Newly designed PdRuBi/N-Graphene catalysts with synergistic effects for enhanced ethylene glycol electro-oxidation

International Nuclear Information System (INIS)

Li, Tengfei; Huang, Yiyin; Ding, Kui; Wu, Peng; Abbas, Syed Comail; Ghausi, Muhammad Arsalan; Zhang, Teng; Wang, Yaobing

2016-01-01

Graphical abstract: We rationally design and synthesize a ternary PdRuBi/NG catalyst with significantly enhanced catalytic activity with synergetic effect of Ru and Bi towards ethylene glycol electro-oxidation. - Abstract: Palladium (Pd)-based catalysts are appealing electro-catalysts for alcohol oxidation reaction in fuel cell, but still not efficient as the complicated oxidation process and sluggish kinetic. Here we rationally design and synthesize a PdRuBi/NG tri-metallic catalyst with space synergetic effect for enhanced ethylene glycol electro-oxidation, in which both Ru and Bi in the catalyst are synergistic effective in promoting catalytic activity of Pd catalytic interlayer by electronic effect and surface modification mechanism respectively. It shows 4.2 times higher peak current density towards ethylene glycol electro-oxidation than commercial Pd/C catalyst, and the catalytic durability is also greatly improved.

The effect of boron concentration on the structure and elastic properties of Ru-Ir alloys: first-principles calculations

Science.gov (United States)

Li, Xiaolong; Zhou, Zhaobo; Hu, Riming; Zhou, Xiaolong; Yu, Jie; Liu, Manmen

2018-04-01

The Phase stability, electronic structure, elastic properties and hardness of Ru-Ir alloys with different B concentration were investigated by first principles calculations. The calculated formation enthaplies and cohesive energies show that these compounds are all thermodynamically stable. Information on electronic structure indicates that they possess metallic characteristic and Ru-Ir-B alloys were composed of the Ru-B and Ir-B covalent bond. The elastic properties were calculated, which included bulk modulus, shear modulus, Young’s modulus, Poisson’s ratio and hardness. The calculated results reveal that the plastic of Ru-Ir-B alloys increase with the increase of the content of B atoms, but the hardness of Ru-Ir-B alloys have no substantial progress with the increase of the content of B atoms. However, it is interesting that the hardness of the Ru-Ir-B compound was improved obviously as the B content was higher than 18 atoms because of a phase structure transition.

The Effect of PtRuIr Nanoparticle Crystallinity in Electrocatalytic Methanol Oxidation

Directory of Open Access Journals (Sweden)

Vladimir Linkov

2013-04-01

Full Text Available Two structural forms of a ternary alloy PtRuIr/C catalyst, one amorphous and one highly crystalline, were synthesized and compared to determine the effect of their respective structures on their activity and stability as anodic catalysts in methanol oxidation. Characterization techniques included TEM, XRD, and EDX. Electrochemical analysis using a glassy carbon disk electrode for cyclic voltammogram and chronoamperometry were tested in a solution of 0.5 mol L−1 CH3OH and 0.5 mol L−1 H2SO4. Amorphous PtRuIr/C catalyst was found to have a larger electrochemical surface area, while the crystalline PtRuIr/C catalyst had both a higher activity in methanol oxidation and increased CO poisoning rate. Crystallinity of the active alloy nanoparticles has a big impact on both methanol oxidation activity and in the CO poisoning rate.

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

International Nuclear Information System (INIS)

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

On formation mechanism of Pd–Ir bimetallic nanoparticles through thermal decomposition of [Pd(NH3)4][IrCl6

International Nuclear Information System (INIS)

Asanova, Tatyana I.; Asanov, Igor P.; Kim, Min-Gyu; Gerasimov, Evgeny Yu.; Zadesenets, Andrey V.; Plyusnin, Pavel E.; Korenev, Sergey V.

2013-01-01

The formation mechanism of Pd–Ir nanoparticles during thermal decomposition of double complex salt [Pd(NH 3 ) 4 ][IrCl 6 ] has been studied by in situ X-ray absorption (XAFS) and photoelectron (XPS) spectroscopies. The changes in the structure of the Pd and Ir closest to the surroundings and chemical states of Pd, Ir, Cl, and N atoms were traced in the range from room temperature to 420 °C in inert atmosphere. It was established that the thermal decomposition process is carried out in 5 steps. The Pd–Ir nanoparticles are formed in pyramidal/rounded Pd-rich (10–200 nm) and dendrite Ir-rich (10–50 nm) solid solutions. A d charge depletion at Ir site and a gain at Pd, as well as the intra-atomic charge redistribution between the outer d and s and p electrons of both Ir and Pd in Pd–Ir nanoparticles, were found to occur.Graphical Abstract

Ir-Ru/Al2O3 catalysts used in satellite propulsion

Directory of Open Access Journals (Sweden)

T.G. Soares Neto

2003-09-01

Full Text Available Ir/Al2O3, Ir-Ru/Al2O3 and Ru/Al2O3, catalysts with total metal contents of 30% were prepared using the methods of incipient wetness and incipient coimpregnation wetness and were tested in a 2N microthruster. Their performances were then compared with that of the Shell 405 commercial catalyst (30% Ir/Al2O3. Tests were performed in continuous and pulsed regimes, where there are steep temperature and pressure gradients, from ambient values up to 650 ºC and 14 bar. Performance stability, thrust produced, temperature and stagnation pressure in the chamber and losses of mass were analyzed and compared to the corresponding parameters in Shell 405 tests. It was observed that the performance of all the above-mentioned catalysts was comparable to that of the commercial one, except for in loss of mass, where the values was higher, which was attributed to the lower mechanical resistance of the support.

[Determination of ru, rh and Pd in 30% trialkyl phosphine oxide (TRPO)-kerosene by inductively coupled plasma-atomic emission spectrum (ICP-AES)].

Science.gov (United States)

Wang, Jian-Chen; Zhang, Lin

2013-07-01

The determination method of Ru, Rh and Pd in 30% TRPO-kerosene ICP-AES was studied by using aqueous calibration reference solution and choosing ethanol as diluent. The effects of the contents of 30% TRPO-kerosene and aqueous solution and the concentration of HNO3 in 30% TRPO-kerosene on the intensities of Ru, Rh and Pd were described. The optimized condition for preparing samples and calibration solutions was chosen as follows: The contents of 30% TRPO-kerosene and aqueous phase were 10% (V/V) and 5% (V/V) respectively and the concentration of HNO3 30% TRPO-kerosene was 0.20 mol x L(-1). The determination method of Au, Ru and Pd was set up according to the above condition. The detection limit, precision and recovery ratio of Ru, Rh and Pd are well. The method is not only used in determination of Au, Ru and Pd in 30% TRPO-kerosene, but also used in other organic phases.

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

Energy Technology Data Exchange (ETDEWEB)

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.

PdRu alloy nanoparticles of solid solution in atomic scale: outperformance towards formic acid electro-oxidation in acidic medium

International Nuclear Information System (INIS)

Miao, Kanghua; Luo, Yun; Zou, Jiasui; Yang, Jun; Zhang, Fengqi; Huang, Lin; Huang, Jie; Kang, Xiongwu; Chen, Shaowei

2017-01-01

Developing catalyst of high performance and low cost toward the electro-oxidation of formic acid on the anode of fuel cell is critical for the commercialization of direct formic acid fuel cells. Here we reported the synthesis of Pd x Ru 10-x (x = 1,3,5,7,9) nanoparticles (NPs) by concurrent reduction of Pd 2+ and Ru 2+ in polyol solution at 200 °C. The particle size of the obtained NPs was confined at 5–15 nm in diameter. X-ray diffraction (XRD) analysis revealed face-centered cubic (fcc) crystal structure for Pd x Ru 10-x (x = 3,5,7,9), with the lattice parameter proportional to the Pd content. The formation of the solid solution in atomic scale was confirmed for the alloy nanoparticles by XRD and the elemental mapping. Williamson-Hall method revealed that the stacking fault was dependent on the alloying extent of the alloy nanoparticles and reached the minimum for Pd 5 Ru 5 , which exhibited the highest activity towards formic acid oxidation among all these prepared samples, with mass activity of 12.6 times higher than that of commercial Pd/C. It was observed that the highest catalytic activity was in agreement with the minimum of the stacking fault of the alloy nanoparticles.

Benzene adsorption and hydrogenation on Pd-Ru alloy by pulse chromatography

International Nuclear Information System (INIS)

Dobrokhotov, V.G.; Pavlova, L.F.; Gryaznov, V.M.

1983-01-01

Pulse chromatography has been applied to investigate benzene adsorption and hydrogenation on the Walls of a capillary of the Pd-6% Ru alloy at different hydrogen contents in the alloy and various methods of hydrogen supply: as a mixture with benzene vapors or by diffusion through the walls of the capillary. It is stated that reversible adsorption of benzene vapors on the Pd-6% Ru alloy at 303 K under the conditions of the β-phase existence in the alloy-hydrogen system does not change whereas in the region of the α-phase existence it slightly increases with a growth of hydrogen pressure. Strongly adsorbed benzene occupies approximately 7% of the surface. Only strongly adsorbed benzene is hydrogenated on the α-phase of the alloy-hydrogen system. Hydrogen supply to the hydrogenation zone by diffusion throUgh the alloy results in supersaturation of the surface active in the reaction of benzene hydrogenation with a chemisorbed hydrogen form

A determination method of Ru, Rh and Pd in high-level liquid waste (HLLW) by cation exchange separation and ICP-AES measurement

International Nuclear Information System (INIS)

Cao Desheng; Duan Shirong; Qin Fengzhou; Li Jinying; Zhang Huaili

1992-01-01

The authors describe a determination method of Ru, Rh and Pd in HLLW with cation-exchange separation and ICP-AES measurement. A sample of HLLW was treated with the hydrochloride acid containing enough sodium chloride, then passed through a strongly acidic cation-exchange resin column, the Ru, Rh and Pd as chloro-complexes go to the eluate while the interference elements are absorbed on the resins in the column. The Ru, Rh and Pd are collected and determined by ICP-AES. The obtained results show that the recovery is 90% and the relative standard deviation is 6% as the Ru content within the range (35-230) x 10 -6 ; the recovery is 106% and RSD is 10% as the Rh content within (2-20) x 10 -6 ; and the recovery of Pd is 72% as its content less than 2 x 10 -6

Electronic Structure of the fcc Transition Metals Ir, Rh, Pt, and Pd

DEFF Research Database (Denmark)

Andersen, O. Krogh

1970-01-01

We give a complete description of a relativistic augmented-plane-wave calculation of the band structures of the paramagnetic fcc transition metals Ir, Rh, Pt, and Pd. The width and position of the d band decrease in the sequence Ir, Pt, Rh, Pd; and N(EF)=13.8,23.2,18.7, and 32.7 (states/atom)/Ry,......We give a complete description of a relativistic augmented-plane-wave calculation of the band structures of the paramagnetic fcc transition metals Ir, Rh, Pt, and Pd. The width and position of the d band decrease in the sequence Ir, Pt, Rh, Pd; and N(EF)=13.8,23.2,18.7, and 32.7 (states....../atom)/Ry, respectively. Spin-orbit coupling is important for all four metals and the coupling parameter varies by 30% over the d bandwidth. Detailed comparisons with de Haas—van Alphen Fermi-surface dimensions have previously been presented and the agreement was very good. Comparison with measured electronic specific...

A novel IrNi@PdIr/C core-shell electrocatalyst with enhanced activity and durability for the hydrogen oxidation reaction in alkaline anion exchange membrane fuel cells.

Science.gov (United States)

Qin, Bowen; Yu, Hongmei; Jia, Jia; Jun, Chi; Gao, Xueqiang; Yao, Dewei; Sun, Xinye; Song, Wei; Yi, Baolian; Shao, Zhigang

2018-03-08

Herein, a novel non-platinum core-shell catalyst, namely, IrNi@PdIr/C was prepared via a galvanic replacement reaction; it exhibits enhanced hydrogen oxidation activity and excellent stability under alkaline conditions. Electrochemical experiments demonstrated that the mass and specific activities at 50 mV of IrNi@PdIr/C are 2.1 and 2.2 times that of commercial Pt/C in 0.1 M KOH at 298 K, respectively. Moreover, accelerated degradation tests have shown that the electrochemically active surface area (ECSA) of IrNi@PdIr/C reduces by only 5.1%, which is almost 4 times less than that of commercial Pt/C and the mass activity at 50 mV of IrNi@PdIr/C after 2000 potential cycles is still 1.8 times higher than that of aged Pt/C. XRD and XPS analysis suggest that the enhanced HOR activity is attributed to the weakening of the hydrogen binding to the PdIr overlayers induced by the IrNi core. The better stability to potential cycling can be associated with the PdIr shell, which inhibits oxide formation. These results suggest that IrNi@PdIr/C is a promising non-platinum anode catalyst for alkaline anion exchange membrane fuel cells.

Atom condensation on an atomically smooth surface: Ir, Re, W, and Pd on Ir(111)

International Nuclear Information System (INIS)

Wang, S.C.; Ehrlich, G.

1991-01-01

The distribution of condensing metal atoms over the two types of sites present on an atomically smooth Ir(111) has been measured in a field ion microscope. For Ir, Re, W, and Pd from a thermal source, condensing on Ir(111) at ∼20 K, the atoms are randomly distributed, as expected if they condense at the first site struck

XPS and STEM study of the interface formation between ultra-thin Ru and Ir OER catalyst layers and perylene red support whiskers

Directory of Open Access Journals (Sweden)

Atanasoska Ljiljana L.

2013-01-01

Full Text Available The interface formation between nano-structured perylene red (PR whiskers and oxygen evolution reaction (OER catalysts ruthenium and iridium has been studied systematically by XPS and STEM. The OER catalyst over-layers with thicknesses ranging from ~0.1 to ~50 nm were vapor deposited onto PR ex-situ. STEM images demonstrate that, with increasing thickness, Ru and Ir transform from amorphous clusters to crystalline nanoparticles, which agglomerate with increased over-layer thickness. XPS data show a strong interaction between Ru and PR. Ir also interacts with PR although not to the extent seen for Ru. At low coverages, the entire Ru deposit is in the reacted state while a small portion of the deposited Ir remains metallic. Ru and Ir bonding occur at the PR carbonyl sites as evidenced by the attenuation of carbonyl photoemission and the emergence of new peak assigned to C-O single bond. The curve fitting analysis and the derived stoichiometry indicates the formation of metallo-organic bonds. The co-existence of oxide bonds is also apparent.

Communication: Enhanced oxygen reduction reaction and its underlying mechanism in Pd-Ir-Co trimetallic alloys

Energy Technology Data Exchange (ETDEWEB)

Ham, Hyung Chul; Hwang, Gyeong S., E-mail: gshwang@che.utexas.edu [Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712 (United States); Manogaran, Dhivya [Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, Texas 78712 (United States); Lee, Kang Hee; Jin, Seon-ah; You, Dae Jong; Pak, Chanho [Energy Lab, Samsung Advanced Institute of Technology, Samsung Electronics Co., Ltd., Suwon (Korea, Republic of); Kwon, Kyungjung [Department of Energy and Mineral Resources Engineering, Sejong University, Seoul 143-747 (Korea, Republic of)

2013-11-28

Based on a combined density functional theory and experimental study, we present that the electrochemical activity of Pd{sub 3}Co alloy catalysts toward oxygen reduction reaction (ORR) can be enhanced by adding a small amount of Ir. While Ir tends to favorably exist in the subsurface layers, the underlying Ir atoms are found to cause a substantial modification in the surface electronic structure. As a consequence, we find that the activation barriers of O/OH hydrogenation reactions are noticeably lowered, which would be mainly responsible for the enhanced ORR activity. Furthermore, our study suggests that the presence of Ir in the near-surface region can suppress Co out-diffusion from the Pd{sub 3}Co substrate, thereby improving the durability of Pd-Ir-Co catalysts. We also discuss the relative roles played by Ir and Co in enhancing the ORR activity relative to monometallic Pd catalysts.

Communication: Enhanced oxygen reduction reaction and its underlying mechanism in Pd-Ir-Co trimetallic alloys

International Nuclear Information System (INIS)

Ham, Hyung Chul; Hwang, Gyeong S.; Manogaran, Dhivya; Lee, Kang Hee; Jin, Seon-ah; You, Dae Jong; Pak, Chanho; Kwon, Kyungjung

2013-01-01

Based on a combined density functional theory and experimental study, we present that the electrochemical activity of Pd 3 Co alloy catalysts toward oxygen reduction reaction (ORR) can be enhanced by adding a small amount of Ir. While Ir tends to favorably exist in the subsurface layers, the underlying Ir atoms are found to cause a substantial modification in the surface electronic structure. As a consequence, we find that the activation barriers of O/OH hydrogenation reactions are noticeably lowered, which would be mainly responsible for the enhanced ORR activity. Furthermore, our study suggests that the presence of Ir in the near-surface region can suppress Co out-diffusion from the Pd 3 Co substrate, thereby improving the durability of Pd-Ir-Co catalysts. We also discuss the relative roles played by Ir and Co in enhancing the ORR activity relative to monometallic Pd catalysts

Electrooxidation as the anaerobic pre-treatment of fats: oleate conversion using RuO2 and IrO2 based anodes.

Science.gov (United States)

Gonçalves, M; Alves, M M; Correia, J P; Marques, I P

2008-11-01

Electrochemical treatment of oleate using RuO2 and IrO2 type dimensionally stable anodes in alkaline medium was performed to develop a feasible anaerobic pre-treatment of fatty effluents. The results showed that the pre-treated solutions over RuO2 were faster degraded by anaerobic consortium than the raw oleate solutions or the electrolysed solutions using IrO2. In batch experiments carried out with pre-treated solutions over RuO2 (100-500mg/L), no lag phases were observed before the methane production onset. On the other hand, raw oleate and pre-treated oleate over IrO2 had originated lag phases of 0-140 and 0-210h, respectively. This study demonstrated that it is advantageous to apply the electrochemical treatment carried out on the RuO2 type DSA in order to achieve a faster biodegradation of lipid-containing effluent and consequently to obtain a faster methane production.

Surface noble metal modified PdM/C (M = Ru, Pt, Au) as anode catalysts for direct ethanol fuel cells

International Nuclear Information System (INIS)

Mao, Han; Huang, Tao; Yu, Aishui

2016-01-01

In this article, we studied the surface noble metal modification on Pd nanoparticles, other than the homogeneous or core-shell structure. The surface modification will lead to the uneven constitution within the nanoparticles and thus more obvious optimization effect toward the catalyst brought by the lattice deformation. The surface of the as-prepared Pd nanoparticles was modified with Ru, Pt or Au by a moderate and green approach, respectively. XPS results confirm the interactive electron effects between Pd and the modified noble metal. Electrochemical measurements show that the surface noble metal modified catalysts not only show higher catalytic activity, but also better stability and durability. The PdM/C catalysts all exhibit good dispersion and very little agglomeration after long-term potential cycles toward ethanol oxidation. With only 10% metallic atomic ratio of Au, PdAu/C catalyst shows extraordinary catalytic activity and stability, the peak current reaches 1700 mA mg"−"1 Pd, about 2.5 times that of Pd/C. Moreover, the PdAu/C maintains 40% of the catalytic activity after 4500 potential cycles. - Highlights: • Pd-based catalysts with complicated exposed facets. • Much enhanced electrocatalytic activity and stability with about 10% noble metal M (M = Ru, Pt, Au) on Pd nanoparticles. • The outstanding electrocatalytic performance of PdAu/C towards ethanol oxidation after the Au modification.

Surface noble metal modified PdM/C (M = Ru, Pt, Au) as anode catalysts for direct ethanol fuel cells

Energy Technology Data Exchange (ETDEWEB)

Mao, Han; Huang, Tao, E-mail: huangt@fudan.edu.cn; Yu, Aishui, E-mail: asyu@fudan.edu.cn

2016-08-15

In this article, we studied the surface noble metal modification on Pd nanoparticles, other than the homogeneous or core-shell structure. The surface modification will lead to the uneven constitution within the nanoparticles and thus more obvious optimization effect toward the catalyst brought by the lattice deformation. The surface of the as-prepared Pd nanoparticles was modified with Ru, Pt or Au by a moderate and green approach, respectively. XPS results confirm the interactive electron effects between Pd and the modified noble metal. Electrochemical measurements show that the surface noble metal modified catalysts not only show higher catalytic activity, but also better stability and durability. The PdM/C catalysts all exhibit good dispersion and very little agglomeration after long-term potential cycles toward ethanol oxidation. With only 10% metallic atomic ratio of Au, PdAu/C catalyst shows extraordinary catalytic activity and stability, the peak current reaches 1700 mA mg{sup −1} Pd, about 2.5 times that of Pd/C. Moreover, the PdAu/C maintains 40% of the catalytic activity after 4500 potential cycles. - Highlights: • Pd-based catalysts with complicated exposed facets. • Much enhanced electrocatalytic activity and stability with about 10% noble metal M (M = Ru, Pt, Au) on Pd nanoparticles. • The outstanding electrocatalytic performance of PdAu/C towards ethanol oxidation after the Au modification.

Effect of spin structure transition in IrMn on the CoPd/IrMn perpendicular exchange biased system

Energy Technology Data Exchange (ETDEWEB)

Janjua, Muhammad Bilal; Guentherodt, Gernot [II. Physikalisches Institut A, RWTH Aachen University, Aachen (Germany)

2011-07-01

The exchange bias (EB) phenomenon is studied in MBE grown Pd(10 nm)/CoPd(x=8,16,30 nm)/IrMn(15 nm)/Pd(4 nm) samples, which exhibit a perpendicular anisotropy of Co22Pd78. These samples are field cooled along the out-of-plane direction and hysteresis loops are measured along both the out-of-plane and in-plane directions. It is observed that there is a transition temperature where the out-of-plane EB becomes greater than the in-plane EB. This behavior of EB is an evidence of the change in the spin structure of the given system, which is also revealed by the magnetization versus temperature measurements of the exchange biased and of the sole IrMn samples. It is found that with increasing temperature there is a spin structure transition in Ir25Mn75 (15nm) related to the 2Q to 3Q transition in the bulk, which is responsible for the increase in out-of-plane EB. A vertical shift in the hysteresis loop is also observed in these exchange biased samples at low temperatures (T<50 K).

Influence of hydrogen on the thermoelectric power of palladium alloyed with neighbouring elements: I. Pd/Ru/H and Pd/Rh/H alloys

CERN Document Server

Szafranski, A W

2003-01-01

Pd/Ru and Pd/Rh alloys have been loaded with hydrogen in high-pressure conditions. The resulting hydrogen contents were close to the stoichiometric composition, H/(Pd + Me) = 1. Lower hydrogen contents have been obtained by successive partial desorptions. The thermoelectric power and electrical resistance of one- and two-phase alloys have been measured simultaneously in the temperature range between 80 and 300 K. A Nordheim-Gorter type correlation of the two quantities has been observed in many cases and the partial thermopowers corresponding to electron-phonon scattering and lattice disorder could be determined. The observed anomalous behaviour of the total and partial thermopowers is attributed to virtual bound states of ruthenium or rhodium.

Bifunctional electrodes with ir and Ru oxide mixtures and pt for unified regenerative cells; Electrodos bifuncionales basados en mezclas de oxidos de Ir y Ru con Pt para celdas regenerativas unificadas

Energy Technology Data Exchange (ETDEWEB)

Duron-Torres, S.M.; Escalante-Garcia, I.L. [Universidad Autonoma de Zacatecas, Zacatecas (Mexico); Cruz, J. C.; Arriaga-Hurtado; L.G. [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica, Pedro Escobedo, Queretaro (Mexico)]. E-mail: duronsm@prodigy.net.mx

2009-09-15

Unified regenerative fuel cells (URFC) represent an attractive option to obtain hydrogen and generate energy using a compact device. Nevertheless, the fusion of a fuel cell (PEMFC) and a water electrolyzer continue to be a challenge because of the wide range of conditions to which this type of device is subject. Because of its kinetic characteristics, oxygen reduction reaction (ORR) in PEMFC and oxygen evolution reaction (OER) in PEMWE are the limiting stages of the URFC depending on the mode of operation. The primary focus of research related to URFC is the obtainment of bifunctional electrocatalysts that satisfactorily perform in both oxygen reactions and support the different working conditions found in a fuel cell and an electrolyzer. The present work contributes to the research on bifunctional electrocatalysts and shows some preliminary results from the electrochemical study of different Pt gcc, IrO{sub 2} and RuO{sub 2} mixtures supported in Ebonex® as oxygen electrodes. The electrochemical characterization with cyclic voltamperometry (CV), linear voltamperometry (LV) and electrochemical impedance spectroscopy (EIS) in H{sub 2}SO{sub 4} 0.5 M, in the absence and present of oxygen shows that Ebonex®-supported bifunctional electrodes IrO{sub 2}-Pt and RuO{sub 2}-Pt present reasonable electrocatalytic properties for oxygen evolution and reduction reactions and present the possibility of their use in an URFC. The Ir- based oxide electrodes show greater stability than ruthenium-oxide electrodes. [Spanish] Las celdas de combustible regenerativas unificadas (URFC) representan una atractiva opcion para la obtencion de hidrogeno y generacion de energia en un dispositivo compacto. Sin embargo, la fusion de una celda de combustible (PEMFC) y un electrolizador de agua (PEMWE) sigue siendo un reto por la amplia gama de condiciones a que se sujeta un dispositivo de este tipo. Por sus caracteristicas cineticas, la reaccion de reduccion de oxigeno (ORR) en la PEMFC y la

A general approach for the synthesis of bimetallic M–Sn (M = Ru, Rh and Ir) catalysts for efficient hydrogenolysis of ester

KAUST Repository

Samal, Akshaya Kumar

2016-11-24

A versatile synthetic method was applied for the preparation of Sn containing bimetallic catalysts. The synthesis was performed by simply mixing the super hydride [LiB(C2H5)(3)H], with a metal (Ru, Rh or Ir) salt and an organotin complex in tetrahydrofuran solvent without using any surfactant. This leads to the formation of monodispersed M-Sn (M = Ru, Rh or Ir) bimetallic nanoparticles (NPs). These bimetallic catalysts show high performances in the hydrogenolysis of ester to the corresponding alcohol.

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

Energy Technology Data Exchange (ETDEWEB)

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)

Oxygen perovskites of type Ba/sub 3/Bsup(III)RuIrO/sub 9/

Energy Technology Data Exchange (ETDEWEB)

Duerrschmidt, E; Kemmler-Sack, S [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

1980-11-01

The black perovskites Ba/sub 3/Bsup(III)RuIrO/sub 9/ with Bsup(III) = La, Nd, Sm, Gd, Dy, Er, Yb, In, Sc are isotypic. They crystallize in a hexagonal BaTiO/sub 3/ structure (sequence (hcc)/sub 2/). The mean oxydation state of the noble metal ions is +4.5.

Low Pt content Pt-Ru-Ir-Sn quaternary catalysts for anodic methanol oxidation in DMFC

Energy Technology Data Exchange (ETDEWEB)

Neburchilov, Vladimir; Wang, Haijiang; Zhang, Jiujun [Institute for Fuel Cell Innovation, National Research Council (Canada)

2007-07-15

In this communication we report our research work on low Pt content Pt-Ru-Ir-Sn quaternary catalysts for use in DMFC anodes. The carbon-supported quaternary metal alloy catalyst was synthesized according to the solution reduction method and was deposited onto a carbon fiber paper or a carbon aerogel nanofoam to form the anode for direct methanol fuel cells. The Pt loading of the electrode is 0.1 mg/cm{sup 2}. The testing results from a three-electrode electrochemical cell show that the simultaneous use of higher Ir (25-35 wt.%) and Sn (10 wt.%) content gives satisfactory stability and higher activity for methanol oxidation than the commercially available E-TEK anode (80%[0.5Pt 0.5Ru]/C on carbon cloth). Energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), scanning electron microscope (SEM), and Bruner-Emmett-Teller method (BET) measurements were carried out to characterize the composition, structure, morphology, and surface area of the developed catalysts. (author)

Noble metal abundances in komatiite suites from Alexo, Ontario and Gorgona Island, Colombia

Science.gov (United States)

Brügmann, G. E.; Arndt, N. T.; Hofmann, A. W.; Tobschall, H. J.

1987-08-01

The distribution of the chalcophile and siderophile metals Cu, Ni, Au, Pd, Ir, Os and Ru in an Archaean komatiite flow from Alexo, Ontario and in a Phanerozoic komatiitic suite of Gorgona Island, Colombia, provides new information about the geochemical behaviour of these elements. Copper, Au and Pd behave as incompatible elements during the crystallization of these ultramafic magmas. In contrast, Ni, Ir, Os and Ru concentrations systematically decrease with decreasing MgO contents, a pattern characteristic of compatible elements. These trends are most probably controlled by olivine crystallization, which implies that Ir, Os and Ru are compatible in olivine. Calculated partition coefficients for Ir, Os and Ru between olivine and the melt are about 1.8. Compared to primitive mantle, parental komatiitic liquids are enriched in (incompatible) Cu, Au and Pd and depleted in (compatible) Ir, Os and Ru. Within both Archaean and Phanerozoic komatiites, noble metal ratios such as Au/Pd, Ir/Os, Os/Ru and Ru/Ir and ratios of lithophile and siderophile elements such as Ti/Pd, Ti/Au are constant and similar to primitive mantle values. This implies that Au and Pd are moderately incompatible elements and that there has been no significant fractionation of siderophile and lithophile elements since the Archaean. Platinum-group element abundances of normal MORB are highly variable and always much lower than in komatiites, because MORB magma is saturated with sulfur and a variable but minor amount of sulfide segregated during mantle melting or during the ascent of magma to the surface. Sulfide deposits associated with komatiites display similar chalcophile element patterns to those of komatiites. Noble metal ratios such as Pd/Ir, Au/Ir, Pd/Os and Pd/Ru can be used to determine the composition of the host komatiite at the time of sulfide segregation.

Spectrochemical study the effect of high energetic ionization radiation on Ru(III, Pd(II and Hg(II complexes

Directory of Open Access Journals (Sweden)

Samar A. Aly

2017-04-01

Thermal studies of these chelates before and after γ-irradiation stable that the complexes of Ru(III and Pd (II after γ-irradiation are more thermal show than Hg(II complexes before and after γ-irradiation.

Effect of Ni and noble metals (Ru, Pd and Pt) on performance of bifunctional MoP/SiO2 for hydroconversion of methyl laurate

Science.gov (United States)

Nie, Ziyang; Zhang, Zhena; Chen, Jixiang

2017-10-01

SiO2 supported bifunctional MoP catalysts modified with different metal promoters (Ni, Ru, Pd, Pt), where Mo/Ni and Mo/M(M = Ru, Pd and Pt) atomic ratios was respectively 10 and 40, were prepared by TPR method from the phosphate precursors. It was found that the introduction of metal promoters facilitated the reduction of phosphate precursor and enhanced the dispersion of MoP. However, the MoP catalyst acidity was scarcely influenced by the small amount of metal promoters. In the hydroconversion of methyl laurate, the promoters enhanced the MoP catalyst activity for conversion of methyl laurate and hydrogenation of alkenes (intermediate), but reduced isomerization ability. Among the promoters, Ru was an optimum to decrease selectivity to alkenes while maintain high selectivity to iso-alkanes, and Mo40RuP showed better stability than MoP. At 380 °C and 3.0 MPa, the conversion of methyl laurate, the total selectivity to C11 and C12 hydrocarbons and the selectivity to iso-alkanes maintained at 100%, ∼94% and ∼30% on Mo40RuP during 102 h, respectively. The good stability of Mo40RuP is ascribed to that the presence of Ru prevented the sintering of MoP particles and suppressed carbon deposition.

Catalytic mechanisms of direct pyrrole synthesis via dehydrogenative coupling mediated by PNP-Ir or PNN-Ru pincer complexes: Crucial role of proton-transfer shuttles in the PNP-Ir system

KAUST Repository

Qu, Shuanglin

2014-04-02

Kempe et al. and Milstein et al. have recently advanced the dehydrogenative coupling methodology to synthesize pyrroles from secondary alcohols (e.g., 3) and β-amino alcohols (e.g., 4), using PNP-Ir (1) and PNN-Ru (2) pincer complexes, respectively. We herein present a DFT study to characterize the catalytic mechanism of these reactions. After precatalyst activation to give active 1A/2A, the transformation proceeds via four stages: 1A/2A-catalyzed alcohol (3) dehydrogenation to give ketone (11), base-facilitated C-N coupling of 11 and 4 to form an imine-alcohol intermediate (18), base-promoted cyclization of 18, and catalyst regeneration via H2 release from 1R/2R. For alcohol dehydrogenations, the bifunctional double hydrogen-transfer pathway is more favorable than that via β-hydride elimination. Generally, proton-transfer (H-transfer) shuttles facilitate various H-transfer processes in both systems. Notwithstanding, H-transfer shuttles play a much more crucial role in the PNP-Ir system than in the PNN-Ru system. Without H-transfer shuttles, the key barriers up to 45.9 kcal/mol in PNP-Ir system are too high to be accessible, while the corresponding barriers (<32.0 kcal/mol) in PNN-Ru system are not unreachable. Another significant difference between the two systems is that the addition of alcohol to 1A giving an alkoxo complex is endergonic by 8.1 kcal/mol, whereas the addition to 2A is exergonic by 8.9 kcal/mol. The thermodynamic difference could be the main reason for PNP-Ir system requiring lower catalyst loading than the PNN-Ru system. We discuss how the differences are resulted in terms of electronic and geometric structures of the catalysts and how to use the features in catalyst development. © 2014 American Chemical Society.

Initial Reduction of CO2 on Pd-, Ru-, and Cu-Doped CeO2(111) Surfaces: Effects of Surface Modification on Catalytic Activity and Selectivity.

Science.gov (United States)

Guo, Chen; Wei, Shuxian; Zhou, Sainan; Zhang, Tian; Wang, Zhaojie; Ng, Siu-Pang; Lu, Xiaoqing; Wu, Chi-Man Lawrence; Guo, Wenyue

2017-08-09

Surface modification by metal doping is an effective treatment technique for improving surface properties for CO 2 reduction. Herein, the effects of doped Pd, Ru, and Cu on the adsorption, activation, and reduction selectivity of CO 2 on CeO 2 (111) were investigated by periodic density functional theory. The doped metals distorted the configuration of a perfect CeO 2 (111) by weakening the adjacent Ce-O bond strength, and Pd doping was beneficial for generating a highly active O vacancy. The analyses of adsorption energy, charge density difference, and density of states confirmed that the doped metals were conducive for enhancing CO 2 adsorption, especially for Cu/CeO 2 (111). The initial reductive dissociation CO 2 → CO* + O* on metal-doped CeO 2 (111) followed the sequence of Cu- > perfect > Pd- > Ru-doped CeO 2 (111); the reductive hydrogenation CO 2 + H → COOH* followed the sequence of Cu- > perfect > Ru- > Pd-doped CeO 2 (111), in which the most competitive route on Cu/CeO 2 (111) was exothermic by 0.52 eV with an energy barrier of 0.16 eV; the reductive hydrogenation CO 2 + H → HCOO* followed the sequence of Ru- > perfect > Pd-doped CeO 2 (111). Energy barrier decomposition analyses were performed to identify the governing factors of bond activation and scission along the initial CO 2 reduction routes. Results of this study provided deep insights into the effect of surface modification on the initial reduction mechanisms of CO 2 on metal-doped CeO 2 (111) surfaces.

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

KAUST Repository

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.

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

KAUST Repository

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.

Measurement of pO2 by luminescence lifetime spectroscopy: A comparative study of the phototoxicity and sensitivity of [Ru(Phen)3 ]2+ and PdTCPP in vivo.

Science.gov (United States)

Huntosova, Veronika; Gerelli, Emmanuel; Horvath, Denis; Wagnieres, Georges

2017-05-01

Dysfunctions in tissue metabolism can be detected at early stages by oxygen partial pressure (pO 2 ) measurement. The measurement of emission lifetimes offers very promising and non-invasive approach to estimate pO 2 in vivo. This study compares two extensively used oxygen sensors and assesses their in vivo oxygen sensitivity and phototoxic effect. Luminescence lifetime of Ru-polypyridyl complex and of Pd-porphyrin is measured in the Chick's Chorioallantoic Membrane (CAM) model with a dedicated optical fiber-based, time-resolved spectrometer. The Pd-porphyrin luminescence lifetimes measured in the CAM model exposed to different pO 2 levels are longer and have a broader dynamic range (10-100 μs) than those of Ru-polypyridyl complex (0.6-1 μs). The combined statistical analysis based on an estimate of the kurtosis and skewness, bootstrapping method and routine normality tests is performed. The indicators of the averages and signal to noise ratio stability are also calculated. The combination of several data processing allows selection of the better sensor for a given application. In particular, it is found that the advantage of Ru-polypyridyl complex over Pd-porphyrin is two-fold: i) Ru-polypyridyl complex datasets have consistently better statistical characteristics, ii) Ru-polypyridyl exhibits lower cytotoxicity. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

IrPd nanoalloys: simulations, from surface segregation to local electronic properties

Energy Technology Data Exchange (ETDEWEB)

Andriamiharintsoa, T. H. [Institut de Physique et Chimie des Matériaux de Strasbourg CNRS-UDS UMR 7504 (France); Rakotomahevitra, A. [Institut pour la Maîtrise de l’Énergie, Faculté des sciences d’Antananarivo (Madagascar); Piccolo, L. [Institut de Recherches sur la Catalyse et l’Environnement de Lyon IRCELYON, UMR 5256 CNRS and Université Lyon 1 (France); Goyhenex, C., E-mail: christine.goyhenex@ipcms.unistra.fr [Institut de Physique et Chimie des Matériaux de Strasbourg CNRS-UDS UMR 7504 (France)

2015-05-15

Using semi-empirical modeling, namely tight-binding at different levels of accuracy, the chemical, crystallographic, and electronic structures of bimetallic IrPd nanoparticles are characterized. For the purpose, model cuboctahedral particles containing 561 atoms are considered. Atomistic simulations show that core–shell nanoparticles are highly stable, with a strong surface segregation of Pd, at least for one atomic shell thickness. Within self-consistent tight-binding calculations founded on the density functional theory, an accurate insight is given into the electronic structure of these materials which have a high potential as catalysts.

Complete titanium substitution by boron in a tetragonal prism: exploring the complex boride series Ti(3-x)Ru(5-y)Ir(y)B(2+x) (0 ≤ x ≤ 1 and 1 theory.

Science.gov (United States)

Fokwa, Boniface P T; Hermus, Martin

2011-04-18

Polycrystalline samples and single crystals of four members of the new complex boride series Ti(3-x)Ru(5-y)Ir(y)B(2+x) (0 ≤ x ≤ 1 and 1 X-ray diffraction as well as energy- and wavelength-dispersive X-ray spectroscopy analyses. They crystallize with the tetragonal Ti(3)Co(5)B(2) structure type in space group P4/mbm (No. 127). Tetragonal prisms of Ru/Ir atoms are filled with titanium in the boron-poorest phase (Ti(3)Ru(2.9)Ir(2.1)B(2)). Gradual substitution of titanium by boron then results in the successive filling of this site by a Ti/B mixture en route to the complete boron occupation, leading to the boron-richest phase (Ti(2)Ru(2.8)Ir(2.2)B(3)). Furthermore, both ruthenium and iridium share two sites in these structures, but a clear Ru/Ir site preference is found. First-principles density functional theory calculations (Vienna ab initio simulation package) on appropriate structural models (using a supercell approach) have provided more evidence on the stability of the boron-richest and -poorest phases, and the calculated lattice parameters corroborate very well with the experimentally found ones. Linear muffin-tin orbital atomic sphere approximation calculations further supported these findings through crystal orbital Hamilton population bonding analyses, which also show that the Ru/Ir-B and Ru/Ir-Ti heteroatomic interactions are mainly responsible for the structural stability of these compounds. Furthermore, some stable and unstable phases of this complex series could be predicted using the rigid-band model. According to the density of states analyses, all phases should be metallic conductors, as was expected from these metal-rich borides.

Fusion of 110Pd with 110Pd

International Nuclear Information System (INIS)

Morawek, W.

1991-07-01

In the framework of this thesis the excitation functions of the systems 110 Pd + 110 Pd and 110 Pd + 104 Ru could be measured. The evaporation-residual-nucleus cross sections is deviating from lighter systems dominated by channels, which arise from evaporation of α particles. In the reaction 110 Pd + 110 Pd no xn channels were observed. In comparison to other reactions qualitatively a strong fusion hindrance of this system is shown. (orig./HSI) [de

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

Energy Technology Data Exchange (ETDEWEB)

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.

Pt{sub X}Ru{sub Y}Ir{sub Z} as a bifunctional electrocatalyst for oxygen reduction reaction in a PEM fuel cell; Pt{sub X}Ru{sub Y}Ir{sub Z} como electrocatalizador bifuncional para la reaccion redox del oxigeno en una celda tipo PEM

Energy Technology Data Exchange (ETDEWEB)

Morales, L.; Fernandez, A.M. [Centro de Investigacion en Energia, Universidad Nacional Autonoma de Mexico, Temixco, Morelos (Mexico)]. E-mail: limos@cie.unam.mx; Cano, U. [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

2009-09-15

This work presents the synthesis and characterization of the ternary material Pt{sub X}Ru{sub Y}Ir{sub Z}, obtained by chemical reduction with NaBH{sub 4}. Two different atomic compositions were developed (sample A and B) in order to observe the kinetic effect, as suggested by the combinatorial libraries. The main objective of this synthesis is to study the oxygen reduction reaction (ORR and OER) and its potential use in the construction of a bifunctional catalyst. In addition, each of the metals are synthesized separately using the same technique in order to make the corresponding comparison. The compounds obtained were characterized by sweep electron microscopy, x-ray diffraction and composition using fluorescence and energy-dispersive x-ray spectroscopy. The results showed a displacement of the x-ray diffraction peaks for Ir and Pt in sample A, and displacement in sample B for Ru and Ir peaks. These changes suggest the possible formation of a solid solution substitution. Separate cyclic and linear voltamperometry studies were performed for the oxygen reduction and release reactions. The electrochemical analysis showed improved kinetic behavior when combining the three metals according to the composition of sample B. [Spanish] En este trabajo se presenta la sintesis y caracterizacion del material ternario Pt{sub X}Ru{sub Y}Ir{sub Z}, elaborado por la tecnica de Reduccion Quimica utilizando al NaBH{sub 4}. Se elaboraron dos composiciones atomicas diferentes (Muestra A y B) con el fin de observar el efecto cinetico, como lo sugieren las librerias combinatorias. El objetivo principal de esta sintesis es para el estudio de la Reaccion Redox del Oxigeno (RRO y REO) y su potencial uso para la construccion de un catalizador bifuncional. Asi mismo, se realiza la sintesis de cada uno de los metales por separado empleando la misma tecnica, con el proposito de realizar la comparacion correspondiente. Los compuestos obtenidos se caracterizaron por Microscopia Electronica de

Thermochemical investigations on intermetallic UMe3 compounds (Me=Ru,Rh,Pd)

International Nuclear Information System (INIS)

Wijbenga, G.

