3

    Sears, Jennifer; Kim, Young-June; Zhao, Yang; Lynn, Jeffrey

    The layered honeycomb material α-RuCl3 is thought to possess unusual magnetic interactions including a strong bond-dependent Kitaev term, offering a potential opportunity to study a material near a well understood spin liquid phase. Although this material orders magnetically at low temperatures and is thus not a realization of a Kitaev spin liquid, it does show a broad continuum of magnetic excitations reminiscent of that expected for the spin liquid phase. It has also been proposed that a magnetic field could destabilize the magnetic order in this material and induce a transition into a spin liquid phase. Low temperature magnetization and specific heat measurements in this material have suggested a complex magnetic phase diagram with multiple unidentified magnetic phases present at low temperature. This has provided motivation for our work characterizing the magnetic transitions and phase diagram in α-RuCl3. I will present detailed bulk measurements combined with magnetic neutron diffraction measurements to map out the phase diagram and identify the various phases present.

  16. Density of states in Mo-Ru amorphous alloys

    Miyakawa, W.

    1985-01-01

    The density of states is calculated for several compositions of amorphous Mo 1-x Ru x . In order to simulate amorphous clusters, the structures (atomic positions) utilized in the calculations were built from a small dense randomly packed unit of hard spheres with periodic boundary conditions. The density of states is calculated from a tight-binding Hamiltonian with hopping integrals parametrized in terms of the ddσ, ddΠ and ddδ molecular integrals. The results for pure Mo and pure Ru, compared in the canonical band aproximation, agree well with the literature. For binary alloys, the comparison of the calculated density of states with the rigid band aproximation results indicates that a more complex approach than the rigid band model must be used, even when the two atoms have similar bands, with band centers at nearly the same energy. The results also indicate that there is no relation between the peak in the superconducting critical temperature as a function of the number of valence eletrons per atom (e/a) in the region near Mo(e/a=6) and the peak of the density of states at the Fermi level in the same region, as has been sugested by some authors. (Author) [pt

  17. Roussel-Uclaf to transfer RU 486 rights.

    1997-04-18

    On April 8, the German pharmaceutical firm Hoechst, under pressure from anti-abortion groups that were boycotting its new allergy medication, Allegra, announced the transfer of the patent rights for the abortifacient mifepristone (RU-486), from Roussel-Uclaf, its subsidiary, to Dr. Edouard Sakiz, a former executive who had been involved in the development of the drug. Dr. Sakiz has established a new company, Exelgyn, to market the drug, which, due to strict company guidelines, is currently available only in France, Sweden, and the United Kingdom. Residency requirements prevent women from traveling to these countries for treatment. Other countries desiring access to RU-486 must meet standards established by Dr. Sakiz: the government must make a formal request and provide a secure means of distribution and good follow-up care. A European manufacturer or distributor has not yet been found. In the United States, the Population Council, a nonprofit organization, has been licensed to manufacture and distribute the drug; it should be available to the general public by the end of this year. Anti-abortion groups continue to boycott all Hoechst products. The Allegra boycott was launched with an April 2 press conference; the groups, which include the National Right to Life Committee, bought full-page ads in "USA Today" and "The Washington Post."

  18. Low leakage Ru-strontium titanate-Ru metal-insulator-metal capacitors for sub-20 nm technology node in dynamic random access memory

    Popovici, M., E-mail: Mihaela.Ioana.Popovici@imec.be; Swerts, J.; Redolfi, A.; Kaczer, B.; Aoulaiche, M.; Radu, I.; Clima, S.; Everaert, J.-L.; Van Elshocht, S.; Jurczak, M. [Imec, Leuven 3001 (Belgium)

    2014-02-24

    Improved metal-insulator-metal capacitor (MIMCAP) stacks with strontium titanate (STO) as dielectric sandwiched between Ru as top and bottom electrode are shown. The Ru/STO/Ru stack demonstrates clearly its potential to reach sub-20 nm technology nodes for dynamic random access memory. Downscaling of the equivalent oxide thickness, leakage current density (J{sub g}) of the MIMCAPs, and physical thickness of the STO have been realized by control of the Sr/Ti ratio and grain size using a heterogeneous TiO{sub 2}/STO based nanolaminate stack deposition and a two-step crystallization anneal. Replacement of TiN with Ru as both top and bottom electrodes reduces the amount of electrically active defects and is essential to achieve a low leakage current in the MIM capacitor.

  19. Partitioning of rhodium and ruthenium between Pd–Rh–Ru and (Ru,Rh)O{sub 2} solid solutions in high-level radioactive waste glass

    Sugawara, Toru, E-mail: toru@gipc.akita-u.ac.jp [Center for Engineering Science, Akita University, 1-1, Tegatagakuenmachi, Akita City, Akita 010-8502 (Japan); Ohira, Toshiaki [Center for Engineering Science, Akita University, 1-1, Tegatagakuenmachi, Akita City, Akita 010-8502 (Japan); Komamine, Satoshi; Ochi, Eiji [Research and Development Department, Reprocessing Business Division, Japan Nuclear Fuel Limited, 4-108, Okitsuke, Obuchi, Rokkasho-mura, Aomori 039-3212 (Japan)

    2015-10-15

    The partitioning of rhodium and ruthenium between Pd–Rh–Ru alloy with a face-centered cubic (FCC) structure and (Ru,Rh)O{sub 2} solid solution has been investigated between 1273 and 1573 K at atmospheric oxygen fugacity. The rhodium and ruthenium contents in FCC increase, while the RhO{sub 2} content in (Ru,Rh)O{sub 2} decreases with increasing temperature due to progressive reduction of the system. Based on the experimental results and previously reported thermodynamic data, the thermodynamic mixing properties of FCC phase and (Ru,Rh)O{sub 2} have been calibrated in an internally consistent manner. Phase equilibrium of platinum grope metals in an HLW glass was calculated by using the obtained thermodynamic parameters.

  20. Thermodynamics of oxygen solutions in Fe-40% Ni-15% Cr melts containing Mn, Si, Ti, Al

    Dashevskij, V.Ya.; Makarova, N.N.; Grigorovich, K.V.; Kashin, V.I.; Polikarpova, N.V.

    2000-01-01

    Thermodynamic analysis and experimental studied are performed for oxygen solutions in Fe-40% Ni-15% Cr melts where Mn, Si, Ti, Al are used as reducing agents. It is revealed that in the alloys studied the affinity of reducing agents to oxygen essentially lower than in liquid iron, nickel and Fe-40% Ni alloy. This is explained by the fact that the oxygen activity in melts noticeably decreases due to a high chromium content whereas the activity of reducing elements increases in a rather less degree. The agreement between analytical and experimental results confirms the validity of the calculation technique [ru

  1. Crystal growth and properties of PbI2 doped with Fe and Ni

    Rybak, O.V.; Lun', Yu.O.; Bordun, I.M.; Omelyan, M.F.

    2005-01-01

    A procedure is described for doping PbI 2 monocrystals with Fe and Ni during vapor-phase growth in a closed system in the presence of excess iodine. The rate of mass transfer in the system and the doping level of the crystals are shown to be governed by the dopant content in the source material and the source temperature. The effect of Fe and Ni doping on the low-temperature (5 K) exciton photoluminescence spectrum of PbI 2 is discussed [ru

  2. PtRu colloid nanoparticles for CO oxidation in microfabricated reactors

    Klerke, Asbjørn; Saadi, Souheil; Toftegaard, Maja Bøg

    2006-01-01

    The catalytic activity of PtRu colloid nanoparticles for CO oxidation is investigated in microfabricated reactors. The measured catalytic performance describes a volcano curve as a function of the Pt/Ru ratio. The apparent activation energies for the different alloy catalysts are between 21 and 1...

  3. Originating relation studies on ancient porcelains of chines Ru and Jun by NAA

    Zhao Weijuan; Xie Jianzhong; Gao Zhengyao; Li Guoxia; Li Rongwu; Zhang Bin

    2002-01-01

    50 samples of glazes and bodies of the ancient Chinese Ru porcelain, Jun porcelain and imitative ancient ceramics were analyzed by neutron activation analysis (NAA). The contents of 36 elements in each sample were measured. The NAA data were statistically treated by fuzzy cluster method and the trend cluster diagram was obtained. Their classes and raw material sources were determined. The results show that although these samples spanned hundreds of years, came from different kilns and had different glazes colors, the bodies of the ancient Chinese Ru porcelain and Jun porcelain belong to the same kind, the glazes of the ancient Chinese Ru porcelain is similar to the glazes of the ancient Chinese Jun porcelain. The originating places of the body raw material were concentrated, and that of the glaze raw materials were scattered, the source of the glaze raw material covered that the body raw material. The ancient Chinese Ru porcelain and Jun porcelain have basically the same raw material sources and the sources of raw material are stable in long time. It is found that most modern Jun porcelain samples are similar to the ancient Chinese Jun porcelain. Two modern Ru porcelain samples are similar to the ancient Chinese Ru porcelain, but another one drifts apart from the ancient Chinese Ru porcelain. Jingdezhen porcelain has no relation to Ru porcelain and Jun porcelain

  4. Scattering of hyperthermal argon atoms from clean and D-covered Ru surfaces

    Ueta, H.; Gleeson, M.A.; Kleyn, A.W.

    2011-01-01

    Hyperthermal Ar atoms were scattered from a Ru(0001) surface held at temperatures of 180, 400 and 600 K, and from a Ru(0001)-(1×1)D surface held at 114 and 180 K. The resultant angular intensity and energy distributions are complex. The in-plane angular distributions have narrow (FWHM ≤ 10°)

  5. Transfer from soil to plants of 106Ru as nitrosyl and as chloride

    Handl, J.

    1988-01-01

    The transfer of 106 Ru in a soil-plant ecosystem was investigated with respect to two chemical forms in compact soil samples under greenhouse conditions with surface and deep-layer contamination. Considerable differences in the uptake of 106 Ru were observed between 106 RuCl3 and 106 Ru-nitrosyl during the first 5-8 wk after the contamination of the soil. The translocation of 106 Ru in the soil showed an inhomogeneous distribution of the radioruthenium, with a great part of the total activity remaining in the upper soil layer between 0 and 5 cm even 10 mo after contamination of the soil surface. During the whole experiment, reemission of 106 Ru into the air was investigated by using special air collectors under different temperature and light conditions. Although a continuous checking out for a time of about 8 mo, no measurable concentrations of 106 Ru could be out for a time of about 8 mo, no measurable concentrations of 106 Ru could be found in examined air filters

  6. Transfer and accumulation of 106Ru from phytoplankton (Dunaliella bioculata) to zooplankton (Artemia salina)

    Izumo, Yoshiro; Takase, Akira

    1982-01-01

    106 Ru is one of the most abundant radionuclides to be released from the unclear-spent fuel reprocessing plant to oceans. This paper deals with transfer and accumulation of the radionuclide from phytoplankton (Dunaliella) to zooplankton (Artemia) in the graizing food chain of marine organisms. Each plankton was reared in the radioactive sea water A (filtrated and circulated through sandy mud, and the radioactive concentration decreased and atteined to constant after addition of 106 Ru), B (not filtrated and circulated, and the radioactive concentration decreased and atteined to constant) and C (not filtrated and circulated, the radioactive concentration decreased, but did not attein to constant), respectively, and investigated accumulations of 106 Ru. Then, accumulations of 106 Ru in Artemia by the ingestion of each diet (Dunaliella) contaminated with 106 Ru in each water, were investigated and compared with those from each water. Concentration factors of 106 Ru for the planktons reared in the radioactive sea waters were different among these waters. The difference can be attributable to that of physicochemical states of 106 Ru in the waters. It was found that 106 Ru would be accumulated by Artemia from the water A about 10 times higher than from the contaminated diet (Dunaliella) in this water, however from the contaminated diet (Dunaliella) in the water B about 2.2 times higher than from the last water. (author)

  7. Preparation and characterization of RuO2/polypyrrole electrodes for supercapacitors

    Li, Xiang; Wu, Yujiao; Zheng, Feng; Ling, Min; Lu, Fanghai

    2014-11-01

    Polypyrrole (PPy) embedded RuO2 electrodes were prepared by the composite method. Precursor solution of RuO2 was coated on tantalum sheet and annealed at 260 °C for 2.5 h to develop a thin film. PPy particles were deposited on RuO2 films and dried at 80 °C for 12 h to form composite electrode. Microstructure and morphology of RuO2/PPy electrode were characterized using Fourier transform infrared spectrometer, X-ray diffraction and scanning electron microscopy, respectively. Our results confirmed that counter ions are incorporated into RuO2 matrix. Structure of the composite with amorphous phase was verified by X-ray diffraction. Analysis by scanning electron microscopy reveals that during grain growth of RuO2/PPy, PPy particle size sharply increases as deposition time is over 20 min. Electrochemical properties of RuO2/PPy electrode were calculated using cyclic voltammetry. As deposition times of PPy are 10, 20, 25 and 30 min, specific capacitances of composite electrodes reach 657, 553, 471 and 396 F g-1, respectively. Cyclic behaviors of RuO2/PPy composite electrodes are stable.

  8. Substrate-mediated enhanced activity of Ru nanoparticles in catalytic hydrogenation of benzene

    Liu, Xin; Meng, Changgong; Han, Yu

    2012-01-01

    . The stability of Ru 13 nanoparticles is enhanced by the defective graphene substrate due to the hybridization between the dsp states of the Ru 13 particle with the sp 2 dangling bonds at the defect sites. The local curvature formed at the interface will also

  9. Investigation of superhalogen behaviour of RuFn (n= 1–7) clusters ...

    2016-08-26

    Aug 26, 2016 ... In the present investigation, interaction of ruthenium (Ru) atoms with fluorine (F) atoms was studied using the density functional theory utilizing B3LYP method. It was found that up to seven F atoms can bind to a single Ru atom which results in increase of electron affinities successively, reaching a peak ...

  10. Hybridization and magnetism in U(Ru, Rh)X, X=Al, Ga

    Sechovsky, V.; Havela, L.; Boer, de F.R.; Veenhuizen, P.A.; Sugiyama, K.; Kuroda, T.; Sugiura, T.; Ono, M.; Date, M.; Yamagishi, A.

    1992-01-01

    Results of magnetic studies of pseudoternary U(Ru, Rh)Al and U(Ru, Rh)Ga systems are presented. Reduction of the 5f-4d hybridization with increasing Rh content is reflected in a gradual transition from paramagnetic (spin fluctuation) behaviour of URuX to ferromagnetism in URhX. The huge uniaxial

  11. Electrocatalytic activity of atomic layer deposited Pt–Ru catalysts onto N-doped carbon nanotubes

    Johansson, Anne-Charlotte Elisabeth Birgitta; Larsen, Jackie Vincent; Verheijen, Marcel A.

    2014-01-01

    (ethylcyclopentadienyl)ruthenium (Ru(EtCp)2), respectively. O2 was used as the reactant in both processes. The composition of the catalysts was easily tuned by varying the Pt-to-Ru ALD cycle ratio. The catalysts were tested toward the CO oxidation and methanol oxidation reaction (MOR) in a three-electrode electrochemical set...

  12. Selective liquid phase hydrogenation of furfural to furfuryl alcohol by Ru/Zr-MOFs

    Yuan, Q.; Zhang, D.; Haandel, van L.; Ye, F.; Xue, T.; Hensen, E.J.M.; Guan, Y.

    2015-01-01

    Selective hydrogenation of furfural to furfuryl alcohol under mild conditions was evaluated over Ru nanoparticles supported on a series of zirconium based metal organic frameworks (UiO-66, UiO-67, Zr6-NDC, MIL-140A, MIL-140B, and MIL-140C). The particle size and oxidation state of Ru in the

  13. Investigation of Novel Electrocatalysts for Metal Supported Solid Oxide Fuel Cells - Ru:GDC

    Sudireddy, Bhaskar Reddy; Nielsen, Jimmy; Thydén, Karl Tor Sune

    2015-01-01

    The electrochemical performance and stability of the planar metal supported solid oxide fuel cells (MS-SOFC) with two different electrocatalytically active materials, namely, Ni:GDC and Ru:GDC were investigated. Ru:GDC with an ASR of 0.322 Ωcm2 performed better than Ni:GDC with an ASR of 0.453 Ωc...

