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Sample records for ruthenium acetate ru3oac6

  1. Acetic Acid Formation by Selective Aerobic Oxidation of Aqueous Ethanol over Heterogeneous Ruthenium Catalysts

    DEFF Research Database (Denmark)

    Gorbanev, Yury; Kegnæs, Søren; Hanning, Christopher William

    2012-01-01

    Heterogeneous catalyst systems comprising ruthenium hydroxide supported on different carrier materials, titania, alumina, ceria, and spinel (MgAl2O4), were applied in selective aerobic oxidation ethanol to form acetic acid, an important bulk chemical and food ingredient. The catalysts were...

  2. Highly dispersed supported ruthenium oxide as an aerobic catalyst for acetic acid synthesis

    DEFF Research Database (Denmark)

    Laursen, Anders Bo; Gorbanev, Yury; Cavalca, Filippo

    2012-01-01

    The increasing need for shifting to renewable feedstocks in the chemical industry has driven research toward using green aerobic, selective oxidation reactions to produce bulk chemicals. Here, we report the use of a ruthenium mixed oxide/hydroxide (RuOx) on different support materials for the sel...

  3. Ruthenium recovery from acetic acid industrial effluent using chemically stable and high-performance polyethylenimine-coated polysulfone-Escherichia coli biomass composite fibers

    International Nuclear Information System (INIS)

    Kim, Sok; Choi, Yoon-E; Yun, Yeoung-Sang

    2016-01-01

    Highlights: • The PEI-PSBF was fabricated and used for Ru recovery from industrial effluent. • PEI-PSBF was not swollen nor dissolved in the effluent. • PEI-PSBF showed superior sorption capacity to commercial resins. • Thin fiber type PEI-PSBF could be successfully applied in flow-through column. - Abstract: Recovery of precious metal ions from waste effluents is of high concern. In general, ruthenium (Ru) is used in the Cativa process as promoter for carbonylation catalyst and discharged into acetic acid effluent. In the present work, we have designed and developed polyethylenimine-coated polysulfone-bacterial biomass composite fiber (PEI-PSBF) to recover Ru from industrial effluent. The sorbent was manufactured by electrostatic attachment of polyethylenimine (PEI) to the surface of polysulfone-biomass composite fiber (PSBF), which was prepared through spinning of the mixture of polysulfone and Escherichia coli biomass in N,N-dimethylformamide (DMF) into water. Developed PEI-PSBF was highly stable in the acetic acid effluent. The maximum sorption capacity of the developed sorbent PEI-PSBF, coated with PEI (with M.W. of 75,000), was 121.28 ± 13.15 mg/g, which was much higher than those of ion exchange resins, TP214, Amberjet 4200, and M500. The PEI-PSBF could be successfully applied in the flow-through column system, showing 120 beds of breakthrough volume.

  4. Ruthenium recovery from acetic acid industrial effluent using chemically stable and high-performance polyethylenimine-coated polysulfone-Escherichia coli biomass composite fibers

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sok [Division of Environmental Science and Ecological Engineering, College of Life Sciences and Biotechnology, Korea University, Seoul 02841 (Korea, Republic of); Division of Semiconductor and Chemical Engineering, Chonbuk National University, Jeonbuk 54896 (Korea, Republic of); Choi, Yoon-E, E-mail: yechoi@korea.ac.kr [Division of Environmental Science and Ecological Engineering, College of Life Sciences and Biotechnology, Korea University, Seoul 02841 (Korea, Republic of); Yun, Yeoung-Sang, E-mail: ysyun@jbnu.ac.kr [Division of Semiconductor and Chemical Engineering, Chonbuk National University, Jeonbuk 54896 (Korea, Republic of); Department of Bioprocess Engineering, Chonbuk National University, Jeonbuk 54896 (Korea, Republic of)

    2016-08-05

    Highlights: • The PEI-PSBF was fabricated and used for Ru recovery from industrial effluent. • PEI-PSBF was not swollen nor dissolved in the effluent. • PEI-PSBF showed superior sorption capacity to commercial resins. • Thin fiber type PEI-PSBF could be successfully applied in flow-through column. - Abstract: Recovery of precious metal ions from waste effluents is of high concern. In general, ruthenium (Ru) is used in the Cativa process as promoter for carbonylation catalyst and discharged into acetic acid effluent. In the present work, we have designed and developed polyethylenimine-coated polysulfone-bacterial biomass composite fiber (PEI-PSBF) to recover Ru from industrial effluent. The sorbent was manufactured by electrostatic attachment of polyethylenimine (PEI) to the surface of polysulfone-biomass composite fiber (PSBF), which was prepared through spinning of the mixture of polysulfone and Escherichia coli biomass in N,N-dimethylformamide (DMF) into water. Developed PEI-PSBF was highly stable in the acetic acid effluent. The maximum sorption capacity of the developed sorbent PEI-PSBF, coated with PEI (with M.W. of 75,000), was 121.28 ± 13.15 mg/g, which was much higher than those of ion exchange resins, TP214, Amberjet 4200, and M500. The PEI-PSBF could be successfully applied in the flow-through column system, showing 120 beds of breakthrough volume.

  5. Ruthenium and Platinum Catalysts Supported on Ce, Zr, Pr-O Mixed Oxides Prepared by Soft Chemistry for Acetic Acid Wet Air Oxidation

    Czech Academy of Sciences Publication Activity Database

    Mikulová, Jana; Rossignol, S.; Barbier Jr., J.; Mesnard, D.; Kappenstein, C.; Duprez, D.

    2007-01-01

    Roč. 72, 1-2 (2007), s. 1-10 ISSN 0926-3373 Institutional research plan: CEZ:AV0Z40720504 Keywords : sol-gel * catalytic wet air oxidation * acetic acid Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 4.651, year: 2007

  6. Mechanistic Insights on C-O and C-C Bond Activation and Hydrogen Insertion during Acetic Acid Hydrogenation Catalyzed by Ruthenium Clusters in Aqueous Medium

    Energy Technology Data Exchange (ETDEWEB)

    Shangguan, Junnan; Olarte, Mariefel V.; Chin, Ya-Huei [Cathy

    2016-06-07

    Catalytic pathways for acetic acid (CH3COOH) and hydrogen (H2) reactions on dispersed Ru clusters in the aqueous medium and the associated kinetic requirements for C-O and C-C bond cleavages and hydrogen insertion are established from rate and isotopic assessments. CH3COOH reacts with H2 in steps that either retain its carbon backbone and lead to ethanol, ethyl acetate, and ethane (47-95 %, 1-23 %, and 2-17 % carbon selectivities, respectively) or break its C-C bond and form methane (1-43 % carbon selectivities) at moderate temperatures (413-523 K) and H2 pressures (10-60 bar, 298 K). Initial CH3COOH activation is the kinetically relevant step, during which CH3C(O)-OH bond cleaves on a metal site pair at Ru cluster surfaces nearly saturated with adsorbed hydroxyl (OH*) and acetate (CH3COO*) intermediates, forming an adsorbed acetyl (CH3CO*) and hydroxyl (OH*) species. Acetic acid turnover rates increase proportionally with both H2 (10-60 bar) and CH3COOH concentrations at low CH3COOH concentrations (<0.83 M), but decrease from first to zero order as the CH3COOH concentration and the CH3COO* coverages increase and the vacant Ru sites concomitantly decrease. Beyond the initial CH3C(O)-OH bond activation, sequential H-insertions on the surface acetyl species (CH3CO*) lead to C2 products and their derivative (ethanol, ethane, and ethyl acetate) and the competitive C-C bond cleavage of CH3CO* causes the eventual methane formation. The instantaneous carbon selectivities towards C2 species (ethanol, ethane, and ethyl acetate) increase linearly with the concentration of proton-type Hδ+ (derived from carboxylic acid dissociation) and chemisorbed H*. The selectivities towards C2 products decrease with increasing temperature, because of higher observed barriers for C-C bond cleavage than H-insertion. This study offers an interpretation of mechanism and energetics and provides kinetic evidence of carboxylic acid assisted proton-type hydrogen (Hδ+) shuffling during H

  7. Radiochemistry of ruthenium

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, W W; Metcalf, S G; Barney, G S

    1984-06-01

    Information on ruthenium is presented. Topics include the following; isotopes and nuclear properties of ruthenium; review of the chemistry of ruthenium including metal and alloys, compounds of ruthenium, and solution chemistry; separation methods including volatilization of RuO{sub 4}, precipitation and coprecipitation, solvent extraction, chromatographic techniques, and analysis for radioruthenium. 445 refs., 7 figs., 23 tabs.

  8. Radiochemistry of ruthenium

    International Nuclear Information System (INIS)

    Schulz, W.W.; Metcalf, S.G.; Barney, G.S.

    1984-01-01

    Information on ruthenium is presented. Topics include the following; isotopes and nuclear properties of ruthenium; review of the chemistry of ruthenium including metal and alloys, compounds of ruthenium, and solution chemistry; separation methods including volatilization of RuO 4 , precipitation and coprecipitation, solvent extraction, chromatographic techniques, and analysis for radioruthenium. 445 refs., 7 figs., 23 tabs

  9. Extraction-spectrophotometric study of ruthenium (4) and osmium (4,8) reaction with 2-mercaptobenzimidazole, 2-mercaptobenzoxazole and 2-mercaptobenzothiazole in acetate buffer solutions

    Energy Technology Data Exchange (ETDEWEB)

    Lomakina, L N; Ignat' eva, T I; Busev, A I [Moskovskij Gosudarstvennyj Univ. (USSR)

    1978-03-01

    The complex formation of Ru(4) and Os(4, 8) with 2-mercaptobenzimidazole (MBI), 2-mercaptobenzoxazole (MBO) and 2-mercaptobenzothiazole (MBT) has been studied spectrophotometrically in acetate buffer solutions. As it has been shown earlier, Os and Ru react with the reagents in the oxidation state of three . Compound polinuclear structures of Ru and Os with MBI and MBO are suggested. A spectrophotometric procedure has been developed of determining Ru and Os (>=10/sup -4/%) with MBO in natural and industrial materials after selective absorption of the tetraoxides during distillation.

  10. Polarographic determination of ruthenium

    International Nuclear Information System (INIS)

    Li Jifu; Duan Shirong; Wu Xi

    1989-01-01

    It is suggested to use 0.5 mol/l HClO 4 -0.5 mol/l NaNO 3 -0.1 mol/l NaClO 4 as supporting electrolyte for determining ruthenium. In the supporting electrolyte there is a clear polarographic wave of ruthenium (IV) at -0.8 V vs. SCE. The wave height of ruthenium(IV) is linear in the range from 0.1 to 0.4 μg. ml -1 . The effect of the component of supporting electroylte and the other ion in the samples on the measurement of ruthenium are studied. The analysis methods for measuring ruthenium in both acidic or basic imitative radioactive waste solutions which is used in study of glass solidification are worked out. Imitative samples are analysised

  11. Synthesis of ruthenium phosphides

    International Nuclear Information System (INIS)

    Chernogorenko, V.B.; Lynchak, K.A.; Kulik, L.Ya.; Shkaravskij, Yu.F.; Klochkov, L.A.

    1977-01-01

    A method of ampoule synthesis of ruthenium phosphides, Ru 2 P, RuP, and RuP 2 , with stepwise heating of stoichimetric charges in a single-zone furnace is developed. A method for synthesizing ruthenium diphosphide by phosphidization of a ruthenium powder with phosphine at 1150 deg C is worked out. The optimum conditions of its manufacture are found by planning an extremal experiment. Interaction of PH 3 with ruthenium proceeds by the diffusion mechanism and obeys the parabolic law. An extraction-photometric method for determining phosphorus in phosphides is elaborated. Ruthenium phosphides are extremely corrosion-resistant in acids and alkalis. Ru 2 P and RuP exhibit metallic conductivity

  12. Ruthenium removing device

    International Nuclear Information System (INIS)

    Kitamura, Masafumi; Shirado, Katsuyuki.

    1990-01-01

    A processing gas supply system and a NO x supply system for supplying NO x to be mixed with processed gases are connected to the gas plenum in the lower portion of reaction vessel. Further, a cleaning station is disposed above the gas plenum for introducing a mixed gas stream from the gas plenum into a liquid detergent thereby trapping NO x and ruthenium reduction products into the liquid detergent. Volatile ruthenium contained in the processed gases is reduced into ruthenium reduction products and formed as mists. They are trapped in the cleaning liquid and the remaining gases are discharged out of the liquid detergent to the outside of the reaction vessel. Accordingly, solid radioactive wastes are not formed and the decontaminating efficiency for volatile ruthenium can be improved. (T.M.)

  13. Analysis of radioactive ruthenium

    International Nuclear Information System (INIS)

    1977-01-01

    This manual explains the procedures of analysis of radioactive ruthenium in the drain water from atomic energy plants. The most important radioactive ruthenium is 106 Ru, and the method of measurement described in this manual is to measure the beta ray of the daughter nuclide 106 Rh. The samples to be measured are collected from seawater, marine living things, and sediment of sea bottom near atomic energy plants. In case of sea water, the ruthenium is separated by the co-precipitation with magnesium hydroxide and distillation or the extraction with carbon tetrachloride, reduction and precipitation. The beta ray of the obtained sample is measured by a gas-flow type low background β counting system. Alkali dissolution-distillation or nitric acid extraction-distillation, reduction and precipitation are applied for marine living things. The sediment of sea bottom is treated with nitric acid or strong phosphoric acid, and distilled then the ruthenium is reduced and precipitated, and the beta-counting of the precipitation is made. The method to fix radioactive ruthenium on polyethylene films after the co-precipitation is also described for reference. The detectable levels by the present methods are 0.05 pCi/l for sea water, 0.1 pCi/g for marine living things, and 20 pCi/kg for the sediment of sea bottom. (Kato, T.)

  14. 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

  15. Ruthenium separation device from radioactive waste

    International Nuclear Information System (INIS)

    Ayabe, Osao.

    1988-01-01

    Purpose: To efficiently oxidize ruthenium in radioactive wastes and evaporize ruthenium tetraoxide after oxidization thereof, thereby improve the separation and recovery rate. Constitution: The device comprises an oxidization vessel for supplying an oxidizing agent into radioactive wastes to oxidize ruthenium in the wastes into ruthenium tetraoxide, and a distillation vessel for introducing radioactive wastes after oxidization, distillating under heating ruthenium tetraoxide leached into the wastes and evaporizing ruthenium tetraoxide. By dividing the device into the oxidizing vessel and the distillation vessel, the oxidizing treatment and the distilling treatment can individually be operated optimally to improve the separation and recovery rate of ruthenium. (Takahashi, M.)

  16. Method of dissolving metal ruthenium

    International Nuclear Information System (INIS)

    Tsuno, Masao; Soda, Yasuhiko; Kuroda, Sadaomi; Koga, Tadaaki.

    1988-01-01

    Purpose: To dissolve and clean metal ruthenium deposited to the inner surface of a dissolving vessel for spent fuel rods. Method: Metal ruthenium is dissolved in a solution of an alkali metal hydroxide to which potassium permanganate is added. As the alkali metal hydroxide used herein there can be mentioned potassium hydroxide, sodium hydroxide and lithium hydroxide can be mentioned, which is used as an aqueous solution from 5 to 20 % concentration in view of the solubility of metal ruthenium and economical merit. Further, potassium permanganate is used by adding to the solution of alkali metal hydroxide at a concentration of 1 to 5 %. (Yoshihara, H.)

  17. Spectroscopic and electrochemical study of polynuclear clusters from ruthenium acetate

    International Nuclear Information System (INIS)

    Cipriano, C.

    1989-01-01

    The chemistry of the trinuclear clusters [Ru sub(3) O (CH sub(3) CO sub(2)) sub(4) L sub(3)] where L = imidazole, pyridine or pyrazine type of ligands, was investigated based on spectroscopic and electrochemical techniques. These complexes are of great interest from the point of view of their electronic and redox properties, providing multisite species for electron transfer processes. They were isolated in solid state, and characterized by means of elementary analyses and infrared spectra. The electrochemical behaviour in acetonitrile solution was typically reversible; the cyclic voltammograms exhibited a series of four or five mono electronic waves ascribed to the sucessive Ru sup(IV) Ru sup(III) Ru sup(III) / Ru sup(III) Ru sup(III) Ru sup(III)/ --- Ru sup(II) Ru sup(II) Ru sup(II) redox couples. The differences between the successive redox potentials were about 1 V, indicating strong metal-metal interaction in the trinuclear Ru sub(3) centre. The E values were strongly sensitive to the nature of the N-heterocyclic ligand, increasing with the pi-acceptor properties of the pyridine and pyrazine derivatives, but in a much less pronounced way in the case of the imidazole derivatives. Resonance Raman studies for the pyrazine cluster showed selective intensification of the vibrational modes of the Ru-pyrazine chromophore, and the trinuclear centre, using excitation wavelengths coinciding with the metal-to-pyrazine and metal-metal bands, respectively. (author)

  18. Electrochemistry of ruthenium acetate trigonal cluster with dimethylsulfoxide and pyridine

    International Nuclear Information System (INIS)

    Alexiou, A.D.P.; Toma, H.E.

    1990-01-01

    The electrochemical behaviour of asymetric cluster with two ligands, pyridine and dimethyl-sulfoxide is studied for determining the changes from cluster oxidation influence on DMSO-Ru ligand and for verifying the ligand isomers which were detected in two systems; [Ru(NHsub(3))dmso] sup(3+/2+) [9] and [Ru(edta)dmso] sup(1-/2-)[10]. (author)

  19. Thermodynamic behaviour of ruthenium at high temperatures

    International Nuclear Information System (INIS)

    Garisto, F.

    1988-01-01

    Thermodynamic equilibrium calculations are used to determine the chemical speciation of ruthenium under postulated reactor accident conditions. The speciation of ruthenium is determined for various values of temperature, pressure, oxygen partial pressure and ruthenium concentration. The importance of these variables, in particular the oxygen partial pressure, in determining the volatility of ruthenium is clearly demonstrated in this report. Reliable thermodynamic data are required to determine the behaviour of ruthenium using equilibrium calculations. Therefore, it was necessary to compile a thermodynamic database for the ruthenium species that can be formed under reactor accident conditions. The origin of the thermodynamic data for the ruthenium species included in our calculations is discussed in detail in Appendix A. 23 refs

  20. Large-scale ruthenium- and enzyme-catalyzed dynamic kinetic resolution of (rac-1-phenylethanol

    Directory of Open Access Journals (Sweden)

    Bäckvall Jan-E

    2007-12-01

    Full Text Available Abstract The scale-up of the ruthenium- and enzyme-catalyzed dynamic kinetic resolution (DKR of (rac-1-phenylethanol (2 is addressed. The immobilized lipase Candida antarctica lipase B (CALB was employed for the resolution, which shows high enantioselectivity in the transesterification. The ruthenium catalyst used, (η 5-C5Ph5RuCl(CO2 1, was shown to possess very high reactivity in the "in situ" redox racemization of 1-phenylethanol (2 in the presence of the immobilized enzyme, and could be used in 0.05 mol% with high efficiency. Commercially available isopropenyl acetate was employed as acylating agent in the lipase-catalyzed transesterifications, which makes the purification of the product very easy. In a successful large-scale DKR of 2, with 0.05 mol% of 1, (R-1-phenylethanol acetate (3 was obtained in 159 g (97% yield in excellent enantiomeric excess (99.8% ee.

  1. Electrochemical studies of ruthenium compounds

    International Nuclear Information System (INIS)

    Kumar Ghosh, B.; Chakravorty, A.

    1989-01-01

    In many ways the chemistry of transition metals is the chemistry of multiple oxidation states and the associated redox phenomena. If a particular element were to be singeld out to illustrate this viewpoint, a model choice would be ruthenium - an element that is directly or indirectly the active centre of a plethora of redox phenomena encompassing ten different oxidation states and a breathtaking diversity of structure and bonding. In the present review the authors are primarily concerned with the oxidation states of certain ligands coordinated to ruthenium. This choice is deliberate since this is one area where the unique power of electrochemical methods is splendidly revealed. Without these methods, development in this area would have been greatly hampered. A brief summary of metal oxidation states is also included as a prelude to the main subject of this review. The authors have generally emphasize the information derived which is of chemical interest leaving the details of formal electrochemical arguments in the background. The authors have reviewed the pattern and systematics of ligand redox in ruthenium complexes. The synergistic combination of electrochemical and spectroscopic methods have vastly increased our understanding of ligand phenomena during the last 15 years or so. This in turn has led to better understanding and new developments in other fields. Photophysics and photochemistry could be cited as examples. (author). 176 refs.; 10 figs.; 10 tabs

  2. Solventless synthesis of ruthenium nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    García-Peña, Nidia G. [Departmento de Tecnociencias, Universidad Nacional Autónoma de México, Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, Cd. Universitaria A.P. 70-186, C.P. 04510 Coyoacán, México D.F. (Mexico); Redón, Rocío, E-mail: rredon@unam.mx [Departmento de Tecnociencias, Universidad Nacional Autónoma de México, Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, Cd. Universitaria A.P. 70-186, C.P. 04510 Coyoacán, México D.F. (Mexico); Herrera-Gomez, Alberto [Estudios Avanzados del Instituto Politécnico Nacional, Campus Juriquilla, Querétaro (Mexico); Fernández-Osorio, Ana Leticia [FES-Cuautitlán, Universidad Nacional Autónoma de México, Edo. de Mexico (Mexico); Bravo-Sanchez, Mariela; Gomez-Sosa, Gustavo [Estudios Avanzados del Instituto Politécnico Nacional, Campus Juriquilla, Querétaro (Mexico)

    2015-06-15

    Graphical abstract: - Highlights: • Successful synthesis of Ru nanoparticles by a cheap, fast and solventless approach was achieved. • The zero-valent state as well as the by-product/impurity free of the mechanochemical obtained Ru nanoparticles was proven by XPS, TEM and XRD. • Compared to two other synthesis strategies, the above-mentioned synthesis was more suitable to obtain smaller particles with fewer impurities in shorter time. - Abstract: This paper presents a novel solventless method for the synthesis of zero-valent ruthenium nanoparticles Ru(0). The proposed method, although not entirely new in the nanomaterials world, was used for the first time to synthesize zero-valent ruthenium nanoparticles. This new approach has proved to be an environmentally friendly, clean, cheap, fast, and reproducible technique which employs low amounts of solvent. It was optimized through varying amounts of reducing salt on a determined quantity of precursor and measuring the effect of this variation on the average particle size obtained. The resulting products were fully characterized by powder XRD, TEM, HR-TEM, and XPS studies, all of which corroborated the purity of the nanoparticles achieved. In order to verify the advantages of our method over other techniques, we compared our nanoparticles with two common colloidal-synthesized ruthenium nanoparticles.

  3. IR-doped ruthenium oxide catalyst for oxygen evolution

    Science.gov (United States)

    Valdez, Thomas I. (Inventor); Narayanan, Sekharipuram R. (Inventor)

    2012-01-01

    A method for preparing a metal-doped ruthenium oxide material by heating a mixture of a doping metal and a source of ruthenium under an inert atmosphere. In some embodiments, the doping metal is in the form of iridium black or lead powder, and the source of ruthenium is a powdered ruthenium oxide. An iridium-doped or lead-doped ruthenium oxide material can perform as an oxygen evolution catalyst and can be fabricated into electrodes for electrolysis cells.

  4. Utilization of ruthenium volatilization at heating of residue containing phosphates and nitrates for ruthenium separation and for its qualitative proof

    International Nuclear Information System (INIS)

    Holgye, Z.

    1979-01-01

    The volatility of ruthenium during the heating of a residue after evaporation of a solution containing ruthenium, phosphates and nitrates may be utilized for the separation of ruthenium from various substances. Sup(103,106) Ru may be rapidly, selectively, and quantitatively separated from fission products mixture. Ruthenium may be also separated in this way from various inorganic salts or from biological material. The volatility of ruthenium may be used also for its qualitative proof. (author)

  5. Interface behaviour and electrical performance of ruthenium ...

    Indian Academy of Sciences (India)

    Rutherford backscattering spectrometry; Raman spectroscopy; oxidation; silicide; Schottky barrier diodes; ruthenium ... water and then dried with nitrogen gas before being loaded into the vacuum ... laser of wavelength 514.6 nm. Full I–V and ...

  6. Ruthenium (4) and ruthenium (3) state in hydrochloric acid solutions under microwave irradiation

    International Nuclear Information System (INIS)

    Bashilov, A.V.; Kuz'min, N.M.; Nesterov, A.A.; Runov, V.K.

    2000-01-01

    Reactions of hydration, poly- and depolymerization, oxidation-reduction processes with ruthenium (4) and ruthenium (3) participation are investigated in hydrochloric acid solutions under microwave irradiation by the methods of molecular absorption spectroscopy in UV visible region taking K 4 [Ru 2 OCl 10 ] as an example. Content of state forms of ruthenium (4) and ruthenium (3), absorption characteristics of forming complexes are calculated. Variation of microwave irradiation parameters and HCl concentration permits to prepare solutions containing [RuCl 6 ] 2+ (95 %) and [(RuOH) 2 (H 2 O) 6 (OH) 2 ] 4+ (98 %) preeminently predominant forms. The role of microwave effect directly is established taking as an example the process of ruthenium (4) hydration [ru

  7. Cyclotron production of ruthenium-97 for radiopharmaceutical applications

    International Nuclear Information System (INIS)

    Music, S.; Gessner, M.

    1980-01-01

    Ruthenium-97 is of interest for clinical practice in nuclear medicine. The combination of the excellent physical and chemical properties of Ruthenium-97 make this isotope worth evaluating. Ruthenium-97 has been prepared by irradiation of a sheet of molybdenum with the internal alpha-beam of the Ruthenium-97 as a function of the alpha particle energy has been measured. The radiochemical separation and its possible clinical applications have been discussed. (author)

  8. Analysis of uranium and its compounds. Ruthenium spectrographic determination

    International Nuclear Information System (INIS)

    Anon.

    Ruthenium determination in uranium and its compounds, suitable for content greater than 0.1 ppm with respect to uranium, by dissolution in sulfuric acid and addition of palladium as an internal standard, separation of the precipitated ruthenium, in the presence of gold, by reduction with zinc, the precipitate is calcined and ruthenium is determined by spectrography [fr

  9. Obtaining of inulin acetate

    OpenAIRE

    Khusenov, Arslonnazar; Rakhmanberdiev, Gappar; Rakhimov, Dilshod; Khalikov, Muzaffar

    2014-01-01

    In the article first obtained inulin ester inulin acetate, by etherification of inulin with acetic anhydride has been exposed. Obtained product has been studied using elementary analysis and IR spectroscopy.

  10. Method of suppressing evaporation loss of ruthenium

    International Nuclear Information System (INIS)

    Muromura, Tadazumi; Sato, Tadashi.

    1987-01-01

    Purpose: To prevent evaporation loss of ruthenium from liquid wastes by adding an aluminum compound upon applying evaporating and drying to solid treatment to reprocessing liquid wastes for spent fuels. Method: An aluminum compound such as aluminum nitrate or aluminum hydroxide to reprocessing liquid wastes of spent fuels such that aluminum/ruthenium mixing ratio corresponds to 1.3 - 70.0 by g/atom ratio (0.34 - 187 by weight ratio), and the liquid mixture is heated to a temperature of about 130 deg C to be evaporated and dried to solidness. This enables to recover ruthenium without settling and depositing insoluble matters in the liquid wastes and without decomposing nitric acid. (Yoshino, Y.)

  11. Adsorption of aliphatic alcohols on ruthenium

    International Nuclear Information System (INIS)

    Shapovalova, L.B.; Zakumbaeva, G.D.

    1977-01-01

    The adsorption is studied of allyl-, propyl- and propargyl alcohols on a ruthenium catalyst-electrode at 20, 30 and 40 deg C in H 2 SO 4 in helium. Above adsorption has been found to grow with increased concentration of the alcohols in the solution. In solutions with the same concentration, propargyl alcohol has been noted to show highest sorptive capacity, followed by that of allyl- and propyl alcohols. With variations in the ruthenium electrode potential, alcohol adsorption occurs via maximum at potential = 0.18

  12. Processing of radioactive ruthenium with aluminosilicate gels

    International Nuclear Information System (INIS)

    Kanno, Takuji; Ichinose, Yasuhiro; Ito, Katsuo

    1979-01-01

    Coprecipitation of radioactive Ru with hydroxides has been studied for the purpose of the management of the high level waste from the nuclear fuel reprocessing. Aluminosilicate gel used as coprecipitant was prepared by addition of aqueous sodium hydroxide to sodium aluminate-sodium silicate solution containing ruthenium nitrate. Ruthenium quantitatively precipitates under the conditions, aluminate > 4 x 10 -2 M, Al/Si 0 C. However, volatilization rate of Ru is suppressed by coating with mullite phase into which aluminosilicate gel transformes above 900 0 C. The amount of Ru volatilized in Ar-flow was reduced to about 10% of that in air-flow. (author)

  13. Ruthenium nanocatalysis on redox reactions.

    Science.gov (United States)

    Veerakumar, Pitchaimani; Ramdass, Arumugam; Rajagopal, Seenivasan

    2013-07-01

    Nanoparticles have generated intense interest over the past 20 years due to their high potential applications in different areas such as catalysis, sensors, nanoscale electronics, fuel and solar cells and optoelectronics. As the large fractions of metal atoms are exposed to the surface, the use of metal nanoparticles as nanocatalysts allows mild reaction conditions and high catalytic efficiency in a large number of chemical transformations. They have emerged as sustainable heterogeneous catalysts and catalyst supports alternative to conventional materials. This review focuses on the synthesis, characterization and catalytic role of ruthenium nanoparticles (RuNPs) on the redox reactions of heteroatom containing organic compounds with the green reagent H2O2, a field that has attracted immense interest among the chemical, materials and industrial communities. We intend to present a broad overview of Ru nanocatalysts for redox reactions with an emphasis on their performance, stability and reusability. The growth in the chemistry of organic sulfoxides and N-oxides during last decade was due to their importance as synthetic intermediates for the production of a wide range of chemically and biologically active molecules. Thus design of efficient methods for the synthesis of sulfoxides and N-oxides becomes important. This review concentrates on the catalysis of RuNPs on the H2O2 oxidation of organic sulfides to sulfoxides and amines to N-oxides. The deoxygenation reactions of sulfoxides to sulfides and reduction of nitro compounds to amines are fundamental reactions in both chemistry and biology. Here, we also highlight the catalysis of metal nanoparticles on the deoxygenation of sulfoxides and sulfones and reduction of nitro compounds with particular emphasis on the mechanistic aspects.

  14. Structure and reactivity of Ruthenium nanoparticles

    DEFF Research Database (Denmark)

    Gavnholt, Jeppe; Schiøtz, Jakob

    2008-01-01

    We present a method for obtaining detailed structural information of ruthenium nanoparticles in at least the diameter range from 1.5 to 5 nm. The method is based on an ensemble approach where a large number of low-energy structures are collected in an ensemble, from which average properties can...

  15. Thermodynamic properties of gaseous ruthenium species.

    Science.gov (United States)

    Miradji, Faoulat; Souvi, Sidi; Cantrel, Laurent; Louis, Florent; Vallet, Valérie

    2015-05-21

    The review of thermodynamic data of ruthenium oxides reveals large uncertainties in some of the standard enthalpies of formation, motivating the use of high-level relativistic correlated quantum chemical methods to reduce the level of discrepancies. The reaction energies leading to the formation of ruthenium oxides RuO, RuO2, RuO3, and RuO4 have been calculated for a series of reactions. The combination of different quantum chemical methods has been investigated [DFT, CASSCF, MRCI, CASPT2, CCSD(T)] in order to predict the geometrical parameters, the energetics including electronic correlation and spin-orbit coupling. The most suitable method for ruthenium compounds is the use of TPSSh-5%HF for geometry optimization, followed by CCSD(T) with complete basis set (CBS) extrapolations for the calculation of the total electronic energies. SO-CASSCF seems to be accurate enough to estimate spin-orbit coupling contributions to the ground-state electronic energies. This methodology yields very accurate standard enthalpies of formations of all species, which are either in excellent agreement with the most reliable experimental data or provide an improved estimate for the others. These new data will be implemented in the thermodynamical databases that are used by the ASTEC code (accident source term evaluation code) to build models of ruthenium chemistry behavior in severe nuclear accident conditions. The paper also discusses the nature of the chemical bonds both from molecular orbital and topological view points.

  16. Enyne Metathesis Catalyzed by Ruthenium Carbene Complexes

    DEFF Research Database (Denmark)

    Poulsen, Carina Storm; Madsen, Robert

    2003-01-01

    Enyne metathesis combines an alkene and an alkyne into a 1,3-diene. The first enyne metathesis reaction catalyzed by a ruthenium carbene complex was reported in 1994. This review covers the advances in this transformation during the last eight years with particular emphasis on methodology...

  17. Support Effect in Hydrodesulfurization over Ruthenium Sulfide

    Czech Academy of Sciences Publication Activity Database

    Gulková, Daniela; Kaluža, Luděk; Vít, Zdeněk; Zdražil, Miroslav

    2009-01-01

    Roč. 51, č. 2 (2009), s. 146-149 ISSN 1337-7027 R&D Projects: GA ČR GA104/06/0705 Institutional research plan: CEZ:AV0Z40720504 Keywords : ruthenium sulfide * hydrodesulfurization * support effect Subject RIV: CC - Organic Chemistry

  18. Ruthenium transport experiments in air ingress accident conditions

    Energy Technology Data Exchange (ETDEWEB)

    Teemu, Karkele; Ulrika, Backman; Ari, Auvinen; Unto, Tapper; Jorma, Jokiniemi [VTT Technical Research Centre of Finland, Fine Particles (Finland); Riitta, Zilliacus; Maija, Lipponen; Tommi, Kekki [VTT Technical Research Centre of Finland, Accident Management (Finland); Jorma, Jokiniemi [Kuopio Univ., Dept. of Environmental Sciences, Fine Particle and Aerosol Technology Lab. (Finland)

    2007-07-01

    In this study the release, transport and speciation of ruthenium in conditions simulating an air ingress accident was studied. Ruthenium dioxide was exposed to oxidising environment at high temperature (1100-1700 K) in a tubular flow furnace. At these conditions volatile ruthenium species were formed. A large fraction of the released ruthenium was deposited in the tube as RuO{sub 2}. Depending on the experimental conditions 1-26 wt% of the released ruthenium was trapped in the outlet filter as RuO{sub 2} particles. In stainless steel tube 0-8.8 wt% of the released ruthenium reached the trapping bottle as gaseous RuO{sub 4}. A few experiments were carried out, in which revaporization of ruthenium deposited on the tube walls was studied. In these experiments, oxidation of RuO{sub 2} took place at a lower temperature. During revaporization experiments 35-65 % of ruthenium was transported as gaseous RuO{sub 4}. In order to close mass balance and achieve better time resolution 4 experiments were carried out using a radioactive tracer. In these experiments ruthenium profiles were measured. These experiments showed that the most important retention mechanism was decomposition of gaseous RuO{sub 3} into RuO{sub 2} as the temperature of the furnace was decreasing. In these experiments the transport rate of gaseous ruthenium was decreasing while the release rate was constant.

  19. Increased electrochemical properties of ruthenium oxide and graphene/ruthenium oxide hybrid dispersed by polyvinylpyrrolidone

    International Nuclear Information System (INIS)

    Chen, Yao; Zhang, Xiong; Zhang, Dacheng; Ma, Yanwei

    2012-01-01

    Highlights: ► A good dispersion of RuO 2 and graphene/RuO 2 is obtained by polyvinylpyrrolidone. ► PVP as a dispersant also can prevent the formation of metal Ru in graphene/RuO 2 . ► The max capacitances of the hybrid and RuO 2 reach 435 and 597 F g −1 at 0.2 A g −1 . ► The hybrid shows the best rate capability of 39% at 50 A g −1 . - Abstract: Ruthenium oxide has been prepared by a sol–gel method. Polyvinylpyrrolidone (PVP) as an excellent polymeric dispersant is adopted to prevent aggregation of ruthenium oxide. In order to enhance the rate capability of ruthenium oxide, graphene with residual oxygen functional groups as a 2D support has been merged into ruthenium oxide. These oxygen functional groups not only favor to form stable few layers of graphene colloids, but also offer the sites to anchor ruthenium oxide nanoparticles. X-ray diffraction infers that PVP can also hinder the partial formation of Ru by blocking the direct contact between the Ru 3+ and the graphene in the sol–gel synthesis of the hybrids. The ruthenium oxide and the graphene/ruthenium oxide hybrids dispersed by PVP have superior electrochemical properties due to good dispersing and protecting ability of PVP. Especially, the hybrids using PVP exhibit the best rate capability, indicating that the composites possess an advanced structure of combining sheets and particles in nano-scale.

  20. Sweetening ruthenium and osmium: organometallic arene complexes containing aspartame.

    Science.gov (United States)

    Gray, Jennifer C; Habtemariam, Abraha; Winnig, Marcel; Meyerhof, Wolfgang; Sadler, Peter J

    2008-09-01

    The novel organometallic sandwich complexes [(eta(6)-p-cymene)Ru(eta(6)-aspartame)](OTf)(2) (1) (OTf = trifluoromethanesulfonate) and [(eta(6)-p-cymene)Os(eta(6)-aspartame)](OTf)(2) (2) incorporating the artificial sweetener aspartame have been synthesised and characterised. A number of properties of aspartame were found to be altered on binding to either metal. The pK(a) values of both the carboxyl and the amino groups of aspartame are lowered by between 0.35 and 0.57 pH units, causing partial deprotonation of the amino group at pH 7.4 (physiological pH). The rate of degradation of aspartame to 3,6-dioxo-5-phenylmethylpiperazine acetic acid (diketopiperazine) increased over threefold from 0.12 to 0.36 h(-1) for 1, and to 0.43 h(-1) for 2. Furthermore, the reduction potential of the ligand shifted from -1.133 to -0.619 V for 2. For the ruthenium complex 1 the process occurred in two steps, the first (at -0.38 V) within a biologically accessible range. This facilitates reactions with biological reductants such as ascorbate. Binding to and activation of the sweet taste receptor was not observed for these metal complexes up to concentrations of 1 mM. The factors which affect the ability of metal-bound aspartame to interact with the receptor site are discussed.

  1. The selective generation of acetic acid directly from synthesis gas

    International Nuclear Information System (INIS)

    Knifton, J.F.

    1986-01-01

    The authors conclude that each of the ruthenium, cobalt and iodide-containing catalyst components have very specific roles to play in the ''melt'' catalyzed conversion of synthesis gas to acetic acid. C 1 -Oxygenate formation is only observed in the presence of ruthenium carbonyls - [Ru(CO) 3 I 3 ] - is here the dominant species - and there is a direct relationship between liquid yield, ΣOAc - productivity and [Ru(CO) 3 I 3 ] - content. Controlled quantities of iodide ensure that initially formed MeOH is rapidly converted to the more reactive methyl iodide. Subsequent cobalt-catalyzed carbonylation to acetic acid may be preparatively attractive (>80% selectivity, good yields) relative to competing syntheses, where the [Co(CO) 4 ] - concentration is maximized that is, where the Co/Ru ratio is >1, the syngas feedstock is rich in CO, and the initial iodide/cobalt ratios are ca. unity. Formation of cobalt-iodide species appears to be a competing, inhibitory step in this catalysis

  2. Contribution to the study of ruthenium fluorides, oxyfluorides and oxides

    International Nuclear Information System (INIS)

    Corbin, Odile.

    1982-08-01

    Studies on the dry processing of spent fuels reveal a poor ruthenium decontamination of plutonium. For a better understanding of this result a study of ruthenium fluorides, oxyfluorides and oxides is carried out here as follows: - bibliographical review; - thermochromatographic identification of the number and nature of compounds formed by fluorination of microquantities of ruthenium; - confirmation of the thermochromatographic results by two other analytical methods: thermogravimetry and infrared spectroscopy [fr

  3. Ruthenium-Catalyzed Aerobic Oxidation of Amines.

    Science.gov (United States)

    Ray, Ritwika; Hazari, Arijit Singha; Lahiri, Goutam Kumar; Maiti, Debabrata

    2018-01-18

    Amine oxidation is one of the fundamental reactions in organic synthesis as it leads to a variety of value-added products such as oximes, nitriles, imines, and amides among many others. These products comprise the key N-containing building blocks in the modern chemical industry, and such transformations, when achieved in the presence of molecular oxygen without using stoichiometric oxidants, are much preferred as they circumvent the production of unwanted wastes. In parallel, the versatility of ruthenium catalysts in various oxidative transformations is well-documented. Herein, this review focuses on aerobic oxidation of amines specifically by using ruthenium catalysts and highlights the major achievements in this direction and challenges that still need to be addressed. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Characterization of self-assembled monolayers on a ruthenium surface

    NARCIS (Netherlands)

    Shaheen, Amrozia; Sturm, Jacobus Marinus; Ricciardi, R.; Huskens, Jurriaan; Lee, Christopher James; Bijkerk, Frederik

    2017-01-01

    We have modified and stabilized the ruthenium surface by depositing a self-assembled monolayer (SAM) of 1-hexadecanethiol on a polycrystalline ruthenium thin film. The growth mechanism, dynamics, and stability of these monolayers were studied. SAMs, deposited under ambient conditions, on

  5. Application of the chemical properties of ruthenium to decontamination processes

    International Nuclear Information System (INIS)

    Fontaine, A.; Berger, D.

    1965-01-01

    The chemical properties of ruthenium in the form of an aqueous solution of the nitrate and of organic tributylphosphate solution are reviewed. From this data, some known examples are given: they demonstrate the processes of separation or of elimination of ruthenium from radioactive waste. (authors) [fr

  6. Volatilization and trapping of ruthenium in high temperature processes

    International Nuclear Information System (INIS)

    Klein, M.; Weyers, C.; Goossens, W.R.A.

    1983-01-01

    This experimental study has indicated the importance of moisture and NO/sub x/ vapors on the volatility and trapping conditions of ruthenium in high temperature processes. Also the process operating conditions have a great influence on the ruthenium behavior in the off-gas purification units. Of particular interest is the observation that the ruthenium release during direct vitrification of simulated high-level liquid waste is a factor of about 5 smaller than the ruthenium release during calcination of this type of waste. Moreover, in the direct vitrification case the ruthenium escapes mostly in the form of an aerosol whereas in the calcination case a volatile ruthenium compound is dominating. Consequently, a specific ruthenium filter is not needed in the off-gas line of a direct vitrifier simplifying in this way the number of units in this off-gas line and avoiding the handling and controlling problems of such a ruthenium filter. In the future, a similar program will be started on the volatility of cesium and antimony in a liquid fed melter and on the technical reliability of the liquid fed melter and its associated gas purification units on a semi-pilote scale under simulated conditions

  7. The biokinetics of ruthenium in the human body

    International Nuclear Information System (INIS)

    Leggett, Richard Wayne

    2011-01-01

    The biokinetics of ruthenium (Ru) in the human body is of interest due mainly to the potential for occupational or environmental exposure to 106Ru (T1/2 = 373.6 d) and 103Ru (T1/2 = 39.3 d), which typically represent a significant portion of the fission products in a reactor inventory. During reactor operations or nuclear fuel reprocessing these ruthenium isotopes may be present as ruthenium tetroxide (RuO4) vapor, a highly mobile form of ruthenium that has been involved in a number of cases of accidental exposure to 106Ru or 103Ru. This paper summarizes the biokinetic database for ruthenium and proposes a new respiratory model for inhaled RuO4 vapor, a new biokinetic for systemic (absorbed) ruthenium, and material-specific gastrointestinal absorption fractions for ruthenium. The proposed respiratory model for RuO4 differs from the current ICRP model mainly in that it depicts slower clearance of deposited activity from the respiratory tract and lower absorption to blood than depicted in the current ICRP model. The proposed systemic biokinetic model depicts more realistic paths of movement of absorbed ruthenium in the body than the current ICRP model and, in contrast to the present model, a less uniform distribution of systemic activity. Implications of the proposed models with regard to inhalation and ingestion dose coefficients for 106Ru are examined.

  8. Ulipristal acetate versus leuprolide acetate for uterine fibroids.

    Science.gov (United States)

    Donnez, Jacques; Tomaszewski, Janusz; Vázquez, Francisco; Bouchard, Philippe; Lemieszczuk, Boguslav; Baró, Francesco; Nouri, Kazem; Selvaggi, Luigi; Sodowski, Krzysztof; Bestel, Elke; Terrill, Paul; Osterloh, Ian; Loumaye, Ernest

    2012-02-02

    The efficacy and side-effect profile of ulipristal acetate as compared with those of leuprolide acetate for the treatment of symptomatic uterine fibroids before surgery are unclear. In this double-blind noninferiority trial, we randomly assigned 307 patients with symptomatic fibroids and excessive uterine bleeding to receive 3 months of daily therapy with oral ulipristal acetate (at a dose of either 5 mg or 10 mg) or once-monthly intramuscular injections of leuprolide acetate (at a dose of 3.75 mg). The primary outcome was the proportion of patients with controlled bleeding at week 13, with a prespecified noninferiority margin of -20%. Uterine bleeding was controlled in 90% of patients receiving 5 mg of ulipristal acetate, in 98% of those receiving 10 mg of ulipristal acetate, and in 89% of those receiving leuprolide acetate, for differences (as compared with leuprolide acetate) of 1.2 percentage points (95% confidence interval [CI], -9.3 to 11.8) for 5 mg of ulipristal acetate and 8.8 percentage points (95% CI, 0.4 to 18.3) for 10 mg of ulipristal acetate. Median times to amenorrhea were 7 days for patients receiving 5 mg of ulipristal acetate, 5 days for those receiving 10 mg of ulipristal acetate, and 21 days for those receiving leuprolide acetate. Moderate-to-severe hot flashes were reported for 11% of patients receiving 5 mg of ulipristal acetate, for 10% of those receiving 10 mg of ulipristal acetate, and for 40% of those receiving leuprolide acetate (P<0.001 for each dose of ulipristal acetate vs. leuprolide acetate). Both the 5-mg and 10-mg daily doses of ulipristal acetate were noninferior to once-monthly leuprolide acetate in controlling uterine bleeding and were significantly less likely to cause hot flashes. (Funded by PregLem; ClinicalTrials.gov number, NCT00740831.).

  9. A new electrochemical sensor containing a film of chitosan-supported ruthenium: detection and quantification of sildenafil citrate and acetaminophen

    Energy Technology Data Exchange (ETDEWEB)

    Delolo, Fabio Godoy; Rodrigues, Claudia; Silva, Monize Martins da; Batista, Alzir Azevedo, E-mail: fabiodelolo@hotmail.com, E-mail: daab@power.ufscar.br [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Departamento de Quimica. Lab. de Estrutura e Reatividade de Compostos Inorganicos; Dinelli, Luis Rogerio [Universidade Federal de Uberlandia (UFU), Ituiutaba, MG (Brazil). Faculdade de Ciencias Integradas do Pontal; Delling, Felix Nicolai; Zukerman-Schpector, Julio [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Departamento de Quimica. Lab. de Cristalografia Estereodinamica e Modelagem Molecular

    2014-03-15

    This work presents the construction of a novel electrochemical sensor for detection of organic analytes, using a glassy carbon electrode (GCE) modified with a chitosan-supported ruthenium film. The ruthenium-chitosan film was obtained starting from the mer-[RuCl{sub 3}(dppb)(H{sub 2}O)] complex as a [1,4-bis(diphenylphosphine)butane] (dppb) precursor, and chitosan (QT). The structure of the chitosan-supported ruthenium film on the surface of the glassy carbon electrode was characterized by UV-Vis spectroscopy, electron paramagnetic resonance (EPR), scanning electron microscopy (SEM), atomic force microscopy (AFM), powder X-ray diffraction (XRD) and atomic absorption spectroscopy (AAS) techniques. The glassy carbon electrode was modified with a film formed from the evaporation of 5 μL of a solution composed of 5 mg chitosan-supported ruthenium (RuQT) in 10 mL of 0.1 mol L{sup -1} acetic acid. The modified electrode was tested as a sensor for sildenafil citrate (Viagra® 50 mg) and acetaminophen (Tylenol®) detection. The technique utilized for these analyses was differential pulse voltammetry (DPV) in 0.1 mol L{sup -1} H{sub 2}SO{sub 4} (pH 1.0) and 0.1 mol L{sup -1} CH{sub 3}COOK (pH 6.5) as supporting electrolyte. All analyses were carried out during a month using the same electrode. The electrode was washed only with water in between the analyses, keeping it in the refrigerator when it was not in use. This electrode was stable during the period utilized showing no degradation and presenting a linear response over the evaluated concentration interval (1.25 × 10{sup -5} to 4.99 × 10{sup -4} mol L{sup -1}). (author)

  10. A new electrochemical sensor containing a film of chitosan-supported ruthenium: detection and quantification of sildenafil citrate and acetaminophen

    International Nuclear Information System (INIS)

    Delolo, Fabio Godoy; Rodrigues, Claudia; Silva, Monize Martins da; Batista, Alzir Azevedo; Dinelli, Luis Rogerio; Delling, Felix Nicolai; Zukerman-Schpector, Julio

    2014-01-01

    This work presents the construction of a novel electrochemical sensor for detection of organic analytes, using a glassy carbon electrode (GCE) modified with a chitosan-supported ruthenium film. The ruthenium-chitosan film was obtained starting from the mer-[RuCl 3 (dppb)(H 2 O)] complex as a [1,4-bis(diphenylphosphine)butane] (dppb) precursor, and chitosan (QT). The structure of the chitosan-supported ruthenium film on the surface of the glassy carbon electrode was characterized by UV-Vis spectroscopy, electron paramagnetic resonance (EPR), scanning electron microscopy (SEM), atomic force microscopy (AFM), powder X-ray diffraction (XRD) and atomic absorption spectroscopy (AAS) techniques. The glassy carbon electrode was modified with a film formed from the evaporation of 5 μL of a solution composed of 5 mg chitosan-supported ruthenium (RuQT) in 10 mL of 0.1 mol L -1 acetic acid. The modified electrode was tested as a sensor for sildenafil citrate (Viagra® 50 mg) and acetaminophen (Tylenol®) detection. The technique utilized for these analyses was differential pulse voltammetry (DPV) in 0.1 mol L -1 H 2 SO 4 (pH 1.0) and 0.1 mol L -1 CH 3 COOK (pH 6.5) as supporting electrolyte. All analyses were carried out during a month using the same electrode. The electrode was washed only with water in between the analyses, keeping it in the refrigerator when it was not in use. This electrode was stable during the period utilized showing no degradation and presenting a linear response over the evaluated concentration interval (1.25 × 10 -5 to 4.99 × 10 -4 mol L -1 ). (author)

  11. Experiments on the behaviour of ruthenium in air ingress accidents

    International Nuclear Information System (INIS)

    Kaerkelae, T.; Backman, Ul; Auvinen, A.; Zilliacus, R.; Lipponen, M.; Kekki, T.; Tapper, U.; Jokiniemi, J.

    2007-03-01

    During routine nuclear reactor operation, ruthenium will accumulate in the fuel in relatively high concentrations. In a severe accident in a nuclear power plant it is possible that air gets into contact with the reactor core. In this case ruthenium may oxidise and form volatile ruthenium species, RuO3 and RuO4, which can be transported into the containment. In order to estimate the amount of gaseous ruthenium species, it is of interest to know, how they are formed and how they behave. In our experiments the formation and transport of volatile ruthenium oxides was studied by exposing RuO2 powder to diverse oxidising atmospheres at a relatively high temperature. Transport of gaseous RuO4 was further investigated by injecting it into the facility in similar conditions. Upon cooling of the gas flow RuO2 aerosol particles were formed in the system. They were removed from the gas stream with plane filters. Gaseous ruthenium species were trapped in 1M NaOH-water solution, which is capable of trapping RuO4 totally. Ruthenium in the solution was filtered for analysis. The determination of ruthenium both in aerosol and in liquid filters was made using instrumental neutron activation analysis (INAA). In order to close the mass balance and to achieve better time resolution seven experiment were carried out using radioactive tracer. In this report, the facility for the ruthenium behaviour study and results from experiments are presented. Preliminary conclusions from the experiments are reported as well. Final conclusions will be made after modelling of the facility is completed in a continuation work of this study. (au)

  12. Experiments on the behaviour of ruthenium in air ingress accidents

    Energy Technology Data Exchange (ETDEWEB)

    Kaerkelae, T.; Backman, Ul; Auvinen, A.; Zilliacus, R.; Lipponen, M.; Kekki, T.; Tapper, U.; Jokiniemi, J. [Technical Research Centre of Finland VTT (Finland)

    2007-03-15

    During routine nuclear reactor operation, ruthenium will accumulate in the fuel in relatively high concentrations. In a severe accident in a nuclear power plant it is possible that air gets into contact with the reactor core. In this case ruthenium may oxidise and form volatile ruthenium species, RuO3 and RuO4, which can be transported into the containment. In order to estimate the amount of gaseous ruthenium species, it is of interest to know, how they are formed and how they behave. In our experiments the formation and transport of volatile ruthenium oxides was studied by exposing RuO2 powder to diverse oxidising atmospheres at a relatively high temperature. Transport of gaseous RuO4 was further investigated by injecting it into the facility in similar conditions. Upon cooling of the gas flow RuO2 aerosol particles were formed in the system. They were removed from the gas stream with plane filters. Gaseous ruthenium species were trapped in 1M NaOH-water solution, which is capable of trapping RuO4 totally. Ruthenium in the solution was filtered for analysis. The determination of ruthenium both in aerosol and in liquid filters was made using instrumental neutron activation analysis (INAA). In order to close the mass balance and to achieve better time resolution seven experiment were carried out using radioactive tracer. In this report, the facility for the ruthenium behaviour study and results from experiments are presented. Preliminary conclusions from the experiments are reported as well. Final conclusions will be made after modelling of the facility is completed in a continuation work of this study. (au)

  13. Characterization of ultrasonic spray pyrolysed ruthenium oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Patil, P.S.; Ennaoui, E.A.; Lokhande, C.D.; Mueller, M.; Giersig, M.; Diesner, K.; Tributsch, H. [Hahn-Meitner-Institut Berlin GmbH (Germany). Bereich Physikalische Chemie

    1997-11-21

    The ultrasonic spray pyrolysis (USP) technique was employed to deposit ruthenium oxide thin films. The films were prepared at 190 C substrate temperature and further annealed at 350 C for 30 min in air. The films were 0.22 {mu} thick and black grey in color. The structural, compositional and optical properties of ruthenium oxide thin films are reported. Contactless transient photoconductivity measurement was carried out to calculate the decay time of excess charge carriers in ruthenium oxide thin films. (orig.) 28 refs.

  14. Hazards and control of ruthenium in the nuclear fuel cycle

    International Nuclear Information System (INIS)

    Eichholz, G.G.

    1978-01-01

    A review is presented of present information on the possible hazards of radioruthenium in the nuclear fuel cycle and its behaviour in nuclear operations and in the environment. The subject is dealt with under the following headings: basic chemical and nuclear properties of ruthenium; chemistry (including the ruthenium-nitric acid system, electrochemistry, extraction processes); ruthenium toxicity; generation of radioruthenium (fallout sources, reactor sources, fuel reprocessing operations); waste treatment (cementation and bitumenization, calcining processes, vitrification); movement in the environment (movement of airborne effluents, liquid effluents and the freshwater environment, marine environment, bottom sediments, marine organisms, terrestrial environments, uptake in vegetation and animals); conclusion. (U.K.)

  15. Scaling-resistance of ruthenium- and ruthenium phosphides powders in argon and air

    International Nuclear Information System (INIS)

    Chernogorebko, V.B.; Semenov-Kobzar', A.A.; Kulik, L.Ya.

    1976-01-01

    The thermal stability of ruthenium phosphides in air diminishes as the content of phosphorus in the compound increases. The temperatures at which active oxidation of the powders starts are as follows: Ru-600, Ru 2 P-590, RuP-390, and RuP 2 -270 0 C. The oxidation of phosphorus in the phosphides proceeds in steps. The atoms of phosphorus which are most accessible to oxygen are first oxidated. Phosphorus atoms in the octahedral spaces are oxidated less easily, simultaneously with the oxidation of the ruthenium atoms. When heated in argon, Ru 2 P and RuP fuse congruently at 1,500 and 1,555 0 C respectively, while RuP 2 dissociates at 950 0 C. (author)

  16. Spectroscopic and electrochemical study of the polynuclear clusters of ruthenium acetate

    International Nuclear Information System (INIS)

    Cipriano, C.

    1989-01-01

    The chemistry of the trinuclear clusters (Ru 3 O (C H 3 CO 2 ) 4 L 3 ) where L = imidazole, pyridine or pyrazine type of ligands, was investigated based on spectroscopic and electrochemical techniques. These complexes are of great interest from the point of view of their electronic and redox properties, providing multi site species for electron transfer processes. They were isolated in solid state, and characterized by means of elementary analyses and infrared spectra. The electrochemical behaviour in acetonitrile solution was typically reversible; the cyclic voltamograms exhibited a series of four or five mono electronic waves ascribed to the successive Ru I V Ru I I I Ru I I I / Ru I I I Ru I I I Ru I I I / ... Ru I I Ru I I Ru I I redox couples. The differences between the successive redox potentials were about 1 V, indicating strong metal-metal interaction in the trinuclear Ru 3 O centre. The E values were strongly sensitive to the nature of the N-heterocyclic ligand, increasing with the pi-acceptor properties of the pyridine and pyrazine derivatives, but in a much less pronounced way in the case of the imidazole derivatives. (author)

  17. Ruthenium, osmium and rhodium complexes of polypyridyl ligands ...

    Indian Academy of Sciences (India)

    Unknown

    Discipline of Silicates and Catalysis, Central Salt and Marine Chemicals ... However, synthetic methods have also been developed to prepare complexes with ... 3.2 Synthesis and characterisation of ruthenium(II) and osmium(II) complexes18, ...

  18. Unsaturated carbone and allenylidene ruthenium complexes from alkynes

    International Nuclear Information System (INIS)

    Bozek, Yu.L.; Diznev, P.A.

    1995-01-01

    The author's studies aimed at activation of terminal alkynes by metal complexes, reactivity patterns and selective preparations of unsaturated carbene, allenylidene and cumulenylidene derivatives of (arene)ruthenium complexes are reviewed. 48 refs

  19. Synthesis of ruthenium (III) complexes with benzimidazole derivatives

    International Nuclear Information System (INIS)

    Vyas, P.C.; Chahar, Yogesh K.; Garg, Yajula; Seth, Gita

    2003-01-01

    Complexes of ruthenium with biologically important benzimidazole derivatives, viz. 2-(2'-hydroxyphenyl) benzimidazole (HOPBI), 2-2'- mercaptophenyl) benzimidazole (HSPBI), 2- (2'-hydroxynaphthyl) benzimidazole (HONBI) have been synthesized and characterized. (author)

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

    Indian Academy of Sciences (India)

    gel method have been employed to prepare ruthenium oxide thin films. Recently ... the potentiostat (263A EG&G, Princeton Applied Research. Potentiostat). .... is a mixed conductor that conducts protons and electrons in acidic solution (as ...

  1. Rare earth-ruthenium-magnesium intermetallics

    Energy Technology Data Exchange (ETDEWEB)

    Stein, Sebastian; Kersting, Marcel; Heletta, Lukas; Poettgen, Rainer [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie

    2017-07-01

    Eight new intermetallic rare earth-ruthenium-magnesium compounds have been synthesized from the elements in sealed niobium ampoules using different annealing sequences in muffle furnaces. The compounds have been characterized by powder and single crystal X-ray diffraction. Sm{sub 9.2}Ru{sub 6}Mg{sub 17.8} (a=939.6(2), c=1779(1) pm), Gd{sub 11}Ru{sub 6}Mg{sub 16} (a=951.9(2), c=1756.8(8) pm), and Tb{sub 10.5}Ru{sub 6}Mg{sub 16.5} (a=942.5(1), c=1758.3(4) pm) crystallize with the tetragonal Nd{sub 9.34}Ru{sub 6}Mg{sub 17.66} type structure, space group I4/mmm. This structure exhibits a complex condensation pattern of square-prisms and square-antiprisms around the magnesium and ruthenium atoms, respectively. Y{sub 2}RuMg{sub 2} (a=344.0(1), c=2019(1) pm) and Tb{sub 2}RuMg{sub 2} (a=341.43(6), c=2054.2(7) pm) adopt the Er{sub 2}RuMg{sub 2} structure and Tm{sub 3}Ru{sub 2}Mg (a=337.72(9), c=1129.8(4) pm) is isotypic with Sc{sub 3}Ru{sub 2}Mg. Tm{sub 3}Ru{sub 2}Mg{sub 2} (a=337.35(9), c=2671(1) pm) and Lu{sub 3}Ru{sub 2}Mg{sub 2} (a=335.83(5), c=2652.2(5) pm) are the first ternary ordered variants of the Ti{sub 3}Cu{sub 4} type, space group I4/mmm. These five compounds belong to a large family of intermetallics which are completely ordered superstructures of the bcc subcell. The group-subgroup scheme for Lu{sub 3}Ru{sub 2}Mg{sub 2} is presented. The common structural motif of all three structure types are ruthenium-centered rare earth cubes reminicent of the CsCl type. Magnetic susceptibility measurements of Y{sub 2}RuMg{sub 2} and Lu{sub 3}Ru{sub 2}Mg{sub 2} samples revealed Pauli paramagnetism of the conduction electrons.

  2. Ruthenium Sensitizers and Their Applications in Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Yuancheng Qin

    2012-01-01

    Full Text Available Dye-sensitized solar cells (DSSCs have attracted considerable attention in recent years due to the possibility of low-cost conversion of photovoltaic energy. The DSSCs-based ruthenium complexes as sensitizers show high efficiency and excellent stability, implying potential practical applications. This review focuses on recent advances in design and preparation of efficient ruthenium sensitizers and their applications in DSSCs, including thiocyanate ruthenium sensitizers and thiocyanate-free ruthenium sensitizers.

  3. Kinetics and Photochemistry of Ruthenium Bisbipyridine Diacetonitrile Complexes: An Interdisciplinary Inorganic and Physical Chemistry Laboratory Exercise

    Science.gov (United States)

    Rapp, Teresa L.; Phillips, Susan R.; Dmochowski, Ivan J.

    2016-01-01

    The study of ruthenium polypyridyl complexes can be widely applied across disciplines in the undergraduate curriculum. Ruthenium photochemistry has advanced many fields including dye-sensitized solar cells, photoredox catalysis, lightdriven water oxidation, and biological electron transfer. Equally promising are ruthenium polypyridyl complexes…

  4. Acetate Kinase Isozymes Confer Robustness in Acetate Metabolism

    DEFF Research Database (Denmark)

    Chan, Siu Hung Joshua; Nørregaard, Lasse; Solem, Christian

    2014-01-01

    transcription structure, determining enzyme characteristics and effect on growth physiology. The results show that the two ACKs are most likely individually transcribed. AckA1 has a much higher turnover number and AckA2 has a much higher affinity for acetate in vitro. Consistently, growth experiments of mutant...... physiological roles in L. lactis to maintain a robust acetate metabolism for fast growth at different extracellular acetate concentrations. The existence of ACK isozymes may reflect a common evolutionary strategy in bacteria in an environment with varying concentrations of acetate.......Acetate kinase (ACK) (EC no: 2.7.2.1) interconverts acetyl-phosphate and acetate to either catabolize or synthesize acetyl-CoA dependent on the metabolic requirement. Among all ACK entries available in UniProt, we found that around 45% are multiple ACKs in some organisms including more than 300...

  5. Towards PSII analogs driven by ruthenium photophysics

    International Nuclear Information System (INIS)

    Olsson, Jerry

    2002-01-01

    A number of model complexes have been prepared in an attempt to develop models for photosystem II (PSII) in green plants. As replacement for the chlorophyll photosensitizer, we have used Ru(ll) tris-2,2-bipyridyl or Ru(ll) bis-2,2';6',2 - terpyridyl complexes linked to a pendant 2,2'-bipyridyl or 2,2';6',2''-terpyridyl moieties via spacers of varying lengths. Manganese (ll) has been covalently linked to the pendant 2,2'-bipyridyl /2,2';6',2''-terpyridyl moieties. The use of different ruthenium centres and spacers has made it possible to make assumptions about the way and how easily manganese is coordinated through self-assembly to the pendant 2,2'-bipyridyl or 2,2';6',2''-terpyridyl groups. Several polynuclear complexes containing a photoactive centre (Ru(ll) tris-2,2'-bipyridine or Ru(ll) bis-2,2';6',2''-terpyridine) or other metal ions (Co 2+ , Fe 2+ , Mn 2= ) have been prepared and characterised. The main work has been focused on organic synthesis and characterisation of polypyridine ligands and coordinated to different metal centres. The complexes have been investigated electrochemically and photophysically. Several new phenol-based ligands have been prepared by organic synthetic methods and characterised by various different methods. (author)

  6. Reactions of dihydridotetrakis(triphenylphosphine)ruthenium(II) with olefins and isolation of new ruthenium-olefin complexes

    International Nuclear Information System (INIS)

    Komiya, Sanshiro; Yamamoto, Akio

    1976-01-01

    Dihydridotetrakis(triphenylphosphine)ruthenium (II), RuH 2 (PPh 3 ) 4 , reacts with olefins (ethylene, propylene, stylene and butadiene) to give olefin-coordinated complexes of the type, Ru(olefin)(PPh 3 ) 3 and equimolar amounts of their hydrogenation products per mol of the dihydride complex. The olefin coordinated with ruthenium can be exchanged with other olefins. Olefin-coordinated complexes easily react with molecular hydrogen to afford tetrahydridotris(triphenylphosphine)ruthenium, RuH 4 (PPh 3 ) 3 , releasing alkane at room temperature, Under hydrogen atmosphere catalytic hydrogenation of the olefins smoothly takes place with RuH 2 (PPh 3 ) 4 . (Ethylene)tris(triphenylphosphine)ruthenium(0) reacts with methyl iodide to give propylene and a trace of butadiene along with methane, ethylene, and small amounts of ethane and butenes. The formation of propylene suggests that oxidative addition involving cleavage of the C-H bond of ethylene to ruthenium giving a hydridovinyl complex may be taking place. Reactions of Ru(C 2 H 4 )(PPh 3 ) 3 with methyl-d 3 iodide and ethyl iodide, and of Ru(C 3 H 6 )(PPh 3 ) 3 with methyl iodide were examined to test the generality of this type of reaction. The reaction of Ru(C 2 H 4 )(PPh 3 ) 3 with CD 3 I released CD 4 and CD 2 H 2 together with CD 3 H suggesting the involvement of α-hydrogen abstraction. (auth.)