1981-10-01

The subject of this thesis is the determination of the thermodynamic properties of the intermetallic compounds of uranium with the light platinum metals, ruthenium, rhodium and palladium. These intermetallics are formed as very stable compounds during fission in nuclear fuel by the reaction of the fission products Ru, Rh and Pd with the matrix. Methods for the preparation of URu 3 , URh 3 and UPd 3 , experiments showing the chemical reactivities of these compounds, and studies of the stoichiometry of hexagonal UPd 3 by X-ray diffraction of solubility experiments of UN and palladium in UPd 3 , are described. Thermodynamic properties of the UMe 3 compounds have been obtained using several experimental thermodynamic techniques: fluorine bomb calorimetry, low-temperature cryogenic calorimetry, high-temperature drop calorimetry and EMF measurements of reversible cells. (Auth.)

Investigation of palladium-103 production and IR07-103Pd brachytherapy seed preparation

International Nuclear Information System (INIS)

Saidi, Pooneh; Sadeghi, Mahdi; Enferadi, Milad; Aslani, Gholamreza

2011-01-01

Highlights: → We report the cyclotron production of 103-palladium via 103 Rh(p,n) 103 Pd reaction. → 103 Pd was absorbed on resin beads for brachytherapy seed preparation. → The optimum absorption of 103 Pd in resin was achieved at 0.5 M HCl. → Version 5 of MCNP code was employed to model a new 103 Pd brachytherapy seed. - Abstract: In this study, design and fabrication of 103 Pd brachytherapy seed was investigated. The excitation functions of 103 Rh(p,n) 103 Pd and 103 Rh(d,2n) 103 Pd reactions were calculated using EMPIRE (version 3.1 Rivoli), ALICE/ASH and TALYS-1.2 codes, the TENDL-2010 database and compared with the published data. Production of 103 Pd was done via 103 Rh(p,n) 103 Pd nuclear reaction. The target was bombarded with 18 MeV protons at 200 μA beam current for 15 h. After irradiation and radiochemical separation of the electroplated rhodium target, the optimum condition for absorption of 103 Pd into Amberlite (registered) IR-93 resin was achieved at 0.5 M HCl. Version 5 of the (MCNP) Monte Carlo radiation transport code was employed to calculate the dosimetric parameters around the 103 Pd brachytherapy seed. Finally the calculated results were compared with published results for other commercial sources.

"McDonald's" reklāmas analīze Latvijā un Maltā - starpkultūru atšķirīgā uztvere

OpenAIRE

Barkēviča, Santa

2016-01-01

Darbā ““McDonald's” reklāmas analīze Latvijā un Maltā – starpkultūru atšķirīgā uztvere” galvenais problēmjautājums, kas jānoskaidro, vai starptautisks uzņēmums var izmantot viena stila reklāmas kampaņu divās dažādās valstīs – Latvijā un Maltā. Galvenais darba mērķis ir noskaidrot, vai starptautisks uzņēmums var veidot vienu reklāmas kampaņu shēmu, un to izmantot dažādās valstīs, kur atrodas tā franšīzes vai filiāles, un kā starpkultūru atšķirība ietekmē reklāmas uztveri. Veicot aptaujas, inte...

Surface studies on graphite furnace platforms covered with Pd, Rh and Ir as modifiers in graphite furnace atomic absorption spectrometry of tellurium

Energy Technology Data Exchange (ETDEWEB)

Pedro, Juana [Area de Química Analítica, Departamento de Química, Facultad de Ingeniería Química, Universidad Nacional del Litoral, Santiago del Estero 2829 (S3000GL.N), Santa Fe (Argentina); Stripekis, Jorge [Laboratorio de Análisis de Trazas, Departamento de Química Inorgánica, Analítica y Química Física, INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria (1428), Buenos Aires (Argentina); Departamento de Ingeniería Química, Instituto Tecnológico de Buenos Aires, Av. Eduardo Madero 399 (1106), Buenos Aires (Argentina); Bonivardi, Adrian [Area de Química Analítica, Departamento de Química, Facultad de Ingeniería Química, Universidad Nacional del Litoral, Santiago del Estero 2829 (S3000GL.N), Santa Fe (Argentina); Tudino, Mabel, E-mail: tudino@qi.fcen.uba.ar [Laboratorio de Análisis de Trazas, Departamento de Química Inorgánica, Analítica y Química Física, INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria (1428), Buenos Aires (Argentina)

2015-05-01

The main objective of this work is the study of correlations between the efficiency of the distribution of the permanent platinum group modifiers Pd, Rh and Ir over the graphite surface with the aim of improving analytical signal of tellurium. Modifier solution was deposited onto the platform and pyrolysed after drying. In the case of Pd, the physical vaporization/deposition technique was also tested. In order to analyze the differences amongst coverings (morphology, topology and distribution), the graphite surfaces were studied with scanning electron microscopy and energy dispersive X-ray microscopy. Micrographs for physical vaporization and pyrolytic deposition of Pd were also analyzed in order to explain the lack of signal obtained for tellurium with the first alternative. Similar micrographs were obtained for pyrolytic deposition of Ir and Rh and then, compared to those of Pd. Ir showed the most homogeneous distribution on the graphite surface and the tallest and sharpest transient. With the aim of improving the analytical signal of tellurium, the correlation between the surface studies and the tellurium transient signal (height, area and shape) is discussed. - Highlights: • Distribution of Rh, Pd and Ir onto graphite furnaces is evaluated by SEM and EDX • Micrographs and spectra showed that surface distribution could influence Te signal. • Ir showed the best signal together with the most homogeneous surface distribution. • Pd-PVD micrographs revealed the absence of graphite and no signal for Te.

New self-assembled material based on Ru nanoparticles and 4-sulfocalix[4]arene as an efficient and recyclable catalyst for reduction of brilliant yellow azo dye in water: a new model catalytic reaction

Energy Technology Data Exchange (ETDEWEB)

Rambabu, Darsi; Pradeep, Chullikkattil P.; Dhir, Abhimanew, E-mail: abhimanew@iitmandi.ac.in [Indian Institute of Technology (India)

2016-12-15

New self-assembled material (Ru@SC) with ruthenium nanoparticles (Ru NPs) and 4-sulfocalix[4]arene (SC) is synthesized in water at room temperature. Ru@SC is characterized by thermal gravimetric analysis, FT-IR, powder x-ray diffraction, TEM and SEM analysis. The size of Ru nanoparticles in the self-assembly is approximately 5 nm. The self-assembled material Ru@SC shows an efficient catalytic reduction of toxic ‘brilliant yellow’ (BY) azo dye. The reduced amine products were successfully separated and confirmed by single-crystal XRD, NMR and UV-Vis spectroscopy. Ru@SC showed a better catalytic activity in comparison with commercial catalysts Ru/C (ruthenium on charcoal 5 %) and Pd/C (palladium on charcoal 5 and 10 %). The catalyst also showed a promising recyclability and heterogeneous nature as a catalyst for reduction of ‘BY’ azo dye.

Improvement of energy conversion efficiency and power generation in direct borohydride-hydrogen peroxide fuel cell: The effect of Ni-M core-shell nanoparticles (M = Pt, Pd, Ru)/Multiwalled Carbon Nanotubes on the cell performance

Science.gov (United States)

Hosseini, M. G.; Mahmoodi, R.

2017-12-01

In this study, core@shell nanoparticles with Ni as a core material and Pt, Pd and Ru as shell materials are synthesized on multiwalled carbon nanotube (MWCNT) as catalyst support using the sequence reduction method. The influence of Ni@Pt, Ni@Pd and Ni@Ru core@shell nanoparticles on MWCNT toward borohydride oxidation in alkaline solution is investigated by various three-electrode electrochemical techniques. Also, the impact of these anodic electrocatalysts on the performance of direct borohydride-hydrogen peroxide fuel cell (DBHPFC) is evaluated. The structural and morphological properties of electrocatalysts are studied by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HR-TEM) and X-ray photoelectron spectroscopy (XPS). The results of three electrode investigations show that Ni@Pd/MWCNT has excellent catalytic activity since borohydride oxidation current density on Ni@Pd/MWCNT (34773.27 A g-1) is 1.37 and 9.19 times higher than those of Ni@Pt/MWCNT (25347.27 A g-1) and Ni@Ru/MWCNT (3782.83 A g-1), respectively. Also, the energy conversion efficiency and power density of DBHPFC with Ni@Pd/MWCNT (246.82 mW cm-2) increase to 34.27% and 51.53% respect to Ni@Pt/MWCNT (162.24 mW cm-2) and Ni@Ru/MWCNT (119.62 mW cm-2), respectively. This study reveals that Ni@Pd/MWCNT has highest activity toward borohydride oxidation and stability in fuel cell.

The sticking probability for H-2 on some transition metals at a hydrogen pressure of 1 bar

DEFF Research Database (Denmark)

Johansson, Martin; Lytken, Ole; Chorkendorff, Ib

2008-01-01

The sticking probability for hydrogen on films of Co, Ni, Cu, Ru, Rh, Pd, Ir, and Pt supported on graphite has been measured at a hydrogen pressure of 1 bar in the temperature range 40–200 °C. The sticking probability is found to increase in the order Ni, Co, Ir, Pd, Pt, Rh, and Ru at temperature...

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

Directory of Open Access Journals (Sweden)

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.

Transition metal-centered trigonal prisms as building units in RE{sub 14}T{sub 3}In{sub 3} (RE = Y, Ho, Er, Tm, Lu; T = Pd, Ir, Pt) and Y{sub 4}IrIn

Energy Technology Data Exchange (ETDEWEB)

Zaremba, R.; Rodewald, U.C.; Poettgen, R. [Inst. fuer Anorganische und Analytische Chemie, Univ. Muenster (Germany)

2007-12-15

The indides RE{sub 14}T{sub 3}In{sub 3} (RE = Y, Ho, Er, Tm, Lu; T = Pd, Ir, Pt) and Y{sub 4}IrIn were synthesized from the elements by are-melting and subsequent annealing for crystal growth. Their structures were characterized on the basis of X-ray powder and single crystal data: Lu{sub 14}Co{sub 3}In{sub 3}-type, space group P4{sub 2}/nmc, a = 970.2(1), c = 2340.7(5) pm for Y{sub 13.95}Pd{sub 3}In{sub 3.05}, a = 959.7(1), c = 2309.0(5) pm for Ho{sub 14}Pd{sub 2.95}In{sub 3}, a = 955.5(1), c = 2305.1(5) pm for Er{sub 14}Pd{sub 3}In{sub 3}, a = 950.9(1), c = 2291.6(5) pm for Tm{sub 13.90}Pd{sub 3}In{sub 3.10}, a = 944.4(1), c = 2275.5(5) pm for Lu{sub 13.93}Pd{sub 3}In{sub 3.07}, a = 962.9(1), c = 2343.0(5) pm for Y{sub 13.86}Ir{sub 2.97}In{sub 3.02}, a = 967.6(1), c = 2347.8(5) pm for Y{sub 13.92}Pt{sub 3.05}In{sub 2.91}, and Gd{sub 4}RhIn-type, space group F anti 43m, a = 1368.6(2) pm for Y{sub 4}IrIn. The main structural motifs are transition metal-centered trigonal prisms of the rare Earth elements which are condensed to two-dimensional networks in the RE{sub 14}T{sub 3}In{sub 3} indides and to a three-dimensional one in Y{sub 4}IrIn. The indium atoms in both structure types show segregation in the metal-rich matrix, i.e. In{sub 2} dumbbells in the RE{sub 14}T{sub 3}In{sub 3} indides (309 pm In2-In2 in Y{sub 13.86}Ir{sub 2.97}In{sub 3.02}) and In{sub 4} tetrahedra (322 pm In-In) in Y{sub 4}IrIn. The crystal chemical peculiarities of both structure types are discussed. (orig.)

PALLADIUM, PLATINUM, RHODIUM, RUTHENIUM AND IRIDIUM IN PERIDOTITES AND CHROMITITES FROM OPHIOLITE COMPLEXES IN NEWFOUNDLAND.

Science.gov (United States)

Page, Norman J; Talkington, Raymond W.

1984-01-01

Samples of spinel lherzolite, harzburgite, dunite, and chromitite from the Bay of Islands, Lewis Hills, Table Mountain, Advocate, North Arm Mountain, White Hills Periodite Point Rousse, Great Bend and Betts Cove ophiolite complexes in Newfoundland were analyzed for the platinum-group elements (PGE) Pd, Pt, Rh, Ru and Ir. The ranges of concentration (in ppb) observed for all rocks are: less than 0. 5 to 77 (Pd), less than 1 to 120 (Pt), less than 0. 5 to 20 (Rh), less than 100 to 250 (Ru) and less than 20 to 83 (Ir). Chondrite-normalized PGE ratios suggest differences between rock types and between complexes. Samples of chromitite and dunite show relative enrichment in Ru and Ir and relative depletion in Pt and Pd.

Magnetic and transport behaviour in Pr3X(X=In,Sn,Ga,Ge,Ni,Co,Ru,Ir) systems

International Nuclear Information System (INIS)

Garde, C.S.; Ray, J.

1998-01-01

Magnetic and transport studies on Pr 3 X (X=In, Sn, Ga, Ge, Ni, Co, Ru, Ir) systems gave evidence for complex magnetic behaviour. All the systems, except X=Sn, exhibit ferromagnetic ordering. The X=Sn system exhibits antiferromagnetic ordering. For X=Ga and Sn, metamagnetic behaviour has been observed. Crystal field effects are found to play an important role in influencing magnetic behaviour. The strength of the crystal field term has also been estimated. (orig.)

Stability and ordering properties of fcc alloys based on Rh, Ir, Pd, and Pt

Czech Academy of Sciences Publication Activity Database

Turchi, P. E. A.; Drchal, Václav; Kudrnovský, Josef

2006-01-01

Roč. 74, č. 6 (2006), 064202/1-064202/12 ISSN 1098-0121 Institutional research plan: CEZ:AV0Z10100520; CEZ:AV0Z1010914 Keywords : alloy phase stability * ordering in alloys * fcc alloys of Rh, Ir, Pd, Pt Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.107, year: 2006

Structural aspects of the new quasi-2-D heavy fermion materials CeIrIns and CeRhIns

International Nuclear Information System (INIS)

Moshopoulou, E.G.; Moshopoulou, E.G.; Fisk, Z.; Sarrao, J.L.; Thompson, J.D.; Fisk, Z.

2002-01-01

The title compounds are new heavy fermion materials. They adopt a quasi two-dimensional crystal structure and exhibit unusual (for a heavy fermion system) low temperature properties. Although the study of their physical and structural behaviour at low temperatures and/or high pressures is still in progress, we present here some results concerning their average crystal structure, and we discuss very briefly their similarities and differences with the compounds CeIn3 and UTGa 5 (T: Co, Ni, Ir, Pd, Cu, Ru). (authors)

New determination of the half-lives of 57Co, 103Ru, sup(103m)Rh, 103Pd, and 109Cd

International Nuclear Information System (INIS)

Vaninbroukx, R.; Grosse, G.; Zehner, W.

1981-01-01

The half-lives of five radionuclides were redetermined by photon-counting techniques using NaI(Tl)- and Si(Li) detectors. The results are: 57 Co: (271.90 +- 0.09)d, 103 Ru: (39.260 +- 0.020)d, sup(103m)Rh: (56.114 +- 0.020)m, 103 Pd: (16.991 +- 0.019)d, and 109 Cd: (461.90 +- 0.30)d. The quoted uncertainties, corresponding to a lσ level, take into account random and systematic uncertainties. (author)

NO reduction by CO over noble-metal catalysts under cycled feedstreams

International Nuclear Information System (INIS)

Muraki, H.; Fujitani, Y.

1986-01-01

The reduction of NO with CO was studied over α-Al/sub 2/O/sub 3/-supported Pt, Pd, Rh, Ru, and Ir catalysts. The activities were measured by using cycled feeds and steady noncycled feed. The activity sequence of the catalysts tested was Rh > Ru > Ir > Pd > Pt. The activities of Pt and Pd catalysts were increased under the cycled feed. The periodic operation effect on the Pt catalyst was more predominant than that on the Pd catalyst. The order of periodic operation effect corresponded to the order of their susceptibility to CO self-poisoning

Conversion of biomass-derived sorbitol to glycols over carbon-materials supported Ru-based catalysts

Science.gov (United States)

Guo, Xingcui; Guan, Jing; Li, Bin; Wang, Xicheng; Mu, Xindong; Liu, Huizhou

2015-11-01

Ruthenium (Ru) supported on activated carbon (AC) and carbon nanotubes (CNTs) was carried out in the hydrogenolysis of sorbitol to ethylene glycol (EG) and 1,2-propanediol (1,2-PD) under the promotion of tungsten (WOx) species and different bases. Their catalytic activities and glycols selectivities strongly depended on the support properties and location of Ru on CNTs, owning to the altered metal-support interactions and electronic state of ruthenium. Ru located outside of the tubes showed excellent catalytic performance than those encapsulated inside the nanotubes. Additionally, the introduction of WOx into Ru/CNTs significantly improved the hydrogenolysis activities, and a complete conversion of sorbitol with up to 60.2% 1,2-PD and EG yields was obtained on RuWOx/CNTs catalyst upon addition of Ca(OH)2. Stability study showed that this catalyst was highly stable against leaching and poisoning and could be recycled several times.

Robustness of dynamic magnetism in the triangle-based antiferromagnets Ba3Ru1- x Ir x Ti2O9 ( x = 0.5 and 0.8)

Science.gov (United States)

Lee, W.-J.; Do, S.-H.; Lee, S.; Choi, Y.-S.; Choi, K.-Y.; Yoon, Sungwon; Suh, Byoungjin; Jang, Zeehoon

2018-01-01

We report on the spin dynamics of the strong spin-orbit coupled antiferromagnets Ba3Ru1- x Ir x Ti2O9 ( x = 0.5 and 0.8), which comprise a mixture of edge- and corner-sharing triangles. Muon spin-relaxation measurements give no hints of long-range magnetic order down to 25 mK. Rather, the muon spin-relaxation rates λ( T) show persistent spin dynamics below 1 K, indicating that fast fluctuations are dominant in spite of Ir4+( J eff = 1/2)/Ru4+( S = 1) randomness. The muon spin depolarization of both compounds is well described by a stretched exponential function with the stretching exponent β = 0.4 (0.6) for x = 0.5 (0.8) at low temperatures, which is larger than β = 1/3 expected for a spin glass. Our results suggest that randomness in the spin number and the exchange interaction induces a partial spin freezing, but the majority of spins remain dynamically fluctuating.

Immune-Related Adverse Events Associated with Anti-PD-1/PD-L1 Treatment for Malignancies: A Meta-Analysis

Directory of Open Access Journals (Sweden)

Peng-Fei Wang

2017-10-01

Full Text Available Background: Treatment of cancers with programmed cell death protein 1 (PD-1 pathway inhibitors can lead to immune-related adverse events (irAEs, which could be serious and even fetal. Therefore, clinicians should be aware of the characteristics of irAEs associated with the use of such drugs.Methods: The MEDLINE, EMBASE, and Cochrane databases were searched to find potential studies using the following strategies: anti-PD-1/PD-L1 treatment; irAEs; and cancer. R© package Meta was used to pool incidence.Results: Forty-six studies representing 12,808 oncologic patients treated with anti-PD-1/PD-L1 agents were included in the meta-analysis. The anti-PD-1/PD-L1 agents included nivolumab, pembrolizumab, atezolizumab, durvalumab, avelumab, and BMS-936559. The tumor types were melanomas, Hodgkin lymphomas, urothelial carcinomas, breast cancers, non-small cell lung cancers, renal cell carcinomas (RCC, colorectal cancers, and others. We described irAEs according to organ systems, namely, the skin (pruritus, rash, maculopapular rash, vitiligo, and dermatitis, endocrine system (hypothyroidism, hyperthyroidism, hypophysitis, thyroiditis, and adrenal insufficiency, digestive system (colitis, diarrhea, pancreatitis, and increased AST/ALT/bilirubin, respiratory system (pneumonitis, lung infiltration, and interstitial lung disease, and urinary system (increased creatinine, nephritis, and renal failure. In patients treated with the PD-1 signaling inhibitors, the overall incidence of irAEs was 26.82% (95% CI, 21.73–32.61; I2, 92.80 in any grade and 6.10% (95% CI, 4.85–7.64; I2, 52.00 in severe grade, respectively. The development of irAEs was unrelated to the dose of anti-PD-1/PD-L1 agents. The incidence of particular irAEs varied when different cancers were treated with different drugs. The incidence of death due to irAEs was around 0.17%.Conclusion: The occurrence of irAEs was organ-specific and related to drug and tumor types.

Radial dose functions for 103Pd, 125I, 169Yb and 192Ir brachytherapy sources: an EGS4 Monte Carlo study

International Nuclear Information System (INIS)

Mainegra, E.

2000-01-01

Radial dose functions g(r) in water around 103 Pd, 125 I, 169 Yb and 192 Ir brachytherapy sources were estimated by means of the EGS4 simulation system and extensively compared with experimental as well as with theoretical results. The DLC-136/PHOTX cross section library, water molecular form factors, bound Compton scattering and Doppler broadening of the Compton-scattered photon energy were considered in the calculations. Use of the point source approach produces reasonably accurate values of the radial dose function only at distances beyond 0.5 cm for 103 Pd sources. It is shown that binding corrections for Compton scattering have a negligible effect on radial dose function for 169 Yb and 192 Ir seeds and for 103 Pd seeds under 5.0 cm from the source centre and for the 125 I seed model 6702 under 8.0 cm. Beyond those limits there is an increasing influence of binding corrections on radial dose function for 103 Pd and 125 I sources. Results in solid water medium underestimate radial dose function for low-energy sources by as much as 6% for 103 Pd and 2.5% for 125 I already at 2 cm from source centre resulting in a direct underestimation of absolute dose rate values. It was found necessary to consider medium boundaries when comparing results for the radial dose function of 169 Yb and 192 Ir sources to avoid discrepancies due to the backscattering contribution in the phantom medium. Values of g(r) for all source types studied are presented. Uncertainties lie under 1% within one standard deviation. (author)

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

International Nuclear Information System (INIS)

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

Effect of HCl Concentration on the Oxidation of LIX 63 and the Subsequent Separation of Pd(II), Pt(IV), Ir(IV) and Rh(III) by Solvent Extraction

Energy Technology Data Exchange (ETDEWEB)

Nguyen, Thi Hong; Lee, Man Seung [Mokpo National University, Jeollanamdo (Korea, Republic of)

2016-10-15

During the selective extraction of Pd(II) by LIX 63 from 6 M HCl solutions containing platinum group metals, an oxidation-reduction reaction occurs between the LIX 63 and Ir(IV). Since the reduced Ir(III) cannot be extracted by solvating and amine extractants, the oxidation-reduction reaction has a significant effect on the separation of Pt(IV), Ir(IV) and Rh(III). Therefore, the effect of HCl concentration on the reduction of Ir(IV) during the extraction with LIX 63 was investigated at 3 and 6 M HCl solutions. The extraction behavior of Iridium by Aliquat 336 from the Pd(II) free raffinate showed that the percentage of iridium extraction rapidly decreased when HCl concentration was increased from 3 to 6 M, indicating that more Ir(IV) was reduced to Ir(III). Extraction schemes for the separation of Pt(IV), iridium and Rh(III) by Aliquat 336 from 3 and 6 M HCl solutions were investigated.

High pressure stability of the monosilicides of cobalt and the platinum group elements

International Nuclear Information System (INIS)

Hernandez, J.A.; Vočadlo, L.; Wood, I.G.

2015-01-01

Highlights: • We model the high-pressure phases of cobalt- and platinum-group-monosilicides. • CoSi, RuSi, OsSi transform with pressure from the ε-FeSi to the CsCl structure. • RhSi and IrSi transform with pressure from the MnP structure to the ε-FeSi structure. • PdSi and PtSi transform with pressure from the MnP structure to the CuTi structure. - Abstract: The high pressure stability of CoSi, RuSi, RhSi, PdSi, OsSi, IrSi and PtSi was investigated by static first-principles calculations up to 300 GPa at 0 K. As found experimentally, at atmospheric pressure, CoSi, RuSi and OsSi were found to adopt the cubic ε-FeSi structure (P2 1 3) whereas RhSi, PdSi, IrSi and PtSi were found to adopt the orthorhombic MnP (Pnma) structure. At high pressure, CoSi, RuSi and OsSi show a phase transition to the CsCl structure (Pm3 ¯ m) structure at 270 GPa, 7 GPa and 6 GPa respectively. RhSi and IrSi were found to transform to an ε-FeSi structure at 10 GPa and 25 GPa. For PdSi and PtSi, a transformation from the MnP structure to the tetragonal CuTi structure (P4/nmm) occurs at 13 GPa and 20 GPa. The pressure dependence of the electronic density of states reveals that RuSi and OsSi are semiconductors in the ε-FeSi structure and become metallic in the CsCl structure. RhSi and IrSi are metals in the MnP structure and become semimetals in their high pressure ε-FeSi form. CoSi in the ε-FeSi configuration is a semimetal. PdSi and PtSi remain metallic throughout up to 300 GPa

Platinum group element enrichments and possible chondritic Ru:Ir across the Frasnian-Famennian boundary, western New York State.

Science.gov (United States)

Over, D J; Conaway, C A; Katz, D J; Goodfellow, W D; Gregoire, D C

1997-08-01

The Frasnian-Famennian boundary is recognized as the culmination of a global mass extinction in the Late Devonian. In western New York State the boundary is a distinct horizon within a pyritic black shale bed of the upper Hanover Shale defined by the first occurrence of Palmatolepis triangularis in the absence of Frasnian conodonts. The boundary is characterized by a minor disconformity marked by a lag concentration of conodonts. Iridium at the boundary is 0.11-0.24 ng/g, two to five times background levels of <0.05 ng/g; other Ir enrichments of 0.38 ng/g and 0.49 ng/g occur within 50 cm of the conodont-constrained boundary. Numerous Ir enrichments in the boundary interval suggest extraterrestrial accretion and platinum group element (PGE) concentration at disconformities, or mobilization and concentration in organic-rich/pyritic-rich laminations from cosmic or terrestrial sources. PGE ratios of Pt/Pd and Ku/Ir at the boundary horizon approximate chondritic ratios and are suggestive of an unaltered extraterrestrial source. These values do not conclusively establish a single extraterrestrial impact as the ultimate cause of the Frasnian-Famennian mass extinction, especially given the presence of similar Ir enrichments elsewhere in the section and the absence at the boundary of microtektites and shocked mineral grains.

Computational modelling of Ti50Pt50-xMx shape memory alloys (M: Ni, Ir or Pd and x = 6.25-43.75 at.%)

CSIR Research Space (South Africa)

Modiba, Rosinah M

2017-09-01

Full Text Available The ab initio density functional theory approach was employed to study the effect of Ni, Ir or Pd addition to the TiPt shape memory alloy. The supercell approach in VASP was used to substitute Pt with 6.25, 18.75, 25.00, 31.25 and 43.75 at.% Ni, Ir...

Affinity for a malignant tumor and organs at the elements in group VIII of the periodic table

International Nuclear Information System (INIS)

Ando, Atsushi; Hisada, Kinichi; Ando, Itsuko.

1975-01-01

In order to investigate the tumor affinity of the radioisotopes, iron(Fe-59), cobalt(Co-58), ruthenium(Ru-103), palladium(Pd-103), osmium(Os-185+191) and iridium(Ir-192), the elements of group VIII in the periodic table were examined, using rats which were subcutaneously transplanted with Yoshida sarcoma. Six preparations, 59 Fe-chloride, 58 Co-chloride, 103 Ru-chloride, 103 Pd-chloride, 185+191 Os-hexachlorosmic acid and 192 Ir-hexachloriridic acid were injected intravenously in to each group of tumor bearing rats. These rats were sacrificed at various periods after injection of each preparation: 3 hours, 24 hours and 48 hours in all preparations, except 59 Fe-chloride with 30 minutes, 3 hours, 24 hours and 48 hours. The radioactivities of the tumor, blood muscle, liver, kidney and spleen were measured by a well-type scintillation counter, and retention values (in every tissue including the tumor were calculated in percent of administered dose per g-tissue weight). 185+191 Os-hexachlorosmic acid had a considerably strong affinity for the malignant tumor. 59 Fe-chloride, 58 Co-chloride, 103 Ru-chloride, 103 Pd-chloride and 192 Ir-hexachloriridic acid did not have any affinity for the malignant tumor. However 59 Fe-chloride had a very strong affinity for blood corpuscles. 103 Pd-chloride had a fairly strong affinity for the kidney and liver, 58 Co-chloride had a fairly affinity for the liver, 103 Ru-chloride, 185+191 Os-hexachlorosmic acid and 192 Ir-hexachloriridic acid had a fairly strong affinity for the kidney. (Evans, J.)

X-ray Lβ215 emission spectrum of Ru in Ru(NH3)6Cl3

International Nuclear Information System (INIS)

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

Intramolecular electron transfer in cyanide bridged adducts comprising Ru(II)/Ru(III) tetracarboxylate and [Mn(I)(CO)(CN)((t)BuNC)(4)] units.

Science.gov (United States)

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.

Magnetic anisotropy in the Kitaev model systems Na2IrO3 and RuCl3

Science.gov (United States)

Chaloupka, Jiří; Khaliullin, Giniyat

2016-08-01

We study the ordered moment direction in the extended Kitaev-Heisenberg model relevant to honeycomb lattice magnets with strong spin-orbit coupling. We utilize numerical diagonalization and analyze the exact cluster ground states using a particular set of spin-coherent states, obtaining thereby quantum corrections to the magnetic anisotropy beyond conventional perturbative methods. It is found that the quantum fluctuations strongly modify the moment direction obtained at a classical level and are thus crucial for a precise quantification of the interactions. The results show that the moment direction is a sensitive probe of the model parameters in real materials. Focusing on the experimentally relevant zigzag phases of the model, we analyze the currently available neutron-diffraction and resonant x-ray-diffraction data on Na2IrO3 and RuCl3 and discuss the parameter regimes plausible in these Kitaev-Heisenberg model systems.

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

International Nuclear Information System (INIS)

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

Dose rate constants for 125I, 103Pd, 192Ir and 169Yb brachytherapy sources: an EGS4 Monte Carlo study

International Nuclear Information System (INIS)

Mainegra, Ernesto; Capote, Roberto; Lopez, Ernesto

1998-01-01

An exhaustive revision of dosimetry data for 192 Ir, 125 I, 103 Pd and 169 Yb brachytherapy sources has been performed by means of the EGS4 simulation system. The DLC-136/PHOTX cross section library, water molecular form factors, bound Compton scattering and Doppler broadening of the Compton-scattered photon energy were considered in the calculations. The absorbed dose rate per unit contained activity in a medium at 1 cm in water and air-kerma strength per unit contained activity for each seed model were calculated, allowing the dose rate constant (DRC) Λ to be estimated. The influence of the calibration procedure on source strength for low-energy brachytherapy seeds is discussed. Conversion factors for 125 I and 103 Pd seeds to obtain the dose rate in liquid water from the dose rate measured in a solid water phantom with a detector calibrated for dose to water were calculated. A theoretical estimate of the DRC for a 103 Pd model 200 seed equal to 0.669±0.002 cGy h -1 U -1 is obtained. Comparison of obtained DRCs with measured and calculated published results shows agreement within 1.5% for 192 Ir, 169 Yb and 125 I sources. (author)

Conductivity study of thermally stabilized RuO2/polythiophene nanocomposites

Science.gov (United States)

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.

On-line measurements of RuO{sub 4} during a PWR severe accident

Energy Technology Data Exchange (ETDEWEB)

Reymond-Laruinaz, S.; Doizi, D. [CEA, DEN, Departement de Physico-chimie, CEA/Saclay, 91191 Gif sur Yvette Cedex, (France); Manceron, L. [Societe Civile Synchrotron SOLEIL, L' Orme des Merisiers, St-Aubin BP48, 91192 Gif-sur-Yvette Cedex, (France); MONARIS, UMR 8233, Universite Pierre et Marie Curie, 4 Place Jussieu, case 49, F-75252 Paris Cedex 05, (France); Boudon, V. [Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS-Universite de Bourgogne, 9 avenue Alain Savary, BP 47870, F-21078 Dijon Cedex, (France); Ducros, G. [CEA, DEN, Departement d' Etudes des Combustibles, CEA/Cadarache, 13108 Saint-Paul-lez-Durance cedex, (France)

2015-07-01

After the Fukushima accident, it became essential to have a way to monitor in real time the evolution of a nuclear reactor during a severe accident, in order to react efficiently and minimize the industrial, ecological and health consequences of the accident. Among gaseous fission products, the tetroxide of ruthenium RuO{sub 4} is of prime importance since it has a significant radiological impact. Ruthenium is a low volatile fission product but in case of the rupture of the vessel lower head by the molten corium, the air entering into the vessel oxidizes Ru into gaseous RuO{sub 4}, which is not trapped by the Filtered Containment Venting Systems. To monitor the presence of RuO{sub 4} allows making a diagnosis of the core degradation and quantifying the release into the atmosphere. To determine the presence of RuO{sub 4}, FTIR spectrometry was selected. To study the feasibility of the monitoring, high-resolution IR measurements were realized at the French synchrotron facility SOLEIL on the infrared beam line AILES. Thereafter, theoretical calculations were done to simulate the FTIR spectrum to describe the specific IR fingerprint of the molecule for each isotope and based on its partial pressure in the air. (authors)

Electrochemical Reduction of CO2 on IrxRu(1–x)O2(110) Surfaces 

DEFF Research Database (Denmark)

Bhowmik, Arghya; Hansen, Heine Anton; Vegge, Tejs

2017-01-01

with oxygen-coordinated intermediates that can circumvent the limitations imposed by the scaling relations on metal catalysts. Here, we introduce an innovative concept of ligand effects in oxide catalysts. Both IrO2 and RuO2 binds OH* and other intermediates from the electrochemical reduction of CO2 (CO2RR......High overpotentials and low faradic efficiencies plague metal catalysts for direct conversion of CO2 to methanol and other liquid fuels. RuO2-based electrocatalysts have been observed to evolve methanol at low overpotentials, which has been attributed to an alternative reaction mechanism......) strongly, but the stable and miscible system IrxRu(1-x)O2 exhibits anomalous weaker binding energy in the presence of CO* spectators, because of Ru–Ir ligand effects. The weakened adsorbate binding leads to a very low CO2RR onset potential (methanol evolution at −0.2 V RHE). An Ir atom at the bridge site...

Synthesis, characterization, DNA binding and catalytic applications of Ru(III) complexes.

Science.gov (United States)

Shoair, A F; El-Shobaky, A R; Azab, E A

2015-01-01

A new series of azodye ligands 5-chloro-3-hydroxy-4-(aryldiazenyl)pyridin-2(1H)-one (HLn) were synthesized by coupling of 5-chloro-3-hydroxypyridin-2(1H)-one with aniline and its p-derivatives. These ligands and their Ru(III) complexes of the type trans-[Ru(Ln)2(AsPh3)2]Cl were characterized by elemental analyses, IR, (1)H NMR and UV-Visible spectra as well as magnetic and thermal measurements. The molar conductance measurements proved that all the complexes are electrolytes. IR spectra show that the ligands (HLn) acts as a monobasic bidentate ligand by coordinating via the nitrogen atom of the azo group (NN) and oxygen atom of the deprotonated phenolic OH group, thereby forming a six-membered chelating ring and concomitant formation of an intramolecular hydrogen bond. The molecular and electronic structures of the investigated compounds (HLn) were also studied using quantum chemical calculations. The calf thymus DNA binding activity of the ligands (HLn) and their Ru(III) complexes were studied by absorption spectra and viscosity measurements. The mechanism and the catalytic oxidation of benzyl alcohol by trans-[Ru(Ln)2(AsPh3)2]Cl with hydrogen peroxide as co-oxidant were described. Copyright © 2015 Elsevier B.V. All rights reserved.

Salt-induced phase separation for the determination of metals as their diethyldithiocarbamate complexes by high-performance liquid chromatography

International Nuclear Information System (INIS)

Mueller, B.J.; Lovett, R.J.

1987-01-01

Reversed-phase high-performance liquid chromatography with ultraviolet detection can be used to determine trace levels of Pt(II), Pd(II), Rh(III), Co(III), Ru(III), and Ir in aqueous solution following complexation with diethyldithiocarbamate. The metal complexes are extracted into acetonitrile from aqueous solution by the addition of a saturated salt solution. Quantitative metal recovery from aqueous solution is achievable for most metals for a wide solution pH range. Detection limits for the metals are <3 ng of metal/mL of original aqueous sample. Analyses of real samples are highly reproducible and sensitive. Ir an interfere in the determination of Pt(II) and Rh(III). A general protocol for chromatographic separation and determination of Pt(II), Pd(II), Rh(III), Ru(III), and Ir in aqueous solution is presented

Synthesis and characterization of Ru(II) complexes with polyfunctional quinazoline-(3H)-4-ones

International Nuclear Information System (INIS)

Prabhakar, B.; Lingaiah, P.; Laxma Reddy, K.

1991-01-01

Few Ru(II) complexes of the type Ru(O-N-O) 2 with tridentate O-N-O donors and of the type RuCl 2 (O-N) 2 with bidentate O-O and O-N donors have been synthesized and characterized on the basis of analytical, conductivity, thermal, magnetic, IR, electronic and PMR spectral data. The IR and PMR spectral data of the metal complexes indicate that the lignads like 2-methyl/phenyl-3-(2'-hydroxybenzalamino) quinazoline-(3H)-4-one(MHBQ/PHBQ) act as uninegative tridentate, 2-methyl/phenyl-3-(carboxymethyl) quinazoline(3H)-4-one (MCMQ/PCMQ) as uninegative bidentate and 2-methyl/phenyl-3-(furfuralamino) quinazoline-(3H)-4-one (MFQ/PFQ), 2-methyl/phenyl-3-(acetamino) quinazoline-(3H)-4-one (MAQ/PAQ), 2-methyl/phenyl3-(uramino)quinazoline-(3H)-4-one (MUQ/PUQ) and 2-methyl/phenyl-3-thiouramino)quinazoline-(3H)-4-one-(MTUQ/PTUQ) as neutral bidentate ligands. The electronic spectral data of the complexes indicate that the arrangement around Ru(II) is octahedral. (author). 25 refs., 2 tabs

Structure of ultrathin Pd films determined by low-energy electron microscopy and diffraction

Energy Technology Data Exchange (ETDEWEB)

Santos, B; De la Figuera, J [Centro de Microanalisis de Materiales, Universidad Autonoma de Madrid, Madrid 28049 (Spain); Puerta, J M; Cerda, J I [Instituto de Ciencia de Materiales, CSIC, Madrid 28049 (Spain); Herranz, T [Instituto de Quimica-Fisica ' Rocasolano' , CSIC, Madrid 28006 (Spain); McCarty, K F [Sandia National Laboratories, Livermore, CA 94550 (United States)], E-mail: benitosantos001@gmail.com

2010-02-15

Palladium (Pd) films have been grown and characterized in situ by low-energy electron diffraction (LEED) and microscopy in two different regimes: ultrathin films 2-6 monolayers (ML) thick on Ru(0001), and {approx}20 ML thick films on both Ru(0001) and W(110). The thinner films are grown at elevated temperature (750 K) and are lattice matched to the Ru(0001) substrate. The thicker films, deposited at room temperature and annealed to 880 K, have a relaxed in-plane lattice spacing. All the films present an fcc stacking sequence as determined by LEED intensity versus energy analysis. In all the films, there is hardly any expansion in the surface-layer interlayer spacing. Two types of twin-related stacking sequences of the Pd layers are found on each substrate. On W(110) the two fcc twin types can occur on a single substrate terrace. On Ru(0001) each substrate terrace has a single twin type and the twin boundaries replicate the substrate steps.

Bonding Properties of a Novel Inorganometallic Complex, Ru(SnPh(3))(2)(CO)(2)(iPr-DAB) (iPr-DAB = N,N'-Diisopropyl-1,4-diaza-1,3-butadiene), and its Stable Radical-Anion, Studied by UV-Vis, IR, and EPR Spectroscopy, (Spectro-) Electrochemistry, and Density Functional Calculations.

Science.gov (United States)

Aarnts, Maxim P.; Wilms, Maikel P.; Peelen, Karin; Fraanje, Jan; Goubitz, Kees; Hartl, Frantisek; Stufkens, Derk J.; Baerends, Evert Jan; Vlcek, Antonín

1996-09-11

Ru(SnPh(3))(2)(CO)(2)(iPr-DAB) was synthesized and characterized by UV-vis, IR, (1)H NMR, (13)C NMR, (119)Sn NMR, and mass (FAB(+)) spectroscopies and by single-crystal X-ray diffraction, which proved the presence of a nearly linear Sn-Ru-Sn unit. Crystals of Ru(SnPh(3))(2)(CO)(2)(iPr-DAB).3.5C(6)H(6) form in the triclinic space group P&onemacr; in a unit cell of dimensions a = 11.662(6) Å, b = 13.902(3) Å, c = 19.643(2) Å, alpha = 71.24(2) degrees, beta = 86.91(4) degrees, gamma = 77.89(3) degrees, and V = 2946(3) Å(3). One-electron reduction of Ru(SnPh(3))(2)(CO)(2)(iPr-DAB) produces the stable radical-anion [Ru(SnPh(3))(2)(CO)(2)(iPr-DAB)](*-) that was characterized by IR, and UV-vis spectroelectrochemistry. Its EPR spectrum shows a signal at g = 1.9960 with well resolved Sn, Ru, and iPr-DAB (H, N) hyperfine couplings. DFT-MO calculations on the model compound Ru(SnH(3))(2)(CO)(2)(H-DAB) reveal that the HOMO is mainly of sigma(Sn-Ru-Sn) character mixed strongly with the lowest pi orbital of the H-DAB ligand. The LUMO (SOMO in the reduced complex) should be viewed as predominantly pi(H-DAB) with an admixture of the sigma(Sn-Ru-Sn) orbital. Accordingly, the lowest-energy absorption band of the neutral species will mainly belong to the sigma(Sn-Ru-Sn)-->pi(iPr-DAB) charge transfer transition. The intrinsic strength of the Ru-Sn bond and the delocalized character of the three-center four-electron Sn-Ru-Sn sigma-bond account for the inherent stability of the radical anion.

Durable Clinical Benefit in Metastatic Renal Cell Carcinoma Patients Who Discontinue PD-1/PD-L1 Therapy for Immune-Related Adverse Events.

Science.gov (United States)

Martini, Dylan J; Hamieh, Lana; McKay, Rana R; Harshman, Lauren C; Brandao, Raphael; Norton, Craig K; Steinharter, John A; Krajewski, Katherine M; Gao, Xin; Schutz, Fabio A; McGregor, Bradley; Bossé, Dominick; Lalani, Aly-Khan A; De Velasco, Guillermo; Michaelson, M Dror; McDermott, David F; Choueiri, Toni K

2018-04-01

The current standard of care for treatment of metastatic renal cell carcinoma (mRCC) patients is PD-1/PD-L1 inhibitors until progression or toxicity. Here, we characterize the clinical outcomes for 19 mRCC patients who experienced an initial clinical response (any degree of tumor shrinkage), but after immune-related adverse events (irAE) discontinued all systemic therapy. Clinical baseline characteristics, outcomes, and survival data were collected. The primary endpoint was time to progression from the date of treatment cessation (TTP). Most patients had clear cell histology and received anti-PD-1/PD-L1 therapy as second-line or later treatment. Median time on PD-1/PD-L1 therapy was 5.5 months (range, 0.7-46.5) and median TTP was 18.4 months (95% CI, 4.7-54.3) per Kaplan-Meier estimation. The irAEs included arthropathies, ophthalmopathies, myositis, pneumonitis, and diarrhea. We demonstrate that 68.4% of patients ( n = 13) experienced durable clinical benefit off treatment (TTP of at least 6 months), with 36% ( n = 7) of patients remaining off subsequent treatment for over a year after their last dose of anti-PD-1/PD-L1. Three patients with tumor growth found in a follow-up visit, underwent subsequent surgical intervention, and remain off systemic treatment. Nine patients (47.4%) have ongoing irAEs. Our results show that patients who benefitted clinically from anti-PD-1/PD-L1 therapy can experience sustained beneficial responses, not needing further therapies after the initial discontinuation of treatment due to irAEs. Investigation of biomarkers indicating sustained benefit to checkpoint blockers are needed. Cancer Immunol Res; 6(4); 402-8. ©2018 AACR . ©2018 American Association for Cancer Research.