  14. Study on provenance of Ru porcelain in yanhedian kiln and official jun porcelain by EDXRF

    Li Guoxia; Guo Min; Zhao Weijuan; Sun Hongwei; Gao Zhengyao; Xie Jianzhong; Wen Chang; Wang Chuan; Li Rongwu; Guo Peiyu; Yang Dawei

    2010-01-01

    To understand the provenance relationship of Ru porcelain in Yanhedian kiln and official Jun porcelain , with energy dispersive x-ray fluorescence spectrometer (EDXRF) measured 56 Ru porcelain in Yanhedian kiln and official Jun porcelain samples of chemical composition of the main volume, analysis results show: Yanhedian kiln Ru porcelain bodies Al 2 O 3 average content Outpaces official Jun porcelain bodies, SiO 2 , K 2 O average below official Jun porcelain bodies; Yanhedian kiln Ru porcelain glazes Al 2 O 3 average content Outpaces official Jun porcelain glaze, SiO 2 , CaO average significantly lower than Jun glaze, two primary body and glaze on porcelain to chemical composition of the averages vary. A display of the peacekeeping two-dimensional scatter analysis supplies of official Jun porcelain bodies focused, Yanhedia kiln Ru porcelain bodies birth supplies comparatively, Jun and Yanhedian kiln Ru porcelain bodies material habitats near but not identical. The official Jun porcelain glazes origin focused, glaze formula changes less, and Yanhedia kiln Ru porcelain glazes origin and formula are scattered. Therefore, Yanhedian kiln Ru porcelain samples and the Official Jun porcelain samples can be commendably differentiated by EDXRF testing and chemical composition scatter analysis. (authors)

  15. Ab-initio calculations of electric field gradient in Ru compounds and ...

    For 3 / 2 + , the quadrupole moment of the first excited state in 99 Ru is obtained as +0.203(3) b, which is considerably lower than the commonly accepted literature value of +0.231(12) b. The results presented in this paper would be useful for the precise determination of quadrupole moment of high spin states in other Ru ...

  16. Lutidine-derived Ru-CNC hydrogenation pincer catalysts with versatile coordination properties

    Filonenko, Georgy A.; Cosimi, Elena; Lefort, Laurent; Conley, Matthew P.; Copéret, Christophe; Lutz, Martin; Hensen, Emiel J M; Pidko, Evgeny A.

    2014-01-01

    Lutidine-derived bis-N-heterocyclic carbene (NHC) ruthenium CNC-pincer complexes (Ru-CNC's) were prepared. Depending on the synthetic procedure, normal (1, 2) or mixed normal/abnormal NHC-complexes (3) are formed. In the presence of phosphazene base, Ru-CNC complexes activate nitriles to give

  17. Enhanced thermal stability of RuO2/polyimide interface for flexible device applications

    Music, Denis; Schmidt, Paul; Chang, Keke

    2017-09-01

    We have studied the thermal stability of RuO2/polyimide (Kapton) interface using experimental and theoretical methods. Based on calorimetric and spectroscopic analyses, this inorganic-organic system does not exhibit any enthalpic peaks as well as all bonds in RuO2 and Kapton are preserved up to 500 °C. In addition, large-scale density functional theory based molecular dynamics, carried out in the same temperature range, validates the electronic structure and points out that numerous Ru-C and a few Ru-O covalent/ionic bonds form across the RuO2/Kapton interface. This indicates strong adhesion, but there is no evidence of Kapton degradation upon thermal excitation. Furthermore, RuO2 does not exhibit any interfacial bonds with N and H in Kapton, providing additional evidence for the thermal stability notion. It is suggested that the RuO2/Kapton interface is stable due to aromatic architecture of Kapton. This enhanced thermal stability renders Kapton an appropriate polymeric substrate for RuO2 containing systems in various applications, especially for flexible microelectronic and energy devices.

  18. Hydrothermal Synthesis of Co-Ru Alloy Particle Catalysts for Hydrogen Generation from Sodium Borohydride

    Marija Kurtinaitienė

    2013-01-01

    Full Text Available We report the synthesis of μm and sub-μm-sized Co, Ru, and Co-Ru alloy species by hydrothermal approach in the aqueous alkaline solutions (pH ≥ 13 containing CoCl2 and/or RuCl3, sodium citrate, and hydrazine hydrate and a study of their catalytic properties for hydrogen generation by hydrolysis of sodium borohydride solution. This way provides a simple platform for fabrication of the ball-shaped Co-Ru alloy catalysts containing up to 12 wt% Ru. Note that bimetallic Co-Ru alloy bowls containing even 7 at.% Ru have demonstrated catalytic properties that are comparable with the ones of pure Ru particles fabricated by the same method. This result is of great importance in view of the preparation of cost-efficient catalysts for hydrogen generation from borohydrides. The morphology and composition of fabricated catalyst particles have been characterized using scanning electron microscopy, energy dispersive X-ray diffraction, and inductively coupled plasma optical emission spectrometry.

  19. Synthesis of Ru/PDMS nano-composites via supercritial deposition

    Ge, Minglan [Dept. of Chemical Engineering, Beijing Institute of Petrochemical Technology, Beijing 102617 (China); Bozbag, Selmi E. [Dept. of Chemical and Biological Engineering, Koç University, 34450 Sariyer, Istanbul (Turkey); Ayala, Christian J.; Aindow, Mark [Department of Materials Science and Engineering, Institute of Materials Science, University of Connecticut, Storrs, CT 06269 (United States); Erkey, Can, E-mail: cerkey@ku.edu.tr [Dept. of Chemical and Biological Engineering, Koç University, 34450 Sariyer, Istanbul (Turkey); Koç University TÜPRAŞ Energy Center (KUTEM), Koç University, 34450 Sariyer, Istanbul (Turkey)

    2016-09-01

    Nanomaterials consisting of Ru nanoparticles dispersed in polydimethylsiloxane films were synthesized by supercritical deposition. The films were impregnated with the organometallic precursor bis(2,2,6,6-tetramethyl-3,5-heptanedionato) (1,5-cyclooctadiene) ruthenium (II) under thermodynamic control in the presence of supercritical carbon dioxide (scCO{sub 2}) at 40 °C and 10.34 MPa. The precursor molecules were then converted to metallic Ru by thermal treatment in flowing N{sub 2} at ambient pressure, resulting in well-dispersed nanoparticles with diameters of ≈2 nm. - Highlights: • PDMS-Ru nanoparticle composites were prepared using supercritical deposition. • PDMS-Ru nanoparticle composites were prepared without using an immobilization agent. • PDMS films were impregnated with Ru(cod)(tmhd){sub 2} in supercritical CO{sub 2}. • The impregnated Ru(cod)(tmhd){sub 2} was then reduced to metallic Ru in flowing N{sub 2}. • The resulting Ru nanoparticles were well-dispersed and had diameters of ≈2 nm.

  20. Influence of Binders and Solvents on Stability of Ru/RuOx Nanoparticles on ITO Nanocrystals as Li-O2 Battery Cathodes.

    Vankova, Svetoslava; Francia, Carlotta; Amici, Julia; Zeng, Juqin; Bodoardo, Silvia; Penazzi, Nerino; Collins, Gillian; Geaney, Hugh; O'Dwyer, Colm

    2017-02-08

    Fundamental research on Li-O 2 batteries remains critical, and the nature of the reactions and stability are paramount for realising the promise of the Li-O 2 system. We report that indium tin oxide (ITO) nanocrystals with supported 1-2 nm oxygen evolution reaction (OER) catalyst Ru/RuO x nanoparticles (NPs) demonstrate efficient OER processes, reduce the recharge overpotential of the cell significantly and maintain catalytic activity to promote a consistent cycling discharge potential in Li-O 2 cells even when the ITO support nanocrystals deteriorate from the very first cycle. The Ru/RuO x nanoparticles lower the charge overpotential compared with those for ITO and carbon-only cathodes and have the greatest effect in DMSO electrolytes with a solution-processable F-free carboxymethyl cellulose (CMC) binder (ITO nanocrystalline materials in DMSO provide efficient Li 2 O 2 decomposition from within the cathode during cycling. We demonstrate that the ITO is actually unstable from the first cycle and is modified by chemical etching, but the Ru/RuO x NPs remain effective OER catalysts for Li 2 O 2 during cycling. The CMC binders avoid PVDF-based side-reactions and improve the cyclability. The deterioration of the ITO nanocrystals is mitigated significantly in cathodes with a CMC binder, and the cells show good cycle life. In mixed DMSO-EMITFSI [EMITFSI=1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide] ionic liquid electrolytes, the Ru/RuO x /ITO materials in Li-O 2 cells cycle very well and maintain a consistently very low charge overpotential of 0.5-0.8 V. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Crystal structure of a mononuclear Ru(II) complex with a back-to-back terpyridine ligand: [RuCl(bpy)(tpy-tpy)](.).

    Rein, Francisca N; Chen, Weizhong; Scott, Brian L; Rocha, Reginaldo C

    2015-09-01

    We report the structural characterization of [6',6''-bis-(pyridin-2-yl)-2,2':4',4'':2'',2'''-quaterpyridine](2,2'-bi-pyridine)-chlorido-ruthenium(II) hexa-fluorido-phosphate, [RuCl(C10H8N2)(C30H20N6)]PF6, which contains the bidentate ligand 2,2'-bi-pyridine (bpy) and the tridendate ligand 6',6''-bis-(pyridin-2-yl)-2,2':4',4'':2'',2'''-quaterpyridine (tpy-tpy). The [RuCl(bpy)(tpy-tpy)](+) monocation has a distorted octa-hedral geometry at the central Ru(II) ion due to the restricted bite angle [159.32 (16)°] of the tridendate ligand. The Ru-bound tpy and bpy moieties are nearly planar and essentially perpendicular to each other with a dihedral angle of 89.78 (11)° between the least-squares planes. The lengths of the two Ru-N bonds for bpy are 2.028 (4) and 2.075 (4) Å, with the shorter bond being opposite to Ru-Cl. For tpy-tpy, the mean Ru-N distance involving the outer N atoms trans to each other is 2.053 (8) Å, whereas the length of the much shorter bond involving the central N atom is 1.936 (4) Å. The Ru-Cl distance is 2.3982 (16) Å. The free uncoordinated moiety of tpy-tpy adopts a trans,trans conformation about the inter-annular C-C bonds, with adjacent pyridyl rings being only approximately coplanar. The crystal packing shows significant π-π stacking inter-actions based on tpy-tpy. The crystal structure reported here is the first for a tpy-tpy complex of ruthenium.

  2. OsWRKY74, a WRKY transcription factor, modulates tolerance to phosphate starvation in rice.

    Dai, Xiaoyan; Wang, Yuanyuan; Zhang, Wen-Hao

    2016-02-01

    The WRKY transcription factor family has 109 members in the rice genome, and has been reported to be involved in the regulation of biotic and abiotic stress in plants. Here, we demonstrated that a rice OsWRKY74 belonging to group III of the WRKY transcription factor family was involved in tolerance to phosphate (Pi) starvation. OsWRKY74 was localized in the nucleus and mainly expressed in roots and leaves. Overexpression of OsWRKY74 significantly enhanced tolerance to Pi starvation, whereas transgenic lines with down-regulation of OsWRKY74 were sensitive to Pi starvation. Root and shoot biomass, and phosphorus (P) concentration in rice OsWRKY74-overexpressing plants were ~16% higher than those of wild-type (WT) plants in Pi-deficient hydroponic solution. In soil pot experiments, >24% increases in tiller number, grain weight and P concentration were observed in rice OsWRKY74-overexpressing plants compared to WT plants when grown in P-deficient medium. Furthermore, Pi starvation-induced changes in root system architecture were more profound in OsWRKY74-overexpressing plants than in WT plants. Expression patterns of a number of Pi-responsive genes were altered in the OsWRKY74-overexpressing and RNA interference lines. In addition, OsWRKY74 may also be involved in the response to deficiencies in iron (Fe) and nitrogen (N) as well as cold stress in rice. In Pi-deficient conditions, OsWRKY74-overexpressing plants exhibited greater accumulation of Fe and up-regulation of the cold-responsive genes than WT plants. These findings highlight the role of OsWRKY74 in modulation of Pi homeostasis and potential crosstalk between P starvation and Fe starvation, and cold stress in rice. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  3. Intramolecular electron transfer in cyanide bridged adducts comprising Ru(II)/Ru(III) tetracarboxylate and [Mn(I)(CO)(CN)((t)BuNC)(4)] units.

    Imhof, Wolfgang; Sterzik, Anke; Krieck, Sven; Schwierz, Markus; Hoffeld, Thomas; Spielberg, Eike T; Plass, Winfried; Patmore, Nathan

    2010-07-21

    Reaction of mixed valence ruthenium tetracarboxylates [Ru(2)(II,III)(R(1)COO)(2)(R(2)COO)(2)Cl] (R(1) = Me, R(2) = 2,4,6-(i)Pr-Ph or R(1) = R(2) = (t)Bu) with two equivalents of the octahedral manganese complex [Mn(I)(CO)(CN)((t)BuNC)(4)] leads to the formation of cyanide bridged heteronuclear coordination compounds of the general formula {[Ru(2)(II,III)(R(1)COO)(2)(R(2)COO)(2)][Mn(I)(CO)(CN)((t)BuNC)(4)](2)}Cl. In solution an intramolecular electron transfer from manganese towards the multiply bonded Ru(2) core occurs that is verified by EPR and IR spectroscopy, magnetic measurements and DFT calculations. Nevertheless, disproportionation of an initially formed {Mn(I)-Ru(2)(II,III)-Mn(I)}(+) adduct into {Mn(II)-Ru(2)(II,III)-Mn(I)}(2+) and {Mn(I)-Ru(2)(II,II)-Mn(I)} species cannot be completely ruled out.

  4. The Ruthenostannylene Complex [Cp*(IXy)H2 Ru-Sn-Trip]: Providing Access to Unusual Ru-Sn Bonded Stanna-imine, Stannene, and Ketenylstannyl Complexes.

    Liu, Hsueh-Ju; Ziegler, Micah S; Tilley, T Don

    2015-05-26

    Reactivity studies of the thermally stable ruthenostannylene complex [Cp*(IXy)(H)2 Ru-Sn-Trip] (1; IXy=1,3-bis(2,6-dimethylphenyl)imidazol-2-ylidene; Cp*=η(5) -C5 Me5 ; Trip=2,4,6-iPr3 C6 H2 ) with a variety of organic substrates are described. Complex 1 reacts with benzoin and an α,β-unsaturated ketone to undergo [1+4] cycloaddition reactions and afford [Cp*(IXy)(H)2 RuSn(κ(2) -O,O-OCPhCPhO)Trip] (2) and [Cp*(IXy)(H)2 RuSn(κ(2) -O,C-OCPhCHCHPh)Trip] (3), respectively. The reaction of 1 with ethyl diazoacetate resulted in a tin-substituted ketene complex [Cp*(IXy)(H)2 RuSn(OC2 H5 )(CHCO)Trip] (4), which is most likely a decomposition product from the putative ruthenium-substituted stannene complex. The isolation of a ruthenium-substituted stannene [Cp*(IXy)(H)2 RuSn(=Flu)Trip] (5) and stanna-imine [Cp*(IXy)(H)2 RuSn(κ(2) -N,O-NSO2 C6 H4 Me)Trip] (6) complexes was achieved by treatment of 1 with 9-diazofluorene and tosyl azide, respectively. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Crystal structures of bromo- and iododerivatives of ruthenium nitroso complexes K2[RuNOX5

    Mikhajlov, Yu.N.; Kanishcheva, A.S.; Svetlov, A.A.