  7. Ruthenium Dioxide Catalysts for the Selective Oxidation of Benzylamine to Benzonitrile: Investigating the Effect of Ruthenium Loading on Physical and Catalytic Properties

    DEFF Research Database (Denmark)

    Nordvang, Emily Catherine; Schill, Leonhard; Riisager, Anders

    2017-01-01

    The oxidative dehydrogenation of benzylamine to benzonitrile was studied in batch and continuous flow processes using ruthenium dioxide catalysts with varying ruthenium loadings. Increased conversions were observed in the continuous flow process compared with the batch process (up to 100% in the ......The oxidative dehydrogenation of benzylamine to benzonitrile was studied in batch and continuous flow processes using ruthenium dioxide catalysts with varying ruthenium loadings. Increased conversions were observed in the continuous flow process compared with the batch process (up to 100......% in the flow process compared with up to 92% in the batch process), with increased selectivity to benzonitrile (82 and 65%, respectively) and benzonitrile yields (84 and 58%, respectively). The major by-product was N-benzylidenebenzylamine. The ruthenium loading in the catalyst was successfully optimised...... and the most active catalyst had a ruthenium loading of 2.5-3.5 wt%....

  8. Hydrothermal synthesis and physicochemical properties of ruthenium(0) nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Dikhtiarenko, A., E-mail: dikhtiarenkoalla@uniovi.es [Departamento de Quimica Organica e Inorganica, Universidad de Oviedo - CINN, 33006 Oviedo (Spain); Khainakov, S.A.; Garcia, J.R.; Gimeno, J. [Departamento de Quimica Organica e Inorganica, Universidad de Oviedo - CINN, 33006 Oviedo (Spain); Pedro, I. de; Fernandez, J. Rodriguez [CITIMAC, Facultad de Ciencias, Universidad de Cantabria, 39005 Santander (Spain); Blanco, J.A. [Departamento de Fisica, Universidad de Oviedo, 33007 Oviedo (Spain)

    2012-09-25

    Highlights: Black-Right-Pointing-Pointer Ruthenium nanoparticles were synthesized by hydrothermal technique. Black-Right-Pointing-Pointer The average size of the nanoparticles are depend on the reducing agent used. Black-Right-Pointing-Pointer The magnetic response seems to be dominated by a paramagnetic contribution characteristic of the band electronic magnetism of the ruthenium(0) nanoparticles. - Abstract: The synthesis of ruthenium nanoparticles in hydrothermal conditions using mild reducing agents (succinic acid, ascorbic acid and sodium citrate) is reported. The shape of the nanoparticles depends on the type of the reducing agent, while the size is more influenced by the pH of the medium. The magnetic response seems to be dominated by a paramagnetic contribution characteristic of the band electronic magnetism of the nanoparticles.

  9. Confinement of ruthenium oxides volatilized during nuclear fuels reprocessing

    International Nuclear Information System (INIS)

    Maas, E.T. Jr.; Longo, J.M.

    1980-01-01

    While many materials have been suggested and employed as trapping agents for gaseous oxides of fission product ruthenium volatilized during nuclear fuels reprocessing, none that is known to form thermodynamically stable compounds with rutheniunm has been utilized. We have employed alkaline earth metal compounds for this purpose because of their ability to form stable mixed metal oxide phases with ruthenium. Results of experiments in which RuO 4 was volatilized from either a solid source (RuO 2 .xH 2 O) or from solution [Ru(NO)(NO 3 ) 3 ] in HNO 3 and passed through beds of alkaline earth metal carbonates and calcium oxide held at 600 to 750 0 C have demonstrated that compounds of formulation MRuO 3 (M = calcium, strontium, barium) are formed. Under oxidizing conditions, these materials exist as stable ceramic phases, whereas under reducing conditions, they are transformed into intimate mixtures of the alkaline earth metal oxide and nonvolatile ruthenium metal

  10. Device for separating ruthenium ion from spent fuel material

    International Nuclear Information System (INIS)

    Izumida, Tatsuo; Sasahira, Akira; Ozawa, Yoshihiro; Kawamura, Fumio.

    1988-01-01

    Purpose: To separate plutonium ions efficiently and selectively from organic solvent containing tributyl phosphate used in the main step of reprocessing process. Constitution: The device comprises, as the main constituent factor, a liquid-liquid contact device for bringing not water soluble organic solvent into contact with a nitric acid solution of spent fuel substances and a liquid-liquid contact-separation device for bringing an organic solvent solution containing spent fuel substances separated with nitric acid into contact again with nitric acid. Then, a device is disposed between two liquid-liquid contact devices for staying ruthenium ions and organic solvent for a sufficient time. In this way, ruthenium ions in the organic solvent containing butyl phosphate are gradually converted into complex compounds combined with tributyl phosphate thereby enabling to separate ruthenium ions efficiently and remarkably reduce the corrosion of equipments. (Horiuchi, T.)

  11. ACETIC ACID AND A BUFFER

    DEFF Research Database (Denmark)

    2009-01-01

    The present invention relates to a composition comprising : a) 0.01-20% wt/wt acetic acid and b) a physiologically tolerable buffer capable of maintaining acetic acid at a pH in the range of 2-7; and use of such a composition as an antimicrobial agent.......The present invention relates to a composition comprising : a) 0.01-20% wt/wt acetic acid and b) a physiologically tolerable buffer capable of maintaining acetic acid at a pH in the range of 2-7; and use of such a composition as an antimicrobial agent....

  12. Thermodynamic data bases for multivalent elements: An example for ruthenium

    International Nuclear Information System (INIS)

    Rard, J.A.

    1987-11-01

    A careful consideration and understanding of fundamental chemistry, thermodynamics, and kinetics is absolutely essential when modeling predominance regions and solubility behavior of elements that exhibit a wide range of valence states. Examples of this are given using the ruthenium-water system at 298.15 K, for which a critically assessed thermochemical data base is available. Ruthenium exhibits the widest range of known aqueous solution valence states. Known solid anhydrous binary oxides of ruthenium are crystalline RuO 2 , RuO 4 , and possibly RuO 3 (thin film), and known hydroxides/hydrated oxides (all amorphous) are Ru(OH) 3 . H 2 O, RuO 2 . 2H 2 O, RuO 2 . H 2 O, and a poorly characterized Ru(V) hydrous oxide. Although the other oxides, hydroxides, and hydrous oxides are generally obtained as precipitates from aqueous solutions, they are thermodynamically unstable with regard to RuO 2 (cr) formation. Characterized aqueous species of ruthenium include RuO 4 (which slowly oxidizes water and which dissociates as a weak acid), RuO 4 - and RuO 4 2- (which probably contain lesser amounts of RuO 3 (OH) 2 - and RuO 3 (OH) 2 2- , respectively, and other species), Ru(OH) 2 2+ , Ru 4 (OH) 12 4+ , Ru(OH) 4 , Ru 3+ , Ru(OH) 2+ , Ru(OH) 2 + , Ru 2+ , and some hydroxytetramers with formal ruthenium valences of 3.75 ≥ Z ≥ 2.0. Potential pH diagrams of the predominance regions change significantly with concentration due to polymerization/depolymerization reactions. Failure to consider the known chemistry of ruthenium can yield large differences in predicted solubilities

  13. Method of removing clogging materials due to ruthenium precipitates and sealing them in device

    International Nuclear Information System (INIS)

    Hoshikawa, Tadahiro; Sasahira, Akira.

    1994-01-01

    In a facility, such as a reprocessing facility, for processing a solution containing a great amount of ruthenium, precipitates due to evaporated ruthenium and cooled NO x are brought into contact with each other to decompose the precipitates due to the evaporated ruthenium. Precipitates due to ruthenium evaporated from the solution are reacted with cooled NO x , and the precipitates of ruthenium are decomposed and returned to the solution in the form of extremely fine particles together with recycling flow from the inner wall of the device. Since the precipitates of ruthenium returned to the solution are stable, they are no more evaporated and precipitated on the inner wall of the device. In the solution processing device having a possibility of clogging, clogging can be prevented and the precipitates of ruthenium can be sealed by decomposing them. (T.M.)

  14. Immobilization of ruthenium phthalocyanine on silica-coated multi-wall partially oriented carbon nanotubes: Electrochemical detection of fenitrothion pesticide

    Energy Technology Data Exchange (ETDEWEB)

    Canevari, Thiago C., E-mail: tccanevari@gmail.com [Engineering School, Mackenzie Presbyterian University, 01302-907 São Paulo, SP (Brazil); Prado, Thiago M.; Cincotto, Fernando H.; Machado, Sergio A.S. [Institute of Chemistry, State University of São Paulo, P.O. Box 780, 13560-970 São Carlos, SP (Brazil)

    2016-04-15

    Highlights: • Hybrid material, SiO{sub 2}/MWCNTs containing ruthenium phthalocyanine (RuPc) synthesized in situ. • Silica containing multi-walled carbon nanotube partially oriented. • Determination of pesticide fenitrothion in orange juice. - Abstract: This paper reports on the determination of the pesticide fenitrothion using a glassy carbon electrode modified with silica-coated, multi-walled, partially oriented carbon nanotubes, SiO{sub 2}/MWCNTs, containing ruthenium phthalocyanine (RuPc) synthesized in situ. The hybrid SiO{sub 2}/MWCNTs/RuPc material was characterized by UV–vis absorption spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM) and differential pulse voltammetry. The modified electrode showed well-defined peaks in the presence of fenitrothion in acetate buffer, pH 4.5, with a sensitivity of 0.0822 μA μM{sup −1} mm{sup −2} and a detection limit of 0.45 ppm. Notably, the modified SiO{sub 2}/MWCNTs/RuPc electrodes with did not suffer from significant influences in the presence of other organophosphorus pesticides during the determination of the fenitrothion pesticide. Moreover, this modified electrode showed excellent performance in the determination of fenitrothion in orange juice.

  15. Drug-loaded Cellulose Acetate and Cellulose Acetate Butyrate Films ...

    African Journals Online (AJOL)

    The purpose of this research work was to evaluate the contribution of formulation variables on release properties of matrix type ocular films containing chloramphenicol as a model drug. This study investigated the use of cellulose acetate and cellulose acetate butyrate as film-forming agents in development of ocular films.

  16. Ruthenium oxide resistors as sensitive elements of composite bolometers

    International Nuclear Information System (INIS)

    Benassai, M.; Gallinaro, G.; Gatti, F.; Siri, S.; Vitale, S.

    1988-01-01

    Bolometers for particle detection made with Ruthenium oxide thermistors could be produced by means of a simple technique on a variety of different materials as substrata. Preliminary results on alpha particle detection with devices realized using commercial RuO 2 thick film resistor (Tfr) are considered positive for devices operating between. 3 and .1 k and determined us to pursue further the idea. Ruthenium oxide resistors on sapphire at the moment are being prepared. The behaviour of these devices st temperatures lower than .1 k has to be investigated in more detail

  17. Determination of oxygen diffusion kinetics during thin film ruthenium oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Coloma Ribera, R., E-mail: r.colomaribera@utwente.nl; Kruijs, R. W. E. van de; Yakshin, A. E.; Bijkerk, F. [MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands)

    2015-08-07

    In situ X-ray reflectivity was used to reveal oxygen diffusion kinetics for thermal oxidation of polycrystalline ruthenium thin films and accurate determination of activation energies for this process. Diffusion rates in nanometer thin RuO{sub 2} films were found to show Arrhenius behaviour. However, a gradual decrease in diffusion rates was observed with oxide growth, with the activation energy increasing from about 2.1 to 2.4 eV. Further exploration of the Arrhenius pre-exponential factor for diffusion process revealed that oxidation of polycrystalline ruthenium joins the class of materials that obey the Meyer-Neldel rule.

  18. Development of a method for analyzing traces of ruthenium in plant materials and determination of the transfer factors soil/plant for ruthenium compounds from reprocessing plants

    International Nuclear Information System (INIS)

    Blasius, E.; Huth, R.; Neumann, W.

    1988-01-01

    In an artificial humous and sandy soil spiked with 106 Ru as RuO 2 and RuCl 3 , pasture grass was grown under artificial illumination in our laboratory. The amounts of ruthenium taken up by the plants were determined by γ-spectrometry. For open-air investigations with pasture grass, wheat and potatoes inactive ruthenium(III) chloride and ruthenium nitrosylchloride were used. Ruthenium was determined by electrothermal atomic absorption spectrometry (ETAAS) after destroying the organic material and concentrating the solution. The concentration and chemical form of the ruthenium exert an unimportant influence on the transfer factor. For the pasture-grass, the stems of wheat and the weed of potatoes it amounts to 0.00005 to 0.0015, for the ear of wheat to about 0.00005. In peeled potatoes there was no ruthenium detectable, therefore the limit of detection leads to a transfer factor ≤ 0.00001. So it is evident that ruthenium is little available for the roots of the plants. In the event of an accident in a nuclear plant the uptake of radioactive ruthenium by roots has only negligible radioecological consequences. This applies even if 50 years of ruthenium enrichment in the soil are assumed. (orig./RB)

  19. Application of the chemical properties of ruthenium to decontamination processes; L'application des proprietes chimiques du ruthenium a des procedes de decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Fontaine, A.; Berger, D. [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

    1965-07-01

    The chemical properties of ruthenium in the form of an aqueous solution of the nitrate and of organic tributylphosphate solution are reviewed. From this data, some known examples are given: they demonstrate the processes of separation or of elimination of ruthenium from radioactive waste. (authors) [French] Les proprietes chimiques du ruthenium en solutions aqueuses nitriques et en solutions organiques de tributylphosphate, sont passees en revue. A partir de ces donnees, quelques exemples connus sont cites: ils exposent des procedes de separation ou d'elimination du ruthenium de dechets radioactifs. (auteurs)

  20. Application of the chemical properties of ruthenium to decontamination processes; L'application des proprietes chimiques du ruthenium a des procedes de decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Fontaine, A; Berger, D [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

    1965-07-01

    The chemical properties of ruthenium in the form of an aqueous solution of the nitrate and of organic tributylphosphate solution are reviewed. From this data, some known examples are given: they demonstrate the processes of separation or of elimination of ruthenium from radioactive waste. (authors) [French] Les proprietes chimiques du ruthenium en solutions aqueuses nitriques et en solutions organiques de tributylphosphate, sont passees en revue. A partir de ces donnees, quelques exemples connus sont cites: ils exposent des procedes de separation ou d'elimination du ruthenium de dechets radioactifs. (auteurs)

  1. Electro-volatilization of ruthenium in nitric medium: influences of ruthenium species nature and models solutions composition

    International Nuclear Information System (INIS)

    Mousset, F.

    2004-12-01

    Ruthenium is one of the fission products in the reprocessing of irradiated fuels that requires a specific processing management. Its elimination, upstream by the PUREX process, has been considered. A process, called electro-volatilization, which take advantage of the RuO 4 volatility, has been optimised in the present study. It consists in a continuous electrolysis of ruthenium solutions in order to generate RuO 4 species that is volatilized and easily trapped. This process goes to satisfying ruthenium elimination yields with RuNO(NO 3 ) 3 (H 2 O) 2 synthetic solutions but not with fuel dissolution solutions. Consequently, this work consisted in the speciation studies of dissolved ruthenium species were carried out by simulating fuel solutions produced by hot acid attack of several ruthenium compounds (Ru(0), RuO 2 ,xH 2 O, polymetallic alloy). In parallel with dissolution kinetic studies, the determination of dissolved species was performed using voltammetry, spectrometry and spectro-electrochemistry. The results showed the co-existence of Ru(IV) and RuNO(NO 2 ) 2 (H 2 O) 3 . Although these species are different from synthetic RuNO(NO 3 ) 3 (H 2 O) 2 , their electro-oxidation behaviour are similar. The electro-volatilization tests of these dissolution solutions yielded to comparable results as the synthetic RuNO(NO 3 ) 3 (H 2 O) 2 solutions. Then, complexity increase of models solutions was performed by in-situ generation of nitrous acid during ruthenium dissolution. Nitrous acid showed a catalytic effect on ruthenium dissolution. Its presence goes to quasi exclusively RuNO(NO 2 ) 2 (H 2 O) 3 species. It is also responsible of the strong n-bond formation between Ru 2+ and NO + . In addition, it has been shown that its reducing action on RuO 4 hinders the electro-volatilization process. Mn 2+ and Ce 3+ cations also reveal, but to a lesser extent, an electro-eater behaviour as well as Pu 4+ and Cr 3+ according to the thermodynamics data. These results allow one to

  2. Acetate metabolism in Methanothrix soehngenii

    NARCIS (Netherlands)

    Jetten, M.S.M.

    1991-01-01

    Acetate is quantitatively the most important intermediate in the anaerobic degradation of soluble organic matter. The conversion rate of acetate by methanogenic bacteria is proposed to be the rate limiting step in this degradation The study of acetoclastic methanogens, therefore is of

  3. The trans influence in mer-trichloronitridobis(triphenylarsine)ruthenium(VI)

    DEFF Research Database (Denmark)

    Magnussen, Magnus; Bendix, Jesper

    2003-01-01

    The title compound, mer-[RuCl(3)N(C(18)H(15)As)(2)], is the first structurally characterized example of a nitride complex in which ruthenium is six-coordinated to monodentate ligands only. The Ru[triple-bond]N bond length [1.6161 (15) A] is relatively long, and the trans influence of the nitride...

  4. Polystyrene with pendant mixed functional ruthenium(II)-terpyridine complexes

    NARCIS (Netherlands)

    Heller, M.; Schubert, U.S.

    2002-01-01

    A vinyl substituted 2,2:6,2-terpyridine and a mixed, bifunctional ruthenium(II)-terpyridine complex bearing a vinyl and a hydroxymethyl group are utilized as comonomers for radical copolymerization with styrene. The resulting polymers are characterized by means of UV-vis spectroscopy and gel

  5. Electroerosion method for preparation of saturated solutions of ruthenium hydroxochloride

    International Nuclear Information System (INIS)

    Mikhalev, V.A.; Andrianov, G.A.; Zhadanov, B.V.; Ryazanov, A.I.

    1987-01-01

    A pilot plant for carrying out electroerosion processes using pulse current of high unit power is developed. The solution process of metallic Ru in concentrated HCl is investigated. The possibility of preparation of ruthenium hydroxochloride solutions of 300 g/l concentration is established; it gives the possibility of Ru solution under conditions similar to the process of salting out

  6. A new approach to synthesize supported ruthenium phosphides for hydrodesulfurization

    International Nuclear Information System (INIS)

    Wang, Qingfang; Wang, Zhiqiang; Yin, Xiaoqian; Zhou, Linxi; Zhang, Minghui

    2016-01-01

    Highlights: • We bring out a new method to synthesize noble metal phosphides at low temperature. • Both RuP and Ru_2P were synthesized using triphenylphosphine as phosphorus sources. • Ru_2P was the better active phase for HDS than RuP and metal Ru. • RuP/SiO_2 prepared by new method had better HDS activity to that by TPR method. - Abstract: Supported noble metal ruthenium phosphides were synthesized by one-step H_2-thermal treatment method using triphenylphosphine (TPP) as phosphorus sources at low temperatures. Two phosphides RuP and Ru_2P can be prepared by this method via varying the molar ratio of metal salt and TPP. The as-prepared phosphides were characterized by X-ray powder diffraction (XRD), low-temperature N_2 adsorption, CO chemisorption and transmission electronic microscopy (TEM). The supported ruthenium phosphides prepared by new method and conventional method together with contradistinctive metallic ruthenium were evaluated in hydrodesulfurization (HDS) of dibenzothiophene (DBT). The catalytic results showed that metal-rich Ru_2P was the better active phase for HDS than RuP and metal Ru. Besides this, ruthenium phosphide catalyst prepared by new method exhibited superior HDS activity to that prepared by conventional method.

  7. A new approach to synthesize supported ruthenium phosphides for hydrodesulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Qingfang [Tianjin Key Laboratory of Water Environment and Resources, Tianjin Normal University, Tianjin 300387 (China); Key Laboratory of Advanced Energy Materials Chemistry (MOE), Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), College of Chemistry, Nankai University, Tianjin 300071 (China); Wang, Zhiqiang [Tianjin Key Laboratory of Water Environment and Resources, Tianjin Normal University, Tianjin 300387 (China); Yin, Xiaoqian; Zhou, Linxi [Key Laboratory of Advanced Energy Materials Chemistry (MOE), Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), College of Chemistry, Nankai University, Tianjin 300071 (China); Zhang, Minghui, E-mail: zhangmh@nankai.edu.cn [Key Laboratory of Advanced Energy Materials Chemistry (MOE), Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), College of Chemistry, Nankai University, Tianjin 300071 (China); College of Chemistry and Environmental Science, Kashgar University, Kashgar 844006 (China)

    2016-02-15

    Highlights: • We bring out a new method to synthesize noble metal phosphides at low temperature. • Both RuP and Ru{sub 2}P were synthesized using triphenylphosphine as phosphorus sources. • Ru{sub 2}P was the better active phase for HDS than RuP and metal Ru. • RuP/SiO{sub 2} prepared by new method had better HDS activity to that by TPR method. - Abstract: Supported noble metal ruthenium phosphides were synthesized by one-step H{sub 2}-thermal treatment method using triphenylphosphine (TPP) as phosphorus sources at low temperatures. Two phosphides RuP and Ru{sub 2}P can be prepared by this method via varying the molar ratio of metal salt and TPP. The as-prepared phosphides were characterized by X-ray powder diffraction (XRD), low-temperature N{sub 2} adsorption, CO chemisorption and transmission electronic microscopy (TEM). The supported ruthenium phosphides prepared by new method and conventional method together with contradistinctive metallic ruthenium were evaluated in hydrodesulfurization (HDS) of dibenzothiophene (DBT). The catalytic results showed that metal-rich Ru{sub 2}P was the better active phase for HDS than RuP and metal Ru. Besides this, ruthenium phosphide catalyst prepared by new method exhibited superior HDS activity to that prepared by conventional method.

  8. Determination of oxygen diffusion kinetics during thin film ruthenium oxidation

    NARCIS (Netherlands)

    Coloma Ribera, R.; van de Kruijs, Robbert Wilhelmus Elisabeth; Yakshin, Andrey; Bijkerk, Frederik

    2015-01-01

    In situ X-ray reflectivity was used to reveal oxygen diffusion kinetics for thermal oxidation of polycrystalline ruthenium thin films and accurate determination of activation energies for this process. Diffusion rates in nanometer thin RuO2 films were found to show Arrhenius behaviour. However, a

  9. An XPS study on ruthenium compounds and catalysts

    International Nuclear Information System (INIS)

    Bianchi, C.L.; Ragaini, V.; Cattania, M.G.

    1991-01-01

    The binding energy (BE) of the relevant peaks of several ruthenium compounds have been measured with a monochromatic small spot XPS. The BE of the 3d 5/2 level of ruthenium is in the range 279.91-282.88 eV. The variation of BE is due either to the variation of the oxidation state or to the different counter-ion. A series of catalysts with varying amounts of ruthenium supported on alumina and prepared using different precursors was also analyzed. The presence of more ruthenium species other than the metal was observed. On the basis of the values previously obtained on unsupported compounds, the species with higher BE were assigned to oxides. On all the samples prepared from RuCl 3 , an additional peak at a very high BE (283.79 eV) has been observed. This peak is related to the presence of chlorine on the surface: it is suggested that it is related to a charge transfer interaction. The influence of this species on the CO reactivity in the Fischer-Tropsch reaction is discussed. (orig.)

  10. Oxidation of ruthenium thin films using atomic oxygen

    Energy Technology Data Exchange (ETDEWEB)

    McCoy, A.P.; Bogan, J.; Brady, A.; Hughes, G.

    2015-12-31

    In this study, the use of atomic oxygen to oxidise ruthenium thin films is assessed. Atomic layer deposited (ALD) ruthenium thin films (~ 3 nm) were exposed to varying amounts of atomic oxygen and the results were compared to the impact of exposures to molecular oxygen. X-ray photoelectron spectroscopy studies reveal substantial oxidation of metallic ruthenium films to RuO{sub 2} at exposures as low as ~ 10{sup 2} L at 575 K when atomic oxygen was used. Higher exposures of molecular oxygen resulted in no metal oxidation highlighting the benefits of using atomic oxygen to form RuO{sub 2}. Additionally, the partial oxidation of these ruthenium films occurred at temperatures as low as 293 K (room temperature) in an atomic oxygen environment. - Highlights: • X-ray photoelectron spectroscopy study of the oxidation of Ru thin films • Oxidation of Ru thin films using atomic oxygen • Comparison between atomic oxygen and molecular oxygen treatments on Ru thin films • Fully oxidised RuO{sub 2} thin films formed with low exposures to atomic oxygen.

  11. The use of ruthenium in various fields of industry

    International Nuclear Information System (INIS)

    Sinitsin, N.M.

    1990-03-01

    Metallic ruthenium, its alloys, and compounds with other metals have a number of valuable and specific properties which allow the usage of ruthenium in various fields of modern technology, which is described here. In the atomic technology, Ru can be used in the building of reactors as a material of construction since its isotopes don't possess a high neutron capture cross section. Ruthenium is used for the preparation of γ- and β-ray emission sources. Isotopes Ru-103 and Ru-106 are widely used as tracers. They are successfully used for the monitoring of production, for the development of new technological and analytical methods of the extraction of Ru, for the cleansing of other valuable metals from Ru, for the monitoring of the thickness of Ru microfilm on the substrate, and for the monitoring of Ru losses in various processes. In the nuclear reactor, during the process of uranium and plutonium decay, large amounts of stable Ru isotopes are formed together with radioactive isotopes. In such a manner, a nuclear reactor can supply Ru. Special attention must be paid to the usage of direct coordination Ru compounds. Ru and its compounds possess a large number of very valuable properties, many of the secrets of Ru must still be discovered. It can be presumed that the demand for ruthenium will grow in the forthcoming years and the range and volume of its applications will increase

  12. Ruthenium based redox flow battery for solar energy storage

    International Nuclear Information System (INIS)

    Chakrabarti, Mohammed Harun; Roberts, Edward Pelham Lindfield; Bae, Chulheung; Saleem, Muhammad

    2011-01-01

    Research highlights: → Undivided redox flow battery employing porous graphite felt electrodes was used. → Ruthenium acetylacetonate dissolved in acetonitrile was the electrolyte. → Charge/discharge conditions were determined for both 0.02 M and 0.1 M electrolytes. → Optimum power output of 0.180 W was also determined for 0.1 M electrolyte. → 55% voltage efficiency was obtained when battery was full of electrolytes. -- Abstract: The technical performance for the operation of a stand alone redox flow battery system for solar energy storage is presented. An undivided reactor configuration has been employed along with porous graphite felt electrodes and ruthenium acetylacetonate as electrolyte in acetonitrile solvent. Limiting current densities are determined for concentrations of 0.02 M and 0.1 M ruthenium acetylacetonate. Based on these, operating conditions for 0.02 M ruthenium acetylacetonate are determined as charging current density of 7 mA/cm 2 , charge electrolyte superficial velocity of 0.0072 cm/s (through the porous electrodes), discharge current density of 2 mA/cm 2 and discharge electrolyte superficial velocity of 0.0045 cm/s. An optimum power output of 35 mW is also obtained upon discharge at 2.1 mA/cm 2 . With an increase in the concentration of ruthenium species from 0.02 M to 0.1 M, the current densities and power output are higher by a factor of five approximately (at same superficial velocities) due to higher mass transport phenomenon. Moreover at 0.02 M concentration the voltage efficiency is better for battery full of electrolytes prior to charging (52.1%) in comparison to an empty battery (40.5%) due to better mass transport phenomenon. Voltage efficiencies are higher as expected at concentrations of 0.1 M ruthenium acetylacetonate (55% when battery is full of electrolytes and 48% when empty) showing that the all-ruthenium redox flow battery has some promise for future applications in solar energy storage. Some improvements for the

  13. Recommendation of ruthenium source for sludge batch flowsheet studies

    Energy Technology Data Exchange (ETDEWEB)

    Woodham, W. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-09-13

    Included herein is a preliminary analysis of previously-generated data from sludge batches 7a, 7b, 8, and 9 sludge simulant and real-waste testing, performed to recommend a form of ruthenium for future sludge batch simulant testing under the nitric-formic flowsheet. Focus is given to reactions present in the Sludge Receipt and Adjustment Tank cycle, given that this cycle historically produces the most changes in chemical composition during Chemical Process Cell processing. Data is presented and analyzed for several runs performed under the nitric-formic flowsheet, with consideration given to effects on the production of hydrogen gas, nitrous oxide gas, consumption of formate, conversion of nitrite to nitrate, and the removal and recovery of mercury during processing. Additionally, a brief discussion is given to the effect of ruthenium source selection under the nitric-glycolic flowsheet. An analysis of data generated from scaled demonstration testing, sludge batch 9 qualification testing, and antifoam degradation testing under the nitric-glycolic flowsheet is presented. Experimental parameters of interest under the nitric-glycolic flowsheet include N2O production, glycolate destruction, conversion of glycolate to formate and oxalate, and the conversion of nitrite to nitrate. To date, the number of real-waste experiments that have been performed under the nitric-glycolic flowsheet is insufficient to provide a complete understanding of the effects of ruthenium source selection in simulant experiments with regard to fidelity to real-waste testing. Therefore, a determination of comparability between the two ruthenium sources as employed under the nitric-glycolic flowsheet is made based on available data in order to inform ruthenium source selection for future testing under the nitric-glycolic flowsheet.

  14. Study on volatilization mechanism of ruthenium tetroxide from nitrosyl ruthenium nitrate by using mass spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Tetsuya, E-mail: tkato@criepi.denken.or.jp [Nuclear Technology Research Laboratory, Central Research Institute of Electric Power Industry, 2-11-1 Iwado-kita, Komae-shi, Tokyo 201-8511 (Japan); Usami, Tsuyoshi; Tsukada, Takeshi [Nuclear Technology Research Laboratory, Central Research Institute of Electric Power Industry, 2-11-1 Iwado-kita, Komae-shi, Tokyo 201-8511 (Japan); Shibata, Yuki; Kodama, Takashi [Safety Technology Division, Japan Nuclear Fuel Ltd., Obuchi, Rokkasho-mura, Aomori 039-3212 (Japan)

    2016-10-15

    In a cooling malfunction accident of a high-level liquid waste (HLLW) tank, behavior of ruthenium (Ru) attracts much attention, since Ru could be oxidized to a volatile chemical form in the boiling and drying of HLLW, and part of radioactive Ru can potentially be released to the environment. In this study, nitrosyl Ru nitrate (Ru(NO)(NO{sub 3}){sub 3}) dissolved in nitric acid (HNO{sub 3}), which is commonly contained in a simulated HLLW, was dried and heated up to 723 K, and the evolved gas was introduced into a mass spectrometer. The well-known volatile species, ruthenium tetroxide (RuO{sub 4}) was detected in a temperature range between 390 K and 500 K with the peak top around 440 K. Various gases such as HNO{sub 3}, nitrogen dioxide (NO{sub 2}), nitrogen monoxide (NO) also evolved due to evaporation of the nitric acid and decomposition of the nitrate ions. The ion current of RuO{sub 4} seems to increase with the increasing decomposition of nitrate, while the evaporation of HNO{sub 3} decreases. More volatilization of RuO{sub 4} was observed from the HNO{sub 3} solution containing not only Ru(NO)(NO{sub 3}){sub 3} but also cerium nitrate (Ce(NO{sub 3}){sub 3}·6H{sub 2}O) which was added for extra supply of nitrate ion, compared with that from the HNO{sub 3} solution containing only Ru(NO)(NO{sub 3}){sub 3}. These experimental results suggest that Ru could be oxidized to form RuO{sub 4} by the nitrate ion as well as HNO{sub 3}. - Graphical abstract: Ion current intensities of the mass numbers corresponding to O, NO, O{sub 2}, NO{sub 2}, HNO{sub 3}, and RuO{sub 4} obtained in mass spectrometry for dried nitric acid solution containing Ru(NO)(NO{sub 3}){sub 3}. Heating rate: 5 K min{sup −1}, sample solution weight: 6.61 mg, contained Ru weight: 0.56 mg. The ion current of RuO{sub 4} increases with the increasing decomposition of nitrate, while the evaporation of HNO{sub 3} decreases. - Highlights: • Nitrosyl Ru nitrate (Ru(NO)(NO{sub 3}){sub 3}) dissolved in

  15. C-N bond cleavage of anilines by a (salen)ruthenium(VI) nitrido complex.

    Science.gov (United States)

    Man, Wai-Lun; Xie, Jianhui; Pan, Yi; Lam, William W Y; Kwong, Hoi-Ki; Ip, Kwok-Wa; Yiu, Shek-Man; Lau, Kai-Chung; Lau, Tai-Chu

    2013-04-17

    We report experimental and computational studies of the facile oxidative C-N bond cleavage of anilines by a (salen)ruthenium(VI) nitrido complex. We provide evidence that the initial step involves nucleophilic attack of aniline at the nitrido ligand of the ruthenium complex, which is followed by proton and electron transfer to afford a (salen)ruthenium(II) diazonium intermediate. This intermediate then undergoes unimolecular decomposition to generate benzene and N2.

  16. Ruthenium(III Chloride Catalyzed Acylation of Alcohols, Phenols, and Thiols in Room Temperature Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Mingzhong Cai

    2009-09-01

    Full Text Available Ruthenium(III chloride-catalyzed acylation of a variety of alcohols, phenols, and thiols was achieved in high yields under mild conditions (room temperature in the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]. The ionic liquid and ruthenium catalyst can be recycled at least 10 times. Our system not only solves the basic problem of ruthenium catalyst reuse, but also avoids the use of volatile acetonitrile as solvent.

  17. Synthesis of PVP-stabilized ruthenium colloids with low boiling point alcohols.

    Science.gov (United States)

    Zhang, Yuqing; Yu, Jiulong; Niu, Haijun; Liu, Hanfan

    2007-09-15

    A route to the preparation of poly(N-vinyl-2-pyrrolidone) (PVP)-stabilized ruthenium colloids by refluxing ruthenium(III) chloride in low boiling point alcohols was developed. Deep purple colloids with shuttle-like ruthenium particles were also synthesized. XPS measurement verified the nanoparticles were in the metallic state. The morphology of metal nanoparticles was characterized by UV-visible absorption spectrophotometry, TEM and XRD.

  18. Experiments on the behaviour of ruthenium in air ingress accidents - Progress report

    International Nuclear Information System (INIS)

    Kaerkelae, T.; Backman, U.; Auvinen, A.; Ziliacus, R.; Lipponen, M.; Kekki, T.; Tapper, U.; Jokiniemi, J.

    2006-02-01

    During routine nuclear reactor operation, ruthenium will accumulate in the fuel in relatively high concentrations. In an accident in a nuclear power plant it is possible that air gets into contact with the reactor core. In this case ruthenium can oxidise and form volatile ruthenium species, RuO3 and RuO4, which can be transported into the containment. In order to estimate the amount of gaseous ruthenium species it is of interest to know, how it is formed and how it behaves. In our experiments RuO2 is exposed to diverse oxidising atmospheres at a relatively high temperature. In this report, the experimental system for the ruthenium behaviour study is presented. Also preliminary results from experiments carried out during year 2005 are reported. In the experiments gaseous ruthenium oxides were produced in a furnace. Upon cooling RuO2 aerosol particles were formed in the system. They were removed with plane filters from the gas stream. Gaseous ruthenium species were trapped in 1M NaOH-water solution, which is capable of trapping RuO4 totally. Ruthenium in the solution was filtered for analysis. The determination of ruthenium both in aerosol and in liquid filters was made using instrumental neutron activation analysis (INAA). In order to close mass balance and achieve better time resolution three experiment using radioactive tracer were carried out. (au)

  19. Optimization of screen-printed ruthenium dioxide electrodes for pH measurements

    International Nuclear Information System (INIS)

    Wyzkiewicz, I.

    2002-01-01

    Optimization of disposable, screen-printed pH-sensors based on ruthenium dioxide is described in this paper. The electrodes were prepared with the use of thick-film technology. The pH-sensitive layers were deposited onto polyester foil. Polymer graphite paste containing ruthenium dioxide from 0% to 90% has been investigated. The dependence of the pH-sensitive layers related to ruthenium dioxide content is presented. The investigation proved that the electrodes containing 40-60% ruthenium dioxide exhibit linear high sensitivity (∼ 50 mV/pH) in the wide range of pH (2 - 11) as well as very good reproducibility. (author)

  20. 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

  1. Surface and sub-surface thermal oxidation of thin ruthenium films

    Energy Technology Data Exchange (ETDEWEB)

    Coloma Ribera, R.; Kruijs, R. W. E. van de; Yakshin, A. E.; Bijkerk, F. [MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands); Kokke, S.; Zoethout, E. [FOM Dutch Institute for Fundamental Energy Research (DIFFER), P.O. Box 1207, 3430 BE Nieuwegein (Netherlands)

    2014-09-29

    A mixed 2D (film) and 3D (nano-column) growth of ruthenium oxide has been experimentally observed for thermally oxidized polycrystalline ruthenium thin films. Furthermore, in situ x-ray reflectivity upon annealing allowed the detection of 2D film growth as two separate layers consisting of low density and high density oxides. Nano-columns grow at the surface of the low density oxide layer, with the growth rate being limited by diffusion of ruthenium through the formed oxide film. Simultaneously, with the growth of the columns, sub-surface high density oxide continues to grow limited by diffusion of oxygen or ruthenium through the oxide film.

  2. Experiments on the behaviour of ruthenium in air ingress accidents - Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Kaerkelae, T.; Backman, U.; Auvinen, A.; Ziliacus, R.; Lipponen, M.; Kekki, T.; Tapper, U.; Jokiniemi, J. [VTT Technical Research Centre of Finland (Finland)

    2006-02-15

    During routine nuclear reactor operation, ruthenium will accumulate in the fuel in relatively high concentrations. In an accident in a nuclear power plant it is possible that air gets into contact with the reactor core. In this case ruthenium can oxidise and form volatile ruthenium species, RuO3 and RuO4, which can be transported into the containment. In order to estimate the amount of gaseous ruthenium species it is of interest to know, how it is formed and how it behaves. In our experiments RuO2 is exposed to diverse oxidising atmospheres at a relatively high temperature. In this report, the experimental system for the ruthenium behaviour study is presented. Also preliminary results from experiments carried out during year 2005 are reported. In the experiments gaseous ruthenium oxides were produced in a furnace. Upon cooling RuO2 aerosol particles were formed in the system. They were removed with plane filters from the gas stream. Gaseous ruthenium species were trapped in 1M NaOH-water solution, which is capable of trapping RuO4 totally. Ruthenium in the solution was filtered for analysis. The determination of ruthenium both in aerosol and in liquid filters was made using instrumental neutron activation analysis (INAA). In order to close mass balance and achieve better time resolution three experiment using radioactive tracer were carried out. (au)

  3. Evaluation of radiolabeled ruthenium compounds as tumor-localizing agents

    International Nuclear Information System (INIS)

    Srivastava, S.C.; Richards, P.; Meinken, G.E.; Som, P.; Atkins, H.L.; Larson, S.M.; Grunbaum, Z.; Rasey, J.S.; Clarke, M.H.; Dowling, M.

    1979-01-01

    This work introduces a new class of radiopharmaceuticals based on ruthenium-97. The excellent physical properties of Ru-97, the high chemical reactivity of Ru, the potential antitumor activity of several Ru coordination compounds, and BLIP production of Ru-97, provide a unique combination for the application of this isotope in nuclear oncology. A systematic study was undertaken on the synthesis, characterization, and evaluation of a number of ruthenium-labeled compounds. In a variety of animal tumor models, several compounds show considerable promise as tumor-localizing agents when compared to gallium-67 citrate. The compounds studied (with Ru in different oxidation states) include ionic Ru, a number of hydrophilic and lipophilic chelates, and various ammine derivatives

  4. Chemical vapor deposition of amorphous ruthenium-phosphorus alloy films

    International Nuclear Information System (INIS)

    Shin Jinhong; Waheed, Abdul; Winkenwerder, Wyatt A.; Kim, Hyun-Woo; Agapiou, Kyriacos; Jones, Richard A.; Hwang, Gyeong S.; Ekerdt, John G.

    2007-01-01

    Chemical vapor deposition growth of amorphous ruthenium-phosphorus films on SiO 2 containing ∼ 15% phosphorus is reported. cis-Ruthenium(II)dihydridotetrakis-(trimethylphosphine), cis-RuH 2 (PMe 3 ) 4 (Me = CH 3 ) was used at growth temperatures ranging from 525 to 575 K. Both Ru and P are zero-valent. The films are metastable, becoming increasingly more polycrystalline upon annealing to 775 and 975 K. Surface studies illustrate that demethylation is quite efficient near 560 K. Precursor adsorption at 135 K or 210 K and heating reveal the precursor undergoes a complex decomposition process in which the hydride and trimethylphosphine ligands are lost at temperatures as low at 280 K. Phosphorus and its manner of incorporation appear responsible for the amorphous-like character. Molecular dynamics simulations are presented to suggest the local structure in the films and the causes for phosphorus stabilizing the amorphous phase

  5. Ruthenium Complexes as NO Donors for Vascular Relaxation Induction

    Directory of Open Access Journals (Sweden)

    Renata Galvão de Lima

    2014-07-01

    Full Text Available Nitric oxide (NO donors are substances that can release NO. Vascular relaxation induction is among the several functions of NO, and the administration of NO donors is a pharmacological alternative to treat hypertension. This review will focus on the physicochemical description of ruthenium-derived NO donor complexes that release NO via reduction and light stimulation. In particular, we will discuss the complexes synthesized by our research group over the last ten years, and we will focus on the vasodilation and arterial pressure control elicited by these complexes. Soluble guanylyl cyclase (sGC and potassium channels are the main targets of the NO species released from the inorganic compounds. We will consider the importance of the chemical structure of the ruthenium complexes and their vascular effects.

  6. Committee's report on ruthenium fall-out incident

    International Nuclear Information System (INIS)

    Borkowski, C.J.; Crawford, J.H.; Livingston, R.; Ritchie, R.H.; Rupp, A.F.; Taylor, E.H.

    1983-07-01

    Investigations of the fall-out incident of November 11 and 12, 1959, by responsible parties (Health Physics Division and Operations Division personnel) established beyond reasonable doubt that the incident had its origin in the expulsion of particles, heavily contaminated with ruthenium, which had been detached from the walls of the electric fan housing and ducts in the off-gas system associated with the brick stack. All available evidence indicates that the particles were loosened during maintenance work on the exhaust damper and the bearings of the electric fan and were carried up the stack in two bursts as particulate fall-out when this fan was put back into service. Radiographic and chemical analysis showed the activity to be almost entirely ruthenium (Ru 106 ) and its daughter rhodium (Rh 106 ) with very little, if any, strontium being present. This report summarizes the findings and sets forth the conclusions and recommendations of the Committee asked to investigate the incident

  7. The Biological Side of Water-Soluble Arene Ruthenium Assemblies

    OpenAIRE

    Therrien, Bruno; Furrer, Julien

    2014-01-01

    This review article covers the synthetic strategies, structural aspects, and host-guest properties of ruthenium metalla-assemblies, with a special focus on their use as drug delivery vectors. The two-dimensional metalla-rectangles show interesting host-guest possibilities but seem less appropriate for being used as drug carriers. On the other hand, metalla-prisms allow encapsulation and possible targeted release of bioactive molecules and consequently show some potential as drug delivery vect...

  8. THE SYNTHESIS AND THE REACTIVITY OF ARENE RUTHENIUM ...

    African Journals Online (AJOL)

    a

    [RuCl(η6-p-cymene)(η2-dppm)][PF6] ruthenium complexes with C2O4(Me4N)2 in the ... the Service de Microanalyse du CNRS (Vernaison/France). .... Once bonded to the Ru(II), the characterization of the oxalato ligand by infrared .... The 1H NMR spectrum shows signals of the aromatic proton resonances at 5.45 and 5.15,.

  9. Allenylidene Complexes of Ruthenium: Synthesis, Spectroscopy and Electron Transfer Properties

    Czech Academy of Sciences Publication Activity Database

    Winter, R. F.; Záliš, Stanislav

    2004-01-01

    Roč. 248, 15/16 (2004), s. 1565-1583 ISSN 0010-8545 R&D Projects: GA ČR GA203/03/0821; GA MŠk OC D14.20 Institutional research plan: CEZ:AV0Z4040901 Keywords : spectroscopy * allenylidine complexes of ruthenium * electron transfer Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 6.446, year: 2004

  10. Behaviour of ruthenium (3) bromocomplexes in nonaqueous solvents

    International Nuclear Information System (INIS)

    Rudnitskaya, O.V.; Miroshnichenko, I.V.; Pichkov, V.N.

    1989-01-01

    Behaviour of K 3 [RuBr 6 ] · H 2 O and K 3 [Ru 2 Br 9 ] in solutions of dimethylsulfoxide and dimethylformamide is investigated by absorption and ESR spectroscopy. Complexes are shown to be labile in solutions, interact easily with solvents. Formation of ruthenium (3) and (2) bromide-dimethylsulfoxide complexes occurs gradually in DMSO, final product is trans-[Ru(DMSO) 4 Br 2

  11. Role of ligands in controlling the regioselectivity in ruthenium ...

    Indian Academy of Sciences (India)

    of Hay and Wadt (LANL2DZ)11 for ruthenium atom and 6-31G(d)12 for other .... C2 atom in 3x/3′ x. To understand the wider role of lig- ands in modulating the regio-selectivity of product for- mation, we have studied the benzoic acid addition to the selected .... at C1 and the localization of electron density in the. M=C double ...

  12. Mechanism of ruthenium dioxide crystallization during high level waste vitrification

    International Nuclear Information System (INIS)

    Boucetta, H.

    2012-01-01

    Ruthenium, arising from the reprocessing of spent uranium oxide fuel, has a low solubility in glass melt. It crystallizes in the form of particles of RuO 2 of acicular or polyhedral morphology dispersed in fission product and actinides waste containment glass. Since the morphology of these particles strongly influences the physico-chemical properties, the knowledge and the control of their mechanism of formation are of major importance. The goal of this work is to determine the chemical reactions responsible for the formation of RuO 2 particles of acicular or polyhedral shape during glass synthesis. Using a simplification approach, the reactions between RuO 2 -NaNO 3 , and more complex calcine RuO 2 -Al 2 O 3 -Na 2 O and a sodium borosilicate glass are studied. In situ scanning electron microscopy and XANES at increasing temperatures are used to follow changes in composition, speciation and morphology of the ruthenium intermediate species. Those compounds are thoroughly characterised by SEM, XRD, HRTEM, and ruthenium K-edge X-ray absorption spectroscopy. This combined approach allows us to show that the ruthenium speciation modification during vitrification is the key of control of the morphology of RuO 2 particles in the glass. In particular, the formation of a specific intermediate compound (Na 3 RuO 4 ) is one of the main steps that lead to the precipitation of needle-shaped RuO 2 particles in the melt. The formation of polyhedral particles, on the contrary, results from the direct incorporation of RuO 2 crystals in the melt followed by an Ostwald ripening mechanism. (author) [fr

  13. Behaviour of ruthenium dioxide particles in borosilicate glasses and melts

    Energy Technology Data Exchange (ETDEWEB)

    Pflieger, Rachel [DEN/DTCD-SCDV/CEA Valrho, Centre de Marcoule, BP17171, 30207 Bagnols-sur-Ceze (France); Institut de Chimie Separative de Marcoule, UMR5257, Centre de Marcoule, BP17171, 30207 Bagnols-sur-Ceze Cedex (France)], E-mail: rachel_pflieger@yahoo.fr; Lefebvre, Leila [DEN/DTCD-SCDV/CEA Valrho, Centre de Marcoule, BP17171, 30207 Bagnols-sur-Ceze (France); Malki, Mohammed [CNRS/CEMHTI-1D Av. de la Recherche Scientifique, 45701 Orleans cedex 2 (France); Polytech Orleans, Universite d' Orleans, 8 rue Leonard de Vinci, 45072 Orleans cedex 2 (France); Allix, Mathieu [CNRS/CEMHTI-1D Av. de la Recherche Scientifique, 45701 Orleans cedex 2 (France); Grandjean, Agnes [DEN/DTCD-SCDV/CEA Valrho, Centre de Marcoule, BP17171, 30207 Bagnols-sur-Ceze (France); Institut de Chimie Separative de Marcoule, UMR5257, Centre de Marcoule, BP17171, 30207 Bagnols-sur-Ceze Cedex (France)

    2009-06-01

    Ruthenium-glass systems are formed during the vitrification of nuclear waste. They are also widely used in micro-electronics because of their unique electrical properties. However, the interaction of this element with the glass matrix remains poorly understood. This work focuses on a RuO{sub 2} particles-nuclear alumino-borosilicate glass system in which the electrical conductivity is known to vary considerably with the RuO{sub 2} content and to become electronic above about 0.5-0.7 vol.% RuO{sub 2} [R. Pflieger, M. Malki, Y. Guari, J. Larionova, A. Grandjean, J. Am. Ceram. Soc., accepted for publication]. Some RuO{sub 2} segregation was observed in SEM/TEM investigations but no continuous chain of RuO{sub 2} particles could be seen. Electron relays between the particles are then necessary for a low-rate percolation, such as the nanoclusters suggested by Adachi et al. [K. Adachi, S. Iida, K. Hayashi, J. Mater. Res. 9 (7) (1994) 1866; K. Adachi, H. Kuno, J. Am. Ceram. Soc. 83 (10) (2000) 2441], which could consist in dissolved ruthenium. Indeed, several observations made here clearly indicate the presence of dissolved ruthenium in the glass matrix, like the modification of the glass density in presence of RuO{sub 2} particles or the diffusion-limited growth of RuO{sub 2} particles in the melt.

  14. 21 CFR 184.1185 - Calcium acetate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium acetate. 184.1185 Section 184.1185 Food and... Substances Affirmed as GRAS § 184.1185 Calcium acetate. (a) Calcium acetate (Ca (C2H3O2)2, CAS Reg. No. 62-54-4), also known as acetate of lime or vinegar salts, is the calcium salt of acetic acid. It may be...

  15. Atomic Layer Deposition of Ruthenium with TiN Interface for Sub-10 nm Advanced Interconnects beyond Copper

    DEFF Research Database (Denmark)

    Wen, Liang Gong; Roussel, Philippe; Pedreira, Olalla Varela

    2016-01-01

    . These extremely scaled ruthenium lines show excellent electromigration behavior. Time-dependent dielectric breakdown measurements reveal negligible ruthenium ion drift into low-kappa dielectrics up to 200 degrees C, demonstrating that ruthenium can be used as a barrierless metallization in interconnects...

  16. Radiation sterilization of hydrocortisone acetate

    International Nuclear Information System (INIS)

    Charef, A.; Boussaha, A.

    1989-09-01

    The feasibility of using high energy ionizing radiation for the sterilization of hydrocortisone acetate was investigated. Hydrocortisone acetate in the form of powder was exposed to different dose levels of gamma radiation using a Cobalt-60 source. The irradiated samples were examined by various physico-chemical techniques in order to detect possible radiolysis products. It was of interest to know if one could insure sterility and retain biological properties of the drug by suitable choice of radiation dose. The results showed that a 10 KGy radiation dose causes no change in the physico-chemical properties of the drug and is sufficient to obtain contaminant-free product

  17. Ruthenium release from thermally overheated nitric acid solution containing ruthenium nitrosyl nitrate and sodium nitrate to solidify

    Energy Technology Data Exchange (ETDEWEB)

    Sawada, Kayo; Ueda, Yasuyuki; Enokida, Youichi [Nuclear Chemical Engineering Laboratory, Nagoya University, Nagoya 4648603 (Japan)

    2016-07-01

    Radioactive ruthenium (Ru) is one of the dominant elemental species released into the environment from a fuel reprocessing plant in a hypothetical design accident due to its relatively higher fission yield and longer half-life. After the hypothetical accident assuming the loss of all electric power and cooling functions, high-level liquid waste (HLLW) may be overheated by the energetic decays of many fission products in it, and Ru may be oxidized to the volatile tetroxide, RuO{sub 4}, which is released through the off-gas pathway. At a reprocessing plant in Japan, alkaline solution from the solvent scrubbing stream is sometimes mixed with the HLLW followed by vitrification, which can be influenced by the addition of sodium nitrate to a simulated HLLW containing ruthenium nitrosyl nitrate that was experimentally evaluated on a small scale using the overheated nitric acid solution of 2 mol/dm{sup 3}, which was kept at 180 Celsius degrees in a glass evaporator placed in a thermostatic bath. The release fraction of Ru increased by approximately 30% by the addition of sodium nitrate. This may be partially explained by the existence of relatively highly concentrated nitrate ions in the liquid phase that oxidize the ruthenium species to RuO{sub 4} during the drying process. (authors)

  18. Catalytic Ammonia Decomposition Over Ruthenium Nanoparticles Supported on Nano-Titanates

    DEFF Research Database (Denmark)

    Klerke, Asbjørn; Klitgaard, Søren Kegnæs; Fehrmann, Rasmus

    2009-01-01

    Nanosized Na2Ti3O7, K2Ti6O13 and Cs2Ti6O13 materials were prepared and used as supports of ruthenium nanoparticles for catalytic ammonia decomposition. It is shown that these catalysts exhibit higher catalytic activity than ruthenium supported on TiO2 nanoparticles promoted with cesium. The diffe...

  19. Surface and sub-surface thermal oxidation of thin ruthenium films

    NARCIS (Netherlands)

    Coloma Ribera, R.; van de Kruijs, Robbert Wilhelmus Elisabeth; Kokke, S.; Zoethout, E.; Yakshin, Andrey; Bijkerk, Frederik

    2014-01-01

    A mixed 2D (film) and 3D (nano-column) growth of ruthenium oxide has been experimentally observed for thermally oxidized polycrystalline ruthenium thin films. Furthermore, in situ x-ray reflectivity upon annealing allowed the detection of 2D film growth as two separate layers consisting of low

  20. Synthesis and characterization of novel heteroleptic ruthenium sensitizer for nanocrystalline dye-sensitized solar cells

    NARCIS (Netherlands)

    Sivakumar, R.; Marcelis, A.T.M.; Anandan, S.

    2009-01-01

    A novel heteroleptic ruthenium complex of the type [Ru(bpin)(dcbpyH2)Cl]Cl (where bpin is 2,6-bis(pyrazol-1-yl)isonicotinic acid and dcbpyH2 is 4,4'-dicarboxy-2,2'-bipyridine) was synthesized and characterized for tuning the LUMO level of the ruthenium sensitizer to achieve greater stabilization in

  1. Ruthenium on chitosan: A recyclable heterogeneous catalyst for aqueous hydration of nitriles to amides

    Science.gov (United States)

    Ruthenium has been immobilized over chitosan by simply stirring an aqueous suspension of chitosan in water with ruthenium chloride and has been utilized for the oxidation of nitriles to amides; the hydration of nitriles occurs in high yield and excellent selectivity, which procee...

  2. Synthesis of methyl acetate from dimethyl ether using group VIII metal salts of phosphotungstic acid

    Energy Technology Data Exchange (ETDEWEB)

    Sardesai, A.; Lee, S.; Tartamella, T.

    2002-04-01

    Dimethyl ether (DME) can be produced much more efficiently in a single-stage, liquid-phase process from natural gas-based syngas as compared to the conventional process via dehydration of methanol. This process, based on dual catalysts slurried in inert oil, alleviates the chemical equilibrium limitation governing the methanol synthesis reaction and concurrently improves per-pass syngas conversion and reactor productivity. The potential, therefore, for production of methyl acetate via dimethyl ether carbonylation is of industrial importance. In the present study, conversion of dimethyl ether and carbon monoxide to methyl acetate is investigated over a variety of group VIII metal-substituted phosphotungstic acid salts. Experimental results of this catalytic reaction using rhodium, iridium, ruthenium, and palladium catalysts are evaluated and compared in terms of selectivity toward methyl acetate. The effects of active metal, support types, multiple metal loading, and feed conditions on carbonylation activity of DME are examined. Iridium metal substituted phosphotungstic acid supported on Davisil type 643 (pore size 150 A, surface area 279 m{sup 2}/g, mesh size 230-425) silica gel shows the highest activity for DME carbonylation. (author)

  3. Desmopressin Acetate in Intracranial Haemorrhage

    Directory of Open Access Journals (Sweden)

    Thomas Kapapa

    2014-01-01

    Full Text Available Introduction. The secondary increase in the size of intracranial haematomas as a result of spontaneous haemorrhage or trauma is of particular relevance in the event of prior intake of platelet aggregation inhibitors. We describe the effect of desmopressin acetate as a means of temporarily stabilising the platelet function. Patients and Methods. The platelet function was analysed in 10 patients who had received single (N=4 or multiple (N=6 doses of acetylsalicylic acid and 3 patients (control group who had not taken acetylsalicylic acid. All subjects had suffered intracranial haemorrhage. Analysis was performed before, half an hour and three hours after administration of desmopressin acetate. Statistical analysis was performed by applying a level of significance of P≤0.05. Results. (1 Platelet function returned to normal 30 minutes after administration of desmopressin acetate. (2 The platelet function worsened again after three hours. (3 There were no complications related to electrolytes or fluid balance. Conclusion. Desmopressin acetate can stabilise the platelet function in neurosurgical patients who have received acetylsalicylic acid prior to surgery without causing transfusion-related side effects or a loss of time. The effect is, however, limited and influenced by the frequency of drug intake. Further controls are needed in neurosurgical patients.

  4. Antibiofilm Properties of Acetic Acid

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Alhede, Morten; Jensen, Peter Østrup

    2014-01-01

    Bacterial biofilms are known to be extremely tolerant toward antibiotics and other antimicrobial agents. These biofilms cause the persistence of chronic infections. Since antibiotics rarely resolve these infections, the only effective treatment of chronic infections is surgical removal of the inf......Bacterial biofilms are known to be extremely tolerant toward antibiotics and other antimicrobial agents. These biofilms cause the persistence of chronic infections. Since antibiotics rarely resolve these infections, the only effective treatment of chronic infections is surgical removal...... of the infected implant, tissue, or organ and thereby the biofilm. Acetic acid is known for its antimicrobial effect on bacteria in general, but has never been thoroughly tested for its efficacy against bacterial biofilms. In this article, we describe complete eradication of both Gram-positive and Gram......-negative biofilms using acetic acid both as a liquid and as a dry salt. In addition, we present our clinical experience of acetic acid treatment of chronic wounds. In conclusion, we here present the first comprehensive in vitro and in vivo testing of acetic acid against bacterial biofilms....

  5. Method of improving the decontaminating efficiency of ruthenium in evaporating treatment of nitric acid

    International Nuclear Information System (INIS)

    Kubota, Kanya; Yamana, Hajime; Takeda, Seiichiro.

    1984-01-01

    Purpose: To significantly improve the ruthenium removing efficiency in a nitric acid solution in an acid recovery system for the recovery of nitric acid from nitric acid liquid wastes through evaporating condensation. Method: Upon evaporating treatment of nitric acid solution containing ruthenium by supplying and heating the solution to a nitric acid evaporating device, hydrazine is previously added to the nitric acid solution. Hydrazine and intermediate reaction product of hydrazine such as azide causes a reduction reaction with intermediate reaction product of ruthenium tetraoxide to suppress the oxidation of ruthenium and thereby improve the decontaminating efficiency of ruthenium. The amount of hydrazine to be added is preferably between 20 - 500 mg/l and most suitably between 200 - 2000 mg/l per one liter of the liquid in the evaporating device. (Seki, T.)

  6. Late side effects of Ruthenium 106 therapy for uveal melanomas

    International Nuclear Information System (INIS)

    Langmann, G.; Faulborn, J.; Poier, E.

    1994-01-01

    When effectiveness is evaluated in brachytherapy with Ruthenium 106 special emphasis has to be put on tumor destruction and late side effects responsible for the definite functional results. We evaluated the late side effects of 22 uveal melanomas, which had been treated with 106 Ruthenium plaques. The tumor prominences ranged from 3 to 10 mm, the diameter from 4 to 9 disc diameters. In 4 patients the tumor involved the posterior pole, 14 melanomas were located in the midperiphery of the fundus, 4 tumors were ciliary body melanomas. The total radiation dose of the apex ranged from 100 to 240 Gy with a corresponding dose to the sclera between 540 to 1000 Gy. Because of the short half life of the plaque we have been using different dose rates (1.6-11 Gy/h). In 17/22 eyes adequate regression could be achieved by Ruthenium therapy alone. In one case additional laser treatment of the macular part of the melanoma had to be performed, Gamma Knife therapy was necessary in another melanoma with 10 mm tumor prominence. 3 recurrences led to enucleation. The mean follow up was 4.8 years ranging from 1 to 7 years. In 2/22 patients opticopathy caused severe visual impairment, in another 2 patients radiation maculopathy and opticopathy was observed. 7/22 developed vasculopathy with neovascularization treated by photocoagulation. In one case of focal radiation maculopathy laser treatment could prevent further visual impairment. The following factors are responsible for a higher incidence of late side effects: 1. High dose rate of the plaques in combination with a high radiation dose to the sclera 2. Location of the tumor within a minimum distance of 2 disc diameters to the optic nerve or macula 3. Tumor location at the ciliary body Laser treatment in case of neovascularization and focal radiation maculopathy is the only effective treatment with regard to late side effects. Ischemic maculopathy and radiation opticopathy are responsible for late visual impairment. (authors)

  7. Radiation related complications after ruthenium plaque radiotherapy of uveal melanoma

    Energy Technology Data Exchange (ETDEWEB)

    Summanen, P.; Immonen, I.; Kivela, T.; Tommila, P.; Tarkkanen, A. [Helsinki Univ. Central Hospital (Finland). Meilahti Clinic; Heikkonen, J. [Helsinki Univ. (Finland). Dept of Radiotherapy and Oncology

    1996-08-01

    The aims were to analyse radiation related complications and secondary enucleation after irradiation of malignant uveal melanoma with ruthenium-106 plaques. A series of 100 consecutive eyes irradiated in 1981-91 was analysed using the life table method and the Cox proportional hazards model. The 3 and 5 year probabilities of being without radiation cataract were 73% and 63%, without neovascular glaucoma 91% and 81%, without vitreous haemorrhage 83% and 74%, without radiation maculopathy 85% and 70%, and without radiation optic neuropathy 90% and 88%, respectively. (Author).

  8. Radiation related complications after ruthenium plaque radiotherapy of uveal melanoma

    International Nuclear Information System (INIS)

    Summanen, P.; Immonen, I.; Kivela, T.; Tommila, P.; Tarkkanen, A.; Heikkonen, J.

    1996-01-01

    The aims were to analyse radiation related complications and secondary enucleation after irradiation of malignant uveal melanoma with ruthenium-106 plaques. A series of 100 consecutive eyes irradiated in 1981-91 was analysed using the life table method and the Cox proportional hazards model. The 3 and 5 year probabilities of being without radiation cataract were 73% and 63%, without neovascular glaucoma 91% and 81%, without vitreous haemorrhage 83% and 74%, without radiation maculopathy 85% and 70%, and without radiation optic neuropathy 90% and 88%, respectively. (Author)

  9. Progress in doping of ruthenium silicide (Ru2Si3)

    International Nuclear Information System (INIS)

    Vining, C.B.; Allevato, C.E.

    1992-01-01

    This paper reports that ruthenium silicide (Ru 2 Si 3 ) is currently under development as a promising thermoelectric material suitable for space power applications. Key to realizing the potentially high figure of merit values of this material is the development of appropriate doping techniques. In this study, manganese and iridium have been identified as useful p- and n-type dopants, respectively. Resistivity values have been reduced by more than 3 orders of magnitude. Anomalous Hall effect results, however, complicate interpretation of some of the results and further effort is required to achieve optimum doping levels

  10. Ruthenium-Catalyzed Dehydrogenative Decarbonylation of Primary Alcohols

    DEFF Research Database (Denmark)

    Mazziotta, Andrea; Madsen, Robert

    2017-01-01

    Dehydrogenative decarbonylation of a primary alcohol involves the release of both dihydrogen and carbon monoxide to afford the one-carbon shorter product. The transformation has now been achieved with a ruthenium-catalyzed protocol by using the complex Ru(COD)Cl2 and the hindered monodentate ligand...... P(o-tolyl)3 in refluxing p-cymene. The reaction can be applied to both benzylic and long chain linear aliphatic alcohols. The intermediate aldehyde can be observed during the transformation, which is therefore believed to proceed through two separate catalytic cycles involving first dehydrogenation...... of the alcohol and then decarbonylation of the resulting aldehyde....

  11. γ radiolysis of cellulose acetate

    International Nuclear Information System (INIS)

    Ali, S.M.; Clay, P.G.

    1979-01-01

    The major degradative process in γ-irradiated cellulose acetate is chain scission. For the dry powder the G/sub s/ value (number of scissions per 100 eV of energy absorbed) was found to be 7.1. The water-swollen material was found to degrade at the higher rate of G/sub s/ = 9.45. Additions of ethanol and methanol to the water brought about reductions in G/sub s/, whereas dissolved nitrous oxide produced an increase in G/sub s/. The useful life of cellulose acetate reverse osmosis membranes exposed to γ radiation was estimated by observations of the water permeation rate during irradiation. Membrane breakdown occurred at 15 Mrad in pure water, but the dose to breakdown was extended to 83 Mrad in the presence of 4% methanol. 3 figures, 1 table

  12. 21 CFR 582.6185 - Calcium acetate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium acetate. 582.6185 Section 582.6185 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Calcium acetate. (a) Product. Calcium acetate. (b) Conditions of use. This substance is generally...

  13. 21 CFR 582.1005 - Acetic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Acetic acid. 582.1005 Section 582.1005 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1005 Acetic acid. (a) Product. Acetic acid. (b) Conditions of use. This substance is generally...

  14. Removal of fission product ruthenium from purex process solutions: thiourea as complexing agent

    International Nuclear Information System (INIS)

    Floh, B.; Abrao, A.

    1980-01-01

    A new method for the treatment of spent uranium fuel is presented. It is based on the Purex Process using thiourea to increase the ruthenium decontamination factor. Thiourea exhibits a strong tendency for the formation of coordination compounds in acidic media. This tendency serves as a basis to transform nitrosyl-ruthenium species into Ru /SC(NH)(NH 2 )/ 2+ and Ru /SC(NH)(NH 2 )/ 3 complexes which are unextractable by TBP-varsol. The best conditions for the ruthenium-thiourea complex formation were found to be: thiourea-ruthenium ratio (mass/mass) close to 42, at 75 0 C, 30 minutes reaction time and aging period of 60 minutes. The ruthenium decontamination factor for a single uranium extraction are ca. 80-100, not interfering with extraction of actinides. These values are rather high in comparison to those obtained using the conventional Purex Process (e.g. F.D. sub(Ru)=10). By this reason the method developed here is suitable for the treatment of spent uranium fuels. Thiourea (100g/l) scrubbing experiments of ruthenium, partially co-extracted with actinides, confirmed the possibility of its removal from the extract. A decontamination greater than 83,5% for ruthenium as fission product is obtained in two stages with this procedure. (Author) [pt

  15. A thermodynamic/mass-transport model for the release of ruthenium from irradiated fuel

    International Nuclear Information System (INIS)

    Garisto, F.; Iglesias, F.C.; Hunt, C.E.L.