Spatial variation of contaminant elements of roadside dust samples from Budapest (Hungary) and Seoul (Republic of Korea), including Pt, Pd and Ir.

Science.gov (United States)

Sager, Manfred; Chon, Hyo-Taek; Marton, Laszlo

2015-02-01

Roadside dusts were studied to explain the spatial variation and present levels of contaminant elements including Pt, Pd and Ir in urban environment and around Budapest (Hungary) and Seoul (Republic of Korea). The samples were collected from six sites of high traffic volumes in Seoul metropolitan city and from two control sites within the suburbs of Seoul, for comparison. Similarly, road dust samples were obtained two times from traffic focal points in Budapest, from the large bridges across the River Danube, from Margitsziget (an island in the Danube in the northern part of Budapest, used for recreation) as well as from main roads (no highways) outside Budapest. The samples were analysed for contaminant elements by ICP-AES and for Pt, Pd and Ir by ICP-MS. The highest Pt, Pd and Ir levels in road dusts were found from major roads with high traffic volume, but correlations with other contaminant elements were low, however. This reflects automobile catalytic converter to be an important source. To interpret the obtained multi-element results in short, pollution index, contamination index and geo-accumulation index were calculated. Finally, the obtained data were compared with total concentrations encountered in dust samples from Madrid, Oslo, Tokyo and Muscat (Oman). Dust samples from Seoul reached top level concentrations for Cd-Zn-As-Co-Cr-Cu-Mo-Ni-Sn. Just Pb was rather low because unleaded gasoline was introduced as compulsory in 1993. Concentrations in Budapest dust samples were lower than from Seoul, except for Pb and Mg. Compared with Madrid as another continental site, Budapest was higher in Co-V-Zn. Dust from Oslo, which is not so large, contained more Mn-Na-Sr than dust from other towns, but less other metals.

The 'Big Karl' magnetic spectrometer - studies of the 103Ru transition nucleus with (d,p) and (p,d) reactions

International Nuclear Information System (INIS)

Huerlimann, W.

1981-04-01

The paper describes the structure and characteristics of the spectrometer and its application in a study of the 102 Ru(d,p) 103 Ru and 104 Ru(p,d) 103 Ru reactions. The study is structured as follows: To begin with the theoretical fundamentals, ion-optical characteristics and layout of BIG KARL are described. Field measurements and analyses carried out on the magnets of the spectrometer are described as well as the functioning of the 'Ht correction coils' used here for the first time to prevent faulty imaging. Chapter IV then describes methods employed so far to optimize resolution for large aperture angles of the spectrometer. Finally, chapter V investigates the 103 Ru transition nucleons on the basis of the 102 Ru(d,p) 103 RU and 104 Ru(p,d) 103 Ru transfer reactions measured in BIG KARL. (orig./HSI) [de

Femtosecond time-resolved vibrational SFG spectroscopy of CO/Ru( 0 0 1 )

Science.gov (United States)

Hess, Ch.; Wolf, M.; Roke, S.; Bonn, M.

2002-04-01

Vibrational sum-frequency generation (SFG) employing femtosecond infrared (IR) laser pulses is used to study the dynamics of the C-O stretch vibration on Ru(0 0 1). Time-resolved measurements of the free induction decay (FID) of the IR-polarization for 0.33 ML CO/Ru(0 0 1) exhibit single exponential decays over three decades corresponding to dephasing times of T2=1.94 ps at 95 K and T2=1.16 ps at 340 K. This is consistent with pure homogeneous broadening due to anharmonic coupling with the thermally activated low-frequency dephasing mode together with a contribution from saturation of the IR transition. In pump-probe SFG experiments using a strong visible (VIS) pump pulse the perturbation of the FID leads to transient line shifts even at negative delay times, i.e. when the IR-VIS SFG probe pair precedes the pump pulse. Based on an analysis of the time-dependent polarization we discuss the influence of the perturbed FID on time-resolved SFG spectra. We investigate how coherent effects affect the SFG spectra and we examine the time resolution in these experiments, in particular in dependence of the dephasing time.

Pd nanowire arrays as electrocatalysts for ethanol electrooxidation

Energy Technology Data Exchange (ETDEWEB)

Wang, Hong; Cheng, Faliang [Dongguan University of Technology, Dongguan 523106 (China); Xu, Changwei; Jiang, Sanping [School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798 (Singapore)

2007-05-15

Highly ordered Pd nanowire arrays were prepared by template-electrodeposition method using anodic aluminum oxide template. The Pd nanowire arrays, in this paper, have high electrochemical active surface and show excellent catalytic properties for ethanol electrooxidation in alkaline media. The activity of Pd nanowire arrays for ethanol oxidation is not only higher that of Pd film, but also higher than that of commercial E-TEK PtRu(2:1 by weight)/C. The micrometer sized pores and channels in nanowire arrays act as structure units. They make liquid fuel diffuse into and products diffuse out of the catalysts layer much easier, therefore, the utilization efficiency of catalysts gets higher. Pd nanowire arrays are stable catalysts for ethanol oxidation. The nanowire arrays may be a great potential in direct ethanol fuel cells and ethanol sensors. (author)

Investigation of chemical modifiers for the determination of lead in fertilizers and limestone using graphite furnace atomic absorption spectrometry with Zeeman-effect background correction and slurry sampling

Energy Technology Data Exchange (ETDEWEB)

Borges, Aline R. [Instituto de Química, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, 91501-970 Porto Alegre, RS (Brazil); Instituto Nacional de Ciência e Tecnologia do CNPq–INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil); Becker, Emilene M.; Dessuy, Morgana B. [Instituto de Química, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, 91501-970 Porto Alegre, RS (Brazil); Vale, Maria Goreti R., E-mail: mgrvale@ufrgs.br [Instituto de Química, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, 91501-970 Porto Alegre, RS (Brazil); Instituto Nacional de Ciência e Tecnologia do CNPq–INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil); Welz, Bernhard [Instituto Nacional de Ciência e Tecnologia do CNPq–INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil); Departamento de Química, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil)

2014-02-01

In this work, chemical modifiers in solution (Pd/Mg, NH{sub 4}H{sub 2}PO{sub 4} and NH{sub 4}NO{sub 3}/Pd) were compared with permanent modifiers (Ir and Ru) for the determination of lead in fertilizer and limestone samples using slurry sampling and graphite furnace atomic absorption spectrometry with Zeeman-effect background correction. The analytical line at 283.3 nm was used due to some spectral interference observed at 217.0 nm. The NH{sub 4}H{sub 2}PO{sub 4} was abandoned due to severe spectral interference even at the 283.3-nm line. For Pd/Mg and NH{sub 4}NO{sub 3}/Pd the optimum pyrolysis and atomization temperatures were 900 °C and 1900 °C, respectively. For Ru and Ir, the integrated absorbance signal was stable up to pyrolysis temperatures of 700 °C and 900 °C, respectively, and up to atomization temperature of 1700 °C. The limit of detection (LOD) was 17 ng g{sup −1} using Pd/Mg and 29 ng g{sup −1} using NH{sub 4}NO{sub 3}/Pd. Among the permanent modifiers investigated, the LOD was 22 ng g{sup −1} Pb for Ir and 10 ng g{sup −1} Pb for Ru. The accuracy of the method was evaluated using the certified reference material NIST SRM 695. Although Ru provided lower LOD, which can be attributed to a lower blank signal, only the modifiers in solution showed concordant values of Pb concentration for the NIST SRM 695 and the most of analyzed samples. Moreover, the Pd/Mg modifier provided the highest sensitivity and for this reason it is more suitable for the determination of Pb in fertilizers samples in slurry; besides this it presented a better signal-to-noise ratio than NH{sub 4}NO{sub 3}/Pd. - Highlights: • Lead has been determined in fertilizers using slurry sampling GF AAS. • The mixture of palladium and magnesium nitrates was found to be the ideal chemical modifier. • Calibration could be carried out against aqueous standard solutions. • The proposed method is much faster than the EPA method, which includes sample digestion.

Thermodynamic assessment of the rhodium-ruthenium-oxygen (Rh-Ru-O) system

Science.gov (United States)

Gossé, S.; Bordier, S.; Guéneau, C.; Brackx, E.; Domenger, R.; Rogez, J.

2018-03-01

Ruthenium (Ru) and rhodium (Rh) are abundant platinum-group metals formed during burn-up of nuclear fuels. Under normal operating conditions, Rh and Ru accumulate and predominantly form metallic precipitates with other fission products like Mo, Pd and Tc. In the framework of vitrification of high-level nuclear waste, these fission products are poorly soluble in molten glasses. They precipitate as metallic particles and oxide phases. Moreover, these Ru and Rh rich phases strongly depend on temperature and the oxygen fugacity of the glass melt. In case of severe accidental conditions with air ingress, oxidation of the Ru and Rh is possible. At low temperatures (T 1422 K for rhodium sesquioxide and T > 1815 K for ruthenium dioxide), they may decompose into (Rh)-FCC or (Ru)-HCP metallic phases and radiotoxic volatile gaseous species. A thermodynamic assessment of the Rh-Ru-O system will enable the prediction of: (1) the metallic and oxide phases that form during the vitrification of high-level nuclear wastes and (2) the release of volatile gaseous species during a severe accident. The Calphad method developed herein employs a thermodynamic approach in the investigation of the thermochemistry of rhodium and ruthenium at high temperatures. Current literature on the thermodynamic properties and phase diagram data enables preliminary thermodynamic assessments of the Rh-O and Ru-O systems. Additionally, select compositions in the ternary Rh-Ru-O system underwent experimental tests to complement data found in literature and to establish the phase equilibria in the ternary system.

Mixed valent perovskites Ba/sub 3/B/sup 3 +/Ru/sub 2/sup(4. 5+)O/sub 9/. Catalytic activity of perovskite oxides with noble metals

Energy Technology Data Exchange (ETDEWEB)

Treiber, U; Kemmler-Sack, S; Ehmann, A; Schaller, H U; Duerrschmidt, E; Thumm, I; Bader, H [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

1981-10-01

The black compounds Ba/sub 3/B/sup 3 +/Ru/sub 2/O/sub 9/ crystallize with B/sup 3 +/ = La, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb, and Y in a hexagonal BaTiO/sub 3/ structure (6L, sequence (hcc)/sub 2/) with an ordered distribution (1:2 order) of B/sup 3 +/ and ruthenium (BO/sub 6/ single octahedra; Ru/sub 2/O/sub 9/ double groups). The mean oxidation state of ruthenium is about +4.5. The properties are compared with those of other isotypic stacking polytypes Ba/sub 3/B/sup 3 +/M/sub 2/sup(4.5)O/sub 9/ (M/sub 2/ = IrRu, Ir/sub 2/, PtRu) and Ba/sub 3/B/sup 2 +/M/sub 2//sup 5 +/O/sub 9/ (M = Ru, Ir). The results of activity tests concerning the efficiency of perovskite oxides with noble metals in respect of the oxidation of CO or CHsub(x) and the reduction of NOsub(x) are reported.

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

Science.gov (United States)

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

Hydrogenation of Lactic Acid to 1,2-propanediol over Ru-based catalysts

NARCIS (Netherlands)

Liu, K.; Huang, X.; Pidko, E.A.; Hensen, E.J.M.

2018-01-01

The catalytic hydrogenation of lactic acid to 1,2-propanediol with supported Ru catalysts in water was investigated. The influence of catalyst support (activated carbon, γ-Al2O3, SiO2, TiO2, and CeO2) and promoters (Pd, Au, Mo, Re, Sn) on the catalytic performance was evaluated. Catalytic tests

Gibbs Free Energy of Formation for Selected Platinum Group Minerals (PGM

Directory of Open Access Journals (Sweden)

Spiros Olivotos

2016-01-01

Full Text Available Thermodynamic data for platinum group (Os, Ir, Ru, Rh, Pd and Pt minerals are very limited. The present study is focused on the calculation of the Gibbs free energy of formation (ΔfG° for selected PGM occurring in layered intrusions and ophiolite complexes worldwide, applying available experimental data on their constituent elements at their standard state (ΔG = G(species − ΔG(elements, using the computer program HSC Chemistry software 6.0. The evaluation of the accuracy of the calculation method was made by the calculation of (ΔGf of rhodium sulfide phases. The calculated values were found to be ingood agreement with those measured in the binary system (Rh + S as a function of temperature by previous authors (Jacob and Gupta (2014. The calculated Gibbs free energy (ΔfG° followed the order RuS2 < (Ir,OsS2 < (Pt, PdS < (Pd, PtTe2, increasing from compatible to incompatible noble metals and from sulfides to tellurides.

Pāru attiecību prezentācija Facebook

OpenAIRE

Ēvalde, Katrīne

2015-01-01

Pētījuma mērķis ir noskaidrot kā pāri prezentē savas attiecības sociālo tīklu portālā Facebook un kā tas ietekme attiecības reālajā dzīvē. Par pētījuma teorētisko bāzi tiek izmantota Ērvinga Gofmaņa dramaturģiskā pieeja. Pētījumā tiek apskatīti jaunieši, kuri ir attiecībās vismaz pus gadu un kuri ir sociālā tīklu portāla Facebook lietotāji. Datu iegūšanas metode ir daļēji strukturētas intervijas ar Facebook lietotājiem, kuri ir pāru attiecībās, un kvantitatīvā kontentanalīze viņu profila kont...

Magnetic and electronic properties in CeTSi3 and CeTGe3 (T: transition metal)

International Nuclear Information System (INIS)

Shimoda, T.; Okuda, Y.; Takeda, Y.; Ida, Y.; Miyauchi, Y.; Kawai, T.; Fujie, T.; Sugitani, I.; Thamizhavel, A.; Matsuda, T.D.; Haga, Y.; Takeuchi, T.; Nakashima, M.; Settai, R.; Onuki, Y.

2007-01-01

We investigated the magnetic properties of CeTSi 3 (T: Ru, Os, Co, Rh, Ir, Pd and Pt) and CeTGe 3 (T: Co, Rh and Ir) by measuring their electrical resistivity and magnetic susceptibility. CeRuSi 3 , CeOsSi 3 and CeCoSi 3 do not order magnetically, with a large Kondo temperature of about 200K. The other compounds order antiferromagnetically, and are very similar to each other in their magnetic and electronic properties, which is related to a large crystalline electric field (CEF) splitting energy of the 4f electron, about 500K in CeIrSi 3

Platinum-group element contents of Karelian kimberlites: Implications for the PGE budget of the sub-continental lithospheric mantle

Science.gov (United States)

Maier, W. D.; O'Brien, H.; Peltonen, P.; Barnes, Sarah-Jane

2017-11-01

We present high-precision isotope dilution data for Os, Ir, Ru, Pt, Pd and Re in Group I and Group II kimberlites from the Karelian craton, as well as 2 samples of the Premier Group I kimberlite pipe from the Kaapvaal craton. The samples have, on average, 1.38 ppb Pt and 1.33 ppb Pd, with Pt/Pd around unity. These PGE levels are markedly lower, by as much as 80%, than those reported previously for kimberlites from South Africa, Brazil and India, but overlap with PGE results reported recently from Canadian kimberlites. Primitive-mantle-normalised chalcophile element patterns are relatively flat from Os to Pt, but Cu, Ni and, somewhat less so, Au are enriched relative to the PGE (e.g., Cu/Pd > 25.000). Pd/Ir ratios are 3,6 on average, lower than in most other mantle melts. The PGE systematics can be largely explained by two components, (i) harzburgite/lherzolite detritus of the SCLM with relatively high IPGE (Os-Ir-Ru)/PPGE (Rh-Pt-Pd) ratios, and (ii) a melt component that has high PPGE/IPGE ratios. By using the concentrations of iridium in the kimberlites as a proxy for the proportion of mantle detritus in the magma, we estimate that the analysed kimberlites contain 3-27% entrained and partially dissolved detritus from the sub-continental lithospheric mantle, consistent with previous estimates of kimberlites elsewhere (Tappe S. et al., 2016, Chem. Geol. 10.1016/j.chemgeo.2016.08.019).

Synthesis, structure, and electronic properties of a dimer of Ru(bpy)2 doubly bridged by methoxide and pyrazolate.

Science.gov (United States)

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

Highly ordered Pd nanowire arrays as effective electrocatalysts for ethanol oxidation in direct alcohol fuel cells

Energy Technology Data Exchange (ETDEWEB)

Xu, C.W. [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Wang, H. [Departement of Applied Chemistry, Dongguan University of Technology, Dongguan 523106 (China); Shen, P.K. [School of Physics and Engineering, Sun Yet-Sen University, Guangzhou 510275 (China); Jiang, S.P.

2007-12-03

Pd nanowire arrays (NWAs) with high electrochemically active surface area are successfully fabricated using anodized aluminum oxide electrodeposition. The electrocatalytic activity and stability of the Pd NWAs for ethanol electrooxidation are not only significantly higher that of conventional Pd film electrodes, but also higher than that of well-established commercial PtRu/C electrocatalysts. The Pd NWAs show great potential as electrocatalysts for ethanol electrooxidation in alkaline media in direct ethanol fuel cells. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

Spectroscopic and biological approach in the characterization of a novel 14-membered [N4] macrocyclic ligand and its Palladium(II), Platinum(II), Ruthenium(III) and Iridium(III) complexes

Science.gov (United States)

Rani, Soni; Kumar, Sumit; Chandra, Sulekh

2014-01-01

A novel, tetradentate nitrogen donor [N4] macrocyclic ligand, i.e. 3,5,14,16-tetramethyl-2,6,13,17-tetraazatricyclo[12,0,07-12] cosa-1(22),2,5,7,9,11,13,16,18,20-decaene(L), has been synthesized and characterized by elemental analyses, IR, Mass, and 1H NMR spectral studies. Complexes of Pd(II), Pt(II), Ru(III) and Ir(III) have been prepared and characterized by elemental analyses, molar conductance measurements, magnetic susceptibility measurements, IR, Mass, electronic spectral and thermal studies. On the basis of molar conductance the complexes may be formulated as [PdL]Cl2, [PtL]Cl2, [Ru(L)Cl2]Cl and [Ir(L)Cl2]Cl. The complexes are insoluble in most common solvents, including water, ethanol, carbon tetrachloride and acetonitrile, but soluble in DMF/DMSO. The value of magnetic moment indicates that all the complexes are diamagnetic except Ru(III) complex which shows magnetic moment corresponding to one unpaired electron. The magnetic moment of Ru(III) complex is 1.73 B.M. at room temperature. The antimicrobial activities of ligand and its complexes have been screened in vitro, as growth inhibiting agents. The antifungal and antibacterial screening were carried out using Food Poison and Disc Diffusion Method against plant pathogenic fungi and bacteria Alternaria porri, Fusarium oxysporum, Xanthomonas compestris and Pseudomonas aeruginosa respectively. The compounds were dissolved in DMSO to get the required solutions. The required medium used for these activities was PDA and nutrient agar.

Spectroscopic and biological approach in the characterization of a novel 14-membered [N4] macrocyclic ligand and its palladium(II), platinum(II), ruthenium(III) and iridium(III) complexes.

Science.gov (United States)

Rani, Soni; Kumar, Sumit; Chandra, Sulekh

2014-01-24

A novel, tetradentate nitrogen donor [N4] macrocyclic ligand, i.e. 3,5,14,16-tetramethyl-2,6,13,17-tetraazatricyclo[12,0,0(7-12)] cosa-1(22),2,5,7,9,11,13,16,18,20-decaene(L), has been synthesized and characterized by elemental analyses, IR, Mass, and (1)H NMR spectral studies. Complexes of Pd(II), Pt(II), Ru(III) and Ir(III) have been prepared and characterized by elemental analyses, molar conductance measurements, magnetic susceptibility measurements, IR, Mass, electronic spectral and thermal studies. On the basis of molar conductance the complexes may be formulated as [PdL]Cl2, [PtL]Cl2, [Ru(L)Cl2]Cl and [Ir(L)Cl2]Cl. The complexes are insoluble in most common solvents, including water, ethanol, carbon tetrachloride and acetonitrile, but soluble in DMF/DMSO. The value of magnetic moment indicates that all the complexes are diamagnetic except Ru(III) complex which shows magnetic moment corresponding to one unpaired electron. The magnetic moment of Ru(III) complex is 1.73 B.M. at room temperature. The antimicrobial activities of ligand and its complexes have been screened in vitro, as growth inhibiting agents. The antifungal and antibacterial screening were carried out using Food Poison and Disc Diffusion Method against plant pathogenic fungi and bacteria Alternaria porri, Fusarium oxysporum, Xanthomonas compestris and Pseudomonas aeruginosa respectively. The compounds were dissolved in DMSO to get the required solutions. The required medium used for these activities was PDA and nutrient agar. Copyright © 2013 Elsevier B.V. All rights reserved.

Determination of geochemical distribution of platinum elements in chromites and related minerals using neutron activation analysis technique

International Nuclear Information System (INIS)

Agiorgitis, G.

1978-08-01

Results of Pt, Pd, Ir, Os and Ru determination in various rocks and minerals using radiochemical neutron activation method are presented and geochemical correlations of the platinum elements studied. The method of analysis was described in detail in 4 progress reports

Formation and nitrile hydrogenation performance of Ru nanoparticles on a K-doped Al2O3 surface.

Science.gov (United States)

Muratsugu, Satoshi; Kityakarn, Sutasinee; Wang, Fei; Ishiguro, Nozomu; Kamachi, Takashi; Yoshizawa, Kazunari; Sekizawa, Oki; Uruga, Tomoya; Tada, Mizuki

2015-10-14

Decarbonylation-promoted Ru nanoparticle formation from Ru3(CO)12 on a basic K-doped Al2O3 surface was investigated by in situ FT-IR and in situ XAFS. Supported Ru3(CO)12 clusters on K-doped Al2O3 were converted stepwise to Ru nanoparticles, which catalyzed the selective hydrogenation of nitriles to the corresponding primary amines via initial decarbonylation, the nucleation of the Ru cluster core, and the growth of metallic Ru nanoparticles on the surface. As a result, small Ru nanoparticles, with an average diameter of less than 2 nm, were formed on the support and acted as efficient catalysts for nitrile hydrogenation at 343 K under hydrogen at atmospheric pressure. The structure and catalytic performance of Ru catalysts depended strongly on the type of oxide support, and the K-doped Al2O3 support acted as a good oxide for the selective nitrile hydrogenation without basic additives like ammonia. The activation of nitriles on the modelled Ru catalyst was also investigated by DFT calculations, and the adsorption structure of a nitrene-like intermediate, which was favourable for high primary amine selectivity, was the most stable structure on Ru compared with other intermediate structures.

Facile synthesis of RuII Schiff base complexes: spectral characterization and antimicrobial applications

International Nuclear Information System (INIS)

Arunachalam, S.; Padma Priya, N.; Shahul Meeran, H.

2014-01-01

Diamagnetic ruthenium (II) complexes of the type (RuCl (CO) (pyridine) (L)) (where L = monobasic tridentate Schiff base ligands) were synthesized by the reactions of Schiff bases derived from the reactions of o-aminobenzoic acid and Knovenegal condensate of β - ketoesters and appropriate ruthenium metal precursor (RuHCl (CO) (PPh 3 ) 2 (py)). Elemental analyses and spectral (FT-IR, UV-Vi s and 1 H, 31 P NMR) studies of all the new synthesized complexes suggest the presence of an octahedral environment around the Ru II ion. Cyclic voltammograms of all the complexes display oxidation and reduction potentials. Superoxide dismutase activity (SOD) of these complexes has also been examined. These complexes were also subjected to study their biocidal activity against Staphylococcus epidermidis, Escherichia coli, Botrytis cinerea and Aspergillus niger. (author)

Microdosimetric evaluation of relative biological effectiveness for 103PD, 125I, 241AM, and 192IR brachytherapy sources

International Nuclear Information System (INIS)

Wuu, C.S.; Kliauga, P.; Zaider, M.; Amols, H.I.

1996-01-01

Purpose: To determine the microdosimetric-derived relative biological effectiveness (RBE) of 103 Pd, 125 I, 241 Am, and 192 Ir brachytherapy sources at low doses and/or low dose rates. Methods and Materials: The Theory of Dual Radiation Action can be used to predict expected RBE values based on the spatial distribution of energy deposition at microscopic levels from these sources. Single-event lineal energy spectra for these isotopes have been obtained both experimentally and theoretically. A grid-defined wall-less proportional counter was used to measure the lineal energy distributions. Unlike conventional Rossi proportional counters, the counter used in these measurements has a conducting nylon fiber as the central collecting anode and has no metal parts. Thus, the Z-dependence of the photoelectric effect is eliminated as a source of measurement error. Single-event spectra for these brachytherapy sources have been also calculated by: (a) the Monte Carlo code MCNP to generate the electron slowing down spectrum, (b) transport of monoenergetic electron tracks, event by event, with our Monte Carlo code DELTA, (c) using the concept of associated volume to obtain the lineal energy distribution f(y) for each monoenergetic electron, and (d) obtaining the composite lineal energy spectrum for a given brachytherapy source based on the electron spectrum calculated at step (a). Results: Relative to 60 Co, the RBE values obtained from this study are: 2.3 for 103 Pd, 2.1 for 125 I, 2.1 for 241 Am, and 1.3 for 192 Ir. Conclusions: These values are consistent with available data from in vitro cell survival experiments. We suggest that, at least for these brachytherapy sources, microdosimetry may be used as a credible alternative to time-consuming (and often uncertain) radiobiological experiments to obtain information on radition quality and make reliable predictions of RBE in low dose rate brachytherapy

Electrocatalytic oxidation of methanol on (Pb) lead modified by Pt, Pt-Ru and Pt-Sn microparticles dispersed into poly(o-phenylenediamine) film

Energy Technology Data Exchange (ETDEWEB)

Golikand, Ahmad Nozad; Maragheh, Mohammad Ghannadi; Irannejad, Leila [Jaber Ibn Hayan Research Lab., Atomic Energy Organization of Iran (AEOI), Tehran (Iran); Golabi, Seyed Mehdi [Electroanalytical Chemistry Lab., Faculty of Chemistry, University of Tabriz, Tabriz (Iran)

2005-08-18

The electrocatalytic oxidation of methanol at a (Pb) lead electrode modified by Pt, Pt-Ru and Pt-Sn microparticles dispersed into poly(o-phenylenediamine) (PoPD) film has been investigated using cyclic voltammetry as analytical technique and 0.5M sulfuric acid as supporting electrolyte. It has been shown that the presence of PoPD film increases considerably the efficiency of deposited Pt and Pt alloys microparticles toward the electrocatalytic oxidation of methanol. The catalytic activity of Pt particles is further enhanced when Ru and especially Sn, is co-deposited in the polymer film. The effects of various parameters such as concentration of methanol, medium temperature as well as the long term stability of modified electrodes have also been investigated. (author)

Palladium, platinum, rhodium, ruthenium, and iridium in chromitites from the Massif du Sud and Tiebaghi massif, New Caledonia.

Science.gov (United States)

Page, N.J.; Cassard, D.; Haffty, J.

1982-01-01

The massive and disseminated podiform chromitites from 43 mines and other occurrences in the area contain up to (in ppb) Pd 9, Pt 45, Rh 31, Ir 410 and Ru 1300. The possble origins of the chromitites are discussed. -K.A.R.

Half-life and intensities of photons of 103Pd isotope

International Nuclear Information System (INIS)

Popov, Yu.S.; Zakharova, L.V.; Kupriyanov, V.N.; Andreev, O.I.; Pakhomov, A.N.; Vakhetov, F.Z.

2001-01-01

Half-life and intensities of photons forming during 103 Pd isotope decay are determined by the methods of semiconductor x-ray and γ-spectrometry. 103 Pd is applied in nuclear medicine for preparation of 103m Rh isomer (T 1/2 =56 min) being used in irradiation of prostate neoplasms. Half-life of 103 Pd isotope is 16±0.6 days, relative intensities of x-ray and γ-photons are: K α /Kβ=5.1±0.4; 358 keV - 100 rel.units; 295 keV - 12.3±0.4 rel.units; 497 keV - 17.6±0.6 rel.units. Errors are represented for confidence probability 95 % [ru

Near infrared photoimmunotherapy with avelumab, an anti-programmed death-ligand 1 (PD-L1) antibody.

Science.gov (United States)

Nagaya, Tadanobu; Nakamura, Yuko; Sato, Kazuhide; Harada, Toshiko; Choyke, Peter L; Hodge, James W; Schlom, Jeffrey; Kobayashi, Hisataka

2017-01-31

Near Infrared-Photoimmunotherapy (NIR-PIT) is a highly selective tumor treatment that employs an antibody-photo-absorber conjugate (APC). Programmed cell death protein-1 ligand (PD-L1) is emerging as a molecular target. Here, we describe the efficacy of NIR-PIT, using fully human IgG1 anti-PD-L1 monoclonal antibody (mAb), avelumab, conjugated to the photo-absorber, IR700DX, in a PD-L1 expressing H441 cell line, papillary adenocarcinoma of lung. Avelumab-IR700 showed specific binding and cell-specific killing was observed after exposure of the cells to NIR in vitro. In the in vivo study, avelumab-IR700 showed high tumor accumulation and high tumor-background ratio. Tumor-bearing mice were separated into 4 groups: (1) no treatment; (2) 100 μg of avelumab-IR700 i.v.; (3) NIR light exposure only, NIR light was administered; (4) 100 μg of avelumab-IR700 i.v., NIR light was administered. Tumor growth was significantly inhibited by NIR-PIT treatment compared with the other groups (p avelumab, is suitable as an APC for NIR-PIT. Furthermore, NIR-PIT with avelumab-IR700 is a promising candidate of the treatment of PD-L1-expressing tumors that could be readily translated to humans.

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

International Nuclear Information System (INIS)

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.)

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

Science.gov (United States)

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.

Spectra and relaxation dynamics of the pseudohalide (PS) vibrational bands for Ru(bpy)2(PS)2 complexes, PS = CN, NCS and N3

International Nuclear Information System (INIS)

Compton, Ryan; Gerardi, Helen K.; Weidinger, Daniel; Brown, Douglas J.; Dressick, Walter J.; Heilweil, Edwin J.; Owrutsky, Jeffrey C.

2013-01-01

Highlights: ► Static and transient infrared spectroscopy of pseudohalide bipyridine ruthenium complexes. ► Vibrational energy relaxes faster for the azide than the thiocyanate and cyanide analogs. ► Intramolecular vibrational relaxation is prevalent in cis-Ru(bpy) 2 (N 3 ) 2 . - Abstract: Static and transient infrared spectroscopy were used to investigate cis-Ru(bpy) 2 (N 3 ) 2 (bpy = 2,2′-bipyridine), cis-Ru(bpy) 2 (NCS) 2 , and cis-Ru(bpy) 2 (CN) 2 in solution. The NC stretching IR band for cis-Ru(bpy) 2 (NCS) 2 appears at higher frequency (∼2106 cm −1 in DMSO) than for the free NCS − anion while the IR bands for the azide and cyanide complexes are closer to those of the respective free anions. The vibrational energy relaxation (VER) lifetime for the azide complex is found to be much shorter (∼5 ps) than for either the NCS or CN species (both ∼70 ps in DMSO) and the lifetimes resemble those for each corresponding free anion in solution. However, for cis-Ru(bpy) 2 (N 3 ) 2 , it is determined that the transition frequency depends more on the solvent than the VER lifetime implying that intramolecular vibrational relaxation is predominant over solvent energy-extracting interactions. These results are compared to the behavior of other related metal complexes in solution

A possible in vivo generator 103Pd/103mRh-Recoil considerations

International Nuclear Information System (INIS)

Rooyen, Johann van; Szucs, Zoltan; Rijn Zeevaart, Jan

2008-01-01

The use of Auger emitters as potential radiopharmaceuticals is increasingly investigated. One such radionuclide of interest is 103m Rh. This can be produced from 103 Ru or from 103 Pd in an in vivo generator. A potential problem with this concept is the recoil of the 103m Rh out of the carrier molecule and even out of the target cell. In order to determine whether this would happen in the 103 Pd/ 103m Rh case calculations were done to prove that this does not happen. From theoretical considerations it seems that the 103 Pd/ 103m Rh in vivo generator system would be possible

Ethanol electrooxidation on Pt/C and Pd/C catalysts promoted with oxide

Energy Technology Data Exchange (ETDEWEB)

Xu, Changwei [Department of Chemistry and Institute of Nanochemistry, Jinan University, Guangzhou 510632 (China); State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-Sen University, Guangzhou 510275 (China); Shen, Pei kang [State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-Sen University, Guangzhou 510275 (China); Liu, Yingliang [Department of Chemistry and Institute of Nanochemistry, Jinan University, Guangzhou 510632 (China)

2007-02-10

This research aims to investigate Pd-based catalysts as a replacement for Pt-based catalysts for ethanol electrooxidation in alkaline media. The results show that Pd/C has a higher catalytic activity and better steady-state behaviour for ethanol oxidation than that of Pt/C. The effect of the addition of CeO{sub 2} and NiO to the Pt/C and Pd/C electrocatalysts on ethanol oxidation is also studied in alkaline media. The electrocatalysts with a weight ratio of noble metal (Pt, Pd) to CeO{sub 2} of 2:1 and a noble metal to NiO ration 6:1 show the highest catalytic activity for ethanol oxidation. The oxide promoted Pt/C and Pd/C electrocatalysts show a higher activity than the commercial E-TEK PtRu/C electrocatalyst for ethanol oxidation in alkaline media. (author)

Anti-PD-L1 Treatment Induced Central Diabetes Insipidus.

Science.gov (United States)

Zhao, Chen; Tella, Sri Harsha; Del Rivero, Jaydira; Kommalapati, Anuhya; Ebenuwa, Ifechukwude; Gulley, James; Strauss, Julius; Brownell, Isaac

2018-02-01

Immune checkpoint inhibitors, including anti-programmed cell death protein 1 (PD-1), anti-programmed cell death protein ligand 1 (PD-L1), and anti-cytotoxic T-lymphocyte antigen 4 (anti-CTLA4) monoclonal antibodies, have been widely used in cancer treatment. They are known to cause immune-related adverse events (irAEs), which resemble autoimmune diseases. Anterior pituitary hypophysitis with secondary hypopituitarism is a frequently reported irAE, especially in patients receiving anti-CTLA4 treatment. In contrast, posterior pituitary involvement, such as central diabetes insipidus (DI), is relatively rare and is unreported in patients undergoing PD-1/PD-L1 blockade. We describe a case of a 73-year-old man with Merkel cell carcinoma who received the anti-PD-L1 monoclonal antibody avelumab and achieved partial response. The patient developed nocturia, polydipsia, and polyuria 3 months after starting avelumab. Further laboratory testing revealed central DI. Avelumab was held and he received desmopressin for the management of central DI. Within 6 weeks after discontinuation of avelumab, the patient's symptoms resolved and he was eventually taken off desmopressin. The patient remained off avelumab and there were no signs or symptoms of DI 2 months after the discontinuation of desmopressin. To our knowledge, this is the first report of central DI associated with anti-PD-L1 immunotherapy. The patient's endocrinopathy was successfully managed by holding treatment with the immune checkpoint inhibitor. This case highlights the importance of early screening and appropriate management of hormonal irAEs in subjects undergoing treatment with immune checkpoint inhibitors to minimize morbidity and mortality. Copyright © 2017 Endocrine Society

Evaluation of colloidal Pd and Pd-alloys as anode electrocatalysts for direct borohydride fuel cells applications

Energy Technology Data Exchange (ETDEWEB)

Atwan, M.H. [General Motors R and D Technical Center, Warren, MI (United States); Gyenge, E.L. [British Columbia Univ., Vancouver, BC (Canada). Dept. of Chemical and Biological Engineering; Northwood, D.O. [Windsor Univ., ON (Canada). Dept. of Mechanical, Automotive and Materials Engineering

2010-07-01

An evaluation was conducted to assess the use of colloidal palladium (Pd) and Pd alloys as anode electrocatalysts for direct borohydride fuel cell applications. A modified Bonneman method was used to investigate borohydride oxidation on supported Pd and Pd-alloy nano-electrocatalysts. Cyclic voltammetry (CV), rotating disk electrode (RDE) voltammetry, and single fuel cell test stations were used to determine Tafel slopes, exchange current densities, oxidation peak potentials, and fuel cell performance. The study also investigated the influence of temperature and oxidant flow and fuel flow rates on fuel cell performance. The study showed that the current density of the fuel cell increased with increases in temperature for all the investigated Pd electrocatalysts. However, the increase in current density was not as high as expected when fuel flow rates were increased. A current density of 50 mA cm{sup -2} was observed at 298 K with a Pd-Ir anode catalyst operating at a cell voltage of 0.5 V. 28 refs., 1 tab., 15 figs.

Support Screening Studies on the Hydrogenation of Levulinic Acid to γ-Valerolactone in Water Using Ru Catalysts

Directory of Open Access Journals (Sweden)

Anna Piskun

2016-08-01

Full Text Available γ-Valerolactone (GVL has been identified as a sustainable platform chemical for the production of carbon-based chemicals. Here we report a screening study on the hydrogenation of levulinic acid (LA to GVL in water using a wide range of ruthenium supported catalysts in a batch set-up (1 wt. % Ru, 90 °C, 45 bar of H2, 2 wt. % catalyst on LA. Eight monometallic catalysts were tested on carbon based(C, carbon nanotubes (CNT and inorganic supports (Al2O3, SiO2, TiO2, ZrO2, Nb2O5 and Beta-12.5. The best result was found for Ru/Beta-12.5 with almost quantitative LA conversion (94% and 66% of GVL yield after 2 h reaction. The remaining product was 4-hydroxypentanoic acid (4-HPA. Catalytic activity for a bimetallic RuPd/TiO2 catalyst was by far lower than for the monometallic Ru catalyst (9% conversion after 2 h. The effects of relevant catalyst properties (average Ru nanoparticle size, Brunauer-Emmett-Teller (BET surface area, micropore area and total acidity on catalyst activity were assessed.

Ir catalysts: Preventing CH3COOH formation in ethanol oxidation

Science.gov (United States)

Miao, Bei; Wu, Zhipeng; Xu, Han; Zhang, Minhua; Chen, Yifei; Wang, Lichang

2017-11-01

Current catalysts used for ethanol oxidation reaction (EOR) cannot effectively prevent CH3COOH formation, and thus become a major hindrance for direct ethanol fuel cell applications. We report an Ir catalyst that shows great promise for a complete EOR based on density functional theory calculations using PBE functional. The reaction barrier on Ir(1 0 0) was found to be 2.10 eV for CH3COOH formation, which is much higher than currently used Pd and Pt, and 0.57 eV for Csbnd C bond cleavage in CHCO species, which are comparable to Pd and Pt. The result suggests future directions for studying optimal complete EOR catalysts.

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

International Nuclear Information System (INIS)

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

Euphrosyne sengrieķu dzīru kontekstā

OpenAIRE

Jemeļjanova, Kristina

2013-01-01

. Šī maģistra darba tēma ir Eyphrosyne sengrieķu dzīru kontekstā. Pētīšanas laikā tika aplūkoti Homēra Odiseja, atnīka lirika, Ksenofonta Dzīres, Platona Dzīres. Dzīru tekstos tika meklēta leksēma ἐυφροσύνη un tika pētīta gan kontekstuālā nozīmē, gan leksiski-semantiskajā nozīmē. Bija svarīgi tekstos atrast informāciju par to, kas rada prieku sengrieķu dzīrotājam. Darba atslēgvārdi: dzīres, prieks, jautrība, ἐυφροσύνη, dialogs, vīns, Homērs, Platons, Ksenofonts, lirika.  ...

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

Energy Technology Data Exchange (ETDEWEB)

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.

Extraction of carrier-free 103Pd from thin rhodium wire irradiated with a proton beam in U-150 cyclotron

International Nuclear Information System (INIS)

Yuldashev, B.S.; Khudajbergenov, U.; Gulamov, I.R.; Mirzarva, M.A.; Rylov, A.A.

2003-01-01

A procedure for preparation of 103 Pd isotope of 99.9 % purity from a thin rhodium wire irradiated by 21 MeV proton beam in a cyclotron was developed. The desired product was prepared by electrolytic dissolution of the irradiated target in 6 M HCl with subsequent extraction of 103 Pd isotope without carrier by dimethylglyoxime in chloroform [ru

Fractionation of the platinum-group elments and Re during crystallization of basalt in Kilauea Iki Lava Lake, Hawaii

Science.gov (United States)

Pitcher, L.; Helz, R.T.; Walker, R.J.; Piccoli, P.

2009-01-01

Kilauea Iki lava lake formed during the 1959 summit eruption of Kilauea Volcano, then crystallized and differentiated over a period of 35??years. It offers an opportunity to evaluate the fractionation behavior of trace elements in a uniquely well-documented basaltic system. A suite of 14 core samples recovered from 1967 to 1981 has been analyzed for 5 platinum-group elements (PGE: Ir, Os, Ru, Pt, Pd), plus Re. These samples have MgO ranging from 2.4 to 26.9??wt.%, with temperatures prior to quench ranging from 1140????C to ambient (110????C). Five eruption samples were also analyzed. Osmium and Ru concentrations vary by nearly four orders of magnitude (0.0006-1.40??ppb for Os and 0.0006-2.01??ppb for Ru) and are positively correlated with MgO content. These elements behaved compatibly during crystallization, mostly likely being concentrated in trace phases (alloy or sulfide) present in olivine phenocrysts or included chromite. Iridium also correlates positively with MgO, although less strongly than Os and Ru. The somewhat poorer correlation for Ir, compared with Os and Ru, may reflect variable loss of Ir as volatile IrF6 in some of the most magnesian samples. Rhenium is negatively correlated with MgO, behaving as an incompatible trace element. Its behavior in the lava lake is complicated by apparent volatile loss of Re, as suggested by a decrease in Re concentration with time of quenching for lake samples vs. eruption samples. Platinum and Pd concentrations are negatively, albeit weakly, correlated with MgO, so these elements were modestly incompatible during crystallization of the major silicate phases. Palladium contents peaked before precipitation of immiscible sulfide liquid, however, and decline sharply in the most differentiated samples. In contrast, Pt appears to have been unaffected by sulfide precipitation. Microprobe data confirm that Pd entered the sulfide liquid before Re, and that Pt is not strongly chalcophile in this system. Occasional high Pt values

Electronic and magnetic properties of infinite 1D chains of paddlewheel carboxylates M2(COOR)4 (M = Mo, W, Ru, Rh, Ir, Cu)

KAUST Repository

Peskov, Maxim

2013-03-14

Dinuclear complexes of transition metals bridged by four carboxylate-groups are examples of stable atomic configurations serving as fundamental building blocks of catalysts and prototypical molecular electronic devices. The electronic structure and magnetic properties of many molecular tetracarboxylate complexes were meticulously studied; however, the properties of the one-dimensional (1D) polymeric chain of associated tetracarboxylates have so far evaded much attention. Using periodic density-functional theory calculations, we analyze the electronic structure of condensed tetracarboxylates Mo(II), W(II), Ru(II), Rh(II), Ir(II), and Cu(II). The relationship between crystal structure of the polymerized tetracarboxylates and the electronic properties of the metal-metal bond in the M24+ core is studied. The electronic effects emanating from the association of dinuclear transition metal tetracarboxylates are important for designing molecular electronic devices. In this study, its influence on both direct and indirect metal-metal interactions, and the electronic structure, in particular transport properties, is discussed. © 2013 American Chemical Society.