    1989-01-01

    Method of X-ray diffraction analysis was used to interpret crystal structure of ruthenium pentahalogenonitroso complexes: K 2 [RuNOBr 5 ] (1) and K 2 [RuOI 5 ] (2). Crystals belong to rhombic syngony, sp.gr. Pcmn. Lattice parameters: (1) - a 7.236(2), b = 10.791(2), c = 13.949(3) A, V = 1089.14(1) A 3 , Z = 4; (2) - a = 7.755(1), b = 11.506(6), c = 14.951(5) A, V 133.97(8) A 3 , Z = 4. It was revealed that lengths of Ru-Br equatorial bonds in (1) exceeded the axial ones, and in the compound (2) the reverse relation was observed. The obtained results were correlated with the structural data for K 2 [RuNOF 5 ]H 2 O and K 2 [RuNOCl 5 ] complexes and similar osmium compounds

  6. Ambipolar thermoelectric power of chemically-exfoliated RuO2 nanosheets

    Kim, Jeongmin; Yoo, Somi; Moon, Hongjae; Kim, Se Yun; Ko, Dong-Su; Roh, Jong Wook; Lee, Wooyoung

    2018-01-01

    The electrical conductivity and Seebeck coefficient of RuO2 nanosheets are enhanced by metal nanoparticle doping using Ag-acetate solutions. In this study, RuO2 monolayer and bilayer nanosheets exfoliated from layered alkali metal ruthenates are transferred to Si substrates for device fabrication, and the temperature dependence of their conductivity and Seebeck coefficients is investigated. For pristine RuO2 nanosheets, the sign of the Seebeck coefficient changes with temperature from 350-450 K. This indicates that the dominant type of charge carrier is dependent on the temperature, and the RuO2 nanosheets show ambipolar carrier transport behavior. By contrast, the sign of the Seebeck coefficient for Ag nanoparticle-doped RuO2 nanosheets does not change with temperature, indicating that the extra charge carriers from metal nanoparticles promote n-type semiconductor behavior.

  7. Characterisation and catalytic properties of Ni, Co, Ce and Ru nanoparticles in mesoporous carbon spheres

    Barros, Francisco A. A. [Universidade Federal do Ceara, Departamento de Quimica Analitica e Fisico-Quimica, Langmuir Lab de Adsorcao e Catalise (Brazil); Castro, Antonio J. R.; Filho, Josue M. [Universidade Federal do Ceara, Departamento de Fisica (Brazil); Viana, Bartolomeu C. [Universidade Federal do Piaui, Departamento de Fisica (Brazil); Campos, Adriana [CETENE Av. Prof. Luiz Freire, Cidade Universitaria (Brazil); Oliveira, Alcineia C., E-mail: alcineia@ufc.br [Universidade Federal do Ceara, Departamento de Quimica Analitica e Fisico-Quimica, Langmuir Lab de Adsorcao e Catalise (Brazil)

    2012-09-15

    Ni, Co, Ce and Ru nanoparticles were inserted into templated carbon using a nanocasting technique and evaluated for the dehydration of glycerol. NiO and CeO{sub 2} preferentially yielded 5 nm uniformly sized particles that filled the mesoporous carbon via a geometric confinement effect. Ru generated Ru{sup o} and RuO{sub 2} nanoparticles that selectively migrated towards the carbon surface and did not undergo sintering, whereas Co nanoparticles containing CoO and Co{sub 3}O{sub 4} showed the opposite behaviour. The stabilising effects of the Ce and Ru nanoparticles on the carbon matrix effectively prevented the aggregation of small particles, resulting in superior catalytic performance in glycerol dehydration.

  8. Electronic-level interactions of tungsten oxide with unsupported Se/Ru electrocatalytic nanoparticles

    Lewera, Adam; Miecznikowski, Krzysztof [Department of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw (Poland); Hunger, Ralf [Institute of Materials Science, Darmstadt University of Technology, Darmstadt (Germany); Kolary-Zurowska, Aneta [Department of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw (Poland); Wieckowski, Andrzej [Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL (United States); Kulesza, Pawel J., E-mail: pkulesza@chem.uw.edu.p [Department of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw (Poland)

    2010-11-01

    Se/Ru nanoparticles - a potent non-platinum catalyst towards oxygen reduction reaction - were modified by hydrated WO{sub 3} and investigated using the rotating disk/ring electrode methods and by synchrotron X-ray photoelectron spectroscopy. The modification resulted in an enhanced catalytic activity towards oxygen reduction reaction (ORR). Our data indicate that the oxygen reduction current starts ca. 70 mV more positive and formation of undesirable hydrogen peroxide has significantly decreased following the modification of Se/Ru with WO{sub 3}. X-ray photoelectron spectroscopy reveals that WO{sub 3} interacts electronically with Se/Ru as the W 4f and Se 3d line-shapes change. We therefore conclude that the electronic interactions between Se/Ru and WO{sub 3} are primarily responsible for the increase in activity and selectivity of the WO{sub 3}-modified Se/Ru towards ORR.

  9. Electronic-level interactions of tungsten oxide with unsupported Se/Ru electrocatalytic nanoparticles

    Lewera, Adam; Miecznikowski, Krzysztof; Hunger, Ralf; Kolary-Zurowska, Aneta; Wieckowski, Andrzej; Kulesza, Pawel J.

    2010-01-01

    Se/Ru nanoparticles - a potent non-platinum catalyst towards oxygen reduction reaction - were modified by hydrated WO 3 and investigated using the rotating disk/ring electrode methods and by synchrotron X-ray photoelectron spectroscopy. The modification resulted in an enhanced catalytic activity towards oxygen reduction reaction (ORR). Our data indicate that the oxygen reduction current starts ca. 70 mV more positive and formation of undesirable hydrogen peroxide has significantly decreased following the modification of Se/Ru with WO 3 . X-ray photoelectron spectroscopy reveals that WO 3 interacts electronically with Se/Ru as the W 4f and Se 3d line-shapes change. We therefore conclude that the electronic interactions between Se/Ru and WO 3 are primarily responsible for the increase in activity and selectivity of the WO 3 -modified Se/Ru towards ORR.

  10. Core-level binding energy shifts in Pt Ru nanoparticles: A puzzle resolved

    Lewera, Adam; Zhou, Wei Ping; Hunger, Ralf; Jaegermann, Wolfram; Wieckowski, Andrzej; Yockel, Scott; Bagus, Paul S.

    2007-10-01

    Synchrotron measurements of Pt and Ru core-level binding energies, BE's, in Pt-Ru nanoparticles, as a function of Pt content, quantify earlier indications that the Pt 4f BE shift is much larger than the Ru 3d BE shift. A complementary theoretical analysis relates the BE shifts to changes in the metal-metal distances as the composition of the nanoparticle changes. We establish that the large Pt and small Ru BE shifts arise from the different response of these metals to changes in the bond distances, an unexpected result. Our results give evidence that the magnitudes of the BE shifts depend on whether the d band is open, as for Ru, or essentially filled, as for Pt.

  11. Uso de agregado leve de EVA em contrapiso argamassado para isolamento ao ruído de impacto em edificações residenciais

    Tutikian, Bernardo Fonseca; Zuchetto, Letícia Kauer; Souza, Rodrigo Périco de; Oliveira, Maria Fernanda Nunes de

    2017-01-01

    Resumo O copolímero etileno acetato de vinila (EVA) é largamente utilizado na indústria calçadista. Entretanto, a geração de resíduos no processo de fabricação é bastante significativa. Com a implementação da norma de desempenho, NBR 15575, os projetos de construções habitacionais devem atender aos níveis de desempenho exigidos. Dentre os requisitos prescritos pela norma está a isolação ao ruído de impacto entre pisos, a qual pode ser otimizada com a utilização de materiais de baixa massa esp...

  12. Efeito do ruído na voz de educadoras de instituições de educação infantil

    Simões-Zenari, Marcia; Bitar, Mariangela Lopes; Nemr, Nair Katia

    2012-01-01

    OBJETIVO: Avaliar a associação entre níveis de ruído presentes em centros de educação infantil e alterações vocais em educadoras. MÉTODOS: Estudo transversal com 28 educadoras de três instituições de educação infantil de São Paulo, SP, em 2009. Os níveis de pressão sonora foram mensurados segundo a Associação Brasileira de Normas Técnicas, com uso de medidor de nível de pressão sonora. As médias foram classificadas de acordo com os níveis de conforto, desconforto e dano auditivo propostos pel...

  13. Synthesis and characterization of bimetallic metal-organic framework Cu-Ru-BTC with HKUST-1 structure.

    Gotthardt, Meike A; Schoch, Roland; Wolf, Silke; Bauer, Matthias; Kleist, Wolfgang

    2015-02-07

    The bimetallic metal-organic framework Cu-Ru-BTC with the stoichiometric formula Cu2.75Ru0.25(BTC)2·xH2O, which is isoreticular to HKUST-1, was successfully prepared in a direct synthesis using mild reaction conditions. The partial substitution of Cu(2+) by Ru(3+) centers in the paddlewheel structure and the absence of other Ru-containing phases was proven using X-ray absorption spectroscopy.

  14. Removal of emerging pollutants by Ru/TiO2-catalyzed permanganate oxidation.

    Zhang, Jing; Sun, Bo; Xiong, Xinmei; Gao, Naiyun; Song, Weihua; Du, Erdeng; Guan, Xiaohong; Zhou, Gongming

    2014-10-15

    TiO2 supported ruthenium nanoparticles, Ru/TiO2 (0.94‰ as Ru), was synthesized to catalyze permanganate oxidation for degrading emerging pollutants (EPs) with diverse organic moieties. The presence of 1.0 g L(-1) Ru/TiO2 increased the second order reaction rate constants of bisphenol A, diclofenac, acetaminophen, sulfamethoxazole, benzotriazole, carbamazepine, butylparaben, diclofenac, ciprofloxacin and aniline at mg L(-1) level (5.0 μM) by permanganate oxidation at pH 7.0 by 0.3-119 times. The second order reaction rate constants of EPs with permanganate or Ru/TiO2-catalyzed permanganate oxidation obtained at EPs concentration of mg L(-1) level (5.0 μM) underestimated those obtained at EPs concentration of μg L(-1) level (0.050 μM). Ru/TiO2-catalyzed permanganate could decompose a mixture of nine EPs at μg L(-1) level efficiently and the second order rate constant for each EP was not decreased due to the competition of other EPs. The toxicity tests revealed that Ru/TiO2-catalyzed permanganate oxidation was effective not only for elimination of EPs but also for detoxification. The removal rates of sulfamethoxazole by Ru/TiO2-catalyzed permanganate oxidation in ten successive cycles remained almost constant in ultrapure water and slightly decreased in Songhua river water since the sixth run, indicating the satisfactory stability of Ru/TiO2. Ru/TiO2-catalyzed permanganate oxidation was selective and could remove selected EPs spiked in real waters more efficiently than chlorination. Therefore, Ru/TiO2-catalyzed permanganate oxidation is promising for removing EPs with electron-rich moieties. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Exposição ao ruído na indústria de transformação no Brasil Exposure to noise in the manufacturing industry in Brazil

    Franciana Cavalcante

    2013-01-01

    Full Text Available A exposição ao ruído no trabalho é o fator de risco modificável mais importante para a perda auditiva em adultos. Na indústria de transformação, a exposição a níveis elevados de pressão sonora afeta um grande número de trabalhadores. As normas brasileiras estabelecem como obrigatório, para todas as empresas, o monitoramento do ruído ocupacional e da condição auditiva dos trabalhadores, assim como garantias para a proteção do trabalhador. No entanto, a aplicação das normas é frágil e pouco se sabe sobre a distribuição de exposição ao ruído no País. Este estudo tem como objetivo investigar e sumarizar a distribuição da exposição ao ruído e do uso do equipamento de proteção auditiva entre trabalhadores da indústria de transformação no Brasil. A menor prevalência de exposição ao ruído dentre os ramos da indústria da transformação é de 45% e poucos são os dados sobre o uso do equipamento de proteção auditiva entre os trabalhadores expostos. Comparando-se os disponíveis para os diferentes ramos de atividade, a exposição ao ruído alcança níveis mais altos no ramo da fabricação de produtos de madeira, onde também se observa a menor proporção de uso do equipamento de proteção auditiva. A escassez de dados sobre as condições de trabalho, exposição ao ruído e proteção auditiva, limita os esforços em fazer com que a saúde auditiva seja incluída entre as prioridades da saúde pública no Brasil.Occupational noise exposure is the most important modifiable risk factor for hearing loss in adults. The manufacturing industry has elevated levels of noise exposure that affect a large number of workers. The Brazilian norms state that noise and hearing function must be monitored, along with safeguards to protect workers, these are compulsory for all companies. However norms enforcement is weak and little is known about noise exposure distribution in the country. The purpose of this study is to

  16. Derivation of the liquidus surface projection for the Al-Pt-Ru system from as-cast samples

    Prins, SN

    2005-11-10

    Full Text Available -rich corner. Two new ternary phases similar to Ru12Pt15Al73 and similar to Ru18Pt28Al64 were observed near the Al-corner. The similarity to Ru12Pt15Al73 phase has a primitive cubic structure, lattice parameter of similar to 0.7721 nm, and is stable to room...

  17. Tropanol esters of metallocene carboxylic acids. Syntheses, labelling with 103Ru and sup(103m)Rh and organ distribution

    Wenzel, M.; Wu, Y.

    1988-01-01

    The tropanol esters of the carboxylic acids of ferrocene, 103 Ru-ruthenocene and sup(103m)Rh-rhodocinium were synthezised. The organ distribution of the 103 Ru or sup(103m)Rh labelled tropanol-esters were investigated. Only the 103 Ru labelled ester showed a high heart/blood ratio. (author)

  18. Associação entre perda auditiva induzida pelo ruído e zumbidos Association between noise-induced hearing loss and tinnitus

    Adriano Dias

    2006-01-01

    Full Text Available O estudo verificou a associação entre perda auditiva induzida por ruído (PAIR e queixa de zumbido em trabalhadores expostos ao ruído ocupacional. Foram entrevistados e avaliados trabalhadores com histórico de exposição ao ruído ocupacional atendidos em dois ambulatórios de audiologia. Estudou-se a existência de associação entre PAIR e ocorrência de zumbido por intermédio do ajuste de modelo de regressão logística, tendo como variável dependente o zumbido e como variável independente a PAIR, classificada em seis graus, controlada pelas co-variáveis idade e tempo de exposição ao ruído. Os dados foram coletados entre abril e outubro de 2003, na Cidade de Bauru, Estado de São Paulo, Brasil, contemplando 284 trabalhadores. Estimou-se que a prevalência de zumbido aumenta de acordo com a evolução do dano auditivo, controlado para a idade e tempo de exposição ao ruído. Os achados justificam o investimento em programas de conservação auditiva particularmente voltados para o controle da emissão de ruídos na fonte e para a intervenção na evolução das perdas auditivas geradas pela exposição ao ruído visando à manutenção da saúde auditiva e à diminuição dos sintomas associados.The objective of this study was to verify an association between noise-induced hearing loss (NIHL and tinnitus in workers exposed to occupational noise. Workers with a history of work noise exposure who attended two audiology outpatient clinics were interviewed and evaluated. The statistical association between NIHL and tinnitus was evaluated using an adjusted linear regression model, with tinnitus as the dependent variable and NIHL, classified into six levels, as the independent variable, with age and length of noise exposure as covariates. Data were collected from 284 workers between April and October, 2003, in Bauru, São Paulo State, Brazil. Tinnitus was observed to increase with the progression of auditory damage, controlled by age

  19. Correlações entre ruído ambiental em sala de aula e voz do professor Correlations between classroom environmental noise and teachers' voice