    1990-01-01

    Some postulated nuclear reactor accidents lead to fuel failures and hence release of fission products into the primary heat transport system (PHTS). To determine the consequences of such accidents, it is important to understand the behavior of fission products both in the PHTS and in the reactor containment building. Ruthenium metal has a high boiling point and is nonvolatile under reducing conditions. However, under oxidizing conditions ruthenium can form volatile oxides at relatively low temperatures and, hence, could escape from failed fuel and enter the containment building. The ruthenium radioisotope Ru-106 presents a potentially significant health risk if it is released outside the reactor containment building. Consequently, it is important to understand the behavior of ruthenium during a nuclear reactor accident. The authors review the thermodynamic behavior of ruthenium at high temperatures. The qualitative behavior of ruthenium, predicted using thermodynamic calculations, is then compared with experimental results from the Chalk River Nuclear Laboratories (CRNL). Finally, a simple thermodynamic/mass-transport model is proposed to explain the release behavior of ruthenium in a steam atmosphere

  16. Dynamics of the contact between a ruthenium surface with a single nanoasperity and a flat ruthenium surface: Molecular dynamics simulations

    International Nuclear Information System (INIS)

    Barros de Oliveira, Alan; Fortini, Andrea; Buldyrev, Sergey V.; Srolovitz, David

    2011-01-01

    We study the dynamics of the contact between a pair of surfaces (with properties designed to mimic ruthenium) via molecular dynamics simulations. In particular, we study the contact between a ruthenium surface with a single nanoasperity and a flat ruthenium surface. The results of such simulations suggest that contact behavior is highly variable. The goal of this study is to investigate the source and degree of this variability. We find that during compression, the behavior of the contact force displacement curves is reproducible, while during contact separation, the behavior is highly variable. Examination of the contact surfaces suggests that two separation mechanisms are in operation and give rise to this variability. One mechanism corresponds to the formation of a bridge between the two surfaces that plastically stretches as the surfaces are drawn apart and eventually separate in shear. This leads to a morphology after separation in which there are opposing asperities on the two surfaces. This plastic separation/bridge formation mechanism leads to a large work of separation. The other mechanism is a more brittle-like mode in which a crack propagates across the base of the asperity (slightly below the asperity/substrate junction) leading to most of the asperity on one surface or the other after separation and a slight depression facing this asperity on the opposing surface. This failure mode corresponds to a smaller work of separation. This failure mode corresponds to a smaller work of separation. Furthermore, contacts made from materials that exhibit predominantly brittle-like behavior will tend to require lower work of separation than those made from ductile-like contact materials.

  17. Quantum chemical studies on electronic structure and photodynamics of ruthenium complexes

    International Nuclear Information System (INIS)

    Freitag, L.

    2015-01-01

    Ruthenium complexes have found their way into many applications in the last decades. Among those, ruthenium polypyridyl compounds have been employed as light harvesting devices and photosensitisers in artificial photosynthesis and molecular photocatalysis. Ruthenium nitrosyl complexes are rapidly emerging as NO delivery agents to biological tissues with promising applications in anticancer photodynamic therapy, thanks to their ability to photorelease nitric oxide (NO). This thesis encompasses computational studies on reactivity, electronic structure, excited states and photodynamics of several ruthenium nitrosyl and polypyridyl complexes. The first part of the thesis deals with ruthenium nitrosyls. The cis-trans isomerisation mechanism of RuHIndNO, a ruthenium nitrosyl derivate of the prominent anti-cancer drug candidate KP1019, is investigated with density functional theory calculations. Next, the electronic structure of the ground and the first excited triplet state of RuHIndNO is studied with multiconfigurational methods including the density-matrix renormalisation group (DMRG). The obtained multiconfigurational wavefunctions and DMRG-based orbital entanglement analysis provides theoretical insight into the non-innocence of the NO ligand in nitrosyl complexes by describing the electron correlation in the Ru--NO bond and assigning oxidation states to the metal and the NO ligand. Another study is performed on excited states of ruthenium nitrosyl complexes with quantum chemical calculations and surface-hopping dynamics to obtain insights into the photodissociation mechanism of NO. The second part of this thesis is devoted to the excited states and photophysics of ruthenium polypyridyl complexes. Accurate excitation energies of tris(2,2-bipyridine)ruthenium (II), the prototype ruthenium polypyridyl are obtained with multiconfigurational calculations assisted by an orbital entanglement analysis. Subsequently, the effect of the ligand substitution on the photophysics

  18. Ruthenium determination by the method of inversion voltammetry on graphite electrode

    Energy Technology Data Exchange (ETDEWEB)

    Dominova, I G; Kolpakova, N A; Stromberg, A G [Tomskij Politekhnicheskij Inst. (USSR)

    1978-12-01

    Optimal conditions for determining ruthenium by inversion voltammetry on a graphite electrode are 0.1 M KCl or KNO/sub 3/, pH 2-3, electrolysis potential - 1.0 V. A linear dependence of ruthenium electrodissolution current on its concentration in the solution makes it possible to use inversion voltammetry for determining 5x10/sup -7/ - 1x10/sup -4/ g-ion Ru/l. Ruthenium can be determined in the presence of a large excess of nickel and copper but commensurable amounts of mercury adn platinum metals interfere.

  19. Ruthenium behaviour in severe nuclear accident conditions - Progress report

    International Nuclear Information System (INIS)

    Backman, U.; Lipponen, M.; Zilliacus, R.; Auvinen, A.; Jokiniemi, J.

    2004-03-01

    In order to prevent the radioactive ruthenium from spreading in gaseous form in case of an accident in a nuclear power plant it is of interest to know how it is formed and how it behaves. In the experiments the behaviour of ruthenium in oxidising atmosphere at high temperatures is studied. The methods for trapping and analysing RuO4 has been studied. It was found that 1M NaOH is capable of trapping RuO4 totally. The determination of Ru from the solution can be made using ICP-MS (inductively coupled plasma mass spectrometry) and from the reduced precipitates on filters by INAA (instrumental neutron activation analysis). The results of the experiments carried out so far is reported. A significant difference in the decomposition rate of gaseous RuO4 depending on the tube material was found. In all experiments only a minor fraction of Ru remained in gaseous form until the bubbler. In order to achieve a better mass balance an experiment using radioactive tracer was carried out. In the decomposition of gaseous Ru needle-shaped RuO2 crystallites were formed. (au)

  20. Ruthenium nitrosyl complexes in radioactive waste solutions in reprocessing plants. Pt. 3

    International Nuclear Information System (INIS)

    Blasius, E.; Mueller, K.

    1984-01-01

    With capillary isotachophoresis and free-flow isotachophoresis it is possible to separate and isolate preparatively the mononuclear cationic ruthenium nitrosyl nitrato complexes. The behaviour of these complexes during storage, concentration and calcination is studied: The conversion of six ruthenium nitrosyl nitrato complexes as a function of time is studied at -36 0 C, 0 0 C, +3 0 C and 100 0 C. The percentage of ruthenium nitrosyl complexes with NO 3 - as ligand increased markedly during concentration experiments. Above 250 0 C NOsub(x) is liberated and the colour of the residue changes from brown to brownish-grey. At 400 0 C ruthenium complexes are no longer detected and the inner walls of the apparatus are covered with RuO 2 . (orig.)

  1. Synthesis and catalytic activity of ruthenium complexes modified with chiral racemic per- and polyfluorooxaalkanoates

    Czech Academy of Sciences Publication Activity Database

    Lipovská, P.; Rathouská, L.; Šimůnek, O.; Hošek, J.; Kolaříková, V.; Rybáčková, M.; Cvačka, Josef; Svoboda, Martin; Kvíčala, J.

    2016-01-01

    Roč. 191, Nov (2016), s. 14-22 ISSN 0022-1139 Institutional support: RVO:61388963 Keywords : racemic * chiral * ruthenium complex * perfluorooxaalkanoate * polyfluorooxaalkanoate Subject RIV: CC - Organic Chemistry Impact factor: 2.101, year: 2016

  2. Dendrimer-Encapsulated Ruthenium Nanoparticles as Catalysts for Lithium-O2 Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharya, Priyanka; Nasybulin, Eduard N.; Engelhard, Mark H.; Kovarik, Libor; Bowden, Mark E.; Li, Shari; Gaspar, Daniel J.; Xu, Wu; Zhang, Jiguang

    2014-12-01

    Dendrimer-encapsulated ruthenium nanoparticles (DEN-Ru) have been used as catalysts in lithium-O2 batteries for the first time. Results obtained from UV-vis spectroscopy, electron microscopy and X-ray photoelectron spectroscopy show that the nanoparticles synthesized by the dendrimer template method are ruthenium oxide instead of metallic ruthenium reported earlier by other groups. The DEN-Ru significantly improve the cycling stability of lithium (Li)-O2 batteries with carbon black electrodes and decrease the charging potential even at low catalyst loading. The monodispersity, porosity and large number of surface functionalities of the dendrimer template prevent the aggregation of the ruthenium nanoparticles making their entire surface area available for catalysis. The potential of using DEN-Ru as stand-alone cathode materials for Li-O2 batteries is also explored.

  3. Extraction of ruthenium thiocyanate and its separation from rhodium by polyurethane foam

    International Nuclear Information System (INIS)

    Al-Bazi, S.J.; Chow, A.

    1984-01-01

    Conditions for the formation and extraction of the thiocyanate complex of ruthenium are reported. Distribution coefficients of more than 10 4 and a capacity of about 0.24 mole per kg of foam were obtained. The effect of the chloride salts of various univalent cations on the extraction of Ru(SCN) 6 3- indicated that the efficiency of ruthenium extraction depends on how well the cation fits into the polyether segment of the polyurethane foam, which agrees with the 'cation-chelation' mechanism. The separation of ruthenium and rhodium indicated that more than 95% of the rhodium remained in the aqueous phase and about 95% of the ruthenium was retained by the polyurethane foam and could be easily recovered. (author)

  4. Some thermophysical properties of ruthenium in the neighbourhood of the melting point

    International Nuclear Information System (INIS)

    Sheindlin, A.E.; Kats, S.A.; Berezin, B.Ya.; Chekhovskoy, V.Ya.; Kenisarin, M.M.

    1975-01-01

    The technique of levitation calorimetry has been used to study for the first time thermophysical properties of ruthenium in the neighbourhood of the melting point. To measure enthalpy a copper block calorimeter with an istohermal jacket has been used. Basing on the values measured the equations for enthalpy of solid and liquid ruthenium within the temperature ranges of 2,270-2,607 K and 2,607-2,760 K respectively have been obtained by the least squares method. In addition the melting temperature of ruthenium and its brightness temperature at the melting point, the wavelength being 0.65 micron, have been measured. The results of the measurements have been used to calculate the heat and entropy of fusion, the specific heat of solid and that of liquid ruthenium and its normal spectral emissivity at the melting point

  5. Flameless atomic absorption determination of ruthenium using a ''Saturn-1'' spectrophotometer

    International Nuclear Information System (INIS)

    Pichkov, V.N.; Sinitsyn, N.M.; Sadikova, F.G.; Govorova, M.I.; Yakshinskij, A.I.

    1980-01-01

    A flameless atomic absorption method is suggested for determining ruthenium in samples of complicated composition using a ''Saturn-1'' spectrophotometer with a L'vov graphite cuvette. The method was used for determining ruthenium in a copper-based sample (10 -3 % Ru) and in electrolyte slurries (10 -3 -10 -2 %). The limit of detection Csub(min, 0.95) = 3.0x10 -3 μg Ru/ml. Other platinum metals do not interfere [ru

  6. Identification of short-lived neutron-rich ruthenium and rhodium isotopes in fission

    International Nuclear Information System (INIS)

    Franz, G.; Herrmann, G.

    1975-01-01

    Short-lived ruthenium and rhodium isotopes ( 107 Ru, 108 Ru, 108 Rh, 109 Ru, 109 Rh, 110 Ru, 110 Rh, 111 Ru, 111 Rh, 112 Ru, 112 Rh, 113 Ru) have been separated from fission products by a rapid chemical procedure and identified by means of γ-ray spectroscopy. Nuclides with half-lives down to 3 sec were accessible. Ruthenium isotopes up to mass number 113 have been identified. (author)

  7. A New Homogeneous Catalyst for the Dehydrogenation of Dimethylamine Borane Starting with Ruthenium(III Acetylacetonate

    Directory of Open Access Journals (Sweden)

    Ebru Ünel Barın

    2015-06-01

    Full Text Available The catalytic activity of ruthenium(III acetylacetonate was investigated for the first time in the dehydrogenation of dimethylamine borane. During catalytic reaction, a new ruthenium(II species is formed in situ from the reduction of ruthenium(III and characterized using UV-Visible, Fourier transform infrared (FTIR, 1H NMR, and mass spectroscopy. The most likely structure suggested for the ruthenium(II species is mer-[Ru(N2Me43(acacH]. Mercury poisoning experiment indicates that the catalytic dehydrogenation of dimethylamine-borane is homogeneous catalysis. The kinetics of the catalytic dehydrogenation of dimethylamine borane starting with Ru(acac3 were studied depending on the catalyst concentration, substrate concentration and temperature. The hydrogen generation was found to be first-order with respect to catalyst concentration and zero-order regarding the substrate concentration. Evaluation of the kinetic data provides the activation parameters for the dehydrogenation reaction: the activation energy Ea = 85 ± 2 kJ·mol−1, the enthalpy of activation ∆H# = 82 ± 2 kJ·mol−1 and the entropy of activation; ∆S# = −85 ± 5 J·mol−1·K−1. The ruthenium(II catalyst formed from the reduction of ruthenium(III acetylacetonate provides 1700 turnovers over 100 hours in hydrogen generation from the dehydrogenation of dimethylamine borane before deactivation at 60 °C.

  8. The Biological Side of Water-Soluble Arene Ruthenium Assemblies

    Directory of Open Access Journals (Sweden)

    Bruno Therrien

    2014-01-01

    Full Text Available This review article covers the synthetic strategies, structural aspects, and host-guest properties of ruthenium metalla-assemblies, with a special focus on their use as drug delivery vectors. The two-dimensional metalla-rectangles show interesting host-guest possibilities but seem less appropriate for being used as drug carriers. On the other hand, metalla-prisms allow encapsulation and possible targeted release of bioactive molecules and consequently show some potential as drug delivery vectors. The reactivity of these metalla-prisms can be fine-tuned to allow a fine control of the guest’s release. The larger metalla-cubes can be used to stabilize the formation of G-quadruplex DNA and can be used to encapsulate and release photoactive molecules such as porphins. These metalla-assemblies demonstrate great prospective in photodynamic therapy.

  9. Raman spectra of ruthenium and tantalum trimers in argon matrices

    Science.gov (United States)

    Fang, Li; Shen, Xiaole; Chen, Xiaoyu; Lombardi, John R.

    2000-12-01

    The resonance Raman spectra of ruthenium trimers (Ru 3) in argon matrices have been obtained. Three resonance Raman transitions were observed between 570 and 590 nm. Two of them (303.4 and 603.7 cm -1) are assigned to the totally symmetric vibrational progression, giving k e=1.86 mdyne/ Å. The line at 581.5 cm-1 is assigned as the origin of a low-lying electronic state. We also report on the observation of a resonance Raman spectrum of tantalum trimers (Ta 3). Observed lines include 251.2 and 501.9 cm-1 which we assign to the fundamental and the first overtone of the symmetric stretch in Ta 3. This gives k e=2.25 mdyne/ Å.

  10. Cathodic processes during ruthenium electrodeposition from a chloride melt

    International Nuclear Information System (INIS)

    Sokol'skij, D.V.

    1985-01-01

    Cathodic processes occurring during the electrolysis of chloride melts in the presence of oxygen-containing impurities were studied. The experiments were carried out at 500, 550 600 and 680 deg C, ruthenium ions concentration in KCl-NaCl-CsCl eutectic melt being 0.4-1.5 mol% and BaO additions 4.8x10 -2 mol%. Temperature dependence of Ru(3) ion diffusion coefficient in the chloride melt (lg D=3.25-1508/T+-0.02) and activation energy of the diffusion process (6.9 k cal/mol) were determined. It is shown that changes of the shape of E, t-curve and the deviation of values determined in the cause of chronopotentiometric investigations from the corresponding values of reversable processes are related in many respects to the participation of oxygen-containing compounds in the cathodic process. Irreversibility of the cathodic process is also connected with metal crystallization during electrodeposition

  11. Evidence for Dynamic Chemical Kinetics at Individual Molecular Ruthenium Catalysts.

    Science.gov (United States)

    Easter, Quinn T; Blum, Suzanne A

    2018-02-05

    Catalytic cycles are typically depicted as possessing time-invariant steps with fixed rates. Yet the true behavior of individual catalysts with respect to time is unknown, hidden by the ensemble averaging inherent to bulk measurements. Evidence is presented for variable chemical kinetics at individual catalysts, with a focus on ring-opening metathesis polymerization catalyzed by the second-generation Grubbs' ruthenium catalyst. Fluorescence microscopy is used to probe the chemical kinetics of the reaction because the technique possesses sufficient sensitivity for the detection of single chemical reactions. Insertion reactions in submicron regions likely occur at groups of many (not single) catalysts, yet not so many that their unique kinetic behavior is ensemble averaged. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. 21 CFR 184.1005 - Acetic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acetic acid. 184.1005 Section 184.1005 Food and... Substances Affirmed as GRAS § 184.1005 Acetic acid. (a) Acetic acid (C2H4O2, CAS Reg. No. 64-19-7) is known as ethanoic acid. It occurs naturally in plant and animal tissues. It is produced by fermentation of...

  13. Separation of carrier-free rhodium isotopes from ruthenium cyclotron targets by the extraction of nitrosylruthenium from hydrochloric acid solution

    International Nuclear Information System (INIS)

    Haasbroek, F.J.; Strelow, F.W.E.; Van der Walt, T.N.

    1981-01-01

    A method is presented for the separation of rhodium isotopes from ruthenium cyclotron targets. After bombardment with deuterons and dissolution of the target material, the ruthenium is converted into a nitrosyl complex by treatment with hydroxylammonium chloride. Aluminium and other elements which have been introduced in the dissolution step, are separated by cation exchange. Ruthenium is then separated by extraction with a mixture of tri-n-butyl phosphate and hexane (4:1), leaving the rhodium in the aqueous phase. No ruthenium is found in the rhodium fraction and the recovery of rhodium is better than 90 per cent [af

  14. Positron scattering from vinyl acetate

    International Nuclear Information System (INIS)

    Chiari, L; Brunger, M J; Zecca, A; Blanco, F; García, G

    2014-01-01

    Using a Beer–Lambert attenuation approach, we report measured total cross sections (TCSs) for positron scattering from vinyl acetate (C 4 H 6 O 2 ) in the incident positron energy range 0.15–50 eV. In addition, we also report an independent atom model with screening corrected additivity rule computation results for the TCSs, differential and integral elastic cross sections, the positronium formation cross section and inelastic integral cross sections. The energy range of these calculations is 1–1000 eV. While there is a reasonable qualitative correspondence between measurement and calculation for the TCSs, in terms of the energy dependence of those cross sections, the theory was found to be a factor of ∼2 larger in magnitude at the lower energies, even after the measured data were corrected for the forward angle scattering effect. (paper)

  15. Design and development of novel MRI compatible zirconium- ruthenium alloys with ultralow magnetic susceptibility.

    Science.gov (United States)

    Li, H F; Zhou, F Y; Li, L; Zheng, Y F

    2016-04-19

    In the present study, novel MRI compatible zirconium-ruthenium alloys with ultralow magnetic susceptibility were developed for biomedical and therapeutic devices under MRI diagnostics environments. The results demonstrated that alloying with ruthenium into pure zirconium would significantly increase the strength and hardness properties. The corrosion resistance of zirconium-ruthenium alloys increased significantly. High cell viability could be found and healthy cell morphology observed when culturing MG 63 osteoblast-like cells and L-929 fibroblast cells with zirconium-ruthenium alloys, whereas the hemolysis rates of zirconium-ruthenium alloys are zirconium-ruthenium alloys (1.25 × 10(-6) cm(3)·g(-1)-1.29 × 10(-6) cm(3)·g(-1) for zirconium-ruthenium alloys) are ultralow, about one-third that of Ti-based alloys (Ti-6Al-4V, ~3.5 × 10(-6) cm(3)·g(-1), CP Ti and Ti-6Al-7Nb, ~3.0 × 10(-6) cm(3)·g(-1)), and one-sixth that of Co-Cr alloys (Co-Cr-Mo, ~7.7 × 10(-6) cm(3)·g(-1)). Among the Zr-Ru alloy series, Zr-1Ru demonstrates enhanced mechanical properties, excellent corrosion resistance and cell viability with lowest magnetic susceptibility, and thus is the optimal Zr-Ru alloy system as therapeutic devices under MRI diagnostics environments.

  16. Behavior of ruthenium in the case of shutdown of the cooling system of HLLW storage tanks

    International Nuclear Information System (INIS)

    Philippe, M.; Mercier, J.P.; Gue, J.P.

    1990-01-01

    The consequences of the failure of the cooling system of fission product storage tanks over a variable period were investigated as part of the safety analysis of the La Hague spent fuel reprocessing plant. Due to the considerable heat release, induced by the fission products, a prolonged shutdown of the tank cooling system could cause the progressive evaporation of the solutions to dryness, and culminate in the formation of volatile species of ruthenium and their release in the tank venting circuit. To determine the fraction of ruthenium likely to be transferred from the storage tanks in volatile or aerosol form during the failure, evaporation tests were conducted by evaporating samples of actual nitric acid solutions of fission products, obtained on the laboratory scale after the reprocessing of several kilograms of MOX fuels irradiated to 30,000 MWday.t -1 . A distillation apparatus was designed to operate with small volume solution samples, reproducing the heating conditions existing in the reprocessing plant within a storage tank for fission products. The main conclusions drawn from these experiments are as follows: - ruthenium is only volatilized in the final phase of evaporation, just before desiccation, - for a final temperature limited to 160 0 C, the total fraction of volatilized ruthenium reaches 12%, in the presence of H 2 0, HN0 3 , N0 x and 0 2 , the volatilized ruthenium recombines mainly in the form of ruthenium nitrosyl nitrates, or decomposes into ruthenium oxide on the walls of the apparatus. Assuming a heating power density of 10 W/liter of concentrate, and a perfectly adiabatic storage system, the minimum time required to reach dryness can be estimated at 90 h, allowing substantial time to take action to restore a cooling source

  17. Behavior of ruthenium in the case of shutdown of the cooling system of HLLW storage tanks

    International Nuclear Information System (INIS)

    Philippe, M.; Mercier, J.P.; Gue, J.P.

    1991-01-01

    The consequences of the failure of the cooling system of fission product storage tanks over a variable period were investigated as part of the safety analysis of the La Hague spent fuel reprocessing plant. Due to the considerable heat release, induced by the fission products, a prolonged shutdown of the tank cooling system could cause the progressive evaporation of the solutions to dryness, and culminate in the formation of volatile species of ruthenium and their release in the tank venting circuit. To determine the fraction of ruthenium likely to be transferred from the storage tanks in volatile or aerosol form during the failure, evaporation tests were conducted by evaporating samples of actual nitric acid solutions of fission products, obtained on the laboratory scale after the reprocessing of several kilograms of MOX fuels irradiated to 30,000 MW day·t -1 . A distillation apparatus was designed to operate with small-volume solution samples, reproducing the heating conditions existing in the reprocessing plant within a storage tank for fission products. The main conclusions drawn from these experiments are as follows: ruthenium is only volatilized in the final phase of evaporation, just before desiccation; for a final temperature limited to 160 degree C, the total fraction of volatilized ruthenium reaches 12%; in the presence of H 2 O, HNO 3 , NO x and O 2 , the volatilized ruthenium recombines mainly in the form of ruthenium nitrosyl nitrates, or decomposes into ruthenium oxide (probably RuO 2 ) on the walls of the apparatus. Assuming a heating power density of 10 W/liter of concentrate, and a perfectly adiabatic storage system, the minimum time required to reach dryness can be estimated at 90 h, allowing substantial time to take action to restore a cooling source

  18. Design and development of novel MRI compatible zirconium- ruthenium alloys with ultralow magnetic susceptibility

    Science.gov (United States)

    Li, H.F.; Zhou, F.Y.; Li, L.; Zheng, Y.F.

    2016-01-01

    In the present study, novel MRI compatible zirconium-ruthenium alloys with ultralow magnetic susceptibility were developed for biomedical and therapeutic devices under MRI diagnostics environments. The results demonstrated that alloying with ruthenium into pure zirconium would significantly increase the strength and hardness properties. The corrosion resistance of zirconium-ruthenium alloys increased significantly. High cell viability could be found and healthy cell morphology observed when culturing MG 63 osteoblast-like cells and L-929 fibroblast cells with zirconium-ruthenium alloys, whereas the hemolysis rates of zirconium-ruthenium alloys are alloys and Ti-based alloys, the magnetic susceptibilities of the zirconium-ruthenium alloys (1.25 × 10−6 cm3·g−1–1.29 × 10−6 cm3·g−1 for zirconium-ruthenium alloys) are ultralow, about one-third that of Ti-based alloys (Ti–6Al–4V, ~3.5 × 10−6 cm3·g−1, CP Ti and Ti–6Al–7Nb, ~3.0 × 10−6 cm3·g−1), and one-sixth that of Co–Cr alloys (Co–Cr–Mo, ~7.7 × 10−6 cm3·g−1). Among the Zr–Ru alloy series, Zr–1Ru demonstrates enhanced mechanical properties, excellent corrosion resistance and cell viability with lowest magnetic susceptibility, and thus is the optimal Zr–Ru alloy system as therapeutic devices under MRI diagnostics environments. PMID:27090955

  19. Ulipristal acetate in emergency contraception.

    Science.gov (United States)

    Goldstajn, Marina Sprem; Baldani, Dinka Pavicić; Skrgatić, Lana; Radaković, Branko; Vrbić, Hrvoje; Canić, Tomislav

    2014-03-01

    Despite the widespread availability of highly effective methods of contraception, unintended pregnancy is common. Unplanned pregnancies have been linked to a range of health, social and economic consequences. Emergency contraception reduces risk of pregnancy after unprotected intercourse, and represents an opportunity to decrease number of unplanned pregnancies and abortions. Emergency contraception pills (ECP) prevent pregnancy by delaying or inhibiting ovulation, without interfering with post fertilization events. If pregnancy has already occurred, ECPs will not be effective, therefore ECPs are not abortificants. Ulipristal acetate (17alpha-acetoxy-11beta-(4N-N,N-dymethilaminophenyl)-19-norpregna--4,9-diene-3,20-dione) is the first drug that was specifically developed and licensed for use as an emergency contraceptive. It is an orally active, synthetic, selective progesterone modulator that acts by binding with high affinity to the human progesterone receptor where it has both antagonist and partial agonist effects. It is a new molecular entity and the first compound in a new pharmacological class defined by the pristal stem. Up on the superior clinical efficacy evidence, UPA has been quickly recognized as the most effective emergency contraceptive pill, and recently recommended as the first prescription choice for all women regardless of the age and timing after intercourse. This article provides literature review of UPA and its role in emergency contraception.

  20. Half-sandwich ruthenium, rhodium and iridium complexes of ...

    Indian Academy of Sciences (India)

    p-cymene/benzene/Cp* and M = Ru/Rh/Ir) with ligand L in methanol. The reaction in 1:2 ... drazine with dipyridyl ketone using glacial acetic acid, we ended up with the .... dimethyl sulphoxide, soluble in hot water (up to 40. ◦. C) and they are ...

  1. Electrochemical behavior of ruthenium (III), rhodium (III) and palladium (II) in 1-butyl-3-methylimidazolium chloride ionic liquid

    Energy Technology Data Exchange (ETDEWEB)

    Jayakumar, M.; Venkatesan, K.A. [Fuel Chemistry Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India); Srinivasan, T.G. [Fuel Chemistry Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India)], E-mail: tgs@igcar.gov.in; Vasudeva Rao, P.R. [Fuel Chemistry Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India)

    2009-11-01

    Electrochemical behavior of ruthenium (III), rhodium (III) and palladium (II) in 1-butyl-3-methylimidazolium chloride (bmimCl) and their ternary and binary solutions in bmimCl was studied at various working electrodes at 373 K by cyclic voltammetry and chronoamperometry. Ruthenium (III) chloride forms a stable solution with bmimCl and the cyclic voltammogram of ruthenium (III) in bmimCl recorded at glassy carbon electrode consisted of several redox waves due to the complex nature of ruthenium to exist in several oxidation states. Electrolysis of ruthenium (III) chloride in bmimCl at the cathodic limit of bmimCl (-1.8 V (vs. Pd)) did not result in ruthenium metal deposition. However, it was deposited from bmimPF{sub 6} and bmimNTf{sub 2} room temperature ionic liquids at -0.8 V (vs. Pd). The electrochemical behavior of ruthenium (III) in bmimCl in the presence of palladium (II) and rhodium (III) was studied by cyclic voltammetry. The presence of palladium (II) in bmimCl favors underpotential deposition of ruthenium metal. The nuclear loop at -0.5 V (vs. Pd) was observed in all solutions when palladium (II) co-existed with other two metal ions. Nucleation and growth of the metal on glassy carbon working electrode was investigated by chronoamperometry. The growth and decay of chronocurrents has been found to follow the instantaneous nucleation model with three-dimensional growth of nuclei.

  2. Ground vs. excited state interaction in ruthenium-thienyl dyads : implications for through bond interactions in multicomponent systems

    NARCIS (Netherlands)

    Henry, William; Browne, Wesley R.; Ronayne, Kate L.; O’Boyle, Noel M.; Vos, Johannes G.; McGarvey, John J.

    2005-01-01

    The vibrational and photophysical properties of mononuclear ruthenium(II) and ruthenium(III) polypyridyl complexes based on the, ligands 2-(5-(pyridin-2"-yl)-1'H-1',2',4'-triaz-3'-yl)-thiophene, 2-(5-(pyrazin-2"-yl)-1'H-1',2,4-triaz-3'-yl)-thiophene, are reported. The effect of the introduction of

  3. Dehydrogenative Coupling of Primary Alcohols To Form Esters Catalyzed by a Ruthenium N-Heterocyclic Carbene Complex

    DEFF Research Database (Denmark)

    Sølvhøj, Amanda Birgitte; Madsen, Robert

    2011-01-01

    The ruthenium complex [RuCl2(IiPr)(p-cymene)] catalyzes the direct condensation of primary alcohols into esters and lactones with the release of hydrogen gas. The reaction is most effective with linear aliphatic alcohols and 1,4-diols and is believed to proceed with a ruthenium dihydride...

  4. A facile one-pot synthesis of ruthenium hydroxide nanoparticles on magnetic silica: Aqueous hydration of nitriles to amides

    Science.gov (United States)

    One-pot synthesis of ruthenium hydroxide nanoparticles on magnetic silica is described which involve the in situ generation of magnetic silica (Fe3O4@ SiO2) and ruthenium hydroxide immobilization; the hydration of nitriles occurs in high yield and excellent selectivity using this...

  5. One-pot hydrothermal synthesis of ruthenium oxide nanodots on reduced graphene oxide sheets for supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Chen Yao [Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Graduate University of Chinese Academy Sciences, Beijing 100049 (China); Zhang Xiong [Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Zhang Dacheng [Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Graduate University of Chinese Academy Sciences, Beijing 100049 (China); Ma Yanwei, E-mail: ywma@mail.iee.ac.cn [Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China)

    2012-01-15

    Highlights: > Graphite oxide instead of graphene as precursor has been used to synthesize reduced graphene oxide/ruthenium oxide composites by a hydrothermal treatment. > Using NaOH solution to adjust pH of GO colloids leads to homogeneous ruthenium oxide deposited on reduced graphene oxide sheets. > A maximum capacitance of 471 F g{sup -1} is obtained at 0.5 A g{sup -1} for the composites when loading 40% of RuO{sub 2} and its life retention reaches 92% after 3000 cycles. - Abstract: Ruthenium oxide nanodots have been deposited on reduced graphene oxide (RGO) sheets homogeneously by hydrothermal and annealing methods. Adding NaOH solution in GO colloids prevents the restack and agglomeration of GO sheets when mixed with ruthenium chloride solution. Local crystallization of RuO{sub 2} in the composites is revealed by X-ray diffraction and transmission electron microscopy. The element mapping image demonstrates the uniform distribution of Ru on RGO sheets. Unlike the pure crystalline RuO{sub 2} exhibiting poor electrochemical performance, the composites present superior capacitive properties. The hydrothermal time is optimized and a maximum of 471 F g{sup -1} is measured in the composites at 0.5 A g{sup -1} when loaded with 45 wt% of RuO{sub 2}. After 3000 cycles, its specific capacitance remains 92% of the maximum capacitance. Our results suggest potential application of the reduced graphene oxide/ruthenium oxide composites to supercapacitors.

  6. Activity and selectivity regulation of synthesis gas reaction over supported ruthenium catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, K; Nobusawa, T; Fukushima, T; Tominaga, H

    1985-01-01

    The catalytic activities of supported ruthenium for synthesis-gas conversion to hydrocarbons was found to be in the following order: TiOS > Nb2O3 > ZrO2 > SiO2 > Ta2O5 > Al2O3 > V2O5 > MoO3 > WO3 > MnO2 > ZnO. Turnover frequencies of the supported ruthenium increased with decrease in dispersion of the metal particles for every carrier material. Even the activities per unit weight of metals were higher for low-dispersion ruthenium of Al2O3, TiO2, and ZrO2. The chain-growth probability of a hydrocarbon product, which is characterized by the Schulz-Flory distribution, increased markedly with decrease in the metal dispersion irrespective of the carrier material. The catalytic activity of ruthenium particles with a dispersed ruthenium increased almost linearly with an increase in reaction pressure (up to at least 2.0 MPa). 23 references, 10 figures, 3 tables.

  7. One-pot hydrothermal synthesis of ruthenium oxide nanodots on reduced graphene oxide sheets for supercapacitors

    International Nuclear Information System (INIS)

    Chen Yao; Zhang Xiong; Zhang Dacheng; Ma Yanwei

    2012-01-01

    Highlights: → Graphite oxide instead of graphene as precursor has been used to synthesize reduced graphene oxide/ruthenium oxide composites by a hydrothermal treatment. → Using NaOH solution to adjust pH of GO colloids leads to homogeneous ruthenium oxide deposited on reduced graphene oxide sheets. → A maximum capacitance of 471 F g -1 is obtained at 0.5 A g -1 for the composites when loading 40% of RuO 2 and its life retention reaches 92% after 3000 cycles. - Abstract: Ruthenium oxide nanodots have been deposited on reduced graphene oxide (RGO) sheets homogeneously by hydrothermal and annealing methods. Adding NaOH solution in GO colloids prevents the restack and agglomeration of GO sheets when mixed with ruthenium chloride solution. Local crystallization of RuO 2 in the composites is revealed by X-ray diffraction and transmission electron microscopy. The element mapping image demonstrates the uniform distribution of Ru on RGO sheets. Unlike the pure crystalline RuO 2 exhibiting poor electrochemical performance, the composites present superior capacitive properties. The hydrothermal time is optimized and a maximum of 471 F g -1 is measured in the composites at 0.5 A g -1 when loaded with 45 wt% of RuO 2 . After 3000 cycles, its specific capacitance remains 92% of the maximum capacitance. Our results suggest potential application of the reduced graphene oxide/ruthenium oxide composites to supercapacitors.

  8. Mitigation of strontium and ruthenium release in the CANDU primary heat transport system

    Energy Technology Data Exchange (ETDEWEB)

    McFarlane, J

    1998-03-01

    In certain severe accident scenarios, low-volatility fission products can appear to contribute significantly to dose, if treated with undue conservatism. Hence a survey was performed, to see if factors that may mitigate release of strontium and ruthenium could be incorporated into safety analyses, to cover parameters such as location in the fuel matrix under normal operating conditions, release from fuel, transport and deposition in the primary heat transport system and chemistry. In addition chemical equilibrium calculations were performed to investigate the volatility of strontium and ruthenium in the presence of uranium and important fission products. Strontium is very soluble in the U0{sub 2} fuel, up to 12 atom %, and hence release is improbable, particularly under oxidizing conditions until volatilization of the fuel matrix itself occurs. Ruthenium, however, can be released at low temperatures, but only under oxidizing conditions. These may occur during a fuel-handling accident or as a result of an end-fitting failure. Under these conditions, the primary heat transport system cannot be credited for retention. The volatile form of ruthenium, RuO{sub 4}(g), is thermally unstable above 381 K and decomposes to RuO{sub 2}(s) and O{sub 2}(g) upon contact with surfaces, a factor that is likely to minimize the release of ruthenium into the environment. (author)

  9. Mitigation of strontium and ruthenium release in the CANDU primary heat transport system

    International Nuclear Information System (INIS)

    McFarlane, J.

    1998-03-01

    In certain severe accident scenarios, low-volatility fission products can appear to contribute significantly to dose, if treated with undue conservatism. Hence a survey was performed, to see if factors that may mitigate release of strontium and ruthenium could be incorporated into safety analyses, to cover parameters such as location in the fuel matrix under normal operating conditions, release from fuel, transport and deposition in the primary heat transport system and chemistry. In addition chemical equilibrium calculations were performed to investigate the volatility of strontium and ruthenium in the presence of uranium and important fission products. Strontium is very soluble in the U0 2 fuel, up to 12 atom %, and hence release is improbable, particularly under oxidizing conditions until volatilization of the fuel matrix itself occurs. Ruthenium, however, can be released at low temperatures, but only under oxidizing conditions. These may occur during a fuel-handling accident or as a result of an end-fitting failure. Under these conditions, the primary heat transport system cannot be credited for retention. The volatile form of ruthenium, RuO 4 (g), is thermally unstable above 381 K and decomposes to RuO 2 (s) and O 2 (g) upon contact with surfaces, a factor that is likely to minimize the release of ruthenium into the environment. (author)

  10. Interaction of ruthenium (4) and osmium (4) with 2-mercaptobenzimidazole, 2-mercaptobenzoxazole and 2-mercaptobenzothiazole in the presence of edta

    International Nuclear Information System (INIS)

    Busev, A.I.; Ignat'eva, T.I.; Lomakina, L.N.

    1975-01-01

    Interaction of ruthenium (4) and osmium (4) with 2-mercaptobenzimidazole (2MBI), 2-mercaptobenzoxazole (2MBO) and 2-mercaptobenzothiazole (2MBT) in the presence of EDTA was studied. The interaction of ruthenium (4) and osmium (4) with EDTA was constidered. Ruthenium complex is formed with constant output at 2-4.5 pH after 30 min.heating. In the lowacid solution (pH 2-4) osmium reacts with EDTA forming soluble compound. Characteristics of ruthenium (4) compound with 2MBI, 2MBO and 2MBT produced in the presence of EDTA are presented. Osmium (4) in the presence of EDTA and above mentioned organic reagents and when heating forms lowsoluble compounds. Possibility of joint determination of ruthenium and osmium with help of 2MBI in the presence of EDTA under conditions of minimum complexing osmium with EDTA was investigated

  11. Interaction of ruthenium (4) and osmium (4) with 2-mercaptobenzimidazole, 2-mercaptobenzoxazole and 2-mercaptobenzothiazole in the presence of EDTA

    Energy Technology Data Exchange (ETDEWEB)

    Busev, A I; Ignat' eva, T I; Lomakina, L N [Moskovskij Gosudarstvennyj Univ. (USSR). Kafedra Analiticheskoj Khimii

    1975-05-01

    Interaction of ruthenium (4) and osmium (4) with 2-mercaptobenzimidazole (2MBI), 2-mercaptobenzoxazole (2MBO) and 2-mercaptobenzothiazole (2MBT) in the presence of EDTA was studied. The interaction of ruthenium (4) and osmium (4) with EDTA was considered. Ruthenium complex is formed with constant output at 2-4.5 pH after 30 min. heating. In the low acid solution (pH 2-4) osmium reacts with EDTA forming soluble compound. Characteristics of ruthenium (4) compound with 2MBI, 2MBO and 2MBT produced in the presence of EDTA are presented. Osmium (4) in the presence of EDTA and above mentioned organic reagents and when heating forms low soluble compounds. Possibility of joint determination of ruthenium and osmium with help of 2MBI in the presence of EDTA under conditions of minimum complexing osmium with EDTA was investigated.

  12. Ruthenium sulfoxides structure and reactivity with nitrogen heterocyclic bases

    International Nuclear Information System (INIS)

    Oliveira, Denise de.

    1990-01-01

    Ruthenium (II) sulfoxides are compounds of great interest in oxidative catalysis and in chemotherapy. In order to contribute for the understanding of the chemistry and electronic structure of this class of compounds, it has been studied a series of [Ru Cl 2 (S-DMSO) 2 L x ] complexes, where x = 1 (polymeric compounds) or 2 (monomers) and L N-heterocyclic ligands (pyridine, pyrazine and imidazole derivatives). The nature of N-heterocyclic ligand and their coordination are of great relevance to the stability, spectroscopic and electrochemical characteristics of the complexes. The trans-interactions are extremely important in this series, influencing the strength of the Ru(II)-> S-DMSO and Ru(II)-> L π-back donation. The DMSO and L ligands are π-acceptors. The metal-> ligand π-back donation is strengthened when the ligand is trans to chloride, which is π-donor, due to trans-cooperative interactions of the type: π-donor -> Ru(II) π-acceptor. Another interesting aspect in the series of [Ru Cl 2 (S-DMSO) 2 L 2 ] complexes is the occurrence of dissociative equilibria in the solution, due to the existence of three types of ligands. It was observed that the trans-N isomer of 2,6-dimethyl pyrazine derivative undergoes thermal substitution, with preferential liabilization of the N-heterocyclic ligand. Chloride ion is the most inert ligand in this complex. (author). 145 refs., 76 figs., 21 tabs

  13. Coordinatively unsaturated ruthenium complexes as efficient alkyneazide cycloaddition catalysts

    KAUST Repository

    Lamberti, Marina; Fortman, George C.; Poater, Albert; Broggi, Julie; Slawin, Alexandra M. Z.; Cavallo, Luigi; Nolan, Steven P.

    2012-01-01

    The performance of 16-electron ruthenium complexes with the general formula Cp*Ru(L)X (in which L = phosphine or N-heterocyclic carbene ligand; X = Cl or OCH2CF3) was explored in azidealkyne cycloaddition reactions that afford the 1,2,3- triazole products. The scope of the Cp*Ru(PiPr 3)Cl precatalyst was investigated for terminal alkynes leading to new 1,5-disubstituted 1,2,3-triazoles in high yields. Mechanistic studies were conducted and revealed a number of proposed intermediates. Cp*Ru- (PiPr3)(2-HCCPh)Cl was observed and characterized by 1H, 13C, and 31P NMR at temperatures between 273 and 213 K. A rare example of N,N-κ2-phosphazide complex, Cp*Ru(κ2- iPr3PN3Bn)Cl, was fully characterized, and a single-crystal X-ray diffraction structure was obtained. DFT calculations describe a complete map of the catalytic reactivity with phenylacetylene and/or benzylazide. © 2012 American Chemical Society.

  14. Graphene Oxide/ Ruthenium Oxide Composites for Supercapacitors Electrodes

    Science.gov (United States)

    Amir, Fatima

    Supercapacitors are electrical energy storage devices with high power density, high rate capability, low maintenance cost, and long life cycle. They complement or replace batteries in harvesting applications when high power delivery is needed. An important improvement in performance of supercapacitors has been achieved through recent advances in the development of new nanostructured materials. Here we will discuss the fabrication of graphene oxide/ ruthenium oxide supercacitors electrodes including electrophoretic deposition. The morphology and structure of the fabricated electrodes were investigated and will be discussed. The electrochemical properties were determined using cyclic voltammetry and galvanostatic charge/discharge techniques and the experiments that demonstrate the excellent capacitive properties of the obtained supercapacitors will also be discussed. The fabrication and characterization of the samples were performed at the Center of Functional Nanomaterials at Brookhaven National Lab. The developed approaches in our study represent an exciting direction for designing the next generation of energy storage devices. This work was supported in part by the U.S. Department of Energy through the Visiting Faculty Program and the research used resources of the Center for Functional Nanomaterials at Brookhaven National Laboratory.

  15. Visual acuity after Ruthenium106 brachytherapy of choroidal melanomas

    International Nuclear Information System (INIS)

    Damato, Bertil; Patel, Imran M.; Campbell, Ian R.; Mayles, Helen M.; Errington, R. Douglas

    2005-01-01

    Purpose: To report on conservation of visual acuity after Ruthenium 106 (Ru-106) brachytherapy of choroidal melanoma. Methods and materials: This study was a noncomparative interventional case series of 458 patients with choroidal melanoma treated at a single center between January 1993 and December 2001. The intervention consisted of Ru-106 brachytherapy delivering minimum scleral and apex doses of 300 Gy and 80 Gy, respectively, using a 15-mm or 20-mm plaque. For discrete, posterior tumors, the plaque was positioned eccentrically with its posterior edge aligned with the posterior tumor margin. To ensure correct plaque positioning, any overlying extraocular muscles were dis-inserted, and the locations of both tumor and plaque edges were confirmed by transillumination and indentation. The main outcome measures were conservation of vision of 20/40 or better, 20/200 or better, and Counting Fingers or better, according to baseline variables. Results: The actuarial rate of conservation of 20/40 or better was 55% at 9 years, loss of such vision correlating with posterior tumor extension (p 106 brachytherapy of posterior choroidal melanoma achieves good conservation of vision if the tumor does not extend close to the optic nerve or fovea

  16. Coordinatively unsaturated ruthenium complexes as efficient alkyneazide cycloaddition catalysts

    KAUST Repository

    Lamberti, Marina

    2012-01-23

    The performance of 16-electron ruthenium complexes with the general formula Cp*Ru(L)X (in which L = phosphine or N-heterocyclic carbene ligand; X = Cl or OCH2CF3) was explored in azidealkyne cycloaddition reactions that afford the 1,2,3- triazole products. The scope of the Cp*Ru(PiPr 3)Cl precatalyst was investigated for terminal alkynes leading to new 1,5-disubstituted 1,2,3-triazoles in high yields. Mechanistic studies were conducted and revealed a number of proposed intermediates. Cp*Ru- (PiPr3)(2-HCCPh)Cl was observed and characterized by 1H, 13C, and 31P NMR at temperatures between 273 and 213 K. A rare example of N,N-κ2-phosphazide complex, Cp*Ru(κ2- iPr3PN3Bn)Cl, was fully characterized, and a single-crystal X-ray diffraction structure was obtained. DFT calculations describe a complete map of the catalytic reactivity with phenylacetylene and/or benzylazide. © 2012 American Chemical Society.

  17. Rapid visual and spectrophotometric nitrite detection by cyclometalated ruthenium complex.

    Science.gov (United States)

    Lo, Hoi-Shing; Lo, Ka-Wai; Yeung, Chi-Fung; Wong, Chun-Yuen

    2017-10-16

    Quantitative determination of nitrite ion (NO 2 - ) is of great importance in environmental and clinical investigations. A rapid visual and spectrophotometric assay for NO 2 - detection was developed based on a newly designed ruthenium complex, [Ru(npy)([9]aneS3)(CO)](ClO 4 ) (denoted as RuNPY; npy = 2-(1-naphthyl)pyridine, [9]aneS3 = 1,4,7-trithiacyclononane). This complex traps NO + produced in acidified NO 2 - solution, and yields observable color change within 1 min at room temperature. The assay features excellent dynamic range (1-840 μmol L -1 ) and high selectivity, and its limit of detection (0.39 μmol L -1 ) is also well below the guideline values for drinking water recommended by WHO and U.S. EPA. Practical use of this assay in tap water and human urine was successfully demonstrated. Overall, the rapidity and selectivity of this assay overcome the problems suffered by the commonly used modified Griess assays for nitrite determination. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Ruthenium(V) oxides from low-temperature hydrothermal synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Hiley, Craig I.; Walton, Richard I. [Department of Chemistry, University of Warwick, Coventry (United Kingdom); Lees, Martin R. [Department of Physics, University of Warwick, Coventry (United Kingdom); Fisher, Janet M.; Thompsett, David [Johnson Matthey Technology Centre, Reading (United Kingdom); Agrestini, Stefano [Max-Planck Institut, CPfS, Dresden (Germany); Smith, Ronald I. [ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Harwell Oxford, Didcot (United Kingdom)

    2014-04-22

    Low-temperature (200 C) hydrothermal synthesis of the ruthenium oxides Ca{sub 1.5}Ru{sub 2}O{sub 7}, SrRu{sub 2}O{sub 6}, and Ba{sub 2}Ru{sub 3}O{sub 9}(OH) is reported. Ca{sub 1.5}Ru{sub 2}O{sub 7} is a defective pyrochlore containing Ru{sup V/VI}; SrRu{sub 2}O{sub 6} is a layered Ru{sup V} oxide with a PbSb{sub 2}O{sub 6} structure, whilst Ba{sub 2}Ru{sub 3}O{sub 9}(OH) has a previously unreported structure type with orthorhombic symmetry solved from synchrotron X-ray and neutron powder diffraction. SrRu{sub 2}O{sub 6} exhibits unusually high-temperature magnetic order, with antiferromagnetism persisting to at least 500 K, and refinement using room temperature neutron powder diffraction data provides the magnetic structure. All three ruthenates are metastable and readily collapse to mixtures of other oxides upon heating in air at temperatures around 300-500 C, suggesting they would be difficult, if not impossible, to isolate under conventional high-temperature solid-state synthesis conditions. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. Placental transfer of ruthenium in rat and guinea-pig

    International Nuclear Information System (INIS)

    Levack, V.M.; Pottinger, H.; Harrison, J.D.

    1994-01-01

    Ruthenium-106 in citrate solution was administered intravenously to rat at different stages of pregnancy and to guinea-pig either before conception or in late pregnancy. The results for rat showed that retention in the embryo/foetus measured at 3-5 days after administration increased from about 0.0002% of injected activity per embryo/foetus on day 12 of gestation to about 0.05% at birth. The relative concentrations of 106 Ru in embryo/foetus and mother (C f /C m ratio) were about 0.1 in each case. Concentrations in the yolk sac on day 12 were about 1% g -1 compared with 0.01% g -1 kin the foetus/ Retention in the guinea-pig foetus in late gestation at 7 days after administration (days 50-57) was about 0.2% injected activity per foetus, corresponding to a C f /C m = 0.2. Retention in each foetoplacental unit was 2% of injected 106 Ru with 50% in the yolk sac, 35% in the placenta and 10% in the foetus. For administration 4 weeks prior to conception, the level of 106 Ru retained in the foetus on day 57 of gestation was two orders of magnitude lower than after short-term administration, with a C f /C m about 0.004. (author)

  20. Electron transfer reactions of ruthenium(II) complexes with polyphenolic acids in micelles

    Energy Technology Data Exchange (ETDEWEB)

    Rajeswari, Angusamy [School of Chemistry, Madurai Kamaraj University, Madurai 625 021 (India); Department of Chemistry, Fatima College, Madurai 625 018 (India); Ramdass, Arumugam [School of Chemistry, Madurai Kamaraj University, Madurai 625 021 (India); Research Department of Chemistry, Aditanar College of Arts and Science, Tiruchendur 628 216 (India); Muthu Mareeswaran, Paulpandian [School of Chemistry, Madurai Kamaraj University, Madurai 625 021 (India); Department of Industrial Chemistry, Alagappa University, Karaikudi 630 003 (India); Rajagopal, Seenivasan, E-mail: rajagopalseenivasan@yahoo.com [School of Chemistry, Madurai Kamaraj University, Madurai 625 021 (India)

    2016-02-15

    The electron transfer in a microhetrogeneous system is a perfect mimic of biological electron transfer. The electron transfer between biologically important phenolic acids and ruthenium (II) complexes is systematically studied in the presence of anionic and cationic micelles. The photophysical properties of these ruthenium (II) complexes with anionic and cationic micelles and their binding abilities with these two type of micelles are also studies using absorption, emission and excited state lifetime spectral techniques. Pseudophase Ion Exchange (PIE) Model is applied to derive mechanism of electron transfer in two types of micelles. - Highlights: • Effect of microhetrogeneous system is studied using ruthenium (II) complexes and gallic acid is studied. • Pseudophase Ion exchange model is applied to derive the mechanism. • Binding constants are in the range of 10{sup 2}–10{sup 4} M{sup −1}.

  1. Stable tracer investigations in humans for assessing the biokinetics of ruthenium and zirconium radionuclides

    International Nuclear Information System (INIS)

    Veronese, I.; Cantone, M.C.; Giussani, A.; Maggioni, T.; Birattari, C.; Bondardi, M.; Groppi, F.; Garlaschelli, I.; Werner, E.; Roth, P.; Hoellriegl, V.; Louvat, P.; Felgenhauer, N.; Zilker, Th.

    2003-01-01

    The interest in the biokinetics of ruthenium and zirconium in humans is justified by the potential radiological risk represented by their radionuclides. Only a few data related to the biokinetics of ruthenium and zirconium in humans are available and, accordingly, the biokinetic models currently recommended by the ICRP for these elements are mainly based on data from animal experiments. The use of stable isotopes as tracers, coupled with a proper analytical technique (nuclear activation analysis with protons) for their determination in biological samples, represents an ethically acceptable methodology for biokinetic investigations, being free from any radiation risk for the volunteer subjects. In this work, the results obtained in eight biokinetic investigations for ruthenium, conducted on a total of three healthy volunteers, and six for zirconium, performed on a total of three subjects, are presented and compared to the predictions of the ICRP models. (author)

  2. Amorphous carbon nanofibres inducing high specific capacitance of deposited hydrous ruthenium oxide

    International Nuclear Information System (INIS)

    Barranco, V.; Pico, F.; Ibanez, J.; Lillo-Rodenas, M.A.; Linares-Solano, A.; Kimura, M.; Oya, A.; Rojas, R.M.; Amarilla, J.M.; Rojo, J.M.

    2009-01-01

    Composites consisting of ruthenium oxide particles deposited on amorphous carbon nanofibres are prepared by a repetitive impregnation procedure. The choice of amorphous carbon nanofibres as support of amorphous ruthenium oxide leads to composites in which the deposited oxide consists of aggregates of extremely small primary particles (1-1.5 nm-size) and showing high porosity (specific surface area of 450 m 2 g -1 ). This special deposition of the oxide seems to favour: (i) high oxide capacitance (1000 Fg -1 ) at high oxide loadings (up to 20 wt%) and (ii) high capacitance retention (ca. 80% from the initial oxide capacitance) at high current densities (200 mA cm -2 ). Amorphous carbon nanofibres are suitable supports for amorphous ruthenium oxide and perhaps for other amorphous oxides acting as active electrode materials.

  3. Estimation of very low concentrations of Ruthenium by spectrophotometric method using barbituric acid as complexing agent

    International Nuclear Information System (INIS)

    Ramakrishna Reddy, S.; Srinivasan, R.; Mallika, C.; Kamachi Mudali, U.; Natarajan, R.

    2012-01-01

    Spectrophotometric method employing numerous chromogenic reagents like thiourea, 1,10-phenanthroline, thiocyanate and tropolone is reported in the literature for the estimation of very low concentrations of Ru. A sensitive spectrophotometric method has been developed for the determination of ruthenium in the concentration range 1.5 to 6.5 ppm in the present work. This method is based on the reaction of ruthenium with barbituric acid to produce ruthenium(ll)tris-violurate, (Ru(H 2 Va) 3 ) -1 complex which gives a stable deep-red coloured solution. The maximum absorption of the complex is at 491 nm due to the inverted t 2g → Π(L-L ligand) electron - transfer transition. The molar absorptivity of the coloured species is 9,851 dm 3 mol -1 cm -1

  4. Luminescence properties of uranyl-acetate species

    Energy Technology Data Exchange (ETDEWEB)

    Brinkmann, Hannes; Moll, Henry [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Inst. of Resource Ecology; Stumpf, Thorsten [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Biogeochemistry

    2017-06-01

    Time-resolved laser-induced fluorescence spectroscopy (TRLFS) was applied to characterize uranium(VI)- acetate species based on their luminescence properties. In contrast to previous interpretations, no indications were detected for the existence of the 1: 3 complex.

  5. Cellulose acetate electrospun nanofibrous membrane: fabrication ...

    Indian Academy of Sciences (India)

    337–343. c Indian Academy of Sciences. ... 1Faculty of Bioscience and Medical Engineering, Universiti Teknologi Malaysia, 81300 Johor, Malaysia ... concentrations were prepared by dissolving the polymer in a mixture of acetic acid/acetone ...

  6. Acetate causes alcohol hangover headache in rats.

    Directory of Open Access Journals (Sweden)

    Christina R Maxwell

    2010-12-01

    Full Text Available The mechanism of veisalgia cephalgia or hangover headache is unknown. Despite a lack of mechanistic studies, there are a number of theories positing congeners, dehydration, or the ethanol metabolite acetaldehyde as causes of hangover headache.We used a chronic headache model to examine how pure ethanol produces increased sensitivity for nociceptive behaviors in normally hydrated rats.Ethanol initially decreased sensitivity to mechanical stimuli on the face (analgesia, followed 4 to 6 hours later by inflammatory pain. Inhibiting alcohol dehydrogenase extended the analgesia whereas inhibiting aldehyde dehydrogenase decreased analgesia. Neither treatment had nociceptive effects. Direct administration of acetate increased nociceptive behaviors suggesting that acetate, not acetaldehyde, accumulation results in hangover-like hypersensitivity in our model. Since adenosine accumulation is a result of acetate formation, we administered an adenosine antagonist that blocked hypersensitivity.Our study shows that acetate contributes to hangover headache. These findings provide insight into the mechanism of hangover headache and the mechanism of headache induction.

  7. Dye sensitized photovoltaic cells: Attaching conjugated polymers to zwitterionic ruthenium dyes

    DEFF Research Database (Denmark)

    Krebs, Frederik C; Biancardo, M.

    2006-01-01

    The synthesis of a zwitterionic ruthenium dye that binds to anatase surfaces and has a built-in functionality that allows for the attachment of a conjugated polymer chain is presented. The system was found to adsorb on the surface of anatase anchored by the ruthenium dye. Two types of devices were...... prepared: standard photoelectrochemical (PEC) solar cells and polymer solar cells. The PEC solar cells employed a sandwich geometry between TiO2 nanoporous photoanodes and Pt counter electrodes using LiI/I-2 in CH3CN as an electrolyte. The polymer solar cells employed planar anatase electrodes...

  8. Ruthenium phosphine complexes as catalysts for alternating co-polymerization of ethylene and CO

    International Nuclear Information System (INIS)

    Gusev, O.V.; Kal'sin, A.M.; Peganov, T.A.; Petrovskij, P.V.; Belov, G.P.; Novikova, E.V.

    2000-01-01

    Ruthenium (2) complexes, [Ru(dppe) 2 (OTs) 2 ] and [Ru(PhP(CH 2 CH 2 CH 2 PPh 2 ) 2 )(OTs) 2 ], where dppe (diphenylphosphino)ethane; OTs = tosylate, were synthesized with the yield of 67 and 76%, respectively, and characterized by 31 P NMR. The properties of the above complexes as catalysts of alternating co-polymerization of ethylene and carbon monoxide were studied. A considerable increase in catalytic activity of the complexes was established in the presence of trifluoroacetic acid and 1,4-benzoquinone. These compounds are the first example of ruthenium complexes that catalyse co-polymerization of ethylene and CO [ru

  9. Behaviour of ruthenium in the case of shutdown of the cooling system of HLLW storage tanks

    International Nuclear Information System (INIS)

    Philippe, M.; Gue, J.P.; Mercier, J.P.

    1990-12-01

    The consequences of the failure of the cooling system of fission product storage tanks over a variable period were investigated as part of the safety analysis of the La Hague spent fuel reprocessing plant. Due to the considerable heat release, induced by the fission products, a prolonged shutdown of the tank cooling system could cause the progressive evaporation of the solutions to dryness, and culminate in the formation of volatile species of ruthenium and their release in the tank venting circuit. To determine the fraction of ruthenium likely to be transferred from the storage tanks in volatile or aerosol form during the failure, evaporation tests were conducted by evaporating samples of actual nitric acid solutions of fission products, obtained on the laboratory scale after the reprocessing of several kilograms of MOX fuels irradiated to 30.000 MW day ·t -1 . A distillation apparatus was designed to operate with small-volume solution samples, reproducing the heating conditions existing in the reprocessing plant within a storage tank for fission products. The main conclusions drawn from these experiments are as follows: - ruthenium is only volatilized in the final phase of evaporation, just before desiccation, - for a final temperature limited to 160 deg. C, the total fraction of volatilized ruthenium reaches 12%, - in the presence of H 2 O, HNO 3 , NO x and O 2 , the volatilized ruthenium recombines mainly in the form of ruthenium nitrosyl nitrates, or decomposes into ruthenium oxide (probably RuO 2 ) on the walls of the apparatus. Assuming a heating power density of 10 W/liter of concentrate, and a perfectly adiabatic storage system, the minimum time required to reach dryness can be estimated at 90 h, allowing substantial time to take action to restore a cooling source. It is probable that, in an industrial storage tank, the heat losses from the tank and the offgas discharge ducts will cause recondensation and internal reflux, which will commensurately delay

  10. General synthesis of (salen)ruthenium(III) complexes via N...N coupling of (salen)ruthenium(VI) nitrides.

    Science.gov (United States)

    Man, Wai-Lun; Kwong, Hoi-Ki; Lam, William W Y; Xiang, Jing; Wong, Tsz-Wing; Lam, Wing-Hong; Wong, Wing-Tak; Peng, Shie-Ming; Lau, Tai-Chu

    2008-07-07

    Reaction of [Ru (VI)(N)(L (1))(MeOH)] (+) (L (1) = N, N'-bis(salicylidene)- o-cyclohexylenediamine dianion) with excess pyridine in CH 3CN produces [Ru (III)(L (1))(py) 2] (+) and N 2. The proposed mechanism involves initial equilibrium formation of [Ru (VI)(N)(L (1))(py)] (+), which undergoes rapid N...N coupling to produce [(py)(L (1))Ru (III) N N-Ru (III)(L (1))(py)] (2+); this is followed by pyridine substituion to give the final product. This ligand-induced N...N coupling of Ru (VI)N is utilized in the preparation of a series of new ruthenium(III) salen complexes, [Ru (III)(L)(X) 2] (+/-) (L = salen ligand; X = H 2O, 1-MeIm, py, Me 2SO, PhNH 2, ( t )BuNH 2, Cl (-) or CN (-)). The structures of [Ru (III)(L (1))(NH 2Ph) 2](PF 6) ( 6), K[Ru (III)(L (1))(CN) 2] ( 9), [Ru (III)(L (2))(NCCH 3) 2][Au (I)(CN) 2] ( 11) (L (2) = N, N'-bis(salicylidene)- o-phenylenediamine dianion) and [N ( n )Bu 4][Ru (III)(L (3))Cl 2] ( 12) (L (3) = N, N'-bis(salicylidene)ethylenediamine dianion) have been determined by X-ray crystallography.

  11. Performance variation from triphenylamine- to carbazole-triphenylamine-rhodaniline-3-acetic acid dyes in dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Chien-Hsin, E-mail: yangch@nuk.edu.tw [Department of Chemical and Materials Engineering, National University of Kaohsiung, Kaohsiung 811, Taiwan (China); Lin, Wen-Churng [Department of Environmental Engineering, Kun Shan University, Tainan 710, Taiwan (China); Wang, Tzong-Liu; Shieh, Yeong-Tarng; Chen, Wen-Janq; Liao, Shao-Hong; Sun, Yu-Kuang [Department of Chemical and Materials Engineering, National University of Kaohsiung, Kaohsiung 811, Taiwan (China)

    2011-10-17

    Highlights: {yields} We synthesized an organic dye of carbazole-rhodaniline-3-acetic acid-triphenylamine. {yields} A dye-sensitized solar cell is fabricated using this dye with efficiency of 4.64%. {yields} Carbazole donor in the dye molecule provides electron in increasing efficiency. {yields} Two rhodaniline-3-acetic acids play a key role in increasing efficiency. {yields} AC impedance proves this dye's effect on enhancing charge transfer in TiO{sub 2}. - Abstract: Organic dyes have been synthesized which contain an extra-electron donor (carbazole) and electron acceptors (rhodaniline-3-acetic acid) on triphenylamines (TPA). Photophysical, electrochemical, and theoretical computational methods have categorized these compounds. Nanocrystalline TiO{sub 2}-based dye-sensitized solar cells (DSSCs) are fabricated using these dye molecules as light-harvesting sensitizers. The overall efficiency of sensitized cells has 4.64% relative to a cis-di(thiocyanato)-bis(2,2'-bipyridyl)-4,4'-dicarboxylate ruthenium (II) (N3 dye)-sensitized device (7.83%) fabricated and measured under the same conditions. Carbazole-electron donation in the dye molecules plays a key role in the increased efficiency. Two rhodaniline-3-acetic acid groups appear to help convey the charge transfer from the excited dye molecules to the conduction band of TiO{sub 2}, leading to a higher efficiency of devices using such a dye. Electrochemical impedance supports this dye's effect on enhancing charge transfer in TiO{sub 2} (e{sup -}). Computations on this dye compound also indicate the larger charge transfer efficiency in the electronically excited state.

  12. Spectrophotometric determination of ruthenium(III) and rhodium(III) after extraction of their cyclohexylthioglycolate complexes into chloroform

    International Nuclear Information System (INIS)

    Rao, A.L.J.; Gupta, Usha; Puri, B.K.

    1986-01-01

    Cyclohexylthioglycolate has been used as a reagent for the spectrophotometric determination of ruthenium(III) and rhodium(III) after the extraction of their complexes into chloroform. Various parameters involved in the extraction have been studied and the composition of the extracted complex has been established in each instance. Ruthenium and rhodium complexes are extracted into chloroform in the pH ranges 5.0-9.0 and 9.0-12.5, respectively. The ruthenium complex absorbs strongly at 365 nm, whereas the rhodium complex shows a maximum absorption at 345 nm. Beer's law is obeyed over the concentration range 6-96 μg for ruthenium and 2-41 μg for rhodium in 10 ml of the chloroform solution. The molar absorptivities are 5.02 x 10 3 l mol -1 cm -1 for ruthenium and 1.60 x 10 4 l mol -1 cm -1 for rhodium. Ten replicate determinations on a sample solution containing 60.3 μg of ruthenium or 20.6 μg of rhodium gave mean absorbances of 0.300 and 0.320 with standard deviations of 0.0021 and 0.0025 and relative standard deviations of 0.70% and 0.78%, respectively. The interference of various ions has been studied and the method has been applied to the determination of the metals in various synthetic samples. Conditions have also been developed for the simultaneous determination of ruthenium and rhodium. (author)

  13. Spectrophotometric determination of ruthenium (III) and rhodium (III) with 9,10-phenanthrenequinone monoxime after extraction into molten naphthalene

    International Nuclear Information System (INIS)

    Wasey, A.; Bansal, R.K.; Puri, B.K.; Satake, Masatada.

    1983-01-01

    9,10-Phenanthrenequinone monoxime has been used as a reagent for the spectrophotometric determination of ruthenium(III) and rhodium(III) after extraction into molten naphthalene. The extracted mixture of the metal complex and naphthalene was dissolved in chloroform and ruthenium and rhodium were determined spectrophotometrically. Beer's law holds in the concentration range of 0.2-4.1 μg/cm 3 for ruthenium and 0.3-5.3 μg/cm 3 for rhodium in 10 cm 3 of the final solution. The molar absorptivities and Sandell sensitivities are calculated to be 9.70 x 10 3 l mol -1 cm -1 and 0.01 μg/cmsup(2 ) (660 nm) for ruthenium and 1.13 x 10 4 l mol -1 cm -1 and 0.009 μg/cm 2 (410 nm) for rhodium respectively. Aliquots containing 2.0 μg of ruthenium and 4.1 μg of rhodium give mean absorbances of 0.192 and 0.451 with standard deviations of 0.0017 and 0.0039, respectively. Interference of various ions has been studied and the method has been applied to the determination of ruthenium and rhodium in various synthetic mixtures. This procedure is also applied to the simultaneous determination of ruthenium and rhodium present together in a solution. (author)

  14. A ruthenium anticancer compound interacts with histones and impacts differently on epigenetic and death pathways compared to cisplatin.