Near infrared photoimmunotherapy with avelumab, an anti-programmed death-ligand 1 (PD-L1) antibody

OpenAIRE

Nagaya, Tadanobu; Nakamura, Yuko; Sato, Kazuhide; Harada, Toshiko; Choyke, Peter L.; Hodge, James W.; Schlom, Jeffrey; Kobayashi, Hisataka

2016-01-01

Near Infrared-Photoimmunotherapy (NIR-PIT) is a highly selective tumor treatment that employs an antibody-photo-absorber conjugate (APC). Programmed cell death protein-1 ligand (PD-L1) is emerging as a molecular target. Here, we describe the efficacy of NIR-PIT, using fully human IgG1 anti-PD-L1 monoclonal antibody (mAb), avelumab, conjugated to the photo-absorber, IR700DX, in a PD-L1 expressing H441 cell line, papillary adenocarcinoma of lung. Avelumab-IR700 showed specific binding and cell-...

Copper-based alloys, crystallographic and crystallochemical parameters of alloys in binary systems Cu-Me (Me=Co, Rh, Ir, Cu, Ag, Au, Ni, Pd, Pt)

Energy Technology Data Exchange (ETDEWEB)

Porobova, Svetlana, E-mail: porobova.sveta@yandex.ru; Loskutov, Oleg, E-mail: lom58@mail.ru [Tomsk State University of Architecture and Building, Russia, Tomsk, 2 Solyanaya sq, Tomsk, 634003 (Russian Federation); Markova, Tat’jana, E-mail: patriot-rf@mail.ru [Siberian State Industrial University. 42 Kirov St., Novokuznetsk, 654007 (Russian Federation); Klopotov, Vladimir, E-mail: vdklopotov@mail.ru [Research Tomsk Polytechnic University, 30 Lenin Ave., Tomsk, 634050 (Russian Federation); Klopotov, Anatoliy, E-mail: klopotovaa@tsuab.ru [Tomsk State University of Architecture and Building, Russia, Tomsk, 2 Solyanaya sq, Tomsk, 634003 (Russian Federation); National Research Tomsk State University, 36, Lenin Ave., Tomsk, 634050 (Russian Federation); Vlasov, Viktor, E-mail: vik@tsuab.ru [Tomsk State University of Architecture and Building, Russia, Tomsk, 2 Solyanaya sq, Tomsk, 634003 (Russian Federation); Research Tomsk Polytechnic University, 30 Lenin Ave., Tomsk, 634050 (Russian Federation)

2016-01-15

The article presents the results of the analysis of phase equilibrium of ordered phases in binary systems based on copper Cu- Me (where Me - Co, Rh, Ir, Ag, Au, Ni, Pd, Pt) to find correlations of crystallochemical and crystallographic factors. It is established that the packing index in disordered solid solutions in binary systems based on copper is close to the value of 0.74 against the background of an insignificant deviation of atomic volumes from the Zen’s law.

Removal Efficiency of Nitrite and Sulfide Pollutants by Electrochemical Process by Using Ti/RuIrO2 Anode

Directory of Open Access Journals (Sweden)

Aris Mukimin

2018-05-01

Full Text Available In general, wastewater treatment by physical, chemical and biological methods are only focused on TSS, BOD and COD removals that the effluent still contains anion pollutant as NO2- and S2-. Electrochemical technology is a proper method for those pollutants treatment due to its fast process, easy operation and minimum amount of sludge. Electrocatalytic reactor with 8 L capacity using Ti/RuIrO2 cylinder as anode and Fe plate as cathode was arranged and applied to treat anion pollutants. Hydraulic retention time (30, 60, 90 and 120 min, salt concentration (250, 500 and 750 mg/L and voltage (4, 5, and 6 V were chosen as operation variables and NO2- and S2- concentrations as parameter indicators. Nitrite removal efficiency reached 75 and 99.7% after 60 and 120 min of electrolysis, respectively, while sulfide could obtain higher efficiency, i.e., 97 and 99.9% after 60 and 90 min, respectively, at operation variables of potential of 5 V and salt of 500 mg/L. Removal process is dominated by indirect oxidation mechanism by HClO/ClO- oxidators generated at anode surface as intermediate products. The lifespan of electrode and electric consumption are two main factors of operation cost. Electric consumed was 0.452 kWh per 1 g nitrite removed.

Cluster pattern analysis of energy deposition sites for the brachytherapy sources 103Pd, 125I, 192Ir, 137Cs, and 60Co.

Science.gov (United States)

Villegas, Fernanda; Tilly, Nina; Bäckström, Gloria; Ahnesjö, Anders

2014-09-21

Analysing the pattern of energy depositions may help elucidate differences in the severity of radiation-induced DNA strand breakage for different radiation qualities. It is often claimed that energy deposition (ED) sites from photon radiation form a uniform random pattern, but there is indication of differences in RBE values among different photon sources used in brachytherapy. The aim of this work is to analyse the spatial patterns of EDs from 103Pd, 125I, 192Ir, 137Cs sources commonly used in brachytherapy and a 60Co source as a reference radiation. The results suggest that there is both a non-uniform and a uniform random component to the frequency distribution of distances to the nearest neighbour ED. The closest neighbouring EDs show high spatial correlation for all investigated radiation qualities, whilst the uniform random component dominates for neighbours with longer distances for the three higher mean photon energy sources (192Ir, 137Cs, and 60Co). The two lower energy photon emitters (103Pd and 125I) present a very small uniform random component. The ratio of frequencies of clusters with respect to 60Co differs up to 15% for the lower energy sources and less than 2% for the higher energy sources when the maximum distance between each pair of EDs is 2 nm. At distances relevant to DNA damage, cluster patterns can be differentiated between the lower and higher energy sources. This may be part of the explanation to the reported difference in RBE values with initial DSB yields as an endpoint for these brachytherapy sources.

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

Energy Technology Data Exchange (ETDEWEB)

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)

Theoretical study on the antitumor properties of Ru(II) complexes containing 2-pyridyl, 2-pyridine-4-carboxylic acid ligands

Science.gov (United States)

Erkan kariper, Sultan; Sayin, Koray; Karakaş, Duran

2017-12-01

[Ru(bipy)2(CppH)]2+(1), [Ru(bipy)2(Cpp-NH-Hex-COOH)]2+(2), [Ru(dppz)2(CppH)]2+(3) and [Ru(dppz)2(Cpp-NH-Hex-COOH)]2+(4) were calculated by Hartree-Fock (HF), Density Functional Theory (DFT) hybrid B3LYP and Moller-Plesset Perturbation (MPn n = 2,3) theory method and CEP-4G, CEP-31G, CEP-121G, LANL2DZ, LANL2MB, SDD basic sets and a mixed basic set with the keyword GEN in gas phase and water. Structure parameters obtained from optimized structures were compared with experimental parameters. M062X/(6-31G(d))(CEP-4G) level was taken into account for the most appropriate calculation level. IR, UV-VIS and NMR spectrums were examined for structural characterization. The optimal structure was identified via structure parameters, IR, UV-VIS and NMR spectrums. For the most compatible structure, the highest molecular orbital energy (EHOMO) which one of the most effective chemical determiners on the antitumor activity of the complexes, the lowest molecular orbital energy (ELUMO), LUMO-HOMO energy gap, hardness (η), softness (σ), electronegativity (χ), chemical potential (μ), electrophilicity index (ω), molar volume (V), dipole moment (DM), total negative charge (TNC), enthalpy (H), entropy (S) and total energy (E) were calculated. The causes of anticancer activity of the complexes have been studied.

High-pressure synthesis and structural, physical properties of CaIr1-xPtxO3 and CaIr1-xRhxO3

Science.gov (United States)

Hirai, S.; Bromiley, G. D.; Klemme, S.; Irifune, T.; Ohfuji, H.; Attfield, P.; Nishiyama, N.

2010-12-01

Since the discovery of the perovskite to post-perovskite transition in MgSiO3 in a laser-heated DAC, wide attention has been focussed on the post-perovskite phase of MgSiO3. This is because the post-perovskite phase is likely to play a key role in Earth’s lowermost mantle, and because the perovskite to post-perovskite transition can explain many features of the D” seismic discontinuity. While it is meaningful to conduct further studies of MgSiO3, the post-perovskite phase of MgSiO3 cannot be quenched to ambient pressure/temperature conditions. Thus, further studies must be conducted using analogue compounds of MgSiO3 post-perovskite, which are quenchable to ambient pressure/temperature conditions. The post-perovskite phase of MgSiO3 crystallizes in a layered structure with CaIrO3-structure. Therefore, it is useful to investigate compounds with CaIrO3-structure. There are only four quenchable oxides with CaIrO3-structure reported to date: CaIrO3, CaPtO3, CaRhO3 and CaRuO3. CaIrO3 can be synthesized at ambient pressure, whilst the other three oxides can only be obtained at high pressure/temperature conditions using a multi-anvil apparatus. Further studies on these materials have revealed structural phase transitions at high P-T and a metal-insulator transition by hole doping. In the case of CaIrO3, The post-perovskite phase of CaIrO3 synthesized at 2GPa, 1373K transforms into a perovskite phase at 2GPa, 1673K. In other words, the perovskite phase can be synthesized at temperatures higher than those needed for synthesizing the post-perovskite phase. This is also the case for CaRhO3 (6GPa, 1873K) and CaRuO3 (23GPa, 1343K), while CaPtO3 remained post-perovskite at higher temperatures. We have succeeded in synthesizing solid solutions between CaIrO3, CaPtO3 and CaRhO3. We have found the systematic change in structural and physical properties of post-perovskite oxides, with composition and P-T, which broadens the future opportunity for studying post-perovskite systems

101Ru NQR study in superconducting CeRu2

International Nuclear Information System (INIS)

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)

First principles study on the interfacial properties of NM/graphdiyne (NM = Pd, Pt, Rh and Ir): The implications for NM growing

Energy Technology Data Exchange (ETDEWEB)

Lu, Zhansheng; Li, Shuo; Lv, Peng [College of Physics and Electronic Engineering, Henan Normal University, Xinxiang 453007 (China); He, Chaozheng, E-mail: hecz2013@nynu.edu.cn [College of Physics and Electronic Engineering, Nanyang Normal University, Nanyang 473061 (China); Ma, Dongwei [School of Physics, Anyang Normal University, Anyang 455000 (China); Yang, Zongxian, E-mail: yzx@henannu.edu.cn [College of Physics and Electronic Engineering, Henan Normal University, Xinxiang 453007 (China); Collaborative Innovation Center of Nano Functional Materials and Applications, Kaifeng (China)

2016-01-01

Graphical abstract: - Highlights: • The NM adatoms belong to embedded adsorption in 18C-hexagon of GDY. • The Rh and Ir/GDY can be applied to single metal catalysts or sensors. • A simple linear relationship between E{sub e-ads} and E{sub b} is presented. • The linear relationship can be used in the noble metal modified GDY. - Abstract: Based on the dispersion-corrected density functional calculations (DFT-D), we systematically studied the adsorption of noble metals (NM), Pd, Pt, Rh and Ir, on graphdiyne (GDY). We present a systematic study on the geometry, embedded adsorption energy and electronic structure of four different adatoms adsorbed on the GDY. The strong interaction between the NM adatoms and the GDY substrate is found with the NM embedded in the 18C-hexagon of the GDY. We investigated the mobility of the NM adatoms on the GDY, and found that the mobility barrier energy increases along with the increasing of the embedded adsorption energy. We present the NM adatoms growth of high concentrations on the GDY. Upon the analysis of the electronic structure and the frontier molecular orbitals, Rh and Ir adatoms of low concentrations (about 1.37 at%) on the GDY have the potential to be applied as single metal catalysts or gas molecule sensors.

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

Energy Technology Data Exchange (ETDEWEB)

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.

Direct hydrodeoxygenation of cellulose and xylan to lower alkanes on ruthenium catalysts in subcritical water

International Nuclear Information System (INIS)

Osaka, Yuriko; Ikeda, Yoichi; Hashizume, Daisuke; Iwamoto, Masakazu

2013-01-01

Nano particles of Ru, Rh, Pd, Ir, Pt, and Au, protected by polyvinyl pyrrolidone (PVP), were applied to the hydrodeoxygenation of cellulose and xylan in water and 5 MPa H 2 at 543 K. The distributions of products generated from cellulose and xylan were roughly similar to each other under the present reaction conditions, and therefore, the former was intensively studied. The Ru-PVP catalyst afforded mainly methane and lower alkanes, rather than producing water soluble organic compounds, such as diols and alcohols, that were formed with the use of the other catalysts. The changes in the product distributions with reaction temperature and time indicated that the reaction consisted of two consecutive reactions: cellulose or xylan → water soluble compounds → hydrogenolysis. The first transformation was promoted in subcritical water, and the second step was catalyzed by the Ru catalyst. The Ru catalyst that was supported on CeO 2 , γ-Al 2 O 3 , or activated carbon yielded a similar product distribution to that on Ru-PVP; however, the loading of Ru on TiO 2 , ZrO 2 , SiO 2 –Al 2 O 3 , or SiO 2 resulted in the increment of diols. After the reaction a small portion of the CeO 2 and most of the SiO 2 –Al 2 O 3 and SiO 2 were dissolved in water, and a portion of the Al 2 O 3 was transformed to boehmite AlO(OH) from the γ-alumina. Little change in the catalytic activity however was observed upon the reuse of Ru/Al 2 O 3 in the second run. Highlights: •One-path hydrodeoxygenation of cellulose and xylan to methane and lower alkanes was studied. •Ru-PVP catalysts gave the best yields among Ru-, Rh-, Pd-, Ir-, Pt-, and Au-PVP. •The reaction pathways were cellulose → water soluble compounds → hydrogenolysis. •The catalytic activity of Ru was greatly dependent on the supports

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

Science.gov (United States)

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

Cutaneous, gastrointestinal, hepatic, endocrine, and renal side-effects of anti-PD-1 therapy.

Science.gov (United States)

Hofmann, Lars; Forschner, Andrea; Loquai, Carmen; Goldinger, Simone M; Zimmer, Lisa; Ugurel, Selma; Schmidgen, Maria I; Gutzmer, Ralf; Utikal, Jochen S; Göppner, Daniela; Hassel, Jessica C; Meier, Friedegund; Tietze, Julia K; Thomas, Ioannis; Weishaupt, Carsten; Leverkus, Martin; Wahl, Renate; Dietrich, Ursula; Garbe, Claus; Kirchberger, Michael C; Eigentler, Thomas; Berking, Carola; Gesierich, Anja; Krackhardt, Angela M; Schadendorf, Dirk; Schuler, Gerold; Dummer, Reinhard; Heinzerling, Lucie M

2016-06-01

Anti-programmed cell death receptor-1 (PD-1) antibodies represent an effective treatment option for metastatic melanoma as well as for other cancer entities. They act via blockade of the PD-1 receptor, an inhibitor of the T-cell effector mechanisms that limit immune responses against tumours. As reported for ipilimumab, the anti-PD-1 antibodies pembrolizumab and nivolumab can induce immune-related adverse events (irAEs). These side-effects affect skin, gastrointestinal tract, liver, endocrine system and other organ systems. Since life-threatening and fatal irAEs have been reported, adequate diagnosis and management are essential. In total, 496 patients with metastatic melanoma from 15 skin cancer centers were treated with pembrolizumab or nivolumab; 242 side-effects were described in 138 patients. In 116 of the 138 patients, side-effects affected the skin, gastrointestinal tract, liver, endocrine, and renal system. Rare side-effects included diabetes mellitus, lichen planus, and pancreas insufficiency due to pancreatitis. Anti-PD1 antibodies can induce a plethora of irAEs. The knowledge of them will allow prompt diagnosis and improve the management resulting in decreased morbidity. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

NARCIS (Netherlands)

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 )

Magnetic properties of Heusler alloy Mn2RuGe and Mn2RuGa ribbons

International Nuclear Information System (INIS)

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

Study of shape phase transition at N = 60 in Zr and Pd

International Nuclear Information System (INIS)

Kumar, Rajesh; Gupta, J.B.; Sharma, S.

2011-01-01

The level structure of Zr, Mo, Ru and Pd in the region of A = 100 has been of much interest recently. At N=60 the level structure varies rather sharply. Below N = 60 the structure is vibrator like and at N > 60, the structure corresponds to a rotor. The use of single term expression for level energies in the study of shape phase transition at N=60 is illustrated here. The much sharper shape transition of Zr and slower for Pd is exhibited. There being only two free parameters one can study the nuclei with fewer levels as well

Spectra and relaxation dynamics of the pseudohalide (PS) vibrational bands for Ru(bpy){sub 2}(PS){sub 2} complexes, PS = CN, NCS and N{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Compton, Ryan; Gerardi, Helen K. [Chemistry Division, Naval Research Laboratory, Washington, DC 20375 (United States); Weidinger, Daniel [SRA International, 4300 Fair Lakes Court, Fairfax, VA 22033 (United States); Brown, Douglas J. [Chemistry Department, US Naval Academy, Annapolis, MD 21402 (United States); Dressick, Walter J. [Center for Bio/Molecular Science and Engineering, Naval Research Laboratory, Washington, DC 20375 (United States); Heilweil, Edwin J. [Radiation and Biomolecular Physics Division, Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Owrutsky, Jeffrey C., E-mail: Jeff.Owrutsky@nrl.navy.mil [Chemistry Division, Naval Research Laboratory, Washington, DC 20375 (United States)

2013-08-30

Highlights: ► Static and transient infrared spectroscopy of pseudohalide bipyridine ruthenium complexes. ► Vibrational energy relaxes faster for the azide than the thiocyanate and cyanide analogs. ► Intramolecular vibrational relaxation is prevalent in cis-Ru(bpy){sub 2}(N{sub 3}){sub 2}. - Abstract: Static and transient infrared spectroscopy were used to investigate cis-Ru(bpy){sub 2}(N{sub 3}){sub 2} (bpy = 2,2′-bipyridine), cis-Ru(bpy){sub 2}(NCS){sub 2}, and cis-Ru(bpy){sub 2}(CN){sub 2} in solution. The NC stretching IR band for cis-Ru(bpy){sub 2}(NCS){sub 2} appears at higher frequency (∼2106 cm{sup −1} in DMSO) than for the free NCS{sup −} anion while the IR bands for the azide and cyanide complexes are closer to those of the respective free anions. The vibrational energy relaxation (VER) lifetime for the azide complex is found to be much shorter (∼5 ps) than for either the NCS or CN species (both ∼70 ps in DMSO) and the lifetimes resemble those for each corresponding free anion in solution. However, for cis-Ru(bpy){sub 2}(N{sub 3}){sub 2}, it is determined that the transition frequency depends more on the solvent than the VER lifetime implying that intramolecular vibrational relaxation is predominant over solvent energy-extracting interactions. These results are compared to the behavior of other related metal complexes in solution.

The platinum group elements and gold: analysis by radiochemical and instrumental neutron activation analysis and relevance to geological exploration and related problems

Energy Technology Data Exchange (ETDEWEB)

Reeves, S; Plimer, I R [Melbourne Univ., Parkville, VIC (Australia). School of Physics

1997-12-31

This paper presents an overview of research conducted with the support of the Australian Institute of Nuclear Science and Engineering, at the University of Melbourne, School of Earth Sciences, Radiochemical Neutron Activation Laboratory. The primary objective of this research is to realize the high potential of the platinum group elements (PGE) and gold to the solution of petrogenetic problems, the study of magma generation and magmatic processes in mafic/ultramafic rock suites, as tracers in hydrothermal ore formation. The PGEs (Os, Ru, Ir, Pt, Pd and Rh) are among the least abundant of all elements on earth with unique properties such as high melting points, high electrical and thermal conductivity, high density, strength and toughness as alloys. They exhibit both siderophile and chalcophile characteristics and are valuable tools in providing information about magmatic processes, in particular S-saturation, as well as crystal fractionation trends. Two distinct groups of PGEs are discerned; the IPGEs (Ru, Os, Ir) and the PPGEs (Pt, Pd, Rh, Au) on the basis of their behaviour during fractionation processes. Using chondrite normalized PGE patterns it is possible to distinguish between sulphides that segregated from primitive magmas, such as komatiites, and sulphides which segregated from more fractionated magmas, such as tholeiites. It is critical to the understanding of these processes to be able to analyse key elements, such as the PGE and gold, in the parts per billion to parts per trillion range. Platinum group elements and Au were determined by radiochemical neutron activation analysis using a modified NiS fire-assay preconcentration technique, adapted from procedures first used by Robert, R.V. D. and van Wyk, E. (1975) . Detection limits are generally 0.005-0.01 ppb (Au and Ir), 0.1-0.2 ppb (Pd and Pt), and 0.1-0.5 ppb for Ru. 9 refs.

The platinum group elements and gold: analysis by radiochemical and instrumental neutron activation analysis and relevance to geological exploration and related problems

Energy Technology Data Exchange (ETDEWEB)

Reeves, S.; Plimer, I. R. [Melbourne Univ., Parkville, VIC (Australia). School of Physics

1996-12-31

This paper presents an overview of research conducted with the support of the Australian Institute of Nuclear Science and Engineering, at the University of Melbourne, School of Earth Sciences, Radiochemical Neutron Activation Laboratory. The primary objective of this research is to realize the high potential of the platinum group elements (PGE) and gold to the solution of petrogenetic problems, the study of magma generation and magmatic processes in mafic/ultramafic rock suites, as tracers in hydrothermal ore formation. The PGEs (Os, Ru, Ir, Pt, Pd and Rh) are among the least abundant of all elements on earth with unique properties such as high melting points, high electrical and thermal conductivity, high density, strength and toughness as alloys. They exhibit both siderophile and chalcophile characteristics and are valuable tools in providing information about magmatic processes, in particular S-saturation, as well as crystal fractionation trends. Two distinct groups of PGEs are discerned; the IPGEs (Ru, Os, Ir) and the PPGEs (Pt, Pd, Rh, Au) on the basis of their behaviour during fractionation processes. Using chondrite normalized PGE patterns it is possible to distinguish between sulphides that segregated from primitive magmas, such as komatiites, and sulphides which segregated from more fractionated magmas, such as tholeiites. It is critical to the understanding of these processes to be able to analyse key elements, such as the PGE and gold, in the parts per billion to parts per trillion range. Platinum group elements and Au were determined by radiochemical neutron activation analysis using a modified NiS fire-assay preconcentration technique, adapted from procedures first used by Robert, R.V. D. and van Wyk, E. (1975) . Detection limits are generally 0.005-0.01 ppb (Au and Ir), 0.1-0.2 ppb (Pd and Pt), and 0.1-0.5 ppb for Ru. 9 refs.

The platinum group elements and gold: analysis by radiochemical and instrumental neutron activation analysis and relevance to geological exploration and related problems

International Nuclear Information System (INIS)

Reeves, S.; Plimer, I. R.

1996-01-01

This paper presents an overview of research conducted with the support of the Australian Institute of Nuclear Science and Engineering, at the University of Melbourne, School of Earth Sciences, Radiochemical Neutron Activation Laboratory. The primary objective of this research is to realize the high potential of the platinum group elements (PGE) and gold to the solution of petrogenetic problems, the study of magma generation and magmatic processes in mafic/ultramafic rock suites, as tracers in hydrothermal ore formation. The PGEs (Os, Ru, Ir, Pt, Pd and Rh) are among the least abundant of all elements on earth with unique properties such as high melting points, high electrical and thermal conductivity, high density, strength and toughness as alloys. They exhibit both siderophile and chalcophile characteristics and are valuable tools in providing information about magmatic processes, in particular S-saturation, as well as crystal fractionation trends. Two distinct groups of PGEs are discerned; the IPGEs (Ru, Os, Ir) and the PPGEs (Pt, Pd, Rh, Au) on the basis of their behaviour during fractionation processes. Using chondrite normalized PGE patterns it is possible to distinguish between sulphides that segregated from primitive magmas, such as komatiites, and sulphides which segregated from more fractionated magmas, such as tholeiites. It is critical to the understanding of these processes to be able to analyse key elements, such as the PGE and gold, in the parts per billion to parts per trillion range. Platinum group elements and Au were determined by radiochemical neutron activation analysis using a modified NiS fire-assay preconcentration technique, adapted from procedures first used by Robert, R.V. D. and van Wyk, E. (1975) . Detection limits are generally 0.005-0.01 ppb (Au and Ir), 0.1-0.2 ppb (Pd and Pt), and 0.1-0.5 ppb for Ru. 9 refs

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)).

Science.gov (United States)

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

103Ru for tumor scanning, 2

International Nuclear Information System (INIS)

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)

Ophthalmologic Baseline Characteristics and 2-Year Ophthalmologic Safety Profile of Pramipexole IR Compared with Ropinirole IR in Patients with Early Parkinson’s Disease

Directory of Open Access Journals (Sweden)

William Seiple

2016-01-01

Full Text Available Background. Parkinson’s disease (PD progressively affects dopaminergic neurotransmission and may affect retinal dopaminergic functions and structures. Objective. This 2-year randomized, open-label, parallel-group, flexible-dose study, NCT00144300, evaluated ophthalmologic safety profiles of immediate-release (IR pramipexole and ropinirole in patients with early idiopathic PD with ≤6 months’ prior dopamine agonist exposure and without preexisting major eye disorders. Methods. Patients received labeled IR regimens of pramipexole (n=121 or ropinirole (n=125 for 2 years. Comprehensive ophthalmologic assessments (COA included corrected acuity, Roth 28-color test, slit-lamp biomicroscopy, intraocular pressure, computerized visual field test, fundus photography, and electroretinography. Results. At baseline, we observed retinal pigmentary epithelium (RPE hypopigmentation not previously reported in PD patients. The estimated relative risk of 2-year COA worsening with pramipexole versus ropinirole was 1.07 (95% CI: 0.71–1.60. Mean changes from baseline in Unified Parkinson’s Disease Rating System parts II+III total scores (pramipexole: 1 year, −4.1±8.9, and 2 years, −0.7±10.1, and ropinirole: 1 year, −3.7±8.2, and 2 years, −1.7±10.5 and Hoehn–Yahr stage distribution showed therapeutic effects on PD symptoms. Safety profiles were consistent with labeling. Conclusions. The risk of retinal deterioration did not differ in early idiopathic PD patients receiving pramipexole versus ropinirole. RPE hypopigmentation at baseline was not previously reported in this population. This trial is registered with NCT00144300.

Excitation function and yield for the 103Rh(d,2n)103Pd nuclear reaction: Optimization of the production of palladium-103

International Nuclear Information System (INIS)

Manenti, Simone; Alí Santoro, María del Carmen; Cotogno, Giulio; Duchemin, Charlotte; Haddad, Ferid; Holzwarth, Uwe; Groppi, Flavia

2017-01-01

Deuteron-induced nuclear reactions for the generation of 103 Pd were investigated using the stacked-foil activation technique on rhodium targets at deuteron energies up to E d = 33 MeV. The excitation functions of the reactions 103 Rh(d,xn) 101,103 Pd, 103 Rh(d,x) 100g,cum,101m,g,102m,g Rh and 103 Rh(d,2p) 103 Ru have been measured, and the Thick-Target Yield for 103 Pd has been calculated.

Latvijas sabiedrisko attiecību aģentūru prakse plānotas krīzes komunikācijas vadīšanā

OpenAIRE

Štokmane, Linda

2014-01-01

Darba nosaukums ir „Latvijas sabiedrisko attiecību aģentūru prakse plānotas krīzes komunikācijas vadīšanā”. Pētījuma problēma - vai krīzes situācijām iespējams sagatavoties un kā iepriekš plānota un sagatavota komunikācija spēj palīdzēt efektīvāk vadīt krīzes situācijas? Bakalaura darba mērķis ir izpētīt, kāda ir Latvijas sab iedrisko attiecību aģentūru prakse un pieredze krīzes komunikācijas plānošanā un vadīšanā. Darba teorētiskā bāze, galvenokārt, balstīta uz situatīvo krīzes komunikāci...

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

Science.gov (United States)

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.

Single neutron pick-up on 104Pd

International Nuclear Information System (INIS)

Rodrigues, M.R.D.; Andre, J.P.A.M. de; Borello-Lewin, T.; Horodynski-Matsushigue, L.B.; Duarte, J.L.M.; Rodrigues, C.L.; Ukita, G.M.

2006-01-01

Low-lying levels of 103 Pd have been investigated through the (d,t) reaction on 104 Pd, at an incident deuteron energy of 15.0 MeV. Outgoing particles were momentum analyzed by an Enge magnetic spectrograph and detected in nuclear emulsion plates, with an energy resolution of 8 keV. Previous (d,t) work suffered from a much worse resolution than that here achieved. A partial analysis of the data obtained is reported, referring to six out of the fourteen scattering angles for which data were obtained. Angular distributions associated with eight of the thirteen levels seen up to 1.1 MeV of excitation have been compared to DWBA one-neutron pick-up predictions. Both, the attributed excitation energy values and the transferred angular momenta are in excellent agreement with the results of other kind of experiments, as tabulated by the Nuclear Data Sheets. Some peculiar structure characteristics, associated with the yrast 5/2 + , 3/2 + and 7/2 + states found in the Ru chain could be recognized also in 103 Pd, pointing to the possibility of a more global understanding of this transitional mass region. (author)

Low dose rate Ir-192 interstitial brachytherapy for prostate cancer

Energy Technology Data Exchange (ETDEWEB)

Oki, Yosuke; Dokiya, Takushi; Yorozu, Atsunori; Suzuki, Takayuki; Saito, Shiro; Monma, Tetsuo; Ohki, Takahiro [National Tokyo Medical Center (Japan); Murai, Masaru; Kubo, Atsushi

2000-04-01

From December 1997 through January 1999, fifteen prostatic cancer patients were treated with low dose rate Ir-192 interstitial brachytherapy using TRUS and perineal template guidance without external radiotherapy. Up to now, as no apparent side effects were found, the safety of this treatment is suggested. In the future, in order to treat prostatic cancer patients with interstitial brachytherapy using I-125 or Pd-103, more investigation for this low dose rate Ir-192 interstitial brachytherapy is needed. (author)

Inner-shell photodetachment from Ru-

International Nuclear Information System (INIS)

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.

A green approach to ethyl acetate: Quantitative conversion of ethanol through direct dehydrogenation in a Pd-Ag membrane reactor

KAUST Repository

Zeng, Gaofeng; Chen, Tao; He, Lipeng; Pinnau, Ingo; Lai, Zhiping; Huang, Kuo-Wei

2012-01-01

Pincers do the trick: The conversion of ethanol to ethyl acetate and hydrogen was achieved using a pincer-Ru catalyst in a Pd-Ag membrane reactor. Near quantitative conversions and yields could be achieved without the need for acid or base promoters

Antibacterial activity of Pd(II) complexes with salicylaldehyde-amino acids Schiff bases ligands.

Science.gov (United States)

Rîmbu, Cristina; Danac, Ramona; Pui, Aurel

2014-01-01

Palladium(II) complexes with Schiff bases ligands derived from salicylaldehyde and amino acids (Ala, Gly, Met, Ser, Val) have been synthesized and characterized by Fourier transform (FT)-IR, UV-Vis and (1)H-NMR spectroscopy. The electrospray mass spectrometry (ES-MS) spectrometry confirms the formation of palladium(II) complexes in 1/2 (M/L) molar ratio. All the Pd(II) complexes 1, [Pd(SalAla)2]Cl2; 2, [Pd(SalGly)2]Cl2; 3, [Pd(SalMet)2]Cl2; 4, [Pd(SalSer)2]Cl2; 5, [Pd(SalVal)2]Cl2; have shown antibacterial activity against Gram-positive bacteria Staphylococcus aureus and Gram-negative bacteria Escherichia coli.

Comparison of hydration reactions for "piano-stool" RAPTA-B and [Ru(η6- arene)(en)Cl]+ complexes: Density functional theory computational study

Science.gov (United States)

Chval, Zdeněk; Futera, Zdeněk; Burda, Jaroslav V.

2011-01-01

The hydration process for two Ru(II) representative half-sandwich complexes: Ru(arene)(pta)Cl2 (from the RAPTA family) and [Ru(arene)(en)Cl]+ (further labeled as Ru_en) were compared with analogous reaction of cisplatin. In the study, quantum chemical methods were employed. All the complexes were optimized at the B3LYP/6-31G(d) level using Conductor Polarizable Continuum Model (CPCM) solvent continuum model and single-point (SP) energy calculations and determination of electronic properties were performed at the B3LYP/6-311++G(2df,2pd)/CPCM level. It was found that the hydration model works fairly well for the replacement of the first chloride by water where an acceptable agreement for both Gibbs free energies and rate constants was obtained. However, in the second hydration step worse agreement of the experimental and calculated values was achieved. In agreement with experimental values, the rate constants for the first step can be ordered as RAPTA-B > Ru_en > cisplatin. The rate constants correlate well with binding energies (BEs) of the Pt/Ru-Cl bond in the reactant complexes. Substitution reactions on Ru_en and cisplatin complexes proceed only via pseudoassociative (associative interchange) mechanism. On the other hand in the case of RAPTA there is also possible a competitive dissociation mechanism with metastable pentacoordinated intermediate. The first hydration step is slightly endothermic for all three complexes by 3-5 kcal/mol. Estimated BEs confirm that the benzene ligand is relatively weakly bonded assuming the fact that it occupies three coordination positions of the Ru(II) cation.

Distribution and PGE mineralization in the formation of chromitite in ophiolite complexes (Ospina-Kitoi Kharanur and ultrabasic massifs of Eastern Sayan, Sousern Siberia)

Science.gov (United States)

Kiseleva, Olga; Zhmodik, Sergei

2015-04-01

New study of PGE in restitic ultrabasic (Kharanur and Ospin-Kitoi) massifs from North and South branches (Dobretsov et al., 1985) of the ophiolite complexes in south-eastern part of the Eastern Sayan show their presence in chromitites of both branches belonging to the different geodynamic settings. Modern concepts model includes several mechanisms of podiform chromitite origin reflected in the chemistry of Cr-spinels (Arai, Yurimoto, 1994; Ballhaus, 1998; Uysal et al., 2009 et al.): 1) partial melting of upper mantle rocks, 2) mixing of primitive melts with melts enriched in SiO2, 3) melt-rock interaction. We estimated the types of interaction of mafic melts with mantle peridotites, with the formation of chromite bodies. For ore chrome spinelides from northern branch (Al2O3) melt = 8 - 14 wt%, (TiO2) melt = 0 - 0,4 wt%, (Fe/Mg) melt = 0,5 - 2,4; Southern branch (Al2O3) melt = 10 - 13 wt%, (TiO2) melt = 0,1 wt%, (Fe/Mg) melt = 0,3 - 1 (Kiseleva, 2014). There are two types of PGE distribution Os-Ir-Ru (I) and Pt-Pd (II). Type I chromitites (mid-Al#Cr-spinels) revealed only Os-Ir-Ru distributions; type II (low-Al#Cr spinelides) show both Os-Ir-Ru and (Pt-Pd) distributions (Kiseleva et al., 2012, 2014). PGE distribution in ultramafic peridotites and chromitites reflects PGE fractionation during partial melting (Barnes et al., 1985; Rehkämper et al., 1997). Processes bringing to extreme fractionation of PGE, may be associated with fluid-saturated supra subduction environment where melting degree near 20% and above is sufficient for the release of PGE from the mantle source (Dick, Bullen, 1984; Naldrett, 2010). Enrichment in PPGE together with a high content of IPGE in same chromite bodies is attributed to the second step of melting, and formation of S-enriched and saturated in PGE melts (Hamlyn, Keays, 1986; Prichard et al., 1996). For type I chromitites platinum group minerals (PGM) are presented by Os-Ir-Ru system. In type II chromitites PGM are represented by Os-Ir-Ru

Synthesis, photophysical and electrochemical characterization of terpyridine-functionalized dendritic oligothiophenes and their Ru(II complexes

Directory of Open Access Journals (Sweden)

Amaresh Mishra

2013-05-01

Full Text Available Pd-catalyzed Sonogashira cross-coupling reactions were used to synthesize novel π-conjugated oligothienylene-ethynylene dendrons and their corresponding terpyridine-based ligands. Their complexation with Ru(II led to interesting novel metallodendrimers with rich spectroscopic properties. All new compounds were fully characterized by 1H and 13C NMR, as well as MALDI–TOF mass spectra. Density functional theory (DFT calculations performed on these complexes gave more insight into the molecular orbital distributions. Photophysical and electrochemical studies were carried out in order to elucidate structure–property relationships and the effect of the dendritic structure on the metal complexes. Photophysical studies of the complexes revealed broad absorption spectra covering from 250 to 600 nm and high molar extinction coefficients. The MLCT emission of these complexes were significantly red-shifted (up to 115 nm compared to the parent [Ru(tpy2]2+ complex.

Development and validation of an ICP-OES method for quantitation of elemental impurities in tablets according to coming US pharmacopeia chapters

DEFF Research Database (Denmark)

Jensen, Celina Støving; Jensen, Henrik; Gammelgaard, Bente

2013-01-01

for quantitation of As, Cd, Cu, Cr, Fe, Hg, Ir, Mn, Mo, Ni, Os, Pb, Pd, Pt, Rh, Ru, V and Zn in tablets according to the new USP chapters was developed. Sample preparation was performed by microwave-assisted acid digestion using a mixture of 65% HNO3 and 37% HCl (3:1, v/v). Limits of detection and quantitation...

Inert anode containing base metal and noble metal useful for the electrolytic production of aluminum

Science.gov (United States)

Ray, Siba P.; Liu, Xinghua

2000-01-01

An inert anode for production of metals such as aluminum is disclosed. The inert anode comprises a base metal selected from Cu and Ag, and at least one noble metal selected from Ag, Pd, Pt, Au, Rh, Ru, Ir and Os. The inert anode may optionally be formed of sintered particles having interior portions containing more base metal than noble metal and exterior portions containing more noble metal than base metal. In a preferred embodiment, the base metal comprises Cu, and the noble metal comprises Ag, Pd or a combination thereof.

CO-free hydrogen production by ethanol steam reforming in a Pd-Ag membrane reactor

NARCIS (Netherlands)

Basile, A.; Gallucci, F.; Iulianelli, A.; Tosti, S.

2008-01-01

In this work, the ethanol steam reforming (ESR) reaction has been studied by using a dense Pd-Ag membrane reactor (MR) by varying the water/ethanol molar ratio between 3:1 and 9:1 in a temperature range of 300-400°C and at 1.3 bar as reaction pressure. The MR was packed with a commercial Ru-based

An experimental study on the geochemical behavior of highly siderophile elements (HSE) and metalloids (As, Se, Sb, Te, Bi) in a mss-iss-pyrite system at 650 °C: A possible magmatic origin for Co-HSE-bearing pyrite and the role of metalloid-rich phases in the fractionation of HSE

Science.gov (United States)

Cafagna, Fabio; Jugo, Pedro J.

2016-04-01

Pyrite, the most abundant sulfide in the Earth's crust, is an accessory mineral in several magmatic sulfide deposits. Although most pyrite is hydrothermal, previous experimental studies have shown that pyrite can also have a primary magmatic origin, by exsolving from monosulfide solid solution (mss) during cooling of a sulfide melt, if sulfur fugacity is sufficiently high. Pyrite from some localities has significant amounts of Co, and complex zonation in some low-melting-point chalcophile elements (LMCE), such as As, Se, Sb, Te, Bi (henceforth referred to as metalloids) and some platinum-group elements (PGE: Ru, Rh, Pd, Os, Ir, Pt). However, the origin of such pyrite and the causes of zonation are not clear. Because the distribution of some of these elements is heterogeneous and seems to be developed in concentric zones, the zonation has been interpreted to represent growth stages, some of them secondary and caused partly by hydrothermal fluids. Better constraints on the origin of Co-PGE-bearing pyrite could help unravel the geochemical processes affecting the sulfide assemblages in which it is found; thus, an experimental study was undertaken to characterize pyrite formation in magmatic sulfide environments and its relationship with metalloids and highly siderophile elements (HSE: PGE, Re, Au). Natural pyrrhotite, chalcopyrite, pentlandite and elemental S were mixed and doped with approximately 50 ppm of each HSE. A mixture of metalloids was added at 0.2 wt.% or 3 wt.% to aliquots of sulfide mixtures. Starting materials were sealed in evacuated silica tubes and fused at 1200 °C. The temperature was subsequently reduced to 750 °C (at 60 °C/h), then to 650 °C (at 0.5 °C/h) to produce relatively large euhedral pyrite crystals, then quenched. The experiments were analyzed using reflected light, SEM, EPMA and LA-ICP-MS. Experimental products contained euhedral pyrite, mss, intermediate solid solution (iss) and metalloid-rich phases, interpreted as quench product

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

Science.gov (United States)

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.

Rapid evaluation of the electrooxidation of fuel compounds with a multiple-electrode setup for direct polymer electrolyte fuel cells

Energy Technology Data Exchange (ETDEWEB)

Fujiwara, Naoko; Siroma, Zyun; Ioroi, Tsutomu; Yasuda, Kazuaki [Research Institute for Ubiquitous Energy Devices, National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577 (Japan)

2007-02-10

Electrochemical oxidation of fuel compounds in acidic media was examined on eight electrodes (Pt, Ru, PtRu, Rh, Ir, Pd, Au, and glassy carbon) simultaneously by multiple cyclic voltammetry (CV) with an electrochemical cell equipped with an eight-electrode configuration. Direct-type polymer electrolyte fuel cells (PEFCs), in which aqueous solutions of the fuel compounds are directly supplied to the anode, were also evaluated. The performances of direct PEFCs with various anode catalysts could be roughly estimated from the results obtained with multiple CV. This multiple evaluation may be useful for identifying novel fuels or electrocatalysts. Methanol, ethanol, ethylene glycol, 2-propanol, and D-glucose were oxidized selectively on Pt or PtRu, as reported previously. However, several compounds that are often used as reducing agents show electrochemical oxidation with unique characteristics. Large current was obtained for the oxidation of formic acid, hypophosphorous acid, and phosphorous acid on a Pd electrode. L-Ascorbic acid and sulfurous acid were oxidized on all of the electrodes used in the present study. (author)

Methods of reforming hydrocarbon fuels using hexaaluminate catalysts

Science.gov (United States)

Gardner, Todd H [Morgantown, WV; Berry, David A [Morgantown, WV; Shekhawat, Dushyant [Morgantown, WV

2012-03-27

A metal substituted hexaaluminate catalyst for reforming hydrocarbon fuels to synthesis gas of the general formula AB.sub.yAl.sub.12-yO.sub.19-.delta., A being selected from alkali metals, alkaline earth metals and lanthanide metals or mixtures thereof. A dopant or surface modifier selected from a transitions metal, a spinel of an oxygen-ion conductor is incorporated. The dopant may be Ca, Cs, K, La, Sr, Ba, Li, Mg, Ce, Co, Fe, Ir, Rh, Ni, Ru, Cu, Pe, Os, Pd, Cr, Mn, W, Re, Sn, Gd, V, Ti, Ag, Au, and mixtures thereof. The oxygen-ion conductor may be a perovskite selected from M'RhO.sub.3, M'PtO.sub.3, M'PdO.sub.3, M'IrO.sub.3, M'RuO.sub.3 wherein M'=Mg, Sr, Ba, La, Ca; a spinel selected from MRh.sub.2O.sub.4, MPt.sub.2O.sub.4, MPd.sub.2O.sub.4, MIr.sub.2O.sub.4, MRu.sub.2O.sub.4 wherein M=Mg, Sr, Ba, La, Ca and mixtures thereof; a florite is selected from M''O.sub.2.