    Rafaela Fernanda Guidini

    2012-12-01

    Full Text Available OBJETIVO: Identificar se existe correlação entre ruído ambiental no interior da sala de aula, intensidade da voz e presença de alteração vocal em professores. MÉTODOS: Foi realizada medição do ruído ambiental em dez salas de escolas municipais de ensino fundamental. A intensidade das vozes das professoras foi medida durante atividade de ensino. Amostras de vogal prolongada [é] e contagem de 1 a 20 emitidas pelas professoras foram analisadas utilizando escala GRBASI. Os resultados obtidos foram correlacionados. RESULTADOS: A média de ruído ambiental sem a presença das crianças em sala de aula variou de 40 a 51 dB(A e com a presença das crianças de 45 a 65 dB(A. Entre as professoras, houve 70% de ocorrência de vozes alteradas no grau geral (G e 90% com tensão na voz (S, variando entre graus discreto e moderado. Constatou-se variação entre 52 dB(A e 68 dB(A na intensidade da voz das professoras, atingindo 7,48 dB(A acima do nível do ruído ambiental. Houve correlação entre a intensidade vocal das professoras e ruído ambiental na presença das crianças durante a aula. CONCLUSÃO: Os níveis de ruído ambiental em sala de aula são altos e se correlacionam com o aumento da intensidade das vozes das professoras. Embora com alta ocorrência de vozes alteradas, não é possível correlacioná-las com o nível de ruído ambiental.PURPOSE: To explore the existence of correlations between environmental noise in classrooms, voice intensity and teacher's vocal problems. METHODS: Environmental noise was measured in 10 classrooms of municipal elementary schools; the intensity of teachers' voice was measured during teaching practice; teachers' speech samples containing emissions of sustained vowel [é] and counting from 1 to 20 were analyzed using the GRBASI protocol; and the results were tested for correlation. RESULTS: The average of environmental noise varied from 40 to 51 dB(A without the presence of children in the classroom, and

  20. Unconventional superconductivity in Sr{sub 2}RuO{sub 4}

    Liu, Ying [Department of Physics and Materials Research Institute, Pennsylvania State University, University Park, PA 16802 (United States); Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093 (China); Mao, Zhi-Qiang [Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118 (United States)

    2015-07-15

    Highlights: • Constraints on and experimental support to unconventional superconductivity in Sr{sub 2}RuO{sub 4}. • Phase-sensitive determination of the pairing symmetry in Sr{sub 2}RuO{sub 4}. • Response of superconductivity to mechanical perturbations. • Superconductivity in non-bulk Sr{sub 2}RuO{sub 4}. • Unresolved issues and outlook in Sr{sub 2}RuO{sub 4} research. - Abstract: Sr{sub 2}RuO{sub 4}, featuring a layered perovskite crystalline and quasi-two-dimensional electronic structure, was first synthesized in 1959. Unconventional, p-wave pairing was predicted for Sr{sub 2}RuO{sub 4} by Rice and Sigrist and Baskaran shortly after superconductivity in this material was discovered in 1994. Experimental evidence for unconventional superconductivity in Sr{sub 2}RuO{sub 4} has been accumulating in the past two decades and reviewed previously. In this article, we will first discuss constraints on the pairing symmetry of superconductivity in Sr{sub 2}RuO{sub 4} and summarize experimental evidence supporting the unconventional pairing symmetry in this material. We will then present several aspects of the experimental determination of the unconventional superconductivity in Sr{sub 2}RuO{sub 4} in some detail. In particular, we will discuss the phase-sensitive measurements that have played an important role in the determination of the pairing symmetry in Sr{sub 2}RuO{sub 4}. The responses of superconductivity to the mechanical perturbations and their implications on the mechanism of superconductivity will be discussed. A brief survey of various non-bulk Sr{sub 2}RuO{sub 4} will also be included to illustrate the many unusual features resulted from the unconventional nature of superconductivity in this material system. Finally, we will discuss some outstanding unresolved issues on Sr{sub 2}RuO{sub 4} and provide an outlook of the future work on Sr{sub 2}RuO{sub 4}.

  1. Methanol oxidation at carbon paste electrodes modified with (Pt–Ru)/carbon aerogels nanocomposites

    Fort, Carmen I., E-mail: iladiu@chem.ubbcluj.ro [Laboratory of Electrochemical Research and Nonconventional Materials, Babes-Bolyai University, Arany Janos 11, RO-400028, Cluj-Napoca (Romania); Cotet, Liviu C. [Laboratory of Electrochemical Research and Nonconventional Materials, Babes-Bolyai University, Arany Janos 11, RO-400028, Cluj-Napoca (Romania); Vasiliu, Florin [The National Institute of Materials Physics, Atomistilor str. 105 bis, PO Box MG. 7, Magurele, RO 077125, Bucharest (Romania); Marginean, Petre [National Institute for Research and Development of Isotopic and Molecular Technologies, RO 400293, Cluj-Napoca (Romania); Danciu, Virginia; Popescu, Ionel C. [Laboratory of Electrochemical Research and Nonconventional Materials, Babes-Bolyai University, Arany Janos 11, RO-400028, Cluj-Napoca (Romania)

    2016-04-01

    Mesoporous carbon aerogels (CAs) impregnated with (Pt–Ru) nanoparticles were prepared, incorporated into carbon paste electrodes (CPEs) and investigated as electrocatalysts for CH{sub 3}OH electro-oxidation. The sol–gel method, followed by supercritical drying with liquid CO{sub 2} and thermal pyrolysis in an inert atmosphere, was used to obtain high mesoporous CAs. (Pt–Ru)/CAs nanocomposites with various (Pt–Ru) loading were prepared by using Ru(AcAc){sub 3} and H{sub 2}PtCl{sub 6} as metal precursors and the impregnation method. The morpho-structural peculiarities of the so prepared (Pt–Ru)/CAs electrocatalysts were examined by using elemental analysis, N{sub 2} adsorption-desorption isotherms, transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), energy dispersive X-ray (EDX) and selected area electron diffraction (SAED). Cyclic voltammetry measurements, carried out at (Pt–Ru)/CA-CPEs incorporating nanocomposites with various Pt–Ru loading and different specific surface areas, showed that CA with the highest specific surface area (843 m{sup 2}/g) and impregnated with 6% (w/w) (Pt–Ru) nanoparticles exhibit the best CH{sub 3}OH electro-oxidation efficiency. The Michaelis–Menten formalism was used to describe the dependence of the oxidation peak current on the CH{sub 3}OH concentration, allowing the estimation of the modified electrodes sensitivities. Thus, for (Pt–Ru, 10%)/CA{sub 535}-CPE was observed the highest sensitivity (12.5 ± 0.8 mA/M) and, at the same time, the highest maximum current density ever reported (153.1 mA/cm{sup 2} for 2 M CH{sub 3}OH and an applied potential of 600 mV vs. SHE). - Highlights: • (Pt–Ru) nanoparticles were deposited on high mesoporous carbon aerogels (CAs). • (Pt–Ru)/CAs were characterized by TEM, EDX, SAED and N{sub 2} adsorption-desorption. • Carbon paste electrodes modified with (Pt–Ru)/CA were used for CH{sub 3}OH oxidation. • (Pt–Ru, 10

  2. 106Ru and 125I radiation dose rate gauge

    Machaj, B.; Swistowski, E.; Do Hoang Cuong

    2002-01-01

    Pulse count rate from plastic scintillator is a measure of the dose rate. Low dead time of measured channel and digital processing of measuring head signal with compensation of dead time enables correct registration of very high pulse count rate. The radiation source is set with an accuracy not worse than 0.1 mm in relation to the scintillator, and the movement of the source in horizontal and vertical direction is done with the accuracy of 0.01 mm. Additionally the gauge permits to measure the source activity and to check the uniform distribution of the radioactive material on the source surface. Random error due to pulse count rate fluctuation is negligible. The error due to instability of PTM gain is approx. 1,5% for 106 Ru and 5% for 125 I. (author)

  3. Oxygen chemisorption on a stepped Ru (approx.001) crystal

    Parrott, S.L.; Praline, G.; Koel, B.E.; White, J.M.; Taylor, T.N.

    1979-01-01

    The 300 K chemisorption of oxygen on a stepped Ru (approx.001) single crystal [17(001) x (100)] gives 2 x 2 complete half-order, 1 x 2 complete or incomplete half-order, and 1 x 1 integral-order LEED patterns depending on oxygen exposure and sample annealing. The corresponding relative AES oxygen signals are 0.25, 0.50, and 1.0, respectively. Under certain surface conditions, the presence of the steps is seen to break the threefold degenerate growth habit of 1 x 2 domains. The 1 x 1 pattern forms at 300 K only after lengthy exposure at relatively high pressure (10 -5 Torr) and is stable to 600 K. Prolonged exposure gives rise to relative AES oxygen signals greater than unity suggesting penetration into the subsurface region

  4. Supramolecular water oxidation with Ru-bda-based catalysts.

    Richmond, Craig J; Matheu, Roc; Poater, Albert; Falivene, Laura; Benet-Buchholz, Jordi; Sala, Xavier; Cavallo, Luigi; Llobet, Antoni

    2014-12-22

    Extremely slow and extremely fast new water oxidation catalysts based on the Ru-bda (bda=2,2'-bipyridine-6,6'-dicarboxylate) systems are reported with turnover frequencies in the range of 1 and 900 cycles s(-1) , respectively. Detailed analyses of the main factors involved in the water oxidation reaction have been carried out and are based on a combination of reactivity tests, electrochemical experiments, and DFT calculations. These analyses give a convergent interpretation that generates a solid understanding of the main factors involved in the water oxidation reaction, which in turn allows the design of catalysts with very low energy barriers in all the steps involved in the water oxidation catalytic cycle. We show that for this type of system π-stacking interactions are the key factors that influence reactivity and by adequately controlling them we can generate exceptionally fast water oxidation catalysts. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. AHP 44: Interview: FILMMAKER: GU RU 'PHRINS LAS1

    AHP

    2017-02-01

    Full Text Available Please introduce yourself. I am Gu ru 'phrin las, born in 1993 in Smin thang Township, Gjig sgril County, Mgo log (Guoluo Tibetan Autonomous Prefecture, Mtsho sngon (Qinghai Province, PR China. My family members are herders. My paternal grandmother (Ngang rus, 1923-2008 raised me. My family had neither a radio nor television, so Grandmother's folktales and stories about her childhood were the main form of entertainment for me. When I was six years old, Father began to teach me basic Tibetan and mathematics. I started school when I was eight years old. I later studied at Mgo log High School in Rta bo (Dawu, at Northwest Nationalities University in Lan gru (Lanzhou, and in Zhi an (Xi'an. My dream is to become a film director. ...

  6. OS X Mountain Lion bible

    Gruman, Galen

    2012-01-01

    The complete guide to Mac OS X, fully updated for the newest release! The Mac's solid, powerful operating system and the exploding popularity of iOS devices are fueling a strong increase in market share for Apple. Previous editions of this book have sold more than 75,000 copies, and this new edition is fully updated with all the exciting features of OS X Mountain Lion, including Game Center, Messages, and Notifications. Written by industry expert Galen Gruman, it covers all the basics and then delves deep into professional and higher-end topics, making it the one book you need to succeed with

  7. OS X Mavericks portable genius

    Spivey, Dwight

    2013-01-01

    Plenty of tips, tricks, and shortcuts help you make the most of Apple's newest OS X OS X Mavericks is Apple's newest operating system, with great new ways to enhance your digital lifestyle. This hip, straightforward guide focuses on helping you get everything you want from your Mac. You'll discover how to customize your computer and workspace, troubleshoot and maintain OS X, and have fun browsing and manipulating images and multimedia. You'll listen to music and podcasts, discover how to work with and connect peripherals, copy music to an iPod, add a printer, sync your Mac to other devices, an

  8. Lattice vibration spectra. 16

    Lutz, H.D.; Willich, P.

    1977-01-01

    The FIR absorption spectra of pyrite type compounds RuS 2 , RuSsub(2-x)Sesub(x), RuSe 2 , RuTe 2 , OsS 2 , OsSe 2 , and PtP 2 as well as loellingite type phosphides FeP 2 , RuP 2 , and OsP 2 are reported. For RuS 2 , RuSe 2 , RuTe 2 , OsS 2 , and PtP 2 all of the five infrared allowed modes (k = 0) are observed. As a first result of a numerical normal coordinate treatment vibration forms of pyrite structure are communicated. The spectra show that lattice forces of corresponding sulfides, tellurides, and phosphides are about the same strength, but increase strongly by substitution of iron by ruthenium and especially of ruthenium by osmium. The lattice constants of the RuSsub(2-x)Sesub(x) solid solution obey Vegard's rule. (author)

  9. Hipertensão arterial entre trabalhadores de petróleo expostos a ruído Arterial hypertension among oil-drilling workers exposed to noise

    Norma Suely Souto Souza

    2001-12-01

    Full Text Available Realizou-se um estudo transversal, com componente retrospectivo, buscando analisar a exposição ocupacional a ruído como possível fator de risco para a hipertensão arterial entre 775 trabalhadores de uma área de perfuração de petróleo. Considerou-se hipertensos os trabalhadores com pressão sangüínea > ou = 140/90mmHg. A exposição ocupacional a ruído foi avaliada através de dois indicadores: (1 exposição à pressão sonora > ou = 85dbA por 10 ou mais anos e (2 perda auditiva induzida pelo ruído (PAIR de moderada a severa. Os efeitos da idade, escolaridade, trabalho de turno e obesidade foram avaliados através de técnicas de estratificação e análise de regressão logística. Associação positiva entre exposição ocupacional a ruído e hipertensão arterial foi evidenciada, usando-se tanto nível/duração de exposição a ruído (RP = 1,8; IC 95%: 1,3-2,4, quanto diagnóstico de PAIR (RP = 1,5; IC 95%: 1,1-2,0 como indicadores de exposição. Considerados os limites do estudo, exposição ocupacional prolongada a ruído parece ser um fator de risco para a hipertensão arterial.A cross-sectional study with a retrospective component was conducted to evaluate occupational noise exposure as a potential risk factor for arterial hypertension among 775 workers from an oil-drilling industry. Hypertension was defined as > or = 140/90mmHg. Occupational noise exposure was measured as: (1 exposure to sound pressure levels > or = 85dbA for 10 years or more and (2 moderate-to-severe noise-induced hearing loss (NIHL. The effects of age, education, shift work, and obesity were evaluated by stratification and logistic regression analysis. A positive association between occupational noise exposure and hypertension was found, using both the level/duration of noise exposure (RP = 1.8; 95% CI: 1.3-2.4 and NIHL (RP = 1.5; 95% CI: 1.1-2.0 as exposure indicators. Considering the study limits, long-term occupational noise exposure thus appears to

  10. La circunferencia de la cintura en niños con sobrepeso y obesidad

    Jaime Pajuelo

    2004-09-01

    Full Text Available Objetivo: Determinar e identificar a los niños que tienen otro riesgo adicional, como es el aumento de la grasa visceral. Material y Métodos: El estudio se llevó a cabo en Centros Educativos Estatales del distrito de Uripa (Apurímac, Trujillo (La Libertad y Lima. La población estudiada fue de 1234 niños entre 6 a 10 años de edad. El 48,6% correspondió al género femenino. A todos los niños se les tomó las siguientes medidas: peso, talla y circunferencia de la cintura (CC. Con las primeras se calculó el índice de masa corporal (IMC. Los valores del IMC fueron analizados con la clasificación de Must y col, identificando el sobrepeso y la obesidad a todos aquellos cuyo IMC se encontrara entre el 85 y 95 y más de 95 percentil, respectivamente. Los valores de la CC fueron analizados con las tablas de Freedman y McCarthy. Resultados: La prevalencia de sobrepeso y obesidad fue 16,5 y 13,9%, respectivamente. El sobrepeso y obesidad, en su conjunto, disminuye conforme avanza la edad. El porcentaje de niños que tuvieron una CC por encima del 90 percentil se incrementó de acuerdo a la edad en que los niños presentaban sobrepeso y obesidad. El promedio de CC de todos los niños fue ligeramente mayor que la de los niños de EU de A y el RU. Conclusiones: Más de la mitad de los niños que tiene sobrepeso y obesidad presenta otro riesgo adicional, al tener la CC por encima de lo normal. Esta sumatoria de riesgos implicaría futuros problemas cardiovasculares, si no se toma las medidas correctivas inmediatamente.