    Science.gov (United States)

    Licona, Cynthia; Spaety, Marie-Elodie; Capuozzo, Antonelle; Ali, Moussa; Santamaria, Rita; Armant, Olivier; Delalande, Francois; Van Dorsselaer, Alain; Cianferani, Sarah; Spencer, John; Pfeffer, Michel; Mellitzer, Georg; Gaiddon, Christian

    2017-01-10

    Ruthenium complexes are considered as potential replacements for platinum compounds in oncotherapy. Their clinical development is handicapped by a lack of consensus on their mode of action. In this study, we identify three histones (H3.1, H2A, H2B) as possible targets for an anticancer redox organoruthenium compound (RDC11). Using purified histones, we confirmed an interaction between the ruthenium complex and histones that impacted on histone complex formation. A comparative study of the ruthenium complex versus cisplatin showed differential epigenetic modifications on histone H3 that correlated with differential expression of histone deacetylase (HDAC) genes. We then characterized the impact of these epigenetic modifications on signaling pathways employing a transcriptomic approach. Clustering analyses showed gene expression signatures specific for cisplatin (42%) and for the ruthenium complex (30%). Signaling pathway analyses pointed to specificities distinguishing the ruthenium complex from cisplatin. For instance, cisplatin triggered preferentially p53 and folate biosynthesis while the ruthenium complex induced endoplasmic reticulum stress and trans-sulfuration pathways. To further understand the role of HDACs in these regulations, we used suberanilohydroxamic acid (SAHA) and showed that it synergized with cisplatin cytotoxicity while antagonizing the ruthenium complex activity. This study provides critical information for the characterization of signaling pathways differentiating both compounds, in particular, by the identification of a non-DNA direct target for an organoruthenium complex.

  15. In vitro evaluation of ruthenium complexes for photodynamic therapy.

    Science.gov (United States)

    Li, Wenna; Xie, Qiang; Lai, Linglin; Mo, Zhentao; Peng, Xiaofang; Leng, Ennian; Zhang, Dandan; Sun, Hongxia; Li, Yiqi; Mei, Wenjie; Gao, Shuying

    2017-06-01

    Photodynamic therapy (PDT) is a promising anti-tumor treatment strategy. Photosensitizer is one of the most important components of PDT. In this work, the anticancer activities of PDT mediated by six new ruthenium porphyrin complexes were screened. The mechanisms of the most efficacious candidate were investigated. Photocytotoxicity of the six porphyrins was tested. The most promising complex, Rup-03, was further investigated using Geimsa staining, which indirectly detects reactive oxygen species (ROS) and subcellular localization. Mitochondrial membrane potential (MMP), cell apoptosis, DNA fragmentation, c-Myc gene expression, and telomerase activities were also assayed. Rup-03 and Rup-04 had the lowest IC 50 values. Rup-03 had an IC 50 value of 29.5±2.3μM in HepG2 cells and 59.0±6.1μM in RAW264.7 cells, while Rup-04 had an IC 50 value of 40.0±3.8μM in SGC-7901 cells. The complexes also induced cellular morphological changes and impaired cellular ability to scavenge ROS, and accumulated preferentially in mitochondria and endoplasmic reticulum. Rup-03 reduced MMP levels, induced apoptosis, and repressed both c-Myc mRNA expression and telomerase activity in HepG2 cells. Among six candidates, Rup-03-mediated PDT is most effective against HepG2 and RAW264.7, with a similar efficacy as that of Rup-04-mediated PDT against SGC-7901 cells. Repression of ROS scavenging activities and c-Myc expression, which mediated DNA damage-induced cell apoptosis and repression of telomerase activity, respectively, were found to be involved in the anticancer mechanisms of Rup-03. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Dealloyed Ruthenium Film Catalysts for Hydrogen Generation from Chemical Hydrides

    Directory of Open Access Journals (Sweden)

    Ramis B. Serin

    2017-07-01

    Full Text Available Thin-film ruthenium (Ru and copper (Cu binary alloys have been prepared on a Teflon™ backing layer by cosputtering of the precious and nonprecious metals, respectively. Alloys were then selectively dealloyed by sulfuric acid as an etchant, and their hydrogen generation catalysts performances were evaluated. Sputtering time and power of Cu atoms have been varied in order to tailor the hydrogen generation performances. Similarly, dealloying time and the sulfuric acid concentration have also been altered to tune the morphologies of the resulted films. A maximum hydrogen generation rate of 35 mL min−1 was achieved when Cu sputtering power and time were 200 W and 60 min and while acid concentration and dealloying time were 18 M and 90 min, respectively. It has also been demonstrated that the Ru content in the alloy after dealloying gradually increased with the increasing the sputtering power of Cu. After 90 min dealloying, the Ru to Cu ratio increased to about 190 times that of bare alloy. This is the key issue for observing higher catalytic activity. Interestingly, we have also presented template-free nanoforest-like structure formation within the context of one-step alloying and dealloying used in this study. Last but not least, the long-time hydrogen generation performances of the catalysts system have also been evaluated along 3600 min. During the first 600 min, the catalytic activity was quite stable, while about 24% of the catalytic activity decayed after 3000 min, which still makes these systems available for the development of robust catalyst systems in the area of hydrogen generation.

  17. {sup 106}Ruthenium Plaque Therapy (RPT) for Retinoblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, Naoya, E-mail: namuraka@ncc.go.jp [Department of Radiation Oncology, National Cancer Center Hospital, Tokyo (Japan); Suzuki, Shigenobu [Department of Ophthalmic Oncology, National Cancer Center Hospital, Tokyo (Japan); Ito, Yoshinori [Department of Radiation Oncology, National Cancer Center Hospital, Tokyo (Japan); Yoshimura, Ryoichi [Department of Diagnostic Radiology and Oncology, Head and Neck Reconstruction Division, Graduate School, Tokyo Medical and Dental University, Tokyo (Japan); Inaba, Koji; Kuroda, Yuki; Morota, Madoka; Mayahara, Hiroshi; Sakudo, Mototake; Wakita, Akihisa; Okamoto, Hiroyuki; Sumi, Minako; Kagami, Yoshikazu [Department of Radiation Oncology, National Cancer Center Hospital, Tokyo (Japan); Nakagawa, Keiichi; Ohtomo, Kuni [Department of Radiology, University of Tokyo Hospital, Tokyo (Japan); Itami, Jun [Department of Radiation Oncology, National Cancer Center Hospital, Tokyo (Japan)

    2012-09-01

    Purpose: To evaluate the effectiveness of episcleral {sup 106}ruthenium plaque therapy (RPT) in the management of retinoblastoma. Methods and Materials: One hundred one RPTs were retrospectively analyzed that were performed in 90 eyes of 85 patients with retinoblastoma at National Cancer Center Hospital between 1998 and 2008. Each RPT had a corresponding tumor and 101 tumors were considered in the analysis of local control. Median follow-up length was 72.8 months. Median patient age at the RPT was 28 months. Median prescribed doses at reference depth and outer surface of the sclera were 47.4 Gy and 162.3 Gy, respectively. Results: Local control rate (LCR) and ocular retention rate (ORR) at 2 years were 33.7% and 58.7%, respectively. Unilateral disease, International Classification of Retinoblastoma group C or more advanced at the first presentation or at the time of RPT, vitreous and/or subretinal seeding, tumor size greater than 5 disc diameter (DD), reference depth greater than 5 mm, dose rate at reference depth lower than 0.7 Gy/hour, dose at the reference depth lower than 35 Gy, and (biologically effective dose with an {alpha}/{beta} ratio of 10 Gy) at the reference depth lower than 40 Gy{sub 10} were associated with unfavorable LCR. Two patients died of metastatic disease. Radiation complications included retinal detachment in 12 eyes (13.3%), proliferative retinopathy in 6 (6.7%), rubeosis iris in 2 (2.2%), and posterior subcapsular cataract in 23 (25.6%). Conclusion: RPT is an effective eye-preserving treatment for retinoblastoma.

  18. Behavior of ruthenium, cesium and antimony during simulated HLLW vitrification

    International Nuclear Information System (INIS)

    Klein, M.; Weyers, C.; Goossens, W.R.A.

    1985-01-01

    The behavior of ruthenium, cesium, and antimony during the vitrification of simulated high-level radioactive liquid wastes (HLLW) in a liquid fed melter was studied on a laboratory scale and on a semi-pilot scale. In the laboratory melter of a 2.5 kg capacity, a series of tests with the simulate traced with 103 Ru, 134 Cs and 124 Sb, has shown that the Ru and Cs losses to the melter effluent are generally higher than 10% whereas the antimony losses remain lower than 0.4%. A wet purification system comprising in series, a dust scrubber, a condenser, an ejector venturi and an NOx washing column retains most of the activity present in the off-gas so that the release fractions for Ru at the absolute filter inlet ranges between 5.10 -3 to 5.10 -5 % of the Ru fed, for Cs the corresponding release fraction ranges between 3.10 -3 to 10 -4 % and for Sb the release fraction ranges between 1.7 10 -4 to 1.7 10 -5 %. The same experiments were performed at a throughput of 1 to 2 1 h -1 of simulated solution in the semi-pilot scale unit RUFUS. The RUFUS unit comprises a glass melter with a 50 kg molten glass capacity and the wet purification train comprises in series a dust scrubber, a condenser, an ejector venturi and an NOx washing column. The tracer tests were restricted to 103 Ru and 134 Cs since the laboratory tests had shown that the antimony losses were very low. The results of the tests are presented

  19. Reaction mechanisms of ruthenium tetroxide mediated oxidations of organic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Froehaug, Astrid Elisabeth

    1995-12-31

    This thesis reports a study of the mechanism of ruthenium tetroxide mediated oxidations of saturated hydrocarbons, ethers, alkenes and alcohols. Several methods were used. The RuO{sub 4}-mediated oxidations of adamantane and cis-decalin were studied in CCl{sub 4}-CH{sub 3}CN-H{sub 2}O and in acetone-water. The rate of reaction was found to be moderately influenced by the polarity of the solvent. Solvent properties other than the polarity were also found to influence the reaction rates. From the oxidations of adamantane and adamantane-1,3,5,7-d{sub 4} two primary kinetic deuterium isotope effects were found. These were comparable with the deuterium isotope effects found for the analogous oxidations of cis-decalin and cis-decalin-d{sub 18}. The results seem to exclude both a one step hydride abstraction reaction mechanism and a one step concerted mechanism, as well as a scheme where two such mechanisms compete. The observations may be explained by a two step reaction mechanism consisting of a pre-equilibrium with formation of a substrate-RuO{sub 4} complex followed by a concerted rate determining reaction. The RuO{sub 4}-mediated oxidation of ethers was of kinetic second order with a small enthalpy of activation and a large negative entropy of activation. Oxidation of cyclopropylmethyl methyl ether gave methyl cyclopropanecarboxylate, no rearranged products were observed. On RuO{sub 4} oxidations in CCl{sub 4} with NaIO{sub 4} as stoichiometric oxidant, no chlorinated products were observed. Several observations not in agreement with a hydride or a hydrogen abstraction mechanism may be explained by assuming that the reaction proceeds by either a concerted reaction or by a reversible oxidative addition of the ether to RuO{sub 4} followed by a slow concerted step. 228 refs., 9 figs., 27 tabs.

  20. Ruthenium porphyrin-induced photodamage in bladder cancer cells.

    Science.gov (United States)

    Bogoeva, Vanya; Siksjø, Monica; Sæterbø, Kristin G; Melø, Thor Bernt; Bjørkøy, Astrid; Lindgren, Mikael; Gederaas, Odrun A

    2016-06-01

    Photodynamic therapy (PDT) is a noninvasive treatment for solid malignant and flat tumors. Light activated sensitizers catalyze photochemical reactions that produce reactive oxygen species which can cause cancer cell death. In this work we investigated the photophysical properties of the photosensitizer ruthenium(II) porphyrin (RuP), along with its PDT efficiency onto rat bladder cancer cells (AY27). Optical spectroscopy verified that RuP is capable to activate singlet oxygen via blue and red absorption bands and inter system crossing (ISC) to the triplet state. In vitro experiments on AY27 indicated increased photo-toxicity of RuP (20μM, 18h incubation) after cell illumination (at 435nm), as a function of blue light exposure. Cell survival fraction was significantly reduced to 14% after illumination of 20μM RuP with 15.6J/cm(2), whereas the "dark toxicity" of 20μM RuP was 17%. Structural and morphological changes of cells were observed, due to RuP accumulation, as well as light-dependent cell death was recorded by confocal microscopy. Flow cytometry verified that PDT-RuP (50μM) triggered significant photo-induced cellular destruction with a photoxicity of (93%±0.9%). Interestingly, the present investigation of RuP-PDT showed that the dominating mode of cell death is necrosis. RuP "dark toxicity" compared to the conventional chemotherapeutic drug cisplatin was higher, both evaluated by the MTT assay (24h). In conclusion, the present investigation shows that RuP with or without photoactivation induces cell death of bladder cancer cells. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Catalytic water oxidation by ruthenium(II) quaterpyridine (qpy) complexes: evidence for ruthenium(III) qpy-N,N'''-dioxide as the real catalysts.

    Science.gov (United States)

    Liu, Yingying; Ng, Siu-Mui; Yiu, Shek-Man; Lam, William W Y; Wei, Xi-Guang; Lau, Kai-Chung; Lau, Tai-Chu

    2014-12-22

    Polypyridyl and related ligands have been widely used for the development of water oxidation catalysts. Supposedly these ligands are oxidation-resistant and can stabilize high-oxidation-state intermediates. In this work a series of ruthenium(II) complexes [Ru(qpy)(L)2 ](2+) (qpy=2,2':6',2'':6'',2'''-quaterpyridine; L=substituted pyridine) have been synthesized and found to catalyze Ce(IV) -driven water oxidation, with turnover numbers of up to 2100. However, these ruthenium complexes are found to function only as precatalysts; first, they have to be oxidized to the qpy-N,N'''-dioxide (ONNO) complexes [Ru(ONNO)(L)2 ](3+) which are the real catalysts for water oxidation. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Biological properties of novel ruthenium- and osmium-nitrosyl complexes with azole heterocycles

    KAUST Repository

    Novak, Maria S.; Bü chel, Gabriel E.; Keppler, Bernhard K.; Jakupec, Michael A.

    2016-01-01

    Since the discovery that nitric oxide (NO) is a physiologically relevant molecule, there has been great interest in the use of metal nitrosyl compounds as antitumor pharmaceuticals. Particularly interesting are those complexes which can deliver NO to biological targets. Ruthenium- and osmium-based compounds offer lower toxicity compared to other metals and show different mechanisms of action as well as different spectra of activity compared to platinum-based drugs. Novel ruthenium- and osmium-nitrosyl complexes with azole heterocycles were studied to elucidate their cytotoxicity and possible interactions with DNA. Apoptosis induction, changes of mitochondrial transmembrane potential and possible formation of reactive oxygen species were investigated as indicators of NO-mediated damage by flow cytometry. Results suggest that ruthenium- and osmium-nitrosyl complexes with the general formula (indazolium)[cis/trans-MCl4(NO)(1H-indazole)] have pronounced cytotoxic potency in cancer cell lines. Especially the more potent ruthenium complexes strongly induce apoptosis associated with depolarization of mitochondrial membranes, and elevated reactive oxygen species levels. Furthermore, a slight yet not unequivocal trend to accumulation of intracellular cyclic guanosine monophosphate attributable to NO-mediated effects was observed.

  3. Surface and sub-surface thermal oxidation of ruthenium thin films

    NARCIS (Netherlands)

    Coloma Ribera, R.; van de Kruijs, Robbert Wilhelmus Elisabeth; Zoethout, E.; Yakshin, Andrey; Bijkerk, Frederik

    2014-01-01

    For next generation Extreme UV photolithography, multilayer coatings may require protective capping layers against surface contamination. Ruthenium, as a low-oxidation metal, is often used as a reference material. The oxidation behaviour of Ru thin films has been studied using X-ray reflectometry

  4. Fabrication of ruthenium metal nanosheets via topotactic metallization of exfoliated ruthenate nanosheets.

    Science.gov (United States)

    Fukuda, Katsutoshi; Sato, Jun; Saida, Takahiro; Sugimoto, Wataru; Ebina, Yasuo; Shibata, Tatsuo; Osada, Minoru; Sasaki, Takayoshi

    2013-03-04

    The metallization behavior of molecularly thin RuO2 nanosheets obtained from complete delamination of layered ruthenates was studied. Interestingly, the RuO2 nanosheets in a monolayer state topotactically transformed into a single layer of Ru atoms, i.e., ruthenium metal nanosheets, which can be regarded as a new family of nanosized metals.

  5. Activity of iridium-ruthenium and iridium-rhodium adsorption catalysts in decomposition of hydrogen peroxide

    Energy Technology Data Exchange (ETDEWEB)

    Zubovich, I A; Mikhaylov, V A; Migulina, N N [Yaroslavskij Politekhnicheskij Inst. (USSR)

    1976-06-01

    Experimental data for the activities of iridium-ruthenium and iridium-rhodium adsorption catalysts in the decomposition of hydrogen peroxide are considered and the results of magnetic susceptibility measurements are presented. It is concluded that surface structures (complexes) may be formed and that micro-electronic feaures play a role in heterogeneous catalysis.

  6. Elimination of ionic interference effects in the atomic absorption spectrometric determination of ruthenium

    International Nuclear Information System (INIS)

    El-Defrawy, M.M.M.; Posta, J.; Beck, M.T.

    1978-01-01

    In connection with work on the catalytic effect of ruthenium complexes, new compounds were prepared. Atomic absorption spectrometry (a.a.s.) was to be used for their analysis. The standard methods could not be applied to the complexes studied, therefore the effect of cyanide ions for elimination of interfering effects has been studied, because of the great stability of cyanide complexes. (Auth.)

  7. Inductively Coupled Plasma Mass Spectrometry: Sample Analysis of Zirconium and Ruthenium in Metal Organic Frameworks

    Science.gov (United States)

    2018-02-01

    linear regression fits for the calibration curves. The goodness of the linear fits are summarized in Table 3 and Figure 1. Table 3. Concentration...and ruthenium at each calibration level. 11 REFERENCES 1. General Requirements for the Competence of Testing and Calibration Laboratories

  8. Hydrogenation of esters catalyzed by ruthenium PN3-Pincer complexes containing an aminophosphine arm

    KAUST Repository

    Chen, Tao

    2014-08-11

    Hydrogenation of esters under mild conditions was achieved using air-stable ruthenium PN3-pincer complexes containing an aminophosphine arm. High efficiency was achieved even in the presence of water. DFT studies suggest a bimolecular proton shuttle mechanism which allows H2 to be activated by the relatively stable catalyst with a reasonably low transition state barrier. © 2014 American Chemical Society.

  9. Biological properties of novel ruthenium- and osmium-nitrosyl complexes with azole heterocycles

    KAUST Repository

    Novak, Maria S.

    2016-03-09

    Since the discovery that nitric oxide (NO) is a physiologically relevant molecule, there has been great interest in the use of metal nitrosyl compounds as antitumor pharmaceuticals. Particularly interesting are those complexes which can deliver NO to biological targets. Ruthenium- and osmium-based compounds offer lower toxicity compared to other metals and show different mechanisms of action as well as different spectra of activity compared to platinum-based drugs. Novel ruthenium- and osmium-nitrosyl complexes with azole heterocycles were studied to elucidate their cytotoxicity and possible interactions with DNA. Apoptosis induction, changes of mitochondrial transmembrane potential and possible formation of reactive oxygen species were investigated as indicators of NO-mediated damage by flow cytometry. Results suggest that ruthenium- and osmium-nitrosyl complexes with the general formula (indazolium)[cis/trans-MCl4(NO)(1H-indazole)] have pronounced cytotoxic potency in cancer cell lines. Especially the more potent ruthenium complexes strongly induce apoptosis associated with depolarization of mitochondrial membranes, and elevated reactive oxygen species levels. Furthermore, a slight yet not unequivocal trend to accumulation of intracellular cyclic guanosine monophosphate attributable to NO-mediated effects was observed.

  10. Design and synthesis of ruthenium(II) OCO pincer type NHC ...

    Indian Academy of Sciences (India)

    The tridentate nature of the tBu(OCO)2− ligand as well as some level of steric protection ... our previous results of ruthenium(II) o-hydroxyaryl sub- stituted bidentate NHC ...... (a) Ribelin T, Katz C E, English D G, Smith S,. Manukyan A K, Day ...

  11. Preliminary assessment of modified borosilicate glasses for chromium and ruthenium immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Farid, Osama M. [Reactors Department, Nuclear Research Center, Atomic Energy Authority of Egypt, P.O. 13759, Inshas, Cairo (Egypt); Centre of Nuclear Engineering (CNE), Department of Materials, Imperial College London, London, SW7 2BP (United Kingdom); Abdel Rahman, R.O., E-mail: alaarehab@yahoo.com [Hot Laboratory Center, Atomic Energy Authority of Egypt, P.O. 13759, Inshas, Cairo (Egypt)

    2017-01-15

    The feasibility of using modified alkali borosilicate glasses for ruthenium and chromium immobilization is preliminary assessed by investigating the immobilization system structure under normal conditions. Within this context, reference alkali borosilicate, and simulated Magnox-modified glasses were prepared and studied. The results indicate that ruthenium is immobilized in the vitreous structure as encapsulated RuO{sub 2} crystallites that act as seeds for heterogeneous nucleation of other crystalline phases. The presence of Zn, as modifier, has contributed to chromium immobilization in zincochromite spinel structure, whereas Ca is accommodated in the vitreous structure. Immobilization performance was evaluated by conducting conservative static leach test and studying the leached glass. Leached glass morphology was altered, where near surface reference glass is leached over 400 nm and simulated Magnox-modified sample is altered over 300 nm. Normalized release rates are within normal range for borosilicate material. For simulated Magnox-modified sample, Ca and alkali structural element, i.e. Na and Li, are leached via ion-exchange reaction. The ion-exchanged fraction equals 1.06 × 10{sup −8} mol/m{sup 2} s and chromium has slightly lower normalized release rate value than ruthenium. - Highlights: • The presence of modifiers and waste oxides led to localized de-vitrification. • Ruthenium is encapsulated within the vitreous glass network as RuO{sub 2} crystals. • Chromium is immobilized within the zincochromite spinel structure. • Pitting and cracks induced by leaching did not affect the immobilization performance.

  12. Dinuclear ruthenium sawhorse-type complexes containing carboxylato bridges and ferrocenyl substituents: Synthesis and electrochemistry

    Czech Academy of Sciences Publication Activity Database

    Auzias, M.; Süss-Fink, G.; Štěpnička, P.; Ludvík, Jiří

    2007-01-01

    Roč. 360, č. 6 (2007), s. 2023-2028 ISSN 0020-1693 Institutional research plan: CEZ:AV0Z40400503 Keywords : carboxylato bridges * dinuclear complexes * ruthenium * electrochemistry Subject RIV: CG - Electrochemistry Impact factor: 1.713, year: 2007

  13. Contribution to the study of the fluorination of ruthenium and its dioxide

    International Nuclear Information System (INIS)

    Courtois, Charles.

    1977-12-01

    Compounds formed during fluorination of ruthenium and its dioxide are studied. By chemical analysis the constitution of these compounds is cleared up. RuF 5 is the main compound formed, but a secondary product is obtained which is RuF 8 . The vapor pressure of this product is given between 178 and 221 0 K, and its infrared spectrum is drawn [fr

  14. A technique for studying digestion by grasshoppers using a 103Ruthenium-labelled marker

    International Nuclear Information System (INIS)

    Gandar, M.V.

    1981-01-01

    103 Ru-labelled tris (I,10-phenanthroline) ruthenium (II) chloride has proved to be a convenient marker in investigating digestion in grasshoppers. Assimilation efficiencies and the retension time of the food in the gut were measured. It is surmised that the technique described in this paper will be applicable to studies of a variety of chewing herbivorous insects. (author)

  15. Structural, spectral, DFT and biological studies on macrocyclic mononuclear ruthenium (II) complexes

    Science.gov (United States)

    Muthukkumar, M.; Kamal, C.; Venkatesh, G.; Kaya, C.; Kaya, S.; Enoch, Israel V. M. V.; Vennila, P.; Rajavel, R.

    2017-11-01

    Macrocyclic mononuclear ruthenium (II) complexes have been synthesized by condensation method [Ru (L1, L2, L3) Cl2] L1 = (C36 H31 N9), L2= (C42H36N8), L3= (C32H32 N8)]. These ruthenium complexes have been established by elemental analyses and spectroscopic techniques (Fourier transform infrared spectroscopy (FT-IR), 1H- nuclear magnetic resonance (NMR), 13C- NMR and Electrospray ionization mass spectrometry (ESI-MS)). The coordination mode of the ligand has been confirmed and the octahedral geometry around the ruthenium ion has been revealed. Binding affinity and binding mode of ruthenium (II) complexes with Bovine serum Albumin (BSA) have been characterized by Emission spectra analysis. UV-Visible and fluorescence spectroscopic techniques have also been utilized to examine the interaction between ligand and its complexes L1, L2, & L3 with BSA. Chemical parameters and molecular structure of Ru (II) complexes L1H, L2H, & L3H have been determined by DFT coupled with B3LYP/6-311G** functional in both the gaseous and aqueous phases.

  16. Ion implantation to improve mechanical and electrical properties of resistive materials based on ruthenium dioxide

    International Nuclear Information System (INIS)

    Byeli, A.V.; Shykh, S.K.; Beresina, V.P.

    1996-01-01

    This paper reports the influence of ion implantation, using different chemical species, on the surface micromorphology, wear resistance, coefficient of friction and electrical resistivity, and its variation during friction for resistive materials based on ruthenium dioxide. It is demonstrated that nitrogen and hydrogen ions are the most effective for modifying surface properties. (Author)

  17. A study of ruthenium complexes of some biologically relevant a-N ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 112; Issue 3. A study of ruthenium complexes of some biologically relevant ∙ -N-heterocyclic ... Author Affiliations. P Sengupta1 S Ghosh1. Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Calcutta 700 032, India ...

  18. New soluble functional polymers by free-radical copolymerization of methacrylates and bipyridine ruthenium complexes

    NARCIS (Netherlands)

    Holder, E.; Meier, M.A.R.; Marin, V.N.; Schubert, U.S.

    2003-01-01

    The luminescent complex [4-(3-hydroxypropyl)-4-methyl-2,2-bipyridine]-bis(2,2-bipyridine)-ruthenium(II)-bis(hexafluoroantimonate) and its methacrylate derivative were successfully synthesized and fully characterized by two-dimensional 1H and 13C{1H} NMR techniques [correlation spectroscopy (COSY)

  19. Electronic Interplay between TTF and Extended-TCNQ Electrophores along a Ruthenium Bis(acetylide) Linker.

    Science.gov (United States)

    Vacher, Antoine; Auffray, Morgan; Barrière, Frédéric; Roisnel, Thierry; Lorcy, Dominique

    2017-11-17

    A bis(TTF-butadiynyl) ruthenium D-D'-D complex, with intramolecular electronic interplay between the three electron-donating electrophores, was easily converted through a cycloaddition-retroelectrocyclization with TCNQ into a D-A-D'-A-D pentad complex, which exhibits an intense intramolecular charge transfer together with an electronic interplay between the two acceptors along the conjugated organometallic bridge.

  20. Graphene/Ruthenium Active Species Aerogel as Electrode for Supercapacitor Applications.

    Science.gov (United States)

    Gigot, Arnaud; Fontana, Marco; Pirri, Candido Fabrizio; Rivolo, Paola

    2017-12-30

    Ruthenium active species containing Ruthenium Sulphide (RuS₂) is synthesized together with a self-assembled reduced graphene oxide (RGO) aerogel by a one-pot hydrothermal synthesis. Ruthenium Chloride and L-Cysteine are used as reactants. The hydrothermal synthesis of the innovative hybrid material occurs at 180 °C for 12 h, by using water as solvent. The structure and morphology of the hybrid material are fully characterized by Raman, XRD, XPS, FESEM and TEM. The XRD and diffraction pattern obtained by TEM display an amorphous nanostructure of RuS₂ on RGO crystallized flakes. The specific capacitance measured in planar configuration in 1 M NaCl electrolyte at 5 mV s -1 is 238 F g -1 . This supercapacitor electrode also exhibits perfect cyclic stability without loss of the specific capacitance after 15,000 cycles. In summary, the RGO/Ruthenium active species hybrid material demonstrates remarkable properties for use as active material for supercapacitor applications.

  1. Reactions of ruthenium and osmium cluster carbonyls with heteroatom-substituted and functionalized alkynes

    International Nuclear Information System (INIS)

    Koridze, A.A.

    2000-01-01

    The results of studies of the reactions of ruthenium and osmium cluster carbonyls with metal (M = Re, Mn, Fe) alkynes, silylalkynes, propargyl alcohols and their derivatives, diynes, enynes, and ferrocenylacetylene are summarized. Intramolecular rearrangements in the cluster complexes including migrations of carbonyl, hydride, and hydrocarbon ligands and the metal core reorganization are considered [ru

  2. Magnetically Recoverable Supported Ruthenium Catalyst for Hydrogenation of Alkynes and Transfer Hydrogenation of Carbonyl Compounds

    Science.gov (United States)

    A ruthenium (Ru) catalyst supported on magnetic nanoparticles (NiFe2O4) has been successfully synthesized and used for hydrogenation of alkynes at room temperature as well as transfer hydrogenation of a number of carbonyl compounds under microwave irradiation conditions. The cata...

  3. Ruthenium-catalyzed cyclization of N-carbamoyl indolines with alkynes: an efficient route to pyrroloquinolinones.

    Science.gov (United States)

    Manoharan, Ramasamy; Jeganmohan, Masilamani

    2015-09-21

    A regioselective synthesis of substituted pyrroloquinolinones via a ruthenium-catalyzed oxidative cyclization of substituted N-carbamoyl indolines with alkynes is described. The cyclization reaction was compatible with various symmetrical and unsymmetrical alkynes including substituted propiolates. Later, we performed the aromatization of pyrroloquinolinones into indole derivatives in the presence of 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ).

  4. Studies On An Aerobic Oxidation Of Dibenzothiophene And Related Compounds Using Ruthenium Catalyst

    Directory of Open Access Journals (Sweden)

    Morishita Y.

    2015-06-01

    Full Text Available An aerobic oxidation of dibenzothiophene and related compounds using a catalytic amount of ruthenium chloride in hydrocarbon solvents at 80°C for 20 h gave the corresponding sulfones in almost quantitative yields. The reaction might proceed via autoxidation of solvents to hydroperoxides and the reaction of sulfur compounds with the resulting hydroperoxides.

  5. Photo-induced DNA cleavage and cytotoxicity of a ruthenium(II) arene anticancer complex

    Czech Academy of Sciences Publication Activity Database

    Brabec, Viktor; Prachařová, J.; Štěpánková, Jana; Sadler, P. J.; Kašpárková, Jana

    2016-01-01

    Roč. 160, JUL2016 (2016), s. 149-155 ISSN 0162-0134 R&D Projects: GA ČR(CZ) GA14-21053S; GA MŠk(CZ) LD14019 Institutional support: RVO:68081707 Keywords : Ruthenium anticancer complex * DNA cleavage * Phototoxicity Subject RIV: BO - Biophysics Impact factor: 3.348, year: 2016

  6. Mixed-ligand complexes of ruthenium(II) incorporating a diazo ...

    Indian Academy of Sciences (India)

    Unknown

    Dedicated to the memory of the late Professor Bhaskar G Maiya. *For correspondence. Mixed-ligand complexes of ruthenium(II) incorporating a diazo ligand: Synthesis .... water (1 : 1) for 5 h to give a dark red solution. The solution was cooled to room temperature. After eva- poration of the solvent, the solid was collected,.

  7. Correlations between electrochemical and spectrochemical parameters of ruthenium sulfoxides series with N-heterocyclic

    International Nuclear Information System (INIS)

    Oliveira, D. de; Toma, H.E.

    1990-01-01

    A systematic study of Ru Cl sub(2) (DMSO) sub(2) L sub(2) derivates, where L = N-heterocyclic base is described, contributing for a best understanding of chemical behaviour and electronic structure of the ruthenium sulfoxides. The correlations between the electrochemical and the spectroscopical parameters of the serie are presented with more emphasis. (author)

  8. Investigation of Ruthenium Dissolution in Advanced Membrane Electrode Assemblies for Direct Methanol Based Fuel Cell Stacks

    Science.gov (United States)

    Valdez, Thomas I.; Firdosy, S.; Koel, B. E.; Narayanan, S. R.

    2005-01-01

    Dissolution of ruthenium was observed in the 80-cell stack. Duration testing was performed in single cell MEAs to determine the pathway of cell degradation. EDAX analysis on each of the single cell MEAs has shown that the Johnson Matthey commercial catalyst is stable in DMFC operation for 250 hours, no ruthenium dissolution was observed. Changes in the hydrophobicity of the cathode backing papers was minimum. Electrode polarization analysis revealed that the MEA performance loss is attributed to changes in the cathode catalyst layer. Ruthenium migration does not seem to occur during cell operation but can occur when methanol is absent from the anode compartment, the cathode compartment has access to air, and the cells in the stack are electrically connected to a load (Shunt Currents). The open-to-air cathode stack design allowed for: a) The MEAs to have continual access to oxygen; and b) The stack to sustain shunt currents. Ruthenium dissolution in a DMFC stack can be prevented by: a) Developing an internally manifolded stacks that seal reactant compartments when not in operation; b) Bringing the cell voltages to zero quickly when not in operation; and c) Limiting the total number of cells to 25 in an effort to limit shunt currents.

  9. Investigation of Ruthenium Dissolution in Advanced Membrane Electrode Assemblies for Direct Methanol Based Fuel Cells Stacks

    Science.gov (United States)

    Valdez, T. I.; Firdosy, S.; Koel, B. E.; Narayanan, S. R.

    2005-01-01

    This viewgraph presentation gives a detailed review of the Direct Methanol Based Fuel Cell (DMFC) stack and investigates the Ruthenium that was found at the exit of the stack. The topics include: 1) Motivation; 2) Pathways for Cell Degradation; 3) Cell Duration Testing; 4) Duration Testing, MEA Analysis; and 5) Stack Degradation Analysis.

  10. Aerobic Oxidation of 5-(Hydroxymethyl)furfural in Ionic Liquids with Solid Ruthenium Hydroxide Catalysts

    DEFF Research Database (Denmark)

    Ståhlberg, Tim Johannes Bjarki; Eyjolfsdottir, Ester; Gorbanev, Yury

    2012-01-01

    The aerobic oxidation of 5-(hydroxymethyl)furfural was investigated over solid ruthenium hydroxide catalysts in ionic liquids at elevated temperatures and pressures. Several different catalyst supports were tested in combination with various ionic liquids. The best result was obtained in [EMIm...

  11. Ruthenium(II)- bipyridyl with extended π-system: Improved thermo ...

    Indian Academy of Sciences (India)

    aInorganic and Physical Chemistry Division, Indian Institute of Chemical Technology, Uppal Road, Tarnaka, ... A new extended thermo-stable high molar extinction coefficient bipyridyl ruthenium(II) complex ... cyanines and metal free organic sensitizers have been ..... Iodide-based ionic liquids are more viscous than.

  12. Tailoring the Selectivity for Electrocatalytic Oxygen Evolution on Ruthenium Oxides by Zinc Substitution

    Czech Academy of Sciences Publication Activity Database

    Petrykin, Valery; Macounová, Kateřina; Shlyakhtin, O. A.; Krtil, Petr

    2010-01-01

    Roč. 49, č. 28 (2010), s. 4813-4815 ISSN 1433-7851 R&D Projects: GA AV ČR IAA400400906 Institutional research plan: CEZ:AV0Z40400503 Keywords : electrocatalysis * ruthenium oxides * zinc substitution Subject RIV: CG - Electrochemistry Impact factor: 12.730, year: 2010

  13. Efficient oxygen reduction reaction using ruthenium tetrakis(diaquaplatinum)octacarboxyphthalocyanine catalyst supported on MWCNT platform

    CSIR Research Space (South Africa)

    Maxakato, NW

    2011-02-01

    Full Text Available -1 Electroanalysis 2011, 23, No. 2, 325 ? 329 Efficient Oxygen Reduction Reaction Using Ruthenium Tetrakis(diaquaplatinum)Octacarboxyphthalocyanine Catalyst Supported on MWCNT Platform Nobanathi W. Maxakato,a Solomon A. Mamuru,a Kenneth I. Ozoemena*a, b a...

  14. Room temperature aerobic oxidation of amines by a nanocrystalline ruthenium oxide pyrochlore nafion composite catalyst.

    Science.gov (United States)

    Venkatesan, Shanmuganathan; Kumar, Annamalai Senthil; Lee, Jyh-Fu; Chan, Ting-Shan; Zen, Jyh-Myng

    2012-05-14

    The aerobic oxidation of primary amines to their respective nitriles has been carried out at room temperature using a highly reusable nanocrystalline ruthenium oxide pyrochlore Nafion composite catalyst (see figure). Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Study of the emission oxidative reactions of ruthenium (II) complex by cationic compounds in anionic micelles

    International Nuclear Information System (INIS)

    Bonilha, J.B.S.

    1985-01-01

    The oxidative quenching of the emission of the tetraanionic complex tris (4,4' dicarboxylate - 2,2' - bipyridine ruthenium (II) in aqueous solution, by both organic and inorganic compounds in presence of anionic detergents, above and below the critical micelle concentration is studied. The organic cations, the inorganic ion and detergents used are shown. (M.J.C.) [pt

  16. Extraction and atomic absorption spectrophotometric determination of iron and ruthenium by using potassium xanthates

    Energy Technology Data Exchange (ETDEWEB)

    Aihara, M; Kiboku, M [Kinki Univ., Higashi-Osaka, Osaka (Japan)

    1981-06-01

    Potassium xanthates (potassium o-alkyl dithiocarbonate; KRX) react with many metal ions, and so the complex formation with iron (II, III) ion and the extraction of their complexes has been studied to some extent, but those of ruthenium (III) have not been. Iron-xanthate and ruthenium-xanthate complexes can be extracted into methyl isobutyl ketone (MIBK) from weakly acidic solution to weakly alkaline solution. For quantitative extraction of iron (20 ..mu..g/40 ml), KRX concentration should be above 2.0 x 10/sup -2/ mol dm/sup -3/ of KEtX, 1.0 x 10/sup -2/ mol dm/sup -3/ of KPrX, and 5.0 x 10/sup -3/ mol dm/sup -3/ of KBtX and KPeX, and for that of ruthenium (202 ..mu..g/40 ml), it should be above 2.0 x 10/sup -1/ mol dm/sup -3/ of KEtX and KPrX. Formation constant of ruthenium-xanthate complexes is presumed to be small. A 100-fold excess of Ni(II), Co(II), Cu(II), WO/sub 4//sup 2 -/, PO/sub 4//sup 3 -/, CrO/sub 4//sup 2 -/, and Cr/sub 2/O/sub 7//sup 2 -/ interfered with the determination of iron, however, the interferences are eliminated by adding 5 ml of 0.1 mol dm/sup -3/ ascorbic acid solution. For the determination of ruthenium, a 50-fold excess of Ag(I), Hg(II), Pb(II), Zn(II), Mn(II), Cr(III), and Pt(II), or a 100-fold excess of NO/sub 2//sup -/, S/sub 2/O/sub 3//sup 2 -/, CrO/sub 4//sup 2 -/ and Cr/sub 2/O/sub 7//sup 2 -/, respectively, interfered. The coefficient of variation after each ten runs, ranges from 0.9% to 3.2% in the determination of 10 ..mu..g, 20 ..mu..g, and 30 ..mu..g of iron, and from 1.4% to 4.3% in the determination of 100 ..mu..g, 200 ..mu..g, and 300 ..mu..g of ruthenium. The determination limit in aqueous samples is 0.02 ppm for iron and 0.2 ppm for ruthenium, when the volume ratio of aqueous phase to organic phase (MIBK) is 10:1.

  17. Analysis of flow fields, temperatures and ruthenium transport in the test facility

    International Nuclear Information System (INIS)

    Kaerkelae, T.; Pyykoenen, J.; Auvinen, A.; Jokiniemi, J.

    2008-03-01

    Ruthenium transport experiments were conducted at VTT during years 2002- 2006. Experiments gave information about ruthenium behaviour in air ingress accident conditions. This study complements those experiments with an analysis of the flows and thermal fields in the test system. Temperature profiles were measured at the walls of the experimental facility. Computational fluid dynamics (CFD) simulations used the measured profiles and provided predictions of flows and temperatures inside the furnace. Ruthenium transport was also modelled with CFD. Thermal characterisation of the reactor demonstrated that buoyancy has a significant role during the cooling after the furnace. A hypothesis of the dominant role of RuO2 and RuO3 condensation on reactor walls gave simulation results that are in accordance with radiotracer measurements of deposition in experiments conducted with furnace at 1500K. Actually, RuO3 does not condensate, but it thermal decomposes to RuO2. This does not seem to have effect on result. Particle formation around the furnace exit could be detected from the comparison of modelling results with the measured profiles. In several other experiments ruthenium behaviour is dominated by other issues. These are related to the complex ruthenium chemistry that includes various surface reactions. Thermal equilibrium indicates significant gaseous RuO4 concentration around 1300 K. It seems that seed particles decreased the catalytic decomposition activity of RuO4 to RuO2 around this temperature pushing the gas concentration towards the equilibrium, and further give rise to gaseous RuO4 transport to low temperatures. At higher temperature increasing mass flow rate of RuO2 particles is likely to catalyse (decomposition) reaction of RuO4 to RuO2. (au)

  18. Synthesis and reactivity of compounds containing ruthenium-carbon, -nitrogen, and -oxygen bonds

    International Nuclear Information System (INIS)

    Hartwig, J.F.

    1990-12-01

    The products and mechanisms of the thermal reactions of several complexes of the general structure (PMe 3 ) 4 Ru(X)(Y) and (DMPM) 2 Ru(X)(Y) where X and Y are hydride, aryl, and benzyl groups, have been investigated. The mechanism of decomposition depends critically on the structure of the complex and the medium in which the thermolysis is carried out. The alkyl hydride complexes are do not react with alkane solvent, but undergo C-H activation processes with aromatic solvents by several different mechanisms. Thermolysis of (PMe 3 ) 4 Ru(Ph)(Me) or (PMe 3 ) 4 Ru(Ph) 2 leads to the ruthenium benzyne complex (PMe 3 ) 4 Ru(η 2 -C 6 H 4 ) (1) by a mechanism which involves reversible dissociation of phosphine. In many ways its chemistry is analogous to that of early rather than late organo transition metal complexes. The synthesis, structure, variable temperature NMR spectroscopy and reactivity of ruthenium complexes containing aryloxide or arylamide ligands are reported. These complexes undergo cleavage of a P-C bond in coordinated trimethylphosphine, insertion of CO and CO 2 and hydrogenolysis. Mechanistic studies on these reactions are described. The generation of a series of reactive ruthenium complexes of the general formula (PMe 3 ) 4 Ru(R)(enolate) is reported. Most of these enolates have been shown to bind to the ruthenium center through the oxygen atom. Two of the enolate complexes 8 and 9 exist in equilibrium between the O- and C-bound forms. The reactions of these compounds are reported, including reactions to form oxygen-containing metallacycles. The structure and reactivity of these ruthenium metallacycles is reported, including their thermal chemistry and reactivity toward protic acids, electrophiles, carbon monoxide, hydrogen and trimethylsilane. 243 refs., 10 tabs

  19. Analysis of flow fields, temperatures and ruthenium transport in the test facility

    Energy Technology Data Exchange (ETDEWEB)

    Kaerkelae, T.; Pyykoenen, J.; Auvinen, A.; Jokiniemi, J. [Technical Research Centre of Finland VTT (Finland)

    2008-03-15

    Ruthenium transport experiments were conducted at VTT during years 2002- 2006. Experiments gave information about ruthenium behaviour in air ingress accident conditions. This study complements those experiments with an analysis of the flows and thermal fields in the test system. Temperature profiles were measured at the walls of the experimental facility. Computational fluid dynamics (CFD) simulations used the measured profiles and provided predictions of flows and temperatures inside the furnace. Ruthenium transport was also modelled with CFD. Thermal characterisation of the reactor demonstrated that buoyancy has a significant role during the cooling after the furnace. A hypothesis of the dominant role of RuO2 and RuO3 condensation on reactor walls gave simulation results that are in accordance with radiotracer measurements of deposition in experiments conducted with furnace at 1500K. Actually, RuO3 does not condensate, but it thermal decomposes to RuO2. This does not seem to have effect on result. Particle formation around the furnace exit could be detected from the comparison of modelling results with the measured profiles. In several other experiments ruthenium behaviour is dominated by other issues. These are related to the complex ruthenium chemistry that includes various surface reactions. Thermal equilibrium indicates significant gaseous RuO4 concentration around 1300 K. It seems that seed particles decreased the catalytic decomposition activity of RuO4 to RuO2 around this temperature pushing the gas concentration towards the equilibrium, and further give rise to gaseous RuO4 transport to low temperatures. At higher temperature increasing mass flow rate of RuO2 particles is likely to catalyse (decomposition) reaction of RuO4 to RuO2. (au)

  20. Synthesis and reactivity of compounds containing ruthenium-carbon, -nitrogen, and -oxygen bonds

    Energy Technology Data Exchange (ETDEWEB)

    Hartwig, J.F.

    1990-12-01

    The products and mechanisms of the thermal reactions of several complexes of the general structure (PMe{sub 3}){sub 4}Ru(X)(Y) and (DMPM){sub 2}Ru(X)(Y) where X and Y are hydride, aryl, and benzyl groups, have been investigated. The mechanism of decomposition depends critically on the structure of the complex and the medium in which the thermolysis is carried out. The alkyl hydride complexes are do not react with alkane solvent, but undergo C-H activation processes with aromatic solvents by several different mechanisms. Thermolysis of (PMe{sub 3}){sub 4}Ru(Ph)(Me) or (PMe{sub 3}){sub 4}Ru(Ph){sub 2} leads to the ruthenium benzyne complex (PMe{sub 3}){sub 4}Ru({eta}{sup 2}-C{sub 6}H{sub 4}) (1) by a mechanism which involves reversible dissociation of phosphine. In many ways its chemistry is analogous to that of early rather than late organo transition metal complexes. The synthesis, structure, variable temperature NMR spectroscopy and reactivity of ruthenium complexes containing aryloxide or arylamide ligands are reported. These complexes undergo cleavage of a P-C bond in coordinated trimethylphosphine, insertion of CO and CO{sub 2} and hydrogenolysis. Mechanistic studies on these reactions are described. The generation of a series of reactive ruthenium complexes of the general formula (PMe{sub 3}){sub 4}Ru(R)(enolate) is reported. Most of these enolates have been shown to bind to the ruthenium center through the oxygen atom. Two of the enolate complexes 8 and 9 exist in equilibrium between the O- and C-bound forms. The reactions of these compounds are reported, including reactions to form oxygen-containing metallacycles. The structure and reactivity of these ruthenium metallacycles is reported, including their thermal chemistry and reactivity toward protic acids, electrophiles, carbon monoxide, hydrogen and trimethylsilane. 243 refs., 10 tabs.

  1. Hydrolysis of Acetic Anhydride in a CSTR

    Directory of Open Access Journals (Sweden)

    Veronica N. Coraci

    2016-05-01

    Full Text Available To find the optimal reactor volume and temperature for the hydrolysis of acetic anhydride at the lowest possible cost with a 90% conversion of acetic anhydride, a formula for the total cost of the reaction was created. Then, the first derivative was taken to find a value for the temperature. This value was then inputted into the second derivative of the equation to find the sign of the value which would indicate whether that point was a minima or maxima value. The minima value would then be the lowest total cost for the optimum reaction to take place.

  2. Characterization of acetate-utilizing methanogenic bacteria, depending on varying acetate concentrations, in a biogas plant. Phase 1

    International Nuclear Information System (INIS)

    Ahring, B.K.

    1994-12-01

    The present report contains the results of a project concerning behaviour of acetate-utilizing methanogenic bacteria in mesophilic and thermophilic biogas plants, collected in 1992 - 1994 period. Labelled acetates (2-C 14 -CH 3 COOH) have been used to characterize the types of methane bacteria populations in the Danish biogas plants, the optimum acetate concentration for these bacteria and acetate metabolism in mesophilic and thermophilic biogas reactors with low acetate concentrations. 2 publications are included. (EG)

  3. Selective deposition of nanostructured ruthenium oxide using Tobacco mosaic virus for micro-supercapacitors in solid Nafion electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Gnerlich, Markus; Ben-Yoav, Hadar; Culver, James N.; Ketchum, Douglas R.; Ghodssi, Reza

    2015-10-01

    A three-dimensional micro-supercapacitor has been developed using a novel bottom-up assembly method combining genetically modified Tobacco mosaic virus (TMV-1Cys), photolithographically defined micropillars and selective deposition of ruthenium oxide on multi-metallic microelectrodes. The three-dimensional microelectrodes consist of a titanium nitride current collector with two functionalized areas: (1) gold coating on the active electrode area promotes TMV-1Cys adhesion, and (2) sacrificial nickel pads dissolve in ruthenium tetroxide plating solution to produce ruthenium oxide on all electrically connected areas. The microfabricated electrodes are arranged in an interdigitated pattern, and the capacitance per electrode has been measured as high as 203 mF cm-2 with solid Nafion electrolyte. The process integration of bio-templated ruthenium oxide with microfabricated electrodes and solid electrolyte is an important advance towards the energy storage needs of mass produced self-sufficient micro-devices.

  4. Nanoengineering of Ruthenium and Platinum-based Nanocatalysts by Continuous-Flow Chemistry for Renewable Energy Applications

    KAUST Repository

    AlYami, Noktan Mohammed

    2017-01-01

    This thesis presents an integrated study of nanocatalysts for heterogenous catalytic and electrochemical processes using pure ruthenium (Ru) with mixed-phase and platinum-based nanomaterials synthesized by continuous-flow chemistry. There are three

  5. A case of anaphylactoid reaction to acetate in acetate-containing bicarbonate dialysate.

    Science.gov (United States)

    Misaki, Taro; Suzuki, Yumiko; Naito, Yoshitaka; Shiooka, Tempei; Isozaki, Taisuke

    2015-05-01

    A 35-year-old man with end-stage kidney disease due to chronic glomerulonephritis was admitted to our hospital to start maintenance hemodialysis (HD). One hour after starting the first session of HD, he experienced general pruritus, urticaria, and dyspnea. Signs and symptoms were resolved by discontinuing HD and administrating an antihistamine drug; HD-associated anaphylactoid reactions were therefore suspected. Over the next few HD sessions, we changed the dialysis membrane, anticoagulant, HD circuit and needle, in that order, but general pruritus and urticaria again appeared within 3 h after starting each session of HD. Finally, when we changed the dialysate from acetate-containing bicarbonate dialysate to acetate-free bicarbonate dialysate, urticaria was clearly less than that seen in previous HD sessions, and subsided after discontinuation of HD. Subsequently, 20 mg of oral prednisolone (PSL) was administered 1 h before starting HD, and the patient did not experience general pruritus, urticaria, or dyspnea after starting the session. When administered acetate-containing bicarbonate dialysate after oral PSL pretreatment, the patient again experienced general pruritus, urticaria and dyspnea. Few reports have been published on the occurrence of anaphylactoid reactions during HD using acetate dialysate. We report a rare case of anaphylactoid reactions with acetate in acetate-containing bicarbonate dialysate that were reduced with the use of acetate-free bicarbonate dialysate and oral PSL pretreatment.

  6. Selective catalytic reduction system and process for treating NOx emissions using a palladium and rhodium or ruthenium catalyst

    Science.gov (United States)

    Sobolevskiy, Anatoly [Orlando, FL; Rossin, Joseph A [Columbus, OH; Knapke, Michael J [Columbus, OH

    2011-07-12

    A process for the catalytic reduction of nitrogen oxides (NOx) in a gas stream (29) in the presence of H.sub.2 is provided. The process comprises contacting the gas stream with a catalyst system (38) comprising zirconia-silica washcoat particles (41), a pre-sulfated zirconia binder (44), and a catalyst combination (40) comprising palladium and at least one of rhodium, ruthenium, or a mixture of ruthenium and rhodium.

  7. Study of some properties of the ruthenium (II) trans-tetra-ammines with nitrogened aromatic heterocyclic ligands

    International Nuclear Information System (INIS)

    Bento, M.L.

    1985-01-01

    The ruthenium (II) complexes trans [Ru(NH 3 ) 4 LL'] (BF 4 ) 2 , where L and L' are 4-picoline, pyridine, isonicatinamide, pyrazine or 4-acetylpyridine are studied. The U.V-visible range spectra, bands in the U.V. and in the visible range is analysed. The spectra and the bands by comparison with other ruthenium (II) ammines are discussed, and a qualitative molecular orbital model is used. (M.J.C.) [pt

  8. Vinyl acetate polymerization by ionizing radiation

    International Nuclear Information System (INIS)

    Mesquita, Andrea Cercan

    2002-01-01

    The aim of this work is the synthesis and characterization of the poly(vinyl acetate) using the ionizing radiation. Six polymerizations of vinyl acetate were carried out using three techniques of polymerization: in bulk, emulsion and solution. In the technique of solution polymerization were used two solvents, the alcohol ethyl and the methylethylketone, in two proportions 1:0.5 and 1:1 related to the monomer. The solutions were irradiated with gamma rays from a 60 Co source, with dose rate between 5.25 kGy/h and 6.26 kGy/h. The polymers obtained were characterized by Fourier Transform Infrared Spectroscopy (FTIR). The glass transition temperature (Tg) was investigated by Differential Scanning Calorimeter (DSC). The molecular weight was analyzed by the technique of Gel Permeation Chromatography (GPC). Tests of density, hardness and Vicat softening temperature were carried out. The infrared spectroscopy and others results confirmed that the polymers obtained by polymerization of vinyl acetate in bulk, emulsion and solution, using ionizing radiation, really correspond at poly(vinyl acetate). (author)

  9. Facile Preparation of (2Z,4E)-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate.

    Science.gov (United States)

    Ding, Liyuan; Yu, Chunbing; Zhao, Zhenqiang; Li, Feifei; Zhang, Jian; Zhong, Guofu

    2017-06-21

    Direct cross-coupling between two alkenes via vinylic C-H bond activation represents an efficient strategy for the synthesis of butadienes with high atomic and step economy. However, this functionality-directed cross-coupling reaction has not been developed, as there are still limited directing groups in practical use. In particular, a stoichiometric amount of oxidant is usually required, producing a large amount of waste. Due to our interest in novel 1,3-butadiene synthesis, we describe the ruthenium-catalyzed olefination of electron-deficient alkenes using allyl acetate and without external oxidant. The reaction of 2-phenyl acrylamide and allyl acetate was chosen as a model reaction, and the desired diene product was obtained in 80% isolated yield with good stereoselectivity (Z,E/Z,Z = 88:12) under optimal conditions: [Ru(p-cymene) Cl2]2 (3 mol %) and AgSbF6 (20 mol %) in DCE at 110 ºC for 16 h. With the optimized catalytic conditions in hand, representative α- and/or β-substituted acrylamides were investigated, and all reacted smoothly, regardless of aliphatic or aromatic groups. Also, differently N-substituted acrylamides have proven to be good substrates. Moreover, we examined the reactivity of different allyl derivatives, suggesting that the chelation of acetate oxygen to the metal is crucial for the catalytic process. Deuterium-labeled experiments were also conducted to investigate the reaction mechanism. Only Z-selective H/D exchanges on acrylamide were observed, indicating a reversible cyclometalation event. In addition, a kinetic isotope effect (KIE) of 3.2 was observed in the intermolecular isotopic study, suggesting that the olefinic C-H metalation step is probably involved in the rate-determining step.

  10. Biotechnological applications of acetic acid bacteria.

    Science.gov (United States)

    Raspor, Peter; Goranovic, Dusan

    2008-01-01

    The acetic acid bacteria (AAB) have important roles in food and beverage production, as well as in the bioproduction of industrial chemicals. In recent years, there have been major advances in understanding their taxonomy, molecular biology, and physiology, and in methods for their isolation and identification. AAB are obligate aerobes that oxidize sugars, sugar alcohols, and ethanol with the production of acetic acid as the major end product. This special type of metabolism differentiates them from all other bacteria. Recently, the AAB taxonomy has been strongly rearranged as new techniques using 16S rRNA sequence analysis have been introduced. Currently, the AAB are classified in ten genera in the family Acetobacteriaceae. AAB can not only play a positive role in the production of selected foods and beverages, but they can also spoil other foods and beverages. AAB occur in sugar- and alcohol-enriched environments. The difficulty of cultivation of AAB on semisolid media in the past resulted in poor knowledge of the species present in industrial processes. The first step of acetic acid production is the conversion of ethanol from a carbohydrate carried out by yeasts, and the second step is the oxidation of ethanol to acetic acid carried out by AAB. Vinegar is traditionally the product of acetous fermentation of natural alcoholic substrates. Depending on the substrate, vinegars can be classified as fruit, starch, or spirit substrate vinegars. Although a variety of bacteria can produce acetic acid, mostly members of Acetobacter, Gluconacetobacter, and Gluconobacter are used commercially. Industrial vinegar manufacturing processes fall into three main categories: slow processes, quick processes, and submerged processes. AAB also play an important role in cocoa production, which represents a significant means of income for some countries. Microbial cellulose, produced by AAB, possesses some excellent physical properties and has potential for many applications. Other

  11. Ruthenium complexing during sorption by graft copolymer of polyacrylonitrile fibre with poly-2-methyl-5-vnylpyridine (PAN-MVP)

    International Nuclear Information System (INIS)

    Simanova, S.A.; Kolmakova, A.I.; Konovalov, L.V.; Kukushkin, Yu.N.; Lysenko, A.A.

    1984-01-01

    The sorption of ruthenium chlorocomplexes is studied on graft copolymer of polyacrylonitrile fibre with poly-2-methyl-5-vinylpyridine (PAN-MVP). The sorption has been performed under static conditions in the course of mixing at 20 and 98 deg from 0.1-2 OM HCl, 0.1-1 m NaCl solutions. The volume of the investigated solutions constituted 25 ml, fibre weight -0.1-0.3 g. Ruthenium concentration in solutions has been changed in the limits of 5x10 3 -2x10 -2 mol/l. The fibre has been preliminarily moistened by a solution containing no ruthenium. In all cases fresh-prepared ruthenium chlorocomplex solutions have been used. It has been found that with temperature increase the PAN-MVP sorption capacitance relative to ruthenium increases (at 20 deg-1.15 mmol/g, at 98 deg-1.70 mmol/g. The ruthenium chlorocomplex sorption by pyridine fibrous sorbent from salt-acid solutions occurs by anionoexchange mechanism and is related to the formation in the sorbent phase of onium chlorocomplexes - (RPyH) 2 [RuCl 6 ]. In the course of sorbents heating pyridine compounds are subject to Anderson regroupping with formation of compounds of diamine type-[Ru(RPy) 2 Cl 4

  12. Kinetic method of ruthenium ion traces determination, basing on the reaction of oxidation of direct blue 6B, by means of hydrogen peroxide

    International Nuclear Information System (INIS)

    Suwinska, T.; Gregorowicz, A.; Matysek-Majewska, D.

    1980-01-01

    A sensitive and selective method of determination of ruthenium ion traces (1.10 - 3 μg/cm 3 ) has been worked out. The method is based on oxidation of direct blue 6B by hydrogen peroxide under acidic conditions at pH = 0,8 - 1,2 in the presence of ruthenium ions as catalyst. The method has been applied for determination of ruthenium traces in Pt, PdCl 2 , PtCl 4 and RhCl 3 .n H 2 O. In these materials ruthenium has been determined within the range of 1,10 - 2 % - 5,10 - 4 %. (author)

  13. Correlation of vapor - liquid equilibrium data for acetic acid - isopropanol - water - isopropyl acetate mixtures

    Directory of Open Access Journals (Sweden)

    B. A. Mandagarán

    2006-03-01

    Full Text Available A correlation procedure for the prediction of vapor - liquid equilibrium of acetic acid - isopropanol - water - isopropyl acetate mixtures has been developed. It is based on the NRTL model for predicting liquid activity coefficients, and on the Hayden-O'Connell second virial coefficients for predicting the vapor phase of systems containing association components. When compared with experimental data the correlation shows a good agreement for binary and ternary data. The correlation also shows good prediction for reactive quaternary data.

  14. Chemical Mechanical Polishing of Ruthenium, Cobalt, and Black Diamond Films

    Science.gov (United States)

    Peethala, Brown Cornelius

    Ta/TaN bilayer serves as the diffusion barrier as well as the adhesion promoter between Cu and the dielectric in 32 nm technology devices. A key concern of future technology devices (layer (vs. a bilayer of Ta/TaN) to act as a barrier. During patterning, they need to be planarized using conventional chemical mechanical polishing (CMP) to achieve a planar surface. However, CMP of these new barrier materials requires novel slurry compositions that provide adequate selectivity towards Cu and dielectric films, and minimize galvanic corrosion. Apart from the application as a barrier, Ru also has been proposed as a lower electrode material in metal-insulator-metal capacitors where high (> 50 nm/min) Ru removal rates (RRs) are required and as a stop layer in magnetic recording head fabrication where low (hydroxide (KOH). It was also determined that increased the ionic strength is not responsible for the observed increase in Ru removal rate. Benzotirazole (BTA) and ascorbic acid were added to the slurry to reduce the open circuit potential (Eoc) difference between Cu and Ru to ˜20 mV from about 550 mV in the absence of additives. A removal mechanism with KIO4 as the oxidizing agent is proposed based on the formation of several ruthenium oxides, some of which formed residues on the polishing pad below a pH of ˜7. Next, a colloidal silica-based slurry with hydrogen peroxide (H 2O2) as the oxidizer (1 wt%), and arginine (0.5 wt%) as the complexing agent was developed to polish Co at pH 10. The Eoc between Cu and Co at the above conditions was reduced to ˜20 mV compared to ˜250 mV in the absence of additives, suggestive of reduced galvanic corrosion during the Co polishing. The slurry also has the advantages of good post-polish surface quality at pH 10, and no dissolution rate. BTA at a concentration of 5mM in this slurry inhibited Cu dissolution rates and yielded a Cu/Co RR ratio of ˜0.8:1 while the open potential difference between Cu and Co was further reduced to ˜10

  15. Reaction of a (Salen)ruthenium(VI) nitrido complex with thiols. C-H bond activation by (Salen)ruthenium(IV) sulfilamido species.

    Science.gov (United States)

    Man, Wai-Lun; Lam, William W Y; Kwong, Hoi-Ki; Peng, Shie-Ming; Wong, Wing-Tak; Lau, Tai-Chu

    2010-01-04

    The reaction of [Ru(VI)(N)(L)(MeOH)](PF(6)) [1; L = N,N'-bis(salicylidene)-o-cyclohexyldiamine dianion] with a stoichiometric amount of RSH in CH(3)CN gives the corresponding (salen)ruthenium(IV) sulfilamido species [Ru(IV){N(H)SR}(L)(NCCH(3))](PF(6)) (2a, R = (t)Bu; 2b, R = Ph). Metathesis of 2a with NaN(3) in methanol affords [Ru(IV){N(H)S(t)Bu}(L)(N(3))] (2c). 2a undergoes further reaction with 1 equiv of RSH to afford a (salen)ruthenium(III) sulfilamine species, [Ru(III){N(H)(2)S(t)Bu}(L)(NCCH(3))](PF(6)) (3). On the other hand, 2b reacts with 2 equiv of PhSH to give a (salen)ruthenium(III) ammine species [Ru(III)(NH(3))(L)(NCCH(3))](PF(6)) (4); this species can also be prepared by treatment of 1 with 3 equiv of PhSH. The X-ray structures of 2c and 4 have been determined. Kinetic studies of the reaction of 1 with excess RSH indicate the following schemes: 1 --> 2a --> 3 (R = (t)Bu), 1 --> 2b --> 4 (R = Ph). The conversion of 1 to 2 probably involves nucleophilic attack of RSH at the nitrido ligand, followed by a proton shift. The conversions of 2a to 3 and 2b to 4 are proposed to involve rate-limiting H-atom abstraction from RSH by 2a or 2b. 2a and 2b are also able to abstract H atoms from hydrocarbons with weak C-H bonds. These reactions occur with large deuterium isotope effects; the kinetic isotope effect values for the oxidation of 9,10-dihydroanthracene, 1,4-cyclohexadiene, and fluorene by 2a are 51, 56, and 11, respectively.

  16. Mechanistic studies of the oxidation of soluble species of ruthenium in nitric acid solutions. Application to the removal of ruthenium from nuclear fuel dissolution solutions

    International Nuclear Information System (INIS)

    Carron, V.

    2001-01-01

    Ruthenium is one of the most troublesome fission products during nuclear fuel reprocessing. His removal from nitric acid fuel dissolution solutions, above the PUREX process, is under consideration. Electro-volatilization could be a possible way to eliminate this element. It consists in the oxidation of soluble ruthenium species coupled with the volatilization of formed RuO 4 . Soluble species are nitrate and nitro complexes of nitrosyl ruthenium RuNO 3+ . The first part of this work deals with the direct oxidation of RuNO 3+ at a golden or a platinum anode. It has been investigated by cyclic voltammetry and infrared and UV-visible reflectance spectroscopy. The oxidation of RuNO 3+ begins with an adsorption step, which precedes the formation of RuO 4 . Then a reaction between RuO 4 and RuNO 3+ occurs to produce a Ru IV compound, which is also electro-oxidized to RuO 4 . The second part concerns potentiostatic electro-volatilization experiences. The rate of electro-volatilization decreases with increasing HNO 3 concentration. At low concentrations, kinetic is controlled by the volatilization of RuO 4 . The rate-determining step is the oxidation of RuNO 3+ at concentrations higher than 1 M. In HNO 3 4 M, the addition of AgNO 3 is required to accelerate the oxidation of RuNO 3+ . The last part is devoted to the study of the indirect oxidation of RuNO 3+ . The electrocatalytic power of electro-generated Ag II is illustrated by voltammetric techniques and potentiostatic electrolysis. The existence of a limit concentration of AgNO 3 is shown (which value depends on experimental conditions) beyond which kinetic is controlled by the RuO 4 volatilization step. These results indicate that the electro-volatilization kinetic could be increased by optimizing the volatilization conditions. (author)

  17. Simultaneous determination of triacetin, acetic ether, butyl acetate and amorolfine hydrochloride in amorolfine liniment by HPLC.