Electrochemical CO2 and CO reduction on metal-functionalized porphyrin-like graphene

DEFF Research Database (Denmark)

Tripkovic, Vladimir; Vanin, Marco; Karamad, Mohammedreza

2013-01-01

Porphyrin-like metal-functionalized graphene structures have been investigated as possible catalysts for CO2 and CO reduction to methane or methanol. The late transition metals (Cu, Ag, Au, Ni, Pd, Pt, Co, Rh, Ir, Fe, Ru, Os) and some p (B, Al, Ga) and s (Mg) metals comprised the center of the po......Porphyrin-like metal-functionalized graphene structures have been investigated as possible catalysts for CO2 and CO reduction to methane or methanol. The late transition metals (Cu, Ag, Au, Ni, Pd, Pt, Co, Rh, Ir, Fe, Ru, Os) and some p (B, Al, Ga) and s (Mg) metals comprised the center...... instead of CO2. Volcano plots were constructed on the basis of scaling relations of reaction intermediates, and from these plots the reaction steps with the highest overpotentials were deduced. The Rh-porphyrin-like functionalized graphene was identified as the most active catalyst for producing methanol...... from CO, featuring an overpotential of 0.22 V. Additionally, we have also examined the hydrogen evolution and oxidation reaction, and in their case, too, Rh-porphyrin turned out to be the best catalyst with an overpotential of 0.15 V. © 2013 American Chemical Society....

Single neutron pick-up on {sup 104}Pd

Energy Technology Data Exchange (ETDEWEB)

Rodrigues, M.R.D.; Andre, J.P.A.M. de; Borello-Lewin, T.; Horodynski-Matsushigue, L.B.; Duarte, J.L.M.; Rodrigues, C.L. [Universidade de Sao Paulo, SP (Brazil). Inst. de Fisica; Ukita, G.M. [Universidade de Santo Amaro, SP (Brazil). Faculdade de Psicologia

2006-12-15

Low-lying levels of {sup 103}Pd have been investigated through the (d,t) reaction on {sup 104}Pd, at an incident deuteron energy of 15.0 MeV. Outgoing particles were momentum analyzed by an Enge magnetic spectrograph and detected in nuclear emulsion plates, with an energy resolution of 8 keV. Previous (d,t) work suffered from a much worse resolution than that here achieved. A partial analysis of the data obtained is reported, referring to six out of the fourteen scattering angles for which data were obtained. Angular distributions associated with eight of the thirteen levels seen up to 1.1 MeV of excitation have been compared to DWBA one-neutron pick-up predictions. Both, the attributed excitation energy values and the transferred angular momenta are in excellent agreement with the results of other kind of experiments, as tabulated by the Nuclear Data Sheets. Some peculiar structure characteristics, associated with the yrast 5/2{sup +}, 3/2{sup +} and 7/2{sup +} states found in the Ru chain could be recognized also in {sup 103}Pd, pointing to the possibility of a more global understanding of this transitional mass region. (author)

Mixed-ligand Ru(II) complexes with 2,2'-bipyridine and aryldiazo-beta-diketonato auxillary ligands: synthesis, physico-chemical study and antitumour properties.

Science.gov (United States)

Mishra, Lallan; Yadaw, Ajay K; Bhattacharya, Subrato; Dubey, Santosh K

2005-05-01

The complexes of Ru(II)-2,2'-bipyridyl with substituted diazopentane-2,4-diones (L1H-L5H) were synthesized and characterized by elemental analyses, conductance, FAB (fast atom bombardment) mass and spectral (IR, UV/Vis (UV/visible), NMR) studies. Molecular geometry optimization of the complexes was also made. None of the complexes luminesce. However, facilitated oxidation of Ru(II) to Ru(III) was evidenced from their lower reduction potential data. The ligands and their complexes were tested for their antitumour activity against a variety of tumour cell lines. Though activity is found to vary with the type of tumour cell lines used, yet complex 5 with naphtyldiazopentane-2,4-dione as co-ligand was found to be a potential compound as it showed in general significant activity against all cell lines studied.

Synthesis and electrochemical study of Pt-based nanoporous materials

International Nuclear Information System (INIS)

Wang Jingpeng; Holt-Hindle, Peter; MacDonald, Duncan; Thomas, Dan F.; Chen Aicheng

2008-01-01

In the present work, a variety of Pt-based bimetallic nanostructured materials including nanoporous Pt, Pt-Ru, Pt-Ir, Pt-Pd and Pt-Pb networks have been directly grown on titanium substrates via a facile hydrothermal method. The as-fabricated electrodes were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction and electrochemical methods. The active surface areas of these nanoporous Pt-based alloy catalysts are increased by over 68 (Pt-Pd), 69 (Pt-Ru) and 113 (Pt-Ir) fold compared to a polycrystalline Pt electrode. All these synthesized nanoporous electrodes exhibit superb electrocatalytic performance towards electrochemical oxidation of methanol and formic acid. Among the five nanoporous Pt-based electrodes, the Pt-Ir shows the highest peak current density at +0.50 V, with 68 times of enhancement compared to the polycrystalline Pt for methanol oxidation, and with 86 times of enhancement in formic acid oxidation; whereas the catalytic activity of the nanoporous Pt-Pb electrode outperforms the other materials in formic acid oxidation at the low potential regions, delivering an enhanced current density by 280-fold compared to the polycrystalline Pt at +0.15 V. The new approach described in this study is suitable for synthesizing a wide range of bi-metallic and tri-metallic nanoporous materials, desirable for electrochemical sensor design and potential application in fuel cells

Synthesis and electrochemical study of Pt-based nanoporous materials

Energy Technology Data Exchange (ETDEWEB)

Wang Jingpeng [Department of Chemistry, Lakehead University, Thunder Bay, Ontario P7B 5E1 (Canada); Department of Chemistry, University of Guelph, Guelph, Ontario N1G 2W1 (Canada); Holt-Hindle, Peter; MacDonald, Duncan [Department of Chemistry, Lakehead University, Thunder Bay, Ontario P7B 5E1 (Canada); Thomas, Dan F. [Department of Chemistry, University of Guelph, Guelph, Ontario N1G 2W1 (Canada); Chen Aicheng [Department of Chemistry, Lakehead University, Thunder Bay, Ontario P7B 5E1 (Canada)], E-mail: aicheng.chen@lakeheadu.ca

2008-10-01

In the present work, a variety of Pt-based bimetallic nanostructured materials including nanoporous Pt, Pt-Ru, Pt-Ir, Pt-Pd and Pt-Pb networks have been directly grown on titanium substrates via a facile hydrothermal method. The as-fabricated electrodes were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction and electrochemical methods. The active surface areas of these nanoporous Pt-based alloy catalysts are increased by over 68 (Pt-Pd), 69 (Pt-Ru) and 113 (Pt-Ir) fold compared to a polycrystalline Pt electrode. All these synthesized nanoporous electrodes exhibit superb electrocatalytic performance towards electrochemical oxidation of methanol and formic acid. Among the five nanoporous Pt-based electrodes, the Pt-Ir shows the highest peak current density at +0.50 V, with 68 times of enhancement compared to the polycrystalline Pt for methanol oxidation, and with 86 times of enhancement in formic acid oxidation; whereas the catalytic activity of the nanoporous Pt-Pb electrode outperforms the other materials in formic acid oxidation at the low potential regions, delivering an enhanced current density by 280-fold compared to the polycrystalline Pt at +0.15 V. The new approach described in this study is suitable for synthesizing a wide range of bi-metallic and tri-metallic nanoporous materials, desirable for electrochemical sensor design and potential application in fuel cells.0.

Synthesis and electrochemical study of Pt-based nanoporous materials

Energy Technology Data Exchange (ETDEWEB)

Wang, Jingpeng [Department of Chemistry, Lakehead University, Thunder Bay, Ontario P7B 5E1 (Canada); Department of Chemistry, University of Guelph, Guelph, Ontario N1G 2W1 (Canada); Holt-Hindle, Peter; MacDonald, Duncan; Chen, Aicheng [Department of Chemistry, Lakehead University, Thunder Bay, Ontario P7B 5E1 (Canada); Thomas, Dan F. [Department of Chemistry, University of Guelph, Guelph, Ontario N1G 2W1 (Canada)

2008-10-01

In the present work, a variety of Pt-based bimetallic nanostructured materials including nanoporous Pt, Pt-Ru, Pt-Ir, Pt-Pd and Pt-Pb networks have been directly grown on titanium substrates via a facile hydrothermal method. The as-fabricated electrodes were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction and electrochemical methods. The active surface areas of these nanoporous Pt-based alloy catalysts are increased by over 68 (Pt-Pd), 69 (Pt-Ru) and 113 (Pt-Ir) fold compared to a polycrystalline Pt electrode. All these synthesized nanoporous electrodes exhibit superb electrocatalytic performance towards electrochemical oxidation of methanol and formic acid. Among the five nanoporous Pt-based electrodes, the Pt-Ir shows the highest peak current density at +0.50 V, with 68 times of enhancement compared to the polycrystalline Pt for methanol oxidation, and with 86 times of enhancement in formic acid oxidation; whereas the catalytic activity of the nanoporous Pt-Pb electrode outperforms the other materials in formic acid oxidation at the low potential regions, delivering an enhanced current density by 280-fold compared to the polycrystalline Pt at +0.15 V. The new approach described in this study is suitable for synthesizing a wide range of bi-metallic and tri-metallic nanoporous materials, desirable for electrochemical sensor design and potential application in fuel cells. (author)

Interpreting intensities in vibrational sum frequency generation (SFG) spectroscopy: CO adsorption on Pd surfaces

Science.gov (United States)

Morkel, M.; Unterhalt, H.; Klüner, T.; Rupprechter, G.; Freund, H.-J.

2005-07-01

The lineshape and intensity of SFG signals of CO adsorbed on supported Pd nanoparticles and Pd(1 1 1) are analyzed. For CO/Pd(1 1 1) nearly symmetric lorentzian lineshapes were observed. Applying two different visible wavelengths for excitation, asymmetric lineshapes observed for the CO/Pd/Al 2O 3/NiAl(1 1 0) system are explained by a lower resonant and a higher non-resonant SFG signal and a change in the phase between resonant and non-resonant signals, most likely originating from an interband transition in the NiAl substrate. The relative intensity of different CO species (hollow, bridge, on-top) was modeled by DFT calculations of IR transition moments and Raman activities. While the (experimental) sensitivity of SFG towards different CO species strongly varies, the calculated IR and Raman activities are rather similar. The inability to exactly reproduce experimental SFG intensities suggests a strong coverage dependence of Raman activities or that non-linear effects occur that can currently not be properly accounted for.

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

International Nuclear Information System (INIS)

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)

Inelastic scattering on 100Ru

International Nuclear Information System (INIS)

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

Synthesis and characterization of PdAg as a catalyst for oxygen reduction reaction in acid medium; Sintesis y caracterizacion de PdAg como catalizador para la reaccion de reduccion de oxigeno en medio acido

Energy Technology Data Exchange (ETDEWEB)

Martinez-Casillas, D. C.; Vazquez-Huerta, G.; Solorza-Feria, O. [Centro de Investigacion y de Estudios Avanzados del IPN, Mexico D.F. (Mexico)]. E-mail: dcmartinez@cinvestav.mx

2009-09-15

This work presents the synthesis of the binary compound PdAg and the electrochemical characterization for oxygen reduction reaction (ORR) in acid medium. The catalyst is obtained from the reduction of Pd(NO{sub 3}){sub 2}·2H{sub 2}O and AgNO{sub 3} with NaBH{sub 4} in THF. The synthesized compound was physically characterized with transmission electron microscopy (TEM), sweep electron microscopy (SEM) and x-ray diffraction (XRD) of powder. Electrochemical studies were conducted to determine the catalytic activity and intrinsic properties of the PdAg material for the ORR in acid medium using cyclic voltamperometry (CV), rotary disc electrode (RDE) and electrochemical impedance spectroscopy (EIS) in a solution of H{sub 2}SO{sub 4} 0.5 M at 25 degrees Celsius. The electrochemical current-potential responses were compared to those of palladium and platinum. The kinetic results showed an increase in the performance of the bimetallic electrocatalyst containing Ag as compared to pure Pd, but less than that obtained with nanometric Pt. The Tafel slopes obtained are roughly120 mV dec-1, similar to that reported for Pt and Pd and for other Ru-based electrocatalysts. [Spanish] En este trabajo se presentan la sintesis del compuesto binario PdAg y su caracterizacion electroquimica para la reaccion de reduccion de oxigeno (RRO) en medio acido. El catalizador se obtuvo a partir de la reduccion de Pd(NO{sub 3}){sub 2}·2H{sub 2}O y AgNO{sub 3} con NaBH{sub 4} en THF. El compuesto sintetizado se caracterizo fisicamente por microscopia electronica de transmision (MET), microscopia electronica de barrido (MEB) y difraccion de rayos X (DRX) de polvos. Se realizaron estudios electroquimicos para determinar la actividad catalitica y las propiedades intrinsecas del material de PdAg para la reaccion de reduccion de oxigeno (RRO) en medio acido, utilizando las tecnicas de voltamperometria ciclica (VC), electrodo disco rotatorio (EDR) y espectroscopia de impedancia electroquimica (EIE), en

DNA-binding, catalytic oxidation, C—C coupling reactions and antibacterial activities of binuclear Ru(II thiosemicarbazone complexes: Synthesis and spectral characterization

Directory of Open Access Journals (Sweden)

Arumugam Manimaran

2012-07-01

Full Text Available New hexa-coordinated binuclear Ru(II thiosemicarbazone complexes of the type {[(B(EPh3(COClRu]2L} (where, E = P or As; B = PPh3 or AsPh3 or pyridine; L = mononucleating NS donor of N-substituted thiosemicarbazones have been synthesized and characterized by elemental analysis, FT-IR, UV–vis and 31P{1H} NMR cyclic voltammetric studies. The DNA-binding studies of Ru(II complexes with calf thymus DNA (CT-DNA were investigated by UV–vis, viscosity measurements, gel-electrophoresis and fluorescence spectroscopy. The new complexes have been used as catalysts in C—C coupling reaction and in the oxidation of alcohols to their corresponding carbonyl compounds by using NMO as co-oxidant and molecular oxygen (O2 atmosphere at ambient temperature. Further, the new binucleating thiosemicarbazone ligands and their Ru(II complexes were also screened for their antibacterial activity against Klebsiella pneumoniae, Shigella sp., Micrococcus luteus, Escherichia coli and Salmonella typhi. From this study, it was found out that the activity of the complexes almost reaches the effectiveness of the conventional bacteriocide.

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

Energy Technology Data Exchange (ETDEWEB)

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)

Reação de bis-inserção de 1,2-difenilacetileno na ligação Pd-C de ciclometalados Bis insertion reaction of 1,2-diphenylacetilene into Pd-C bond of cyclometallated species

Directory of Open Access Journals (Sweden)

Sandra Regina Ananias

2003-01-01

Full Text Available The present paper deals with the bis-insertion reactions of 1,2-diphenylacetylene into Pd-C bond of the cyclopalladated complexes [Pd(dmba(µ-NCO]2 (1 and [Pd(dmba(MeCN2](NO3 (2 (dmba = N,N-dimethylbenzylamine, MeCN = acetonitrile. Two new complexes [Pd{PhC=CPh-CPh=CPhC6H4CH2N(CH 32}(NCO] (3 and [Pd{PhC=CPh-CPh=CPhC6H4CH2N(CH 32}(NO3 ] (4 were obtained and characterized by IR and NMR spectroscopy and elemental analysis.

Light Activation of a Cysteine Protease Inhibitor: Caging of a Peptidomimetic Nitrile with RuII(bpy)2

Science.gov (United States)

Respondek, Tomasz; Garner, Robert N.; Herroon, Mackenzie K.; Podgorski, Izabela; Turro, Claudia; Kodanko, Jeremy J.

2013-01-01

A novel method for caging protease inhibitors is described. The complex [RuII(bpy)2(1)2](PF6)2 (2) was prepared from the nitrile-based peptidomimetic inhibitor Ac-Phe-NHCH2CN (1). 1H NMR, UV-vis and IR spectroscopic and mass spectrometric data confirm that two equiv of inhibitor 1 bind to RuII through the nitrile functional group. Complex 2 shows excellent stability in aqueous solution in the dark and fast release of 1 upon irradiation with visible light. Due to binding to the RuII center, the nitriles of complex 2 are caged, and 2 does not act as a potent enzyme inhibitor. However, when 2 is irradiated, it releases 1 that inhibits the cysteine proteases papain and cathepsins B, K and L, up to two times more potently than 1 alone. Ratios for IC50 values for 2 range from 6:1 to 33:1 under dark vs. light conditions, against isolated enzymes and in human cell lysates, confirming a high level of photoinduced enzyme inhibition is obtained with this method. PMID:21973207

Anodic incineration of phthalic anhydride using RuO2–IrO2–SnO2–TiO2 coated on Ti anode

Directory of Open Access Journals (Sweden)

S. Chellammal

2016-11-01

Full Text Available Phthalic anhydride is a toxic and non-biodegradable organic compound and is widely used for the production of dyes. This paper has investigated the electrochemical oxidation of phthalic anhydride in an undivided cell at different experimental parameters such as pH, current density and supporting electrolytes on the anode of titanium substrate coated with mixed metal oxides of RuO2, IrO2, SnO2 and TiO2 prepared by thermal decomposition method. The surface morphology and the structure of the above anode were characterized by scanning electron microscopy, electron dispersion microscopy and X-ray diffraction. The study shows that the electrode exhibits good electro catalytic activity together with chemical stability during the treatment of the phthalic anhydride. At pH 3, the maximum removal of COD of 88% with energy consumption of 30.5 kW h kg−1 was achieved by the addition of 10 g l−1 NaCl in 0.2 mol dm−3 Na2SO4 at 5 Adm−2. This electrolytic investigation offers an attractive alternative method for the destruction of industrial effluents contaminated with phthalic anhydride.

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

Science.gov (United States)

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).

Improvement of sulfur resistance of Pd/Ce-Zr-Al-O catalysts for CO oxidation

Science.gov (United States)

Shin, Haebin; Baek, Minsung; Ro, Youngsoo; Song, Changyeol; Lee, Kwan-Young; Song, In Kyu

2018-01-01

Two kinds of mesoporous ceria-zirconia-alumina supports were prepared by a single-step epoxide-driven sol-gel method (SGCZA) and by a co-precipitation method (PCZA). Palladium catalysts supported on these materials were then prepared by a wet impregnation method (Pd/SGCZA and Pd/PCZA). The prepared catalysts were applied to the CO oxidation reaction before and after sulfur aging. XRD and N2 adsorption-desorption analyses revealed that these two catalysts retained different physicochemical properties. Pd/SGCZA had higher surface area and larger pore volume than Pd/PCZA before and after sulfur aging. TPR (Temperature-programmed reduction), CO chemisorption, FT-IR, and XPS analyses showed that the catalysts were differently influenced by sulfur species. Pd/SGCZA formed less sulfate and retained higher palladium dispersion than Pd/PCZA after sulfur aging. In the CO oxidation, Pd/PCZA showed better activity than Pd/SGCZA before sulfur aging. However, Pd/SGCZA showed higher CO conversion than Pd/PCZA after sulfur aging. We concluded that Pd/SGCZA was less poisoned by sulfur species than Pd/PCZA.

Activity of ruthenium, rhodium, iridium-ruthenium and iridium-rhodium adsorbed catalysts in dehydrogenation of formic acid

Energy Technology Data Exchange (ETDEWEB)

Mikhailov, V A; Zubovich, I A [Yaroslavskij Politekhnicheskij Inst. (USSR)

1977-04-01

The activity of Ru-, Rh- (Ir+nRu)- and (Ir+nRn) catalysts on sugar carbon and silicon dioxide in decomposition of HCOOH was studied. The catalyst activity increases in the series Ir+nRh). The highest activity is displayed by (Ir+nRh) catalysts on silicon dioxide. The results obtained point to activity of single centres (Ru)/sub 1/ and (Rh)/sub 1/ in the reaction of dehydration of HCOOH. It is shown that in the course of preparation of (Ir+nRh)- and (Ir+nRu)-catalysts the Ir atoms interact with Ru(Rh), and variable-composition structures are formed.

Hydrothermal synthesis of highly crystalline RuS2 nanoparticles as cathodic catalysts in the methanol fuel cell and hydrochloric acid electrolysis

International Nuclear Information System (INIS)

Li, Yanjuan; Li, Nan; Yanagisawa, Kazumichi; Li, Xiaotian; Yan, Xiao

2015-01-01

Highlights: • Highly crystalline RuS 2 nanoparticles have been first synthesized by a “one-step” hydrothermal method. • The product presents a pure cubic phase of stoichiometric ratio RuS 2 with average particle size of 14.8 nm. • RuS 2 nanoparticles were used as cathodic catalysts in methanol fuel cell and hydrochloric acid electrolysis. • The catalyst outperforms commercial Pt/C in methanol tolerance and stability towards Cl − . - Abstract: Highly crystalline ruthenium sulfide (RuS 2 ) nanoparticles have been first synthesized by a “one-step” hydrothermal method at 400 °C, using ruthenium chloride and thiourea as reactants. The products were characterized by powder X-ray diffraction (XRD), scanning electron microscopy/energy disperse spectroscopy (SEM/EDS), thermo gravimetric-differential thermal analyze (TG-DTA), transmission electron microscopy equipped with selected area electron diffraction (TEM/SAED). Fourier transform infrared spectra (IR), and X-ray photoelectron spectroscopy (XPS). XRD result illustrates that the highly crystalline product presents a pure cubic phase of stoichiometric ratio RuS 2 and the average particle size is 14.8 nm. SEM and TEM images display the products have irregular shape of 6–25 nm. XPS analyst indicates that the sulfur exists in the form of S 2 2− . Cyclic voltammetry (CV), rotating disk electrode (RDE), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS) measurements are conducted to evaluate the electrocatalytic activity and stability of the highly crystalline RuS 2 nanoparticles in oxygen reduction reaction (ORR) for methanol fuel cell and hydrochloric acid electrolysis. The results illustrate that RuS 2 is active towards oxygen reduction reaction. Although the activity of RuS 2 is lower than that of Pt/C, the RuS 2 catalyst outperforms commercial Pt/C in methanol tolerance and stability towards Cl −

Thermodynamic assessment of the Al-Ru system

CSIR Research Space (South Africa)

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...

Catalytic mechanisms of direct pyrrole synthesis via dehydrogenative coupling mediated by PNP-Ir or PNN-Ru pincer complexes: Crucial role of proton-transfer shuttles in the PNP-Ir system

KAUST Repository

Qu, Shuanglin; Dang, Yanfeng; Song, Chunyu; Wen, Mingwei; Huang, Kuo-Wei; Wang, Zhixiang

2014-01-01

lower catalyst loading than the PNN-Ru system. We discuss how the differences are resulted in terms of electronic and geometric structures of the catalysts and how to use the features in catalyst development. © 2014 American Chemical Society.

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

International Nuclear Information System (INIS)

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

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

Science.gov (United States)

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.

Oxidation study of Cr-Ru hard coatings

Energy Technology Data Exchange (ETDEWEB)

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.

Palladium, platinum, rhodium, iridium and ruthenium in chromite- rich rocks from the Samail ophiolite, Oman.

Science.gov (United States)

Page, N.J.; Pallister, J.S.; Brown, M.A.; Smewing, J.D.; Haffty, J.

1982-01-01

30 samples of chromitite and chromite-rich rocks from two stratigraphic sections, 250 km apart, through the basal ultramafic member of the Samail ophiolite were spectrographically analysed for platinum-group elements (PGE) and for Co, Cu, Ni and V. These data are reported as are Cr/(Cr + Al), Mg/(Mg + Fe) and wt.% TiO2 for most samples. The chromitite occurs as pods or lenses in rocks of mantle origin or as discontinuous layers at the base of the overlying cumulus sequence. PGE abundances in both sections are similar, with average contents in chromite-rich rocks: Pd 8 ppb, Pt 14 ppb, Rh 6 ppb, Ir 48 ppb and Ru 135 ppb. The PGE data, combined with major-element and petrographic data on the chromitite, suggest: 1) relatively larger Ir and Ru contents and highest total PGE in the middle part of each section; 2) PGE concentrations and ratios do not correlate with coexisting silicate and chromite abundances or chromite compositions; 3) Pd/PGE, on average, increases upward in each section; 4) Samail PGE concentrations, particularly Rh, Pt and Pd, are lower than the average values for chromite-rich rocks in stratiform intrusions. 2) suggests that PGEs occur in discrete alloy or sulphide phases rather than in the major oxides or silicates, and 4) suggests that chromite-rich rocks from the oceanic upper mantle are depleted in PGE with respect to chondrites. L.C.C.

PGE mineralization and melt composition of chromitites in Proterozoic ophiolite complexes of Eastern Sayan, Southern Siberia

Directory of Open Access Journals (Sweden)

O. Kiseleva

2017-07-01

Full Text Available The Ospino-Kitoi and Kharanur ultrabasic massifs represent the northern and southern ophiolite branches respectively of the Upper Onot ophiolitic nappe and they are located in the southeastern part of the Eastern Sayan (SEPES ophiolites. Podiform chromitites with PGE mineralization occur as lensoid pods within dunites and rarely in harzburgites or serpentinized peridotites. The chromitites are classified into type I and type II based on their Cr#. Type I (Cr# = 59–85 occurs in both northern and southern branches, whereas type II (Cr# = 76–90 occurs only in the northern branch. PGE contents range from ∑PGE 88–1189 ppb, Pt/Ir 0.04–0.42 to ∑PGE 250–1700 ppb, Pt/Ir 0.03–0.25 for type I chromitites of the northern and southern branches respectively. The type II chromitites of the northern branch have ∑PGE contents higher than that of type I (468–8617 ppb, Pt/Ir 0.1–0.33. Parental melt compositions, in equilibrium with podiform chromitites, are in the range of boninitic melts and vary in Al2O3, TiO2 and FeO/MgO contents from those of type I and type II chromitites. Calculated melt compositions for type I chromitites are (Al2O3melt = 10.6–13.5 wt.%, (TiO2melt = 0.01–0.44 wt.%, (Fe/Mgmelt = 0.42–1.81; those for type II chromitites are: (Al2O3melt = 7.8–10.5 wt.%, (TiO2melt = 0.01–0.25 wt.%, (Fe/Mgmelt = 0.5–2.4. Chromitites are further divided into Os-Ir-Ru (I and Pt-Pd (II based on their PGE patterns. The type I chromitites show only the Os-Ir-Ru pattern whereas type II shows both Os-Ir-Ru and Pt-Pd patterns. PGE mineralization in type I chromitites is represented by the Os-Ir-Ru system, whereas in type II it is represented by the Os-Ir-Ru-Rh-Pt system. These results indicate that chromitites and PGE mineralization in the northern branch formed in a suprasubduction setting from a fluid-rich boninitic melt during active subduction. However, the chromitites and PGE mineralization of the southern

Recoil effect on β-decaying in vivo generators, interpreted for 103Pd/103mRh

International Nuclear Information System (INIS)

Szucs, Zoltan; Rooyen, Johann van; Zeevaart, Jan Rijn

2009-01-01

The use of Auger emitters as potential radiopharmaceuticals is being increasingly investigated. One of the radionuclides of interest is 103m Rh, which can be produced from 103 Ru or 103 Pd in an in vivo generator. A potential problem, however, is the recoil of the 103m Rh out of the carrier molecule and even out of the target cell. In order to determine the likelihood of this happening in the 103 Pd/ 103m Rh, case calculations were made to prove that this does not happen. The equations were generalised for all radionuclides with an atomic mass of 10-240 as a tool for determining the recoil threshold of any β-emitting radionuclide.

Synthesis, Photophysical and Electrochemical Properties of a Mixed Bipyridyl-Phenanthrolyl Ligand Ru(II Heteroleptic Complex Having trans-2-Methyl-2-butenoic Acid Functionalities

Directory of Open Access Journals (Sweden)

Adewale O. Adeloye

2011-09-01

Full Text Available In this work, two ligands: 4-(trans-2-Methyl-2-butenoic acid-2,2'-bipyridine (L1 and 5-(trans-2-methyl-2-butenoic acid-1,10-phenanthroline (L2, with the corresponding mixed-ligand heteroleptic Ru(II complex were synthesized and characterized by FT-IR, 1H-, 13C-NMR spectroscopy and elemental analysis. The influence of the mixed functionalized polypyridyl ruthenium(II complex on the photophysical and electrochemical properties were investigated and compared to individual single-ligand homoleptic complexes. Interestingly, the mixed-ligand complex formulated as [RuL1L2(NCS2] exhibits broad and intense metal-to-ligand charge transfer (MLCT absorption with a high molar extinction coefficient (λmax = 514 nm, ε = 69,700 M−1 cm−1, better than those of individual single-ligand complexes, [Ru(L12(NCS2] and [Ru(L22(NCS2], and a strong photoluminescence intensity ratio in the red region at λem = 686 nm. The electrochemical properties of the complex indicated that the redox processes are ligand-based.

Personības iezīmju atšķirības cilvēkiem ar atšķirīgu dzimšanas pozīciju

OpenAIRE

Aļeksejevs, Dzintis

2015-01-01

Bakalaura darba mērķis ir apkopot literatūru un galvenās atziņas par dzimšanas secību un tās pozīcijām, personības iezīmēm, izpētīt katrai dzimšanas secības pozīcijai raksturīgās personības iezīmes, kā arī veikt pētījumu, lai noskaidrotu – vai starp cilvēkiem ar atšķirīgu dzimšanas pozīciju pastāv personības iezīmju atšķirības? Pētījumā piedalījās 186 cilvēki vecumā no 18 – 74 gadiem. Lai noskaidrotu atbildi uz pētījuma jautājumu, tika izmantota sekojoša metode: Lielā Piecinieka apta...

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

Energy Technology Data Exchange (ETDEWEB)

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)

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

Science.gov (United States)

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.

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

International Nuclear Information System (INIS)

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)

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

International Nuclear Information System (INIS)

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

A green approach to ethyl acetate: Quantitative conversion of ethanol through direct dehydrogenation in a Pd-Ag membrane reactor

KAUST Repository

Zeng, Gaofeng

2012-11-07

Pincers do the trick: The conversion of ethanol to ethyl acetate and hydrogen was achieved using a pincer-Ru catalyst in a Pd-Ag membrane reactor. Near quantitative conversions and yields could be achieved without the need for acid or base promoters or hydrogen acceptors (see scheme). © 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Multicenter Evaluation of the Tolerability of Combined Treatment With PD-1 and CTLA-4 Immune Checkpoint Inhibitors and Palliative Radiation Therapy

Energy Technology Data Exchange (ETDEWEB)

Bang, Andrew [Department of Radiation Oncology, Brigham and Women' s Hospital/Dana-Farber Cancer Institute, Boston, Massachusetts (United States); Division of Radiation Oncology, University of Ottawa, Ottawa, Ontario (Canada); Wilhite, Tyler J. [Harvard Medical School, Boston, Massachusetts (United States); Pike, Luke R.G. [Harvard Radiation Oncology Program, Brigham and Women' s Hospital/Dana-Farber Cancer Institute, Boston, Massachusetts (United States); Cagney, Daniel N.; Aizer, Ayal A.; Taylor, Allison; Spektor, Alexander; Krishnan, Monica [Department of Radiation Oncology, Brigham and Women' s Hospital/Dana-Farber Cancer Institute, Boston, Massachusetts (United States); Ott, Patrick A. [Department of Medical Oncology and Center for Immuno-Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts (United States); Balboni, Tracy A. [Department of Radiation Oncology, Brigham and Women' s Hospital/Dana-Farber Cancer Institute, Boston, Massachusetts (United States); Hodi, F. Stephen [Department of Medical Oncology and Center for Immuno-Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts (United States); Schoenfeld, Jonathan D., E-mail: jdschoenfeld@partners.org [Department of Radiation Oncology, Brigham and Women' s Hospital/Dana-Farber Cancer Institute, Boston, Massachusetts (United States)

2017-06-01

Purpose: To analyze immune-related adverse events (ir-AEs) in patients treated with radiation and immune checkpoint blockade. Methods and Materials: We retrospectively reviewed records from patients with metastatic non-small cell lung cancer, melanoma, or renal cell cancer who received at least 1 cycle of a CTLA-4 or PD-1 inhibitor and radiation. Immune-related adverse events, defined using Common Terminology Criteria for Adverse Events version 4.0, were tabulated in relation to treatment variables, and associations with sequencing and timing were assessed. Results: We identified 133 patients, of whom 28 received a CTLA-4 inhibitor alone, 88 received a PD-1 inhibitor alone, and 17 received both classes of inhibitors either sequentially (n=13) or concurrently (n=4). Fifty-six patients received radiation within 14 days of an immune checkpoint inhibitor. Forty-six patients experienced at least 1 ir-AE (34.6%). Patients receiving both CTLA-4 and PD-1 inhibitors experienced more any-grade ir-AEs as compared with either individually (71% vs 29%, P=.0008). Any-grade ir-AEs occurred in 39% of patients in whom radiation was administered within 14 days of immunotherapy, compared with 23% of other patients (P=.06) and more often in patients who received higher equivalent dose in 2-Gy fractions (EQD2) EQD2 (P=.01). However, most toxicities were mild. There were no associations between site irradiated and specific ir-AEs. Conclusions: Our data suggest the combination of focal palliative radiation and CTLA-4 and/or PD-1 inhibitors is well tolerated, with manageable ir-AEs that did not seem to be associated with the particular site irradiated. Although conclusions are limited by the heterogeneity of patients and treatments, and future confirmatory studies are needed, this information can help guide clinical practice for patients receiving immune checkpoint therapy who require palliative radiation therapy.

Ropes eye plaque brachytherapy dosimetry for two models of 103Pd seeds

International Nuclear Information System (INIS)

Saidi, P.; Sadeghi, M.; Shirazi, A.; Tenreiro, C.

2011-01-01

Full text: Brachytherapy dose distributions are calculated for I5 m m ROPES eye plaque loaded with model Theragenics200 and IR06-103Pd seeds. The effects of stainless steel backing and Acrylic insert on dose distribution along the central axis of the eye plaque and at critical ocular structure are investigated. Monte Carlo simulation was carried out with the Version 5 of the MCNP. The dose at critical ocular structure by considering the eye composition was calculated. Results are compared with the calculated data for CaMS eye plaque loaded with Theragenics200 palladium-103 seeds and model 6711 iodine-125 seed. The air kerma strength of the IR06- 103Pd seed to deliver 85 Gy in apex of tumor in water medium was calculated to be 4.10 U/seed. Along the central axis of stainless steel plaque loaded with new 103Pd seeds in Acrylic insert, the dose reduction relative to water is 6.9% at 5 mm (apex). Removal of the Acrylic insert from the plaque (replacing with water) did not make significantly difference in dose reduction results (O.2%). The presence of the stainless steel backing results in dose enhancement near the plaque relative to water. Doses at points of interest are higher for ROPES eye plaque when compared to CaMS eye plaque. The dosimetric parameters calculated in this work for the new palladium seed, showed that in dosimetry point of view, the IR06-103Pd seed is suitable for use in brachytherapy. The effect of Acrylic insert on dose distribution is negligible and the main effect on dose reduction is due to the presence of stainless steel plaque backing. (author)

Palladium and ruthenium supported silver migration in 3C–silicon carbide

Energy Technology Data Exchange (ETDEWEB)

O’Connell, Jacques Herman, E-mail: jacques.oconnell@gmail.com [Center for High Resolution Electron Microscopy, Nelson Mandela Metropolitan University, PO Box 77000, Port Elizabeth 6031 (South Africa); Neethling, Johannes Henoch [Center for High Resolution Electron Microscopy, Nelson Mandela Metropolitan University, Port Elizabeth (South Africa)

2015-01-15

Surrogate TRISO particles were infiltrated with a Pd Ag mixture and heat treated at 1000 °C to investigate the effect of Pd on Ag transport through current state of the art TRISO coatings for use in HTGRs. The experiment was repeated with Ru instead of Pd because of the similarities in the reaction between Pd and Ru with SiC. It was found that both Pd and Ru form their respective silicides after heat treatment together with the simultaneous precipitation of graphite. In both cases Ag was concentrated along the leading edge of the reaction zone which itself was concentrated along grain boundaries. However, the effect of Pd was much more pronounced than that of Ru making Ru at most a secondary contributor to Ag migration through SiC in TRISO fuel.

Palladium and ruthenium supported silver migration in 3C–silicon carbide

International Nuclear Information System (INIS)

O’Connell, Jacques Herman; Neethling, Johannes Henoch

2015-01-01

Surrogate TRISO particles were infiltrated with a Pd Ag mixture and heat treated at 1000 °C to investigate the effect of Pd on Ag transport through current state of the art TRISO coatings for use in HTGRs. The experiment was repeated with Ru instead of Pd because of the similarities in the reaction between Pd and Ru with SiC. It was found that both Pd and Ru form their respective silicides after heat treatment together with the simultaneous precipitation of graphite. In both cases Ag was concentrated along the leading edge of the reaction zone which itself was concentrated along grain boundaries. However, the effect of Pd was much more pronounced than that of Ru making Ru at most a secondary contributor to Ag migration through SiC in TRISO fuel

Increased Expression and Modulated Regulatory Activity of Coinhibitory Receptors PD-1, TIGIT, and TIM-3 in Lymphocytes From Patients With Systemic Sclerosis.

Science.gov (United States)

Fleury, Michelle; Belkina, Anna C; Proctor, Elizabeth A; Zammitti, Christopher; Simms, Robert W; Lauffenburger, Douglas A; Snyder-Cappione, Jennifer E; Lafyatis, Robert; Dooms, Hans

2018-04-01

Immune dysfunction is an important component of the disease process underlying systemic sclerosis (SSc), but the mechanisms contributing to altered immune cell function in SSc remain poorly defined. This study was undertaken to measure the expression and function of the coinhibitory receptors (co-IRs) programmed cell death 1 (PD-1), T cell immunoglobulin and ITIM domain (TIGIT), T cell immunoglobulin and mucin domain 3 (TIM-3), and lymphocyte activation gene 3 (LAG-3) in lymphocyte subsets from the peripheral blood of patients with SSc. Co-IR expression levels on subsets of immune cells were analyzed using a 16-color flow cytometry panel. The functional role of co-IRs was determined by measuring cytokine production after in vitro stimulation of SSc and healthy control peripheral blood mononuclear cells (PBMCs) in the presence of co-IR-blocking antibodies. Supernatants from cultures of stimulated PBMCs were added to SSc fibroblasts, and their impact on fibroblast gene expression was measured. Mathematical modeling was used to reveal differences between co-IR functions in SSc patients and healthy controls. Levels of the co-IRs PD-1 and TIGIT were increased, and each was coexpressed, in distinct T cell subsets from SSc patients compared to healthy controls. Levels of TIM-3 were increased in SSc natural killer cells. PD-1, TIGIT, and TIM-3 antibody blockade revealed patient-specific roles of each of these co-IRs in modulating activation-induced T cell cytokine production. In contrast to healthy subjects, blockade of TIGIT and TIM-3, but not PD-1, failed to reverse inhibited cytokine production in SSc patients, indicating that enhanced T cell exhaustion is present in SSc. Finally, cytokines secreted in anti-TIM-3-treated PBMC cultures distinctly changed the gene expression profile in SSc fibroblasts. The altered expression and regulatory capacity of co-IRs in SSc lymphocytes may contribute to disease pathophysiology by modulating the cytokine-mediated cross-talk of

18FDG-PET predicts pharmacodynamic response to OSI-906, a dual IGF-1R/IR inhibitor, in preclinical mouse models of lung cancer.

Science.gov (United States)

McKinley, Eliot T; Bugaj, Joseph E; Zhao, Ping; Guleryuz, Saffet; Mantis, Christine; Gokhale, Prafulla C; Wild, Robert; Manning, H Charles

2011-05-15

To evaluate 2-deoxy-2-[(18)F]fluoro-d-glucose positron emission tomography imaging ((18)FDG-PET) as a predictive, noninvasive, pharmacodynamic (PD) biomarker of response following administration of a small-molecule insulin-like growth factor-1 receptor and insulin receptor (IGF-1R/IR) inhibitor, OSI-906. In vitro uptake studies of (3)H-2-deoxy glucose following OSI-906 exposure were conducted evaluating correlation of dose with inhibition of IGF-1R/IR as well as markers of downstream pathways and glucose metabolism. Similarly, in vivo PD effects were evaluated in human tumor cell line xenografts propagated in athymic nude mice by (18)FDG-PET at 2, 4, and 24 hours following a single treatment of OSI-906 for the correlation of inhibition of receptor targets and downstream markers. Uptake of (3)H-2-deoxy glucose and (18)FDG was significantly diminished following OSI-906 exposure in sensitive tumor cells and subcutaneous xenografts (NCI-H292) but not in an insensitive model lacking IGF-1R expression (NCI-H441). Diminished PD (18)FDG-PET, collected immediately following the initial treatment agreed with inhibition of pIGF-1R/pIR, reduced PI3K (phosphoinositide 3-kinase) and MAPK (mitogen activated protein kinase) pathway activity, and predicted tumor growth arrest as measured by high-resolution ultrasound imaging. (18)FDG-PET seems to serve as a rapid, noninvasive PD marker of IGF-1R/IR inhibition following a single dose of OSI-906 and should be explored clinically as a predictive clinical biomarker in patients undergoing IGF-1R/IR-directed cancer therapy. ©2011 AACR.

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

International Nuclear Information System (INIS)

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.

Competition between spin-orbit coupling, magnetism, and dimerization in the honeycomb iridates: α -Li2IrO3 under pressure

Science.gov (United States)

Hermann, V.; Altmeyer, M.; Ebad-Allah, J.; Freund, F.; Jesche, A.; Tsirlin, A. A.; Hanfland, M.; Gegenwart, P.; Mazin, I. I.; Khomskii, D. I.; Valentí, R.; Kuntscher, C. A.

2018-02-01

Single-crystal x-ray diffraction studies with synchrotron radiation on the honeycomb iridate α -Li2IrO3 reveal a pressure-induced structural phase transition with symmetry lowering from monoclinic to triclinic at a critical pressure of Pc=3.8 GPa. According to the evolution of the lattice parameters with pressure, the transition mainly affects the a b plane and thereby the Ir hexagon network, leading to the formation of Ir-Ir dimers. These observations are independently predicted and corroborated by our ab initio density functional theory calculations where we find that the appearance of Ir-Ir dimers at finite pressure is a consequence of a subtle interplay between magnetism, correlation, spin-orbit coupling, and covalent bonding. Our results further suggest that at Pc the system undergoes a magnetic collapse. Finally we provide a general picture of competing interactions for the honeycomb lattices A2M O3 with A =Li , Na and M =Ir , Ru.