  11. Preparation of supported PtRu/C electrocatalyst for direct methanol fuel cells

    Jiang Luhua; Sun Gongquan; Zhao Xinsheng; Zhou Zhenhua; Yan Shiyou; Tang Shuihua; Wang Guoxiong; Zhou Bing; Xin Qin

    2005-01-01

    In this work, high-surface supported PtRu/C were prepared with Ru(NO)(NO 3 ) 3 and [Pt(H 2 NCH 2 CH 2 NH 2 ) 2 ]Cl 2 as the precursors and hydrogen as a reducing agent. XRD and TEM analyses showed that the PtRu/C catalysts with different loadings possessed small and homogeneous metal particles. Even at high metal loading (40 wt.% Pt, 20 wt.% Ru) the mean metal particle size is less than 4 nm. Meanwhile, the calculated Pt crystalline lattice parameter and Pt (2 2 0) peak position indicated that the geometric structure of Pt was modified by Ru atoms. Among the prepared catalysts, the lattice parameter of 40-20 wt.% PtRu/C contract most. Cyclic voltammetry (CV), chronoamperometry (CA), CO stripping and single direct methanol fuel cell tests jointly suggested that the 40-20 wt.% PtRu/C catalyst has the highest electrochemical activity for methanol oxidation

  12. Thin RuO2 conducting films grown by MOCVD for microelectronic applications

    Froehlich, K.; Cambel, V.; Machajdik, D.; Pignard, S.; Baumann, P. K.; Lindner, J.; Schumacher, M.

    2002-01-01

    We have prepared thin RuO 2 films by MOCVD using thermal evaporation of Ru(thd) 2 (cod) solid precursor. The films were prepared at deposition temperatures between 250 and 500 grad C on silicon and sapphire substrates. Different structure was observed for the RuO 2 films on these substrates; the films on Si substrate were polycrystalline, while X-ray diffraction analysis revealed epitaxial growth of RuO 2 on sapphire substrates. Polycrystalline RuO 2 films prepared at temperatures below 300 grad C on Si substrate exhibit smooth surface and excellent step coverage. Highly conformal growth of the RuO 2 films at low temperature and low pressure results in nearly 100% step coverage for sub-mm features with 1:1 aspect ratio. Resistivity of the polycrystalline RuO 2 at room temperature ranged between 100 and 200 μ x Ω x cm. These films are suitable for CMOS and RAM applications. (Authors)

  13. Carbon monoxide oxidation on a Au(111 surface modified by spontaneously deposited Ru

    ROLF-JÜRGEN BEHM

    2001-04-01

    Full Text Available The spontaneous deposition of Ru on Au(111 was performed in 10-3 M RuCl3 + 0.5 M H2SO4 solution. The obtained surface was characterized by STM under potential control in 0.5 M H2SO4 solution. The coverage of the Au(111 terraces by deposited Ru was estimated by STM to be 0.02 ML. Step decoration could be noticed in the STM images, which indicates that the steps, as lined defects, are active sites for the nucleation of Ru monolayer islands, while the random distribution of Ru nuclei, observed on the terraces indicates point defects as active sites. The electrocatalytic activity of Au(111 surface modified by spontaneously deposited Ru was studied towards CO oxidation. The significant enhancement in the reaction rate compared to CO oxidation on a pure Au(111 surface, indicated that the edges of the deposited Ru islands were the active sites for the reaction.

  14. Pt-Ru nanoparticles supported on functionalized carbon as electrocatalysts for the methanol oxidation

    Salgado, J.R.C.; Fernandes, J.C.S.; Botelho do Rego, A.M.; Ferraria, A.M.; Duarte, R.G.; Ferreira, M.G.S.

    2011-01-01

    Highlights: → The functionalized carbon using acid solutions contains surface oxygenated groups. → Uniform dispersion of PtRu nanoparticles on the carbon surface was achieved. → Physical analysis showed the formation of PtRu alloy catalysts on functionalized carbon. → PtRu alloy catalysts on functionalized carbon enhanced the methanol oxidation rate. - Abstract: Platinum-ruthenium alloy electrocatalysts, for methanol oxidation reaction, were prepared on carbons thermally treated in helium atmosphere or chemically functionalized in H 2 O 2 , or in HNO 3 + H 2 SO 4 or in HNO 3 solutions. The functionalized carbon that is produced using acid solutions contains more surface oxygenated functional groups than carbon treated with H 2 O 2 solution or HeTT. The XRD/HR-TEM analysis have showed the existence of a higher alloying degree for Pt-Ru electrocatalysts supported on functionalized carbon, which present superior electrocatalytic performance, assessed by cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy, as compared to electrocatalysts on unfunctionalized carbon. It also was found that Pt-Ru alloy electrocatalysts on functionalized carbon improve the reaction rate compared to Pt-Ru on carbons treated with H 2 O 2 solution and thermally. A mechanism is discussed, where oxygenated groups generated from acid functionalization of carbon and adsorbed on Pt-Ru electrocatalysts are considered to enhance the electrocatalytic activity of the methanol oxidation reaction.

  15. Effects of composition on structure and activity of PtRu/C catalysts.

    Wiltshire, Richard J K; King, Colin R; Rose, Abigail; Wells, Peter P; Davies, Hazel; Hogarth, Martin P; Thompsett, David; Theobald, Brian; Mosselmans, Fredrick W; Roberts, Mark; Russell, Andrea E

    2009-04-07

    A series of carbon supported PtRu bimetallic catalysts with varying Pt:Ru ratio were prepared and characterised using ex situ and in situ XRD, in situ EXAFS at 0 V vs. RHE, ex situ XPS and monolayer CO stripping voltammetry. Although the catalysts were found to be well mixed/alloyed, with no evidence of unalloyed Ru (oxides) present, the surfaces of the electrocatalyst nanoparticles were found to be enriched with Pt compared to the nominal bulk composition. The methanol oxidation activities of the catalysts were determined in 1.0 mol dm(-3) H2SO4. In agreement with published studies of polycrystalline bulk PtRu alloys the catalyst with a 0.6 surface fraction of Pt was found to give the best methanol oxidation activity at 30 degrees C. However, at 80 degrees C a greater surface fraction of Ru could be tolerated, with some activity at low current densities found for a Pt surface fraction as low as 0.2. The results support the conclusion that a limited amount of methanol dehydrogenation occurs at Ru sites or Ru dominated surface ensembles at 80 degrees C.

  16. Spray pyrolysed Ru:TiO2 thin film electrodes prepared for electrochemical supercapacitor

    Fugare, B. Y.; Thakur, A. V.; Kore, R. M.; Lokhande, B. J.

    2018-04-01

    Ru doped TiO2 thin films are prepared by using 0.06 M aqueous solution of potassium titanium oxalate (pto), and 0.005 M aqueous solution of ruthenium tri chloride (RuCl3) precursors. The deposition was carried on stainless steel (SS) by using well known ultrasonic spray pyrolysis technique (USPT) at 723° K by maintaining the spray rate 12 cc/min and compressed air flow rate 10 Lmin-1. Prepared Ru:TiO2 thin films were characterized by structurally, morphologically and electrochemically. Deposited RuO2 shows amorphous structure and TiO2 shows tetragonal crystal structure with rutile as prominent phase at very low decomposition temperature. SEM micrographs of RuO2 exhibits porous, interconnected, spherical grains type morphology and TiO2 shows porous, nanorods and nanoplates like morphology and also Ru doped TiO2 shows porous, spherical, granular and nanorods type morphology. The electrochemical cyclic voltammetery shows mixed capacitive behavior. The achieved highest value of specific capacitance 2692 F/g was Ru doped TiO2 electrode in 0.5 M H2SO4.

  17. Estrogen and progesterone receptors in human decidua after RU486 treatment.

    Shi, W L; Wang, J D; Fu, Y; Zhu, P D

    1993-07-01

    To examine RU486 action on decidua at the level of cellular estrogen receptor (ER) and P receptor (PR). Controlled basic study for contragestion mechanism of mifepristone. Normal human volunteers in an academic research environment. Sixty women with 6 to 7 weeks of gestation who voluntarily requested termination of pregnancy were recruited and randomly divided into three groups. A single dose of 200 mg RU486 was orally administered to the two treatment groups 12 and 24 hours, respectively, before surgical interruption of pregnancies. Placebo was used for control group. Decidual tissues were collected right after operation. Immunocytochemical reactions of PR and ER in decidua after RU486 treatment were compared with the control subjects. The differences of the reaction in decidual area with or without trophoblast invasion were noted. RU486 treatment increased PR and ER staining in vessel and stroma of decidua without trophoblast invasion (decidua parietalis) but not in decidua with trophoblast invasion (decidua capsularis or basalis). Chi-squared analysis indicated a significant increase in the number of ER-positive samples after RU486 treatment. The decidua parietalis was the primary target site of RU486. The lack of RU486 effect on decidua capsularis implied that trophoblast invasion prevented against antiprogestin impact.

  18. Espaços Livres

    Silvio Soares Macedo

    1995-06-01

    Full Text Available O texto apresenta um painel sobre os conceitos básicos que dirigem o entendimento do paisagismo urbano, tendo como elemento de referência os espaços livres. Discute-se a questão das áreas verdes, das áreas de circulação, da qualificação dos espaços livres e da composição de suas estruturas morfológicas e de alguns dos principais padrões de organização espacial das cidades brasileiras contemporâneas - das quadras, jardins às áreas verticalizadas

  19. Local structure distortion induced by Ti dopants boosting the pseudocapacitance of RuO2-based supercapacitors

    Chen, I.-Li; Wei, Yu-Chen; Lu, Kueih-Tzu; Chen, Tsan-Yao; Hu, Chi-Chang; Chen, Jin-Ming

    2015-09-01

    Binary oxides with atomic ratios of Ru/Ti = 90/10, 70/30, and 50/50 were fabricated using H2O2-oxidative precipitation with the assistance of a cetyltrimethylammonium bromide (CTAB) template, followed by a thermal treatment at 200 °C. The characteristics of electron structure and local structure extracted from X-ray absorption spectroscopy (XAS) and transmission electron microscopy (TEM) analyses indicate that incorporation of Ti into the RuO2 lattice produces not only the local structural distortion of the RuO6 octahedra in (Ru-Ti)O2 with an increase in the central Ru-Ru distance but also a local crystallization of RuO2. Among the three binary oxides studied, (Ru70-Ti30)O2 exhibits a capacitance improvement of about 1.4-fold relative to the CTAB-modified RuO2, mainly due to the enhanced crystallinity of the distorted RuO6 structure rather than the surface area effect. Upon increasing the extent of Ti doping, the deteriorated supercapacitive performance of (Ru50-Ti50)O2 results from the formation of localized nano-clusters of TiO2 crystallites. These results provide insight into the important role of Ti doping in RuO2 that boosts the pseudocapacitive performance for RuO2-based supercapacitors. The present result is crucial for the design of new binary oxides for supercapacitor applications with extraordinary performance.Binary oxides with atomic ratios of Ru/Ti = 90/10, 70/30, and 50/50 were fabricated using H2O2-oxidative precipitation with the assistance of a cetyltrimethylammonium bromide (CTAB) template, followed by a thermal treatment at 200 °C. The characteristics of electron structure and local structure extracted from X-ray absorption spectroscopy (XAS) and transmission electron microscopy (TEM) analyses indicate that incorporation of Ti into the RuO2 lattice produces not only the local structural distortion of the RuO6 octahedra in (Ru-Ti)O2 with an increase in the central Ru-Ru distance but also a local crystallization of RuO2. Among the three binary

  20. Fri os fra det onde

    Frandsen, Johs. Nørregaard

    2009-01-01

    Anmeldelse af Ole Bordedals film: Fri os fra det onde. Filmen bruger provinsen som metafor for de menenskelige udkanter og eksistentielle randområder, ligesom han skildrer det ondes princip Udgivelsesdato: maj......Anmeldelse af Ole Bordedals film: Fri os fra det onde. Filmen bruger provinsen som metafor for de menenskelige udkanter og eksistentielle randområder, ligesom han skildrer det ondes princip Udgivelsesdato: maj...

  1. The electrocatalytic application of RuO2 in direct borohydride fuel cells

    Yang, Xiaodong; Wei, Xiaozhu; Liu, Ce; Liu, Yongning

    2014-01-01

    A high electrocatalytic activity of RuO 2 has been found for oxygen reduction reaction (ORR) in the cathode of direct borohydride fuel cells (DBFCs). The electron transfer number n during the ORR changes from 3.58 to 3.86 and the percentage of the intermediate product H 2 O 2 decreases from 20.8% to 7.2% correspondingly when the disk potential scans negatively from −0.39 V to −0.8 V versus Hg/HgO. Peak power densities of 425 mW cm −2 has been obtained at 60 °C, when RuO 2 has been used as a cathodic catalyst in DBFCs. RuO 2 displays low sensitivity to the BH 4 − oxidation in DBFCs. Moreover, RuO 2 , as a cathodic catalyst, demonstrates a superb stability during a 200-h durability test. The identical X-ray diffraction (XRD) patterns of the RuO 2 before and after the durability test also prove its stability. - Highlights: • RuO 2 exhibits oxygen reduction reaction (ORR) activity in an alkaline solution. • RuO 2 provides 3.58–3.86 electron transfer number during the ORR. • Direct borohydride fuel cell (DBFC) with RuO 2 cathode displays a peak power density of 425 mW cm −2 at 60 °C. • DBFC with RuO 2 cathode exhibits a superb stability during a 200-h durability test

  2. Effect of TiO_2 Loading on Pt-Ru Catalysts During Alcohol Electrooxidation

    Hasa, Bjorn; Kalamaras, Evangelos; Papaioannou, Evangelos I.; Vakros, John; Sygellou, Labrini; Katsaounis, Alexandros

    2015-01-01

    Highlights: • TiO_2 can be used to modify Pt-Ru based electrodes for alcohol oxidation. • TiO_2 modified electrodes with lower amount of metals had higher active surface area than pure Pt-Ru electrodes. • TiO_2 modified electrodes showed comparable performance with pure Pt-Ru electrode both in a single cell and in a PEM fuel cell under alcohol fuelling. - Abstract: In this study, Pt-Ru based electrodes modified by TiO_2 were prepared by means of thermal decomposition of chloride and isopropoxide precursors on Ti substrates, characterised by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), electrochemical techniques and CO stripping and used as anodes for alcohol oxidation. The minimization of the metal loading without electrocatalytic activity losses was also explored. TiO_2 was chosen due to its chemical stability, low cost and excellent properties as substrate for metal dispersion. It was found that TiO_2 loading up to 50% results in a 3-fold increase of the Electrochemically Active Surface (EAS). This conclusion has been confirmed by CO stripping experiments. All samples have been evaluated during the electrochemical oxidation of methanol, ethanol and glycerol. In all cases, the Pt_2_5-Ru_2_5-(TiO_2)_5_0 electrode had better electrocatalytic activity than the pure Pt_5_0-Ru_5_0 anode. The best modified electrode, (Pt_2_5-Ru_2_5-(TiO_2)_5_0), was also evaluated as anode in a PEM fuel cell under methanol fuelling conditions. The observed higher performance of the TiO_2 modified electrodes was attributed to the enhanced Pt-Ru dispersion as well as the formation of smaller Pt and Ru particles.

  3. Photoelectron diffraction of magnetic ultrathin films: Fe/Cu(001)

    Tobin, J.G. (Lawrence Livermore National Lab., CA (USA)); Wagner, M.K. (Wisconsin Univ., Madison, WI (USA). Dept. of Chemistry); Guo, X.Q.; Tong, S.Y. (Wisconsin Univ., Milwaukee, WI (USA). Dept. of Physics)

    1991-01-03

    The preliminary results of an ongoing investigation of Fe/Cu(001) are presented here. Energy dependent photoelectron diffraction, including the spin-dependent variant using the multiplet split Fe3s state, is being used to investigate the nanoscale structures formed by near-monolayer deposits of Fe onto Cu(001). Core-level photoemission from the Fe3p and Fe3s states has been generated using synchrotron radiation as the tunable excitation source. Tentatively, a comparison of the experimental Fe3p cross section measurements with multiple scattering calculations indicates that the Fe is in a fourfold hollow site with a spacing of 3.6{Angstrom} between it and the atom directly beneath it, in the third layer. This is consistent with an FCC structure. The possibility of utilizing spin-dependent photoelectron diffraction to investigate magnetic ultrathin films will be demonstrated, using our preliminary spectra of the multiplet-split Fe3s os near-monolayer Fe/Cu(001). 18 refs., 10 figs.