    Science.gov (United States)

    Gao, Yuan; Li, Li; Zhang, Jianjun; Shu, Wenjuan; Gao, Liqiong

    2012-04-01

    A simple, rapid, specific and precise reversed-phase high-performance liquid chromatographic method was developed for simultaneous estimation of triacetin, acetic ether, butyl acetate and amorolfine in marketed pharmaceutical liniment. Chromatographic separation was performed on a Shimadzu VP-ODS C(18) column using the mixture of citric acid-hydrochloric acid-sodium hydrate buffer (pH 3.0), acetonitrile and methanol (32:30:38) as the mobile phase at a flow rate of 1.0 mL/min with UV-detection at 215 nm. The method separated the four components simultaneously in less than 10 min. The validation of the method was performed with respect to specificity, linearity, accuracy, and precision. The calibration curves were linear in the range of 35.1-81.9 μ/mL for triacetin, 431.1-1005.9 μ/mL for acetic ether, 167.0-389.7 μ/mL for butyl acetate and 151.0-352.3 μ/mL for amorolfine. The mean 100% spiked recovery for triacetin, acetic ether, butyl acetate and amorolfine is 99.43 ± 0.42, 101.5 ± 1.09, 101.4 ± 1.02 and 100.8 ± 0.69, respectively. The intra-day and inter-day relative standard deviation values were liniment.

  18. Effects of culture conditions on acetic acid production by bacteria ...

    African Journals Online (AJOL)

    SARAH

    2015-11-30

    Nov 30, 2015 ... acid under certain culture conditions similar to cocoa fermentation stress. However ... Keywords: Acetic acid bacteria, acetic acid production, Cocoa fermentation, culture conditions ..... American Society Microbiology Press, pp.

  19. Electrooxidative Ruthenium-Catalyzed C-H/O-H Annulation by Weak O-Coordination.

    Science.gov (United States)

    Qiu, Youai; Tian, Cong; Massignan, Leonardo; Rogge, Torben; Ackermann, Lutz

    2018-05-14

    Electrocatalysis has been identified as a powerful strategy for organometallic catalysis, and yet electrocatalytic C-H activation is restricted to strongly N-coordinating directing groups. The first example of electrocatalytic C-H activation by weak O-coordination is presented, in which a versatile ruthenium(II) carboxylate catalyst enables electrooxidative C-H/O-H functionalization for alkyne annulations in the absence of metal oxidants; thereby exploiting sustainable electricity as the sole oxidant. Mechanistic insights provide strong support for a facile organometallic C-H ruthenation and an effective electrochemical reoxidation of the key ruthenium(0) intermediate. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Study of methods for removing strontium, plutonium, and ruthenium from Savannah River Plant waste supernate

    International Nuclear Information System (INIS)

    Wiley, J.R.

    1976-06-01

    As a part of long-term waste management studies at the Savannah River Laboratory, tests were made to study removal of strontium, plutonium, and ruthenium from simulated and actual waste supernates. Plutonium was sorbed by Duolite ARC-359 ion exchange resin, the same resin that is used to remove cesium from waste supernate. Strontium was removed from supernate by sorption on a chelating resin Chelex 100, or by precipitation as Sr 3 (PO 4 ) 2 . Activities of 137 Cs, 90 Sr, and 238-241 Pu remaining in processed waste supernate should be 1-10 nanocuries of each element per gram of salt. Of the methods that were tested, none was adequate for plant-scale removal of ruthenium

  1. Ruthenium complexing in sorption by granulated sorbents with ethylene diamine and diethyl amine groups

    International Nuclear Information System (INIS)

    Simanova, S.A.; Kolmakova, A.I.; Konovalov, L.V.; Kukushkin, Yu.N.; Kalalova, E.

    1986-01-01

    The sorption process of ruthenium (4) chlorocomplexes - K 2 (RuCl 6 ) macroporous granulated copolymers of glycidylmethacrylate ethylene dimethacrylate with ethylene diamine and diethyl amine has been studied. Sorption has been carried out under the static conditions (at 20 and 98 deg C) from 0.1-2.0 MxHCl and 1.0 M NaCl solutions. It is established that the sorption from acidic solutions proceeds according to anion exchange mechanism with formation of onium chlorocomplexes in the sorbent phase, subjecting to Anderson regrouping during the heating. During the sorption from neutral solutions the second-sphere coordination of polymer amino groups accirs near ruthenium atom and amino-chloride complexes are formed in the sorbent phase

  2. In Situ FTIR and NMR Spectroscopic Investigations on Ruthenium-Based Catalysts for Alkene Hydroformylation.

    Science.gov (United States)

    Kubis, Christoph; Profir, Irina; Fleischer, Ivana; Baumann, Wolfgang; Selent, Detlef; Fischer, Christine; Spannenberg, Anke; Ludwig, Ralf; Hess, Dieter; Franke, Robert; Börner, Armin

    2016-02-18

    Homogeneous ruthenium complexes modified by imidazole-substituted monophosphines as catalysts for various highly efficient hydroformylation reactions were characterized by in situ IR spectroscopy under reaction conditions and NMR spectroscopy. A proper protocol for the preformation reaction from [Ru3 (CO)12] is decisive to prevent the formation of inactive ligand-modified polynuclear complexes. During catalysis, ligand-modified mononuclear ruthenium(0) carbonyls were detected as resting states. Changes in the ligand structure have a crucial impact on the coordination behavior of the ligand and consequently on the catalytic performance. The substitution of CO by a nitrogen atom of the imidazolyl moiety in the ligand is not a general feature, but it takes place when structural prerequisites of the ligand are fulfilled. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Recent advances in the ruthenium-catalyzed hydroarylation of alkynes with aromatics: synthesis of trisubstituted alkenes.

    Science.gov (United States)

    Manikandan, Rajendran; Jeganmohan, Masilamani

    2015-11-14

    The hydroarylation of alkynes with substituted aromatics in the presence of a metal catalyst via chelation-assisted C-H bond activation is a powerful method to synthesize trisubstituted alkenes. Chelation-assisted C-H bond activation can be done by two ways: (a) an oxidative addition pathway and (b) a deprotonation pathway. Generally, a mixture of cis and trans stereoisomeric as well as regioisomeric trisubstituted alkenes was observed in an oxidative addition pathway. In the deprotonation pathway, the hydroarylation reaction can be done in a highly regio- and stereoselective manner, and enables preparation of the expected trisubstituted alkenes in a highly selective manner. Generally, ruthenium, rhodium and cobalt complexes are used as catalysts in the reaction. In this review, a ruthenium-catalyzed hydroarylation of alkynes with substituted aromatics is covered completely. The hydroarylation reaction of alkynes with amide, azole, carbamate, phosphine oxide, amine, acetyl, sulfoxide and sulphur directed aromatics is discussed.

  4. Electro-volatilization of ruthenium in nitric medium: influences of ruthenium species nature and models solutions composition; Electro-volatilisation du ruthenium en milieu nitrique: influence de la nature des formes chimiques du ruthenium et de la composition des solutions modeles de dissolution

    Energy Technology Data Exchange (ETDEWEB)

    Mousset, F

    2004-12-15

    Ruthenium is one of the fission products in the reprocessing of irradiated fuels that requires a specific processing management. Its elimination, upstream by the PUREX process, has been considered. A process, called electro-volatilization, which take advantage of the RuO{sub 4} volatility, has been optimised in the present study. It consists in a continuous electrolysis of ruthenium solutions in order to generate RuO{sub 4} species that is volatilized and easily trapped. This process goes to satisfying ruthenium elimination yields with RuNO(NO{sub 3}){sub 3}(H{sub 2}O){sub 2} synthetic solutions but not with fuel dissolution solutions. Consequently, this work consisted in the speciation studies of dissolved ruthenium species were carried out by simulating fuel solutions produced by hot acid attack of several ruthenium compounds (Ru(0), RuO{sub 2},xH{sub 2}O, polymetallic alloy). In parallel with dissolution kinetic studies, the determination of dissolved species was performed using voltammetry, spectrometry and spectro-electrochemistry. The results showed the co-existence of Ru(IV) and RuNO(NO{sub 2}){sub 2}(H{sub 2}O){sub 3}. Although these species are different from synthetic RuNO(NO{sub 3}){sub 3}(H{sub 2}O){sub 2}, their electro-oxidation behaviour are similar. The electro-volatilization tests of these dissolution solutions yielded to comparable results as the synthetic RuNO(NO{sub 3}){sub 3}(H{sub 2}O){sub 2} solutions. Then, complexity increase of models solutions was performed by in-situ generation of nitrous acid during ruthenium dissolution. Nitrous acid showed a catalytic effect on ruthenium dissolution. Its presence goes to quasi exclusively RuNO(NO{sub 2}){sub 2}(H{sub 2}O){sub 3} species. It is also responsible of the strong n-bond formation between Ru{sup 2+} and NO{sup +}. In addition, it has been shown that its reducing action on RuO{sub 4} hinders the electro-volatilization process. Mn{sup 2+} and Ce{sup 3+} cations also reveal, but to a lesser

  5. Investigation of the process for ruthenium fixation on stainless steel in concentrated nitric environment

    International Nuclear Information System (INIS)

    Massit, Hubert

    1987-01-01

    This research thesis reports the development of a process and the determination of the conditions for the fixation of insoluble ruthenium compounds on a Z2CN180 stainless steel in a concentrated nitric environment. The original characteristics and results of this research work are the use of a rotating disk to control the hydrodynamic conditions of suspension particle transport towards the collector surface, and the application of X ray spectrometry of solid deposits of ruthenium compounds fixed on this surface. Characterization techniques (granulometry, Auger electron spectroscopy or AES, electron spectroscopy for chemical analysis or ESCA) allowed the assessment of the influence of various parameters (size, surface chemical composition) on the studied process. Electrochemical techniques are used to show the role of particle-substrate Coulomb interactions, on the quantity of fixed particles and on fixation kinetics. The author evokes possible developments and applications, notably decontamination processes [fr

  6. Studies of dissolution solutions of ruthenium metal, oxide and mixed compounds in nitric acid

    International Nuclear Information System (INIS)

    Mousset, F.; Eysseric, C.; Bedioui, F.

    2004-01-01

    Ruthenium is one of the fission products generated by irradiated nuclear fuel. It is present throughout all the steps of nuclear fuel reprocessing-particularly during extraction-and requires special attention due to its complex chemistry and high βγ activity. An innovative electro-volatilization process is now being developed to take advantage of the volatility of RuO 4 in order to eliminate it at the head end of the Purex process and thus reduce the number of extraction cycles. Although the process operates successfully with synthetic nitrato-RuNO 3+ solutions, difficulties have been encountered in extrapolating it to real-like dissolution solutions. In order to better approximate the chemical forms of ruthenium found in fuel dissolution solutions, kinetic and speciation studies on dissolved species were undertaken with RuO 2 ,xH 2 O and Ru 0 in nitric acid media. (authors)

  7. Effect of solvent on Se-modified ruthenium/carbon catalyst for oxygen reduction

    Directory of Open Access Journals (Sweden)

    Chuanxiang Zhang

    2014-12-01

    Full Text Available Se-modified ruthenium supporting on carbon (Sex–Ru/C electrocatalyst was prepared by solvothermal one-step synthesis method. The reaction mechanism was revealed after discussing impact of different solvents (i-propanol and EG in solvotermal reaction. The result showed that the grain size of Se-modified ruthenium electrocatalyst was as small as 1 to 3 nm and highly dispersed on carbon surface. X-ray photoelectron spectroscopy (XPS presented that selenium mainly existed in the catalyst in the form of elemental selenium and selenium oxides when the solvent was EG and i-propanol, respectively. The oxygen reduction reaction (ORR performance was improved by appearance of selenium oxides.

  8. Forefront of PUREX system engineering. Chemistry and engineering of ruthenium, technetium and neptunium

    International Nuclear Information System (INIS)

    2004-07-01

    The paper reports the activity of the research committee organized by the Atomic Energy Society of Japan on 'Ruthenium and Technetium Chemistry in the PUREX System', with focusing on basic behaviors of ruthenium, technetium and neptunium in the PUREX process, the principles of plant design, and behaviors during the final waste treatment. The scope of the work includes the following major topics: (1) basic solution and solid-state chemistry; (2) basic solution and solid-state chemistry of minor actinides in particular, Np; (3) partitioning chemistry in the PUREX system and environmental behavior of the components; (4) processes of recovery, purification, and utilization of rare metal fission products; (5) field data on plant design, operation, decontamination, and decommissioning; (6) numerical process simulations and process control technologies; (7) compilation of a data base for process chemistry and plant engineering. (S. Ohno)

  9. Avalanches in Mn12-Acetate: ``Magnetic Burning"

    Science.gov (United States)

    McHugh, Sean; Suzuki, Y.; Graybill, D.; Sarachik, M. P.; Avraham, N.; Myasoedov, Y.; Shtrikman, H.; Zeldov, E.; Bagai, R.; Chakov, N. E.; Christou, G.

    2006-03-01

    From local time-resolved measurements of fast reversal of the magnetization in single crystals of the molecular magnet Mn12-acetate, we have shown[1] that the magnetization avalanche spreads as a narrow interface that propagates through the crystal at a constant velocity roughly two orders of magnitude smaller than the speed of sound. This phenomenon is closely analogous to the propagation of a flame front (deflagration) through a flammable chemical substance. The propagation speed of the avalanche depends on the energy stored in each molecule, which can be controlled and tuned using an external magnetic field. We report studies of propagation speed with different external fields in Mn12-acetate. [1] Yoko Suzuki, M.P. Sarachik, E.M. Chudnovsky, S. McHugh, R. Gonzalez-Rubio, N. Avraham, Y. Myasoedov, H. Shtrikman, E. Zeldov, N.E. Chakov and G. Christou, Phys. Rev. Lett. 95, 147201 (2005).

  10. Neutron scattering studies of Mn12-acetate

    International Nuclear Information System (INIS)

    Robinson, R.A.

    2000-01-01

    Full text: The S=10 magnetic molecule Mn 12 -acetate, which crystallises into a tetragonal crystal structure, has attracted substantial recent attention by virtue of its low temperature bulk magnetic properties, which give evidence for resonant quantum tunnelling of the magnetisation. We report a full neutron crystal structure including positions of all protons/deuterons, including the solvated water and acetic acid, a polarised-neutron study of the real space magnetisation, which confirms a simple magnetic-structure model for the molecule, albeit with reduced Mn moments, and inelastic neutron scattering data containing both the excitations within the 21-fold degenerate S=10 manifold, and those from S=10 to the S=9 manifolds. Both manifolds are split by uniaxial magnetic anisotropy, and we report coefficients for 2nd and 4th-order terms in the magnetic Hamiltonian

  11. A mixed ruthenium polypyridyl complex containing a PEG-bipyridine macroligand

    Energy Technology Data Exchange (ETDEWEB)

    Marin, Veronica; Holder, Elisabeth; Meier, Michael A.R.; Hoogenboom, Richard; Schubert, Ulrich S. [Laboratory of Macromolecular Chemistry and Nanoscience, Eindhoven University of Technology and Dutch Polymer Institute (DPI), P. O. Box 513, 5600 MB Eindhoven (Netherlands)

    2004-04-06

    An amino-functionalized bipyridine ligand was prepared in order to serve as a bridging unit to an activated low-molecular-weight monomethyl ether of poly(ethylene glycol) (PEG). Coordination of a ruthenium(II) phenantroline precursor onto the formed PEG-containing bipyridine ligand yielded a metal-containing polymer which shows interesting properties for solar cell applications. (Abstract Copyright [2004], Wiley Periodicals, Inc.)

  12. Ruthenium(II) pincer complexes with oxazoline arms for efficient transfer hydrogenation reactions

    KAUST Repository

    Chen, Tao

    2012-08-01

    Well-defined P NN CN pincer ruthenium complexes bearing both strong phosphine and weak oxazoline donors were developed. These easily accessible complexes exhibit significantly better catalytic activity in transfer hydrogenation of ketones compared to their PN 3P analogs. These reactions proceed under mild and base-free conditions via protonation- deprotonation of the \\'NH\\' group in the aromatization-dearomatization process. © 2012 Elsevier Ltd. All rights reserved.

  13. Preparation and characterization of nickel-caffeine and ruthenium-arborine complexes

    International Nuclear Information System (INIS)

    Rusmidah Ali

    1998-01-01

    In this study, two types of complexes were synthesised, namely, nickel-cafeine and ruthenium-arborine by using NiCl 2 6H 2 O and RuCl 3 3H 2 O as starting materials. The complexes were characterised using far- and near infrared and CHN analysis. The proposed complexes were (Ni(kaf)Cl 2 ) 4 and (RuCl 3 Ab)EtOH

  14. Cytogenotoxic effects of two potential anticancer Ruthenium(III Schiff Bases complexes

    Directory of Open Access Journals (Sweden)

    Izet Eminovic

    2016-10-01

    Full Text Available Introduction: Treatment of cancer has been subject of great interest. Researchers are continuously searching for new medicines. In this sense, ruthenium complexes have big potential. Some evidences suggest that ruthenium compounds possess anticancer activities. We synthesized two recently published ruthenium(III complexes with bidentate O,N and tridentate O,O,N Schiff bases derived from 5-substituted salicylaldehyde and aminophenol or anilineare. These compounds showed affinity for binding to the DNA molecule, however, insufficient data are available regarding their possible toxic effects on biological systems.Methods: In the present study we evaluated genotoxic, cytotoxic, and cytostatic effects of Na[RuCl2(L12] and Na[Ru(L22], using the Allium cepa assay.Results: Different toxic effects were observed depending on the substance, tested concentration, and endpoint measured. In general, the tested compounds significantly lowered the root growth and mitotic index values as compared to the control group. Additionally, a wide range of abnormal mitotic stages, both clastogenic and non-clastogenic were observed in the treated cells. Na[RuCl2(L12] significantly increased the frequency of sticky metaphases, chromosome bridges, micronuclei, impaired chromosome segregation, as well as number of apoptotic and necrotic cells over the controls. In contrast, Na[Ru(L22] did not show significant evidence of genotoxicity with regard to chromosome aberrations and micronuclei, however, significant differences were detected in the number of apoptotic and necrotic cells when the highest concentration was applied.Conclusions: In this study we demonstrated antiproliferative effects of Na[RuCl2(L12] and Na[Ru(L22]. At clinical level, these results could be interesting for further studies on anticancer potential of the ruthenium(III complexes using animal models.

  15. Ruthenium-catalysed decomposition of formic acid: Fuel cell and catalytic applications

    KAUST Repository

    Piola, Lorenzo

    2017-08-08

    The decomposition of formic acid into H2 and CO2 was successfully performed using a ruthenium hydride catalyst, without any concomitant CO evolution. The reaction mechanism is investigated by means of density functional theory calculations (DFT). The generated H2 was further exploited in a fuel cell to produce electricity. The catalytic hydrogenation of conjugated olefins, using this dihydrogen generation procedure, is also reported.

  16. Synergistic Interaction within Bifunctional Ruthenium Nanoparticle/SILP Catalysts for the Selective Hydrodeoxygenation of Phenols.

    Science.gov (United States)

    Luska, Kylie L; Migowski, Pedro; El Sayed, Sami; Leitner, Walter

    2015-12-21

    Ruthenium nanoparticles immobilized on acid-functionalized supported ionic liquid phases (Ru NPs@SILPs) act as efficient bifunctional catalysts in the hydrodeoxygenation of phenolic substrates under batch and continuous flow conditions. A synergistic interaction between the metal sites and acid groups within the bifunctional catalyst leads to enhanced catalytic activities for the overall transformation as compared to the individual steps catalyzed by the separate catalytic functionalities. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Ruthenium-catalyzed direct C3 alkylation of indoles with α,β-unsaturated ketones.

    Science.gov (United States)

    Li, Shuai-Shuai; Lin, Hui; Zhang, Xiao-Mei; Dong, Lin

    2015-01-28

    In this paper, a simple and highly efficient ruthenium-catalyzed direct C3 alkylation of indoles with various α,β-unsaturated ketones without chelation assistance has been developed. This novel C-H activation methodology exhibits a broad substrate scope such as different substituted indoles, pyrroles, and other azoles. Further synthetic applications of the alkylation products can lead to more attractive 3,4-fused tricyclic indoles.

  18. Modification of Ammonia Decomposition Activity of Ruthenium Nanoparticles by N-Doping of CNT Supports

    OpenAIRE

    Bell, Tamsin; Zhan, G; Wu, Kejun; Torrente Murciano, Laura

    2017-01-01

    The use of ammonia as a hydrogen vector has the potential to unlock the hydrogen economy. In this context, this paper presents novel insights into improving the ammonia decomposition activity of ruthenium nanoparticles supported on carbon nanotubes (CNT) by nitrogen doping. Our results can be applied to develop more active systems capable of delivering hydrogen on demand, with a view to move towards the low temperature target of less than 150 °C. Herein we demonstrate that nitrogen doping of ...

  19. Ruthenium(II)-catalyzed direct addition of indole/pyrrole C2-H bonds to alkynes.

    Science.gov (United States)

    Liang, Libo; Fu, Shaomin; Lin, Dongen; Zhang, Xiao-Qi; Deng, Yuanfu; Jiang, Huanfeng; Zeng, Wei

    2014-10-17

    A ruthenium-catalyzed C2-hydroindolation of alkynes has been achieved. This protocol provides a rapid and concise access to kinds of 2-alkenyl-substituted N-(2-pyridyl)indoles in which the pyridyl moiety can be easily removed to afford free (N-H) indoles under mild conditions. Various arenes and alkynes, including electron-deficient and electron-rich internal alkynes and terminal alkynes, allow for this transformation.

  20. Ruthenium-catalysed decomposition of formic acid: Fuel cell and catalytic applications

    KAUST Repository

    Piola, Lorenzo; Ferná ndez-Salas, José A.; Nahra, Fady; Poater, Albert; Cavallo, Luigi; Nolan, Steven P.

    2017-01-01

    The decomposition of formic acid into H2 and CO2 was successfully performed using a ruthenium hydride catalyst, without any concomitant CO evolution. The reaction mechanism is investigated by means of density functional theory calculations (DFT). The generated H2 was further exploited in a fuel cell to produce electricity. The catalytic hydrogenation of conjugated olefins, using this dihydrogen generation procedure, is also reported.

  1. Improvements in iodine and ruthenium removal from advanced liquid processing system

    Energy Technology Data Exchange (ETDEWEB)

    Skibo, A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-09-27

    SRNL has considerable experience in designing, engineering, and operating systems for removing iodine-129 (I-129) and ruthenium-106 (Ru-106) from waste streams that are directly analogous to the Advanced Liquid Processing System (ALPS) waste streams. SRNL proposes to provide the technical background and design and engineering support for an improved I-129 and Ru-106 removal system for application to ALPS on the Fukushima Daiichi Nuclear Power Station (NPS).

  2. Ammonia synthesis in the presence of rhodium-ruthenium-iridium carbonyl clusters

    International Nuclear Information System (INIS)

    Fedoseev, I.V.; Solov'ev, N.V.

    2007-01-01

    Researches in the field of platinum metal coordination compounds, where nitrogen enters as a ligand in coordination sphere of metal, are discussed. Results of experiments on the ammonia synthesis during the CO+N 2 mixture passing through alkali solution containing mixture of carbonyl clusters of rhodium, ruthenium and iridium at atmospheric pressure are given. Technique of the experiment and steps of assumed reactions of nitrogen fixation by Rh, Ir and Ru carbonyl clusters are demonstrated [ru

  3. Acetate in Oz: Some Strategic Moves

    Directory of Open Access Journals (Sweden)

    Colin Webb

    2005-08-01

    Full Text Available I would like to add my voice to the words of congratulations and thanks to the British Library for organising this forum, and for their generosity in making it possible for me to come across the world to be part of it. The issues we are discussing today have an importance extending beyond cellulose acetate, as they reflect our ability as custodians to deal with common threats to the documentary heritage we are charged with preserving. As I will argue later, we need to see this situation in the context of the full range of preservation management issues that face our institutions. While it imposes a burden and a challenge on us as preservation managers, it also presents opportunities to sort out some things that have needed attention for some time. I have been asked to talk about problems with cellulose acetate microfilm collections in Australia, and specifically the strategies – both national and local – that have been adopted or at least explored in response to those problems. In the time I have I will not be going into any of these in great detail, but I hope I can give you some sense of the situation down under, and perhaps draw out a few issues that might make this more than just an ‘us too’ session! One thing to emphasise from the start is that we have had a number of goes at dealing with acetate microfilm collections: it is not a newly discovered problem in Australia. One significant context in which we have been working is that of a national strategy for all kinds of cellulose acetate collection materials. Explaining this national strategy will form a major part of my presentation, with issues and approaches specific to microfilm discussed towards the end.

  4. Sequential Electrodeposition of Platinum-Ruthenium at Boron-Doped Diamond Electrodes for Methanol Oxidation

    Directory of Open Access Journals (Sweden)

    Ileana González-González

    2011-01-01

    Full Text Available Sequential electrodeposition of Pt and Ru on boron-doped diamond (BDD films, in 0.5 M H2SO4 by cyclic voltammetry, has been prepared. The potential cycling, in the aqueous solutions of the respective metals, was between 0.00 and 1.00 V versus Ag/AgCl. The catalyst composites, Pt and PtRu, deposited on BDD film substrates, were tested for methanol oxidation. The modified diamond surfaces were also characterized by scanning electron microscopy-X-ray fluorescence-energy dispersive spectroscopy, X-ray photoelectron spectroscopy, and Auger electron spectroscopy. The scanning Auger electron spectroscopy mapping showed the ruthenium signal only in areas where platinum was electrodeposited. Ruthenium does not deposit on the oxidized diamond surface of the boron-doped diamond. Particles with 5–10% of ruthenium with respect to platinum exhibited better performance for methanol oxidation in terms of methanol oxidation peak current and chronoamperometric current stability. The electrogenerated •OH radicals on BDD may interact with Pt surface, participating in the methanol oxidation as shown in oxidation current and the shift in the peak position. The conductive diamond surface is a good candidate as the support for the platinum electrocatalyst, because it ensures catalytic activity, which compares with the used carbon, and higher stability under severe anodic and cathodic conditions.

  5. Synthesis and characterization of ruthenium fluorides and oxide fluorides with high oxidation states

    International Nuclear Information System (INIS)

    Meublat, L.

    1989-10-01

    The synthesis of ruthenium fluorides and oxide fluorides with high oxidation states was attempted from dioxide RuO 2 and tetroxide RuO 4 . Three fluorinating agents were used: fluorine, chlorine trifluoride and krypton difluoride. The reactions were achieved in anhydrous hydrogen fluoride at room temperature. Thus, the reaction of RuO 4 with CIF 3 enabled us to prepare chloryl hexafluororuthenate (V), CIO 2 + RuF 6 - , a new compound well identified by vibrational spectroscopy (infra-red and Raman), the structure of which was determined. The reaction of KrF 2 with RuO 4 gave the oxide tetrafluoride RuOF 4 , the previously published syntheses and properties of which were not in agreement with each other. This compound was definitely characterized here by chemical analysis, infra-red spectroscopy and X-ray powder diffraction. The product of thermal decomposition (70 0 C) of RuOF 4 is presumably RuF 4 since only oxygen is liberated during this decomposition. At last, the reaction of KrF 2 with RuO 2 probably leads to the formation of the new oxide fluoride RuO 2 F 4 . Indeed, no oxygen is given off during this reaction, the chemical analysis of the red-orange coloured solid residue is almost in agreement with the one proposed and its infra-red absorption spectrum indicates the presence of ruthenium-oxygen and ruthenium-terminal and bridging fluorine bonds [fr

  6. Synthesis and characterization of ruthenium fluorides and oxide fluorides with high oxidation states

    International Nuclear Information System (INIS)

    Meublat, L.

    1989-01-01

    The synthesis of ruthenium fluorides and oxide fluorides with high oxidation states was attempted from dioxide RuO 2 and tetroxide RuO 4 . Three fluorinating agents were used: fluorine, chlorine trifluoride and krypton difluoride. The reactions were achieved in anhydrous hydrogen fluoride at room temperature. Thus, the reaction of RuO 4 with CIF 3 enabled us to prepare chloryl hexafluororuthenate (V), ClO 2 + RuF 6 - , a new compound well idendified by vibrational spectroscopy (infra-red and Raman), the structure of which was determined. The reaction of KrF 2 with RuO 4 gave the oxide tetrafluoride RuOF 4 , the previously published syntheses and properties of which were not in agreement with each other. This compound was definitely characterized here by chemical analysis, infra-red spectroscopy and X-ray powder diffraction. The product of thermal decomposition (70 0 C) of RuOF 4 is presumably RuF 4 since only oxygen is liberated during this decomposition. At last, the reaction of KrF 2 with RuO 2 probably leads to the formation of the new oxide fluoride RuO 2 F 4 . Indeed, no oxygen is given off during this reaction, the chemical analysis of the red-orange coloured solid residue is almost in agreement with the one proposed and its infra-red absorption spectrum indicates the presence of ruthenium-oxygen and ruthenium-terminal and bridging fluorine bonds [fr

  7. Tracking the Oxygen Status in the Cell Nucleus with a Hoechst-Tagged Phosphorescent Ruthenium Complex.

    Science.gov (United States)

    Hara, Daiki; Umehara, Yui; Son, Aoi; Asahi, Wataru; Misu, Sotaro; Kurihara, Ryohsuke; Kondo, Teruyuki; Tanabe, Kazuhito

    2018-05-04

    Molecular oxygen in living cells is distributed and consumed inhomogeneously, depending on the activity of each organelle. Therefore, tractable methods that can be used to monitor the oxygen status in each organelle are needed to understand cellular function. Here we report the design of a new oxygen-sensing probe for use in the cell nucleus. We prepared "Ru-Hoechsts", each consisting of a phosphorescent ruthenium complex linked to a Hoechst 33258 moiety, and characterized their properties as oxygen sensors. The Hoechst unit shows strong DNA-binding properties in the nucleus, and the ruthenium complex shows oxygen-dependent phosphorescence. Thus, Ru-Hoechsts accumulated in the cell nucleus and showed oxygen-dependent signals that could be monitored. Of the Ru-Hoechsts prepared in this study, Ru-Hoechst b, in which the ruthenium complex and the Hoechst unit were linked through a hexyl chain, showed the most suitable properties for monitoring the oxygen status. Ru-Hoechsts are probes with high potential for visualizing oxygen fluctuations in the nucleus. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Antipyrilquinoneimine dye formation by coupling aniline derivatives with 4-aminoantipyrine in the presence of ruthenium nanoparticles

    International Nuclear Information System (INIS)

    Kasthuri, J.; Santhanalakshmi, J.; Rajendiran, N.

    2008-01-01

    The coupling of 4-aminoantipyrine with aniline derivatives catalyzed by ruthenium nanoparticles has been studied by UV-Vis spectroscopy in aqueous medium. The rate constant for antipyrilquinoneimine dye formation depends on the nature of the aniline substituent and the p H, ionic strength and temperature of the reaction medium. The maximum rate constant of the dye formation reaction is observed at p H 3.6. Aniline derivatives with electron donating substituents show higher rate constant values than those with electron withdrawing substituents, with increasing rate constant values in the order: N,N-dimethyl aniline> a-toluidine> o-chloroaniline > m-chloroaniline. With pseudo first order kinetics, the total order is 1.0 + 1.0 + 1.0 = 3.0, which includes the orders with respect to amine, 4-aminoantipyrine and ruthenium nanoparticles. Studies on these effects help to complete the kinetic analysis as well as propose the reaction pathway. Furthermore, TEM measurement confirms that the nano scalar size of the ruthenium nanoparticles is 7 nm

  9. Ruthenium-modified cytochrome c: temperature dependence of the rate of intramolecular electron transfer

    International Nuclear Information System (INIS)

    Isied, S.S.; Kuehn, C.; Worosila, G.

    1984-01-01

    The ruthenium-modified horse heart cytochrome c, Ru(III)-cyt c(III), where the ruthenium is bound to the histidines-33 residue has been synthesized and characterized by ruthenium analysis, UV-vis and CD spectra, and differential pulse polarography and cyclic voltammetry. The intermediate Ru(III)-cyt c(III) has been generated by pulse-radioanalysis with use of four different radicals, CO 2 -., (CH 3 )COH., (CH 2 OH) 3 CCHOH, and -OCCH(OH)C(OH)CO 2 -. The rate of intramolecular electron transfer within the Ru(III)-cyt c(III) complex and its temperature dependence were determined over a 40 0 C temperature range with the CO 2 -. radical. At 25 0 C, these values are k/sub u/=53 +/- s/sup -1/ (pH 7.01 M phosphate buffer, 0.1 M NaHCO 2 ), ΔH/sup +/=3.5 +/- 0.2 kcal mol/sup -1/, and ΔS/sup +/=-39 +/- 1 eu

  10. About the value of Ruthenium 106 brachytherapy in the treatment of uveal melanomas

    International Nuclear Information System (INIS)

    Langmann, G.; Mosboeck, G.; Stuecklschwaiger, G.; Muellner, K.; Lechner, H.; Faulborn, J.

    2002-01-01

    Background: to investigate the clinical course, sequelae and visual function of uveal melanomas treated with Ruthenium 106 brachytherapy. Patients and method: 47 patients who underwent Ruthenium 106 brachytherapy between 1985 and 2000 were evaluated using Kaplan Meier statistical method. Mean follow up interval was 22 month (range 8 - 152 months). Results: Local tumor control rate was 85 %, 5 years possibility to avoid enucleation was 75 %. The most important sequelae were radiation optic neuropathy (29 %), maculopathy (37 %) and radiation retinopathy (32 %). After terminating the study the 34 % of the patients achieved a visual acuity of 20/40 and more, another 34 % had a visual function of 20/200 and lower. Conclusion: Ruthenium 106 brachytherapy is our method of choice in small medium sized uveal melanomas and a maximum tumor prominence of 6 mm. Tumors have to be located in the midperiphery and outer periphery of the fundus including the ciliary body. In addition to the indications introduced by Lommatzsch we treated ciliary body melanomas with a tumor base more than 3 clock hours (by shifting the plaque) as an alternative therapy to enucleation. (author)

  11. High-pressure catalytic chemical vapor deposition of ferromagnetic ruthenium-containing carbon nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Khavrus, Vyacheslav O., E-mail: V.Khavrus@ifw-dresden.de; Ibrahim, E. M. M.; Bachmatiuk, Alicja; Ruemmeli, Mark H.; Wolter, A. U. B.; Hampel, Silke; Leonhardt, Albrecht [IFW Dresden (Germany)

    2012-06-15

    We report on the high-pressure catalytic chemical vapor deposition (CCVD) of ruthenium nanoparticles (NPs) and single-walled carbon nanotubes (SWCNTs) by means of gas-phase decomposition of acetonitrile and ruthenocene in a tubular quartz flow reactor at 950 Degree-Sign C and at elevated pressures (between 2 and 8 bar). The deposited material consists of Ru metal cores with sizes ranging between 1 and 3 nm surrounded by a carbon matrix. The high-pressure CCVD seems to be an effective route to obtain composite materials containing metallic NPs, Ru in this work, inside a nanostructured carbon matrix protecting them from oxidation in ambient air. We find that in contradiction to the weak paramagnetic properties characterizing bulk ruthenium, the synthesized samples are ferromagnetic as predicted for nanosized particles of nonmagnetic materials. At low pressure, the very small ruthenium catalyst particles are able to catalyze growth of SWCNTs. Their yield decreases with increasing reaction pressure. Transmission electron microscopy, selected area energy-dispersive X-ray analysis, Raman spectroscopy, and magnetic measurements were used to analyze and confirm properties of the synthesized NPs and nanotubes. A discussion on the growth mechanism of the Ru-containing nanostructures is presented.

  12. Ruthenium(II) carbonyl compounds with the 4'-chloro-2,2':6',2''-terpyridine ligand.

    Science.gov (United States)

    Tatikonda, Rajendhraprasad; Haukka, Matti

    2017-04-01

    Two ruthenium carbonyl complexes with the 4'-chloro-2,2':6',2''-terpyridine ligand (tpy-Cl, C 15 H 10 ClN 3 ), i.e. [RuCl(tpy-Cl)(CO) 2 ][RuCl 3 (CO) 3 ] (I) [systematic name: cis -di-carbonyl-chlorido(4'-chloro-2,2':6',2''-terpyridine-κ 3 N )ruthenium(II) fac -tricarbonyltri-chlorido-ruthenate(II)], and [RuCl 2 (tpy-Cl)(CO) 2 ] (II) [ cis -dicarbonyl- trans -di-chlorido(4'-chloro-2,2':6',2''-terpyridine-κ 2 N 1 , N 1' )ruthenium(II)], were synthesized and characterized by single-crystal X-ray diffraction. The Ru II atoms in both centrosymmetric structures (I) and (II) display similar, slightly distorted octa-hedral coordination spheres. The coordination sphere in the complex cation in compound (I) is defined by three N atoms of the tridentate tpy-Cl ligand, two carbonyl carbon atoms and one chlorido ligand; the charge is balanced by an octa-hedral [Ru(CO) 3 Cl 3 ] - counter-anion. In the neutral compound (II), the tpy-Cl ligand coordinates to the metal only through two of its N atoms. The coordination sphere of the Ru II atom is completed by two carbonyl and two chlorido ligands. In the crystal structures of both (I) and (II), weak C-H⋯Cl inter-actions are observed.

  13. Oxidative dissolution of ruthenium deposits onto stainless steel by permanganate ions in alkaline medium

    Energy Technology Data Exchange (ETDEWEB)

    Floquet, S.; Eysseric, C.; Maurel, D. [Commissariat a l' Energie Atomique (CEA/Valrho), Bagnols-sur-Ceze (France)

    2008-07-01

    During spent nuclear fuel reprocessing ruthenium is liable to form black ruthenium deposits on the stainless steel walls of process equipments. These deposits promote corrosion and can eventually obstruct the off-gas lines. The results of decontamination of 304L stainless steel test specimens covered with RuO(OH){sub 2} . xH{sub 2}O deposits by permanganate ions in alkaline medium are described. The ruthenium deposits were dissolved by oxidation of RuO(OH){sub 2} to RuO{sub 4}{sup 2-} ions, while the permanganate ions were reduced to MnO{sub 4}{sup 2-} ions and then to manganese dioxide MnO{sub 2}. The parameters affecting the kinetics of oxidative dissolution of these deposits were examined. The results indicate that the oxidative dissolution kinetics depends on the instantaneous surface area of the deposit, and that the dissolution rate increases with the concentrations of MnO{sub 4}{sup -} and OH{sup -} ions. (orig.)

  14. Surface heterogeneity and ionization of Cs promoter in carbon-based ruthenium catalyst for ammonia synthesis

    International Nuclear Information System (INIS)

    Kotarba, Andrzej; Dmytrzyk, Jaromir; Rarog-Pilecka, Wioletta; Kowalczyk, Zbigniew

    2003-01-01

    Second-generation ammonia synthesis cesium-doped ruthenium catalyst supported on turbostratic carbon was investigated by the species resolved thermal alkali desorption method (SR-TAD). Energetic barriers for cesium ions (2.86 eV), ground state (1.96 eV) and electronically excited atoms (5.76 eV) desorbing from the Cs-Ru/C catalyst were determined. In the case of ruthenium-free Cs/C system, cesium desorbs as ground state atoms only, with an energy barrier of 2.87 eV. The work functions determined by the thermionic emission of electrons from Cs/C and Cs-Ru/C were of the same value (2.9 eV). It was concluded that ruthenium induces heterogeneous distribution of cesium on the catalyst surface. The promoter stability is reduced on low work function areas and its surface ionization on high work function areas opens the ionic desorption channel. The Cs desorption from the catalyst is discussed in terms of the literature data for the cesium/graphite system

  15. Potentiometric titrations in anhydrous acetic acid

    International Nuclear Information System (INIS)

    Le Port, L.

    1966-03-01

    The method used for studying anhydrous acetic acid is potentiometry with a glass electrode. We have in this way studied the titration of common inorganic acids (HClO 4 - HBr - H 2 SO 4 - HCl - HNO 3 - H 3 PO 4 ) and of some metallic salts. Furthermore we have shown that complex acids are formed between HCl and some metallic chlorides. An analysis of the titration curves for the inorganic acids against pyridinium chloride has made it possible to calculate a certain number of values for the dissociation pK of these acids and of the corresponding pyridinium salts. The titration of metallic perchlorates constitutes a method of studying the stability of acetates; we have thus been able to draw up a classification for some of these acetates. The metallic chlorides studied fall into two groups according to their behaviour in weak or strong acids. The differences have been explained on the basis of the role played by solvolysis. In the third part we have studied the acidic properties of mixtures of HCl with certain metallic chlorides. This work has demonstrated the existence, in certain cases, of acid complexes of the type (HCl) m MCl n . (author) [fr

  16. Ultrasound-assisted dyeing of cellulose acetate.

    Science.gov (United States)

    Udrescu, C; Ferrero, F; Periolatto, M

    2014-07-01

    The possibility of reducing the use of auxiliaries in conventional cellulose acetate dyeing with Disperse Red 50 using ultrasound technique was studied as an alternative to the standard procedure. Dyeing of cellulose acetate yarn was carried out by using either mechanical agitation alone, with and without auxiliaries, or coupling mechanical and ultrasound agitation in the bath where the temperature range was maintained between 60 and 80 °C. The best results of dyeing kinetics were obtained with ultrasound coupled with mechanical agitation without auxiliaries (90% of bath exhaustion value at 80 °C). Hence the corresponding half dyeing times, absorption rate constants according to Cegarra-Puente modified equation and ultrasound efficiency were calculated confirming the synergic effect of sonication on the dyeing kinetics. Moreover the apparent activation energies were also evaluated and the positive effect of ultrasound added to mechanical agitation was evidenced by the lower value (48 kJ/mol) in comparison with 112 and 169 kJ/mol for mechanical stirring alone with auxiliaries and without, respectively. Finally, the fastness tests gave good values for samples dyed with ultrasound technique even without auxiliaries. Moreover color measurements on dyed yarns showed that the color yield obtained by ultrasound-assisted dyeing at 80 °C of cellulose acetate without using additional chemicals into the dye bath reached the same value yielded by mechanical agitation, but with remarkably shorter time. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Enzymatic Systems for Cellulose Acetate Degradation

    Directory of Open Access Journals (Sweden)

    Oskar Haske-Cornelius

    2017-09-01

    Full Text Available Cellulose acetate (CA-based materials, like cigarette filters, contribute to landscape pollution challenging municipal authorities and manufacturers. This study investigates the potential of enzymes to degrade CA and to be potentially incorporated into the respective materials, enhancing biodegradation. Deacetylation studies based on Liquid Chromatography-Mass Spectrometry-Time of Flight (LC-MS-TOF, High Performance Liquid Chromatography (HPLC, and spectrophotometric analysis showed that the tested esterases were able to deacetylate the plasticizer triacetin (glycerol triacetate and glucose pentaacetate (cellulose acetate model compound. The most effective esterases for deacetylation belong to the enzyme family 2 (AXE55, AXE 53, GAE, they deacetylated CA with a degree of acetylation of up to 1.8. A combination of esterases and cellulases showed synergistic effects, the absolute glucose recovery for CA 1.8 was increased from 15% to 28% when an enzymatic deacetylation was performed. Lytic polysaccharide monooxygenase (LPMO, and cellobiohydrolase were able to cleave cellulose acetates with a degree of acetylation of up to 1.4, whereas chitinase showed no activity. In general, the degree of substitution, chain length, and acetyl group distribution were found to affect CA degradation. This study shows that, for a successful enzyme-based deacetylation system, a cocktail of enzymes, which will randomly cleave and generate shorter CA fragments, is the most suitable.

  18. Fermentation characteristics of Fusarium oxysporum grown on acetate

    DEFF Research Database (Denmark)

    Panagiotou, Gianni; Pachidou, Fotini; Petroutsos, Dimitris

    2008-01-01

    In this study, the growth characteristics of Fusarium oxysporum were evaluated in minimal medium using acetate or different mixtures of acetate and glucose as carbon source. The minimum inhibitory concentration (MIC) of acetic acid that F oxysporum cells could tolerate was 0.8% w/v while glucose ...

  19. 21 CFR 582.5892 - a-Tocopherol acetate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false a-Tocopherol acetate. 582.5892 Section 582.5892 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5892 a-Tocopherol acetate. (a) Product. a-Tocopherol acetate. (b) Conditions of use. This...

  20. 21 CFR 182.8892 - α-Tocopherol acetate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true α-Tocopherol acetate. 182.8892 Section 182.8892 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD...-Tocopherol acetate. (a) Product. α-Tocopherol acetate. (b) Conditions of use. This substance is generally...

  1. 21 CFR 177.1350 - Ethylene-vinyl acetate copolymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-vinyl acetate copolymers. 177.1350 Section... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1350 Ethylene-vinyl acetate copolymers. Ethylene-vinyl acetate copolymers may be safely used as articles or components of articles...

  2. Kinetics of Ethyl Acetate Synthesis Catalyzed by Acidic Resins

    Science.gov (United States)

    Antunes, Bruno M.; Cardoso, Simao P.; Silva, Carlos M.; Portugal, Ines

    2011-01-01

    A low-cost experiment to carry out the second-order reversible reaction of acetic acid esterification with ethanol to produce ethyl acetate is presented to illustrate concepts of kinetics and reactor modeling. The reaction is performed in a batch reactor, and the acetic acid concentration is measured by acid-base titration versus time. The…

  3. Acetic acid extraction from aqueous solutions using fatty acids

    NARCIS (Netherlands)

    IJmker, H.M.; Gramblicka, M.; Kersten, Sascha R.A.; van der Ham, Aloysius G.J.; Schuur, Boelo

    2014-01-01

    A major challenge for production of acetic acid via bio-based routes is cost-effective concentration and purification of the acetic acid from the aqueous solutions, for which liquid–liquid extraction is a possible method. A main challenge in extraction of acetic acid from dilute aqueous solutions is

  4. Addressing Cellulose Acetate Microfilm from a British Library perspective

    Directory of Open Access Journals (Sweden)

    Helen Shenton

    2005-08-01

    Full Text Available This paper is about cellulose acetate microfilm from the British Library perspective. It traces how acetate microfilm became an issue for the British Library and describes cellulose acetate deterioration. This is followed by details of what has already been done about the situation and what action is planned for the future.

  5. Preparation, thermogravimetric study and infrared spectra of rare earth acetates

    International Nuclear Information System (INIS)

    Graehlert, X.; Starke, M.

    1992-01-01

    The anhydrous and the hydrated acetates of Ho, Er, Tm, Yb and Lu have been prepared. The compounds obtained have been investigated by thermogravimetric analysis and infrared spectroscopy. The thermal decomposition of the rare earth acetates may proceed via various steps. It depends on both the number of crystal water molecules in the acetates and the rare earth element's behaviour. (orig.)

  6. Air-oxidized linalyl acetate - an emerging fragrance allergen?

    Science.gov (United States)

    Hagvall, Lina; Berglund, Victoria; Bråred Christensson, Johanna

    2015-04-01

    Linalyl acetate is a fragrance chemical that is prone to autoxidation. Exposure to linalyl acetate occurs through cosmetic products and essential oils, but is difficult to assess, as linalyl acetate is not labelled in the EU. To investigate the frequencies of contact allergy to oxidized linalyl acetate among dermatitis patients, and to investigate the autoxidation of linalyl acetate in terms of hydroperoxide formation and sensitization potency. Hydroperoxide formation in air-exposed linalyl acetate was determined with high-performance liquid chromatography. The sensitization potencies of hydroperoxides were determined with the local lymph node assay. One thousand seven hundred and seventeen patients were patch tested with oxidized linalyl acetate at 6.0% in petrolatum. Of the patients, 2.2% showed positive reactions to oxidized linalyl acetate. Forty-three per cent of the positive patients also had positive patch test reactions to other fragrance markers. Linalyl acetate hydroperoxides were detected early in the autoxidation process, and accumulated to a concentration of 37% after 42 weeks of air exposure. The linalyl acetate hydroperoxides were classified as moderate sensitizers. The frequency of positive reactions to oxidized linalyl acetate is comparable to that of previously studied oxidized fragrance terpenes. Oxidized linalyl acetate could thus be a common fragrance contact allergen. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Application of the ruthenium and technetium thermodynamic data bases used in the EQ3/6 geochemical codes

    International Nuclear Information System (INIS)

    Isherwood, D.

    1985-04-01

    Based on a critical review of the available thermodynamic data, computerized data bases for technetium and ruthenium were created for use with the EQ3/6 geochemical computer codes. The technetium data base contains thermodynamic data for 8 aqueous species and 15 solids; 26 aqueous species and 9 solids were included in the ruthenium data base. The EQ3NR code was used to calculate solubility limits for ruthenium (8 x 10 -16 M) in ground water from Yucca Mountain, a potential nuclear waste repository site near the Nevada Test Site (NTS). The code confirmed the essentially unlimited solubility of technetium in oxidizing conditions, such as those that are believed to exist in the unsaturated zone at Yucca Mountain and the Cambric Nuclear event site at the NTS. Ruthenium migration observed from the Cambric site was evaluated. The solubility limit for ruthenium (as the aqueous species RuO 4 - ) when constrained by RuO 2 is approximately equal to the concentration of ruthenium found in the cavity ground water (i.e., 2.1 x 10 -11 vs 4.5 x 10 -11 M). Differences in ruthenium solubility limits between Yucca Mountain and Cambric are primarily due to differences in ground-water pH. Technetium solubility (3 x 10 -8 M) for moderately reducing conditions (Eh = -0.1 V) using the metastable oxide, TcO 2 .2H 2 O, as the solubility constraint is within the range of experimental values recently published in a study of technetium sorption on basalt. Previously published technetium solubilities of 10 -12 to 10 -16 M were apparently based on a technetium data base that did not include aqueous species other than TcO 4 - . When TcO(OH) 2 0 is included in the data base, the calculated values are much closer to the experimental results. Eh-pH diagrams were also generated for a variety of conditions using the SOLUPLOT code

  8. Acetic acid sclerotheraphy of renal cysts

    International Nuclear Information System (INIS)

    Hong, Hoon Pyo; Oh, Joo Hyeong; Yoon, Yup; Kong, Keun Young; Kim, Eui Jong; Goo, Jang Sung

    1998-01-01

    Sclerotherapy for renal cysts was performed, using 50% acetic acid as new sclerosing agent. We report the methods and results of this procedure. Fifteen patients underwent sclerotherapy for renal cyst, using 50% acetic acid. Because four patients were lost to follow-up, only 11 of the 15 were included in this study. The renal cysts, including one infected case, were diagnosed by ultrasonograpy (n=3D10) ormagnetic resonance imaging (n=3D1). The patient group consisted of four men and seven women(mean age, 59 years; range, 23-77). At first, the cyst was completely aspirated, and 25 volume% of aspirated volume was replaced with 50% sterile acetic acid through the drainage catheter. During the follwing 20 minutes, the patient changed position, and the acetic acid was then removed from the cyst. Finally, the drainage catheter was removed, after cleaning the cyst with saline. After treatment of infection by antibiotics and catheter drainage for 7 days, sclerotherapy in the infected case followed the same procedure. In order to observe changes in the size of renal cysts and recurrence, all patients were followed up by ultrasound between 2 and 8 months. We defined response to therapy as follows:complete regression as under 5 volume%, partial regression as 5-50 volume% and no response as more than 50 volume% of initial cyst volume. No clinically significant complication occured during the procedures or follow-up periods. All cysts regressed completely during follow-up of 8 months. Complete regression occurred as follows: two cysts at 2 months, seven cysts at 4 months, two cysts at 6 months. Two cysts showed residues at the last follow-up, at 4 and 6 months, respectively. The volume of residual cysts decreased to under 5 volume% of initial volume, however. Completely regressed cysts did not recurr during follow-up. Acetic acid sclerotherapy for renal cysts showed good results, regardless of the dilution of sclerosing agent with residual cyst fluid, and no significant

  9. Tailoring Ruthenium Exposure to Enhance the Performance of fcc Platinum@Ruthenium Core-Shell Electrocatalysts in the Oxygen Evolution Reaction

    KAUST Repository

    AlYami, Noktan

    2016-05-17

    The catalytic properties of noble metal nanocrystals are a function of their size, structure, and surface composition. In particular, achieving high activity without sacrificing stability is essential for designing commercially viable catalysts. A major challenge in designing state-of-the-art Ru-based catalysts for the oxygen evolution reaction (OER), which is a key step in water splitting, is the poor stability and surface tailorability of these catalysts. In this study, we designed rapidly synthesizable size-controlled, morphology-selective, and surface-tailored platinum-ruthenium core-shell (Pt@Ru) and alloy (PtRu) nanocatalysts in a scalable continuous-flow reactor. These core-shell nanoparticles with atomically precise shells were produced in a single synthetic step with carbon monoxide as the reducing agent. By varying the metal precursor concentration, a dendritic or layer-by-layer ruthenium shell can be grown. The catalytic activities of the synthesized Pt@Ru and PtRu nanoparticles exhibit noticeably higher electrocatalytic activity in the OER compared to that of pure Pt and Ru nanoparticles. Promisingly, Pt@Ru nanocrystals with a ~2-3 atomic layer Ru cuboctahedral shell surpass conventional Ru nanoparticles in terms of both durability and activity.

  10. Tailoring Ruthenium Exposure to Enhance the Performance of fcc Platinum@Ruthenium Core-Shell Electrocatalysts in the Oxygen Evolution Reaction

    KAUST Repository

    AlYami, Noktan; LaGrow, Alec P.; Joya, khurram; Hwang, Jinyeon; Katsiev, Khabiboulakh; Anjum, Dalaver H.; Losovyj, Yaroslav; Sinatra, Lutfan; Kim, Jin Young; Bakr, Osman

    2016-01-01

    The catalytic properties of noble metal nanocrystals are a function of their size, structure, and surface composition. In particular, achieving high activity without sacrificing stability is essential for designing commercially viable catalysts. A major challenge in designing state-of-the-art Ru-based catalysts for the oxygen evolution reaction (OER), which is a key step in water splitting, is the poor stability and surface tailorability of these catalysts. In this study, we designed rapidly synthesizable size-controlled, morphology-selective, and surface-tailored platinum-ruthenium core-shell (Pt@Ru) and alloy (PtRu) nanocatalysts in a scalable continuous-flow reactor. These core-shell nanoparticles with atomically precise shells were produced in a single synthetic step with carbon monoxide as the reducing agent. By varying the metal precursor concentration, a dendritic or layer-by-layer ruthenium shell can be grown. The catalytic activities of the synthesized Pt@Ru and PtRu nanoparticles exhibit noticeably higher electrocatalytic activity in the OER compared to that of pure Pt and Ru nanoparticles. Promisingly, Pt@Ru nanocrystals with a ~2-3 atomic layer Ru cuboctahedral shell surpass conventional Ru nanoparticles in terms of both durability and activity.

  11. Overview on mechanisms of acetic acid resistance in acetic acid bacteria.

    Science.gov (United States)

    Wang, Bin; Shao, Yanchun; Chen, Fusheng

    2015-02-01

    Acetic acid bacteria (AAB) are a group of gram-negative or gram-variable bacteria which possess an obligate aerobic property with oxygen as the terminal electron acceptor, meanwhile transform ethanol and sugar to corresponding aldehydes, ketones and organic acids. Since the first genus Acetobacter of AAB was established in 1898, 16 AAB genera have been recorded so far. As the main producer of a world-wide condiment, vinegar, AAB have evolved an elegant adaptive system that enables them to survive and produce a high concentration of acetic acid. Some researches and reviews focused on mechanisms of acid resistance in enteric bacteria and made the mechanisms thoroughly understood, while a few investigations did in AAB. As the related technologies with proteome, transcriptome and genome were rapidly developed and applied to AAB research, some plausible mechanisms conferring acetic acid resistance in some AAB strains have been published. In this review, the related mechanisms of AAB against acetic acid with acetic acid assimilation, transportation systems, cell morphology and membrane compositions, adaptation response, and fermentation conditions will be described. Finally, a framework for future research for anti-acid AAB will be provided.

  12. Deposition and properties of cobalt- and ruthenium-based ultra-thin films

    Science.gov (United States)

    Henderson, Lucas Benjamin

    Future copper interconnect systems will require replacement of the materials that currently comprise both the liner layer(s) and the capping layer. Ruthenium has previously been considered as a material that could function as a single material liner, however its poor ability to prevent copper diffusion makes it incompatible with liner requirements. A recently described chemical vapor deposition route to amorphous ruthenium-phosphorus alloy films could correct this problem by eliminating the grain boundaries found in pure ruthenium films. Bias-temperature stressing of capacitor structures using 5 nm ruthenium-phosphorus film as a barrier to copper diffusion and analysis of the times-to-failure at accelerated temperature and field conditions implies that ruthenium-phosphorus performs acceptably as a diffusion barrier for temperatures above 165°C. The future problems associated with the copper capping layer are primarily due to the poor adhesion between copper and the current Si-based capping layers. Cobalt, which adheres well to copper, has been widely proposed to replace the Si-based materials, but its ability to prevent copper diffusion must be improved if it is to be successfully implemented in the interconnect. Using a dual-source chemistry of dicobaltoctacarbonyl and trimethylphosphine at temperatures from 250-350°C, amorphous cobalt-phosphorus can be deposited by chemical vapor deposition. The films contain elemental cobalt and phosphorus, plus some carbon impurity, which is incorporated in the film as both graphitic and carbidic (bonded to cobalt) carbon. When deposited on copper, the adhesion between the two materials remains strong despite the presence of phosphorus and carbon at the interface, but the selectivity for growth on copper compared to silicon dioxide is poor and must be improved prior to consideration for application in interconnect systems. A single molecule precursor containing both cobalt and phosphorus atoms, tetrakis

  13. Mathematical modelling of brittle phase precipitation in complex ruthenium containing nickel-based superalloys

    International Nuclear Information System (INIS)

    Rettig, Ralf

    2010-01-01

    A new model has been developed in this work which is capable of simulating the precipitation kinetics of brittle phases, especially TCP-phases (topologically close packed phases) in ruthenium containing superalloys. The model simultaneously simulates the nucleation and the growth stage of precipitation for any number of precipitating phases. The CALPHAD method (Calculation of Phase Diagrams) is employed to calculate thermodynamic properties, such as the driving force or phase compositions in equilibrium. For calculation of diffusion coefficients, kinetic mobility databases which are also based on the CALPHAD-method are used. The model is fully capable of handling multicomponent effects, which are common in complex superalloys. Metastable phases can be treated and will automatically be dissolved if they get unstable. As the model is based on the general CALPHAD method, it can be applied to a broad range of precipitation processes in different alloys as long as the relevant thermodynamic and kinetic databases are available. The developed model proves that the TCP-phases precipitate in a sequence of phases. The first phase that is often formed is the metastable σ-phase because it has the lowest interface energy due to low-energy planes at the interface between matrix and precipitate. After several hundred hours the stable μ- and P-phases start to precipitate by nucleating at the σ-phase which is energetically favourable. During the growth of these stable phases the sigma-phase is continuously dissolved. It can be shown by thermodynamic CALPHAD calculations that the sigma-phase has a lower Gibbs free enthalpy than the μ- and P-phase. All required parameters of the model, such as interface energy and nucleate densities, have been estimated. The mechanisms of suppression of TCP-phase precipitation in the presence of ruthenium in superalloys were investigated with the newly developed model. It is shown by the simulations that ruthenium mostly affects the nucleation

  14. Variation of the Sterical Properties of the N-Heterocyclic Carbene Coligand in Thermally Triggerable Ruthenium-Based Olefin Metathesis Precatalysts/Initiators

    KAUST Repository

    Pump, Eva; Leitgeb, Anita; Kozłowska, Anna; Torvisco, Ana; Falivene, Laura; Cavallo, Luigi; Grela, Karol; Slugovc, Christian

    2015-01-01

    A series of ruthenium complexes based on the κ(C,N)-(2-(benzo[h]quinolin-10-yl)methylidene ruthenium dichloride fragment featuring different neutral coligands L (L = 1,3-bis(2,6-diisopropylphenyl)-4,5-dihydroimidazol-2-ylidene (SIPr), 1,3-bis(2

  15. Detoxification of biomass derived acetate via metabolic conversion to ethanol, acetone, isopropanol, or ethyl acetate

    Science.gov (United States)

    Sillers, William Ryan; Van Dijken, Hans; Licht, Steve; Shaw, IV, Arthur J.; Gilbert, Alan Benjamin; Argyros, Aaron; Froehlich, Allan C.; McBride, John E.; Xu, Haowen; Hogsett, David A.; Rajgarhia, Vineet B.

    2017-03-28

    One aspect of the invention relates to a genetically modified thermophilic or mesophilic microorganism, wherein a first native gene is partially, substantially, or completely deleted, silenced, inactivated, or down-regulated, which first native gene encodes a first native enzyme involved in the metabolic production of an organic acid or a salt thereof, thereby increasing the native ability of said thermophilic or mesophilic microorganism to produce lactate or acetate as a fermentation product. In certain embodiments, the aforementioned microorganism further comprises a first non-native gene, which first non-native gene encodes a first non-native enzyme involved in the metabolic production of lactate or acetate. Another aspect of the invention relates to a process for converting lignocellulosic biomass to lactate or acetate, comprising contacting lignocellulosic biomass with a genetically modified thermophilic or mesophilic microorganism.

  16. Acetic acid removal from corn stover hydrolysate using ethyl acetate and the impact on Saccharomyces cerevisiae bioethanol fermentation.

    Science.gov (United States)

    Aghazadeh, Mahdieh; Ladisch, Michael R; Engelberth, Abigail S

    2016-07-08

    Acetic acid is introduced into cellulose conversion processes as a consequence of composition of lignocellulose feedstocks, causing significant inhibition of adapted, genetically modified and wild-type S. cerevisiae in bioethanol fermentation. While adaptation or modification of yeast may reduce inhibition, the most effective approach is to remove the acetic acid prior to fermentation. This work addresses liquid-liquid extraction of acetic acid from biomass hydrolysate through a pathway that mitigates acetic acid inhibition while avoiding the negative effects of the extractant, which itself may exhibit inhibition. Candidate solvents were selected using simulation results from Aspen Plus™, based on their ability to extract acetic acid which was confirmed by experimentation. All solvents showed varying degrees of toxicity toward yeast, but the relative volatility of ethyl acetate enabled its use as simple vacuum evaporation could reduce small concentrations of aqueous ethyl acetate to minimally inhibitory levels. The toxicity threshold of ethyl acetate, in the presence of acetic acid, was found to be 10 g L(-1) . The fermentation was enhanced by extracting 90% of the acetic acid using ethyl acetate, followed by vacuum evaporation to remove 88% removal of residual ethyl acetate along with 10% of the broth. NRRL Y-1546 yeast was used to demonstrate a 13% increase in concentration, 14% in ethanol specific production rate, and 11% ethanol yield. This study demonstrated that extraction of acetic acid with ethyl acetate followed by evaporative removal of ethyl acetate from the raffinate phase has potential to significantly enhance ethanol fermentation in a corn stover bioethanol facility. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:929-937, 2016. © 2016 American Institute of Chemical Engineers.

  17. Tuning magnetization avalanches in Mn12-acetate

    Science.gov (United States)

    Wen, Bo; McHugh, S.; Ma, Xiang; Sarachik, M. P.; Myasoedov, Y.; Shtrikman, H.; Zeldov, E.; Bagai, R.; Christou, G.

    2009-03-01

    We report the results of a systematic study of magnetic avalanches (abrupt magnetization reversals) in the molecular magnet Mn12-acetate using a micron-sized Hall sensor array. Measurements were taken for: (a) fixed magnetic field (constant barrier against spin reversal); and (b) fixed energy release obtained by adjusting the barrier and δM. A detailed comparison with the theory of magnetic deflagration of Garanin and Chudnovsky [1] will be presented and discussed. [1] D. A. Garanin and E. M. Chudnovsky, Phys. Rev. B 76, 054410 (2007)

  18. CCDC 992954: Experimental Crystal Structure Determination : chloro-bis(1-cyclododecyl-3-mesitylimidazol-2-ylidene)-(2-(isopropoxy)benzylidene)-ruthenium tetrafluoroborate ethyl acetate solvate

    KAUST Repository

    Rouen, Mathieu

    2015-01-01

    An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

  19. 3-Methylindole-Based Tripodal Tetraphosphine Ruthenium Complexes in N2 Coordination and Reduction and Formic Acid Dehydrogenation

    Directory of Open Access Journals (Sweden)

    Fenna F. van de Watering

    2017-10-01

    Full Text Available The ruthenium(II complexes RuCl2L1H, RuCl2L1CF3, RuCl2L1OMe and RuCl2L2H were synthesized from [Ru(η6-benzeneCl(μ-Cl]2 and the corresponding tripodal tris-3-methylindolephosphine-based ligands L1H, L1CF3, L1OMe, and L2H. Stoichiometric reduction of these complexes with KC8 yielded the corresponding ruthenium(0 dinitrogen complexes. The latter complexes were studied in the N2 reduction with chlorosilanes and KC8, yielding stoichiometric amounts of the silylamines. The synthesized ruthenium(II complexes are also active catalysts for the formic acid dehydrogenation reaction.

  20. Amidines for versatile ruthenium(II)-catalyzed oxidative C-H activations with internal alkynes and acrylates.

    Science.gov (United States)

    Li, Jie; John, Michael; Ackermann, Lutz

    2014-04-25

    Cationic ruthenium complexes derived from KPF6 or AgOAc enabled efficient oxidative CH functionalizations on aryl and heteroaryl amidines. Thus, oxidative annulations of diversely decorated internal alkynes provided expedient access to 1-aminoisoquinolines, while catalyzed C-H activations with substituted acrylates gave rise to structurally novel 1-iminoisoindolines. The powerful ruthenium(II) catalysts displayed a remarkably high site-, regio- and, chemoselectivity. Therefore, the catalytic system proved tolerant of a variety of important electrophilic functional groups. Detailed mechanistic studies provided strong support for the cationic ruthenium(II) catalysts to operate by a facile, reversible C-H activation. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Immunotoxicity of trenbolone acetate in Japanese quail

    Science.gov (United States)

    Quinn, M.J.; McKernan, M.; Lavoie, E.T.; Ottinger, M.A.

    2007-01-01

    Trenbolone acetate is a synthetic androgen that is currently used as a growth promoter in many meat-exporting countries. Despite industry laboratories classifying trenbolone as nonteratogenic, data showed that embryonic exposure to this androgenic chemical altered development of the immune system in Japanese quail. Trenbolone is lipophilic, persistent, and released into the environment in manure used as soil fertilizer. This is the first study to date to assess this chemical's immunotoxic effects in an avian species. A one-time injection of trenbolone into yolks was administered to mimic maternal deposition, and subsequent effects on the development and function of the immune system were determined in chicks and adults. Development of the bursa of Fabricius, an organ responsible for development of the humoral arm of the immune system, was disrupted, as indicated by lower masse, and smaller and fewer follicles at day 1 of hatch. Morphological differences in the bursas persisted in adults, although no differences in either two measures of immune function were observed. Total numbers of circulating leukocytes were reduced and heterophil-lymphocyte ratios were elevated in chicks but not adults. This study shows that trenbolone acetate is teratogenic and immunotoxic in Japanese quail, and provides evidence that the quail immune system may be fairly resilient to embryonic endocrine-disrupting chemical-induced alterations following no further exposure posthatch.