Ni@Ru and NiCo@Ru Core-Shell Hexagonal Nanosandwiches with a Compositionally Tunable Core and a Regioselectively Grown Shell.

Science.gov (United States)

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.

Electronic structure of transition metal dichalcogenides PdTe2 and Cu0.05PdTe2 superconductors obtained by angle-resolved photoemission spectroscopy

International Nuclear Information System (INIS)

Liu Yan; Zhao Jian-Zhou; Yu Li; Hu Cheng; Liu De-Fa; Peng Ying-Ying; Xie Zhuo-Jin; He Jun-Feng; Chen Chao-Yu; Feng Ya; Yi He-Mian; Liu Xu; Zhao Lin; He Shao-Long; Liu Guo-Dong; Dong Xiao-Li; Zhang Jun; Lin Cheng-Tian; Chen Chuang-Tian; Xu Zu-Yan

2015-01-01

The layered transition metal chalcogenides have been a fertile land in solid state physics for many decades. Various MX 2 -type transition metal dichalcogenides, such as WTe 2 , IrTe 2 , and MoS 2 , have triggered great attention recently, either for the discovery of novel phenomena or some extreme or exotic physical properties, or for their potential applications. PdTe 2 is a superconductor in the class of transition metal dichalcogenides, and superconductivity is enhanced in its Cu-intercalated form, Cu 0.05 PdTe 2 . It is important to study the electronic structures of PdTe 2 and its intercalated form in order to explore for new phenomena and physical properties and understand the related superconductivity enhancement mechanism. Here we report systematic high resolution angle-resolved photoemission (ARPES) studies on PdTe 2 and Cu 0.05 PdTe 2 single crystals, combined with the band structure calculations. We present in detail for the first time the complex multi-band Fermi surface topology and densely-arranged band structure of these compounds. By carefully examining the electronic structures of the two systems, we find that Cu-intercalation in PdTe 2 results in electron-doping, which causes the band structure to shift downwards by nearly 16 meV in Cu 0.05 PdTe 2 . Our results lay a foundation for further exploration and investigation on PdTe 2 and related superconductors. (rapid communication)

Pseudogap behavior of RuP probed by photoemission spectroscopy

OpenAIRE

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...

Direct determination of platinum group elements and their distributions in geological and environmental samples at the ng g{sup -1} level using LA-ICP-IDMS

Energy Technology Data Exchange (ETDEWEB)

Boulyga, Sergei F.; Heumann, Klaus G. [Johannes Gutenberg-University Mainz, Institute of Inorganic Chemistry and Analytical Chemistry, Mainz (Germany)

2005-10-01

Laser ablation inductively coupled plasma isotope dilution mass spectrometry (LA-ICP-IDMS) was applied to the direct and simultaneous determination of the platinum group elements (PGEs) Pt, Pd, Ru, and Ir in geological and environmental samples. A special laser ablation system with high ablation rates was used, along with sector field ICP-MS. Special attention was paid to deriving the distributions of PGEs in the pulverized samples. IDMS could not be applied to the (mono-isotopic) Rh, but the similar ablation behavior of Ru and Rh allowed Rh to be simultaneously determined via relative sensitivity coefficients. The laser ablation process produces hardly any oxide ions (which usually cause interference in PGE analysis with liquid sample injection), so the ICP-MS can be run in its low mass resolution but high-sensitivity mode. The detection limits obtained for the geological samples were 0.16 ng g{sup -1}, 0.14 ng g{sup -1}, 0.08 ng g{sup -1}, 0.01 ng g{sup -1} and 0.06 ng g{sup -1} for Ru, Rh, Pd, Ir and Pt, respectively. LA-ICP-IDMS was applied to different geological reference materials (TDB-1, WGB-1, UMT-1, WMG-1, SARM-7) and the road dust reference material BCR-723, which are only certified for some of the PGEs. Comparisons with certified values as well as with indicative values from the literature demonstrated the validity of the LA-ICP-IDMS method. The PGE concentrations in subsamples of the road dust reference material correspond to a normal distribution, whereas the distributions in the geological reference materials TDB-1, WGB-1, UMT-1, WMG-1, and SARM-7 are more complex. For example, in the case of Ru, a logarithmic normal distribution best fits the analyzed concentrations in TDB-1 subsamples, whereas a pronounced nugget effect was found for Pt in most geological samples. (orig.)

Direct determination of platinum group elements and their distributions in geological and environmental samples at the ng g(-1) level using LA-ICP-IDMS.

Science.gov (United States)

Boulyga, Sergei F; Heumann, Klaus G

2005-10-01

Laser ablation inductively coupled plasma isotope dilution mass spectrometry (LA-ICP-IDMS) was applied to the direct and simultaneous determination of the platinum group elements (PGEs) Pt, Pd, Ru, and Ir in geological and environmental samples. A special laser ablation system with high ablation rates was used, along with sector field ICP-MS. Special attention was paid to deriving the distributions of PGEs in the pulverized samples. IDMS could not be applied to the (mono-isotopic) Rh, but the similar ablation behavior of Ru and Rh allowed Rh to be simultaneously determined via relative sensitivity coefficients. The laser ablation process produces hardly any oxide ions (which usually cause interference in PGE analysis with liquid sample injection), so the ICP-MS can be run in its low mass resolution but high-sensitivity mode. The detection limits obtained for the geological samples were 0.16 ng g(-1), 0.14 ng g(-1), 0.08 ng g(-1), 0.01 ng g(-1) and 0.06 ng g(-1) for Ru, Rh, Pd, Ir and Pt, respectively. LA-ICP-IDMS was applied to different geological reference materials (TDB-1, WGB-1, UMT-1, WMG-1, SARM-7) and the road dust reference material BCR-723, which are only certified for some of the PGEs. Comparisons with certified values as well as with indicative values from the literature demonstrated the validity of the LA-ICP-IDMS method. The PGE concentrations in subsamples of the road dust reference material correspond to a normal distribution, whereas the distributions in the geological reference materials TDB-1, WGB-1, UMT-1, WMG-1, and SARM-7 are more complex. For example, in the case of Ru, a logarithmic normal distribution best fits the analyzed concentrations in TDB-1 subsamples, whereas a pronounced nugget effect was found for Pt in most geological samples.

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

Energy Technology Data Exchange (ETDEWEB)

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)

Nonalloyed carbon-supported PtRu catalysts for PEMFC applications

NARCIS (Netherlands)

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

Platinum-Group Elements in Soils and Street Dust of the Southeastern Administrative District of Moscow

Science.gov (United States)

Ladonin, D. V.

2018-03-01

The contents of five platinum-group metals (Ru, Rh, Pd, Ir, and Pt) in soils and street dust of the Southeastern administrative district (SEAD) of Moscow have been determined. The contents of these elements in soils may considerably exceed their natural abundances in the lithosphere and are characterized by considerable variability and asymmetric frequency distribution. A close correlation between Rh, Pd, and Pt contents in soils and street dust has been shown. The data on the contents of the elements and the ratios between them suggest that motor vehicles are the major source of pollution of soils and street dust in the studied district.

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

Energy Technology Data Exchange (ETDEWEB)

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.

Nonalloyed carbon-supported PtRu catalysts for PEMFC applications

NARCIS (Netherlands)

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

Formation of graphene on Ru(0001) surface

Institute of Scientific and Technical Information of China (English)

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.

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

Science.gov (United States)

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.

The influence of alizarin and fluorescein on the photoactivity of Ni, Pt and Ru-doped TiO2 layers

International Nuclear Information System (INIS)

Rosu, Marcela-Corina; Suciu, Ramona-Crina; Lazar, Mihaela D.; Bratu, I.

2013-01-01

Highlights: ► The Ni, Pt, Ru-doped TiO 2 materials and sensitized with alizarin and fluorescein dyes were prepared by wet chemical route. ► The samples were characterized by: UV–vis spectroscopy, spectrofluorimetry, FT/IR spectroscopy and microscopy, X-ray diffraction and N 2 physisorption measurements. ► A combined influence of the dopants and dyes was observed, leading to a beneficial effect to TiO 2 photoactivity. -- Abstract: The doping with different metal ions and sensitization with organic compounds are two well known methods used to improve the photoactivity of TiO 2 . In this respect, the metallic ions-doped TiO 2 samples were prepared by embedding Ni, Pt and Ru ions into TiO 2 crystalline network and then, each sample was sensitized with alizarin and fluorescein dyes. The qualitative evaluation of prepared TiO 2 -based materials was made by: UV–vis spectroscopy, spectrofluorimetry, FT/IR spectroscopy and microscopy, X-ray diffraction and N 2 physisorption measurements. The optoelectronic properties investigated by UV–vis spectroscopy show that the optical response of Ni-doped TiO 2 layer shifts to visible. The X-ray spectra do not show peaks of nickel, platinum and ruthenium oxide crystals or pure metals. The FT/IR spectra proved the presence of dye molecules adsorbed on titania nanoparticles surface. These results demonstrated that the studied dopants and dyes have potential to promote modified TiO 2 -based materials as good candidates to be used in photolectrocatalytic processes

Reactions of ethanol on Ru

NARCIS (Netherlands)

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

Synthesis of iridacarborane halide complexes [(η-9-SMe2-7,8-C2B9H10)IrX2]2 (X=Cl, Br, I)

International Nuclear Information System (INIS)

Kudinov, A.R.; Perekalin, D.S.; Petrovskij, P.V.

2001-01-01

By interaction between Na[9-SMe 2 -7,8-C 2 B 9 H 10 ] and [(Cod)IrCl] 2 (Cod - cycloocta-1,5-diene) iridium complex (η-9-SMe 2 -7,8-C 2 B 9 H 10 )Ir(Cod), which under the action of anhydrous hydrohalogenic acids HX (X=Cl, Br, I) yields iridacarborane halide complexes [(η-9-SMe 2 -7,8-C 2 B 9 H 10 )IrX 2 ] 2 , being analogs of cyclopentadienyl complexes [(C 5 Me 5 )IrX 2 ] 2 . The complexes prepared were characterized on the basis of data of elementary analysis and 1 H, 11 B NMR spectra [ru

Breakdown of Spin-Waves in Anisotropic Magnets: Spin Dynamics in α-RuCl3

Science.gov (United States)

Winter, Stephen; Riedl, Kira; Honecker, Andreas; Valenti, Roser

α -RuCl3 has recently emerged as a promising candidate for realizing the hexagonal Kitaev model in a real material. Similar to the related iridates (e.g. Na2IrO3), complex magnetic interactions arise from a competition between various similar energy scales, including spin-orbit coupling (SOC), Hund's coupling, and crystal-field splitting. Due to this complexity, the correct spin Hamiltonians for such systems remain hotly debated. For α-RuCl3, a combination of ab-initio calculations, microscopic considerations, and analysis of the static magnetic response have suggested off-diagonal couplings (Γ ,Γ') and long-range interactions in addition to the expected Kitaev exchange. However, the effect of such additional terms on the dynamic response remains unclear. In this contribution, we discuss the recently measured inelastic neutron scattering response in the context of realistic proposals for the microscopic spin Hamiltonian. We conclude that the observed scattering continuum, which has been taken as a signature of Kitaev spin liquid physics, likely persists over a broad range of parameters.

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

Directory of Open Access Journals (Sweden)

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.

Hydrothermal synthesis of highly crystalline RuS{sub 2} nanoparticles as cathodic catalysts in the methanol fuel cell and hydrochloric acid electrolysis

Energy Technology Data Exchange (ETDEWEB)

Li, Yanjuan [Key Laboratory of Marine Chemistry Theory and Technology, Minisry of Education Ocean University of China, Qingdao, 266100 (China); College of Material Science and Engineering, Key Laboratory of Automobile Materials of Ministry of Education, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Li, Nan, E-mail: lin@jlu.edu.cn [College of Material Science and Engineering, Key Laboratory of Automobile Materials of Ministry of Education, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Yanagisawa, Kazumichi [Research Laboratory of Hydrothermal Chemistry, Kochi University, Kochi 780-8520 (Japan); Li, Xiaotian [College of Material Science and Engineering, Key Laboratory of Automobile Materials of Ministry of Education, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Yan, Xiao [Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), College of Physics, Jilin University, Changchun 130012 (China)

2015-05-15

Highlights: • Highly crystalline RuS{sub 2} nanoparticles have been first synthesized by a “one-step” hydrothermal method. • The product presents a pure cubic phase of stoichiometric ratio RuS{sub 2} with average particle size of 14.8 nm. • RuS{sub 2} nanoparticles were used as cathodic catalysts in methanol fuel cell and hydrochloric acid electrolysis. • The catalyst outperforms commercial Pt/C in methanol tolerance and stability towards Cl{sup −}. - Abstract: Highly crystalline ruthenium sulfide (RuS{sub 2}) nanoparticles have been first synthesized by a “one-step” hydrothermal method at 400 °C, using ruthenium chloride and thiourea as reactants. The products were characterized by powder X-ray diffraction (XRD), scanning electron microscopy/energy disperse spectroscopy (SEM/EDS), thermo gravimetric-differential thermal analyze (TG-DTA), transmission electron microscopy equipped with selected area electron diffraction (TEM/SAED). Fourier transform infrared spectra (IR), and X-ray photoelectron spectroscopy (XPS). XRD result illustrates that the highly crystalline product presents a pure cubic phase of stoichiometric ratio RuS{sub 2} and the average particle size is 14.8 nm. SEM and TEM images display the products have irregular shape of 6–25 nm. XPS analyst indicates that the sulfur exists in the form of S{sub 2}{sup 2−}. Cyclic voltammetry (CV), rotating disk electrode (RDE), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS) measurements are conducted to evaluate the electrocatalytic activity and stability of the highly crystalline RuS{sub 2} nanoparticles in oxygen reduction reaction (ORR) for methanol fuel cell and hydrochloric acid electrolysis. The results illustrate that RuS{sub 2} is active towards oxygen reduction reaction. Although the activity of RuS{sub 2} is lower than that of Pt/C, the RuS{sub 2} catalyst outperforms commercial Pt/C in methanol tolerance and stability towards Cl{sup −}.

Round table on RU486.

Science.gov (United States)

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.

Two crystalline modifications of RuO4

International Nuclear Information System (INIS)

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

Synthesis and spectral studies of Pd(II) complexes with 2, 3-disubstituted quinazolin-(3H)-4-ones

International Nuclear Information System (INIS)

Prabhakar, B.; Lingaiah, P.; Laxima Reddy, K.

1991-01-01

A number of palladium(II) complexes of bidentate O-O and O-N donors, 2,3-disubstituted quinazoline-(3H)-4-ones, have been synthesized and characterized based on analytical, conductivity, magnetic, thermal, IR, electronic and PMR spectral data. The complexes of Pd(II) with ligands such as 2-(R)-3-(X)-substituted quinazoline-(3H)-4-ones, where R=methyl/phenyl and X=2'-hydroxybenzalimino (MHBQ/PHBQ), carboxymethyl (MCMQ/PCMQ), furfuralimino (MFQ/PFQ), acetamino (MAQ/PAQ), uramino (MUQ/PUQ) and thiouramino (MTUQ/PTUQ), yielded the complexes of the type [Pd(O-N) 2 ]Cl 2 and [Pd(O-O) 2 ]. The IR and PMR spectral data of the metal complexes indicate that MHQB, PHQB, MCMQ, and PCMQ act as uninegative bidentate ligands whereas MFQ, PFQ, MAQ, PAQ, MUQ, PUQ, MTUQ and PTUQ act as neutral bidentate ligands. The electronic spectral studies of these complexes indicate that they were square-planar geometry. (author). 23 refs., 2 tabs

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

Energy Technology Data Exchange (ETDEWEB)

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.

(Electronic structure and reactivities of transition metal clusters)

Energy Technology Data Exchange (ETDEWEB)

1992-01-01

The following are reported: theoretical calculations (configuration interaction, relativistic effective core potentials, polyatomics, CASSCF); proposed theoretical studies (clusters of Cu, Ag, Au, Ni, Pt, Pd, Rh, Ir, Os, Ru; transition metal cluster ions; transition metal carbide clusters; bimetallic mixed transition metal clusters); reactivity studies on transition metal clusters (reactivity with H{sub 2}, C{sub 2}H{sub 4}, hydrocarbons; NO and CO chemisorption on surfaces). Computer facilities and codes to be used, are described. 192 refs, 13 figs.

Procedure for the preparation of catalysts for application in catalytic gas phase reactions

International Nuclear Information System (INIS)

1976-01-01

The invention describes the preparation of catalysts to be used in catalytic reactions in the gaseous phase. The catalytic material is disposed at the surface of a ceramic or carbon substrate (av. particle size 0.1 μ - 0.5 cm, surface area smaller than 20 m 2 /g) by bombardment of the catalytic material (Pt, Rh, Pd, Ru, Os, Ir) with energetic ions (Ne, Ar, Kr, Xe) in the vicinity of the substrate in medium vacuum

Efficient Synthesis of Ir-Polyoxometalate Cluster Using a Continuous Flow Apparatus and STM Investigation of Its Coassembly Behavior on HOPG Surface.

Science.gov (United States)

Zhang, Junyong; Chang, Shaoqing; Suryanto, Bryan H R; Gong, Chunhua; Zeng, Xianghua; Zhao, Chuan; Zeng, Qingdao; Xie, Jingli

2016-06-06

Taking advantage of a continuous-flow apparatus, the iridium(III)-containing polytungstate cluster K12Na2H2[Ir2Cl8P2W20O72]·37H2O (1) was obtained in a reasonable yield (13% based on IrCl3·H2O). Compound 1 was characterized by Fourier transform IR, UV-visible, (31)P NMR, electrospray ionization mass spectrometry (ESI-MS), and thermogravimetric analysis measurements. (31)P NMR, ESI-MS, and elemental analysis all indicated 1 was a new polytungstate cluster compared with the reported K14[(IrCl4)KP2W20O72] compound. Intriguingly, the successful isolation of 1 relied on the custom-built flow apparatus, demonstrating the uniqueness of continuous-flow chemistry to achieve crystalline materials. The catalytic properties of 1 were assessed by investigating the activity on catalyzing the electro-oxidation of ruthenium tris-2,2'-bipyridine [Ru(bpy)3](2+/3+). The voltammetric behavior suggested a coupled catalytic behavior between [Ru(bpy)3](3+/2+) and 1. Furthermore, on the highly oriented pyrolytic graphite surface, 1,3,5-tris(10-carboxydecyloxy) benzene (TCDB) was used as the two-dimensional host network to coassemble cluster 1; the surface morphology was observed by scanning tunneling microscope technique. "S"-shape of 1 was observed, indicating that the cluster could be accommodated in the cavity formed by two TCDB host molecules, leading to a TCDB/cluster binary structure.

The influence of alizarin and fluorescein on the photoactivity of Ni, Pt and Ru-doped TiO{sub 2} layers

Energy Technology Data Exchange (ETDEWEB)

Rosu, Marcela-Corina, E-mail: marcela.rosu@itim-cj.ro [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath Street, 400293, Cluj-Napoca (Romania); Suciu, Ramona-Crina; Lazar, Mihaela D.; Bratu, I. [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath Street, 400293, Cluj-Napoca (Romania)

2013-04-20

Highlights: ► The Ni, Pt, Ru-doped TiO{sub 2} materials and sensitized with alizarin and fluorescein dyes were prepared by wet chemical route. ► The samples were characterized by: UV–vis spectroscopy, spectrofluorimetry, FT/IR spectroscopy and microscopy, X-ray diffraction and N{sub 2} physisorption measurements. ► A combined influence of the dopants and dyes was observed, leading to a beneficial effect to TiO{sub 2} photoactivity. -- Abstract: The doping with different metal ions and sensitization with organic compounds are two well known methods used to improve the photoactivity of TiO{sub 2}. In this respect, the metallic ions-doped TiO{sub 2} samples were prepared by embedding Ni, Pt and Ru ions into TiO{sub 2} crystalline network and then, each sample was sensitized with alizarin and fluorescein dyes. The qualitative evaluation of prepared TiO{sub 2}-based materials was made by: UV–vis spectroscopy, spectrofluorimetry, FT/IR spectroscopy and microscopy, X-ray diffraction and N{sub 2} physisorption measurements. The optoelectronic properties investigated by UV–vis spectroscopy show that the optical response of Ni-doped TiO{sub 2} layer shifts to visible. The X-ray spectra do not show peaks of nickel, platinum and ruthenium oxide crystals or pure metals. The FT/IR spectra proved the presence of dye molecules adsorbed on titania nanoparticles surface. These results demonstrated that the studied dopants and dyes have potential to promote modified TiO{sub 2}-based materials as good candidates to be used in photolectrocatalytic processes.

Direct determination of cadmium in Orujo spirit samples by electrothermal atomic absorption spectrometry: Comparative study of different chemical modifiers

International Nuclear Information System (INIS)

Vilar Farinas, M.; Barciela Garcia, J.; Garcia Martin, S.; Pena Crecente, R.; Herrero Latorre, C.

2007-01-01

In this work, several analytical methods are proposed for cadmium determination in Orujo spirit samples using electrothermal atomic absorption spectrometry (ETAAS). Permanent chemical modifiers thermally coated on the platforms inserted in pyrolytic graphite tubes (such as W, Ir, Ru, W-Ir and W-Ru) were comparatively studied in relation to common chemical modifier mixtures [Pd-Mg(NO 3 ) 2 and (NH 4 )H 2 PO 4 -Mg(NO 3 ) 2 ] for cadmium stabilization. Different ETAAS Cd determination methods based on the indicated modifiers have been developed. In each case, pyrolysis and atomization temperatures, atomization shapes, characteristic masses and detection limits as well as other analytical characteristics have been determined. All the assayed modifiers (permanent and conventional) were capable of achieving the appropriate stabilization of the analyte, with the exception of Ru and W-Ru. Moreover, for all developed methods, recoveries (99-102%) and precision (R.S.D. lower than 10%) were acceptable. Taking into account the analytical performance (best detection limit LOD = 0.01 μg L -1 ), the ETAAS method based on the use of W as a permanent modifier was selected for further direct Cd determinations in Orujo samples from Galicia (NW Spain). The chosen method was applied in the determination of the Cd content in 38 representative Galician samples. The cadmium concentrations ranged -1

Synthesis of Ru/PDMS nano-composites via supercritial deposition

Energy Technology Data Exchange (ETDEWEB)

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.

Carbon monoxide oxidation on bimetallic Ru/Au(111 surfaces

Directory of Open Access Journals (Sweden)

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.

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

Energy Technology Data Exchange (ETDEWEB)

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

Effects of countercations on the structures and redox and spectroscopic properties of diruthenium catecholate complexes with ligand-unsupported Ru-Ru bonds.

Science.gov (United States)

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.

In situ formed catalytically active ruthenium nanocatalyst in room temperature dehydrogenation/dehydrocoupling of ammonia-borane from Ru(cod)(cot) precatalyst.

Science.gov (United States)

Zahmakiran, Mehmet; Ayvalı, Tuğçe; Philippot, Karine

2012-03-20

The development of simply prepared and effective catalytic materials for dehydrocoupling/dehydrogenation of ammonia-borane (AB; NH(3)BH(3)) under mild conditions remains a challenge in the field of hydrogen economy and material science. Reported herein is the discovery of in situ generated ruthenium nanocatalyst as a new catalytic system for this important reaction. They are formed in situ during the dehydrogenation of AB in THF at 25 °C in the absence of any stabilizing agent starting with homogeneous Ru(cod)(cot) precatalyst (cod = 1,5-η(2)-cyclooctadiene; cot = 1,3,5-η(3)-cyclooctatriene). The preliminary characterization of the reaction solutions and the products was done by using ICP-OES, ATR-IR, TEM, XPS, ZC-TEM, GC, EA, and (11)B, (15)N, and (1)H NMR, which reveal that ruthenium nanocatalyst is generated in situ during the dehydrogenation of AB from homogeneous Ru(cod)(cot) precatalyst and B-N polymers formed at the initial stage of the catalytic reaction take part in the stabilization of this ruthenium nanocatalyst. Moreover, following the recently updated approach (Bayram, E.; et al. J. Am. Chem. Soc.2011, 133, 18889) by performing Hg(0), CS(2) poisoning experiments, nanofiltration, time-dependent TEM analyses, and kinetic investigation of active catalyst formation to distinguish single metal or in the present case subnanometer Ru(n) cluster-based catalysis from polymetallic Ru(0)(n) nanoparticle catalysis reveals that in situ formed Ru(n) clusters (not Ru(0)(n) nanoparticles) are kinetically dominant catalytically active species in our catalytic system. The resulting ruthenium catalyst provides 120 total turnovers over 5 h with an initial turnover frequency (TOF) value of 35 h(-1) at room temperature with the generation of more than 1.0 equiv H(2) at the complete conversion of AB to polyaminoborane (PAB; [NH(2)BH(2)](n)) and polyborazylene (PB; [NHBH](n)) units.

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

CSIR Research Space (South Africa)

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...

Manifestations of Kitaev physics in thermodynamic properties of hexagonal iridates and α-RuCl3

Science.gov (United States)

Tsirlin, Alexander

Kitaev model is hard to achieve in real materials. Best candidates available so far are hexagonal iridates M2IrO3 (M = Li and Na) and the recently discovered α-RuCl3 featuring hexagonal layers coupled by weak van der Waals bonding. I will review recent progress in crystal growth of these materials and compare their thermodynamic properties. Both hexagonal iridates and α-RuCl3 feature highly anisotropic Curie-Weiss temperatures that not only differ in magnitude but also change sign depending on the direction of the applied magnetic field. Néel temperatures are largely suppressed compared to the energy scale of the Curie-Weiss temperatures. These experimental observations will be linked to features of the electronic structure and to structural peculiarities associated with deviations from the ideal hexagonal symmetry. I will also discuss how the different nature of ligand atoms affects electronic structure and magnetic superexchange. This work has been done in collaboration with M. Majumder, M. Schmidt, M. Baenitz, F. Freund, and P. Gegenwart.

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

OpenAIRE

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...

The synthesis and structural characterization of novel transition metal fluorides

Energy Technology Data Exchange (ETDEWEB)

Casteel, W.J. Jr.

1992-09-01

High purity KMF[sub 6] and K[sub 2]MF[sub 6] salts (M = Mo,Re, Ru, Os, Ir, Pt) are obtained from reduction hexafluorides. A rhombohedral unit cell is observed for KReF[sub 6]. Fluoride ion capture by Lewis acids from the hexafluorometallate (IV) salts affords high purity tetrafluorides for M = Mo, Re, Ru, Os, and Pd. The structure of RuF[sub 4] is determined from X-ray synchrotron and neutron powder data. Unit cells based on theorthorhombic PdF[sub 4] type cell are derived from X-ray powder data for ReF[sub 4] and OsF[sub 4]. Fluoride ion capture from KAgF[sub 4] provides the thermally unstable trifluoride as a bright, red, diamagnetic solid. The structure solution of AgF[sub 3] and redetermination of the AuF[sub 3] structure from X-ray synchrotron and neutron powder data demonstrate that the two are isostnictural. Thermal decomposition product of AgF[sub 3] is the mixed valence compound Ag[sup II]Ag[sub 2][sup III]F[sub 8]. Several new salts containing the (Ag - F)[sub n][sup n+] chain cation are prepared. The first linear (Ag - F)[sub n][sup n+] chain is observed in AgF[sup +]BF[sub 4 [sup [minus

Rare earth-rich cadmium compounds RE{sub 10}TCd{sub 3} (RE = Y, Tb, Dy, Ho, Er, Tm, Lu; T = Rh, Pd, Ir, Pt) with an ordered Co{sub 2}Al{sub 5}-type structure

Energy Technology Data Exchange (ETDEWEB)

Block, Theresa; Klenner, Steffen; Heletta, Lukas; Poettgen, Rainer [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie

2018-04-01

Eighteen new rare earth-rich intermetallic phases RE{sub 10}TCd{sub 3} (RE = Y, Tb, Dy, Ho, Er, Tm, Lu; T = Rh, Pd, Ir, Pt) were obtained by induction melting of the elements in sealed niobium ampoules followed by annealing in muffle furnaces. All samples were characterized by X-ray powder diffraction. The structures of four representatives were refined from single-crystal X-ray diffractometer data: ordered Co{sub 2}Al{sub 5} type, P6{sub 3}/mmc, a = 951.2(1), c = 962.9(2) pm, wR = 0.0460, 595 F{sup 2} values, 20 parameters for Er{sub 10}RhCd{sub 3}; a = 945.17(4), c = 943.33(4), wR = 0.0395, 582 F{sup 2} values, 21 parameters for Lu{sub 9.89}PdCd{sub 3.11}; a = 964.16(6), c = 974.93(6) pm, wR = 0.0463, 614 F{sup 2} values, 21 parameters for Y{sub 10}Ir{sub 1.09}Cd{sub 2.91}; a = 955.33(3), c = 974.56(3) pm, wR = 0.0508, 607 F{sup 2} values, 22 refined parameters for Dy{sub 9.92}IrCd{sub 3.08}. Refinements of the occupancy parameters revealed small homogeneity ranges resulting from RE/Cd, respectively T/Cd mixing. The basic building units of the RE{sub 10}TCd{sub 3} phases are transition metal-centered RE{sub 6} trigonal prisms (TP) that are condensed with double-pairs of empty RE{sub 6} octahedra via common triangular faces. A second type of rods is formed by slightly distorted RE3 rate at Cd{sub 6}RE{sub 6} icosahedra which are condensed via Cd{sub 3} triangular faces. The shortest interatomic distances occur for RE-T, compatible with strong covalent bonding interactions. Temperature dependent magnetic susceptibility measurements were performed for RE{sub 10}RhCd{sub 3} (RE = Dy-Tm, Lu), RE{sub 10}IrCd{sub 3} (RE = Er, Tm, Lu) and RE{sub 10}PtCd{sub 3} (RE = Y, Lu). While Y{sub 10}PtCd{sub 3} and Lu{sub 10}TCd{sub 3} (T = Rh, Ir, Pt) show Pauli paramagnetic behavior, the compounds containing paramagnetic rare earth elements show Curie-Weiss behavior (the experimental magnetic moments indicate stable trivalent RE{sup 3+}) and magnetic ordering at low temperatures

Green synthesis of Pd NPs from Pimpinella tirupatiensis plant extract and their application in photocatalytic activity dye degradation

Science.gov (United States)

Narasaiah, Palajonna; Mandal, Badal Kumar; Sarada, N. C.

2017-11-01

The present report the synthesis of palladium nanoparticles through the green method route offers few advantages over the common chemical and physical procedures, as it is an easy and fast, eco-friendly and does not involve any costly chemicals as well as hazardous chemicals. In this study, we reported synthesis of Pd NPs by using the Pimpinella tirupatiensis plant Extract (PTPE). The synthesized Pd NPs was characterization using different technique such as UV-Visible for the formation of Pd NPs. FT-IR spectroscopy was performed to detect the bio-active molecules liable for reduction and capping of biogenic Pd NPs. Crystallinity of Pd NPs conformed by powder - XRD. In the present study performed photo catalytic activity of synthesized Pd NPs using organic dye such as Congo red (CR). Hence, this study concludes the PTPE aqueous extract produced Pd NPs can be act as promising material for the degradation of organic pollutants.

Nanoscale decomposition of Nb-Ru-O

Science.gov (United States)

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.

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

Energy Technology Data Exchange (ETDEWEB)

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.

The provenance investigation on ancient chinese Ru porcelains by NAA

International Nuclear Information System (INIS)

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

Alkaline Ionic Liquid Modified Pd/C Catalyst as an Efficient Catalyst for Oxidation of 5-Hydroxymethylfurfural

Directory of Open Access Journals (Sweden)

Zou Bin

2018-01-01

Full Text Available Conversion of HMF into FDCA was carried out by a simple and green process based on alkaline ionic liquid (IL modified Pd/C catalyst (Pd/C-OH−. Alkaline ionic liquids were chosen to optimize Pd/C catalyst for special hydrophilicity and hydrophobicity, redox stability, and unique dissolving abilities for polar compounds. The Pd/C-OH− catalyst was successfully prepared and characterized by SEM, XRD, TG, FT-IR, and CO2-TPD technologies. Loading of alkaline ionic liquid on the surface of Pd/C was 2.54 mmol·g−1. The catalyst showed excellent catalytic activity in the HMF oxidation after optimization of reaction temperature, reaction time, catalyst amount, and solvent. Supported alkaline ionic liquid (IL could be a substitute and promotion for homogeneous base (NaOH. Under optimal reaction conditions, high HMF conversion of 100% and FDCA yield of 82.39% were achieved over Pd/C-OH− catalyst in water at 373 K for 24 h.

Optimization of Temperature Sensing with Polymer-Embedded Luminescent Ru(II Complexes

Directory of Open Access Journals (Sweden)

Nelia Bustamante

2018-02-01

Full Text Available Temperature is a key parameter in many fields and luminescence-based temperature sensing is a solution for those applications in which traditional (mechanical, electrical, or IR-based thermometers struggle. Amongst the indicator dyes for luminescence thermometry, Ru(II polyazaheteroaromatic complexes are an appealing option to profit from the widespread commercial technologies for oxygen optosensing based on them. Six ruthenium dyes have been studied, engineering their structure for both photostability and highest temperature sensitivity of their luminescence. The most apt Ru(II complex turned out to be bis(1,10-phenanthroline(4-chloro-1,10-phenanthrolineruthenium(II, due to the combination of two strong-field chelating ligands (phen and a substituent with electron withdrawing effect on a conjugated position of the third ligand (4-Clphen. In order to produce functional sensors, the dye has been best embedded into poly(ethyl cyanoacrylate, due to its low permeability to O2, high temperature sensitivity of the indicator dye incorporated into this polymer, ease of fabrication, and excellent optical quality. Thermosensitive elements have been fabricated thereof as optical fiber tips for macroscopic applications (water courses monitoring and thin spots for microscopic uses (temperature measurements in cell culture-on-a-chip. With such dye/polymer combination, temperature sensing based on luminescence lifetime measurements allows 0.05 °C resolution with linear response in the range of interest (0–40 °C.

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

Energy Technology Data Exchange (ETDEWEB)

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.

Characterization of Pb(Zr, Ti)O3 thin films fabricated by plasma enhanced chemical vapor deposition on Ir-based electrodes

International Nuclear Information System (INIS)

Lee, Hee-Chul; Lee, Won-Jong

2002-01-01

Structural and electrical characteristics of Pb(Zr, Ti)O 3 (PZT) ferroelectric thin films deposited on various Ir-based electrodes (Ir, IrO 2 , and Pt/IrO 2 ) using electron cyclotron resonance plasma enhanced chemical vapor deposition were investigated. On the Ir electrode, stoichiometric PZT films with pure perovskite phase could be obtained over a very wide range of processing conditions. However, PZT films prepared on the IrO 2 electrode contain a large amount of PbO x phases and exhibited high Pb-excess composition. The deposition characteristics were dependent on the behavior of PbO molecules on the electrode surface. The PZT thin film capacitors prepared on the Ir bottom electrode showed different electrical properties depending on top electrode materials. The PZT capacitors with Ir, IrO 2 , and Pt top electrodes showed good leakage current characteristics, whereas those with the Ru top electrode showed a very high leakage current density. The PZT capacitor exhibited the best fatigue endurance with an IrO 2 top electrode. An Ir top electrode provided better fatigue endurance than a Pt top electrode. The PZT capacitor with an Ir-based electrode is thought to be attractive for the application to ferroelectric random access memory devices because of its wide processing window for a high-quality ferroelectric film and good polarization, fatigue, and leakage current characteristics

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

Energy Technology Data Exchange (ETDEWEB)

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)

Hydrogenation of tetralin in the presence of dibenzothiophene and quinoline on Pt-Pd/SiO{sub 2}-Al{sub 2}O{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Gutierrez, O.Y.; Yu, Y.; Jentys, A.; Lercher, J.A. [Technische Univ. Muenchen, Garching (Germany). Dept. of Chemistry and Catalysis Research Center

2012-07-01

Three Pt-Pd catalysts with 0.3 and 0.5 wt.% of Pt and Pd, respectively, were supported on amorphous silica alumina with Al{sub 2}O{sub 3}:SiO{sub 2} wt.% ratios of 20:80, 30:70 and 55:45. The materials were characterized by physisorption of N{sub 2}, TEM, X-ray absorption spectroscopy and adsorption of pyridine and CO followed by IR spectroscopy. The EXAFS fitting and IR characterization showed that bimodal distributions of monometallic Pd and bimetallic Pt-Pd particles. The bimetallic particles in all catalysts have a Pt-rich core and a Pd-rich shell. However, the degree of alloying and proportion of exposed Pt increases with increasing concentration of Lewis acid sites (LAS) in the support, probably because the LAS are good anchoring sites for Pt species. The activity of the catalysts for the hydrogenation of tetralin in the presence of DBT and quinoline, and the corresponding selectivity to cis-decalin increase with the proportion of exposed Pt. Therefore, in the presence of DBT and quinoline the morphology of bimetallic clusters is the parameter determining its hydrogenation performance. (orig.)

Generator separation of 103Ru//sup 103m/Rh

International Nuclear Information System (INIS)

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

PtRu/C and PtRuBi/C electrocatalysts prepared by two different methodologies of borohydride reduction process for ethanol electro-oxidation

Energy Technology Data Exchange (ETDEWEB)

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)

PtRu/C and PtRuBi/C electrocatalysts prepared by two different methodologies of borohydride reduction process for ethanol electro-oxidation

International Nuclear Information System (INIS)

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)

High-Density Stacked Ru Nanocrystals for Nonvolatile Memory Application

International Nuclear Information System (INIS)

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

Lanthanum benzoyl acetonates: an IR and mass spectrometric study of the composition and structure

International Nuclear Information System (INIS)

Kostyuk, N.N.; Dik, T.A.; Tereshko, N.V.

2005-01-01

IR spectroscopy and mass spectrometry were used to study the structure of lanthanum chelates of benzoyl acetone (1-phenyl-1,3-butadione, HBA) of the following compositions: La(BA) 3 · EtOH, La(BA) 2 , La(BA) 2 · CH 3 CN, and La(BA) 2 · HDA, where EtOH = ethanol, HDA = nonadecanoic acid. It is demonstrated that a quasi-aromatic metalloring is formed in lanthanum chelates studied. Stable metal-containing fragments of the molecular ions of lanthanum bis- and tris-benzoylacetonate were identified [ru

Platinum monolayer electrocatalysts for oxygen reduction: effect of substrates, and long-term stability

Directory of Open Access Journals (Sweden)

J. ZHANG

2005-03-01

Full Text Available We describe a novel concept for a Ptmonolayer electrocatalyst and present the results of our electrochemical, X-ray absorption spectroscopy, and scanning tunneling microscopy studies. The electrocatalysts were prepared by a new method for depositing Pt monolayers involving the galvanic displacement by Pt of an underpotentially deposited Cu monolayer on substrates of Au (111, Ir(111, Pd(111, Rh(111 and Ru(0001 single crylstals, and Pd nanoparticles. The kinetics of O2 reduction showed significant enhancement with Pt monolayers on Pd(111 and Pd nanoparticle surfaces in comparisonwith the reaction on Pt(111 and Pt nanoparticles, respectively. This increase in catalytic activity is attributed partly to the decreased formation of PtOH, as shown by in situ X-ray absorption spectroscopy. The results illustrate that placing a Pt monolayer on a suitable substrate of metal nanoparticles is an attractive way of designing better O2 reduction electrocatalysts with very low Pt contents.

Metal Carbon Eutectics to Extend the Use of the Fixed-Point Technique in Precision IR Thermometry

Science.gov (United States)

Battuello, M.; Girard, F.; Florio, M.

2008-06-01

The high-temperature extension of the fixed-point technique for primary calibration of precision infrared (IR) thermometers was investigated both through mathematical simulations and laboratory investigations. Simulations were performed with Co C (1,324°C) and Pd C (1, 492°C) eutectic fixed points, and a precision IR thermometer was calibrated from the In point (156.5985°C) up to the Co C point. Mathematical simulations suggested the possibility of directly deriving the transition temperature of the Co C and Pd C points by extrapolating the calibration derived from fixed-point measurements from In to the Cu point. Both temperatures, as a result of the low uncertainty associated with the In Cu calibration and the high number of fixed points involved in the calibration process, can be derived with an uncertainty of 0.11°C for Co C and 0.18°C for Pd C. A transition temperature of 1,324.3°C for Co C was determined from the experimental verification, a value higher than, but compatible with, the one proposed by the thermometry community for inclusion as a secondary reference point for ITS-90 dissemination, i.e., 1,324.0°C.

Single Pd Atoms on θ-Al2O3 (010) Surface do not Catalyze NO Oxidation.

Science.gov (United States)

Narula, Chaitanya K; Allard, Lawrence F; Moses-DeBusk, Melanie; Stocks, G Malcom; Wu, Zili

2017-04-03

New convenient wet-chemistry synthetic routes have made it possible to explore catalytic activities of a variety of single supported atoms, however, the single supported atoms on inert substrates (e.g. alumina) are limited to adatoms and cations of Pt, Pd, and Ru. Previously, we have found that single supported Pt atoms are remarkable NO oxidation catalysts. In contrast, we report that Pd single atoms are completely inactive for NO oxidation. The diffuse reflectance infra-red spectroscopy (DRIFTS) results show the absence of nitrate formation on catalyst. To explain these results, we explored modified Langmuir-Hinshelwood type pathways that have been proposed for oxidation reactions on single supported atom. In the first pathway, we find that there is energy barrier for the release of NO 2 which prevent NO oxidation. In the second pathway, our results show that there is no driving force for the formation of O=N-O-O intermediate or nitrate on single supported Pd atoms. The decomposition of nitrate, if formed, is an endothermic event.

Ethanol steam reforming kinetics of a Pd-Ag membrane reactor

Energy Technology Data Exchange (ETDEWEB)

Tosti, Silvano; Borelli, Rodolfo; Borgognoni, Fabio [ENEA, Dipartimento FPN, C.R. ENEA Frascati, Via E. Fermi 45, Frascati (RM) I-00044 (Italy); Basile, Angelo [Institute on Membrane Technology, ITM-CNR, c/o Univ. of Calabria, via P. Bucci, Cubo 17/C, 87030 Rende (CS) (Italy); Castelli, Stefano [ENEA, Dipartimento ACS, C.R. ENEA Casaccia, Via Anguillarese 301, Roma I-00123 (Italy); Fabbricino, Massimiliano; Licusati, Celeste [Dept. of Hydraulic and Environmental Engineering, Univ. of Naples Federico II, Via Claudio 21, Naples 80125 (Italy); Gallucci, Fausto [Fundamentals of Chemical Reaction Engineering Group, Faculty of Science and Technology, University of Twente, Enschede (Netherlands)

2009-06-15

The ethanol steam reforming reaction carried out in a Pd-based tubular membrane reactor has been modelled via a finite element code. The model considers the membrane tube divided into finite volume elements where the mass balances for both lumen and shell sides are carried out accordingly to the reaction and permeation kinetics. Especially, a simplified ''power law'' has been applied for the reaction kinetics: the comparison with experimental data obtained by using three different kinds of catalyst (Ru, Pt and Ni based) permitted defining the coefficients of the kinetics expression as well as to validate the model. Based on the Damkohler-Peclet analysis, the optimization of the membrane reformer has been also approached. (author)

Crystal structure of a mononuclear Ru(II) complex with a back-to-back terpyridine ligand: [RuCl(bpy)(tpy-tpy)](.).