  4. Radiologic evaluation of os odontoideum

    Lee, Eun Ju; Chung, Tae Sub; Suh, Jung Ho; Kim, Dong Ik; Kim, Yong Soo; Park, Hyoung Chun; Oh, Soung Hoon [Yonsei University College of Medicine, Seoul (Korea, Republic of)

    1988-10-15

    We took an analysis on the clinical and radiologic findings of os odontoideum, which had been regarded as relatively uncommon disease, on 5 patients whom we have recently experienced. Our results were as follows: 1. Os odontoideums were incidentally discovered during the radiologic evaluation of traumatised 4 cases, who had been well being. Another one case of os odontoideum was associated with multiple epiphyseal dysplasia. 2. General radiologic findings of os odontoideum were a round or oval and hypoplastic ossicle separated from the base of odontoid process by wise gap. 3. Alanto-Axial instability was developed in 5 cases of os odontoideum by flexion and extension stress view of lateral cervical spine. 4. Flexion views of lateral cervical spine showed narrowing of anteroposterior diameter of spinal canal which were available at atlantoaxial level on 5 cases of os odontoidum. 5. CT myelogram and cervical myelogram showed anteriorly compressed dural sac and deformed spinal cord by body of axis at the atlanto-axial level.

  5. Isolation of high quality graphene from Ru by solution phase intercalation

    Koren, E.; Sutter, E.; Bliznakov, S.; Ivars-Barcelo, F.; Sutter, P.

    2013-09-01

    We introduce a method for isolating graphene grown on epitaxial Ru(0001)/α-Al2O3. The strong graphene/Ru(0001) coupling is weakened by electrochemically driven intercalation of hydrogen underpotentially deposited in aqueous KOH solution, which allows the penetration of water molecules at the graphene/Ru(0001) interface. Following these electrochemically driven processes, the graphene can be isolated by electrochemical hydrogen evolution and transferred to arbitrary supports. Raman and transport measurements demonstrate the high quality of the transferred graphene. Our results show that intercalation, typically carried out in vacuum, can be extended to solution environments for graphene processing under ambient conditions.

  6. Steam and CO2 reforming of methane over a Ru/ZrO2 catalyst

    Jakobsen, Jon Geest; Jørgensen, T.L.; Chorkendorff, Ib

    2010-01-01

    The kinetics of methane steam reforming over a Ru/ZrO2 catalyst was studied at 1.3 bar total pressure and in the temperature range 425-575 degrees C. These data were fitted by combining a reactor model with a series of kinetic models. The best fit was obtained by a model with methane dissociative...... adsorption as the rate limiting step and with CO and H adspecies partly blocking the active sites. The Ru/ZrO2 catalyst was characterized by TEM and H-2 chemisorption. By comparison of ex situ and in situ TEM, it is evident that Ru particles with diameters of...

  7. Challenges in bimetallic multilayer structure formation: Pt growth on Cu monolayers on Ru(0001)

    Mancera, Luis A.; Engstfeld, Albert Kilian; Bensch, Andreas

    2017-01-01

    In a joint experimental and theoretical study, we investigated the formation and morphology of PtCu/Ru(0001) bimetallic surfaces grown at room and higher temperatures under UHV conditions. We obtained the PtCu/Ru(0001) surfaces by deposition of Pt atoms on a previously created Cu/Ru(0001) structure...... which includes only one Cu monolayer. Bimetallic surfaces prepared at different Pt coverages are investigated using STM imaging, revealing the existence of reconstruction lines and Cu islands. Although primarily created Cu islands continue growing in size by increasing Pt coverage, a continuous...

  8. Orientation-Dependent Oxygen Evolution on RuO2 without Lattice Exchange

    Stoerzinger, Kelsey A.; Diaz-Morales, Oscar; Kolb, Manuel

    2017-01-01

    the potential involvement of lattice oxygen in the OER mechanism with online electrochemical mass spectrometry, which showed no evidence of oxygen exchange on these oriented facets in acidic or basic electrolytes. Similar results were obtained for polyoriented RuO2 films and particles, in contrast to previous...... work, suggesting lattice oxygen is not exchanged in catalyzing OER on crystalline RuO2 surfaces. This hypothesis is supported by the correlation of activity with the number of active Ru-sites calculated by density functional theory, where more active facets bind oxygen more weakly. This new...

  9. EDXRF analysis of Yanhedian Ru kiln and Jun official kiln porcelain

    Wen Chang; Zhao Huixian; Li Guoxia; Gao Zhengyao; Zhao Weijuan; Sun Hongwei; Guo Min; Xie Jianzhong; Li Rongwu; Guo Peiyu

    2009-01-01

    The chemical components of the body and glaze samples of some Ru porcelains from Yanhedian kiln and Jun official porcelains from Juntai kiln are determined by the technology of Energy Dispersive X-ray Fluorescence(EDXRF) in this work. The difference of the two kiln's glaze and body are analyzed by factor analysis method of Multi-dimensional statistical analysis. The results indicate that Yanhedian Ru porcelains can be well distinguished from Jun official porcelains from Juntai kiln. This evidence once again proves that Jun ceramics and Ru ceramics can be distinguished obviously. (authors)

  10. Epitaxial YBa2Cu3O7-δ/Sr2RuO4 heterostructures

    Schlom, D.G.; Merritt, B.A.; Madhavan, S.

    1997-01-01

    The anisotropic oxide superconductors YBa 2 Cu 3 O 7-δ and Sr 2 RuO 4 have been epitaxially combined in various ways (c-axis on c-axis, c-axis on a-axis, and a-axis on a-axis) though the use of appropriate substrates. Phase-pure a-axis oriented or c-axis oriented epitaxial Sr 2 RuO 4 films were grown by pulsed laser deposition. YBa 2 Cu 3 O 7-δ films were then grown on both orientations of Sr 2 RuO 4 films and the resulting epitaxy was characterized

  11. Perda auditiva induzida pelo ruído em trabalhadores de metalúrgica Noise induced hearing loss in metallurgical workers

    Simone Adad Araújo

    Full Text Available Introdução: A perda auditiva induzida pelo ruído é uma patologia insidiosa cumulativa, que cresce ao longo dos anos de exposição ao ruído associado ao ambiente de trabalho. Objetivos: Identificar e quantificar a ocorrência de alterações auditivas sugestivas de Perda Auditiva Induzida pelo Ruído e os principais sintomas otorrinolaringológicos referidos pelos trabalhadores. Forma de estudo: prospectivo clínico randomizado. Casuística e métodos: Pesquisa realizada no período de janeiro a março de 2000 com 187 trabalhadores de indústria metalúrgica no município de Goiânia, avaliados por médicos otorrinolaringologistas através de roteiro de entrevista e audiometria ocupacional. Resultados: Foram obtidas audiometrias ocupacionais sendo: 21% sugestivas de PAIR, 72%, normais e 7%, sugestivas de outras doenças auditivas. Os sintomas auditivos mais freqüentes foram: dificuldade de compreensão da fala, 12%; hipoacusia, 7%; tinitus, 13%; sensação de plenitude auricular, 4%; otorreia, 6%; tonturas, 12%. Conclusão: Concluímos que em metalúrgica há ocorrência de alterações auditivas sugestivas de Perda Auditiva Induzida pelo Ruído e queixa de sintomas otorrinolaringológicos significativos.Introduction: Noise induced hearing loss is a cumulative pathological disease that increases over the years with exposure to noise associated with the work atmosphere. Objectives: To identify and quantify the occurrence of hearing loss suggestive of Noise Induced Hearing Loss (NIHL and the principle otolaryngological symptoms referred to by workers. Study design: prospective clinical randomized. Material and method: Research was carried out from January to March of 2000 with 187 metallurgical workers in the city of Goiânia, who were evaluated by otolaryngologists by means of a combination of interviews and occupational hearing exams. Results: Occupational hearing tests results were: 21% suggestive of NIHL, 72% normal, and 7% suggestive of

  12. Exposição ocupacional ao ruído e acidentes do trabalho Occupational noise exposure and work accidents

    Adriano Dias

    2006-10-01

    Full Text Available O objetivo deste estudo foi verificar se a exposição ocupacional ao ruído é um fator de risco relevante para acidentes do trabalho na cidade de Piracicaba, São Paulo, Brasil. Foi realizado um estudo caso-controle de base hospitalar. Os casos foram 600 trabalhadores entre 15 e 60 anos que sofreram acidentes ocupacionais típicos entre maio e outubro de 2004, atendidos na Central de Ortopedia e Traumatologia de Piracicaba. Os controles foram 822 trabalhadores entre 15 e 60 anos que sofreram acidente não ocupacional e receberam o primeiro atendimento no serviço ou foram trabalhadores acompanhantes dos acidentados. Foi ajustado um modelo de regressão logística múltipla, tendo como variável independente o acidente do trabalho, controlada por co-variáveis de interesse, entre elas a exposição ao ruído. Estimou-se que o risco de sofrer acidente do trabalho é cerca de duas vezes maior entre trabalhadores expostos ao ruído, controlado para diversas co-variáveis. A exposição ocupacional ao ruído não só deteriora a saúde auditiva do trabalhador, mas também se constitui em fator de risco para acidentes do trabalho.The purpose of this study was to verify whether occupational noise exposure is a significant risk factor for work accidents in the city of Piracicaba, São Paulo State, Brazil. This hospital-based case-control study included 600 workers aged 15-60 who suffered typical occupational accidents between May and October 2004 and were seen at the Piracicaba Orthopedics and Trauma Center. The control group comprised 822 workers, aged 15-60, who were also seen at the Center, and either had a non-occupational accident or were accompanying someone who had suffered an accident. A multiple logistic regression model was adjusted with work accident as an independent variable, controlled by covariables of interest such as noise exposure. The risk of having a work accident was about twice as high among workers exposed to noise, after

  13. Intensidade de ruído em hospital de 222 leitos na 18ª Regional de Saúde - PR Noise level in a 222 bed hospital in the 18th health region - PR

    Marcelo Henrique Otenio

    2007-04-01

    Full Text Available A poluição sonora ambiental torna-se hoje onipresente e beira o intolerável. Nos hospitais, os avanços tecnológicos trazem, como conseqüência, níveis de ruído potencialmente danosos. Muito do ruído no hospital provém mais de dentro, do que de fora desse ambiente, sendo as principais causas de ruído em Unidade de Terapia Intensiva, por exemplo, os equipamentos e a conversação entre a equipe hospitalar. O objetivo deste trabalho foi avaliar o nível de ruído nos diversos ambientes hospitalares, em Hospital de 222 leitos na 18ª RS de Saúde - PR. MATERIAIS E MÉTODOS: Conduziu-se, em março de 2005 no período de 24 horas, em dez setores. Forma de Estudo: Aferição do nível de ruído ambiental utilizando um Decibelímetro modelo 1350. RESULTADOS: O nível de ruído encontrado em nosso estudo apresentou média total de 63,7 dB(A, que excede os valores máximos permitidos de 45 dB recomendados pela Associação Brasileira de Normas Técnicas (1987. CONCLUSÃO: Nos setores analisados, o nível de ruído encontrado neste está consideravelmente acima do recomendado. A equipe hospitalar deve estar consciente do ruído e dos efeitos deste, para que possa atuar de maneira mais efetiva na redução da poluição sonora, beneficiando assim a função laborativa dos profissionais e recuperação dos pacientes.Environment noise pollution is common place today, at intolerable levels. In hospitals, technological developments have, as a consequence, potentially harmful noise levels. Much of the hospital noise comes from inside, rather than outside, and the major source of such noise is the Intensive Care Unit, for example equipment and hospital staff talk. Our goal with the present study was to investigate the noise level present in the different hospital environments, within a 222 bed hospital located at the 18th health zone, PR. MATERIALS AND METHODS: The study was carried out in March, 2005, during a period of 24 hours, in tem different

  14. Percepção do ruído hospitalar em funcionários de uma maternidade do município de São Bernardo do Campo

    Ferreira, Aidilma Silva

    2013-01-01

    O ruído representa um importante problema de saúde pública. Os hospitais, que deveriam fornecer adequadas condições de conforto acústico aos seus pacientes e funcionários, não são considerados ambientes silenciosos, o que pode trazer prejuízo à saúde destes. Objetivo. Verificar a exposição a ruído ocupacional da equipe de profissionais de saúde que atua em setores de assistência a recém-nascido e investigar suas queixas auditivas e não auditivas. Método. A amostra foi composta por 34 técnicas...

  15. Mudança significativa do limiar auditivo em trabalhadores expostos a diferentes níveis de ruído Significant auditory threshold shift among workers exposed to different noise levels

    Flavia Cardoso Oliva

    2011-09-01

    Full Text Available OBJETIVO: Avaliar a audição e a ocorrência de mudança significativa do limiar auditivo em trabalhadores de frigoríficos expostos a níveis de ruído abaixo das Normas e Regulamentações nacionais e internacionais e compará-los com trabalhadores expostos a níveis de ruído considerados excessivos. MÉTODOS: Utilizou-se um banco de dados contendo informações longitudinais de 266 trabalhadores. Foram selecionados trabalhadores com um mínimo de três exames audiométricos e os que continham dados de exposição ao ruído. Foram mantidos 63 exames, classificados de acordo com sua exposição ao ruído em três níveis: 79 a 84,9 dB(A, 85 a 89,9 dB(A e 90 a 98,8 dB(A. Foi avaliada a ocorrência de perdas auditivas e de mudança significativa de limiar auditivo dos participantes de cada subgrupo. RESULTADOS: Verificou-se diferenças em todas as frequências nos testes de comparação entre a média dos limiares auditivos para cada frequência em função do nível de exposição ao ruído. A correlação entre a ocorrência de Perda Auditiva Induzida por Níveis de Pressão Sonora Elevados (PAINPSE e os anos de exposição ao ruído dentro da empresa atual foi significativa (R=0,373; p=0,079. Foram encontradas mudanças permanentes de limiar auditivo nos três níveis de exposição ao ruído. CONCLUSÃO: Os achados do presente estudo sugerem a existência de uma associação entre mudança significativa do limiar auditivo dos trabalhadores e os anos de exposição ao ruído considerado de baixo risco.PURPOSE: To assess the hearing status and signs of significant auditory threshold shifts in meat-processing facility workers who are exposed to noise levels below nationally and internationally recommended exposure limits, and to compare these results with data from workers exposed to excessive noise levels. METHODS: Longitudinal audiometric data from 266 workers were evaluated, and only workers with a minimum of three audiometric test results

  16. Preparation and characterization of multi-walled carbon nanotube (MWCNTs)-supported Pt-Ru catalyst for methanol electrooxidation

    Yang Chunwei [Department of Applied Chemistry, Harbin Institute of Technology, Harbin 150001 (China)], E-mail: cw.yang@hit.edu.cn; Wang Dianlong; Hu Xinguo; Dai Changsong [Department of Applied Chemistry, Harbin Institute of Technology, Harbin 150001 (China); Zhang Liang [School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China)

    2008-01-10

    Multi-walled carbon nanotubes (MWCNTs) as a support of PtRu catalyst nanocomposites were prepared by colloid method in this work. Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) all indicate that ultrasonic treatment can effectively functionalize MWCNTs, endowing them with groups that can act as nucleation sites which can favor well-dispersed deposition of PtRu clusters on their surface. The PtRu/MWCNTs catalysts have a high and homogeneous dispersion of spherical PtRu metal particles with a narrow particle-size distribution. From XPS tests, in PtRu/MWCNTs catalysts Ru can weaken the out-shell electrons of Pt because a part of Ru form alloy with Pt. The remnant Ru exists in oxidation and provides abundant oxygen to nearby Pt, as accelerated desorption and oxidation of intermediate products of methanol oxidation at surface of Pt. By a series of electrochemistry measurements, the PtRu/MWCNTs catalysts display significantly higher performance than the PtRu/XC-72 catalysts. Finally, schematic procedures for the oxidation of MWCNTs and synthesis of PtRu/MWCNTs catalysts were given.