  2. Glycerol transesterification with ethyl acetate to synthesize acetins using ethyl acetate as reactant and entrainer

    Directory of Open Access Journals (Sweden)

    Amin Shafiei

    2017-03-01

    Full Text Available Transesterification of glycerol with ethyl acetate was performed over acidic catalysts in the batch and semi-batch systems. Ethyl acetate was used as reactant and entrainer to remove the produced ethanol during the reaction, through azeotrope formation. Since the azeotrope of ethyl acetate and ethanol forms at 70 oC, all the experiments were performed at this temperature. Para-toluene sulfonic acid, sulfuric acid, and Amberlyst 36 were used as catalyst. The effect of process parameters including ethyl acetate to glycerol molar ratio (6-12, reaction time (3-9 h, and the catalyst to glycerol weight (2.5-9.0%, on the conversion and products selectivities were investigated. Under reflux conditions, 100% glycerol conversion was obtained with 45%, 44%, and 11% selectivity to monoacetin, diacetin, and triacetin, respectively. Azeotropic reactive distillation led to 100% conversion of glycerol with selectivities of 3%, 48% and 49% for monoacetin, diacetin, and triacetin. During the azeotropic reactive distillation, it was possible to remove ethanol to shift the equilibrium towards diacetin and triacetin. Therefore, the total selectivity to diacetin and triacetin was increased from 55% to 97% through azeotropic distillation.

  3. In-situ XPS analysis of oxidized and reduced plasma deposited ruthenium-based thin catalytic films

    Science.gov (United States)

    Balcerzak, Jacek; Redzynia, Wiktor; Tyczkowski, Jacek

    2017-12-01

    A novel in-situ study of the surface molecular structure of catalytically active ruthenium-based films subjected to the oxidation (in oxygen) and reduction (in hydrogen) was performed in a Cat-Cell reactor combined with a XPS spectrometer. The films were produced by the plasma deposition method (PEMOCVD). It was found that the films contained ruthenium at different oxidation states: metallic (Ru0), RuO2 (Ru+4), and other RuOx (Ru+x), of which content could be changed by the oxidation or reduction, depending on the process temperature. These results allow to predict the behavior of the Ru-based catalysts in different redox environments.

  4. Dehydrogenative Synthesis of Imines from Alcohols and Amines Catalyzed by a Ruthenium N-Heterocyclic Carbene Complex

    DEFF Research Database (Denmark)

    Maggi, Agnese; Madsen, Robert

    2012-01-01

    A new method for the direct synthesis of imines from alcohols and amines is described where hydrogen gas is liberated. The reaction is catalyzed by the ruthenium N-heterocyclic carbene complex [RuCl2(IiPr)(p-cymene)] in the presence of the ligand DABCO and molecular sieves. The imination can...... be applied to a variety of primary alcohols and amines and can be combined with a subsequent addition reaction. A deuterium labeling experiment indicates that the catalytically active species is a ruthenium dihydride. The reaction is believed to proceed by initial dehydrogenation of the alcohol...

  5. Heterotrophic utilization of acetate and glucose in Swartvlei, South Africa

    International Nuclear Information System (INIS)

    Robarts, R.D.

    1979-01-01

    The utilization of dissolved organic compounds in Swartvlei was measured by the addition of single concentrations of 14 C-labelled acetate and glucose to water samples. The results indicated acetate uptake was greatest in the aerobic zone while glucose was predominantly utilized in the anaerobic zone. With the exception of two months, integral glucose uptake was usually greater than the uptake of acetate. In August and September 1971 acetate was indicated as being utilized predominantly by flagellates and in December 1971 by dinoflagellates. During the remainder of the study, bacteria were assumed to be responsible for the uptake of acetate. The extensive weed beds which surround the upper reaches of Swartvlei may be a major source of acetate and glucose in the pelagic water column

  6. 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.

  7. The effect of annealing temperature on the optical properties of a ruthenium complex thin film

    Energy Technology Data Exchange (ETDEWEB)

    Ocakoglu, Kasim, E-mail: kasim.ocakoglu@mersin.edu.tr [Advanced Technology Research & Application Center, Mersin University, TR-33343, Yenisehir, Mersin (Turkey); Department of Energy Systems Engineering, Faculty of Technology, Mersin University, TR-33480 Mersin (Turkey); Okur, Salih, E-mail: salih.okur@ikc.edu.tr [Department of Materials Science and Engineering, Faculty of Engineering and Architecture, Izmir Katip Celebi University, Izmir (Turkey); Aydin, Hasan [Izmir Institute of Technology, Department of Material Science and Engineering, Gulbahce Campus, 35430, Urla, Izmir (Turkey); Emen, Fatih Mehmet [Faculty of Arts and Sciences, Department of Chemistry, Mehmet Akif Ersoy University, TR-15030 Burdur (Turkey)

    2016-08-01

    The stability of the optical parameters of a ruthenium polypyridyl complex (Ru-PC K314) film under varying annealing temperatures between 278 K and 673 K was investigated. The ruthenium polypyridyl complex thin film was prepared on a quartz substrate by drop casting technique. The transmission of the film was recorded by using Ultraviolet/Visible/Near Infrared spectrophotometer and the optical band gap energy of the as-deposited film was determined around 2.20 eV. The optical parameters such as refractive index, extinction coefficient, and dielectric constant of the film were determined and the annealing effect on these parameters was investigated. The results show that Ru PC K314 film is quite stable up to 595 K, and the rate of the optical band gap energy change was found to be 5.23 × 10{sup −5} eV/K. Furthermore, the thermal analysis studies were carried out in the range 298–673 K. The Differential Thermal Analysis/Thermal Gravimmetry/Differantial Thermal Gravimmetry curves show that the decomposition is incomplete in the temperature range 298–673 K. Ru-PC K314 is thermally stable up to 387 K. The decomposition starts at 387 K with elimination of functional groups such as CO{sub 2}, CO molecules and SO{sub 3}H group was eliminated between 614 K and 666 K. - Highlights: • Optical parameters of a ruthenium polypyridyl complex film under varying annealing temperatures • The film is quite stable up to 573 K. • The rate of change of optical energy gap was obtained as 5.23 × 10{sup −5} eV/K.

  8. Nano-scale islands of ruthenium oxide as an electrochemical sensor for iodate and periodate determination

    International Nuclear Information System (INIS)

    Chatraei, Fatemeh; Zare, Hamid R.

    2013-01-01

    In this study, a promising electrochemical sensor was fabricated by the electrodeposition of nano-scale islands of ruthenium oxide (ruthenium oxide nanoparticles, RuON) on a glassy carbon electrode (RuON–GCE). Then, the electrocatalytic oxidation of iodate and periodate was investigated on it, using cyclic voltammetry, chronoamperometry and amperometry as diagnostic techniques. The charge transfer coefficient, α, and the charge transfer rate constant, k s , for electron transfer between RuON and GCE were calculated as 0.5 ± 0.03 and 9.0 ± 0.7 s −1 respectively. A comparison of the data obtained from the electrocatalytic reduction of iodate and periodate at a bare GCE (BGCE) and RuON–GCE clearly shows that the unique electronic properties of nanoparticles definitely improve the characteristics of iodate and periodate electrocatalytic reduction. The kinetic parameters such as the electron transfer coefficient, α, and the heterogeneous electron transfer rate constant, k′, for the reduction of iodate and periodate at RuON–GCE surface were determined using cyclic voltammetry. Amperometry revealed a good linear relationship between the peak current and the concentration of iodate and periodate. The detection limits of 0.9 and 0.2 μM were calculated for iodate and periodate respectively. Highlights: ► Ruthenium oxide nanoparticles, RuON, were used for electrocatalytic reduction iodate and periodate. ► Formal potential, E 0 ′, of the surface redox couple of RuON is pH-dependent. ► The heterogeneous electron transfer rate constant values between both analytes and RuON were calculated.

  9. Preparations and characterization of some carbonyl-(1-cyanoethyl)ruthenium(II) complexes

    Energy Technology Data Exchange (ETDEWEB)

    Hiraki, Katsuma; Ochi, Naoyuki; Kitamura, Tsuneyuki; Sasada, Yoko [Nagasaki Univ. (Japan); Shinoda, Sumio

    1982-08-01

    A hydridoruthenium(II) complex (RuClH(CO)(PPh/sub 3/)/sub 3/) reacted easily with acrylonitrile and fumaronitrile to give chloro-bridged binuclear (1-cyanoethyl)ruthenium(II) complexes, ((Ru(MeCHCN)Cl(CO)(PPh/sub 3/)/sub 2/)/sub 2/) (2) and ((Ru(NCCH/sub 2/CHCN)Cl(CO)(PPh/sub 3/)/sub 2/)/sub 2/), respectively. Complex 2 reacted with 4-picoline (pic), Na(BHPz/sub 3/) (Pz = 1-pyrazolyl), Na(BPz/sub 4/), and Na(Et/sub 2/NCS/sub 2/).3H/sub 2/O to afford the corresponding (1-cyanoethyl)ruthenium(II) complexes, ((Ru(MeCHCN)Cl(CO)(pic)(PPh/sub 3/))/sub 2/) (3), (Ru(MeCHCN)(BHPz/sub 3/)(CO)(PPh/sub 3/)) (accompanied by a small amount of (Ru/sub 2/(MeCHCN)/sub 2/Cl(BHPz/sub 3/)(CO)/sub 2/(PPh/sub 3/)/sub 4/)), (Ru/sub 2/(MeCHCN)/sub 2/Cl(BPz/sub 4/)(CO)/sub 2/(PPh/sub 3/)/sub 2/), and Na(Ru(MeCHCN)Cl(Et/sub 2/NCS/sub 2/)(CO)(PPh/sub 3/)), respectively. Complex 3 reacted with thallium (I) acetylacetonate (Tl(acac)), resulting in the formation of ((Ru(MeCHCN)(acac)(CO)(PPh/sub 3/))/sub 2/) and (Ru(MeCHCN)(acad)(CO)(pic)(PPh/sub 3/)). These new complexes were characterized by means of elemental analysis and spectroscopic data. The diastereoisomerism was also discussed as regards these (1-cyanoethyl)ruthenium(II) complexes.

  10. Bioimaging of isosteric osmium and ruthenium anticancer agents by LA-ICP-MS.

    Science.gov (United States)

    Klose, Matthias H M; Theiner, Sarah; Kornauth, Christoph; Meier-Menches, Samuel M; Heffeter, Petra; Berger, Walter; Koellensperger, Gunda; Keppler, Bernhard K

    2018-03-01

    Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) was used to study the spatial distribution of two metallodrugs with anticancer activities in vivo, namely the organoruthenium plecstatin-1 (1) and its isosteric osmium analogue (2), in liver, kidneys, muscles and tumours of treated mice bearing a CT-26 tumour after single-dose i.p. administration. To the best of our knowledge, this is the first time that the spatial distribution of an osmium drug candidate has been investigated using LA-ICP-MS in tissues. Independent measurements of the average ruthenium and osmium concentration via microwave digestion and ICP-MS in organs and tumours were in good agreement with the LA-ICP-MS results. Matrix-matched standards (MMS) ranging from 1 to 30 μg g -1 were prepared to quantify the spatial distributions of the metals and the average metal content of the MMS samples was additionally quantified by ICP-MS after microwave digestion. The recoveries for osmium and ruthenium in the MMS were 105% and 101% on average, respectively, validating the sample preparation procedure of the MMS. Preparation of MMS was carried out under an argon atmosphere to prevent oxidation of osmium-species to the volatile OsO 4 . The highest metal concentrations were found in the liver, followed by kidney, lung and tumour tissues, while muscles displayed only very low quantities of the respective metal. Both metallodrugs accumulated in the cortex of the kidneys more strongly compared to the medulla. Interestingly, osmium from 2 was largely located at the periphery and tissue edges, whereas ruthenium from 1 was observed to penetrate deeper into the organs and tumours.

  11. Teratogenic effects of lead acetate on kidney

    International Nuclear Information System (INIS)

    Jabeen, R.; Tahir, M.; Waqas, S.

    2010-01-01

    Background: Lead remains a considerable occupational and public health problem, which is known to cause a number of adverse effects in both men and women. Conflicting reports have appeared on lead induced nephrotoxicity in experimental studies in the past. There is hardly any work on its teratogenic effects on kidney. Present study was therefore designed to investigate the effects of lead acetate on developing kidney. Methods: Twelve mice were used as experimental model and were divided into two groups of six animals each; group A served as control group and B was used as an experimental group. Lead acetate (10 mg/kg) dissolved in 0.02 ml of distilled water was administered as a single daily dose orally to group B whereas weight related amount of distilled water was given to group A for the entire period of experiment. On 18 day of gestation foetuses were dissected free of uterine wall under the dissecting microscope and were sacrificed; kidneys were removed and fixed in 10% formalin, dehydrated in ascending grades of alcohol, cleared in xylene and infiltrated with filtered paraffin. The paraffin blocks were made and five micron thin sections were obtained using a rotary microtome. The sections were stained with Hematoxylin and eosin and, PAS; these were examined under light microscope. Results: Significant decrease in cortical thickness was observed which varied from 578.6 +- 1.4 mu m in group A to 515.6 +- 5 mu m in group B (p<0.001). Diameter of renal corpuscles varied from 57.7 +- 0.07 mu m in group A to 50.5 +- 0.07 mu m in group B (p<0.001). Moderate cortical tubular atrophy showing thickening of endothelial basement membrane in glomeruli, desquamated epithelium with degenerated nuclei in proximal and distal tubules were observed in group B in contrast to group A. Conclusion: The results of the investigation indicated that lead acetate administration to the dams produced deleterious effects on the developing kidney in mice. (author)

  12. Proton conductivity and relaxation properties of chitosan-acetate films

    International Nuclear Information System (INIS)

    Prokhorov, E.; Luna-Bárcenas, G.; González-Campos, J.B.; Kovalenko, Yu.; García-Carvajal, Z.Y.; Mota-Morales, J.

    2016-01-01

    Graphical abstract: Temperature dependence of conductivity, the number of density and proton mobility in chitosan-acetate film. - Highlights: • DD, conductivity, Vogel temperature dependent on the concentration of acetic acid. • Proton conductivity of CS-acetate films interpreted using two Grotthuss mechanisms. • Transformation between two mechanisms observed at the glass transition temperature. - Abstract: The effect of aqueous acetic acid solution concentration during the preparation of chitosan-acetate (CS-acetate) films on the conductivity and relaxation properties were studied by dielectric and FTIR spectroscopies, TGA measurements and X-Ray diffraction. Analyses of the experimental results on the degree of deacetylation, water absorption, conductivity, Vogel temperature and activation energy demonstrate a strong dependence of these parameters on the concentration of the acid acetic solutions from which the films have been obtained. The proton conductivity and relaxation properties of CS-acetate films have been interpreted using two Grotthuss “structural diffusion” and “pack-acid” mechanisms. The transformation between these two mechanisms observed at temperature higher than CS-acetate glass transition temperature is due to an increase in the thermal motion of CS chains, water evaporation, hydrogen bond between water molecules and side groups of CS breaking and formation of new bonds between NH 3 + and acetate ions. Additionally, application of the Rice and Roth model allowed estimating the temperature dependence of proton number and their mobility in CS-acetate films. A systematic interpretation on the appropriate conductivity mechanism will help trigger the design of smart materials used in flexible electronic, solid polymer electrolytes for fuel cells and solid polymer batteries based on CS-acetate films.

  13. Background-free, high sensitivity staining of proteins in one- and two-dimensional sodium dodecyl sulfate-polyacrylamide gels using a luminescent ruthenium complex.

    Science.gov (United States)

    Berggren, K; Chernokalskaya, E; Steinberg, T H; Kemper, C; Lopez, M F; Diwu, Z; Haugland, R P; Patton, W F

    2000-07-01

    SYPRO Ruby dye is a permanent stain comprised of ruthenium as part of an organic complex that interacts noncovalently with proteins. SYPRO Ruby Protein Gel Stain provides a sensitive, gentle, fluorescence-based method for detecting proteins in one-dimensional and two-dimensional sodium dodecyl sulfate-polyacrylamide gels. Proteins are fixed, stained from 3h to overnight and then rinsed in deionized water or dilute methanol/acetic acid solution for 30 min. The stain can be visualized using a wide range of excitation sources commonly used in image analysis systems including a 302 nm UV-B transilluminator, 473 nm second harmonic generation (SHG) laser, 488 nm argon-ion laser, 532 nm yttrium-aluminum-garnet (YAG) laser, xenon arc lamp, blue fluorescent light bulb or blue light-emitting diode (LED). The sensitivity of SYPRO Ruby Protein Gel Stain is superior to colloidal Coomassie Brilliant Blue (CBB) stain or monobromobimane labeling and comparable with the highest sensitivity silver or zinc-imidazole staining procedures available. The linear dynamic range of SYPRO Ruby Protein Gel stain extends over three orders of magnitude, which is vastly superior to silver, zinc-imidazole, monobromobimane and CBB stain. The fluorescent stain does not contain superfluous chemicals (formaldehyde, glutaraldehyde, Tween-20) that frequently interfere with peptide identification in mass spectrometry. While peptide mass profiles are severely altered in protein samples prelabeled with monobromobimane, successful identification of proteins by peptide mass profiling using matrix-assisted laser desorption/ionization mass spectrometry was easily performed after protein detection with SYPRO Ruby Protein Gel stain.

  14. Ruthenium-Catalyzed Formal Dehydrative [4 + 2] Cycloaddition of Enamides and Alkynes for the Synthesis of Highly Substituted Pyridines: Reaction Development and Mechanistic Study.

    Science.gov (United States)

    Wu, Jicheng; Xu, Wenbo; Yu, Zhi-Xiang; Wang, Jian

    2015-07-29

    Reported herein is a ruthenium-catalyzed formal dehydrative [4 + 2] cycloaddition of enamides and alkynes, representing a mild and economic protocol for the construction of highly substituted pyridines. Notably, the features of broad substrate scope, high efficiency, good functional group tolerance, and excellent regioselectivities were observed for this reaction. Density functional theory (DFT) calculations and experiments have been carried out to understand the mechanism and regiochemistry. DFT calculations suggested that this formal dehydrative [4 + 2] reaction starts with a concerted metalation deprotonation of the enamide by the acetate group in the Ru catalyst, which generates a six-membered ruthenacycle intermediate. Then alkyne inserts into the Ru-C bond of the six-membered ruthenacycle, giving rise to an eight-membered ruthenacycle intermediate. The carbonyl group (which comes originally from the enamide substrate and is coordinated to the Ru center in the eight-membered ruthenacycle intermediate) then inserts into the Ru-C bond to give an intermediate, which produces the final pyridine product through further dehydration. Alkyne insertion step is a regio-determining step and prefers to have the aryl groups of the used alkynes stay away from the catalyst in order to avoid repulsion of aryl group with the enamide moiety in the six-membered ruthenacycle and to keep the conjugation between the aryl group and the triple C-C bond of the alkynes. Consequently, the aryl groups of the used alkynes are in the β-position of the final pyridines, and the present reaction has high regioselectivity.

  15. A feasible kinetic model for the hydrogen oxidation on ruthenium electrodes

    International Nuclear Information System (INIS)

    Rau, M.S.; Gennero de Chialvo, M.R.; Chialvo, A.C.

    2010-01-01

    The hydrogen oxidation reaction (hor) was studied on a polycrystalline ruthenium electrode in H 2 SO 4 solution at different rotation rates (ω). The experimental polarization curves recorded on steady state show the existence of a maximum current with a non-linear dependence of the current density on ω 1/2 . On the basis of the Tafel-Heyrovsky-Volmer kinetic mechanism, coupled with a process of inhibition of active sites by the reversible electroadsorption of hydroxyl species, it was possible to appropriately describe the origin of the maximum current. The corresponding set of kinetic parameters was also calculated from the correlation of the experimental results with the proposed kinetic model.

  16. Dynamic modeling of the cesium, strontium, and ruthenium transfer to grass and vegetables

    International Nuclear Information System (INIS)

    Renaud, P.; Real, J.; Maubert, H.; Roussel-Debet, S.

    1999-01-01

    From 1988 to 1993, the Nuclear Safety and Protection Institute (Institut de Protection et de Surete Nucleaire -- IPSN) conducted experimental programs focused on transfers to vegetation following accidental localized deposits of radioactive aerosols. In relation to vegetable crops (fruit, leaves, and root vegetables) and meadow grass these experiments have enabled a determination of the factors involved in the transfer of cesium, strontium, and ruthenium at successive harvests, or cuttings, in respect of various time lags after contamination. The dynamic modeling given by these results allows an evaluation of changes in the mass activity of vegetables and grass during the months following deposit. It constitutes part of the ASTRAL post-accident radioecology model

  17. Electrochemical capacitance of nanocomposite films formed by loading carbon nanotubes with ruthenium oxide

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae-Kyung [Department of Chemical Engineering, University of Seoul, 90 Chonnong-dong, Tongdaemun-gu, Seoul (Korea, Republic of); Pathan, Habib M.; Jung, Kwang-Deog; Joo, Oh-Shim [Eco-Nano Research Center, Korea Institute of Science and Technology (KIST), P.O. Box 131, Cheongryang, Seoul (Korea, Republic of)

    2006-09-22

    This work reports the supercapacitive properties of composite films of multiwalled carbon nanotubes (MWNT) and ruthenium oxide (RuO{sub 2}). Transmission and scanning electron microscopy, cyclic voltammetry, and electrochemical studies revealed that the nanoporous three-dimensional arrangement of RuO{sub 2}-coated MWNT in these films facilitated the improvement of electron and ion transfer relative to MWNT films. The capacitance was measured for films of different RuO{sub 2} loading, revealing specific capacitances per mass as high as 628Fg{sup -1}. The energy storage density of the electrode has increased about three times as compared to MWNT treated with piranha solution. (author)

  18. Ruthenium Grubbs’ catalyst nanostructures grown by UV-excimer-laser ablation for self-healing applications

    International Nuclear Information System (INIS)

    Aïssa, B.; Nechache, R.; Haddad, E.; Jamroz, W.; Merle, P.G.; Rosei, F.

    2012-01-01

    Highlights: ► Successful preparation of 5-Ethylidene-2-Norbornene (5E2N) monomer reacted with Ruthenium Grubbs’ Catalyst (RGC) composite. ► The kinetics of the 5E2N ring opening metathesis polymerization (ROMP) is effective in a large temperature range (−20 to 45 °C). ► The kinetics of the 5E2N ROMP is occurring at very short time scales ( −4 Vol.%, occurring at very short time reaction. This approach opens new prospects for using healing agent nanocomposite materials for self-repair functionality, thereby obtaining a higher catalytic efficiency per unit mass.

  19. Half -sand wish ruthenium complexes of heterocyclic-dithio carboxylato ligands

    International Nuclear Information System (INIS)

    El-khateeb, M.; Al-Noaimi, M.; Harb, M.; Gorls, H.; Weigand, W.

    2008-01-01

    The heterocyclic-dithio carboxylato complexes Cp Ru(PPh 3 )(κ 2 S,S-S 2 C-h et) [h et= 2-C 4 H 3 O (1), 2-C 4 H 3 S (2), 1-C 4 H 8 N (3)] are obtained by the reaction of the ruthenium chloride, Cp Ru(PPh 3 ) 2 CI, with the anions, h et-CS 2 . The X-ray structure of Cp Ru(PPh 3 )(κ 2 S, S-S 2 C-1- C 4 H 8 N) (3) is determined by single crystal X-ray diffraction.

  20. The contrasting chemistry and cancer cell cytotoxicity of bipyridine and bipyridinediol ruthenium(II) arene complexes

    Czech Academy of Sciences Publication Activity Database

    Bugarcic, T.; Habtemariam, A.; Štěpánková, Jana; Heringová, Pavla; Kašpárková, Jana; Deeth, R.J.; Johnstone, R.D.L.; Prescimone, A.; Parkin, A.; Parsons, S.; Brabec, Viktor; Sadler, P.J.

    2008-01-01

    Roč. 47, č. 24 (2008), s. 11470-11486 ISSN 0020-1669 R&D Projects: GA MŠk(CZ) LC06030; GA MŠk(CZ) ME08017; GA MŠk(CZ) OC08003; GA AV ČR(CZ) 1QS500040581; GA AV ČR(CZ) KAN200200651; GA AV ČR(CZ) IAA400040803; GA MZd(CZ) NR8562 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : DNA * ruthenium * cancer Subject RIV: BO - Biophysics Impact factor: 4.147, year: 2008

  1. Volatilization and trapping of ruthenium during calcination of nitric acid solutions

    International Nuclear Information System (INIS)

    Klein, M.; Weyers, C.; Goossens, W.R.A.; Smet, M. de; Trine, J.

    1983-01-01

    Solid radioactive aerosols and semi-volatile fission products e.g. Ru, Cs, Sb are generated during high level liquid waste calcination and vitrification processes. The retention of Ruthenium was studied because of its strong tendency to form volatile compounds in oxidative media. Since RuO 4 was the suspected form for high temperature processes, the study was carried out on the behaviour of RuO 4 and its retention on adsorbants and catalysts for various gas compositions. The behaviour of volatilized Ru species obtained by calcination of nitrosyl Ru compounds was then compared with the RuO 4 case

  2. An alternative pathway for production of acetonitrile: ruthenium catalysed aerobic dehydrogenation of ethylamine

    DEFF Research Database (Denmark)

    Corker, Emily; Mentzel, Uffe Vie; Mielby, Jerrik Jørgen

    2013-01-01

    The oxidative synthesis of acetonitrile from ethylamine was studied using a supported ruthenium catalyst. The reaction was conducted in both batch and flow processes and high conversions (over 85%) were achieved in both cases. Selectivity of both reactions was improved by optimisation of reaction...... conditions, achieving over 90% selectivity in the batch process and 80% selectivity in the continuous flow process. The use of a selective solid catalyst that utilises a feedstock that can be derived from biomass, dioxygen as the oxidant and water as the solvent represents a new, green route...

  3. Ruthenium(ii)-catalyzed olefination via carbonyl reductive cross-coupling.

    Science.gov (United States)

    Wei, Wei; Dai, Xi-Jie; Wang, Haining; Li, Chenchen; Yang, Xiaobo; Li, Chao-Jun

    2017-12-01

    Natural availability of carbonyl groups offers reductive carbonyl coupling tremendous synthetic potential for efficient olefin synthesis, yet the catalytic carbonyl cross-coupling remains largely elusive. We report herein such a reaction, mediated by hydrazine under ruthenium(ii) catalysis. This method enables facile and selective cross-couplings of two unsymmetrical carbonyl compounds in either an intermolecular or intramolecular fashion. Moreover, this chemistry accommodates a variety of substrates, proceeds under mild reaction conditions with good functional group tolerance, and generates stoichiometric benign byproducts. Importantly, the coexistence of KO t Bu and bidentate phosphine dmpe is vital to this transformation.

  4. Synthesis and characterisation of ruthenium(III) complexes with benzimidazole derivatives

    International Nuclear Information System (INIS)

    Vyas, P.C.; Kaur, N.; Goel, A.K.; Vyas, S.

    1995-01-01

    Complexes of ruthenium trichloride with biologically important benzimidazole derivatives, viz., 2-(hydroxy methyl) benzimidazole, 2-(l-hydroxy ethyl) benzimidazole, 2-(mercapto methyl) benzimidazole, 2-(l-mercapto ethyl) benzimidazole, and 2,2'-bis-benzimidazole have been synthesized by reacting the above metal chloride and ligands respectively in 1:3 molar ratio. These complexes are characterised on the basis of elemental analysis, molar conductance data, room temperature, magnetic moment values, electronic spectral and IR spectral studies. (author). 17 refs., 2 tabs

  5. Evaluation of Ruthenium Capture Methods for Tritium Pretreatment Off-Gas Streams

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, Barry B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jubin, Robert Thomas [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bruffey, Stephanie H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Strachan, Denis M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-07-01

    In the reprocessing of used nuclear fuel, radioactive elements are released into various plant off-gas streams. While much research and development has focused on the abatement of the volatile nuclides 3H, 14C, 85Kr, and 129I, the potential release of semivolatile isotopes that could also report to the off-gas streams in a reprocessing facility has been examined. Ruthenium (as 106Ru) has been identified as one of the semivolatile nuclides requiring the greatest degree of abatement prior to discharging the plant off-gas to the environment.

  6. Bifunctional amine-tethered ruthenium(II) arene complexes form monofunctional adducts on DNA

    Czech Academy of Sciences Publication Activity Database

    Melchart, M.; Habtemariam, A.; Nováková, Olga; Moggach, S.A.; Fabbiani, F.P.A.; Parsons, S.; Brabec, Viktor; Sadler, P.J.

    2007-01-01

    Roč. 46, č. 21 (2007), s. 8950-8962 ISSN 0020-1669 R&D Projects: GA ČR(CZ) GA305/05/2030; GA ČR(CZ) GA203/06/1239; GA AV ČR(CZ) 1QS500040581; GA AV ČR(CZ) KAN200200651 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : DNA * ruthenium * cancer Subject RIV: BO - Biophysics Impact factor: 4.123, year: 2007

  7. Ruthenium-catalyzed reactions--a treasure trove of atom-economic transformations.

    Science.gov (United States)

    Trost, Barry M; Frederiksen, Mathias U; Rudd, Michael T

    2005-10-21

    The demand for new chemicals spanning the fields of health care to materials science combined with the pressure to produce these substances in an environmentally benign fashion pose great challenges to the synthetic chemical community. The maximization of synthetic efficiency by the conversion of simple building blocks into complex targets remains a fundamental goal. In this context, ruthenium complexes catalyze a number of non-metathesis conversions and allow the rapid assembly of complex molecules with high selectivity and atom economy. These complexes often exhibit unusual reactivity. Careful consideration of the mechanistic underpinnings of the transformations can lead to the design of new reactions and the discovery of new reactivity.

  8. Glatiramer Acetate-associated Refractory Immune Thrombocytopenic Purpura

    Directory of Open Access Journals (Sweden)

    Iftach Sagy

    2016-04-01

    Full Text Available We present a case of glatiramer acetate-associated refractory immune thrombocytopenic purpura (ITP in a female patient with multiple sclerosis. A search of MEDLINE/PubMed did not find any connection between glatiramer acetate and thrombocytopenia, specifically ITP. The autoimmune reaction was resistant to conservative ITP treatment, and was eventually managed only by splenectomy. To the best of our knowledge, this is the first report of glatiramer acetate-associated ITP. Physicians should be aware of this condition, and consider performing routine blood counts at the beginning of glatiramer acetate treatment.

  9. Omics analysis of acetic acid tolerance in Saccharomyces cerevisiae.

    Science.gov (United States)

    Geng, Peng; Zhang, Liang; Shi, Gui Yang

    2017-05-01

    Acetic acid is an inhibitor in industrial processes such as wine making and bioethanol production from cellulosic hydrolysate. It causes energy depletion, inhibition of metabolic enzyme activity, growth arrest and ethanol productivity losses in Saccharomyces cerevisiae. Therefore, understanding the mechanisms of the yeast responses to acetic acid stress is essential for improving acetic acid tolerance and ethanol production. Although 329 genes associated with acetic acid tolerance have been identified in the Saccharomyces genome and included in the database ( http://www.yeastgenome.org/observable/resistance_to_acetic_acid/overview ), the cellular mechanistic responses to acetic acid remain unclear in this organism. Post-genomic approaches such as transcriptomics, proteomics, metabolomics and chemogenomics are being applied to yeast and are providing insight into the mechanisms and interactions of genes, proteins and other components that together determine complex quantitative phenotypic traits such as acetic acid tolerance. This review focuses on these omics approaches in the response to acetic acid in S. cerevisiae. Additionally, several novel strains with improved acetic acid tolerance have been engineered by modifying key genes, and the application of these strains and recently acquired knowledge to industrial processes is also discussed.

  10. The method of quantitative determination of iodine in acetic acid

    International Nuclear Information System (INIS)

    Sukhomlinov, A.B.; Kalinchenko, N.B.

    1988-01-01

    Method for separate determination of J 2 and J - concentrations in acetic acid is suggested. Iodine concentration in acetic acid is determined by measuring potential of iodine-selective electrode first in the initial solution of acetic acid, where molecular iodine dissociation equals 0.5, and then in acetic acid, with alkali (NaOH) addition up to pH > 3, where molecular iodine dissociation equals 1. Determination is conducted in 5x10 -7 -5x10 -6 mol/l concentration range with relative standard deviation not more than 0.1. 1 fig

  11. Recovery of acetic acid from waste streams by extractive distillation.

    Science.gov (United States)

    Demiral, H; Yildirim, M Ercengiz

    2003-01-01

    Wastes have been considered to be a serious worldwide environmental problem in recent years. Because of increasing pollution, these wastes should be treated. However, industrial wastes can contain a number of valuable organic components. Recovery of these components is important economically. Using conventional distillation techniques, the separation of acetic acid and water is both impractical and uneconomical, because it often requires large number of trays and a high reflux ratio. In practice special techniques are used depending on the concentration of acetic acid. Between 30 and 70% (w/w) acetic acid contents, extractive distillation was suggested. Extractive distillation is a multicomponent-rectification method similar in purpose to azeotropic distillation. In extractive distillation, to a binary mixture which is difficult or impossible to separate by ordinary means, a third component termed an entrainer is added which alters the relative volatility of the original constituents, thus permitting the separation. In our department acetic acid is used as a solvent during the obtaining of cobalt(III) acetate from cobalt(II) acetate by an electrochemical method. After the operation, the remaining waste contains acetic acid. In thiswork, acetic acid which has been found in this waste was recovered by extractive distillation. Adiponitrile and sulfolane were used as high boiling solvents and the effects of solvent feed rate/solution feed rate ratio and type were investigated. According to the experimental results, it was seem that the recovery of acetic acid from waste streams is possible by extractive distillation.

  12. Ulipristal acetate as an emergency contraceptive agent.

    Science.gov (United States)

    Martinez, Alan M; Thomas, Michael A

    2012-09-01

    Emergency contraceptive agents play a crucial role in preventing unplanned pregnancy. These agents and devices have been studied since the 1960s and have had varied results in terms of side effects and efficacy. A new oral tablet for emergency contraception (EC), ulipristal acetate (UPA) , is a selective progesterone receptor modulator and can be used up to 120 h following unprotected intercourse, without an increase in adverse effects or a decrease in efficacy. This article reviews studies that evaluate the pharmacodynamics, pharmacokinetics, clinical efficacy, and safety profile of UPA as an emergency contraceptive agent. UPA, a selective progesterone receptor modulator, is administered as a single 30 mg dose for EC. This agent provides a comparable, if not better, efficacy and side effect profile than seen with levonorgestrel or mifepristone. Because it has both agonistic and antagonistic effects on the progesterone receptor, ongoing clinical trials are documenting UPA's use for patients with endometriosis and as an extended use contraceptive.

  13. Ulipristal acetate: a new emergency contraceptive.

    Science.gov (United States)

    Sullivan, Jade L; Bulloch, Marilyn N

    2011-07-01

    Ulipristal acetate (UPA) is a newly developed emergency contraceptive currently available in the USA and Europe. It is approved as a 30 mg one-time dose taken within 120 h (5 days) of unprotected intercourse or failed contraception. This selective progesterone receptor modulator appears to be more effective than the levonorgestrel-containing emergency contraceptive, which must be taken within 72 h of unprotected intercourse. According to pharmacodynamic trials, UPA delays follicular maturation and ovulation. In addition, UPA may modulate the endometrium. Both Phase III clinical trials found that UPA does not lose efficacy within the 120-h dosing interval. Throughout all phases of clinical studies, UPA was shown to be well tolerated with only minimal adverse drug reactions, all of which are similar to competitor therapies.

  14. Acetic Acid Bacteria as Symbionts of Insects

    KAUST Repository

    Crotti, Elena; Chouaia, Bessem; Alma, Alberto; Favia, Guido; Bandi, Claudio; Bourtzis, Kostas; Daffonchio, Daniele

    2016-01-01

    Acetic acid bacteria (AAB) are being increasingly described as associating with different insect species that rely on sugar-based diets. AAB have been found in several insect orders, among them Diptera, Hemiptera, and Hymenoptera, including several vectors of plant, animal, and human diseases. AAB have been shown to associate with the epithelia of different organs of the host, they are able to move within the insect’s body and to be transmitted horizontally and vertically. Here, we review the ecology of AAB and examine their relationships with different insect models including mosquitoes, leafhoppers, and honey bees. We also discuss the potential use of AAB in symbiont-based control strategies, such as “Trojan-horse” agents, to block the transmission of vector-borne diseases.

  15. Acetic Acid Bacteria as Symbionts of Insects

    KAUST Repository

    Crotti, Elena

    2016-06-14

    Acetic acid bacteria (AAB) are being increasingly described as associating with different insect species that rely on sugar-based diets. AAB have been found in several insect orders, among them Diptera, Hemiptera, and Hymenoptera, including several vectors of plant, animal, and human diseases. AAB have been shown to associate with the epithelia of different organs of the host, they are able to move within the insect’s body and to be transmitted horizontally and vertically. Here, we review the ecology of AAB and examine their relationships with different insect models including mosquitoes, leafhoppers, and honey bees. We also discuss the potential use of AAB in symbiont-based control strategies, such as “Trojan-horse” agents, to block the transmission of vector-borne diseases.

  16. Emergency Contraception Options: Focus on Ulipristal Acetate

    Directory of Open Access Journals (Sweden)

    Sharon T. Cameron

    2012-01-01

    Full Text Available Ulipristal acetate (UPA is a progesterone receptor modulator that is available for emergency contraception (EC and can be taken up to 120 hours after unprotected intercourse. A meta-analysis of clinical trials comparing UPA with levonorgestrel (LNG for EC, demonstrated that UPA has higher efficacy than LNG. This higher efficacy is supported by biomedical studies that have demonstrated that UPA is a more potent inhibitor of ovulation, being able to delay ovulation in the immediate preovulatory period, when LNG is no longer effective. A recent study that explored risk factors for failure of EC, demonstrated that obese women were at increased risk of EC failure, with either UPA or LNG. However, failure was significantly less amongst women receiving UPA than those receiving LNG. There is growing evidence therefore, that UPA should be the preferred oral method of EC.

  17. Emergency contraception: potential role of ulipristal acetate

    Directory of Open Access Journals (Sweden)

    Kristina Gemzell-Danielsson

    2010-04-01

    Full Text Available Kristina Gemzell-Danielsson, Chun-Xia MengDepartment of Women’s and Children’s Health, Division of Obstetrics and Gynecology, Karolinska Institutet, Stockholm, SwedenAbstract: Unintended pregnancy is a global reproductive health problem. Emergency contraception (EC provides women with a safe means of preventing unwanted pregnancies after having unprotected intercourse. While 1.5 mg of levonorgestrel (LNG as a single dose or in 2 doses with 12 hours apart is the currently gold standard EC regimen, a single dose of 30 mg ulipristal acetate (UPA has recently been proposed for EC use up to 120 hours of unprotected intercourse with similar side effect profiles as LNG. The main mechanism of action of both LNG and UPA for EC is delaying or inhibiting ovulation. However, the ‘window of effect’ for LNG EC seems to be rather narrow, beginning after selection of the dominant follicular and ending when luteinizing hormone peak begins to rise, whereas UPA appears to have a direct inhibitory effect on follicular rupture which allows it to be also effective even when administered shortly before ovulation, a time period when use of LNG is no longer effective. These experimental findings are in line with results from a series of clinical trials conducted recently which demonstrate that UPA seems to have higher EC efficacy compared to LNG. This review summarizes some of the data available on UPA used after unprotected intercourse with the purpose to provide evidence that UPA, a new type of second-generation progesterone receptor modulator, represents a new evolutionary step in EC treatment.Keywords: emergency contraception, ulipristal acetate, levonorgestrel

  18. Spectral sensitization of SrTiO3 photoanodes with binuclear 1,10-phenanthroline bis(2,2'-bipyridine) complexes of ruthenium(II) and tris(2,2'-bipyridine) ruthenium(II)

    NARCIS (Netherlands)

    Tinnemans, A.H.A.; Mackor, A.

    1981-01-01

    A single crystal of strontium titanate, used as a photoanode for the photoelectrolysis of water, has been sensitized by mono‐ and binuclear ruthenium(II) complexes in acidic solution for visible light. The dependence of the photocurrent density on light intensity, dye concentration, wavelength and

  19. Oxidation of indole-3-acetic acid to oxindole-3-acetic acid by an enzyme preparation from Zea mays

    Science.gov (United States)

    Reinecke, D. M.; Bandurski, R. S.

    1988-01-01

    Indole-3-acetic acid is oxidized to oxindole-3-acetic acid by Zea mays tissue extracts. Shoot, root, and endosperm tissues have enzyme activities of 1 to 10 picomoles per hour per milligram protein. The enzyme is heat labile, is soluble, and requires oxygen for activity. Cofactors of mixed function oxygenase, peroxidase, and intermolecular dioxygenase are not stimulatory to enzymic activity. A heat-stable, detergent-extractable component from corn enhances enzyme activity 6- to 10-fold. This is the first demonstration of the in vitro enzymic oxidation of indole-3-acetic acid to oxindole-3-acetic acid in higher plants.

  20. The behaviour of tungsten electrodes in a mixture of acetic acid and acetic anhydride

    International Nuclear Information System (INIS)

    Pastor, T.J.; Vajgand, V.H.

    1976-01-01

    Tungsten electrodes have advantageously been used for potentiometric end-point detection in perchloric acid titration of bases in a mixture of acetic acid and acetic anhydride. They have also given good results in biamperometric detection of the equivalence point in continuous coulometric titration of small quantities of bases and acids in the same solvent. Tungsten electrodes in the presence of quinhydrone behave like platinum electrodes, but in biamperometric end-point determination in the absence of quinhydrone it is better to remove the oxide layer from their surface. Some other factors affecting their behaviour have also been studied. Errors in determination do not exceed +-2% even in titration of very small quantities of substances. (author)

  1. Kinetic Modelling and Experimental Study of Small Esters: Methyl Acetate and Ethyl Acetate

    KAUST Repository

    Ahmed, Ahfaz; Mehl, Marco; Lokachari, Nitin; Nilsson, Elna J.K.; Konnov, Alexander A.; Wagnon, Scott W.; Pitz, William J.; Curran, Henry J.; Roberts, William L.; Sarathy, Mani

    2017-01-01

    A detailed chemical kinetic mechanism comprising methyl acetate and ethyl acetate has been developed based on the previous work by Westbrook et al. [1]. The newly developed kinetic mechanism has been updated with new reaction rates from recent theoretical studies. To validate this model, shock tube experiments measuring ignition delay time have been conducted at 15 & 30 bar and equivalence ratio 0.5, 1.0 and 2.0. Another set of experiments measuring laminar burning velocity was also performed on a heat flux burner at atmospheric pressure over wide range of equivalence ratios [~0.7-1.4]. The new mechanism shows significant improvement in prediction of experimental data over earlier model across the range of experiments.

  2. Kinetic Modelling and Experimental Study of Small Esters: Methyl Acetate and Ethyl Acetate

    KAUST Repository

    Ahmed, Ahfaz

    2017-12-14

    A detailed chemical kinetic mechanism comprising methyl acetate and ethyl acetate has been developed based on the previous work by Westbrook et al. [1]. The newly developed kinetic mechanism has been updated with new reaction rates from recent theoretical studies. To validate this model, shock tube experiments measuring ignition delay time have been conducted at 15 & 30 bar and equivalence ratio 0.5, 1.0 and 2.0. Another set of experiments measuring laminar burning velocity was also performed on a heat flux burner at atmospheric pressure over wide range of equivalence ratios [~0.7-1.4]. The new mechanism shows significant improvement in prediction of experimental data over earlier model across the range of experiments.

  3. TBP 20% diluent/H N O3/H2 O liquid-liquid extraction system: equilibrium data normalization of nitric acid, ruthenium and zirconium

    International Nuclear Information System (INIS)

    Oliveira, C.A.L.G. de; Araujo, B.F. de.

    1991-11-01

    The extraction behavior of nitric acid, nitrosyl ruthenium nitrate and zirconium hydroxide nitrate in the system tri-n-butyl phosphate (TBP) 20% -diluent was studied. The main purpose was to obtain enough data to elaborate process flowsheets for the treatment of irradiated uranium fuels. During the runs, the equilibrium diagrams of nitric acid, ruthenium and zirconium were settled. From the achieved data, the influence of nitric acid, ruthenium, zirconium and nitrate ions concentration in the aqueous phase was checked. Furthermore, the density and the surface tension of the aqueous and organic phases were determined, gathering the interfacial tension after the contact between the phases. (author)

  4. Pretreatment with U(IV) solution for improving the decontamination of ruthenium

    International Nuclear Information System (INIS)

    Huang Haoxin; Qi Zhanshun; Zhu Guohui

    1993-01-01

    The ruthenium decontamination factor in Purex process falls quickly in successive TBP cycles. So, it is necessary to change the chemical states of RuNO complexes in order to improve DF Ru in the uranium purification cycle. Hydrazine nitrate is being used to transform RuNO complexes into in-extractable Ru(III)and Ru(IV). However, hydrazine nitrate may be inverted into hydrazoic acid which is dangerous and can bring an unstable factor. Pretreatment using U(IV) solution provides another method to improve the decontamination of ruthenium in Purex process. 0.02 mol/lU(IV) solution can transform RuNO complexes into inextricable species by heating in water bath. The D Ru can be decreased by a factor of 10-20. U(IV) pretreatment does not bring any harmful chemical in process. The acidity has a very large influence on the effect of pretreatment. The higher the acidity is, the worse the effect will be

  5. 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

  6. Electrophoretic deposition (EPD) of hydrous ruthenium oxides with PTFE and their supercapacitor performances

    International Nuclear Information System (INIS)

    Jang, Jong H.; Machida, Kenji; Kim, Yuri; Naoi, Katsuhiko

    2006-01-01

    The effect of PTFE addition was investigated for the electrophoretic deposition (EPD) of hydrous ruthenium oxide electrodes. Mechanical stability of electrode layers, together with deposition yield, was enhanced by using hydrous ruthenium oxide/PTFE dispersions. High supercapacitor performance was obtained for the electrodes prepared with 2% PTFE and 10% water. When PTFE content was higher, the rate capability became poor with low electronic conductivity; higher water content than 10% resulted in non-uniform depositions with poor cycleability and power capability. When electrodes were heat treated at 200 deg. C for 10 h, the specific energy was as high as 17.6 Wh/kg based on single electrode (at 200 W/kg); while utilizable energy was lower with heat treatment time of 1 and 50 h, due to the high resistance and gradual crystallization, respectively. With PTFE addition and heat treatment at 200 deg. C for 10 h, the specific capacitance was increased by 31% (460 → 599 F/g at ca. 0.6 mg/cm 2 ) at 10 mV/s, and the deposition weight was increased up to 1.7 mg/cm 2 with initial capacitance of 350 F/g

  7. Synthesis and electrochemistry of tri- and tetranuclear polypyridine derivations of ruthenium

    International Nuclear Information System (INIS)

    Francis, A.M.A.

    1990-01-01

    The synthesis of clusters of ruthenium is the focus of this work. The electrochemistry of metal cluster derivatives of ruthenium, iron and osmium are reviewed. The ability of these compounds to undergo more than one electron transfer reaction and to act as electron reservoirs is evident. The synthesis and characterisation of a range of polypyridine derivatives of [Ru 3 (CO) 12 ]; [Ru 3 (CO) 10 (napy)]; [Ru 3 (CO) 10 (bipy)]; [Ru 4 H 4 (CO) 12 ]; [Ru 4 H 4 (CO) 8 (bipy) 2 ] and [Ru 4 H 4 (CO) 10 (bipy)] were dealt with. The crystal structures of [Ru 3 (CO) 10 (napy)] and [Ru 4 H 4 (CO) 10 (bipy)] were also determined. The six compounds were fully investigated and a mechanism for their electrochemical reduction was postulated based on their observed experimental data, and that of the relevant compounds. The techniques used are also described and a brief introduction to the actual theory and practise of these techniques is discussed. 132 refs., 33 figs., 22 tabs

  8. Tunability of photoswitchable ruthenium sulfoxide compounds on the basis of ligand substitution

    Energy Technology Data Exchange (ETDEWEB)

    Eicke, Sebastian; Dieckmann, Volker; Springfeld, Kristin; Imlau, Mirco [Deparment of Physics, University of Osnabrueck (Germany)

    2010-07-01

    Photoswitchable ruthenium sulfoxide compounds provide a light-induced linkage isomerization in combination with pronounced changes in characteristic optical properties. As representative of the ruthenium sulfoxide group the molecular compound [Ru(bpy){sub 2}(R-OSO)]{sup +} (OSO: 2-methylsulfinylbenzoate) can be tuned in its optical properties by the substitution of the photoswitchable ligands (R=Bn, BnCl, BnMe). These modified sulfoxides were studied in respect to their photochromic properties and kinetics of the generation and relaxation of the light-induced isomers. The kinetics were determined by pump-probe technique and show in each case two reversible thermal decay processes following Arrhenius law. The two photo-excited states offer lifetimes in the magnitude of {tau}{sub 1}{approx}10{sup 3} s and {tau}{sub 2}{approx}10{sup 4} s at room temperature with activation energies about E{sub A,I}=0.72 eV to 0.92 eV and E{sub A,II}=0.8 eV to 1.00 eV. Another respresentative of the photoswitchable sulfoxides is the [Ru(bpy){sub 2}(pySO)]{sup 2+} compound. This molecule is the first sulfoxide which allows for reversible switching between the ground and metastable states by light exposure. With this compound the sulfoxides are highly qualified for optical data storage on a molecular scale.

  9. Synthesis, characterization and dielectric properties of polynorbornadiene–clay nanocomposites by ROMP using intercalated Ruthenium catalyst

    International Nuclear Information System (INIS)

    Yalçınkaya, Esra Evrim; Balcan, Mehmet; Güler, Çetin

    2013-01-01

    Polynorbornadiene clay nanocomposites were prepared for the first time by the ring opening metathesis polymerization (ROMP) using modified montmorillonite and polynorbornadiene the latter of which is used commonly in electric–electronic industry. The Na–MMT clay was modified by a quaternary ammonium salt containing Ruthenium complex as a suitable catalyst and intercalant as well. The norbornadiene monomers were polymerized within the modified montmorillonite layers by in-situ polymerization method in different clay loading degrees. Intercalation ability of the Ru catalyst and partially exfoliated nanocomposite structure were proved by powder X-ray Diffraction (XRD) Spectroscopy and Transmission Electron Microscopy (TEM) methods. The nanocomposite materials with high thermal degradation temperature and low dielectric constant compared to the pure polynorbornadiene were obtained. The dielectric constants decreased with the increase of the clay content. - Highlights: • Polynorbornadiene–clay nanocomposites were prepared for the first time. • Ruthenium complex was assigned as both suitable catalyst and intercalant. • The norbornadiene was polymerized by in-situ polymerization method. • Exfoliation/intercalation structures were found to be related with loading degree. • PNBD–MMT nanocomposites had a higher thermal degradation temperature and lower dielectric constant

  10. Ruthenium nanoparticles decorated curl-like porous carbons for high performance supercapacitors

    Science.gov (United States)

    Lou, Bih-Show; Veerakumar, Pitchaimani; Chen, Shen-Ming; Veeramani, Vediyappan; Madhu, Rajesh; Liu, Shang-Bin

    2016-01-01

    The synthesis of highly dispersed and stable ruthenium nanoparticles (RuNPs; ca. 2-3 nm) on porous activated carbons derived from Moringa Oleifera fruit shells (MOC) is reported and were exploited for supercapacitor applications. The Ru/MOC composites so fabricated using the biowaste carbon source and ruthenium acetylacetonate as the co-feeding metal precursors were activated at elevated temperatures (600-900 oC) in the presence of ZnCl2 as the pore generating and chemical activating agent. The as-prepared MOC carbonized at 900 oC was found to possess a high specific surface area (2522 m2 g-1) and co-existing micro- and mesoporosities. Upon incorporating RuNPs, the Ru/MOC nanocomposites loaded with modest amount of metallic Ru (1.0-1.5 wt%) exhibit remarkable electrochemical and capacitive properties, achiving a maximum capacitance of 291 F g-1 at a current density of 1 A g-1 in 1.0 M H2SO4 electrolyte. These highly stable and durable Ru/MOC electrodes, which can be facily fabricated by the eco-friendly and cost-effective route, should have great potentials for practical applications in energy storage, biosensing, and catalysis.

  11. The influence of a new fabrication procedure on the catalytic activity of ruthenium-selenium catalysts

    International Nuclear Information System (INIS)

    Cheng, H.; Yuan, W.; Scott, K.

    2006-01-01

    A new procedure has been introduced to enhance catalytic activity of ruthenium-selenium electro-catalysts for oxygen reduction, in which materials are treated under hydrogen atmosphere at elevated temperatures. The characterisation using scanning electron microscopy, energy dispersive spectroscopy or energy dispersive X-ray spectroscopy exhibited that the treatment at 400 deg. C made catalysts denser while their porous nature remained, led to a good degree of crystallinity and an optimum Se:Ru ratio. The half cell test confirms feasibility of the new procedure; the catalyst treated at 400 deg. C gave the highest reduction current (55.9 mA cm -2 at -0.4 V) and a low methanol oxidation effect coefficient (3.8%). The direct methanol fuel cell with the RuSe 400 deg. C cathode catalyst (2 mg RuSe cm -2 ) generated a power density of 33.8 mW cm -2 using 2 M methanol and 2 bar oxygen at 90 deg. C. The new procedure produced the catalysts with low decay rates. The best sample was compared to the Pt and to the reported ruthenium-selenium catalyst. Possible reasons for the observations are discussed

  12. The effect of NO2 on spectroscopic and structural properties of evaporated ruthenium phthalocyanine dimer

    International Nuclear Information System (INIS)

    Alagna, Lucilla; Capobianchi, Aldo; Paoletti, Anna Maria; Pennesi, Giovanna; Rossi, Gentilina; Casaletto, Maria Pia; Generosi, Amanda; Paci, Barbara; Albertini, Valerio Rossi

    2006-01-01

    The chemical interaction between NO 2 gas and dimeric ruthenium phthalocyanine (RuPc) 2 (Pc = phthalocyanine ligand) films has been investigated by different techniques: UV-Visible spectroscopy, X-ray Photoelectron Spectroscopy (XPS) and Extended X-ray Absorption Fine Structure (EXAFS). The optical spectra in the Q band region (700-500 nm) registered 'in situ' enabled to follow the evolution of the process in real time indicating that a two steps reaction, showing two clear isosbestic points, occurs. The first phase was essentially characterised by: (a) the rapid disappearance of the 608 and 420 nm shoulders; (b) the intensity decrease of the main absorption peak and (c) the appearance of a new adsorption band centred around 510 nm. In the second step the remarkable feature is a further lowering of the main peak with the simultaneous decrease of the new 510 nm absorption. These spectral changes suggested that a chemical reaction occurred between NO 2 and ruthenium phthalocyanine with the formation of a radical species due to the macrocycle oxidation. The kinetics indicates that the adsorption of gas by the evaporated (RuPc) 2 film is a complex process involving more than one independent mechanism. XPS and EXAFS spectra collected before and after gas exposure showed that the central metals (Ru) were also involved in the oxidation process. The reversibility of the process has been also tested by treating the films at different temperatures, the original optical spectrum being not completely recovered

  13. Synthesis and Catalytic Applications of Ruthenium(0) Nanoparticles in Click Chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Avvaru Praveen; Baek, Minwook; Sridhar, Chirumarry; Kumar, Begari Prem; Lee, Yongill [Changwon National Univ., Changwon (Korea, Republic of)

    2014-04-15

    Here we report a facile synthesis of ruthenium (Ru) Nanoparticles (NPs) by chemical co-precipitation method. The calcination of ruthenium hydroxide samples at 500 .deg. C under hydrogen atmosphere lead to the formation of Ru{sup 0} NPs. The size and aggregation of Ru NPs depends on the pH of the medium, and type of surfactant and its concentration. The X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope image (TEM) analyses of particles indicated the formation of Ru{sup 0} NPs, and have 10 to 20 nm sizes. As-synthesized Ru{sup 0} NPs are characterized and investigated their catalytic ability in click chemistry (azide-alkyne cycloaddition reactions), showing good results in terms of reactivity. Interestingly, small structural differences in triazines influence the catalytic activity of Ru{sup 0} nanocatalysts. Click chemistry has recently emerged to become one of the most powerful tools in drug discovery, chemical biology, proteomics, medical sciences and nanotechnology/nanomedicine. In addition, preliminary tests of recycling showed good results with neither loss of activity or significant precipitation.

  14. Behavior of ruthenium, cesium and antimony in high temperature processes for waste conditioning

    International Nuclear Information System (INIS)

    Klein, M.; Weyers, C.; Goossens, W.R.A.

    1985-01-01

    The fission products and the actinides of high level radioactive liquid wastes can be immobilized by incorporation into a glass matrix prior to disposal. The behaviour of so-called semi-volatile products during the vitrification process has been studied by the C.E.N./S.C.K. in Mol since 1979 in the framework of a contract with DWK of Germany in support to the HAW technological program PAMELA. The experiments were performed on laboratory and semi-pilot scale using simulated LEWC solutions tagged with radioisotopes of three suspected volatile fission products, namely ruthenium, cesium and antimony. The releases of these semi-volatile compounds to the off-gases have been investigated for a liquid fed melter as a function of the operational conditions. The study of a wet purification system, comprising in series of a dust scrubber, a condensor, an ejector venturi and an NOsub(x) column, has shown that cesium appears to be the reference isotope for the volatile elements released from the melter. Ruthenium seems not to be a problem from the point of view of gas purification although local radiation problems caused by deposits on metal surfaces cannot be excluded. (Auth.)

  15. Effect of Support in Heterogeneous Ruthenium Catalysts Used for the Selective Aerobic Oxidation of HMF in Water

    DEFF Research Database (Denmark)

    Gorbanev, Yury; Kegnæs, Søren; Riisager, Anders

    2011-01-01

    Heterogeneous ruthenium-based catalysts were applied in the selective, aerobic oxidation of 5-hydroxymethylfurfural, a versatile biomass-derived chemical, to form 2,5-furandicarboxylic acid. The oxidation reactions were performed in water with dioxygen as the oxidant at different pressures without...

  16. Selective Aerobic Oxidation of 5-Hydroxymethylfurfural in Water Over Solid Ruthenium Hydroxide Catalysts with Magnesium-Based Supports

    DEFF Research Database (Denmark)

    Gorbanev, Yury; Kegnæs, Søren; Riisager, Anders

    2011-01-01

    Solid catalyst systems comprised of ruthenium hydroxide supported on magnesium-based carrier materials (spinel, magnesium oxide and hydrotalcite) were investigated for the selective, aqueous aerobic oxidation of the biomass-derived chemical 5-hydroxymethylfurfural into 2,5-furandicarboxylic acid...

  17. Characterisation and application of new carboxylic acid-functionalised ruthenium complexes as dye-sensitisers for solar cells

    DEFF Research Database (Denmark)

    Duprez, Virginie; Biancardo, Matteo; Krebs, Frederik C

    2007-01-01

    A series of ruthenium complexes with and without TiO2, anchoring carboxylic acid groups have been synthesised and characterised using nuclear magnetic resonance (NMR), UV-vis and luminescence. These complexes were adsorbed on thin films of the wide band-gap semiconductor anatase and were tested a...

  18. Determination of ruthenium in photographic emulsions - Development and comparison of different sample treatments and mass spectrometric methods

    NARCIS (Netherlands)

    Krystek, Petra; Heumann, Klaus G.

    1999-01-01

    Different sample treatment procedures were combined with inductively coupled plasma mass spectrometry (ICP-MS) and negative thermal ionisation mass spectrometry (NTI-MS) for the determination of ruthenium traces in photographic emulsions. Dissolution of the samples in concentrated ammonia solution

  19. The thermodynamic effects of ligand structure on the molecular recognition of mononuclear ruthenium polypyridyl complexes with B-DNA

    Science.gov (United States)

    The ruthenium(II) polypyridyl complexes (RPCs), [(phen)2Ru(tatpp)]Cl2 (3Cl2) and [(phen)2Ru (tatpp)Ru(phen)2]Cl4 (4Cl4), containing the large planar and redox-active tetraazatetrapyrido- pentacene (tatpp) ligand, cleave DNA in the presence of reducing agents in cell-free assays and show significant...

  20. Electrodeposited nano-scale islands of ruthenium oxide as a bifunctional electrocatalyst for simultaneous catalytic oxidation of hydrazine and hydroxylamine

    Energy Technology Data Exchange (ETDEWEB)

    Zare, Hamid R., E-mail: hrzare@yazduni.ac.ir [Department of Chemistry, Yazd University, P.O. Box 89195-741, Yazd (Iran, Islamic Republic of); Nanotechnology Research Center, Yazd University, P.O. Box 89195-741, Yazd (Iran, Islamic Republic of); Hashemi, S. Hossein; Benvidi, Ali [Department of Chemistry, Yazd University, P.O. Box 89195-741, Yazd (Iran, Islamic Republic of)

    2010-06-04

    For the first time, an electrodeposited nano-scale islands of ruthenium oxide (ruthenium oxide nanoparticles), as an excellent bifunctional electrocatalyst, was successfully used for hydrazine and hydroxylamine electrocatalytic oxidation. The results show that, at the present bifunctional modified electrode, two different redox couples of ruthenium oxides serve as electrocatalysts for simultaneous electrocatalytic oxidation of hydrazine and hydroxylamine. At the modified electrode surface, the peaks of differential pulse voltammetry (DPV) for hydrazine and hydroxylamine oxidation were clearly separated from each other when they co-exited in solution. Thus, it was possible to simultaneously determine hydrazine and hydroxylamine in the samples at a ruthenium oxide nanoparticles modified glassy carbon electrode (RuON-GCE). Linear calibration curves were obtained for 2.0-268.3 {mu}M and 268.3-417.3 {mu}M of hydrazine and for 4.0-33.8 {mu}M and 33.8-78.3 {mu}M of hydroxylamine at the modified electrode surface using an amperometric method. The amperometric method also exhibited the detection limits of 0.15 {mu}M and 0.45 {mu}M for hydrazine and hydroxylamine respectively. RuON-GCE was satisfactorily used for determination of spiked hydrazine in two water samples. Moreover, the studied bifunctional modified electrode exhibited high sensitivity, good repeatability, wide linear range and long-term stability.

  1. Catalytic hydroprocessing of lignin β-O-4 ether bond model compound phenethyl phenyl ether over ruthenium catalysts

    NARCIS (Netherlands)

    Gomez-Monedero, B.; Faria, J.; Bimbela, F.; Ruiz, M.P.

    2017-01-01

    The catalytic hydroprocessing of phenethyl phenyl ether (PPE), a model compound of one of the most significant ether linkages within lignin structure, β-O-4, has been studied. Reactions were carried out using two ruthenium-based catalysts, supported on different materials: 3.8 wt.% Ru/C and 3.9 wt.%

  2. Reactivity studies of eta sup (6)-p-cymene ruthenium(II) carboxylato complexes towards azide some neutral ligands

    Digital Repository Service at National Institute of Oceanography (India)

    Singh, K.S.; Kollipara, M.R.

    sub (2)O sub (4)(7) or C sub (2)CH sub (2)O sub (4)(10)] have been prepared by the reaction of [(p-cymene)RuCl sub (2)]sub (2) with the corresponding sodium salts of the carboxylic acids. Treatment of (eta sup (6)-p-cymene) ruthenium(II) carboxylato...

  3. Ruthenium-modified MCM-41 mesoporous molecular sieve and Y zeolite catalysts for selective hydrogenation of cinnamaldehyde

    Czech Academy of Sciences Publication Activity Database

    Hájek, J.; Kumar, N.; Mäki-Arvela, P.; Salmi, T.; Murzin, D. Z.; Paseka, Ivo; Heikkilä, T.; Laine, E.; Laukkanen, P.; Väyrynen, J.

    2003-01-01

    Roč. 251, č. 2 (2003), s. 385-396 ISSN 0926-860X R&D Projects: GA ČR GA104/03/0409 Institutional research plan: CEZ:AV0Z4032918 Keywords : mesoporous molecular sieve * zeolites * ruthenium Subject RIV: CA - Inorganic Chemistry Impact factor: 2.825, year: 2003

  4. Ruthenium supported on magnetic nanoparticles: An efficient and recoverable catalyst for hydrogenation of alkynes and transfer hydrogenation of carbonyl compounds

    Science.gov (United States)

    Ruthenium supported on surface modified magnetic nanoparticles (NiFe2O4) has been successfully synthesized and applied for hydrogenation of alkynes at room temperature as well as transfer hydrogenation of a number of carbonyl compounds under microwave irradiation conditions. The ...

  5. New carboxy-functionalized terpyridines as precursors for zwitterionic ruthenium complexes for polymer-based solar cells

    DEFF Research Database (Denmark)

    Duprez, V.; Krebs, Frederik C

    2006-01-01

    New carboxy-terpyridines selectively functionalized at the 4-, 4'- and 4"-positions were prepared in a three-step procedure with good yields using, the Krohnke reaction followed by saponification. Their complexation with ruthenium led to symmetric and unsymmetric terpyridinyl zwitterionic complexes...

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

    International Nuclear Information System (INIS)

    Balcerzak, M.

    1985-01-01

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

  7. Synthesis, photo-, and electrochemistry of ruthenium bis(bipyridine) complexes comprising a N-heterocyclic carbene ligand.

    Science.gov (United States)

    Leigh, Vivienne; Ghattas, Wadih; Lalrempuia, Ralte; Müller-Bunz, Helge; Pryce, Mary T; Albrecht, Martin

    2013-05-06

    Analogues of [Ru(bpy)3](2+) were prepared in which one pyridine ligand site is substituted by a N-heterocyclic carbene (NHC) ligand, that is, either by an imidazolylidene with a variable wingtip group R (R = Me, 3a; R = Et, 3b; R = iPr, 3c), or by a benzimidazolylidene (Me wingtip group, 3d), or by a 1,2,3-triazolylidene (Me wingtip group, 3e). All complexes were characterized spectroscopically, photophysically, and electrochemically. An increase of the size of the wingtip groups from Me to Et or iPr groups distorts the octahedral geometry (NMR spectroscopy) and curtails the reversibility of the ruthenium oxidation. NHC ligands with methyl wingtip groups display reversible ruthenium oxidation at a potential that reflects the donor properties of the NHC ligand (triazolylidene > imidazolylidene > benzimidazolylidene). The most attractive properties were measured for the triazolylidene ruthenium complex 3e, featuring the smallest gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) in the series (2.41 eV), a slightly red-shifted absorption profile, and reasonable excited-state lifetime (188 ns) when compared to [Ru(bpy)3](2+). These features demonstrate the potential utility of triazolylidene ruthenium complexes as photosensitizers for solar energy conversion.