Science.gov (United States)

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.

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

Science.gov (United States)

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.

Electron correlation in CaRuO3 and SrRuO3

International Nuclear Information System (INIS)

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)

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

International Nuclear Information System (INIS)

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

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

International Nuclear Information System (INIS)

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)

Between Localization and Delocalization: Ru(cod)2+ Units in the Zintl Clusters [Bi9 {Ru(cod)}2 ]3- and [Tl2 Bi6 {Ru(cod)}]2.

Science.gov (United States)

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.

Highly-efficient photocatalytic degradation of methylene blue by PoPD-modified TiO 2 nanocomposites due to photosensitization-synergetic effect of TiO2 with PoPD.

Science.gov (United States)

Yang, Chuanxi; Dong, Wenping; Cui, Guanwei; Zhao, Yingqiang; Shi, Xifeng; Xia, Xinyuan; Tang, Bo; Wang, Weiliang

2017-06-21

Poly-o-phenylenediamine modified TiO 2 nanocomposites were successfully synthesized via an 'in situ' oxidative polymerization method. The modified nanocomposites were characterized by BET, XRD, TEM, FT-IR, TGA, XPS, EA and UV-Vis DRS. The photocatalytic degradation of methylene blue was chosen as a model reaction to evaluate the photocatalytic activities of TiO 2 and PoPD/TiO 2 . The results indicated that PoPD/TiO 2 nanocomposites exhibited good photocatalytic activity and stability. The photocatalytic activity of PoPD/TiO 2 increased as the initial pH increased because of electrostatic adsorption between the photocatalyst and MB as well as the generation of ·OH, whereas it exhibited an earlier increasing and later decreasing trend as the concentration of the photocatalyst increased owing to the absorption of visible light. The photocatalytic stability of the PoPD/TiO 2 nanocomposite was dependent on the stability of its structure. Based on radical trapping experiments and ESR measurements, the origin of oxidizing ability of PoPD/TiO 2 nanocomposites on photocatalytic degradation of MB was proposed, which taking into account of ·OH and ·O 2 - were the first and second important ROS, respectively. The possible photocatalytic mechanism and photocatalytic activity enhanced mechanism has been proposed, taking into account the photosensitization effect and synergetic effect of TiO 2 with PoPD.

General aspects of surface alloy formation

Energy Technology Data Exchange (ETDEWEB)

Bergbreiter, Andreas; Engstfeld, Albert K.; Roetter, Ralf T.; Hoster, Harry E.; Behm, R. Juergen [Institute of Surface Chemistry and Catalysis, Ulm University, D-89069 Ulm (Germany); Berko, Andras

2010-07-01

Surface confined alloys are excellent model systems for studies of structure-property relationships of bimetallic surfaces. They are formed by deposition of a guest metal B onto a substrate A, followed by annealing to a temperature, where place exchange between adatoms and atoms from the underlying surface layer becomes possible and diffusion into the bulk is sufficiently slow. We exemplarily confirmed by scanning tunneling microscopy and Auger electron spectroscopy for PtRu/Ru(0001), PdRu/Ru(0001), AuPt/Pt(111), AgPt/Pt(111), and AgPd/Pd(111), surface alloys are obtained for systems where metal B has a negative surface segregation energy within metal A. By exchanging A and B, however, AB surface alloys are most likely overgrown by metal B, which we demonstrate for RuPt/Pt(111) in comparison to PtRu/Ru(0001).

Unconventional superconductivity in Sr{sub 2}RuO{sub 4}

Energy Technology Data Exchange (ETDEWEB)

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}.

Removal of platinum group metals contained in molten glass using copper

International Nuclear Information System (INIS)

Uruga, Kazuyoshi; Sawada, Kayo; Arita, Yuji; Enokida, Youichi; Yamamoto, Ichiro

2007-01-01

Removal of platinum group metals (PGMs) such as Pd, Ru, and RuO 2 from molten glass by using various amounts of liquid Cu was done as a basic study on a new vitrification process for a high-level radio-active waste. We prepared two types of borosilicate glasses containing PGMs and Cu, respectively. These glasses were mixed together and heated at 1,473 K for 4h in Ar atmosphere. More than 95% of Pd were removed as a spherical metal button composed of Pd-Cu alloy when Cu was added in an amount 0.5 times the weight of Pd. Nearly 95% of Ru was also removed as a spherical button with 2.5-5 times as much Cu addition as Ru in weight. Ruthenium oxide was reduced to metallic Ru by a reaction with Cu in the molten glass. The removal fraction was increased by increasing the amount of Cu and reached 63% when Cu addition was 7.5 times as much as RuO 2 in weight. By addition of Si as a reducing agent, nearly 90% of Pd and Ru were removed with Cu and Si metal composites even under O 2 :Ar=20:80 (v/v) condition. (author)

A rapid NiS bead technique for measurements of picogram concentrations of platinum group elements (PGEs) following neutron activation

International Nuclear Information System (INIS)

Das, A.; Shukla, A.D.

1999-01-01

To measure picogram amounts of PGEs in terrestrial and extraterrestrial samples we have modified the NiS fire assay technique in conjunction with neutron activation analysis. Os, Ir and Ru are almost quantitatively concentrated in the NiS bead. The method should be applicable to other elements (Pt, Pd, and Rh) but these could not be analyzed because of the short half life of their daughter isotopes. The results also show that the chalcophhile elements like Ag also can be quantitatively estimated using this method. (author)

Influence of Binders and Solvents on Stability of Ru/RuOx Nanoparticles on ITO Nanocrystals as Li-O2 Battery Cathodes.

Science.gov (United States)

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.

Direct determination of cadmium in Orujo spirit samples by electrothermal atomic absorption spectrometry: Comparative study of different chemical modifiers

Energy Technology Data Exchange (ETDEWEB)

Vilar Farinas, M. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias, Universidad de Santiago de Compostela, Campus de Lugo, 27002 Lugo (Spain); Barciela Garcia, J. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias, Universidad de Santiago de Compostela, Campus de Lugo, 27002 Lugo (Spain); Garcia Martin, S. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias, Universidad de Santiago de Compostela, Campus de Lugo, 27002 Lugo (Spain); Pena Crecente, R. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias, Universidad de Santiago de Compostela, Campus de Lugo, 27002 Lugo (Spain); Herrero Latorre, C. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias, Universidad de Santiago de Compostela, Campus de Lugo, 27002 Lugo (Spain)]. E-mail: cherrero@lugo.usc.es

2007-05-22

In this work, several analytical methods are proposed for cadmium determination in Orujo spirit samples using electrothermal atomic absorption spectrometry (ETAAS). Permanent chemical modifiers thermally coated on the platforms inserted in pyrolytic graphite tubes (such as W, Ir, Ru, W-Ir and W-Ru) were comparatively studied in relation to common chemical modifier mixtures [Pd-Mg(NO{sub 3}){sub 2} and (NH{sub 4})H{sub 2}PO{sub 4}-Mg(NO{sub 3}){sub 2}] for cadmium stabilization. Different ETAAS Cd determination methods based on the indicated modifiers have been developed. In each case, pyrolysis and atomization temperatures, atomization shapes, characteristic masses and detection limits as well as other analytical characteristics have been determined. All the assayed modifiers (permanent and conventional) were capable of achieving the appropriate stabilization of the analyte, with the exception of Ru and W-Ru. Moreover, for all developed methods, recoveries (99-102%) and precision (R.S.D. lower than 10%) were acceptable. Taking into account the analytical performance (best detection limit LOD = 0.01 {mu}g L{sup -1}), the ETAAS method based on the use of W as a permanent modifier was selected for further direct Cd determinations in Orujo samples from Galicia (NW Spain). The chosen method was applied in the determination of the Cd content in 38 representative Galician samples. The cadmium concentrations ranged

Perpendicular magnetic anisotropy in Co{sub X}Pd{sub 100−X} alloys for magnetic tunnel junctions

Energy Technology Data Exchange (ETDEWEB)

Clark, B.D.; Natarajarathinam, A.; Tadisina, Z.R. [Center for Materials for Information Technology, University of Alabama, Tuscaloosa, AL 35487 (United States); Chen, P.J.; Shull, R.D. [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Gupta, S., E-mail: Sgupta@eng.ua.edu [Center for Materials for Information Technology, University of Alabama, Tuscaloosa, AL 35487 (United States)

2017-08-15

Highlights: • CoPd alloy perpendicular anisotropy dependent on composition and thickness. • CIPT results show that TMR tracks with PMA of CoPd. • Potential replacement for Co/Pd multilayers. - Abstract: CoFeB/MgO-based perpendicular magnetic tunnel junctions (p-MTJ’s) with high anisotropy and low damping are critical for spin-torque transfer random access memory (STT-RAM). Most schemes of making the pinned CoFeB fully perpendicular require ferrimagnets with high damping constants, a high temperature-grown L1{sub 0} alloy, or an overly complex multilayered synthetic antiferromagnet (SyAF). We report a compositional study of perpendicular Co{sub x}Pd alloy-pinned Co{sub 20}Fe{sub 60}B{sub 20}/MgO based MTJ stacks, grown at moderate temperatures in a planetary deposition system. The perpendicular anisotropy of the Co{sub x}Pd alloy films can be tuned based on the layer thickness and composition. The films were characterized by alternating gradient magnetometry (AGM), energy-dispersive X-rays (EDX), and X-ray diffraction (XRD). Current-in-plane tunneling (CIPT) measurements have also been performed on the compositionally varied Co{sub x}Pd MTJ stacks. The Co{sub x}Pd alloy becomes fully perpendicular at approximately x = 30% (atomic fraction) Co. Full-film MTJ stacks of Si/SiO{sub 2}/MgO (13)/Co{sub X}Pd{sub 100−x} (50)/Ta (0.3)/CoFeB (1)/MgO (1.6)/CoFeB (1)/Ta (5)/Ru (10), with the numbers enclosed in parentheses being the layer thicknesses in nm, were sputtered onto thermally oxidized silicon substrates and in-situ lamp annealed at 400 °C for 5 min. CIPT measurements indicate that the highest TMR is observed for the CoPd composition with the highest perpendicular magnetic anisotropy.

Platinum Group Elements (PGE) geochemistry of komatiites and boninites from Dharwar Craton, India: Implications for mantle melting processes

Science.gov (United States)

Saha, Abhishek; Manikyamba, C.; Santosh, M.; Ganguly, Sohini; Khelen, Arubam C.; Subramanyam, K. S. V.

2015-06-01

High MgO volcanic rocks having elevated concentrations of Ni and Cr are potential hosts for platinum group elements (PGE) owing to their primitive mantle origin and eruption at high temperatures. Though their higher PGE abundance is economically significant in mineral exploration studies, their lower concentrations are also valuable geochemical tools to evaluate petrogenetic processes. In this paper an attempt has been made to evaluate the PGE geochemistry of high MgO volcanic rocks from two greenstone belts of western and eastern Dharwar Craton and to discuss different mantle processes operative at diverse geodynamic settings during the Neoarchean time. The Bababudan greenstone belt of western and Gadwal greenstone belt of eastern Dharwar Cratons are dominantly composed of high MgO volcanic rocks which, based on distinct geochemical characteristics, have been identified as komatiites and boninites respectively. The Bababudan komatiites are essentially composed of olivine and clinopyroxene with rare plagioclase tending towards komatiitic basalts. The Gadwal boninites contain clinopyroxene, recrystallized hornblende with minor orthopyroxene, plagioclase and sulphide minerals. The Bababudan komatiites are Al-undepleted type (Al2O3/TiO2 = 23-59) with distinctly high MgO (27.4-35.8 wt.%), Ni (509-1066 ppm) and Cr (136-3036 ppm) contents. These rocks have low ΣPGE (9-42 ppb) contents with 0.2-2.4 ppb Iridium (Ir), 0.2-1.4 ppb Osmium (Os) and 0.4-4.4 ppb Ruthenium (Ru) among Iridium group PGE (IPGE); and 1.4-16.2 ppb Platinum (Pt), 2.8-19 ppb Palladium (Pd) and 0.2-9.8 ppb Rhodium (Rh) among Platinum group PGE (PPGE). The Gadwal boninites are high-Ca boninites with CaO/Al2O3 ratios varying between 0.8 and 1.0, with 12-24 wt.% MgO, 821-1168 ppm Ni and 2307-2765 ppm Cr. They show higher concentration of total PGE (82-207 ppb) with Pt concentration ranging from 13 to 19 ppb, Pd between 65 and 180 ppb and Rh in the range of 1.4-3 ppb compared to the Bababudan komatiites. Ir

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

NARCIS (Netherlands)

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

Structural, optical and magnetic characterization of Ru doped ZnO nanorods

International Nuclear Information System (INIS)

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

Synthesis and Characterization of a Ru(II Complex with Functionalized Phenanthroline Ligands Having Single-Double Linked Anthracenyl and 1-Methoxy-1-buten-3-yne Moieties

Directory of Open Access Journals (Sweden)

Adewale O. Adeloye

2010-10-01

Full Text Available Two series of bidentate polypyridine ligands, made of phenanthroline chelating subunits having substituted mono-and di-anthracenyl groups, and 1-methoxy-1-buten-3-yne at the 4 and 7-positions with the corresponding heteroleptic Ru(II complex have been synthesized and characterized. The complex is formulated as [(Ru(L1(L2(NCS2], (where L1 = 4-(9-dianthracenyl-10-(2,3-dimethylacrylic acid-7-(9-anthracenyl-10-(2,3-dimethylacrylic acid-1,10-phenanthroline and L2 = 4,7-bis(1-methoxy-1-buten-3-yne-1,10-phenanthroline. The Ru(II complex shows characteristic broad and intense metal-to-ligand charge transfer (MLCT bands absorption and appreciable photoluminescence spanning the visible region. The ligands and complex were characterized by FT-IR, 1H, 13C NMR spectroscopy, UV-Vis, photoluminescence and elemental analysis (see in supplementary materials. The anchoring groups in both ligands have allowed an extended delocalization of acceptor orbital of the metal-to-ligand charge-transfer (MLCT excited state.

Synthesis, characterization and thermal decomposition of [Pd2 (C2-dmba (µ-SO4 (SO22

Directory of Open Access Journals (Sweden)

Caires Antonio Carlos Fávero

1998-01-01

Full Text Available The bridged sulphate complex [Pd2 (C²,dmba (µ-SO4 (SO22] has been obtained by reacting a saturated solution of SO2 in methanol and the cyclometallated compound [Pd(C²,N-dmba(µ-N3] 2; (dmba = N,N-dimethylbenzylamine, at room temperature for 24 h. Reaction product was characterized by elemental analysis, NMR comprising 13C{¹H} and ¹H nuclei and I.R. spectrum's measurements. Thermal behavior has been investigated and residual products identified by X-ray powder diffraction.

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

Science.gov (United States)

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

Quasi-zero-dimensional cobalt-doped CeO2 dots on Pd catalysts for alcohol electro-oxidation with enhanced poisoning-tolerance.

Science.gov (United States)

Tan, Qiang; Zhu, Haiyan; Guo, Shengwu; Chen, Yuanzhen; Jiang, Tao; Shu, Chengyong; Chong, Shaokun; Hultman, Benjamin; Liu, Yongning; Wu, Gang

2017-08-31

Deactivation of an anode catalyst resulting from the poisoning of CO ad -like intermediates is one of the major problems for methanol and ethanol electro-oxidation reactions (MOR & EOR), and remains a grand challenge towards achieving high performance for direct alcohol fuel cells (DAFCs). Herein, we report a new approach for the preparation of ultrafine cobalt-doped CeO 2 dots (Co-CeO 2 , d = 3.6 nm), which can be an effective anti-poisoning promoter for Pd catalysts towards MOR and EOR in alkaline media. Compared to Pd/CeO 2 and pure Pd, the hybrid Pd/Co-CeO 2 nanocomposite catalyst exhibited a much enhanced activity and remarkable anti-poisoning ability for both MOR and EOR. The nanocomposite catalyst showed much higher mass activity (4×) than a state-of-the-art PtRu catalyst. The promotional mechanism was elucidated using extensive characterization and density-functional theory (DFT). A bifunctional effect of the Co-CeO 2 dots was discovered to be due to (i) an enhanced electronic interaction between Co-CeO 2 and Pd dots and (ii) the increased oxygen storage capacity of Co-CeO 2 dots to facilitate the oxidation of CO ad . Therefore, the Pd/Co-CeO 2 nanocomposite appears to be a promising catalyst for advanced DAFCs with low cost and high performance.

Synthesis and characterization of Pd@M(x)Cu(1-x) (M = Au, Pd, and Pt) nanocages with porous walls and a yolk-shell structure through galvanic replacement reactions.

Science.gov (United States)

Xie, Shuifen; Jin, Mingshang; Tao, Jing; Wang, Yucai; Xie, Zhaoxiong; Zhu, Yimei; Xia, Younan

2012-11-19

This paper describes the synthesis of Pd@M(x)Cu(1-x) (M = Au, Pd, and Pt) nanocages with a yolk-shell structure through galvanic replacement reactions that involve Pd@Cu core-shell nanocubes as sacrificial templates and ethylene glycol as the solvent. Compared with the most commonly used templates based on Ag, Cu offers a much lower reduction potential (0.34 versus 0.80 V), making the galvanic reaction more easily to conduct, even at room temperature. Our structural and compositional characterizations indicated that the products were hollow inside, and each one of them contained porous M-Cu alloy walls and a Pd cube in the interior. For the Pd@Au(x)Cu(1-x) yolk-shell nanocages, they displayed broad extinction peaks extending from the visible to the near-IR region. Our mechanistic study revealed that the dissolution of the Cu shell preferred to start from the slightly truncated corners and then progressed toward the interior, because the Cu {100} side faces were protected by a surface capping layer of hexadecylamine. This galvanic approach can also be extended to generating other hollow metal nanostructures by using different combinations of Cu nanostructures and salt precursors. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Enhanced interfacial Dzyaloshinskii-Moriya interaction and isolated skyrmions in the inversion-symmetry-broken Ru/Co/W/Ru films

Science.gov (United States)

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.

Activity of carbon supported Pt3Ru2 nanocatalyst in CO oxidation

Directory of Open Access Journals (Sweden)

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.

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

International Nuclear Information System (INIS)

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

RuBee and RFID A confidential summary,May 2009

Institute of Scientific and Technical Information of China (English)

无

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

Methanol oxidation catalysis and substructure of PtRu bimetallic nanoparticles

Energy Technology Data Exchange (ETDEWEB)

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)

Methanol Electro-Oxidation on Pt-Ru Alloy Nanoparticles Supported on Carbon Nanotubes

Directory of Open Access Journals (Sweden)

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.

Ruthenium determination in new composite materials by coulometric titration with generated iron(2)

International Nuclear Information System (INIS)

Butakova, N.A.; Oganesyan, L.B.

1983-01-01

A coulometric technique is developed for ruthenium (4) titration with generated iron (2) in a mixture of hydrochloric-, sulfuric- and phosphoric acids with potentiometric and biammetric indication of the final titration point. Bi (3), Pd (2), Nb (5), Pt (4) Pb (2), Rh (3) do not interfere with the titration. Together with Ru (4) titrated are Ir (4), V (5), Au (3). The method is applied to analyze commercial samples of ruthenium dioxides, lead- and bismuth ruthenites, ruthenium pentafluorides containing 30-80% of ruthenium. The Ssub(r) values do not exceed 0.002

Measurement of activation yields for platinum group elements using Bremsstrahlung radiation with end-point energies in the range 11-14 MeV

Energy Technology Data Exchange (ETDEWEB)

Tickner, James, E-mail: james.tickner@csiro.a [CSIRO Process Science and Engineering, PMB 5, Menai, NSW 2234 (Australia); Bencardino, Raffaele; Roach, Greg [CSIRO Process Science and Engineering, PMB 5, Menai, NSW 2234 (Australia)

2010-01-15

Activation yields have been measured for (gamma,n) reactions of the elements Ru, Rh, Pd, Ir and Pt. Metallic foils of natural isotopic composition were irradiated using Bremsstrahlung radiation produced from an electron linear accelerator operated with electron beam energies in the range 11-14 MeV. Activation products, including both unstable ground states and metastates were measured using a high-purity germanium detector. Cross-sections were estimated from the yield data by assuming a simple two-parameter model for the shape of the cross-section with energy.

Measurement of activation yields for platinum group elements using Bremsstrahlung radiation with end-point energies in the range 11-14 MeV

International Nuclear Information System (INIS)

Tickner, James; Bencardino, Raffaele; Roach, Greg

2010-01-01

Activation yields have been measured for (γ,n) reactions of the elements Ru, Rh, Pd, Ir and Pt. Metallic foils of natural isotopic composition were irradiated using Bremsstrahlung radiation produced from an electron linear accelerator operated with electron beam energies in the range 11-14 MeV. Activation products, including both unstable ground states and metastates were measured using a high-purity germanium detector. Cross-sections were estimated from the yield data by assuming a simple two-parameter model for the shape of the cross-section with energy.

A novel ferrimagnetic irido-cuprate: IrSr2GdCu2O8

International Nuclear Information System (INIS)

Dos Santos-Garcia, A.J.; Aguirre, Myriam H.; Moran, E.; Saez Puche, R.; Alario-Franco, M.A.

2006-01-01

We have performed an investigation of the structural, microstructural and magnetic properties of the new compound IrSr 2 GdCu 2 O 8 . The sample was prepared under high temperature (∼1393K) and high-pressure conditions (∼60Kbars) in a Belt type apparatus. X-ray diffraction (XRD) analysis shows that this irido-cuprate is isostructural with the corresponding Ru-1212 phase. Structurally, this material shows an interesting hierarchy of ordering phenomena, whose observation actually depends on the technique used to analyze the material: from a 'simple' cell a p xa p x3a p which is supported by XRD, through a 'diagonal' one, ∼2a p x2a p x3a p as seen by SAED, to a microdomain texture of this last one cell supported by HREM. A ferrimagnetic Ir IV -Gd III spin ordering is observed below 15K. The iridium oxidation state seems to be +4

Separation of 103Pd from metal Rhodium by dry distillation

International Nuclear Information System (INIS)

Szuecs, Z.; Takacs, S.

2009-01-01

Complete text of publication follows. Introduction. The use of Auger emitters as potential radiopharmaceuticals is increasingly investigated. One such radionuclide of interest is 103m Rh. This can be produced from 103 Ru or from 103 Pd in an in vivo generator. It has been proven on theoretical considerations that use of 103 Pd/ 103m Rh in vivo generator will be successful in delivering 103 mRh to a target site when complexed to a tumor selective carrier. 103 Pd is widely used in internal radiotherapy with one of the production routes via the irradiation of Rh by protons in a cyclotron. The charged particle production of 103 Pd is the only way for no-carrier -added production of this radionuclide, which is required for use in nuclear medicine. However, the widely used separation technique to get 103 Pd from the target material (as well as recovery of the Rh) by wet chemistry is a very complicated, labour intensive and expensive procedure, resulting in low yields of 103 Pd and high amounts of radioactive waste. An alternative more efficient separation and production technology can be developed based on differential evaporation. The principle is the following: The produced 103 Pd 'contaminating' new element within the crystal structure of the Rh target can be forced to diffuse out from the deformed crystal lattice by heating up the target. In this process the 103 Pd accumulates on the surface of the target from where it can be evaporated. A prerequisite for this process is that the target metal (Rh) has a different partial pressure than the evaporated metal (Pd). The thick target yield is 6MBq/μ Ah and the activities of potential contaminating radioisotopes produced by side reaction are negligible, if the energy of the irradiating beam will be chosen precisely. The natural abundance of 116 Cd is 7,5%, it means that the price of the enriched material is reasonable. A potential cyclotron facility with α-beam was found at JINR, Dubna, Russia where the radiochemical

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

International Nuclear Information System (INIS)

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

Performance of Pd on activated carbon as hydrogen electrode with respect to hydrogen yield in a single cell proton exchange membrane (PEM) water electrolyser

Energy Technology Data Exchange (ETDEWEB)

Naga Mahesh, K.; Sarada Prasad, J.; Venkateswer Rao, M.; Himabindu, V. [Centre for Environment, Institute of Science and Technology, Jawaharlal Nehru Technological University Hyderabad, Kukatpally, Hyderabad 500085 (A.P.) (India); Yerramilli, Anjaneyulu [TLGVRC, JSU Box 18739, Jackson State University, Jackson, MS 32917 - 0939 (United States); Raghunathan Rao, P. [Fuel cell section, Heavy Water Division, Bhabha Atomic Research Centre, Trombay, Mumbai - 400 085 (India)

2009-08-15

Palladium (Pd) on activated carbon is used as electrocatalyst coated on Nafion 115 membrane as Hydrogen electrode and RuO{sub 2} is coated on other side of membrane used as oxygen electrode. 5 wt% and 10 wt% Pd on activated carbon is prepared as membrane electrode assembly (MEA) and investigated the performance of the same using inhouse prepared 10 cm{sup 2} single cell. The performance of the single cell assembly and the hydrogen yield are reported during electrolysis operation at temperatures 27 C, 45 C and 65 C at 0.1, 0.2, 0.3, 0.4, 0.5 A/cm{sup 2} current densities with respect to voltages. (author)

Thiolato-bridged RuIIAgIRuII trinuclear complex composed of bis(bipyridine)ruthenium(II) units with chelating 2-aminoethanethiolate: conversion to a disulfide-bridged RuIIRuII dinuclear complex.

Science.gov (United States)

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.

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

KAUST Repository

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.

Preparation and characterization of RuO2/polypyrrole electrodes for supercapacitors

Science.gov (United States)

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.

Status of the development of RU-43 fuel at INR Pitesti

International Nuclear Information System (INIS)

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.)

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.

Science.gov (United States)

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.

NOVEL RU-NI-S ELECTRODE CATALYST FOR PEMFC

Science.gov (United States)

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...

Synthesis and spectroscopic studies of biologically active tetraazamacrocyclic complexes of Mn(II, Co(II, Ni(II, Pd(II and Pt(II

Directory of Open Access Journals (Sweden)

Monika Tyagi

2014-01-01

Full Text Available Complexes of Mn(II, Co(II, Ni(II, Pd(II and Pt(II were synthesized with the macrocyclic ligand, i.e., 2,3,9,10-tetraketo-1,4,8,11-tetraazacycoletradecane. The ligand was prepared by the [2 + 2] condensation of diethyloxalate and 1,3-diamino propane and characterized by elemental analysis, mass, IR and 1H NMR spectral studies. All the complexes were characterized by elemental analysis, molar conductance, magnetic susceptibility measurements, IR, electronic and electron paramagnetic resonance spectral studies. The molar conductance measurements of Mn(II, Co(II and Ni(II complexes in DMF correspond to non electrolyte nature, whereas Pd(II and Pt(II complexes are 1:2 electrolyte. On the basis of spectral studies an octahedral geometry has been assigned for Mn(II, Co(II and Ni(II complexes, whereas square planar geometry assigned for Pd(II and Pt(II. In vitro the ligand and its metal complexes were evaluated against plant pathogenic fungi (Fusarium odum, Aspergillus niger and Rhizoctonia bataticola and some compounds found to be more active as commercially available fungicide like Chlorothalonil.

Phase transition of the orthorhombic fluorite-related compounds Ln{sub 3}IrO{sub 7} (Ln = Pr, Nd, Sm, Eu)

Energy Technology Data Exchange (ETDEWEB)

Hinatsu, Yukio, E-mail: hinatsu@sci.hokudai.ac.j [Division of Chemistry, Graduate School of Science, Hokkaido University, Sapporo 060-0810 (Japan); Doi, Yoshihiro; Nishimine, Hiroaki; Wakeshima, Makoto [Division of Chemistry, Graduate School of Science, Hokkaido University, Sapporo 060-0810 (Japan); Sato, Mineo [Department of Chemistry and Chemical Engineering, Faculty of Engineering, Niigata University, 8050 Ikarashi 2-nocho, Niigata 950-2181 (Japan)

2009-12-04

Rare earth iridium oxides Ln{sub 3}IrO{sub 7} (Ln = Pr, Nd, Sm, and Eu) were prepared and their structures were determined by X-ray diffraction measurements. At room temperature, Pr{sub 3}IrO{sub 7} crystallized in an orthorhombic superstructure of cubic fluorite with space group Cmcm. The differential thermal analysis (DTA) and specific heat measurements for Ln{sub 3}IrO{sub 7} (Ln = Pr, Nd, Sm, and Eu) showed a phase transition at 262, 342, 420, and 485 K, respectively. At low temperatures, Ln{sub 3}IrO{sub 7} crystallized in a monoclinic structure with the space group P2{sub 1}/n. The transition temperatures increased with decreasing the ionic radius of rare earths, which indicates that the transition is stress-induced and occurs with the lattice contraction on cooling. These results for Ln{sub 3}IrO{sub 7} were compared with the phase transitions observed for Ln{sub 3}MoO{sub 7}, Ln{sub 3}RuO{sub 7}, Ln{sub 3}ReO{sub 7}, and Ln{sub 3}OsO{sub 7}.

Ru(III) catalyzed permanganate oxidation of aniline at environmentally relevant pH.

Science.gov (United States)

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.

Cationic Protic Imidazolylidene NHC Complexes of Cp*IrCl+ and Cp*RhCl+ with a Pyridyl Tether Formed at Ambient Temperature

Directory of Open Access Journals (Sweden)

Douglas B. Grotjahn

2018-02-01

Full Text Available Protic NHC (PNHC complexes with N1H, N2-alkyl/aryl imidazolylidene ligands are relatively rare, and routes for their synthesis differ from what is used to make non-protic analogs. Prior work from our group and others showed that in the presence of a tethering ligand (phosphine or in one case, pyridine, CpM and Cp*M (M = Ir, Ru PNHC complexes could be made by heating. Here, we find that the use of ionizing agents to activate [Cp*MIIICl(μ-Cl]2 (M = Ir, Rh allows for what we believe is unprecedented ambient temperature formation of PNHC complexes from neutral imidazoles; the product complexes are able to perform transfer hydrogenation.

Development of antifouling of electrochemical solid-state dissolved oxygen sensors based on nanostructured Cu0.4Ru3.4O7 + RuO2 sensing electrodes

International Nuclear Information System (INIS)

Zhuiykov, Serge; Kalantar-zadeh, Kourosh

2012-01-01

Tailoring nanostructured sensing electrode materials to high antifouling resistance has been one of the main priorities of the development of water quality sensors in the 21st century. Nanostructured Cu 0.4 Ru 3.4 O 7 + RuO 2 -SEs have been developed to address the bio-fouling problem. The change in Cu 0.4 Ru 3.4 O 7 + RuO 2 structural development being promoted by advances in nano- and micro-scale pattering. Nanostructured Cu 0.4 Ru 3.4 O 7 + RuO 2 -SEs with different mol% of Cu 2 O were screen-printed on alumina sensor substrates and were consequently subjected to a 3-month field trial at the Water Treatment Plant. Their structural and electrochemical properties before and after the experiment were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical cyclic voltammerty (CV) techniques. The relationship between dissolved oxygen (DO) and the sensor's potential difference was found to be relatively linear, with the maximum sensitivity of −46 mV per decade being achieved at 20 mol% Cu 2 O at 7.27 pH. Moreover, a 3-month field trial in the sewerage environment has shown that Cu 0.4 Ru 3.4 O 7 + RuO 2 -SE with 20 mol% of Cu 2 O possesses much higher defences against bio-fouling than the same SE with only 10 mol% of Cu 2 O. The super-hydrophobic property of the developed Cu 0.4 Ru 3.4 O 7 + RuO 2 complex oxide has been considered as one of the essential pre-requisites for high antifouling resistance. Multiple antifouling defence strategies from biomimetic to bio-inspired must be incorporated in further development of nanostructured oxide SE to solve problems of bio-fouling on the sensor's SE.

Effect of an in-plane ligand on the electronic structures of bromo-bridged nano-wire Ni-Pd mixed-metal complexes, [Ni(1-x)Pd(x)(bn)2Br]Br2 (bn = 2S,3S-diaminobutane).

Science.gov (United States)

Sasaki, Mari; Wu, Hashen; Kawakami, Daisuke; Takaishi, Shinya; Kajiwara, Takashi; Miyasaka, Hitoshi; Breedlove, Brian K; Yamashita, Masahiro; Kishida, Hideo; Matsuzaki, Hiroyuki; Okamoto, Hiroshi; Tanaka, Hisaaki; Kuroda, Shinichi

2009-08-03

Single crystals of quasi-one-dimensional bromo-bridged Ni-Pd mixed-metal complexes with 2S,3S-diaminobutane (bn) as an in-plane ligand, [Ni(1-x)Pd(x)(bn)(2)Br]Br(2), were obtained by using an electrochemical oxidation method involving mixed methanol/2-propanol (1:1) solutions containing different ratios of [Ni(II)(bn)(2)]Br(2) and [Pd(II)(bn)(2)]Br(2). To investigate the competition between the electron-correlation of the Ni(III) states, or Mott-Hubbard states (MH), and the electron-phonon interaction of the Pd(II)-Pd(IV) mixed valence states, or charge-density-wave states (CDW), in the Ni-Pd mixed-metal compounds, X-ray structure analyses, X-ray oscillation photograph, and Raman, IR, ESR, and single-crystal reflectance spectra were analyzed. In addition, the local electronic structures of Ni-Pd mixed-metal single crystals were directly investigated by using scanning tunneling microscopy (STM) at room temperature and ambient pressure. The oxidation states of [Ni(1-x)Pd(x)(bn)(2)Br]Br(2) changed from a M(II)-M(IV) mixed valence state to a M(III) MH state at a critical mixing ratio (x(c)) of approximately 0.8, which is lower than that of [Ni(1-x)Pd(x)(chxn)(2)Br]Br(2) (chxn = 1R,2R-diaminocyclohexane) (x(c) approximately 0.9) reported previously. The lower value of x(c) for [Ni(1-x)Pd(x)(bn)(2)Br]Br(2) can be explained by the difference in their CDW dimensionalities because the three-dimensional CDW ordering in [Pd(bn)(2)Br]Br(2) observed by using X-ray diffuse scattering stabilizes the Pd(II)-Pd(IV) mixed valence state more than two-dimensional CDW ordering in [Pd(chxn)(2)Br]Br(2) does, which has been reported previously.

Gamma-gamma angular correlation measurement in the 100 Ru

International Nuclear Information System (INIS)

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)

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

International Nuclear Information System (INIS)

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

Electro-oxidation of methanol and ethanol using PtRu/C, PtSn/C and PtSnRu/C electrocatalysts prepared by an alcohol-reduction process

Science.gov (United States)

Neto, Almir Oliveira; Dias, Ricardo R.; Tusi, Marcelo M.; Linardi, Marcelo; Spinacé, Estevam V.

PtRu/C, PtSn/C and PtSnRu/C electrocatalysts were prepared by the alcohol reduction process using ethylene glycol as the solvent and reduction agent and Vulcan Carbon XC72 as the support. The electrocatalysts were characterized by EDX, XRD and cyclic voltammetry. The electrochemical oxidation of methanol and ethanol were studied by chronoamperometry using a thin porous coating technique. The PtSn/C electrocatalyst prepared by this methodology showed superior performance compared to the PtRu/C and PtSnRu/C electrocatalysts for methanol and ethanol oxidation at room temperature.

Adsorption of n-butane on graphene/Ru(0001)—A molecular beam scattering study

Energy Technology Data Exchange (ETDEWEB)

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.

Adsorption of n-butane on graphene/Ru(0001)—A molecular beam scattering study

International Nuclear Information System (INIS)

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.

The Ruthenostannylene Complex [Cp*(IXy)H2 Ru-Sn-Trip]: Providing Access to Unusual Ru-Sn Bonded Stanna-imine, Stannene, and Ketenylstannyl Complexes.

Science.gov (United States)

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.

DFT Simulation of Structural and Optical Properties of 9-Aminoacridine Half-Sandwich Ru(II), Rh(III), and Ir(III) Antitumoral Complexes and Their Interaction with DNA.

Science.gov (United States)

Cerón-Carrasco, José Pedro; Ruiz, José; Vicente, Consuelo; de Haro, Concepción; Bautista, Delia; Zúñiga, José; Requena, Alberto

2017-08-08

In this work, we use DFT-based methods to simulate the chemical structures, optical properties, and interaction with DNA of a recently synthesized chelated C^N 9-aminoacridine arene Ru(II) anticancer agent and two new closely related Rh(III) and Ir(III) complexes using DFT-based methods. Four chemical models and a number of theoretical approaches, which representatively include the PBE0, B97D, ωB97X, ωB97X-D, M06, and M06-L density functionals and the LANL2DZ, def2-SVP, and def2-TZVP basis sets, are tested. The best overall accuracy/cost performance for the optimization process is reached at the ωB97X-D/def2-SVP and M06/def2-SVP levels of theory. Inclusion of explicit solvent molecules (CHCl 3 ) further refines the geometry, while taking into account the crystal network gives no significant improvements of the computed bond distances and angles. The analysis of the excited states reveals that the M06 level matches better the experimental absorption spectra, compared to ωB97X-D. The use of the M06/def2-SVP approach is therefore a well-balanced method to study theoretically the bioactivity of this type of antitumoral complexes, so we couple this TD-DFT approach to molecular dynamics simulations in order to assess their reactivity with DNA. The reported results demonstrate that these drugs could be used to inject electrons into DNA, which might broaden their applications in photoactivated chemotherapy and as new materials for DNA-based electrochemical nanodevices.

Low leakage Ru-strontium titanate-Ru metal-insulator-metal capacitors for sub-20 nm technology node in dynamic random access memory

Energy Technology Data Exchange (ETDEWEB)

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.

Current Diagnosis and Management of Immune Related Adverse Events (irAEs Induced by Immune Checkpoint Inhibitor Therapy

Directory of Open Access Journals (Sweden)

Vivek Kumar

2017-02-01

Full Text Available The indications of immune checkpoint inhibitors (ICIs are set to rise further with the approval of newer agent like atezolimumab for use in patients with advanced stage urothelial carcinoma. More frequent use of ICIs has improved our understanding of their unique side effects, which are known as immune-related adverse events (irAEs. The spectrum of irAEs has expanded beyond more common manifestations such as dermatological, gastrointestinal and endocrine effects to rarer presentations involving nervous, hematopoietic and urinary systems. There are new safety data accumulating on ICIs in patients with previously diagnosed autoimmune conditions. It is challenging for clinicians to continuously update their working knowledge to diagnose and manage these events successfully. If diagnosed timely, the majority of events are completely reversible, and temporary immunosuppression with glucocorticoids, infliximab or other agents is warranted only in the most severe grade illnesses. The same principles of management will possibly apply as newer anti- cytotoxic T lymphocytes-associated antigen 4 (CTLA-4 and programmed cell death protein 1 (PD-1/PD-L1 antibodies are introduced. The current focus of research is for prophylaxis and for biomarkers to predict the onset of these toxicities. In this review we summarize the irAEs of ICIs and emphasize their growing spectrum and their management algorithms, to update oncology practitioners.

Synthesis of thiadiazolobenzamide via cyclization of thioxothiourea and its Ni and Pd complexes

Directory of Open Access Journals (Sweden)

Adhami Forogh

2012-01-01

Full Text Available In this study, the new compound, N-(3-methyl-4- oxo[1,3,4]thiadiazolo[2,3-c][1,2,4]triazin-7-yl benzamide, could be obtained via two different reactions: 1 reaction of 4-amino-6-Methyl-3- (Methylsulfanyl-1,2,4-triazin-5-one with benzoyl isothiocyanate under removal of methylmercaptane, 2 reaction of 4-amino-6-Methyl-3-thioxo- 1,2,4-triazin-5-one with benzoyl isothiocyanate under elimination of hydrogen sulfide. In both reactions a new bond between sulfur and nitrogen atoms was formed and a five-membered ring was created. The oxo thiadiazolo benzamide was characterized by IR-, 1HNMR- and 13CNMR spectroscopy as well as by Mass spectrometry. X-ray crystallography was used to shed light on the structure of this new compound. Two new complexes could be generated by coordination of oxo thiadiazolo benzamide to Pd(II and Ni(II ions. These complexes have been analyzed by IR-, 1HNMR- and 13CNMR spectroscopy, conductometry and Thermal gravimetry (TGA. Theoretical QM Calculation GIAO has also been applied to predict the structure of the Pd complex.

Ambipolar thermoelectric power of chemically-exfoliated RuO2 nanosheets

Science.gov (United States)

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.

The Spectroscopic and Conductive Properties of Ru(II Complexes with Potential Anticancer Properties

Directory of Open Access Journals (Sweden)

Adebayo A. Adeniyi

2014-01-01

Full Text Available Different density functional methods (DFT have been used to optimize and study the chemistry of five potential anticancer complexes in terms of their electronic, conductive, and spectroscopic properties. Many of the computed properties in addition to the IR and QTAIM analysis of the NMR are dipole moment vector (μi, linear polarizability tensor (αij, first hyperpolarizability tensors (βijk, polarizability exaltation index (Γ, and chemical hardness (η of the complexes. Stable low energy geometries are obtained using basis set with effective core potential (ECP approximation but, in the computation of atomic or molecular properties, the metal Ru atom is better treated with higher all electron basis set like DGDZVP. The spectroscopic features like the IR of the metal-ligand bonds and the isotropic NMR shielding tensor of the coordinated atoms are significantly influenced by the chemical environment of the participating atoms. The carboxylic and pyrazole units are found to significantly enhance the polarizabilities and hyperpolarizabilities of the complexes while the chloride only improves the polarity of the complexes. Fermi contacts (FC have the highest effect followed by the PSO among all the four Ramsey terms which defined the total spin-spin coupling constant J (HZ of these complexes.

bond activation and catalysis by Ru -pac complexes

Indian Academy of Sciences (India)

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-.

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

Science.gov (United States)

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).

Magnetic Excitations in α-RuCl3

Science.gov (United States)

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.

Partitioning of rhodium and ruthenium between Pd–Rh–Ru and (Ru,Rh)O{sub 2} solid solutions in high-level radioactive waste glass

Energy Technology Data Exchange (ETDEWEB)

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.

Superconductivity and Competing Ordered Phase in RuPn (Pn = As, P)

Science.gov (United States)

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.

Electro-oxidation of methanol and ethanol using PtRu/C, PtSn/C and PtSnRu/C electrocatalysts prepared by an alcohol-reduction process

Energy Technology Data Exchange (ETDEWEB)

Neto, Almir Oliveira; Dias, Ricardo R.; Tusi, Marcelo M.; Linardi, Marcelo; Spinace, Estevam V. [Instituto de Pesquisas Energeticas e Nucleares, IPEN-CNEN/SP, Av. Prof. Lineu Prestes 2242, Cidade Universitaria, CEP 05508-900 Sao Paulo, SP (Brazil)

2007-03-30

PtRu/C, PtSn/C and PtSnRu/C electrocatalysts were prepared by the alcohol reduction process using ethylene glycol as the solvent and reduction agent and Vulcan Carbon XC72 as the support. The electrocatalysts were characterized by EDX, XRD and cyclic voltammetry. The electrochemical oxidation of methanol and ethanol were studied by chronoamperometry using a thin porous coating technique. The PtSn/C electrocatalyst prepared by this methodology showed superior performance compared to the PtRu/C and PtSnRu/C electrocatalysts for methanol and ethanol oxidation at room temperature. (author)

Interaction between exo-nido-ruthenacarborane [Cl(Ph3P)2Ru]-5,6,10-(μ-H)3-10-H-7,8-C2B9H8 and bromine

International Nuclear Information System (INIS)

Timofeev, S.V.; Lobanova, I.A.; Petrovskij, P.V.; Starikova, Z.A.; Bregadze, V.I.