  17. Preparation and characterization of multi-walled carbon nanotube (MWCNTs)-supported Pt-Ru catalyst for methanol electrooxidation

    Yang Chunwei; Wang Dianlong; Hu Xinguo; Dai Changsong; Zhang Liang

    2008-01-01

    Multi-walled carbon nanotubes (MWCNTs) as a support of PtRu catalyst nanocomposites were prepared by colloid method in this work. Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) all indicate that ultrasonic treatment can effectively functionalize MWCNTs, endowing them with groups that can act as nucleation sites which can favor well-dispersed deposition of PtRu clusters on their surface. The PtRu/MWCNTs catalysts have a high and homogeneous dispersion of spherical PtRu metal particles with a narrow particle-size distribution. From XPS tests, in PtRu/MWCNTs catalysts Ru can weaken the out-shell electrons of Pt because a part of Ru form alloy with Pt. The remnant Ru exists in oxidation and provides abundant oxygen to nearby Pt, as accelerated desorption and oxidation of intermediate products of methanol oxidation at surface of Pt. By a series of electrochemistry measurements, the PtRu/MWCNTs catalysts display significantly higher performance than the PtRu/XC-72 catalysts. Finally, schematic procedures for the oxidation of MWCNTs and synthesis of PtRu/MWCNTs catalysts were given

  18. Electro-oxidation of borohydride on colloidal Os and Os-alloys (Os-Sn, Os-Mo and Os-V)

    Atwan, M.H.; Northwood, D.O. [Windsor Univ., ON (Canada). Dept. of Mechanical, Automotive and Materials Engineering; Gyenge, E.L. [British Columbia Univ., Vancouver, BC (Canada). Dept. of Chemical and Biological Engineering

    2005-10-15

    Preliminary experimental studies have demonstrated the possibility of using sodium borohydride (NaBH{sub 4}) oxidation catalysis by osmium (Os) in 2 M sodium hydroxide (NaOH) in the presence of thiourea as an inhibitor to hydrogen (H{sub 2}) evolution. The usefulness of this information for low-temperature direct fuel cells involving the anodic oxidation of fuels such as methanol, ethanol and sodium borohydride was discussed with reference to the challenge of high anode surface overpotential affecting the power output of direct fuel cells. This study examined the cyclic voltammetry features of supported colloidal Os and Os alloys with molybdenum, vanadium and tin, in the presence of NaBH{sub 4}. It also examined the potential for electrocatalysis in direct borohydride fuel cells (DBFC). Colloidal Os and Os alloys were tested for their use as electrocatalysts for oxidation of borohydride. The features of an Os cyclic voltammogram in alkaline media with and without BH{sub 4} were discussed along with the redox mediated oxidation of BH{sub 4}. Cyclic voltammetry and chronopotentiometry tests showed that colloidal Os 20 per cent weight supported on Vulcan XC-72R possessed electrocatalytic activity toward borohydride oxidation while the investigated Os-alloys were catalytically inactive. Chronopotentiometry experiments also showed that the 20 per cent weight Os gave the lowest anodic potential, and is therefore recommended as the anode electrocatalyst in direct borohydride fuel cells. 29 refs., 1 tab., 7 figs.

  19. Preparation of highly dispersed Ru-Sn bimetallic supported catalysts from the single source precursors Cp(PPh32Ru-SnX3 (X = Cl or Br

    Ana Cláudia Bernardes Silva

    2003-06-01

    Full Text Available In this work highly dispersed Ru-Sn bimetallic catalysts have been prepared from organobimetallic Cp(PPh32Ru-SnX3 (X = Cl or Br complexes. These single source precursors can be easily impregnated in high surface area supports, such as activated carbon and sol-gel SiO2, and upon controlled thermal treatment the ligands are released as volatile products resulting in the formation of the bimetallic system Ru-Sn. Catalytic reactions, such as hydrodechlorination of CCl4 and chlorobenzene and TPR (Temperature Programmed Reduction experiments carried out with these RuSn catalysts suggested a strong interaction between Ruthenium and Tin. Mössbauer measurements showed that these materials when exposed to air are immediately oxidized to form Sn (IV. It was shown that upon controlled reduction conditions with H2 it is possible to reduce selectively Sn to different oxidation states and different phases. The Sn oxidation state showed significant effect on the catalytic hydrogenation of 1,5-cyclooctadiene. The use of these single source precursors with a controlled decomposition/reduction procedure allows the preparation of unique catalysts with an intimate interaction between the components ruthenium and tin and the possibility of varying the Sn oxidation state around the Ru metal.

  20. Enhanced interfacial Dzyaloshinskii-Moriya interaction and isolated skyrmions in the inversion-symmetry-broken Ru/Co/W/Ru films

    Samardak, Alexander; Kolesnikov, Alexander; Stebliy, Maksim; Chebotkevich, Ludmila; Sadovnikov, Alexandr; Nikitov, Sergei; Talapatra, Abhishek; Mohanty, Jyoti; Ognev, Alexey

    2018-05-01

    An enhancement of the spin-orbit effects arising on an interface between a ferromagnet (FM) and a heavy metal (HM) is possible through the strong breaking of the structural inversion symmetry in the layered films. Here, we show that an introduction of an ultrathin W interlayer between Co and Ru in Ru/Co/Ru films enables to preserve perpendicular magnetic anisotropy (PMA) and simultaneously induce a large interfacial Dzyaloshinskii-Moriya interaction (iDMI). The study of the spin-wave propagation in the Damon-Eshbach geometry by Brillouin light scattering spectroscopy reveals the drastic increase in the iDMI value with the increase in W thickness (tW). The maximum iDMI of -3.1 erg/cm2 is observed for tW = 0.24 nm, which is 10 times larger than for the quasi-symmetrical Ru/Co/Ru films. We demonstrate the evidence of the spontaneous field-driven nucleation of isolated skyrmions supported by micromagnetic simulations. Magnetic force microscopy measurements reveal the existence of sub-100-nm skyrmions in the zero magnetic field. The ability to simultaneously control the strength of PMA and iDMI in quasi-symmetrical HM/FM/HM trilayer systems through the interface engineered inversion asymmetry at the nanoscale excites new fundamental and practical interest in ultrathin ferromagnets, which are a potential host for stable magnetic skyrmions.

  1. Nearest-neighbor Kitaev exchange blocked by charge order in electron-doped α -RuCl3

    Koitzsch, A.; Habenicht, C.; Müller, E.; Knupfer, M.; Büchner, B.; Kretschmer, S.; Richter, M.; van den Brink, J.; Börrnert, F.; Nowak, D.; Isaeva, A.; Doert, Th.

    2017-10-01

    A quantum spin liquid might be realized in α -RuCl3 , a honeycomb-lattice magnetic material with substantial spin-orbit coupling. Moreover, α -RuCl3 is a Mott insulator, which implies the possibility that novel exotic phases occur upon doping. Here, we study the electronic structure of this material when intercalated with potassium by photoemission spectroscopy, electron energy loss spectroscopy, and density functional theory calculations. We obtain a stable stoichiometry at K0.5RuCl3 . This gives rise to a peculiar charge disproportionation into formally Ru2 + (4 d6 ) and Ru3 + (4 d5 ). Every Ru 4 d5 site with one hole in the t2 g shell is surrounded by nearest neighbors of 4 d6 character, where the t2 g level is full and magnetically inert. Thus, each type of Ru site forms a triangular lattice, and nearest-neighbor interactions of the original honeycomb are blocked.

  2. Avaliação audiológica em trabalhadores expostos a ruído e praguicida Audiological evaluation in workers exposed to noise and pesticide

    Heraldo Lorena Guida

    2010-08-01

    Full Text Available A perda auditiva induzida por ruído é estudada há muitos anos, e atualmente a literatura especializada estuda também a ação sinérgica dos produtos químicos, uma vez que eles podem ser potencialmente ototóxicos. OBJETIVO: Pesquisar os achados audiológicos em trabalhadores expostos ao ruído ocupacional e a praguicidas e comparar com os dados obtidos em trabalhadores expostos ao ruído. FORMA DE ESTUDO: Clínico retrospectivo. MATERIAL E MÉTODO: Foram analisados os prontuários de indivíduos que foram expostos ao praguicida e ao ruído (grupo I, e indivíduos que foram somente expostos ao ruído (grupo II. RESULTADOS: A classificação dos achados audiométricos revelou para o grupo I: 35% orelhas normais, 53,75% com perda auditiva de grau 1 e 11,25% com perda de grau 2. Enquanto que o grupo II apresentou 57,5% de orelhas normais, 40% com perda auditiva de grau 1 e apenas 2,5% com perda de grau 2. A análise dos achados audiométricos demonstrou também uma piora significativa após a comparação entre os limiares do grupo I e grupo II, na frequência de 3 kHz orelha esquerda e na frequência de 4kHz em ambas as orelhas. CONCLUSÃO: A análise mostrou que o grupo I tem limiares audiométricos piores comparado ao grupo II.Noise-induced hearing loss has been studied for many years and today many experts also investigate the synergic action of chemical products, since they can be potentially ototoxic. AIM: to investigate the audiological findings in workers exposed to occupational noise and pesticide and to compare it to data from noise-exposed workers. STUDY DESIGN: Clinical retrospective. MATERIAL AND METHOD: individuals that had been exposed to pesticide and noise (group I, and individuals that had been exposed to noise only (group II. RESULTS: The classification of the audiometric findings showed in that group I: 35% had normal hearing thresholds, 53.75% had degree 1 hearing loss and 11.25% had degree 2 hearing loss; and group II had

  3. Photochemical Properties and Reactivity of a Ru Compound Containing an NAD/NADH-Functionalized 1,10-Phenanthroline Ligand.

    Kobayashi, Katsuaki; Ohtsu, Hideki; Nozaki, Koichi; Kitagawa, Susumu; Tanaka, Koji

    2016-03-07

    An NAD/NADH-functionalized ligand, benzo[b]pyrido[3,2-f][1,7]-phenanthroline (bpp), was newly synthesized. A Ru compound containing the bpp ligand, [Ru(bpp)(bpy)2](2+), underwent 2e(-) and 2H(+) reduction, generating the NADH form of the compound, [Ru(bppHH)(bpy)2](2+), in response to visible light irradiation in CH3CN/TEA/H2O (8/1/1). The UV-vis and fluorescent spectra of both [Ru(bpp)(bpy)2](2+) and [Ru(bppHH)(bpy)2](2+) resembled the spectra of [Ru(bpy)3](2+). Both complexes exhibited strong emission, with quantum yields of 0.086 and 0.031, respectively; values that are much higher than those obtained from the NAD/NADH-functionalized complexes [Ru(pbn)(bpy)2](2+) and [Ru(pbnHH)(bpy)2](2+) (pbn = (2-(2-pyridyl)benzo[b]-1.5-naphthyridine, pbnHH = hydrogenated form of pbn). The reduction potential of the bpp ligand in [Ru(bpp)(bpy)2](2+) (-1.28 V vs SCE) is much more negative than that of the pbn ligand in [Ru(pbn)(bpy)2](2+) (-0.74 V), although the oxidation potentials of bppHH and pbnHH are essentially equal (0.95 V). These results indicate that the electrochemical oxidation of the dihydropyridine moiety in the NADH-type ligand was independent of the π system, including the Ru polypyridyl framework. [Ru(bppHH)(bpy)2](2+) allowed the photoreduction of oxygen, generating H2O2 in 92% yield based on [Ru(bppHH)(bpy)2](2+). H2O2 production took place via singlet oxygen generated by the energy transfer from excited [Ru(bppHH)(bpy)2](2+) to triplet oxygen.

  4. Effect of the structure of Pt-Ru/C particles on COad monolayer vibrational properties and electrooxidation kinetics

    Maillard, Frederic; Bonnefont, Antoine; Chatenet, Marian; Guetaz, Laure; Doisneau-Cottignies, Beatrice; Roussel, Herve; Stimming, Ulrich

    2007-01-01

    In this paper, we combined FTIR spectroscopy and CO ad stripping voltammetry to investigate CO ad adsorption and electrooxidation on Pt-Ru/C nanoparticles. The Pt:Ru elemental composition and the metal loading were determined by ICP-AES. The X-ray diffraction patterns of the Pt-Ru/C indicated formation of a Pt-Ru (fcc) alloy. HREM images revealed an increase in the fraction of agglomerated Pt-Ru/C particles with increasing the metal loading and showed that agglomerated Pt-Ru/C nanoparticles present structural defects such as twins or grain boundaries. In addition, isolated Pt-Ru/C nanoparticles have similar mean particle size (ca. 2.5 nm) and particle size distributions whatever the metal loading. Therefore, we could determine precisely the effect of particle agglomeration on the CO ad vibrational properties and electrooxidation kinetics. FTIR measurements revealed a main CO ad stretching band at ca. ν-bar CO L =2030cm -1 , which we ascribed to a-top CO ad on Pt domains electronically modified by the presence of Ru. As the metal loading increased, the position of this band was blue shifted by ca. 5 cm -1 and a shoulder around 2005 cm -1 developed, which was ascribed to a-top CO ad on Ru domains. The reason for this was suggested to be the increasing size of Ru domains on agglomerated Pt-Ru/C particles, which lifts dipole-dipole coupling and allows two vibrational features to be observed (CO ad /Ru, CO ad /Pt). This is evidence that FTIR spectroscopy can be used to probe small chemical fluctuations of the Pt-Ru/C surface. Finally, we comment on the CO ad electrooxidation kinetics. We observed that CO ad was converted more easily into CO 2 as the metal loading, i.e. the fraction of agglomerated Pt-Ru/C nanoparticles, increased

  5. iOS and OS X network programming cookbook

    Hoffman, Jon

    2014-01-01

    This book follows a recipe-based approach that will heavily focus on the code and how to integrate the samples with the reader's projects.Each recipe consists of one or more methods that you can put directly into your app and use.This book is ideal for developers that want to create network applications for the Apple OS X or iOS platforms. All examples are written in Objective-C using XCode as the IDE. Knowledge of Objective-C and X-Code is essential.

  6. Development of a database for the prediction of phases in Pt-Al-Cr-Ru alloys for high-temperature and corrosive environments: Al-Cr-Ru

    Suess, R.; Watson, A.; Cornish, L.A.; Compton, D.N.

    2009-01-01

    Platinum-based alloys for high-temperature corrosive environments are being developed which have microstructures that are analogous to the γ/γ' microstructure of the nickel-based superalloys. The need for a predictive thermodynamic database for these alloys was identified. Because experimental studies suggested that such a database should be based on Pt-Al-Cr-Ru, the Al-Cr-Ru system is of importance in this research programme. Using the CALPHAD method and Thermo-Calc software, existing binary data were used to optimise a ternary database for Al-Cr-Ru against available experimental ternary data. The database gives good predictions with regards to phase equilibria in the system as well as the nature of the primary solidification phases.

  7. Band structure of metallic pyrochlore ruthenates Bi2Ru2O7 and Pb2Ru2O/sub 6.5/

    Hsu, W.Y.; Kasowski, R.V.; Miller, T.; Chiang, T.

    1988-01-01

    The band structure of Bi 2 Ru 2 O 7 and Pb 2 Ru 2 O/sub 6.5/ has been computed self-consistently from first principles for the first time by the pseudofunction method. We discover that the 6s bands of Bi and Pb are very deep and unlikely to contribute to the metallic behavior as previously believed. The unoccupied 6p bands, however, are only several eV above the Fermi energy and are mixed with the Ru 4d band at the Fermi surface via the framework O atoms, leading to band conduction and delocalized magnetic moments. The predicted location of the 6s bands and the location and width of the O 2p band are confirmed by synchrotron radiation and ultraviolet electron spectroscopy of single crystals

  8. Coherent electron-correlation compatible with random atom stacking in amorphous Ce-Ru alloys

    Homma, Yoshiya; Sumiyama, Kenji; Yamauchi, Hiroshi; Suzuki, Kenji

    1997-01-01

    The amorphous Ce-Ru alloys produced by the sputtering technique show the following distinct behaviors at low temperatures. The electronic specific heat coefficient rapidly increases below 5 K for Ce-19 and 42 at.%Ru alloys with decreasing temperature, T, (a heavy fermion behavior). The electrical resistivity displays -logT dependence at T > 40 K (an incoherent or impurity Kondo effect). Is slightly decreases at T < 30 K for Ce-19 and 42 at.%Ru alloys (a coherent Kondo effect), while it abruptly decreases at 2.5 K for 82 at.%Ru (a superconducting phenomenon). These coherent states may originate from the strong mixing and correlation of 4f-electrons and conduction-electrons even in the random alloy system. (author)

  9. Separation and determination of 103Ru in samples of fission 99Mo

    Aghazarian, V.P.; Duran, Adrian P.; Mondino, Angel V.