  8. Plasma-assisted synthesis of monodispersed and robust Ruthenium ultrafine nanocatalysts for organosilane oxidation and oxygen evolution reactions

    NARCIS (Netherlands)

    Gnanakumar, E.S.; Ng, W.; Filiz, B.C.; Rothenberg, G.; Wang, S.; Xu, H.; Pastor-Pérez, L.; Pastor-Blas, M.M.; Sepúlveda-Escribano, A.; Yan, N.; Shiju, N.R.

    2017-01-01

    We report a facile and general approach for preparing ultrafine ruthenium nanocatalysts by using a plasma-assisted synthesis at <100 °C. The resulting Ru nanoparticles are monodispersed (typical size 2 nm) and remain that way upon loading onto carbon and TiO2 supports. This gives robust catalysts

  9. Mono and dinuclear iridium, rhodium and ruthenium complexes containing chelating carboxylato pyrazine ligands: Synthesis, molecular structure and electrochemistry

    Czech Academy of Sciences Publication Activity Database

    Govindaswamy, P.; Therrien, B.; Süss-Fink, G.; Štěpnička, P.; Ludvík, Jiří

    2007-01-01

    Roč. 692, č. 8 (2007), s. 1661-1671 ISSN 0022-328X R&D Projects: GA MŠk LC510; GA MŠk(CZ) LC06070 Institutional research plan: CEZ:AV0Z40400503 Keywords : dinuclear complexes * iridium * rhodium * ruthenium * electrochemistry Subject RIV: CG - Electrochemistry Impact factor: 2.168, year: 2007

  10. Caprolactone-based bipyridine macroligands for novel ruthenium polypyridyl complexes for applications in dye-sensitized solar cells

    NARCIS (Netherlands)

    Marin, V.N.; Holder, E.; Hoogenboom, R.; Schubert, U.S.

    2004-01-01

    In an attempt to reduce electrolyte loss in solar cells, the use of sold or quasi-solid state electrolytes is advantageous. The authors synthesized a metal contg. polymer via two synthetic pathways. In the first, a bipyridine-bisphenanthroline ruthenium metal complex with a hydroxy functionality was

  11. A nanogravimmetric investigation of the charging processes on ruthenium oxide thin films and their effect on methanol oxidation

    International Nuclear Information System (INIS)

    Santos, M.C.; Cogo, L.; Tanimoto, S.T.; Calegaro, M.L.; Bulhoes, L.O.S

    2006-01-01

    The charging processes and methanol oxidation that occur during the oxidation-reduction cycles in a ruthenium oxide thin film electrode (deposited by the sol-gel method on Pt covered quartz crystals) were investigated by using cyclic voltammetry, chronoamperometry and electrochemical quartz crystal nanobalance techniques. The ruthenium oxide rutile phase structure was determined by X-ray diffraction analysis. The results obtained during the charging of rutile ruthenium oxide films indicate that in the anodic sweep the transition from Ru(II) to Ru(VI) occurs followed by proton de-intercalation. In the cathodic sweep, electron injection occurs followed by proton intercalation, leading to Ru(II). The proton intercalation/de-intercalation processes can be inferred from the mass/charge relationship which gives a slope close to 1 g mol -1 (multiplied by the Faraday constant) corresponding to the molar mass of hydrogen. From the chronoamperometric measurements, charge and mass saturation of the RuO 2 thin films was observed (440 ng cm -2 ) during the charging processes, which is related to the total number of active sites in these films. Using the electrochemical quartz crystal nanobalance technique to study the methanol oxidation reaction at these films was possible to demonstrate that bulk oxidation occurs without the formation of strongly adsorbed intermediates such as CO ads , demonstrating that Pt electrodes modified by ruthenium oxide particles can be promising catalysts for the methanol oxidation as already shown in the literature

  12. Determination of gold osmium and ruthenium through iodine-azide reaction in presence of 2- or 6- mercaptopurine

    International Nuclear Information System (INIS)

    Matusiewicz, H.; Kurzawa, Z.

    1978-01-01

    The composition of osmium and ruthenium complexes with 6-mercaptopurine has been determined. The sensitivity of the method was enhanced due to a proper choice of the optimal time of the formation of these complexes and the time of equilibrium attainment in the presence of excess of azide. Also the gold complex with 2-mercaptopurine was investigated. (author)

  13. Study of the ruthenium fission-product behavior in the containment, in the case of a nuclear reactor severe accident

    International Nuclear Information System (INIS)

    Mun, Ch.

    2007-03-01

    Ruthenium tetroxide is an extremely volatile and highly radio-toxic species. During a severe accident with air ingress in the reactor vessel, ruthenium oxides may reach the reactor containment building in significant quantities. Therefore, a better understanding of the RuO 4 (g) behaviour in the containment atmosphere is of primary importance for the assessment of radiological consequences, in the case of potential releases of this species into the environment. A RuO 4 (g) decomposition kinetic law was determined. Steam seems to play a catalytic role, as well as the presence of ruthenium dioxide deposits. The temperature is also a key parameter. The nature of the substrate, stainless steel or paint, did not exhibit any chemical affinities with RuO 4 (g). This absence of reactivity was confirmed by XPS analyses, which indicate the presence of the same species in the Ru deposits surface layer whatever the substrates considered. It has been concluded that RuO 4 (g) decomposition corresponds to a bulk gas phase decomposition. The ruthenium re-volatilization phenomenon under irradiation from Ru deposits was also highlighted. An oxidation kinetic law was determined. The increase of the temperature and the steam concentration promote significantly the oxidation reaction. The establishment of Ru behavioural laws allowed making a modelling of the Ru source term. The results of the reactor calculations indicate that the values obtained for 106 Ru source term are closed to the reference value considered currently by the IRSN, for 900 MWe PWR safety analysis. (author)

  14. Hydrogenation of fast pyrolyis oil and model compounds in a two-phase aqueous organic system using homogeneous ruthenium catalysts

    NARCIS (Netherlands)

    Mahfud, F. H.; Ghijsen, F.; Heeres, H. J.

    2007-01-01

    The use of homogeneous ruthenium catalysts to hydrogenate the water-soluble fraction of pyrolysis oil is reported. Pyrolysis oil, which is obtained by fast pyrolysis of lignocellulosic biomass at 450-600 degrees C, contains significant amounts of aldehydes and ketones (e.g. 1-hydroxy-2-propanone (1)

  15. Through-Space Paramagnetic NMR Effects in Host-Guest Complexes: Potential Ruthenium(III) Metallodrugs with Macrocyclic Carriers.

    Science.gov (United States)

    Chyba, Jan; Novák, Martin; Munzarová, Petra; Novotný, Jan; Marek, Radek

    2018-04-05

    The potential of paramagnetic ruthenium(III) compounds for use as anticancer metallodrugs has been investigated extensively during the past several decades. However, the means by which these ruthenium compounds are transported and distributed in living bodies remain relatively unexplored. In this work, we prepared several novel ruthenium(III) compounds with the general structure Na + [ trans-Ru III Cl 4 (DMSO)(L)] - (DMSO = dimethyl sulfoxide), where L stands for pyridine or imidazole linked with adamantane, a hydrophobic chemophore. The supramolecular interactions of these compounds with macrocyclic carriers of the cyclodextrin (CD) and cucurbit[ n]uril (CB) families were investigated by NMR spectroscopy, X-ray diffraction analysis, isothermal titration calorimetry, and relativistic DFT methods. The long-range hyperfine NMR effects of the paramagnetic guest on the host macrocycle are related to the distance between them and their relative orientation in the host-guest complex. The CD and CB macrocyclic carriers being studied in this account can be attached to a vector that attracts the drug-carrier system to a specific biological target and our investigation thus introduces a new possibility in the field of targeted delivery of anticancer metallodrugs based on ruthenium(III) compounds.

  16. Application of the ruthenium and technetium thermodynamic data bases used in the EQ3/6 geochemical codes

    Energy Technology Data Exchange (ETDEWEB)

    Isherwood, D.

    1985-04-01

    Based on a critical review of the available thermodynamic data, computerized data bases for technetium and ruthenium were created for use with the EQ3/6 geochemical computer codes. The technetium data base contains thermodynamic data for 8 aqueous species and 15 solids; 26 aqueous species and 9 solids were included in the ruthenium data base. The EQ3NR code was used to calculate solubility limits for ruthenium (8 x 10{sup -16} M) in ground water from Yucca Mountain, a potential nuclear waste repository site near the Nevada Test Site (NTS). The code confirmed the essentially unlimited solubility of technetium in oxidizing conditions, such as those that are believed to exist in the unsaturated zone at Yucca Mountain and the Cambric Nuclear event site at the NTS. Ruthenium migration observed from the Cambric site was evaluated. The solubility limit for ruthenium (as the aqueous species RuO{sub 4}{sup -}) when constrained by RuO{sub 2} is approximately equal to the concentration of ruthenium found in the cavity ground water (i.e., 2.1 x 10{sup -11} vs 4.5 x 10{sup -11} M). Differences in ruthenium solubility limits between Yucca Mountain and Cambric are primarily due to differences in ground-water pH. Technetium solubility (3 x 10{sup -8} M) for moderately reducing conditions (Eh = -0.1 V) using the metastable oxide, TcO{sub 2}.2H{sub 2}O, as the solubility constraint is within the range of experimental values recently published in a study of technetium sorption on basalt. Previously published technetium solubilities of 10{sup -12} to 10{sup -16} M were apparently based on a technetium data base that did not include aqueous species other than TcO{sub 4}{sup -}. When TcO(OH){sub 2}{sup 0} is included in the data base, the calculated values are much closer to the experimental results. Eh-pH diagrams were also generated for a variety of conditions using the SOLUPLOT code.

  17. Modelling and Simulation of the Batch Hydrolysis of Acetic ...

    African Journals Online (AJOL)

    The kinetic modelling of the batch synthesis of acetic acid from acetic anhydride was investigated. The kinetic data of the reaction was obtained by conducting the hydrolysis reaction in a batch reactor. A dynamic model was formulated for this process and simulation was carried out using gPROMS® an advanced process ...

  18. Effect of antimicrobial agents on cellulose acetate nano composites properties

    International Nuclear Information System (INIS)

    Rodriguez, Francisco J.; Bruna, Julio E.; Galotto, Maria J.; Guarda, Abel; Sepulveda, Hugo

    2011-01-01

    Nano composites based on cellulose acetate, Cloisite 30B, triethyl citrate and thymol or cinnamaldehyde were prepared using a dissolution casting technique. The effect of thymol and cinnamaldehyde on the cellulose acetate nano composite properties was evaluated by XRD and DSC. Important changes on the thermal properties and morphological structure were observed according to thymol and cinnamaldehyde content. (author)

  19. Depot Medroxyprogesterone Acetate (Depo-Provlera) as a Contrac ...

    African Journals Online (AJOL)

    Depot Medroxyprogesterone Acetate (Depo-Provlera) as a Contrac·eptive Preparation. Basil Bloch. Abstract. Experience with depot medroxyprogesterone acetate as a contraceptive preparation in 7 335 patients for a total of 38 714 months over a 3-year period is described. The discontinuation rate was 18.3% and the ...

  20. Effect of antimicrobial agents on cellulose acetate nano composites properties

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, Francisco J.; Bruna, Julio E.; Galotto, Maria J.; Guarda, Abel; Sepulveda, Hugo, E-mail: francisco.rodriguez.m@usach.cl [Center for the Development of Nanoscience and Nanotechnology (CEDENNA). Universidad de Santiago de Chile. Faculty of Technology. Department of Food Science and Technology. Food Packaging Laboratory. Santiago (Chile)

    2011-07-01

    Nano composites based on cellulose acetate, Cloisite 30B, triethyl citrate and thymol or cinnamaldehyde were prepared using a dissolution casting technique. The effect of thymol and cinnamaldehyde on the cellulose acetate nano composite properties was evaluated by XRD and DSC. Important changes on the thermal properties and morphological structure were observed according to thymol and cinnamaldehyde content. (author)

  1. Development of Chitosan Acetate Films for Transdermal Delivery of ...

    African Journals Online (AJOL)

    Methods: Chitosan acetate was chemically modified with acetaldehyde and the solution was prepared with 1 % acetic acid, in which was dissolved propranolol hydrochloride, was cast as films in Petri dish and characterised by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and ...

  2. Acetalization of furfural with zeolites under benign reaction conditions

    DEFF Research Database (Denmark)

    Rubio-Caballeroa, Juan Miguel; Shunmugavel, Saravanamurugan; Maireles-Torres, Pedro

    2014-01-01

    Acetalization is a viable method to protect carbonyl functionalities in organic compounds and offers apotential synthetic strategy for synthesizing derived chemicals. In this work, several families of commer-cial zeolites have been employed as solid acid catalysts in the acetalization of furfural...

  3. modelling and simulation of the batch hydrolysis of acetic ing

    African Journals Online (AJOL)

    eobe

    The kinetic modelling of the batch synthesis of acetic acid from acetic. The kinetic modelling of ... integral method of analysis to determine the kinetic parameters .... Equation (5) is applied to all the components ... In common chemical engineering terminology, the degree of ..... of Physical Organic Chemistry, Vol. 25, Number ...

  4. Bioelectrochemical Ethanol Production through Mediated Acetate Reduction by Mixed Cultures

    NARCIS (Netherlands)

    Steinbusch, K.J.J.; Hamelers, H.V.M.; Schaap, J.D.; Kampman, C.; Buisman, C.J.N.

    2010-01-01

    Biological acetate reduction with hydrogen is a potential method to convert wet biomass waste into ethanol. Since the ethanol concentration and reaction rates are low, this research studies the feasibility of using an electrode, in stead of hydrogen, as an electron donor for biological acetate

  5. Ruthenium release modelling in air and steam atmospheres under severe accident conditions using the MAAP4 code

    International Nuclear Information System (INIS)

    Beuzet, Emilie; Lamy, Jean-Sylvestre; Perron, Hadrien; Simoni, Eric; Ducros, Gérard

    2012-01-01

    Highlights: ► We developed a new modelling of fuel oxidation and ruthenium release in the EDF version of the MAAP4 code. ► We validated this model against some VERCORS experiments. ► Ruthenium release prediction quantitatively and qualitatively well reproduced under air and steam atmospheres. - Abstract: In a nuclear power plant (NPP), a severe accident is a low probability sequence that can lead to core fusion and fission product (FP) release to the environment (source term). For instance during a loss-of-coolant accident, water vaporization and core uncovery can occur due to decay heat. These phenomena enhance core degradation and, subsequently, molten materials can relocate to the lower head of the vessel. Heat exchange between the debris and the vessel may cause its rupture and air ingress. After lower head failure, steam and air entering in the vessel can lead to degradation and oxidation of materials that are still intact in the core. Indeed, Zircaloy-4 cladding oxidation is very exothermic and fuel interaction with the cladding material can decrease its melting temperature by several hundred of Kelvin. FP release can thus be increased, noticeably that of ruthenium under oxidizing conditions. Ruthenium is of particular interest because of its high radio-toxicity due to 103 Ru and 106 Ru isotopes and its ability to form highly volatile compounds, even at room temperature, such as gaseous ruthenium tetra-oxide (RuO 4 ). It is consequently of great need to understand phenomena governing steam and air oxidation of the fuel and ruthenium release as prerequisites for the source term issues. A review of existing data on these phenomena shows relatively good understanding. In terms of oxygen affinity, the fuel is oxidized before ruthenium, from UO 2 to UO 2+x . Its oxidation is a rate-controlling surface exchange reaction with the atmosphere, so that the stoichiometric deviation and oxygen partial pressure increase. High temperatures combined with the presence

  6. Disorder effects in Mn(12)-acetate at 83 K.

    Science.gov (United States)

    Cornia, Andrea; Fabretti, Antonio Costantino; Sessoli, Roberta; Sorace, Lorenzo; Gatteschi, Dante; Barra, Anne-Laure; Daiguebonne, Carole; Roisnel, Thierry

    2002-07-01

    The structure of hexadeca-mu-acetato-tetraaquadodeca-mu(3)-oxo-dodecamanganese bis(acetic acid) tetrahydrate, [Mn(12)O(12)(CH(3)COO)(16)(H(2)O)(4)] x 2CH(3)COOH x 4H(2)O, known as Mn(12)-acetate, has been determined at 83 (2) K by X-ray diffraction methods. The fourfold (S(4)) molecular symmetry is disrupted by a strong hydrogen-bonding interaction with the disordered acetic acid molecule of solvation, which displaces one of the acetate ligands in the cluster. Up to six Mn(12) isomers are potentially present in the crystal lattice, which differ in the number and arrangement of hydrogen-bonded acetic acid molecules. These results considerably improve the structural information available on this molecular nanomagnet, which was first synthesized and characterized by Lis [Acta Cryst. (1980), B36, 2042-2046].

  7. Aerobic oxidation of aqueous ethanol using heterogeneous gold catalysts: Efficient routes to acetic acid and ethyl acetate

    DEFF Research Database (Denmark)

    Jørgensen, Betina; Christiansen, Sofie Egholm; Thomsen, M.L.D.

    2007-01-01

    The aerobic oxidation of aqueous ethanol to produce acetic acid and ethyl acetate was studied using heterogeneous gold catalysts. Comparing the performance of Au/MgAl2O4 and Au/TiO2 showed that these two catalysts exhibited similar performance in the reaction. By proper selection of the reaction...

  8. Measurement of the rates of oxindole-3-acetic acid turnover, and indole-3-acetic acid oxidation in Zea mays seedlings

    Science.gov (United States)

    Nonhebel, H. M.; Bandurski, R. S. (Principal Investigator)

    1986-01-01

    Oxindole-3-acetic acid is the principal catabolite of indole-3-acetic acid in Zea mays seedlings. In this paper measurements of the turnover of oxindole-3-acetic acid are presented and used to calculate the rate of indole-3-acetic acid oxidation. [3H]Oxindole-3-acetic acid was applied to the endosperm of Zea mays seedlings and allowed to equilibrate for 24 h before the start of the experiment. The subsequent decrease in its specific activity was used to calculate the turnover rate. The average half-life of oxindole-3-acetic acid in the shoots was found to be 30 h while that in the kernels had an average half-life of 35h. Using previously published values of the pool sizes of oxindole-3-acetic acid in shoots and kernels from seedlings of the same age and variety, and grown under the same conditions, the rate of indole-3-acetic acid oxidation was calculated to be 1.1 pmol plant-1 h-1 in the shoots and 7.1 pmol plant-1 h-1 in the kernels.

  9. Hydrolyses of alpha-naphthyl acetate, beta-naphthyl acetate, and acetyl-DL-phenylalanine beta-naphthyl ester

    DEFF Research Database (Denmark)

    Kirkeby, S; Moe, D

    1983-01-01

    Using simultaneous coupling azo dye techniques kidney enzymes active against alpha-naphthyl acetate, beta-naphthyl acetate, and acetyl-DL-phenylalanine beta-naphthyl ester are characterized. The enzymes show identical distribution in the section. The banding patterns in zymograms are the same after...

  10. Ruthenium(II)-tris-bipyridine and titaniumdioxide - photocatalysts for solar induced water remediation; Ruthenium(II)-tris-bipyridin und Titandioxid - Photokatalysatoren zum solarinduzierten Abbau von Schadstoffen

    Energy Technology Data Exchange (ETDEWEB)

    Bossmann, S [Lehrstuhl fuer Umweltmesstechnik, Engler-Bunte-Inst., Karlsruhe Univ. (Germany)

    1997-01-01

    The photophysical and photochemical properties of photocatalysts capable of working under solar-light-irradiation are of great interest. An especially promising application is the development of low-cost `Advanced Oxidation Procedures` (AOP). The aim of this endeavor is the detoxification of hazardous chemicals in wastewaters, which cannot be treated by conventional techniques. The mineralization of the most (highly) toxic chemicals to CO{sub 2}, H{sub 2}O and simple inorganic compounds is favored by thermodynamics, however various difficulties such as kinetic barriers and hindered diffusion exist in systems for heterogeneous photocatalysis. In that respect, Ruthenium(II)-tris-bipyridine ([Ru(bpy){sub 3}]{sup 2+}) and TiO{sub 2} - codoped photocatalysts offer several advantages. The photoreactive centers consist of supramolecular units of [Ru(bpy){sub 3}]{sup 2+} and TiO{sub 2} - nanocrystals. Pollutants, such as our model compound 2,4-Dimethylaniline, diffuse through the framework of zeolite Y and undergo oxidative degradation at the reactive centers of the photocatalysts in the presence of H{sub 2}O{sub 2}. Under the aspect of application, the size of the zeolite Y-particles (diameter: 1x10{sup -6} m in average) permits their easy handling in filtration and recyling operations. (orig.) [Deutsch] Die photophysikalischen und -chemischen Eigenschaften von Katalysatoren, die das Licht der Sonne als kostenguenstige Energiequelle ausnutzen, treten immer staerker in den Vordergrund des Interesses. Dies gilt vor allem fuer ihren Einsatz in `Advanced Oxidation Technologies` (AOT`s) zur Entgiftung toxischer Substanzen im Abwasser. Die Mineralisation der meisten (hoch)giftigen Chemikalien zu CO{sub 2}, H{sub 2}O und einfachen anorganischen Verbindungen ist zwar thermodynamisch beguenstigt, es treten jedoch sowohl kinetische Hemmschwellen als auch Diffusionshindernisse in der heterogenen Photokatalyse auf. Ruthenium(II)-tris-bipyridin ([Ru(bpy){sub 3}]{sup 2+}) und TiO{sub 2

  11. Microsomal metabolism of trenbolone acetate metabolites ...

    Science.gov (United States)

    Trenbolone acetate (TBA) is a synthetic growth promoter widely used in animal agriculture, and its metabolites are suspected endocrine disrupting compounds in agriculturally impacted receiving waters. However, beyond the three widely recognized TBA metabolites (17-trenbolone, 17-trenbolone and trendione), little is known about other metabolites formed in vivo and subsequently discharged into the environment, with some evidence suggesting these unknown metabolites comprise a majority of the TBA mass dosed to the animal. Here, we explored the metabolism of the three known TBA metabolites using rat liver microsome studies. All TBA metabolites are transformed into a complex mixture of monohydroxylated products. Based on product characterization, the majority are more polar than the parent metabolites but maintain their characteristic trienone backbone. A minor degree of interconversion between known metabolites was also observed, as were higher order hydroxylated products with a greater extent of reaction. Notably, the distribution and yield of products were generally comparable across a series of variably induced rat liver microsomes, as well as during additional studies with human and bovine liver microsomes. Bioassays conducted with mixtures of these transformation products suggest that androgen receptor (AR) binding activity is diminished as a result of the microsomal treatment, suggesting that the transformation products are generally less potent than

  12. Simultaneous production of acetic and gluconic acids by a thermotolerant Acetobacter strain during acetous fermentation in a bioreactor.

    Science.gov (United States)

    Mounir, Majid; Shafiei, Rasoul; Zarmehrkhorshid, Raziyeh; Hamouda, Allal; Ismaili Alaoui, Mustapha; Thonart, Philippe

    2016-02-01

    The activity of bacterial strains significantly influences the quality and the taste of vinegar. Previous studies of acetic acid bacteria have primarily focused on the ability of bacterial strains to produce high amounts of acetic acid. However, few studies have examined the production of gluconic acid during acetous fermentation at high temperatures. The production of vinegar at high temperatures by two strains of acetic acid bacteria isolated from apple and cactus fruits, namely AF01 and CV01, respectively, was evaluated in this study. The simultaneous production of gluconic and acetic acids was also examined in this study. Biochemical and molecular identification based on a 16s rDNA sequence analysis confirmed that these strains can be classified as Acetobacter pasteurianus. To assess the ability of the isolated strains to grow and produce acetic acid and gluconic acid at high temperatures, a semi-continuous fermentation was performed in a 20-L bioreactor. The two strains abundantly grew at a high temperature (41°C). At the end of the fermentation, the AF01 and CV01 strains yielded acetic acid concentrations of 7.64% (w/v) and 10.08% (w/v), respectively. Interestingly, CV01 was able to simultaneously produce acetic and gluconic acids during acetic fermentation, whereas AF01 mainly produced acetic acid. In addition, CV01 was less sensitive to ethanol depletion during semi-continuous fermentation. Finally, the enzymatic study showed that the two strains exhibited high ADH and ALDH enzyme activity at 38°C compared with the mesophilic reference strain LMG 1632, which was significantly susceptible to thermal inactivation. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  13. Vapour pressures and vapour-liquid equilibria of propyl acetate and isobutyl acetate with ethanol or 2-propanol at 0.15 MPa. Binary systems

    Directory of Open Access Journals (Sweden)

    Susial Pedro

    2012-01-01

    Full Text Available Vapour pressures of propyl acetate, isobutyl acetate and 2-propanol from 0.004 to 1.6 MPa absolute pressure and VLE data for the binary systems propyl acetate+ethanol, propyl acetate+2-propanol, isobutyl acetate+ethanol and isobutyl acetate+2-propanol at 0.15 MPa have been determined. The experimental VLE data were verified with the test of van Ness and the Fredenslund criterion. The propyl acetate+ethanol or +2-propanol binary systems have an azeotropic point at 0.15 MPa. The different versions of the UNIFAC and ASOG group contribution models were applied.

  14. Studying the effect of Ruthenium on High Temperature Mechanical Properties of Nickel Based Superalloys and Determining the Universal Behavior of Ruthenium at Atomic Scale with respect to alloying elements, Stress and Temperature

    Directory of Open Access Journals (Sweden)

    Sriswaroop Dasari

    2016-10-01

    Full Text Available Any property of a material is a function of its microstructure and microstructure is a function of material composition. So, to maximize the desired properties of a material, one has to understand the evolution of microstructure which in turn is nothing but the reflection of the role of alloying elements. Research has not been done to understand the universal behavior of a certain base/alloying element. Let’s take the example of Cl- ion in HCl, we all know that in general, chloride ion can only be replaced by Fluoride or oxygen ion and that no other ion can replace it. But when you consider a metal like Ni, Co, Cr, Fe etc. there is no establishment that it behaves only in a certain way. Though I concord to the fact that discovery of universal behavior of Ni is lot complex than chloride ion, I think that future research should be focused in this direction also. Superalloys are the candidate materials required to improve thermal efficiency of a gas turbine by allowing higher turbine inlet gas temperatures. Gas turbines are the heart of local power systems, next generation jet engines and high performance space rockets. Recent research in superalloys showed that addition of some alloying elements in minor quantities can result in drastic change in properties. Such an alloying element is Ruthenium (Ru. Addition of Ruthenium to superalloys has shown improvement in mechanical properties by an order of magnitude. However reasons for such improvement are not known yet. Hence, there is a need to identify its role and discover the universal behavior of ruthenium to utilize it efficiently. In this proposal, we study materials with different compositions that are derived based on one ruthenium containing superalloy, and different thermomechanical history. Based on the evolution of microstructures and results of mechanical testing, we plan to determine the exact role of Ruthenium and prediction of its behavior with respect to other elements in the material

  15. Biosynthetic origin of acetic acid using SNIF-NMR

    International Nuclear Information System (INIS)

    Boffo, Elisangela Fabiana; Ferreira, Antonio Gilberto

    2006-01-01

    The main purpose of this work is to describe the use of the technique Site-Specific Natural Isotopic Fractionation of hydrogen (SNIF-NMR), using 2 H and 1 H NMR spectroscopy, to investigate the biosynthetic origin of acetic acid in commercial samples of Brazilian vinegar. This method is based on the deuterium to hydrogen ratio at a specific position (methyl group) of acetic acid obtained by fermentation, through different biosynthetic mechanisms, which result in different isotopic ratios. We measured the isotopic ratio of vinegars obtained through C 3 , C 4 , and CAM biosynthetic mechanisms, blends of C 3 and C 4 (agrins) and synthetic acetic acid. (author)

  16. Ulipristal acetate versus placebo for fibroid treatment before surgery.

    Science.gov (United States)

    Donnez, Jacques; Tatarchuk, Tetyana F; Bouchard, Philippe; Puscasiu, Lucian; Zakharenko, Nataliya F; Ivanova, Tatiana; Ugocsai, Gyula; Mara, Michal; Jilla, Manju P; Bestel, Elke; Terrill, Paul; Osterloh, Ian; Loumaye, Ernest

    2012-02-02

    The efficacy and safety of oral ulipristal acetate for the treatment of symptomatic uterine fibroids before surgery are uncertain. We randomly assigned women with symptomatic fibroids, excessive uterine bleeding (a score of >100 on the pictorial blood-loss assessment chart [PBAC, an objective assessment of blood loss, in which monthly scores range from 0 to >500, with higher numbers indicating more bleeding]) and anemia (hemoglobin level of ≤10.2 g per deciliter) to receive treatment for up to 13 weeks with oral ulipristal acetate at a dose of 5 mg per day (96 women) or 10 mg per day (98 women) or to receive placebo (48 women). All patients received iron supplementation. The coprimary efficacy end points were control of uterine bleeding (PBAC score of <75) and reduction of fibroid volume at week 13, after which patients could undergo surgery. At 13 weeks, uterine bleeding was controlled in 91% of the women receiving 5 mg of ulipristal acetate, 92% of those receiving 10 mg of ulipristal acetate, and 19% of those receiving placebo (P<0.001 for the comparison of each dose of ulipristal acetate with placebo). The rates of amenorrhea were 73%, 82%, and 6%, respectively, with amenorrhea occurring within 10 days in the majority of patients receiving ulipristal acetate. The median changes in total fibroid volume were -21%, -12%, and +3% (P=0.002 for the comparison of 5 mg of ulipristal acetate with placebo, and P=0.006 for the comparison of 10 mg of ulipristal acetate with placebo). Ulipristal acetate induced benign histologic endometrial changes that had resolved by 6 months after the end of therapy. Serious adverse events occurred in one patient during treatment with 10 mg of ulipristal acetate (uterine hemorrhage) and in one patient during receipt of placebo (fibroid protruding through the cervix). Headache and breast tenderness were the most common adverse events associated with ulipristal acetate but did not occur significantly more frequently than with placebo

  17. Acetate:succinate CoA-transferase in the hydrogenosomes of Trichomonas vaginalis: Identification and characterization

    NARCIS (Netherlands)

    K.W.A. Grinsven; S. Rosnowsky (Silke); S.W.H. van Weelden (Susanne); S. Pütz (Simone); M. van der Giezen (Mark); W. Martin (William); J.J. van Hellemond (Jaap); A.G.M. Tielens (Aloysius); K. Henze (Katrin)

    2008-01-01

    textabstractAcetate:succinate CoA-transferases (ASCT) are acetate-producing enzymes in hydrogenosomes, anaerobically functioning mitochondria and in the aerobically functioning mitochondria of trypanosomatids. Although acetate is produced in the hydrogenosomes of a number of anaerobic microbial

  18. Consequences of the electronic tuning of latent ruthenium-based olefin metathesis catalysts on their reactivity

    KAUST Repository

    Żukowska, Karolina

    2015-08-20

    Two ruthenium olefin metathesis initiators featuring electronically modified quinoline-based chelating carbene ligands are introduced. Their reactivity in RCM and ROMP reactions was tested and the results were compared to those obtained with the parent unsubstituted compound. The studied complexes are very stable at high temperatures up to 140 °C. The placement of an electron-withdrawing functionality translates into an enhanced activity in RCM. While electronically modified precatalysts, which exist predominantly in the trans-dichloro configuration, gave mostly the RCM and a minor amount of the cycloisomerization product, the unmodified congener, which preferentially exists as its cis-dichloro isomer, shows a switched reactivity. The position of the equilibrium between the cis- and the trans-dichloro species was found to be the crucial factor governing the reactivity of the complexes.

  19. Magnetic anisotropy of graphene quantum dots decorated with a ruthenium adatom

    Directory of Open Access Journals (Sweden)

    Igor Beljakov

    2013-07-01

    Full Text Available The creation of magnetic storage devices by decoration of a graphene sheet by magnetic transition-metal adatoms, utilizing the high in-plane versus out-of-plane magnetic anisotropy energy (MAE, has recently been proposed. This concept is extended in our density-functional-based modeling study by incorporating the influence of the graphene edge on the MAE. We consider triangular graphene flakes with both armchair and zigzag edges in which a single ruthenium adatom is placed at symmetrically inequivalent positions. Depending on the edge-type, the graphene edge was found to influence the MAE in opposite ways: for the armchair flake the MAE increases close to the edge, while the opposite is true for the zigzag edge. Additionally, in-plane pinning of the magnetization direction perpendicular to the edge itself is observed for the first time.

  20. X-Ray structure and cytotoxic activity of a picolinate ruthenium(II–arene complex

    Directory of Open Access Journals (Sweden)

    IVANKA IVANOVIĆ

    2011-01-01

    Full Text Available A ruthenium(II–arene complex with picolinic acid, [(η6-p-cymeneRuCl(pico]∙H2O, was prepared by the reaction of [(η6-p-cymeneRuCl2]2 with picolinic acid in a 1:2 molar ratio in 2-propanol. The compound was characterized by elemental analysis, and IR and NMR spectroscopy. X-ray diffraction analysis showed that the molecule adopts a “three-leg piano-stool” geometry, which is common for this type of complexes. The cytotoxic activity of the complex was tested in two human cancer cell lines HeLa (cervix and FemX (melanoma by MTT assay. The IC50 values were at 82.0 and 36.2 µmol dm-3 for HeLa and FemX cells, respectively.

  1. Dehydrogenation of Formic Acid Catalyzed by a Ruthenium Complex with an N,N′-Diimine Ligand

    KAUST Repository

    Guan, Chao

    2016-12-17

    We report a ruthenium complex containing an N,N′-diimine ligand for the selective decomposition of formic acid to H and CO in water in the absence of any organic additives. A turnover frequency of 12000 h and a turnover number of 350 000 at 90 °C were achieved in the HCOOH/HCOONa aqueous solution. Efficient production of high-pressure H and CO (24.0 MPa (3480 psi)) was achieved through the decomposition of formic acid with no formation of CO. Mechanistic studies by NMR and DFT calculations indicate that there may be two competitive pathways for the key hydride transfer rate-determining step in the catalytic process.

  2. Crystal structures of bromo- and iododerivatives of ruthenium nitroso complexes K2[RuNOX5

    International Nuclear Information System (INIS)

    Mikhajlov, Yu.N.; Kanishcheva, A.S.; Svetlov, A.A.

    1989-01-01

    Method of X-ray diffraction analysis was used to interpret crystal structure of ruthenium pentahalogenonitroso complexes: K 2 [RuNOBr 5 ] (1) and K 2 [RuOI 5 ] (2). Crystals belong to rhombic syngony, sp.gr. Pcmn. Lattice parameters: (1) - a 7.236(2), b = 10.791(2), c = 13.949(3) A, V = 1089.14(1) A 3 , Z = 4; (2) - a = 7.755(1), b = 11.506(6), c = 14.951(5) A, V 133.97(8) A 3 , Z = 4. It was revealed that lengths of Ru-Br equatorial bonds in (1) exceeded the axial ones, and in the compound (2) the reverse relation was observed. The obtained results were correlated with the structural data for K 2 [RuNOF 5 ]H 2 O and K 2 [RuNOCl 5 ] complexes and similar osmium compounds

  3. Kinetic investigation of the chlorine reduction reaction on electrochemically oxidised ruthenium

    International Nuclear Information System (INIS)

    Thomassen, M.; Karlsen, C.; Borresen, B.; Tunold, R.

    2006-01-01

    The rate and mechanism of the electroreduction of chlorine on electrooxidised ruthenium has been investigated with focus on the effect of solution pH. Current/potential curves for the reduction process in solutions with constant chloride concentration of 1.0 mol dm -3 and varying H + concentration have been obtained with the use of the rotating disk electrode technique (RDE). It was found that the chlorine reduction rate is highly inhibited in solutions with high H + concentrations and that it can be satisfactorily described by the Erenburg mechanism, previously suggested for the chlorine evolution on RuO 2 and RTO. The expression of the kinetic current as a function of chlorine and H + concentration was obtained by solving the elementary rate equations of the kinetic mechanism. The kinetic constants obtained from the correlation of the kinetic current expression to the experimental data were used to simulate the dependence of the surface coverages and elementary reaction rates on overpotential

  4. Transmutation of technetium into stable ruthenium in high flux conceptual research reactor

    International Nuclear Information System (INIS)

    Amrani, N.; Boucenna, A.

    2007-01-01

    The effectiveness of transmutation for the long lived fission product technetium-99 in high flux research reactor, considering its large capture cross section in thermal and epithermal region is evaluated. The calculation of Ruthenium concentration evolution under irradiation was performed using Chain Solver 2.20 code. The approximation used for the transmutation calculation is the assumption that the influence of change in irradiated materials structures on the reactor operator mode characteristics is insignificant. The results on Technetium transmutation in high flux research reactor suggested an effective use of this kind of research reactors. The evaluation brings a new concept of multi-recycle Technetium transmutation using HFR T RAN (High Flux Research Reactor for Transmutation)

  5. Ruthenium Tris(2-pyridylmethyl)amine as an Effective Photocaging Group for Nitriles

    Science.gov (United States)

    2015-01-01

    Ruthenium(II) tris(2-pyridylmethyl)amine (TPA) is an effective caging group for nitriles that provides high levels of control over the enzyme activity with light. Two caged nitriles were prepared, [Ru(TPA)(MeCN)2](PF6)2 (1) and [Ru(TPA)(3)2](PF6)2 (2), where 3 is the cathepsin K inhibitor Cbz-Leu-NHCH2CN, and characterized by various spectroscopic techniques and mass spectrometry. Both 1 and 2 show the release of a single nitrile within 20 min of irradiation with 365 nm light. Complex 2 acts as a potent, photoactivated inhibitor of human cathepsin K. IC50 values were determined for 2 and 3. Enzyme inhibition for 2 was enhanced by a factor of 89 upon exposure to light, with IC50 values of 63 nM (light) and 5.6 μM (dark). PMID:24661182

  6. Consequences of the electronic tuning of latent ruthenium-based olefin metathesis catalysts on their reactivity

    KAUST Repository

    Żukowska, Karolina; Pump, Eva; Pazio, Aleksandra E; Woźniak, Krzysztof; Cavallo, Luigi; Slugovc, Christian

    2015-01-01

    Two ruthenium olefin metathesis initiators featuring electronically modified quinoline-based chelating carbene ligands are introduced. Their reactivity in RCM and ROMP reactions was tested and the results were compared to those obtained with the parent unsubstituted compound. The studied complexes are very stable at high temperatures up to 140 °C. The placement of an electron-withdrawing functionality translates into an enhanced activity in RCM. While electronically modified precatalysts, which exist predominantly in the trans-dichloro configuration, gave mostly the RCM and a minor amount of the cycloisomerization product, the unmodified congener, which preferentially exists as its cis-dichloro isomer, shows a switched reactivity. The position of the equilibrium between the cis- and the trans-dichloro species was found to be the crucial factor governing the reactivity of the complexes.

  7. Effect of annealing temperature on electrochemical characteristics of ruthenium oxide/multi-walled carbon nanotube composites

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Min-Kang [Department of Chemistry, Inha University, 253, Incheon 402-751 (Korea, Republic of); Saouab, Abdelghani [Department of Mechanical Engineering, University of Le Havre, Place Robert Schuman, BP 4006, 76610 Le Havre (France); Park, Soo-Jin, E-mail: sjpark@inha.ac.k [Department of Chemistry, Inha University, 253, Incheon 402-751 (Korea, Republic of)

    2010-02-25

    The preparation and characterization of high-surface-area ruthenium oxide (RuO{sub 2})/multi-walled carbon nanotubes (MWCNTs) composite electrodes for use in supercapacitors is reported in this work. The RuO{sub 2}/MWCNTs composites were prepared by the polyol process of RuO{sub 2} into MWCNTs and by Ru annealing in air before mixed with MWCNTs. The chemically oxidized and annealed Ru nanoparticles contribute a pseudocapacitance to the electrodes and dramatically improve the energy storage characteristics of the MWCNTs. These composites annealed at 200 deg. C demonstrate specific capacitances in excess of 130 F/g in comparison to 80 F/g for pristine MWCNTs. The annealing temperature is found to play an important role, as it affects the electrochemical performance of annealed RuO{sub 2}/MWCNTs composites critically due to its influence on the diffusion of protons into the structure.

  8. Hydroformylation and kinetics of 1-hexene over ruthenium, cobalt and rhodium zerolite catalysts

    International Nuclear Information System (INIS)

    Wang, C.; Wei, W.

    1989-01-01

    In this paper, six kinds of catalysts were prepared by cation exchange with rhodium, ruthenium and cobalt chloropentaamino dichoride and zeolites. Effects such as support materials, PPH 3 to metal ratio, reaction temperature, total pressure, H 2 /CO ratio, reaction time and solvents have been investigated in an autoclave. The most favorable results of 1-hexene hydroformylation were obtained in the temperature range 100-150 degrees C at a pressure of 5.0MPa (H 2 /CO=1:1) and the addition of free PPh 3 . The bimetallic catalysts showed high catalytic activing for hydroformylation because of the synergistic effect of bimetallic systems. This paper reports the results of experiments and catalysts characterization by means of IR and XRD spectroscopy

  9. Theoretical characterization of the surface composition of ruthenium nanoparticles in equilibrium with syngas

    Science.gov (United States)

    Cusinato, Lucy; Martínez-Prieto, Luis M.; Chaudret, Bruno; Del Rosal, Iker; Poteau, Romuald

    2016-05-01

    A deeper understanding of the relationship between experimental reaction conditions and the surface composition of nanoparticles is crucial in order to elucidate mechanisms involved in nanocatalysis. In the framework of the Fischer-Tropsch synthesis, a resolution of this complex puzzle requires a detailed understanding of the interaction of CO and H with the surface of the catalyst. In this context, the single- and co-adsorption of CO and H to the surface of a 1 nm ruthenium nanoparticle has been investigated with density functional theory. Using several indexes (d-band center, crystal overlap Hamilton population, density of states), a systematic analysis of the bond properties and of the electronic states has also been done, in order to bring an understanding of structure/property relationships at the nanoscale. The H : CO surface composition of this ruthenium nanoparticle exposed to syngas has been evaluated according to a thermodynamic model fed with DFT energies. Such ab initio thermodynamic calculations give access to the optimal H : CO coverage values under a wide range of experimental conditions, through the construction of free energy phase diagrams. Surprisingly, under the Fischer-Tropsch synthesis experimental conditions, and in agreement with new experiments, only CO species are adsorbed at the surface of the nanoparticle. These findings shed new light on the possible reaction pathways underlying the Fischer-Tropsch synthesis, and specifically the initiation of the reaction. It is finally shown that the joint knowledge of the surface composition and energy descriptors can help to identify possible reaction intermediates.A deeper understanding of the relationship between experimental reaction conditions and the surface composition of nanoparticles is crucial in order to elucidate mechanisms involved in nanocatalysis. In the framework of the Fischer-Tropsch synthesis, a resolution of this complex puzzle requires a detailed understanding of the interaction

  10. Photoluminescence quenching of chemically functionalized porous silicon by a ruthenium cluster

    Energy Technology Data Exchange (ETDEWEB)

    Boukherroub, R.; Wayner, D.D.M. [Steacie Institute for Molecular Sciences, National Research Council of Canada, Ottawa, Ontario (Canada); Lockwood, D.J. [Institute for Microstructural Sciences, National Research Council of Canada, Ottawa, Ontario (Canada); Zargarian, D. [Chemistry Department, University of Montreal, C.P. 6128, succursale, Centre-ville, Montreal QC (Canada)

    2003-05-01

    This paper describes photoluminescence (PL) quenching of hydrogen-terminated and chemically derivatized porous silicon (PSi) nanostructures by a green ruthenium cluster (I). Chemisorption of freshly prepared PSi surfaces in a hexane solution of the Ru cluster for several days at room temperature led to a complete quenching of the PSi PL. The only visible PL was due to the original PL of the cluster. When the PSi surface functionalized with undecylenic acid was immersed in the same hexane solution of (I), the PSi PL was completely quenched and accompanied with a shift to a lower energy of the cluster PL. This shift was assigned to the formation of an ester linkage resulting from the nucleophilic attack of the PO anion of the cluster on the terminal acid functional group. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

  11. Photoluminescence quenching of chemically functionalized porous silicon by a ruthenium cluster

    Science.gov (United States)

    Boukherroub, R.; Wayner, D. D. M.; Lockwood, D. J.; Zargarian, D.

    2003-05-01

    This paper describes photoluminescence (PL) quenching of hydrogen-terminated and chemically derivatized porous silicon (PSi) nanostructures by a green ruthenium cluster (I). Chemisorption of freshly prepared PSi surfaces in a hexane solution of the Ru cluster for several days at room temperature led to a complete quenching of the PSi PL. The only visible PL was due to the original PL of the cluster. When the PSi surface functionalized with undecylenic acid was immersed in the same hexane solution of (I), the PSi PL was completely quenched and accompanied with a shift to a lower energy of the cluster PL. This shift was assigned to the formation of an ester linkage resulting from the nucleophilic attack of the PO anion of the cluster on the terminal acid functional group.

  12. Catalytic behaviors of ruthenium dioxide films deposited on ferroelectrics substrates, by spin coating process

    International Nuclear Information System (INIS)

    Khachane, M.; Nowakowski, P.; Villain, S.; Gavarri, J.R.; Muller, Ch.; Elaatmani, M.; Outzourhite, A.; Luk'yanchuk, I.; Zegzouti, A.; Daoud, M.

    2007-01-01

    Catalytic ruthenium dioxide films were deposited by spin-coating process on ferroelectric films mainly constituted of SrBi 2 Ta 2 O 9 (SBT) and Ba 2 NaNb 5 O 15 (BNN) phases. After thermal treatment under air, these ferroelectric-catalytic systems were characterized by X-ray diffraction and scanning electron microscopy (SEM). SEM images showed that RuO 2 film morphology depended on substrate nature. A study of CH 4 conversion into CO 2 and H 2 O was carried out using these catalytic-ferroelectric multilayers: the conversion was analyzed from Fourier transform infrared (FTIR) spectroscopy, at various temperatures. Improved catalytic properties were observed for RuO 2 films deposited on BNN oxide layer

  13. Dry reforming of methane in the presence of ruthenium-based catalysts

    International Nuclear Information System (INIS)

    Safariamin, M.; Tidahy, L.H.; Abi-Aad, E.; Siffert, St.; Aboukais, A.

    2009-01-01

    The catalytic activities of ruthenium-based catalysts (5 wt% Ru) supported on alumina, ceria and ceria/alumina with different proportions of ceria (nCe 10 Al, n = 1, 3, 5; n = atomic ratio) were studied for the methane reforming reaction with CO 2 (CH 4 / CO 2 = 1) in the temperature range of 400-800 C. Evaluation of coke deposited after the reaction showed carbon deposition on Ru catalysts supported on CeO 2 , 1Ce 10 Al and 3Ce 10 Al, but not on Ru/Al 2 O 3 and Ru/5Ce 10 Al. Moreover, the sample Ru/5Ce 10 Al exhibited a higher activity than the other catalysts. (authors)

  14. Photolabile ruthenium complexes to cage and release a highly cytotoxic anticancer agent.

    Science.gov (United States)

    Wei, Jianhua; Renfrew, Anna K

    2018-02-01

    CHS-828 (N-(6-(4-chlorophenoxy)hexyl)-N'-cyano-N″-4-pyridyl guanidine) is an anticancer agent with low bioavailability and high systemic toxicity. Here we present an approach to improve the therapeutic profile of the drug using photolabile ruthenium complexes to generate light-activated prodrugs of CHS-828. Both prodrug complexes are stable in the dark but release CHS-828 when irradiated with visible light. The complexes are water-soluble and accumulate in tumour cells in very high concentrations, predominantly in the mitochondria. Both prodrug complexes are significantly less cyototoxic than free CHS-828 in the dark but their toxicity increases up to 10-fold in combination with visible light. The cellular responses to light treatment are consistent with release of the cytotoxic CHS-828 ligand. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Light olefins from synthesis gas using ruthenium on rare earth oxide catalysts

    International Nuclear Information System (INIS)

    Bruce, L.; Hardin, S.; Hoang, M.; Turney, T.

    1988-01-01

    The interaction of ruthenium carbonyl, Ru/sub 3/(CO)/sub 12/ with rare earth oxides of high surface area, >50m/sup 2/g/sup -1/, has been studied. [Ru/sub 3/(μ H)(CO)/sub 10/(μ-OM=)] is formed on holmia, but on lanthana only [Ru(CO)/sub 2/]/sub n/ species are observed. Reduction of the carbonyl ligands takes place at <573K to give catalysts for the hydrogenation of carbon monoxide with activity and selectivity dependent on the particular rare earth oxide and pretreatment. Over ceria, the product is up to 55 wt% C2-5 olefins. A similar selectivity is obtained over lanthana only after redispersion through a reduction-oxidation-reduction cycle

  16. Elaboration of strontium ruthenium oxide thin films on metal substrates by chemical solution deposition

    Energy Technology Data Exchange (ETDEWEB)

    Seveno, R. [Universite de Nantes, Institut de Recherche en Electrotechnique et Electronique de Nantes Atlantique (IREENA), 2, rue de la Houssiniere, BP 92208, 44322 Nantes Cedex 3 (France)]. E-mail: raynald.seveno@univ-nantes.fr; Braud, A. [Universite de Nantes, Institut de Recherche en Electrotechnique et Electronique de Nantes Atlantique (IREENA), 2, rue de la Houssiniere, BP 92208, 44322 Nantes Cedex 3 (France); Gundel, H.W. [Universite de Nantes, Institut de Recherche en Electrotechnique et Electronique de Nantes Atlantique (IREENA), 2, rue de la Houssiniere, BP 92208, 44322 Nantes Cedex 3 (France)

    2005-12-22

    In order to improve the structural interface between a metal substrate and a lead zirconate titanate (Pb(ZrTi)O{sub 3}, PZT) ferroelectric thin film, the elaboration of strontium ruthenium oxide (SrRuO{sub 3}) by chemical solution deposition is studied. The SrRuO{sub 3} thin films were realized by multiple spin-coating technique and the temperature of the rapid thermal annealing process was optimized. The crystallization behavior was examined by X-ray diffraction; surface analyses using scanning electron microscope and atomic force microscope techniques showed the influence of the SrRuO{sub 3} layer at the interface PZT/metal on the morphology of the ferroelectric thin film. From the electrical measurements, a coercive electric field around 25 kV/cm and a remanent polarization of approximately 30 {mu}C/cm were found.

  17. Amide Synthesis from Alcohols and Amines Catalyzed by Ruthenium N-Heterocyclic Carbene Complexes

    DEFF Research Database (Denmark)

    Dam, Johan Hygum; Osztrovszky, Gyorgyi; Nordstrøm, Lars Ulrik Rubæk

    2010-01-01

    The direct synthesis of amides from alcohols and amines is described with the simultaneous liberation of dihydrogen. The reaction does not require any stoichiometric additives or hydrogen acceptors and is catalyzed by ruthenium N-heterocyclic carbene complexes. Three different catalyst systems...... are presented that all employ 1,3-diisopropylimidazol-2-ylidene (IiPr) as the carbene ligand. In addition, potassium tert-butoxide and a tricycloalkylphosphine are required for the amidation to proceed. In the first system, the active catalyst is generated in situ from [RuCl2(cod)] (cod = 1,5-cyclooctadiene), 1...... chloride and base. A range of different primary alcohols and amines have been coupled in the presence of the three catalyst systems to afford the corresponding amides in moderate to excellent yields. The best results are obtained with sterically unhindered alcohols and amines. The three catalyst systems do...

  18. Synthesis of phosphonic acid derivatized bipyridine ligands and their ruthenium complexes.

    Science.gov (United States)

    Norris, Michael R; Concepcion, Javier J; Glasson, Christopher R K; Fang, Zhen; Lapides, Alexander M; Ashford, Dennis L; Templeton, Joseph L; Meyer, Thomas J

    2013-11-04

    Water-stable, surface-bound chromophores, catalysts, and assemblies are an essential element in dye-sensitized photoelectrosynthesis cells for the generation of solar fuels by water splitting and CO2 reduction to CO, other oxygenates, or hydrocarbons. Phosphonic acid derivatives provide a basis for stable chemical binding on metal oxide surfaces. We report here the efficient synthesis of 4,4'-bis(diethylphosphonomethyl)-2,2'-bipyridine and 4,4'-bis(diethylphosphonate)-2,2'-bipyridine, as well as the mono-, bis-, and tris-substituted ruthenium complexes, [Ru(bpy)2(Pbpy)](2+), [Ru(bpy)(Pbpy)2](2+), [Ru(Pbpy)3](2+), [Ru(bpy)2(CPbpy)](2+), [Ru(bpy)(CPbpy)2](2+), and [Ru(CPbpy)3](2+) [bpy = 2,2'-bipyridine; Pbpy = 4,4'-bis(phosphonic acid)-2,2'-bipyridine; CPbpy = 4,4'-bis(methylphosphonic acid)-2,2'-bipyridine].

  19. Synthesis and spectroscopic properties of Tris(2,2'-bipyridine)ruthenium(II) in zeolite Y

    International Nuclear Information System (INIS)

    DeWilde, W.; Peeters, G.; Lunsford, J.H.

    1980-01-01

    Tris(2,2'-bipyridine)ruthenium(II) complexes have been synthesized within the large cavities of dehydrated Y-type zeolites by allowing bipyridine to react with a Ru(NH 3 ) 6 -Y form of the zeolite. The resulting Ru(bpy) 3 2+ complexes are characterized by absorption and emission bands similar to those found in aqueous solutions. The relatively high concentration of the Ru(bpy) 3 2+ complexes resulted in concentration quenching. As the addition of water to the samples approached saturation, the luminescence was quenched; however, small amounts of water increased the luminescence in a sample which contained 2.8 complexes per unit cell. Emission was also quenched upon addition of O 2 to the zeolite, with the effect being more pronounced in samples having a smaller concentration of complexes. 30 references, 6 figures, 1 table

  20. Multifaceted catalytic hydrogenation of amides via diverse activation of a sterically confined bipyridine-ruthenium framework.

    Science.gov (United States)

    Miura, Takashi; Naruto, Masayuki; Toda, Katsuaki; Shimomura, Taiki; Saito, Susumu

    2017-05-16

    Amides are ubiquitous and abundant in nature and our society, but are very stable and reluctant to salt-free, catalytic chemical transformations. Through the activation of a "sterically confined bipyridine-ruthenium (Ru) framework (molecularly well-designed site to confine adsorbed H 2 in)" of a precatalyst, catalytic hydrogenation of formamides through polyamide is achieved under a wide range of reaction conditions. Both C=O bond and C-N bond cleavage of a lactam became also possible using a single precatalyst. That is, catalyst diversity is induced by activation and stepwise multiple hydrogenation of a single precatalyst when the conditions are varied. The versatile catalysts have different structures and different resting states for multifaceted amide hydrogenation, but the common structure produced upon reaction with H 2 , which catalyzes hydrogenation, seems to be "H-Ru-N-H."

  1. Electronic effects of ruthenium-catalyzed [3+2]-cycloaddition of alkynes and azides

    KAUST Repository

    Hou, Duenren

    2010-11-01

    A combined experimental and theoretical study of ruthenium-catalyzed azide-alkyne cycloaddition (RuAAC) reactions is presented and various electronic analyses were conducted to provide a basis in understanding the observed regioselectivity of the 1,2,3-triazole products. Computational studies using density functional theory (DFT) and atoms in molecules quantum theory (AIM) further yield fresh details on the electronic factors that determine the regioselectivity in the RuAAC. It is found that the formation of 1,2,3-triazole products is irreversible and from the Hammett study, the pathway involving a vinyl cationic intermediate is ruled out. The electronic effect favors the formation of 5-electron-donating-group substituted-1,2,3-trizoles. © 2010 Elsevier Ltd. All rights reserved.

  2. How phenyl makes a difference: mechanistic insights into the ruthenium( ii )-catalysed isomerisation of allylic alcohols

    KAUST Repository

    Manzini, Simone

    2013-10-16

    [RuCl(η5-3-phenylindenyl)(PPh3)2] (1) has been shown to be a highly active catalyst for the isomerisation of allylic alcohols to the corresponding ketones. A variety of substrates undergo the transformation, typically with 0.25-0.5 mol% of catalyst at room temperature, outperforming commonly-used complexes such as [RuCl(Cp)(PPh3) 2] and [RuCl(η5-indenyl)(PPh3) 2]. Mechanistic experiments and density functional theory have been employed to investigate the mechanism and understand the effect of catalyst structure on reactivity. These investigations suggest a oxo-π-allyl mechanism is in operation, avoiding intermediate ruthenium hydride complexes and leading to a characteristic 1,3-deuterium shift. Important mechanistic insights from DFT and experiments also allowed for the design of a protocol that expands the scope of the transformation to include primary allylic alcohols. © 2013 The Royal Society of Chemistry.

  3. In situ chemical synthesis of ruthenium oxide/reduced graphene oxide nanocomposites for electrochemical capacitor applications.

    Science.gov (United States)

    Kim, Ji-Young; Kim, Kwang-Heon; Yoon, Seung-Beom; Kim, Hyun-Kyung; Park, Sang-Hoon; Kim, Kwang-Bum

    2013-08-07

    An in situ chemical synthesis approach has been developed to prepare ruthenium oxide/reduced graphene oxide (RGO) nanocomposites. It is found that as the C/O ratio increases, the number density of RuO2 nanoparticles decreases, because the chemical interaction between the Ru ions and the oxygen-containing functional groups provides anchoring sites where the nucleation of particles takes place. For electrochemical capacitor applications, the microwave-hydrothermal process was carried out to improve the conductivity of RGO in RuO2/RGO nanocomposites. The significant improvement in capacitance and high rate capability might result from the RuO2 nanoparticles used as spacers that make the interior layers of the reduced graphene oxide electrode available for electrolyte access.

  4. Nonlinear optical properties of systems based on ruthenium(II) tetra-15-crown-5-phthalocyaninate

    International Nuclear Information System (INIS)

    Grishina, A.D.; Gorbunova, Yu.G.; Enakieva, Yu.Yu.; Krivenko, T.V.; Savel'ev, V.V.; Vannikov, A.V.; Tsivadze, A.Yu.

    2008-01-01

    The third-order nonlinear optical properties of the ruthenium (II) complex with tetra-15-crown-5-phthalocyanine and axially coordinated triethylenediamine molecules (R 4 Pc)Ru(TED) 2 were analyzed by means of the z-scanning technique. A solution of (R 4 Pc)Ru(TED) 2 in tetrachloroethane was exposed to nanosecond laser pulses at a wavelength of 1064 nm. It was found that the third-order molecular polarizability of the Ru(II) complex is 4.5 x 10 -32 cm 4 /C (esu). The polarizability per molecule increases by a factor of 3.6 when the single molecule occurs in a supramolecular assembly of (R 4 Pc)Ru(TED) 2 complexes. The photoelectric and photorefractive properties at 1064 nm of polymer composites, determined by the supramolecular assemblies that exhibits optical absorption and photoelectric sensitivity in the near IR region, are reported [ru

  5. Elaboration of strontium ruthenium oxide thin films on metal substrates by chemical solution deposition

    International Nuclear Information System (INIS)

    Seveno, R.; Braud, A.; Gundel, H.W.

    2005-01-01

    In order to improve the structural interface between a metal substrate and a lead zirconate titanate (Pb(ZrTi)O 3 , PZT) ferroelectric thin film, the elaboration of strontium ruthenium oxide (SrRuO 3 ) by chemical solution deposition is studied. The SrRuO 3 thin films were realized by multiple spin-coating technique and the temperature of the rapid thermal annealing process was optimized. The crystallization behavior was examined by X-ray diffraction; surface analyses using scanning electron microscope and atomic force microscope techniques showed the influence of the SrRuO 3 layer at the interface PZT/metal on the morphology of the ferroelectric thin film. From the electrical measurements, a coercive electric field around 25 kV/cm and a remanent polarization of approximately 30 μC/cm were found

  6. Electronic effects of ruthenium-catalyzed [3+2]-cycloaddition of alkynes and azides

    KAUST Repository

    Hou, Duenren; Kuan, Tingchun; Li, YuKai; Lee, Richmond; Huang, Kuo-Wei

    2010-01-01

    A combined experimental and theoretical study of ruthenium-catalyzed azide-alkyne cycloaddition (RuAAC) reactions is presented and various electronic analyses were conducted to provide a basis in understanding the observed regioselectivity of the 1,2,3-triazole products. Computational studies using density functional theory (DFT) and atoms in molecules quantum theory (AIM) further yield fresh details on the electronic factors that determine the regioselectivity in the RuAAC. It is found that the formation of 1,2,3-triazole products is irreversible and from the Hammett study, the pathway involving a vinyl cationic intermediate is ruled out. The electronic effect favors the formation of 5-electron-donating-group substituted-1,2,3-trizoles. © 2010 Elsevier Ltd. All rights reserved.

  7. RutheniumII Complexes bearing Fused Polycyclic Ligands: From Fundamental Aspects to Potential Applications

    Directory of Open Access Journals (Sweden)

    Ludovic Troian-Gautier

    2014-04-01

    Full Text Available In this review, we first discuss the photophysics reported in the literature for mononuclear ruthenium complexes bearing ligands with extended aromaticity such as dipyrido[3,2-a:2',3'-c]phenazine (DPPZ, tetrapyrido[3,2-a:2',3'-c:3'',2''-h:2''',3'''-j]-phenazine (TPPHZ,  tetrapyrido[3,2-a:2',3'-c:3'',2''-h:2''',3'''-j]acridine (TPAC, 1,10-phenanthrolino[5,6-b]1,4,5,8,9,12-hexaazatriphenylene (PHEHAT 9,11,20,22-tetraaza- tetrapyrido[3,2-a:2',3'-c:3'',2''-l:2''',3'''-n]pentacene (TATPP, etc. Photophysical properties of binuclear and polynuclear complexes based on these extended ligands are then reported. We finally develop the use of binuclear complexes with extended π-systems for applications such as photocatalysis.

  8. Molecular characterization of kerogens by mild selective chemical degradation - ruthenium tetroxide oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Boucher, R.J.; Standen, G.; Eglinton, G. (University of Bristol, Bristol (UK). Organic Geochemistry Unit)

    1991-06-01

    Molecular characterization of two kerogen isolates (Messel and Kimmeridge Clay), two kerogen-rich shales (green River and Maoming) and a coal, (Loy Yang) was undertaken using selective chemical degradation with ruthenium tetroxide (RuO{sub 4}). The RuO{sub 4} oxidation gave extracts which were soluble in dichloromethane and contained series of straight chain monocarboxylic acids, {alpha},{omega}-dicarboxylic acids, branched mono- and dicarboxylic acids, isoprenoid and cyclic acids. Straight chain carboxylic acids were predominant (65-87% of quantified chromatogram components for the range of sedimentary organic matter studied), reflecting the major content of polymethylene chains in these kerogens. This mild, oxidative technique serves to differentiate kerogens at a molecular level, thereby supplementing existing conventional chemical, pyrolytic, n.m.r. and other techniques. 39 refs., 3 figs., 5 tabs.

  9. How phenyl makes a difference: mechanistic insights into the ruthenium( ii )-catalysed isomerisation of allylic alcohols

    KAUST Repository

    Manzini, Simone; Poater, Albert; Nelson, David J.; Cavallo, Luigi; Nolan, Steven P.

    2013-01-01

    [RuCl(η5-3-phenylindenyl)(PPh3)2] (1) has been shown to be a highly active catalyst for the isomerisation of allylic alcohols to the corresponding ketones. A variety of substrates undergo the transformation, typically with 0.25-0.5 mol% of catalyst at room temperature, outperforming commonly-used complexes such as [RuCl(Cp)(PPh3) 2] and [RuCl(η5-indenyl)(PPh3) 2]. Mechanistic experiments and density functional theory have been employed to investigate the mechanism and understand the effect of catalyst structure on reactivity. These investigations suggest a oxo-π-allyl mechanism is in operation, avoiding intermediate ruthenium hydride complexes and leading to a characteristic 1,3-deuterium shift. Important mechanistic insights from DFT and experiments also allowed for the design of a protocol that expands the scope of the transformation to include primary allylic alcohols. © 2013 The Royal Society of Chemistry.

  10. Inhibition of Ice Growth and Recrystallization by Zirconium Acetate and Zirconium Acetate Hydroxide

    Science.gov (United States)

    Mizrahy, Ortal; Bar-Dolev, Maya; Guy, Shlomit; Braslavsky, Ido

    2013-01-01

    The control over ice crystal growth, melting, and shaping is important in a variety of fields, including cell and food preservation and ice templating for the production of composite materials. Control over ice growth remains a challenge in industry, and the demand for new cryoprotectants is high. Naturally occurring cryoprotectants, such as antifreeze proteins (AFPs), present one solution for modulating ice crystal growth; however, the production of AFPs is expensive and inefficient. These obstacles can be overcome by identifying synthetic substitutes with similar AFP properties. Zirconium acetate (ZRA) was recently found to induce the formation of hexagonal cavities in materials prepared by ice templating. Here, we continue this line of study and examine the effects of ZRA and a related compound, zirconium acetate hydroxide (ZRAH), on ice growth, shaping, and recrystallization. We found that the growth rate of ice crystals was significantly reduced in the presence of ZRA and ZRAH, and that solutions containing these compounds display a small degree of thermal hysteresis, depending on the solution pH. The compounds were found to inhibit recrystallization in a manner similar to that observed in the presence of AFPs. The favorable properties of ZRA and ZRAH suggest tremendous potential utility in industrial applications. PMID:23555701

  11. Calcination of calcium acetate and calcium magnesium acetate: effect of the reacting atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Adanez, J.; Diego, L.F. de; Garcia-Labiano, F. [Instituto de Carboquimica, Zaragoza (Spain). Dept. of Energy and Environment

    1999-04-01

    The calcination process of the calcium acetate (CA) and calcium magnesium acetate (CMA) was investigated as a previous step for coal gas desulfurisation during sorbent injection at high temperatures because the excellent results demonstrated by these sorbents as sulfur removal agents both in combustion and gasification processes. As pore structure developed during calcination is one of the most important characteristics of the sorbent related with the later reaction with the gaseous pollutants, several calcination tests were conducted in a drop tube reactor at temperatures from 700{degree}C to 1100{degree}C, and residence times from 0.8 to 2.4 s. Four different gas atmospheres were used for comparative purposes: inert, oxidising, reducing, and non-calcining (pure CO{sub 2}). Despite the advantage of the high porous cenospheric structure developed by these sorbents during their injection at high temperature, calcination of the CaCO{sub 3} was not complete even at the longest residence time, 2.4 s, and the highest temperature, 1100{degree}C, tested. An important effect of the reacting atmosphere on the calcination conversion and on the sorbent pore structure was detected. The CO{sub 2} concentration around the particle, both that fed in the reacting gases or that generated by organic material combustion, seems to be responsible for the final calcination conversions obtained in each case, also affecting the sintering suffered by the sorbents. 19 refs., 10 figs.