2001-01-01

Interaction between exo-nido-ruthenacarborane [Cl(Ph 3 P) 2 Ru]-5,6,10-(μ-H) 3 -10-H-7,8-C 2 B 9 H 8 with bromine in CH 2 Cl 2 solutions at 0 deg C studied using the methods of elementary analysis, NMR, IR spectroscopy and X-ray diffraction analysis. It was ascertained that the reaction gives rise to bromine atom substitution for chlorine atom in octahedral surrounding of ruthenium atom with formation of complex [Br(Ph 3 P) 2 Ru]-5,6,10-(μ-H) 3 -10-H-7,8-C 2 B 9 H 8 . The complex is crystallized in monoclinic crystal system with the following unit cell parameters a = 12.592 (1), b = 20.687 (2), c = 16.628 (2) A, β = 94.372 (3) deg, sp. gr. P2 1 /n, Z = 4. Coordination octahedron of ruthenium atom is formed by three hydrogen atoms bound with boron atoms in one triangular face of carborane, two phosphorus atoms and one bromine atom [ru

Effect of B-site cation stoichiometry on electrical fatigue of RuO2//Pb(ZrxTi1-x)O3//RuO2 capacitors

International Nuclear Information System (INIS)

Al-Shareef, H.N.; Tuttle, B.A.; Warren, W.L.; Headley, T.J.; Dimos, D.; Voigt, J.A.; Nasby, R.D.

1996-01-01

There have been numerous reports that Pb(Zr x Ti 1-x )O 3 (PZT) thin-film capacitors with RuO 2 electrodes and compositions near the morphotropic phase boundary exhibit minimal decrease in switched polarization with electric-field cycling. We show that the fatigue performance of RuO 2 //PZT//RuO 2 capacitors strongly depends on PZT film composition. Specifically, we demonstrate that the rate of polarization fatigue increases with increasing Ti content for PZT thin films of tetragonal crystal symmetry deposited on RuO 2 electrodes. As the Ti content of the PZT films increased, the film gain morphology changed from columnar to granular and the volume percent of a fluorite-type second phase decreased. These microstructural trends and the possibility that the electrode material acts as a sink for oxygen vacancies are discussed to explain the fatigue dependence on B-site cation ratio for PZT films with RuO 2 electrodes. copyright 1996 American Institute of Physics

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

International Nuclear Information System (INIS)

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.

CO-induced Pd segregation and the effect of subsurface Pd on CO adsorption on CuPd surfaces

International Nuclear Information System (INIS)

Padama, A A B; Villaos, R A B; Albia, J R; Diño, W A; Nakanishi, H; Kasai, H

2017-01-01

We report results of our study on the adsorption of CO on CuPd surfaces with bulk stoichiometric and nonstoichiometric layers using density functional theory (DFT). We found that the presence of Pd atoms in the subsurface layer promotes the adsorption of CO. We also observed CO-induced Pd segregation on the CuPd surface and we attribute this to the strong CO–Pd interaction. Lastly, we showed that the adsorption of CO promotes Pd–Pd interaction as compared to the pristine surface which promotes strong Cu–Pd interaction. These results indicate that CO adsorption on CuPd surfaces can be tuned by taking advantage of the CO-induced segregation and by considering the role of subsurface Pd atoms. (paper)

Basal cell carcinoma: PD-L1/PD-1 checkpoint expression and tumor regression after PD-1 blockade.

Science.gov (United States)

Lipson, Evan J; Lilo, Mohammed T; Ogurtsova, Aleksandra; Esandrio, Jessica; Xu, Haiying; Brothers, Patricia; Schollenberger, Megan; Sharfman, William H; Taube, Janis M

2017-01-01

Monoclonal antibodies that block immune regulatory proteins such as programmed death-1 (PD-1) have demonstrated remarkable efficacy in controlling the growth of multiple tumor types. Unresectable or metastatic basal cell carcinoma, however, has largely gone untested. Because PD-Ligand-1 (PD-L1) expression in other tumor types has been associated with response to anti-PD-1, we investigated the expression of PD-L1 and its association with PD-1 expression in the basal cell carcinoma tumor microenvironment. Among 40 basal cell carcinoma specimens, 9/40 (22%) demonstrated PD-L1 expression on tumor cells, and 33/40 (82%) demonstrated PD-L1 expression on tumor-infiltrating lymphocytes and associated macrophages. PD-L1 was observed in close geographic association to PD-1+ tumor infiltrating lymphocytes. Additionally, we present, here, the first report of an objective anti-tumor response to pembrolizumab (anti-PD-1) in a patient with metastatic PD-L1 (+) basal cell carcinoma, whose disease had previously progressed through hedgehog pathway-directed therapy. The patient remains in a partial response 14 months after initiation of therapy. Taken together, our findings provide a rationale for testing anti-PD-1 therapy in patients with advanced basal cell carcinoma, either as initial treatment or after acquired resistance to hedgehog pathway inhibition.

Selective Hydrogenation of Acrolein Over Pd Model Catalysts: Temperature and Particle-Size Effects.

Science.gov (United States)

O'Brien, Casey P; Dostert, Karl-Heinz; Schauermann, Swetlana; Freund, Hans-Joachim

2016-10-24

The selectivity in the hydrogenation of acrolein over Fe 3 O 4 -supported Pd nanoparticles has been investigated as a function of nanoparticle size in the 220-270 K temperature range. While Pd(111) shows nearly 100 % selectivity towards the desired hydrogenation of the C=O bond to produce propenol, Pd nanoparticles were found to be much less selective towards this product. In situ detection of surface species by using IR-reflection absorption spectroscopy shows that the selectivity towards propenol critically depends on the formation of an oxopropyl spectator species. While an overlayer of oxopropyl species is effectively formed on Pd(111) turning the surface highly selective for propenol formation, this process is strongly hindered on Pd nanoparticles by acrolein decomposition resulting in CO formation. We show that the extent of acrolein decomposition can be tuned by varying the particle size and the reaction temperature. As a result, significant production of propenol is observed over 12 nm Pd nanoparticles at 250 K, while smaller (4 and 7 nm) nanoparticles did not produce propenol at any of the temperatures investigated. The possible origin of particle-size dependence of propenol formation is discussed. This work demonstrates that the selectivity in the hydrogenation of acrolein is controlled by the relative rates of acrolein partial hydrogenation to oxopropyl surface species and of acrolein decomposition, which has significant implications for rational catalyst design. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Preparation of supported PtRu/C electrocatalyst for direct methanol fuel cells

International Nuclear Information System (INIS)

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

Thin RuO2 conducting films grown by MOCVD for microelectronic applications

International Nuclear Information System (INIS)

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)

Vibrationally enhanced associative photodesorption of H{sub 2} (D{sub 2}) from Ru(0001). Quantum and classical approaches

Energy Technology Data Exchange (ETDEWEB)

Vazhappilly, Tijo Joseph

2008-04-15

This thesis investigates the femtosecond laser induced associative photodesorption of hydrogen, H{sub 2}, and deuterium, D{sub 2}, from a ruthenium metal surface. One of the goals of the present thesis is to suggest, on the basis of theoretical simulations, strategies to control/enhance the photodesorption yield from Ru(0001). For this purpose, we suggest a hybrid scheme to control the reaction, where the adsorbate vibrations are initially excited by an infrared (IR) pulse, prior to the vis pulse. Both adiabatic and non-adiabatic representations for photoinduced desorption problems are employed here. The adiabatic representation is realized within the classical picture using Molecular Dynamics (MD) with electronic frictions. In a quantum mechanical description, non-adiabatic representations are employed within open-system density matrix theory. The time evolution of the desorption process is studied using a two-mode reduced dimensionality model with one vibrational coordinate and one translational coordinate of the adsorbate. The ground and excited electronic state potentials, and dipole function for the IR excitation are taken from first principles. The IR driven vibrational excitation of adsorbate modes with moderate efficiency is achieved by (modified) {pi}-pulses or/and optimal control theory. The fluence dependence of the desorption reaction is computed by including the electronic temperature of the metal calculated from the two-temperature model. We then employed the IR+vis strategy in both models. Here, we found that vibrational excitation indeed promotes the desorption of hydrogen and deuterium. (orig.)

Evidence for coexisting magnetic order in frustrated three-dimensional honeycomb iridates Li2IrO3

Science.gov (United States)

Breznay, Nicholas; Ruiz, Alejandro; Frano, Alex; Analytis, James

The search for unconventional magnetism has found a fertile hunting ground in 5d iridium oxide (iridate) materials. The competition between coulomb, spin-orbit, and crystal field energy scales in honeycomb iridates leads to a quantum magnetic system with localized spin-1/2 moments communicating through spin-anisotropic Kitaev exchange interactions. Although early and ongoing work has focused on layered two-dimensional honeycomb compounds such as Na2IrO3 and a 4d analog, RuCl3, recently discovered polytypes of Li2IrO3 take on three-dimensional honeycomb structures. Bulk thermodynamic studies, as well as recent resonant x-ray diffraction and absorption spectroscopy experiments, have uncovered a rich phase diagram for these three-dimensional honeycomb iridates. Low temperature incommensurate and commensurate magnetic orders can be stabilized by tuning the applied magnetic field, displaying a delicate coexistence that signals highly frustrated magnetism.

Laminated structure in internally oxidized Ru-Ta coatings

Energy Technology Data Exchange (ETDEWEB)

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.

Impaired Insulin Signaling is Associated with Hepatic Mitochondrial Dysfunction in IR+/−-IRS-1+/− Double Heterozygous (IR-IRS1dh Mice

Directory of Open Access Journals (Sweden)

Andras Franko

2017-05-01

Full Text Available Mitochondria play a pivotal role in energy metabolism, but whether insulin signaling per se could regulate mitochondrial function has not been identified yet. To investigate whether mitochondrial function is regulated by insulin signaling, we analyzed muscle and liver of insulin receptor (IR+/−-insulin receptor substrate-1 (IRS-1+/− double heterozygous (IR-IRS1dh mice, a well described model for insulin resistance. IR-IRS1dh mice were studied at the age of 6 and 12 months and glucose metabolism was determined by glucose and insulin tolerance tests. Mitochondrial enzyme activities, oxygen consumption, and membrane potential were assessed using spectrophotometric, respirometric, and proton motive force analysis, respectively. IR-IRS1dh mice showed elevated serum insulin levels. Hepatic mitochondrial oxygen consumption was reduced in IR-IRS1dh animals at 12 months of age. Furthermore, 6-month-old IR-IRS1dh mice demonstrated enhanced mitochondrial respiration in skeletal muscle, but a tendency of impaired glucose tolerance. On the other hand, 12-month-old IR-IRS1dh mice showed improved glucose tolerance, but normal muscle mitochondrial function. Our data revealed that deficiency in IR/IRS-1 resulted in normal or even elevated skeletal muscle, but impaired hepatic mitochondrial function, suggesting a direct cross-talk between insulin signaling and mitochondria in the liver.

Robust ultra-thin RuMo alloy film as a seedless Cu diffusion barrier

International Nuclear Information System (INIS)

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.

"Job-Sharing" Storage of Hydrogen in Ru/Li₂O Nanocomposites.

Science.gov (United States)

Fu, Lijun; Tang, Kun; Oh, Hyunchul; Manickam, Kandavel; Bräuniger, Thomas; Chandran, C Vinod; Menzel, Alexander; Hirscher, Michael; Samuelis, Dominik; Maier, Joachim

2015-06-10

A "job-sharing" hydrogen storage mechanism is proposed and experimentally investigated in Ru/Li2O nanocomposites in which H(+) is accommodated on the Li2O side, while H(-) or e(-) is stored on the side of Ru. Thermal desorption-mass spectroscopy results show that after loading with D2, Ru/Li2O exhibits an extra desorption peak, which is in contrast to Ru nanoparticles or ball-milled Li2O alone, indicating a synergistic hydrogen storage effect due to the presence of both phases. By varying the ratio of the two phases, it is shown that the effect increases monotonically with the area of the heterojunctions, indicating interface related hydrogen storage. X-ray diffraction, Fourier transform infrared spectroscopy, and nuclear magnetic resonance results show that a weak LiO···D bond is formed after loading in Ru/Li2O nanocomposites with D2. The storage-pressure curve seems to favor H(+)/H(-) over H(+)/e(-) mechanism.

Molecular mechanism of PD-1/PD-L1 blockade via anti-PD-L1 antibodies atezolizumab and durvalumab.

Science.gov (United States)

Lee, Hyun Tae; Lee, Ju Yeon; Lim, Heejin; Lee, Sang Hyung; Moon, Yu Jeong; Pyo, Hyo Jeong; Ryu, Seong Eon; Shin, Woori; Heo, Yong-Seok

2017-07-17

In 2016 and 2017, monoclonal antibodies targeting PD-L1, including atezolizumab, durvalumab, and avelumab, were approved by the FDA for the treatment of multiple advanced cancers. And many other anti-PD-L1 antibodies are under clinical trials. Recently, the crystal structures of PD-L1 in complex with BMS-936559 and avelumab have been determined, revealing details of the antigen-antibody interactions. However, it is still unknown how atezolizumab and durvalumab specifically recognize PD-L1, although this is important for investigating novel binding sites on PD-L1 targeted by other therapeutic antibodies for the design and improvement of anti-PD-L1 agents. Here, we report the crystal structures of PD-L1 in complex with atezolizumab and durvalumab to elucidate the precise epitopes involved and the structural basis for PD-1/PD-L1 blockade by these antibodies. A comprehensive comparison of PD-L1 interactions with anti-PD-L1 antibodies provides a better understanding of the mechanism of PD-L1 blockade as well as new insights into the rational design of improved anti-PD-L1 therapeutics.

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

International Nuclear Information System (INIS)

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)

Synthesis and thermoelectric properties of RuO2 nanorods

International Nuclear Information System (INIS)

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.

Solvent-Mediated Eco-Friendly Synthesis and Characterization of Monodispersed Bimetallic Ag/Pd Nano composites for Sensing and Raman Scattering Applications

International Nuclear Information System (INIS)

Sathiyadevi, G.; Loganathan, B.; Karthikeyan, B.; Karthikeyan, B.

2014-01-01

The solvent-mediated eco-friendly monodispersed Ag/Pd bimetallic nano composites (BNCs) having thick core and thin shell have been prepared through novel green chemical solvent reduction method. Reducing solvent, dimethyl formamide (DMF) is employed for the controlled green synthesis. Characterization of the synthesized Ag/Pd BNCs has been done by x-ray diffraction (XRD) studies, high-resolution scanning electron microscopy (HR-SEM), energy-dispersive X-ray analysis (EDX), and high-resolution transmission electron microscopy (HR-TEM) with selected area electron diffraction (SAED) pattern. The nature of the interaction of L-cysteine with Ag/Pd BNCs has been studied by using surface plasmon spectroscopy, Fourier transform-infrared spectroscopy (FT-IR), cyclic voltammetry (CV), and theoretical methods.

Shortcomings of the industrial quality assurance of {sup 106}Ru ophthalmic plaques; Therapierelevante Schwachstellen bei der industriellen Qualitaetssicherung von {sup 106}Ru-Augenapplikatoren

Energy Technology Data Exchange (ETDEWEB)

Kaulich, T.W.; Nuesslin, F. [Universitaetsklinik fuer Radioonkologie, Tuebingen (Germany). Abt. Medizinische Physik; Zurheide, J. [BrainLAB AG, Heimstetten (Germany); Fluehs, D. [Abt. Strahlentherapie, Bereich klinische Strahlenphysik, Universitaetsklinikum Essen (Germany); Haug, T. [Isotopenlabor der Univ. Tuebingen (Germany); Bamberg, M. [Abt. Radioonkologie, Universitaetsklinik fuer Radioonkologie, Tuebingen (Germany)

2001-11-01

Background: Beta emitting {sup 106}Ru applicators manufactured by Bebig GmbH (Berlin, Germany) are widely used to treat intraocular tumors. The applicators are fixed to the bulbus and removed after several days. The following therapy relevant defects have been detected by an internal clinical acceptance test: risk of leakage and inconsistent dose-rate specifications by the manufacturer. In the meantime, components of the internal clinical acceptance test have been adopted successfully by the manufacturer of the {sup 106}Ru ophthalmic plaques. Material and Method: {sup 106}Ru ophthalmic plaques were tested with the following internal clinical acceptance tests: visual inspection, surface contamination, leakage, and dose-rate verification. The surface contamination test consists of a wet wipe test at moderate pressure. For the leakage test of the {sup 106}Ru ophthalmic plaques a clinically relevant scenario was developed in which the contact of the applicator with human tissue is simulated. In the course of it the applicator is inserted into Ringer's solution for several days. The certified energy dose-rate statements of the manufacturer are examined with a 1 mm{sup 3} plastic scintillator for consistency. (orig.) [German] Hintergrund: {sup 106}Ru-Augenapplikatoren der Fa. Bebig (Berlin) werden zur strahlentherapeutischen Behandlung von intraokularen Tumoren eingesetzt. Die Applikatoren werden sklerakontaktierend am Bulbus fixiert und nach mehreren Tagen wieder entfernt. Durch eine klinikinterne Eingangspruefung wurden folgende therapierelevante Maengel bei den Augenapplikatoren entdeckt: mangelhafte Dichtheit und inkonsistente Dosisleistungsangaben des Herstellers. Ein Teil dieser klinikinternen Eingangspruefung wurde inzwischen vom Hersteller der {sup 106}Ru-Augenapplikatoren uebernommen und erfolgreich eingesetzt. Material und Methode: Es wurden {sup 106}Ru-Augenapplikatoren durch folgende klinikinterne Eingangspruefungen getestet: optische Inspektion

Estrogen and progesterone receptors in human decidua after RU486 treatment.

Science.gov (United States)

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.

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

DEFF Research Database (Denmark)

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...

Visible-light-assisted SLCs template synthesis of sea anemone-like Pd/PANI nanocomposites with high electrocatalytic activity for methane oxidation in acidic medium

Science.gov (United States)

Tan, De-Xin; Wang, Yan-Li

2018-03-01

Sea anemone-like palladium (Pd)/polyaniline (PANI) nanocomposites were synthesized via visible-light-assisted swollen liquid crystals (SLCs) template method. The resulting samples were characterized by transmission electron microscopy (TEM), selected area electron diffraction (SAED), energy dispersive spectrometer (EDS), x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), ultraviolet-visible (UV–vis) absorption spectroscopy and Fourier transform infrared (FT-IR) spectroscopy, respectively. The electrocatalytic properties of Pd/PANI nanocomposites modified glass carbon electrode (GCE) for methane oxidation were investigated by cycle voltammetry (CV) and chronoamperometry. Those dispersed sea anemone-like Pd/PANI nanocomposites had an average diameter of 320 nm. The obtained Pd nanoparticles with an average diameter of about 45 nm were uniformly distributed in PANI matrix. Sea anemone-like Pd/PANI nanocomposites exhibited excellent electrocatalytic activity and stability for oxidation of methane (CH4).

The electrocatalytic application of RuO2 in direct borohydride fuel cells

International Nuclear Information System (INIS)

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

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

International Nuclear Information System (INIS)

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

Direct evidence for double-exchange coupling in Ru- substituted La0.7Pb0.3Mn 1 - x Ru x O3, 0.0 <= x <= 0.4

Science.gov (United States)

Sundar Manoharan, S.; Sahu, R. K.; Rao, M. L.; Elefant, D.; Schneider, C. M.

2002-08-01

The La0.7Pb0.3Mn 1 - x Ru x O3 (0.0 innate relationship between Mn and Ru ions by a unique double-exchange mediated transport behavior. This is exonerated by the coexistence of Tp and Tc (range 330 K 245 K for 0.0 30%, the hole carrier mass influences the transport property. X-ray absorption spectra suggest that the Tc-Tp match is due to the transport mediated by the Mn3+/Mn4+ leftrightarrow Ru4+/Ru5+ redox pair and also due to the broad low-spin Ru:4d conduction band. For x > 0.2, T < 0.5Tc obeys a modified variable-range hopping model, where kT0 propto (M/Ms)2, suggesting a random magnetic potential which localizes the charge carriers.

Transfer from soil to plants of 106Ru as nitrosyl and as chloride

International Nuclear Information System (INIS)

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

Enhanced thermal stability of RuO2/polyimide interface for flexible device applications

Science.gov (United States)

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.

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

Indian Academy of Sciences (India)

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 ...

Size dependent reactivity of metal nanoparticles and alloys supported on HOPG, probed by the H-D exchange and the NH3 decomposition reactions

DEFF Research Database (Denmark)

Fiordaliso, Elisabetta Maria

this investigation have been summarized in a scientific article which has been submitted to the Journal of Physical Chemistry. The second reaction investigated in this thesis is the NH3 decomposition reaction, relevant for hydrogen storage and production in a COx free environment, which has been performed on Ru, Ir......, Rh and Pt thin films, on Ru nanoparticles and on Ir/Ru alloys. Preliminary results indicated that Ru is the most active among the selected metals, but no definitive conclusions can be drawn on the effect of the particle diameter on the decomposition rate. In the case of the Ru/Ir alloys, it is found...

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

International Nuclear Information System (INIS)

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

Mesoporous Pt and Pt/Ru alloy electrocatalysts for methanol oxidation

Energy Technology Data Exchange (ETDEWEB)

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)

Fingerprint elements scatter analysis on ancient chinese Ru porcelains samples

International Nuclear Information System (INIS)

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

O2-enhanced methanol oxidation reaction at novel Pt-Ru-C co-sputtered electrodes

International Nuclear Information System (INIS)

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

Removal of emerging pollutants by Ru/TiO2-catalyzed permanganate oxidation.

Science.gov (United States)

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.

Anti-tumor immunotherapy by blockade of the PD-1/PD-L1 pathway with recombinant human PD-1-IgV.

Science.gov (United States)

Zhang, C; Wu, S; Xue, X; Li, M; Qin, X; Li, W; Han, W; Zhang, Y

2008-01-01

Blockade of the programmed death-1 (PD-1)/PD-ligand 1 (PD-L1) pathway can delay tumor growth and prolong the survival of tumor-bearing mice. The extracellular immunoglobulin (Ig) V domain of PD-1 is important for the interaction between PD-1 and PD-L1, suggesting that PD-1-IgV may be a potential target for anti-tumor immunotherapy. The extracellular sequence of human PD-1-IgV (hPD-1-IgV) was expressed in Escherichia coli and purified. The anti-tumor effect of hPD-1-IgV on tumor-bearing mice was tested. hPD-1-IgV recombinant protein could bind PD-L1 at molecular and cellular levels and enhance Cytotoxic T Lymphocyte (CTL) activity and anti-tumor effect on tumor-bearing mice in vivo. The percentage of CD4(+)CD25(+) T cells in tumor-bearing mice was decreased compared with control mice after administration of the recombinant protein. Our results suggest that inhibition of the interaction between PD-1 and PD-L1 by hPD-1-IgV may be a promising strategy for specific tumor immunotherapy.

Core-level binding energy shifts in Pt Ru nanoparticles: A puzzle resolved

Science.gov (United States)

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.

RU fuel development program for an advanced fuel cycle in Korea

International Nuclear Information System (INIS)

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

Ru (amp)(bipy)Cl

Indian Academy of Sciences (India)

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.

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

Science.gov (United States)

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.

Radiolytic synthesis of carbon-supported PtRu nanoparticles using high-energy electron beam: effect of pH control on the PtRu mixing state and the methanol oxidation activity

International Nuclear Information System (INIS)

Ohkubo, Yuji; Kageyama, Satoru; Seino, Satoshi; Nakagawa, Takashi; Kugai, Junichiro; Nitani, Hiroaki; Ueno, Koji; Yamamoto, Takao A.

2013-01-01

Electrode catalysts composed of carbon-supported PtRu nanoparticles (PtRu/C) for use as a direct methanol fuel cell anode were synthesized by the reduction of precursor ions in an aqueous solution via irradiation with a high-energy electron beam. The effect of pH control in the precursor solution on the PtRu mixing state and the methanol oxidation activity was studied in order to enhance the catalytic activity for methanol oxidation. The PtRu/C structures were characterized by transmission electron microscopy, inductively coupled plasma atomic emission spectrometry, X-ray fluorescence spectrometry, and X-ray diffraction and X-ray absorption fine structure techniques. The methanol oxidation activity was evaluated by linear sweep voltammetry. The initial pH of the precursor solution has little influence on the average grain size for the metal particles (approximately 3.5 nm) on the carbon particle supports, but the dispersibility of the metal particles, PtRu mixing state, and methanol oxidation activity differed. The maintenance of a low pH in the precursor solution gave the best dispersibility of the PtRu nanoparticles supported on the surface of the carbon particles, whereas, a high pH gave the best PtRu mixing state and the highest oxidation current although a low dispersibility of the PtRu nanoparticles supported on the surface of the carbon particles was obtained. The PtRu mixing state strongly correlated with the methanol oxidation current. In addition, a high pH was more effective for PtRu mixing when using an electron beam irradiation reduction method, because the complexation reaction of the chelating agents was improved, which resulted in an enhancement of the catalytic activity for methanol oxidation.

Radiolytic synthesis of carbon-supported PtRu nanoparticles using high-energy electron beam: effect of pH control on the PtRu mixing state and the methanol oxidation activity

Energy Technology Data Exchange (ETDEWEB)

Ohkubo, Yuji, E-mail: okubo@mit.eng.osaka-u.ac.jp; Kageyama, Satoru; Seino, Satoshi; Nakagawa, Takashi; Kugai, Junichiro [Osaka University, Graduate School of Engineering (Japan); Nitani, Hiroaki [High Energy Accelerator Research Organization (KEK), Institute of Materials Structure Science (Japan); Ueno, Koji [Japan Electron Beam Irradiation Service Ltd (Japan); Yamamoto, Takao A. [Osaka University, Graduate School of Engineering (Japan)

2013-05-15

Electrode catalysts composed of carbon-supported PtRu nanoparticles (PtRu/C) for use as a direct methanol fuel cell anode were synthesized by the reduction of precursor ions in an aqueous solution via irradiation with a high-energy electron beam. The effect of pH control in the precursor solution on the PtRu mixing state and the methanol oxidation activity was studied in order to enhance the catalytic activity for methanol oxidation. The PtRu/C structures were characterized by transmission electron microscopy, inductively coupled plasma atomic emission spectrometry, X-ray fluorescence spectrometry, and X-ray diffraction and X-ray absorption fine structure techniques. The methanol oxidation activity was evaluated by linear sweep voltammetry. The initial pH of the precursor solution has little influence on the average grain size for the metal particles (approximately 3.5 nm) on the carbon particle supports, but the dispersibility of the metal particles, PtRu mixing state, and methanol oxidation activity differed. The maintenance of a low pH in the precursor solution gave the best dispersibility of the PtRu nanoparticles supported on the surface of the carbon particles, whereas, a high pH gave the best PtRu mixing state and the highest oxidation current although a low dispersibility of the PtRu nanoparticles supported on the surface of the carbon particles was obtained. The PtRu mixing state strongly correlated with the methanol oxidation current. In addition, a high pH was more effective for PtRu mixing when using an electron beam irradiation reduction method, because the complexation reaction of the chelating agents was improved, which resulted in an enhancement of the catalytic activity for methanol oxidation.

Interaction of cis-[Ru(DMSO)4Cl2] with acetate-ion in solutions

International Nuclear Information System (INIS)

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

Effects of composition on structure and activity of PtRu/C catalysts.

Science.gov (United States)

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.

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

International Nuclear Information System (INIS)

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.

Synthesis, characterization and thermal properties of palladium(II complexes containing phenyltetrazole. Crystal structure of trans-[C40H64N8 O2PdCl2

Directory of Open Access Journals (Sweden)

Gallardo Hugo

2000-01-01

Full Text Available The new 5-(n-alkoxyphenyl-2-n-alkyltetrazole (L¹ and alpha,omega-bis-[5-(4-pentoxyphenyl-2-alkanetetrazoles] (L² ligands and their Pd(II complexes have been synthesized. The X-ray diffraction study of the palladium complex with L¹ reveals a mononuclear structure in which the geometry of the Pd(L¹2Cl2 chromophore is planar as required by the inversion center at the palladium atom, where each molecule of phenyltetrazole binds to the metal ion in a monodentate fashion via a Pd-N1 sigma-bond. For the palladium complex with L², a dinuclear structure ([Pd2(L²2Cl4 ] has been proposed on the basis of NMR and IR spectroscopy.

Carbon monoxide oxidation on a Au(111 surface modified by spontaneously deposited Ru

Directory of Open Access Journals (Sweden)

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.

Adsorption of RuSex (x =1–5) cluster on Se-doped graphene: First principle calculations

International Nuclear Information System (INIS)

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

Study the Polyol Process of Preparing the ru Doped FePt Nanoparticles

Science.gov (United States)

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.

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

International Nuclear Information System (INIS)

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

Iridates and RuCl3 - from Heisenberg antiferromagnets to potential Kitaev spin-liquids

Science.gov (United States)

van den Brink, Jeroen

The observed richness of topological states on the single-electron level prompts the question what kind of topological phases can develop in more strongly correlated, many-body electron systems. Correlation effects, in particular intra- and inter-orbital electron-electron interactions, are very substantial in 3 d transition-metal compounds such as the copper oxides, but the spin-orbit coupling (SOC) is weak. In 5 d transition-metal compounds such as iridates, the interesting situation arises that the SOC and Coulomb interactions meet on the same energy scale. The electronic structure of iridates thus depends on a strong competition between the electronic hopping amplitudes, local energy-level splittings, electron-electron interaction strengths, and the SOC of the Ir 5d electrons. The interplay of these ingredients offers the potential to stabilise relatively well-understood states such as a 2D Heisenberg-like antiferromagnet in Sr2IrO4, but in principle also far more exotic ones, such a topological Kitaev quantum spin liquid, in (hyper)honeycomb iridates. I will discuss the microscopic electronic structures of these iridates, their proximity to idealized Heisenberg and Kitaev models and our contributions to establishing the physical factors that appear to have preempted the realization of quantum spin liquid phases so far and include a discussion on the 4d transition metal chloride RuCl3. Supported by SFB 1143 of the Deutsche Forschungsgemeinschaft.

Titrimetric determination of ruthenium

International Nuclear Information System (INIS)

Velichko, V.V.; Belyaeva, T.I.; Kudinova, V.K.; Usatenko, Yu.I.

1978-01-01

Titration of ruthenium(4) hydrochloric-acid solutions with Mohr's salt, hydroquinone, and thiourea has been studied with the use of biampero- and potentiometric indication of the titration end point (t.e.p.) Potentiometric and amperometric indication of the t.e.p. is applicable when Ru(4) concentration is from 20 to 6000 mkg in 20 ml of the titrated solution; biamperometric indication can be used at a concentration of 5-1000 mkg in the same volume. It has been established that titration of Ru(4) (in the form of the Na 2 RuCl 6 solution) with Mohr's salt is not hindered by the presence of 1000-fold excess of alkaline and alkali-earth metals, Al, Ti(4), Mn(2), Cr(3), Fe(3), Co, Ni, Cu, Zn, Ga, Ge(4), As, Se, Mo(6), Cd, In, and Te; 100-fold excess of Rh, Pd, W, Bi, and Sn; 10-fold excess of Ag, Au, Pt, Hg, Os. Along with Ru(4) titrated are Ir(4), Te(3), V(5), and Ce(4). Selectivity of hydroquinone and thiourea is lower. Titrimetric procedure of determining ruthenium has been tested for ruthenium alloy containing cobalt tungsten. It cannot be recommended for analysis of the samples which dissolve in aqua regia

Hydrothermal Synthesis of Co-Ru Alloy Particle Catalysts for Hydrogen Generation from Sodium Borohydride

Directory of Open Access Journals (Sweden)

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.

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

International Nuclear Information System (INIS)

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

A new Kaempferol-based Ru(II) coordination complex, Ru(kaem)Cl(DMSO)3: Structure and absorption-emission spectroscopy study

International Nuclear Information System (INIS)

Shao, Ming Wei; Gang, Jong Back; Kim, Sang Ho; Yoon, Min Young

2016-01-01

Recent interest in developing a new anticancer drug with low side effects has led to the study of the combination of two new anticancer drugs. Although both kaempferol (kaem) and Ru-based metal complexes have not been proven as effective drugs, their unique anticancer activities with reduced side effects have drawn our attention to the need for further studies on their potential in anticancer application. Herein, we report the synthesis, characterization, structure, and spectroscopic properties of a kaem-based Ru (II) complex, RuCl(kaem)(DMSO) 3 (1). Because of the presence of a catechol-like functional group in its dihydropyran ring, kaem can strongly bind to the Ru(II) metal center in a basic medium. The molecular structure of the complex was characterized by spectroscopic studies and X-ray crystal structure analysis. In addition, the complex forms a molecular dimer as a result of the cooperative effect of H-bonding and π–π stacking interactions. Moreover, the molecular dimer forms a ladder-like one-dimensional network structure by water mediated H-bonding that further extended into a three-dimensional packing structure. UV–Vis spectroscopy studies of the complex demonstrated the appearance of a strong metal to ligand charge transfer (MLCT) band in the visible region with strong fluorescence emission derived from the MLCT. Further studies are now in progress to demonstrate synergetic anticancer activity

Methanol oxidation at carbon paste electrodes modified with (Pt–Ru)/carbon aerogels nanocomposites

Energy Technology Data Exchange (ETDEWEB)

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

Local structure distortion induced by Ti dopants boosting the pseudocapacitance of RuO2-based supercapacitors

Science.gov (United States)

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

Dynamical spin structure factors of α-RuCl3

Science.gov (United States)

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.

Inter-taxa differences in root uptake of 103/106Ru by plants

International Nuclear Information System (INIS)

Willey, N.J.; Fawcett, K.

2006-01-01

Ruthenium-106 is of potential radioecological importance but soil-to-plant Transfer Factors for it are available only for few plant species. A Residual Maximum Likelihood (REML) procedure was used to construct a database of relative 103/106 Ru concentrations in 114 species of flowering plants including 106 species from experiments and 12 species from the literature (with 4 species in both). An Analysis of Variance (ANOVA), coded using a recent phylogeny for flowering plants, was used to identify a significant phylogenetic effect on relative mean 103/106 Ru concentrations in flowering plants. There were differences of 2465-fold in the concentration to which plant species took up 103/106 Ru. Thirty-nine percent of the variance in inter-species differences could be ascribed to the taxonomic level of Order or above. Plants in the Orders Geraniales and Asterales had notably high uptake of 103/106 Ru compared to other plant groups. Plants on the Commelinoid monocot clades, and especially the Poaceae, had notably low uptake of 103/106 Ru. These data demonstrate that plant species are not independent units for 103/106 Ru concentrations but are linked through phylogeny. It is concluded that models of soil-to-plant transfer of 103/106 Ru should assume that; neither soil variables alone affect transfer nor plant species are independent units, and taking account of plant phylogeny might aid predictions of soil-to-plant transfer of 103/106 Ru, especially for species for which Transfer Factors are not available

Selective separation of long-lived fission products in nuclear spent fuel

International Nuclear Information System (INIS)

Ozawa, Masaki; Ikegami, Tetsuo; Asakura, Toshihide; Morita, Yasuji

2003-01-01

A catalytic electrolytic extraction (CEE) method has been studied to separate rare metal fission products (Pd, Ru, Rh, Tc, Te and Se). Some of them are long-lived radioactive, but are potentially strategic materials. In CEE process, Pd 2+ cation itself would not only be easily deposited from various nitric acid solutions but also enhance the deposition of RuNO 3+ and ReO 4 by acting as Pd adatom . Monte than 99% of the recovery ratio was attained for RuNo 3+ and Pd 2+ . Fundamental radio-electrochemical property of FPs/TRU in the synthetic and real dissolver solution is being investigated in the new JAERI-JNC collaboration frame. For the extended recycling of such FPs (including Cs/Sr), new precedent research programs are on-going involving universities. (author)

RuO2 pH Sensor with Super-Glue-Inspired Reference Electrode

OpenAIRE

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...

High-throughput screening of small-molecule adsorption in MOF-74

Science.gov (United States)

Thonhauser, T.; Canepa, P.

2014-03-01

Using high-throughput screening coupled with state-of-the-art van der Waals density functional theory, we investigate the adsorption properties of four important molecules, H2, CO2, CH4, and H2O in MOF-74-  with  = Be, Mg, Al, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Zr, Nb, Ru, Rh, Pd, La, W, Os, Ir, and Pt. We show that high-throughput techniques can aid in speeding up the development and refinement of effective materials for hydrogen storage, carbon capture, and gas separation. The exploration of the configurational adsorption space allows us to extract crucial information concerning, for example, the competition of water with CO2 for the adsorption binding sites. We find that only a few noble metals--Rh, Pd, Os, Ir, and Pt--favor the adsorption of CO2 and hence are potential candidates for effective carbon-capture materials. Our findings further reveal significant differences in the binding characteristics of H2, CO2, CH4, and H2O within the MOF structure, indicating that molecular blends can be successfully separated by these nano-porous materials. Supported by DOE DE-FG02-08ER46491.

Kinetic study of methanol oxidation on carbon-supported PtRu electrocatalyst

International Nuclear Information System (INIS)

Gojkovic, S.Lj.; Vidakovic, T.R.; Durovic, D.R.

2003-01-01

Methanol electrooxidation was investigated on the carbon-supported PtRu electrocatalyst (1:1 atomic ratio) in acid media. X-ray diffraction measurement indicated alloying of Pt and Ru. Cyclic voltammetry of the sample reflects the amount of Ru in the catalyst and its ability to adsorb OH radicals. Tafel plots for the oxidation of 0.02-3 M methanol in the solutions containing 0.05-1 M HClO 4 and in the temperature range 27-40 deg. C showed reasonably well-defined linear region with the slope of about 115 mV dec -1 at the low currents, irrespective of the experimental conditions employed. Reaction order with respect to methanol was found to be 0.5. A correlation between methanol oxidation rate and pseudocapacitive current of OH adsorption on Ru sites was established. It was proposed that bifunctional mechanism is operative with the reaction between methanol residues adsorbed on Pt sites and OH radicals adsorbed on Ru sites as the rate-determining step

Supraconductivity of TR-Ru3Si2 compounds (TR = La, Ce)

International Nuclear Information System (INIS)

Godart, C.; Gupta, L.C.; Parks, R.D.; Rauschwalbe, U.; Alheim, U.; Gottwick, U.; Lieke, W.; Steglich, F.

1984-01-01

A new family of superconducting ternary silicides MRu 3 Si 2 with M = La (Tsub(s) approximately 7 K), Y and Th was discovered by Barz and Vandenberg. Same compounds with M from Nd to Tm are magnetic and not superconductors. We studied superconductivity in the solid solution Cesub(1-x)Lasub(x)Ru 3 Si 2 of hexagonal structure from x = 0 to 1. CeRu 3 Si 2 is type II superconductor (Tsub(s) approximately 1 K), like LaRu 3 Si 2 , and is mixed valent (M.V.). Spin fluctuations temperature (Tsub(sf) approximately 440 K) is between these of non superconducting M.V. like CeSn 3 (Tsub(sf) approximately 270) and these of superconducting M.V. like CeRu 2 (Tsub(sf) approximately 770 K). Cesub(1-x)Lasub(x)Ru 3 Si 2 is the first M.V. system of Ce which is superconductor from x = 0 to 1 [fr

Methanol resistant ruthenium electrocatalysts for oxygen reduction synthesized by pyrolysis of Ru{sub 3}(CO){sub 12} in different atmospheres

Energy Technology Data Exchange (ETDEWEB)

Altamirano-Gutierrez, A.; Jimenez-Sandoval, O.; Uribe-Godinez, J.; Borja-Arco, E. [Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional (Cinvestav), Unidad Queretaro, Apartado Postal 1-798, Queretaro, Qro. 76001 (Mexico); Castellanos, R.H. [Universidad del Papaloapan, Campus Tuxtepec, Circuito Central No. 200, Col. Parque Industrial, Tuxtepec, Oax. 68301 (Mexico); Olivares-Ramirez, J.M. [Universidad Tecnologica de San Juan del Rio, Av. La Palma No. 125, Col. Vista Hermosa, San Juan del Rio, Qro. 76800 (Mexico)

2009-10-15

Novel ruthenium electrocatalysts for the oxygen reduction reaction (ORR) were prepared by pyrolysis of Ru{sub 3}(CO){sub 12} in three atmospheres: neutral (N{sub 2}), partially oxidative (air) and partially reductive (70:30 N{sub 2}/H{sub 2}), at temperatures in the 80-700 C range. The materials were characterized by FT-IR spectroscopy, X-ray diffraction and scanning electron microscopy. A thermogravimetric analysis of the Ru{sub 3}(CO){sub 12} precursor in the three atmospheres was also performed. The electrocatalytic properties of the materials were evaluated by rotating disk electrode measurements in 0.5 mol L{sup -1} H{sub 2}SO{sub 4}. The kinetic parameters, such as the Tafel slope, exchange current density and charge transfer coefficient, are reported. The catalysts prepared in N{sub 2} and N{sub 2}/H{sub 2}, in general, show a higher performance than those synthesized in air. In the two nitrogen containing atmospheres, a pyrolysis temperature of 360 C seems to lead to better electrocatalytic properties for the ORR. The new electrocatalysts are also tolerant to methanol concentrations as high as 2.0 mol L{sup -1}. (author)

Triaxial shapes in the ground states of even-even neutron-rich Ru isotopes

Energy Technology Data Exchange (ETDEWEB)

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.

Supercapacitive performance of hydrous ruthenium oxide (RuO2 ...

Indian Academy of Sciences (India)

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 ...

Spray pyrolysed Ru:TiO2 thin film electrodes prepared for electrochemical supercapacitor

Science.gov (United States)

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.

Bibliotekāru loma bibliotēkas un bibliotekāra tēla veidošanā Tīmekļa 2.0 resursos

OpenAIRE

Moskina, Viktorija

2010-01-01

Tīmeklis 2.0 sniedz lielākas iespējas nekā vienkārši meklēt, lasīt un pārvietoties informācijas telpā. Tas ir interaktīvs: virtuālās sarunas, personalizācija, individuālisms. Uzsvars uz cilvēku mijiedarbību raksturo Tīmekli 2.0 kā izteikti sociālu tīmekli, kurš pirmajā plāna izvirza indivīdu prasmi socializēties. Pētījuma mērķis ir noskaidrot, cik veiksmīgi bibliotekāri tiek galā ar bibliotēkas un bibliotekāru tēla veidošanu Tīmekļa 2.0 resursos un sniegt ieteikumus Latvijas bibliotekārie...

Soft magnetic properties of FeRuGaSi alloy films: SOFMAX

International Nuclear Information System (INIS)

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

Band structure of metallic pyrochlore ruthenates Bi2Ru2O7 and Pb2Ru2O/sub 6.5/

International Nuclear Information System (INIS)

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