    2003-01-01

    In Argentina 99 Mo is produced in the RA-3 reactor at the Ezeiza Atomic Center (CAE), by irradiation of miniplates of Al/U (90% 235 U) alloy. The 99 Mo separation is carried out at the Fission Radioisotopes Production Plant. Quality control is important to assure the quality of molybdenum that is produced in CAE. A new method to purify and on line quantify 103 Ru as an impurity present in 99 Mo samples was developed. This procedure is based in the RuO 4 volatilization and its dissolution in NaOH 6M. This is necessary due to the fact that 103 Ru cannot be detected in presence of high activities of 99 Mo without previous separation. This method allows a quantitative, specific, efficient, fast and reproducible separation of 103 Ru from 99 Mo. (author)

  10. α,β-Unsaturated imines via Ru-catalyzed coupling of allylic alcohols and amines.

    Rigoli, Jared W; Moyer, Sara A; Pearce, Simon D; Schomaker, Jennifer M

    2012-03-07

    A convenient synthesis of α,β-unsaturated imines requiring only an allylic alcohol, an amine and a Ru catalyst has been developed. The use of large excesses of oxidant and the purification of sensitive intermediates can be avoided.

  11. Mesoporous Pt and Pt/Ru alloy electrocatalysts for methanol oxidation

    Franceschini, Esteban A. [Grupo de Celdas de Combustible, Departamento de Fisica de la Materia Condensada, Centro Atomico Constituyentes, CNEA. Av. General Paz 1499 (1650), San Martin, Buenos Aires (Argentina); Planes, Gabriel A. [Departamento de Quimica, Facultad de Ciencias Exactas, Fisicoquimicas y Naturales, Universidad Nacional de Rio Cuarto, Agencia Postal No 3, 5800, Rio Cuarto (Argentina); Williams, Federico J. [Departamento de Quimica Inorganica, Analitica y Quimica-Fisica, INQUIMAE CONICET, Facultad Ciencias Exactas y Naturales, Pabellon 2, Ciudad Universitaria, Buenos Aires (Argentina); Soler-Illia, Galo J.A.A. [Gerencia de Quimica, Centro Atomico Constituyentes, CNEA. Av. General Paz 1499 (1650), San Martin, Buenos Aires (Argentina); Corti, Horacio R. [Grupo de Celdas de Combustible, Departamento de Fisica de la Materia Condensada, Centro Atomico Constituyentes, CNEA. Av. General Paz 1499 (1650), San Martin, Buenos Aires (Argentina); Departamento de Quimica Inorganica, Analitica y Quimica-Fisica, INQUIMAE CONICET, Facultad Ciencias Exactas y Naturales, Pabellon 2, Ciudad Universitaria, Buenos Aires (Argentina)

    2011-02-15

    Mesoporous Pt and Pt/Ru catalysts with 2D-hexagonal mesostructure were synthesized using a triblock poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) copolymer (Pluronic F127 {sup registered}) template, on a gold support. Large electrochemical surface areas were observed for the catalysts prepared at high overpotentials. Compared to the Pt catalyst, the Pt/Ru alloy containing 3 at% of Ru exhibited lower onset potential and more than three times the limit mass activity for methanol oxidation. This behavior is assigned to the larger pore size of the mesoporous Pt and Pt/Ru catalysts obtained with this template that seems to improve the methanol accessibility to the active sites compared to those obtained using lyotropic liquid crystals. (author)

  12. CANDU RU fuel manufacturing basic technology development and advanced fuel verification tests

    Chung, Chang Hwan; Chang, S.K.; Hong, S.D.

    1999-04-01

    A PHWR advanced fuel named the CANFLEX fuel has been developed through a KAERI/AECL joint Program. The KAERI made fuel bundle was tested at the KAERI Hot Test Loop for the performance verification of the bundle design. The major test activities were the fuel bundle cross-flow test, the endurance fretting/vibration test, the freon CHF test, and the fuel bundle heat-up test. KAERI also has developing a more advanced PHWR fuel, the CANFLEX-RU fuel, using recovered uranium to extend fuel burn-up in the CANDU reactors. For the purpose of proving safety of the RU handling techniques and appraising feasibility of the CANFLEX-RU fuel fabrication in near future, a physical, chemical and radiological characterization of the RU powder and pellets was performed. (author). 54 refs., 46 tabs., 62 figs

  13. Fermi surfaces of YRu2Si2 and LaRu2Si2

    Settai, R.; Ikezawa, H.; Toshima, H.; Takashita, M.; Ebihara, T.; Sugawara, H.; Kimura, T.; Motoki, K.; Onuki, Y.

    1995-01-01

    We have measured the de Haas-van Alphen effect of YRu 2 Si 2 and LaRu 2 Si 2 to clarify the Fermi surfaces and cyclotron masses. Main hole-Fermi surfaces of both compounds with a distorted ellipsoid shape are similar, occupying about half of the Brillouin zone. The small hole-Fermi surfaces with the shape of a rugby ball are three in number for LaRu 2 Si 2 , and one for YRu 2 Si 2 . An electron-Fermi surface consists of a doughnut like shape for LaRu 2 Si 2 , while a cylinder along the [001] direction and a multiply-connected shape exist for YRu 2 Si 2 . The cyclotron masses of YRu 2 Si 2 are a little larger than those of LaRu 2 Si 2 . ((orig.))

  14. Conductivity study of thermally stabilized RuO2/polythiophene nanocomposites

    Hebbar, Vidyashree; Bhajantri, R. F.

    2018-04-01

    The polymer nanocomposites of Ruthenium oxide (RuO2) filled polythiophene (PT) were synthesized by polymerization using chemical method. The purity of the synthesized polymer composite is verified using X-Ray diffraction (XRD). The structural discrepancies of the RuO2 filled PT composites are studied by Fourier transform infrared (FT-IR) spectroscopy. The phase transition and thermal stability of the prepared composite is revised by thermal characterization such as differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The DC conductivity of RuO2 filled PT composite in the form of pellets is calculated using current-voltage (I-V) characterization by two-probe method. The enhancement in conductivity with increased RuO2 content in PT matrix is examined, which is the required property for electrical and electronic applications in supercapacitors.

  15. CANDU RU fuel manufacturing basic technology development and advanced fuel verification tests

    Chung, Chang Hwan; Chang, S.K.; Hong, S.D. [and others

    1999-04-01

    A PHWR advanced fuel named the CANFLEX fuel has been developed through a KAERI/AECL joint Program. The KAERI made fuel bundle was tested at the KAERI Hot Test Loop for the performance verification of the bundle design. The major test activities were the fuel bundle cross-flow test, the endurance fretting/vibration test, the freon CHF test, and the fuel bundle heat-up test. KAERI also has developing a more advanced PHWR fuel, the CANFLEX-RU fuel, using recovered uranium to extend fuel burn-up in the CANDU reactors. For the purpose of proving safety of the RU handling techniques and appraising feasibility of the CANFLEX-RU fuel fabrication in near future, a physical, chemical and radiological characterization of the RU powder and pellets was performed. (author). 54 refs., 46 tabs., 62 figs.

  16. Reaction of H{sub 2}S with MoRu(CO){sub 6}(dppm){sub 2} to give H{sub 2} and a bridged-sulfide product via hydrido-sulfhydryl intermediates (dppm equals Ph{sub 2}PCH{sub 2}PPh{sub 2})

    Khorasani-Motlagh, M. [Sistan and Baluchestan Univ., Zahedan (Iran, Islamic Republic of). Dept. of Chemistry; Safari, N. [Shahid Beheshti Univ., Tehran (Iran, Islamic Republic of). Dept. of Chemistry; Pamplin, C.B.; Patrick, B.O.; James, B.R. [British Columbia Univ., Vancouver, BC (Canada). Dept. of Chemistry

    2006-02-15

    The reactivity of hydrogen sulphide toward transition metal complexes was studied with particular focus on the reactions of hydrogen sulphide (H{sub 2}S) with solutions of bimetallic-dppm complexes. The complex MoRu(CO){sub 6}({mu}-dppm){sub 2} (1) (dppm equals Ph{sub 2}PCH{sub 2}PPh{sub 2}) reaction toward hydrogen sulphide was examined because of the fact that Ru is the second-row analogue of Fe and because of the key role of sulphur ligands in the Mo-Fe enzyme systems. This paper reported on the interaction of the Mo-Ru complex with hydrogen sulphide to form the bridged sulphide complex Mo(CO){sub 2}({mu}-CO)({mu}-S)(dppm){sub 2}Ru(CO) which can be synthesized with elemental sulphur. Oxidative addition of H{sub 2}S to MoRu(CO){sub 6}({mu}-dppm){sub 2} (1) at 20 degrees C in toluene yields an isolable complex formulated as Mo(CO){sub 3}({mu}-SH)({mu}-CO)({mu}-dppm){sub 2}RuH(CO) (2) via the possible intermediate Mo(CO){sub 3}({mu}-H)({mu}-CO)({mu}-dppm){sub 2}Ru(SH)(CO) (4) (dppm equals Ph{sub 2}PCH{sub 2}PPh{sub 2}) that is detectable at lower temperatures. Over 2 days, species 2 in toluene lost H{sub 2} (and CO) to yield the bridged-sulfide product, Mo(CO){sub 2}({mu}-CO)({mu}-S)({mu}-dppm){sub 2}Ru(CO) (5) that is also formed directly from the reaction of 1 with elemental sulfur. The solid-state molecular structure of 5 was determined by X-ray crystallography. A further hydrido-sulfhydryl species was found to be in equilibrium with 2 at ambient temperature. It was concluded that it is not impossible that hydrogen sulphide can react in a concerted manner with dimetallic precursors, without prior formation of an adduct. 24 refs., 2 tabs., 3 figs.

  17. CANFLEX-RU fuel development programs as one option of advanced fuel cycles in Korea

    Suk, Ho Chun; Sim, Ki-Seob; Chung, Jang Hwan

    1999-01-01

    As one of the possible fuel cycles in Korea, RU (Recycled Uranium) fuel offers a very attractive alternative to the use of NU (Natural Uranium) and SEU in the CANDU reactors, because Korea is a unique country having both PWR and CANDU reactors. Korea can therefore exploit the natural synergism between the two reactor types to minimise overall waste production, and maximise energy derived from the fuel, by burning the spent fuel from its PWR reactors in CANDU reactors. Potential benefits can be derived from a number of stages in the fuel cycle: no enrichment required, no enrichment tails, direct conversion to UO 2 lower sensitivity to 234 U and 236 U absorption in the CANDU reactor, expected lower cost relative to NU and SEU. These benefits all fit well with the PWR-CANDU fuel cycle synergy. RU arising from the reprocessing of European and Japanese oxide spent fuel by 2000 is projected to be approaching 25,000 te. The use of RU fuel in a CANDU-6 reactor should result in no serious radiological difficulties and no requirements for special precautions and should not require any new technologies for the fuel fabrication and handling. A KAERI's feasibility shows that the use of the CANFLEX bundle as the carrier for RU will be compatible with the reactor design, current safety and operational requirements, and there will be no significant fuel performance difference from the CANDU 37-element NU fuel bundle. Compared with the 37-element NU bundle, the RU fuel has significantly improved fuel cycle economics derived from increased burnups, a large reduction in fuel requirements and spent fuel arisings and the potential lower cost for RU material. There is the potential for annual fuel cost savings to be in the range of one-third to two-thirds, with enhanced operating margins using RU in the CANFLEX bundle design. These benefits provide the rationale for justifying R and D effort on the use of RU fuel for advanced fuel cycles in the CANDU reactors of Korea. The RU fuel

  18. RU fuel development program for an advanced fuel cycle in Korea

    Suk, Hochum; Sim, Kiseob; Kim, Bongghi; Inch, W.W.; Page, R.

    1998-01-01

    Korea is a unique country, having both PWR and CANDU reactors. Korea can therefore exploit the natural synergism between the two reactor types to minimize overall waste production, and maximize energy derived from the fuel, by ultimately burning the spent fuel from its PWR reactors in CANDU reactors. As one of the possible fuel cycles, Recovered Uranium (RU) fuel offers a very attractive alternative to the use of Natural Uranium (NU) and slightly enriched uranium (SEU) in CANDU reactors. Potential benefits can be derived from a number of stages in the fuel cycle: no enrichment required, therefore no enrichment tails, direct conversion to UO 2 , lower sensitivity to 234 U and 236U absorption in the CANDU reactor, and expected lower cost relative to NU and SEU. These benefits all fit well with the PWR-CANDU fuel cycle synergy. RU arising from the conventional reprocessing of European and Japanese oxide spent fuel by 2000 is projected to be approaching 25,000 te. The use of RU fuel in a CANDU 6 reactor should result in no serious radiological difficulties and no requirements for special precautions and should not require any new technologies for the fuel fabrication and handling. The use of the CANDU Flexible Fueling (CANFLEX) bundle as the carrier for RU will be fully compatible with the reactor design, current safety and operational requirements, and there will be improved fuel performance compared with the CANDU 37-element NU fuel bundle. Compared with the 37-element NU bundle, the RU fuel has significantly improved fuel cycle economics derived from increased burnups, a large reduction in both fuel requirements and spent fuel, arisings, and the potential lower cost for RU material. There is the potential for annual fuel cost savings in the range of one-third to two-thirds, with enhanced operating margins using RU in the CANFLEX bundle design. These benefits provide the rationale for justifying R and D efforts on the use of RU fuel for advanced fuel cycles in CANDU

  19. iOS 6 foundations

    Feiler, Jesse

    2013-01-01

    A practical introduction for using iOS 6 to create universal apps If you have prior experience programming in an object-oriented language and are eager to start building universal apps for iPad and iPhone (including the iPod touch), then this is the book for you! Using the latest version of iOS (iOS 6) along with the latest version of Xcode (Xcode 4.5), this book is a practical introduction rather than just a catalog of components. Full-color and packed with groundbreaking, innovative designs, this book teaches you how to create eye-catching, unique apps. Teaches you the va

  20. Between Localization and Delocalization: Ru(cod)2+ Units in the Zintl Clusters [Bi9 {Ru(cod)}2 ]3- and [Tl2 Bi6 {Ru(cod)}]2.

    Lichtenberger, Niels; Spang, Nils; Eichhöfer, Andreas; Dehnen, Stefanie

    2017-10-16

    Reactions of [K(crypt-222)] 2 (TlBi 3 )⋅0.5 en (1 b) with [Ru(cod)(H 2 CC(Me)CH 2 ) 2 ] (A) in 1,2-diaminoethane (en) led to the formation of two compounds with new bismuth-rich cluster anions, [K(crypt-222)] 3 [Bi 9 {Ru(cod)} 2 ]⋅1.5 en (2) and [K(crypt-222)] 2 [Tl 2 Bi 6 {Ru(cod)}]⋅2 tol (3), alongside the salt of a binary nido cluster, [K(crypt-222)] 3 (Tl 4 Bi 5 )⋅2 en (4). The anions in 2 and 3 are two further examples of rare heterometallic clusters containing Ru atoms. As one cod ligand is retained on each Ru atom in both clusters, the anions may be viewed as intermediates on the way towards larger, ligand-free intermetalloid clusters. Quantum-chemical studies provided insight into the bonding situation in these clusters. According to these studies, the anion of 2 features both electron-precise and electron-deficient parts. Electrospray ionization mass spectrometry analysis indicated that the clusters undergo stepwise fragmentation. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.