  12. Cosolvent gel-like materials from partially hydrolyzed poly(vinyl acetate)s and borax.

    Science.gov (United States)

    Angelova, Lora V; Terech, Pierre; Natali, Irene; Dei, Luigi; Carretti, Emiliano; Weiss, Richard G

    2011-09-20

    A gel-like, high-viscosity polymeric dispersion (HVPD) based on cross-linked borate, partially hydrolyzed poly(vinyl acetate) (xPVAc, where x is the percent hydrolysis) is described. Unlike hydro-HVPDs prepared from poly(vinyl alcohol) (PVA) and borate, the liquid portion of these materials can be composed of up to 75% of an organic cosolvent because of the influence of residual acetate groups on the polymer backbone. The effects of the degree of hydrolysis, molecular weight, polymer and cross-linker concentrations, and type and amount of organic cosolvent on the rheological and structural properties of the materials are investigated. The stability of the systems is explored through rheological and melting-range studies. (11)B NMR and small-angle neutron scattering (SANS) are used to probe the structure of the dispersions. The addition of an organic liquid to the xPVAc-borate HVPDs results in a drastic increase in the number of cross-linked borate species as well as the agglomeration of the polymer into bundles. These effects result in an increase in the relaxation time and thermal stability of the networks. The ability to make xPVAc-borate HVPDs with very large amounts of and rather different organic liquids, with very different rheological properties that can be controlled easily, opens new possibilities for applications of PVAc-based dispersions. © 2011 American Chemical Society

  13. Study of alkaline-earth element complexes in anhydrous acetic acid

    International Nuclear Information System (INIS)

    Petit, N.

    1968-10-01

    We have studied the complexes of alkaline-earth elements in anhydrous acetic acid. Using glass-electrode potentiometry we have studied the titration of alkaline earth acetates with perchloric acid which is the strongest acid in anhydrous acetic acid. These titrations have shown that the basic strength of these acetates increases as follows: Mg 4 ); the mixed acetate-acid sulfate complex of barium: Ba (OAc)(HSO 4 ); the mixed acetate-chloride of barium: Ba (OAc)(Cl). (author) [fr

  14. Electrical characterisation of ruthenium Schottky contacts on n-Ge (1 0 0)

    Energy Technology Data Exchange (ETDEWEB)

    Chawanda, Albert, E-mail: albert.chawanda@up.ac.za [Department of Physics, University of Pretoria, Pretoria 0002 (South Africa); Department of Physics, Midlands State University, Bag 9055, Gweru (Zimbabwe); Nyamhere, Cloud [Department of Physics, Nelson Mandela Metropolitan University, Box 7700, Port Elizabeth 6031 (South Africa); Auret, Francois D.; Nel, Jacqueline M.; Mtangi, Wilbert; Diale, Mmatsae [Department of Physics, University of Pretoria, Pretoria 0002 (South Africa)

    2012-05-15

    Ruthenium (Ru) Schottky contacts were fabricated on n-Ge (1 0 0) by electron beam deposition. Current-voltage (I-V), deep level transient spectroscopy (DLTS), and Laplace-DLTS techniques were used to characterise the as-deposited and annealed Ru/n-Ge (1 0 0) Schottky contacts. The variation of the electrical properties of the Ru samples annealed between 25 Degree-Sign C and 575 Degree-Sign C indicates the formation of two phases of ruthenium germanide. After Ru Schottky contacts fabrication, an electron trap at 0.38 eV below the conduction band with capture cross section of 1.0 Multiplication-Sign 10{sup -14} cm{sup -2} is the only detectable electron trap. The hole traps at 0.09, 0.15, 0.27 and 0.30 eV above the valence band with capture cross sections of 7.8 Multiplication-Sign 10{sup -13} cm{sup -2}, 7.1 Multiplication-Sign 10{sup -13} cm{sup -2}, 2.4 Multiplication-Sign 10{sup -13} cm{sup -2} and 6.2 Multiplication-Sign 10{sup -13} cm{sup -2}, respectively, were observed in the as-deposited Ru Schottky contacts. The hole trap H(0.30) is the prominent single acceptor level of the E-centre, and H(0.09) is the third charge state of the E-centre. H(0.27) shows some reverse annealing and reaches a maximum concentration at 225 Degree-Sign C and anneals out after 350 Degree-Sign C. This trap is strongly believed to be V-Sb{sub 2} complex formed from the annealing of V-Sb defect centre.

  15. Iodide Ion Pairing with Highly Charged Ruthenium Polypyridyl Cations in CH3CN.

    Science.gov (United States)

    Swords, Wesley B; Li, Guocan; Meyer, Gerald J

    2015-05-04

    A series of three highly charged cationic ruthenium(II) polypyridyl complexes of the general formula [Ru(deeb)3-x(tmam)x](PF6)2x+2, where deeb is 4,4'-diethyl ester-2,2'-bipyridine and tmam is 4,4'-bis[(trimethylamino)methyl]-2,2'-bipyridine, were synthesized and characterized and are referred to as 1, 2, or 3 based on the number of tmam ligands. Crystals suitable for X-ray crystallography were obtained for the homoleptic complex 3, which was found to possess D3 symmetry over the entire ruthenium complex. The complexes displayed visible absorption spectra typical of metal-to-ligand charge-transfer (MLCT) transitions. In acetonitrile, quasi-reversible waves were assigned to Ru(III/II) electron transfer, with formal reduction potentials that shifted negative as the number of tmam ligands was increased. Room temperature photoluminescence was observed in acetonitrile with quantum yields of ϕ ∼ 0.1 and lifetimes of τ ∼ 2 μs. The spectroscopic and electrochemical data were most consistent with excited-state localization on the deeb ligand for 1 and 2 and on the tmam ligand for 3. The addition of tetrabutylammonium iodide to the complexes dissolved in a CH3CN solution led to changes in the UV-vis absorption spectra consistent with ion pairing. A Benesi-Hildebrand-type analysis of these data revealed equilibrium constants that increased with the cationic charge 1 10(8) s(-1). The possible relevance of this work to solar energy conversion and dye-sensitized solar cells is discussed.

  16. Electronic structure investigation of atomic layer deposition ruthenium(oxide) thin films using photoemission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, Michael, E-mail: mvschaefer@mail.usf.edu, E-mail: schlaf@mail.usf.edu [Department of Physics, University of South Florida, Tampa, Florida 33620 (United States); Schlaf, Rudy, E-mail: mvschaefer@mail.usf.edu, E-mail: schlaf@mail.usf.edu [Department of Electrical Engineering, University of South Florida, Tampa, Florida 33620 (United States)

    2015-08-14

    Analyzing and manipulating the electronic band line-up of interfaces in novel micro- and nanoelectronic devices is important to achieve further advancement in this field. Such band alignment modifications can be achieved by introducing thin conformal interfacial dipole layers. Atomic layer deposition (ALD), enabling angstrom-precise control over thin film thickness, is an ideal technique for this challenge. Ruthenium (Ru{sup 0}) and its oxide (RuO{sub 2}) have gained interest in the past decade as interfacial dipole layers because of their favorable properties like metal-equivalent work functions, conductivity, etc. In this study, initial results of the electronic structure investigation of ALD Ru{sup 0} and RuO{sub 2} films via photoemission spectroscopy are presented. These experiments give insight into the band alignment, growth behavior, surface structure termination, and dipole formation. The experiments were performed in an integrated vacuum system attached to a home-built, stop-flow type ALD reactor without exposing the samples to the ambient in between deposition and analysis. Bis(ethylcyclopentadienyl)ruthenium(II) was used as precursor and oxygen as reactant. The analysis chamber was outfitted with X-ray photoemission spectroscopy (LIXPS, XPS). The determined growth modes are consistent with a strong growth inhibition situation with a maximum average growth rate of 0.21 Å/cycle for RuO{sub 2} and 0.04 Å/cycle for Ru.{sup 0} An interface dipole of up to −0.93 eV was observed, supporting the assumption of a strongly physisorbed interface. A separate experiment where the surface of a RuO film was sputtered suggests that the surface is terminated by an intermediate, stable, non-stoichiometric RuO{sub 2}/OH compound whose surface is saturated with hydroxyl groups.

  17. Electronic structure investigation of atomic layer deposition ruthenium(oxide) thin films using photoemission spectroscopy

    Science.gov (United States)

    Schaefer, Michael; Schlaf, Rudy

    2015-08-01

    Analyzing and manipulating the electronic band line-up of interfaces in novel micro- and nanoelectronic devices is important to achieve further advancement in this field. Such band alignment modifications can be achieved by introducing thin conformal interfacial dipole layers. Atomic layer deposition (ALD), enabling angstrom-precise control over thin film thickness, is an ideal technique for this challenge. Ruthenium (Ru0) and its oxide (RuO2) have gained interest in the past decade as interfacial dipole layers because of their favorable properties like metal-equivalent work functions, conductivity, etc. In this study, initial results of the electronic structure investigation of ALD Ru0 and RuO2 films via photoemission spectroscopy are presented. These experiments give insight into the band alignment, growth behavior, surface structure termination, and dipole formation. The experiments were performed in an integrated vacuum system attached to a home-built, stop-flow type ALD reactor without exposing the samples to the ambient in between deposition and analysis. Bis(ethylcyclopentadienyl)ruthenium(II) was used as precursor and oxygen as reactant. The analysis chamber was outfitted with X-ray photoemission spectroscopy (LIXPS, XPS). The determined growth modes are consistent with a strong growth inhibition situation with a maximum average growth rate of 0.21 Å/cycle for RuO2 and 0.04 Å/cycle for Ru.0 An interface dipole of up to -0.93 eV was observed, supporting the assumption of a strongly physisorbed interface. A separate experiment where the surface of a RuO film was sputtered suggests that the surface is terminated by an intermediate, stable, non-stoichiometric RuO2/OH compound whose surface is saturated with hydroxyl groups.

  18. Electronic structure investigation of atomic layer deposition ruthenium(oxide) thin films using photoemission spectroscopy

    International Nuclear Information System (INIS)

    Schaefer, Michael; Schlaf, Rudy

    2015-01-01

    Analyzing and manipulating the electronic band line-up of interfaces in novel micro- and nanoelectronic devices is important to achieve further advancement in this field. Such band alignment modifications can be achieved by introducing thin conformal interfacial dipole layers. Atomic layer deposition (ALD), enabling angstrom-precise control over thin film thickness, is an ideal technique for this challenge. Ruthenium (Ru 0 ) and its oxide (RuO 2 ) have gained interest in the past decade as interfacial dipole layers because of their favorable properties like metal-equivalent work functions, conductivity, etc. In this study, initial results of the electronic structure investigation of ALD Ru 0 and RuO 2 films via photoemission spectroscopy are presented. These experiments give insight into the band alignment, growth behavior, surface structure termination, and dipole formation. The experiments were performed in an integrated vacuum system attached to a home-built, stop-flow type ALD reactor without exposing the samples to the ambient in between deposition and analysis. Bis(ethylcyclopentadienyl)ruthenium(II) was used as precursor and oxygen as reactant. The analysis chamber was outfitted with X-ray photoemission spectroscopy (LIXPS, XPS). The determined growth modes are consistent with a strong growth inhibition situation with a maximum average growth rate of 0.21 Å/cycle for RuO 2 and 0.04 Å/cycle for Ru. 0 An interface dipole of up to −0.93 eV was observed, supporting the assumption of a strongly physisorbed interface. A separate experiment where the surface of a RuO film was sputtered suggests that the surface is terminated by an intermediate, stable, non-stoichiometric RuO 2 /OH compound whose surface is saturated with hydroxyl groups

  19. Nonenzymatic amperometric sensor for ascorbic acid based on hollow gold/ruthenium nanoshells

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Ara; Kang, Minkyung; Cha, Areum; Jang, Hye Su [Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750 (Korea, Republic of); Shim, Jun Ho [Department of Chemistry, Daegu University, Gyeongsan 712-714 (Korea, Republic of); Lee, Nam-Suk [National Center for Nanomaterials Technology (NCNT), Pohang University of Science and Technology (POSTECH), Pohang 790-784 (Korea, Republic of); Kim, Myung Hwa [Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750 (Korea, Republic of); Lee, Youngmi, E-mail: youngmilee@ewha.ac.kr [Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750 (Korea, Republic of); Lee, Chongmok, E-mail: cmlee@ewha.ac.kr [Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750 (Korea, Republic of)

    2014-03-01

    Highlights: • We synthesized hollow gold/ruthenium (hAu–Ru) nanoshells for ascorbic acid sensing. • The hAu–Ru nanoshells showed sensitivity of 426 μA mM⁻¹ cm⁻² for ascorbic acid. • Good selectivity against glucose, uric acid, dopamine, 4-acetamidophenol, and NADH. • The linear dynamic range appeared from zero to 2.0 mM (R = 0.9995). • Response time (1.6 s) and low detection limit (2.2 μM) were obtained at pH 7.40. Abstract: We report a new nonenzymatic amperometric detection of ascorbic acid (AA) using a glassy carbon (GC) disk electrode modified with hollow gold/ruthenium (hAu–Ru) nanoshells, which exhibited decent sensing characteristics. The hAu–Ru nanoshells were prepared by the incorporation of Ru on hollow gold (hAu) nanoshells from Co nanoparticle templates, which enabled AA selectivity against glucose without aid of enzyme or membrane. The structure and electrocatalytic activities of the hAu–Ru catalysts were characterized by spectroscopic and electrochemical techniques. The hAu–Ru loaded on GC electrode (hAu–Ru/GC) showed sensitivity of 426 μA mM⁻¹ cm⁻² (normalized to the GC disk area) for the linear dynamic range of <5 μM to 2 mM AA at physiological pH. The response time and detection limit were 1.6 s and 2.2 μM, respectively. Furthermore, the hAu–Ru/GC electrode displayed remarkable selectivity for ascorbic acid over all potential biological interferents, including glucose, uric acid (UA), dopamine (DA), 4-acetamidophenol (AP), and nicotinamide adenine dinucleotide (NADH), which could be especially good for biological sensing.

  20. Anti-Leishmania activity of new ruthenium(II) complexes: Effect on parasite-host interaction.

    Science.gov (United States)

    Costa, Mônica S; Gonçalves, Yasmim G; Nunes, Débora C O; Napolitano, Danielle R; Maia, Pedro I S; Rodrigues, Renata S; Rodrigues, Veridiana M; Von Poelhsitz, Gustavo; Yoneyama, Kelly A G

    2017-10-01

    Leishmaniasis is a parasitic disease caused by protozoa of the genus Leishmania. The many complications presented by the current treatment - including high toxicity, high cost and parasite resistance - make the development of new therapeutic agents indispensable. The present study aims to evaluate the anti-Leishmania potential of new ruthenium(II) complexes, cis‑[Ru II (η 2 -O 2 CR)(dppm) 2 ]PF 6 , with dppm=bis(diphenylphosphino)methane and R=4-butylbenzoate (bbato) 1, 4-(methylthio)benzoate (mtbato) 2 and 3-hydroxy-4-methoxybenzoate (hmxbato) 3, in promastigote cytotoxicity and their effect on parasite-host interaction. The cytotoxicity of complexes was analyzed by MTT assay against Leishmania (Leishmania) amazonensis, Leishmania (Viannia) braziliensis, Leishmania (Leishmania) infantum promastigotes and the murine macrophage (RAW 264.7). The effect of complexes on parasite-host interaction was evaluated by in vitro infectivity assay performed in the presence of two different concentrations of each complex: the promastigote IC 50 value and the concentration nontoxic to 90% of RAW 264.7 macrophages. Complexes 1-3 exhibited potent cytotoxic activity against all Leishmania species assayed. The IC 50 values ranged from 7.52-12.59μM (complex 1); 0.70-3.28μM (complex 2) and 0.52-1.75μM (complex 3). All complexes significantly inhibited the infectivity index at both tested concentrations. The infectivity inhibitions ranged from 37 to 85%. Interestingly, the infectivity inhibitions due to complex action did not differ significantly at either of the tested concentrations, except for the complex 1 against Leishmania (Leishmania) infantum. The infectivity inhibitions resulted from reductions in both percentage of infected macrophages and number of parasites per macrophage. Taken together the results suggest remarkable leishmanicidal activity in vitro by these new ruthenium(II) complexes. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Nonenzymatic amperometric sensor for ascorbic acid based on hollow gold/ruthenium nanoshells

    International Nuclear Information System (INIS)

    Jo, Ara; Kang, Minkyung; Cha, Areum; Jang, Hye Su; Shim, Jun Ho; Lee, Nam-Suk; Kim, Myung Hwa; Lee, Youngmi; Lee, Chongmok

    2014-01-01

    Highlights: • We synthesized hollow gold/ruthenium (hAu–Ru) nanoshells for ascorbic acid sensing. • The hAu–Ru nanoshells showed sensitivity of 426 μA mM −1 cm −2 for ascorbic acid. • Good selectivity against glucose, uric acid, dopamine, 4-acetamidophenol, and NADH. • The linear dynamic range appeared from zero to 2.0 mM (R = 0.9995). • Response time (1.6 s) and low detection limit (2.2 μM) were obtained at pH 7.40. - Abstract: We report a new nonenzymatic amperometric detection of ascorbic acid (AA) using a glassy carbon (GC) disk electrode modified with hollow gold/ruthenium (hAu–Ru) nanoshells, which exhibited decent sensing characteristics. The hAu–Ru nanoshells were prepared by the incorporation of Ru on hollow gold (hAu) nanoshells from Co nanoparticle templates, which enabled AA selectivity against glucose without aid of enzyme or membrane. The structure and electrocatalytic activities of the hAu–Ru catalysts were characterized by spectroscopic and electrochemical techniques. The hAu–Ru loaded on GC electrode (hAu–Ru/GC) showed sensitivity of 426 μA mM −1 cm −2 (normalized to the GC disk area) for the linear dynamic range of <5 μM to 2 mM AA at physiological pH. The response time and detection limit were 1.6 s and 2.2 μM, respectively. Furthermore, the hAu–Ru/GC electrode displayed remarkable selectivity for ascorbic acid over all potential biological interferents, including glucose, uric acid (UA), dopamine (DA), 4-acetamidophenol (AP), and nicotinamide adenine dinucleotide (NADH), which could be especially good for biological sensing

  2. Synthesis, structure, DNA binding and anticancer activity of mixed ligand ruthenium(II) complex

    Science.gov (United States)

    Gilewska, Agnieszka; Masternak, Joanna; Kazimierczuk, Katarzyna; Trynda, Justyna; Wietrzyk, Joanna; Barszcz, Barbara

    2018-03-01

    In order to obtain a potential chemotherapeutic which is not affected on the normal BALB/3T3 cell line, a new arene ruthenium(II) complex {[RuCl(L1)(η6-p-cymene)]PF6}2 · H2O has been synthesized by a direct reaction of precursor, [{(η6-p-cymene)Ru(μ-Cl)}2Cl2], with N,N-chelating ligand (L1 - 2,2‧-bis(4,5-dimethylimidazole). The compound has been fully characterized by elemental analysis, X-ray diffraction, IR, UV-Vis and 1H, 13C NMR spectroscopies. X-ray analysis have confirmed that the compound crystallized in the monoclinic group Cc as an inversion twin. The asymmetric unit contains two symmetrically independent cationic complexes [RuCl(L1)(η6-p-cymene)]+ whose charge is balanced by two PF6- counterions. The shape of each cationic coordination polyhedral can be described as a distorted dodecahedron and shows a typical piano-stool geometry. In addition, an analysis of the crystal structure and the Hirshfeld surface analysis were used to detect and visualize important hydrogen bonds and intermolecular interaction. Moreover, the antiproliferative behavior of the obtained complex was assayed against three human cells: MV-4-11, LoVo, MCF-7 and BALB/3T3 - normal mice fibroblast cells. To predict a binding mode, a potential interaction of ruthenium complex with calf thymus DNA (CT-DNA) has been explored using UV absorption and circular dichroism (CD).

  3. Synthesis and Catalytic Hydrogen Transfer Reaction of Ruthenium(II) Complex

    International Nuclear Information System (INIS)

    Son, Jung Ik; Kim, Aram; Noh, Hui Bog; Lee, Hyun Ju; Shim, Yoon Bo; Park, Kang Hyun

    2012-01-01

    The ruthenium(II) complex [Ru(bpy) 2 -(PhenTPy)] was synthesized, and used for the transfer hydrogenation of ketones and the desired products were obtained in good yield. Based on the presented results, transition-metal complexes can be used as catalysts for a wide range of organic transformations. The relationship between the electro-reduction current density and temperature are being examined in this laboratory. Attempts to improve the catalytic activity and determine the transfer hydrogenation mechanism are currently in progress. The catalytic hydrogenation of a ketone is a basic and critical process for making many types of alcohols used as the final products and precursors in the pharmaceutical, agrochemical, flavor, fragrance, materials, and fine chemicals industries. The catalytic hydrogenation process developed by Noyori is a very attractive process. Formic acid and 2-propanol have been used extensively as hydrogenation sources. The advantage of using 2-propanol as a hydrogen source is that the only side product will be acetone, which can be removed easily during the workup process. Hydrogen transfer (HT) catalysis, which generates alcohols through the reduction of ketones, is an attractive protocol that is used widely. Ruthenium(II) complexes are the most useful catalysts for the hydrogen transfer (HT) of ketones. In this method, a highly active catalytic system employs a transition metal as a catalyst to synthesize alcohols, and is a replacement for the hydrogen-using hydrogenation process. The most active system is based on Ru, Rh and Ir, which includes a nitrogen ligand that facilitates the formation of a catalytically active hydride and phosphorus

  4. Bis(bipyridine)ruthenium(II) complexes with an aliphatic sulfinato donor: synthesis, characterization, and properties.

    Science.gov (United States)

    Tamura, Motoshi; Tsuge, Kiyoshi; Igashira-Kamiyama, Asako; Konno, Takumi

    2011-06-06

    Treatment of a thiolato-bridged Ru(II)Ag(I)Ru(II) trinuclear complex, [Ag{Ru(aet)(bpy)(2)}(2)](3+) (aet = 2-aminoethanthiolate; bpy = 2,2'-bipyridine), with NaI in aqueous ethanol under an aerobic condition afforded a mononuclear ruthenium(II) complex having an S-bonded sulfinato group, [1](+) ([Ru(aesi-N, S)(bpy)(2)](+) (aesi = 2-aminoethanesulfinate)). Similar treatment of optically active isomers of an analogous Ru(II)Ag(I)Ru(II) trinuclear complex, Δ(D)Δ(D)- and Λ(D)Λ(D)-[Ag{Ru(d-Hpen-O,S)(bpy)(2)}(2)](3+) (d-pen = d-penicillaminate), with NaI also produced mononuclear ruthenium(II) isomers with an S-bonded sulfinato group, Δ(D)- and Λ(D)-[2](+) ([Ru(d-Hpsi-O,S)(bpy)(2)](+) (d-psi = d-penicillaminesulfinate)), respectively, retaining the bidentate-O,S coordination mode of a d-Hpen ligand and the absolute configuration (Δ or Λ) about a Ru(II) center. On refluxing in water, the Δ(D) isomer of [2](+) underwent a linkage isomerization to form Δ(D)-[3] (+) ([Ru(d-Hpsi-N,S)(bpy)(2)](+)), in which a d-Hpsi ligand coordinates to a Ru(II) center in a bidentate-N,S mode. Complexes [1](+), Δ(D)- and Λ(D)-[2](+), and Δ(D)-[3](+) were fully characterized by electronic absorption, CD, NMR, and IR spectroscopies, together with single-crystal X-ray crystallography. The electrochemical properties of these complexes, which are highly dependent on the coordination mode of sulfinate ligands, are also described. © 2011 American Chemical Society

  5. Towards a rational design of ruthenium CO2 hydrogenation catalysts by Ab initio metadynamics.

    Science.gov (United States)

    Urakawa, Atsushi; Iannuzzi, Marcella; Hutter, Jürg; Baiker, Alfons

    2007-01-01

    Complete reaction pathways relevant to CO2 hydrogenation by using a homogeneous ruthenium dihydride catalyst ([Ru(dmpe)2H2], dmpe=Me2PCH2CH2PMe2) have been investigated by ab initio metadynamics. This approach has allowed reaction intermediates to be identified and free-energy profiles to be calculated, which provide new insights into the experimentally observed reaction pathway. Our simulations indicate that CO2 insertion, which leads to the formation of formate complexes, proceeds by a concerted insertion mechanism. It is a rapid and direct process with a relatively low activation barrier, which is in agreement with experimental observations. Subsequent H2 insertion into the formate--Ru complex, which leads to the formation of formic acid, instead occurs via an intermediate [Ru(eta2-H2)] complex in which the molecular hydrogen coordinates to the ruthenium center and interacts weakly with the formate group. This step has been identified as the rate-limiting step. The reaction completes by hydrogen transfer from the [Ru(eta2-H2)] complex to the formate oxygen atom, which forms a dihydrogen-bonded Ru--HHO(CHO) complex. The activation energy for the H2 insertion step is lower for the trans isomer than for the cis isomer. A simple measure of the catalytic activity was proposed based on the structure of the transition state of the identified rate-limiting step. From this measure, the relationship between catalysts with different ligands and their experimental catalytic activities can be explained.

  6. Design of a Free-Ruthenium In2S3 Crystalline Photosensitized Solar Cell

    Directory of Open Access Journals (Sweden)

    Byeong Sub Kwak

    2014-01-01

    Full Text Available A new type of sulfide-based, solid-state dye material that is sensitive to visible radiation was assessed as a potential replacement for commercial ruthenium complex dyes in a dye-sensitized solar cell (DSSC assembly. The In2S3 crystals on the surface of the TiO2 bottom blocking layer were grown as a solid-state dye material. Scanning electron microscopy of In2S3 revealed a microsized, 3D-connected sheet-like shape, which was confirmed by X-ray diffraction to be a beta-structure. The efficiency of the dye-sensitized solar cells assembled with a layer grown with In2S3 increased with increasing In2S3 mole concentrations to 0.05 M (1.02% but decreased at concentrations greater than 0.6~0.8%. This suggests that crystalline In2S3 acts as a dye sensitized to visible radiation, but the short-circuit current density is too low compared to the commercially available ruthenium dye. This suggests that In2S3 crystals did not grow densely but were bulk-grown with large pores, resulting in a smaller amount of In2S3 per unit area. Two IPCE curves were observed, which were assigned to TiO2 and In2S3, meaning that the TiO2 surfaces were covered completely with In2S3 crystals. The exposure of TiO2 eventually leads to a reaction with the electrolytes, resulting in lower quantum efficiency.

  7. Synthesis and Catalytic Hydrogen Transfer Reaction of Ruthenium(II) Complex

    Energy Technology Data Exchange (ETDEWEB)

    Son, Jung Ik; Kim, Aram; Noh, Hui Bog; Lee, Hyun Ju; Shim, Yoon Bo; Park, Kang Hyun [Pusan National University, Busan (Korea, Republic of)

    2012-01-15

    The ruthenium(II) complex [Ru(bpy){sub 2}-(PhenTPy)] was synthesized, and used for the transfer hydrogenation of ketones and the desired products were obtained in good yield. Based on the presented results, transition-metal complexes can be used as catalysts for a wide range of organic transformations. The relationship between the electro-reduction current density and temperature are being examined in this laboratory. Attempts to improve the catalytic activity and determine the transfer hydrogenation mechanism are currently in progress. The catalytic hydrogenation of a ketone is a basic and critical process for making many types of alcohols used as the final products and precursors in the pharmaceutical, agrochemical, flavor, fragrance, materials, and fine chemicals industries. The catalytic hydrogenation process developed by Noyori is a very attractive process. Formic acid and 2-propanol have been used extensively as hydrogenation sources. The advantage of using 2-propanol as a hydrogen source is that the only side product will be acetone, which can be removed easily during the workup process. Hydrogen transfer (HT) catalysis, which generates alcohols through the reduction of ketones, is an attractive protocol that is used widely. Ruthenium(II) complexes are the most useful catalysts for the hydrogen transfer (HT) of ketones. In this method, a highly active catalytic system employs a transition metal as a catalyst to synthesize alcohols, and is a replacement for the hydrogen-using hydrogenation process. The most active system is based on Ru, Rh and Ir, which includes a nitrogen ligand that facilitates the formation of a catalytically active hydride and phosphorus.

  8. Controlled free radical polymerization of vinyl acetate with cobalt ...

    Indian Academy of Sciences (India)

    The high molecular weight of polyvinyl acetate (PVAc) with its relatively low molecular distribution without unreacted monomer ... properties of the polymer indicated a lower glass transition state. The easily ..... vision software). The ease of ...

  9. Analysis of acetal toilet fill valve supply line nut failure

    Directory of Open Access Journals (Sweden)

    Anthony Timpanaro

    2017-10-01

    Full Text Available In recent years, there has been a rise in the number of product liability cases involving the failure of toilet water supply line acetal plastic nuts. These nuts can fail in service, causing water leaks that result in significant property and financial losses. This study examines three possible failure modes of acetal plastic toilet water supply nuts. The three failure modes tested were all due to over load failure of the acetal nut and are as follows: (1 Overtightening of the supply line acetal nut, (2 Supply line lateral pull and, (3 Embrittled supply line lateral pull. Additionally, a “hand-tight” torque survey was conducted. The fracture surfaces and characteristics of these failure tests were examined with Stereo Microscopy and Scanning Electron Microscopy (SEM. The failure modes were compared and contrasted to provide guidance in determination of cause in these investigations.

  10. α-Mangostin suppresses 12-o-tetradecanoylphorbol-13- acetate ...

    African Journals Online (AJOL)

    α-Mangostin, Matrix metalloproteinase, Osteosarcoma, Cell migration, 12-O-. Tetradecanoylphorbol-13-acetate ... International Pharmaceutical Abstract, Chemical Abstracts, Embase, Index Copernicus, EBSCO, African. Index Medicus, JournalSeek .... The results were analyzed using Student's t-test, and differences were.

  11. Chemistry and electrochemistry in trifluoroacetic acid. Comparison with acetic acid

    International Nuclear Information System (INIS)

    Petit, Gerard

    1972-01-01

    As the trifluoroacetic acid is, with the acetic acid, one of most often used carboxylic acids as solvent, notably in organic chemistry, this research thesis addresses some relatively simple complexing and redox reactions to highlight the peculiar feature of this acid, and to explain its very much different behaviour with respect to acetic acid. The author develops the notion of acidity level in solvents of low dielectric constant. The second part addresses a specific solvent: BF 3 (CH 3 COOH) 2 . The boron trifluoride strengthens the acidity of acetic acid and modifies its chemical and physical-chemical properties. In the third part, the author compares solvent properties of CF 3 COOH and CH 3 COOH. Noticed differences explain why the trifluoroacetic acid is a more interesting reaction environment than acetic acid for reactions such as electrophilic substitutions or protein solubilisation [fr

  12. The study of 2-acetylaminotoluene ozonolysis in acetic ACID

    OpenAIRE

    Галстян, Андрій Генрійович

    2014-01-01

    The kinetics and mechanism of ozone reaction with 2-aminotoluene and its acylated derivative in acetic acid were studied in order to determine the possibility of obtaining 2-aminobenzoic acid.It is shown that the 2-aminotoluene ozonolysis reaction in acetic acid solution runs at high speed, and preferably on the free electron pair of the amino group to form mainly resinous compounds; oxidation products by the methyl group of the substrate are not formed under these conditions. The ozone attac...

  13. Acetate transiently inhibits myocardial contraction by increasing mitochondrial calcium uptake.

    Science.gov (United States)

    Schooley, James F; Namboodiri, Aryan M A; Cox, Rachel T; Bünger, Rolf; Flagg, Thomas P

    2014-12-09

    There is a close relationship between cardiovascular disease and cardiac energy metabolism, and we have previously demonstrated that palmitate inhibits myocyte contraction by increasing Kv channel activity and decreasing the action potential duration. Glucose and long chain fatty acids are the major fuel sources supporting cardiac function; however, cardiac myocytes can utilize a variety of substrates for energy generation, and previous studies demonstrate the acetate is rapidly taken up and oxidized by the heart. In this study, we tested the effects of acetate on contractile function of isolated mouse ventricular myocytes. Acute exposure of myocytes to 10 mM sodium acetate caused a marked, but transient, decrease in systolic sarcomere shortening (1.49 ± 0.20% vs. 5.58 ± 0.49% in control), accompanied by a significant increase in diastolic sarcomere length (1.81 ± 0.01 μm vs. 1.77 ± 0.01 μm in control), with a near linear dose response in the 1-10 mM range. Unlike palmitate, acetate caused no change in action potential duration; however, acetate markedly increased mitochondrial Ca(2+) uptake. Moreover, pretreatment of cells with the mitochondrial Ca(2+) uptake blocker, Ru-360 (10 μM), markedly suppressed the effect of acetate on contraction. Lehninger and others have previously demonstrated that the anions of weak aliphatic acids such as acetate stimulate Ca(2+) uptake in isolated mitochondria. Here we show that this effect of acetate appears to extend to isolated cardiac myocytes where it transiently modulates cell contraction.

  14. Proteome analysis of Acetobacter pasteurianus during acetic acid fermentation.

    Science.gov (United States)

    Andrés-Barrao, Cristina; Saad, Maged M; Chappuis, Marie-Louise; Boffa, Mauro; Perret, Xavier; Ortega Pérez, Ruben; Barja, François

    2012-03-16

    Acetic acid bacteria (AAB) are Gram-negative, strictly aerobic microorganisms that show a unique resistance to ethanol (EtOH) and acetic acid (AcH). Members of the Acetobacter and Gluconacetobacter genera are capable of transforming EtOH into AcH via the alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) enzymes and are used for the industrial production of vinegar. Several mechanisms have been proposed to explain how AAB resist high concentrations of AcH, such as the assimilation of acetate through the tricarboxylic acid (TCA) cycle, the export of acetate by various transporters and modifications of the outer membrane. However, except for a few acetate-specific proteins, little is known about the global proteome responses to AcH. In this study, we used 2D-DIGE to compare the proteome of Acetobacter pasteurianus LMG 1262(T) when growing in glucose or ethanol and in the presence of acetic acid. Interesting protein spots were selected using the ANOVA p-value of 0.05 as threshold and 1.5-fold as the minimal level of differential expression, and a total of 53 proteins were successfully identified. Additionally, the size of AAB was reduced by approximately 30% in length as a consequence of the acidity. A modification in the membrane polysaccharides was also revealed by PATAg specific staining. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. Influence of calcium acetate on rye bread volume

    Directory of Open Access Journals (Sweden)

    Katharina FUCKERER

    2016-01-01

    Full Text Available Abstract The positive accepted savoury taste of rye bread is dependent on acetate concentration in the dough of such breads. In order to study how calcium acetate influences rye bread properties, the pH of rye doughs fortified with calcium acetate and the resulting volume of the breads were measured. Furthermore, CO2 formation of yeast with added calcium acetate and yeast with different pH levels (4, 7, 9 were measured. Thereby, it was determined that the addition of calcium acetate increased the pH of dough from 4.42 to 5.29 and significantly reduced the volume of the breads from 1235.19 mL to 885.52 mL. It could be proven that bread volume was affected by a 30.9% lower CO2 amount production of yeast, although bread volume was not affected by changing pH levels. Due to reduced bread volume, high concentrations of calcium acetate additions are not recommended for improving rye bread taste.

  16. Atomic layer deposition of ruthenium on plasma-treated vertically aligned carbon nanotubes for high-performance ultracapacitors.

    Science.gov (United States)

    Kim, Jun Woo; Kim, Byungwoo; Park, Suk Won; Kim, Woong; Shim, Joon Hyung

    2014-10-31

    It is challenging to realize a conformal metal coating by atomic layer deposition (ALD) because of the high surface energy of metals. In this study, ALD of ruthenium (Ru) on vertically aligned carbon nanotubes (CNTs) was carried out. To activate the surface of CNTs that lack surface functional groups essential for ALD, oxygen plasma was applied ex situ before ALD. X-ray photoelectron spectroscopy and Raman spectroscopy confirmed surface activation of CNTs by the plasma pretreatment. Transmission electron microscopy analysis with energy-dispersive x-ray spectroscopy composition mapping showed that ALD Ru grew conformally along CNTs walls. ALD Ru/CNTs were electrochemically oxidized to ruthenium oxide (RuOx) that can be a potentially useful candidate for use in the electrodes of ultracapacitors. Electrode performance of RuOx/CNTs was evaluated using cyclic voltammetry and galvanostatic charge-discharge measurements.

  17. p-chloro- and p-bromo-benzoylacetoneoxime as the spectrophotometric reagents for palladium and ruthenium(III)

    International Nuclear Information System (INIS)

    Yeole, V.V.; Langade, A.D.; Shinde, V.M.

    1980-01-01

    A procedure is described for the extractive spectrophotometric determination of palladium or ruthenium(III) using p-chloro or p-bromobenzoylacetoneoxime as the reagent. The yellow palladium complexes which are extracted into chloroform from an aqueous solution of pH 3.5, absorb as 400 nm and conform to Beer's law in the range of 10 to 100 μg of Pd/10 ml of organic phase. The orange-red ruthenium complexes which are extracted into ethylacetate from an aqueous solution of pH 5.0, absorbs at 475 nm and conforms to Beer's law in the range of 20 to 200 μg of Ru/10 ml of organic phase. The molar absorptivities, Sandell's sensitivities and instability constants are reported. (author)

  18. Ruthenium(II)-catalysed remote C-H alkylations as a versatile platform to meta-decorated arenes

    Science.gov (United States)

    Li, Jie; Korvorapun, Korkit; de Sarkar, Suman; Rogge, Torben; Burns, David J.; Warratz, Svenja; Ackermann, Lutz

    2017-06-01

    The full control of positional selectivity is of prime importance in C-H activation technology. Chelation assistance served as the stimulus for the development of a plethora of ortho-selective arene functionalizations. In sharp contrast, meta-selective C-H functionalizations continue to be scarce, with all ruthenium-catalysed transformations currently requiring difficult to remove or modify nitrogen-containing heterocycles. Herein, we describe a unifying concept to access a wealth of meta-decorated arenes by a unique arene ligand effect in proximity-induced ruthenium(II) C-H activation catalysis. The transformative nature of our strategy is mirrored by providing a step-economical entry to a range of meta-substituted arenes, including ketones, acids, amines and phenols--key structural motifs in crop protection, material sciences, medicinal chemistry and pharmaceutical industries.

  19. Flow-injection chemiluminescent determination of estrogen benzoate using the tris(1,10-phenanthroline) ruthenium(II)-permanganate system.

    Science.gov (United States)

    Ma, Yan; Cao, Wei; Qiao, Shuang; Liu, Wenwen; Yang, Jinghe

    2011-01-01

    Chemiluminescence (CL) detection for the determination of estrogen benzoate, using the reaction of tris(1,10-phenanthroline)ruthenium(II)-Na(2)SO(3)-permanganate, is described. This method is based on the CL reaction of estrogen benzoate (EB) with acidic potassium permanganate and tris(1,10-phenanthroline)ruthenium(II). The CL intensity is greatly enhanced when Na(2)SO(3) is added. After optimization of the different experimental parameters, a calibration graph for estrogen benzoate is linear in the range 0.05-10 µg/mL. The 3 s limit of detection is 0.024 µg/mL and the relative standard deviation was 1.3% for 1.0 µg/mL estrogen benzoate (n = 11). This proposed method was successfully applied to commercial injection samples and emulsion cosmetics. The mechanism of CL reaction was also studied. Copyright © 2011 John Wiley & Sons, Ltd.

  20. Ruthenium-platinum bimetallic catalysts supported on silica: characterization and study of benzene hydrogenation and CO methanation

    Energy Technology Data Exchange (ETDEWEB)

    Chakrabarty, D.K.; Rao, K.M.; Sundararaman, N.; Chandavar, K.

    1986-12-15

    Ru-Pt/SiO/sub 2/ bimetallic catalysts with varying Ru:Pt ratio have been prepared and studied with the aim to establish if they contain coclusters or isolated ruthenium and platinum particles. X-ray diffraction studies show that individual crystallites of ruthenium and platinum are present and no coclusters are formed. Metal dispersion has been determined by hydrogen chemisorption and surface composition of the catalysts has been obtained from XPS. It was found that preoxidation of the catalysts prior to reduction is essential for good platinum dispersion. The experimental turnover number (TN) for benzene hydrogenation on the bimetallic catalysts agrees very well with that of the weighted average on the individual metal catalysts and this may be taken as a kinetic evidence for the absence of coclusters. Carbon monoxide methanation activity of the bimetallic catalysts is quite similar to that of the supported platinum catalyst. 6 refs., 6 figs., 2 tabs.

  1. Ligand-accelerated activation of strong C-H bonds of alkanes by a (salen)ruthenium(VI)-nitrido complex.

    Science.gov (United States)

    Man, Wai-Lun; Lam, William W Y; Kwong, Hoi-Ki; Yiu, Shek-Man; Lau, Tai-Chu

    2012-09-03

    Kinetic and mechanistic studies on the intermolecular activation of strong C-H bonds of alkanes by a (salen)ruthenium(VI) nitride were performed. The initial, rate-limiting step, the hydrogen atom transfer (HAT) from the alkane to Ru(VI)≡N, generates Ru(V)=NH and RC·HCH(2)R. The following steps involve N-rebound and desaturation. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Density functional theory based QSAR study of ruthenium (II) antitumor drugs and their interactions with xanthine oxidoreductase

    International Nuclear Information System (INIS)

    Mondal, Paritosh; Das, Dharitri

    2013-01-01

    Transition metal containing drugs have been used intensely for their potential anticancer activities. Platinum drugs have been used successfully for the treatment of cancer. However, these drugs have severe drawbacks including unwanted side effects, drug resistance and ineffectiveness towards some of cancers. Therefore scientists are searching for new drugs to solve these problems, and Ruthenium coordination compounds have been found effective alternatives to platinum coordination drugs

  3. Disposable biosensor based on cathodic electrochemiluminescence of tris(2,2-bipyridine)ruthenium(II) for uric acid determination

    Energy Technology Data Exchange (ETDEWEB)

    Ballesta-Claver, J.; Rodríguez-Gómez, R. [ECsens, Department of Analytical Chemistry, Campus Fuentenueva, Faculty of Sciences, University of Granada, E-18071 Granada (Spain); Capitán-Vallvey, L.F., E-mail: lcapitan@ugr.es [ECsens, Department of Analytical Chemistry, Campus Fuentenueva, Faculty of Sciences, University of Granada, E-18071 Granada (Spain)

    2013-04-03

    Highlights: ► Cathodic ECL offers conventional and non-aggressive analysis conditions. ► The ECL hydrogen peroxide/ruthenium complex system for uric acid determination is novel. ► The ruthenium complex is electrochemically immobilized on graphite screen-printed electrodes. ► The quantification of the uric acid is based on a Stern–Volmer type equation. ► The use of the cathodic ECL working methodology reduces interferences during analysis. -- Abstract: A new method for uric acid (UA) determination based on the quenching of the cathodic ECL of the tris(2,2-bipyridine)ruthenium(II)–uricase system is described. The biosensor is based on a double-layer design containing first tris(2,2-bipyridine)ruthenium(II) (Ru(bpy){sub 3}{sup 2+}) electrochemically immobilized on graphite screen-printed cells and uricase in chitosan as a second layer. The uric acid biosensing is based on the ECL quenching produced by uric acid over the cathodic ECL caused by immobilized Ru(bpy){sub 3}{sup 2+} in the presence of uricase. The use of a −1.1 V pulse for 1 s with a dwelling time of 10 s makes it possible to estimate the initial enzymatic rate, which is used as the analytical signal. The Stern–Volmer type calibration function shows a dynamic range from 1.0 × 10{sup −5} to 1.0 × 10{sup −3} M with a limit of detection of 3.1 × 10{sup −6} M and an accuracy of 13.6% (1.0 × 10{sup −4} M, n = 5) as relative standard deviation. Satisfactory results were obtained for urine samples, creating an affordable alternative for uric acid determination.

  4. Ru-OSO coordination photogenerated at 100 K in tetraammineaqua(sulfur dioxide)ruthenium(II) (±)-camphorsulfonate.

    Science.gov (United States)

    Phillips, Anthony E; Cole, Jacqueline M; d'Almeida, Thierry; Low, Kian Sing

    2012-02-06

    The photoinduced O-bound coordination mode in RuSO(2) complexes, previously observed only at 13 K, has been generated at 100 K in tetraammineaqua(sulfur dioxide)ruthenium(II) (±)-camphorsulfonate. This coordination state, often denoted MS1, decays to the η(2)-bound MS2 state, with an estimated half-life of 3.4(8) h and a long-lived population of 2.9(4)% at 120 K.

  5. Nanoengineering of Ruthenium and Platinum-based Nanocatalysts by Continuous-Flow Chemistry for Renewable Energy Applications

    KAUST Repository

    AlYami, Noktan Mohammed

    2017-04-15

    This thesis presents an integrated study of nanocatalysts for heterogenous catalytic and electrochemical processes using pure ruthenium (Ru) with mixed-phase and platinum-based nanomaterials synthesized by continuous-flow chemistry. There are three major challenges to the application of nanomaterials in heterogenous catalytic reactions and electrocatalytic processes in acidic solution. These challenges are the following: (i) controlling the size, shape and crystallography of nanoparticles to give the best catalytic properties, (ii) scaling these nanoparticles up to a commercial quantity (kg per day) and (iii) making stable nanoparticles that can be used catalytically without degrading in acidic electrolytes. Some crucial limitations of these nanostructured materials in energy conversion and storage applications were overcome by continuous-flow chemistry. By using a continuous-flow reactor, the creation of scalable nanoparticle systems was achieved and their functionality was modified to control the nanoparticles’ physical and chemical characteristics. The nanoparticles were also tested for long-term stability, to make sure these nanoparticles were feasible under realistic working conditions. These nanoparticles are (1) shape- and crystallography-controlled ruthenium (Ru) nanoparticles, (2) size-controlled platinum-metal (Pt-M= nickel (Ni) & copper (Cu)) nanooctahedra (while maintaining morphology) and (3) core-shell platinum@ruthenium (Pt@Ru) nanoparticles where an ultrathin ruthenium shell was templated onto the platinum core. Thus, a complete experimental validation of the formation of a scalable amount of these nanoparticles and their catalytic activity and stability towards the oxygen evolution reaction (OER) in acid medium, hydrolysis of ammonia borane (AB) along with plausible explanations were provided.

  6. Studies on the interaction of benzotriazole (a corrosion inibitor) with the ruthenium (II) (III) ammincomplexes and pentacyanoferrate (II)

    International Nuclear Information System (INIS)

    Espinoza R, R.L.

    1985-01-01

    Some studies on the interaction of benzotriazole with the aquapentacyanoferrate (II), aquapentaamminruthenium (II) and cis-and trans-(NH 3 ) 4 Ru(H 2 O) 2 2+ complexes are described. The reactions, substituted products and complexes production are demonstrated. The absorption bands for the ammine (benzotriazole) and ruthenium (II) complexes as well as the activation parameters and kinetics of reactions are discussed. (M.J.C.) [pt

  7. Quantum chemical interpretation of redox properties of ruthenium complexes with vinyl and TCNX type non-innocent ligands

    Czech Academy of Sciences Publication Activity Database

    Záliš, Stanislav; Winter, R. F.; Kaim, W.

    2010-01-01

    Roč. 254, 13-14 (2010), s. 1383-1396 ISSN 0010-8545 R&D Projects: GA MŠk OC 139; GA MŠk 1P05OC068; GA AV ČR KAN100400702; GA MŠk OC09043 Institutional research plan: CEZ:AV0Z40400503 Keywords : density functional thoery * non-innocent ligands * ruthenium Subject RIV: CG - Electrochemistry Impact factor: 10.018, year: 2010

  8. Disposable biosensor based on cathodic electrochemiluminescence of tris(2,2-bipyridine)ruthenium(II) for uric acid determination

    International Nuclear Information System (INIS)

    Ballesta-Claver, J.; Rodríguez-Gómez, R.; Capitán-Vallvey, L.F.

    2013-01-01

    Highlights: ► Cathodic ECL offers conventional and non-aggressive analysis conditions. ► The ECL hydrogen peroxide/ruthenium complex system for uric acid determination is novel. ► The ruthenium complex is electrochemically immobilized on graphite screen-printed electrodes. ► The quantification of the uric acid is based on a Stern–Volmer type equation. ► The use of the cathodic ECL working methodology reduces interferences during analysis. -- Abstract: A new method for uric acid (UA) determination based on the quenching of the cathodic ECL of the tris(2,2-bipyridine)ruthenium(II)–uricase system is described. The biosensor is based on a double-layer design containing first tris(2,2-bipyridine)ruthenium(II) (Ru(bpy) 3 2+ ) electrochemically immobilized on graphite screen-printed cells and uricase in chitosan as a second layer. The uric acid biosensing is based on the ECL quenching produced by uric acid over the cathodic ECL caused by immobilized Ru(bpy) 3 2+ in the presence of uricase. The use of a −1.1 V pulse for 1 s with a dwelling time of 10 s makes it possible to estimate the initial enzymatic rate, which is used as the analytical signal. The Stern–Volmer type calibration function shows a dynamic range from 1.0 × 10 −5 to 1.0 × 10 −3 M with a limit of detection of 3.1 × 10 −6 M and an accuracy of 13.6% (1.0 × 10 −4 M, n = 5) as relative standard deviation. Satisfactory results were obtained for urine samples, creating an affordable alternative for uric acid determination

  9. Tetrazole acetic acid: Tautomers, conformers, and isomerization

    Energy Technology Data Exchange (ETDEWEB)

    Araujo-Andrade, C. [Unidad Académica de Física de la Universidad Autónoma de Zacatecas, Zacatecas (Mexico); Department of Chemistry, University of Coimbra, 3004-535 Coimbra (Portugal); Reva, I., E-mail: reva@qui.uc.pt; Fausto, R. [Department of Chemistry, University of Coimbra, 3004-535 Coimbra (Portugal)

    2014-02-14

    Monomers of (tetrazol-5-yl)-acetic acid (TAA) were obtained by sublimation of the crystalline compound and the resulting vapors were isolated in cryogenic nitrogen matrices at 13 K. The conformational and tautomeric composition of TAA in the matrix was characterized by infrared spectroscopy and vibrational calculations carried out at the B3LYP/6-311++G(d,p) level. TAA may adopt two tautomeric modifications, 1H- and 2H-, depending on the position of the annular hydrogen atom. Two-dimensional potential energy surfaces (PESs) of TAA were theoretically calculated at the MP2/6-311++G(d,p) level, for each tautomer. Four and six symmetry-unique minima were located on these PESs, for 1H- and 2H-TAA, respectively. The energetics of the detected minima was subsequently refined by calculations at the QCISD level. Two 1H- and three 2H-conformers fall within the 0–8 kJ mol{sup −1} energy range and should be appreciably populated at the sublimation temperature (∼330 K). Observation of only one conformer for each tautomer (1ccc and 2pcc) is explained in terms of calculated barriers to conformational rearrangements. All conformers with the cis O=COH moiety are separated by low barriers (less than 10 kJ mol{sup −1}) and collapse to the most stable 1ccc (1H-) and 2pcc (2H-) forms during deposition of the matrix. On the trans O=COH surfaces, the relative energies are very high (between 12 and 27 kJ mol{sup −1}). The trans forms are not thermally populated at the sublimation conditions and were not detected in matrices. One high-energy form in each tautomer, 1cct (1H-) and 2pct (2H-), was found to differ from the most stable form only by rotation of the OH group and separated from other forms by high barriers. This opened a perspective for their stabilization in a matrix. 1cct and 2pct were generated in the matrices selectively by means of narrow-band near-infrared (NIR) irradiations of the samples at 6920 and 6937 cm{sup −1}, where the first OH stretching overtone

  10. Separation of the noble metals ruthenium and palladium from nitric acid solution of the nuclear fuel reprocessing containing complexing agents

    International Nuclear Information System (INIS)

    Ghafourian, H.

    1989-06-01

    Two extraction chromatographic techniques have been developed. N'N diethylthiourea (DETU), which forms complexes with ruthenium that can be retained on an AG50W-X2 ion exchanger, has proved to be a suitable reagent. The structures of these complexes were elucidated by electrophoresis, ion exchange and IR spectroscopy. Under the same conditions Pd forms an insoluble DETU-complex of the formula [Pd(DETU) 4 ] 2+ , which allows the separation of this metal quantitatively. With regard to the application of the developed technique for recovery of the mentioned noble metals from dissolver residues of the nuclear fuel reprocessing, comparative studies were carried out for accompanying fission product nuclides and actinides such as Mo, Tc, Zr, Ce, U and Pu. It was found out that no complex between diethylthiourea and the fission products zirconium, molybdenum and cerium and the actinides uranium, plutonium and americium were formed. Technetium, which was originally present as pertechnetate, is reduced to Tc(IV) and retained on the cation exchanger together with ruthenium. Ruthenium was eluted with 6 M HNO 3 . The efficiency of the developed process has been demonstrated with simulated solutions. The achieved decontamination factors ranged from 10 2 to 10 6 depending on the nuclide. (orig./RB) [de

  11. Synthesis and characterization of branched fcc/hcp ruthenium nanostructures and their catalytic activity in ammonia borane hydrolysis

    KAUST Repository

    AlYami, Noktan

    2018-01-30

    Several systems have shown the ability to stabilize uncommon crystal structures during the synthesis of metallic nanoparticles. By tailoring the nanoparticle crystal structure, the physical and chemical properties of the particles can also be controlled. Herein, we first synthesized branched nanoparticles of mixed hcp/fcc ruthenium, which were formed using tungsten carbonyl [W(CO)6] as both a reducing agent and a source of carbon monoxide. The branched particles were formed from multiple particulates off a central core. High-resolution transmission electron microscopy (HRTEM) clearly showed that the branched structures consisted of aligned hcp crystal domains, a mixture of fcc and hcp crystal domains with several defects and misalignments, and particles that contained multiple cores and branches. Branched particles were also formed with molybdenum carbonyl [Mo(CO)6], and faceted particles of hcp and fcc particles were formed with Re2(CO)10 as a carbon monoxide source. Without metal carbonyls, small particles of spherical hcp ruthenium were produced, and their size could be controlled by the selection of the precursor. The ruthenium nanoparticles were tested for ammonia borane hydrolysis; the branched nanoparticles were more reactive for catalytic hydrogen evolution than the faceted hcp/fcc nanoparticles or the spherical hcp nanoparticles. This work showcases the potential of crystal phase engineering of transition metal nanoparticles by different carbon monoxide precursors for tailoring their catalytic reactivity.

  12. Nitrile-functionalized ruthenium nanoparticles: charge delocalization through Ru − N ≡ C interface

    International Nuclear Information System (INIS)

    Zhang, Fengqi; Huang, Lin; Zou, Jiasui; Yan, Jinwu; Zhu, Jiaying; Kang, Xiongwu; Chen, Shaowei

    2017-01-01

    Ruthenium nanoparticles (2.06 ± 0.46 nm in diameter) were stabilized by the self-assembly of nitrile molecules onto the ruthenium colloid surface by virtue of the formation of Ru−N≡C interfacial bonding linkages. Thermogravimetric analysis showed that there were about 63 nitrile ligands per nanoparticle, corresponding to an average molecular footprint of 22.4 Å 2 . Proton nuclear magnetic resonance (NMR) studies suggested an end-on configuration of the nitrile moiety on the metal core surface. Meanwhile, infrared measurements showed that the C≡N stretch red-shifted from 2246 to 1944 cm −1 upon adsorption on the nanoparticle surfaces, as confirmed by 15 N isotopic labeling. This apparent red-shift suggests extensive intraparticle charge delocalization, which was further manifested by photoluminescence measurements of 1-cyanopyrene-functionalized ruthenium nanoparticles that exhibited a red shift of 40 nm of the emission maximum, in comparison to that of free monomers. The results further highlight the significance of metal−organic contacts in the manipulation of the dynamics of intraparticle charge transfer and the nanoparticle optical and electronic properties.

  13. Tris(2,2'-bipyridyl) ruthenium(II)-bisoprolol-based electrochemiluminescence coupled with capillary zone electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Wang Jingwu [Department of Chemistry, Nanchang University, Nanchang 330031 (China)], E-mail: wangjingwu@ncu.edu.cn; Zhang Xiaojun; Pi Fangfang [Department of Chemistry, Nanchang University, Nanchang 330031 (China); Wang Xiaoxia [Graduate School of Engineering, University of Fukui, Fukui 910-8507 (Japan); Yang Nianjun [Diamond Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Central 2-13, 1-1-1 Umezono, Tsukuba 305-8568 (Japan)], E-mail: nianjun.yang@iaf.fraunhofer.de

    2009-03-01

    Capillary zone electrophoresis (CZE) coupled with tris(2,2'-bipyridyl) ruthenium(II)-based end-column electrogenerated chemiluminescence (ECL) has been utilized to detect bisoprolol in drugs and tablets after its separation from metoprolol. Tetrahydrofuran was used as an additive in the running buffer to obtain the absolute ECL peak of bisoprolol. Bisoprolol reacts as a co-reactant in tris(2,2'-bipyridyl) ruthenium(II) ECL system. Under the optimized experimental conditions, bisoprolol was separated successfully and efficiently from metoprolol and other co-existed materials in tablets and urine samples. The ECL intensity of tris(2,2'-bipyridyl) ruthenium(II)-bisoprolol-based system is linear with the concentration of bisoprolol from 1.5 {mu}M to 0.3 mM with a detection limit of 0.3 {mu}M. Relative standard derivations of the ECL intensity are 2.58% for the detection of 15 {mu}M bisoprolol. This method is a simple, rapid, selective, and sensitive. It was applied successfully for the monitoring of bisoprolol in market available tablets and human urine samples.

  14. Electrochemical behavior of ruthenium-hexacyanoferrate modified glassy carbon electrode and catalytic activity towards ethanol electro oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Wendell M.; Marques, Aldalea L.B., E-mail: aldalea.ufma@hotmail.com [Universidade Federal do Maranhao (UFMA), Sao Luis, MA (Brazil). Departamento de Quimica Tecnologica; Cardoso, William S.; Marques, Edmar P.; Bezerra, Cicero W.B. [Universidade Federal do Maranhao (UFMA), Sao Luis, MA (Brazil). Departamento de Qumica; Ferreira, Antonio Ap. P. [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Araraquara, SP (Brazil). Instituto de Quimica; Song, Chaojie; Zhang, Jiujun [Energy, Mining and Environment Portfolio, National Research Council of Canada, Vancouver, BC (Canada)

    2013-04-15

    Ruthenium-based hexacyanoferrate (RuHCF) thin film modified glassy carbon electrode was prepared by drop evaporation method. The RuHCF modified electrode exhibited four redox couples in strong acidic solution (pH 1.5) attributed to Fe(CN){sub 6}{sup 3-} ion and three ruthenium forms (Ru(II), Ru(III) and Ru(IV)), characteristic of ruthenium oxide compounds. The modified electrode displayed excellent electrocatalytic activity towards ethanol oxidation in the potential region where electrochemical processes Ru(III)-O-Ru(IV) and Ru(IV)-O-Ru(VI) occur. Impedance spectroscopy data indicated that the charge transfer resistance decreased with the increase of the applied potential and ethanol concentration, indicating the use of the RuHCF modified electrode as an ethanol sensor. Under optimized conditions, the sensor responded linearly and rapidly to ethanol concentration between 0.03 and 0.4 mol L{sup -1} with a limit of detection of 0.76 mmol L{sup -1}, suggesting an adequate sensitivity in ethanol analyses. (author)

  15. Nitrile-functionalized ruthenium nanoparticles: charge delocalization through Ru − N ≡ C interface

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Fengqi; Huang, Lin; Zou, Jiasui [South China University of Technology, New Energy Research Institute, School of Environment and Energy, Guangzhou Higher Education Mega Centre (China); Yan, Jinwu; Zhu, Jiaying [South China University of Technology, School of Bioscience and Bioengineering, Guangzhou Higher Education Mega Centre (China); Kang, Xiongwu, E-mail: esxkang@scut.edu.cn; Chen, Shaowei, E-mail: shaowei@ucsc.edu [South China University of Technology, New Energy Research Institute, School of Environment and Energy, Guangzhou Higher Education Mega Centre (China)

    2017-03-15

    Ruthenium nanoparticles (2.06 ± 0.46 nm in diameter) were stabilized by the self-assembly of nitrile molecules onto the ruthenium colloid surface by virtue of the formation of Ru−N≡C interfacial bonding linkages. Thermogravimetric analysis showed that there were about 63 nitrile ligands per nanoparticle, corresponding to an average molecular footprint of 22.4 Å{sup 2}. Proton nuclear magnetic resonance (NMR) studies suggested an end-on configuration of the nitrile moiety on the metal core surface. Meanwhile, infrared measurements showed that the C≡N stretch red-shifted from 2246 to 1944 cm{sup −1} upon adsorption on the nanoparticle surfaces, as confirmed by {sup 15}N isotopic labeling. This apparent red-shift suggests extensive intraparticle charge delocalization, which was further manifested by photoluminescence measurements of 1-cyanopyrene-functionalized ruthenium nanoparticles that exhibited a red shift of 40 nm of the emission maximum, in comparison to that of free monomers. The results further highlight the significance of metal−organic contacts in the manipulation of the dynamics of intraparticle charge transfer and the nanoparticle optical and electronic properties.

  16. A simple and selective spectrophotometric flow injection determination of trace amounts of ruthenium by catalytic oxidation of safranin-O

    Energy Technology Data Exchange (ETDEWEB)

    Rezaei, Behzad [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-84111 (Iran, Islamic Republic of)], E-mail: rezaei@cc.iut.ac.ir; Keyvanfard, Mohsen [Faculty of Science, Majlesi Campus, Islamic Azad University, Isfahan (Iran, Islamic Republic of)

    2008-03-01

    In this work, a simple, selective and rapid flow injection method has been developed for determination of ruthenium. The method is based on its catalytic effect on the oxidation of safranin-O by metaperiodate. The reaction was monitored spectrophotometrically by measuring safranin-O absorbance at {lambda}{sub max} = 521. The reagents and manifold variables, which have influences on the sensitivity, were investigated and the optimum conditions were established. The optimized conditions made it possible to determine ruthenium in the ranges of 0.4-20.0 ng/mL ({delta}A = 0.2819C{sub Ru} + 1.1840) and 20.0-100.0 ng/mL ({delta}A = 0.0984C{sub Ru} + 7.9391) with a detection limit of 0.095 ng/mL and a sample rate of 30 {+-} 5 samples/h. Relative standard deviation for the five replicate measurements was less than 1.84%. The proposed method has been successfully applied for analysis of ultra trace amounts of ruthenium in real samples.

  17. A simple and selective spectrophotometric flow injection determination of trace amounts of ruthenium by catalytic oxidation of safranin-O

    International Nuclear Information System (INIS)

    Rezaei, Behzad; Keyvanfard, Mohsen

    2008-01-01

    In this work, a simple, selective and rapid flow injection method has been developed for determination of ruthenium. The method is based on its catalytic effect on the oxidation of safranin-O by metaperiodate. The reaction was monitored spectrophotometrically by measuring safranin-O absorbance at λ max = 521. The reagents and manifold variables, which have influences on the sensitivity, were investigated and the optimum conditions were established. The optimized conditions made it possible to determine ruthenium in the ranges of 0.4-20.0 ng/mL (ΔA = 0.2819C Ru + 1.1840) and 20.0-100.0 ng/mL (ΔA = 0.0984C Ru + 7.9391) with a detection limit of 0.095 ng/mL and a sample rate of 30 ± 5 samples/h. Relative standard deviation for the five replicate measurements was less than 1.84%. The proposed method has been successfully applied for analysis of ultra trace amounts of ruthenium in real samples

  18. Additive effects of acetic acid upon hydrothermal reaction of amylopectin

    International Nuclear Information System (INIS)

    Sugano, Motoyuki; Katoh, Harumi; Komatsu, Akihiro; Kobayashi, Hiroshi; Okado, Kohta; Kakuta, Yusuke; Hirano, Katsumi

    2012-01-01

    It is well known that over 0.8 kg kg −1 of starch is consisted of amylopectin (AP). In this study, production of glucose for raw material of ethanol by hydrothermal reaction of AP as one of the model compound of food is discussed. Further, additive effects of acetic acid upon hydrothermal reactions of AP are also investigated. During hydrothermal reaction of AP, production of glucose occurred above 453 K, and the glucose yield increased to 0.48 kg kg −1 at 473 K. Upon hydrothermal reaction of AP at 473 K, prolongation of the holding time was not effective for the increase of the glucose yield. Upon hydrothermal reaction of AP at 473 K for 0 s, the glucose yield increased significantly by addition between 0.26 mol L −1 and 0.52 mol L −1 of acetic acid. However, the glucose yield decreased and the yield of the other constituents increased with the increases of concentration of acetic acid from 0.65 mol L −1 to 3.33 mol L −1 . It was considered that hydrolysis of AP to yield glucose was enhanced due to the increase of the amount of proton derived from acetic acid during hydrothermal reaction with 0.52 mol L −1 of acetic acid. -- Highlights: ► Glucose production by hydrothermal reaction of amylopectin (AP) at 473 K. ► Glucose yield increased to 0.48 kg kg -1 at 473 K. ► Prolongation of holding time was not effective for glucose yield. ► Glucose yield increased significantly by acetic acid (0.26–0.52 mol L-1) addition. ► Hydrolysis of AP to glucose was enhanced due to increase of proton from acetic acid.

  19. 21 CFR 862.1390 - 5-Hydroxyindole acetic acid/serotonin test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false 5-Hydroxyindole acetic acid/serotonin test system... Test Systems § 862.1390 5-Hydroxyindole acetic acid/serotonin test system. (a) Identification. A 5-hydroxyindole acetic acid/serotonin test system is a device intended to measure 5-hydroxyindole acetic acid...

  20. Electronic state of ruthenium deposited onto oxide supports: An XPS study taking into account the final state effects

    International Nuclear Information System (INIS)

    Larichev, Yurii V.; Moroz, Boris L.; Bukhtiyarov, Valerii I.

    2011-01-01

    The electronic state of ruthenium in the supported Ru/EO x (EO x = MgO, Al 2 O 3 or SiO 2 ) catalysts prepared by with the use of Ru(OH)Cl 3 or Ru(acac) 3 (acac = acetylacetonate) and reduced with H 2 at 723 K is characterized by X-ray photoelectron spectroscopy (XPS) in the Ru 3d, Cl 2p and O 1s regions. The influence of the final state effects (the differential charging and variation of the relaxation energy) on the binding energy (BE) of Ru 3d 5/2 core level measured for supported Ru nanoparticles is estimated by comparison of the Fermi levels and the modified Auger parameters determined for the Ru/EO x samples with the corresponding characteristics of the bulk Ru metal. It is found that the negative shift of the Ru 3d 5/2 peak which is observed in the spectrum of ruthenium deposited onto MgO (BE = 279.5-279.7 eV) with respect to that of Ru black (BE = 280.2 eV) or ruthenium supported on γ-Al 2 O 3 and SiO 2 (BE = 280.4 eV) is caused not by the transfer of electron density from basic sites of MgO, as considered earlier, but by the differential charging of the supported Ru particles compared with the support surface. Correction for the differential charging value reveals that the initial state energies of ruthenium in the Ru/EO x systems are almost identical (BE = 280.5 ± 0.1 eV) irrespectively of acid-base properties of the support, the mean size of supported Ru crystallites (within the range of 2-10 nm) and the surface Cl content. The results obtained suggest that the difference in ammonia synthesis activity between the Ru catalysts supported on MgO and on the acidic supports is accounted for by not different electronic state of ruthenium on the surface of these oxides but by some other reasons.